1 /* Support routines for Value Range Propagation (VRP).
2 Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
3 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@redhat.com>.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
29 #include "basic-block.h"
30 #include "tree-flow.h"
31 #include "tree-pass.h"
32 #include "tree-dump.h"
34 #include "tree-pretty-print.h"
35 #include "gimple-pretty-print.h"
36 #include "diagnostic-core.h"
39 #include "tree-scalar-evolution.h"
40 #include "tree-ssa-propagate.h"
41 #include "tree-chrec.h"
42 #include "gimple-fold.h"
47 /* Type of value ranges. See value_range_d for a description of these
49 enum value_range_type
{ VR_UNDEFINED
, VR_RANGE
, VR_ANTI_RANGE
, VR_VARYING
};
51 /* Range of values that can be associated with an SSA_NAME after VRP
55 /* Lattice value represented by this range. */
56 enum value_range_type type
;
58 /* Minimum and maximum values represented by this range. These
59 values should be interpreted as follows:
61 - If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must
64 - If TYPE == VR_RANGE then MIN holds the minimum value and
65 MAX holds the maximum value of the range [MIN, MAX].
67 - If TYPE == ANTI_RANGE the variable is known to NOT
68 take any values in the range [MIN, MAX]. */
72 /* Set of SSA names whose value ranges are equivalent to this one.
73 This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE. */
77 typedef struct value_range_d value_range_t
;
79 /* Set of SSA names found live during the RPO traversal of the function
80 for still active basic-blocks. */
83 /* Return true if the SSA name NAME is live on the edge E. */
86 live_on_edge (edge e
, tree name
)
88 return (live
[e
->dest
->index
]
89 && TEST_BIT (live
[e
->dest
->index
], SSA_NAME_VERSION (name
)));
92 /* Local functions. */
93 static int compare_values (tree val1
, tree val2
);
94 static int compare_values_warnv (tree val1
, tree val2
, bool *);
95 static void vrp_meet (value_range_t
*, value_range_t
*);
96 static tree
vrp_evaluate_conditional_warnv_with_ops (enum tree_code
,
97 tree
, tree
, bool, bool *,
100 /* Location information for ASSERT_EXPRs. Each instance of this
101 structure describes an ASSERT_EXPR for an SSA name. Since a single
102 SSA name may have more than one assertion associated with it, these
103 locations are kept in a linked list attached to the corresponding
105 struct assert_locus_d
107 /* Basic block where the assertion would be inserted. */
110 /* Some assertions need to be inserted on an edge (e.g., assertions
111 generated by COND_EXPRs). In those cases, BB will be NULL. */
114 /* Pointer to the statement that generated this assertion. */
115 gimple_stmt_iterator si
;
117 /* Predicate code for the ASSERT_EXPR. Must be COMPARISON_CLASS_P. */
118 enum tree_code comp_code
;
120 /* Value being compared against. */
123 /* Expression to compare. */
126 /* Next node in the linked list. */
127 struct assert_locus_d
*next
;
130 typedef struct assert_locus_d
*assert_locus_t
;
132 /* If bit I is present, it means that SSA name N_i has a list of
133 assertions that should be inserted in the IL. */
134 static bitmap need_assert_for
;
136 /* Array of locations lists where to insert assertions. ASSERTS_FOR[I]
137 holds a list of ASSERT_LOCUS_T nodes that describe where
138 ASSERT_EXPRs for SSA name N_I should be inserted. */
139 static assert_locus_t
*asserts_for
;
141 /* Value range array. After propagation, VR_VALUE[I] holds the range
142 of values that SSA name N_I may take. */
143 static unsigned num_vr_values
;
144 static value_range_t
**vr_value
;
145 static bool values_propagated
;
147 /* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the
148 number of executable edges we saw the last time we visited the
150 static int *vr_phi_edge_counts
;
157 static VEC (edge
, heap
) *to_remove_edges
;
158 DEF_VEC_O(switch_update
);
159 DEF_VEC_ALLOC_O(switch_update
, heap
);
160 static VEC (switch_update
, heap
) *to_update_switch_stmts
;
163 /* Return the maximum value for TYPE. */
166 vrp_val_max (const_tree type
)
168 if (!INTEGRAL_TYPE_P (type
))
171 return TYPE_MAX_VALUE (type
);
174 /* Return the minimum value for TYPE. */
177 vrp_val_min (const_tree type
)
179 if (!INTEGRAL_TYPE_P (type
))
182 return TYPE_MIN_VALUE (type
);
185 /* Return whether VAL is equal to the maximum value of its type. This
186 will be true for a positive overflow infinity. We can't do a
187 simple equality comparison with TYPE_MAX_VALUE because C typedefs
188 and Ada subtypes can produce types whose TYPE_MAX_VALUE is not ==
189 to the integer constant with the same value in the type. */
192 vrp_val_is_max (const_tree val
)
194 tree type_max
= vrp_val_max (TREE_TYPE (val
));
195 return (val
== type_max
196 || (type_max
!= NULL_TREE
197 && operand_equal_p (val
, type_max
, 0)));
200 /* Return whether VAL is equal to the minimum value of its type. This
201 will be true for a negative overflow infinity. */
204 vrp_val_is_min (const_tree val
)
206 tree type_min
= vrp_val_min (TREE_TYPE (val
));
207 return (val
== type_min
208 || (type_min
!= NULL_TREE
209 && operand_equal_p (val
, type_min
, 0)));
213 /* Return whether TYPE should use an overflow infinity distinct from
214 TYPE_{MIN,MAX}_VALUE. We use an overflow infinity value to
215 represent a signed overflow during VRP computations. An infinity
216 is distinct from a half-range, which will go from some number to
217 TYPE_{MIN,MAX}_VALUE. */
220 needs_overflow_infinity (const_tree type
)
222 return INTEGRAL_TYPE_P (type
) && !TYPE_OVERFLOW_WRAPS (type
);
225 /* Return whether TYPE can support our overflow infinity
226 representation: we use the TREE_OVERFLOW flag, which only exists
227 for constants. If TYPE doesn't support this, we don't optimize
228 cases which would require signed overflow--we drop them to
232 supports_overflow_infinity (const_tree type
)
234 tree min
= vrp_val_min (type
), max
= vrp_val_max (type
);
235 #ifdef ENABLE_CHECKING
236 gcc_assert (needs_overflow_infinity (type
));
238 return (min
!= NULL_TREE
239 && CONSTANT_CLASS_P (min
)
241 && CONSTANT_CLASS_P (max
));
244 /* VAL is the maximum or minimum value of a type. Return a
245 corresponding overflow infinity. */
248 make_overflow_infinity (tree val
)
250 gcc_checking_assert (val
!= NULL_TREE
&& CONSTANT_CLASS_P (val
));
251 val
= copy_node (val
);
252 TREE_OVERFLOW (val
) = 1;
256 /* Return a negative overflow infinity for TYPE. */
259 negative_overflow_infinity (tree type
)
261 gcc_checking_assert (supports_overflow_infinity (type
));
262 return make_overflow_infinity (vrp_val_min (type
));
265 /* Return a positive overflow infinity for TYPE. */
268 positive_overflow_infinity (tree type
)
270 gcc_checking_assert (supports_overflow_infinity (type
));
271 return make_overflow_infinity (vrp_val_max (type
));
274 /* Return whether VAL is a negative overflow infinity. */
277 is_negative_overflow_infinity (const_tree val
)
279 return (needs_overflow_infinity (TREE_TYPE (val
))
280 && CONSTANT_CLASS_P (val
)
281 && TREE_OVERFLOW (val
)
282 && vrp_val_is_min (val
));
285 /* Return whether VAL is a positive overflow infinity. */
288 is_positive_overflow_infinity (const_tree val
)
290 return (needs_overflow_infinity (TREE_TYPE (val
))
291 && CONSTANT_CLASS_P (val
)
292 && TREE_OVERFLOW (val
)
293 && vrp_val_is_max (val
));
296 /* Return whether VAL is a positive or negative overflow infinity. */
299 is_overflow_infinity (const_tree val
)
301 return (needs_overflow_infinity (TREE_TYPE (val
))
302 && CONSTANT_CLASS_P (val
)
303 && TREE_OVERFLOW (val
)
304 && (vrp_val_is_min (val
) || vrp_val_is_max (val
)));
307 /* Return whether STMT has a constant rhs that is_overflow_infinity. */
310 stmt_overflow_infinity (gimple stmt
)
312 if (is_gimple_assign (stmt
)
313 && get_gimple_rhs_class (gimple_assign_rhs_code (stmt
)) ==
315 return is_overflow_infinity (gimple_assign_rhs1 (stmt
));
319 /* If VAL is now an overflow infinity, return VAL. Otherwise, return
320 the same value with TREE_OVERFLOW clear. This can be used to avoid
321 confusing a regular value with an overflow value. */
324 avoid_overflow_infinity (tree val
)
326 if (!is_overflow_infinity (val
))
329 if (vrp_val_is_max (val
))
330 return vrp_val_max (TREE_TYPE (val
));
333 gcc_checking_assert (vrp_val_is_min (val
));
334 return vrp_val_min (TREE_TYPE (val
));
339 /* Return true if ARG is marked with the nonnull attribute in the
340 current function signature. */
343 nonnull_arg_p (const_tree arg
)
345 tree t
, attrs
, fntype
;
346 unsigned HOST_WIDE_INT arg_num
;
348 gcc_assert (TREE_CODE (arg
) == PARM_DECL
&& POINTER_TYPE_P (TREE_TYPE (arg
)));
350 /* The static chain decl is always non null. */
351 if (arg
== cfun
->static_chain_decl
)
354 fntype
= TREE_TYPE (current_function_decl
);
355 attrs
= lookup_attribute ("nonnull", TYPE_ATTRIBUTES (fntype
));
357 /* If "nonnull" wasn't specified, we know nothing about the argument. */
358 if (attrs
== NULL_TREE
)
361 /* If "nonnull" applies to all the arguments, then ARG is non-null. */
362 if (TREE_VALUE (attrs
) == NULL_TREE
)
365 /* Get the position number for ARG in the function signature. */
366 for (arg_num
= 1, t
= DECL_ARGUMENTS (current_function_decl
);
368 t
= DECL_CHAIN (t
), arg_num
++)
374 gcc_assert (t
== arg
);
376 /* Now see if ARG_NUM is mentioned in the nonnull list. */
377 for (t
= TREE_VALUE (attrs
); t
; t
= TREE_CHAIN (t
))
379 if (compare_tree_int (TREE_VALUE (t
), arg_num
) == 0)
387 /* Set value range VR to VR_VARYING. */
390 set_value_range_to_varying (value_range_t
*vr
)
392 vr
->type
= VR_VARYING
;
393 vr
->min
= vr
->max
= NULL_TREE
;
395 bitmap_clear (vr
->equiv
);
399 /* Set value range VR to {T, MIN, MAX, EQUIV}. */
402 set_value_range (value_range_t
*vr
, enum value_range_type t
, tree min
,
403 tree max
, bitmap equiv
)
405 #if defined ENABLE_CHECKING
406 /* Check the validity of the range. */
407 if (t
== VR_RANGE
|| t
== VR_ANTI_RANGE
)
411 gcc_assert (min
&& max
);
413 if (INTEGRAL_TYPE_P (TREE_TYPE (min
)) && t
== VR_ANTI_RANGE
)
414 gcc_assert (!vrp_val_is_min (min
) || !vrp_val_is_max (max
));
416 cmp
= compare_values (min
, max
);
417 gcc_assert (cmp
== 0 || cmp
== -1 || cmp
== -2);
419 if (needs_overflow_infinity (TREE_TYPE (min
)))
420 gcc_assert (!is_overflow_infinity (min
)
421 || !is_overflow_infinity (max
));
424 if (t
== VR_UNDEFINED
|| t
== VR_VARYING
)
425 gcc_assert (min
== NULL_TREE
&& max
== NULL_TREE
);
427 if (t
== VR_UNDEFINED
|| t
== VR_VARYING
)
428 gcc_assert (equiv
== NULL
|| bitmap_empty_p (equiv
));
435 /* Since updating the equivalence set involves deep copying the
436 bitmaps, only do it if absolutely necessary. */
437 if (vr
->equiv
== NULL
439 vr
->equiv
= BITMAP_ALLOC (NULL
);
441 if (equiv
!= vr
->equiv
)
443 if (equiv
&& !bitmap_empty_p (equiv
))
444 bitmap_copy (vr
->equiv
, equiv
);
446 bitmap_clear (vr
->equiv
);
451 /* Set value range VR to the canonical form of {T, MIN, MAX, EQUIV}.
452 This means adjusting T, MIN and MAX representing the case of a
453 wrapping range with MAX < MIN covering [MIN, type_max] U [type_min, MAX]
454 as anti-rage ~[MAX+1, MIN-1]. Likewise for wrapping anti-ranges.
455 In corner cases where MAX+1 or MIN-1 wraps this will fall back
457 This routine exists to ease canonicalization in the case where we
458 extract ranges from var + CST op limit. */
461 set_and_canonicalize_value_range (value_range_t
*vr
, enum value_range_type t
,
462 tree min
, tree max
, bitmap equiv
)
464 /* Nothing to canonicalize for symbolic or unknown or varying ranges. */
466 && t
!= VR_ANTI_RANGE
)
467 || TREE_CODE (min
) != INTEGER_CST
468 || TREE_CODE (max
) != INTEGER_CST
)
470 set_value_range (vr
, t
, min
, max
, equiv
);
474 /* Wrong order for min and max, to swap them and the VR type we need
476 if (tree_int_cst_lt (max
, min
))
478 tree one
= build_int_cst (TREE_TYPE (min
), 1);
479 tree tmp
= int_const_binop (PLUS_EXPR
, max
, one
);
480 max
= int_const_binop (MINUS_EXPR
, min
, one
);
483 /* There's one corner case, if we had [C+1, C] before we now have
484 that again. But this represents an empty value range, so drop
485 to varying in this case. */
486 if (tree_int_cst_lt (max
, min
))
488 set_value_range_to_varying (vr
);
492 t
= t
== VR_RANGE
? VR_ANTI_RANGE
: VR_RANGE
;
495 /* Anti-ranges that can be represented as ranges should be so. */
496 if (t
== VR_ANTI_RANGE
)
498 bool is_min
= vrp_val_is_min (min
);
499 bool is_max
= vrp_val_is_max (max
);
501 if (is_min
&& is_max
)
503 /* We cannot deal with empty ranges, drop to varying. */
504 set_value_range_to_varying (vr
);
508 /* As a special exception preserve non-null ranges. */
509 && !(TYPE_UNSIGNED (TREE_TYPE (min
))
510 && integer_zerop (max
)))
512 tree one
= build_int_cst (TREE_TYPE (max
), 1);
513 min
= int_const_binop (PLUS_EXPR
, max
, one
);
514 max
= vrp_val_max (TREE_TYPE (max
));
519 tree one
= build_int_cst (TREE_TYPE (min
), 1);
520 max
= int_const_binop (MINUS_EXPR
, min
, one
);
521 min
= vrp_val_min (TREE_TYPE (min
));
526 set_value_range (vr
, t
, min
, max
, equiv
);
529 /* Copy value range FROM into value range TO. */
532 copy_value_range (value_range_t
*to
, value_range_t
*from
)
534 set_value_range (to
, from
->type
, from
->min
, from
->max
, from
->equiv
);
537 /* Set value range VR to a single value. This function is only called
538 with values we get from statements, and exists to clear the
539 TREE_OVERFLOW flag so that we don't think we have an overflow
540 infinity when we shouldn't. */
543 set_value_range_to_value (value_range_t
*vr
, tree val
, bitmap equiv
)
545 gcc_assert (is_gimple_min_invariant (val
));
546 val
= avoid_overflow_infinity (val
);
547 set_value_range (vr
, VR_RANGE
, val
, val
, equiv
);
550 /* Set value range VR to a non-negative range of type TYPE.
551 OVERFLOW_INFINITY indicates whether to use an overflow infinity
552 rather than TYPE_MAX_VALUE; this should be true if we determine
553 that the range is nonnegative based on the assumption that signed
554 overflow does not occur. */
557 set_value_range_to_nonnegative (value_range_t
*vr
, tree type
,
558 bool overflow_infinity
)
562 if (overflow_infinity
&& !supports_overflow_infinity (type
))
564 set_value_range_to_varying (vr
);
568 zero
= build_int_cst (type
, 0);
569 set_value_range (vr
, VR_RANGE
, zero
,
571 ? positive_overflow_infinity (type
)
572 : TYPE_MAX_VALUE (type
)),
576 /* Set value range VR to a non-NULL range of type TYPE. */
579 set_value_range_to_nonnull (value_range_t
*vr
, tree type
)
581 tree zero
= build_int_cst (type
, 0);
582 set_value_range (vr
, VR_ANTI_RANGE
, zero
, zero
, vr
->equiv
);
586 /* Set value range VR to a NULL range of type TYPE. */
589 set_value_range_to_null (value_range_t
*vr
, tree type
)
591 set_value_range_to_value (vr
, build_int_cst (type
, 0), vr
->equiv
);
595 /* Set value range VR to a range of a truthvalue of type TYPE. */
598 set_value_range_to_truthvalue (value_range_t
*vr
, tree type
)
600 if (TYPE_PRECISION (type
) == 1)
601 set_value_range_to_varying (vr
);
603 set_value_range (vr
, VR_RANGE
,
604 build_int_cst (type
, 0), build_int_cst (type
, 1),
609 /* Set value range VR to VR_UNDEFINED. */
612 set_value_range_to_undefined (value_range_t
*vr
)
614 vr
->type
= VR_UNDEFINED
;
615 vr
->min
= vr
->max
= NULL_TREE
;
617 bitmap_clear (vr
->equiv
);
621 /* If abs (min) < abs (max), set VR to [-max, max], if
622 abs (min) >= abs (max), set VR to [-min, min]. */
625 abs_extent_range (value_range_t
*vr
, tree min
, tree max
)
629 gcc_assert (TREE_CODE (min
) == INTEGER_CST
);
630 gcc_assert (TREE_CODE (max
) == INTEGER_CST
);
631 gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (min
)));
632 gcc_assert (!TYPE_UNSIGNED (TREE_TYPE (min
)));
633 min
= fold_unary (ABS_EXPR
, TREE_TYPE (min
), min
);
634 max
= fold_unary (ABS_EXPR
, TREE_TYPE (max
), max
);
635 if (TREE_OVERFLOW (min
) || TREE_OVERFLOW (max
))
637 set_value_range_to_varying (vr
);
640 cmp
= compare_values (min
, max
);
642 min
= fold_unary (NEGATE_EXPR
, TREE_TYPE (min
), max
);
643 else if (cmp
== 0 || cmp
== 1)
646 min
= fold_unary (NEGATE_EXPR
, TREE_TYPE (min
), min
);
650 set_value_range_to_varying (vr
);
653 set_and_canonicalize_value_range (vr
, VR_RANGE
, min
, max
, NULL
);
657 /* Return value range information for VAR.
659 If we have no values ranges recorded (ie, VRP is not running), then
660 return NULL. Otherwise create an empty range if none existed for VAR. */
662 static value_range_t
*
663 get_value_range (const_tree var
)
665 static const struct value_range_d vr_const_varying
666 = { VR_VARYING
, NULL_TREE
, NULL_TREE
, NULL
};
669 unsigned ver
= SSA_NAME_VERSION (var
);
671 /* If we have no recorded ranges, then return NULL. */
675 /* If we query the range for a new SSA name return an unmodifiable VARYING.
676 We should get here at most from the substitute-and-fold stage which
677 will never try to change values. */
678 if (ver
>= num_vr_values
)
679 return CONST_CAST (value_range_t
*, &vr_const_varying
);
685 /* After propagation finished do not allocate new value-ranges. */
686 if (values_propagated
)
687 return CONST_CAST (value_range_t
*, &vr_const_varying
);
689 /* Create a default value range. */
690 vr_value
[ver
] = vr
= XCNEW (value_range_t
);
692 /* Defer allocating the equivalence set. */
695 /* If VAR is a default definition of a parameter, the variable can
696 take any value in VAR's type. */
697 sym
= SSA_NAME_VAR (var
);
698 if (SSA_NAME_IS_DEFAULT_DEF (var
)
699 && TREE_CODE (sym
) == PARM_DECL
)
701 /* Try to use the "nonnull" attribute to create ~[0, 0]
702 anti-ranges for pointers. Note that this is only valid with
703 default definitions of PARM_DECLs. */
704 if (POINTER_TYPE_P (TREE_TYPE (sym
))
705 && nonnull_arg_p (sym
))
706 set_value_range_to_nonnull (vr
, TREE_TYPE (sym
));
708 set_value_range_to_varying (vr
);
714 /* Return true, if VAL1 and VAL2 are equal values for VRP purposes. */
717 vrp_operand_equal_p (const_tree val1
, const_tree val2
)
721 if (!val1
|| !val2
|| !operand_equal_p (val1
, val2
, 0))
723 if (is_overflow_infinity (val1
))
724 return is_overflow_infinity (val2
);
728 /* Return true, if the bitmaps B1 and B2 are equal. */
731 vrp_bitmap_equal_p (const_bitmap b1
, const_bitmap b2
)
734 || ((!b1
|| bitmap_empty_p (b1
))
735 && (!b2
|| bitmap_empty_p (b2
)))
737 && bitmap_equal_p (b1
, b2
)));
740 /* Update the value range and equivalence set for variable VAR to
741 NEW_VR. Return true if NEW_VR is different from VAR's previous
744 NOTE: This function assumes that NEW_VR is a temporary value range
745 object created for the sole purpose of updating VAR's range. The
746 storage used by the equivalence set from NEW_VR will be freed by
747 this function. Do not call update_value_range when NEW_VR
748 is the range object associated with another SSA name. */
751 update_value_range (const_tree var
, value_range_t
*new_vr
)
753 value_range_t
*old_vr
;
756 /* Update the value range, if necessary. */
757 old_vr
= get_value_range (var
);
758 is_new
= old_vr
->type
!= new_vr
->type
759 || !vrp_operand_equal_p (old_vr
->min
, new_vr
->min
)
760 || !vrp_operand_equal_p (old_vr
->max
, new_vr
->max
)
761 || !vrp_bitmap_equal_p (old_vr
->equiv
, new_vr
->equiv
);
764 set_value_range (old_vr
, new_vr
->type
, new_vr
->min
, new_vr
->max
,
767 BITMAP_FREE (new_vr
->equiv
);
773 /* Add VAR and VAR's equivalence set to EQUIV. This is the central
774 point where equivalence processing can be turned on/off. */
777 add_equivalence (bitmap
*equiv
, const_tree var
)
779 unsigned ver
= SSA_NAME_VERSION (var
);
780 value_range_t
*vr
= vr_value
[ver
];
783 *equiv
= BITMAP_ALLOC (NULL
);
784 bitmap_set_bit (*equiv
, ver
);
786 bitmap_ior_into (*equiv
, vr
->equiv
);
790 /* Return true if VR is ~[0, 0]. */
793 range_is_nonnull (value_range_t
*vr
)
795 return vr
->type
== VR_ANTI_RANGE
796 && integer_zerop (vr
->min
)
797 && integer_zerop (vr
->max
);
801 /* Return true if VR is [0, 0]. */
804 range_is_null (value_range_t
*vr
)
806 return vr
->type
== VR_RANGE
807 && integer_zerop (vr
->min
)
808 && integer_zerop (vr
->max
);
811 /* Return true if max and min of VR are INTEGER_CST. It's not necessary
815 range_int_cst_p (value_range_t
*vr
)
817 return (vr
->type
== VR_RANGE
818 && TREE_CODE (vr
->max
) == INTEGER_CST
819 && TREE_CODE (vr
->min
) == INTEGER_CST
820 && !TREE_OVERFLOW (vr
->max
)
821 && !TREE_OVERFLOW (vr
->min
));
824 /* Return true if VR is a INTEGER_CST singleton. */
827 range_int_cst_singleton_p (value_range_t
*vr
)
829 return (range_int_cst_p (vr
)
830 && tree_int_cst_equal (vr
->min
, vr
->max
));
833 /* Return true if value range VR involves at least one symbol. */
836 symbolic_range_p (value_range_t
*vr
)
838 return (!is_gimple_min_invariant (vr
->min
)
839 || !is_gimple_min_invariant (vr
->max
));
842 /* Return true if value range VR uses an overflow infinity. */
845 overflow_infinity_range_p (value_range_t
*vr
)
847 return (vr
->type
== VR_RANGE
848 && (is_overflow_infinity (vr
->min
)
849 || is_overflow_infinity (vr
->max
)));
852 /* Return false if we can not make a valid comparison based on VR;
853 this will be the case if it uses an overflow infinity and overflow
854 is not undefined (i.e., -fno-strict-overflow is in effect).
855 Otherwise return true, and set *STRICT_OVERFLOW_P to true if VR
856 uses an overflow infinity. */
859 usable_range_p (value_range_t
*vr
, bool *strict_overflow_p
)
861 gcc_assert (vr
->type
== VR_RANGE
);
862 if (is_overflow_infinity (vr
->min
))
864 *strict_overflow_p
= true;
865 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr
->min
)))
868 if (is_overflow_infinity (vr
->max
))
870 *strict_overflow_p
= true;
871 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr
->max
)))
878 /* Return true if the result of assignment STMT is know to be non-negative.
879 If the return value is based on the assumption that signed overflow is
880 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
881 *STRICT_OVERFLOW_P.*/
884 gimple_assign_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
886 enum tree_code code
= gimple_assign_rhs_code (stmt
);
887 switch (get_gimple_rhs_class (code
))
889 case GIMPLE_UNARY_RHS
:
890 return tree_unary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt
),
891 gimple_expr_type (stmt
),
892 gimple_assign_rhs1 (stmt
),
894 case GIMPLE_BINARY_RHS
:
895 return tree_binary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt
),
896 gimple_expr_type (stmt
),
897 gimple_assign_rhs1 (stmt
),
898 gimple_assign_rhs2 (stmt
),
900 case GIMPLE_TERNARY_RHS
:
902 case GIMPLE_SINGLE_RHS
:
903 return tree_single_nonnegative_warnv_p (gimple_assign_rhs1 (stmt
),
905 case GIMPLE_INVALID_RHS
:
912 /* Return true if return value of call STMT is know to be non-negative.
913 If the return value is based on the assumption that signed overflow is
914 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
915 *STRICT_OVERFLOW_P.*/
918 gimple_call_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
920 tree arg0
= gimple_call_num_args (stmt
) > 0 ?
921 gimple_call_arg (stmt
, 0) : NULL_TREE
;
922 tree arg1
= gimple_call_num_args (stmt
) > 1 ?
923 gimple_call_arg (stmt
, 1) : NULL_TREE
;
925 return tree_call_nonnegative_warnv_p (gimple_expr_type (stmt
),
926 gimple_call_fndecl (stmt
),
932 /* Return true if STMT is know to to compute a non-negative value.
933 If the return value is based on the assumption that signed overflow is
934 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
935 *STRICT_OVERFLOW_P.*/
938 gimple_stmt_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
940 switch (gimple_code (stmt
))
943 return gimple_assign_nonnegative_warnv_p (stmt
, strict_overflow_p
);
945 return gimple_call_nonnegative_warnv_p (stmt
, strict_overflow_p
);
951 /* Return true if the result of assignment STMT is know to be non-zero.
952 If the return value is based on the assumption that signed overflow is
953 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
954 *STRICT_OVERFLOW_P.*/
957 gimple_assign_nonzero_warnv_p (gimple stmt
, bool *strict_overflow_p
)
959 enum tree_code code
= gimple_assign_rhs_code (stmt
);
960 switch (get_gimple_rhs_class (code
))
962 case GIMPLE_UNARY_RHS
:
963 return tree_unary_nonzero_warnv_p (gimple_assign_rhs_code (stmt
),
964 gimple_expr_type (stmt
),
965 gimple_assign_rhs1 (stmt
),
967 case GIMPLE_BINARY_RHS
:
968 return tree_binary_nonzero_warnv_p (gimple_assign_rhs_code (stmt
),
969 gimple_expr_type (stmt
),
970 gimple_assign_rhs1 (stmt
),
971 gimple_assign_rhs2 (stmt
),
973 case GIMPLE_TERNARY_RHS
:
975 case GIMPLE_SINGLE_RHS
:
976 return tree_single_nonzero_warnv_p (gimple_assign_rhs1 (stmt
),
978 case GIMPLE_INVALID_RHS
:
985 /* Return true if STMT is know to to compute a non-zero value.
986 If the return value is based on the assumption that signed overflow is
987 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
988 *STRICT_OVERFLOW_P.*/
991 gimple_stmt_nonzero_warnv_p (gimple stmt
, bool *strict_overflow_p
)
993 switch (gimple_code (stmt
))
996 return gimple_assign_nonzero_warnv_p (stmt
, strict_overflow_p
);
998 return gimple_alloca_call_p (stmt
);
1004 /* Like tree_expr_nonzero_warnv_p, but this function uses value ranges
1008 vrp_stmt_computes_nonzero (gimple stmt
, bool *strict_overflow_p
)
1010 if (gimple_stmt_nonzero_warnv_p (stmt
, strict_overflow_p
))
1013 /* If we have an expression of the form &X->a, then the expression
1014 is nonnull if X is nonnull. */
1015 if (is_gimple_assign (stmt
)
1016 && gimple_assign_rhs_code (stmt
) == ADDR_EXPR
)
1018 tree expr
= gimple_assign_rhs1 (stmt
);
1019 tree base
= get_base_address (TREE_OPERAND (expr
, 0));
1021 if (base
!= NULL_TREE
1022 && TREE_CODE (base
) == MEM_REF
1023 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1025 value_range_t
*vr
= get_value_range (TREE_OPERAND (base
, 0));
1026 if (range_is_nonnull (vr
))
1034 /* Returns true if EXPR is a valid value (as expected by compare_values) --
1035 a gimple invariant, or SSA_NAME +- CST. */
1038 valid_value_p (tree expr
)
1040 if (TREE_CODE (expr
) == SSA_NAME
)
1043 if (TREE_CODE (expr
) == PLUS_EXPR
1044 || TREE_CODE (expr
) == MINUS_EXPR
)
1045 return (TREE_CODE (TREE_OPERAND (expr
, 0)) == SSA_NAME
1046 && TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
);
1048 return is_gimple_min_invariant (expr
);
1054 -2 if those are incomparable. */
1056 operand_less_p (tree val
, tree val2
)
1058 /* LT is folded faster than GE and others. Inline the common case. */
1059 if (TREE_CODE (val
) == INTEGER_CST
&& TREE_CODE (val2
) == INTEGER_CST
)
1061 if (TYPE_UNSIGNED (TREE_TYPE (val
)))
1062 return INT_CST_LT_UNSIGNED (val
, val2
);
1065 if (INT_CST_LT (val
, val2
))
1073 fold_defer_overflow_warnings ();
1075 tcmp
= fold_binary_to_constant (LT_EXPR
, boolean_type_node
, val
, val2
);
1077 fold_undefer_and_ignore_overflow_warnings ();
1080 || TREE_CODE (tcmp
) != INTEGER_CST
)
1083 if (!integer_zerop (tcmp
))
1087 /* val >= val2, not considering overflow infinity. */
1088 if (is_negative_overflow_infinity (val
))
1089 return is_negative_overflow_infinity (val2
) ? 0 : 1;
1090 else if (is_positive_overflow_infinity (val2
))
1091 return is_positive_overflow_infinity (val
) ? 0 : 1;
1096 /* Compare two values VAL1 and VAL2. Return
1098 -2 if VAL1 and VAL2 cannot be compared at compile-time,
1101 +1 if VAL1 > VAL2, and
1104 This is similar to tree_int_cst_compare but supports pointer values
1105 and values that cannot be compared at compile time.
