1 /* Support routines for Value Range Propagation (VRP).
2 Copyright (C) 2005-2016 Free Software Foundation, Inc.
3 Contributed by Diego Novillo <dnovillo@redhat.com>.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
25 #include "insn-codes.h"
30 #include "tree-pass.h"
32 #include "optabs-tree.h"
33 #include "gimple-pretty-print.h"
34 #include "diagnostic-core.h"
36 #include "fold-const.h"
37 #include "stor-layout.h"
40 #include "gimple-fold.h"
42 #include "gimple-iterator.h"
43 #include "gimple-walk.h"
45 #include "tree-ssa-loop-manip.h"
46 #include "tree-ssa-loop-niter.h"
47 #include "tree-ssa-loop.h"
48 #include "tree-into-ssa.h"
52 #include "tree-scalar-evolution.h"
53 #include "tree-ssa-propagate.h"
54 #include "tree-chrec.h"
55 #include "tree-ssa-threadupdate.h"
56 #include "tree-ssa-scopedtables.h"
57 #include "tree-ssa-threadedge.h"
60 #include "case-cfn-macros.h"
62 /* Range of values that can be associated with an SSA_NAME after VRP
66 /* Lattice value represented by this range. */
67 enum value_range_type type
;
69 /* Minimum and maximum values represented by this range. These
70 values should be interpreted as follows:
72 - If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must
75 - If TYPE == VR_RANGE then MIN holds the minimum value and
76 MAX holds the maximum value of the range [MIN, MAX].
78 - If TYPE == ANTI_RANGE the variable is known to NOT
79 take any values in the range [MIN, MAX]. */
83 /* Set of SSA names whose value ranges are equivalent to this one.
84 This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE. */
88 #define VR_INITIALIZER { VR_UNDEFINED, NULL_TREE, NULL_TREE, NULL }
90 /* Set of SSA names found live during the RPO traversal of the function
91 for still active basic-blocks. */
94 /* Return true if the SSA name NAME is live on the edge E. */
97 live_on_edge (edge e
, tree name
)
99 return (live
[e
->dest
->index
]
100 && bitmap_bit_p (live
[e
->dest
->index
], SSA_NAME_VERSION (name
)));
103 /* Local functions. */
104 static int compare_values (tree val1
, tree val2
);
105 static int compare_values_warnv (tree val1
, tree val2
, bool *);
106 static void vrp_meet (value_range
*, value_range
*);
107 static void vrp_intersect_ranges (value_range
*, value_range
*);
108 static tree
vrp_evaluate_conditional_warnv_with_ops (enum tree_code
,
109 tree
, tree
, bool, bool *,
112 /* Location information for ASSERT_EXPRs. Each instance of this
113 structure describes an ASSERT_EXPR for an SSA name. Since a single
114 SSA name may have more than one assertion associated with it, these
115 locations are kept in a linked list attached to the corresponding
119 /* Basic block where the assertion would be inserted. */
122 /* Some assertions need to be inserted on an edge (e.g., assertions
123 generated by COND_EXPRs). In those cases, BB will be NULL. */
126 /* Pointer to the statement that generated this assertion. */
127 gimple_stmt_iterator si
;
129 /* Predicate code for the ASSERT_EXPR. Must be COMPARISON_CLASS_P. */
130 enum tree_code comp_code
;
132 /* Value being compared against. */
135 /* Expression to compare. */
138 /* Next node in the linked list. */
142 /* If bit I is present, it means that SSA name N_i has a list of
143 assertions that should be inserted in the IL. */
144 static bitmap need_assert_for
;
146 /* Array of locations lists where to insert assertions. ASSERTS_FOR[I]
147 holds a list of ASSERT_LOCUS_T nodes that describe where
148 ASSERT_EXPRs for SSA name N_I should be inserted. */
149 static assert_locus
**asserts_for
;
151 /* Value range array. After propagation, VR_VALUE[I] holds the range
152 of values that SSA name N_I may take. */
153 static unsigned num_vr_values
;
154 static value_range
**vr_value
;
155 static bool values_propagated
;
157 /* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the
158 number of executable edges we saw the last time we visited the
160 static int *vr_phi_edge_counts
;
162 struct switch_update
{
167 static vec
<edge
> to_remove_edges
;
168 static vec
<switch_update
> to_update_switch_stmts
;
171 /* Return the maximum value for TYPE. */
174 vrp_val_max (const_tree type
)
176 if (!INTEGRAL_TYPE_P (type
))
179 return TYPE_MAX_VALUE (type
);
182 /* Return the minimum value for TYPE. */
185 vrp_val_min (const_tree type
)
187 if (!INTEGRAL_TYPE_P (type
))
190 return TYPE_MIN_VALUE (type
);
193 /* Return whether VAL is equal to the maximum value of its type. This
194 will be true for a positive overflow infinity. We can't do a
195 simple equality comparison with TYPE_MAX_VALUE because C typedefs
196 and Ada subtypes can produce types whose TYPE_MAX_VALUE is not ==
197 to the integer constant with the same value in the type. */
200 vrp_val_is_max (const_tree val
)
202 tree type_max
= vrp_val_max (TREE_TYPE (val
));
203 return (val
== type_max
204 || (type_max
!= NULL_TREE
205 && operand_equal_p (val
, type_max
, 0)));
208 /* Return whether VAL is equal to the minimum value of its type. This
209 will be true for a negative overflow infinity. */
212 vrp_val_is_min (const_tree val
)
214 tree type_min
= vrp_val_min (TREE_TYPE (val
));
215 return (val
== type_min
216 || (type_min
!= NULL_TREE
217 && operand_equal_p (val
, type_min
, 0)));
221 /* Return whether TYPE should use an overflow infinity distinct from
222 TYPE_{MIN,MAX}_VALUE. We use an overflow infinity value to
223 represent a signed overflow during VRP computations. An infinity
224 is distinct from a half-range, which will go from some number to
225 TYPE_{MIN,MAX}_VALUE. */
228 needs_overflow_infinity (const_tree type
)
230 return INTEGRAL_TYPE_P (type
) && !TYPE_OVERFLOW_WRAPS (type
);
233 /* Return whether TYPE can support our overflow infinity
234 representation: we use the TREE_OVERFLOW flag, which only exists
235 for constants. If TYPE doesn't support this, we don't optimize
236 cases which would require signed overflow--we drop them to
240 supports_overflow_infinity (const_tree type
)
242 tree min
= vrp_val_min (type
), max
= vrp_val_max (type
);
243 gcc_checking_assert (needs_overflow_infinity (type
));
244 return (min
!= NULL_TREE
245 && CONSTANT_CLASS_P (min
)
247 && CONSTANT_CLASS_P (max
));
250 /* VAL is the maximum or minimum value of a type. Return a
251 corresponding overflow infinity. */
254 make_overflow_infinity (tree val
)
256 gcc_checking_assert (val
!= NULL_TREE
&& CONSTANT_CLASS_P (val
));
257 val
= copy_node (val
);
258 TREE_OVERFLOW (val
) = 1;
262 /* Return a negative overflow infinity for TYPE. */
265 negative_overflow_infinity (tree type
)
267 gcc_checking_assert (supports_overflow_infinity (type
));
268 return make_overflow_infinity (vrp_val_min (type
));
271 /* Return a positive overflow infinity for TYPE. */
274 positive_overflow_infinity (tree type
)
276 gcc_checking_assert (supports_overflow_infinity (type
));
277 return make_overflow_infinity (vrp_val_max (type
));
280 /* Return whether VAL is a negative overflow infinity. */
283 is_negative_overflow_infinity (const_tree val
)
285 return (TREE_OVERFLOW_P (val
)
286 && needs_overflow_infinity (TREE_TYPE (val
))
287 && vrp_val_is_min (val
));
290 /* Return whether VAL is a positive overflow infinity. */
293 is_positive_overflow_infinity (const_tree val
)
295 return (TREE_OVERFLOW_P (val
)
296 && needs_overflow_infinity (TREE_TYPE (val
))
297 && vrp_val_is_max (val
));
300 /* Return whether VAL is a positive or negative overflow infinity. */
303 is_overflow_infinity (const_tree val
)
305 return (TREE_OVERFLOW_P (val
)
306 && needs_overflow_infinity (TREE_TYPE (val
))
307 && (vrp_val_is_min (val
) || vrp_val_is_max (val
)));
310 /* Return whether STMT has a constant rhs that is_overflow_infinity. */
313 stmt_overflow_infinity (gimple
*stmt
)
315 if (is_gimple_assign (stmt
)
316 && get_gimple_rhs_class (gimple_assign_rhs_code (stmt
)) ==
318 return is_overflow_infinity (gimple_assign_rhs1 (stmt
));
322 /* If VAL is now an overflow infinity, return VAL. Otherwise, return
323 the same value with TREE_OVERFLOW clear. This can be used to avoid
324 confusing a regular value with an overflow value. */
327 avoid_overflow_infinity (tree val
)
329 if (!is_overflow_infinity (val
))
332 if (vrp_val_is_max (val
))
333 return vrp_val_max (TREE_TYPE (val
));
336 gcc_checking_assert (vrp_val_is_min (val
));
337 return vrp_val_min (TREE_TYPE (val
));
342 /* Set value range VR to VR_UNDEFINED. */
345 set_value_range_to_undefined (value_range
*vr
)
347 vr
->type
= VR_UNDEFINED
;
348 vr
->min
= vr
->max
= NULL_TREE
;
350 bitmap_clear (vr
->equiv
);
354 /* Set value range VR to VR_VARYING. */
357 set_value_range_to_varying (value_range
*vr
)
359 vr
->type
= VR_VARYING
;
360 vr
->min
= vr
->max
= NULL_TREE
;
362 bitmap_clear (vr
->equiv
);
366 /* Set value range VR to {T, MIN, MAX, EQUIV}. */
369 set_value_range (value_range
*vr
, enum value_range_type t
, tree min
,
370 tree max
, bitmap equiv
)
372 /* Check the validity of the range. */
374 && (t
== VR_RANGE
|| t
== VR_ANTI_RANGE
))
378 gcc_assert (min
&& max
);
380 gcc_assert ((!TREE_OVERFLOW_P (min
) || is_overflow_infinity (min
))
381 && (!TREE_OVERFLOW_P (max
) || is_overflow_infinity (max
)));
383 if (INTEGRAL_TYPE_P (TREE_TYPE (min
)) && t
== VR_ANTI_RANGE
)
384 gcc_assert (!vrp_val_is_min (min
) || !vrp_val_is_max (max
));
386 cmp
= compare_values (min
, max
);
387 gcc_assert (cmp
== 0 || cmp
== -1 || cmp
== -2);
389 if (needs_overflow_infinity (TREE_TYPE (min
)))
390 gcc_assert (!is_overflow_infinity (min
)
391 || !is_overflow_infinity (max
));
395 && (t
== VR_UNDEFINED
|| t
== VR_VARYING
))
397 gcc_assert (min
== NULL_TREE
&& max
== NULL_TREE
);
398 gcc_assert (equiv
== NULL
|| bitmap_empty_p (equiv
));
405 /* Since updating the equivalence set involves deep copying the
406 bitmaps, only do it if absolutely necessary. */
407 if (vr
->equiv
== NULL
409 vr
->equiv
= BITMAP_ALLOC (NULL
);
411 if (equiv
!= vr
->equiv
)
413 if (equiv
&& !bitmap_empty_p (equiv
))
414 bitmap_copy (vr
->equiv
, equiv
);
416 bitmap_clear (vr
->equiv
);
421 /* Set value range VR to the canonical form of {T, MIN, MAX, EQUIV}.
422 This means adjusting T, MIN and MAX representing the case of a
423 wrapping range with MAX < MIN covering [MIN, type_max] U [type_min, MAX]
424 as anti-rage ~[MAX+1, MIN-1]. Likewise for wrapping anti-ranges.
425 In corner cases where MAX+1 or MIN-1 wraps this will fall back
427 This routine exists to ease canonicalization in the case where we
428 extract ranges from var + CST op limit. */
431 set_and_canonicalize_value_range (value_range
*vr
, enum value_range_type t
,
432 tree min
, tree max
, bitmap equiv
)
434 /* Use the canonical setters for VR_UNDEFINED and VR_VARYING. */
435 if (t
== VR_UNDEFINED
)
437 set_value_range_to_undefined (vr
);
440 else if (t
== VR_VARYING
)
442 set_value_range_to_varying (vr
);
446 /* Nothing to canonicalize for symbolic ranges. */
447 if (TREE_CODE (min
) != INTEGER_CST
448 || TREE_CODE (max
) != INTEGER_CST
)
450 set_value_range (vr
, t
, min
, max
, equiv
);
454 /* Wrong order for min and max, to swap them and the VR type we need
456 if (tree_int_cst_lt (max
, min
))
460 /* For one bit precision if max < min, then the swapped
461 range covers all values, so for VR_RANGE it is varying and
462 for VR_ANTI_RANGE empty range, so drop to varying as well. */
463 if (TYPE_PRECISION (TREE_TYPE (min
)) == 1)
465 set_value_range_to_varying (vr
);
469 one
= build_int_cst (TREE_TYPE (min
), 1);
470 tmp
= int_const_binop (PLUS_EXPR
, max
, one
);
471 max
= int_const_binop (MINUS_EXPR
, min
, one
);
474 /* There's one corner case, if we had [C+1, C] before we now have
475 that again. But this represents an empty value range, so drop
476 to varying in this case. */
477 if (tree_int_cst_lt (max
, min
))
479 set_value_range_to_varying (vr
);
483 t
= t
== VR_RANGE
? VR_ANTI_RANGE
: VR_RANGE
;
486 /* Anti-ranges that can be represented as ranges should be so. */
487 if (t
== VR_ANTI_RANGE
)
489 bool is_min
= vrp_val_is_min (min
);
490 bool is_max
= vrp_val_is_max (max
);
492 if (is_min
&& is_max
)
494 /* We cannot deal with empty ranges, drop to varying.
495 ??? This could be VR_UNDEFINED instead. */
496 set_value_range_to_varying (vr
);
499 else if (TYPE_PRECISION (TREE_TYPE (min
)) == 1
500 && (is_min
|| is_max
))
502 /* Non-empty boolean ranges can always be represented
503 as a singleton range. */
505 min
= max
= vrp_val_max (TREE_TYPE (min
));
507 min
= max
= vrp_val_min (TREE_TYPE (min
));
511 /* As a special exception preserve non-null ranges. */
512 && !(TYPE_UNSIGNED (TREE_TYPE (min
))
513 && integer_zerop (max
)))
515 tree one
= build_int_cst (TREE_TYPE (max
), 1);
516 min
= int_const_binop (PLUS_EXPR
, max
, one
);
517 max
= vrp_val_max (TREE_TYPE (max
));
522 tree one
= build_int_cst (TREE_TYPE (min
), 1);
523 max
= int_const_binop (MINUS_EXPR
, min
, one
);
524 min
= vrp_val_min (TREE_TYPE (min
));
529 /* Drop [-INF(OVF), +INF(OVF)] to varying. */
530 if (needs_overflow_infinity (TREE_TYPE (min
))
531 && is_overflow_infinity (min
)
532 && is_overflow_infinity (max
))
534 set_value_range_to_varying (vr
);
538 set_value_range (vr
, t
, min
, max
, equiv
);
541 /* Copy value range FROM into value range TO. */
544 copy_value_range (value_range
*to
, value_range
*from
)
546 set_value_range (to
, from
->type
, from
->min
, from
->max
, from
->equiv
);
549 /* Set value range VR to a single value. This function is only called
550 with values we get from statements, and exists to clear the
551 TREE_OVERFLOW flag so that we don't think we have an overflow
552 infinity when we shouldn't. */
555 set_value_range_to_value (value_range
*vr
, tree val
, bitmap equiv
)
557 gcc_assert (is_gimple_min_invariant (val
));
558 if (TREE_OVERFLOW_P (val
))
559 val
= drop_tree_overflow (val
);
560 set_value_range (vr
, VR_RANGE
, val
, val
, equiv
);
563 /* Set value range VR to a non-negative range of type TYPE.
564 OVERFLOW_INFINITY indicates whether to use an overflow infinity
565 rather than TYPE_MAX_VALUE; this should be true if we determine
566 that the range is nonnegative based on the assumption that signed
567 overflow does not occur. */
570 set_value_range_to_nonnegative (value_range
*vr
, tree type
,
571 bool overflow_infinity
)
575 if (overflow_infinity
&& !supports_overflow_infinity (type
))
577 set_value_range_to_varying (vr
);
581 zero
= build_int_cst (type
, 0);
582 set_value_range (vr
, VR_RANGE
, zero
,
584 ? positive_overflow_infinity (type
)
585 : TYPE_MAX_VALUE (type
)),
589 /* Set value range VR to a non-NULL range of type TYPE. */
592 set_value_range_to_nonnull (value_range
*vr
, tree type
)
594 tree zero
= build_int_cst (type
, 0);
595 set_value_range (vr
, VR_ANTI_RANGE
, zero
, zero
, vr
->equiv
);
599 /* Set value range VR to a NULL range of type TYPE. */
602 set_value_range_to_null (value_range
*vr
, tree type
)
604 set_value_range_to_value (vr
, build_int_cst (type
, 0), vr
->equiv
);
608 /* Set value range VR to a range of a truthvalue of type TYPE. */
611 set_value_range_to_truthvalue (value_range
*vr
, tree type
)
613 if (TYPE_PRECISION (type
) == 1)
614 set_value_range_to_varying (vr
);
616 set_value_range (vr
, VR_RANGE
,
617 build_int_cst (type
, 0), build_int_cst (type
, 1),
622 /* If abs (min) < abs (max), set VR to [-max, max], if
623 abs (min) >= abs (max), set VR to [-min, min]. */
626 abs_extent_range (value_range
*vr
, tree min
, tree max
)
630 gcc_assert (TREE_CODE (min
) == INTEGER_CST
);
631 gcc_assert (TREE_CODE (max
) == INTEGER_CST
);
632 gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (min
)));
633 gcc_assert (!TYPE_UNSIGNED (TREE_TYPE (min
)));
634 min
= fold_unary (ABS_EXPR
, TREE_TYPE (min
), min
);
635 max
= fold_unary (ABS_EXPR
, TREE_TYPE (max
), max
);
636 if (TREE_OVERFLOW (min
) || TREE_OVERFLOW (max
))
638 set_value_range_to_varying (vr
);
641 cmp
= compare_values (min
, max
);
643 min
= fold_unary (NEGATE_EXPR
, TREE_TYPE (min
), max
);
644 else if (cmp
== 0 || cmp
== 1)
647 min
= fold_unary (NEGATE_EXPR
, TREE_TYPE (min
), min
);
651 set_value_range_to_varying (vr
);
654 set_and_canonicalize_value_range (vr
, VR_RANGE
, min
, max
, NULL
);
658 /* Return value range information for VAR.
660 If we have no values ranges recorded (ie, VRP is not running), then
661 return NULL. Otherwise create an empty range if none existed for VAR. */
664 get_value_range (const_tree var
)
666 static const value_range vr_const_varying
667 = { VR_VARYING
, NULL_TREE
, NULL_TREE
, NULL
};
670 unsigned ver
= SSA_NAME_VERSION (var
);
672 /* If we have no recorded ranges, then return NULL. */
676 /* If we query the range for a new SSA name return an unmodifiable VARYING.
677 We should get here at most from the substitute-and-fold stage which
678 will never try to change values. */
679 if (ver
>= num_vr_values
)
680 return CONST_CAST (value_range
*, &vr_const_varying
);
686 /* After propagation finished do not allocate new value-ranges. */
687 if (values_propagated
)
688 return CONST_CAST (value_range
*, &vr_const_varying
);
690 /* Create a default value range. */
691 vr_value
[ver
] = vr
= XCNEW (value_range
);
693 /* Defer allocating the equivalence set. */
696 /* If VAR is a default definition of a parameter, the variable can
697 take any value in VAR's type. */
698 if (SSA_NAME_IS_DEFAULT_DEF (var
))
700 sym
= SSA_NAME_VAR (var
);
701 if (TREE_CODE (sym
) == PARM_DECL
)
703 /* Try to use the "nonnull" attribute to create ~[0, 0]
704 anti-ranges for pointers. Note that this is only valid with
705 default definitions of PARM_DECLs. */
706 if (POINTER_TYPE_P (TREE_TYPE (sym
))
707 && nonnull_arg_p (sym
))
708 set_value_range_to_nonnull (vr
, TREE_TYPE (sym
));
710 set_value_range_to_varying (vr
);
712 else if (TREE_CODE (sym
) == RESULT_DECL
713 && DECL_BY_REFERENCE (sym
))
714 set_value_range_to_nonnull (vr
, TREE_TYPE (sym
));
720 /* Return true, if VAL1 and VAL2 are equal values for VRP purposes. */
723 vrp_operand_equal_p (const_tree val1
, const_tree val2
)
727 if (!val1
|| !val2
|| !operand_equal_p (val1
, val2
, 0))
729 return is_overflow_infinity (val1
) == is_overflow_infinity (val2
);
732 /* Return true, if the bitmaps B1 and B2 are equal. */
735 vrp_bitmap_equal_p (const_bitmap b1
, const_bitmap b2
)
738 || ((!b1
|| bitmap_empty_p (b1
))
739 && (!b2
|| bitmap_empty_p (b2
)))
741 && bitmap_equal_p (b1
, b2
)));
744 /* Update the value range and equivalence set for variable VAR to
745 NEW_VR. Return true if NEW_VR is different from VAR's previous
748 NOTE: This function assumes that NEW_VR is a temporary value range
749 object created for the sole purpose of updating VAR's range. The
750 storage used by the equivalence set from NEW_VR will be freed by
751 this function. Do not call update_value_range when NEW_VR
752 is the range object associated with another SSA name. */
755 update_value_range (const_tree var
, value_range
*new_vr
)
760 /* If there is a value-range on the SSA name from earlier analysis
762 if (INTEGRAL_TYPE_P (TREE_TYPE (var
)))
765 value_range_type rtype
= get_range_info (var
, &min
, &max
);
766 if (rtype
== VR_RANGE
|| rtype
== VR_ANTI_RANGE
)
770 nr
.min
= wide_int_to_tree (TREE_TYPE (var
), min
);
771 nr
.max
= wide_int_to_tree (TREE_TYPE (var
), max
);
773 vrp_intersect_ranges (new_vr
, &nr
);
777 /* Update the value range, if necessary. */
778 old_vr
= get_value_range (var
);
779 is_new
= old_vr
->type
!= new_vr
->type
780 || !vrp_operand_equal_p (old_vr
->min
, new_vr
->min
)
781 || !vrp_operand_equal_p (old_vr
->max
, new_vr
->max
)
782 || !vrp_bitmap_equal_p (old_vr
->equiv
, new_vr
->equiv
);
786 /* Do not allow transitions up the lattice. The following
787 is slightly more awkward than just new_vr->type < old_vr->type
788 because VR_RANGE and VR_ANTI_RANGE need to be considered
789 the same. We may not have is_new when transitioning to
790 UNDEFINED. If old_vr->type is VARYING, we shouldn't be
792 if (new_vr
->type
== VR_UNDEFINED
)
794 BITMAP_FREE (new_vr
->equiv
);
795 set_value_range_to_varying (old_vr
);
796 set_value_range_to_varying (new_vr
);
800 set_value_range (old_vr
, new_vr
->type
, new_vr
->min
, new_vr
->max
,
804 BITMAP_FREE (new_vr
->equiv
);
810 /* Add VAR and VAR's equivalence set to EQUIV. This is the central
811 point where equivalence processing can be turned on/off. */
814 add_equivalence (bitmap
*equiv
, const_tree var
)
816 unsigned ver
= SSA_NAME_VERSION (var
);
817 value_range
*vr
= vr_value
[ver
];
820 *equiv
= BITMAP_ALLOC (NULL
);
821 bitmap_set_bit (*equiv
, ver
);
823 bitmap_ior_into (*equiv
, vr
->equiv
);
827 /* Return true if VR is ~[0, 0]. */
830 range_is_nonnull (value_range
*vr
)
832 return vr
->type
== VR_ANTI_RANGE
833 && integer_zerop (vr
->min
)
834 && integer_zerop (vr
->max
);
838 /* Return true if VR is [0, 0]. */
841 range_is_null (value_range
*vr
)
843 return vr
->type
== VR_RANGE
844 && integer_zerop (vr
->min
)
845 && integer_zerop (vr
->max
);
848 /* Return true if max and min of VR are INTEGER_CST. It's not necessary
852 range_int_cst_p (value_range
*vr
)
854 return (vr
->type
== VR_RANGE
855 && TREE_CODE (vr
->max
) == INTEGER_CST
856 && TREE_CODE (vr
->min
) == INTEGER_CST
);
859 /* Return true if VR is a INTEGER_CST singleton. */
862 range_int_cst_singleton_p (value_range
*vr
)
864 return (range_int_cst_p (vr
)
865 && !is_overflow_infinity (vr
->min
)
866 && !is_overflow_infinity (vr
->max
)
867 && tree_int_cst_equal (vr
->min
, vr
->max
));
870 /* Return true if value range VR involves at least one symbol. */
873 symbolic_range_p (value_range
*vr
)
875 return (!is_gimple_min_invariant (vr
->min
)
876 || !is_gimple_min_invariant (vr
->max
));
879 /* Return the single symbol (an SSA_NAME) contained in T if any, or NULL_TREE
880 otherwise. We only handle additive operations and set NEG to true if the
881 symbol is negated and INV to the invariant part, if any. */
884 get_single_symbol (tree t
, bool *neg
, tree
*inv
)
889 if (TREE_CODE (t
) == PLUS_EXPR
890 || TREE_CODE (t
) == POINTER_PLUS_EXPR
891 || TREE_CODE (t
) == MINUS_EXPR
)
893 if (is_gimple_min_invariant (TREE_OPERAND (t
, 0)))
895 neg_
= (TREE_CODE (t
) == MINUS_EXPR
);
896 inv_
= TREE_OPERAND (t
, 0);
897 t
= TREE_OPERAND (t
, 1);
899 else if (is_gimple_min_invariant (TREE_OPERAND (t
, 1)))
902 inv_
= TREE_OPERAND (t
, 1);
903 t
= TREE_OPERAND (t
, 0);
914 if (TREE_CODE (t
) == NEGATE_EXPR
)
916 t
= TREE_OPERAND (t
, 0);
920 if (TREE_CODE (t
) != SSA_NAME
)
928 /* The reverse operation: build a symbolic expression with TYPE
929 from symbol SYM, negated according to NEG, and invariant INV. */
932 build_symbolic_expr (tree type
, tree sym
, bool neg
, tree inv
)
934 const bool pointer_p
= POINTER_TYPE_P (type
);
938 t
= build1 (NEGATE_EXPR
, type
, t
);
940 if (integer_zerop (inv
))
943 return build2 (pointer_p
? POINTER_PLUS_EXPR
: PLUS_EXPR
, type
, t
, inv
);
946 /* Return true if value range VR involves exactly one symbol SYM. */
949 symbolic_range_based_on_p (value_range
*vr
, const_tree sym
)
951 bool neg
, min_has_symbol
, max_has_symbol
;
954 if (is_gimple_min_invariant (vr
->min
))
955 min_has_symbol
= false;
956 else if (get_single_symbol (vr
->min
, &neg
, &inv
) == sym
)
957 min_has_symbol
= true;
961 if (is_gimple_min_invariant (vr
->max
))
962 max_has_symbol
= false;
963 else if (get_single_symbol (vr
->max
, &neg
, &inv
) == sym
)
964 max_has_symbol
= true;
968 return (min_has_symbol
|| max_has_symbol
);
971 /* Return true if value range VR uses an overflow infinity. */
974 overflow_infinity_range_p (value_range
*vr
)
976 return (vr
->type
== VR_RANGE
977 && (is_overflow_infinity (vr
->min
)
978 || is_overflow_infinity (vr
->max
)));
981 /* Return false if we can not make a valid comparison based on VR;
982 this will be the case if it uses an overflow infinity and overflow
983 is not undefined (i.e., -fno-strict-overflow is in effect).
984 Otherwise return true, and set *STRICT_OVERFLOW_P to true if VR
985 uses an overflow infinity. */
988 usable_range_p (value_range
*vr
, bool *strict_overflow_p
)
990 gcc_assert (vr
->type
== VR_RANGE
);
991 if (is_overflow_infinity (vr
->min
))
993 *strict_overflow_p
= true;
994 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr
->min
)))
997 if (is_overflow_infinity (vr
->max
))
999 *strict_overflow_p
= true;
1000 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr
->max
)))
1006 /* Return true if the result of assignment STMT is know to be non-zero.
1007 If the return value is based on the assumption that signed overflow is
1008 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
1009 *STRICT_OVERFLOW_P.*/
1012 gimple_assign_nonzero_warnv_p (gimple
*stmt
, bool *strict_overflow_p
)
1014 enum tree_code code
= gimple_assign_rhs_code (stmt
);
1015 switch (get_gimple_rhs_class (code
))
1017 case GIMPLE_UNARY_RHS
:
1018 return tree_unary_nonzero_warnv_p (gimple_assign_rhs_code (stmt
),
1019 gimple_expr_type (stmt
),
1020 gimple_assign_rhs1 (stmt
),
1022 case GIMPLE_BINARY_RHS
:
1023 return tree_binary_nonzero_warnv_p (gimple_assign_rhs_code (stmt
),
1024 gimple_expr_type (stmt
),
1025 gimple_assign_rhs1 (stmt
),
1026 gimple_assign_rhs2 (stmt
),
1028 case GIMPLE_TERNARY_RHS
:
1030 case GIMPLE_SINGLE_RHS
:
1031 return tree_single_nonzero_warnv_p (gimple_assign_rhs1 (stmt
),
1033 case GIMPLE_INVALID_RHS
:
1040 /* Return true if STMT is known to compute a non-zero value.
1041 If the return value is based on the assumption that signed overflow is
1042 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
1043 *STRICT_OVERFLOW_P.*/
1046 gimple_stmt_nonzero_warnv_p (gimple
*stmt
, bool *strict_overflow_p
)
1048 switch (gimple_code (stmt
))
1051 return gimple_assign_nonzero_warnv_p (stmt
, strict_overflow_p
);
1054 tree fndecl
= gimple_call_fndecl (stmt
);
1055 if (!fndecl
) return false;
1056 if (flag_delete_null_pointer_checks
&& !flag_check_new
1057 && DECL_IS_OPERATOR_NEW (fndecl
)
1058 && !TREE_NOTHROW (fndecl
))
1060 /* References are always non-NULL. */
1061 if (flag_delete_null_pointer_checks
1062 && TREE_CODE (TREE_TYPE (fndecl
)) == REFERENCE_TYPE
)
1064 if (flag_delete_null_pointer_checks
&&
1065 lookup_attribute ("returns_nonnull",
1066 TYPE_ATTRIBUTES (gimple_call_fntype (stmt
))))
1068 return gimple_alloca_call_p (stmt
);
1075 /* Like tree_expr_nonzero_warnv_p, but this function uses value ranges
1079 vrp_stmt_computes_nonzero (gimple
*stmt
, bool *strict_overflow_p
)
1081 if (gimple_stmt_nonzero_warnv_p (stmt
, strict_overflow_p
))
1084 /* If we have an expression of the form &X->a, then the expression
1085 is nonnull if X is nonnull. */
1086 if (is_gimple_assign (stmt
)
1087 && gimple_assign_rhs_code (stmt
) == ADDR_EXPR
)
1089 tree expr
= gimple_assign_rhs1 (stmt
);
1090 tree base
= get_base_address (TREE_OPERAND (expr
, 0));
1092 if (base
!= NULL_TREE
1093 && TREE_CODE (base
) == MEM_REF
1094 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1096 value_range
*vr
= get_value_range (TREE_OPERAND (base
, 0));
1097 if (range_is_nonnull (vr
))
1105 /* Returns true if EXPR is a valid value (as expected by compare_values) --
1106 a gimple invariant, or SSA_NAME +- CST. */
1109 valid_value_p (tree expr
)
1111 if (TREE_CODE (expr
) == SSA_NAME
)
1114 if (TREE_CODE (expr
) == PLUS_EXPR
1115 || TREE_CODE (expr
) == MINUS_EXPR
)
1116 return (TREE_CODE (TREE_OPERAND (expr
, 0)) == SSA_NAME
1117 && TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
);
1119 return is_gimple_min_invariant (expr
);
1125 -2 if those are incomparable. */
1127 operand_less_p (tree val
, tree val2
)
1129 /* LT is folded faster than GE and others. Inline the common case. */
1130 if (TREE_CODE (val
) == INTEGER_CST
&& TREE_CODE (val2
) == INTEGER_CST
)
1131 return tree_int_cst_lt (val
, val2
);
1136 fold_defer_overflow_warnings ();
1138 tcmp
= fold_binary_to_constant (LT_EXPR
, boolean_type_node
, val
, val2
);
1140 fold_undefer_and_ignore_overflow_warnings ();
1143 || TREE_CODE (tcmp
) != INTEGER_CST
)
1146 if (!integer_zerop (tcmp
))
1150 /* val >= val2, not considering overflow infinity. */
1151 if (is_negative_overflow_infinity (val
))
1152 return is_negative_overflow_infinity (val2
) ? 0 : 1;
1153 else if (is_positive_overflow_infinity (val2
))
1154 return is_positive_overflow_infinity (val
) ? 0 : 1;
1159 /* Compare two values VAL1 and VAL2. Return
1161 -2 if VAL1 and VAL2 cannot be compared at compile-time,
1164 +1 if VAL1 > VAL2, and
1167 This is similar to tree_int_cst_compare but supports pointer values
1168 and values that cannot be compared at compile time.
1170 If STRICT_OVERFLOW_P is not NULL, then set *STRICT_OVERFLOW_P to
1171 true if the return value is only valid if we assume that signed
1172 overflow is undefined. */
1175 compare_values_warnv (tree val1
, tree val2
, bool *strict_overflow_p
)
1180 /* Below we rely on the fact that VAL1 and VAL2 are both pointers or
1182 gcc_assert (POINTER_TYPE_P (TREE_TYPE (val1
))
1183 == POINTER_TYPE_P (TREE_TYPE (val2
)));
1185 /* Convert the two values into the same type. This is needed because
1186 sizetype causes sign extension even for unsigned types. */
1187 val2
= fold_convert (TREE_TYPE (val1
), val2
);
1188 STRIP_USELESS_TYPE_CONVERSION (val2
);
1190 if ((TREE_CODE (val1
) == SSA_NAME
1191 || (TREE_CODE (val1
) == NEGATE_EXPR
1192 && TREE_CODE (TREE_OPERAND (val1
, 0)) == SSA_NAME
)
1193 || TREE_CODE (val1
) == PLUS_EXPR
1194 || TREE_CODE (val1
) == MINUS_EXPR
)
1195 && (TREE_CODE (val2
) == SSA_NAME
1196 || (TREE_CODE (val2
) == NEGATE_EXPR
1197 && TREE_CODE (TREE_OPERAND (val2
, 0)) == SSA_NAME
)
1198 || TREE_CODE (val2
) == PLUS_EXPR
1199 || TREE_CODE (val2
) == MINUS_EXPR
))
1201 tree n1
, c1
, n2
, c2
;
1202 enum tree_code code1
, code2
;
1204 /* If VAL1 and VAL2 are of the form '[-]NAME [+-] CST' or 'NAME',
1205 return -1 or +1 accordingly. If VAL1 and VAL2 don't use the
1206 same name, return -2. */
1207 if (TREE_CODE (val1
) == SSA_NAME
|| TREE_CODE (val1
) == NEGATE_EXPR
)
1215 code1
= TREE_CODE (val1
);
1216 n1
= TREE_OPERAND (val1
, 0);
1217 c1
= TREE_OPERAND (val1
, 1);
1218 if (tree_int_cst_sgn (c1
) == -1)
1220 if (is_negative_overflow_infinity (c1
))
1222 c1
= fold_unary_to_constant (NEGATE_EXPR
, TREE_TYPE (c1
), c1
);
1225 code1
= code1
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
;
1229 if (TREE_CODE (val2
) == SSA_NAME
|| TREE_CODE (val2
) == NEGATE_EXPR
)
1237 code2
= TREE_CODE (val2
);
1238 n2
= TREE_OPERAND (val2
, 0);
1239 c2
= TREE_OPERAND (val2
, 1);
1240 if (tree_int_cst_sgn (c2
) == -1)
1242 if (is_negative_overflow_infinity (c2
))
1244 c2
= fold_unary_to_constant (NEGATE_EXPR
, TREE_TYPE (c2
), c2
);
1247 code2
= code2
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
;
1251 /* Both values must use the same name. */
1252 if (TREE_CODE (n1
) == NEGATE_EXPR
&& TREE_CODE (n2
) == NEGATE_EXPR
)
1254 n1
= TREE_OPERAND (n1
, 0);
1255 n2
= TREE_OPERAND (n2
, 0);
1260 if (code1
== SSA_NAME
&& code2
== SSA_NAME
)
1264 /* If overflow is defined we cannot simplify more. */
1265 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1
)))
1268 if (strict_overflow_p
!= NULL
1269 && (code1
== SSA_NAME
|| !TREE_NO_WARNING (val1
))
1270 && (code2
== SSA_NAME
|| !TREE_NO_WARNING (val2
)))
1271 *strict_overflow_p
= true;
1273 if (code1
== SSA_NAME
)
1275 if (code2
== PLUS_EXPR
)
1276 /* NAME < NAME + CST */
1278 else if (code2
== MINUS_EXPR
)
1279 /* NAME > NAME - CST */
1282 else if (code1
== PLUS_EXPR
)
1284 if (code2
== SSA_NAME
)
1285 /* NAME + CST > NAME */
1287 else if (code2
== PLUS_EXPR
)
1288 /* NAME + CST1 > NAME + CST2, if CST1 > CST2 */
1289 return compare_values_warnv (c1
, c2
, strict_overflow_p
);
1290 else if (code2
== MINUS_EXPR
)
1291 /* NAME + CST1 > NAME - CST2 */
1294 else if (code1
== MINUS_EXPR
)
1296 if (code2
== SSA_NAME
)
1297 /* NAME - CST < NAME */
1299 else if (code2
== PLUS_EXPR
)
1300 /* NAME - CST1 < NAME + CST2 */
1302 else if (code2
== MINUS_EXPR
)
1303 /* NAME - CST1 > NAME - CST2, if CST1 < CST2. Notice that
1304 C1 and C2 are swapped in the call to compare_values. */
1305 return compare_values_warnv (c2
, c1
, strict_overflow_p
);
1311 /* We cannot compare non-constants. */
1312 if (!is_gimple_min_invariant (val1
) || !is_gimple_min_invariant (val2
))
1315 if (!POINTER_TYPE_P (TREE_TYPE (val1
)))
1317 /* We cannot compare overflowed values, except for overflow
1319 if (TREE_OVERFLOW (val1
) || TREE_OVERFLOW (val2
))
1321 if (strict_overflow_p
!= NULL
)
1322 *strict_overflow_p
= true;
1323 if (is_negative_overflow_infinity (val1
))
1324 return is_negative_overflow_infinity (val2
) ? 0 : -1;
1325 else if (is_negative_overflow_infinity (val2
))
1327 else if (is_positive_overflow_infinity (val1
))
1328 return is_positive_overflow_infinity (val2
) ? 0 : 1;
1329 else if (is_positive_overflow_infinity (val2
))
1334 return tree_int_cst_compare (val1
, val2
);
1340 /* First see if VAL1 and VAL2 are not the same. */
1341 if (val1
== val2
|| operand_equal_p (val1
, val2
, 0))
1344 /* If VAL1 is a lower address than VAL2, return -1. */
1345 if (operand_less_p (val1
, val2
) == 1)
1348 /* If VAL1 is a higher address than VAL2, return +1. */
1349 if (operand_less_p (val2
, val1
) == 1)
1352 /* If VAL1 is different than VAL2, return +2.
1353 For integer constants we either have already returned -1 or 1
1354 or they are equivalent. We still might succeed in proving
1355 something about non-trivial operands. */
1356 if (TREE_CODE (val1
) != INTEGER_CST
1357 || TREE_CODE (val2
) != INTEGER_CST
)
1359 t
= fold_binary_to_constant (NE_EXPR
, boolean_type_node
, val1
, val2
);
1360 if (t
&& integer_onep (t
))
1368 /* Compare values like compare_values_warnv, but treat comparisons of
1369 nonconstants which rely on undefined overflow as incomparable. */
1372 compare_values (tree val1
, tree val2
)
1378 ret
= compare_values_warnv (val1
, val2
, &sop
);
1380 && (!is_gimple_min_invariant (val1
) || !is_gimple_min_invariant (val2
)))
1386 /* Return 1 if VAL is inside value range MIN <= VAL <= MAX,
1387 0 if VAL is not inside [MIN, MAX],
1388 -2 if we cannot tell either way.
1390 Benchmark compile/20001226-1.c compilation time after changing this
1394 value_inside_range (tree val
, tree min
, tree max
)
1398 cmp1
= operand_less_p (val
, min
);
1404 cmp2
= operand_less_p (max
, val
);
1412 /* Return true if value ranges VR0 and VR1 have a non-empty
1415 Benchmark compile/20001226-1.c compilation time after changing this
1420 value_ranges_intersect_p (value_range
*vr0
, value_range
*vr1
)
1422 /* The value ranges do not intersect if the maximum of the first range is
1423 less than the minimum of the second range or vice versa.