1107 If STRICT_OVERFLOW_P is not NULL, then set *STRICT_OVERFLOW_P to
1108 true if the return value is only valid if we assume that signed
1109 overflow is undefined. */
1112 compare_values_warnv (tree val1
, tree val2
, bool *strict_overflow_p
)
1117 /* Below we rely on the fact that VAL1 and VAL2 are both pointers or
1119 gcc_assert (POINTER_TYPE_P (TREE_TYPE (val1
))
1120 == POINTER_TYPE_P (TREE_TYPE (val2
)));
1121 /* Convert the two values into the same type. This is needed because
1122 sizetype causes sign extension even for unsigned types. */
1123 val2
= fold_convert (TREE_TYPE (val1
), val2
);
1124 STRIP_USELESS_TYPE_CONVERSION (val2
);
1126 if ((TREE_CODE (val1
) == SSA_NAME
1127 || TREE_CODE (val1
) == PLUS_EXPR
1128 || TREE_CODE (val1
) == MINUS_EXPR
)
1129 && (TREE_CODE (val2
) == SSA_NAME
1130 || TREE_CODE (val2
) == PLUS_EXPR
1131 || TREE_CODE (val2
) == MINUS_EXPR
))
1133 tree n1
, c1
, n2
, c2
;
1134 enum tree_code code1
, code2
;
1136 /* If VAL1 and VAL2 are of the form 'NAME [+-] CST' or 'NAME',
1137 return -1 or +1 accordingly. If VAL1 and VAL2 don't use the
1138 same name, return -2. */
1139 if (TREE_CODE (val1
) == SSA_NAME
)
1147 code1
= TREE_CODE (val1
);
1148 n1
= TREE_OPERAND (val1
, 0);
1149 c1
= TREE_OPERAND (val1
, 1);
1150 if (tree_int_cst_sgn (c1
) == -1)
1152 if (is_negative_overflow_infinity (c1
))
1154 c1
= fold_unary_to_constant (NEGATE_EXPR
, TREE_TYPE (c1
), c1
);
1157 code1
= code1
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
;
1161 if (TREE_CODE (val2
) == SSA_NAME
)
1169 code2
= TREE_CODE (val2
);
1170 n2
= TREE_OPERAND (val2
, 0);
1171 c2
= TREE_OPERAND (val2
, 1);
1172 if (tree_int_cst_sgn (c2
) == -1)
1174 if (is_negative_overflow_infinity (c2
))
1176 c2
= fold_unary_to_constant (NEGATE_EXPR
, TREE_TYPE (c2
), c2
);
1179 code2
= code2
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
;
1183 /* Both values must use the same name. */
1187 if (code1
== SSA_NAME
1188 && code2
== SSA_NAME
)
1192 /* If overflow is defined we cannot simplify more. */
1193 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1
)))
1196 if (strict_overflow_p
!= NULL
1197 && (code1
== SSA_NAME
|| !TREE_NO_WARNING (val1
))
1198 && (code2
== SSA_NAME
|| !TREE_NO_WARNING (val2
)))
1199 *strict_overflow_p
= true;
1201 if (code1
== SSA_NAME
)
1203 if (code2
== PLUS_EXPR
)
1204 /* NAME < NAME + CST */
1206 else if (code2
== MINUS_EXPR
)
1207 /* NAME > NAME - CST */
1210 else if (code1
== PLUS_EXPR
)
1212 if (code2
== SSA_NAME
)
1213 /* NAME + CST > NAME */
1215 else if (code2
== PLUS_EXPR
)
1216 /* NAME + CST1 > NAME + CST2, if CST1 > CST2 */
1217 return compare_values_warnv (c1
, c2
, strict_overflow_p
);
1218 else if (code2
== MINUS_EXPR
)
1219 /* NAME + CST1 > NAME - CST2 */
1222 else if (code1
== MINUS_EXPR
)
1224 if (code2
== SSA_NAME
)
1225 /* NAME - CST < NAME */
1227 else if (code2
== PLUS_EXPR
)
1228 /* NAME - CST1 < NAME + CST2 */
1230 else if (code2
== MINUS_EXPR
)
1231 /* NAME - CST1 > NAME - CST2, if CST1 < CST2. Notice that
1232 C1 and C2 are swapped in the call to compare_values. */
1233 return compare_values_warnv (c2
, c1
, strict_overflow_p
);
1239 /* We cannot compare non-constants. */
1240 if (!is_gimple_min_invariant (val1
) || !is_gimple_min_invariant (val2
))
1243 if (!POINTER_TYPE_P (TREE_TYPE (val1
)))
1245 /* We cannot compare overflowed values, except for overflow
1247 if (TREE_OVERFLOW (val1
) || TREE_OVERFLOW (val2
))
1249 if (strict_overflow_p
!= NULL
)
1250 *strict_overflow_p
= true;
1251 if (is_negative_overflow_infinity (val1
))
1252 return is_negative_overflow_infinity (val2
) ? 0 : -1;
1253 else if (is_negative_overflow_infinity (val2
))
1255 else if (is_positive_overflow_infinity (val1
))
1256 return is_positive_overflow_infinity (val2
) ? 0 : 1;
1257 else if (is_positive_overflow_infinity (val2
))
1262 return tree_int_cst_compare (val1
, val2
);
1268 /* First see if VAL1 and VAL2 are not the same. */
1269 if (val1
== val2
|| operand_equal_p (val1
, val2
, 0))
1272 /* If VAL1 is a lower address than VAL2, return -1. */
1273 if (operand_less_p (val1
, val2
) == 1)
1276 /* If VAL1 is a higher address than VAL2, return +1. */
1277 if (operand_less_p (val2
, val1
) == 1)
1280 /* If VAL1 is different than VAL2, return +2.
1281 For integer constants we either have already returned -1 or 1
1282 or they are equivalent. We still might succeed in proving
1283 something about non-trivial operands. */
1284 if (TREE_CODE (val1
) != INTEGER_CST
1285 || TREE_CODE (val2
) != INTEGER_CST
)
1287 t
= fold_binary_to_constant (NE_EXPR
, boolean_type_node
, val1
, val2
);
1288 if (t
&& integer_onep (t
))
1296 /* Compare values like compare_values_warnv, but treat comparisons of
1297 nonconstants which rely on undefined overflow as incomparable. */
1300 compare_values (tree val1
, tree val2
)
1306 ret
= compare_values_warnv (val1
, val2
, &sop
);
1308 && (!is_gimple_min_invariant (val1
) || !is_gimple_min_invariant (val2
)))
1314 /* Return 1 if VAL is inside value range VR (VR->MIN <= VAL <= VR->MAX),
1315 0 if VAL is not inside VR,
1316 -2 if we cannot tell either way.
1318 FIXME, the current semantics of this functions are a bit quirky
1319 when taken in the context of VRP. In here we do not care
1320 about VR's type. If VR is the anti-range ~[3, 5] the call
1321 value_inside_range (4, VR) will return 1.
1323 This is counter-intuitive in a strict sense, but the callers
1324 currently expect this. They are calling the function
1325 merely to determine whether VR->MIN <= VAL <= VR->MAX. The
1326 callers are applying the VR_RANGE/VR_ANTI_RANGE semantics
1329 This also applies to value_ranges_intersect_p and
1330 range_includes_zero_p. The semantics of VR_RANGE and
1331 VR_ANTI_RANGE should be encoded here, but that also means
1332 adapting the users of these functions to the new semantics.
1334 Benchmark compile/20001226-1.c compilation time after changing this
1338 value_inside_range (tree val
, value_range_t
* vr
)
1342 cmp1
= operand_less_p (val
, vr
->min
);
1348 cmp2
= operand_less_p (vr
->max
, val
);
1356 /* Return true if value ranges VR0 and VR1 have a non-empty
1359 Benchmark compile/20001226-1.c compilation time after changing this
1364 value_ranges_intersect_p (value_range_t
*vr0
, value_range_t
*vr1
)
1366 /* The value ranges do not intersect if the maximum of the first range is
1367 less than the minimum of the second range or vice versa.
1368 When those relations are unknown, we can't do any better. */
1369 if (operand_less_p (vr0
->max
, vr1
->min
) != 0)
1371 if (operand_less_p (vr1
->max
, vr0
->min
) != 0)
1377 /* Return true if VR includes the value zero, false otherwise. FIXME,
1378 currently this will return false for an anti-range like ~[-4, 3].
1379 This will be wrong when the semantics of value_inside_range are
1380 modified (currently the users of this function expect these
1384 range_includes_zero_p (value_range_t
*vr
)
1388 gcc_assert (vr
->type
!= VR_UNDEFINED
1389 && vr
->type
!= VR_VARYING
1390 && !symbolic_range_p (vr
));
1392 zero
= build_int_cst (TREE_TYPE (vr
->min
), 0);
1393 return (value_inside_range (zero
, vr
) == 1);
1396 /* Return true if *VR is know to only contain nonnegative values. */
1399 value_range_nonnegative_p (value_range_t
*vr
)
1401 if (vr
->type
== VR_RANGE
)
1403 int result
= compare_values (vr
->min
, integer_zero_node
);
1404 return (result
== 0 || result
== 1);
1406 else if (vr
->type
== VR_ANTI_RANGE
)
1408 int result
= compare_values (vr
->max
, integer_zero_node
);
1409 return result
== -1;
1415 /* Return true if T, an SSA_NAME, is known to be nonnegative. Return
1416 false otherwise or if no value range information is available. */
1419 ssa_name_nonnegative_p (const_tree t
)
1421 value_range_t
*vr
= get_value_range (t
);
1423 if (INTEGRAL_TYPE_P (t
)
1424 && TYPE_UNSIGNED (t
))
1430 return value_range_nonnegative_p (vr
);
1433 /* If *VR has a value rante that is a single constant value return that,
1434 otherwise return NULL_TREE. */
1437 value_range_constant_singleton (value_range_t
*vr
)
1439 if (vr
->type
== VR_RANGE
1440 && operand_equal_p (vr
->min
, vr
->max
, 0)
1441 && is_gimple_min_invariant (vr
->min
))
1447 /* If OP has a value range with a single constant value return that,
1448 otherwise return NULL_TREE. This returns OP itself if OP is a
1452 op_with_constant_singleton_value_range (tree op
)
1454 if (is_gimple_min_invariant (op
))
1457 if (TREE_CODE (op
) != SSA_NAME
)
1460 return value_range_constant_singleton (get_value_range (op
));
1463 /* Return true if op is in a boolean [0, 1] value-range. */
1466 op_with_boolean_value_range_p (tree op
)
1470 if (TYPE_PRECISION (TREE_TYPE (op
)) == 1)
1473 if (integer_zerop (op
)
1474 || integer_onep (op
))
1477 if (TREE_CODE (op
) != SSA_NAME
)
1480 vr
= get_value_range (op
);
1481 return (vr
->type
== VR_RANGE
1482 && integer_zerop (vr
->min
)
1483 && integer_onep (vr
->max
));
1486 /* Extract value range information from an ASSERT_EXPR EXPR and store
1490 extract_range_from_assert (value_range_t
*vr_p
, tree expr
)
1492 tree var
, cond
, limit
, min
, max
, type
;
1493 value_range_t
*var_vr
, *limit_vr
;
1494 enum tree_code cond_code
;
1496 var
= ASSERT_EXPR_VAR (expr
);
1497 cond
= ASSERT_EXPR_COND (expr
);
1499 gcc_assert (COMPARISON_CLASS_P (cond
));
1501 /* Find VAR in the ASSERT_EXPR conditional. */
1502 if (var
== TREE_OPERAND (cond
, 0)
1503 || TREE_CODE (TREE_OPERAND (cond
, 0)) == PLUS_EXPR
1504 || TREE_CODE (TREE_OPERAND (cond
, 0)) == NOP_EXPR
)
1506 /* If the predicate is of the form VAR COMP LIMIT, then we just
1507 take LIMIT from the RHS and use the same comparison code. */
1508 cond_code
= TREE_CODE (cond
);
1509 limit
= TREE_OPERAND (cond
, 1);
1510 cond
= TREE_OPERAND (cond
, 0);
1514 /* If the predicate is of the form LIMIT COMP VAR, then we need
1515 to flip around the comparison code to create the proper range
1517 cond_code
= swap_tree_comparison (TREE_CODE (cond
));
1518 limit
= TREE_OPERAND (cond
, 0);
1519 cond
= TREE_OPERAND (cond
, 1);
1522 limit
= avoid_overflow_infinity (limit
);
1524 type
= TREE_TYPE (limit
);
1525 gcc_assert (limit
!= var
);
1527 /* For pointer arithmetic, we only keep track of pointer equality
1529 if (POINTER_TYPE_P (type
) && cond_code
!= NE_EXPR
&& cond_code
!= EQ_EXPR
)
1531 set_value_range_to_varying (vr_p
);
1535 /* If LIMIT is another SSA name and LIMIT has a range of its own,
1536 try to use LIMIT's range to avoid creating symbolic ranges
1538 limit_vr
= (TREE_CODE (limit
) == SSA_NAME
) ? get_value_range (limit
) : NULL
;
1540 /* LIMIT's range is only interesting if it has any useful information. */
1542 && (limit_vr
->type
== VR_UNDEFINED
1543 || limit_vr
->type
== VR_VARYING
1544 || symbolic_range_p (limit_vr
)))
1547 /* Initially, the new range has the same set of equivalences of
1548 VAR's range. This will be revised before returning the final
1549 value. Since assertions may be chained via mutually exclusive
1550 predicates, we will need to trim the set of equivalences before
1552 gcc_assert (vr_p
->equiv
== NULL
);
1553 add_equivalence (&vr_p
->equiv
, var
);
1555 /* Extract a new range based on the asserted comparison for VAR and
1556 LIMIT's value range. Notice that if LIMIT has an anti-range, we
1557 will only use it for equality comparisons (EQ_EXPR). For any
1558 other kind of assertion, we cannot derive a range from LIMIT's
1559 anti-range that can be used to describe the new range. For
1560 instance, ASSERT_EXPR <x_2, x_2 <= b_4>. If b_4 is ~[2, 10],
1561 then b_4 takes on the ranges [-INF, 1] and [11, +INF]. There is
1562 no single range for x_2 that could describe LE_EXPR, so we might
1563 as well build the range [b_4, +INF] for it.
1564 One special case we handle is extracting a range from a
1565 range test encoded as (unsigned)var + CST <= limit. */
1566 if (TREE_CODE (cond
) == NOP_EXPR
1567 || TREE_CODE (cond
) == PLUS_EXPR
)
1569 if (TREE_CODE (cond
) == PLUS_EXPR
)
1571 min
= fold_build1 (NEGATE_EXPR
, TREE_TYPE (TREE_OPERAND (cond
, 1)),
1572 TREE_OPERAND (cond
, 1));
1573 max
= int_const_binop (PLUS_EXPR
, limit
, min
);
1574 cond
= TREE_OPERAND (cond
, 0);
1578 min
= build_int_cst (TREE_TYPE (var
), 0);
1582 /* Make sure to not set TREE_OVERFLOW on the final type
1583 conversion. We are willingly interpreting large positive
1584 unsigned values as negative singed values here. */
1585 min
= force_fit_type_double (TREE_TYPE (var
), tree_to_double_int (min
),
1587 max
= force_fit_type_double (TREE_TYPE (var
), tree_to_double_int (max
),
1590 /* We can transform a max, min range to an anti-range or
1591 vice-versa. Use set_and_canonicalize_value_range which does
1593 if (cond_code
== LE_EXPR
)
1594 set_and_canonicalize_value_range (vr_p
, VR_RANGE
,
1595 min
, max
, vr_p
->equiv
);
1596 else if (cond_code
== GT_EXPR
)
1597 set_and_canonicalize_value_range (vr_p
, VR_ANTI_RANGE
,
1598 min
, max
, vr_p
->equiv
);
1602 else if (cond_code
== EQ_EXPR
)
1604 enum value_range_type range_type
;
1608 range_type
= limit_vr
->type
;
1609 min
= limit_vr
->min
;
1610 max
= limit_vr
->max
;
1614 range_type
= VR_RANGE
;
1619 set_value_range (vr_p
, range_type
, min
, max
, vr_p
->equiv
);
1621 /* When asserting the equality VAR == LIMIT and LIMIT is another
1622 SSA name, the new range will also inherit the equivalence set
1624 if (TREE_CODE (limit
) == SSA_NAME
)
1625 add_equivalence (&vr_p
->equiv
, limit
);
1627 else if (cond_code
== NE_EXPR
)
1629 /* As described above, when LIMIT's range is an anti-range and
1630 this assertion is an inequality (NE_EXPR), then we cannot
1631 derive anything from the anti-range. For instance, if
1632 LIMIT's range was ~[0, 0], the assertion 'VAR != LIMIT' does
1633 not imply that VAR's range is [0, 0]. So, in the case of
1634 anti-ranges, we just assert the inequality using LIMIT and
1637 If LIMIT_VR is a range, we can only use it to build a new
1638 anti-range if LIMIT_VR is a single-valued range. For
1639 instance, if LIMIT_VR is [0, 1], the predicate
1640 VAR != [0, 1] does not mean that VAR's range is ~[0, 1].
1641 Rather, it means that for value 0 VAR should be ~[0, 0]
1642 and for value 1, VAR should be ~[1, 1]. We cannot
1643 represent these ranges.
1645 The only situation in which we can build a valid
1646 anti-range is when LIMIT_VR is a single-valued range
1647 (i.e., LIMIT_VR->MIN == LIMIT_VR->MAX). In that case,
1648 build the anti-range ~[LIMIT_VR->MIN, LIMIT_VR->MAX]. */
1650 && limit_vr
->type
== VR_RANGE
1651 && compare_values (limit_vr
->min
, limit_vr
->max
) == 0)
1653 min
= limit_vr
->min
;
1654 max
= limit_vr
->max
;
1658 /* In any other case, we cannot use LIMIT's range to build a
1659 valid anti-range. */
1663 /* If MIN and MAX cover the whole range for their type, then
1664 just use the original LIMIT. */
1665 if (INTEGRAL_TYPE_P (type
)
1666 && vrp_val_is_min (min
)
1667 && vrp_val_is_max (max
))
1670 set_value_range (vr_p
, VR_ANTI_RANGE
, min
, max
, vr_p
->equiv
);
1672 else if (cond_code
== LE_EXPR
|| cond_code
== LT_EXPR
)
1674 min
= TYPE_MIN_VALUE (type
);
1676 if (limit_vr
== NULL
|| limit_vr
->type
== VR_ANTI_RANGE
)
1680 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1681 range [MIN, N2] for LE_EXPR and [MIN, N2 - 1] for
1683 max
= limit_vr
->max
;
1686 /* If the maximum value forces us to be out of bounds, simply punt.
1687 It would be pointless to try and do anything more since this
1688 all should be optimized away above us. */
1689 if ((cond_code
== LT_EXPR
1690 && compare_values (max
, min
) == 0)
1691 || (CONSTANT_CLASS_P (max
) && TREE_OVERFLOW (max
)))
1692 set_value_range_to_varying (vr_p
);
1695 /* For LT_EXPR, we create the range [MIN, MAX - 1]. */
1696 if (cond_code
== LT_EXPR
)
1698 tree one
= build_int_cst (type
, 1);
1699 max
= fold_build2 (MINUS_EXPR
, type
, max
, one
);
1701 TREE_NO_WARNING (max
) = 1;
1704 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1707 else if (cond_code
== GE_EXPR
|| cond_code
== GT_EXPR
)
1709 max
= TYPE_MAX_VALUE (type
);
1711 if (limit_vr
== NULL
|| limit_vr
->type
== VR_ANTI_RANGE
)
1715 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1716 range [N1, MAX] for GE_EXPR and [N1 + 1, MAX] for
1718 min
= limit_vr
->min
;
1721 /* If the minimum value forces us to be out of bounds, simply punt.
1722 It would be pointless to try and do anything more since this
1723 all should be optimized away above us. */
1724 if ((cond_code
== GT_EXPR
1725 && compare_values (min
, max
) == 0)
1726 || (CONSTANT_CLASS_P (min
) && TREE_OVERFLOW (min
)))
1727 set_value_range_to_varying (vr_p
);
1730 /* For GT_EXPR, we create the range [MIN + 1, MAX]. */
1731 if (cond_code
== GT_EXPR
)
1733 tree one
= build_int_cst (type
, 1);
1734 min
= fold_build2 (PLUS_EXPR
, type
, min
, one
);
1736 TREE_NO_WARNING (min
) = 1;
1739 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1745 /* If VAR already had a known range, it may happen that the new
1746 range we have computed and VAR's range are not compatible. For
1750 p_6 = ASSERT_EXPR <p_5, p_5 == NULL>;
1752 p_8 = ASSERT_EXPR <p_6, p_6 != NULL>;
1754 While the above comes from a faulty program, it will cause an ICE
1755 later because p_8 and p_6 will have incompatible ranges and at
1756 the same time will be considered equivalent. A similar situation
1760 i_6 = ASSERT_EXPR <i_5, i_5 > 10>;
1762 i_7 = ASSERT_EXPR <i_6, i_6 < 5>;
1764 Again i_6 and i_7 will have incompatible ranges. It would be
1765 pointless to try and do anything with i_7's range because
1766 anything dominated by 'if (i_5 < 5)' will be optimized away.
1767 Note, due to the wa in which simulation proceeds, the statement
1768 i_7 = ASSERT_EXPR <...> we would never be visited because the
1769 conditional 'if (i_5 < 5)' always evaluates to false. However,
1770 this extra check does not hurt and may protect against future
1771 changes to VRP that may get into a situation similar to the
1772 NULL pointer dereference example.
1774 Note that these compatibility tests are only needed when dealing
1775 with ranges or a mix of range and anti-range. If VAR_VR and VR_P
1776 are both anti-ranges, they will always be compatible, because two
1777 anti-ranges will always have a non-empty intersection. */
1779 var_vr
= get_value_range (var
);
1781 /* We may need to make adjustments when VR_P and VAR_VR are numeric
1782 ranges or anti-ranges. */
1783 if (vr_p
->type
== VR_VARYING
1784 || vr_p
->type
== VR_UNDEFINED
1785 || var_vr
->type
== VR_VARYING
1786 || var_vr
->type
== VR_UNDEFINED
1787 || symbolic_range_p (vr_p
)
1788 || symbolic_range_p (var_vr
))
1791 if (var_vr
->type
== VR_RANGE
&& vr_p
->type
== VR_RANGE
)
1793 /* If the two ranges have a non-empty intersection, we can
1794 refine the resulting range. Since the assert expression
1795 creates an equivalency and at the same time it asserts a
1796 predicate, we can take the intersection of the two ranges to
1797 get better precision. */
1798 if (value_ranges_intersect_p (var_vr
, vr_p
))
1800 /* Use the larger of the two minimums. */
1801 if (compare_values (vr_p
->min
, var_vr
->min
) == -1)
1806 /* Use the smaller of the two maximums. */
1807 if (compare_values (vr_p
->max
, var_vr
->max
) == 1)
1812 set_value_range (vr_p
, vr_p
->type
, min
, max
, vr_p
->equiv
);
1816 /* The two ranges do not intersect, set the new range to
1817 VARYING, because we will not be able to do anything
1818 meaningful with it. */
1819 set_value_range_to_varying (vr_p
);
1822 else if ((var_vr
->type
== VR_RANGE
&& vr_p
->type
== VR_ANTI_RANGE
)
1823 || (var_vr
->type
== VR_ANTI_RANGE
&& vr_p
->type
== VR_RANGE
))
1825 /* A range and an anti-range will cancel each other only if
1826 their ends are the same. For instance, in the example above,
1827 p_8's range ~[0, 0] and p_6's range [0, 0] are incompatible,
1828 so VR_P should be set to VR_VARYING. */
1829 if (compare_values (var_vr
->min
, vr_p
->min
) == 0
1830 && compare_values (var_vr
->max
, vr_p
->max
) == 0)
1831 set_value_range_to_varying (vr_p
);
1834 tree min
, max
, anti_min
, anti_max
, real_min
, real_max
;
1837 /* We want to compute the logical AND of the two ranges;
1838 there are three cases to consider.
1841 1. The VR_ANTI_RANGE range is completely within the
1842 VR_RANGE and the endpoints of the ranges are
1843 different. In that case the resulting range
1844 should be whichever range is more precise.
1845 Typically that will be the VR_RANGE.
1847 2. The VR_ANTI_RANGE is completely disjoint from
1848 the VR_RANGE. In this case the resulting range
1849 should be the VR_RANGE.
1851 3. There is some overlap between the VR_ANTI_RANGE
1854 3a. If the high limit of the VR_ANTI_RANGE resides
1855 within the VR_RANGE, then the result is a new
1856 VR_RANGE starting at the high limit of the
1857 VR_ANTI_RANGE + 1 and extending to the
1858 high limit of the original VR_RANGE.
1860 3b. If the low limit of the VR_ANTI_RANGE resides
1861 within the VR_RANGE, then the result is a new
1862 VR_RANGE starting at the low limit of the original
1863 VR_RANGE and extending to the low limit of the
1864 VR_ANTI_RANGE - 1. */
1865 if (vr_p
->type
== VR_ANTI_RANGE
)
1867 anti_min
= vr_p
->min
;
1868 anti_max
= vr_p
->max
;
1869 real_min
= var_vr
->min
;
1870 real_max
= var_vr
->max
;
1874 anti_min
= var_vr
->min
;
1875 anti_max
= var_vr
->max
;
1876 real_min
= vr_p
->min
;
1877 real_max
= vr_p
->max
;
1881 /* Case 1, VR_ANTI_RANGE completely within VR_RANGE,
1882 not including any endpoints. */
1883 if (compare_values (anti_max
, real_max
) == -1
1884 && compare_values (anti_min
, real_min
) == 1)
1886 /* If the range is covering the whole valid range of
1887 the type keep the anti-range. */
1888 if (!vrp_val_is_min (real_min
)
1889 || !vrp_val_is_max (real_max
))
1890 set_value_range (vr_p
, VR_RANGE
, real_min
,
1891 real_max
, vr_p
->equiv
);
1893 /* Case 2, VR_ANTI_RANGE completely disjoint from
1895 else if (compare_values (anti_min
, real_max
) == 1
1896 || compare_values (anti_max
, real_min
) == -1)
1898 set_value_range (vr_p
, VR_RANGE
, real_min
,
1899 real_max
, vr_p
->equiv
);
1901 /* Case 3a, the anti-range extends into the low
1902 part of the real range. Thus creating a new
1903 low for the real range. */
1904 else if (((cmp
= compare_values (anti_max
, real_min
)) == 1
1906 && compare_values (anti_max
, real_max
) == -1)
1908 gcc_assert (!is_positive_overflow_infinity (anti_max
));
1909 if (needs_overflow_infinity (TREE_TYPE (anti_max
))
1910 && vrp_val_is_max (anti_max
))
1912 if (!supports_overflow_infinity (TREE_TYPE (var_vr
->min
)))
1914 set_value_range_to_varying (vr_p
);
1917 min
= positive_overflow_infinity (TREE_TYPE (var_vr
->min
));
1919 else if (!POINTER_TYPE_P (TREE_TYPE (var_vr
->min
)))
1920 min
= fold_build2 (PLUS_EXPR
, TREE_TYPE (var_vr
->min
),
1922 build_int_cst (TREE_TYPE (var_vr
->min
), 1));
1924 min
= fold_build_pointer_plus_hwi (anti_max
, 1);
1926 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1928 /* Case 3b, the anti-range extends into the high
1929 part of the real range. Thus creating a new
1930 higher for the real range. */
1931 else if (compare_values (anti_min
, real_min
) == 1
1932 && ((cmp
= compare_values (anti_min
, real_max
)) == -1
1935 gcc_assert (!is_negative_overflow_infinity (anti_min
));
1936 if (needs_overflow_infinity (TREE_TYPE (anti_min
))
1937 && vrp_val_is_min (anti_min
))
1939 if (!supports_overflow_infinity (TREE_TYPE (var_vr
->min
)))
1941 set_value_range_to_varying (vr_p
);
1944 max
= negative_overflow_infinity (TREE_TYPE (var_vr
->min
));
1946 else if (!POINTER_TYPE_P (TREE_TYPE (var_vr
->min
)))
1947 max
= fold_build2 (MINUS_EXPR
, TREE_TYPE (var_vr
->min
),
1949 build_int_cst (TREE_TYPE (var_vr
->min
), 1));
1951 max
= fold_build_pointer_plus_hwi (anti_min
, -1);
1953 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1960 /* Extract range information from SSA name VAR and store it in VR. If
1961 VAR has an interesting range, use it. Otherwise, create the
1962 range [VAR, VAR] and return it. This is useful in situations where
1963 we may have conditionals testing values of VARYING names. For
1970 Even if y_5 is deemed VARYING, we can determine that x_3 > y_5 is
1974 extract_range_from_ssa_name (value_range_t
*vr
, tree var
)
1976 value_range_t
*var_vr
= get_value_range (var
);
1978 if (var_vr
->type
!= VR_UNDEFINED
&& var_vr
->type
!= VR_VARYING
)
1979 copy_value_range (vr
, var_vr
);
1981 set_value_range (vr
, VR_RANGE
, var
, var
, NULL
);
1983 add_equivalence (&vr
->equiv
, var
);
1987 /* Wrapper around int_const_binop. If the operation overflows and we
1988 are not using wrapping arithmetic, then adjust the result to be
1989 -INF or +INF depending on CODE, VAL1 and VAL2. This can return
1990 NULL_TREE if we need to use an overflow infinity representation but
1991 the type does not support it. */
1994 vrp_int_const_binop (enum tree_code code
, tree val1
, tree val2
)
1998 res
= int_const_binop (code
, val1
, val2
);
2000 /* If we are using unsigned arithmetic, operate symbolically
2001 on -INF and +INF as int_const_binop only handles signed overflow. */
2002 if (TYPE_UNSIGNED (TREE_TYPE (val1
)))
2004 int checkz
= compare_values (res
, val1
);
2005 bool overflow
= false;
2007 /* Ensure that res = val1 [+*] val2 >= val1
2008 or that res = val1 - val2 <= val1. */
2009 if ((code
== PLUS_EXPR
2010 && !(checkz
== 1 || checkz
== 0))
2011 || (code
== MINUS_EXPR
2012 && !(checkz
== 0 || checkz
== -1)))
2016 /* Checking for multiplication overflow is done by dividing the
2017 output of the multiplication by the first input of the
2018 multiplication. If the result of that division operation is
2019 not equal to the second input of the multiplication, then the
2020 multiplication overflowed. */
2021 else if (code
== MULT_EXPR
&& !integer_zerop (val1
))
2023 tree tmp
= int_const_binop (TRUNC_DIV_EXPR
,
2026 int check
= compare_values (tmp
, val2
);
2034 res
= copy_node (res
);
2035 TREE_OVERFLOW (res
) = 1;
2039 else if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (val1
)))
2040 /* If the singed operation wraps then int_const_binop has done
2041 everything we want. */
2043 else if ((TREE_OVERFLOW (res
)
2044 && !TREE_OVERFLOW (val1
)
2045 && !TREE_OVERFLOW (val2
))
2046 || is_overflow_infinity (val1
)
2047 || is_overflow_infinity (val2
))
2049 /* If the operation overflowed but neither VAL1 nor VAL2 are
2050 overflown, return -INF or +INF depending on the operation
2051 and the combination of signs of the operands. */
2052 int sgn1
= tree_int_cst_sgn (val1
);
2053 int sgn2
= tree_int_cst_sgn (val2
);
2055 if (needs_overflow_infinity (TREE_TYPE (res
))
2056 && !supports_overflow_infinity (TREE_TYPE (res
)))
2059 /* We have to punt on adding infinities of different signs,
2060 since we can't tell what the sign of the result should be.