1424 When those relations are unknown, we can't do any better. */
1425 if (operand_less_p (vr0
->max
, vr1
->min
) != 0)
1427 if (operand_less_p (vr1
->max
, vr0
->min
) != 0)
1433 /* Return 1 if [MIN, MAX] includes the value zero, 0 if it does not
1434 include the value zero, -2 if we cannot tell. */
1437 range_includes_zero_p (tree min
, tree max
)
1439 tree zero
= build_int_cst (TREE_TYPE (min
), 0);
1440 return value_inside_range (zero
, min
, max
);
1443 /* Return true if *VR is know to only contain nonnegative values. */
1446 value_range_nonnegative_p (value_range
*vr
)
1448 /* Testing for VR_ANTI_RANGE is not useful here as any anti-range
1449 which would return a useful value should be encoded as a
1451 if (vr
->type
== VR_RANGE
)
1453 int result
= compare_values (vr
->min
, integer_zero_node
);
1454 return (result
== 0 || result
== 1);
1460 /* If *VR has a value rante that is a single constant value return that,
1461 otherwise return NULL_TREE. */
1464 value_range_constant_singleton (value_range
*vr
)
1466 if (vr
->type
== VR_RANGE
1467 && operand_equal_p (vr
->min
, vr
->max
, 0)
1468 && is_gimple_min_invariant (vr
->min
))
1474 /* If OP has a value range with a single constant value return that,
1475 otherwise return NULL_TREE. This returns OP itself if OP is a
1479 op_with_constant_singleton_value_range (tree op
)
1481 if (is_gimple_min_invariant (op
))
1484 if (TREE_CODE (op
) != SSA_NAME
)
1487 return value_range_constant_singleton (get_value_range (op
));
1490 /* Return true if op is in a boolean [0, 1] value-range. */
1493 op_with_boolean_value_range_p (tree op
)
1497 if (TYPE_PRECISION (TREE_TYPE (op
)) == 1)
1500 if (integer_zerop (op
)
1501 || integer_onep (op
))
1504 if (TREE_CODE (op
) != SSA_NAME
)
1507 vr
= get_value_range (op
);
1508 return (vr
->type
== VR_RANGE
1509 && integer_zerop (vr
->min
)
1510 && integer_onep (vr
->max
));
1513 /* Extract value range information from an ASSERT_EXPR EXPR and store
1517 extract_range_from_assert (value_range
*vr_p
, tree expr
)
1519 tree var
, cond
, limit
, min
, max
, type
;
1520 value_range
*limit_vr
;
1521 enum tree_code cond_code
;
1523 var
= ASSERT_EXPR_VAR (expr
);
1524 cond
= ASSERT_EXPR_COND (expr
);
1526 gcc_assert (COMPARISON_CLASS_P (cond
));
1528 /* Find VAR in the ASSERT_EXPR conditional. */
1529 if (var
== TREE_OPERAND (cond
, 0)
1530 || TREE_CODE (TREE_OPERAND (cond
, 0)) == PLUS_EXPR
1531 || TREE_CODE (TREE_OPERAND (cond
, 0)) == NOP_EXPR
)
1533 /* If the predicate is of the form VAR COMP LIMIT, then we just
1534 take LIMIT from the RHS and use the same comparison code. */
1535 cond_code
= TREE_CODE (cond
);
1536 limit
= TREE_OPERAND (cond
, 1);
1537 cond
= TREE_OPERAND (cond
, 0);
1541 /* If the predicate is of the form LIMIT COMP VAR, then we need
1542 to flip around the comparison code to create the proper range
1544 cond_code
= swap_tree_comparison (TREE_CODE (cond
));
1545 limit
= TREE_OPERAND (cond
, 0);
1546 cond
= TREE_OPERAND (cond
, 1);
1549 limit
= avoid_overflow_infinity (limit
);
1551 type
= TREE_TYPE (var
);
1552 gcc_assert (limit
!= var
);
1554 /* For pointer arithmetic, we only keep track of pointer equality
1556 if (POINTER_TYPE_P (type
) && cond_code
!= NE_EXPR
&& cond_code
!= EQ_EXPR
)
1558 set_value_range_to_varying (vr_p
);
1562 /* If LIMIT is another SSA name and LIMIT has a range of its own,
1563 try to use LIMIT's range to avoid creating symbolic ranges
1565 limit_vr
= (TREE_CODE (limit
) == SSA_NAME
) ? get_value_range (limit
) : NULL
;
1567 /* LIMIT's range is only interesting if it has any useful information. */
1569 && (limit_vr
->type
== VR_UNDEFINED
1570 || limit_vr
->type
== VR_VARYING
1571 || symbolic_range_p (limit_vr
)))
1574 /* Initially, the new range has the same set of equivalences of
1575 VAR's range. This will be revised before returning the final
1576 value. Since assertions may be chained via mutually exclusive
1577 predicates, we will need to trim the set of equivalences before
1579 gcc_assert (vr_p
->equiv
== NULL
);
1580 add_equivalence (&vr_p
->equiv
, var
);
1582 /* Extract a new range based on the asserted comparison for VAR and
1583 LIMIT's value range. Notice that if LIMIT has an anti-range, we
1584 will only use it for equality comparisons (EQ_EXPR). For any
1585 other kind of assertion, we cannot derive a range from LIMIT's
1586 anti-range that can be used to describe the new range. For
1587 instance, ASSERT_EXPR <x_2, x_2 <= b_4>. If b_4 is ~[2, 10],
1588 then b_4 takes on the ranges [-INF, 1] and [11, +INF]. There is
1589 no single range for x_2 that could describe LE_EXPR, so we might
1590 as well build the range [b_4, +INF] for it.
1591 One special case we handle is extracting a range from a
1592 range test encoded as (unsigned)var + CST <= limit. */
1593 if (TREE_CODE (cond
) == NOP_EXPR
1594 || TREE_CODE (cond
) == PLUS_EXPR
)
1596 if (TREE_CODE (cond
) == PLUS_EXPR
)
1598 min
= fold_build1 (NEGATE_EXPR
, TREE_TYPE (TREE_OPERAND (cond
, 1)),
1599 TREE_OPERAND (cond
, 1));
1600 max
= int_const_binop (PLUS_EXPR
, limit
, min
);
1601 cond
= TREE_OPERAND (cond
, 0);
1605 min
= build_int_cst (TREE_TYPE (var
), 0);
1609 /* Make sure to not set TREE_OVERFLOW on the final type
1610 conversion. We are willingly interpreting large positive
1611 unsigned values as negative signed values here. */
1612 min
= force_fit_type (TREE_TYPE (var
), wi::to_widest (min
), 0, false);
1613 max
= force_fit_type (TREE_TYPE (var
), wi::to_widest (max
), 0, false);
1615 /* We can transform a max, min range to an anti-range or
1616 vice-versa. Use set_and_canonicalize_value_range which does
1618 if (cond_code
== LE_EXPR
)
1619 set_and_canonicalize_value_range (vr_p
, VR_RANGE
,
1620 min
, max
, vr_p
->equiv
);
1621 else if (cond_code
== GT_EXPR
)
1622 set_and_canonicalize_value_range (vr_p
, VR_ANTI_RANGE
,
1623 min
, max
, vr_p
->equiv
);
1627 else if (cond_code
== EQ_EXPR
)
1629 enum value_range_type range_type
;
1633 range_type
= limit_vr
->type
;
1634 min
= limit_vr
->min
;
1635 max
= limit_vr
->max
;
1639 range_type
= VR_RANGE
;
1644 set_value_range (vr_p
, range_type
, min
, max
, vr_p
->equiv
);
1646 /* When asserting the equality VAR == LIMIT and LIMIT is another
1647 SSA name, the new range will also inherit the equivalence set
1649 if (TREE_CODE (limit
) == SSA_NAME
)
1650 add_equivalence (&vr_p
->equiv
, limit
);
1652 else if (cond_code
== NE_EXPR
)
1654 /* As described above, when LIMIT's range is an anti-range and
1655 this assertion is an inequality (NE_EXPR), then we cannot
1656 derive anything from the anti-range. For instance, if
1657 LIMIT's range was ~[0, 0], the assertion 'VAR != LIMIT' does
1658 not imply that VAR's range is [0, 0]. So, in the case of
1659 anti-ranges, we just assert the inequality using LIMIT and
1662 If LIMIT_VR is a range, we can only use it to build a new
1663 anti-range if LIMIT_VR is a single-valued range. For
1664 instance, if LIMIT_VR is [0, 1], the predicate
1665 VAR != [0, 1] does not mean that VAR's range is ~[0, 1].
1666 Rather, it means that for value 0 VAR should be ~[0, 0]
1667 and for value 1, VAR should be ~[1, 1]. We cannot
1668 represent these ranges.
1670 The only situation in which we can build a valid
1671 anti-range is when LIMIT_VR is a single-valued range
1672 (i.e., LIMIT_VR->MIN == LIMIT_VR->MAX). In that case,
1673 build the anti-range ~[LIMIT_VR->MIN, LIMIT_VR->MAX]. */
1675 && limit_vr
->type
== VR_RANGE
1676 && compare_values (limit_vr
->min
, limit_vr
->max
) == 0)
1678 min
= limit_vr
->min
;
1679 max
= limit_vr
->max
;
1683 /* In any other case, we cannot use LIMIT's range to build a
1684 valid anti-range. */
1688 /* If MIN and MAX cover the whole range for their type, then
1689 just use the original LIMIT. */
1690 if (INTEGRAL_TYPE_P (type
)
1691 && vrp_val_is_min (min
)
1692 && vrp_val_is_max (max
))
1695 set_and_canonicalize_value_range (vr_p
, VR_ANTI_RANGE
,
1696 min
, max
, vr_p
->equiv
);
1698 else if (cond_code
== LE_EXPR
|| cond_code
== LT_EXPR
)
1700 min
= TYPE_MIN_VALUE (type
);
1702 if (limit_vr
== NULL
|| limit_vr
->type
== VR_ANTI_RANGE
)
1706 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1707 range [MIN, N2] for LE_EXPR and [MIN, N2 - 1] for
1709 max
= limit_vr
->max
;
1712 /* If the maximum value forces us to be out of bounds, simply punt.
1713 It would be pointless to try and do anything more since this
1714 all should be optimized away above us. */
1715 if ((cond_code
== LT_EXPR
1716 && compare_values (max
, min
) == 0)
1717 || is_overflow_infinity (max
))
1718 set_value_range_to_varying (vr_p
);
1721 /* For LT_EXPR, we create the range [MIN, MAX - 1]. */
1722 if (cond_code
== LT_EXPR
)
1724 if (TYPE_PRECISION (TREE_TYPE (max
)) == 1
1725 && !TYPE_UNSIGNED (TREE_TYPE (max
)))
1726 max
= fold_build2 (PLUS_EXPR
, TREE_TYPE (max
), max
,
1727 build_int_cst (TREE_TYPE (max
), -1));
1729 max
= fold_build2 (MINUS_EXPR
, TREE_TYPE (max
), max
,
1730 build_int_cst (TREE_TYPE (max
), 1));
1732 TREE_NO_WARNING (max
) = 1;
1735 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1738 else if (cond_code
== GE_EXPR
|| cond_code
== GT_EXPR
)
1740 max
= TYPE_MAX_VALUE (type
);
1742 if (limit_vr
== NULL
|| limit_vr
->type
== VR_ANTI_RANGE
)
1746 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1747 range [N1, MAX] for GE_EXPR and [N1 + 1, MAX] for
1749 min
= limit_vr
->min
;
1752 /* If the minimum value forces us to be out of bounds, simply punt.
1753 It would be pointless to try and do anything more since this
1754 all should be optimized away above us. */
1755 if ((cond_code
== GT_EXPR
1756 && compare_values (min
, max
) == 0)
1757 || is_overflow_infinity (min
))
1758 set_value_range_to_varying (vr_p
);
1761 /* For GT_EXPR, we create the range [MIN + 1, MAX]. */
1762 if (cond_code
== GT_EXPR
)
1764 if (TYPE_PRECISION (TREE_TYPE (min
)) == 1
1765 && !TYPE_UNSIGNED (TREE_TYPE (min
)))
1766 min
= fold_build2 (MINUS_EXPR
, TREE_TYPE (min
), min
,
1767 build_int_cst (TREE_TYPE (min
), -1));
1769 min
= fold_build2 (PLUS_EXPR
, TREE_TYPE (min
), min
,
1770 build_int_cst (TREE_TYPE (min
), 1));
1772 TREE_NO_WARNING (min
) = 1;
1775 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1781 /* Finally intersect the new range with what we already know about var. */
1782 vrp_intersect_ranges (vr_p
, get_value_range (var
));
1786 /* Extract range information from SSA name VAR and store it in VR. If
1787 VAR has an interesting range, use it. Otherwise, create the
1788 range [VAR, VAR] and return it. This is useful in situations where
1789 we may have conditionals testing values of VARYING names. For
1796 Even if y_5 is deemed VARYING, we can determine that x_3 > y_5 is
1800 extract_range_from_ssa_name (value_range
*vr
, tree var
)
1802 value_range
*var_vr
= get_value_range (var
);
1804 if (var_vr
->type
!= VR_VARYING
)
1805 copy_value_range (vr
, var_vr
);
1807 set_value_range (vr
, VR_RANGE
, var
, var
, NULL
);
1809 add_equivalence (&vr
->equiv
, var
);
1813 /* Wrapper around int_const_binop. If the operation overflows and we
1814 are not using wrapping arithmetic, then adjust the result to be
1815 -INF or +INF depending on CODE, VAL1 and VAL2. This can return
1816 NULL_TREE if we need to use an overflow infinity representation but
1817 the type does not support it. */
1820 vrp_int_const_binop (enum tree_code code
, tree val1
, tree val2
)
1824 res
= int_const_binop (code
, val1
, val2
);
1826 /* If we are using unsigned arithmetic, operate symbolically
1827 on -INF and +INF as int_const_binop only handles signed overflow. */
1828 if (TYPE_UNSIGNED (TREE_TYPE (val1
)))
1830 int checkz
= compare_values (res
, val1
);
1831 bool overflow
= false;
1833 /* Ensure that res = val1 [+*] val2 >= val1
1834 or that res = val1 - val2 <= val1. */
1835 if ((code
== PLUS_EXPR
1836 && !(checkz
== 1 || checkz
== 0))
1837 || (code
== MINUS_EXPR
1838 && !(checkz
== 0 || checkz
== -1)))
1842 /* Checking for multiplication overflow is done by dividing the
1843 output of the multiplication by the first input of the
1844 multiplication. If the result of that division operation is
1845 not equal to the second input of the multiplication, then the
1846 multiplication overflowed. */
1847 else if (code
== MULT_EXPR
&& !integer_zerop (val1
))
1849 tree tmp
= int_const_binop (TRUNC_DIV_EXPR
,
1852 int check
= compare_values (tmp
, val2
);
1860 res
= copy_node (res
);
1861 TREE_OVERFLOW (res
) = 1;
1865 else if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (val1
)))
1866 /* If the singed operation wraps then int_const_binop has done
1867 everything we want. */
1869 /* Signed division of -1/0 overflows and by the time it gets here
1870 returns NULL_TREE. */
1873 else if ((TREE_OVERFLOW (res
)
1874 && !TREE_OVERFLOW (val1
)
1875 && !TREE_OVERFLOW (val2
))
1876 || is_overflow_infinity (val1
)
1877 || is_overflow_infinity (val2
))
1879 /* If the operation overflowed but neither VAL1 nor VAL2 are
1880 overflown, return -INF or +INF depending on the operation
1881 and the combination of signs of the operands. */
1882 int sgn1
= tree_int_cst_sgn (val1
);
1883 int sgn2
= tree_int_cst_sgn (val2
);
1885 if (needs_overflow_infinity (TREE_TYPE (res
))
1886 && !supports_overflow_infinity (TREE_TYPE (res
)))
1889 /* We have to punt on adding infinities of different signs,
1890 since we can't tell what the sign of the result should be.
1891 Likewise for subtracting infinities of the same sign. */
1892 if (((code
== PLUS_EXPR
&& sgn1
!= sgn2
)
1893 || (code
== MINUS_EXPR
&& sgn1
== sgn2
))
1894 && is_overflow_infinity (val1
)
1895 && is_overflow_infinity (val2
))
1898 /* Don't try to handle division or shifting of infinities. */
1899 if ((code
== TRUNC_DIV_EXPR
1900 || code
== FLOOR_DIV_EXPR
1901 || code
== CEIL_DIV_EXPR
1902 || code
== EXACT_DIV_EXPR
1903 || code
== ROUND_DIV_EXPR
1904 || code
== RSHIFT_EXPR
)
1905 && (is_overflow_infinity (val1
)
1906 || is_overflow_infinity (val2
)))
1909 /* Notice that we only need to handle the restricted set of
1910 operations handled by extract_range_from_binary_expr.
1911 Among them, only multiplication, addition and subtraction
1912 can yield overflow without overflown operands because we
1913 are working with integral types only... except in the
1914 case VAL1 = -INF and VAL2 = -1 which overflows to +INF
1915 for division too. */
1917 /* For multiplication, the sign of the overflow is given
1918 by the comparison of the signs of the operands. */
1919 if ((code
== MULT_EXPR
&& sgn1
== sgn2
)
1920 /* For addition, the operands must be of the same sign
1921 to yield an overflow. Its sign is therefore that
1922 of one of the operands, for example the first. For
1923 infinite operands X + -INF is negative, not positive. */
1924 || (code
== PLUS_EXPR
1926 ? !is_negative_overflow_infinity (val2
)
1927 : is_positive_overflow_infinity (val2
)))
1928 /* For subtraction, non-infinite operands must be of
1929 different signs to yield an overflow. Its sign is
1930 therefore that of the first operand or the opposite of
1931 that of the second operand. A first operand of 0 counts
1932 as positive here, for the corner case 0 - (-INF), which
1933 overflows, but must yield +INF. For infinite operands 0
1934 - INF is negative, not positive. */
1935 || (code
== MINUS_EXPR
1937 ? !is_positive_overflow_infinity (val2
)
1938 : is_negative_overflow_infinity (val2
)))
1939 /* We only get in here with positive shift count, so the
1940 overflow direction is the same as the sign of val1.
1941 Actually rshift does not overflow at all, but we only
1942 handle the case of shifting overflowed -INF and +INF. */
1943 || (code
== RSHIFT_EXPR
1945 /* For division, the only case is -INF / -1 = +INF. */
1946 || code
== TRUNC_DIV_EXPR
1947 || code
== FLOOR_DIV_EXPR
1948 || code
== CEIL_DIV_EXPR
1949 || code
== EXACT_DIV_EXPR
1950 || code
== ROUND_DIV_EXPR
)
1951 return (needs_overflow_infinity (TREE_TYPE (res
))
1952 ? positive_overflow_infinity (TREE_TYPE (res
))
1953 : TYPE_MAX_VALUE (TREE_TYPE (res
)));
1955 return (needs_overflow_infinity (TREE_TYPE (res
))
1956 ? negative_overflow_infinity (TREE_TYPE (res
))
1957 : TYPE_MIN_VALUE (TREE_TYPE (res
)));
1964 /* For range VR compute two wide_int bitmasks. In *MAY_BE_NONZERO
1965 bitmask if some bit is unset, it means for all numbers in the range
1966 the bit is 0, otherwise it might be 0 or 1. In *MUST_BE_NONZERO
1967 bitmask if some bit is set, it means for all numbers in the range
1968 the bit is 1, otherwise it might be 0 or 1. */
1971 zero_nonzero_bits_from_vr (const tree expr_type
,
1973 wide_int
*may_be_nonzero
,
1974 wide_int
*must_be_nonzero
)
1976 *may_be_nonzero
= wi::minus_one (TYPE_PRECISION (expr_type
));
1977 *must_be_nonzero
= wi::zero (TYPE_PRECISION (expr_type
));
1978 if (!range_int_cst_p (vr
)
1979 || is_overflow_infinity (vr
->min
)
1980 || is_overflow_infinity (vr
->max
))
1983 if (range_int_cst_singleton_p (vr
))
1985 *may_be_nonzero
= vr
->min
;
1986 *must_be_nonzero
= *may_be_nonzero
;
1988 else if (tree_int_cst_sgn (vr
->min
) >= 0
1989 || tree_int_cst_sgn (vr
->max
) < 0)
1991 wide_int xor_mask
= wi::bit_xor (vr
->min
, vr
->max
);
1992 *may_be_nonzero
= wi::bit_or (vr
->min
, vr
->max
);
1993 *must_be_nonzero
= wi::bit_and (vr
->min
, vr
->max
);
1996 wide_int mask
= wi::mask (wi::floor_log2 (xor_mask
), false,
1997 may_be_nonzero
->get_precision ());
1998 *may_be_nonzero
= *may_be_nonzero
| mask
;
1999 *must_be_nonzero
= must_be_nonzero
->and_not (mask
);
2006 /* Create two value-ranges in *VR0 and *VR1 from the anti-range *AR
2007 so that *VR0 U *VR1 == *AR. Returns true if that is possible,
2008 false otherwise. If *AR can be represented with a single range
2009 *VR1 will be VR_UNDEFINED. */
2012 ranges_from_anti_range (value_range
*ar
,
2013 value_range
*vr0
, value_range
*vr1
)
2015 tree type
= TREE_TYPE (ar
->min
);
2017 vr0
->type
= VR_UNDEFINED
;
2018 vr1
->type
= VR_UNDEFINED
;
2020 if (ar
->type
!= VR_ANTI_RANGE
2021 || TREE_CODE (ar
->min
) != INTEGER_CST
2022 || TREE_CODE (ar
->max
) != INTEGER_CST
2023 || !vrp_val_min (type
)
2024 || !vrp_val_max (type
))
2027 if (!vrp_val_is_min (ar
->min
))
2029 vr0
->type
= VR_RANGE
;
2030 vr0
->min
= vrp_val_min (type
);
2031 vr0
->max
= wide_int_to_tree (type
, wi::sub (ar
->min
, 1));
2033 if (!vrp_val_is_max (ar
->max
))
2035 vr1
->type
= VR_RANGE
;
2036 vr1
->min
= wide_int_to_tree (type
, wi::add (ar
->max
, 1));
2037 vr1
->max
= vrp_val_max (type
);
2039 if (vr0
->type
== VR_UNDEFINED
)
2042 vr1
->type
= VR_UNDEFINED
;
2045 return vr0
->type
!= VR_UNDEFINED
;
2048 /* Helper to extract a value-range *VR for a multiplicative operation
2052 extract_range_from_multiplicative_op_1 (value_range
*vr
,
2053 enum tree_code code
,
2054 value_range
*vr0
, value_range
*vr1
)
2056 enum value_range_type type
;
2063 /* Multiplications, divisions and shifts are a bit tricky to handle,
2064 depending on the mix of signs we have in the two ranges, we
2065 need to operate on different values to get the minimum and
2066 maximum values for the new range. One approach is to figure
2067 out all the variations of range combinations and do the
2070 However, this involves several calls to compare_values and it
2071 is pretty convoluted. It's simpler to do the 4 operations
2072 (MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
2073 MAX1) and then figure the smallest and largest values to form
2075 gcc_assert (code
== MULT_EXPR
2076 || code
== TRUNC_DIV_EXPR
2077 || code
== FLOOR_DIV_EXPR
2078 || code
== CEIL_DIV_EXPR
2079 || code
== EXACT_DIV_EXPR
2080 || code
== ROUND_DIV_EXPR
2081 || code
== RSHIFT_EXPR
2082 || code
== LSHIFT_EXPR
);
2083 gcc_assert ((vr0
->type
== VR_RANGE
2084 || (code
== MULT_EXPR
&& vr0
->type
== VR_ANTI_RANGE
))
2085 && vr0
->type
== vr1
->type
);
2089 /* Compute the 4 cross operations. */
2091 val
[0] = vrp_int_const_binop (code
, vr0
->min
, vr1
->min
);
2092 if (val
[0] == NULL_TREE
)
2095 if (vr1
->max
== vr1
->min
)
2099 val
[1] = vrp_int_const_binop (code
, vr0
->min
, vr1
->max
);
2100 if (val
[1] == NULL_TREE
)
2104 if (vr0
->max
== vr0
->min
)
2108 val
[2] = vrp_int_const_binop (code
, vr0
->max
, vr1
->min
);
2109 if (val
[2] == NULL_TREE
)
2113 if (vr0
->min
== vr0
->max
|| vr1
->min
== vr1
->max
)
2117 val
[3] = vrp_int_const_binop (code
, vr0
->max
, vr1
->max
);
2118 if (val
[3] == NULL_TREE
)
2124 set_value_range_to_varying (vr
);
2128 /* Set MIN to the minimum of VAL[i] and MAX to the maximum
2132 for (i
= 1; i
< 4; i
++)
2134 if (!is_gimple_min_invariant (min
)
2135 || (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2136 || !is_gimple_min_invariant (max
)
2137 || (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2142 if (!is_gimple_min_invariant (val
[i
])
2143 || (TREE_OVERFLOW (val
[i
])
2144 && !is_overflow_infinity (val
[i
])))
2146 /* If we found an overflowed value, set MIN and MAX
2147 to it so that we set the resulting range to
2153 if (compare_values (val
[i
], min
) == -1)
2156 if (compare_values (val
[i
], max
) == 1)
2161 /* If either MIN or MAX overflowed, then set the resulting range to
2162 VARYING. But we do accept an overflow infinity
2164 if (min
== NULL_TREE
2165 || !is_gimple_min_invariant (min
)
2166 || (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2168 || !is_gimple_min_invariant (max
)
2169 || (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2171 set_value_range_to_varying (vr
);
2177 2) [-INF, +-INF(OVF)]
2178 3) [+-INF(OVF), +INF]
2179 4) [+-INF(OVF), +-INF(OVF)]
2180 We learn nothing when we have INF and INF(OVF) on both sides.
2181 Note that we do accept [-INF, -INF] and [+INF, +INF] without
2183 if ((vrp_val_is_min (min
) || is_overflow_infinity (min
))
2184 && (vrp_val_is_max (max
) || is_overflow_infinity (max
)))
2186 set_value_range_to_varying (vr
);
2190 cmp
= compare_values (min
, max
);
2191 if (cmp
== -2 || cmp
== 1)
2193 /* If the new range has its limits swapped around (MIN > MAX),
2194 then the operation caused one of them to wrap around, mark
2195 the new range VARYING. */
2196 set_value_range_to_varying (vr
);
2199 set_value_range (vr
, type
, min
, max
, NULL
);
2202 /* Extract range information from a binary operation CODE based on
2203 the ranges of each of its operands *VR0 and *VR1 with resulting
2204 type EXPR_TYPE. The resulting range is stored in *VR. */
2207 extract_range_from_binary_expr_1 (value_range
*vr
,
2208 enum tree_code code
, tree expr_type
,
2209 value_range
*vr0_
, value_range
*vr1_
)
2211 value_range vr0
= *vr0_
, vr1
= *vr1_
;
2212 value_range vrtem0
= VR_INITIALIZER
, vrtem1
= VR_INITIALIZER
;
2213 enum value_range_type type
;
2214 tree min
= NULL_TREE
, max
= NULL_TREE
;
2217 if (!INTEGRAL_TYPE_P (expr_type
)
2218 && !POINTER_TYPE_P (expr_type
))
2220 set_value_range_to_varying (vr
);
2224 /* Not all binary expressions can be applied to ranges in a
2225 meaningful way. Handle only arithmetic operations. */
2226 if (code
!= PLUS_EXPR
2227 && code
!= MINUS_EXPR
2228 && code
!= POINTER_PLUS_EXPR
2229 && code
!= MULT_EXPR
2230 && code
!= TRUNC_DIV_EXPR
2231 && code
!= FLOOR_DIV_EXPR
2232 && code
!= CEIL_DIV_EXPR
2233 && code
!= EXACT_DIV_EXPR
2234 && code
!= ROUND_DIV_EXPR
2235 && code
!= TRUNC_MOD_EXPR
2236 && code
!= RSHIFT_EXPR
2237 && code
!= LSHIFT_EXPR
2240 && code
!= BIT_AND_EXPR
2241 && code
!= BIT_IOR_EXPR
2242 && code
!= BIT_XOR_EXPR
)
2244 set_value_range_to_varying (vr
);
2248 /* If both ranges are UNDEFINED, so is the result. */
2249 if (vr0
.type
== VR_UNDEFINED
&& vr1
.type
== VR_UNDEFINED
)
2251 set_value_range_to_undefined (vr
);
2254 /* If one of the ranges is UNDEFINED drop it to VARYING for the following
2255 code. At some point we may want to special-case operations that
2256 have UNDEFINED result for all or some value-ranges of the not UNDEFINED
2258 else if (vr0
.type
== VR_UNDEFINED
)
2259 set_value_range_to_varying (&vr0
);
2260 else if (vr1
.type
== VR_UNDEFINED
)
2261 set_value_range_to_varying (&vr1
);
2263 /* Now canonicalize anti-ranges to ranges when they are not symbolic
2264 and express ~[] op X as ([]' op X) U ([]'' op X). */
2265 if (vr0
.type
== VR_ANTI_RANGE
2266 && ranges_from_anti_range (&vr0
, &vrtem0
, &vrtem1
))
2268 extract_range_from_binary_expr_1 (vr
, code
, expr_type
, &vrtem0
, vr1_
);
2269 if (vrtem1
.type
!= VR_UNDEFINED
)
2271 value_range vrres
= VR_INITIALIZER
;
2272 extract_range_from_binary_expr_1 (&vrres
, code
, expr_type
,
2274 vrp_meet (vr
, &vrres
);
2278 /* Likewise for X op ~[]. */
2279 if (vr1
.type
== VR_ANTI_RANGE
2280 && ranges_from_anti_range (&vr1
, &vrtem0
, &vrtem1
))
2282 extract_range_from_binary_expr_1 (vr
, code
, expr_type
, vr0_
, &vrtem0
);
2283 if (vrtem1
.type
!= VR_UNDEFINED
)
2285 value_range vrres
= VR_INITIALIZER
;
2286 extract_range_from_binary_expr_1 (&vrres
, code
, expr_type
,
2288 vrp_meet (vr
, &vrres
);
2293 /* The type of the resulting value range defaults to VR0.TYPE. */
2296 /* Refuse to operate on VARYING ranges, ranges of different kinds
2297 and symbolic ranges. As an exception, we allow BIT_{AND,IOR}
2298 because we may be able to derive a useful range even if one of
2299 the operands is VR_VARYING or symbolic range. Similarly for
2300 divisions, MIN/MAX and PLUS/MINUS.
2302 TODO, we may be able to derive anti-ranges in some cases. */
2303 if (code
!= BIT_AND_EXPR
2304 && code
!= BIT_IOR_EXPR
2305 && code
!= TRUNC_DIV_EXPR
2306 && code
!= FLOOR_DIV_EXPR
2307 && code
!= CEIL_DIV_EXPR
2308 && code
!= EXACT_DIV_EXPR
2309 && code
!= ROUND_DIV_EXPR
2310 && code
!= TRUNC_MOD_EXPR
2313 && code
!= PLUS_EXPR
2314 && code
!= MINUS_EXPR
2315 && code
!= RSHIFT_EXPR
2316 && (vr0
.type
== VR_VARYING
2317 || vr1
.type
== VR_VARYING
2318 || vr0
.type
!= vr1
.type
2319 || symbolic_range_p (&vr0
)
2320 || symbolic_range_p (&vr1
)))
2322 set_value_range_to_varying (vr
);
2326 /* Now evaluate the expression to determine the new range. */
2327 if (POINTER_TYPE_P (expr_type
))
2329 if (code
== MIN_EXPR
|| code
== MAX_EXPR
)
2331 /* For MIN/MAX expressions with pointers, we only care about
2332 nullness, if both are non null, then the result is nonnull.
2333 If both are null, then the result is null. Otherwise they
2335 if (range_is_nonnull (&vr0
) && range_is_nonnull (&vr1
))
2336 set_value_range_to_nonnull (vr
, expr_type
);
2337 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
2338 set_value_range_to_null (vr
, expr_type
);
2340 set_value_range_to_varying (vr
);
2342 else if (code
== POINTER_PLUS_EXPR
)
2344 /* For pointer types, we are really only interested in asserting
2345 whether the expression evaluates to non-NULL. */
2346 if (range_is_nonnull (&vr0
) || range_is_nonnull (&vr1
))
2347 set_value_range_to_nonnull (vr
, expr_type
);
2348 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
2349 set_value_range_to_null (vr
, expr_type
);
2351 set_value_range_to_varying (vr
);
2353 else if (code
== BIT_AND_EXPR
)
2355 /* For pointer types, we are really only interested in asserting
2356 whether the expression evaluates to non-NULL. */
2357 if (range_is_nonnull (&vr0
) && range_is_nonnull (&vr1
))
2358 set_value_range_to_nonnull (vr
, expr_type
);
2359 else if (range_is_null (&vr0
) || range_is_null (&vr1
))
2360 set_value_range_to_null (vr
, expr_type
);
2362 set_value_range_to_varying (vr
);
2365 set_value_range_to_varying (vr
);
2370 /* For integer ranges, apply the operation to each end of the
2371 range and see what we end up with. */
2372 if (code
== PLUS_EXPR
|| code
== MINUS_EXPR
)
2374 const bool minus_p
= (code
== MINUS_EXPR
);
2375 tree min_op0
= vr0
.min
;
2376 tree min_op1
= minus_p
? vr1
.max
: vr1
.min
;
2377 tree max_op0
= vr0
.max
;
2378 tree max_op1
= minus_p
? vr1
.min
: vr1
.max
;
2379 tree sym_min_op0
= NULL_TREE
;
2380 tree sym_min_op1
= NULL_TREE
;
2381 tree sym_max_op0
= NULL_TREE
;
2382 tree sym_max_op1
= NULL_TREE
;
2383 bool neg_min_op0
, neg_min_op1
, neg_max_op0
, neg_max_op1
;
2385 /* If we have a PLUS or MINUS with two VR_RANGEs, either constant or
2386 single-symbolic ranges, try to compute the precise resulting range,
2387 but only if we know that this resulting range will also be constant
2388 or single-symbolic. */
2389 if (vr0
.type
== VR_RANGE
&& vr1
.type
== VR_RANGE
2390 && (TREE_CODE (min_op0
) == INTEGER_CST
2392 = get_single_symbol (min_op0
, &neg_min_op0
, &min_op0
)))
2393 && (TREE_CODE (min_op1
) == INTEGER_CST
2395 = get_single_symbol (min_op1
, &neg_min_op1
, &min_op1
)))
2396 && (!(sym_min_op0
&& sym_min_op1
)
2397 || (sym_min_op0
== sym_min_op1
2398 && neg_min_op0
== (minus_p
? neg_min_op1
: !neg_min_op1
)))
2399 && (TREE_CODE (max_op0
) == INTEGER_CST
2401 = get_single_symbol (max_op0
, &neg_max_op0
, &max_op0
)))
2402 && (TREE_CODE (max_op1
) == INTEGER_CST
2404 = get_single_symbol (max_op1
, &neg_max_op1
, &max_op1
)))
2405 && (!(sym_max_op0
&& sym_max_op1
)
2406 || (sym_max_op0
== sym_max_op1
2407 && neg_max_op0
== (minus_p
? neg_max_op1
: !neg_max_op1
))))
2409 const signop sgn
= TYPE_SIGN (expr_type
);
2410 const unsigned int prec
= TYPE_PRECISION (expr_type
);
2411 wide_int type_min
, type_max
, wmin
, wmax
;
2415 /* Get the lower and upper bounds of the type. */
2416 if (TYPE_OVERFLOW_WRAPS (expr_type
))
2418 type_min
= wi::min_value (prec
, sgn
);
2419 type_max
= wi::max_value (prec
, sgn
);
2423 type_min
= vrp_val_min (expr_type
);
2424 type_max
= vrp_val_max (expr_type
);
2427 /* Combine the lower bounds, if any. */
2428 if (min_op0
&& min_op1
)
2432 wmin
= wi::sub (min_op0
, min_op1
);
2434 /* Check for overflow. */
2435 if (wi::cmp (0, min_op1
, sgn
)
2436 != wi::cmp (wmin
, min_op0
, sgn
))
2437 min_ovf
= wi::cmp (min_op0
, min_op1
, sgn
);
2441 wmin
= wi::add (min_op0
, min_op1
);
2443 /* Check for overflow. */
2444 if (wi::cmp (min_op1
, 0, sgn
)
2445 != wi::cmp (wmin
, min_op0
, sgn
))
2446 min_ovf
= wi::cmp (min_op0
, wmin
, sgn
);
2452 wmin
= minus_p
? wi::neg (min_op1
) : min_op1
;
2454 wmin
= wi::shwi (0, prec
);
2456 /* Combine the upper bounds, if any. */
2457 if (max_op0
&& max_op1
)
2461 wmax
= wi::sub (max_op0
, max_op1
);
2463 /* Check for overflow. */
2464 if (wi::cmp (0, max_op1
, sgn
)
2465 != wi::cmp (wmax
, max_op0
, sgn
))
2466 max_ovf
= wi::cmp (max_op0
, max_op1
, sgn
);
2470 wmax
= wi::add (max_op0
, max_op1
);
2472 if (wi::cmp (max_op1
, 0, sgn
)
2473 != wi::cmp (wmax
, max_op0
, sgn
))
2474 max_ovf
= wi::cmp (max_op0
, wmax
, sgn
);
2480 wmax
= minus_p
? wi::neg (max_op1
) : max_op1
;
2482 wmax
= wi::shwi (0, prec
);
2484 /* Check for type overflow. */
2487 if (wi::cmp (wmin
, type_min
, sgn
) == -1)
2489 else if (wi::cmp (wmin
, type_max
, sgn
) == 1)
2494 if (wi::cmp (wmax
, type_min
, sgn
) == -1)
2496 else if (wi::cmp (wmax
, type_max
, sgn
) == 1)
2500 /* If we have overflow for the constant part and the resulting
2501 range will be symbolic, drop to VR_VARYING. */
2502 if ((min_ovf
&& sym_min_op0
!= sym_min_op1
)
2503 || (max_ovf
&& sym_max_op0
!= sym_max_op1
))
2505 set_value_range_to_varying (vr
);
2509 if (TYPE_OVERFLOW_WRAPS (expr_type
))
2511 /* If overflow wraps, truncate the values and adjust the
2512 range kind and bounds appropriately. */
2513 wide_int tmin
= wide_int::from (wmin
, prec
, sgn
);
2514 wide_int tmax
= wide_int::from (wmax
, prec
, sgn
);
2515 if (min_ovf
== max_ovf
)
2517 /* No overflow or both overflow or underflow. The
2518 range kind stays VR_RANGE. */
2519 min
= wide_int_to_tree (expr_type
, tmin
);
2520 max
= wide_int_to_tree (expr_type
, tmax
);
2522 else if (min_ovf
== -1 && max_ovf
== 1)
2524 /* Underflow and overflow, drop to VR_VARYING. */
2525 set_value_range_to_varying (vr
);
2530 /* Min underflow or max overflow. The range kind
2531 changes to VR_ANTI_RANGE. */
2532 bool covers
= false;
2533 wide_int tem
= tmin
;
2534 gcc_assert ((min_ovf
== -1 && max_ovf
== 0)
2535 || (max_ovf
== 1 && min_ovf
== 0));
2536 type
= VR_ANTI_RANGE
;
2538 if (wi::cmp (tmin
, tmax
, sgn
) < 0)
2541 if (wi::cmp (tmax
, tem
, sgn
) > 0)
2543 /* If the anti-range would cover nothing, drop to varying.
2544 Likewise if the anti-range bounds are outside of the
2546 if (covers
|| wi::cmp (tmin
, tmax
, sgn
) > 0)
2548 set_value_range_to_varying (vr
);
2551 min
= wide_int_to_tree (expr_type
, tmin
);
2552 max
= wide_int_to_tree (expr_type
, tmax
);
2557 /* If overflow does not wrap, saturate to the types min/max
2561 if (needs_overflow_infinity (expr_type
)
2562 && supports_overflow_infinity (expr_type
))
2563 min
= negative_overflow_infinity (expr_type
);
2565 min
= wide_int_to_tree (expr_type
, type_min
);
2567 else if (min_ovf
== 1)
2569 if (needs_overflow_infinity (expr_type
)
2570 && supports_overflow_infinity (expr_type
))
2571 min
= positive_overflow_infinity (expr_type
);
2573 min
= wide_int_to_tree (expr_type
, type_max
);
2576 min
= wide_int_to_tree (expr_type
, wmin
);
2580 if (needs_overflow_infinity (expr_type
)
2581 && supports_overflow_infinity (expr_type
))
2582 max
= negative_overflow_infinity (expr_type
);
2584 max
= wide_int_to_tree (expr_type
, type_min
);
2586 else if (max_ovf
== 1)
2588 if (needs_overflow_infinity (expr_type
)
2589 && supports_overflow_infinity (expr_type
))
2590 max
= positive_overflow_infinity (expr_type
);
2592 max
= wide_int_to_tree (expr_type
, type_max
);
2595 max
= wide_int_to_tree (expr_type
, wmax
);
2598 if (needs_overflow_infinity (expr_type
)
2599 && supports_overflow_infinity (expr_type
))
2601 if ((min_op0
&& is_negative_overflow_infinity (min_op0
))
2604 ? is_positive_overflow_infinity (min_op1
)
2605 : is_negative_overflow_infinity (min_op1
))))
2606 min
= negative_overflow_infinity (expr_type
);
2607 if ((max_op0
&& is_positive_overflow_infinity (max_op0
))
2610 ? is_negative_overflow_infinity (max_op1
)
2611 : is_positive_overflow_infinity (max_op1
))))
2612 max
= positive_overflow_infinity (expr_type
);
2615 /* If the result lower bound is constant, we're done;
2616 otherwise, build the symbolic lower bound. */
2617 if (sym_min_op0
== sym_min_op1
)
2619 else if (sym_min_op0
)
2620 min
= build_symbolic_expr (expr_type
, sym_min_op0
,
2622 else if (sym_min_op1
)
2623 min
= build_symbolic_expr (expr_type
, sym_min_op1
,
2624 neg_min_op1
^ minus_p
, min
);
2626 /* Likewise for the upper bound. */
2627 if (sym_max_op0
== sym_max_op1
)
2629 else if (sym_max_op0
)
2630 max
= build_symbolic_expr (expr_type
, sym_max_op0
,
2632 else if (sym_max_op1
)
2633 max
= build_symbolic_expr (expr_type
, sym_max_op1
,
2634 neg_max_op1
^ minus_p
, max
);
2638 /* For other cases, for example if we have a PLUS_EXPR with two
2639 VR_ANTI_RANGEs, drop to VR_VARYING. It would take more effort
2640 to compute a precise range for such a case.
2641 ??? General even mixed range kind operations can be expressed
2642 by for example transforming ~[3, 5] + [1, 2] to range-only
2643 operations and a union primitive:
2644 [-INF, 2] + [1, 2] U [5, +INF] + [1, 2]
2645 [-INF+1, 4] U [6, +INF(OVF)]
2646 though usually the union is not exactly representable with
2647 a single range or anti-range as the above is
2648 [-INF+1, +INF(OVF)] intersected with ~[5, 5]
2649 but one could use a scheme similar to equivalences for this. */
2650 set_value_range_to_varying (vr
);
2654 else if (code
== MIN_EXPR
2655 || code
== MAX_EXPR
)
2657 if (vr0
.type
== VR_RANGE
2658 && !symbolic_range_p (&vr0
))
2661 if (vr1
.type
== VR_RANGE
2662 && !symbolic_range_p (&vr1
))
2664 /* For operations that make the resulting range directly
2665 proportional to the original ranges, apply the operation to
2666 the same end of each range. */
2667 min
= vrp_int_const_binop (code
, vr0
.min
, vr1
.min
);
2668 max
= vrp_int_const_binop (code
, vr0
.max
, vr1
.max
);
2670 else if (code
== MIN_EXPR
)
2672 min
= vrp_val_min (expr_type
);
2675 else if (code
== MAX_EXPR
)
2678 max
= vrp_val_max (expr_type
);
2681 else if (vr1
.type
== VR_RANGE
2682 && !symbolic_range_p (&vr1
))
2685 if (code
== MIN_EXPR
)
2687 min
= vrp_val_min (expr_type
);
2690 else if (code
== MAX_EXPR
)
2693 max
= vrp_val_max (expr_type
);
2698 set_value_range_to_varying (vr
);
2702 else if (code
== MULT_EXPR
)
2704 /* Fancy code so that with unsigned, [-3,-1]*[-3,-1] does not
2705 drop to varying. This test requires 2*prec bits if both
2706 operands are signed and 2*prec + 2 bits if either is not. */
2708 signop sign
= TYPE_SIGN (expr_type
);
2709 unsigned int prec
= TYPE_PRECISION (expr_type
);
2711 if (range_int_cst_p (&vr0
)
2712 && range_int_cst_p (&vr1
)
2713 && TYPE_OVERFLOW_WRAPS (expr_type
))
2715 typedef FIXED_WIDE_INT (WIDE_INT_MAX_PRECISION
* 2) vrp_int
;
2716 typedef generic_wide_int
2717 <wi::extended_tree
<WIDE_INT_MAX_PRECISION
* 2> > vrp_int_cst
;
2718 vrp_int sizem1
= wi::mask
<vrp_int
> (prec
, false);
2719 vrp_int size
= sizem1
+ 1;
2721 /* Extend the values using the sign of the result to PREC2.
2722 From here on out, everthing is just signed math no matter
2723 what the input types were. */
2724 vrp_int min0
= vrp_int_cst (vr0
.min
);
2725 vrp_int max0
= vrp_int_cst (vr0
.max
);
2726 vrp_int min1
= vrp_int_cst (vr1
.min
);
2727 vrp_int max1
= vrp_int_cst (vr1
.max
);
2728 /* Canonicalize the intervals. */
2729 if (sign
== UNSIGNED
)
2731 if (wi::ltu_p (size
, min0
+ max0
))
2737 if (wi::ltu_p (size
, min1
+ max1
))
2744 vrp_int prod0
= min0
* min1
;
2745 vrp_int prod1
= min0
* max1
;
2746 vrp_int prod2
= max0
* min1
;
2747 vrp_int prod3
= max0
* max1
;
2749 /* Sort the 4 products so that min is in prod0 and max is in
2751 /* min0min1 > max0max1 */
2753 std::swap (prod0
, prod3
);
2755 /* min0max1 > max0min1 */
2757 std::swap (prod1
, prod2
);
2760 std::swap (prod0
, prod1
);
2763 std::swap (prod2
, prod3
);
2765 /* diff = max - min. */
2766 prod2
= prod3
- prod0
;
2767 if (wi::geu_p (prod2
, sizem1
))
2769 /* the range covers all values. */
2770 set_value_range_to_varying (vr
);
2774 /* The following should handle the wrapping and selecting
2775 VR_ANTI_RANGE for us. */
2776 min
= wide_int_to_tree (expr_type
, prod0
);
2777 max
= wide_int_to_tree (expr_type
, prod3
);
2778 set_and_canonicalize_value_range (vr
, VR_RANGE
, min
, max
, NULL
);
2782 /* If we have an unsigned MULT_EXPR with two VR_ANTI_RANGEs,
2783 drop to VR_VARYING. It would take more effort to compute a
2784 precise range for such a case. For example, if we have
2785 op0 == 65536 and op1 == 65536 with their ranges both being
2786 ~[0,0] on a 32-bit machine, we would have op0 * op1 == 0, so
2787 we cannot claim that the product is in ~[0,0]. Note that we
2788 are guaranteed to have vr0.type == vr1.type at this
2790 if (vr0
.type
== VR_ANTI_RANGE
2791 && !TYPE_OVERFLOW_UNDEFINED (expr_type
))
2793 set_value_range_to_varying (vr
);
2797 extract_range_from_multiplicative_op_1 (vr
, code
, &vr0
, &vr1
);
2800 else if (code
== RSHIFT_EXPR
2801 || code
== LSHIFT_EXPR
)
2803 /* If we have a RSHIFT_EXPR with any shift values outside [0..prec-1],
2804 then drop to VR_VARYING. Outside of this range we get undefined
2805 behavior from the shift operation. We cannot even trust
2806 SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl
2807 shifts, and the operation at the tree level may be widened. */
2808 if (range_int_cst_p (&vr1
)
2809 && compare_tree_int (vr1
.min
, 0) >= 0
2810 && compare_tree_int (vr1
.max
, TYPE_PRECISION (expr_type
)) == -1)
2812 if (code
== RSHIFT_EXPR
)
2814 /* Even if vr0 is VARYING or otherwise not usable, we can derive
2815 useful ranges just from the shift count. E.g.
2816 x >> 63 for signed 64-bit x is always [-1, 0]. */
2817 if (vr0
.type
!= VR_RANGE
|| symbolic_range_p (&vr0
))
2819 vr0
.type
= type
= VR_RANGE
;
2820 vr0
.min
= vrp_val_min (expr_type
);
2821 vr0
.max
= vrp_val_max (expr_type
);
2823 extract_range_from_multiplicative_op_1 (vr
, code
, &vr0
, &vr1
);
2826 /* We can map lshifts by constants to MULT_EXPR handling. */
2827 else if (code
== LSHIFT_EXPR
2828 && range_int_cst_singleton_p (&vr1
))
2830 bool saved_flag_wrapv
;
2831 value_range vr1p
= VR_INITIALIZER
;
2832 vr1p
.type
= VR_RANGE
;
2833 vr1p
.min
= (wide_int_to_tree
2835 wi::set_bit_in_zero (tree_to_shwi (vr1
.min
),
2836 TYPE_PRECISION (expr_type
))));
2837 vr1p
.max
= vr1p
.min
;
2838 /* We have to use a wrapping multiply though as signed overflow
2839 on lshifts is implementation defined in C89. */
2840 saved_flag_wrapv
= flag_wrapv
;
2842 extract_range_from_binary_expr_1 (vr
, MULT_EXPR
, expr_type
,
2844 flag_wrapv
= saved_flag_wrapv
;
2847 else if (code
== LSHIFT_EXPR
2848 && range_int_cst_p (&vr0
))
2850 int prec
= TYPE_PRECISION (expr_type
);
2851 int overflow_pos
= prec
;
2853 wide_int low_bound
, high_bound
;
2854 bool uns
= TYPE_UNSIGNED (expr_type
);
2855 bool in_bounds
= false;
2860 bound_shift
= overflow_pos
- tree_to_shwi (vr1
.max
);
2861 /* If bound_shift == HOST_BITS_PER_WIDE_INT, the llshift can
2862 overflow. However, for that to happen, vr1.max needs to be
2863 zero, which means vr1 is a singleton range of zero, which
2864 means it should be handled by the previous LSHIFT_EXPR
2866 wide_int bound
= wi::set_bit_in_zero (bound_shift
, prec
);
2867 wide_int complement
= ~(bound
- 1);
2872 high_bound
= complement
;
2873 if (wi::ltu_p (vr0
.max
, low_bound
))
2875 /* [5, 6] << [1, 2] == [10, 24]. */
2876 /* We're shifting out only zeroes, the value increases
2880 else if (wi::ltu_p (high_bound
, vr0
.min
))
2882 /* [0xffffff00, 0xffffffff] << [1, 2]
2883 == [0xfffffc00, 0xfffffffe]. */
2884 /* We're shifting out only ones, the value decreases
2891 /* [-1, 1] << [1, 2] == [-4, 4]. */
2892 low_bound
= complement
;
2894 if (wi::lts_p (vr0
.max
, high_bound
)
2895 && wi::lts_p (low_bound
, vr0
.min
))
2897 /* For non-negative numbers, we're shifting out only
2898 zeroes, the value increases monotonically.
2899 For negative numbers, we're shifting out only ones, the
2900 value decreases monotomically. */
2907 extract_range_from_multiplicative_op_1 (vr
, code
, &vr0
, &vr1
);
2912 set_value_range_to_varying (vr
);
2915 else if (code
== TRUNC_DIV_EXPR
2916 || code
== FLOOR_DIV_EXPR
2917 || code
== CEIL_DIV_EXPR
2918 || code
== EXACT_DIV_EXPR
2919 || code
== ROUND_DIV_EXPR
)
2921 if (vr0
.type
!= VR_RANGE
|| symbolic_range_p (&vr0
))
2923 /* For division, if op1 has VR_RANGE but op0 does not, something
2924 can be deduced just from that range. Say [min, max] / [4, max]
2925 gives [min / 4, max / 4] range. */
2926 if (vr1
.type
== VR_RANGE
2927 && !symbolic_range_p (&vr1
)
2928 && range_includes_zero_p (vr1
.min
, vr1
.max
) == 0)
2930 vr0
.type
= type
= VR_RANGE
;
2931 vr0
.min
= vrp_val_min (expr_type
);
2932 vr0
.max
= vrp_val_max (expr_type
);
2936 set_value_range_to_varying (vr
);
2941 /* For divisions, if flag_non_call_exceptions is true, we must
2942 not eliminate a division by zero. */
2943 if (cfun
->can_throw_non_call_exceptions
2944 && (vr1
.type
!= VR_RANGE
2945 || range_includes_zero_p (vr1
.min
, vr1
.max
) != 0))
2947 set_value_range_to_varying (vr
);
2951 /* For divisions, if op0 is VR_RANGE, we can deduce a range
2952 even if op1 is VR_VARYING, VR_ANTI_RANGE, symbolic or can
2954 if (vr0
.type
== VR_RANGE
2955 && (vr1
.type
!= VR_RANGE
2956 || range_includes_zero_p (vr1
.min
, vr1
.max
) != 0))
2958 tree zero
= build_int_cst (TREE_TYPE (vr0
.min
), 0);
2963 if (TYPE_UNSIGNED (expr_type
)
2964 || value_range_nonnegative_p (&vr1
))
2966 /* For unsigned division or when divisor is known
2967 to be non-negative, the range has to cover
2968 all numbers from 0 to max for positive max
2969 and all numbers from min to 0 for negative min. */
2970 cmp
= compare_values (vr0
.max
, zero
);
2973 /* When vr0.max < 0, vr1.min != 0 and value
2974 ranges for dividend and divisor are available. */
2975 if (vr1
.type
== VR_RANGE
2976 && !symbolic_range_p (&vr0
)
2977 && !symbolic_range_p (&vr1
)
2978 && compare_values (vr1
.min
, zero
) != 0)
2979 max
= int_const_binop (code
, vr0
.max
, vr1
.min
);
2983 else if (cmp
== 0 || cmp
== 1)
2987 cmp
= compare_values (vr0
.min
, zero
);
2990 /* For unsigned division when value ranges for dividend
2991 and divisor are available. */
2992 if (vr1
.type
== VR_RANGE
2993 && !symbolic_range_p (&vr0
)
2994 && !symbolic_range_p (&vr1
))
2995 min
= int_const_binop (code
, vr0
.min
, vr1
.max
);
2999 else if (cmp
== 0 || cmp
== -1)
3006 /* Otherwise the range is -max .. max or min .. -min
3007 depending on which bound is bigger in absolute value,
3008 as the division can change the sign. */
3009 abs_extent_range (vr
, vr0
.min
, vr0
.max
);
3012 if (type
== VR_VARYING
)
3014 set_value_range_to_varying (vr
);
3018 else if (!symbolic_range_p (&vr0
) && !symbolic_range_p (&vr1
))
3020 extract_range_from_multiplicative_op_1 (vr
, code
, &vr0
, &vr1
);
3024 else if (code
== TRUNC_MOD_EXPR
)
3026 if (range_is_null (&vr1
))
3028 set_value_range_to_undefined (vr
);
3031 /* ABS (A % B) < ABS (B) and either
3032 0 <= A % B <= A or A <= A % B <= 0. */
3034 signop sgn
= TYPE_SIGN (expr_type
);
3035 unsigned int prec
= TYPE_PRECISION (expr_type
);
3036 wide_int wmin
, wmax
, tmp
;
3037 wide_int zero
= wi::zero (prec
);
3038 wide_int one
= wi::one (prec
);
3039 if (vr1
.type
== VR_RANGE
&& !symbolic_range_p (&vr1
))
3041 wmax
= wi::sub (vr1
.max
, one
);
3044 tmp
= wi::sub (wi::minus_one (prec
), vr1
.min
);
3045 wmax
= wi::smax (wmax
, tmp
);
3050 wmax
= wi::max_value (prec
, sgn
);
3051 /* X % INT_MIN may be INT_MAX. */
3052 if (sgn
== UNSIGNED
)
3056 if (sgn
== UNSIGNED
)
3061 if (vr0
.type
== VR_RANGE
&& TREE_CODE (vr0
.min
) == INTEGER_CST
)
3064 if (wi::gts_p (tmp
, zero
))
3066 wmin
= wi::smax (wmin
, tmp
);
3070 if (vr0
.type
== VR_RANGE
&& TREE_CODE (vr0
.max
) == INTEGER_CST
)
3073 if (sgn
== SIGNED
&& wi::neg_p (tmp
))
3075 wmax
= wi::min (wmax
, tmp
, sgn
);
3078 min
= wide_int_to_tree (expr_type
, wmin
);
3079 max
= wide_int_to_tree (expr_type
, wmax
);
3081 else if (code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
)
3083 bool int_cst_range0
, int_cst_range1
;
3084 wide_int may_be_nonzero0
, may_be_nonzero1
;
3085 wide_int must_be_nonzero0
, must_be_nonzero1
;
3087 int_cst_range0
= zero_nonzero_bits_from_vr (expr_type
, &vr0
,
3090 int_cst_range1
= zero_nonzero_bits_from_vr (expr_type
, &vr1
,
3095 if (code
== BIT_AND_EXPR
)
3097 min
= wide_int_to_tree (expr_type
,
3098 must_be_nonzero0
& must_be_nonzero1
);
3099 wide_int wmax
= may_be_nonzero0
& may_be_nonzero1
;
3100 /* If both input ranges contain only negative values we can
3101 truncate the result range maximum to the minimum of the
3102 input range maxima. */
3103 if (int_cst_range0
&& int_cst_range1
3104 && tree_int_cst_sgn (vr0
.max
) < 0
3105 && tree_int_cst_sgn (vr1
.max
) < 0)
3107 wmax
= wi::min (wmax
, vr0
.max
, TYPE_SIGN (expr_type
));
3108 wmax
= wi::min (wmax
, vr1
.max
, TYPE_SIGN (expr_type
));
3110 /* If either input range contains only non-negative values
3111 we can truncate the result range maximum to the respective
3112 maximum of the input range. */
3113 if (int_cst_range0
&& tree_int_cst_sgn (vr0
.min
) >= 0)
3114 wmax
= wi::min (wmax
, vr0
.max
, TYPE_SIGN (expr_type
));
3115 if (int_cst_range1
&& tree_int_cst_sgn (vr1
.min
) >= 0)
3116 wmax
= wi::min (wmax
, vr1
.max
, TYPE_SIGN (expr_type
));
3117 max
= wide_int_to_tree (expr_type
, wmax
);
3119 else if (code
== BIT_IOR_EXPR
)
3121 max
= wide_int_to_tree (expr_type
,
3122 may_be_nonzero0
| may_be_nonzero1
);
3123 wide_int wmin
= must_be_nonzero0
| must_be_nonzero1
;
3124 /* If the input ranges contain only positive values we can
3125 truncate the minimum of the result range to the maximum
3126 of the input range minima. */
3127 if (int_cst_range0
&& int_cst_range1
3128 && tree_int_cst_sgn (vr0
.min
) >= 0
3129 && tree_int_cst_sgn (vr1
.min
) >= 0)
3131 wmin
= wi::max (wmin
, vr0
.min
, TYPE_SIGN (expr_type
));
3132 wmin
= wi::max (wmin
, vr1
.min
, TYPE_SIGN (expr_type
));
3134 /* If either input range contains only negative values
3135 we can truncate the minimum of the result range to the
3136 respective minimum range. */
3137 if (int_cst_range0
&& tree_int_cst_sgn (vr0
.max
) < 0)
3138 wmin
= wi::max (wmin
, vr0
.min
, TYPE_SIGN (expr_type
));
3139 if (int_cst_range1
&& tree_int_cst_sgn (vr1
.max
) < 0)
3140 wmin
= wi::max (wmin
, vr1
.min
, TYPE_SIGN (expr_type
));
3141 min
= wide_int_to_tree (expr_type
, wmin
);
3143 else if (code
== BIT_XOR_EXPR
)
3145 wide_int result_zero_bits
= ((must_be_nonzero0
& must_be_nonzero1
)
3146 | ~(may_be_nonzero0
| may_be_nonzero1
));
3147 wide_int result_one_bits
3148 = (must_be_nonzero0
.and_not (may_be_nonzero1
)
3149 | must_be_nonzero1
.and_not (may_be_nonzero0
));
3150 max
= wide_int_to_tree (expr_type
, ~result_zero_bits
);
3151 min
= wide_int_to_tree (expr_type
, result_one_bits
);
3152 /* If the range has all positive or all negative values the
3153 result is better than VARYING. */
3154 if (tree_int_cst_sgn (min
) < 0
3155 || tree_int_cst_sgn (max
) >= 0)
3158 max
= min
= NULL_TREE
;
3164 /* If either MIN or MAX overflowed, then set the resulting range to
3165 VARYING. But we do accept an overflow infinity representation. */
3166 if (min
== NULL_TREE
3167 || (TREE_OVERFLOW_P (min
) && !is_overflow_infinity (min
))
3169 || (TREE_OVERFLOW_P (max
) && !is_overflow_infinity (max
)))
3171 set_value_range_to_varying (vr
);
3177 2) [-INF, +-INF(OVF)]
3178 3) [+-INF(OVF), +INF]
3179 4) [+-INF(OVF), +-INF(OVF)]
3180 We learn nothing when we have INF and INF(OVF) on both sides.
3181 Note that we do accept [-INF, -INF] and [+INF, +INF] without
3183 if ((vrp_val_is_min (min
) || is_overflow_infinity (min
))
3184 && (vrp_val_is_max (max
) || is_overflow_infinity (max
)))
3186 set_value_range_to_varying (vr
);
3190 cmp
= compare_values (min
, max
);
3191 if (cmp
== -2 || cmp
== 1)
3193 /* If the new range has its limits swapped around (MIN > MAX),
3194 then the operation caused one of them to wrap around, mark
3195 the new range VARYING. */
3196 set_value_range_to_varying (vr
);
3199 set_value_range (vr
, type
, min
, max
, NULL
);
3202 /* Extract range information from a binary expression OP0 CODE OP1 based on
3203 the ranges of each of its operands with resulting type EXPR_TYPE.
3204 The resulting range is stored in *VR. */
3207 extract_range_from_binary_expr (value_range
*vr
,
3208 enum tree_code code
,
3209 tree expr_type
, tree op0
, tree op1
)
3211 value_range vr0
= VR_INITIALIZER
;
3212 value_range vr1
= VR_INITIALIZER
;
3214 /* Get value ranges for each operand. For constant operands, create
3215 a new value range with the operand to simplify processing. */
3216 if (TREE_CODE (op0
) == SSA_NAME
)
3217 vr0
= *(get_value_range (op0
));
3218 else if (is_gimple_min_invariant (op0
))
3219 set_value_range_to_value (&vr0
, op0
, NULL
);
3221 set_value_range_to_varying (&vr0
);
3223 if (TREE_CODE (op1
) == SSA_NAME
)
3224 vr1
= *(get_value_range (op1
));
3225 else if (is_gimple_min_invariant (op1
))
3226 set_value_range_to_value (&vr1
, op1
, NULL
);
3228 set_value_range_to_varying (&vr1
);
3230 extract_range_from_binary_expr_1 (vr
, code
, expr_type
, &vr0
, &vr1
);
3232 /* Try harder for PLUS and MINUS if the range of one operand is symbolic
3233 and based on the other operand, for example if it was deduced from a
3234 symbolic comparison. When a bound of the range of the first operand
3235 is invariant, we set the corresponding bound of the new range to INF
3236 in order to avoid recursing on the range of the second operand. */
3237 if (vr
->type
== VR_VARYING
3238 && (code
== PLUS_EXPR
|| code
== MINUS_EXPR
)
3239 && TREE_CODE (op1
) == SSA_NAME
3240 && vr0
.type
== VR_RANGE
3241 && symbolic_range_based_on_p (&vr0
, op1
))
3243 const bool minus_p
= (code
== MINUS_EXPR
);
3244 value_range n_vr1
= VR_INITIALIZER
;
3246 /* Try with VR0 and [-INF, OP1]. */
3247 if (is_gimple_min_invariant (minus_p
? vr0
.max
: vr0
.min
))
3248 set_value_range (&n_vr1
, VR_RANGE
, vrp_val_min (expr_type
), op1
, NULL
);
3250 /* Try with VR0 and [OP1, +INF]. */
3251 else if (is_gimple_min_invariant (minus_p
? vr0
.min
: vr0
.max
))
3252 set_value_range (&n_vr1
, VR_RANGE
, op1
, vrp_val_max (expr_type
), NULL
);
3254 /* Try with VR0 and [OP1, OP1]. */
3256 set_value_range (&n_vr1
, VR_RANGE
, op1
, op1
, NULL
);
3258 extract_range_from_binary_expr_1 (vr
, code
, expr_type
, &vr0
, &n_vr1
);
3261 if (vr
->type
== VR_VARYING
3262 && (code
== PLUS_EXPR
|| code
== MINUS_EXPR
)
3263 && TREE_CODE (op0
) == SSA_NAME
3264 && vr1
.type
== VR_RANGE
3265 && symbolic_range_based_on_p (&vr1
, op0
))
3267 const bool minus_p
= (code
== MINUS_EXPR
);
3268 value_range n_vr0
= VR_INITIALIZER
;
3270 /* Try with [-INF, OP0] and VR1. */
3271 if (is_gimple_min_invariant (minus_p
? vr1
.max
: vr1
.min
))
3272 set_value_range (&n_vr0
, VR_RANGE
, vrp_val_min (expr_type
), op0
, NULL
);
3274 /* Try with [OP0, +INF] and VR1. */
3275 else if (is_gimple_min_invariant (minus_p
? vr1
.min
: vr1
.max
))
3276 set_value_range (&n_vr0
, VR_RANGE
, op0
, vrp_val_max (expr_type
), NULL
);
3278 /* Try with [OP0, OP0] and VR1. */
3280 set_value_range (&n_vr0
, VR_RANGE
, op0
, op0
, NULL
);
3282 extract_range_from_binary_expr_1 (vr
, code
, expr_type
, &n_vr0
, &vr1
);
3286 /* Extract range information from a unary operation CODE based on
3287 the range of its operand *VR0 with type OP0_TYPE with resulting type TYPE.
3288 The resulting range is stored in *VR. */
3291 extract_range_from_unary_expr_1 (value_range
*vr
,
3292 enum tree_code code
, tree type
,
3293 value_range
*vr0_
, tree op0_type
)
3295 value_range vr0
= *vr0_
, vrtem0
= VR_INITIALIZER
, vrtem1
= VR_INITIALIZER
;
3297 /* VRP only operates on integral and pointer types. */
3298 if (!(INTEGRAL_TYPE_P (op0_type
)
3299 || POINTER_TYPE_P (op0_type
))
3300 || !(INTEGRAL_TYPE_P (type
)
3301 || POINTER_TYPE_P (type
)))
3303 set_value_range_to_varying (vr
);
3307 /* If VR0 is UNDEFINED, so is the result. */
3308 if (vr0
.type
== VR_UNDEFINED
)
3310 set_value_range_to_undefined (vr
);
3314 /* Handle operations that we express in terms of others. */
3315 if (code
== PAREN_EXPR
|| code
== OBJ_TYPE_REF
)
3317 /* PAREN_EXPR and OBJ_TYPE_REF are simple copies. */
3318 copy_value_range (vr
, &vr0
);
3321 else if (code
== NEGATE_EXPR
)
3323 /* -X is simply 0 - X, so re-use existing code that also handles
3324 anti-ranges fine. */
3325 value_range zero
= VR_INITIALIZER
;
3326 set_value_range_to_value (&zero
, build_int_cst (type
, 0), NULL
);
3327 extract_range_from_binary_expr_1 (vr
, MINUS_EXPR
, type
, &zero
, &vr0
);
3330 else if (code
== BIT_NOT_EXPR
)
3332 /* ~X is simply -1 - X, so re-use existing code that also handles
3333 anti-ranges fine. */
3334 value_range minusone
= VR_INITIALIZER
;
3335 set_value_range_to_value (&minusone
, build_int_cst (type
, -1), NULL
);
3336 extract_range_from_binary_expr_1 (vr
, MINUS_EXPR
,
3337 type
, &minusone
, &vr0
);
3341 /* Now canonicalize anti-ranges to ranges when they are not symbolic
3342 and express op ~[] as (op []') U (op []''). */
3343 if (vr0
.type
== VR_ANTI_RANGE
3344 && ranges_from_anti_range (&vr0
, &vrtem0
, &vrtem1
))
3346 extract_range_from_unary_expr_1 (vr
, code
, type
, &vrtem0
, op0_type
);
3347 if (vrtem1
.type
!= VR_UNDEFINED
)
3349 value_range vrres
= VR_INITIALIZER
;
3350 extract_range_from_unary_expr_1 (&vrres
, code
, type
,
3352 vrp_meet (vr
, &vrres
);
3357 if (CONVERT_EXPR_CODE_P (code
))
3359 tree inner_type
= op0_type
;
3360 tree outer_type
= type
;
3362 /* If the expression evaluates to a pointer, we are only interested in
3363 determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */
3364 if (POINTER_TYPE_P (type
))
3366 if (range_is_nonnull (&vr0
))
3367 set_value_range_to_nonnull (vr
, type
);
3368 else if (range_is_null (&vr0
))
3369 set_value_range_to_null (vr
, type
);
3371 set_value_range_to_varying (vr
);
3375 /* If VR0 is varying and we increase the type precision, assume
3376 a full range for the following transformation. */
3377 if (vr0
.type
== VR_VARYING
3378 && INTEGRAL_TYPE_P (inner_type
)
3379 && TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
))
3381 vr0
.type
= VR_RANGE
;
3382 vr0
.min
= TYPE_MIN_VALUE (inner_type
);
3383 vr0
.max
= TYPE_MAX_VALUE (inner_type
);
3386 /* If VR0 is a constant range or anti-range and the conversion is
3387 not truncating we can convert the min and max values and
3388 canonicalize the resulting range. Otherwise we can do the
3389 conversion if the size of the range is less than what the
3390 precision of the target type can represent and the range is
3391 not an anti-range. */
3392 if ((vr0
.type
== VR_RANGE
3393 || vr0
.type
== VR_ANTI_RANGE
)
3394 && TREE_CODE (vr0
.min
) == INTEGER_CST
3395 && TREE_CODE (vr0
.max
) == INTEGER_CST
3396 && (!is_overflow_infinity (vr0
.min
)
3397 || (vr0
.type
== VR_RANGE
3398 && TYPE_PRECISION (outer_type
) > TYPE_PRECISION (inner_type
)
3399 && needs_overflow_infinity (outer_type
)
3400 && supports_overflow_infinity (outer_type
)))
3401 && (!is_overflow_infinity (vr0
.max
)
3402 || (vr0
.type
== VR_RANGE
3403 && TYPE_PRECISION (outer_type
) > TYPE_PRECISION (inner_type
)
3404 && needs_overflow_infinity (outer_type
)
3405 && supports_overflow_infinity (outer_type
)))
3406 && (TYPE_PRECISION (outer_type
) >= TYPE_PRECISION (inner_type
)
3407 || (vr0
.type
== VR_RANGE
3408 && integer_zerop (int_const_binop (RSHIFT_EXPR
,
3409 int_const_binop (MINUS_EXPR
, vr0
.max
, vr0
.min
),
3410 size_int (TYPE_PRECISION (outer_type
)))))))
3412 tree new_min
, new_max
;
3413 if (is_overflow_infinity (vr0
.min
))
3414 new_min
= negative_overflow_infinity (outer_type
);
3416 new_min
= force_fit_type (outer_type
, wi::to_widest (vr0
.min
),
3418 if (is_overflow_infinity (vr0
.max
))
3419 new_max
= positive_overflow_infinity (outer_type
);
3421 new_max
= force_fit_type (outer_type
, wi::to_widest (vr0
.max
),
3423 set_and_canonicalize_value_range (vr
, vr0
.type
,
3424 new_min
, new_max
, NULL
);
3428 set_value_range_to_varying (vr
);
3431 else if (code
== ABS_EXPR
)
3436 /* Pass through vr0 in the easy cases. */
3437 if (TYPE_UNSIGNED (type
)
3438 || value_range_nonnegative_p (&vr0
))
3440 copy_value_range (vr
, &vr0
);
3444 /* For the remaining varying or symbolic ranges we can't do anything
3446 if (vr0
.type
== VR_VARYING
3447 || symbolic_range_p (&vr0
))
3449 set_value_range_to_varying (vr
);
3453 /* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a
3455 if (!TYPE_OVERFLOW_UNDEFINED (type
)
3456 && ((vr0
.type
== VR_RANGE
3457 && vrp_val_is_min (vr0
.min
))
3458 || (vr0
.type
== VR_ANTI_RANGE
3459 && !vrp_val_is_min (vr0
.min
))))
3461 set_value_range_to_varying (vr
);
3465 /* ABS_EXPR may flip the range around, if the original range
3466 included negative values. */
3467 if (is_overflow_infinity (vr0
.min
))
3468 min
= positive_overflow_infinity (type
);
3469 else if (!vrp_val_is_min (vr0
.min
))
3470 min
= fold_unary_to_constant (code
, type
, vr0
.min
);
3471 else if (!needs_overflow_infinity (type
))
3472 min
= TYPE_MAX_VALUE (type
);
3473 else if (supports_overflow_infinity (type
))
3474 min
= positive_overflow_infinity (type
);
3477 set_value_range_to_varying (vr
);
3481 if (is_overflow_infinity (vr0
.max
))
3482 max
= positive_overflow_infinity (type
);
3483 else if (!vrp_val_is_min (vr0
.max
))
3484 max
= fold_unary_to_constant (code
, type
, vr0
.max
);
3485 else if (!needs_overflow_infinity (type
))
3486 max
= TYPE_MAX_VALUE (type
);
3487 else if (supports_overflow_infinity (type
)
3488 /* We shouldn't generate [+INF, +INF] as set_value_range
3489 doesn't like this and ICEs. */
3490 && !is_positive_overflow_infinity (min
))
3491 max
= positive_overflow_infinity (type
);
3494 set_value_range_to_varying (vr
);
3498 cmp
= compare_values (min
, max
);
3500 /* If a VR_ANTI_RANGEs contains zero, then we have
3501 ~[-INF, min(MIN, MAX)]. */
3502 if (vr0
.type
== VR_ANTI_RANGE
)
3504 if (range_includes_zero_p (vr0
.min
, vr0
.max
) == 1)
3506 /* Take the lower of the two values. */
3510 /* Create ~[-INF, min (abs(MIN), abs(MAX))]
3511 or ~[-INF + 1, min (abs(MIN), abs(MAX))] when
3512 flag_wrapv is set and the original anti-range doesn't include
3513 TYPE_MIN_VALUE, remember -TYPE_MIN_VALUE = TYPE_MIN_VALUE. */
3514 if (TYPE_OVERFLOW_WRAPS (type
))
3516 tree type_min_value
= TYPE_MIN_VALUE (type
);
3518 min
= (vr0
.min
!= type_min_value
3519 ? int_const_binop (PLUS_EXPR
, type_min_value
,
3520 build_int_cst (TREE_TYPE (type_min_value
), 1))
3525 if (overflow_infinity_range_p (&vr0
))
3526 min
= negative_overflow_infinity (type
);
3528 min
= TYPE_MIN_VALUE (type
);
3533 /* All else has failed, so create the range [0, INF], even for
3534 flag_wrapv since TYPE_MIN_VALUE is in the original
3536 vr0
.type
= VR_RANGE
;
3537 min
= build_int_cst (type
, 0);
3538 if (needs_overflow_infinity (type
))
3540 if (supports_overflow_infinity (type
))
3541 max
= positive_overflow_infinity (type
);
3544 set_value_range_to_varying (vr
);
3549 max
= TYPE_MAX_VALUE (type
);
3553 /* If the range contains zero then we know that the minimum value in the
3554 range will be zero. */
3555 else if (range_includes_zero_p (vr0
.min
, vr0
.max
) == 1)
3559 min
= build_int_cst (type
, 0);
3563 /* If the range was reversed, swap MIN and MAX. */
3565 std::swap (min
, max
);
3568 cmp
= compare_values (min
, max
);
3569 if (cmp
== -2 || cmp
== 1)
3571 /* If the new range has its limits swapped around (MIN > MAX),
3572 then the operation caused one of them to wrap around, mark
3573 the new range VARYING. */
3574 set_value_range_to_varying (vr
);
3577 set_value_range (vr
, vr0
.type
, min
, max
, NULL
);
3581 /* For unhandled operations fall back to varying. */
3582 set_value_range_to_varying (vr
);
3587 /* Extract range information from a unary expression CODE OP0 based on
3588 the range of its operand with resulting type TYPE.
3589 The resulting range is stored in *VR. */
3592 extract_range_from_unary_expr (value_range
*vr
, enum tree_code code
,
3593 tree type
, tree op0
)
3595 value_range vr0
= VR_INITIALIZER
;
3597 /* Get value ranges for the operand. For constant operands, create
3598 a new value range with the operand to simplify processing. */
3599 if (TREE_CODE (op0
) == SSA_NAME
)
3600 vr0
= *(get_value_range (op0
));
3601 else if (is_gimple_min_invariant (op0
))
3602 set_value_range_to_value (&vr0
, op0
, NULL
);
3604 set_value_range_to_varying (&vr0
);
3606 extract_range_from_unary_expr_1 (vr
, code
, type
, &vr0
, TREE_TYPE (op0
));
3610 /* Extract range information from a conditional expression STMT based on
3611 the ranges of each of its operands and the expression code. */
3614 extract_range_from_cond_expr (value_range
*vr
, gassign
*stmt
)
3617 value_range vr0
= VR_INITIALIZER
;
3618 value_range vr1
= VR_INITIALIZER
;
3620 /* Get value ranges for each operand. For constant operands, create
3621 a new value range with the operand to simplify processing. */
3622 op0
= gimple_assign_rhs2 (stmt
);
3623 if (TREE_CODE (op0
) == SSA_NAME
)
3624 vr0
= *(get_value_range (op0
));
3625 else if (is_gimple_min_invariant (op0
))
3626 set_value_range_to_value (&vr0
, op0
, NULL
);
3628 set_value_range_to_varying (&vr0
);
3630 op1
= gimple_assign_rhs3 (stmt
);
3631 if (TREE_CODE (op1
) == SSA_NAME
)
3632 vr1
= *(get_value_range (op1
));
3633 else if (is_gimple_min_invariant (op1
))
3634 set_value_range_to_value (&vr1
, op1
, NULL
);
3636 set_value_range_to_varying (&vr1
);
3638 /* The resulting value range is the union of the operand ranges */
3639 copy_value_range (vr
, &vr0
);
3640 vrp_meet (vr
, &vr1
);
3644 /* Extract range information from a comparison expression EXPR based
3645 on the range of its operand and the expression code. */
3648 extract_range_from_comparison (value_range
*vr
, enum tree_code code
,
3649 tree type
, tree op0
, tree op1
)
3654 val
= vrp_evaluate_conditional_warnv_with_ops (code
, op0
, op1
, false, &sop
,
3657 /* A disadvantage of using a special infinity as an overflow
3658 representation is that we lose the ability to record overflow
3659 when we don't have an infinity. So we have to ignore a result
3660 which relies on overflow. */
3662 if (val
&& !is_overflow_infinity (val
) && !sop
)
3664 /* Since this expression was found on the RHS of an assignment,
3665 its type may be different from _Bool. Convert VAL to EXPR's
3667 val
= fold_convert (type
, val
);
3668 if (is_gimple_min_invariant (val
))
3669 set_value_range_to_value (vr
, val
, vr
->equiv
);
3671 set_value_range (vr
, VR_RANGE
, val
, val
, vr
->equiv
);
3674 /* The result of a comparison is always true or false. */
3675 set_value_range_to_truthvalue (vr
, type
);
3678 /* Helper function for simplify_internal_call_using_ranges and
3679 extract_range_basic. Return true if OP0 SUBCODE OP1 for
3680 SUBCODE {PLUS,MINUS,MULT}_EXPR is known to never overflow or
3681 always overflow. Set *OVF to true if it is known to always
3685 check_for_binary_op_overflow (enum tree_code subcode
, tree type
,
3686 tree op0
, tree op1
, bool *ovf
)
3688 value_range vr0
= VR_INITIALIZER
;
3689 value_range vr1
= VR_INITIALIZER
;
3690 if (TREE_CODE (op0
) == SSA_NAME
)
3691 vr0
= *get_value_range (op0
);
3692 else if (TREE_CODE (op0
) == INTEGER_CST
)
3693 set_value_range_to_value (&vr0
, op0
, NULL
);
3695 set_value_range_to_varying (&vr0
);
3697 if (TREE_CODE (op1
) == SSA_NAME
)
3698 vr1
= *get_value_range (op1
);
3699 else if (TREE_CODE (op1
) == INTEGER_CST
)
3700 set_value_range_to_value (&vr1
, op1
, NULL
);
3702 set_value_range_to_varying (&vr1
);
3704 if (!range_int_cst_p (&vr0
)
3705 || TREE_OVERFLOW (vr0
.min
)
3706 || TREE_OVERFLOW (vr0
.max
))
3708 vr0
.min
= vrp_val_min (TREE_TYPE (op0
));
3709 vr0
.max
= vrp_val_max (TREE_TYPE (op0
));
3711 if (!range_int_cst_p (&vr1
)
3712 || TREE_OVERFLOW (vr1
.min
)
3713 || TREE_OVERFLOW (vr1
.max
))
3715 vr1
.min
= vrp_val_min (TREE_TYPE (op1
));
3716 vr1
.max
= vrp_val_max (TREE_TYPE (op1
));
3718 *ovf
= arith_overflowed_p (subcode
, type
, vr0
.min
,
3719 subcode
== MINUS_EXPR
? vr1
.max
: vr1
.min
);
3720 if (arith_overflowed_p (subcode
, type
, vr0
.max
,
3721 subcode
== MINUS_EXPR
? vr1
.min
: vr1
.max
) != *ovf
)
3723 if (subcode
== MULT_EXPR
)
3725 if (arith_overflowed_p (subcode
, type
, vr0
.min
, vr1
.max
) != *ovf
3726 || arith_overflowed_p (subcode
, type
, vr0
.max
, vr1
.min
) != *ovf
)
3731 /* So far we found that there is an overflow on the boundaries.
3732 That doesn't prove that there is an overflow even for all values
3733 in between the boundaries. For that compute widest_int range
3734 of the result and see if it doesn't overlap the range of
3736 widest_int wmin
, wmax
;
3739 w
[0] = wi::to_widest (vr0
.min
);
3740 w
[1] = wi::to_widest (vr0
.max
);
3741 w
[2] = wi::to_widest (vr1
.min
);
3742 w
[3] = wi::to_widest (vr1
.max
);
3743 for (i
= 0; i
< 4; i
++)
3749 wt
= wi::add (w
[i
& 1], w
[2 + (i
& 2) / 2]);
3752 wt
= wi::sub (w
[i
& 1], w
[2 + (i
& 2) / 2]);
3755 wt
= wi::mul (w
[i
& 1], w
[2 + (i
& 2) / 2]);
3767 wmin
= wi::smin (wmin
, wt
);
3768 wmax
= wi::smax (wmax
, wt
);
3771 /* The result of op0 CODE op1 is known to be in range
3773 widest_int wtmin
= wi::to_widest (vrp_val_min (type
));
3774 widest_int wtmax
= wi::to_widest (vrp_val_max (type
));
3775 /* If all values in [wmin, wmax] are smaller than
3776 [wtmin, wtmax] or all are larger than [wtmin, wtmax],
3777 the arithmetic operation will always overflow. */
3778 if (wmax
< wtmin
|| wmin
> wtmax
)
3785 /* Try to derive a nonnegative or nonzero range out of STMT relying
3786 primarily on generic routines in fold in conjunction with range data.
3787 Store the result in *VR */
3790 extract_range_basic (value_range
*vr
, gimple
*stmt
)
3793 tree type
= gimple_expr_type (stmt
);
3795 if (is_gimple_call (stmt
))
3798 int mini
, maxi
, zerov
= 0, prec
;
3799 enum tree_code subcode
= ERROR_MARK
;
3800 combined_fn cfn
= gimple_call_combined_fn (stmt
);
3804 case CFN_BUILT_IN_CONSTANT_P
:
3805 /* If the call is __builtin_constant_p and the argument is a
3806 function parameter resolve it to false. This avoids bogus
3807 array bound warnings.
3808 ??? We could do this as early as inlining is finished. */
3809 arg
= gimple_call_arg (stmt
, 0);
3810 if (TREE_CODE (arg
) == SSA_NAME
3811 && SSA_NAME_IS_DEFAULT_DEF (arg
)
3812 && TREE_CODE (SSA_NAME_VAR (arg
)) == PARM_DECL
)
3814 set_value_range_to_null (vr
, type
);
3818 /* Both __builtin_ffs* and __builtin_popcount return
3822 arg
= gimple_call_arg (stmt
, 0);
3823 prec
= TYPE_PRECISION (TREE_TYPE (arg
));
3826 if (TREE_CODE (arg
) == SSA_NAME
)
3828 value_range
*vr0
= get_value_range (arg
);
3829 /* If arg is non-zero, then ffs or popcount
3831 if (((vr0
->type
== VR_RANGE
3832 && range_includes_zero_p (vr0
->min
, vr0
->max
) == 0)
3833 || (vr0
->type
== VR_ANTI_RANGE
3834 && range_includes_zero_p (vr0
->min
, vr0
->max
) == 1))
3835 && !is_overflow_infinity (vr0
->min
)
3836 && !is_overflow_infinity (vr0
->max
))
3838 /* If some high bits are known to be zero,
3839 we can decrease the maximum. */
3840 if (vr0
->type
== VR_RANGE
3841 && TREE_CODE (vr0
->max
) == INTEGER_CST
3842 && !operand_less_p (vr0
->min
,
3843 build_zero_cst (TREE_TYPE (vr0
->min
)))
3844 && !is_overflow_infinity (vr0
->max
))
3845 maxi
= tree_floor_log2 (vr0
->max
) + 1;
3848 /* __builtin_parity* returns [0, 1]. */
3853 /* __builtin_c[lt]z* return [0, prec-1], except for
3854 when the argument is 0, but that is undefined behavior.