2061 Likewise for subtracting infinities of the same sign. */
2062 if (((code
== PLUS_EXPR
&& sgn1
!= sgn2
)
2063 || (code
== MINUS_EXPR
&& sgn1
== sgn2
))
2064 && is_overflow_infinity (val1
)
2065 && is_overflow_infinity (val2
))
2068 /* Don't try to handle division or shifting of infinities. */
2069 if ((code
== TRUNC_DIV_EXPR
2070 || code
== FLOOR_DIV_EXPR
2071 || code
== CEIL_DIV_EXPR
2072 || code
== EXACT_DIV_EXPR
2073 || code
== ROUND_DIV_EXPR
2074 || code
== RSHIFT_EXPR
)
2075 && (is_overflow_infinity (val1
)
2076 || is_overflow_infinity (val2
)))
2079 /* Notice that we only need to handle the restricted set of
2080 operations handled by extract_range_from_binary_expr.
2081 Among them, only multiplication, addition and subtraction
2082 can yield overflow without overflown operands because we
2083 are working with integral types only... except in the
2084 case VAL1 = -INF and VAL2 = -1 which overflows to +INF
2085 for division too. */
2087 /* For multiplication, the sign of the overflow is given
2088 by the comparison of the signs of the operands. */
2089 if ((code
== MULT_EXPR
&& sgn1
== sgn2
)
2090 /* For addition, the operands must be of the same sign
2091 to yield an overflow. Its sign is therefore that
2092 of one of the operands, for example the first. For
2093 infinite operands X + -INF is negative, not positive. */
2094 || (code
== PLUS_EXPR
2096 ? !is_negative_overflow_infinity (val2
)
2097 : is_positive_overflow_infinity (val2
)))
2098 /* For subtraction, non-infinite operands must be of
2099 different signs to yield an overflow. Its sign is
2100 therefore that of the first operand or the opposite of
2101 that of the second operand. A first operand of 0 counts
2102 as positive here, for the corner case 0 - (-INF), which
2103 overflows, but must yield +INF. For infinite operands 0
2104 - INF is negative, not positive. */
2105 || (code
== MINUS_EXPR
2107 ? !is_positive_overflow_infinity (val2
)
2108 : is_negative_overflow_infinity (val2
)))
2109 /* We only get in here with positive shift count, so the
2110 overflow direction is the same as the sign of val1.
2111 Actually rshift does not overflow at all, but we only
2112 handle the case of shifting overflowed -INF and +INF. */
2113 || (code
== RSHIFT_EXPR
2115 /* For division, the only case is -INF / -1 = +INF. */
2116 || code
== TRUNC_DIV_EXPR
2117 || code
== FLOOR_DIV_EXPR
2118 || code
== CEIL_DIV_EXPR
2119 || code
== EXACT_DIV_EXPR
2120 || code
== ROUND_DIV_EXPR
)
2121 return (needs_overflow_infinity (TREE_TYPE (res
))
2122 ? positive_overflow_infinity (TREE_TYPE (res
))
2123 : TYPE_MAX_VALUE (TREE_TYPE (res
)));
2125 return (needs_overflow_infinity (TREE_TYPE (res
))
2126 ? negative_overflow_infinity (TREE_TYPE (res
))
2127 : TYPE_MIN_VALUE (TREE_TYPE (res
)));
2134 /* For range VR compute two double_int bitmasks. In *MAY_BE_NONZERO
2135 bitmask if some bit is unset, it means for all numbers in the range
2136 the bit is 0, otherwise it might be 0 or 1. In *MUST_BE_NONZERO
2137 bitmask if some bit is set, it means for all numbers in the range
2138 the bit is 1, otherwise it might be 0 or 1. */
2141 zero_nonzero_bits_from_vr (value_range_t
*vr
, double_int
*may_be_nonzero
,
2142 double_int
*must_be_nonzero
)
2144 may_be_nonzero
->low
= ALL_ONES
;
2145 may_be_nonzero
->high
= ALL_ONES
;
2146 must_be_nonzero
->low
= 0;
2147 must_be_nonzero
->high
= 0;
2148 if (range_int_cst_p (vr
))
2150 if (range_int_cst_singleton_p (vr
))
2152 *may_be_nonzero
= tree_to_double_int (vr
->min
);
2153 *must_be_nonzero
= *may_be_nonzero
;
2155 else if (tree_int_cst_sgn (vr
->min
) >= 0)
2157 double_int dmin
= tree_to_double_int (vr
->min
);
2158 double_int dmax
= tree_to_double_int (vr
->max
);
2159 double_int xor_mask
= double_int_xor (dmin
, dmax
);
2160 *may_be_nonzero
= double_int_ior (dmin
, dmax
);
2161 *must_be_nonzero
= double_int_and (dmin
, dmax
);
2162 if (xor_mask
.high
!= 0)
2164 unsigned HOST_WIDE_INT mask
2165 = ((unsigned HOST_WIDE_INT
) 1
2166 << floor_log2 (xor_mask
.high
)) - 1;
2167 may_be_nonzero
->low
= ALL_ONES
;
2168 may_be_nonzero
->high
|= mask
;
2169 must_be_nonzero
->low
= 0;
2170 must_be_nonzero
->high
&= ~mask
;
2172 else if (xor_mask
.low
!= 0)
2174 unsigned HOST_WIDE_INT mask
2175 = ((unsigned HOST_WIDE_INT
) 1
2176 << floor_log2 (xor_mask
.low
)) - 1;
2177 may_be_nonzero
->low
|= mask
;
2178 must_be_nonzero
->low
&= ~mask
;
2187 /* Extract range information from a binary operation CODE based on
2188 the ranges of each of its operands, *VR0 and *VR1 with resulting
2189 type EXPR_TYPE. The resulting range is stored in *VR. */
2192 extract_range_from_binary_expr_1 (value_range_t
*vr
,
2193 enum tree_code code
, tree expr_type
,
2194 value_range_t
*vr0_
, value_range_t
*vr1_
)
2196 value_range_t vr0
= *vr0_
, vr1
= *vr1_
;
2197 enum value_range_type type
;
2201 /* Not all binary expressions can be applied to ranges in a
2202 meaningful way. Handle only arithmetic operations. */
2203 if (code
!= PLUS_EXPR
2204 && code
!= MINUS_EXPR
2205 && code
!= POINTER_PLUS_EXPR
2206 && code
!= MULT_EXPR
2207 && code
!= TRUNC_DIV_EXPR
2208 && code
!= FLOOR_DIV_EXPR
2209 && code
!= CEIL_DIV_EXPR
2210 && code
!= EXACT_DIV_EXPR
2211 && code
!= ROUND_DIV_EXPR
2212 && code
!= TRUNC_MOD_EXPR
2213 && code
!= RSHIFT_EXPR
2216 && code
!= BIT_AND_EXPR
2217 && code
!= BIT_IOR_EXPR
2218 && code
!= BIT_XOR_EXPR
)
2220 set_value_range_to_varying (vr
);
2224 /* If both ranges are UNDEFINED, so is the result. */
2225 if (vr0
.type
== VR_UNDEFINED
&& vr1
.type
== VR_UNDEFINED
)
2227 set_value_range_to_undefined (vr
);
2230 /* If one of the ranges is UNDEFINED drop it to VARYING for the following
2231 code. At some point we may want to special-case operations that
2232 have UNDEFINED result for all or some value-ranges of the not UNDEFINED
2234 else if (vr0
.type
== VR_UNDEFINED
)
2235 set_value_range_to_varying (&vr0
);
2236 else if (vr1
.type
== VR_UNDEFINED
)
2237 set_value_range_to_varying (&vr1
);
2239 /* The type of the resulting value range defaults to VR0.TYPE. */
2242 /* Refuse to operate on VARYING ranges, ranges of different kinds
2243 and symbolic ranges. As an exception, we allow BIT_AND_EXPR
2244 because we may be able to derive a useful range even if one of
2245 the operands is VR_VARYING or symbolic range. Similarly for
2246 divisions. TODO, we may be able to derive anti-ranges in
2248 if (code
!= BIT_AND_EXPR
2249 && code
!= BIT_IOR_EXPR
2250 && code
!= TRUNC_DIV_EXPR
2251 && code
!= FLOOR_DIV_EXPR
2252 && code
!= CEIL_DIV_EXPR
2253 && code
!= EXACT_DIV_EXPR
2254 && code
!= ROUND_DIV_EXPR
2255 && code
!= TRUNC_MOD_EXPR
2256 && (vr0
.type
== VR_VARYING
2257 || vr1
.type
== VR_VARYING
2258 || vr0
.type
!= vr1
.type
2259 || symbolic_range_p (&vr0
)
2260 || symbolic_range_p (&vr1
)))
2262 set_value_range_to_varying (vr
);
2266 /* Now evaluate the expression to determine the new range. */
2267 if (POINTER_TYPE_P (expr_type
))
2269 if (code
== MIN_EXPR
|| code
== MAX_EXPR
)
2271 /* For MIN/MAX expressions with pointers, we only care about
2272 nullness, if both are non null, then the result is nonnull.
2273 If both are null, then the result is null. Otherwise they
2275 if (range_is_nonnull (&vr0
) && range_is_nonnull (&vr1
))
2276 set_value_range_to_nonnull (vr
, expr_type
);
2277 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
2278 set_value_range_to_null (vr
, expr_type
);
2280 set_value_range_to_varying (vr
);
2282 else if (code
== POINTER_PLUS_EXPR
)
2284 /* For pointer types, we are really only interested in asserting
2285 whether the expression evaluates to non-NULL. */
2286 if (range_is_nonnull (&vr0
) || range_is_nonnull (&vr1
))
2287 set_value_range_to_nonnull (vr
, expr_type
);
2288 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
2289 set_value_range_to_null (vr
, expr_type
);
2291 set_value_range_to_varying (vr
);
2293 else if (code
== BIT_AND_EXPR
)
2295 /* For pointer types, we are really only interested in asserting
2296 whether the expression evaluates to non-NULL. */
2297 if (range_is_nonnull (&vr0
) && range_is_nonnull (&vr1
))
2298 set_value_range_to_nonnull (vr
, expr_type
);
2299 else if (range_is_null (&vr0
) || range_is_null (&vr1
))
2300 set_value_range_to_null (vr
, expr_type
);
2302 set_value_range_to_varying (vr
);
2305 set_value_range_to_varying (vr
);
2310 /* For integer ranges, apply the operation to each end of the
2311 range and see what we end up with. */
2312 if (code
== PLUS_EXPR
2314 || code
== MAX_EXPR
)
2316 /* If we have a PLUS_EXPR with two VR_ANTI_RANGEs, drop to
2317 VR_VARYING. It would take more effort to compute a precise
2318 range for such a case. For example, if we have op0 == 1 and
2319 op1 == -1 with their ranges both being ~[0,0], we would have
2320 op0 + op1 == 0, so we cannot claim that the sum is in ~[0,0].
2321 Note that we are guaranteed to have vr0.type == vr1.type at
2323 if (vr0
.type
== VR_ANTI_RANGE
)
2325 if (code
== PLUS_EXPR
)
2327 set_value_range_to_varying (vr
);
2330 /* For MIN_EXPR and MAX_EXPR with two VR_ANTI_RANGEs,
2331 the resulting VR_ANTI_RANGE is the same - intersection
2332 of the two ranges. */
2333 min
= vrp_int_const_binop (MAX_EXPR
, vr0
.min
, vr1
.min
);
2334 max
= vrp_int_const_binop (MIN_EXPR
, vr0
.max
, vr1
.max
);
2338 /* For operations that make the resulting range directly
2339 proportional to the original ranges, apply the operation to
2340 the same end of each range. */
2341 min
= vrp_int_const_binop (code
, vr0
.min
, vr1
.min
);
2342 max
= vrp_int_const_binop (code
, vr0
.max
, vr1
.max
);
2345 /* If both additions overflowed the range kind is still correct.
2346 This happens regularly with subtracting something in unsigned
2348 ??? See PR30318 for all the cases we do not handle. */
2349 if (code
== PLUS_EXPR
2350 && (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2351 && (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2353 min
= build_int_cst_wide (TREE_TYPE (min
),
2354 TREE_INT_CST_LOW (min
),
2355 TREE_INT_CST_HIGH (min
));
2356 max
= build_int_cst_wide (TREE_TYPE (max
),
2357 TREE_INT_CST_LOW (max
),
2358 TREE_INT_CST_HIGH (max
));
2361 else if (code
== MULT_EXPR
2362 || code
== TRUNC_DIV_EXPR
2363 || code
== FLOOR_DIV_EXPR
2364 || code
== CEIL_DIV_EXPR
2365 || code
== EXACT_DIV_EXPR
2366 || code
== ROUND_DIV_EXPR
2367 || code
== RSHIFT_EXPR
)
2373 /* If we have an unsigned MULT_EXPR with two VR_ANTI_RANGEs,
2374 drop to VR_VARYING. It would take more effort to compute a
2375 precise range for such a case. For example, if we have
2376 op0 == 65536 and op1 == 65536 with their ranges both being
2377 ~[0,0] on a 32-bit machine, we would have op0 * op1 == 0, so
2378 we cannot claim that the product is in ~[0,0]. Note that we
2379 are guaranteed to have vr0.type == vr1.type at this
2381 if (code
== MULT_EXPR
2382 && vr0
.type
== VR_ANTI_RANGE
2383 && !TYPE_OVERFLOW_UNDEFINED (expr_type
))
2385 set_value_range_to_varying (vr
);
2389 /* If we have a RSHIFT_EXPR with any shift values outside [0..prec-1],
2390 then drop to VR_VARYING. Outside of this range we get undefined
2391 behavior from the shift operation. We cannot even trust
2392 SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl
2393 shifts, and the operation at the tree level may be widened. */
2394 if (code
== RSHIFT_EXPR
)
2396 if (vr1
.type
!= VR_RANGE
2397 || !value_range_nonnegative_p (&vr1
)
2398 || TREE_CODE (vr1
.max
) != INTEGER_CST
2399 || compare_tree_int (vr1
.max
,
2400 TYPE_PRECISION (expr_type
) - 1) == 1)
2402 set_value_range_to_varying (vr
);
2407 else if ((code
== TRUNC_DIV_EXPR
2408 || code
== FLOOR_DIV_EXPR
2409 || code
== CEIL_DIV_EXPR
2410 || code
== EXACT_DIV_EXPR
2411 || code
== ROUND_DIV_EXPR
)
2412 && (vr0
.type
!= VR_RANGE
|| symbolic_range_p (&vr0
)))
2414 /* For division, if op1 has VR_RANGE but op0 does not, something
2415 can be deduced just from that range. Say [min, max] / [4, max]
2416 gives [min / 4, max / 4] range. */
2417 if (vr1
.type
== VR_RANGE
2418 && !symbolic_range_p (&vr1
)
2419 && !range_includes_zero_p (&vr1
))
2421 vr0
.type
= type
= VR_RANGE
;
2422 vr0
.min
= vrp_val_min (expr_type
);
2423 vr0
.max
= vrp_val_max (expr_type
);
2427 set_value_range_to_varying (vr
);
2432 /* For divisions, if flag_non_call_exceptions is true, we must
2433 not eliminate a division by zero. */
2434 if ((code
== TRUNC_DIV_EXPR
2435 || code
== FLOOR_DIV_EXPR
2436 || code
== CEIL_DIV_EXPR
2437 || code
== EXACT_DIV_EXPR
2438 || code
== ROUND_DIV_EXPR
)
2439 && cfun
->can_throw_non_call_exceptions
2440 && (vr1
.type
!= VR_RANGE
2441 || symbolic_range_p (&vr1
)
2442 || range_includes_zero_p (&vr1
)))
2444 set_value_range_to_varying (vr
);
2448 /* For divisions, if op0 is VR_RANGE, we can deduce a range
2449 even if op1 is VR_VARYING, VR_ANTI_RANGE, symbolic or can
2451 if ((code
== TRUNC_DIV_EXPR
2452 || code
== FLOOR_DIV_EXPR
2453 || code
== CEIL_DIV_EXPR
2454 || code
== EXACT_DIV_EXPR
2455 || code
== ROUND_DIV_EXPR
)
2456 && vr0
.type
== VR_RANGE
2457 && (vr1
.type
!= VR_RANGE
2458 || symbolic_range_p (&vr1
)
2459 || range_includes_zero_p (&vr1
)))
2461 tree zero
= build_int_cst (TREE_TYPE (vr0
.min
), 0);
2467 if (TYPE_UNSIGNED (expr_type
)
2468 || value_range_nonnegative_p (&vr1
))
2470 /* For unsigned division or when divisor is known
2471 to be non-negative, the range has to cover
2472 all numbers from 0 to max for positive max
2473 and all numbers from min to 0 for negative min. */
2474 cmp
= compare_values (vr0
.max
, zero
);
2477 else if (cmp
== 0 || cmp
== 1)
2481 cmp
= compare_values (vr0
.min
, zero
);
2484 else if (cmp
== 0 || cmp
== -1)
2491 /* Otherwise the range is -max .. max or min .. -min
2492 depending on which bound is bigger in absolute value,
2493 as the division can change the sign. */
2494 abs_extent_range (vr
, vr0
.min
, vr0
.max
);
2497 if (type
== VR_VARYING
)
2499 set_value_range_to_varying (vr
);
2504 /* Multiplications and divisions are a bit tricky to handle,
2505 depending on the mix of signs we have in the two ranges, we
2506 need to operate on different values to get the minimum and
2507 maximum values for the new range. One approach is to figure
2508 out all the variations of range combinations and do the
2511 However, this involves several calls to compare_values and it
2512 is pretty convoluted. It's simpler to do the 4 operations
2513 (MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
2514 MAX1) and then figure the smallest and largest values to form
2518 gcc_assert ((vr0
.type
== VR_RANGE
2519 || (code
== MULT_EXPR
&& vr0
.type
== VR_ANTI_RANGE
))
2520 && vr0
.type
== vr1
.type
);
2522 /* Compute the 4 cross operations. */
2524 val
[0] = vrp_int_const_binop (code
, vr0
.min
, vr1
.min
);
2525 if (val
[0] == NULL_TREE
)
2528 if (vr1
.max
== vr1
.min
)
2532 val
[1] = vrp_int_const_binop (code
, vr0
.min
, vr1
.max
);
2533 if (val
[1] == NULL_TREE
)
2537 if (vr0
.max
== vr0
.min
)
2541 val
[2] = vrp_int_const_binop (code
, vr0
.max
, vr1
.min
);
2542 if (val
[2] == NULL_TREE
)
2546 if (vr0
.min
== vr0
.max
|| vr1
.min
== vr1
.max
)
2550 val
[3] = vrp_int_const_binop (code
, vr0
.max
, vr1
.max
);
2551 if (val
[3] == NULL_TREE
)
2557 set_value_range_to_varying (vr
);
2561 /* Set MIN to the minimum of VAL[i] and MAX to the maximum
2565 for (i
= 1; i
< 4; i
++)
2567 if (!is_gimple_min_invariant (min
)
2568 || (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2569 || !is_gimple_min_invariant (max
)
2570 || (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2575 if (!is_gimple_min_invariant (val
[i
])
2576 || (TREE_OVERFLOW (val
[i
])
2577 && !is_overflow_infinity (val
[i
])))
2579 /* If we found an overflowed value, set MIN and MAX
2580 to it so that we set the resulting range to
2586 if (compare_values (val
[i
], min
) == -1)
2589 if (compare_values (val
[i
], max
) == 1)
2595 else if (code
== TRUNC_MOD_EXPR
)
2597 if (vr1
.type
!= VR_RANGE
2598 || symbolic_range_p (&vr1
)
2599 || range_includes_zero_p (&vr1
)
2600 || vrp_val_is_min (vr1
.min
))
2602 set_value_range_to_varying (vr
);
2606 /* Compute MAX <|vr1.min|, |vr1.max|> - 1. */
2607 max
= fold_unary_to_constant (ABS_EXPR
, expr_type
, vr1
.min
);
2608 if (tree_int_cst_lt (max
, vr1
.max
))
2610 max
= int_const_binop (MINUS_EXPR
, max
, integer_one_node
);
2611 /* If the dividend is non-negative the modulus will be
2612 non-negative as well. */
2613 if (TYPE_UNSIGNED (expr_type
)
2614 || value_range_nonnegative_p (&vr0
))
2615 min
= build_int_cst (TREE_TYPE (max
), 0);
2617 min
= fold_unary_to_constant (NEGATE_EXPR
, expr_type
, max
);
2619 else if (code
== MINUS_EXPR
)
2621 /* If we have a MINUS_EXPR with two VR_ANTI_RANGEs, drop to
2622 VR_VARYING. It would take more effort to compute a precise
2623 range for such a case. For example, if we have op0 == 1 and
2624 op1 == 1 with their ranges both being ~[0,0], we would have
2625 op0 - op1 == 0, so we cannot claim that the difference is in
2626 ~[0,0]. Note that we are guaranteed to have
2627 vr0.type == vr1.type at this point. */
2628 if (vr0
.type
== VR_ANTI_RANGE
)
2630 set_value_range_to_varying (vr
);
2634 /* For MINUS_EXPR, apply the operation to the opposite ends of
2636 min
= vrp_int_const_binop (code
, vr0
.min
, vr1
.max
);
2637 max
= vrp_int_const_binop (code
, vr0
.max
, vr1
.min
);
2639 else if (code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
)
2641 bool int_cst_range0
, int_cst_range1
;
2642 double_int may_be_nonzero0
, may_be_nonzero1
;
2643 double_int must_be_nonzero0
, must_be_nonzero1
;
2645 int_cst_range0
= zero_nonzero_bits_from_vr (&vr0
, &may_be_nonzero0
,
2647 int_cst_range1
= zero_nonzero_bits_from_vr (&vr1
, &may_be_nonzero1
,
2651 if (code
== BIT_AND_EXPR
)
2653 min
= double_int_to_tree (expr_type
,
2654 double_int_and (must_be_nonzero0
,
2656 max
= double_int_to_tree (expr_type
,
2657 double_int_and (may_be_nonzero0
,
2659 if (tree_int_cst_sgn (min
) < 0)
2661 if (tree_int_cst_sgn (max
) < 0)
2663 if (int_cst_range0
&& tree_int_cst_sgn (vr0
.min
) >= 0)
2665 if (min
== NULL_TREE
)
2666 min
= build_int_cst (expr_type
, 0);
2667 if (max
== NULL_TREE
|| tree_int_cst_lt (vr0
.max
, max
))
2670 if (int_cst_range1
&& tree_int_cst_sgn (vr1
.min
) >= 0)
2672 if (min
== NULL_TREE
)
2673 min
= build_int_cst (expr_type
, 0);
2674 if (max
== NULL_TREE
|| tree_int_cst_lt (vr1
.max
, max
))
2678 else if (code
== BIT_IOR_EXPR
)
2680 min
= double_int_to_tree (expr_type
,
2681 double_int_ior (must_be_nonzero0
,
2683 max
= double_int_to_tree (expr_type
,
2684 double_int_ior (may_be_nonzero0
,
2686 if (tree_int_cst_sgn (max
) < 0)
2690 if (tree_int_cst_sgn (min
) < 0)
2693 min
= vrp_int_const_binop (MAX_EXPR
, min
, vr0
.min
);
2696 min
= vrp_int_const_binop (MAX_EXPR
, min
, vr1
.min
);
2698 else if (code
== BIT_XOR_EXPR
)
2700 double_int result_zero_bits
, result_one_bits
;
2702 = double_int_ior (double_int_and (must_be_nonzero0
,
2705 (double_int_ior (may_be_nonzero0
,
2708 = double_int_ior (double_int_and
2710 double_int_not (may_be_nonzero1
)),
2713 double_int_not (may_be_nonzero0
)));
2714 max
= double_int_to_tree (expr_type
,
2715 double_int_not (result_zero_bits
));
2716 min
= double_int_to_tree (expr_type
, result_one_bits
);
2717 /* Return a [min, max] range if we know the
2718 result range is either positive or negative. */
2719 if (tree_int_cst_sgn (max
) >= 0)
2720 /* The range is bound by a lower value of 0. */;
2721 else if (tree_int_cst_sgn (min
) < 0)
2722 /* The range is bound by an upper value of -1. */;
2724 /* We don't know whether the sign bit is set or not. */
2725 max
= min
= NULL_TREE
;
2729 set_value_range_to_varying (vr
);
2736 /* If either MIN or MAX overflowed, then set the resulting range to
2737 VARYING. But we do accept an overflow infinity
2739 if (min
== NULL_TREE
2740 || !is_gimple_min_invariant (min
)
2741 || (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2743 || !is_gimple_min_invariant (max
)
2744 || (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2746 set_value_range_to_varying (vr
);
2752 2) [-INF, +-INF(OVF)]
2753 3) [+-INF(OVF), +INF]
2754 4) [+-INF(OVF), +-INF(OVF)]
2755 We learn nothing when we have INF and INF(OVF) on both sides.
2756 Note that we do accept [-INF, -INF] and [+INF, +INF] without
2758 if ((vrp_val_is_min (min
) || is_overflow_infinity (min
))
2759 && (vrp_val_is_max (max
) || is_overflow_infinity (max
)))
2761 set_value_range_to_varying (vr
);
2765 cmp
= compare_values (min
, max
);
2766 if (cmp
== -2 || cmp
== 1)
2768 /* If the new range has its limits swapped around (MIN > MAX),
2769 then the operation caused one of them to wrap around, mark
2770 the new range VARYING. */
2771 set_value_range_to_varying (vr
);
2774 set_value_range (vr
, type
, min
, max
, NULL
);
2777 /* Extract range information from a binary expression OP0 CODE OP1 based on
2778 the ranges of each of its operands with resulting type EXPR_TYPE.
2779 The resulting range is stored in *VR. */
2782 extract_range_from_binary_expr (value_range_t
*vr
,
2783 enum tree_code code
,
2784 tree expr_type
, tree op0
, tree op1
)
2786 value_range_t vr0
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
2787 value_range_t vr1
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
2789 /* Get value ranges for each operand. For constant operands, create
2790 a new value range with the operand to simplify processing. */
2791 if (TREE_CODE (op0
) == SSA_NAME
)
2792 vr0
= *(get_value_range (op0
));
2793 else if (is_gimple_min_invariant (op0
))
2794 set_value_range_to_value (&vr0
, op0
, NULL
);
2796 set_value_range_to_varying (&vr0
);
2798 if (TREE_CODE (op1
) == SSA_NAME
)
2799 vr1
= *(get_value_range (op1
));
2800 else if (is_gimple_min_invariant (op1
))
2801 set_value_range_to_value (&vr1
, op1
, NULL
);
2803 set_value_range_to_varying (&vr1
);
2805 extract_range_from_binary_expr_1 (vr
, code
, expr_type
, &vr0
, &vr1
);
2808 /* Extract range information from a unary operation CODE based on
2809 the range of its operand *VR0 with type OP0_TYPE with resulting type TYPE.