3855 On many targets where the CLZ RTL or optab value is defined
3856 for 0 the value is prec, so include that in the range
3859 arg
= gimple_call_arg (stmt
, 0);
3860 prec
= TYPE_PRECISION (TREE_TYPE (arg
));
3863 if (optab_handler (clz_optab
, TYPE_MODE (TREE_TYPE (arg
)))
3865 && CLZ_DEFINED_VALUE_AT_ZERO (TYPE_MODE (TREE_TYPE (arg
)),
3867 /* Handle only the single common value. */
3869 /* Magic value to give up, unless vr0 proves
3872 if (TREE_CODE (arg
) == SSA_NAME
)
3874 value_range
*vr0
= get_value_range (arg
);
3875 /* From clz of VR_RANGE minimum we can compute
3877 if (vr0
->type
== VR_RANGE
3878 && TREE_CODE (vr0
->min
) == INTEGER_CST
3879 && !is_overflow_infinity (vr0
->min
))
3881 maxi
= prec
- 1 - tree_floor_log2 (vr0
->min
);
3885 else if (vr0
->type
== VR_ANTI_RANGE
3886 && integer_zerop (vr0
->min
)
3887 && !is_overflow_infinity (vr0
->min
))
3894 /* From clz of VR_RANGE maximum we can compute
3896 if (vr0
->type
== VR_RANGE
3897 && TREE_CODE (vr0
->max
) == INTEGER_CST
3898 && !is_overflow_infinity (vr0
->max
))
3900 mini
= prec
- 1 - tree_floor_log2 (vr0
->max
);
3908 /* __builtin_ctz* return [0, prec-1], except for
3909 when the argument is 0, but that is undefined behavior.
3910 If there is a ctz optab for this mode and
3911 CTZ_DEFINED_VALUE_AT_ZERO, include that in the range,
3912 otherwise just assume 0 won't be seen. */
3914 arg
= gimple_call_arg (stmt
, 0);
3915 prec
= TYPE_PRECISION (TREE_TYPE (arg
));
3918 if (optab_handler (ctz_optab
, TYPE_MODE (TREE_TYPE (arg
)))
3920 && CTZ_DEFINED_VALUE_AT_ZERO (TYPE_MODE (TREE_TYPE (arg
)),
3923 /* Handle only the two common values. */
3926 else if (zerov
== prec
)
3929 /* Magic value to give up, unless vr0 proves
3933 if (TREE_CODE (arg
) == SSA_NAME
)
3935 value_range
*vr0
= get_value_range (arg
);
3936 /* If arg is non-zero, then use [0, prec - 1]. */
3937 if (((vr0
->type
== VR_RANGE
3938 && integer_nonzerop (vr0
->min
))
3939 || (vr0
->type
== VR_ANTI_RANGE
3940 && integer_zerop (vr0
->min
)))
3941 && !is_overflow_infinity (vr0
->min
))
3946 /* If some high bits are known to be zero,
3947 we can decrease the result maximum. */
3948 if (vr0
->type
== VR_RANGE
3949 && TREE_CODE (vr0
->max
) == INTEGER_CST
3950 && !is_overflow_infinity (vr0
->max
))
3952 maxi
= tree_floor_log2 (vr0
->max
);
3953 /* For vr0 [0, 0] give up. */
3961 /* __builtin_clrsb* returns [0, prec-1]. */
3963 arg
= gimple_call_arg (stmt
, 0);
3964 prec
= TYPE_PRECISION (TREE_TYPE (arg
));
3969 set_value_range (vr
, VR_RANGE
, build_int_cst (type
, mini
),
3970 build_int_cst (type
, maxi
), NULL
);
3972 case CFN_UBSAN_CHECK_ADD
:
3973 subcode
= PLUS_EXPR
;
3975 case CFN_UBSAN_CHECK_SUB
:
3976 subcode
= MINUS_EXPR
;
3978 case CFN_UBSAN_CHECK_MUL
:
3979 subcode
= MULT_EXPR
;
3981 case CFN_GOACC_DIM_SIZE
:
3982 case CFN_GOACC_DIM_POS
:
3983 /* Optimizing these two internal functions helps the loop
3984 optimizer eliminate outer comparisons. Size is [1,N]
3985 and pos is [0,N-1]. */
3987 bool is_pos
= cfn
== CFN_GOACC_DIM_POS
;
3988 int axis
= get_oacc_ifn_dim_arg (stmt
);
3989 int size
= get_oacc_fn_dim_size (current_function_decl
, axis
);
3992 /* If it's dynamic, the backend might know a hardware
3994 size
= targetm
.goacc
.dim_limit (axis
);
3996 tree type
= TREE_TYPE (gimple_call_lhs (stmt
));
3997 set_value_range (vr
, VR_RANGE
,
3998 build_int_cst (type
, is_pos
? 0 : 1),
3999 size
? build_int_cst (type
, size
- is_pos
)
4000 : vrp_val_max (type
), NULL
);
4006 if (subcode
!= ERROR_MARK
)
4008 bool saved_flag_wrapv
= flag_wrapv
;
4009 /* Pretend the arithmetics is wrapping. If there is
4010 any overflow, we'll complain, but will actually do
4011 wrapping operation. */
4013 extract_range_from_binary_expr (vr
, subcode
, type
,
4014 gimple_call_arg (stmt
, 0),
4015 gimple_call_arg (stmt
, 1));
4016 flag_wrapv
= saved_flag_wrapv
;
4018 /* If for both arguments vrp_valueize returned non-NULL,
4019 this should have been already folded and if not, it
4020 wasn't folded because of overflow. Avoid removing the
4021 UBSAN_CHECK_* calls in that case. */
4022 if (vr
->type
== VR_RANGE
4023 && (vr
->min
== vr
->max
4024 || operand_equal_p (vr
->min
, vr
->max
, 0)))
4025 set_value_range_to_varying (vr
);
4029 /* Handle extraction of the two results (result of arithmetics and
4030 a flag whether arithmetics overflowed) from {ADD,SUB,MUL}_OVERFLOW
4031 internal function. */
4032 else if (is_gimple_assign (stmt
)
4033 && (gimple_assign_rhs_code (stmt
) == REALPART_EXPR
4034 || gimple_assign_rhs_code (stmt
) == IMAGPART_EXPR
)
4035 && INTEGRAL_TYPE_P (type
))
4037 enum tree_code code
= gimple_assign_rhs_code (stmt
);
4038 tree op
= gimple_assign_rhs1 (stmt
);
4039 if (TREE_CODE (op
) == code
&& TREE_CODE (TREE_OPERAND (op
, 0)) == SSA_NAME
)
4041 gimple
*g
= SSA_NAME_DEF_STMT (TREE_OPERAND (op
, 0));
4042 if (is_gimple_call (g
) && gimple_call_internal_p (g
))
4044 enum tree_code subcode
= ERROR_MARK
;
4045 switch (gimple_call_internal_fn (g
))
4047 case IFN_ADD_OVERFLOW
:
4048 subcode
= PLUS_EXPR
;
4050 case IFN_SUB_OVERFLOW
:
4051 subcode
= MINUS_EXPR
;
4053 case IFN_MUL_OVERFLOW
:
4054 subcode
= MULT_EXPR
;
4059 if (subcode
!= ERROR_MARK
)
4061 tree op0
= gimple_call_arg (g
, 0);
4062 tree op1
= gimple_call_arg (g
, 1);
4063 if (code
== IMAGPART_EXPR
)
4066 if (check_for_binary_op_overflow (subcode
, type
,
4068 set_value_range_to_value (vr
,
4069 build_int_cst (type
, ovf
),
4072 set_value_range (vr
, VR_RANGE
, build_int_cst (type
, 0),
4073 build_int_cst (type
, 1), NULL
);
4075 else if (types_compatible_p (type
, TREE_TYPE (op0
))
4076 && types_compatible_p (type
, TREE_TYPE (op1
)))
4078 bool saved_flag_wrapv
= flag_wrapv
;
4079 /* Pretend the arithmetics is wrapping. If there is
4080 any overflow, IMAGPART_EXPR will be set. */
4082 extract_range_from_binary_expr (vr
, subcode
, type
,
4084 flag_wrapv
= saved_flag_wrapv
;
4088 value_range vr0
= VR_INITIALIZER
;
4089 value_range vr1
= VR_INITIALIZER
;
4090 bool saved_flag_wrapv
= flag_wrapv
;
4091 /* Pretend the arithmetics is wrapping. If there is
4092 any overflow, IMAGPART_EXPR will be set. */
4094 extract_range_from_unary_expr (&vr0
, NOP_EXPR
,
4096 extract_range_from_unary_expr (&vr1
, NOP_EXPR
,
4098 extract_range_from_binary_expr_1 (vr
, subcode
, type
,
4100 flag_wrapv
= saved_flag_wrapv
;
4107 if (INTEGRAL_TYPE_P (type
)
4108 && gimple_stmt_nonnegative_warnv_p (stmt
, &sop
))
4109 set_value_range_to_nonnegative (vr
, type
,
4110 sop
|| stmt_overflow_infinity (stmt
));
4111 else if (vrp_stmt_computes_nonzero (stmt
, &sop
)
4113 set_value_range_to_nonnull (vr
, type
);
4115 set_value_range_to_varying (vr
);
4119 /* Try to compute a useful range out of assignment STMT and store it
4123 extract_range_from_assignment (value_range
*vr
, gassign
*stmt
)
4125 enum tree_code code
= gimple_assign_rhs_code (stmt
);
4127 if (code
== ASSERT_EXPR
)
4128 extract_range_from_assert (vr
, gimple_assign_rhs1 (stmt
));
4129 else if (code
== SSA_NAME
)
4130 extract_range_from_ssa_name (vr
, gimple_assign_rhs1 (stmt
));
4131 else if (TREE_CODE_CLASS (code
) == tcc_binary
)
4132 extract_range_from_binary_expr (vr
, gimple_assign_rhs_code (stmt
),
4133 gimple_expr_type (stmt
),
4134 gimple_assign_rhs1 (stmt
),
4135 gimple_assign_rhs2 (stmt
));
4136 else if (TREE_CODE_CLASS (code
) == tcc_unary
)
4137 extract_range_from_unary_expr (vr
, gimple_assign_rhs_code (stmt
),
4138 gimple_expr_type (stmt
),
4139 gimple_assign_rhs1 (stmt
));
4140 else if (code
== COND_EXPR
)
4141 extract_range_from_cond_expr (vr
, stmt
);
4142 else if (TREE_CODE_CLASS (code
) == tcc_comparison
)
4143 extract_range_from_comparison (vr
, gimple_assign_rhs_code (stmt
),
4144 gimple_expr_type (stmt
),
4145 gimple_assign_rhs1 (stmt
),
4146 gimple_assign_rhs2 (stmt
));
4147 else if (get_gimple_rhs_class (code
) == GIMPLE_SINGLE_RHS
4148 && is_gimple_min_invariant (gimple_assign_rhs1 (stmt
)))
4149 set_value_range_to_value (vr
, gimple_assign_rhs1 (stmt
), NULL
);
4151 set_value_range_to_varying (vr
);
4153 if (vr
->type
== VR_VARYING
)
4154 extract_range_basic (vr
, stmt
);
4157 /* Given a range VR, a LOOP and a variable VAR, determine whether it
4158 would be profitable to adjust VR using scalar evolution information
4159 for VAR. If so, update VR with the new limits. */
4162 adjust_range_with_scev (value_range
*vr
, struct loop
*loop
,
4163 gimple
*stmt
, tree var
)
4165 tree init
, step
, chrec
, tmin
, tmax
, min
, max
, type
, tem
;
4166 enum ev_direction dir
;
4168 /* TODO. Don't adjust anti-ranges. An anti-range may provide
4169 better opportunities than a regular range, but I'm not sure. */
4170 if (vr
->type
== VR_ANTI_RANGE
)
4173 chrec
= instantiate_parameters (loop
, analyze_scalar_evolution (loop
, var
));
4175 /* Like in PR19590, scev can return a constant function. */
4176 if (is_gimple_min_invariant (chrec
))
4178 set_value_range_to_value (vr
, chrec
, vr
->equiv
);
4182 if (TREE_CODE (chrec
) != POLYNOMIAL_CHREC
)
4185 init
= initial_condition_in_loop_num (chrec
, loop
->num
);
4186 tem
= op_with_constant_singleton_value_range (init
);
4189 step
= evolution_part_in_loop_num (chrec
, loop
->num
);
4190 tem
= op_with_constant_singleton_value_range (step
);
4194 /* If STEP is symbolic, we can't know whether INIT will be the
4195 minimum or maximum value in the range. Also, unless INIT is
4196 a simple expression, compare_values and possibly other functions
4197 in tree-vrp won't be able to handle it. */
4198 if (step
== NULL_TREE
4199 || !is_gimple_min_invariant (step
)
4200 || !valid_value_p (init
))
4203 dir
= scev_direction (chrec
);
4204 if (/* Do not adjust ranges if we do not know whether the iv increases
4205 or decreases, ... */
4206 dir
== EV_DIR_UNKNOWN
4207 /* ... or if it may wrap. */
4208 || scev_probably_wraps_p (init
, step
, stmt
, get_chrec_loop (chrec
),
4212 /* We use TYPE_MIN_VALUE and TYPE_MAX_VALUE here instead of
4213 negative_overflow_infinity and positive_overflow_infinity,
4214 because we have concluded that the loop probably does not
4217 type
= TREE_TYPE (var
);
4218 if (POINTER_TYPE_P (type
) || !TYPE_MIN_VALUE (type
))
4219 tmin
= lower_bound_in_type (type
, type
);
4221 tmin
= TYPE_MIN_VALUE (type
);
4222 if (POINTER_TYPE_P (type
) || !TYPE_MAX_VALUE (type
))
4223 tmax
= upper_bound_in_type (type
, type
);
4225 tmax
= TYPE_MAX_VALUE (type
);
4227 /* Try to use estimated number of iterations for the loop to constrain the
4228 final value in the evolution. */
4229 if (TREE_CODE (step
) == INTEGER_CST
4230 && is_gimple_val (init
)
4231 && (TREE_CODE (init
) != SSA_NAME
4232 || get_value_range (init
)->type
== VR_RANGE
))
4236 /* We are only entering here for loop header PHI nodes, so using
4237 the number of latch executions is the correct thing to use. */
4238 if (max_loop_iterations (loop
, &nit
))
4240 value_range maxvr
= VR_INITIALIZER
;
4241 signop sgn
= TYPE_SIGN (TREE_TYPE (step
));
4244 widest_int wtmp
= wi::mul (wi::to_widest (step
), nit
, sgn
,
4246 /* If the multiplication overflowed we can't do a meaningful
4247 adjustment. Likewise if the result doesn't fit in the type
4248 of the induction variable. For a signed type we have to
4249 check whether the result has the expected signedness which
4250 is that of the step as number of iterations is unsigned. */
4252 && wi::fits_to_tree_p (wtmp
, TREE_TYPE (init
))
4254 || wi::gts_p (wtmp
, 0) == wi::gts_p (step
, 0)))
4256 tem
= wide_int_to_tree (TREE_TYPE (init
), wtmp
);
4257 extract_range_from_binary_expr (&maxvr
, PLUS_EXPR
,
4258 TREE_TYPE (init
), init
, tem
);
4259 /* Likewise if the addition did. */
4260 if (maxvr
.type
== VR_RANGE
)
4262 value_range initvr
= VR_INITIALIZER
;
4264 if (TREE_CODE (init
) == SSA_NAME
)
4265 initvr
= *(get_value_range (init
));
4266 else if (is_gimple_min_invariant (init
))
4267 set_value_range_to_value (&initvr
, init
, NULL
);
4271 /* Check if init + nit * step overflows. Though we checked
4272 scev {init, step}_loop doesn't wrap, it is not enough
4273 because the loop may exit immediately. Overflow could
4274 happen in the plus expression in this case. */
4275 if ((dir
== EV_DIR_DECREASES
4276 && (is_negative_overflow_infinity (maxvr
.min
)
4277 || compare_values (maxvr
.min
, initvr
.min
) != -1))
4278 || (dir
== EV_DIR_GROWS
4279 && (is_positive_overflow_infinity (maxvr
.max
)
4280 || compare_values (maxvr
.max
, initvr
.max
) != 1)))
4290 if (vr
->type
== VR_VARYING
|| vr
->type
== VR_UNDEFINED
)
4295 /* For VARYING or UNDEFINED ranges, just about anything we get
4296 from scalar evolutions should be better. */
4298 if (dir
== EV_DIR_DECREASES
)
4303 else if (vr
->type
== VR_RANGE
)
4308 if (dir
== EV_DIR_DECREASES
)
4310 /* INIT is the maximum value. If INIT is lower than VR->MAX
4311 but no smaller than VR->MIN, set VR->MAX to INIT. */
4312 if (compare_values (init
, max
) == -1)
4315 /* According to the loop information, the variable does not
4316 overflow. If we think it does, probably because of an
4317 overflow due to arithmetic on a different INF value,
4319 if (is_negative_overflow_infinity (min
)
4320 || compare_values (min
, tmin
) == -1)
4326 /* If INIT is bigger than VR->MIN, set VR->MIN to INIT. */
4327 if (compare_values (init
, min
) == 1)
4330 if (is_positive_overflow_infinity (max
)
4331 || compare_values (tmax
, max
) == -1)
4338 /* If we just created an invalid range with the minimum
4339 greater than the maximum, we fail conservatively.
4340 This should happen only in unreachable
4341 parts of code, or for invalid programs. */
4342 if (compare_values (min
, max
) == 1
4343 || (is_negative_overflow_infinity (min
)
4344 && is_positive_overflow_infinity (max
)))
4347 /* Even for valid range info, sometimes overflow flag will leak in.
4348 As GIMPLE IL should have no constants with TREE_OVERFLOW set, we
4349 drop them except for +-overflow_infinity which still need special
4350 handling in vrp pass. */
4351 if (TREE_OVERFLOW_P (min
)
4352 && ! is_negative_overflow_infinity (min
))
4353 min
= drop_tree_overflow (min
);
4354 if (TREE_OVERFLOW_P (max
)
4355 && ! is_positive_overflow_infinity (max
))
4356 max
= drop_tree_overflow (max
);
4358 set_value_range (vr
, VR_RANGE
, min
, max
, vr
->equiv
);
4362 /* Given two numeric value ranges VR0, VR1 and a comparison code COMP:
4364 - Return BOOLEAN_TRUE_NODE if VR0 COMP VR1 always returns true for
4365 all the values in the ranges.
4367 - Return BOOLEAN_FALSE_NODE if the comparison always returns false.
4369 - Return NULL_TREE if it is not always possible to determine the
4370 value of the comparison.
4372 Also set *STRICT_OVERFLOW_P to indicate whether a range with an
4373 overflow infinity was used in the test. */
4377 compare_ranges (enum tree_code comp
, value_range
*vr0
, value_range
*vr1
,
4378 bool *strict_overflow_p
)
4380 /* VARYING or UNDEFINED ranges cannot be compared. */
4381 if (vr0
->type
== VR_VARYING
4382 || vr0
->type
== VR_UNDEFINED
4383 || vr1
->type
== VR_VARYING
4384 || vr1
->type
== VR_UNDEFINED
)
4387 /* Anti-ranges need to be handled separately. */
4388 if (vr0
->type
== VR_ANTI_RANGE
|| vr1
->type
== VR_ANTI_RANGE
)
4390 /* If both are anti-ranges, then we cannot compute any
4392 if (vr0
->type
== VR_ANTI_RANGE
&& vr1
->type
== VR_ANTI_RANGE
)
4395 /* These comparisons are never statically computable. */
4402 /* Equality can be computed only between a range and an
4403 anti-range. ~[VAL1, VAL2] == [VAL1, VAL2] is always false. */
4404 if (vr0
->type
== VR_RANGE
)
4406 /* To simplify processing, make VR0 the anti-range. */
4407 value_range
*tmp
= vr0
;
4412 gcc_assert (comp
== NE_EXPR
|| comp
== EQ_EXPR
);
4414 if (compare_values_warnv (vr0
->min
, vr1
->min
, strict_overflow_p
) == 0
4415 && compare_values_warnv (vr0
->max
, vr1
->max
, strict_overflow_p
) == 0)
4416 return (comp
== NE_EXPR
) ? boolean_true_node
: boolean_false_node
;
4421 if (!usable_range_p (vr0
, strict_overflow_p
)
4422 || !usable_range_p (vr1
, strict_overflow_p
))
4425 /* Simplify processing. If COMP is GT_EXPR or GE_EXPR, switch the
4426 operands around and change the comparison code. */
4427 if (comp
== GT_EXPR
|| comp
== GE_EXPR
)
4429 comp
= (comp
== GT_EXPR
) ? LT_EXPR
: LE_EXPR
;
4430 std::swap (vr0
, vr1
);
4433 if (comp
== EQ_EXPR
)
4435 /* Equality may only be computed if both ranges represent
4436 exactly one value. */
4437 if (compare_values_warnv (vr0
->min
, vr0
->max
, strict_overflow_p
) == 0
4438 && compare_values_warnv (vr1
->min
, vr1
->max
, strict_overflow_p
) == 0)
4440 int cmp_min
= compare_values_warnv (vr0
->min
, vr1
->min
,
4442 int cmp_max
= compare_values_warnv (vr0
->max
, vr1
->max
,
4444 if (cmp_min
== 0 && cmp_max
== 0)
4445 return boolean_true_node
;
4446 else if (cmp_min
!= -2 && cmp_max
!= -2)
4447 return boolean_false_node
;
4449 /* If [V0_MIN, V1_MAX] < [V1_MIN, V1_MAX] then V0 != V1. */
4450 else if (compare_values_warnv (vr0
->min
, vr1
->max
,
4451 strict_overflow_p
) == 1
4452 || compare_values_warnv (vr1
->min
, vr0
->max
,
4453 strict_overflow_p
) == 1)
4454 return boolean_false_node
;
4458 else if (comp
== NE_EXPR
)
4462 /* If VR0 is completely to the left or completely to the right
4463 of VR1, they are always different. Notice that we need to
4464 make sure that both comparisons yield similar results to
4465 avoid comparing values that cannot be compared at
4467 cmp1
= compare_values_warnv (vr0
->max
, vr1
->min
, strict_overflow_p
);
4468 cmp2
= compare_values_warnv (vr0
->min
, vr1
->max
, strict_overflow_p
);
4469 if ((cmp1
== -1 && cmp2
== -1) || (cmp1
== 1 && cmp2
== 1))
4470 return boolean_true_node
;
4472 /* If VR0 and VR1 represent a single value and are identical,
4474 else if (compare_values_warnv (vr0
->min
, vr0
->max
,
4475 strict_overflow_p
) == 0
4476 && compare_values_warnv (vr1
->min
, vr1
->max
,
4477 strict_overflow_p
) == 0
4478 && compare_values_warnv (vr0
->min
, vr1
->min
,
4479 strict_overflow_p
) == 0
4480 && compare_values_warnv (vr0
->max
, vr1
->max
,
4481 strict_overflow_p
) == 0)
4482 return boolean_false_node
;
4484 /* Otherwise, they may or may not be different. */
4488 else if (comp
== LT_EXPR
|| comp
== LE_EXPR
)
4492 /* If VR0 is to the left of VR1, return true. */
4493 tst
= compare_values_warnv (vr0
->max
, vr1
->min
, strict_overflow_p
);
4494 if ((comp
== LT_EXPR
&& tst
== -1)
4495 || (comp
== LE_EXPR
&& (tst
== -1 || tst
== 0)))
4497 if (overflow_infinity_range_p (vr0
)
4498 || overflow_infinity_range_p (vr1
))
4499 *strict_overflow_p
= true;
4500 return boolean_true_node
;
4503 /* If VR0 is to the right of VR1, return false. */
4504 tst
= compare_values_warnv (vr0
->min
, vr1
->max
, strict_overflow_p
);
4505 if ((comp
== LT_EXPR
&& (tst
== 0 || tst
== 1))
4506 || (comp
== LE_EXPR
&& tst
== 1))
4508 if (overflow_infinity_range_p (vr0
)
4509 || overflow_infinity_range_p (vr1
))
4510 *strict_overflow_p
= true;
4511 return boolean_false_node
;
4514 /* Otherwise, we don't know. */
4522 /* Given a value range VR, a value VAL and a comparison code COMP, return
4523 BOOLEAN_TRUE_NODE if VR COMP VAL always returns true for all the
4524 values in VR. Return BOOLEAN_FALSE_NODE if the comparison
4525 always returns false. Return NULL_TREE if it is not always
4526 possible to determine the value of the comparison. Also set
4527 *STRICT_OVERFLOW_P to indicate whether a range with an overflow
4528 infinity was used in the test. */
4531 compare_range_with_value (enum tree_code comp
, value_range
*vr
, tree val
,
4532 bool *strict_overflow_p
)
4534 if (vr
->type
== VR_VARYING
|| vr
->type
== VR_UNDEFINED
)
4537 /* Anti-ranges need to be handled separately. */
4538 if (vr
->type
== VR_ANTI_RANGE
)
4540 /* For anti-ranges, the only predicates that we can compute at
4541 compile time are equality and inequality. */
4548 /* ~[VAL_1, VAL_2] OP VAL is known if VAL_1 <= VAL <= VAL_2. */
4549 if (value_inside_range (val
, vr
->min
, vr
->max
) == 1)
4550 return (comp
== NE_EXPR
) ? boolean_true_node
: boolean_false_node
;
4555 if (!usable_range_p (vr
, strict_overflow_p
))
4558 if (comp
== EQ_EXPR
)
4560 /* EQ_EXPR may only be computed if VR represents exactly
4562 if (compare_values_warnv (vr
->min
, vr
->max
, strict_overflow_p
) == 0)
4564 int cmp
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
4566 return boolean_true_node
;
4567 else if (cmp
== -1 || cmp
== 1 || cmp
== 2)
4568 return boolean_false_node
;
4570 else if (compare_values_warnv (val
, vr
->min
, strict_overflow_p
) == -1
4571 || compare_values_warnv (vr
->max
, val
, strict_overflow_p
) == -1)
4572 return boolean_false_node
;
4576 else if (comp
== NE_EXPR
)
4578 /* If VAL is not inside VR, then they are always different. */
4579 if (compare_values_warnv (vr
->max
, val
, strict_overflow_p
) == -1
4580 || compare_values_warnv (vr
->min
, val
, strict_overflow_p
) == 1)
4581 return boolean_true_node
;
4583 /* If VR represents exactly one value equal to VAL, then return
4585 if (compare_values_warnv (vr
->min
, vr
->max
, strict_overflow_p
) == 0
4586 && compare_values_warnv (vr
->min
, val
, strict_overflow_p
) == 0)
4587 return boolean_false_node
;
4589 /* Otherwise, they may or may not be different. */
4592 else if (comp
== LT_EXPR
|| comp
== LE_EXPR
)
4596 /* If VR is to the left of VAL, return true. */
4597 tst
= compare_values_warnv (vr
->max
, val
, strict_overflow_p
);
4598 if ((comp
== LT_EXPR
&& tst
== -1)
4599 || (comp
== LE_EXPR
&& (tst
== -1 || tst
== 0)))
4601 if (overflow_infinity_range_p (vr
))
4602 *strict_overflow_p
= true;
4603 return boolean_true_node
;
4606 /* If VR is to the right of VAL, return false. */
4607 tst
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
4608 if ((comp
== LT_EXPR
&& (tst
== 0 || tst
== 1))
4609 || (comp
== LE_EXPR
&& tst
== 1))
4611 if (overflow_infinity_range_p (vr
))
4612 *strict_overflow_p
= true;
4613 return boolean_false_node
;
4616 /* Otherwise, we don't know. */
4619 else if (comp
== GT_EXPR
|| comp
== GE_EXPR
)
4623 /* If VR is to the right of VAL, return true. */
4624 tst
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
4625 if ((comp
== GT_EXPR
&& tst
== 1)
4626 || (comp
== GE_EXPR
&& (tst
== 0 || tst
== 1)))
4628 if (overflow_infinity_range_p (vr
))
4629 *strict_overflow_p
= true;
4630 return boolean_true_node
;
4633 /* If VR is to the left of VAL, return false. */
4634 tst
= compare_values_warnv (vr
->max
, val
, strict_overflow_p
);
4635 if ((comp
== GT_EXPR
&& (tst
== -1 || tst
== 0))
4636 || (comp
== GE_EXPR
&& tst
== -1))
4638 if (overflow_infinity_range_p (vr
))
4639 *strict_overflow_p
= true;
4640 return boolean_false_node
;
4643 /* Otherwise, we don't know. */
4651 /* Debugging dumps. */
4653 void dump_value_range (FILE *, value_range
*);
4654 void debug_value_range (value_range
*);
4655 void dump_all_value_ranges (FILE *);
4656 void debug_all_value_ranges (void);
4657 void dump_vr_equiv (FILE *, bitmap
);
4658 void debug_vr_equiv (bitmap
);
4661 /* Dump value range VR to FILE. */
4664 dump_value_range (FILE *file
, value_range
*vr
)
4667 fprintf (file
, "[]");
4668 else if (vr
->type
== VR_UNDEFINED
)
4669 fprintf (file
, "UNDEFINED");
4670 else if (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
)
4672 tree type
= TREE_TYPE (vr
->min
);
4674 fprintf (file
, "%s[", (vr
->type
== VR_ANTI_RANGE
) ? "~" : "");
4676 if (is_negative_overflow_infinity (vr
->min
))
4677 fprintf (file
, "-INF(OVF)");
4678 else if (INTEGRAL_TYPE_P (type
)
4679 && !TYPE_UNSIGNED (type
)
4680 && vrp_val_is_min (vr
->min
))
4681 fprintf (file
, "-INF");
4683 print_generic_expr (file
, vr
->min
, 0);
4685 fprintf (file
, ", ");
4687 if (is_positive_overflow_infinity (vr
->max
))
4688 fprintf (file
, "+INF(OVF)");
4689 else if (INTEGRAL_TYPE_P (type
)
4690 && vrp_val_is_max (vr
->max
))
4691 fprintf (file
, "+INF");
4693 print_generic_expr (file
, vr
->max
, 0);
4695 fprintf (file
, "]");
4702 fprintf (file
, " EQUIVALENCES: { ");
4704 EXECUTE_IF_SET_IN_BITMAP (vr
->equiv
, 0, i
, bi
)
4706 print_generic_expr (file
, ssa_name (i
), 0);
4707 fprintf (file
, " ");
4711 fprintf (file
, "} (%u elements)", c
);
4714 else if (vr
->type
== VR_VARYING
)
4715 fprintf (file
, "VARYING");
4717 fprintf (file
, "INVALID RANGE");
4721 /* Dump value range VR to stderr. */
4724 debug_value_range (value_range
*vr
)
4726 dump_value_range (stderr
, vr
);
4727 fprintf (stderr
, "\n");
4731 /* Dump value ranges of all SSA_NAMEs to FILE. */
4734 dump_all_value_ranges (FILE *file
)
4738 for (i
= 0; i
< num_vr_values
; i
++)
4742 print_generic_expr (file
, ssa_name (i
), 0);
4743 fprintf (file
, ": ");
4744 dump_value_range (file
, vr_value
[i
]);
4745 fprintf (file
, "\n");
4749 fprintf (file
, "\n");
4753 /* Dump all value ranges to stderr. */
4756 debug_all_value_ranges (void)
4758 dump_all_value_ranges (stderr
);
4762 /* Given a COND_EXPR COND of the form 'V OP W', and an SSA name V,
4763 create a new SSA name N and return the assertion assignment
4764 'N = ASSERT_EXPR <V, V OP W>'. */
4767 build_assert_expr_for (tree cond
, tree v
)
4772 gcc_assert (TREE_CODE (v
) == SSA_NAME
4773 && COMPARISON_CLASS_P (cond
));
4775 a
= build2 (ASSERT_EXPR
, TREE_TYPE (v
), v
, cond
);
4776 assertion
= gimple_build_assign (NULL_TREE
, a
);
4778 /* The new ASSERT_EXPR, creates a new SSA name that replaces the
4779 operand of the ASSERT_EXPR. Create it so the new name and the old one
4780 are registered in the replacement table so that we can fix the SSA web
4781 after adding all the ASSERT_EXPRs. */
4782 create_new_def_for (v
, assertion
, NULL
);
4788 /* Return false if EXPR is a predicate expression involving floating
4792 fp_predicate (gimple
*stmt
)
4794 GIMPLE_CHECK (stmt
, GIMPLE_COND
);
4796 return FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (stmt
)));
4799 /* If the range of values taken by OP can be inferred after STMT executes,
4800 return the comparison code (COMP_CODE_P) and value (VAL_P) that
4801 describes the inferred range. Return true if a range could be
4805 infer_value_range (gimple
*stmt
, tree op
, tree_code
*comp_code_p
, tree
*val_p
)
4808 *comp_code_p
= ERROR_MARK
;
4810 /* Do not attempt to infer anything in names that flow through
4812 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op
))
4815 /* Similarly, don't infer anything from statements that may throw
4816 exceptions. ??? Relax this requirement? */
4817 if (stmt_could_throw_p (stmt
))
4820 /* If STMT is the last statement of a basic block with no normal
4821 successors, there is no point inferring anything about any of its
4822 operands. We would not be able to find a proper insertion point
4823 for the assertion, anyway. */
4824 if (stmt_ends_bb_p (stmt
))
4829 FOR_EACH_EDGE (e
, ei
, gimple_bb (stmt
)->succs
)
4830 if (!(e
->flags
& EDGE_ABNORMAL
))
4836 if (infer_nonnull_range (stmt
, op
))
4838 *val_p
= build_int_cst (TREE_TYPE (op
), 0);
4839 *comp_code_p
= NE_EXPR
;
4847 void dump_asserts_for (FILE *, tree
);
4848 void debug_asserts_for (tree
);
4849 void dump_all_asserts (FILE *);
4850 void debug_all_asserts (void);
4852 /* Dump all the registered assertions for NAME to FILE. */
4855 dump_asserts_for (FILE *file
, tree name
)
4859 fprintf (file
, "Assertions to be inserted for ");
4860 print_generic_expr (file
, name
, 0);
4861 fprintf (file
, "\n");
4863 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
4866 fprintf (file
, "\t");
4867 print_gimple_stmt (file
, gsi_stmt (loc
->si
), 0, 0);
4868 fprintf (file
, "\n\tBB #%d", loc
->bb
->index
);
4871 fprintf (file
, "\n\tEDGE %d->%d", loc
->e
->src
->index
,
4872 loc
->e
->dest
->index
);
4873 dump_edge_info (file
, loc
->e
, dump_flags
, 0);
4875 fprintf (file
, "\n\tPREDICATE: ");
4876 print_generic_expr (file
, name
, 0);
4877 fprintf (file
, " %s ", get_tree_code_name (loc
->comp_code
));
4878 print_generic_expr (file
, loc
->val
, 0);
4879 fprintf (file
, "\n\n");
4883 fprintf (file
, "\n");
4887 /* Dump all the registered assertions for NAME to stderr. */
4890 debug_asserts_for (tree name
)
4892 dump_asserts_for (stderr
, name
);
4896 /* Dump all the registered assertions for all the names to FILE. */
4899 dump_all_asserts (FILE *file
)
4904 fprintf (file
, "\nASSERT_EXPRs to be inserted\n\n");
4905 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
4906 dump_asserts_for (file
, ssa_name (i
));
4907 fprintf (file
, "\n");
4911 /* Dump all the registered assertions for all the names to stderr. */
4914 debug_all_asserts (void)
4916 dump_all_asserts (stderr
);
4920 /* If NAME doesn't have an ASSERT_EXPR registered for asserting
4921 'EXPR COMP_CODE VAL' at a location that dominates block BB or
4922 E->DEST, then register this location as a possible insertion point
4923 for ASSERT_EXPR <NAME, EXPR COMP_CODE VAL>.
4925 BB, E and SI provide the exact insertion point for the new
4926 ASSERT_EXPR. If BB is NULL, then the ASSERT_EXPR is to be inserted
4927 on edge E. Otherwise, if E is NULL, the ASSERT_EXPR is inserted on
4928 BB. If SI points to a COND_EXPR or a SWITCH_EXPR statement, then E
4929 must not be NULL. */
4932 register_new_assert_for (tree name
, tree expr
,
4933 enum tree_code comp_code
,
4937 gimple_stmt_iterator si
)
4939 assert_locus
*n
, *loc
, *last_loc
;
4940 basic_block dest_bb
;
4942 gcc_checking_assert (bb
== NULL
|| e
== NULL
);
4945 gcc_checking_assert (gimple_code (gsi_stmt (si
)) != GIMPLE_COND
4946 && gimple_code (gsi_stmt (si
)) != GIMPLE_SWITCH
);
4948 /* Never build an assert comparing against an integer constant with
4949 TREE_OVERFLOW set. This confuses our undefined overflow warning
4951 if (TREE_OVERFLOW_P (val
))
4952 val
= drop_tree_overflow (val
);
4954 /* The new assertion A will be inserted at BB or E. We need to
4955 determine if the new location is dominated by a previously
4956 registered location for A. If we are doing an edge insertion,
4957 assume that A will be inserted at E->DEST. Note that this is not
4960 If E is a critical edge, it will be split. But even if E is
4961 split, the new block will dominate the same set of blocks that
4964 The reverse, however, is not true, blocks dominated by E->DEST
4965 will not be dominated by the new block created to split E. So,
4966 if the insertion location is on a critical edge, we will not use
4967 the new location to move another assertion previously registered
4968 at a block dominated by E->DEST. */
4969 dest_bb
= (bb
) ? bb
: e
->dest
;
4971 /* If NAME already has an ASSERT_EXPR registered for COMP_CODE and
4972 VAL at a block dominating DEST_BB, then we don't need to insert a new
4973 one. Similarly, if the same assertion already exists at a block
4974 dominated by DEST_BB and the new location is not on a critical
4975 edge, then update the existing location for the assertion (i.e.,
4976 move the assertion up in the dominance tree).
4978 Note, this is implemented as a simple linked list because there
4979 should not be more than a handful of assertions registered per
4980 name. If this becomes a performance problem, a table hashed by
4981 COMP_CODE and VAL could be implemented. */
4982 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
4986 if (loc
->comp_code
== comp_code
4988 || operand_equal_p (loc
->val
, val
, 0))
4989 && (loc
->expr
== expr
4990 || operand_equal_p (loc
->expr
, expr
, 0)))
4992 /* If E is not a critical edge and DEST_BB
4993 dominates the existing location for the assertion, move
4994 the assertion up in the dominance tree by updating its
4995 location information. */
4996 if ((e
== NULL
|| !EDGE_CRITICAL_P (e
))
4997 && dominated_by_p (CDI_DOMINATORS
, loc
->bb
, dest_bb
))
5006 /* Update the last node of the list and move to the next one. */
5011 /* If we didn't find an assertion already registered for
5012 NAME COMP_CODE VAL, add a new one at the end of the list of
5013 assertions associated with NAME. */
5014 n
= XNEW (struct assert_locus
);
5018 n
->comp_code
= comp_code
;
5026 asserts_for
[SSA_NAME_VERSION (name
)] = n
;
5028 bitmap_set_bit (need_assert_for
, SSA_NAME_VERSION (name
));
5031 /* (COND_OP0 COND_CODE COND_OP1) is a predicate which uses NAME.
5032 Extract a suitable test code and value and store them into *CODE_P and
5033 *VAL_P so the predicate is normalized to NAME *CODE_P *VAL_P.
5035 If no extraction was possible, return FALSE, otherwise return TRUE.
5037 If INVERT is true, then we invert the result stored into *CODE_P. */
5040 extract_code_and_val_from_cond_with_ops (tree name
, enum tree_code cond_code
,
5041 tree cond_op0
, tree cond_op1
,
5042 bool invert
, enum tree_code
*code_p
,
5045 enum tree_code comp_code
;
5048 /* Otherwise, we have a comparison of the form NAME COMP VAL
5049 or VAL COMP NAME. */
5050 if (name
== cond_op1
)
5052 /* If the predicate is of the form VAL COMP NAME, flip
5053 COMP around because we need to register NAME as the
5054 first operand in the predicate. */
5055 comp_code
= swap_tree_comparison (cond_code
);
5060 /* The comparison is of the form NAME COMP VAL, so the
5061 comparison code remains unchanged. */
5062 comp_code
= cond_code
;
5066 /* Invert the comparison code as necessary. */
5068 comp_code
= invert_tree_comparison (comp_code
, 0);
5070 /* VRP only handles integral and pointer types. */
5071 if (! INTEGRAL_TYPE_P (TREE_TYPE (val
))
5072 && ! POINTER_TYPE_P (TREE_TYPE (val
)))
5075 /* Do not register always-false predicates.
5076 FIXME: this works around a limitation in fold() when dealing with
5077 enumerations. Given 'enum { N1, N2 } x;', fold will not
5078 fold 'if (x > N2)' to 'if (0)'. */
5079 if ((comp_code
== GT_EXPR
|| comp_code
== LT_EXPR
)
5080 && INTEGRAL_TYPE_P (TREE_TYPE (val
)))
5082 tree min
= TYPE_MIN_VALUE (TREE_TYPE (val
));
5083 tree max
= TYPE_MAX_VALUE (TREE_TYPE (val
));
5085 if (comp_code
== GT_EXPR
5087 || compare_values (val
, max
) == 0))
5090 if (comp_code
== LT_EXPR
5092 || compare_values (val
, min
) == 0))
5095 *code_p
= comp_code
;
5100 /* Find out smallest RES where RES > VAL && (RES & MASK) == RES, if any
5101 (otherwise return VAL). VAL and MASK must be zero-extended for
5102 precision PREC. If SGNBIT is non-zero, first xor VAL with SGNBIT
5103 (to transform signed values into unsigned) and at the end xor
5107 masked_increment (const wide_int
&val_in
, const wide_int
&mask
,
5108 const wide_int
&sgnbit
, unsigned int prec
)
5110 wide_int bit
= wi::one (prec
), res
;
5113 wide_int val
= val_in
^ sgnbit
;
5114 for (i
= 0; i
< prec
; i
++, bit
+= bit
)
5117 if ((res
& bit
) == 0)
5120 res
= (val
+ bit
).and_not (res
);
5122 if (wi::gtu_p (res
, val
))
5123 return res
^ sgnbit
;
5125 return val
^ sgnbit
;
5128 /* Try to register an edge assertion for SSA name NAME on edge E for
5129 the condition COND contributing to the conditional jump pointed to by BSI.
5130 Invert the condition COND if INVERT is true. */
5133 register_edge_assert_for_2 (tree name
, edge e
, gimple_stmt_iterator bsi
,
5134 enum tree_code cond_code
,
5135 tree cond_op0
, tree cond_op1
, bool invert
)
5138 enum tree_code comp_code
;
5140 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
5143 invert
, &comp_code
, &val
))
5146 /* Only register an ASSERT_EXPR if NAME was found in the sub-graph
5147 reachable from E. */
5148 if (live_on_edge (e
, name
))
5149 register_new_assert_for (name
, name
, comp_code
, val
, NULL
, e
, bsi
);
5151 /* In the case of NAME <= CST and NAME being defined as
5152 NAME = (unsigned) NAME2 + CST2 we can assert NAME2 >= -CST2
5153 and NAME2 <= CST - CST2. We can do the same for NAME > CST.
5154 This catches range and anti-range tests. */
5155 if ((comp_code
== LE_EXPR
5156 || comp_code
== GT_EXPR
)
5157 && TREE_CODE (val
) == INTEGER_CST
5158 && TYPE_UNSIGNED (TREE_TYPE (val
)))
5160 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
5161 tree cst2
= NULL_TREE
, name2
= NULL_TREE
, name3
= NULL_TREE
;
5163 /* Extract CST2 from the (optional) addition. */
5164 if (is_gimple_assign (def_stmt
)
5165 && gimple_assign_rhs_code (def_stmt
) == PLUS_EXPR
)
5167 name2
= gimple_assign_rhs1 (def_stmt
);
5168 cst2
= gimple_assign_rhs2 (def_stmt
);
5169 if (TREE_CODE (name2
) == SSA_NAME
5170 && TREE_CODE (cst2
) == INTEGER_CST
)
5171 def_stmt
= SSA_NAME_DEF_STMT (name2
);
5174 /* Extract NAME2 from the (optional) sign-changing cast. */
5175 if (gimple_assign_cast_p (def_stmt
))
5177 if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
))
5178 && ! TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))
5179 && (TYPE_PRECISION (gimple_expr_type (def_stmt
))
5180 == TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))))
5181 name3
= gimple_assign_rhs1 (def_stmt
);
5184 /* If name3 is used later, create an ASSERT_EXPR for it. */
5185 if (name3
!= NULL_TREE
5186 && TREE_CODE (name3
) == SSA_NAME
5187 && (cst2
== NULL_TREE
5188 || TREE_CODE (cst2
) == INTEGER_CST
)
5189 && INTEGRAL_TYPE_P (TREE_TYPE (name3
))
5190 && live_on_edge (e
, name3
))
5194 /* Build an expression for the range test. */
5195 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), name3
);
5196 if (cst2
!= NULL_TREE
)
5197 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
5201 fprintf (dump_file
, "Adding assert for ");
5202 print_generic_expr (dump_file
, name3
, 0);
5203 fprintf (dump_file
, " from ");
5204 print_generic_expr (dump_file
, tmp
, 0);
5205 fprintf (dump_file
, "\n");
5208 register_new_assert_for (name3
, tmp
, comp_code
, val
, NULL
, e
, bsi
);
5211 /* If name2 is used later, create an ASSERT_EXPR for it. */
5212 if (name2
!= NULL_TREE
5213 && TREE_CODE (name2
) == SSA_NAME
5214 && TREE_CODE (cst2
) == INTEGER_CST
5215 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
5216 && live_on_edge (e
, name2
))
5220 /* Build an expression for the range test. */
5222 if (TREE_TYPE (name
) != TREE_TYPE (name2
))
5223 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), tmp
);
5224 if (cst2
!= NULL_TREE
)
5225 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
5229 fprintf (dump_file
, "Adding assert for ");
5230 print_generic_expr (dump_file
, name2
, 0);
5231 fprintf (dump_file
, " from ");
5232 print_generic_expr (dump_file
, tmp
, 0);
5233 fprintf (dump_file
, "\n");
5236 register_new_assert_for (name2
, tmp
, comp_code
, val
, NULL
, e
, bsi
);
5240 /* In the case of post-in/decrement tests like if (i++) ... and uses
5241 of the in/decremented value on the edge the extra name we want to
5242 assert for is not on the def chain of the name compared. Instead
5243 it is in the set of use stmts.
5244 Similar cases happen for conversions that were simplified through
5245 fold_{sign_changed,widened}_comparison. */
5246 if ((comp_code
== NE_EXPR
5247 || comp_code
== EQ_EXPR
)
5248 && TREE_CODE (val
) == INTEGER_CST
)
5250 imm_use_iterator ui
;
5252 FOR_EACH_IMM_USE_STMT (use_stmt
, ui
, name
)
5254 if (!is_gimple_assign (use_stmt
))
5257 /* Cut off to use-stmts that are dominating the predecessor. */
5258 if (!dominated_by_p (CDI_DOMINATORS
, e
->src
, gimple_bb (use_stmt
)))
5261 tree name2
= gimple_assign_lhs (use_stmt
);
5262 if (TREE_CODE (name2
) != SSA_NAME
5263 || !live_on_edge (e
, name2
))
5266 enum tree_code code
= gimple_assign_rhs_code (use_stmt
);
5268 if (code
== PLUS_EXPR
5269 || code
== MINUS_EXPR
)
5271 cst
= gimple_assign_rhs2 (use_stmt
);
5272 if (TREE_CODE (cst
) != INTEGER_CST
)
5274 cst
= int_const_binop (code
, val
, cst
);
5276 else if (CONVERT_EXPR_CODE_P (code
))
5278 /* For truncating conversions we cannot record
5280 if (comp_code
== NE_EXPR
5281 && (TYPE_PRECISION (TREE_TYPE (name2
))
5282 < TYPE_PRECISION (TREE_TYPE (name
))))
5284 cst
= fold_convert (TREE_TYPE (name2
), val
);
5289 if (TREE_OVERFLOW_P (cst
))
5290 cst
= drop_tree_overflow (cst
);
5291 register_new_assert_for (name2
, name2
, comp_code
, cst
,
5296 if (TREE_CODE_CLASS (comp_code
) == tcc_comparison
5297 && TREE_CODE (val
) == INTEGER_CST
)
5299 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
5300 tree name2
= NULL_TREE
, names
[2], cst2
= NULL_TREE
;
5301 tree val2
= NULL_TREE
;
5302 unsigned int prec
= TYPE_PRECISION (TREE_TYPE (val
));
5303 wide_int mask
= wi::zero (prec
);
5304 unsigned int nprec
= prec
;
5305 enum tree_code rhs_code
= ERROR_MARK
;
5307 if (is_gimple_assign (def_stmt
))
5308 rhs_code
= gimple_assign_rhs_code (def_stmt
);
5310 /* In the case of NAME != CST1 where NAME = A +- CST2 we can
5311 assert that A != CST1 -+ CST2. */
5312 if ((comp_code
== EQ_EXPR
|| comp_code
== NE_EXPR
)
5313 && (rhs_code
== PLUS_EXPR
|| rhs_code
== MINUS_EXPR
))
5315 tree op0
= gimple_assign_rhs1 (def_stmt
);
5316 tree op1
= gimple_assign_rhs2 (def_stmt
);
5317 if (TREE_CODE (op0
) == SSA_NAME
5318 && TREE_CODE (op1
) == INTEGER_CST
5319 && live_on_edge (e
, op0
))
5321 enum tree_code reverse_op
= (rhs_code
== PLUS_EXPR
5322 ? MINUS_EXPR
: PLUS_EXPR
);
5323 op1
= int_const_binop (reverse_op
, val
, op1
);
5324 if (TREE_OVERFLOW (op1
))
5325 op1
= drop_tree_overflow (op1
);
5326 register_new_assert_for (op0
, op0
, comp_code
, op1
, NULL
, e
, bsi
);
5330 /* Add asserts for NAME cmp CST and NAME being defined
5331 as NAME = (int) NAME2. */
5332 if (!TYPE_UNSIGNED (TREE_TYPE (val
))
5333 && (comp_code
== LE_EXPR
|| comp_code
== LT_EXPR
5334 || comp_code
== GT_EXPR
|| comp_code
== GE_EXPR
)
5335 && gimple_assign_cast_p (def_stmt
))
5337 name2
= gimple_assign_rhs1 (def_stmt
);
5338 if (CONVERT_EXPR_CODE_P (rhs_code
)
5339 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
5340 && TYPE_UNSIGNED (TREE_TYPE (name2
))
5341 && prec
== TYPE_PRECISION (TREE_TYPE (name2
))
5342 && (comp_code
== LE_EXPR
|| comp_code
== GT_EXPR
5343 || !tree_int_cst_equal (val
,
5344 TYPE_MIN_VALUE (TREE_TYPE (val
))))
5345 && live_on_edge (e
, name2
))
5348 enum tree_code new_comp_code
= comp_code
;
5350 cst
= fold_convert (TREE_TYPE (name2
),
5351 TYPE_MIN_VALUE (TREE_TYPE (val
)));
5352 /* Build an expression for the range test. */
5353 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name2
), name2
, cst
);
5354 cst
= fold_build2 (PLUS_EXPR
, TREE_TYPE (name2
), cst
,
5355 fold_convert (TREE_TYPE (name2
), val
));
5356 if (comp_code
== LT_EXPR
|| comp_code
== GE_EXPR
)
5358 new_comp_code
= comp_code
== LT_EXPR
? LE_EXPR
: GT_EXPR
;
5359 cst
= fold_build2 (MINUS_EXPR
, TREE_TYPE (name2
), cst
,
5360 build_int_cst (TREE_TYPE (name2
), 1));
5365 fprintf (dump_file
, "Adding assert for ");
5366 print_generic_expr (dump_file
, name2
, 0);
5367 fprintf (dump_file
, " from ");
5368 print_generic_expr (dump_file
, tmp
, 0);
5369 fprintf (dump_file
, "\n");
5372 register_new_assert_for (name2
, tmp
, new_comp_code
, cst
, NULL
,
5377 /* Add asserts for NAME cmp CST and NAME being defined as
5378 NAME = NAME2 >> CST2.
5380 Extract CST2 from the right shift. */
5381 if (rhs_code
== RSHIFT_EXPR
)
5383 name2
= gimple_assign_rhs1 (def_stmt
);
5384 cst2
= gimple_assign_rhs2 (def_stmt
);
5385 if (TREE_CODE (name2
) == SSA_NAME
5386 && tree_fits_uhwi_p (cst2
)
5387 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
5388 && IN_RANGE (tree_to_uhwi (cst2
), 1, prec
- 1)
5389 && prec
== GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (val
)))
5390 && live_on_edge (e
, name2
))
5392 mask
= wi::mask (tree_to_uhwi (cst2
), false, prec
);
5393 val2
= fold_binary (LSHIFT_EXPR
, TREE_TYPE (val
), val
, cst2
);
5396 if (val2
!= NULL_TREE
5397 && TREE_CODE (val2
) == INTEGER_CST
5398 && simple_cst_equal (fold_build2 (RSHIFT_EXPR
,
5402 enum tree_code new_comp_code
= comp_code
;
5406 if (comp_code
== EQ_EXPR
|| comp_code
== NE_EXPR
)
5408 if (!TYPE_UNSIGNED (TREE_TYPE (val
)))
5410 tree type
= build_nonstandard_integer_type (prec
, 1);
5411 tmp
= build1 (NOP_EXPR
, type
, name2
);
5412 val2
= fold_convert (type
, val2
);
5414 tmp
= fold_build2 (MINUS_EXPR
, TREE_TYPE (tmp
), tmp
, val2
);
5415 new_val
= wide_int_to_tree (TREE_TYPE (tmp
), mask
);
5416 new_comp_code
= comp_code
== EQ_EXPR
? LE_EXPR
: GT_EXPR
;
5418 else if (comp_code
== LT_EXPR
|| comp_code
== GE_EXPR
)
5421 = wi::min_value (prec
, TYPE_SIGN (TREE_TYPE (val
)));
5423 if (minval
== new_val
)
5424 new_val
= NULL_TREE
;
5429 = wi::max_value (prec
, TYPE_SIGN (TREE_TYPE (val
)));
5432 new_val
= NULL_TREE
;
5434 new_val
= wide_int_to_tree (TREE_TYPE (val2
), mask
);
5441 fprintf (dump_file
, "Adding assert for ");
5442 print_generic_expr (dump_file
, name2
, 0);
5443 fprintf (dump_file
, " from ");
5444 print_generic_expr (dump_file
, tmp
, 0);
5445 fprintf (dump_file
, "\n");
5448 register_new_assert_for (name2
, tmp
, new_comp_code
, new_val
,
5453 /* Add asserts for NAME cmp CST and NAME being defined as
5454 NAME = NAME2 & CST2.
5456 Extract CST2 from the and.
5459 NAME = (unsigned) NAME2;
5460 casts where NAME's type is unsigned and has smaller precision
5461 than NAME2's type as if it was NAME = NAME2 & MASK. */
5462 names
[0] = NULL_TREE
;
5463 names
[1] = NULL_TREE
;
5465 if (rhs_code
== BIT_AND_EXPR
5466 || (CONVERT_EXPR_CODE_P (rhs_code
)
5467 && INTEGRAL_TYPE_P (TREE_TYPE (val
))
5468 && TYPE_UNSIGNED (TREE_TYPE (val
))
5469 && TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))
5472 name2
= gimple_assign_rhs1 (def_stmt
);
5473 if (rhs_code
== BIT_AND_EXPR
)
5474 cst2
= gimple_assign_rhs2 (def_stmt
);
5477 cst2
= TYPE_MAX_VALUE (TREE_TYPE (val
));
5478 nprec
= TYPE_PRECISION (TREE_TYPE (name2
));
5480 if (TREE_CODE (name2
) == SSA_NAME
5481 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
5482 && TREE_CODE (cst2
) == INTEGER_CST
5483 && !integer_zerop (cst2
)
5485 || TYPE_UNSIGNED (TREE_TYPE (val
))))
5487 gimple
*def_stmt2
= SSA_NAME_DEF_STMT (name2
);
5488 if (gimple_assign_cast_p (def_stmt2
))
5490 names
[1] = gimple_assign_rhs1 (def_stmt2
);
5491 if (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt2
))
5492 || !INTEGRAL_TYPE_P (TREE_TYPE (names
[1]))
5493 || (TYPE_PRECISION (TREE_TYPE (name2
))
5494 != TYPE_PRECISION (TREE_TYPE (names
[1])))
5495 || !live_on_edge (e
, names
[1]))
5496 names
[1] = NULL_TREE
;
5498 if (live_on_edge (e
, name2
))
5502 if (names
[0] || names
[1])
5504 wide_int minv
, maxv
, valv
, cst2v
;
5505 wide_int tem
, sgnbit
;
5506 bool valid_p
= false, valn
, cst2n
;
5507 enum tree_code ccode
= comp_code
;
5509 valv
= wide_int::from (val
, nprec
, UNSIGNED
);
5510 cst2v
= wide_int::from (cst2
, nprec
, UNSIGNED
);
5511 valn
= wi::neg_p (valv
, TYPE_SIGN (TREE_TYPE (val
)));
5512 cst2n
= wi::neg_p (cst2v
, TYPE_SIGN (TREE_TYPE (val
)));
5513 /* If CST2 doesn't have most significant bit set,
5514 but VAL is negative, we have comparison like
5515 if ((x & 0x123) > -4) (always true). Just give up. */
5519 sgnbit
= wi::set_bit_in_zero (nprec
- 1, nprec
);
5521 sgnbit
= wi::zero (nprec
);
5522 minv
= valv
& cst2v
;
5526 /* Minimum unsigned value for equality is VAL & CST2
5527 (should be equal to VAL, otherwise we probably should
5528 have folded the comparison into false) and
5529 maximum unsigned value is VAL | ~CST2. */
5530 maxv
= valv
| ~cst2v
;
5535 tem
= valv
| ~cst2v
;
5536 /* If VAL is 0, handle (X & CST2) != 0 as (X & CST2) > 0U. */
5540 sgnbit
= wi::zero (nprec
);
5543 /* If (VAL | ~CST2) is all ones, handle it as
5544 (X & CST2) < VAL. */
5549 sgnbit
= wi::zero (nprec
);
5552 if (!cst2n
&& wi::neg_p (cst2v
))
5553 sgnbit
= wi::set_bit_in_zero (nprec
- 1, nprec
);
5562 if (tem
== wi::mask (nprec
- 1, false, nprec
))
5568 sgnbit
= wi::zero (nprec
);
5573 /* Minimum unsigned value for >= if (VAL & CST2) == VAL
5574 is VAL and maximum unsigned value is ~0. For signed
5575 comparison, if CST2 doesn't have most significant bit
5576 set, handle it similarly. If CST2 has MSB set,
5577 the minimum is the same, and maximum is ~0U/2. */
5580 /* If (VAL & CST2) != VAL, X & CST2 can't be equal to
5582 minv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
5586 maxv
= wi::mask (nprec
- (cst2n
? 1 : 0), false, nprec
);
5592 /* Find out smallest MINV where MINV > VAL
5593 && (MINV & CST2) == MINV, if any. If VAL is signed and
5594 CST2 has MSB set, compute it biased by 1 << (nprec - 1). */
5595 minv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
5598 maxv
= wi::mask (nprec
- (cst2n
? 1 : 0), false, nprec
);
5603 /* Minimum unsigned value for <= is 0 and maximum
5604 unsigned value is VAL | ~CST2 if (VAL & CST2) == VAL.
5605 Otherwise, find smallest VAL2 where VAL2 > VAL
5606 && (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2
5608 For signed comparison, if CST2 doesn't have most
5609 significant bit set, handle it similarly. If CST2 has
5610 MSB set, the maximum is the same and minimum is INT_MIN. */
5615 maxv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
5627 /* Minimum unsigned value for < is 0 and maximum
5628 unsigned value is (VAL-1) | ~CST2 if (VAL & CST2) == VAL.
5629 Otherwise, find smallest VAL2 where VAL2 > VAL
5630 && (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2
5632 For signed comparison, if CST2 doesn't have most
5633 significant bit set, handle it similarly. If CST2 has
5634 MSB set, the maximum is the same and minimum is INT_MIN. */
5643 maxv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
5657 && (maxv
- minv
) != -1)
5659 tree tmp
, new_val
, type
;
5662 for (i
= 0; i
< 2; i
++)
5665 wide_int maxv2
= maxv
;
5667 type
= TREE_TYPE (names
[i
]);
5668 if (!TYPE_UNSIGNED (type
))
5670 type
= build_nonstandard_integer_type (nprec
, 1);
5671 tmp
= build1 (NOP_EXPR
, type
, names
[i
]);
5675 tmp
= build2 (PLUS_EXPR
, type
, tmp
,
5676 wide_int_to_tree (type
, -minv
));
5677 maxv2
= maxv
- minv
;
5679 new_val
= wide_int_to_tree (type
, maxv2
);
5683 fprintf (dump_file
, "Adding assert for ");
5684 print_generic_expr (dump_file
, names
[i
], 0);
5685 fprintf (dump_file
, " from ");
5686 print_generic_expr (dump_file
, tmp
, 0);
5687 fprintf (dump_file
, "\n");
5690 register_new_assert_for (names
[i
], tmp
, LE_EXPR
,
5691 new_val
, NULL
, e
, bsi
);
5698 /* OP is an operand of a truth value expression which is known to have
5699 a particular value. Register any asserts for OP and for any
5700 operands in OP's defining statement.
5702 If CODE is EQ_EXPR, then we want to register OP is zero (false),
5703 if CODE is NE_EXPR, then we want to register OP is nonzero (true). */
5706 register_edge_assert_for_1 (tree op
, enum tree_code code
,
5707 edge e
, gimple_stmt_iterator bsi
)
5711 enum tree_code rhs_code
;
5713 /* We only care about SSA_NAMEs. */
5714 if (TREE_CODE (op
) != SSA_NAME
)
5717 /* We know that OP will have a zero or nonzero value. If OP is used
5718 more than once go ahead and register an assert for OP. */
5719 if (live_on_edge (e
, op
))
5721 val
= build_int_cst (TREE_TYPE (op
), 0);
5722 register_new_assert_for (op
, op
, code
, val
, NULL
, e
, bsi
);
5725 /* Now look at how OP is set. If it's set from a comparison,
5726 a truth operation or some bit operations, then we may be able
5727 to register information about the operands of that assignment. */
5728 op_def
= SSA_NAME_DEF_STMT (op
);
5729 if (gimple_code (op_def
) != GIMPLE_ASSIGN
)
5732 rhs_code
= gimple_assign_rhs_code (op_def
);
5734 if (TREE_CODE_CLASS (rhs_code
) == tcc_comparison
)
5736 bool invert
= (code
== EQ_EXPR
? true : false);
5737 tree op0
= gimple_assign_rhs1 (op_def
);
5738 tree op1
= gimple_assign_rhs2 (op_def
);
5740 if (TREE_CODE (op0
) == SSA_NAME
)
5741 register_edge_assert_for_2 (op0
, e
, bsi
, rhs_code
, op0
, op1
, invert
);
5742 if (TREE_CODE (op1
) == SSA_NAME
)
5743 register_edge_assert_for_2 (op1
, e
, bsi
, rhs_code
, op0
, op1
, invert
);
5745 else if ((code
== NE_EXPR
5746 && gimple_assign_rhs_code (op_def
) == BIT_AND_EXPR
)
5748 && gimple_assign_rhs_code (op_def
) == BIT_IOR_EXPR
))
5750 /* Recurse on each operand. */
5751 tree op0
= gimple_assign_rhs1 (op_def
);
5752 tree op1
= gimple_assign_rhs2 (op_def
);
5753 if (TREE_CODE (op0
) == SSA_NAME
5754 && has_single_use (op0
))
5755 register_edge_assert_for_1 (op0
, code
, e
, bsi
);
5756 if (TREE_CODE (op1
) == SSA_NAME
5757 && has_single_use (op1
))
5758 register_edge_assert_for_1 (op1
, code
, e
, bsi
);
5760 else if (gimple_assign_rhs_code (op_def
) == BIT_NOT_EXPR
5761 && TYPE_PRECISION (TREE_TYPE (gimple_assign_lhs (op_def
))) == 1)
5763 /* Recurse, flipping CODE. */
5764 code
= invert_tree_comparison (code
, false);
5765 register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
), code
, e
, bsi
);
5767 else if (gimple_assign_rhs_code (op_def
) == SSA_NAME
)
5769 /* Recurse through the copy. */
5770 register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
), code
, e
, bsi
);
5772 else if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (op_def
)))
5774 /* Recurse through the type conversion, unless it is a narrowing
5775 conversion or conversion from non-integral type. */
5776 tree rhs
= gimple_assign_rhs1 (op_def
);
5777 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs
))
5778 && (TYPE_PRECISION (TREE_TYPE (rhs
))
5779 <= TYPE_PRECISION (TREE_TYPE (op
))))
5780 register_edge_assert_for_1 (rhs
, code
, e
, bsi
);
5784 /* Try to register an edge assertion for SSA name NAME on edge E for
5785 the condition COND contributing to the conditional jump pointed to by
5789 register_edge_assert_for (tree name
, edge e
, gimple_stmt_iterator si
,
5790 enum tree_code cond_code
, tree cond_op0
,
5794 enum tree_code comp_code
;
5795 bool is_else_edge
= (e
->flags
& EDGE_FALSE_VALUE
) != 0;
5797 /* Do not attempt to infer anything in names that flow through
5799 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name
))
5802 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
5808 /* Register ASSERT_EXPRs for name. */
5809 register_edge_assert_for_2 (name
, e
, si
, cond_code
, cond_op0
,
5810 cond_op1
, is_else_edge
);
5813 /* If COND is effectively an equality test of an SSA_NAME against
5814 the value zero or one, then we may be able to assert values
5815 for SSA_NAMEs which flow into COND. */
5817 /* In the case of NAME == 1 or NAME != 0, for BIT_AND_EXPR defining
5818 statement of NAME we can assert both operands of the BIT_AND_EXPR
5819 have nonzero value. */
5820 if (((comp_code
== EQ_EXPR
&& integer_onep (val
))
5821 || (comp_code
== NE_EXPR
&& integer_zerop (val
))))
5823 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
5825 if (is_gimple_assign (def_stmt
)
5826 && gimple_assign_rhs_code (def_stmt
) == BIT_AND_EXPR
)
5828 tree op0
= gimple_assign_rhs1 (def_stmt
);
5829 tree op1
= gimple_assign_rhs2 (def_stmt
);
5830 register_edge_assert_for_1 (op0
, NE_EXPR
, e
, si
);
5831 register_edge_assert_for_1 (op1
, NE_EXPR
, e
, si
);
5835 /* In the case of NAME == 0 or NAME != 1, for BIT_IOR_EXPR defining
5836 statement of NAME we can assert both operands of the BIT_IOR_EXPR
5838 if (((comp_code
== EQ_EXPR
&& integer_zerop (val
))
5839 || (comp_code
== NE_EXPR
&& integer_onep (val
))))
5841 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
5843 /* For BIT_IOR_EXPR only if NAME == 0 both operands have
5844 necessarily zero value, or if type-precision is one. */
5845 if (is_gimple_assign (def_stmt
)
5846 && (gimple_assign_rhs_code (def_stmt
) == BIT_IOR_EXPR
5847 && (TYPE_PRECISION (TREE_TYPE (name
)) == 1
5848 || comp_code
== EQ_EXPR
)))
5850 tree op0
= gimple_assign_rhs1 (def_stmt
);
5851 tree op1
= gimple_assign_rhs2 (def_stmt
);
5852 register_edge_assert_for_1 (op0
, EQ_EXPR
, e
, si
);
5853 register_edge_assert_for_1 (op1
, EQ_EXPR
, e
, si
);
5859 /* Determine whether the outgoing edges of BB should receive an
5860 ASSERT_EXPR for each of the operands of BB's LAST statement.
5861 The last statement of BB must be a COND_EXPR.
5863 If any of the sub-graphs rooted at BB have an interesting use of
5864 the predicate operands, an assert location node is added to the
5865 list of assertions for the corresponding operands. */
5868 find_conditional_asserts (basic_block bb
, gcond
*last
)
5870 gimple_stmt_iterator bsi
;
5876 bsi
= gsi_for_stmt (last
);
5878 /* Look for uses of the operands in each of the sub-graphs
5879 rooted at BB. We need to check each of the outgoing edges
5880 separately, so that we know what kind of ASSERT_EXPR to
5882 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5887 /* Register the necessary assertions for each operand in the
5888 conditional predicate. */
5889 FOR_EACH_SSA_TREE_OPERAND (op
, last
, iter
, SSA_OP_USE
)
5890 register_edge_assert_for (op
, e
, bsi
,
5891 gimple_cond_code (last
),
5892 gimple_cond_lhs (last
),
5893 gimple_cond_rhs (last
));
5903 /* Compare two case labels sorting first by the destination bb index
5904 and then by the case value. */
5907 compare_case_labels (const void *p1
, const void *p2
)
5909 const struct case_info
*ci1
= (const struct case_info
*) p1
;
5910 const struct case_info
*ci2
= (const struct case_info
*) p2
;
5911 int idx1
= ci1
->bb
->index
;
5912 int idx2
= ci2
->bb
->index
;
5916 else if (idx1
== idx2
)
5918 /* Make sure the default label is first in a group. */
5919 if (!CASE_LOW (ci1
->expr
))
5921 else if (!CASE_LOW (ci2
->expr
))
5924 return tree_int_cst_compare (CASE_LOW (ci1
->expr
),
5925 CASE_LOW (ci2
->expr
));
5931 /* Determine whether the outgoing edges of BB should receive an
5932 ASSERT_EXPR for each of the operands of BB's LAST statement.
5933 The last statement of BB must be a SWITCH_EXPR.
5935 If any of the sub-graphs rooted at BB have an interesting use of
5936 the predicate operands, an assert location node is added to the
5937 list of assertions for the corresponding operands. */
5940 find_switch_asserts (basic_block bb
, gswitch
*last
)
5942 gimple_stmt_iterator bsi
;
5945 struct case_info
*ci
;
5946 size_t n
= gimple_switch_num_labels (last
);
5947 #if GCC_VERSION >= 4000
5950 /* Work around GCC 3.4 bug (PR 37086). */
5951 volatile unsigned int idx
;
5954 bsi
= gsi_for_stmt (last
);
5955 op
= gimple_switch_index (last
);
5956 if (TREE_CODE (op
) != SSA_NAME
)
5959 /* Build a vector of case labels sorted by destination label. */
5960 ci
= XNEWVEC (struct case_info
, n
);
5961 for (idx
= 0; idx
< n
; ++idx
)
5963 ci
[idx
].expr
= gimple_switch_label (last
, idx
);
5964 ci
[idx
].bb
= label_to_block (CASE_LABEL (ci
[idx
].expr
));
5966 qsort (ci
, n
, sizeof (struct case_info
), compare_case_labels
);
5968 for (idx
= 0; idx
< n
; ++idx
)
5971 tree cl
= ci
[idx
].expr
;
5972 basic_block cbb
= ci
[idx
].bb
;
5974 min
= CASE_LOW (cl
);
5975 max
= CASE_HIGH (cl
);
5977 /* If there are multiple case labels with the same destination
5978 we need to combine them to a single value range for the edge. */
5979 if (idx
+ 1 < n
&& cbb
== ci
[idx
+ 1].bb
)
5981 /* Skip labels until the last of the group. */
5984 } while (idx
< n
&& cbb
== ci
[idx
].bb
);
5987 /* Pick up the maximum of the case label range. */
5988 if (CASE_HIGH (ci
[idx
].expr
))
5989 max
= CASE_HIGH (ci
[idx
].expr
);
5991 max
= CASE_LOW (ci
[idx
].expr
);
5994 /* Nothing to do if the range includes the default label until we
5995 can register anti-ranges. */
5996 if (min
== NULL_TREE
)
5999 /* Find the edge to register the assert expr on. */
6000 e
= find_edge (bb
, cbb
);
6002 /* Register the necessary assertions for the operand in the
6004 register_edge_assert_for (op
, e
, bsi
,
6005 max
? GE_EXPR
: EQ_EXPR
,
6006 op
, fold_convert (TREE_TYPE (op
), min
));
6008 register_edge_assert_for (op
, e
, bsi
, LE_EXPR
, op
,
6009 fold_convert (TREE_TYPE (op
), max
));
6016 /* Traverse all the statements in block BB looking for statements that
6017 may generate useful assertions for the SSA names in their operand.
6018 If a statement produces a useful assertion A for name N_i, then the
6019 list of assertions already generated for N_i is scanned to
6020 determine if A is actually needed.
6022 If N_i already had the assertion A at a location dominating the
6023 current location, then nothing needs to be done. Otherwise, the
6024 new location for A is recorded instead.
6026 1- For every statement S in BB, all the variables used by S are
6027 added to bitmap FOUND_IN_SUBGRAPH.
6029 2- If statement S uses an operand N in a way that exposes a known
6030 value range for N, then if N was not already generated by an
6031 ASSERT_EXPR, create a new assert location for N. For instance,
6032 if N is a pointer and the statement dereferences it, we can
6033 assume that N is not NULL.
6035 3- COND_EXPRs are a special case of #2. We can derive range
6036 information from the predicate but need to insert different
6037 ASSERT_EXPRs for each of the sub-graphs rooted at the
6038 conditional block. If the last statement of BB is a conditional
6039 expression of the form 'X op Y', then
6041 a) Remove X and Y from the set FOUND_IN_SUBGRAPH.
6043 b) If the conditional is the only entry point to the sub-graph
6044 corresponding to the THEN_CLAUSE, recurse into it. On
6045 return, if X and/or Y are marked in FOUND_IN_SUBGRAPH, then
6046 an ASSERT_EXPR is added for the corresponding variable.
6048 c) Repeat step (b) on the ELSE_CLAUSE.
6050 d) Mark X and Y in FOUND_IN_SUBGRAPH.
6059 In this case, an assertion on the THEN clause is useful to
6060 determine that 'a' is always 9 on that edge. However, an assertion
6061 on the ELSE clause would be unnecessary.
6063 4- If BB does not end in a conditional expression, then we recurse
6064 into BB's dominator children.
6066 At the end of the recursive traversal, every SSA name will have a
6067 list of locations where ASSERT_EXPRs should be added. When a new
6068 location for name N is found, it is registered by calling
6069 register_new_assert_for. That function keeps track of all the
6070 registered assertions to prevent adding unnecessary assertions.
6071 For instance, if a pointer P_4 is dereferenced more than once in a
6072 dominator tree, only the location dominating all the dereference of
6073 P_4 will receive an ASSERT_EXPR. */
6076 find_assert_locations_1 (basic_block bb
, sbitmap live
)
6080 last
= last_stmt (bb
);
6082 /* If BB's last statement is a conditional statement involving integer
6083 operands, determine if we need to add ASSERT_EXPRs. */
6085 && gimple_code (last
) == GIMPLE_COND
6086 && !fp_predicate (last
)
6087 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
6088 find_conditional_asserts (bb
, as_a
<gcond
*> (last
));
6090 /* If BB's last statement is a switch statement involving integer
6091 operands, determine if we need to add ASSERT_EXPRs. */
6093 && gimple_code (last
) == GIMPLE_SWITCH
6094 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
6095 find_switch_asserts (bb
, as_a
<gswitch
*> (last
));
6097 /* Traverse all the statements in BB marking used names and looking
6098 for statements that may infer assertions for their used operands. */
6099 for (gimple_stmt_iterator si
= gsi_last_bb (bb
); !gsi_end_p (si
);
6106 stmt
= gsi_stmt (si
);
6108 if (is_gimple_debug (stmt
))
6111 /* See if we can derive an assertion for any of STMT's operands. */
6112 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_USE
)
6115 enum tree_code comp_code
;
6117 /* If op is not live beyond this stmt, do not bother to insert
6119 if (!bitmap_bit_p (live
, SSA_NAME_VERSION (op
)))
6122 /* If OP is used in such a way that we can infer a value
6123 range for it, and we don't find a previous assertion for
6124 it, create a new assertion location node for OP. */
6125 if (infer_value_range (stmt
, op
, &comp_code
, &value
))
6127 /* If we are able to infer a nonzero value range for OP,
6128 then walk backwards through the use-def chain to see if OP
6129 was set via a typecast.
6131 If so, then we can also infer a nonzero value range
6132 for the operand of the NOP_EXPR. */
6133 if (comp_code
== NE_EXPR
&& integer_zerop (value
))
6136 gimple
*def_stmt
= SSA_NAME_DEF_STMT (t
);
6138 while (is_gimple_assign (def_stmt
)
6139 && CONVERT_EXPR_CODE_P
6140 (gimple_assign_rhs_code (def_stmt
))
6142 (gimple_assign_rhs1 (def_stmt
)) == SSA_NAME
6144 (TREE_TYPE (gimple_assign_rhs1 (def_stmt
))))
6146 t
= gimple_assign_rhs1 (def_stmt
);
6147 def_stmt
= SSA_NAME_DEF_STMT (t
);
6149 /* Note we want to register the assert for the
6150 operand of the NOP_EXPR after SI, not after the
6152 if (bitmap_bit_p (live
, SSA_NAME_VERSION (t
)))
6153 register_new_assert_for (t
, t
, comp_code
, value
,
6158 register_new_assert_for (op
, op
, comp_code
, value
, bb
, NULL
, si
);
6163 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_USE
)
6164 bitmap_set_bit (live
, SSA_NAME_VERSION (op
));
6165 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_DEF
)
6166 bitmap_clear_bit (live
, SSA_NAME_VERSION (op
));
6169 /* Traverse all PHI nodes in BB, updating live. */
6170 for (gphi_iterator si
= gsi_start_phis (bb
); !gsi_end_p (si
);
6173 use_operand_p arg_p
;
6175 gphi
*phi
= si
.phi ();
6176 tree res
= gimple_phi_result (phi
);
6178 if (virtual_operand_p (res
))
6181 FOR_EACH_PHI_ARG (arg_p
, phi
, i
, SSA_OP_USE
)
6183 tree arg
= USE_FROM_PTR (arg_p
);
6184 if (TREE_CODE (arg
) == SSA_NAME
)
6185 bitmap_set_bit (live
, SSA_NAME_VERSION (arg
));
6188 bitmap_clear_bit (live
, SSA_NAME_VERSION (res
));
6192 /* Do an RPO walk over the function computing SSA name liveness
6193 on-the-fly and deciding on assert expressions to insert. */
6196 find_assert_locations (void)
6198 int *rpo
= XNEWVEC (int, last_basic_block_for_fn (cfun
));
6199 int *bb_rpo
= XNEWVEC (int, last_basic_block_for_fn (cfun
));
6200 int *last_rpo
= XCNEWVEC (int, last_basic_block_for_fn (cfun
));
6203 live
= XCNEWVEC (sbitmap
, last_basic_block_for_fn (cfun
));
6204 rpo_cnt
= pre_and_rev_post_order_compute (NULL
, rpo
, false);
6205 for (i
= 0; i
< rpo_cnt
; ++i
)
6208 /* Pre-seed loop latch liveness from loop header PHI nodes. Due to
6209 the order we compute liveness and insert asserts we otherwise
6210 fail to insert asserts into the loop latch. */
6212 FOR_EACH_LOOP (loop
, 0)
6214 i
= loop
->latch
->index
;
6215 unsigned int j
= single_succ_edge (loop
->latch
)->dest_idx
;
6216 for (gphi_iterator gsi
= gsi_start_phis (loop
->header
);
6217 !gsi_end_p (gsi
); gsi_next (&gsi
))
6219 gphi
*phi
= gsi
.phi ();
6220 if (virtual_operand_p (gimple_phi_result (phi
)))
6222 tree arg
= gimple_phi_arg_def (phi
, j
);
6223 if (TREE_CODE (arg
) == SSA_NAME
)
6225 if (live
[i
] == NULL
)
6227 live
[i
] = sbitmap_alloc (num_ssa_names
);
6228 bitmap_clear (live
[i
]);
6230 bitmap_set_bit (live
[i
], SSA_NAME_VERSION (arg
));
6235 for (i
= rpo_cnt
- 1; i
>= 0; --i
)
6237 basic_block bb
= BASIC_BLOCK_FOR_FN (cfun
, rpo
[i
]);
6243 live
[rpo
[i
]] = sbitmap_alloc (num_ssa_names
);
6244 bitmap_clear (live
[rpo
[i
]]);
6247 /* Process BB and update the live information with uses in
6249 find_assert_locations_1 (bb
, live
[rpo
[i
]]);
6251 /* Merge liveness into the predecessor blocks and free it. */
6252 if (!bitmap_empty_p (live
[rpo
[i
]]))
6255 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
6257 int pred
= e
->src
->index
;
6258 if ((e
->flags
& EDGE_DFS_BACK
) || pred
== ENTRY_BLOCK
)
6263 live
[pred
] = sbitmap_alloc (num_ssa_names
);
6264 bitmap_clear (live
[pred
]);
6266 bitmap_ior (live
[pred
], live
[pred
], live
[rpo
[i
]]);
6268 if (bb_rpo
[pred
] < pred_rpo
)
6269 pred_rpo
= bb_rpo
[pred
];
6272 /* Record the RPO number of the last visited block that needs
6273 live information from this block. */
6274 last_rpo
[rpo
[i
]] = pred_rpo
;
6278 sbitmap_free (live
[rpo
[i
]]);
6279 live
[rpo
[i
]] = NULL
;
6282 /* We can free all successors live bitmaps if all their
6283 predecessors have been visited already. */
6284 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
6285 if (last_rpo
[e
->dest
->index
] == i
6286 && live
[e
->dest
->index
])
6288 sbitmap_free (live
[e
->dest
->index
]);
6289 live
[e
->dest
->index
] = NULL
;
6294 XDELETEVEC (bb_rpo
);
6295 XDELETEVEC (last_rpo
);
6296 for (i
= 0; i
< last_basic_block_for_fn (cfun
); ++i
)
6298 sbitmap_free (live
[i
]);
6302 /* Create an ASSERT_EXPR for NAME and insert it in the location
6303 indicated by LOC. Return true if we made any edge insertions. */
6306 process_assert_insertions_for (tree name
, assert_locus
*loc
)
6308 /* Build the comparison expression NAME_i COMP_CODE VAL. */
6311 gimple
*assert_stmt
;
6315 /* If we have X <=> X do not insert an assert expr for that. */
6316 if (loc
->expr
== loc
->val
)
6319 cond
= build2 (loc
->comp_code
, boolean_type_node
, loc
->expr
, loc
->val
);
6320 assert_stmt
= build_assert_expr_for (cond
, name
);
6323 /* We have been asked to insert the assertion on an edge. This
6324 is used only by COND_EXPR and SWITCH_EXPR assertions. */
6325 gcc_checking_assert (gimple_code (gsi_stmt (loc
->si
)) == GIMPLE_COND
6326 || (gimple_code (gsi_stmt (loc
->si
))
6329 gsi_insert_on_edge (loc
->e
, assert_stmt
);
6333 /* Otherwise, we can insert right after LOC->SI iff the
6334 statement must not be the last statement in the block. */
6335 stmt
= gsi_stmt (loc
->si
);
6336 if (!stmt_ends_bb_p (stmt
))
6338 gsi_insert_after (&loc
->si
, assert_stmt
, GSI_SAME_STMT
);
6342 /* If STMT must be the last statement in BB, we can only insert new
6343 assertions on the non-abnormal edge out of BB. Note that since
6344 STMT is not control flow, there may only be one non-abnormal edge
6346 FOR_EACH_EDGE (e
, ei
, loc
->bb
->succs
)
6347 if (!(e
->flags
& EDGE_ABNORMAL
))
6349 gsi_insert_on_edge (e
, assert_stmt
);
6357 /* Process all the insertions registered for every name N_i registered
6358 in NEED_ASSERT_FOR. The list of assertions to be inserted are
6359 found in ASSERTS_FOR[i]. */
6362 process_assert_insertions (void)
6366 bool update_edges_p
= false;
6367 int num_asserts
= 0;
6369 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6370 dump_all_asserts (dump_file
);
6372 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
6374 assert_locus
*loc
= asserts_for
[i
];
6379 assert_locus
*next
= loc
->next
;
6380 update_edges_p
|= process_assert_insertions_for (ssa_name (i
), loc
);
6388 gsi_commit_edge_inserts ();
6390 statistics_counter_event (cfun
, "Number of ASSERT_EXPR expressions inserted",
6395 /* Traverse the flowgraph looking for conditional jumps to insert range
6396 expressions. These range expressions are meant to provide information
6397 to optimizations that need to reason in terms of value ranges. They
6398 will not be expanded into RTL. For instance, given:
6407 this pass will transform the code into:
6413 x = ASSERT_EXPR <x, x < y>
6418 y = ASSERT_EXPR <y, x >= y>
6422 The idea is that once copy and constant propagation have run, other
6423 optimizations will be able to determine what ranges of values can 'x'
6424 take in different paths of the code, simply by checking the reaching
6425 definition of 'x'. */
6428 insert_range_assertions (void)
6430 need_assert_for
= BITMAP_ALLOC (NULL
);
6431 asserts_for
= XCNEWVEC (assert_locus
*, num_ssa_names
);
6433 calculate_dominance_info (CDI_DOMINATORS
);
6435 find_assert_locations ();
6436 if (!bitmap_empty_p (need_assert_for
))
6438 process_assert_insertions ();
6439 update_ssa (TODO_update_ssa_no_phi
);
6442 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6444 fprintf (dump_file
, "\nSSA form after inserting ASSERT_EXPRs\n");
6445 dump_function_to_file (current_function_decl
, dump_file
, dump_flags
);
6449 BITMAP_FREE (need_assert_for
);
6452 /* Checks one ARRAY_REF in REF, located at LOCUS. Ignores flexible arrays
6453 and "struct" hacks. If VRP can determine that the
6454 array subscript is a constant, check if it is outside valid
6455 range. If the array subscript is a RANGE, warn if it is
6456 non-overlapping with valid range.