2810 The The resulting range is stored in *VR. */
2813 extract_range_from_unary_expr_1 (value_range_t
*vr
,
2814 enum tree_code code
, tree type
,
2815 value_range_t
*vr0_
, tree op0_type
)
2817 value_range_t vr0
= *vr0_
;
2821 /* If VR0 is UNDEFINED, so is the result. */
2822 if (vr0
.type
== VR_UNDEFINED
)
2824 set_value_range_to_undefined (vr
);
2828 /* Refuse to operate on certain unary expressions for which we
2829 cannot easily determine a resulting range. */
2830 if (code
== FIX_TRUNC_EXPR
2831 || code
== FLOAT_EXPR
2832 || code
== CONJ_EXPR
)
2834 set_value_range_to_varying (vr
);
2838 /* Refuse to operate on symbolic ranges, or if neither operand is
2839 a pointer or integral type. */
2840 if ((!INTEGRAL_TYPE_P (op0_type
)
2841 && !POINTER_TYPE_P (op0_type
))
2842 || (vr0
.type
!= VR_VARYING
2843 && symbolic_range_p (&vr0
)))
2845 set_value_range_to_varying (vr
);
2849 /* If the expression involves pointers, we are only interested in
2850 determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */
2851 if (POINTER_TYPE_P (type
) || POINTER_TYPE_P (op0_type
))
2853 if (range_is_nonnull (&vr0
))
2854 set_value_range_to_nonnull (vr
, type
);
2855 else if (range_is_null (&vr0
))
2856 set_value_range_to_null (vr
, type
);
2858 set_value_range_to_varying (vr
);
2862 /* Handle unary expressions on integer ranges. */
2863 if (CONVERT_EXPR_CODE_P (code
)
2864 && INTEGRAL_TYPE_P (type
)
2865 && INTEGRAL_TYPE_P (op0_type
))
2867 tree inner_type
= op0_type
;
2868 tree outer_type
= type
;
2870 /* If VR0 is varying and we increase the type precision, assume
2871 a full range for the following transformation. */
2872 if (vr0
.type
== VR_VARYING
2873 && TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
))
2875 vr0
.type
= VR_RANGE
;
2876 vr0
.min
= TYPE_MIN_VALUE (inner_type
);
2877 vr0
.max
= TYPE_MAX_VALUE (inner_type
);
2880 /* If VR0 is a constant range or anti-range and the conversion is
2881 not truncating we can convert the min and max values and
2882 canonicalize the resulting range. Otherwise we can do the
2883 conversion if the size of the range is less than what the
2884 precision of the target type can represent and the range is
2885 not an anti-range. */
2886 if ((vr0
.type
== VR_RANGE
2887 || vr0
.type
== VR_ANTI_RANGE
)
2888 && TREE_CODE (vr0
.min
) == INTEGER_CST
2889 && TREE_CODE (vr0
.max
) == INTEGER_CST
2890 && (!is_overflow_infinity (vr0
.min
)
2891 || (vr0
.type
== VR_RANGE
2892 && TYPE_PRECISION (outer_type
) > TYPE_PRECISION (inner_type
)
2893 && needs_overflow_infinity (outer_type
)
2894 && supports_overflow_infinity (outer_type
)))
2895 && (!is_overflow_infinity (vr0
.max
)
2896 || (vr0
.type
== VR_RANGE
2897 && TYPE_PRECISION (outer_type
) > TYPE_PRECISION (inner_type
)
2898 && needs_overflow_infinity (outer_type
)
2899 && supports_overflow_infinity (outer_type
)))
2900 && (TYPE_PRECISION (outer_type
) >= TYPE_PRECISION (inner_type
)
2901 || (vr0
.type
== VR_RANGE
2902 && integer_zerop (int_const_binop (RSHIFT_EXPR
,
2903 int_const_binop (MINUS_EXPR
, vr0
.max
, vr0
.min
),
2904 size_int (TYPE_PRECISION (outer_type
)))))))
2906 tree new_min
, new_max
;
2907 new_min
= force_fit_type_double (outer_type
,
2908 tree_to_double_int (vr0
.min
),
2910 new_max
= force_fit_type_double (outer_type
,
2911 tree_to_double_int (vr0
.max
),
2913 if (is_overflow_infinity (vr0
.min
))
2914 new_min
= negative_overflow_infinity (outer_type
);
2915 if (is_overflow_infinity (vr0
.max
))
2916 new_max
= positive_overflow_infinity (outer_type
);
2917 set_and_canonicalize_value_range (vr
, vr0
.type
,
2918 new_min
, new_max
, NULL
);
2922 set_value_range_to_varying (vr
);
2926 /* Conversion of a VR_VARYING value to a wider type can result
2927 in a usable range. So wait until after we've handled conversions
2928 before dropping the result to VR_VARYING if we had a source
2929 operand that is VR_VARYING. */
2930 if (vr0
.type
== VR_VARYING
)
2932 set_value_range_to_varying (vr
);
2936 /* Apply the operation to each end of the range and see what we end
2938 if (code
== NEGATE_EXPR
2939 && !TYPE_UNSIGNED (type
))
2941 /* NEGATE_EXPR flips the range around. We need to treat
2942 TYPE_MIN_VALUE specially. */
2943 if (is_positive_overflow_infinity (vr0
.max
))
2944 min
= negative_overflow_infinity (type
);
2945 else if (is_negative_overflow_infinity (vr0
.max
))
2946 min
= positive_overflow_infinity (type
);
2947 else if (!vrp_val_is_min (vr0
.max
))
2948 min
= fold_unary_to_constant (code
, type
, vr0
.max
);
2949 else if (needs_overflow_infinity (type
))
2951 if (supports_overflow_infinity (type
)
2952 && !is_overflow_infinity (vr0
.min
)
2953 && !vrp_val_is_min (vr0
.min
))
2954 min
= positive_overflow_infinity (type
);
2957 set_value_range_to_varying (vr
);
2962 min
= TYPE_MIN_VALUE (type
);
2964 if (is_positive_overflow_infinity (vr0
.min
))
2965 max
= negative_overflow_infinity (type
);
2966 else if (is_negative_overflow_infinity (vr0
.min
))
2967 max
= positive_overflow_infinity (type
);
2968 else if (!vrp_val_is_min (vr0
.min
))
2969 max
= fold_unary_to_constant (code
, type
, vr0
.min
);
2970 else if (needs_overflow_infinity (type
))
2972 if (supports_overflow_infinity (type
))
2973 max
= positive_overflow_infinity (type
);
2976 set_value_range_to_varying (vr
);
2981 max
= TYPE_MIN_VALUE (type
);
2983 else if (code
== NEGATE_EXPR
2984 && TYPE_UNSIGNED (type
))
2986 if (!range_includes_zero_p (&vr0
))
2988 max
= fold_unary_to_constant (code
, type
, vr0
.min
);
2989 min
= fold_unary_to_constant (code
, type
, vr0
.max
);
2993 if (range_is_null (&vr0
))
2994 set_value_range_to_null (vr
, type
);
2996 set_value_range_to_varying (vr
);
3000 else if (code
== ABS_EXPR
3001 && !TYPE_UNSIGNED (type
))
3003 /* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a
3005 if (!TYPE_OVERFLOW_UNDEFINED (type
)
3006 && ((vr0
.type
== VR_RANGE
3007 && vrp_val_is_min (vr0
.min
))
3008 || (vr0
.type
== VR_ANTI_RANGE
3009 && !vrp_val_is_min (vr0
.min
)
3010 && !range_includes_zero_p (&vr0
))))
3012 set_value_range_to_varying (vr
);
3016 /* ABS_EXPR may flip the range around, if the original range
3017 included negative values. */
3018 if (is_overflow_infinity (vr0
.min
))
3019 min
= positive_overflow_infinity (type
);
3020 else if (!vrp_val_is_min (vr0
.min
))
3021 min
= fold_unary_to_constant (code
, type
, vr0
.min
);
3022 else if (!needs_overflow_infinity (type
))
3023 min
= TYPE_MAX_VALUE (type
);
3024 else if (supports_overflow_infinity (type
))
3025 min
= positive_overflow_infinity (type
);
3028 set_value_range_to_varying (vr
);
3032 if (is_overflow_infinity (vr0
.max
))
3033 max
= positive_overflow_infinity (type
);
3034 else if (!vrp_val_is_min (vr0
.max
))
3035 max
= fold_unary_to_constant (code
, type
, vr0
.max
);
3036 else if (!needs_overflow_infinity (type
))
3037 max
= TYPE_MAX_VALUE (type
);
3038 else if (supports_overflow_infinity (type
)
3039 /* We shouldn't generate [+INF, +INF] as set_value_range
3040 doesn't like this and ICEs. */
3041 && !is_positive_overflow_infinity (min
))
3042 max
= positive_overflow_infinity (type
);
3045 set_value_range_to_varying (vr
);
3049 cmp
= compare_values (min
, max
);
3051 /* If a VR_ANTI_RANGEs contains zero, then we have
3052 ~[-INF, min(MIN, MAX)]. */
3053 if (vr0
.type
== VR_ANTI_RANGE
)
3055 if (range_includes_zero_p (&vr0
))
3057 /* Take the lower of the two values. */
3061 /* Create ~[-INF, min (abs(MIN), abs(MAX))]
3062 or ~[-INF + 1, min (abs(MIN), abs(MAX))] when
3063 flag_wrapv is set and the original anti-range doesn't include
3064 TYPE_MIN_VALUE, remember -TYPE_MIN_VALUE = TYPE_MIN_VALUE. */
3065 if (TYPE_OVERFLOW_WRAPS (type
))
3067 tree type_min_value
= TYPE_MIN_VALUE (type
);
3069 min
= (vr0
.min
!= type_min_value
3070 ? int_const_binop (PLUS_EXPR
, type_min_value
,
3076 if (overflow_infinity_range_p (&vr0
))
3077 min
= negative_overflow_infinity (type
);
3079 min
= TYPE_MIN_VALUE (type
);
3084 /* All else has failed, so create the range [0, INF], even for
3085 flag_wrapv since TYPE_MIN_VALUE is in the original
3087 vr0
.type
= VR_RANGE
;
3088 min
= build_int_cst (type
, 0);
3089 if (needs_overflow_infinity (type
))
3091 if (supports_overflow_infinity (type
))
3092 max
= positive_overflow_infinity (type
);
3095 set_value_range_to_varying (vr
);
3100 max
= TYPE_MAX_VALUE (type
);
3104 /* If the range contains zero then we know that the minimum value in the
3105 range will be zero. */
3106 else if (range_includes_zero_p (&vr0
))
3110 min
= build_int_cst (type
, 0);
3114 /* If the range was reversed, swap MIN and MAX. */
3123 else if (code
== BIT_NOT_EXPR
)
3125 /* ~X is simply -1 - X, so re-use existing code that also handles
3126 anti-ranges fine. */
3127 value_range_t minusone
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3128 set_value_range_to_value (&minusone
, build_int_cst (type
, -1), NULL
);
3129 extract_range_from_binary_expr_1 (vr
, MINUS_EXPR
,
3130 type
, &minusone
, &vr0
);
3135 /* Otherwise, operate on each end of the range. */
3136 min
= fold_unary_to_constant (code
, type
, vr0
.min
);
3137 max
= fold_unary_to_constant (code
, type
, vr0
.max
);
3139 if (needs_overflow_infinity (type
))
3141 gcc_assert (code
!= NEGATE_EXPR
&& code
!= ABS_EXPR
);
3143 /* If both sides have overflowed, we don't know
3145 if ((is_overflow_infinity (vr0
.min
)
3146 || TREE_OVERFLOW (min
))
3147 && (is_overflow_infinity (vr0
.max
)
3148 || TREE_OVERFLOW (max
)))
3150 set_value_range_to_varying (vr
);
3154 if (is_overflow_infinity (vr0
.min
))
3156 else if (TREE_OVERFLOW (min
))
3158 if (supports_overflow_infinity (type
))
3159 min
= (tree_int_cst_sgn (min
) >= 0
3160 ? positive_overflow_infinity (TREE_TYPE (min
))
3161 : negative_overflow_infinity (TREE_TYPE (min
)));
3164 set_value_range_to_varying (vr
);
3169 if (is_overflow_infinity (vr0
.max
))
3171 else if (TREE_OVERFLOW (max
))
3173 if (supports_overflow_infinity (type
))
3174 max
= (tree_int_cst_sgn (max
) >= 0
3175 ? positive_overflow_infinity (TREE_TYPE (max
))
3176 : negative_overflow_infinity (TREE_TYPE (max
)));
3179 set_value_range_to_varying (vr
);
3186 cmp
= compare_values (min
, max
);
3187 if (cmp
== -2 || cmp
== 1)
3189 /* If the new range has its limits swapped around (MIN > MAX),
3190 then the operation caused one of them to wrap around, mark
3191 the new range VARYING. */
3192 set_value_range_to_varying (vr
);
3195 set_value_range (vr
, vr0
.type
, min
, max
, NULL
);
3199 /* Extract range information from a unary expression CODE OP0 based on
3200 the range of its operand with resulting type TYPE.
3201 The resulting range is stored in *VR. */
3204 extract_range_from_unary_expr (value_range_t
*vr
, enum tree_code code
,
3205 tree type
, tree op0
)
3207 value_range_t vr0
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3209 /* Get value ranges for the operand. For constant operands, create
3210 a new value range with the operand to simplify processing. */
3211 if (TREE_CODE (op0
) == SSA_NAME
)
3212 vr0
= *(get_value_range (op0
));
3213 else if (is_gimple_min_invariant (op0
))
3214 set_value_range_to_value (&vr0
, op0
, NULL
);
3216 set_value_range_to_varying (&vr0
);
3218 extract_range_from_unary_expr_1 (vr
, code
, type
, &vr0
, TREE_TYPE (op0
));
3222 /* Extract range information from a conditional expression EXPR based on
3223 the ranges of each of its operands and the expression code. */
3226 extract_range_from_cond_expr (value_range_t
*vr
, tree expr
)
3229 value_range_t vr0
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3230 value_range_t vr1
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3232 /* Get value ranges for each operand. For constant operands, create
3233 a new value range with the operand to simplify processing. */
3234 op0
= COND_EXPR_THEN (expr
);
3235 if (TREE_CODE (op0
) == SSA_NAME
)
3236 vr0
= *(get_value_range (op0
));
3237 else if (is_gimple_min_invariant (op0
))
3238 set_value_range_to_value (&vr0
, op0
, NULL
);
3240 set_value_range_to_varying (&vr0
);
3242 op1
= COND_EXPR_ELSE (expr
);
3243 if (TREE_CODE (op1
) == SSA_NAME
)
3244 vr1
= *(get_value_range (op1
));
3245 else if (is_gimple_min_invariant (op1
))
3246 set_value_range_to_value (&vr1
, op1
, NULL
);
3248 set_value_range_to_varying (&vr1
);
3250 /* The resulting value range is the union of the operand ranges */
3251 vrp_meet (&vr0
, &vr1
);
3252 copy_value_range (vr
, &vr0
);
3256 /* Extract range information from a comparison expression EXPR based
3257 on the range of its operand and the expression code. */
3260 extract_range_from_comparison (value_range_t
*vr
, enum tree_code code
,
3261 tree type
, tree op0
, tree op1
)
3266 val
= vrp_evaluate_conditional_warnv_with_ops (code
, op0
, op1
, false, &sop
,
3269 /* A disadvantage of using a special infinity as an overflow
3270 representation is that we lose the ability to record overflow
3271 when we don't have an infinity. So we have to ignore a result
3272 which relies on overflow. */
3274 if (val
&& !is_overflow_infinity (val
) && !sop
)
3276 /* Since this expression was found on the RHS of an assignment,
3277 its type may be different from _Bool. Convert VAL to EXPR's
3279 val
= fold_convert (type
, val
);
3280 if (is_gimple_min_invariant (val
))
3281 set_value_range_to_value (vr
, val
, vr
->equiv
);
3283 set_value_range (vr
, VR_RANGE
, val
, val
, vr
->equiv
);
3286 /* The result of a comparison is always true or false. */
3287 set_value_range_to_truthvalue (vr
, type
);
3290 /* Try to derive a nonnegative or nonzero range out of STMT relying
3291 primarily on generic routines in fold in conjunction with range data.
3292 Store the result in *VR */
3295 extract_range_basic (value_range_t
*vr
, gimple stmt
)
3298 tree type
= gimple_expr_type (stmt
);
3300 if (INTEGRAL_TYPE_P (type
)
3301 && gimple_stmt_nonnegative_warnv_p (stmt
, &sop
))
3302 set_value_range_to_nonnegative (vr
, type
,
3303 sop
|| stmt_overflow_infinity (stmt
));
3304 else if (vrp_stmt_computes_nonzero (stmt
, &sop
)
3306 set_value_range_to_nonnull (vr
, type
);
3308 set_value_range_to_varying (vr
);
3312 /* Try to compute a useful range out of assignment STMT and store it
3316 extract_range_from_assignment (value_range_t
*vr
, gimple stmt
)
3318 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3320 if (code
== ASSERT_EXPR
)
3321 extract_range_from_assert (vr
, gimple_assign_rhs1 (stmt
));
3322 else if (code
== SSA_NAME
)
3323 extract_range_from_ssa_name (vr
, gimple_assign_rhs1 (stmt
));
3324 else if (TREE_CODE_CLASS (code
) == tcc_binary
)
3325 extract_range_from_binary_expr (vr
, gimple_assign_rhs_code (stmt
),
3326 gimple_expr_type (stmt
),
3327 gimple_assign_rhs1 (stmt
),
3328 gimple_assign_rhs2 (stmt
));
3329 else if (TREE_CODE_CLASS (code
) == tcc_unary
)
3330 extract_range_from_unary_expr (vr
, gimple_assign_rhs_code (stmt
),
3331 gimple_expr_type (stmt
),
3332 gimple_assign_rhs1 (stmt
));
3333 else if (code
== COND_EXPR
)
3334 extract_range_from_cond_expr (vr
, gimple_assign_rhs1 (stmt
));
3335 else if (TREE_CODE_CLASS (code
) == tcc_comparison
)
3336 extract_range_from_comparison (vr
, gimple_assign_rhs_code (stmt
),
3337 gimple_expr_type (stmt
),
3338 gimple_assign_rhs1 (stmt
),
3339 gimple_assign_rhs2 (stmt
));
3340 else if (get_gimple_rhs_class (code
) == GIMPLE_SINGLE_RHS
3341 && is_gimple_min_invariant (gimple_assign_rhs1 (stmt
)))
3342 set_value_range_to_value (vr
, gimple_assign_rhs1 (stmt
), NULL
);
3344 set_value_range_to_varying (vr
);
3346 if (vr
->type
== VR_VARYING
)
3347 extract_range_basic (vr
, stmt
);
3350 /* Given a range VR, a LOOP and a variable VAR, determine whether it
3351 would be profitable to adjust VR using scalar evolution information
3352 for VAR. If so, update VR with the new limits. */
3355 adjust_range_with_scev (value_range_t
*vr
, struct loop
*loop
,
3356 gimple stmt
, tree var
)
3358 tree init
, step
, chrec
, tmin
, tmax
, min
, max
, type
, tem
;
3359 enum ev_direction dir
;
3361 /* TODO. Don't adjust anti-ranges. An anti-range may provide
3362 better opportunities than a regular range, but I'm not sure. */
3363 if (vr
->type
== VR_ANTI_RANGE
)
3366 chrec
= instantiate_parameters (loop
, analyze_scalar_evolution (loop
, var
));
3368 /* Like in PR19590, scev can return a constant function. */
3369 if (is_gimple_min_invariant (chrec
))
3371 set_value_range_to_value (vr
, chrec
, vr
->equiv
);
3375 if (TREE_CODE (chrec
) != POLYNOMIAL_CHREC
)
3378 init
= initial_condition_in_loop_num (chrec
, loop
->num
);
3379 tem
= op_with_constant_singleton_value_range (init
);
3382 step
= evolution_part_in_loop_num (chrec
, loop
->num
);
3383 tem
= op_with_constant_singleton_value_range (step
);
3387 /* If STEP is symbolic, we can't know whether INIT will be the
3388 minimum or maximum value in the range. Also, unless INIT is
3389 a simple expression, compare_values and possibly other functions
3390 in tree-vrp won't be able to handle it. */
3391 if (step
== NULL_TREE
3392 || !is_gimple_min_invariant (step
)
3393 || !valid_value_p (init
))
3396 dir
= scev_direction (chrec
);
3397 if (/* Do not adjust ranges if we do not know whether the iv increases
3398 or decreases, ... */
3399 dir
== EV_DIR_UNKNOWN
3400 /* ... or if it may wrap. */
3401 || scev_probably_wraps_p (init
, step
, stmt
, get_chrec_loop (chrec
),
3405 /* We use TYPE_MIN_VALUE and TYPE_MAX_VALUE here instead of
3406 negative_overflow_infinity and positive_overflow_infinity,
3407 because we have concluded that the loop probably does not
3410 type
= TREE_TYPE (var
);
3411 if (POINTER_TYPE_P (type
) || !TYPE_MIN_VALUE (type
))
3412 tmin
= lower_bound_in_type (type
, type
);
3414 tmin
= TYPE_MIN_VALUE (type
);
3415 if (POINTER_TYPE_P (type
) || !TYPE_MAX_VALUE (type
))
3416 tmax
= upper_bound_in_type (type
, type
);
3418 tmax
= TYPE_MAX_VALUE (type
);
3420 /* Try to use estimated number of iterations for the loop to constrain the
3421 final value in the evolution. */
3422 if (TREE_CODE (step
) == INTEGER_CST
3423 && is_gimple_val (init
)
3424 && (TREE_CODE (init
) != SSA_NAME
3425 || get_value_range (init
)->type
== VR_RANGE
))
3429 if (estimated_loop_iterations (loop
, true, &nit
))
3431 value_range_t maxvr
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3433 bool unsigned_p
= TYPE_UNSIGNED (TREE_TYPE (step
));
3436 dtmp
= double_int_mul_with_sign (tree_to_double_int (step
), nit
,
3437 unsigned_p
, &overflow
);
3438 /* If the multiplication overflowed we can't do a meaningful
3439 adjustment. Likewise if the result doesn't fit in the type
3440 of the induction variable. For a signed type we have to
3441 check whether the result has the expected signedness which
3442 is that of the step as number of iterations is unsigned. */
3444 && double_int_fits_to_tree_p (TREE_TYPE (init
), dtmp
)
3446 || ((dtmp
.high
^ TREE_INT_CST_HIGH (step
)) >= 0)))
3448 tem
= double_int_to_tree (TREE_TYPE (init
), dtmp
);
3449 extract_range_from_binary_expr (&maxvr
, PLUS_EXPR
,
3450 TREE_TYPE (init
), init
, tem
);
3451 /* Likewise if the addition did. */
3452 if (maxvr
.type
== VR_RANGE
)
3461 if (vr
->type
== VR_VARYING
|| vr
->type
== VR_UNDEFINED
)
3466 /* For VARYING or UNDEFINED ranges, just about anything we get
3467 from scalar evolutions should be better. */
3469 if (dir
== EV_DIR_DECREASES
)
3474 /* If we would create an invalid range, then just assume we
3475 know absolutely nothing. This may be over-conservative,
3476 but it's clearly safe, and should happen only in unreachable
3477 parts of code, or for invalid programs. */
3478 if (compare_values (min
, max
) == 1)
3481 set_value_range (vr
, VR_RANGE
, min
, max
, vr
->equiv
);
3483 else if (vr
->type
== VR_RANGE
)
3488 if (dir
== EV_DIR_DECREASES
)
3490 /* INIT is the maximum value. If INIT is lower than VR->MAX
3491 but no smaller than VR->MIN, set VR->MAX to INIT. */
3492 if (compare_values (init
, max
) == -1)
3495 /* According to the loop information, the variable does not
3496 overflow. If we think it does, probably because of an
3497 overflow due to arithmetic on a different INF value,
3499 if (is_negative_overflow_infinity (min
)
3500 || compare_values (min
, tmin
) == -1)
3506 /* If INIT is bigger than VR->MIN, set VR->MIN to INIT. */
3507 if (compare_values (init
, min
) == 1)
3510 if (is_positive_overflow_infinity (max
)
3511 || compare_values (tmax
, max
) == -1)
3515 /* If we just created an invalid range with the minimum
3516 greater than the maximum, we fail conservatively.
3517 This should happen only in unreachable
3518 parts of code, or for invalid programs. */
3519 if (compare_values (min
, max
) == 1)
3522 set_value_range (vr
, VR_RANGE
, min
, max
, vr
->equiv
);
3526 /* Return true if VAR may overflow at STMT. This checks any available
3527 loop information to see if we can determine that VAR does not
3531 vrp_var_may_overflow (tree var
, gimple stmt
)
3534 tree chrec
, init
, step
;
3536 if (current_loops
== NULL
)
3539 l
= loop_containing_stmt (stmt
);
3544 chrec
= instantiate_parameters (l
, analyze_scalar_evolution (l
, var
));
3545 if (TREE_CODE (chrec
) != POLYNOMIAL_CHREC
)
3548 init
= initial_condition_in_loop_num (chrec
, l
->num
);
3549 step
= evolution_part_in_loop_num (chrec
, l
->num
);
3551 if (step
== NULL_TREE
3552 || !is_gimple_min_invariant (step
)
3553 || !valid_value_p (init
))
3556 /* If we get here, we know something useful about VAR based on the
3557 loop information. If it wraps, it may overflow. */
3559 if (scev_probably_wraps_p (init
, step
, stmt
, get_chrec_loop (chrec
),
3563 if (dump_file
&& (dump_flags
& TDF_DETAILS
) != 0)
3565 print_generic_expr (dump_file
, var
, 0);
3566 fprintf (dump_file
, ": loop information indicates does not overflow\n");
3573 /* Given two numeric value ranges VR0, VR1 and a comparison code COMP:
3575 - Return BOOLEAN_TRUE_NODE if VR0 COMP VR1 always returns true for
3576 all the values in the ranges.
3578 - Return BOOLEAN_FALSE_NODE if the comparison always returns false.
3580 - Return NULL_TREE if it is not always possible to determine the
3581 value of the comparison.
3583 Also set *STRICT_OVERFLOW_P to indicate whether a range with an
3584 overflow infinity was used in the test. */
3588 compare_ranges (enum tree_code comp
, value_range_t
*vr0
, value_range_t
*vr1
,
3589 bool *strict_overflow_p
)
3591 /* VARYING or UNDEFINED ranges cannot be compared. */
3592 if (vr0
->type
== VR_VARYING
3593 || vr0
->type
== VR_UNDEFINED
3594 || vr1
->type
== VR_VARYING
3595 || vr1
->type
== VR_UNDEFINED
)
3598 /* Anti-ranges need to be handled separately. */
3599 if (vr0
->type
== VR_ANTI_RANGE
|| vr1
->type
== VR_ANTI_RANGE
)
3601 /* If both are anti-ranges, then we cannot compute any
3603 if (vr0
->type
== VR_ANTI_RANGE
&& vr1
->type
== VR_ANTI_RANGE
)
3606 /* These comparisons are never statically computable. */
3613 /* Equality can be computed only between a range and an
3614 anti-range. ~[VAL1, VAL2] == [VAL1, VAL2] is always false. */
3615 if (vr0
->type
== VR_RANGE
)
3617 /* To simplify processing, make VR0 the anti-range. */
3618 value_range_t
*tmp
= vr0
;
3623 gcc_assert (comp
== NE_EXPR
|| comp
== EQ_EXPR
);
3625 if (compare_values_warnv (vr0
->min
, vr1
->min
, strict_overflow_p
) == 0
3626 && compare_values_warnv (vr0
->max
, vr1
->max
, strict_overflow_p
) == 0)
3627 return (comp
== NE_EXPR
) ? boolean_true_node
: boolean_false_node
;
3632 if (!usable_range_p (vr0
, strict_overflow_p
)
3633 || !usable_range_p (vr1
, strict_overflow_p
))
3636 /* Simplify processing. If COMP is GT_EXPR or GE_EXPR, switch the
3637 operands around and change the comparison code. */
3638 if (comp
== GT_EXPR
|| comp
== GE_EXPR
)
3641 comp
= (comp
== GT_EXPR
) ? LT_EXPR
: LE_EXPR
;
3647 if (comp
== EQ_EXPR
)
3649 /* Equality may only be computed if both ranges represent
3650 exactly one value. */
3651 if (compare_values_warnv (vr0
->min
, vr0
->max
, strict_overflow_p
) == 0
3652 && compare_values_warnv (vr1
->min
, vr1
->max
, strict_overflow_p
) == 0)
3654 int cmp_min
= compare_values_warnv (vr0
->min
, vr1
->min
,
3656 int cmp_max
= compare_values_warnv (vr0
->max
, vr1
->max
,
3658 if (cmp_min
== 0 && cmp_max
== 0)
3659 return boolean_true_node
;
3660 else if (cmp_min
!= -2 && cmp_max
!= -2)
3661 return boolean_false_node
;
3663 /* If [V0_MIN, V1_MAX] < [V1_MIN, V1_MAX] then V0 != V1. */
3664 else if (compare_values_warnv (vr0
->min
, vr1
->max
,
3665 strict_overflow_p
) == 1
3666 || compare_values_warnv (vr1
->min
, vr0
->max
,
3667 strict_overflow_p
) == 1)
3668 return boolean_false_node
;
3672 else if (comp
== NE_EXPR
)
3676 /* If VR0 is completely to the left or completely to the right
3677 of VR1, they are always different. Notice that we need to
3678 make sure that both comparisons yield similar results to
3679 avoid comparing values that cannot be compared at
3681 cmp1
= compare_values_warnv (vr0
->max
, vr1
->min
, strict_overflow_p
);
3682 cmp2
= compare_values_warnv (vr0
->min
, vr1
->max
, strict_overflow_p
);
3683 if ((cmp1
== -1 && cmp2
== -1) || (cmp1
== 1 && cmp2
== 1))
3684 return boolean_true_node
;
3686 /* If VR0 and VR1 represent a single value and are identical,
3688 else if (compare_values_warnv (vr0
->min
, vr0
->max
,
3689 strict_overflow_p
) == 0
3690 && compare_values_warnv (vr1
->min
, vr1
->max
,
3691 strict_overflow_p
) == 0
3692 && compare_values_warnv (vr0
->min
, vr1
->min
,
3693 strict_overflow_p
) == 0
3694 && compare_values_warnv (vr0
->max
, vr1
->max
,
3695 strict_overflow_p
) == 0)
3696 return boolean_false_node
;
3698 /* Otherwise, they may or may not be different. */
3702 else if (comp
== LT_EXPR
|| comp
== LE_EXPR
)
3706 /* If VR0 is to the left of VR1, return true. */
3707 tst
= compare_values_warnv (vr0
->max
, vr1
->min
, strict_overflow_p
);
3708 if ((comp
== LT_EXPR
&& tst
== -1)
3709 || (comp
== LE_EXPR
&& (tst
== -1 || tst
== 0)))
3711 if (overflow_infinity_range_p (vr0
)
3712 || overflow_infinity_range_p (vr1
))
3713 *strict_overflow_p
= true;
3714 return boolean_true_node
;
3717 /* If VR0 is to the right of VR1, return false. */
3718 tst
= compare_values_warnv (vr0
->min
, vr1
->max
, strict_overflow_p
);
3719 if ((comp
== LT_EXPR
&& (tst
== 0 || tst
== 1))
3720 || (comp
== LE_EXPR
&& tst
== 1))
3722 if (overflow_infinity_range_p (vr0
)
3723 || overflow_infinity_range_p (vr1
))
3724 *strict_overflow_p
= true;
3725 return boolean_false_node
;
3728 /* Otherwise, we don't know. */
3736 /* Given a value range VR, a value VAL and a comparison code COMP, return
3737 BOOLEAN_TRUE_NODE if VR COMP VAL always returns true for all the
3738 values in VR. Return BOOLEAN_FALSE_NODE if the comparison
3739 always returns false. Return NULL_TREE if it is not always
3740 possible to determine the value of the comparison. Also set
3741 *STRICT_OVERFLOW_P to indicate whether a range with an overflow
3742 infinity was used in the test. */
3745 compare_range_with_value (enum tree_code comp
, value_range_t
*vr
, tree val
,
3746 bool *strict_overflow_p
)
3748 if (vr
->type
== VR_VARYING
|| vr
->type
== VR_UNDEFINED
)
3751 /* Anti-ranges need to be handled separately. */
3752 if (vr
->type
== VR_ANTI_RANGE
)
3754 /* For anti-ranges, the only predicates that we can compute at
3755 compile time are equality and inequality. */
3762 /* ~[VAL_1, VAL_2] OP VAL is known if VAL_1 <= VAL <= VAL_2. */
3763 if (value_inside_range (val
, vr
) == 1)
3764 return (comp
== NE_EXPR
) ? boolean_true_node
: boolean_false_node
;
3769 if (!usable_range_p (vr
, strict_overflow_p
))
3772 if (comp
== EQ_EXPR
)
3774 /* EQ_EXPR may only be computed if VR represents exactly
3776 if (compare_values_warnv (vr
->min
, vr
->max
, strict_overflow_p
) == 0)
3778 int cmp
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
3780 return boolean_true_node
;
3781 else if (cmp
== -1 || cmp
== 1 || cmp
== 2)
3782 return boolean_false_node
;
3784 else if (compare_values_warnv (val
, vr
->min
, strict_overflow_p
) == -1
3785 || compare_values_warnv (vr
->max
, val
, strict_overflow_p
) == -1)
3786 return boolean_false_node
;
3790 else if (comp
== NE_EXPR
)
3792 /* If VAL is not inside VR, then they are always different. */
3793 if (compare_values_warnv (vr
->max
, val
, strict_overflow_p
) == -1
3794 || compare_values_warnv (vr
->min
, val
, strict_overflow_p
) == 1)
3795 return boolean_true_node
;
3797 /* If VR represents exactly one value equal to VAL, then return
3799 if (compare_values_warnv (vr
->min
, vr
->max
, strict_overflow_p
) == 0
3800 && compare_values_warnv (vr
->min
, val
, strict_overflow_p
) == 0)
3801 return boolean_false_node
;
3803 /* Otherwise, they may or may not be different. */
3806 else if (comp
== LT_EXPR
|| comp
== LE_EXPR
)
3810 /* If VR is to the left of VAL, return true. */
3811 tst
= compare_values_warnv (vr
->max
, val
, strict_overflow_p
);
3812 if ((comp
== LT_EXPR
&& tst
== -1)
3813 || (comp
== LE_EXPR
&& (tst
== -1 || tst
== 0)))
3815 if (overflow_infinity_range_p (vr
))
3816 *strict_overflow_p
= true;
3817 return boolean_true_node
;
3820 /* If VR is to the right of VAL, return false. */
3821 tst
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
3822 if ((comp
== LT_EXPR
&& (tst
== 0 || tst
== 1))
3823 || (comp
== LE_EXPR
&& tst
== 1))
3825 if (overflow_infinity_range_p (vr
))
3826 *strict_overflow_p
= true;
3827 return boolean_false_node
;
3830 /* Otherwise, we don't know. */
3833 else if (comp
== GT_EXPR
|| comp
== GE_EXPR
)
3837 /* If VR is to the right of VAL, return true. */
3838 tst
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
3839 if ((comp
== GT_EXPR
&& tst
== 1)
3840 || (comp
== GE_EXPR
&& (tst
== 0 || tst
== 1)))
3842 if (overflow_infinity_range_p (vr
))
3843 *strict_overflow_p
= true;
3844 return boolean_true_node
;
3847 /* If VR is to the left of VAL, return false. */
3848 tst
= compare_values_warnv (vr
->max
, val
, strict_overflow_p
);
3849 if ((comp
== GT_EXPR
&& (tst
== -1 || tst
== 0))
3850 || (comp
== GE_EXPR
&& tst
== -1))
3852 if (overflow_infinity_range_p (vr
))
3853 *strict_overflow_p
= true;
3854 return boolean_false_node
;
3857 /* Otherwise, we don't know. */
3865 /* Debugging dumps. */
3867 void dump_value_range (FILE *, value_range_t
*);
3868 void debug_value_range (value_range_t
*);
3869 void dump_all_value_ranges (FILE *);
3870 void debug_all_value_ranges (void);
3871 void dump_vr_equiv (FILE *, bitmap
);
3872 void debug_vr_equiv (bitmap
);
3875 /* Dump value range VR to FILE. */
3878 dump_value_range (FILE *file
, value_range_t
*vr
)
3881 fprintf (file
, "[]");
3882 else if (vr
->type
== VR_UNDEFINED
)
3883 fprintf (file
, "UNDEFINED");
3884 else if (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
)
3886 tree type
= TREE_TYPE (vr
->min
);
3888 fprintf (file
, "%s[", (vr
->type
== VR_ANTI_RANGE
) ? "~" : "");
3890 if (is_negative_overflow_infinity (vr
->min
))
3891 fprintf (file
, "-INF(OVF)");
3892 else if (INTEGRAL_TYPE_P (type
)
3893 && !TYPE_UNSIGNED (type
)
3894 && vrp_val_is_min (vr
->min
))
3895 fprintf (file
, "-INF");
3897 print_generic_expr (file
, vr
->min
, 0);
3899 fprintf (file
, ", ");
3901 if (is_positive_overflow_infinity (vr
->max
))
3902 fprintf (file
, "+INF(OVF)");
3903 else if (INTEGRAL_TYPE_P (type
)
3904 && vrp_val_is_max (vr
->max
))
3905 fprintf (file
, "+INF");
3907 print_generic_expr (file
, vr
->max
, 0);
3909 fprintf (file
, "]");
3916 fprintf (file
, " EQUIVALENCES: { ");
3918 EXECUTE_IF_SET_IN_BITMAP (vr
->equiv
, 0, i
, bi
)
3920 print_generic_expr (file
, ssa_name (i
), 0);
3921 fprintf (file
, " ");
3925 fprintf (file
, "} (%u elements)", c
);
3928 else if (vr
->type
== VR_VARYING
)
3929 fprintf (file
, "VARYING");
3931 fprintf (file
, "INVALID RANGE");
3935 /* Dump value range VR to stderr. */
3938 debug_value_range (value_range_t
*vr
)
3940 dump_value_range (stderr
, vr
);
3941 fprintf (stderr
, "\n");
3945 /* Dump value ranges of all SSA_NAMEs to FILE. */
3948 dump_all_value_ranges (FILE *file
)
3952 for (i
= 0; i
< num_vr_values
; i
++)
3956 print_generic_expr (file
, ssa_name (i
), 0);
3957 fprintf (file
, ": ");
3958 dump_value_range (file
, vr_value
[i
]);
3959 fprintf (file
, "\n");
3963 fprintf (file
, "\n");
3967 /* Dump all value ranges to stderr. */
3970 debug_all_value_ranges (void)
3972 dump_all_value_ranges (stderr
);
3976 /* Given a COND_EXPR COND of the form 'V OP W', and an SSA name V,
3977 create a new SSA name N and return the assertion assignment
3978 'V = ASSERT_EXPR <V, V OP W>'. */
3981 build_assert_expr_for (tree cond
, tree v
)
3986 gcc_assert (TREE_CODE (v
) == SSA_NAME
);
3987 n
= duplicate_ssa_name (v
, NULL
);
3989 if (COMPARISON_CLASS_P (cond
))
3991 tree a
= build2 (ASSERT_EXPR
, TREE_TYPE (v
), v
, cond
);
3992 assertion
= gimple_build_assign (n
, a
);
3994 else if (TREE_CODE (cond
) == SSA_NAME
)
3996 /* Given V, build the assignment N = true. */
3997 gcc_assert (v
== cond
);
3998 assertion
= gimple_build_assign (n
, boolean_true_node
);
4003 SSA_NAME_DEF_STMT (n
) = assertion
;
4005 /* The new ASSERT_EXPR, creates a new SSA name that replaces the
4006 operand of the ASSERT_EXPR. Register the new name and the old one
4007 in the replacement table so that we can fix the SSA web after
4008 adding all the ASSERT_EXPRs. */
4009 register_new_name_mapping (n
, v
);
4015 /* Return false if EXPR is a predicate expression involving floating
4019 fp_predicate (gimple stmt
)
4021 GIMPLE_CHECK (stmt
, GIMPLE_COND
);
4023 return FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (stmt
)));
4027 /* If the range of values taken by OP can be inferred after STMT executes,
4028 return the comparison code (COMP_CODE_P) and value (VAL_P) that
4029 describes the inferred range. Return true if a range could be
4033 infer_value_range (gimple stmt
, tree op
, enum tree_code
*comp_code_p
, tree
*val_p
)
4036 *comp_code_p
= ERROR_MARK
;
4038 /* Do not attempt to infer anything in names that flow through
4040 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op
))
4043 /* Similarly, don't infer anything from statements that may throw
4045 if (stmt_could_throw_p (stmt
))
4048 /* If STMT is the last statement of a basic block with no
4049 successors, there is no point inferring anything about any of its
4050 operands. We would not be able to find a proper insertion point
4051 for the assertion, anyway. */
4052 if (stmt_ends_bb_p (stmt
) && EDGE_COUNT (gimple_bb (stmt
)->succs
) == 0)
4055 /* We can only assume that a pointer dereference will yield
4056 non-NULL if -fdelete-null-pointer-checks is enabled. */
4057 if (flag_delete_null_pointer_checks
4058 && POINTER_TYPE_P (TREE_TYPE (op
))
4059 && gimple_code (stmt
) != GIMPLE_ASM
)
4061 unsigned num_uses
, num_loads
, num_stores
;
4063 count_uses_and_derefs (op
, stmt
, &num_uses
, &num_loads
, &num_stores
);
4064 if (num_loads
+ num_stores
> 0)
4066 *val_p
= build_int_cst (TREE_TYPE (op
), 0);
4067 *comp_code_p
= NE_EXPR
;
4076 void dump_asserts_for (FILE *, tree
);
4077 void debug_asserts_for (tree
);
4078 void dump_all_asserts (FILE *);
4079 void debug_all_asserts (void);
4081 /* Dump all the registered assertions for NAME to FILE. */
4084 dump_asserts_for (FILE *file
, tree name
)
4088 fprintf (file
, "Assertions to be inserted for ");
4089 print_generic_expr (file
, name
, 0);
4090 fprintf (file
, "\n");
4092 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
4095 fprintf (file
, "\t");
4096 print_gimple_stmt (file
, gsi_stmt (loc
->si
), 0, 0);
4097 fprintf (file
, "\n\tBB #%d", loc
->bb
->index
);
4100 fprintf (file
, "\n\tEDGE %d->%d", loc
->e
->src
->index
,
4101 loc
->e
->dest
->index
);
4102 dump_edge_info (file
, loc
->e
, 0);
4104 fprintf (file
, "\n\tPREDICATE: ");
4105 print_generic_expr (file
, name
, 0);
4106 fprintf (file
, " %s ", tree_code_name
[(int)loc
->comp_code
]);
4107 print_generic_expr (file
, loc
->val
, 0);
4108 fprintf (file
, "\n\n");
4112 fprintf (file
, "\n");
4116 /* Dump all the registered assertions for NAME to stderr. */
4119 debug_asserts_for (tree name
)
4121 dump_asserts_for (stderr
, name
);
4125 /* Dump all the registered assertions for all the names to FILE. */
4128 dump_all_asserts (FILE *file
)
4133 fprintf (file
, "\nASSERT_EXPRs to be inserted\n\n");
4134 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
4135 dump_asserts_for (file
, ssa_name (i
));
4136 fprintf (file
, "\n");
4140 /* Dump all the registered assertions for all the names to stderr. */
4143 debug_all_asserts (void)
4145 dump_all_asserts (stderr
);
4149 /* If NAME doesn't have an ASSERT_EXPR registered for asserting
4150 'EXPR COMP_CODE VAL' at a location that dominates block BB or
4151 E->DEST, then register this location as a possible insertion point
4152 for ASSERT_EXPR <NAME, EXPR COMP_CODE VAL>.