6457 IGNORE_OFF_BY_ONE is true if the ARRAY_REF is inside a ADDR_EXPR. */
6460 check_array_ref (location_t location
, tree ref
, bool ignore_off_by_one
)
6462 value_range
*vr
= NULL
;
6463 tree low_sub
, up_sub
;
6464 tree low_bound
, up_bound
, up_bound_p1
;
6466 if (TREE_NO_WARNING (ref
))
6469 low_sub
= up_sub
= TREE_OPERAND (ref
, 1);
6470 up_bound
= array_ref_up_bound (ref
);
6472 /* Can not check flexible arrays. */
6474 || TREE_CODE (up_bound
) != INTEGER_CST
)
6477 /* Accesses to trailing arrays via pointers may access storage
6478 beyond the types array bounds. */
6479 if (warn_array_bounds
< 2
6480 && array_at_struct_end_p (ref
))
6483 low_bound
= array_ref_low_bound (ref
);
6484 up_bound_p1
= int_const_binop (PLUS_EXPR
, up_bound
,
6485 build_int_cst (TREE_TYPE (up_bound
), 1));
6488 if (tree_int_cst_equal (low_bound
, up_bound_p1
))
6490 warning_at (location
, OPT_Warray_bounds
,
6491 "array subscript is above array bounds");
6492 TREE_NO_WARNING (ref
) = 1;
6495 if (TREE_CODE (low_sub
) == SSA_NAME
)
6497 vr
= get_value_range (low_sub
);
6498 if (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
)
6500 low_sub
= vr
->type
== VR_RANGE
? vr
->max
: vr
->min
;
6501 up_sub
= vr
->type
== VR_RANGE
? vr
->min
: vr
->max
;
6505 if (vr
&& vr
->type
== VR_ANTI_RANGE
)
6507 if (TREE_CODE (up_sub
) == INTEGER_CST
6508 && (ignore_off_by_one
6509 ? tree_int_cst_lt (up_bound
, up_sub
)
6510 : tree_int_cst_le (up_bound
, up_sub
))
6511 && TREE_CODE (low_sub
) == INTEGER_CST
6512 && tree_int_cst_le (low_sub
, low_bound
))
6514 warning_at (location
, OPT_Warray_bounds
,
6515 "array subscript is outside array bounds");
6516 TREE_NO_WARNING (ref
) = 1;
6519 else if (TREE_CODE (up_sub
) == INTEGER_CST
6520 && (ignore_off_by_one
6521 ? !tree_int_cst_le (up_sub
, up_bound_p1
)
6522 : !tree_int_cst_le (up_sub
, up_bound
)))
6524 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6526 fprintf (dump_file
, "Array bound warning for ");
6527 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, ref
);
6528 fprintf (dump_file
, "\n");
6530 warning_at (location
, OPT_Warray_bounds
,
6531 "array subscript is above array bounds");
6532 TREE_NO_WARNING (ref
) = 1;
6534 else if (TREE_CODE (low_sub
) == INTEGER_CST
6535 && tree_int_cst_lt (low_sub
, low_bound
))
6537 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6539 fprintf (dump_file
, "Array bound warning for ");
6540 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, ref
);
6541 fprintf (dump_file
, "\n");
6543 warning_at (location
, OPT_Warray_bounds
,
6544 "array subscript is below array bounds");
6545 TREE_NO_WARNING (ref
) = 1;
6549 /* Searches if the expr T, located at LOCATION computes
6550 address of an ARRAY_REF, and call check_array_ref on it. */
6553 search_for_addr_array (tree t
, location_t location
)
6555 /* Check each ARRAY_REFs in the reference chain. */
6558 if (TREE_CODE (t
) == ARRAY_REF
)
6559 check_array_ref (location
, t
, true /*ignore_off_by_one*/);
6561 t
= TREE_OPERAND (t
, 0);
6563 while (handled_component_p (t
));
6565 if (TREE_CODE (t
) == MEM_REF
6566 && TREE_CODE (TREE_OPERAND (t
, 0)) == ADDR_EXPR
6567 && !TREE_NO_WARNING (t
))
6569 tree tem
= TREE_OPERAND (TREE_OPERAND (t
, 0), 0);
6570 tree low_bound
, up_bound
, el_sz
;
6572 if (TREE_CODE (TREE_TYPE (tem
)) != ARRAY_TYPE
6573 || TREE_CODE (TREE_TYPE (TREE_TYPE (tem
))) == ARRAY_TYPE
6574 || !TYPE_DOMAIN (TREE_TYPE (tem
)))
6577 low_bound
= TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (tem
)));
6578 up_bound
= TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (tem
)));
6579 el_sz
= TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (tem
)));
6581 || TREE_CODE (low_bound
) != INTEGER_CST
6583 || TREE_CODE (up_bound
) != INTEGER_CST
6585 || TREE_CODE (el_sz
) != INTEGER_CST
)
6588 idx
= mem_ref_offset (t
);
6589 idx
= wi::sdiv_trunc (idx
, wi::to_offset (el_sz
));
6592 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6594 fprintf (dump_file
, "Array bound warning for ");
6595 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, t
);
6596 fprintf (dump_file
, "\n");
6598 warning_at (location
, OPT_Warray_bounds
,
6599 "array subscript is below array bounds");
6600 TREE_NO_WARNING (t
) = 1;
6602 else if (idx
> (wi::to_offset (up_bound
)
6603 - wi::to_offset (low_bound
) + 1))
6605 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6607 fprintf (dump_file
, "Array bound warning for ");
6608 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, t
);
6609 fprintf (dump_file
, "\n");
6611 warning_at (location
, OPT_Warray_bounds
,
6612 "array subscript is above array bounds");
6613 TREE_NO_WARNING (t
) = 1;
6618 /* walk_tree() callback that checks if *TP is
6619 an ARRAY_REF inside an ADDR_EXPR (in which an array
6620 subscript one outside the valid range is allowed). Call
6621 check_array_ref for each ARRAY_REF found. The location is
6625 check_array_bounds (tree
*tp
, int *walk_subtree
, void *data
)
6628 struct walk_stmt_info
*wi
= (struct walk_stmt_info
*) data
;
6629 location_t location
;
6631 if (EXPR_HAS_LOCATION (t
))
6632 location
= EXPR_LOCATION (t
);
6635 location_t
*locp
= (location_t
*) wi
->info
;
6639 *walk_subtree
= TRUE
;
6641 if (TREE_CODE (t
) == ARRAY_REF
)
6642 check_array_ref (location
, t
, false /*ignore_off_by_one*/);
6644 else if (TREE_CODE (t
) == ADDR_EXPR
)
6646 search_for_addr_array (t
, location
);
6647 *walk_subtree
= FALSE
;
6653 /* Walk over all statements of all reachable BBs and call check_array_bounds
6657 check_all_array_refs (void)
6660 gimple_stmt_iterator si
;
6662 FOR_EACH_BB_FN (bb
, cfun
)
6666 bool executable
= false;
6668 /* Skip blocks that were found to be unreachable. */
6669 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
6670 executable
|= !!(e
->flags
& EDGE_EXECUTABLE
);
6674 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
6676 gimple
*stmt
= gsi_stmt (si
);
6677 struct walk_stmt_info wi
;
6678 if (!gimple_has_location (stmt
)
6679 || is_gimple_debug (stmt
))
6682 memset (&wi
, 0, sizeof (wi
));
6684 location_t loc
= gimple_location (stmt
);
6687 walk_gimple_op (gsi_stmt (si
),
6694 /* Return true if all imm uses of VAR are either in STMT, or
6695 feed (optionally through a chain of single imm uses) GIMPLE_COND
6696 in basic block COND_BB. */
6699 all_imm_uses_in_stmt_or_feed_cond (tree var
, gimple
*stmt
, basic_block cond_bb
)
6701 use_operand_p use_p
, use2_p
;
6702 imm_use_iterator iter
;
6704 FOR_EACH_IMM_USE_FAST (use_p
, iter
, var
)
6705 if (USE_STMT (use_p
) != stmt
)
6707 gimple
*use_stmt
= USE_STMT (use_p
), *use_stmt2
;
6708 if (is_gimple_debug (use_stmt
))
6710 while (is_gimple_assign (use_stmt
)
6711 && TREE_CODE (gimple_assign_lhs (use_stmt
)) == SSA_NAME
6712 && single_imm_use (gimple_assign_lhs (use_stmt
),
6713 &use2_p
, &use_stmt2
))
6714 use_stmt
= use_stmt2
;
6715 if (gimple_code (use_stmt
) != GIMPLE_COND
6716 || gimple_bb (use_stmt
) != cond_bb
)
6729 __builtin_unreachable ();
6731 x_5 = ASSERT_EXPR <x_3, ...>;
6732 If x_3 has no other immediate uses (checked by caller),
6733 var is the x_3 var from ASSERT_EXPR, we can clear low 5 bits
6734 from the non-zero bitmask. */
6737 maybe_set_nonzero_bits (basic_block bb
, tree var
)
6739 edge e
= single_pred_edge (bb
);
6740 basic_block cond_bb
= e
->src
;
6741 gimple
*stmt
= last_stmt (cond_bb
);
6745 || gimple_code (stmt
) != GIMPLE_COND
6746 || gimple_cond_code (stmt
) != ((e
->flags
& EDGE_TRUE_VALUE
)
6747 ? EQ_EXPR
: NE_EXPR
)
6748 || TREE_CODE (gimple_cond_lhs (stmt
)) != SSA_NAME
6749 || !integer_zerop (gimple_cond_rhs (stmt
)))
6752 stmt
= SSA_NAME_DEF_STMT (gimple_cond_lhs (stmt
));
6753 if (!is_gimple_assign (stmt
)
6754 || gimple_assign_rhs_code (stmt
) != BIT_AND_EXPR
6755 || TREE_CODE (gimple_assign_rhs2 (stmt
)) != INTEGER_CST
)
6757 if (gimple_assign_rhs1 (stmt
) != var
)
6761 if (TREE_CODE (gimple_assign_rhs1 (stmt
)) != SSA_NAME
)
6763 stmt2
= SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt
));
6764 if (!gimple_assign_cast_p (stmt2
)
6765 || gimple_assign_rhs1 (stmt2
) != var
6766 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt2
))
6767 || (TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (stmt
)))
6768 != TYPE_PRECISION (TREE_TYPE (var
))))
6771 cst
= gimple_assign_rhs2 (stmt
);
6772 set_nonzero_bits (var
, wi::bit_and_not (get_nonzero_bits (var
), cst
));
6775 /* Convert range assertion expressions into the implied copies and
6776 copy propagate away the copies. Doing the trivial copy propagation
6777 here avoids the need to run the full copy propagation pass after
6780 FIXME, this will eventually lead to copy propagation removing the
6781 names that had useful range information attached to them. For
6782 instance, if we had the assertion N_i = ASSERT_EXPR <N_j, N_j > 3>,
6783 then N_i will have the range [3, +INF].
6785 However, by converting the assertion into the implied copy
6786 operation N_i = N_j, we will then copy-propagate N_j into the uses
6787 of N_i and lose the range information. We may want to hold on to
6788 ASSERT_EXPRs a little while longer as the ranges could be used in
6789 things like jump threading.
6791 The problem with keeping ASSERT_EXPRs around is that passes after
6792 VRP need to handle them appropriately.
6794 Another approach would be to make the range information a first
6795 class property of the SSA_NAME so that it can be queried from
6796 any pass. This is made somewhat more complex by the need for
6797 multiple ranges to be associated with one SSA_NAME. */
6800 remove_range_assertions (void)
6803 gimple_stmt_iterator si
;
6804 /* 1 if looking at ASSERT_EXPRs immediately at the beginning of
6805 a basic block preceeded by GIMPLE_COND branching to it and
6806 __builtin_trap, -1 if not yet checked, 0 otherwise. */
6809 /* Note that the BSI iterator bump happens at the bottom of the
6810 loop and no bump is necessary if we're removing the statement
6811 referenced by the current BSI. */
6812 FOR_EACH_BB_FN (bb
, cfun
)
6813 for (si
= gsi_after_labels (bb
), is_unreachable
= -1; !gsi_end_p (si
);)
6815 gimple
*stmt
= gsi_stmt (si
);
6818 if (is_gimple_assign (stmt
)
6819 && gimple_assign_rhs_code (stmt
) == ASSERT_EXPR
)
6821 tree lhs
= gimple_assign_lhs (stmt
);
6822 tree rhs
= gimple_assign_rhs1 (stmt
);
6824 use_operand_p use_p
;
6825 imm_use_iterator iter
;
6827 var
= ASSERT_EXPR_VAR (rhs
);
6828 gcc_assert (TREE_CODE (var
) == SSA_NAME
);
6830 if (!POINTER_TYPE_P (TREE_TYPE (lhs
))
6831 && SSA_NAME_RANGE_INFO (lhs
))
6833 if (is_unreachable
== -1)
6836 if (single_pred_p (bb
)
6837 && assert_unreachable_fallthru_edge_p
6838 (single_pred_edge (bb
)))
6842 if (x_7 >= 10 && x_7 < 20)
6843 __builtin_unreachable ();
6844 x_8 = ASSERT_EXPR <x_7, ...>;
6845 if the only uses of x_7 are in the ASSERT_EXPR and
6846 in the condition. In that case, we can copy the
6847 range info from x_8 computed in this pass also
6850 && all_imm_uses_in_stmt_or_feed_cond (var
, stmt
,
6853 set_range_info (var
, SSA_NAME_RANGE_TYPE (lhs
),
6854 SSA_NAME_RANGE_INFO (lhs
)->get_min (),
6855 SSA_NAME_RANGE_INFO (lhs
)->get_max ());
6856 maybe_set_nonzero_bits (bb
, var
);
6860 /* Propagate the RHS into every use of the LHS. */
6861 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, lhs
)
6862 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
6863 SET_USE (use_p
, var
);
6865 /* And finally, remove the copy, it is not needed. */
6866 gsi_remove (&si
, true);
6867 release_defs (stmt
);
6871 if (!is_gimple_debug (gsi_stmt (si
)))
6879 /* Return true if STMT is interesting for VRP. */
6882 stmt_interesting_for_vrp (gimple
*stmt
)
6884 if (gimple_code (stmt
) == GIMPLE_PHI
)
6886 tree res
= gimple_phi_result (stmt
);
6887 return (!virtual_operand_p (res
)
6888 && (INTEGRAL_TYPE_P (TREE_TYPE (res
))
6889 || POINTER_TYPE_P (TREE_TYPE (res
))));
6891 else if (is_gimple_assign (stmt
) || is_gimple_call (stmt
))
6893 tree lhs
= gimple_get_lhs (stmt
);
6895 /* In general, assignments with virtual operands are not useful
6896 for deriving ranges, with the obvious exception of calls to
6897 builtin functions. */
6898 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
6899 && (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
6900 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
6901 && (is_gimple_call (stmt
)
6902 || !gimple_vuse (stmt
)))
6904 else if (is_gimple_call (stmt
) && gimple_call_internal_p (stmt
))
6905 switch (gimple_call_internal_fn (stmt
))
6907 case IFN_ADD_OVERFLOW
:
6908 case IFN_SUB_OVERFLOW
:
6909 case IFN_MUL_OVERFLOW
:
6910 /* These internal calls return _Complex integer type,
6911 but are interesting to VRP nevertheless. */
6912 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
)
6919 else if (gimple_code (stmt
) == GIMPLE_COND
6920 || gimple_code (stmt
) == GIMPLE_SWITCH
)
6927 /* Initialize local data structures for VRP. */
6930 vrp_initialize (void)
6934 values_propagated
= false;
6935 num_vr_values
= num_ssa_names
;
6936 vr_value
= XCNEWVEC (value_range
*, num_vr_values
);
6937 vr_phi_edge_counts
= XCNEWVEC (int, num_ssa_names
);
6939 FOR_EACH_BB_FN (bb
, cfun
)
6941 for (gphi_iterator si
= gsi_start_phis (bb
); !gsi_end_p (si
);
6944 gphi
*phi
= si
.phi ();
6945 if (!stmt_interesting_for_vrp (phi
))
6947 tree lhs
= PHI_RESULT (phi
);
6948 set_value_range_to_varying (get_value_range (lhs
));
6949 prop_set_simulate_again (phi
, false);
6952 prop_set_simulate_again (phi
, true);
6955 for (gimple_stmt_iterator si
= gsi_start_bb (bb
); !gsi_end_p (si
);
6958 gimple
*stmt
= gsi_stmt (si
);
6960 /* If the statement is a control insn, then we do not
6961 want to avoid simulating the statement once. Failure
6962 to do so means that those edges will never get added. */
6963 if (stmt_ends_bb_p (stmt
))
6964 prop_set_simulate_again (stmt
, true);
6965 else if (!stmt_interesting_for_vrp (stmt
))
6969 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, i
, SSA_OP_DEF
)
6970 set_value_range_to_varying (get_value_range (def
));
6971 prop_set_simulate_again (stmt
, false);
6974 prop_set_simulate_again (stmt
, true);
6979 /* Return the singleton value-range for NAME or NAME. */
6982 vrp_valueize (tree name
)
6984 if (TREE_CODE (name
) == SSA_NAME
)
6986 value_range
*vr
= get_value_range (name
);
6987 if (vr
->type
== VR_RANGE
6988 && (vr
->min
== vr
->max
6989 || operand_equal_p (vr
->min
, vr
->max
, 0)))
6995 /* Return the singleton value-range for NAME if that is a constant
6996 but signal to not follow SSA edges. */
6999 vrp_valueize_1 (tree name
)
7001 if (TREE_CODE (name
) == SSA_NAME
)
7003 /* If the definition may be simulated again we cannot follow
7004 this SSA edge as the SSA propagator does not necessarily
7005 re-visit the use. */
7006 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
7007 if (!gimple_nop_p (def_stmt
)
7008 && prop_simulate_again_p (def_stmt
))
7010 value_range
*vr
= get_value_range (name
);
7011 if (range_int_cst_singleton_p (vr
))
7017 /* Visit assignment STMT. If it produces an interesting range, record
7018 the SSA name in *OUTPUT_P. */
7020 static enum ssa_prop_result
7021 vrp_visit_assignment_or_call (gimple
*stmt
, tree
*output_p
)
7025 enum gimple_code code
= gimple_code (stmt
);
7026 lhs
= gimple_get_lhs (stmt
);
7028 /* We only keep track of ranges in integral and pointer types. */
7029 if (TREE_CODE (lhs
) == SSA_NAME
7030 && ((INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
7031 /* It is valid to have NULL MIN/MAX values on a type. See
7032 build_range_type. */
7033 && TYPE_MIN_VALUE (TREE_TYPE (lhs
))
7034 && TYPE_MAX_VALUE (TREE_TYPE (lhs
)))
7035 || POINTER_TYPE_P (TREE_TYPE (lhs
))))
7037 value_range new_vr
= VR_INITIALIZER
;
7039 /* Try folding the statement to a constant first. */
7040 tree tem
= gimple_fold_stmt_to_constant_1 (stmt
, vrp_valueize
,
7042 if (tem
&& is_gimple_min_invariant (tem
))
7043 set_value_range_to_value (&new_vr
, tem
, NULL
);
7044 /* Then dispatch to value-range extracting functions. */
7045 else if (code
== GIMPLE_CALL
)
7046 extract_range_basic (&new_vr
, stmt
);
7048 extract_range_from_assignment (&new_vr
, as_a
<gassign
*> (stmt
));
7050 if (update_value_range (lhs
, &new_vr
))
7054 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7056 fprintf (dump_file
, "Found new range for ");
7057 print_generic_expr (dump_file
, lhs
, 0);
7058 fprintf (dump_file
, ": ");
7059 dump_value_range (dump_file
, &new_vr
);
7060 fprintf (dump_file
, "\n");
7063 if (new_vr
.type
== VR_VARYING
)
7064 return SSA_PROP_VARYING
;
7066 return SSA_PROP_INTERESTING
;
7069 return SSA_PROP_NOT_INTERESTING
;
7071 else if (is_gimple_call (stmt
) && gimple_call_internal_p (stmt
))
7072 switch (gimple_call_internal_fn (stmt
))
7074 case IFN_ADD_OVERFLOW
:
7075 case IFN_SUB_OVERFLOW
:
7076 case IFN_MUL_OVERFLOW
:
7077 /* These internal calls return _Complex integer type,
7078 which VRP does not track, but the immediate uses
7079 thereof might be interesting. */
7080 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
)
7082 imm_use_iterator iter
;
7083 use_operand_p use_p
;
7084 enum ssa_prop_result res
= SSA_PROP_VARYING
;
7086 set_value_range_to_varying (get_value_range (lhs
));
7088 FOR_EACH_IMM_USE_FAST (use_p
, iter
, lhs
)
7090 gimple
*use_stmt
= USE_STMT (use_p
);
7091 if (!is_gimple_assign (use_stmt
))
7093 enum tree_code rhs_code
= gimple_assign_rhs_code (use_stmt
);
7094 if (rhs_code
!= REALPART_EXPR
&& rhs_code
!= IMAGPART_EXPR
)
7096 tree rhs1
= gimple_assign_rhs1 (use_stmt
);
7097 tree use_lhs
= gimple_assign_lhs (use_stmt
);
7098 if (TREE_CODE (rhs1
) != rhs_code
7099 || TREE_OPERAND (rhs1
, 0) != lhs
7100 || TREE_CODE (use_lhs
) != SSA_NAME
7101 || !stmt_interesting_for_vrp (use_stmt
)
7102 || (!INTEGRAL_TYPE_P (TREE_TYPE (use_lhs
))
7103 || !TYPE_MIN_VALUE (TREE_TYPE (use_lhs
))
7104 || !TYPE_MAX_VALUE (TREE_TYPE (use_lhs
))))
7107 /* If there is a change in the value range for any of the
7108 REALPART_EXPR/IMAGPART_EXPR immediate uses, return
7109 SSA_PROP_INTERESTING. If there are any REALPART_EXPR
7110 or IMAGPART_EXPR immediate uses, but none of them have
7111 a change in their value ranges, return
7112 SSA_PROP_NOT_INTERESTING. If there are no
7113 {REAL,IMAG}PART_EXPR uses at all,
7114 return SSA_PROP_VARYING. */
7115 value_range new_vr
= VR_INITIALIZER
;
7116 extract_range_basic (&new_vr
, use_stmt
);
7117 value_range
*old_vr
= get_value_range (use_lhs
);
7118 if (old_vr
->type
!= new_vr
.type
7119 || !vrp_operand_equal_p (old_vr
->min
, new_vr
.min
)
7120 || !vrp_operand_equal_p (old_vr
->max
, new_vr
.max
)
7121 || !vrp_bitmap_equal_p (old_vr
->equiv
, new_vr
.equiv
))
7122 res
= SSA_PROP_INTERESTING
;
7124 res
= SSA_PROP_NOT_INTERESTING
;
7125 BITMAP_FREE (new_vr
.equiv
);
7126 if (res
== SSA_PROP_INTERESTING
)
7140 /* Every other statement produces no useful ranges. */
7141 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_DEF
)
7142 set_value_range_to_varying (get_value_range (def
));
7144 return SSA_PROP_VARYING
;
7147 /* Helper that gets the value range of the SSA_NAME with version I
7148 or a symbolic range containing the SSA_NAME only if the value range
7149 is varying or undefined. */
7151 static inline value_range
7152 get_vr_for_comparison (int i
)
7154 value_range vr
= *get_value_range (ssa_name (i
));
7156 /* If name N_i does not have a valid range, use N_i as its own
7157 range. This allows us to compare against names that may
7158 have N_i in their ranges. */
7159 if (vr
.type
== VR_VARYING
|| vr
.type
== VR_UNDEFINED
)
7162 vr
.min
= ssa_name (i
);
7163 vr
.max
= ssa_name (i
);
7169 /* Compare all the value ranges for names equivalent to VAR with VAL
7170 using comparison code COMP. Return the same value returned by
7171 compare_range_with_value, including the setting of
7172 *STRICT_OVERFLOW_P. */
7175 compare_name_with_value (enum tree_code comp
, tree var
, tree val
,
7176 bool *strict_overflow_p
, bool use_equiv_p
)
7182 int used_strict_overflow
;
7184 value_range equiv_vr
;
7186 /* Get the set of equivalences for VAR. */
7187 e
= get_value_range (var
)->equiv
;
7189 /* Start at -1. Set it to 0 if we do a comparison without relying
7190 on overflow, or 1 if all comparisons rely on overflow. */
7191 used_strict_overflow
= -1;
7193 /* Compare vars' value range with val. */
7194 equiv_vr
= get_vr_for_comparison (SSA_NAME_VERSION (var
));
7196 retval
= compare_range_with_value (comp
, &equiv_vr
, val
, &sop
);
7198 used_strict_overflow
= sop
? 1 : 0;
7200 /* If the equiv set is empty we have done all work we need to do. */
7204 && used_strict_overflow
> 0)
7205 *strict_overflow_p
= true;
7209 EXECUTE_IF_SET_IN_BITMAP (e
, 0, i
, bi
)
7212 && ! SSA_NAME_IS_DEFAULT_DEF (ssa_name (i
))
7213 && prop_simulate_again_p (SSA_NAME_DEF_STMT (ssa_name (i
))))
7216 equiv_vr
= get_vr_for_comparison (i
);
7218 t
= compare_range_with_value (comp
, &equiv_vr
, val
, &sop
);
7221 /* If we get different answers from different members
7222 of the equivalence set this check must be in a dead
7223 code region. Folding it to a trap representation
7224 would be correct here. For now just return don't-know. */
7234 used_strict_overflow
= 0;
7235 else if (used_strict_overflow
< 0)
7236 used_strict_overflow
= 1;
7241 && used_strict_overflow
> 0)
7242 *strict_overflow_p
= true;
7248 /* Given a comparison code COMP and names N1 and N2, compare all the
7249 ranges equivalent to N1 against all the ranges equivalent to N2
7250 to determine the value of N1 COMP N2. Return the same value
7251 returned by compare_ranges. Set *STRICT_OVERFLOW_P to indicate
7252 whether we relied on an overflow infinity in the comparison. */
7256 compare_names (enum tree_code comp
, tree n1
, tree n2
,
7257 bool *strict_overflow_p
)
7261 bitmap_iterator bi1
, bi2
;
7263 int used_strict_overflow
;
7264 static bitmap_obstack
*s_obstack
= NULL
;
7265 static bitmap s_e1
= NULL
, s_e2
= NULL
;
7267 /* Compare the ranges of every name equivalent to N1 against the
7268 ranges of every name equivalent to N2. */
7269 e1
= get_value_range (n1
)->equiv
;
7270 e2
= get_value_range (n2
)->equiv
;
7272 /* Use the fake bitmaps if e1 or e2 are not available. */
7273 if (s_obstack
== NULL
)
7275 s_obstack
= XNEW (bitmap_obstack
);
7276 bitmap_obstack_initialize (s_obstack
);
7277 s_e1
= BITMAP_ALLOC (s_obstack
);
7278 s_e2
= BITMAP_ALLOC (s_obstack
);
7285 /* Add N1 and N2 to their own set of equivalences to avoid
7286 duplicating the body of the loop just to check N1 and N2
7288 bitmap_set_bit (e1
, SSA_NAME_VERSION (n1
));
7289 bitmap_set_bit (e2
, SSA_NAME_VERSION (n2
));
7291 /* If the equivalence sets have a common intersection, then the two
7292 names can be compared without checking their ranges. */
7293 if (bitmap_intersect_p (e1
, e2
))
7295 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
7296 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
7298 return (comp
== EQ_EXPR
|| comp
== GE_EXPR
|| comp
== LE_EXPR
)
7300 : boolean_false_node
;
7303 /* Start at -1. Set it to 0 if we do a comparison without relying
7304 on overflow, or 1 if all comparisons rely on overflow. */
7305 used_strict_overflow
= -1;
7307 /* Otherwise, compare all the equivalent ranges. First, add N1 and
7308 N2 to their own set of equivalences to avoid duplicating the body
7309 of the loop just to check N1 and N2 ranges. */
7310 EXECUTE_IF_SET_IN_BITMAP (e1
, 0, i1
, bi1
)
7312 value_range vr1
= get_vr_for_comparison (i1
);
7314 t
= retval
= NULL_TREE
;
7315 EXECUTE_IF_SET_IN_BITMAP (e2
, 0, i2
, bi2
)
7319 value_range vr2
= get_vr_for_comparison (i2
);
7321 t
= compare_ranges (comp
, &vr1
, &vr2
, &sop
);
7324 /* If we get different answers from different members
7325 of the equivalence set this check must be in a dead
7326 code region. Folding it to a trap representation
7327 would be correct here. For now just return don't-know. */
7331 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
7332 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
7338 used_strict_overflow
= 0;
7339 else if (used_strict_overflow
< 0)
7340 used_strict_overflow
= 1;
7346 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
7347 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
7348 if (used_strict_overflow
> 0)
7349 *strict_overflow_p
= true;
7354 /* None of the equivalent ranges are useful in computing this
7356 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
7357 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
7361 /* Helper function for vrp_evaluate_conditional_warnv & other
7365 vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code code
,
7367 bool * strict_overflow_p
)
7369 value_range
*vr0
, *vr1
;
7371 vr0
= (TREE_CODE (op0
) == SSA_NAME
) ? get_value_range (op0
) : NULL
;
7372 vr1
= (TREE_CODE (op1
) == SSA_NAME
) ? get_value_range (op1
) : NULL
;
7374 tree res
= NULL_TREE
;
7376 res
= compare_ranges (code
, vr0
, vr1
, strict_overflow_p
);
7378 res
= compare_range_with_value (code
, vr0
, op1
, strict_overflow_p
);
7380 res
= (compare_range_with_value
7381 (swap_tree_comparison (code
), vr1
, op0
, strict_overflow_p
));
7385 /* Helper function for vrp_evaluate_conditional_warnv. */
7388 vrp_evaluate_conditional_warnv_with_ops (enum tree_code code
, tree op0
,
7389 tree op1
, bool use_equiv_p
,
7390 bool *strict_overflow_p
, bool *only_ranges
)
7394 *only_ranges
= true;
7396 /* We only deal with integral and pointer types. */
7397 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0
))
7398 && !POINTER_TYPE_P (TREE_TYPE (op0
)))
7401 if ((ret
= vrp_evaluate_conditional_warnv_with_ops_using_ranges
7402 (code
, op0
, op1
, strict_overflow_p
)))
7405 *only_ranges
= false;
7406 /* Do not use compare_names during propagation, it's quadratic. */
7407 if (TREE_CODE (op0
) == SSA_NAME
&& TREE_CODE (op1
) == SSA_NAME
7409 return compare_names (code
, op0
, op1
, strict_overflow_p
);
7410 else if (TREE_CODE (op0
) == SSA_NAME
)
7411 return compare_name_with_value (code
, op0
, op1
,
7412 strict_overflow_p
, use_equiv_p
);
7413 else if (TREE_CODE (op1
) == SSA_NAME
)
7414 return compare_name_with_value (swap_tree_comparison (code
), op1
, op0
,
7415 strict_overflow_p
, use_equiv_p
);
7419 /* Given (CODE OP0 OP1) within STMT, try to simplify it based on value range
7420 information. Return NULL if the conditional can not be evaluated.
7421 The ranges of all the names equivalent with the operands in COND
7422 will be used when trying to compute the value. If the result is
7423 based on undefined signed overflow, issue a warning if
7427 vrp_evaluate_conditional (tree_code code
, tree op0
, tree op1
, gimple
*stmt
)
7433 /* Some passes and foldings leak constants with overflow flag set
7434 into the IL. Avoid doing wrong things with these and bail out. */
7435 if ((TREE_CODE (op0
) == INTEGER_CST
7436 && TREE_OVERFLOW (op0
))
7437 || (TREE_CODE (op1
) == INTEGER_CST
7438 && TREE_OVERFLOW (op1
)))
7442 ret
= vrp_evaluate_conditional_warnv_with_ops (code
, op0
, op1
, true, &sop
,
7447 enum warn_strict_overflow_code wc
;
7448 const char* warnmsg
;
7450 if (is_gimple_min_invariant (ret
))
7452 wc
= WARN_STRICT_OVERFLOW_CONDITIONAL
;
7453 warnmsg
= G_("assuming signed overflow does not occur when "
7454 "simplifying conditional to constant");
7458 wc
= WARN_STRICT_OVERFLOW_COMPARISON
;
7459 warnmsg
= G_("assuming signed overflow does not occur when "
7460 "simplifying conditional");
7463 if (issue_strict_overflow_warning (wc
))
7465 location_t location
;
7467 if (!gimple_has_location (stmt
))
7468 location
= input_location
;
7470 location
= gimple_location (stmt
);
7471 warning_at (location
, OPT_Wstrict_overflow
, "%s", warnmsg
);
7475 if (warn_type_limits
7476 && ret
&& only_ranges
7477 && TREE_CODE_CLASS (code
) == tcc_comparison
7478 && TREE_CODE (op0
) == SSA_NAME
)
7480 /* If the comparison is being folded and the operand on the LHS
7481 is being compared against a constant value that is outside of
7482 the natural range of OP0's type, then the predicate will
7483 always fold regardless of the value of OP0. If -Wtype-limits
7484 was specified, emit a warning. */
7485 tree type
= TREE_TYPE (op0
);
7486 value_range
*vr0
= get_value_range (op0
);
7488 if (vr0
->type
== VR_RANGE
7489 && INTEGRAL_TYPE_P (type
)
7490 && vrp_val_is_min (vr0
->min
)
7491 && vrp_val_is_max (vr0
->max
)
7492 && is_gimple_min_invariant (op1
))
7494 location_t location
;
7496 if (!gimple_has_location (stmt
))
7497 location
= input_location
;
7499 location
= gimple_location (stmt
);
7501 warning_at (location
, OPT_Wtype_limits
,
7503 ? G_("comparison always false "
7504 "due to limited range of data type")
7505 : G_("comparison always true "
7506 "due to limited range of data type"));
7514 /* Visit conditional statement STMT. If we can determine which edge
7515 will be taken out of STMT's basic block, record it in
7516 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
7517 SSA_PROP_VARYING. */
7519 static enum ssa_prop_result
7520 vrp_visit_cond_stmt (gcond
*stmt
, edge
*taken_edge_p
)
7525 *taken_edge_p
= NULL
;
7527 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7532 fprintf (dump_file
, "\nVisiting conditional with predicate: ");
7533 print_gimple_stmt (dump_file
, stmt
, 0, 0);
7534 fprintf (dump_file
, "\nWith known ranges\n");
7536 FOR_EACH_SSA_TREE_OPERAND (use
, stmt
, i
, SSA_OP_USE
)
7538 fprintf (dump_file
, "\t");
7539 print_generic_expr (dump_file
, use
, 0);
7540 fprintf (dump_file
, ": ");
7541 dump_value_range (dump_file
, vr_value
[SSA_NAME_VERSION (use
)]);
7544 fprintf (dump_file
, "\n");
7547 /* Compute the value of the predicate COND by checking the known
7548 ranges of each of its operands.
7550 Note that we cannot evaluate all the equivalent ranges here
7551 because those ranges may not yet be final and with the current
7552 propagation strategy, we cannot determine when the value ranges
7553 of the names in the equivalence set have changed.
7555 For instance, given the following code fragment
7559 i_14 = ASSERT_EXPR <i_5, i_5 != 0>
7563 Assume that on the first visit to i_14, i_5 has the temporary
7564 range [8, 8] because the second argument to the PHI function is
7565 not yet executable. We derive the range ~[0, 0] for i_14 and the
7566 equivalence set { i_5 }. So, when we visit 'if (i_14 == 1)' for
7567 the first time, since i_14 is equivalent to the range [8, 8], we
7568 determine that the predicate is always false.
7570 On the next round of propagation, i_13 is determined to be
7571 VARYING, which causes i_5 to drop down to VARYING. So, another
7572 visit to i_14 is scheduled. In this second visit, we compute the
7573 exact same range and equivalence set for i_14, namely ~[0, 0] and
7574 { i_5 }. But we did not have the previous range for i_5
7575 registered, so vrp_visit_assignment thinks that the range for
7576 i_14 has not changed. Therefore, the predicate 'if (i_14 == 1)'
7577 is not visited again, which stops propagation from visiting
7578 statements in the THEN clause of that if().
7580 To properly fix this we would need to keep the previous range
7581 value for the names in the equivalence set. This way we would've
7582 discovered that from one visit to the other i_5 changed from
7583 range [8, 8] to VR_VARYING.
7585 However, fixing this apparent limitation may not be worth the
7586 additional checking. Testing on several code bases (GCC, DLV,
7587 MICO, TRAMP3D and SPEC2000) showed that doing this results in
7588 4 more predicates folded in SPEC. */
7591 val
= vrp_evaluate_conditional_warnv_with_ops (gimple_cond_code (stmt
),
7592 gimple_cond_lhs (stmt
),
7593 gimple_cond_rhs (stmt
),
7598 *taken_edge_p
= find_taken_edge (gimple_bb (stmt
), val
);
7601 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7603 "\nIgnoring predicate evaluation because "
7604 "it assumes that signed overflow is undefined");
7609 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7611 fprintf (dump_file
, "\nPredicate evaluates to: ");
7612 if (val
== NULL_TREE
)
7613 fprintf (dump_file
, "DON'T KNOW\n");
7615 print_generic_stmt (dump_file
, val
, 0);
7618 return (*taken_edge_p
) ? SSA_PROP_INTERESTING
: SSA_PROP_VARYING
;
7621 /* Searches the case label vector VEC for the index *IDX of the CASE_LABEL
7622 that includes the value VAL. The search is restricted to the range
7623 [START_IDX, n - 1] where n is the size of VEC.
7625 If there is a CASE_LABEL for VAL, its index is placed in IDX and true is
7628 If there is no CASE_LABEL for VAL and there is one that is larger than VAL,
7629 it is placed in IDX and false is returned.
7631 If VAL is larger than any CASE_LABEL, n is placed on IDX and false is
7635 find_case_label_index (gswitch
*stmt
, size_t start_idx
, tree val
, size_t *idx
)
7637 size_t n
= gimple_switch_num_labels (stmt
);
7640 /* Find case label for minimum of the value range or the next one.
7641 At each iteration we are searching in [low, high - 1]. */
7643 for (low
= start_idx
, high
= n
; high
!= low
; )
7647 /* Note that i != high, so we never ask for n. */
7648 size_t i
= (high
+ low
) / 2;
7649 t
= gimple_switch_label (stmt
, i
);
7651 /* Cache the result of comparing CASE_LOW and val. */
7652 cmp
= tree_int_cst_compare (CASE_LOW (t
), val
);
7656 /* Ranges cannot be empty. */
7665 if (CASE_HIGH (t
) != NULL
7666 && tree_int_cst_compare (CASE_HIGH (t
), val
) >= 0)
7678 /* Searches the case label vector VEC for the range of CASE_LABELs that is used
7679 for values between MIN and MAX. The first index is placed in MIN_IDX. The
7680 last index is placed in MAX_IDX. If the range of CASE_LABELs is empty
7681 then MAX_IDX < MIN_IDX.
7682 Returns true if the default label is not needed. */
7685 find_case_label_range (gswitch
*stmt
, tree min
, tree max
, size_t *min_idx
,
7689 bool min_take_default
= !find_case_label_index (stmt
, 1, min
, &i
);
7690 bool max_take_default
= !find_case_label_index (stmt
, i
, max
, &j
);
7694 && max_take_default
)
7696 /* Only the default case label reached.
7697 Return an empty range. */
7704 bool take_default
= min_take_default
|| max_take_default
;
7708 if (max_take_default
)
7711 /* If the case label range is continuous, we do not need
7712 the default case label. Verify that. */
7713 high
= CASE_LOW (gimple_switch_label (stmt
, i
));
7714 if (CASE_HIGH (gimple_switch_label (stmt
, i
)))
7715 high
= CASE_HIGH (gimple_switch_label (stmt
, i
));
7716 for (k
= i
+ 1; k
<= j
; ++k
)
7718 low
= CASE_LOW (gimple_switch_label (stmt
, k
));
7719 if (!integer_onep (int_const_binop (MINUS_EXPR
, low
, high
)))
7721 take_default
= true;
7725 if (CASE_HIGH (gimple_switch_label (stmt
, k
)))
7726 high
= CASE_HIGH (gimple_switch_label (stmt
, k
));
7731 return !take_default
;
7735 /* Searches the case label vector VEC for the ranges of CASE_LABELs that are
7736 used in range VR. The indices are placed in MIN_IDX1, MAX_IDX, MIN_IDX2 and
7737 MAX_IDX2. If the ranges of CASE_LABELs are empty then MAX_IDX1 < MIN_IDX1.
7738 Returns true if the default label is not needed. */
7741 find_case_label_ranges (gswitch
*stmt
, value_range
*vr
, size_t *min_idx1
,
7742 size_t *max_idx1
, size_t *min_idx2
,
7746 unsigned int n
= gimple_switch_num_labels (stmt
);
7748 tree case_low
, case_high
;
7749 tree min
= vr
->min
, max
= vr
->max
;
7751 gcc_checking_assert (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
);
7753 take_default
= !find_case_label_range (stmt
, min
, max
, &i
, &j
);
7755 /* Set second range to emtpy. */
7759 if (vr
->type
== VR_RANGE
)
7763 return !take_default
;
7766 /* Set first range to all case labels. */
7773 /* Make sure all the values of case labels [i , j] are contained in
7774 range [MIN, MAX]. */
7775 case_low
= CASE_LOW (gimple_switch_label (stmt
, i
));
7776 case_high
= CASE_HIGH (gimple_switch_label (stmt
, j
));
7777 if (tree_int_cst_compare (case_low
, min
) < 0)
7779 if (case_high
!= NULL_TREE
7780 && tree_int_cst_compare (max
, case_high
) < 0)
7786 /* If the range spans case labels [i, j], the corresponding anti-range spans
7787 the labels [1, i - 1] and [j + 1, n - 1]. */
7813 /* Visit switch statement STMT. If we can determine which edge
7814 will be taken out of STMT's basic block, record it in
7815 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
7816 SSA_PROP_VARYING. */
7818 static enum ssa_prop_result
7819 vrp_visit_switch_stmt (gswitch
*stmt
, edge
*taken_edge_p
)
7823 size_t i
= 0, j
= 0, k
, l
;
7826 *taken_edge_p
= NULL
;
7827 op
= gimple_switch_index (stmt
);
7828 if (TREE_CODE (op
) != SSA_NAME
)
7829 return SSA_PROP_VARYING
;
7831 vr
= get_value_range (op
);
7832 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7834 fprintf (dump_file
, "\nVisiting switch expression with operand ");
7835 print_generic_expr (dump_file
, op
, 0);
7836 fprintf (dump_file
, " with known range ");
7837 dump_value_range (dump_file
, vr
);
7838 fprintf (dump_file
, "\n");
7841 if ((vr
->type
!= VR_RANGE
7842 && vr
->type
!= VR_ANTI_RANGE
)
7843 || symbolic_range_p (vr
))
7844 return SSA_PROP_VARYING
;
7846 /* Find the single edge that is taken from the switch expression. */
7847 take_default
= !find_case_label_ranges (stmt
, vr
, &i
, &j
, &k
, &l
);
7849 /* Check if the range spans no CASE_LABEL. If so, we only reach the default
7853 gcc_assert (take_default
);
7854 val
= gimple_switch_default_label (stmt
);
7858 /* Check if labels with index i to j and maybe the default label
7859 are all reaching the same label. */
7861 val
= gimple_switch_label (stmt
, i
);
7863 && CASE_LABEL (gimple_switch_default_label (stmt
))
7864 != CASE_LABEL (val
))
7866 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7867 fprintf (dump_file
, " not a single destination for this "
7869 return SSA_PROP_VARYING
;
7871 for (++i
; i
<= j
; ++i
)
7873 if (CASE_LABEL (gimple_switch_label (stmt
, i
)) != CASE_LABEL (val
))
7875 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7876 fprintf (dump_file
, " not a single destination for this "
7878 return SSA_PROP_VARYING
;
7883 if (CASE_LABEL (gimple_switch_label (stmt
, k
)) != CASE_LABEL (val
))
7885 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7886 fprintf (dump_file
, " not a single destination for this "
7888 return SSA_PROP_VARYING
;
7893 *taken_edge_p
= find_edge (gimple_bb (stmt
),
7894 label_to_block (CASE_LABEL (val
)));
7896 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7898 fprintf (dump_file
, " will take edge to ");
7899 print_generic_stmt (dump_file
, CASE_LABEL (val
), 0);
7902 return SSA_PROP_INTERESTING
;
7906 /* Evaluate statement STMT. If the statement produces a useful range,
7907 return SSA_PROP_INTERESTING and record the SSA name with the
7908 interesting range into *OUTPUT_P.