4154 BB, E and SI provide the exact insertion point for the new
4155 ASSERT_EXPR. If BB is NULL, then the ASSERT_EXPR is to be inserted
4156 on edge E. Otherwise, if E is NULL, the ASSERT_EXPR is inserted on
4157 BB. If SI points to a COND_EXPR or a SWITCH_EXPR statement, then E
4158 must not be NULL. */
4161 register_new_assert_for (tree name
, tree expr
,
4162 enum tree_code comp_code
,
4166 gimple_stmt_iterator si
)
4168 assert_locus_t n
, loc
, last_loc
;
4169 basic_block dest_bb
;
4171 gcc_checking_assert (bb
== NULL
|| e
== NULL
);
4174 gcc_checking_assert (gimple_code (gsi_stmt (si
)) != GIMPLE_COND
4175 && gimple_code (gsi_stmt (si
)) != GIMPLE_SWITCH
);
4177 /* Never build an assert comparing against an integer constant with
4178 TREE_OVERFLOW set. This confuses our undefined overflow warning
4180 if (TREE_CODE (val
) == INTEGER_CST
4181 && TREE_OVERFLOW (val
))
4182 val
= build_int_cst_wide (TREE_TYPE (val
),
4183 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
));
4185 /* The new assertion A will be inserted at BB or E. We need to
4186 determine if the new location is dominated by a previously
4187 registered location for A. If we are doing an edge insertion,
4188 assume that A will be inserted at E->DEST. Note that this is not
4191 If E is a critical edge, it will be split. But even if E is
4192 split, the new block will dominate the same set of blocks that
4195 The reverse, however, is not true, blocks dominated by E->DEST
4196 will not be dominated by the new block created to split E. So,
4197 if the insertion location is on a critical edge, we will not use
4198 the new location to move another assertion previously registered
4199 at a block dominated by E->DEST. */
4200 dest_bb
= (bb
) ? bb
: e
->dest
;
4202 /* If NAME already has an ASSERT_EXPR registered for COMP_CODE and
4203 VAL at a block dominating DEST_BB, then we don't need to insert a new
4204 one. Similarly, if the same assertion already exists at a block
4205 dominated by DEST_BB and the new location is not on a critical
4206 edge, then update the existing location for the assertion (i.e.,
4207 move the assertion up in the dominance tree).
4209 Note, this is implemented as a simple linked list because there
4210 should not be more than a handful of assertions registered per
4211 name. If this becomes a performance problem, a table hashed by
4212 COMP_CODE and VAL could be implemented. */
4213 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
4217 if (loc
->comp_code
== comp_code
4219 || operand_equal_p (loc
->val
, val
, 0))
4220 && (loc
->expr
== expr
4221 || operand_equal_p (loc
->expr
, expr
, 0)))
4223 /* If the assertion NAME COMP_CODE VAL has already been
4224 registered at a basic block that dominates DEST_BB, then
4225 we don't need to insert the same assertion again. Note
4226 that we don't check strict dominance here to avoid
4227 replicating the same assertion inside the same basic
4228 block more than once (e.g., when a pointer is
4229 dereferenced several times inside a block).
4231 An exception to this rule are edge insertions. If the
4232 new assertion is to be inserted on edge E, then it will
4233 dominate all the other insertions that we may want to
4234 insert in DEST_BB. So, if we are doing an edge
4235 insertion, don't do this dominance check. */
4237 && dominated_by_p (CDI_DOMINATORS
, dest_bb
, loc
->bb
))
4240 /* Otherwise, if E is not a critical edge and DEST_BB
4241 dominates the existing location for the assertion, move
4242 the assertion up in the dominance tree by updating its
4243 location information. */
4244 if ((e
== NULL
|| !EDGE_CRITICAL_P (e
))
4245 && dominated_by_p (CDI_DOMINATORS
, loc
->bb
, dest_bb
))
4254 /* Update the last node of the list and move to the next one. */
4259 /* If we didn't find an assertion already registered for
4260 NAME COMP_CODE VAL, add a new one at the end of the list of
4261 assertions associated with NAME. */
4262 n
= XNEW (struct assert_locus_d
);
4266 n
->comp_code
= comp_code
;
4274 asserts_for
[SSA_NAME_VERSION (name
)] = n
;
4276 bitmap_set_bit (need_assert_for
, SSA_NAME_VERSION (name
));
4279 /* (COND_OP0 COND_CODE COND_OP1) is a predicate which uses NAME.
4280 Extract a suitable test code and value and store them into *CODE_P and
4281 *VAL_P so the predicate is normalized to NAME *CODE_P *VAL_P.
4283 If no extraction was possible, return FALSE, otherwise return TRUE.
4285 If INVERT is true, then we invert the result stored into *CODE_P. */
4288 extract_code_and_val_from_cond_with_ops (tree name
, enum tree_code cond_code
,
4289 tree cond_op0
, tree cond_op1
,
4290 bool invert
, enum tree_code
*code_p
,
4293 enum tree_code comp_code
;
4296 /* Otherwise, we have a comparison of the form NAME COMP VAL
4297 or VAL COMP NAME. */
4298 if (name
== cond_op1
)
4300 /* If the predicate is of the form VAL COMP NAME, flip
4301 COMP around because we need to register NAME as the
4302 first operand in the predicate. */
4303 comp_code
= swap_tree_comparison (cond_code
);
4308 /* The comparison is of the form NAME COMP VAL, so the
4309 comparison code remains unchanged. */
4310 comp_code
= cond_code
;
4314 /* Invert the comparison code as necessary. */
4316 comp_code
= invert_tree_comparison (comp_code
, 0);
4318 /* VRP does not handle float types. */
4319 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (val
)))
4322 /* Do not register always-false predicates.
4323 FIXME: this works around a limitation in fold() when dealing with
4324 enumerations. Given 'enum { N1, N2 } x;', fold will not
4325 fold 'if (x > N2)' to 'if (0)'. */
4326 if ((comp_code
== GT_EXPR
|| comp_code
== LT_EXPR
)
4327 && INTEGRAL_TYPE_P (TREE_TYPE (val
)))
4329 tree min
= TYPE_MIN_VALUE (TREE_TYPE (val
));
4330 tree max
= TYPE_MAX_VALUE (TREE_TYPE (val
));
4332 if (comp_code
== GT_EXPR
4334 || compare_values (val
, max
) == 0))
4337 if (comp_code
== LT_EXPR
4339 || compare_values (val
, min
) == 0))
4342 *code_p
= comp_code
;
4347 /* Try to register an edge assertion for SSA name NAME on edge E for
4348 the condition COND contributing to the conditional jump pointed to by BSI.
4349 Invert the condition COND if INVERT is true.
4350 Return true if an assertion for NAME could be registered. */
4353 register_edge_assert_for_2 (tree name
, edge e
, gimple_stmt_iterator bsi
,
4354 enum tree_code cond_code
,
4355 tree cond_op0
, tree cond_op1
, bool invert
)
4358 enum tree_code comp_code
;
4359 bool retval
= false;
4361 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
4364 invert
, &comp_code
, &val
))
4367 /* Only register an ASSERT_EXPR if NAME was found in the sub-graph
4368 reachable from E. */
4369 if (live_on_edge (e
, name
)
4370 && !has_single_use (name
))
4372 register_new_assert_for (name
, name
, comp_code
, val
, NULL
, e
, bsi
);
4376 /* In the case of NAME <= CST and NAME being defined as
4377 NAME = (unsigned) NAME2 + CST2 we can assert NAME2 >= -CST2
4378 and NAME2 <= CST - CST2. We can do the same for NAME > CST.
4379 This catches range and anti-range tests. */
4380 if ((comp_code
== LE_EXPR
4381 || comp_code
== GT_EXPR
)
4382 && TREE_CODE (val
) == INTEGER_CST
4383 && TYPE_UNSIGNED (TREE_TYPE (val
)))
4385 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
4386 tree cst2
= NULL_TREE
, name2
= NULL_TREE
, name3
= NULL_TREE
;
4388 /* Extract CST2 from the (optional) addition. */
4389 if (is_gimple_assign (def_stmt
)
4390 && gimple_assign_rhs_code (def_stmt
) == PLUS_EXPR
)
4392 name2
= gimple_assign_rhs1 (def_stmt
);
4393 cst2
= gimple_assign_rhs2 (def_stmt
);
4394 if (TREE_CODE (name2
) == SSA_NAME
4395 && TREE_CODE (cst2
) == INTEGER_CST
)
4396 def_stmt
= SSA_NAME_DEF_STMT (name2
);
4399 /* Extract NAME2 from the (optional) sign-changing cast. */
4400 if (gimple_assign_cast_p (def_stmt
))
4402 if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
))
4403 && ! TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))
4404 && (TYPE_PRECISION (gimple_expr_type (def_stmt
))
4405 == TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))))
4406 name3
= gimple_assign_rhs1 (def_stmt
);
4409 /* If name3 is used later, create an ASSERT_EXPR for it. */
4410 if (name3
!= NULL_TREE
4411 && TREE_CODE (name3
) == SSA_NAME
4412 && (cst2
== NULL_TREE
4413 || TREE_CODE (cst2
) == INTEGER_CST
)
4414 && INTEGRAL_TYPE_P (TREE_TYPE (name3
))
4415 && live_on_edge (e
, name3
)
4416 && !has_single_use (name3
))
4420 /* Build an expression for the range test. */
4421 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), name3
);
4422 if (cst2
!= NULL_TREE
)
4423 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
4427 fprintf (dump_file
, "Adding assert for ");
4428 print_generic_expr (dump_file
, name3
, 0);
4429 fprintf (dump_file
, " from ");
4430 print_generic_expr (dump_file
, tmp
, 0);
4431 fprintf (dump_file
, "\n");
4434 register_new_assert_for (name3
, tmp
, comp_code
, val
, NULL
, e
, bsi
);
4439 /* If name2 is used later, create an ASSERT_EXPR for it. */
4440 if (name2
!= NULL_TREE
4441 && TREE_CODE (name2
) == SSA_NAME
4442 && TREE_CODE (cst2
) == INTEGER_CST
4443 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
4444 && live_on_edge (e
, name2
)
4445 && !has_single_use (name2
))
4449 /* Build an expression for the range test. */
4451 if (TREE_TYPE (name
) != TREE_TYPE (name2
))
4452 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), tmp
);
4453 if (cst2
!= NULL_TREE
)
4454 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
4458 fprintf (dump_file
, "Adding assert for ");
4459 print_generic_expr (dump_file
, name2
, 0);
4460 fprintf (dump_file
, " from ");
4461 print_generic_expr (dump_file
, tmp
, 0);
4462 fprintf (dump_file
, "\n");
4465 register_new_assert_for (name2
, tmp
, comp_code
, val
, NULL
, e
, bsi
);
4474 /* OP is an operand of a truth value expression which is known to have
4475 a particular value. Register any asserts for OP and for any
4476 operands in OP's defining statement.
4478 If CODE is EQ_EXPR, then we want to register OP is zero (false),
4479 if CODE is NE_EXPR, then we want to register OP is nonzero (true). */
4482 register_edge_assert_for_1 (tree op
, enum tree_code code
,
4483 edge e
, gimple_stmt_iterator bsi
)
4485 bool retval
= false;
4488 enum tree_code rhs_code
;
4490 /* We only care about SSA_NAMEs. */
4491 if (TREE_CODE (op
) != SSA_NAME
)
4494 /* We know that OP will have a zero or nonzero value. If OP is used
4495 more than once go ahead and register an assert for OP.
4497 The FOUND_IN_SUBGRAPH support is not helpful in this situation as
4498 it will always be set for OP (because OP is used in a COND_EXPR in
4500 if (!has_single_use (op
))
4502 val
= build_int_cst (TREE_TYPE (op
), 0);
4503 register_new_assert_for (op
, op
, code
, val
, NULL
, e
, bsi
);
4507 /* Now look at how OP is set. If it's set from a comparison,
4508 a truth operation or some bit operations, then we may be able
4509 to register information about the operands of that assignment. */
4510 op_def
= SSA_NAME_DEF_STMT (op
);
4511 if (gimple_code (op_def
) != GIMPLE_ASSIGN
)
4514 rhs_code
= gimple_assign_rhs_code (op_def
);
4516 if (TREE_CODE_CLASS (rhs_code
) == tcc_comparison
)
4518 bool invert
= (code
== EQ_EXPR
? true : false);
4519 tree op0
= gimple_assign_rhs1 (op_def
);
4520 tree op1
= gimple_assign_rhs2 (op_def
);
4522 if (TREE_CODE (op0
) == SSA_NAME
)
4523 retval
|= register_edge_assert_for_2 (op0
, e
, bsi
, rhs_code
, op0
, op1
,
4525 if (TREE_CODE (op1
) == SSA_NAME
)
4526 retval
|= register_edge_assert_for_2 (op1
, e
, bsi
, rhs_code
, op0
, op1
,
4529 else if ((code
== NE_EXPR
4530 && gimple_assign_rhs_code (op_def
) == BIT_AND_EXPR
)
4532 && gimple_assign_rhs_code (op_def
) == BIT_IOR_EXPR
))
4534 /* Recurse on each operand. */
4535 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4537 retval
|= register_edge_assert_for_1 (gimple_assign_rhs2 (op_def
),
4540 else if (gimple_assign_rhs_code (op_def
) == BIT_NOT_EXPR
4541 && TYPE_PRECISION (TREE_TYPE (gimple_assign_lhs (op_def
))) == 1)
4543 /* Recurse, flipping CODE. */
4544 code
= invert_tree_comparison (code
, false);
4545 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4548 else if (gimple_assign_rhs_code (op_def
) == SSA_NAME
)
4550 /* Recurse through the copy. */
4551 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4554 else if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (op_def
)))
4556 /* Recurse through the type conversion. */
4557 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4564 /* Try to register an edge assertion for SSA name NAME on edge E for
4565 the condition COND contributing to the conditional jump pointed to by SI.
4566 Return true if an assertion for NAME could be registered. */
4569 register_edge_assert_for (tree name
, edge e
, gimple_stmt_iterator si
,
4570 enum tree_code cond_code
, tree cond_op0
,
4574 enum tree_code comp_code
;
4575 bool retval
= false;
4576 bool is_else_edge
= (e
->flags
& EDGE_FALSE_VALUE
) != 0;
4578 /* Do not attempt to infer anything in names that flow through
4580 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name
))
4583 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
4589 /* Register ASSERT_EXPRs for name. */
4590 retval
|= register_edge_assert_for_2 (name
, e
, si
, cond_code
, cond_op0
,
4591 cond_op1
, is_else_edge
);
4594 /* If COND is effectively an equality test of an SSA_NAME against
4595 the value zero or one, then we may be able to assert values
4596 for SSA_NAMEs which flow into COND. */
4598 /* In the case of NAME == 1 or NAME != 0, for BIT_AND_EXPR defining
4599 statement of NAME we can assert both operands of the BIT_AND_EXPR
4600 have nonzero value. */
4601 if (((comp_code
== EQ_EXPR
&& integer_onep (val
))
4602 || (comp_code
== NE_EXPR
&& integer_zerop (val
))))
4604 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
4606 if (is_gimple_assign (def_stmt
)
4607 && gimple_assign_rhs_code (def_stmt
) == BIT_AND_EXPR
)
4609 tree op0
= gimple_assign_rhs1 (def_stmt
);
4610 tree op1
= gimple_assign_rhs2 (def_stmt
);
4611 retval
|= register_edge_assert_for_1 (op0
, NE_EXPR
, e
, si
);
4612 retval
|= register_edge_assert_for_1 (op1
, NE_EXPR
, e
, si
);
4616 /* In the case of NAME == 0 or NAME != 1, for BIT_IOR_EXPR defining
4617 statement of NAME we can assert both operands of the BIT_IOR_EXPR
4619 if (((comp_code
== EQ_EXPR
&& integer_zerop (val
))
4620 || (comp_code
== NE_EXPR
&& integer_onep (val
))))
4622 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
4624 /* For BIT_IOR_EXPR only if NAME == 0 both operands have
4625 necessarily zero value, or if type-precision is one. */
4626 if (is_gimple_assign (def_stmt
)
4627 && (gimple_assign_rhs_code (def_stmt
) == BIT_IOR_EXPR
4628 && (TYPE_PRECISION (TREE_TYPE (name
)) == 1
4629 || comp_code
== EQ_EXPR
)))
4631 tree op0
= gimple_assign_rhs1 (def_stmt
);
4632 tree op1
= gimple_assign_rhs2 (def_stmt
);
4633 retval
|= register_edge_assert_for_1 (op0
, EQ_EXPR
, e
, si
);
4634 retval
|= register_edge_assert_for_1 (op1
, EQ_EXPR
, e
, si
);
4642 /* Determine whether the outgoing edges of BB should receive an
4643 ASSERT_EXPR for each of the operands of BB's LAST statement.
4644 The last statement of BB must be a COND_EXPR.
4646 If any of the sub-graphs rooted at BB have an interesting use of
4647 the predicate operands, an assert location node is added to the
4648 list of assertions for the corresponding operands. */
4651 find_conditional_asserts (basic_block bb
, gimple last
)
4654 gimple_stmt_iterator bsi
;
4660 need_assert
= false;
4661 bsi
= gsi_for_stmt (last
);
4663 /* Look for uses of the operands in each of the sub-graphs
4664 rooted at BB. We need to check each of the outgoing edges
4665 separately, so that we know what kind of ASSERT_EXPR to
4667 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4672 /* Register the necessary assertions for each operand in the
4673 conditional predicate. */
4674 FOR_EACH_SSA_TREE_OPERAND (op
, last
, iter
, SSA_OP_USE
)
4676 need_assert
|= register_edge_assert_for (op
, e
, bsi
,
4677 gimple_cond_code (last
),
4678 gimple_cond_lhs (last
),
4679 gimple_cond_rhs (last
));
4692 /* Compare two case labels sorting first by the destination bb index
4693 and then by the case value. */
4696 compare_case_labels (const void *p1
, const void *p2
)
4698 const struct case_info
*ci1
= (const struct case_info
*) p1
;
4699 const struct case_info
*ci2
= (const struct case_info
*) p2
;
4700 int idx1
= ci1
->bb
->index
;
4701 int idx2
= ci2
->bb
->index
;
4705 else if (idx1
== idx2
)
4707 /* Make sure the default label is first in a group. */
4708 if (!CASE_LOW (ci1
->expr
))
4710 else if (!CASE_LOW (ci2
->expr
))
4713 return tree_int_cst_compare (CASE_LOW (ci1
->expr
),
4714 CASE_LOW (ci2
->expr
));
4720 /* Determine whether the outgoing edges of BB should receive an
4721 ASSERT_EXPR for each of the operands of BB's LAST statement.
4722 The last statement of BB must be a SWITCH_EXPR.
4724 If any of the sub-graphs rooted at BB have an interesting use of
4725 the predicate operands, an assert location node is added to the
4726 list of assertions for the corresponding operands. */
4729 find_switch_asserts (basic_block bb
, gimple last
)
4732 gimple_stmt_iterator bsi
;
4735 struct case_info
*ci
;
4736 size_t n
= gimple_switch_num_labels (last
);
4737 #if GCC_VERSION >= 4000
4740 /* Work around GCC 3.4 bug (PR 37086). */
4741 volatile unsigned int idx
;
4744 need_assert
= false;
4745 bsi
= gsi_for_stmt (last
);
4746 op
= gimple_switch_index (last
);
4747 if (TREE_CODE (op
) != SSA_NAME
)
4750 /* Build a vector of case labels sorted by destination label. */
4751 ci
= XNEWVEC (struct case_info
, n
);
4752 for (idx
= 0; idx
< n
; ++idx
)
4754 ci
[idx
].expr
= gimple_switch_label (last
, idx
);
4755 ci
[idx
].bb
= label_to_block (CASE_LABEL (ci
[idx
].expr
));
4757 qsort (ci
, n
, sizeof (struct case_info
), compare_case_labels
);
4759 for (idx
= 0; idx
< n
; ++idx
)
4762 tree cl
= ci
[idx
].expr
;
4763 basic_block cbb
= ci
[idx
].bb
;
4765 min
= CASE_LOW (cl
);
4766 max
= CASE_HIGH (cl
);
4768 /* If there are multiple case labels with the same destination
4769 we need to combine them to a single value range for the edge. */
4770 if (idx
+ 1 < n
&& cbb
== ci
[idx
+ 1].bb
)
4772 /* Skip labels until the last of the group. */
4775 } while (idx
< n
&& cbb
== ci
[idx
].bb
);
4778 /* Pick up the maximum of the case label range. */
4779 if (CASE_HIGH (ci
[idx
].expr
))
4780 max
= CASE_HIGH (ci
[idx
].expr
);
4782 max
= CASE_LOW (ci
[idx
].expr
);
4785 /* Nothing to do if the range includes the default label until we
4786 can register anti-ranges. */
4787 if (min
== NULL_TREE
)
4790 /* Find the edge to register the assert expr on. */
4791 e
= find_edge (bb
, cbb
);
4793 /* Register the necessary assertions for the operand in the
4795 need_assert
|= register_edge_assert_for (op
, e
, bsi
,
4796 max
? GE_EXPR
: EQ_EXPR
,
4798 fold_convert (TREE_TYPE (op
),
4802 need_assert
|= register_edge_assert_for (op
, e
, bsi
, LE_EXPR
,
4804 fold_convert (TREE_TYPE (op
),
4814 /* Traverse all the statements in block BB looking for statements that
4815 may generate useful assertions for the SSA names in their operand.
4816 If a statement produces a useful assertion A for name N_i, then the
4817 list of assertions already generated for N_i is scanned to
4818 determine if A is actually needed.
4820 If N_i already had the assertion A at a location dominating the
4821 current location, then nothing needs to be done. Otherwise, the
4822 new location for A is recorded instead.
4824 1- For every statement S in BB, all the variables used by S are
4825 added to bitmap FOUND_IN_SUBGRAPH.
4827 2- If statement S uses an operand N in a way that exposes a known
4828 value range for N, then if N was not already generated by an
4829 ASSERT_EXPR, create a new assert location for N. For instance,
4830 if N is a pointer and the statement dereferences it, we can
4831 assume that N is not NULL.
4833 3- COND_EXPRs are a special case of #2. We can derive range
4834 information from the predicate but need to insert different
4835 ASSERT_EXPRs for each of the sub-graphs rooted at the
4836 conditional block. If the last statement of BB is a conditional
4837 expression of the form 'X op Y', then
4839 a) Remove X and Y from the set FOUND_IN_SUBGRAPH.
4841 b) If the conditional is the only entry point to the sub-graph
4842 corresponding to the THEN_CLAUSE, recurse into it. On
4843 return, if X and/or Y are marked in FOUND_IN_SUBGRAPH, then
4844 an ASSERT_EXPR is added for the corresponding variable.
4846 c) Repeat step (b) on the ELSE_CLAUSE.
4848 d) Mark X and Y in FOUND_IN_SUBGRAPH.
4857 In this case, an assertion on the THEN clause is useful to
4858 determine that 'a' is always 9 on that edge. However, an assertion
4859 on the ELSE clause would be unnecessary.
4861 4- If BB does not end in a conditional expression, then we recurse
4862 into BB's dominator children.
4864 At the end of the recursive traversal, every SSA name will have a
4865 list of locations where ASSERT_EXPRs should be added. When a new
4866 location for name N is found, it is registered by calling
4867 register_new_assert_for. That function keeps track of all the
4868 registered assertions to prevent adding unnecessary assertions.
4869 For instance, if a pointer P_4 is dereferenced more than once in a
4870 dominator tree, only the location dominating all the dereference of
4871 P_4 will receive an ASSERT_EXPR.
4873 If this function returns true, then it means that there are names
4874 for which we need to generate ASSERT_EXPRs. Those assertions are
4875 inserted by process_assert_insertions. */
4878 find_assert_locations_1 (basic_block bb
, sbitmap live
)
4880 gimple_stmt_iterator si
;
4885 need_assert
= false;
4886 last
= last_stmt (bb
);
4888 /* If BB's last statement is a conditional statement involving integer
4889 operands, determine if we need to add ASSERT_EXPRs. */
4891 && gimple_code (last
) == GIMPLE_COND
4892 && !fp_predicate (last
)
4893 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
4894 need_assert
|= find_conditional_asserts (bb
, last
);
4896 /* If BB's last statement is a switch statement involving integer
4897 operands, determine if we need to add ASSERT_EXPRs. */
4899 && gimple_code (last
) == GIMPLE_SWITCH
4900 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
4901 need_assert
|= find_switch_asserts (bb
, last
);
4903 /* Traverse all the statements in BB marking used names and looking
4904 for statements that may infer assertions for their used operands. */
4905 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
4911 stmt
= gsi_stmt (si
);
4913 if (is_gimple_debug (stmt
))
4916 /* See if we can derive an assertion for any of STMT's operands. */
4917 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_USE
)
4920 enum tree_code comp_code
;
4922 /* Mark OP in our live bitmap. */
4923 SET_BIT (live
, SSA_NAME_VERSION (op
));
4925 /* If OP is used in such a way that we can infer a value
4926 range for it, and we don't find a previous assertion for
4927 it, create a new assertion location node for OP. */
4928 if (infer_value_range (stmt
, op
, &comp_code
, &value
))
4930 /* If we are able to infer a nonzero value range for OP,
4931 then walk backwards through the use-def chain to see if OP
4932 was set via a typecast.
4934 If so, then we can also infer a nonzero value range
4935 for the operand of the NOP_EXPR. */
4936 if (comp_code
== NE_EXPR
&& integer_zerop (value
))
4939 gimple def_stmt
= SSA_NAME_DEF_STMT (t
);
4941 while (is_gimple_assign (def_stmt
)
4942 && gimple_assign_rhs_code (def_stmt
) == NOP_EXPR
4944 (gimple_assign_rhs1 (def_stmt
)) == SSA_NAME
4946 (TREE_TYPE (gimple_assign_rhs1 (def_stmt
))))
4948 t
= gimple_assign_rhs1 (def_stmt
);
4949 def_stmt
= SSA_NAME_DEF_STMT (t
);
4951 /* Note we want to register the assert for the
4952 operand of the NOP_EXPR after SI, not after the
4954 if (! has_single_use (t
))
4956 register_new_assert_for (t
, t
, comp_code
, value
,
4963 /* If OP is used only once, namely in this STMT, don't
4964 bother creating an ASSERT_EXPR for it. Such an
4965 ASSERT_EXPR would do nothing but increase compile time. */
4966 if (!has_single_use (op
))
4968 register_new_assert_for (op
, op
, comp_code
, value
,
4976 /* Traverse all PHI nodes in BB marking used operands. */
4977 for (si
= gsi_start_phis (bb
); !gsi_end_p(si
); gsi_next (&si
))
4979 use_operand_p arg_p
;
4981 phi
= gsi_stmt (si
);
4983 FOR_EACH_PHI_ARG (arg_p
, phi
, i
, SSA_OP_USE
)
4985 tree arg
= USE_FROM_PTR (arg_p
);
4986 if (TREE_CODE (arg
) == SSA_NAME
)
4987 SET_BIT (live
, SSA_NAME_VERSION (arg
));
4994 /* Do an RPO walk over the function computing SSA name liveness
4995 on-the-fly and deciding on assert expressions to insert.
4996 Returns true if there are assert expressions to be inserted. */
4999 find_assert_locations (void)
5001 int *rpo
= XCNEWVEC (int, last_basic_block
+ NUM_FIXED_BLOCKS
);
5002 int *bb_rpo
= XCNEWVEC (int, last_basic_block
+ NUM_FIXED_BLOCKS
);
5003 int *last_rpo
= XCNEWVEC (int, last_basic_block
+ NUM_FIXED_BLOCKS
);
5007 live
= XCNEWVEC (sbitmap
, last_basic_block
+ NUM_FIXED_BLOCKS
);
5008 rpo_cnt
= pre_and_rev_post_order_compute (NULL
, rpo
, false);
5009 for (i
= 0; i
< rpo_cnt
; ++i
)
5012 need_asserts
= false;
5013 for (i
= rpo_cnt
-1; i
>= 0; --i
)
5015 basic_block bb
= BASIC_BLOCK (rpo
[i
]);
5021 live
[rpo
[i
]] = sbitmap_alloc (num_ssa_names
);
5022 sbitmap_zero (live
[rpo
[i
]]);
5025 /* Process BB and update the live information with uses in
5027 need_asserts
|= find_assert_locations_1 (bb
, live
[rpo
[i
]]);
5029 /* Merge liveness into the predecessor blocks and free it. */
5030 if (!sbitmap_empty_p (live
[rpo
[i
]]))
5033 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
5035 int pred
= e
->src
->index
;
5036 if (e
->flags
& EDGE_DFS_BACK
)
5041 live
[pred
] = sbitmap_alloc (num_ssa_names
);
5042 sbitmap_zero (live
[pred
]);
5044 sbitmap_a_or_b (live
[pred
], live
[pred
], live
[rpo
[i
]]);
5046 if (bb_rpo
[pred
] < pred_rpo
)
5047 pred_rpo
= bb_rpo
[pred
];
5050 /* Record the RPO number of the last visited block that needs
5051 live information from this block. */
5052 last_rpo
[rpo
[i
]] = pred_rpo
;
5056 sbitmap_free (live
[rpo
[i
]]);
5057 live
[rpo
[i
]] = NULL
;
5060 /* We can free all successors live bitmaps if all their
5061 predecessors have been visited already. */
5062 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5063 if (last_rpo
[e
->dest
->index
] == i
5064 && live
[e
->dest
->index
])
5066 sbitmap_free (live
[e
->dest
->index
]);
5067 live
[e
->dest
->index
] = NULL
;
5072 XDELETEVEC (bb_rpo
);
5073 XDELETEVEC (last_rpo
);
5074 for (i
= 0; i
< last_basic_block
+ NUM_FIXED_BLOCKS
; ++i
)
5076 sbitmap_free (live
[i
]);
5079 return need_asserts
;
5082 /* Create an ASSERT_EXPR for NAME and insert it in the location
5083 indicated by LOC. Return true if we made any edge insertions. */
5086 process_assert_insertions_for (tree name
, assert_locus_t loc
)
5088 /* Build the comparison expression NAME_i COMP_CODE VAL. */
5095 /* If we have X <=> X do not insert an assert expr for that. */
5096 if (loc
->expr
== loc
->val
)
5099 cond
= build2 (loc
->comp_code
, boolean_type_node
, loc
->expr
, loc
->val
);
5100 assert_stmt
= build_assert_expr_for (cond
, name
);
5103 /* We have been asked to insert the assertion on an edge. This
5104 is used only by COND_EXPR and SWITCH_EXPR assertions. */
5105 gcc_checking_assert (gimple_code (gsi_stmt (loc
->si
)) == GIMPLE_COND
5106 || (gimple_code (gsi_stmt (loc
->si
))
5109 gsi_insert_on_edge (loc
->e
, assert_stmt
);
5113 /* Otherwise, we can insert right after LOC->SI iff the
5114 statement must not be the last statement in the block. */
5115 stmt
= gsi_stmt (loc
->si
);
5116 if (!stmt_ends_bb_p (stmt
))
5118 gsi_insert_after (&loc
->si
, assert_stmt
, GSI_SAME_STMT
);
5122 /* If STMT must be the last statement in BB, we can only insert new
5123 assertions on the non-abnormal edge out of BB. Note that since
5124 STMT is not control flow, there may only be one non-abnormal edge
5126 FOR_EACH_EDGE (e
, ei
, loc
->bb
->succs
)
5127 if (!(e
->flags
& EDGE_ABNORMAL
))
5129 gsi_insert_on_edge (e
, assert_stmt
);
5137 /* Process all the insertions registered for every name N_i registered
5138 in NEED_ASSERT_FOR. The list of assertions to be inserted are
5139 found in ASSERTS_FOR[i]. */
5142 process_assert_insertions (void)
5146 bool update_edges_p
= false;
5147 int num_asserts
= 0;
5149 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5150 dump_all_asserts (dump_file
);
5152 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
5154 assert_locus_t loc
= asserts_for
[i
];
5159 assert_locus_t next
= loc
->next
;
5160 update_edges_p
|= process_assert_insertions_for (ssa_name (i
), loc
);
5168 gsi_commit_edge_inserts ();
5170 statistics_counter_event (cfun
, "Number of ASSERT_EXPR expressions inserted",
5175 /* Traverse the flowgraph looking for conditional jumps to insert range
5176 expressions. These range expressions are meant to provide information
5177 to optimizations that need to reason in terms of value ranges. They
5178 will not be expanded into RTL. For instance, given:
5187 this pass will transform the code into:
5193 x = ASSERT_EXPR <x, x < y>
5198 y = ASSERT_EXPR <y, x <= y>
5202 The idea is that once copy and constant propagation have run, other
5203 optimizations will be able to determine what ranges of values can 'x'
5204 take in different paths of the code, simply by checking the reaching
5205 definition of 'x'. */
5208 insert_range_assertions (void)
5210 need_assert_for
= BITMAP_ALLOC (NULL
);
5211 asserts_for
= XCNEWVEC (assert_locus_t
, num_ssa_names
);
5213 calculate_dominance_info (CDI_DOMINATORS
);
5215 if (find_assert_locations ())
5217 process_assert_insertions ();
5218 update_ssa (TODO_update_ssa_no_phi
);
5221 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5223 fprintf (dump_file
, "\nSSA form after inserting ASSERT_EXPRs\n");
5224 dump_function_to_file (current_function_decl
, dump_file
, dump_flags
);
5228 BITMAP_FREE (need_assert_for
);
5231 /* Checks one ARRAY_REF in REF, located at LOCUS. Ignores flexible arrays
5232 and "struct" hacks. If VRP can determine that the
5233 array subscript is a constant, check if it is outside valid
5234 range. If the array subscript is a RANGE, warn if it is
5235 non-overlapping with valid range.
5236 IGNORE_OFF_BY_ONE is true if the ARRAY_REF is inside a ADDR_EXPR. */
5239 check_array_ref (location_t location
, tree ref
, bool ignore_off_by_one
)
5241 value_range_t
* vr
= NULL
;
5242 tree low_sub
, up_sub
;
5243 tree low_bound
, up_bound
, up_bound_p1
;
5246 if (TREE_NO_WARNING (ref
))
5249 low_sub
= up_sub
= TREE_OPERAND (ref
, 1);
5250 up_bound
= array_ref_up_bound (ref
);
5252 /* Can not check flexible arrays. */
5254 || TREE_CODE (up_bound
) != INTEGER_CST
)
5257 /* Accesses to trailing arrays via pointers may access storage
5258 beyond the types array bounds. */
5259 base
= get_base_address (ref
);
5260 if (base
&& TREE_CODE (base
) == MEM_REF
)
5262 tree cref
, next
= NULL_TREE
;
5264 if (TREE_CODE (TREE_OPERAND (ref
, 0)) != COMPONENT_REF
)
5267 cref
= TREE_OPERAND (ref
, 0);
5268 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (cref
, 0))) == RECORD_TYPE
)
5269 for (next
= DECL_CHAIN (TREE_OPERAND (cref
, 1));
5270 next
&& TREE_CODE (next
) != FIELD_DECL
;
5271 next
= DECL_CHAIN (next
))
5274 /* If this is the last field in a struct type or a field in a
5275 union type do not warn. */
5280 low_bound
= array_ref_low_bound (ref
);
5281 up_bound_p1
= int_const_binop (PLUS_EXPR
, up_bound
, integer_one_node
);
5283 if (TREE_CODE (low_sub
) == SSA_NAME
)
5285 vr
= get_value_range (low_sub
);
5286 if (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
)
5288 low_sub
= vr
->type
== VR_RANGE
? vr
->max
: vr
->min
;
5289 up_sub
= vr
->type
== VR_RANGE
? vr
->min
: vr
->max
;
5293 if (vr
&& vr
->type
== VR_ANTI_RANGE
)
5295 if (TREE_CODE (up_sub
) == INTEGER_CST
5296 && tree_int_cst_lt (up_bound
, up_sub
)
5297 && TREE_CODE (low_sub
) == INTEGER_CST
5298 && tree_int_cst_lt (low_sub
, low_bound
))
5300 warning_at (location
, OPT_Warray_bounds
,
5301 "array subscript is outside array bounds");
5302 TREE_NO_WARNING (ref
) = 1;
5305 else if (TREE_CODE (up_sub
) == INTEGER_CST
5306 && (ignore_off_by_one
5307 ? (tree_int_cst_lt (up_bound
, up_sub
)
5308 && !tree_int_cst_equal (up_bound_p1
, up_sub
))
5309 : (tree_int_cst_lt (up_bound
, up_sub
)
5310 || tree_int_cst_equal (up_bound_p1
, up_sub
))))
5312 warning_at (location
, OPT_Warray_bounds
,
5313 "array subscript is above array bounds");
5314 TREE_NO_WARNING (ref
) = 1;
5316 else if (TREE_CODE (low_sub
) == INTEGER_CST
5317 && tree_int_cst_lt (low_sub
, low_bound
))
5319 warning_at (location
, OPT_Warray_bounds
,
5320 "array subscript is below array bounds");
5321 TREE_NO_WARNING (ref
) = 1;
5325 /* Searches if the expr T, located at LOCATION computes
5326 address of an ARRAY_REF, and call check_array_ref on it. */
5329 search_for_addr_array (tree t
, location_t location
)
5331 while (TREE_CODE (t
) == SSA_NAME
)
5333 gimple g
= SSA_NAME_DEF_STMT (t
);
5335 if (gimple_code (g
) != GIMPLE_ASSIGN
)
5338 if (get_gimple_rhs_class (gimple_assign_rhs_code (g
))
5339 != GIMPLE_SINGLE_RHS
)
5342 t
= gimple_assign_rhs1 (g
);
5346 /* We are only interested in addresses of ARRAY_REF's. */
5347 if (TREE_CODE (t
) != ADDR_EXPR
)
5350 /* Check each ARRAY_REFs in the reference chain. */
5353 if (TREE_CODE (t
) == ARRAY_REF
)
5354 check_array_ref (location
, t
, true /*ignore_off_by_one*/);
5356 t
= TREE_OPERAND (t
, 0);
5358 while (handled_component_p (t
));
5360 if (TREE_CODE (t
) == MEM_REF
5361 && TREE_CODE (TREE_OPERAND (t
, 0)) == ADDR_EXPR
5362 && !TREE_NO_WARNING (t
))
5364 tree tem
= TREE_OPERAND (TREE_OPERAND (t
, 0), 0);
5365 tree low_bound
, up_bound
, el_sz
;
5367 if (TREE_CODE (TREE_TYPE (tem
)) != ARRAY_TYPE
5368 || TREE_CODE (TREE_TYPE (TREE_TYPE (tem
))) == ARRAY_TYPE
5369 || !TYPE_DOMAIN (TREE_TYPE (tem
)))
5372 low_bound
= TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (tem
)));
5373 up_bound
= TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (tem
)));
5374 el_sz
= TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (tem
)));
5376 || TREE_CODE (low_bound
) != INTEGER_CST
5378 || TREE_CODE (up_bound
) != INTEGER_CST
5380 || TREE_CODE (el_sz
) != INTEGER_CST
)
5383 idx
= mem_ref_offset (t
);
5384 idx
= double_int_sdiv (idx
, tree_to_double_int (el_sz
), TRUNC_DIV_EXPR
);
5385 if (double_int_scmp (idx
, double_int_zero
) < 0)
5387 warning_at (location
, OPT_Warray_bounds
,
5388 "array subscript is below array bounds");
5389 TREE_NO_WARNING (t
) = 1;
5391 else if (double_int_scmp (idx
,
5394 (tree_to_double_int (up_bound
),
5396 (tree_to_double_int (low_bound
))),
5397 double_int_one
)) > 0)
5399 warning_at (location
, OPT_Warray_bounds
,
5400 "array subscript is above array bounds");
5401 TREE_NO_WARNING (t
) = 1;
5406 /* walk_tree() callback that checks if *TP is
5407 an ARRAY_REF inside an ADDR_EXPR (in which an array
5408 subscript one outside the valid range is allowed). Call
5409 check_array_ref for each ARRAY_REF found. The location is
5413 check_array_bounds (tree
*tp
, int *walk_subtree
, void *data
)
5416 struct walk_stmt_info
*wi
= (struct walk_stmt_info
*) data
;
5417 location_t location
;
5419 if (EXPR_HAS_LOCATION (t
))
5420 location
= EXPR_LOCATION (t
);
5423 location_t
*locp
= (location_t
*) wi
->info
;
5427 *walk_subtree
= TRUE
;
5429 if (TREE_CODE (t
) == ARRAY_REF
)
5430 check_array_ref (location
, t
, false /*ignore_off_by_one*/);
5432 if (TREE_CODE (t
) == MEM_REF
5433 || (TREE_CODE (t
) == RETURN_EXPR
&& TREE_OPERAND (t
, 0)))
5434 search_for_addr_array (TREE_OPERAND (t
, 0), location
);
5436 if (TREE_CODE (t
) == ADDR_EXPR
)
5437 *walk_subtree
= FALSE
;
5442 /* Walk over all statements of all reachable BBs and call check_array_bounds
5446 check_all_array_refs (void)
5449 gimple_stmt_iterator si
;
5455 bool executable
= false;
5457 /* Skip blocks that were found to be unreachable. */
5458 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
5459 executable
|= !!(e
->flags
& EDGE_EXECUTABLE
);
5463 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
5465 gimple stmt
= gsi_stmt (si
);
5466 struct walk_stmt_info wi
;
5467 if (!gimple_has_location (stmt
))
5470 if (is_gimple_call (stmt
))
5473 size_t n
= gimple_call_num_args (stmt
);
5474 for (i
= 0; i
< n
; i
++)
5476 tree arg
= gimple_call_arg (stmt
, i
);
5477 search_for_addr_array (arg
, gimple_location (stmt
));
5482 memset (&wi
, 0, sizeof (wi
));
5483 wi
.info
= CONST_CAST (void *, (const void *)
5484 gimple_location_ptr (stmt
));
5486 walk_gimple_op (gsi_stmt (si
),
5494 /* Convert range assertion expressions into the implied copies and
5495 copy propagate away the copies. Doing the trivial copy propagation
5496 here avoids the need to run the full copy propagation pass after
5499 FIXME, this will eventually lead to copy propagation removing the
5500 names that had useful range information attached to them. For
5501 instance, if we had the assertion N_i = ASSERT_EXPR <N_j, N_j > 3>,
5502 then N_i will have the range [3, +INF].
5504 However, by converting the assertion into the implied copy
5505 operation N_i = N_j, we will then copy-propagate N_j into the uses
5506 of N_i and lose the range information. We may want to hold on to
5507 ASSERT_EXPRs a little while longer as the ranges could be used in
5508 things like jump threading.
5510 The problem with keeping ASSERT_EXPRs around is that passes after
5511 VRP need to handle them appropriately.
5513 Another approach would be to make the range information a first
5514 class property of the SSA_NAME so that it can be queried from
5515 any pass. This is made somewhat more complex by the need for
5516 multiple ranges to be associated with one SSA_NAME. */
5519 remove_range_assertions (void)
5522 gimple_stmt_iterator si
;
5524 /* Note that the BSI iterator bump happens at the bottom of the
5525 loop and no bump is necessary if we're removing the statement
5526 referenced by the current BSI. */
5528 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
);)
5530 gimple stmt
= gsi_stmt (si
);
5533 if (is_gimple_assign (stmt
)
5534 && gimple_assign_rhs_code (stmt
) == ASSERT_EXPR
)
5536 tree rhs
= gimple_assign_rhs1 (stmt
);
5538 tree cond
= fold (ASSERT_EXPR_COND (rhs
));
5539 use_operand_p use_p
;
5540 imm_use_iterator iter
;
5542 gcc_assert (cond
!= boolean_false_node
);
5544 /* Propagate the RHS into every use of the LHS. */
5545 var
= ASSERT_EXPR_VAR (rhs
);
5546 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
,
5547 gimple_assign_lhs (stmt
))
5548 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
5550 SET_USE (use_p
, var
);
5551 gcc_assert (TREE_CODE (var
) == SSA_NAME
);
5554 /* And finally, remove the copy, it is not needed. */
5555 gsi_remove (&si
, true);
5556 release_defs (stmt
);
5564 /* Return true if STMT is interesting for VRP. */
5567 stmt_interesting_for_vrp (gimple stmt
)
5569 if (gimple_code (stmt
) == GIMPLE_PHI
5570 && is_gimple_reg (gimple_phi_result (stmt
))
5571 && (INTEGRAL_TYPE_P (TREE_TYPE (gimple_phi_result (stmt
)))
5572 || POINTER_TYPE_P (TREE_TYPE (gimple_phi_result (stmt
)))))
5574 else if (is_gimple_assign (stmt
) || is_gimple_call (stmt
))
5576 tree lhs
= gimple_get_lhs (stmt
);
5578 /* In general, assignments with virtual operands are not useful
5579 for deriving ranges, with the obvious exception of calls to
5580 builtin functions. */
5581 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
5582 && (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
5583 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
5584 && ((is_gimple_call (stmt
)
5585 && gimple_call_fndecl (stmt
) != NULL_TREE
5586 && DECL_IS_BUILTIN (gimple_call_fndecl (stmt
)))
5587 || !gimple_vuse (stmt
)))
5590 else if (gimple_code (stmt
) == GIMPLE_COND
5591 || gimple_code (stmt
) == GIMPLE_SWITCH
)
5598 /* Initialize local data structures for VRP. */
5601 vrp_initialize (void)
5605 values_propagated
= false;
5606 num_vr_values
= num_ssa_names
;
5607 vr_value
= XCNEWVEC (value_range_t
*, num_vr_values
);
5608 vr_phi_edge_counts
= XCNEWVEC (int, num_ssa_names
);
5612 gimple_stmt_iterator si
;
5614 for (si
= gsi_start_phis (bb
); !gsi_end_p (si
); gsi_next (&si
))
5616 gimple phi
= gsi_stmt (si
);
5617 if (!stmt_interesting_for_vrp (phi
))
5619 tree lhs
= PHI_RESULT (phi
);
5620 set_value_range_to_varying (get_value_range (lhs
));
5621 prop_set_simulate_again (phi
, false);
5624 prop_set_simulate_again (phi
, true);
5627 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
5629 gimple stmt
= gsi_stmt (si
);
5631 /* If the statement is a control insn, then we do not
5632 want to avoid simulating the statement once. Failure
5633 to do so means that those edges will never get added. */
5634 if (stmt_ends_bb_p (stmt
))
5635 prop_set_simulate_again (stmt
, true);
5636 else if (!stmt_interesting_for_vrp (stmt
))
5640 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, i
, SSA_OP_DEF
)
5641 set_value_range_to_varying (get_value_range (def
));
5642 prop_set_simulate_again (stmt
, false);
5645 prop_set_simulate_again (stmt
, true);
5650 /* Return the singleton value-range for NAME or NAME. */
5653 vrp_valueize (tree name
)
5655 if (TREE_CODE (name
) == SSA_NAME
)
5657 value_range_t
*vr
= get_value_range (name
);
5658 if (vr
->type
== VR_RANGE
5659 && (vr
->min
== vr
->max
5660 || operand_equal_p (vr
->min
, vr
->max
, 0)))
5666 /* Visit assignment STMT. If it produces an interesting range, record
5667 the SSA name in *OUTPUT_P. */
5669 static enum ssa_prop_result
5670 vrp_visit_assignment_or_call (gimple stmt
, tree
*output_p
)
5674 enum gimple_code code
= gimple_code (stmt
);
5675 lhs
= gimple_get_lhs (stmt
);
5677 /* We only keep track of ranges in integral and pointer types. */
5678 if (TREE_CODE (lhs
) == SSA_NAME
5679 && ((INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
5680 /* It is valid to have NULL MIN/MAX values on a type. See
5681 build_range_type. */
5682 && TYPE_MIN_VALUE (TREE_TYPE (lhs
))
5683 && TYPE_MAX_VALUE (TREE_TYPE (lhs
)))
5684 || POINTER_TYPE_P (TREE_TYPE (lhs
))))
5686 value_range_t new_vr
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
5688 /* Try folding the statement to a constant first. */
5689 tree tem
= gimple_fold_stmt_to_constant (stmt
, vrp_valueize
);
5690 if (tem
&& !is_overflow_infinity (tem
))
5691 set_value_range (&new_vr
, VR_RANGE
, tem
, tem
, NULL
);
5692 /* Then dispatch to value-range extracting functions. */
5693 else if (code
== GIMPLE_CALL
)
5694 extract_range_basic (&new_vr
, stmt
);
5696 extract_range_from_assignment (&new_vr
, stmt
);
5698 if (update_value_range (lhs
, &new_vr
))
5702 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5704 fprintf (dump_file
, "Found new range for ");
5705 print_generic_expr (dump_file
, lhs
, 0);
5706 fprintf (dump_file
, ": ");
5707 dump_value_range (dump_file
, &new_vr
);
5708 fprintf (dump_file
, "\n\n");
5711 if (new_vr
.type
== VR_VARYING
)
5712 return SSA_PROP_VARYING
;
5714 return SSA_PROP_INTERESTING
;
5717 return SSA_PROP_NOT_INTERESTING
;
5720 /* Every other statement produces no useful ranges. */
5721 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_DEF
)
5722 set_value_range_to_varying (get_value_range (def
));
5724 return SSA_PROP_VARYING
;
5727 /* Helper that gets the value range of the SSA_NAME with version I
5728 or a symbolic range containing the SSA_NAME only if the value range
5729 is varying or undefined. */
5731 static inline value_range_t
5732 get_vr_for_comparison (int i
)
5734 value_range_t vr
= *get_value_range (ssa_name (i
));
5736 /* If name N_i does not have a valid range, use N_i as its own
5737 range. This allows us to compare against names that may
5738 have N_i in their ranges. */
5739 if (vr
.type
== VR_VARYING
|| vr
.type
== VR_UNDEFINED
)
5742 vr
.min
= ssa_name (i
);
5743 vr
.max
= ssa_name (i
);
5749 /* Compare all the value ranges for names equivalent to VAR with VAL
5750 using comparison code COMP. Return the same value returned by
5751 compare_range_with_value, including the setting of
5752 *STRICT_OVERFLOW_P. */
5755 compare_name_with_value (enum tree_code comp
, tree var
, tree val
,
5756 bool *strict_overflow_p
)
5762 int used_strict_overflow
;
5764 value_range_t equiv_vr
;
5766 /* Get the set of equivalences for VAR. */
5767 e
= get_value_range (var
)->equiv
;
5769 /* Start at -1. Set it to 0 if we do a comparison without relying
5770 on overflow, or 1 if all comparisons rely on overflow. */
5771 used_strict_overflow
= -1;
5773 /* Compare vars' value range with val. */
5774 equiv_vr
= get_vr_for_comparison (SSA_NAME_VERSION (var
));
5776 retval
= compare_range_with_value (comp
, &equiv_vr
, val
, &sop
);
5778 used_strict_overflow
= sop
? 1 : 0;
5780 /* If the equiv set is empty we have done all work we need to do. */
5784 && used_strict_overflow
> 0)
5785 *strict_overflow_p
= true;
5789 EXECUTE_IF_SET_IN_BITMAP (e
, 0, i
, bi
)
5791 equiv_vr
= get_vr_for_comparison (i
);
5793 t
= compare_range_with_value (comp
, &equiv_vr
, val
, &sop
);
5796 /* If we get different answers from different members
5797 of the equivalence set this check must be in a dead
5798 code region. Folding it to a trap representation
5799 would be correct here. For now just return don't-know. */
5809 used_strict_overflow
= 0;
5810 else if (used_strict_overflow
< 0)
5811 used_strict_overflow
= 1;
5816 && used_strict_overflow
> 0)
5817 *strict_overflow_p
= true;
5823 /* Given a comparison code COMP and names N1 and N2, compare all the
5824 ranges equivalent to N1 against all the ranges equivalent to N2
5825 to determine the value of N1 COMP N2. Return the same value
5826 returned by compare_ranges. Set *STRICT_OVERFLOW_P to indicate
5827 whether we relied on an overflow infinity in the comparison. */
5831 compare_names (enum tree_code comp
, tree n1
, tree n2
,
5832 bool *strict_overflow_p
)
5836 bitmap_iterator bi1
, bi2
;
5838 int used_strict_overflow
;
5839 static bitmap_obstack
*s_obstack
= NULL
;
5840 static bitmap s_e1
= NULL
, s_e2
= NULL
;
5842 /* Compare the ranges of every name equivalent to N1 against the
5843 ranges of every name equivalent to N2. */
5844 e1
= get_value_range (n1
)->equiv
;
5845 e2
= get_value_range (n2
)->equiv
;
5847 /* Use the fake bitmaps if e1 or e2 are not available. */
5848 if (s_obstack
== NULL
)
5850 s_obstack
= XNEW (bitmap_obstack
);
5851 bitmap_obstack_initialize (s_obstack
);
5852 s_e1
= BITMAP_ALLOC (s_obstack
);
5853 s_e2
= BITMAP_ALLOC (s_obstack
);
5860 /* Add N1 and N2 to their own set of equivalences to avoid
5861 duplicating the body of the loop just to check N1 and N2
5863 bitmap_set_bit (e1
, SSA_NAME_VERSION (n1
));
5864 bitmap_set_bit (e2
, SSA_NAME_VERSION (n2
));
5866 /* If the equivalence sets have a common intersection, then the two
5867 names can be compared without checking their ranges. */
5868 if (bitmap_intersect_p (e1
, e2
))
5870 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5871 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5873 return (comp
== EQ_EXPR
|| comp
== GE_EXPR
|| comp
== LE_EXPR
)
5875 : boolean_false_node
;
5878 /* Start at -1. Set it to 0 if we do a comparison without relying
5879 on overflow, or 1 if all comparisons rely on overflow. */
5880 used_strict_overflow
= -1;
5882 /* Otherwise, compare all the equivalent ranges. First, add N1 and
5883 N2 to their own set of equivalences to avoid duplicating the body
5884 of the loop just to check N1 and N2 ranges. */
5885 EXECUTE_IF_SET_IN_BITMAP (e1
, 0, i1
, bi1
)
5887 value_range_t vr1
= get_vr_for_comparison (i1
);
5889 t
= retval
= NULL_TREE
;
5890 EXECUTE_IF_SET_IN_BITMAP (e2
, 0, i2
, bi2
)
5894 value_range_t vr2
= get_vr_for_comparison (i2
);
5896 t
= compare_ranges (comp
, &vr1
, &vr2
, &sop
);
5899 /* If we get different answers from different members
5900 of the equivalence set this check must be in a dead
5901 code region. Folding it to a trap representation
5902 would be correct here. For now just return don't-know. */
5906 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5907 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5913 used_strict_overflow
= 0;
5914 else if (used_strict_overflow
< 0)
5915 used_strict_overflow
= 1;
5921 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5922 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5923 if (used_strict_overflow
> 0)
5924 *strict_overflow_p
= true;
5929 /* None of the equivalent ranges are useful in computing this
5931 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5932 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5936 /* Helper function for vrp_evaluate_conditional_warnv. */
5939 vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code code
,
5941 bool * strict_overflow_p
)
5943 value_range_t
*vr0
, *vr1
;
5945 vr0
= (TREE_CODE (op0
) == SSA_NAME
) ? get_value_range (op0
) : NULL
;
5946 vr1
= (TREE_CODE (op1
) == SSA_NAME
) ? get_value_range (op1
) : NULL
;
5949 return compare_ranges (code
, vr0
, vr1
, strict_overflow_p
);
5950 else if (vr0
&& vr1
== NULL
)
5951 return compare_range_with_value (code
, vr0
, op1
, strict_overflow_p
);
5952 else if (vr0
== NULL
&& vr1
)
5953 return (compare_range_with_value
5954 (swap_tree_comparison (code
), vr1
, op0
, strict_overflow_p
));
5958 /* Helper function for vrp_evaluate_conditional_warnv. */
5961 vrp_evaluate_conditional_warnv_with_ops (enum tree_code code
, tree op0
,
5962 tree op1
, bool use_equiv_p
,
5963 bool *strict_overflow_p
, bool *only_ranges
)
5967 *only_ranges
= true;
5969 /* We only deal with integral and pointer types. */
5970 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0
))
5971 && !POINTER_TYPE_P (TREE_TYPE (op0
)))
5977 && (ret
= vrp_evaluate_conditional_warnv_with_ops_using_ranges
5978 (code
, op0
, op1
, strict_overflow_p
)))
5980 *only_ranges
= false;
5981 if (TREE_CODE (op0
) == SSA_NAME
&& TREE_CODE (op1
) == SSA_NAME
)
5982 return compare_names (code
, op0
, op1
, strict_overflow_p
);
5983 else if (TREE_CODE (op0
) == SSA_NAME
)
5984 return compare_name_with_value (code
, op0
, op1
, strict_overflow_p
);
5985 else if (TREE_CODE (op1
) == SSA_NAME
)
5986 return (compare_name_with_value
5987 (swap_tree_comparison (code
), op1
, op0
, strict_overflow_p
));
5990 return vrp_evaluate_conditional_warnv_with_ops_using_ranges (code
, op0
, op1
,
5995 /* Given (CODE OP0 OP1) within STMT, try to simplify it based on value range
5996 information. Return NULL if the conditional can not be evaluated.