7910 If STMT is a conditional branch and we can determine its truth
7911 value, the taken edge is recorded in *TAKEN_EDGE_P.
7913 If STMT produces a varying value, return SSA_PROP_VARYING. */
7915 static enum ssa_prop_result
7916 vrp_visit_stmt (gimple
*stmt
, edge
*taken_edge_p
, tree
*output_p
)
7921 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7923 fprintf (dump_file
, "\nVisiting statement:\n");
7924 print_gimple_stmt (dump_file
, stmt
, 0, dump_flags
);
7927 if (!stmt_interesting_for_vrp (stmt
))
7928 gcc_assert (stmt_ends_bb_p (stmt
));
7929 else if (is_gimple_assign (stmt
) || is_gimple_call (stmt
))
7930 return vrp_visit_assignment_or_call (stmt
, output_p
);
7931 else if (gimple_code (stmt
) == GIMPLE_COND
)
7932 return vrp_visit_cond_stmt (as_a
<gcond
*> (stmt
), taken_edge_p
);
7933 else if (gimple_code (stmt
) == GIMPLE_SWITCH
)
7934 return vrp_visit_switch_stmt (as_a
<gswitch
*> (stmt
), taken_edge_p
);
7936 /* All other statements produce nothing of interest for VRP, so mark
7937 their outputs varying and prevent further simulation. */
7938 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_DEF
)
7939 set_value_range_to_varying (get_value_range (def
));
7941 return SSA_PROP_VARYING
;
7944 /* Union the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and
7945 { VR1TYPE, VR0MIN, VR0MAX } and store the result
7946 in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest
7947 possible such range. The resulting range is not canonicalized. */
7950 union_ranges (enum value_range_type
*vr0type
,
7951 tree
*vr0min
, tree
*vr0max
,
7952 enum value_range_type vr1type
,
7953 tree vr1min
, tree vr1max
)
7955 bool mineq
= operand_equal_p (*vr0min
, vr1min
, 0);
7956 bool maxeq
= operand_equal_p (*vr0max
, vr1max
, 0);
7958 /* [] is vr0, () is vr1 in the following classification comments. */
7962 if (*vr0type
== vr1type
)
7963 /* Nothing to do for equal ranges. */
7965 else if ((*vr0type
== VR_RANGE
7966 && vr1type
== VR_ANTI_RANGE
)
7967 || (*vr0type
== VR_ANTI_RANGE
7968 && vr1type
== VR_RANGE
))
7970 /* For anti-range with range union the result is varying. */
7976 else if (operand_less_p (*vr0max
, vr1min
) == 1
7977 || operand_less_p (vr1max
, *vr0min
) == 1)
7979 /* [ ] ( ) or ( ) [ ]
7980 If the ranges have an empty intersection, result of the union
7981 operation is the anti-range or if both are anti-ranges
7983 if (*vr0type
== VR_ANTI_RANGE
7984 && vr1type
== VR_ANTI_RANGE
)
7986 else if (*vr0type
== VR_ANTI_RANGE
7987 && vr1type
== VR_RANGE
)
7989 else if (*vr0type
== VR_RANGE
7990 && vr1type
== VR_ANTI_RANGE
)
7996 else if (*vr0type
== VR_RANGE
7997 && vr1type
== VR_RANGE
)
7999 /* The result is the convex hull of both ranges. */
8000 if (operand_less_p (*vr0max
, vr1min
) == 1)
8002 /* If the result can be an anti-range, create one. */
8003 if (TREE_CODE (*vr0max
) == INTEGER_CST
8004 && TREE_CODE (vr1min
) == INTEGER_CST
8005 && vrp_val_is_min (*vr0min
)
8006 && vrp_val_is_max (vr1max
))
8008 tree min
= int_const_binop (PLUS_EXPR
,
8010 build_int_cst (TREE_TYPE (*vr0max
), 1));
8011 tree max
= int_const_binop (MINUS_EXPR
,
8013 build_int_cst (TREE_TYPE (vr1min
), 1));
8014 if (!operand_less_p (max
, min
))
8016 *vr0type
= VR_ANTI_RANGE
;
8028 /* If the result can be an anti-range, create one. */
8029 if (TREE_CODE (vr1max
) == INTEGER_CST
8030 && TREE_CODE (*vr0min
) == INTEGER_CST
8031 && vrp_val_is_min (vr1min
)
8032 && vrp_val_is_max (*vr0max
))
8034 tree min
= int_const_binop (PLUS_EXPR
,
8036 build_int_cst (TREE_TYPE (vr1max
), 1));
8037 tree max
= int_const_binop (MINUS_EXPR
,
8039 build_int_cst (TREE_TYPE (*vr0min
), 1));
8040 if (!operand_less_p (max
, min
))
8042 *vr0type
= VR_ANTI_RANGE
;
8056 else if ((maxeq
|| operand_less_p (vr1max
, *vr0max
) == 1)
8057 && (mineq
|| operand_less_p (*vr0min
, vr1min
) == 1))
8059 /* [ ( ) ] or [( ) ] or [ ( )] */
8060 if (*vr0type
== VR_RANGE
8061 && vr1type
== VR_RANGE
)
8063 else if (*vr0type
== VR_ANTI_RANGE
8064 && vr1type
== VR_ANTI_RANGE
)
8070 else if (*vr0type
== VR_ANTI_RANGE
8071 && vr1type
== VR_RANGE
)
8073 /* Arbitrarily choose the right or left gap. */
8074 if (!mineq
&& TREE_CODE (vr1min
) == INTEGER_CST
)
8075 *vr0max
= int_const_binop (MINUS_EXPR
, vr1min
,
8076 build_int_cst (TREE_TYPE (vr1min
), 1));
8077 else if (!maxeq
&& TREE_CODE (vr1max
) == INTEGER_CST
)
8078 *vr0min
= int_const_binop (PLUS_EXPR
, vr1max
,
8079 build_int_cst (TREE_TYPE (vr1max
), 1));
8083 else if (*vr0type
== VR_RANGE
8084 && vr1type
== VR_ANTI_RANGE
)
8085 /* The result covers everything. */
8090 else if ((maxeq
|| operand_less_p (*vr0max
, vr1max
) == 1)
8091 && (mineq
|| operand_less_p (vr1min
, *vr0min
) == 1))
8093 /* ( [ ] ) or ([ ] ) or ( [ ]) */
8094 if (*vr0type
== VR_RANGE
8095 && vr1type
== VR_RANGE
)
8101 else if (*vr0type
== VR_ANTI_RANGE
8102 && vr1type
== VR_ANTI_RANGE
)
8104 else if (*vr0type
== VR_RANGE
8105 && vr1type
== VR_ANTI_RANGE
)
8107 *vr0type
= VR_ANTI_RANGE
;
8108 if (!mineq
&& TREE_CODE (*vr0min
) == INTEGER_CST
)
8110 *vr0max
= int_const_binop (MINUS_EXPR
, *vr0min
,
8111 build_int_cst (TREE_TYPE (*vr0min
), 1));
8114 else if (!maxeq
&& TREE_CODE (*vr0max
) == INTEGER_CST
)
8116 *vr0min
= int_const_binop (PLUS_EXPR
, *vr0max
,
8117 build_int_cst (TREE_TYPE (*vr0max
), 1));
8123 else if (*vr0type
== VR_ANTI_RANGE
8124 && vr1type
== VR_RANGE
)
8125 /* The result covers everything. */
8130 else if ((operand_less_p (vr1min
, *vr0max
) == 1
8131 || operand_equal_p (vr1min
, *vr0max
, 0))
8132 && operand_less_p (*vr0min
, vr1min
) == 1
8133 && operand_less_p (*vr0max
, vr1max
) == 1)
8135 /* [ ( ] ) or [ ]( ) */
8136 if (*vr0type
== VR_RANGE
8137 && vr1type
== VR_RANGE
)
8139 else if (*vr0type
== VR_ANTI_RANGE
8140 && vr1type
== VR_ANTI_RANGE
)
8142 else if (*vr0type
== VR_ANTI_RANGE
8143 && vr1type
== VR_RANGE
)
8145 if (TREE_CODE (vr1min
) == INTEGER_CST
)
8146 *vr0max
= int_const_binop (MINUS_EXPR
, vr1min
,
8147 build_int_cst (TREE_TYPE (vr1min
), 1));
8151 else if (*vr0type
== VR_RANGE
8152 && vr1type
== VR_ANTI_RANGE
)
8154 if (TREE_CODE (*vr0max
) == INTEGER_CST
)
8157 *vr0min
= int_const_binop (PLUS_EXPR
, *vr0max
,
8158 build_int_cst (TREE_TYPE (*vr0max
), 1));
8167 else if ((operand_less_p (*vr0min
, vr1max
) == 1
8168 || operand_equal_p (*vr0min
, vr1max
, 0))
8169 && operand_less_p (vr1min
, *vr0min
) == 1
8170 && operand_less_p (vr1max
, *vr0max
) == 1)
8172 /* ( [ ) ] or ( )[ ] */
8173 if (*vr0type
== VR_RANGE
8174 && vr1type
== VR_RANGE
)
8176 else if (*vr0type
== VR_ANTI_RANGE
8177 && vr1type
== VR_ANTI_RANGE
)
8179 else if (*vr0type
== VR_ANTI_RANGE
8180 && vr1type
== VR_RANGE
)
8182 if (TREE_CODE (vr1max
) == INTEGER_CST
)
8183 *vr0min
= int_const_binop (PLUS_EXPR
, vr1max
,
8184 build_int_cst (TREE_TYPE (vr1max
), 1));
8188 else if (*vr0type
== VR_RANGE
8189 && vr1type
== VR_ANTI_RANGE
)
8191 if (TREE_CODE (*vr0min
) == INTEGER_CST
)
8195 *vr0max
= int_const_binop (MINUS_EXPR
, *vr0min
,
8196 build_int_cst (TREE_TYPE (*vr0min
), 1));
8210 *vr0type
= VR_VARYING
;
8211 *vr0min
= NULL_TREE
;
8212 *vr0max
= NULL_TREE
;
8215 /* Intersect the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and
8216 { VR1TYPE, VR0MIN, VR0MAX } and store the result
8217 in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest
8218 possible such range. The resulting range is not canonicalized. */
8221 intersect_ranges (enum value_range_type
*vr0type
,
8222 tree
*vr0min
, tree
*vr0max
,
8223 enum value_range_type vr1type
,
8224 tree vr1min
, tree vr1max
)
8226 bool mineq
= operand_equal_p (*vr0min
, vr1min
, 0);
8227 bool maxeq
= operand_equal_p (*vr0max
, vr1max
, 0);
8229 /* [] is vr0, () is vr1 in the following classification comments. */
8233 if (*vr0type
== vr1type
)
8234 /* Nothing to do for equal ranges. */
8236 else if ((*vr0type
== VR_RANGE
8237 && vr1type
== VR_ANTI_RANGE
)
8238 || (*vr0type
== VR_ANTI_RANGE
8239 && vr1type
== VR_RANGE
))
8241 /* For anti-range with range intersection the result is empty. */
8242 *vr0type
= VR_UNDEFINED
;
8243 *vr0min
= NULL_TREE
;
8244 *vr0max
= NULL_TREE
;
8249 else if (operand_less_p (*vr0max
, vr1min
) == 1
8250 || operand_less_p (vr1max
, *vr0min
) == 1)
8252 /* [ ] ( ) or ( ) [ ]
8253 If the ranges have an empty intersection, the result of the
8254 intersect operation is the range for intersecting an
8255 anti-range with a range or empty when intersecting two ranges. */
8256 if (*vr0type
== VR_RANGE
8257 && vr1type
== VR_ANTI_RANGE
)
8259 else if (*vr0type
== VR_ANTI_RANGE
8260 && vr1type
== VR_RANGE
)
8266 else if (*vr0type
== VR_RANGE
8267 && vr1type
== VR_RANGE
)
8269 *vr0type
= VR_UNDEFINED
;
8270 *vr0min
= NULL_TREE
;
8271 *vr0max
= NULL_TREE
;
8273 else if (*vr0type
== VR_ANTI_RANGE
8274 && vr1type
== VR_ANTI_RANGE
)
8276 /* If the anti-ranges are adjacent to each other merge them. */
8277 if (TREE_CODE (*vr0max
) == INTEGER_CST
8278 && TREE_CODE (vr1min
) == INTEGER_CST
8279 && operand_less_p (*vr0max
, vr1min
) == 1
8280 && integer_onep (int_const_binop (MINUS_EXPR
,
8283 else if (TREE_CODE (vr1max
) == INTEGER_CST
8284 && TREE_CODE (*vr0min
) == INTEGER_CST
8285 && operand_less_p (vr1max
, *vr0min
) == 1
8286 && integer_onep (int_const_binop (MINUS_EXPR
,
8289 /* Else arbitrarily take VR0. */
8292 else if ((maxeq
|| operand_less_p (vr1max
, *vr0max
) == 1)
8293 && (mineq
|| operand_less_p (*vr0min
, vr1min
) == 1))
8295 /* [ ( ) ] or [( ) ] or [ ( )] */
8296 if (*vr0type
== VR_RANGE
8297 && vr1type
== VR_RANGE
)
8299 /* If both are ranges the result is the inner one. */
8304 else if (*vr0type
== VR_RANGE
8305 && vr1type
== VR_ANTI_RANGE
)
8307 /* Choose the right gap if the left one is empty. */
8310 if (TREE_CODE (vr1max
) == INTEGER_CST
)
8311 *vr0min
= int_const_binop (PLUS_EXPR
, vr1max
,
8312 build_int_cst (TREE_TYPE (vr1max
), 1));
8316 /* Choose the left gap if the right one is empty. */
8319 if (TREE_CODE (vr1min
) == INTEGER_CST
)
8320 *vr0max
= int_const_binop (MINUS_EXPR
, vr1min
,
8321 build_int_cst (TREE_TYPE (vr1min
), 1));
8325 /* Choose the anti-range if the range is effectively varying. */
8326 else if (vrp_val_is_min (*vr0min
)
8327 && vrp_val_is_max (*vr0max
))
8333 /* Else choose the range. */
8335 else if (*vr0type
== VR_ANTI_RANGE
8336 && vr1type
== VR_ANTI_RANGE
)
8337 /* If both are anti-ranges the result is the outer one. */
8339 else if (*vr0type
== VR_ANTI_RANGE
8340 && vr1type
== VR_RANGE
)
8342 /* The intersection is empty. */
8343 *vr0type
= VR_UNDEFINED
;
8344 *vr0min
= NULL_TREE
;
8345 *vr0max
= NULL_TREE
;
8350 else if ((maxeq
|| operand_less_p (*vr0max
, vr1max
) == 1)
8351 && (mineq
|| operand_less_p (vr1min
, *vr0min
) == 1))
8353 /* ( [ ] ) or ([ ] ) or ( [ ]) */
8354 if (*vr0type
== VR_RANGE
8355 && vr1type
== VR_RANGE
)
8356 /* Choose the inner range. */
8358 else if (*vr0type
== VR_ANTI_RANGE
8359 && vr1type
== VR_RANGE
)
8361 /* Choose the right gap if the left is empty. */
8364 *vr0type
= VR_RANGE
;
8365 if (TREE_CODE (*vr0max
) == INTEGER_CST
)
8366 *vr0min
= int_const_binop (PLUS_EXPR
, *vr0max
,
8367 build_int_cst (TREE_TYPE (*vr0max
), 1));
8372 /* Choose the left gap if the right is empty. */
8375 *vr0type
= VR_RANGE
;
8376 if (TREE_CODE (*vr0min
) == INTEGER_CST
)
8377 *vr0max
= int_const_binop (MINUS_EXPR
, *vr0min
,
8378 build_int_cst (TREE_TYPE (*vr0min
), 1));
8383 /* Choose the anti-range if the range is effectively varying. */
8384 else if (vrp_val_is_min (vr1min
)
8385 && vrp_val_is_max (vr1max
))
8387 /* Else choose the range. */
8395 else if (*vr0type
== VR_ANTI_RANGE
8396 && vr1type
== VR_ANTI_RANGE
)
8398 /* If both are anti-ranges the result is the outer one. */
8403 else if (vr1type
== VR_ANTI_RANGE
8404 && *vr0type
== VR_RANGE
)
8406 /* The intersection is empty. */
8407 *vr0type
= VR_UNDEFINED
;
8408 *vr0min
= NULL_TREE
;
8409 *vr0max
= NULL_TREE
;
8414 else if ((operand_less_p (vr1min
, *vr0max
) == 1
8415 || operand_equal_p (vr1min
, *vr0max
, 0))
8416 && operand_less_p (*vr0min
, vr1min
) == 1)
8418 /* [ ( ] ) or [ ]( ) */
8419 if (*vr0type
== VR_ANTI_RANGE
8420 && vr1type
== VR_ANTI_RANGE
)
8422 else if (*vr0type
== VR_RANGE
8423 && vr1type
== VR_RANGE
)
8425 else if (*vr0type
== VR_RANGE
8426 && vr1type
== VR_ANTI_RANGE
)
8428 if (TREE_CODE (vr1min
) == INTEGER_CST
)
8429 *vr0max
= int_const_binop (MINUS_EXPR
, vr1min
,
8430 build_int_cst (TREE_TYPE (vr1min
), 1));
8434 else if (*vr0type
== VR_ANTI_RANGE
8435 && vr1type
== VR_RANGE
)
8437 *vr0type
= VR_RANGE
;
8438 if (TREE_CODE (*vr0max
) == INTEGER_CST
)
8439 *vr0min
= int_const_binop (PLUS_EXPR
, *vr0max
,
8440 build_int_cst (TREE_TYPE (*vr0max
), 1));
8448 else if ((operand_less_p (*vr0min
, vr1max
) == 1
8449 || operand_equal_p (*vr0min
, vr1max
, 0))
8450 && operand_less_p (vr1min
, *vr0min
) == 1)
8452 /* ( [ ) ] or ( )[ ] */
8453 if (*vr0type
== VR_ANTI_RANGE
8454 && vr1type
== VR_ANTI_RANGE
)
8456 else if (*vr0type
== VR_RANGE
8457 && vr1type
== VR_RANGE
)
8459 else if (*vr0type
== VR_RANGE
8460 && vr1type
== VR_ANTI_RANGE
)
8462 if (TREE_CODE (vr1max
) == INTEGER_CST
)
8463 *vr0min
= int_const_binop (PLUS_EXPR
, vr1max
,
8464 build_int_cst (TREE_TYPE (vr1max
), 1));
8468 else if (*vr0type
== VR_ANTI_RANGE
8469 && vr1type
== VR_RANGE
)
8471 *vr0type
= VR_RANGE
;
8472 if (TREE_CODE (*vr0min
) == INTEGER_CST
)
8473 *vr0max
= int_const_binop (MINUS_EXPR
, *vr0min
,
8474 build_int_cst (TREE_TYPE (*vr0min
), 1));
8483 /* As a fallback simply use { *VRTYPE, *VR0MIN, *VR0MAX } as
8484 result for the intersection. That's always a conservative
8485 correct estimate. */
8491 /* Intersect the two value-ranges *VR0 and *VR1 and store the result
8492 in *VR0. This may not be the smallest possible such range. */
8495 vrp_intersect_ranges_1 (value_range
*vr0
, value_range
*vr1
)
8499 /* If either range is VR_VARYING the other one wins. */
8500 if (vr1
->type
== VR_VARYING
)
8502 if (vr0
->type
== VR_VARYING
)
8504 copy_value_range (vr0
, vr1
);
8508 /* When either range is VR_UNDEFINED the resulting range is
8509 VR_UNDEFINED, too. */
8510 if (vr0
->type
== VR_UNDEFINED
)
8512 if (vr1
->type
== VR_UNDEFINED
)
8514 set_value_range_to_undefined (vr0
);
8518 /* Save the original vr0 so we can return it as conservative intersection
8519 result when our worker turns things to varying. */
8521 intersect_ranges (&vr0
->type
, &vr0
->min
, &vr0
->max
,
8522 vr1
->type
, vr1
->min
, vr1
->max
);
8523 /* Make sure to canonicalize the result though as the inversion of a
8524 VR_RANGE can still be a VR_RANGE. */
8525 set_and_canonicalize_value_range (vr0
, vr0
->type
,
8526 vr0
->min
, vr0
->max
, vr0
->equiv
);
8527 /* If that failed, use the saved original VR0. */
8528 if (vr0
->type
== VR_VARYING
)
8533 /* If the result is VR_UNDEFINED there is no need to mess with
8534 the equivalencies. */
8535 if (vr0
->type
== VR_UNDEFINED
)
8538 /* The resulting set of equivalences for range intersection is the union of
8540 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
8541 bitmap_ior_into (vr0
->equiv
, vr1
->equiv
);
8542 else if (vr1
->equiv
&& !vr0
->equiv
)
8543 bitmap_copy (vr0
->equiv
, vr1
->equiv
);
8547 vrp_intersect_ranges (value_range
*vr0
, value_range
*vr1
)
8549 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8551 fprintf (dump_file
, "Intersecting\n ");
8552 dump_value_range (dump_file
, vr0
);
8553 fprintf (dump_file
, "\nand\n ");
8554 dump_value_range (dump_file
, vr1
);
8555 fprintf (dump_file
, "\n");
8557 vrp_intersect_ranges_1 (vr0
, vr1
);
8558 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8560 fprintf (dump_file
, "to\n ");
8561 dump_value_range (dump_file
, vr0
);
8562 fprintf (dump_file
, "\n");
8566 /* Meet operation for value ranges. Given two value ranges VR0 and
8567 VR1, store in VR0 a range that contains both VR0 and VR1. This
8568 may not be the smallest possible such range. */
8571 vrp_meet_1 (value_range
*vr0
, value_range
*vr1
)
8575 if (vr0
->type
== VR_UNDEFINED
)
8577 set_value_range (vr0
, vr1
->type
, vr1
->min
, vr1
->max
, vr1
->equiv
);
8581 if (vr1
->type
== VR_UNDEFINED
)
8583 /* VR0 already has the resulting range. */
8587 if (vr0
->type
== VR_VARYING
)
8589 /* Nothing to do. VR0 already has the resulting range. */
8593 if (vr1
->type
== VR_VARYING
)
8595 set_value_range_to_varying (vr0
);
8600 union_ranges (&vr0
->type
, &vr0
->min
, &vr0
->max
,
8601 vr1
->type
, vr1
->min
, vr1
->max
);
8602 if (vr0
->type
== VR_VARYING
)
8604 /* Failed to find an efficient meet. Before giving up and setting
8605 the result to VARYING, see if we can at least derive a useful
8606 anti-range. FIXME, all this nonsense about distinguishing
8607 anti-ranges from ranges is necessary because of the odd
8608 semantics of range_includes_zero_p and friends. */
8609 if (((saved
.type
== VR_RANGE
8610 && range_includes_zero_p (saved
.min
, saved
.max
) == 0)
8611 || (saved
.type
== VR_ANTI_RANGE
8612 && range_includes_zero_p (saved
.min
, saved
.max
) == 1))
8613 && ((vr1
->type
== VR_RANGE
8614 && range_includes_zero_p (vr1
->min
, vr1
->max
) == 0)
8615 || (vr1
->type
== VR_ANTI_RANGE
8616 && range_includes_zero_p (vr1
->min
, vr1
->max
) == 1)))
8618 set_value_range_to_nonnull (vr0
, TREE_TYPE (saved
.min
));
8620 /* Since this meet operation did not result from the meeting of
8621 two equivalent names, VR0 cannot have any equivalences. */
8623 bitmap_clear (vr0
->equiv
);
8627 set_value_range_to_varying (vr0
);
8630 set_and_canonicalize_value_range (vr0
, vr0
->type
, vr0
->min
, vr0
->max
,
8632 if (vr0
->type
== VR_VARYING
)
8635 /* The resulting set of equivalences is always the intersection of
8637 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
8638 bitmap_and_into (vr0
->equiv
, vr1
->equiv
);
8639 else if (vr0
->equiv
&& !vr1
->equiv
)
8640 bitmap_clear (vr0
->equiv
);
8644 vrp_meet (value_range
*vr0
, value_range
*vr1
)
8646 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8648 fprintf (dump_file
, "Meeting\n ");
8649 dump_value_range (dump_file
, vr0
);
8650 fprintf (dump_file
, "\nand\n ");
8651 dump_value_range (dump_file
, vr1
);
8652 fprintf (dump_file
, "\n");
8654 vrp_meet_1 (vr0
, vr1
);
8655 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8657 fprintf (dump_file
, "to\n ");
8658 dump_value_range (dump_file
, vr0
);
8659 fprintf (dump_file
, "\n");
8664 /* Visit all arguments for PHI node PHI that flow through executable
8665 edges. If a valid value range can be derived from all the incoming
8666 value ranges, set a new range for the LHS of PHI. */
8668 static enum ssa_prop_result
8669 vrp_visit_phi_node (gphi
*phi
)
8672 tree lhs
= PHI_RESULT (phi
);
8673 value_range
*lhs_vr
= get_value_range (lhs
);
8674 value_range vr_result
= VR_INITIALIZER
;
8676 int edges
, old_edges
;
8679 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8681 fprintf (dump_file
, "\nVisiting PHI node: ");
8682 print_gimple_stmt (dump_file
, phi
, 0, dump_flags
);
8686 for (i
= 0; i
< gimple_phi_num_args (phi
); i
++)
8688 edge e
= gimple_phi_arg_edge (phi
, i
);
8690 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8693 " Argument #%d (%d -> %d %sexecutable)\n",
8694 (int) i
, e
->src
->index
, e
->dest
->index
,
8695 (e
->flags
& EDGE_EXECUTABLE
) ? "" : "not ");
8698 if (e
->flags
& EDGE_EXECUTABLE
)
8700 tree arg
= PHI_ARG_DEF (phi
, i
);
8705 if (TREE_CODE (arg
) == SSA_NAME
)
8707 vr_arg
= *(get_value_range (arg
));
8708 /* Do not allow equivalences or symbolic ranges to leak in from
8709 backedges. That creates invalid equivalencies.
8710 See PR53465 and PR54767. */
8711 if (e
->flags
& EDGE_DFS_BACK
)
8713 if (vr_arg
.type
== VR_RANGE
8714 || vr_arg
.type
== VR_ANTI_RANGE
)
8716 vr_arg
.equiv
= NULL
;
8717 if (symbolic_range_p (&vr_arg
))
8719 vr_arg
.type
= VR_VARYING
;
8720 vr_arg
.min
= NULL_TREE
;
8721 vr_arg
.max
= NULL_TREE
;
8727 /* If the non-backedge arguments range is VR_VARYING then
8728 we can still try recording a simple equivalence. */
8729 if (vr_arg
.type
== VR_VARYING
)
8731 vr_arg
.type
= VR_RANGE
;
8734 vr_arg
.equiv
= NULL
;
8740 if (TREE_OVERFLOW_P (arg
))
8741 arg
= drop_tree_overflow (arg
);
8743 vr_arg
.type
= VR_RANGE
;
8746 vr_arg
.equiv
= NULL
;
8749 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8751 fprintf (dump_file
, "\t");
8752 print_generic_expr (dump_file
, arg
, dump_flags
);
8753 fprintf (dump_file
, ": ");
8754 dump_value_range (dump_file
, &vr_arg
);
8755 fprintf (dump_file
, "\n");
8759 copy_value_range (&vr_result
, &vr_arg
);
8761 vrp_meet (&vr_result
, &vr_arg
);
8764 if (vr_result
.type
== VR_VARYING
)
8769 if (vr_result
.type
== VR_VARYING
)
8771 else if (vr_result
.type
== VR_UNDEFINED
)
8774 old_edges
= vr_phi_edge_counts
[SSA_NAME_VERSION (lhs
)];
8775 vr_phi_edge_counts
[SSA_NAME_VERSION (lhs
)] = edges
;
8777 /* To prevent infinite iterations in the algorithm, derive ranges
8778 when the new value is slightly bigger or smaller than the
8779 previous one. We don't do this if we have seen a new executable
8780 edge; this helps us avoid an overflow infinity for conditionals
8781 which are not in a loop. If the old value-range was VR_UNDEFINED
8782 use the updated range and iterate one more time. */
8784 && gimple_phi_num_args (phi
) > 1
8785 && edges
== old_edges
8786 && lhs_vr
->type
!= VR_UNDEFINED
)
8788 /* Compare old and new ranges, fall back to varying if the
8789 values are not comparable. */
8790 int cmp_min
= compare_values (lhs_vr
->min
, vr_result
.min
);
8793 int cmp_max
= compare_values (lhs_vr
->max
, vr_result
.max
);
8797 /* For non VR_RANGE or for pointers fall back to varying if
8798 the range changed. */
8799 if ((lhs_vr
->type
!= VR_RANGE
|| vr_result
.type
!= VR_RANGE
8800 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
8801 && (cmp_min
!= 0 || cmp_max
!= 0))
8804 /* If the new minimum is larger than the previous one
8805 retain the old value. If the new minimum value is smaller
8806 than the previous one and not -INF go all the way to -INF + 1.
8807 In the first case, to avoid infinite bouncing between different
8808 minimums, and in the other case to avoid iterating millions of
8809 times to reach -INF. Going to -INF + 1 also lets the following
8810 iteration compute whether there will be any overflow, at the
8811 expense of one additional iteration. */
8813 vr_result
.min
= lhs_vr
->min
;
8814 else if (cmp_min
> 0
8815 && !vrp_val_is_min (vr_result
.min
))
8817 = int_const_binop (PLUS_EXPR
,
8818 vrp_val_min (TREE_TYPE (vr_result
.min
)),
8819 build_int_cst (TREE_TYPE (vr_result
.min
), 1));
8821 /* Similarly for the maximum value. */
8823 vr_result
.max
= lhs_vr
->max
;
8824 else if (cmp_max
< 0
8825 && !vrp_val_is_max (vr_result
.max
))
8827 = int_const_binop (MINUS_EXPR
,
8828 vrp_val_max (TREE_TYPE (vr_result
.min
)),
8829 build_int_cst (TREE_TYPE (vr_result
.min
), 1));
8831 /* If we dropped either bound to +-INF then if this is a loop
8832 PHI node SCEV may known more about its value-range. */
8833 if (cmp_min
> 0 || cmp_min
< 0
8834 || cmp_max
< 0 || cmp_max
> 0)
8837 goto infinite_check
;
8840 /* If the new range is different than the previous value, keep
8843 if (update_value_range (lhs
, &vr_result
))
8845 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8847 fprintf (dump_file
, "Found new range for ");
8848 print_generic_expr (dump_file
, lhs
, 0);
8849 fprintf (dump_file
, ": ");
8850 dump_value_range (dump_file
, &vr_result
);
8851 fprintf (dump_file
, "\n");
8854 if (vr_result
.type
== VR_VARYING
)
8855 return SSA_PROP_VARYING
;
8857 return SSA_PROP_INTERESTING
;
8860 /* Nothing changed, don't add outgoing edges. */
8861 return SSA_PROP_NOT_INTERESTING
;
8864 set_value_range_to_varying (&vr_result
);
8867 /* If this is a loop PHI node SCEV may known more about its value-range.
8868 scev_check can be reached from two paths, one is a fall through from above
8869 "varying" label, the other is direct goto from code block which tries to
8870 avoid infinite simulation. */
8871 if ((l
= loop_containing_stmt (phi
))
8872 && l
->header
== gimple_bb (phi
))
8873 adjust_range_with_scev (&vr_result
, l
, phi
, lhs
);
8876 /* If we will end up with a (-INF, +INF) range, set it to
8877 VARYING. Same if the previous max value was invalid for
8878 the type and we end up with vr_result.min > vr_result.max. */
8879 if ((vr_result
.type
== VR_RANGE
|| vr_result
.type
== VR_ANTI_RANGE
)
8880 && !((vrp_val_is_max (vr_result
.max
) && vrp_val_is_min (vr_result
.min
))
8881 || compare_values (vr_result
.min
, vr_result
.max
) > 0))
8884 /* No match found. Set the LHS to VARYING. */
8885 set_value_range_to_varying (lhs_vr
);
8886 return SSA_PROP_VARYING
;
8889 /* Simplify boolean operations if the source is known
8890 to be already a boolean. */
8892 simplify_truth_ops_using_ranges (gimple_stmt_iterator
*gsi
, gimple
*stmt
)
8894 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
8896 bool need_conversion
;
8898 /* We handle only !=/== case here. */
8899 gcc_assert (rhs_code
== EQ_EXPR
|| rhs_code
== NE_EXPR
);
8901 op0
= gimple_assign_rhs1 (stmt
);
8902 if (!op_with_boolean_value_range_p (op0
))
8905 op1
= gimple_assign_rhs2 (stmt
);
8906 if (!op_with_boolean_value_range_p (op1
))
8909 /* Reduce number of cases to handle to NE_EXPR. As there is no
8910 BIT_XNOR_EXPR we cannot replace A == B with a single statement. */
8911 if (rhs_code
== EQ_EXPR
)
8913 if (TREE_CODE (op1
) == INTEGER_CST
)
8914 op1
= int_const_binop (BIT_XOR_EXPR
, op1
,
8915 build_int_cst (TREE_TYPE (op1
), 1));
8920 lhs
= gimple_assign_lhs (stmt
);
8922 = !useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (op0
));
8924 /* Make sure to not sign-extend a 1-bit 1 when converting the result. */
8926 && !TYPE_UNSIGNED (TREE_TYPE (op0
))
8927 && TYPE_PRECISION (TREE_TYPE (op0
)) == 1
8928 && TYPE_PRECISION (TREE_TYPE (lhs
)) > 1)
8931 /* For A != 0 we can substitute A itself. */
8932 if (integer_zerop (op1
))
8933 gimple_assign_set_rhs_with_ops (gsi
,
8935 ? NOP_EXPR
: TREE_CODE (op0
), op0
);
8936 /* For A != B we substitute A ^ B. Either with conversion. */
8937 else if (need_conversion
)
8939 tree tem
= make_ssa_name (TREE_TYPE (op0
));
8941 = gimple_build_assign (tem
, BIT_XOR_EXPR
, op0
, op1
);
8942 gsi_insert_before (gsi
, newop
, GSI_SAME_STMT
);
8943 if (INTEGRAL_TYPE_P (TREE_TYPE (tem
))
8944 && TYPE_PRECISION (TREE_TYPE (tem
)) > 1)
8945 set_range_info (tem
, VR_RANGE
,
8946 wi::zero (TYPE_PRECISION (TREE_TYPE (tem
))),
8947 wi::one (TYPE_PRECISION (TREE_TYPE (tem
))));
8948 gimple_assign_set_rhs_with_ops (gsi
, NOP_EXPR
, tem
);
8952 gimple_assign_set_rhs_with_ops (gsi
, BIT_XOR_EXPR
, op0
, op1
);
8953 update_stmt (gsi_stmt (*gsi
));
8958 /* Simplify a division or modulo operator to a right shift or
8959 bitwise and if the first operand is unsigned or is greater
8960 than zero and the second operand is an exact power of two.
8961 For TRUNC_MOD_EXPR op0 % op1 with constant op1, optimize it
8962 into just op0 if op0's range is known to be a subset of
8963 [-op1 + 1, op1 - 1] for signed and [0, op1 - 1] for unsigned
8967 simplify_div_or_mod_using_ranges (gimple_stmt_iterator
*gsi
, gimple
*stmt
)
8969 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
8971 tree op0
= gimple_assign_rhs1 (stmt
);
8972 tree op1
= gimple_assign_rhs2 (stmt
);
8973 value_range
*vr
= get_value_range (op0
);
8975 if (rhs_code
== TRUNC_MOD_EXPR
8976 && TREE_CODE (op1
) == INTEGER_CST
8977 && tree_int_cst_sgn (op1
) == 1
8978 && range_int_cst_p (vr
)
8979 && tree_int_cst_lt (vr
->max
, op1
))
8981 if (TYPE_UNSIGNED (TREE_TYPE (op0
))
8982 || tree_int_cst_sgn (vr
->min
) >= 0
8983 || tree_int_cst_lt (fold_unary (NEGATE_EXPR
, TREE_TYPE (op1
), op1
),
8986 /* If op0 already has the range op0 % op1 has,
8987 then TRUNC_MOD_EXPR won't change anything. */
8988 gimple_stmt_iterator gsi
= gsi_for_stmt (stmt
);
8989 gimple_assign_set_rhs_from_tree (&gsi
, op0
);
8995 if (!integer_pow2p (op1
))
8997 /* X % -Y can be only optimized into X % Y either if
8998 X is not INT_MIN, or Y is not -1. Fold it now, as after
8999 remove_range_assertions the range info might be not available
9001 if (rhs_code
== TRUNC_MOD_EXPR
9002 && fold_stmt (gsi
, follow_single_use_edges
))
9007 if (TYPE_UNSIGNED (TREE_TYPE (op0
)))
9008 val
= integer_one_node
;
9013 val
= compare_range_with_value (GE_EXPR
, vr
, integer_zero_node
, &sop
);
9017 && integer_onep (val
)
9018 && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
9020 location_t location
;
9022 if (!gimple_has_location (stmt
))
9023 location
= input_location
;
9025 location
= gimple_location (stmt
);
9026 warning_at (location
, OPT_Wstrict_overflow
,
9027 "assuming signed overflow does not occur when "
9028 "simplifying %</%> or %<%%%> to %<>>%> or %<&%>");
9032 if (val
&& integer_onep (val
))
9036 if (rhs_code
== TRUNC_DIV_EXPR
)
9038 t
= build_int_cst (integer_type_node
, tree_log2 (op1
));
9039 gimple_assign_set_rhs_code (stmt
, RSHIFT_EXPR
);
9040 gimple_assign_set_rhs1 (stmt
, op0
);
9041 gimple_assign_set_rhs2 (stmt
, t
);
9045 t
= build_int_cst (TREE_TYPE (op1
), 1);
9046 t
= int_const_binop (MINUS_EXPR
, op1
, t
);
9047 t
= fold_convert (TREE_TYPE (op0
), t
);
9049 gimple_assign_set_rhs_code (stmt
, BIT_AND_EXPR
);
9050 gimple_assign_set_rhs1 (stmt
, op0
);
9051 gimple_assign_set_rhs2 (stmt
, t
);
9061 /* Simplify a min or max if the ranges of the two operands are
9062 disjoint. Return true if we do simplify. */
9065 simplify_min_or_max_using_ranges (gimple
*stmt
)
9067 tree op0
= gimple_assign_rhs1 (stmt
);
9068 tree op1
= gimple_assign_rhs2 (stmt
);
9072 val
= (vrp_evaluate_conditional_warnv_with_ops_using_ranges
9073 (LE_EXPR
, op0
, op1
, &sop
));
9077 val
= (vrp_evaluate_conditional_warnv_with_ops_using_ranges
9078 (LT_EXPR
, op0
, op1
, &sop
));
9083 if (sop
&& issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
9085 location_t location
;
9087 if (!gimple_has_location (stmt
))
9088 location
= input_location
;
9090 location
= gimple_location (stmt
);
9091 warning_at (location
, OPT_Wstrict_overflow
,
9092 "assuming signed overflow does not occur when "
9093 "simplifying %<min/max (X,Y)%> to %<X%> or %<Y%>");
9096 /* VAL == TRUE -> OP0 < or <= op1
9097 VAL == FALSE -> OP0 > or >= op1. */
9098 tree res
= ((gimple_assign_rhs_code (stmt
) == MAX_EXPR
)
9099 == integer_zerop (val
)) ? op0
: op1
;
9100 gimple_stmt_iterator gsi
= gsi_for_stmt (stmt
);
9101 gimple_assign_set_rhs_from_tree (&gsi
, res
);
9109 /* If the operand to an ABS_EXPR is >= 0, then eliminate the
9110 ABS_EXPR. If the operand is <= 0, then simplify the
9111 ABS_EXPR into a NEGATE_EXPR. */
9114 simplify_abs_using_ranges (gimple
*stmt
)
9116 tree op
= gimple_assign_rhs1 (stmt
);
9117 value_range
*vr
= get_value_range (op
);
9124 val
= compare_range_with_value (LE_EXPR
, vr
, integer_zero_node
, &sop
);
9127 /* The range is neither <= 0 nor > 0. Now see if it is
9128 either < 0 or >= 0. */
9130 val
= compare_range_with_value (LT_EXPR
, vr
, integer_zero_node
,
9136 if (sop
&& issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
9138 location_t location
;
9140 if (!gimple_has_location (stmt
))
9141 location
= input_location
;
9143 location
= gimple_location (stmt
);
9144 warning_at (location
, OPT_Wstrict_overflow
,
9145 "assuming signed overflow does not occur when "
9146 "simplifying %<abs (X)%> to %<X%> or %<-X%>");
9149 gimple_assign_set_rhs1 (stmt
, op
);
9150 if (integer_zerop (val
))
9151 gimple_assign_set_rhs_code (stmt
, SSA_NAME
);
9153 gimple_assign_set_rhs_code (stmt
, NEGATE_EXPR
);
9162 /* Optimize away redundant BIT_AND_EXPR and BIT_IOR_EXPR.