5997 The ranges of all the names equivalent with the operands in COND
5998 will be used when trying to compute the value. If the result is
5999 based on undefined signed overflow, issue a warning if
6003 vrp_evaluate_conditional (enum tree_code code
, tree op0
, tree op1
, gimple stmt
)
6009 /* Some passes and foldings leak constants with overflow flag set
6010 into the IL. Avoid doing wrong things with these and bail out. */
6011 if ((TREE_CODE (op0
) == INTEGER_CST
6012 && TREE_OVERFLOW (op0
))
6013 || (TREE_CODE (op1
) == INTEGER_CST
6014 && TREE_OVERFLOW (op1
)))
6018 ret
= vrp_evaluate_conditional_warnv_with_ops (code
, op0
, op1
, true, &sop
,
6023 enum warn_strict_overflow_code wc
;
6024 const char* warnmsg
;
6026 if (is_gimple_min_invariant (ret
))
6028 wc
= WARN_STRICT_OVERFLOW_CONDITIONAL
;
6029 warnmsg
= G_("assuming signed overflow does not occur when "
6030 "simplifying conditional to constant");
6034 wc
= WARN_STRICT_OVERFLOW_COMPARISON
;
6035 warnmsg
= G_("assuming signed overflow does not occur when "
6036 "simplifying conditional");
6039 if (issue_strict_overflow_warning (wc
))
6041 location_t location
;
6043 if (!gimple_has_location (stmt
))
6044 location
= input_location
;
6046 location
= gimple_location (stmt
);
6047 warning_at (location
, OPT_Wstrict_overflow
, "%s", warnmsg
);
6051 if (warn_type_limits
6052 && ret
&& only_ranges
6053 && TREE_CODE_CLASS (code
) == tcc_comparison
6054 && TREE_CODE (op0
) == SSA_NAME
)
6056 /* If the comparison is being folded and the operand on the LHS
6057 is being compared against a constant value that is outside of
6058 the natural range of OP0's type, then the predicate will
6059 always fold regardless of the value of OP0. If -Wtype-limits
6060 was specified, emit a warning. */
6061 tree type
= TREE_TYPE (op0
);
6062 value_range_t
*vr0
= get_value_range (op0
);
6064 if (vr0
->type
!= VR_VARYING
6065 && INTEGRAL_TYPE_P (type
)
6066 && vrp_val_is_min (vr0
->min
)
6067 && vrp_val_is_max (vr0
->max
)
6068 && is_gimple_min_invariant (op1
))
6070 location_t location
;
6072 if (!gimple_has_location (stmt
))
6073 location
= input_location
;
6075 location
= gimple_location (stmt
);
6077 warning_at (location
, OPT_Wtype_limits
,
6079 ? G_("comparison always false "
6080 "due to limited range of data type")
6081 : G_("comparison always true "
6082 "due to limited range of data type"));
6090 /* Visit conditional statement STMT. If we can determine which edge
6091 will be taken out of STMT's basic block, record it in
6092 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
6093 SSA_PROP_VARYING. */
6095 static enum ssa_prop_result
6096 vrp_visit_cond_stmt (gimple stmt
, edge
*taken_edge_p
)
6101 *taken_edge_p
= NULL
;
6103 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6108 fprintf (dump_file
, "\nVisiting conditional with predicate: ");
6109 print_gimple_stmt (dump_file
, stmt
, 0, 0);
6110 fprintf (dump_file
, "\nWith known ranges\n");
6112 FOR_EACH_SSA_TREE_OPERAND (use
, stmt
, i
, SSA_OP_USE
)
6114 fprintf (dump_file
, "\t");
6115 print_generic_expr (dump_file
, use
, 0);
6116 fprintf (dump_file
, ": ");
6117 dump_value_range (dump_file
, vr_value
[SSA_NAME_VERSION (use
)]);
6120 fprintf (dump_file
, "\n");
6123 /* Compute the value of the predicate COND by checking the known
6124 ranges of each of its operands.
6126 Note that we cannot evaluate all the equivalent ranges here
6127 because those ranges may not yet be final and with the current
6128 propagation strategy, we cannot determine when the value ranges
6129 of the names in the equivalence set have changed.
6131 For instance, given the following code fragment
6135 i_14 = ASSERT_EXPR <i_5, i_5 != 0>
6139 Assume that on the first visit to i_14, i_5 has the temporary
6140 range [8, 8] because the second argument to the PHI function is
6141 not yet executable. We derive the range ~[0, 0] for i_14 and the
6142 equivalence set { i_5 }. So, when we visit 'if (i_14 == 1)' for
6143 the first time, since i_14 is equivalent to the range [8, 8], we
6144 determine that the predicate is always false.
6146 On the next round of propagation, i_13 is determined to be
6147 VARYING, which causes i_5 to drop down to VARYING. So, another
6148 visit to i_14 is scheduled. In this second visit, we compute the
6149 exact same range and equivalence set for i_14, namely ~[0, 0] and
6150 { i_5 }. But we did not have the previous range for i_5
6151 registered, so vrp_visit_assignment thinks that the range for
6152 i_14 has not changed. Therefore, the predicate 'if (i_14 == 1)'
6153 is not visited again, which stops propagation from visiting
6154 statements in the THEN clause of that if().
6156 To properly fix this we would need to keep the previous range
6157 value for the names in the equivalence set. This way we would've
6158 discovered that from one visit to the other i_5 changed from
6159 range [8, 8] to VR_VARYING.
6161 However, fixing this apparent limitation may not be worth the
6162 additional checking. Testing on several code bases (GCC, DLV,
6163 MICO, TRAMP3D and SPEC2000) showed that doing this results in
6164 4 more predicates folded in SPEC. */
6167 val
= vrp_evaluate_conditional_warnv_with_ops (gimple_cond_code (stmt
),
6168 gimple_cond_lhs (stmt
),
6169 gimple_cond_rhs (stmt
),
6174 *taken_edge_p
= find_taken_edge (gimple_bb (stmt
), val
);
6177 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6179 "\nIgnoring predicate evaluation because "
6180 "it assumes that signed overflow is undefined");
6185 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6187 fprintf (dump_file
, "\nPredicate evaluates to: ");
6188 if (val
== NULL_TREE
)
6189 fprintf (dump_file
, "DON'T KNOW\n");
6191 print_generic_stmt (dump_file
, val
, 0);
6194 return (*taken_edge_p
) ? SSA_PROP_INTERESTING
: SSA_PROP_VARYING
;
6197 /* Searches the case label vector VEC for the index *IDX of the CASE_LABEL
6198 that includes the value VAL. The search is restricted to the range
6199 [START_IDX, n - 1] where n is the size of VEC.
6201 If there is a CASE_LABEL for VAL, its index is placed in IDX and true is
6204 If there is no CASE_LABEL for VAL and there is one that is larger than VAL,
6205 it is placed in IDX and false is returned.
6207 If VAL is larger than any CASE_LABEL, n is placed on IDX and false is
6211 find_case_label_index (gimple stmt
, size_t start_idx
, tree val
, size_t *idx
)
6213 size_t n
= gimple_switch_num_labels (stmt
);
6216 /* Find case label for minimum of the value range or the next one.
6217 At each iteration we are searching in [low, high - 1]. */
6219 for (low
= start_idx
, high
= n
; high
!= low
; )
6223 /* Note that i != high, so we never ask for n. */
6224 size_t i
= (high
+ low
) / 2;
6225 t
= gimple_switch_label (stmt
, i
);
6227 /* Cache the result of comparing CASE_LOW and val. */
6228 cmp
= tree_int_cst_compare (CASE_LOW (t
), val
);
6232 /* Ranges cannot be empty. */
6241 if (CASE_HIGH (t
) != NULL
6242 && tree_int_cst_compare (CASE_HIGH (t
), val
) >= 0)
6254 /* Searches the case label vector VEC for the range of CASE_LABELs that is used
6255 for values between MIN and MAX. The first index is placed in MIN_IDX. The
6256 last index is placed in MAX_IDX. If the range of CASE_LABELs is empty
6257 then MAX_IDX < MIN_IDX.
6258 Returns true if the default label is not needed. */
6261 find_case_label_range (gimple stmt
, tree min
, tree max
, size_t *min_idx
,
6265 bool min_take_default
= !find_case_label_index (stmt
, 1, min
, &i
);
6266 bool max_take_default
= !find_case_label_index (stmt
, i
, max
, &j
);
6270 && max_take_default
)
6272 /* Only the default case label reached.
6273 Return an empty range. */
6280 bool take_default
= min_take_default
|| max_take_default
;
6284 if (max_take_default
)
6287 /* If the case label range is continuous, we do not need
6288 the default case label. Verify that. */
6289 high
= CASE_LOW (gimple_switch_label (stmt
, i
));
6290 if (CASE_HIGH (gimple_switch_label (stmt
, i
)))
6291 high
= CASE_HIGH (gimple_switch_label (stmt
, i
));
6292 for (k
= i
+ 1; k
<= j
; ++k
)
6294 low
= CASE_LOW (gimple_switch_label (stmt
, k
));
6295 if (!integer_onep (int_const_binop (MINUS_EXPR
, low
, high
)))
6297 take_default
= true;
6301 if (CASE_HIGH (gimple_switch_label (stmt
, k
)))
6302 high
= CASE_HIGH (gimple_switch_label (stmt
, k
));
6307 return !take_default
;
6311 /* Visit switch statement STMT. If we can determine which edge
6312 will be taken out of STMT's basic block, record it in
6313 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
6314 SSA_PROP_VARYING. */
6316 static enum ssa_prop_result
6317 vrp_visit_switch_stmt (gimple stmt
, edge
*taken_edge_p
)
6321 size_t i
= 0, j
= 0;
6324 *taken_edge_p
= NULL
;
6325 op
= gimple_switch_index (stmt
);
6326 if (TREE_CODE (op
) != SSA_NAME
)
6327 return SSA_PROP_VARYING
;
6329 vr
= get_value_range (op
);
6330 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6332 fprintf (dump_file
, "\nVisiting switch expression with operand ");
6333 print_generic_expr (dump_file
, op
, 0);
6334 fprintf (dump_file
, " with known range ");
6335 dump_value_range (dump_file
, vr
);
6336 fprintf (dump_file
, "\n");
6339 if (vr
->type
!= VR_RANGE
6340 || symbolic_range_p (vr
))
6341 return SSA_PROP_VARYING
;
6343 /* Find the single edge that is taken from the switch expression. */
6344 take_default
= !find_case_label_range (stmt
, vr
->min
, vr
->max
, &i
, &j
);
6346 /* Check if the range spans no CASE_LABEL. If so, we only reach the default
6350 gcc_assert (take_default
);
6351 val
= gimple_switch_default_label (stmt
);
6355 /* Check if labels with index i to j and maybe the default label
6356 are all reaching the same label. */
6358 val
= gimple_switch_label (stmt
, i
);
6360 && CASE_LABEL (gimple_switch_default_label (stmt
))
6361 != CASE_LABEL (val
))
6363 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6364 fprintf (dump_file
, " not a single destination for this "
6366 return SSA_PROP_VARYING
;
6368 for (++i
; i
<= j
; ++i
)
6370 if (CASE_LABEL (gimple_switch_label (stmt
, i
)) != CASE_LABEL (val
))
6372 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6373 fprintf (dump_file
, " not a single destination for this "
6375 return SSA_PROP_VARYING
;
6380 *taken_edge_p
= find_edge (gimple_bb (stmt
),
6381 label_to_block (CASE_LABEL (val
)));
6383 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6385 fprintf (dump_file
, " will take edge to ");
6386 print_generic_stmt (dump_file
, CASE_LABEL (val
), 0);
6389 return SSA_PROP_INTERESTING
;
6393 /* Evaluate statement STMT. If the statement produces a useful range,
6394 return SSA_PROP_INTERESTING and record the SSA name with the
6395 interesting range into *OUTPUT_P.
6397 If STMT is a conditional branch and we can determine its truth
6398 value, the taken edge is recorded in *TAKEN_EDGE_P.
6400 If STMT produces a varying value, return SSA_PROP_VARYING. */
6402 static enum ssa_prop_result
6403 vrp_visit_stmt (gimple stmt
, edge
*taken_edge_p
, tree
*output_p
)
6408 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6410 fprintf (dump_file
, "\nVisiting statement:\n");
6411 print_gimple_stmt (dump_file
, stmt
, 0, dump_flags
);
6412 fprintf (dump_file
, "\n");
6415 if (!stmt_interesting_for_vrp (stmt
))
6416 gcc_assert (stmt_ends_bb_p (stmt
));
6417 else if (is_gimple_assign (stmt
) || is_gimple_call (stmt
))
6419 /* In general, assignments with virtual operands are not useful
6420 for deriving ranges, with the obvious exception of calls to
6421 builtin functions. */
6422 if ((is_gimple_call (stmt
)
6423 && gimple_call_fndecl (stmt
) != NULL_TREE
6424 && DECL_IS_BUILTIN (gimple_call_fndecl (stmt
)))
6425 || !gimple_vuse (stmt
))
6426 return vrp_visit_assignment_or_call (stmt
, output_p
);
6428 else if (gimple_code (stmt
) == GIMPLE_COND
)
6429 return vrp_visit_cond_stmt (stmt
, taken_edge_p
);
6430 else if (gimple_code (stmt
) == GIMPLE_SWITCH
)
6431 return vrp_visit_switch_stmt (stmt
, taken_edge_p
);
6433 /* All other statements produce nothing of interest for VRP, so mark
6434 their outputs varying and prevent further simulation. */
6435 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_DEF
)
6436 set_value_range_to_varying (get_value_range (def
));
6438 return SSA_PROP_VARYING
;
6442 /* Meet operation for value ranges. Given two value ranges VR0 and
6443 VR1, store in VR0 a range that contains both VR0 and VR1. This
6444 may not be the smallest possible such range. */
6447 vrp_meet (value_range_t
*vr0
, value_range_t
*vr1
)
6449 if (vr0
->type
== VR_UNDEFINED
)
6451 copy_value_range (vr0
, vr1
);
6455 if (vr1
->type
== VR_UNDEFINED
)
6457 /* Nothing to do. VR0 already has the resulting range. */
6461 if (vr0
->type
== VR_VARYING
)
6463 /* Nothing to do. VR0 already has the resulting range. */
6467 if (vr1
->type
== VR_VARYING
)
6469 set_value_range_to_varying (vr0
);
6473 if (vr0
->type
== VR_RANGE
&& vr1
->type
== VR_RANGE
)
6478 /* Compute the convex hull of the ranges. The lower limit of
6479 the new range is the minimum of the two ranges. If they
6480 cannot be compared, then give up. */
6481 cmp
= compare_values (vr0
->min
, vr1
->min
);
6482 if (cmp
== 0 || cmp
== 1)
6489 /* Similarly, the upper limit of the new range is the maximum
6490 of the two ranges. If they cannot be compared, then
6492 cmp
= compare_values (vr0
->max
, vr1
->max
);
6493 if (cmp
== 0 || cmp
== -1)
6500 /* Check for useless ranges. */
6501 if (INTEGRAL_TYPE_P (TREE_TYPE (min
))
6502 && ((vrp_val_is_min (min
) || is_overflow_infinity (min
))
6503 && (vrp_val_is_max (max
) || is_overflow_infinity (max
))))
6506 /* The resulting set of equivalences is the intersection of
6508 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
6509 bitmap_and_into (vr0
->equiv
, vr1
->equiv
);
6510 else if (vr0
->equiv
&& !vr1
->equiv
)
6511 bitmap_clear (vr0
->equiv
);
6513 set_value_range (vr0
, vr0
->type
, min
, max
, vr0
->equiv
);
6515 else if (vr0
->type
== VR_ANTI_RANGE
&& vr1
->type
== VR_ANTI_RANGE
)
6517 /* Two anti-ranges meet only if their complements intersect.
6518 Only handle the case of identical ranges. */
6519 if (compare_values (vr0
->min
, vr1
->min
) == 0
6520 && compare_values (vr0
->max
, vr1
->max
) == 0
6521 && compare_values (vr0
->min
, vr0
->max
) == 0)
6523 /* The resulting set of equivalences is the intersection of
6525 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
6526 bitmap_and_into (vr0
->equiv
, vr1
->equiv
);
6527 else if (vr0
->equiv
&& !vr1
->equiv
)
6528 bitmap_clear (vr0
->equiv
);
6533 else if (vr0
->type
== VR_ANTI_RANGE
|| vr1
->type
== VR_ANTI_RANGE
)
6535 /* For a numeric range [VAL1, VAL2] and an anti-range ~[VAL3, VAL4],
6536 only handle the case where the ranges have an empty intersection.
6537 The result of the meet operation is the anti-range. */
6538 if (!symbolic_range_p (vr0
)
6539 && !symbolic_range_p (vr1
)
6540 && !value_ranges_intersect_p (vr0
, vr1
))
6542 /* Copy most of VR1 into VR0. Don't copy VR1's equivalence
6543 set. We need to compute the intersection of the two
6544 equivalence sets. */
6545 if (vr1
->type
== VR_ANTI_RANGE
)
6546 set_value_range (vr0
, vr1
->type
, vr1
->min
, vr1
->max
, vr0
->equiv
);
6548 /* The resulting set of equivalences is the intersection of
6550 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
6551 bitmap_and_into (vr0
->equiv
, vr1
->equiv
);
6552 else if (vr0
->equiv
&& !vr1
->equiv
)
6553 bitmap_clear (vr0
->equiv
);
6564 /* Failed to find an efficient meet. Before giving up and setting
6565 the result to VARYING, see if we can at least derive a useful
6566 anti-range. FIXME, all this nonsense about distinguishing
6567 anti-ranges from ranges is necessary because of the odd
6568 semantics of range_includes_zero_p and friends. */
6569 if (!symbolic_range_p (vr0
)
6570 && ((vr0
->type
== VR_RANGE
&& !range_includes_zero_p (vr0
))
6571 || (vr0
->type
== VR_ANTI_RANGE
&& range_includes_zero_p (vr0
)))
6572 && !symbolic_range_p (vr1
)
6573 && ((vr1
->type
== VR_RANGE
&& !range_includes_zero_p (vr1
))
6574 || (vr1
->type
== VR_ANTI_RANGE
&& range_includes_zero_p (vr1
))))
6576 set_value_range_to_nonnull (vr0
, TREE_TYPE (vr0
->min
));
6578 /* Since this meet operation did not result from the meeting of
6579 two equivalent names, VR0 cannot have any equivalences. */
6581 bitmap_clear (vr0
->equiv
);
6584 set_value_range_to_varying (vr0
);
6588 /* Visit all arguments for PHI node PHI that flow through executable
6589 edges. If a valid value range can be derived from all the incoming
6590 value ranges, set a new range for the LHS of PHI. */
6592 static enum ssa_prop_result
6593 vrp_visit_phi_node (gimple phi
)
6596 tree lhs
= PHI_RESULT (phi
);
6597 value_range_t
*lhs_vr
= get_value_range (lhs
);
6598 value_range_t vr_result
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
6599 int edges
, old_edges
;
6602 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6604 fprintf (dump_file
, "\nVisiting PHI node: ");
6605 print_gimple_stmt (dump_file
, phi
, 0, dump_flags
);
6609 for (i
= 0; i
< gimple_phi_num_args (phi
); i
++)
6611 edge e
= gimple_phi_arg_edge (phi
, i
);
6613 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6616 "\n Argument #%d (%d -> %d %sexecutable)\n",
6617 (int) i
, e
->src
->index
, e
->dest
->index
,
6618 (e
->flags
& EDGE_EXECUTABLE
) ? "" : "not ");
6621 if (e
->flags
& EDGE_EXECUTABLE
)
6623 tree arg
= PHI_ARG_DEF (phi
, i
);
6624 value_range_t vr_arg
;
6628 if (TREE_CODE (arg
) == SSA_NAME
)
6630 vr_arg
= *(get_value_range (arg
));
6634 if (is_overflow_infinity (arg
))
6636 arg
= copy_node (arg
);
6637 TREE_OVERFLOW (arg
) = 0;
6640 vr_arg
.type
= VR_RANGE
;
6643 vr_arg
.equiv
= NULL
;
6646 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6648 fprintf (dump_file
, "\t");
6649 print_generic_expr (dump_file
, arg
, dump_flags
);
6650 fprintf (dump_file
, "\n\tValue: ");
6651 dump_value_range (dump_file
, &vr_arg
);
6652 fprintf (dump_file
, "\n");
6655 vrp_meet (&vr_result
, &vr_arg
);
6657 if (vr_result
.type
== VR_VARYING
)
6662 if (vr_result
.type
== VR_VARYING
)
6664 else if (vr_result
.type
== VR_UNDEFINED
)
6667 old_edges
= vr_phi_edge_counts
[SSA_NAME_VERSION (lhs
)];
6668 vr_phi_edge_counts
[SSA_NAME_VERSION (lhs
)] = edges
;
6670 /* To prevent infinite iterations in the algorithm, derive ranges
6671 when the new value is slightly bigger or smaller than the
6672 previous one. We don't do this if we have seen a new executable
6673 edge; this helps us avoid an overflow infinity for conditionals
6674 which are not in a loop. */
6676 && gimple_phi_num_args (phi
) > 1
6677 && edges
== old_edges
)
6679 int cmp_min
= compare_values (lhs_vr
->min
, vr_result
.min
);
6680 int cmp_max
= compare_values (lhs_vr
->max
, vr_result
.max
);
6682 /* For non VR_RANGE or for pointers fall back to varying if
6683 the range changed. */
6684 if ((lhs_vr
->type
!= VR_RANGE
|| vr_result
.type
!= VR_RANGE
6685 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
6686 && (cmp_min
!= 0 || cmp_max
!= 0))
6689 /* If the new minimum is smaller or larger than the previous
6690 one, go all the way to -INF. In the first case, to avoid
6691 iterating millions of times to reach -INF, and in the
6692 other case to avoid infinite bouncing between different
6694 if (cmp_min
> 0 || cmp_min
< 0)
6696 if (!needs_overflow_infinity (TREE_TYPE (vr_result
.min
))
6697 || !vrp_var_may_overflow (lhs
, phi
))
6698 vr_result
.min
= TYPE_MIN_VALUE (TREE_TYPE (vr_result
.min
));
6699 else if (supports_overflow_infinity (TREE_TYPE (vr_result
.min
)))
6701 negative_overflow_infinity (TREE_TYPE (vr_result
.min
));
6704 /* Similarly, if the new maximum is smaller or larger than
6705 the previous one, go all the way to +INF. */
6706 if (cmp_max
< 0 || cmp_max
> 0)
6708 if (!needs_overflow_infinity (TREE_TYPE (vr_result
.max
))
6709 || !vrp_var_may_overflow (lhs
, phi
))
6710 vr_result
.max
= TYPE_MAX_VALUE (TREE_TYPE (vr_result
.max
));
6711 else if (supports_overflow_infinity (TREE_TYPE (vr_result
.max
)))
6713 positive_overflow_infinity (TREE_TYPE (vr_result
.max
));
6716 /* If we dropped either bound to +-INF then if this is a loop
6717 PHI node SCEV may known more about its value-range. */
6718 if ((cmp_min
> 0 || cmp_min
< 0
6719 || cmp_max
< 0 || cmp_max
> 0)
6721 && (l
= loop_containing_stmt (phi
))
6722 && l
->header
== gimple_bb (phi
))
6723 adjust_range_with_scev (&vr_result
, l
, phi
, lhs
);
6725 /* If we will end up with a (-INF, +INF) range, set it to
6726 VARYING. Same if the previous max value was invalid for
6727 the type and we end up with vr_result.min > vr_result.max. */
6728 if ((vrp_val_is_max (vr_result
.max
)
6729 && vrp_val_is_min (vr_result
.min
))
6730 || compare_values (vr_result
.min
,
6735 /* If the new range is different than the previous value, keep
6738 if (update_value_range (lhs
, &vr_result
))
6740 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6742 fprintf (dump_file
, "Found new range for ");
6743 print_generic_expr (dump_file
, lhs
, 0);
6744 fprintf (dump_file
, ": ");
6745 dump_value_range (dump_file
, &vr_result
);
6746 fprintf (dump_file
, "\n\n");
6749 return SSA_PROP_INTERESTING
;
6752 /* Nothing changed, don't add outgoing edges. */
6753 return SSA_PROP_NOT_INTERESTING
;
6755 /* No match found. Set the LHS to VARYING. */
6757 set_value_range_to_varying (lhs_vr
);
6758 return SSA_PROP_VARYING
;
6761 /* Simplify boolean operations if the source is known
6762 to be already a boolean. */
6764 simplify_truth_ops_using_ranges (gimple_stmt_iterator
*gsi
, gimple stmt
)
6766 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
6768 bool need_conversion
;
6770 /* We handle only !=/== case here. */
6771 gcc_assert (rhs_code
== EQ_EXPR
|| rhs_code
== NE_EXPR
);
6773 op0
= gimple_assign_rhs1 (stmt
);
6774 if (!op_with_boolean_value_range_p (op0
))
6777 op1
= gimple_assign_rhs2 (stmt
);
6778 if (!op_with_boolean_value_range_p (op1
))
6781 /* Reduce number of cases to handle to NE_EXPR. As there is no
6782 BIT_XNOR_EXPR we cannot replace A == B with a single statement. */
6783 if (rhs_code
== EQ_EXPR
)
6785 if (TREE_CODE (op1
) == INTEGER_CST
)
6786 op1
= int_const_binop (BIT_XOR_EXPR
, op1
, integer_one_node
);
6791 lhs
= gimple_assign_lhs (stmt
);
6793 = !useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (op0
));
6795 /* Make sure to not sign-extend a 1-bit 1 when converting the result. */
6797 && !TYPE_UNSIGNED (TREE_TYPE (op0
))
6798 && TYPE_PRECISION (TREE_TYPE (op0
)) == 1
6799 && TYPE_PRECISION (TREE_TYPE (lhs
)) > 1)
6802 /* For A != 0 we can substitute A itself. */
6803 if (integer_zerop (op1
))
6804 gimple_assign_set_rhs_with_ops (gsi
,
6806 ? NOP_EXPR
: TREE_CODE (op0
),
6808 /* For A != B we substitute A ^ B. Either with conversion. */
6809 else if (need_conversion
)
6812 tree tem
= create_tmp_reg (TREE_TYPE (op0
), NULL
);
6813 newop
= gimple_build_assign_with_ops (BIT_XOR_EXPR
, tem
, op0
, op1
);
6814 tem
= make_ssa_name (tem
, newop
);
6815 gimple_assign_set_lhs (newop
, tem
);
6816 gsi_insert_before (gsi
, newop
, GSI_SAME_STMT
);
6817 update_stmt (newop
);
6818 gimple_assign_set_rhs_with_ops (gsi
, NOP_EXPR
, tem
, NULL_TREE
);
6822 gimple_assign_set_rhs_with_ops (gsi
, BIT_XOR_EXPR
, op0
, op1
);
6823 update_stmt (gsi_stmt (*gsi
));
6828 /* Simplify a division or modulo operator to a right shift or
6829 bitwise and if the first operand is unsigned or is greater
6830 than zero and the second operand is an exact power of two. */
6833 simplify_div_or_mod_using_ranges (gimple stmt
)
6835 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
6837 tree op0
= gimple_assign_rhs1 (stmt
);
6838 tree op1
= gimple_assign_rhs2 (stmt
);
6839 value_range_t
*vr
= get_value_range (gimple_assign_rhs1 (stmt
));
6841 if (TYPE_UNSIGNED (TREE_TYPE (op0
)))
6843 val
= integer_one_node
;
6849 val
= compare_range_with_value (GE_EXPR
, vr
, integer_zero_node
, &sop
);
6853 && integer_onep (val
)
6854 && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
6856 location_t location
;
6858 if (!gimple_has_location (stmt
))
6859 location
= input_location
;
6861 location
= gimple_location (stmt
);
6862 warning_at (location
, OPT_Wstrict_overflow
,
6863 "assuming signed overflow does not occur when "
6864 "simplifying %</%> or %<%%%> to %<>>%> or %<&%>");
6868 if (val
&& integer_onep (val
))
6872 if (rhs_code
== TRUNC_DIV_EXPR
)
6874 t
= build_int_cst (integer_type_node
, tree_log2 (op1
));
6875 gimple_assign_set_rhs_code (stmt
, RSHIFT_EXPR
);
6876 gimple_assign_set_rhs1 (stmt
, op0
);
6877 gimple_assign_set_rhs2 (stmt
, t
);
6881 t
= build_int_cst (TREE_TYPE (op1
), 1);
6882 t
= int_const_binop (MINUS_EXPR
, op1
, t
);
6883 t
= fold_convert (TREE_TYPE (op0
), t
);
6885 gimple_assign_set_rhs_code (stmt
, BIT_AND_EXPR
);
6886 gimple_assign_set_rhs1 (stmt
, op0
);
6887 gimple_assign_set_rhs2 (stmt
, t
);
6897 /* If the operand to an ABS_EXPR is >= 0, then eliminate the
6898 ABS_EXPR. If the operand is <= 0, then simplify the
6899 ABS_EXPR into a NEGATE_EXPR. */
6902 simplify_abs_using_ranges (gimple stmt
)
6905 tree op
= gimple_assign_rhs1 (stmt
);
6906 tree type
= TREE_TYPE (op
);
6907 value_range_t
*vr
= get_value_range (op
);
6909 if (TYPE_UNSIGNED (type
))
6911 val
= integer_zero_node
;
6917 val
= compare_range_with_value (LE_EXPR
, vr
, integer_zero_node
, &sop
);
6921 val
= compare_range_with_value (GE_EXPR
, vr
, integer_zero_node
,
6926 if (integer_zerop (val
))
6927 val
= integer_one_node
;
6928 else if (integer_onep (val
))
6929 val
= integer_zero_node
;
6934 && (integer_onep (val
) || integer_zerop (val
)))
6936 if (sop
&& issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
6938 location_t location
;
6940 if (!gimple_has_location (stmt
))
6941 location
= input_location
;
6943 location
= gimple_location (stmt
);
6944 warning_at (location
, OPT_Wstrict_overflow
,
6945 "assuming signed overflow does not occur when "
6946 "simplifying %<abs (X)%> to %<X%> or %<-X%>");
6949 gimple_assign_set_rhs1 (stmt
, op
);
6950 if (integer_onep (val
))
6951 gimple_assign_set_rhs_code (stmt
, NEGATE_EXPR
);
6953 gimple_assign_set_rhs_code (stmt
, SSA_NAME
);
6962 /* Optimize away redundant BIT_AND_EXPR and BIT_IOR_EXPR.