9163 If all the bits that are being cleared by & are already
9164 known to be zero from VR, or all the bits that are being
9165 set by | are already known to be one from VR, the bit
9166 operation is redundant. */
9169 simplify_bit_ops_using_ranges (gimple_stmt_iterator
*gsi
, gimple
*stmt
)
9171 tree op0
= gimple_assign_rhs1 (stmt
);
9172 tree op1
= gimple_assign_rhs2 (stmt
);
9173 tree op
= NULL_TREE
;
9174 value_range vr0
= VR_INITIALIZER
;
9175 value_range vr1
= VR_INITIALIZER
;
9176 wide_int may_be_nonzero0
, may_be_nonzero1
;
9177 wide_int must_be_nonzero0
, must_be_nonzero1
;
9180 if (TREE_CODE (op0
) == SSA_NAME
)
9181 vr0
= *(get_value_range (op0
));
9182 else if (is_gimple_min_invariant (op0
))
9183 set_value_range_to_value (&vr0
, op0
, NULL
);
9187 if (TREE_CODE (op1
) == SSA_NAME
)
9188 vr1
= *(get_value_range (op1
));
9189 else if (is_gimple_min_invariant (op1
))
9190 set_value_range_to_value (&vr1
, op1
, NULL
);
9194 if (!zero_nonzero_bits_from_vr (TREE_TYPE (op0
), &vr0
, &may_be_nonzero0
,
9197 if (!zero_nonzero_bits_from_vr (TREE_TYPE (op1
), &vr1
, &may_be_nonzero1
,
9201 switch (gimple_assign_rhs_code (stmt
))
9204 mask
= may_be_nonzero0
.and_not (must_be_nonzero1
);
9210 mask
= may_be_nonzero1
.and_not (must_be_nonzero0
);
9218 mask
= may_be_nonzero0
.and_not (must_be_nonzero1
);
9224 mask
= may_be_nonzero1
.and_not (must_be_nonzero0
);
9235 if (op
== NULL_TREE
)
9238 gimple_assign_set_rhs_with_ops (gsi
, TREE_CODE (op
), op
);
9239 update_stmt (gsi_stmt (*gsi
));
9243 /* We are comparing trees OP0 and OP1 using COND_CODE. OP0 has
9244 a known value range VR.
9246 If there is one and only one value which will satisfy the
9247 conditional, then return that value. Else return NULL.
9249 If signed overflow must be undefined for the value to satisfy
9250 the conditional, then set *STRICT_OVERFLOW_P to true. */
9253 test_for_singularity (enum tree_code cond_code
, tree op0
,
9254 tree op1
, value_range
*vr
,
9255 bool *strict_overflow_p
)
9260 /* Extract minimum/maximum values which satisfy the conditional as it was
9262 if (cond_code
== LE_EXPR
|| cond_code
== LT_EXPR
)
9264 /* This should not be negative infinity; there is no overflow
9266 min
= TYPE_MIN_VALUE (TREE_TYPE (op0
));
9269 if (cond_code
== LT_EXPR
&& !is_overflow_infinity (max
))
9271 tree one
= build_int_cst (TREE_TYPE (op0
), 1);
9272 max
= fold_build2 (MINUS_EXPR
, TREE_TYPE (op0
), max
, one
);
9274 TREE_NO_WARNING (max
) = 1;
9277 else if (cond_code
== GE_EXPR
|| cond_code
== GT_EXPR
)
9279 /* This should not be positive infinity; there is no overflow
9281 max
= TYPE_MAX_VALUE (TREE_TYPE (op0
));
9284 if (cond_code
== GT_EXPR
&& !is_overflow_infinity (min
))
9286 tree one
= build_int_cst (TREE_TYPE (op0
), 1);
9287 min
= fold_build2 (PLUS_EXPR
, TREE_TYPE (op0
), min
, one
);
9289 TREE_NO_WARNING (min
) = 1;
9293 /* Now refine the minimum and maximum values using any
9294 value range information we have for op0. */
9297 if (compare_values (vr
->min
, min
) == 1)
9299 if (compare_values (vr
->max
, max
) == -1)
9302 /* If the new min/max values have converged to a single value,
9303 then there is only one value which can satisfy the condition,
9304 return that value. */
9305 if (operand_equal_p (min
, max
, 0) && is_gimple_min_invariant (min
))
9307 if ((cond_code
== LE_EXPR
|| cond_code
== LT_EXPR
)
9308 && is_overflow_infinity (vr
->max
))
9309 *strict_overflow_p
= true;
9310 if ((cond_code
== GE_EXPR
|| cond_code
== GT_EXPR
)
9311 && is_overflow_infinity (vr
->min
))
9312 *strict_overflow_p
= true;
9320 /* Return whether the value range *VR fits in an integer type specified
9321 by PRECISION and UNSIGNED_P. */
9324 range_fits_type_p (value_range
*vr
, unsigned dest_precision
, signop dest_sgn
)
9327 unsigned src_precision
;
9331 /* We can only handle integral and pointer types. */
9332 src_type
= TREE_TYPE (vr
->min
);
9333 if (!INTEGRAL_TYPE_P (src_type
)
9334 && !POINTER_TYPE_P (src_type
))
9337 /* An extension is fine unless VR is SIGNED and dest_sgn is UNSIGNED,
9338 and so is an identity transform. */
9339 src_precision
= TYPE_PRECISION (TREE_TYPE (vr
->min
));
9340 src_sgn
= TYPE_SIGN (src_type
);
9341 if ((src_precision
< dest_precision
9342 && !(dest_sgn
== UNSIGNED
&& src_sgn
== SIGNED
))
9343 || (src_precision
== dest_precision
&& src_sgn
== dest_sgn
))
9346 /* Now we can only handle ranges with constant bounds. */
9347 if (vr
->type
!= VR_RANGE
9348 || TREE_CODE (vr
->min
) != INTEGER_CST
9349 || TREE_CODE (vr
->max
) != INTEGER_CST
)
9352 /* For sign changes, the MSB of the wide_int has to be clear.
9353 An unsigned value with its MSB set cannot be represented by
9354 a signed wide_int, while a negative value cannot be represented
9355 by an unsigned wide_int. */
9356 if (src_sgn
!= dest_sgn
9357 && (wi::lts_p (vr
->min
, 0) || wi::lts_p (vr
->max
, 0)))
9360 /* Then we can perform the conversion on both ends and compare
9361 the result for equality. */
9362 tem
= wi::ext (wi::to_widest (vr
->min
), dest_precision
, dest_sgn
);
9363 if (tem
!= wi::to_widest (vr
->min
))
9365 tem
= wi::ext (wi::to_widest (vr
->max
), dest_precision
, dest_sgn
);
9366 if (tem
!= wi::to_widest (vr
->max
))
9372 /* Simplify a conditional using a relational operator to an equality
9373 test if the range information indicates only one value can satisfy
9374 the original conditional. */
9377 simplify_cond_using_ranges (gcond
*stmt
)
9379 tree op0
= gimple_cond_lhs (stmt
);
9380 tree op1
= gimple_cond_rhs (stmt
);
9381 enum tree_code cond_code
= gimple_cond_code (stmt
);
9383 if (cond_code
!= NE_EXPR
9384 && cond_code
!= EQ_EXPR
9385 && TREE_CODE (op0
) == SSA_NAME
9386 && INTEGRAL_TYPE_P (TREE_TYPE (op0
))
9387 && is_gimple_min_invariant (op1
))
9389 value_range
*vr
= get_value_range (op0
);
9391 /* If we have range information for OP0, then we might be
9392 able to simplify this conditional. */
9393 if (vr
->type
== VR_RANGE
)
9395 enum warn_strict_overflow_code wc
= WARN_STRICT_OVERFLOW_COMPARISON
;
9397 tree new_tree
= test_for_singularity (cond_code
, op0
, op1
, vr
, &sop
);
9400 && (!sop
|| TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0
))))
9404 fprintf (dump_file
, "Simplified relational ");
9405 print_gimple_stmt (dump_file
, stmt
, 0, 0);
9406 fprintf (dump_file
, " into ");
9409 gimple_cond_set_code (stmt
, EQ_EXPR
);
9410 gimple_cond_set_lhs (stmt
, op0
);
9411 gimple_cond_set_rhs (stmt
, new_tree
);
9417 print_gimple_stmt (dump_file
, stmt
, 0, 0);
9418 fprintf (dump_file
, "\n");
9421 if (sop
&& issue_strict_overflow_warning (wc
))
9423 location_t location
= input_location
;
9424 if (gimple_has_location (stmt
))
9425 location
= gimple_location (stmt
);
9427 warning_at (location
, OPT_Wstrict_overflow
,
9428 "assuming signed overflow does not occur when "
9429 "simplifying conditional");
9435 /* Try again after inverting the condition. We only deal
9436 with integral types here, so no need to worry about
9437 issues with inverting FP comparisons. */
9439 new_tree
= test_for_singularity
9440 (invert_tree_comparison (cond_code
, false),
9441 op0
, op1
, vr
, &sop
);
9444 && (!sop
|| TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0
))))
9448 fprintf (dump_file
, "Simplified relational ");
9449 print_gimple_stmt (dump_file
, stmt
, 0, 0);
9450 fprintf (dump_file
, " into ");
9453 gimple_cond_set_code (stmt
, NE_EXPR
);
9454 gimple_cond_set_lhs (stmt
, op0
);
9455 gimple_cond_set_rhs (stmt
, new_tree
);
9461 print_gimple_stmt (dump_file
, stmt
, 0, 0);
9462 fprintf (dump_file
, "\n");
9465 if (sop
&& issue_strict_overflow_warning (wc
))
9467 location_t location
= input_location
;
9468 if (gimple_has_location (stmt
))
9469 location
= gimple_location (stmt
);
9471 warning_at (location
, OPT_Wstrict_overflow
,
9472 "assuming signed overflow does not occur when "
9473 "simplifying conditional");
9481 /* If we have a comparison of an SSA_NAME (OP0) against a constant,
9482 see if OP0 was set by a type conversion where the source of
9483 the conversion is another SSA_NAME with a range that fits
9484 into the range of OP0's type.
9486 If so, the conversion is redundant as the earlier SSA_NAME can be
9487 used for the comparison directly if we just massage the constant in the
9489 if (TREE_CODE (op0
) == SSA_NAME
9490 && TREE_CODE (op1
) == INTEGER_CST
)
9492 gimple
*def_stmt
= SSA_NAME_DEF_STMT (op0
);
9495 if (!is_gimple_assign (def_stmt
)
9496 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
)))
9499 innerop
= gimple_assign_rhs1 (def_stmt
);
9501 if (TREE_CODE (innerop
) == SSA_NAME
9502 && !POINTER_TYPE_P (TREE_TYPE (innerop
))
9503 && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (innerop
)
9504 && desired_pro_or_demotion_p (TREE_TYPE (innerop
), TREE_TYPE (op0
)))
9506 value_range
*vr
= get_value_range (innerop
);
9508 if (range_int_cst_p (vr
)
9509 && range_fits_type_p (vr
,
9510 TYPE_PRECISION (TREE_TYPE (op0
)),
9511 TYPE_SIGN (TREE_TYPE (op0
)))
9512 && int_fits_type_p (op1
, TREE_TYPE (innerop
))
9513 /* The range must not have overflowed, or if it did overflow
9514 we must not be wrapping/trapping overflow and optimizing
9515 with strict overflow semantics. */
9516 && ((!is_negative_overflow_infinity (vr
->min
)
9517 && !is_positive_overflow_infinity (vr
->max
))
9518 || TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (innerop
))))
9520 /* If the range overflowed and the user has asked for warnings
9521 when strict overflow semantics were used to optimize code,
9522 issue an appropriate warning. */
9523 if (cond_code
!= EQ_EXPR
&& cond_code
!= NE_EXPR
9524 && (is_negative_overflow_infinity (vr
->min
)
9525 || is_positive_overflow_infinity (vr
->max
))
9526 && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_CONDITIONAL
))
9528 location_t location
;
9530 if (!gimple_has_location (stmt
))
9531 location
= input_location
;
9533 location
= gimple_location (stmt
);
9534 warning_at (location
, OPT_Wstrict_overflow
,
9535 "assuming signed overflow does not occur when "
9536 "simplifying conditional");
9539 tree newconst
= fold_convert (TREE_TYPE (innerop
), op1
);
9540 gimple_cond_set_lhs (stmt
, innerop
);
9541 gimple_cond_set_rhs (stmt
, newconst
);
9550 /* Simplify a switch statement using the value range of the switch
9554 simplify_switch_using_ranges (gswitch
*stmt
)
9556 tree op
= gimple_switch_index (stmt
);
9561 size_t i
= 0, j
= 0, n
, n2
;
9564 size_t k
= 1, l
= 0;
9566 if (TREE_CODE (op
) == SSA_NAME
)
9568 vr
= get_value_range (op
);
9570 /* We can only handle integer ranges. */
9571 if ((vr
->type
!= VR_RANGE
9572 && vr
->type
!= VR_ANTI_RANGE
)
9573 || symbolic_range_p (vr
))
9576 /* Find case label for min/max of the value range. */
9577 take_default
= !find_case_label_ranges (stmt
, vr
, &i
, &j
, &k
, &l
);
9579 else if (TREE_CODE (op
) == INTEGER_CST
)
9581 take_default
= !find_case_label_index (stmt
, 1, op
, &i
);
9595 n
= gimple_switch_num_labels (stmt
);
9597 /* Bail out if this is just all edges taken. */
9603 /* Build a new vector of taken case labels. */
9604 vec2
= make_tree_vec (j
- i
+ 1 + l
- k
+ 1 + (int)take_default
);
9607 /* Add the default edge, if necessary. */
9609 TREE_VEC_ELT (vec2
, n2
++) = gimple_switch_default_label (stmt
);
9611 for (; i
<= j
; ++i
, ++n2
)
9612 TREE_VEC_ELT (vec2
, n2
) = gimple_switch_label (stmt
, i
);
9614 for (; k
<= l
; ++k
, ++n2
)
9615 TREE_VEC_ELT (vec2
, n2
) = gimple_switch_label (stmt
, k
);
9617 /* Mark needed edges. */
9618 for (i
= 0; i
< n2
; ++i
)
9620 e
= find_edge (gimple_bb (stmt
),
9621 label_to_block (CASE_LABEL (TREE_VEC_ELT (vec2
, i
))));
9622 e
->aux
= (void *)-1;
9625 /* Queue not needed edges for later removal. */
9626 FOR_EACH_EDGE (e
, ei
, gimple_bb (stmt
)->succs
)
9628 if (e
->aux
== (void *)-1)
9634 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
9636 fprintf (dump_file
, "removing unreachable case label\n");
9638 to_remove_edges
.safe_push (e
);
9639 e
->flags
&= ~EDGE_EXECUTABLE
;
9642 /* And queue an update for the stmt. */
9645 to_update_switch_stmts
.safe_push (su
);
9649 /* Simplify an integral conversion from an SSA name in STMT. */
9652 simplify_conversion_using_ranges (gimple
*stmt
)
9654 tree innerop
, middleop
, finaltype
;
9656 signop inner_sgn
, middle_sgn
, final_sgn
;
9657 unsigned inner_prec
, middle_prec
, final_prec
;
9658 widest_int innermin
, innermed
, innermax
, middlemin
, middlemed
, middlemax
;
9660 finaltype
= TREE_TYPE (gimple_assign_lhs (stmt
));
9661 if (!INTEGRAL_TYPE_P (finaltype
))
9663 middleop
= gimple_assign_rhs1 (stmt
);
9664 def_stmt
= SSA_NAME_DEF_STMT (middleop
);
9665 if (!is_gimple_assign (def_stmt
)
9666 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
)))
9668 innerop
= gimple_assign_rhs1 (def_stmt
);
9669 if (TREE_CODE (innerop
) != SSA_NAME
9670 || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (innerop
))
9673 /* Get the value-range of the inner operand. Use get_range_info in
9674 case innerop was created during substitute-and-fold. */
9675 wide_int imin
, imax
;
9676 if (!INTEGRAL_TYPE_P (TREE_TYPE (innerop
))
9677 || get_range_info (innerop
, &imin
, &imax
) != VR_RANGE
)
9679 innermin
= widest_int::from (imin
, TYPE_SIGN (TREE_TYPE (innerop
)));
9680 innermax
= widest_int::from (imax
, TYPE_SIGN (TREE_TYPE (innerop
)));
9682 /* Simulate the conversion chain to check if the result is equal if
9683 the middle conversion is removed. */
9684 inner_prec
= TYPE_PRECISION (TREE_TYPE (innerop
));
9685 middle_prec
= TYPE_PRECISION (TREE_TYPE (middleop
));
9686 final_prec
= TYPE_PRECISION (finaltype
);
9688 /* If the first conversion is not injective, the second must not
9690 if (wi::gtu_p (innermax
- innermin
,
9691 wi::mask
<widest_int
> (middle_prec
, false))
9692 && middle_prec
< final_prec
)
9694 /* We also want a medium value so that we can track the effect that
9695 narrowing conversions with sign change have. */
9696 inner_sgn
= TYPE_SIGN (TREE_TYPE (innerop
));
9697 if (inner_sgn
== UNSIGNED
)
9698 innermed
= wi::shifted_mask
<widest_int
> (1, inner_prec
- 1, false);
9701 if (wi::cmp (innermin
, innermed
, inner_sgn
) >= 0
9702 || wi::cmp (innermed
, innermax
, inner_sgn
) >= 0)
9703 innermed
= innermin
;
9705 middle_sgn
= TYPE_SIGN (TREE_TYPE (middleop
));
9706 middlemin
= wi::ext (innermin
, middle_prec
, middle_sgn
);
9707 middlemed
= wi::ext (innermed
, middle_prec
, middle_sgn
);
9708 middlemax
= wi::ext (innermax
, middle_prec
, middle_sgn
);
9710 /* Require that the final conversion applied to both the original
9711 and the intermediate range produces the same result. */
9712 final_sgn
= TYPE_SIGN (finaltype
);
9713 if (wi::ext (middlemin
, final_prec
, final_sgn
)
9714 != wi::ext (innermin
, final_prec
, final_sgn
)
9715 || wi::ext (middlemed
, final_prec
, final_sgn
)
9716 != wi::ext (innermed
, final_prec
, final_sgn
)
9717 || wi::ext (middlemax
, final_prec
, final_sgn
)
9718 != wi::ext (innermax
, final_prec
, final_sgn
))
9721 gimple_assign_set_rhs1 (stmt
, innerop
);
9726 /* Simplify a conversion from integral SSA name to float in STMT. */
9729 simplify_float_conversion_using_ranges (gimple_stmt_iterator
*gsi
,
9732 tree rhs1
= gimple_assign_rhs1 (stmt
);
9733 value_range
*vr
= get_value_range (rhs1
);
9734 machine_mode fltmode
= TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt
)));
9739 /* We can only handle constant ranges. */
9740 if (vr
->type
!= VR_RANGE
9741 || TREE_CODE (vr
->min
) != INTEGER_CST
9742 || TREE_CODE (vr
->max
) != INTEGER_CST
)
9745 /* First check if we can use a signed type in place of an unsigned. */
9746 if (TYPE_UNSIGNED (TREE_TYPE (rhs1
))
9747 && (can_float_p (fltmode
, TYPE_MODE (TREE_TYPE (rhs1
)), 0)
9748 != CODE_FOR_nothing
)
9749 && range_fits_type_p (vr
, TYPE_PRECISION (TREE_TYPE (rhs1
)), SIGNED
))
9750 mode
= TYPE_MODE (TREE_TYPE (rhs1
));
9751 /* If we can do the conversion in the current input mode do nothing. */
9752 else if (can_float_p (fltmode
, TYPE_MODE (TREE_TYPE (rhs1
)),
9753 TYPE_UNSIGNED (TREE_TYPE (rhs1
))) != CODE_FOR_nothing
)
9755 /* Otherwise search for a mode we can use, starting from the narrowest
9756 integer mode available. */
9759 mode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
9762 /* If we cannot do a signed conversion to float from mode
9763 or if the value-range does not fit in the signed type
9764 try with a wider mode. */
9765 if (can_float_p (fltmode
, mode
, 0) != CODE_FOR_nothing
9766 && range_fits_type_p (vr
, GET_MODE_PRECISION (mode
), SIGNED
))
9769 mode
= GET_MODE_WIDER_MODE (mode
);
9770 /* But do not widen the input. Instead leave that to the
9771 optabs expansion code. */
9772 if (GET_MODE_PRECISION (mode
) > TYPE_PRECISION (TREE_TYPE (rhs1
)))
9775 while (mode
!= VOIDmode
);
9776 if (mode
== VOIDmode
)
9780 /* It works, insert a truncation or sign-change before the
9781 float conversion. */
9782 tem
= make_ssa_name (build_nonstandard_integer_type
9783 (GET_MODE_PRECISION (mode
), 0));
9784 conv
= gimple_build_assign (tem
, NOP_EXPR
, rhs1
);
9785 gsi_insert_before (gsi
, conv
, GSI_SAME_STMT
);
9786 gimple_assign_set_rhs1 (stmt
, tem
);
9792 /* Simplify an internal fn call using ranges if possible. */
9795 simplify_internal_call_using_ranges (gimple_stmt_iterator
*gsi
, gimple
*stmt
)
9797 enum tree_code subcode
;
9798 bool is_ubsan
= false;
9800 switch (gimple_call_internal_fn (stmt
))
9802 case IFN_UBSAN_CHECK_ADD
:
9803 subcode
= PLUS_EXPR
;
9806 case IFN_UBSAN_CHECK_SUB
:
9807 subcode
= MINUS_EXPR
;
9810 case IFN_UBSAN_CHECK_MUL
:
9811 subcode
= MULT_EXPR
;
9814 case IFN_ADD_OVERFLOW
:
9815 subcode
= PLUS_EXPR
;
9817 case IFN_SUB_OVERFLOW
:
9818 subcode
= MINUS_EXPR
;
9820 case IFN_MUL_OVERFLOW
:
9821 subcode
= MULT_EXPR
;
9827 tree op0
= gimple_call_arg (stmt
, 0);
9828 tree op1
= gimple_call_arg (stmt
, 1);
9831 type
= TREE_TYPE (op0
);
9832 else if (gimple_call_lhs (stmt
) == NULL_TREE
)
9835 type
= TREE_TYPE (TREE_TYPE (gimple_call_lhs (stmt
)));
9836 if (!check_for_binary_op_overflow (subcode
, type
, op0
, op1
, &ovf
)
9837 || (is_ubsan
&& ovf
))
9841 location_t loc
= gimple_location (stmt
);
9843 g
= gimple_build_assign (gimple_call_lhs (stmt
), subcode
, op0
, op1
);
9846 int prec
= TYPE_PRECISION (type
);
9849 || !useless_type_conversion_p (type
, TREE_TYPE (op0
))
9850 || !useless_type_conversion_p (type
, TREE_TYPE (op1
)))
9851 utype
= build_nonstandard_integer_type (prec
, 1);
9852 if (TREE_CODE (op0
) == INTEGER_CST
)
9853 op0
= fold_convert (utype
, op0
);
9854 else if (!useless_type_conversion_p (utype
, TREE_TYPE (op0
)))
9856 g
= gimple_build_assign (make_ssa_name (utype
), NOP_EXPR
, op0
);
9857 gimple_set_location (g
, loc
);
9858 gsi_insert_before (gsi
, g
, GSI_SAME_STMT
);
9859 op0
= gimple_assign_lhs (g
);
9861 if (TREE_CODE (op1
) == INTEGER_CST
)
9862 op1
= fold_convert (utype
, op1
);
9863 else if (!useless_type_conversion_p (utype
, TREE_TYPE (op1
)))
9865 g
= gimple_build_assign (make_ssa_name (utype
), NOP_EXPR
, op1
);
9866 gimple_set_location (g
, loc
);
9867 gsi_insert_before (gsi
, g
, GSI_SAME_STMT
);
9868 op1
= gimple_assign_lhs (g
);
9870 g
= gimple_build_assign (make_ssa_name (utype
), subcode
, op0
, op1
);
9871 gimple_set_location (g
, loc
);
9872 gsi_insert_before (gsi
, g
, GSI_SAME_STMT
);
9875 g
= gimple_build_assign (make_ssa_name (type
), NOP_EXPR
,
9876 gimple_assign_lhs (g
));
9877 gimple_set_location (g
, loc
);
9878 gsi_insert_before (gsi
, g
, GSI_SAME_STMT
);
9880 g
= gimple_build_assign (gimple_call_lhs (stmt
), COMPLEX_EXPR
,
9881 gimple_assign_lhs (g
),
9882 build_int_cst (type
, ovf
));
9884 gimple_set_location (g
, loc
);
9885 gsi_replace (gsi
, g
, false);
9889 /* Simplify STMT using ranges if possible. */
9892 simplify_stmt_using_ranges (gimple_stmt_iterator
*gsi
)
9894 gimple
*stmt
= gsi_stmt (*gsi
);
9895 if (is_gimple_assign (stmt
))
9897 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
9898 tree rhs1
= gimple_assign_rhs1 (stmt
);
9904 /* Transform EQ_EXPR, NE_EXPR into BIT_XOR_EXPR or identity
9905 if the RHS is zero or one, and the LHS are known to be boolean
9907 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
9908 return simplify_truth_ops_using_ranges (gsi
, stmt
);
9911 /* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
9912 and BIT_AND_EXPR respectively if the first operand is greater
9913 than zero and the second operand is an exact power of two.
9914 Also optimize TRUNC_MOD_EXPR away if the second operand is
9915 constant and the first operand already has the right value
9917 case TRUNC_DIV_EXPR
:
9918 case TRUNC_MOD_EXPR
:
9919 if (TREE_CODE (rhs1
) == SSA_NAME
9920 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
9921 return simplify_div_or_mod_using_ranges (gsi
, stmt
);
9924 /* Transform ABS (X) into X or -X as appropriate. */
9926 if (TREE_CODE (rhs1
) == SSA_NAME
9927 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
9928 return simplify_abs_using_ranges (stmt
);
9933 /* Optimize away BIT_AND_EXPR and BIT_IOR_EXPR
9934 if all the bits being cleared are already cleared or
9935 all the bits being set are already set. */
9936 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
9937 return simplify_bit_ops_using_ranges (gsi
, stmt
);
9941 if (TREE_CODE (rhs1
) == SSA_NAME
9942 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
9943 return simplify_conversion_using_ranges (stmt
);
9947 if (TREE_CODE (rhs1
) == SSA_NAME
9948 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
9949 return simplify_float_conversion_using_ranges (gsi
, stmt
);
9954 return simplify_min_or_max_using_ranges (stmt
);
9961 else if (gimple_code (stmt
) == GIMPLE_COND
)
9962 return simplify_cond_using_ranges (as_a
<gcond
*> (stmt
));
9963 else if (gimple_code (stmt
) == GIMPLE_SWITCH
)
9964 return simplify_switch_using_ranges (as_a
<gswitch
*> (stmt
));
9965 else if (is_gimple_call (stmt
)
9966 && gimple_call_internal_p (stmt
))
9967 return simplify_internal_call_using_ranges (gsi
, stmt
);
9972 /* If the statement pointed by SI has a predicate whose value can be
9973 computed using the value range information computed by VRP, compute
9974 its value and return true. Otherwise, return false. */
9977 fold_predicate_in (gimple_stmt_iterator
*si
)
9979 bool assignment_p
= false;
9981 gimple
*stmt
= gsi_stmt (*si
);
9983 if (is_gimple_assign (stmt
)
9984 && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt
)) == tcc_comparison
)
9986 assignment_p
= true;
9987 val
= vrp_evaluate_conditional (gimple_assign_rhs_code (stmt
),
9988 gimple_assign_rhs1 (stmt
),
9989 gimple_assign_rhs2 (stmt
),
9992 else if (gcond
*cond_stmt
= dyn_cast
<gcond
*> (stmt
))
9993 val
= vrp_evaluate_conditional (gimple_cond_code (cond_stmt
),
9994 gimple_cond_lhs (cond_stmt
),
9995 gimple_cond_rhs (cond_stmt
),
10003 val
= fold_convert (gimple_expr_type (stmt
), val
);
10007 fprintf (dump_file
, "Folding predicate ");
10008 print_gimple_expr (dump_file
, stmt
, 0, 0);
10009 fprintf (dump_file
, " to ");
10010 print_generic_expr (dump_file
, val
, 0);
10011 fprintf (dump_file
, "\n");
10014 if (is_gimple_assign (stmt
))
10015 gimple_assign_set_rhs_from_tree (si
, val
);
10018 gcc_assert (gimple_code (stmt
) == GIMPLE_COND
);
10019 gcond
*cond_stmt
= as_a
<gcond
*> (stmt
);
10020 if (integer_zerop (val
))
10021 gimple_cond_make_false (cond_stmt
);
10022 else if (integer_onep (val
))
10023 gimple_cond_make_true (cond_stmt
);
10025 gcc_unreachable ();
10034 /* Callback for substitute_and_fold folding the stmt at *SI. */
10037 vrp_fold_stmt (gimple_stmt_iterator
*si
)
10039 if (fold_predicate_in (si
))
10042 return simplify_stmt_using_ranges (si
);
10045 /* Unwindable const/copy equivalences. */
10046 const_and_copies
*equiv_stack
;
10048 /* A trivial wrapper so that we can present the generic jump threading
10049 code with a simple API for simplifying statements. STMT is the
10050 statement we want to simplify, WITHIN_STMT provides the location
10051 for any overflow warnings. */
10054 simplify_stmt_for_jump_threading (gimple
*stmt
, gimple
*within_stmt
,
10055 class avail_exprs_stack
*avail_exprs_stack ATTRIBUTE_UNUSED
)
10057 if (gcond
*cond_stmt
= dyn_cast
<gcond
*> (stmt
))
10058 return vrp_evaluate_conditional (gimple_cond_code (cond_stmt
),
10059 gimple_cond_lhs (cond_stmt
),
10060 gimple_cond_rhs (cond_stmt
),
10063 if (gassign
*assign_stmt
= dyn_cast
<gassign
*> (stmt
))
10065 value_range new_vr
= VR_INITIALIZER
;
10066 tree lhs
= gimple_assign_lhs (assign_stmt
);
10068 if (TREE_CODE (lhs
) == SSA_NAME
10069 && (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
10070 || POINTER_TYPE_P (TREE_TYPE (lhs
))))
10072 extract_range_from_assignment (&new_vr
, assign_stmt
);
10073 if (range_int_cst_singleton_p (&new_vr
))
10081 /* Blocks which have more than one predecessor and more than
10082 one successor present jump threading opportunities, i.e.,
10083 when the block is reached from a specific predecessor, we
10084 may be able to determine which of the outgoing edges will
10085 be traversed. When this optimization applies, we are able
10086 to avoid conditionals at runtime and we may expose secondary
10087 optimization opportunities.
10089 This routine is effectively a driver for the generic jump
10090 threading code. It basically just presents the generic code
10091 with edges that may be suitable for jump threading.
10093 Unlike DOM, we do not iterate VRP if jump threading was successful.
10094 While iterating may expose new opportunities for VRP, it is expected
10095 those opportunities would be very limited and the compile time cost
10096 to expose those opportunities would be significant.
10098 As jump threading opportunities are discovered, they are registered
10099 for later realization. */
10102 identify_jump_threads (void)
10109 /* Ugh. When substituting values earlier in this pass we can
10110 wipe the dominance information. So rebuild the dominator
10111 information as we need it within the jump threading code. */
10112 calculate_dominance_info (CDI_DOMINATORS
);
10114 /* We do not allow VRP information to be used for jump threading
10115 across a back edge in the CFG. Otherwise it becomes too
10116 difficult to avoid eliminating loop exit tests. Of course
10117 EDGE_DFS_BACK is not accurate at this time so we have to
10119 mark_dfs_back_edges ();
10121 /* Do not thread across edges we are about to remove. Just marking
10122 them as EDGE_IGNORE will do. */
10123 FOR_EACH_VEC_ELT (to_remove_edges
, i
, e
)
10124 e
->flags
|= EDGE_IGNORE
;
10126 /* Allocate our unwinder stack to unwind any temporary equivalences
10127 that might be recorded. */
10128 equiv_stack
= new const_and_copies ();
10130 /* To avoid lots of silly node creation, we create a single
10131 conditional and just modify it in-place when attempting to
10133 dummy
= gimple_build_cond (EQ_EXPR
,
10134 integer_zero_node
, integer_zero_node
,
10137 /* Walk through all the blocks finding those which present a
10138 potential jump threading opportunity. We could set this up
10139 as a dominator walker and record data during the walk, but
10140 I doubt it's worth the effort for the classes of jump
10141 threading opportunities we are trying to identify at this
10142 point in compilation. */
10143 FOR_EACH_BB_FN (bb
, cfun
)
10147 /* If the generic jump threading code does not find this block
10148 interesting, then there is nothing to do. */
10149 if (! potentially_threadable_block (bb
))
10152 last
= last_stmt (bb
);
10154 /* We're basically looking for a switch or any kind of conditional with
10155 integral or pointer type arguments. Note the type of the second
10156 argument will be the same as the first argument, so no need to
10157 check it explicitly.
10159 We also handle the case where there are no statements in the
10160 block. This come up with forwarder blocks that are not
10161 optimized away because they lead to a loop header. But we do
10162 want to thread through them as we can sometimes thread to the
10163 loop exit which is obviously profitable. */
10165 || gimple_code (last
) == GIMPLE_SWITCH
10166 || (gimple_code (last
) == GIMPLE_COND
10167 && TREE_CODE (gimple_cond_lhs (last
)) == SSA_NAME
10168 && (INTEGRAL_TYPE_P (TREE_TYPE (gimple_cond_lhs (last
)))
10169 || POINTER_TYPE_P (TREE_TYPE (gimple_cond_lhs (last
))))
10170 && (TREE_CODE (gimple_cond_rhs (last
)) == SSA_NAME
10171 || is_gimple_min_invariant (gimple_cond_rhs (last
)))))
10175 /* We've got a block with multiple predecessors and multiple
10176 successors which also ends in a suitable conditional or
10177 switch statement. For each predecessor, see if we can thread
10178 it to a specific successor. */
10179 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
10181 /* Do not thread across edges marked to ignoreor abnormal
10182 edges in the CFG. */
10183 if (e
->flags
& (EDGE_IGNORE
| EDGE_COMPLEX
))
10186 thread_across_edge (dummy
, e
, true, equiv_stack
, NULL
,
10187 simplify_stmt_for_jump_threading
);
10192 /* Clear EDGE_IGNORE. */
10193 FOR_EACH_VEC_ELT (to_remove_edges
, i
, e
)
10194 e
->flags
&= ~EDGE_IGNORE
;
10196 /* We do not actually update the CFG or SSA graphs at this point as
10197 ASSERT_EXPRs are still in the IL and cfg cleanup code does not yet
10198 handle ASSERT_EXPRs gracefully. */
10201 /* We identified all the jump threading opportunities earlier, but could
10202 not transform the CFG at that time. This routine transforms the
10203 CFG and arranges for the dominator tree to be rebuilt if necessary.
10205 Note the SSA graph update will occur during the normal TODO
10206 processing by the pass manager. */
10208 finalize_jump_threads (void)
10210 thread_through_all_blocks (false);
10211 delete equiv_stack
;
10215 /* Traverse all the blocks folding conditionals with known ranges. */
10218 vrp_finalize (bool warn_array_bounds_p
)
10222 values_propagated
= true;
10226 fprintf (dump_file
, "\nValue ranges after VRP:\n\n");
10227 dump_all_value_ranges (dump_file
);
10228 fprintf (dump_file
, "\n");
10231 /* Set value range to non pointer SSA_NAMEs. */
10232 for (i
= 0; i
< num_vr_values
; i
++)
10235 tree name
= ssa_name (i
);
10238 || POINTER_TYPE_P (TREE_TYPE (name
))
10239 || (vr_value
[i
]->type
== VR_VARYING
)
10240 || (vr_value
[i
]->type
== VR_UNDEFINED
))
10243 if ((TREE_CODE (vr_value
[i
]->min
) == INTEGER_CST
)
10244 && (TREE_CODE (vr_value
[i
]->max
) == INTEGER_CST
)
10245 && (vr_value
[i
]->type
== VR_RANGE
10246 || vr_value
[i
]->type
== VR_ANTI_RANGE
))
10247 set_range_info (name
, vr_value
[i
]->type
, vr_value
[i
]->min
,
10251 substitute_and_fold (op_with_constant_singleton_value_range
,
10252 vrp_fold_stmt
, false);
10254 if (warn_array_bounds
&& warn_array_bounds_p
)
10255 check_all_array_refs ();
10257 /* We must identify jump threading opportunities before we release
10258 the datastructures built by VRP. */
10259 identify_jump_threads ();
10261 /* Free allocated memory. */
10262 for (i
= 0; i
< num_vr_values
; i
++)
10265 BITMAP_FREE (vr_value
[i
]->equiv
);
10266 free (vr_value
[i
]);
10270 free (vr_phi_edge_counts
);
10272 /* So that we can distinguish between VRP data being available
10273 and not available. */
10275 vr_phi_edge_counts
= NULL
;
10279 /* Main entry point to VRP (Value Range Propagation). This pass is
10280 loosely based on J. R. C. Patterson, ``Accurate Static Branch
10281 Prediction by Value Range Propagation,'' in SIGPLAN Conference on
10282 Programming Language Design and Implementation, pp. 67-78, 1995.
10283 Also available at http://citeseer.ist.psu.edu/patterson95accurate.html
10285 This is essentially an SSA-CCP pass modified to deal with ranges
10286 instead of constants.
10288 While propagating ranges, we may find that two or more SSA name
10289 have equivalent, though distinct ranges. For instance,
10292 2 p_4 = ASSERT_EXPR <p_3, p_3 != 0>
10294 4 p_5 = ASSERT_EXPR <p_4, p_4 == q_2>;
10298 In the code above, pointer p_5 has range [q_2, q_2], but from the
10299 code we can also determine that p_5 cannot be NULL and, if q_2 had
10300 a non-varying range, p_5's range should also be compatible with it.
10302 These equivalences are created by two expressions: ASSERT_EXPR and
10303 copy operations. Since p_5 is an assertion on p_4, and p_4 was the
10304 result of another assertion, then we can use the fact that p_5 and
10305 p_4 are equivalent when evaluating p_5's range.
10307 Together with value ranges, we also propagate these equivalences
10308 between names so that we can take advantage of information from
10309 multiple ranges when doing final replacement. Note that this
10310 equivalency relation is transitive but not symmetric.
10312 In the example above, p_5 is equivalent to p_4, q_2 and p_3, but we
10313 cannot assert that q_2 is equivalent to p_5 because q_2 may be used
10314 in contexts where that assertion does not hold (e.g., in line 6).
10316 TODO, the main difference between this pass and Patterson's is that
10317 we do not propagate edge probabilities. We only compute whether
10318 edges can be taken or not. That is, instead of having a spectrum
10319 of jump probabilities between 0 and 1, we only deal with 0, 1 and
10320 DON'T KNOW. In the future, it may be worthwhile to propagate
10321 probabilities to aid branch prediction. */
10323 static unsigned int
10324 execute_vrp (bool warn_array_bounds_p
)
10330 loop_optimizer_init (LOOPS_NORMAL
| LOOPS_HAVE_RECORDED_EXITS
);
10331 rewrite_into_loop_closed_ssa (NULL
, TODO_update_ssa
);
10332 scev_initialize ();
10334 /* ??? This ends up using stale EDGE_DFS_BACK for liveness computation.
10335 Inserting assertions may split edges which will invalidate
10337 insert_range_assertions ();
10339 to_remove_edges
.create (10);
10340 to_update_switch_stmts
.create (5);
10341 threadedge_initialize_values ();
10343 /* For visiting PHI nodes we need EDGE_DFS_BACK computed. */
10344 mark_dfs_back_edges ();
10347 ssa_propagate (vrp_visit_stmt
, vrp_visit_phi_node
);
10348 vrp_finalize (warn_array_bounds_p
);
10350 free_numbers_of_iterations_estimates (cfun
);
10352 /* ASSERT_EXPRs must be removed before finalizing jump threads
10353 as finalizing jump threads calls the CFG cleanup code which
10354 does not properly handle ASSERT_EXPRs. */
10355 remove_range_assertions ();
10357 /* If we exposed any new variables, go ahead and put them into
10358 SSA form now, before we handle jump threading. This simplifies
10359 interactions between rewriting of _DECL nodes into SSA form
10360 and rewriting SSA_NAME nodes into SSA form after block
10361 duplication and CFG manipulation. */
10362 update_ssa (TODO_update_ssa
);
10364 finalize_jump_threads ();
10366 /* Remove dead edges from SWITCH_EXPR optimization. This leaves the
10367 CFG in a broken state and requires a cfg_cleanup run. */
10368 FOR_EACH_VEC_ELT (to_remove_edges
, i
, e
)
10370 /* Update SWITCH_EXPR case label vector. */
10371 FOR_EACH_VEC_ELT (to_update_switch_stmts
, i
, su
)
10374 size_t n
= TREE_VEC_LENGTH (su
->vec
);
10376 gimple_switch_set_num_labels (su
->stmt
, n
);
10377 for (j
= 0; j
< n
; j
++)
10378 gimple_switch_set_label (su
->stmt
, j
, TREE_VEC_ELT (su
->vec
, j
));
10379 /* As we may have replaced the default label with a regular one
10380 make sure to make it a real default label again. This ensures
10381 optimal expansion. */
10382 label
= gimple_switch_label (su
->stmt
, 0);
10383 CASE_LOW (label
) = NULL_TREE
;
10384 CASE_HIGH (label
) = NULL_TREE
;
10387 if (to_remove_edges
.length () > 0)
10389 free_dominance_info (CDI_DOMINATORS
);
10390 loops_state_set (LOOPS_NEED_FIXUP
);
10393 to_remove_edges
.release ();
10394 to_update_switch_stmts
.release ();
10395 threadedge_finalize_values ();
10398 loop_optimizer_finalize ();
10404 const pass_data pass_data_vrp
=
10406 GIMPLE_PASS
, /* type */
10408 OPTGROUP_NONE
, /* optinfo_flags */
10409 TV_TREE_VRP
, /* tv_id */
10410 PROP_ssa
, /* properties_required */
10411 0, /* properties_provided */
10412 0, /* properties_destroyed */
10413 0, /* todo_flags_start */
10414 ( TODO_cleanup_cfg
| TODO_update_ssa
), /* todo_flags_finish */
10417 class pass_vrp
: public gimple_opt_pass
10420 pass_vrp (gcc::context
*ctxt
)
10421 : gimple_opt_pass (pass_data_vrp
, ctxt
), warn_array_bounds_p (false)
10424 /* opt_pass methods: */
10425 opt_pass
* clone () { return new pass_vrp (m_ctxt
); }
10426 void set_pass_param (unsigned int n
, bool param
)
10428 gcc_assert (n
== 0);
10429 warn_array_bounds_p
= param
;
10431 virtual bool gate (function
*) { return flag_tree_vrp
!= 0; }
10432 virtual unsigned int execute (function
*)
10433 { return execute_vrp (warn_array_bounds_p
); }
10436 bool warn_array_bounds_p
;
10437 }; // class pass_vrp
10439 } // anon namespace
10442 make_pass_vrp (gcc::context
*ctxt
)
10444 return new pass_vrp (ctxt
);