6963 If all the bits that are being cleared by & are already
6964 known to be zero from VR, or all the bits that are being
6965 set by | are already known to be one from VR, the bit
6966 operation is redundant. */
6969 simplify_bit_ops_using_ranges (gimple_stmt_iterator
*gsi
, gimple stmt
)
6971 tree op0
= gimple_assign_rhs1 (stmt
);
6972 tree op1
= gimple_assign_rhs2 (stmt
);
6973 tree op
= NULL_TREE
;
6974 value_range_t vr0
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
6975 value_range_t vr1
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
6976 double_int may_be_nonzero0
, may_be_nonzero1
;
6977 double_int must_be_nonzero0
, must_be_nonzero1
;
6980 if (TREE_CODE (op0
) == SSA_NAME
)
6981 vr0
= *(get_value_range (op0
));
6982 else if (is_gimple_min_invariant (op0
))
6983 set_value_range_to_value (&vr0
, op0
, NULL
);
6987 if (TREE_CODE (op1
) == SSA_NAME
)
6988 vr1
= *(get_value_range (op1
));
6989 else if (is_gimple_min_invariant (op1
))
6990 set_value_range_to_value (&vr1
, op1
, NULL
);
6994 if (!zero_nonzero_bits_from_vr (&vr0
, &may_be_nonzero0
, &must_be_nonzero0
))
6996 if (!zero_nonzero_bits_from_vr (&vr1
, &may_be_nonzero1
, &must_be_nonzero1
))
6999 switch (gimple_assign_rhs_code (stmt
))
7002 mask
= double_int_and_not (may_be_nonzero0
, must_be_nonzero1
);
7003 if (double_int_zero_p (mask
))
7008 mask
= double_int_and_not (may_be_nonzero1
, must_be_nonzero0
);
7009 if (double_int_zero_p (mask
))
7016 mask
= double_int_and_not (may_be_nonzero0
, must_be_nonzero1
);
7017 if (double_int_zero_p (mask
))
7022 mask
= double_int_and_not (may_be_nonzero1
, must_be_nonzero0
);
7023 if (double_int_zero_p (mask
))
7033 if (op
== NULL_TREE
)
7036 gimple_assign_set_rhs_with_ops (gsi
, TREE_CODE (op
), op
, NULL
);
7037 update_stmt (gsi_stmt (*gsi
));
7041 /* We are comparing trees OP0 and OP1 using COND_CODE. OP0 has
7042 a known value range VR.
7044 If there is one and only one value which will satisfy the
7045 conditional, then return that value. Else return NULL. */
7048 test_for_singularity (enum tree_code cond_code
, tree op0
,
7049 tree op1
, value_range_t
*vr
)
7054 /* Extract minimum/maximum values which satisfy the
7055 the conditional as it was written. */
7056 if (cond_code
== LE_EXPR
|| cond_code
== LT_EXPR
)
7058 /* This should not be negative infinity; there is no overflow
7060 min
= TYPE_MIN_VALUE (TREE_TYPE (op0
));
7063 if (cond_code
== LT_EXPR
&& !is_overflow_infinity (max
))
7065 tree one
= build_int_cst (TREE_TYPE (op0
), 1);
7066 max
= fold_build2 (MINUS_EXPR
, TREE_TYPE (op0
), max
, one
);
7068 TREE_NO_WARNING (max
) = 1;
7071 else if (cond_code
== GE_EXPR
|| cond_code
== GT_EXPR
)
7073 /* This should not be positive infinity; there is no overflow
7075 max
= TYPE_MAX_VALUE (TREE_TYPE (op0
));
7078 if (cond_code
== GT_EXPR
&& !is_overflow_infinity (min
))
7080 tree one
= build_int_cst (TREE_TYPE (op0
), 1);
7081 min
= fold_build2 (PLUS_EXPR
, TREE_TYPE (op0
), min
, one
);
7083 TREE_NO_WARNING (min
) = 1;
7087 /* Now refine the minimum and maximum values using any
7088 value range information we have for op0. */
7091 if (compare_values (vr
->min
, min
) == 1)
7093 if (compare_values (vr
->max
, max
) == -1)
7096 /* If the new min/max values have converged to a single value,
7097 then there is only one value which can satisfy the condition,
7098 return that value. */
7099 if (operand_equal_p (min
, max
, 0) && is_gimple_min_invariant (min
))
7105 /* Simplify a conditional using a relational operator to an equality
7106 test if the range information indicates only one value can satisfy
7107 the original conditional. */
7110 simplify_cond_using_ranges (gimple stmt
)
7112 tree op0
= gimple_cond_lhs (stmt
);
7113 tree op1
= gimple_cond_rhs (stmt
);
7114 enum tree_code cond_code
= gimple_cond_code (stmt
);
7116 if (cond_code
!= NE_EXPR
7117 && cond_code
!= EQ_EXPR
7118 && TREE_CODE (op0
) == SSA_NAME
7119 && INTEGRAL_TYPE_P (TREE_TYPE (op0
))
7120 && is_gimple_min_invariant (op1
))
7122 value_range_t
*vr
= get_value_range (op0
);
7124 /* If we have range information for OP0, then we might be
7125 able to simplify this conditional. */
7126 if (vr
->type
== VR_RANGE
)
7128 tree new_tree
= test_for_singularity (cond_code
, op0
, op1
, vr
);
7134 fprintf (dump_file
, "Simplified relational ");
7135 print_gimple_stmt (dump_file
, stmt
, 0, 0);
7136 fprintf (dump_file
, " into ");
7139 gimple_cond_set_code (stmt
, EQ_EXPR
);
7140 gimple_cond_set_lhs (stmt
, op0
);
7141 gimple_cond_set_rhs (stmt
, new_tree
);
7147 print_gimple_stmt (dump_file
, stmt
, 0, 0);
7148 fprintf (dump_file
, "\n");
7154 /* Try again after inverting the condition. We only deal
7155 with integral types here, so no need to worry about
7156 issues with inverting FP comparisons. */
7157 cond_code
= invert_tree_comparison (cond_code
, false);
7158 new_tree
= test_for_singularity (cond_code
, op0
, op1
, vr
);
7164 fprintf (dump_file
, "Simplified relational ");
7165 print_gimple_stmt (dump_file
, stmt
, 0, 0);
7166 fprintf (dump_file
, " into ");
7169 gimple_cond_set_code (stmt
, NE_EXPR
);
7170 gimple_cond_set_lhs (stmt
, op0
);
7171 gimple_cond_set_rhs (stmt
, new_tree
);
7177 print_gimple_stmt (dump_file
, stmt
, 0, 0);
7178 fprintf (dump_file
, "\n");
7189 /* Simplify a switch statement using the value range of the switch
7193 simplify_switch_using_ranges (gimple stmt
)
7195 tree op
= gimple_switch_index (stmt
);
7200 size_t i
= 0, j
= 0, n
, n2
;
7204 if (TREE_CODE (op
) == SSA_NAME
)
7206 vr
= get_value_range (op
);
7208 /* We can only handle integer ranges. */
7209 if (vr
->type
!= VR_RANGE
7210 || symbolic_range_p (vr
))
7213 /* Find case label for min/max of the value range. */
7214 take_default
= !find_case_label_range (stmt
, vr
->min
, vr
->max
, &i
, &j
);
7216 else if (TREE_CODE (op
) == INTEGER_CST
)
7218 take_default
= !find_case_label_index (stmt
, 1, op
, &i
);
7232 n
= gimple_switch_num_labels (stmt
);
7234 /* Bail out if this is just all edges taken. */
7240 /* Build a new vector of taken case labels. */
7241 vec2
= make_tree_vec (j
- i
+ 1 + (int)take_default
);
7244 /* Add the default edge, if necessary. */
7246 TREE_VEC_ELT (vec2
, n2
++) = gimple_switch_default_label (stmt
);
7248 for (; i
<= j
; ++i
, ++n2
)
7249 TREE_VEC_ELT (vec2
, n2
) = gimple_switch_label (stmt
, i
);
7251 /* Mark needed edges. */
7252 for (i
= 0; i
< n2
; ++i
)
7254 e
= find_edge (gimple_bb (stmt
),
7255 label_to_block (CASE_LABEL (TREE_VEC_ELT (vec2
, i
))));
7256 e
->aux
= (void *)-1;
7259 /* Queue not needed edges for later removal. */
7260 FOR_EACH_EDGE (e
, ei
, gimple_bb (stmt
)->succs
)
7262 if (e
->aux
== (void *)-1)
7268 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7270 fprintf (dump_file
, "removing unreachable case label\n");
7272 VEC_safe_push (edge
, heap
, to_remove_edges
, e
);
7273 e
->flags
&= ~EDGE_EXECUTABLE
;
7276 /* And queue an update for the stmt. */
7279 VEC_safe_push (switch_update
, heap
, to_update_switch_stmts
, &su
);
7283 /* Simplify an integral conversion from an SSA name in STMT. */
7286 simplify_conversion_using_ranges (gimple stmt
)
7288 tree innerop
, middleop
, finaltype
;
7290 value_range_t
*innervr
;
7291 double_int innermin
, innermax
, middlemin
, middlemax
;
7293 finaltype
= TREE_TYPE (gimple_assign_lhs (stmt
));
7294 if (!INTEGRAL_TYPE_P (finaltype
))
7296 middleop
= gimple_assign_rhs1 (stmt
);
7297 def_stmt
= SSA_NAME_DEF_STMT (middleop
);
7298 if (!is_gimple_assign (def_stmt
)
7299 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
)))
7301 innerop
= gimple_assign_rhs1 (def_stmt
);
7302 if (TREE_CODE (innerop
) != SSA_NAME
)
7305 /* Get the value-range of the inner operand. */
7306 innervr
= get_value_range (innerop
);
7307 if (innervr
->type
!= VR_RANGE
7308 || TREE_CODE (innervr
->min
) != INTEGER_CST
7309 || TREE_CODE (innervr
->max
) != INTEGER_CST
)
7312 /* Simulate the conversion chain to check if the result is equal if
7313 the middle conversion is removed. */
7314 innermin
= tree_to_double_int (innervr
->min
);
7315 innermax
= tree_to_double_int (innervr
->max
);
7316 middlemin
= double_int_ext (innermin
, TYPE_PRECISION (TREE_TYPE (middleop
)),
7317 TYPE_UNSIGNED (TREE_TYPE (middleop
)));
7318 middlemax
= double_int_ext (innermax
, TYPE_PRECISION (TREE_TYPE (middleop
)),
7319 TYPE_UNSIGNED (TREE_TYPE (middleop
)));
7320 /* If the middle values do not represent a proper range fail. */
7321 if (double_int_cmp (middlemin
, middlemax
,
7322 TYPE_UNSIGNED (TREE_TYPE (middleop
))) > 0)
7324 if (!double_int_equal_p (double_int_ext (middlemin
,
7325 TYPE_PRECISION (finaltype
),
7326 TYPE_UNSIGNED (finaltype
)),
7327 double_int_ext (innermin
,
7328 TYPE_PRECISION (finaltype
),
7329 TYPE_UNSIGNED (finaltype
)))
7330 || !double_int_equal_p (double_int_ext (middlemax
,
7331 TYPE_PRECISION (finaltype
),
7332 TYPE_UNSIGNED (finaltype
)),
7333 double_int_ext (innermax
,
7334 TYPE_PRECISION (finaltype
),
7335 TYPE_UNSIGNED (finaltype
))))
7338 gimple_assign_set_rhs1 (stmt
, innerop
);
7343 /* Return whether the value range *VR fits in an integer type specified
7344 by PRECISION and UNSIGNED_P. */
7347 range_fits_type_p (value_range_t
*vr
, unsigned precision
, bool unsigned_p
)
7350 unsigned src_precision
;
7353 /* We can only handle integral and pointer types. */
7354 src_type
= TREE_TYPE (vr
->min
);
7355 if (!INTEGRAL_TYPE_P (src_type
)
7356 && !POINTER_TYPE_P (src_type
))
7359 /* An extension is always fine, so is an identity transform. */
7360 src_precision
= TYPE_PRECISION (TREE_TYPE (vr
->min
));
7361 if (src_precision
< precision
7362 || (src_precision
== precision
7363 && TYPE_UNSIGNED (src_type
) == unsigned_p
))
7366 /* Now we can only handle ranges with constant bounds. */
7367 if (vr
->type
!= VR_RANGE
7368 || TREE_CODE (vr
->min
) != INTEGER_CST
7369 || TREE_CODE (vr
->max
) != INTEGER_CST
)
7372 /* For precision-preserving sign-changes the MSB of the double-int
7374 if (src_precision
== precision
7375 && (TREE_INT_CST_HIGH (vr
->min
) | TREE_INT_CST_HIGH (vr
->max
)) < 0)
7378 /* Then we can perform the conversion on both ends and compare
7379 the result for equality. */
7380 tem
= double_int_ext (tree_to_double_int (vr
->min
), precision
, unsigned_p
);
7381 if (!double_int_equal_p (tree_to_double_int (vr
->min
), tem
))
7383 tem
= double_int_ext (tree_to_double_int (vr
->max
), precision
, unsigned_p
);
7384 if (!double_int_equal_p (tree_to_double_int (vr
->max
), tem
))
7390 /* Simplify a conversion from integral SSA name to float in STMT. */
7393 simplify_float_conversion_using_ranges (gimple_stmt_iterator
*gsi
, gimple stmt
)
7395 tree rhs1
= gimple_assign_rhs1 (stmt
);
7396 value_range_t
*vr
= get_value_range (rhs1
);
7397 enum machine_mode fltmode
= TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt
)));
7398 enum machine_mode mode
;
7402 /* We can only handle constant ranges. */
7403 if (vr
->type
!= VR_RANGE
7404 || TREE_CODE (vr
->min
) != INTEGER_CST
7405 || TREE_CODE (vr
->max
) != INTEGER_CST
)
7408 /* First check if we can use a signed type in place of an unsigned. */
7409 if (TYPE_UNSIGNED (TREE_TYPE (rhs1
))
7410 && (can_float_p (fltmode
, TYPE_MODE (TREE_TYPE (rhs1
)), 0)
7411 != CODE_FOR_nothing
)
7412 && range_fits_type_p (vr
, GET_MODE_PRECISION
7413 (TYPE_MODE (TREE_TYPE (rhs1
))), 0))
7414 mode
= TYPE_MODE (TREE_TYPE (rhs1
));
7415 /* If we can do the conversion in the current input mode do nothing. */
7416 else if (can_float_p (fltmode
, TYPE_MODE (TREE_TYPE (rhs1
)),
7417 TYPE_UNSIGNED (TREE_TYPE (rhs1
))))
7419 /* Otherwise search for a mode we can use, starting from the narrowest
7420 integer mode available. */
7423 mode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
7426 /* If we cannot do a signed conversion to float from mode
7427 or if the value-range does not fit in the signed type
7428 try with a wider mode. */
7429 if (can_float_p (fltmode
, mode
, 0) != CODE_FOR_nothing
7430 && range_fits_type_p (vr
, GET_MODE_PRECISION (mode
), 0))
7433 mode
= GET_MODE_WIDER_MODE (mode
);
7434 /* But do not widen the input. Instead leave that to the
7435 optabs expansion code. */
7436 if (GET_MODE_PRECISION (mode
) > TYPE_PRECISION (TREE_TYPE (rhs1
)))
7439 while (mode
!= VOIDmode
);
7440 if (mode
== VOIDmode
)
7444 /* It works, insert a truncation or sign-change before the
7445 float conversion. */
7446 tem
= create_tmp_var (build_nonstandard_integer_type
7447 (GET_MODE_PRECISION (mode
), 0), NULL
);
7448 conv
= gimple_build_assign_with_ops (NOP_EXPR
, tem
, rhs1
, NULL_TREE
);
7449 tem
= make_ssa_name (tem
, conv
);
7450 gimple_assign_set_lhs (conv
, tem
);
7451 gsi_insert_before (gsi
, conv
, GSI_SAME_STMT
);
7452 gimple_assign_set_rhs1 (stmt
, tem
);
7458 /* Simplify STMT using ranges if possible. */
7461 simplify_stmt_using_ranges (gimple_stmt_iterator
*gsi
)
7463 gimple stmt
= gsi_stmt (*gsi
);
7464 if (is_gimple_assign (stmt
))
7466 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
7467 tree rhs1
= gimple_assign_rhs1 (stmt
);
7473 /* Transform EQ_EXPR, NE_EXPR into BIT_XOR_EXPR or identity
7474 if the RHS is zero or one, and the LHS are known to be boolean
7476 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
7477 return simplify_truth_ops_using_ranges (gsi
, stmt
);
7480 /* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
7481 and BIT_AND_EXPR respectively if the first operand is greater
7482 than zero and the second operand is an exact power of two. */
7483 case TRUNC_DIV_EXPR
:
7484 case TRUNC_MOD_EXPR
:
7485 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
7486 && integer_pow2p (gimple_assign_rhs2 (stmt
)))
7487 return simplify_div_or_mod_using_ranges (stmt
);
7490 /* Transform ABS (X) into X or -X as appropriate. */
7492 if (TREE_CODE (rhs1
) == SSA_NAME
7493 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
7494 return simplify_abs_using_ranges (stmt
);
7499 /* Optimize away BIT_AND_EXPR and BIT_IOR_EXPR
7500 if all the bits being cleared are already cleared or
7501 all the bits being set are already set. */
7502 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
7503 return simplify_bit_ops_using_ranges (gsi
, stmt
);
7507 if (TREE_CODE (rhs1
) == SSA_NAME
7508 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
7509 return simplify_conversion_using_ranges (stmt
);
7513 if (TREE_CODE (rhs1
) == SSA_NAME
7514 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
7515 return simplify_float_conversion_using_ranges (gsi
, stmt
);
7522 else if (gimple_code (stmt
) == GIMPLE_COND
)
7523 return simplify_cond_using_ranges (stmt
);
7524 else if (gimple_code (stmt
) == GIMPLE_SWITCH
)
7525 return simplify_switch_using_ranges (stmt
);
7530 /* If the statement pointed by SI has a predicate whose value can be
7531 computed using the value range information computed by VRP, compute
7532 its value and return true. Otherwise, return false. */
7535 fold_predicate_in (gimple_stmt_iterator
*si
)
7537 bool assignment_p
= false;
7539 gimple stmt
= gsi_stmt (*si
);
7541 if (is_gimple_assign (stmt
)
7542 && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt
)) == tcc_comparison
)
7544 assignment_p
= true;
7545 val
= vrp_evaluate_conditional (gimple_assign_rhs_code (stmt
),
7546 gimple_assign_rhs1 (stmt
),
7547 gimple_assign_rhs2 (stmt
),
7550 else if (gimple_code (stmt
) == GIMPLE_COND
)
7551 val
= vrp_evaluate_conditional (gimple_cond_code (stmt
),
7552 gimple_cond_lhs (stmt
),
7553 gimple_cond_rhs (stmt
),
7561 val
= fold_convert (gimple_expr_type (stmt
), val
);
7565 fprintf (dump_file
, "Folding predicate ");
7566 print_gimple_expr (dump_file
, stmt
, 0, 0);
7567 fprintf (dump_file
, " to ");
7568 print_generic_expr (dump_file
, val
, 0);
7569 fprintf (dump_file
, "\n");
7572 if (is_gimple_assign (stmt
))
7573 gimple_assign_set_rhs_from_tree (si
, val
);
7576 gcc_assert (gimple_code (stmt
) == GIMPLE_COND
);
7577 if (integer_zerop (val
))
7578 gimple_cond_make_false (stmt
);
7579 else if (integer_onep (val
))
7580 gimple_cond_make_true (stmt
);
7591 /* Callback for substitute_and_fold folding the stmt at *SI. */
7594 vrp_fold_stmt (gimple_stmt_iterator
*si
)
7596 if (fold_predicate_in (si
))
7599 return simplify_stmt_using_ranges (si
);
7602 /* Stack of dest,src equivalency pairs that need to be restored after
7603 each attempt to thread a block's incoming edge to an outgoing edge.
7605 A NULL entry is used to mark the end of pairs which need to be
7607 static VEC(tree
,heap
) *stack
;
7609 /* A trivial wrapper so that we can present the generic jump threading
7610 code with a simple API for simplifying statements. STMT is the
7611 statement we want to simplify, WITHIN_STMT provides the location
7612 for any overflow warnings. */
7615 simplify_stmt_for_jump_threading (gimple stmt
, gimple within_stmt
)
7617 /* We only use VRP information to simplify conditionals. This is
7618 overly conservative, but it's unclear if doing more would be
7619 worth the compile time cost. */
7620 if (gimple_code (stmt
) != GIMPLE_COND
)
7623 return vrp_evaluate_conditional (gimple_cond_code (stmt
),
7624 gimple_cond_lhs (stmt
),
7625 gimple_cond_rhs (stmt
), within_stmt
);
7628 /* Blocks which have more than one predecessor and more than
7629 one successor present jump threading opportunities, i.e.,
7630 when the block is reached from a specific predecessor, we
7631 may be able to determine which of the outgoing edges will
7632 be traversed. When this optimization applies, we are able
7633 to avoid conditionals at runtime and we may expose secondary
7634 optimization opportunities.
7636 This routine is effectively a driver for the generic jump
7637 threading code. It basically just presents the generic code
7638 with edges that may be suitable for jump threading.
7640 Unlike DOM, we do not iterate VRP if jump threading was successful.
7641 While iterating may expose new opportunities for VRP, it is expected
7642 those opportunities would be very limited and the compile time cost
7643 to expose those opportunities would be significant.
7645 As jump threading opportunities are discovered, they are registered
7646 for later realization. */
7649 identify_jump_threads (void)
7656 /* Ugh. When substituting values earlier in this pass we can
7657 wipe the dominance information. So rebuild the dominator
7658 information as we need it within the jump threading code. */
7659 calculate_dominance_info (CDI_DOMINATORS
);
7661 /* We do not allow VRP information to be used for jump threading
7662 across a back edge in the CFG. Otherwise it becomes too
7663 difficult to avoid eliminating loop exit tests. Of course
7664 EDGE_DFS_BACK is not accurate at this time so we have to
7666 mark_dfs_back_edges ();
7668 /* Do not thread across edges we are about to remove. Just marking
7669 them as EDGE_DFS_BACK will do. */
7670 FOR_EACH_VEC_ELT (edge
, to_remove_edges
, i
, e
)
7671 e
->flags
|= EDGE_DFS_BACK
;
7673 /* Allocate our unwinder stack to unwind any temporary equivalences
7674 that might be recorded. */
7675 stack
= VEC_alloc (tree
, heap
, 20);
7677 /* To avoid lots of silly node creation, we create a single
7678 conditional and just modify it in-place when attempting to
7680 dummy
= gimple_build_cond (EQ_EXPR
,
7681 integer_zero_node
, integer_zero_node
,
7684 /* Walk through all the blocks finding those which present a
7685 potential jump threading opportunity. We could set this up
7686 as a dominator walker and record data during the walk, but
7687 I doubt it's worth the effort for the classes of jump
7688 threading opportunities we are trying to identify at this
7689 point in compilation. */
7694 /* If the generic jump threading code does not find this block
7695 interesting, then there is nothing to do. */
7696 if (! potentially_threadable_block (bb
))
7699 /* We only care about blocks ending in a COND_EXPR. While there
7700 may be some value in handling SWITCH_EXPR here, I doubt it's
7701 terribly important. */
7702 last
= gsi_stmt (gsi_last_bb (bb
));
7704 /* We're basically looking for a switch or any kind of conditional with
7705 integral or pointer type arguments. Note the type of the second
7706 argument will be the same as the first argument, so no need to
7707 check it explicitly. */
7708 if (gimple_code (last
) == GIMPLE_SWITCH
7709 || (gimple_code (last
) == GIMPLE_COND
7710 && TREE_CODE (gimple_cond_lhs (last
)) == SSA_NAME
7711 && (INTEGRAL_TYPE_P (TREE_TYPE (gimple_cond_lhs (last
)))
7712 || POINTER_TYPE_P (TREE_TYPE (gimple_cond_lhs (last
))))
7713 && (TREE_CODE (gimple_cond_rhs (last
)) == SSA_NAME
7714 || is_gimple_min_invariant (gimple_cond_rhs (last
)))))
7718 /* We've got a block with multiple predecessors and multiple
7719 successors which also ends in a suitable conditional or
7720 switch statement. For each predecessor, see if we can thread
7721 it to a specific successor. */
7722 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
7724 /* Do not thread across back edges or abnormal edges
7726 if (e
->flags
& (EDGE_DFS_BACK
| EDGE_COMPLEX
))
7729 thread_across_edge (dummy
, e
, true, &stack
,
7730 simplify_stmt_for_jump_threading
);
7735 /* We do not actually update the CFG or SSA graphs at this point as
7736 ASSERT_EXPRs are still in the IL and cfg cleanup code does not yet
7737 handle ASSERT_EXPRs gracefully. */
7740 /* We identified all the jump threading opportunities earlier, but could
7741 not transform the CFG at that time. This routine transforms the
7742 CFG and arranges for the dominator tree to be rebuilt if necessary.
7744 Note the SSA graph update will occur during the normal TODO
7745 processing by the pass manager. */
7747 finalize_jump_threads (void)
7749 thread_through_all_blocks (false);
7750 VEC_free (tree
, heap
, stack
);
7754 /* Traverse all the blocks folding conditionals with known ranges. */
7761 values_propagated
= true;
7765 fprintf (dump_file
, "\nValue ranges after VRP:\n\n");
7766 dump_all_value_ranges (dump_file
);
7767 fprintf (dump_file
, "\n");
7770 substitute_and_fold (op_with_constant_singleton_value_range
,
7771 vrp_fold_stmt
, false);
7773 if (warn_array_bounds
)
7774 check_all_array_refs ();
7776 /* We must identify jump threading opportunities before we release
7777 the datastructures built by VRP. */
7778 identify_jump_threads ();
7780 /* Free allocated memory. */
7781 for (i
= 0; i
< num_vr_values
; i
++)
7784 BITMAP_FREE (vr_value
[i
]->equiv
);
7789 free (vr_phi_edge_counts
);
7791 /* So that we can distinguish between VRP data being available
7792 and not available. */
7794 vr_phi_edge_counts
= NULL
;
7798 /* Main entry point to VRP (Value Range Propagation). This pass is
7799 loosely based on J. R. C. Patterson, ``Accurate Static Branch
7800 Prediction by Value Range Propagation,'' in SIGPLAN Conference on
7801 Programming Language Design and Implementation, pp. 67-78, 1995.
7802 Also available at http://citeseer.ist.psu.edu/patterson95accurate.html
7804 This is essentially an SSA-CCP pass modified to deal with ranges
7805 instead of constants.
7807 While propagating ranges, we may find that two or more SSA name
7808 have equivalent, though distinct ranges. For instance,
7811 2 p_4 = ASSERT_EXPR <p_3, p_3 != 0>
7813 4 p_5 = ASSERT_EXPR <p_4, p_4 == q_2>;
7817 In the code above, pointer p_5 has range [q_2, q_2], but from the
7818 code we can also determine that p_5 cannot be NULL and, if q_2 had
7819 a non-varying range, p_5's range should also be compatible with it.
7821 These equivalences are created by two expressions: ASSERT_EXPR and
7822 copy operations. Since p_5 is an assertion on p_4, and p_4 was the
7823 result of another assertion, then we can use the fact that p_5 and
7824 p_4 are equivalent when evaluating p_5's range.
7826 Together with value ranges, we also propagate these equivalences
7827 between names so that we can take advantage of information from
7828 multiple ranges when doing final replacement. Note that this
7829 equivalency relation is transitive but not symmetric.
7831 In the example above, p_5 is equivalent to p_4, q_2 and p_3, but we
7832 cannot assert that q_2 is equivalent to p_5 because q_2 may be used
7833 in contexts where that assertion does not hold (e.g., in line 6).
7835 TODO, the main difference between this pass and Patterson's is that
7836 we do not propagate edge probabilities. We only compute whether
7837 edges can be taken or not. That is, instead of having a spectrum
7838 of jump probabilities between 0 and 1, we only deal with 0, 1 and
7839 DON'T KNOW. In the future, it may be worthwhile to propagate
7840 probabilities to aid branch prediction. */
7849 loop_optimizer_init (LOOPS_NORMAL
| LOOPS_HAVE_RECORDED_EXITS
);
7850 rewrite_into_loop_closed_ssa (NULL
, TODO_update_ssa
);
7853 insert_range_assertions ();
7855 /* Estimate number of iterations - but do not use undefined behavior
7856 for this. We can't do this lazily as other functions may compute
7857 this using undefined behavior. */
7858 free_numbers_of_iterations_estimates ();
7859 estimate_numbers_of_iterations (false);
7861 to_remove_edges
= VEC_alloc (edge
, heap
, 10);
7862 to_update_switch_stmts
= VEC_alloc (switch_update
, heap
, 5);
7863 threadedge_initialize_values ();
7866 ssa_propagate (vrp_visit_stmt
, vrp_visit_phi_node
);
7869 free_numbers_of_iterations_estimates ();
7871 /* ASSERT_EXPRs must be removed before finalizing jump threads
7872 as finalizing jump threads calls the CFG cleanup code which
7873 does not properly handle ASSERT_EXPRs. */
7874 remove_range_assertions ();
7876 /* If we exposed any new variables, go ahead and put them into
7877 SSA form now, before we handle jump threading. This simplifies
7878 interactions between rewriting of _DECL nodes into SSA form
7879 and rewriting SSA_NAME nodes into SSA form after block
7880 duplication and CFG manipulation. */
7881 update_ssa (TODO_update_ssa
);
7883 finalize_jump_threads ();
7885 /* Remove dead edges from SWITCH_EXPR optimization. This leaves the
7886 CFG in a broken state and requires a cfg_cleanup run. */
7887 FOR_EACH_VEC_ELT (edge
, to_remove_edges
, i
, e
)
7889 /* Update SWITCH_EXPR case label vector. */
7890 FOR_EACH_VEC_ELT (switch_update
, to_update_switch_stmts
, i
, su
)
7893 size_t n
= TREE_VEC_LENGTH (su
->vec
);
7895 gimple_switch_set_num_labels (su
->stmt
, n
);
7896 for (j
= 0; j
< n
; j
++)
7897 gimple_switch_set_label (su
->stmt
, j
, TREE_VEC_ELT (su
->vec
, j
));
7898 /* As we may have replaced the default label with a regular one
7899 make sure to make it a real default label again. This ensures
7900 optimal expansion. */
7901 label
= gimple_switch_default_label (su
->stmt
);
7902 CASE_LOW (label
) = NULL_TREE
;
7903 CASE_HIGH (label
) = NULL_TREE
;
7906 if (VEC_length (edge
, to_remove_edges
) > 0)
7907 free_dominance_info (CDI_DOMINATORS
);
7909 VEC_free (edge
, heap
, to_remove_edges
);
7910 VEC_free (switch_update
, heap
, to_update_switch_stmts
);
7911 threadedge_finalize_values ();
7914 loop_optimizer_finalize ();
7921 return flag_tree_vrp
!= 0;
7924 struct gimple_opt_pass pass_vrp
=
7929 gate_vrp
, /* gate */
7930 execute_vrp
, /* execute */
7933 0, /* static_pass_number */
7934 TV_TREE_VRP
, /* tv_id */
7935 PROP_ssa
, /* properties_required */
7936 0, /* properties_provided */
7937 0, /* properties_destroyed */
7938 0, /* todo_flags_start */
7943 | TODO_ggc_collect
/* todo_flags_finish */