1 /* Support routines for Value Range Propagation (VRP).
2 Copyright (C) 2005-2019 Free Software Foundation, Inc.
3 Contributed by Diego Novillo <dnovillo@redhat.com>.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
25 #include "insn-codes.h"
30 #include "tree-pass.h"
32 #include "optabs-tree.h"
33 #include "gimple-pretty-print.h"
34 #include "diagnostic-core.h"
36 #include "fold-const.h"
37 #include "stor-layout.h"
40 #include "gimple-fold.h"
42 #include "gimple-iterator.h"
43 #include "gimple-walk.h"
46 #include "tree-ssa-loop-manip.h"
47 #include "tree-ssa-loop-niter.h"
48 #include "tree-ssa-loop.h"
49 #include "tree-into-ssa.h"
53 #include "tree-scalar-evolution.h"
54 #include "tree-ssa-propagate.h"
55 #include "tree-chrec.h"
56 #include "tree-ssa-threadupdate.h"
57 #include "tree-ssa-scopedtables.h"
58 #include "tree-ssa-threadedge.h"
59 #include "omp-general.h"
61 #include "case-cfn-macros.h"
63 #include "alloc-pool.h"
65 #include "tree-cfgcleanup.h"
66 #include "stringpool.h"
68 #include "vr-values.h"
70 #include "wide-int-range.h"
72 /* Set of SSA names found live during the RPO traversal of the function
73 for still active basic-blocks. */
77 value_range_base::set (enum value_range_kind kind
, tree min
, tree max
)
87 value_range::set_equiv (bitmap equiv
)
89 /* Since updating the equivalence set involves deep copying the
90 bitmaps, only do it if absolutely necessary.
92 All equivalence bitmaps are allocated from the same obstack. So
93 we can use the obstack associated with EQUIV to allocate vr->equiv. */
96 m_equiv
= BITMAP_ALLOC (equiv
->obstack
);
100 if (equiv
&& !bitmap_empty_p (equiv
))
101 bitmap_copy (m_equiv
, equiv
);
103 bitmap_clear (m_equiv
);
107 /* Initialize value_range. */
110 value_range::set (enum value_range_kind kind
, tree min
, tree max
,
113 value_range_base::set (kind
, min
, max
);
119 value_range_base::value_range_base (value_range_kind kind
, tree min
, tree max
)
121 set (kind
, min
, max
);
124 value_range::value_range (value_range_kind kind
, tree min
, tree max
,
128 set (kind
, min
, max
, equiv
);
131 value_range::value_range (const value_range_base
&other
)
134 set (other
.kind (), other
.min(), other
.max (), NULL
);
137 /* Like set, but keep the equivalences in place. */
140 value_range::update (value_range_kind kind
, tree min
, tree max
)
143 (kind
!= VR_UNDEFINED
&& kind
!= VR_VARYING
) ? m_equiv
: NULL
);
146 /* Copy value_range in FROM into THIS while avoiding bitmap sharing.
148 Note: The code that avoids the bitmap sharing looks at the existing
149 this->m_equiv, so this function cannot be used to initalize an
150 object. Use the constructors for initialization. */
153 value_range::deep_copy (const value_range
*from
)
155 set (from
->m_kind
, from
->min (), from
->max (), from
->m_equiv
);
159 value_range::move (value_range
*from
)
161 set (from
->m_kind
, from
->min (), from
->max ());
162 m_equiv
= from
->m_equiv
;
163 from
->m_equiv
= NULL
;
166 /* Check the validity of the range. */
169 value_range_base::check ()
178 gcc_assert (m_min
&& m_max
);
180 gcc_assert (!TREE_OVERFLOW_P (m_min
) && !TREE_OVERFLOW_P (m_max
));
182 /* Creating ~[-MIN, +MAX] is stupid because that would be
184 if (INTEGRAL_TYPE_P (TREE_TYPE (m_min
)) && m_kind
== VR_ANTI_RANGE
)
185 gcc_assert (!vrp_val_is_min (m_min
) || !vrp_val_is_max (m_max
));
187 cmp
= compare_values (m_min
, m_max
);
188 gcc_assert (cmp
== 0 || cmp
== -1 || cmp
== -2);
193 gcc_assert (!min () && !max ());
201 value_range::check ()
203 value_range_base::check ();
208 gcc_assert (!m_equiv
|| bitmap_empty_p (m_equiv
));
213 /* Equality operator. We purposely do not overload ==, to avoid
214 confusion with the equality bitmap in the derived value_range
218 value_range_base::equal_p (const value_range_base
&other
) const
220 return (m_kind
== other
.m_kind
221 && vrp_operand_equal_p (m_min
, other
.m_min
)
222 && vrp_operand_equal_p (m_max
, other
.m_max
));
225 /* Returns TRUE if THIS == OTHER. Ignores the equivalence bitmap if
226 IGNORE_EQUIVS is TRUE. */
229 value_range::equal_p (const value_range
&other
, bool ignore_equivs
) const
231 return (value_range_base::equal_p (other
)
233 || vrp_bitmap_equal_p (m_equiv
, other
.m_equiv
)));
236 /* Return TRUE if this is a symbolic range. */
239 value_range_base::symbolic_p () const
241 return (!varying_p ()
243 && (!is_gimple_min_invariant (m_min
)
244 || !is_gimple_min_invariant (m_max
)));
247 /* NOTE: This is not the inverse of symbolic_p because the range
248 could also be varying or undefined. Ideally they should be inverse
249 of each other, with varying only applying to symbolics. Varying of
250 constants would be represented as [-MIN, +MAX]. */
253 value_range_base::constant_p () const
255 return (!varying_p ()
257 && TREE_CODE (m_min
) == INTEGER_CST
258 && TREE_CODE (m_max
) == INTEGER_CST
);
262 value_range_base::set_undefined ()
264 set (VR_UNDEFINED
, NULL
, NULL
);
268 value_range::set_undefined ()
270 set (VR_UNDEFINED
, NULL
, NULL
, NULL
);
274 value_range_base::set_varying ()
276 set (VR_VARYING
, NULL
, NULL
);
280 value_range::set_varying ()
282 set (VR_VARYING
, NULL
, NULL
, NULL
);
285 /* Return TRUE if it is possible that range contains VAL. */
288 value_range_base::may_contain_p (tree val
) const
296 if (m_kind
== VR_ANTI_RANGE
)
298 int res
= value_inside_range (val
, min (), max ());
299 return res
== 0 || res
== -2;
301 return value_inside_range (val
, min (), max ()) != 0;
305 value_range::equiv_clear ()
308 bitmap_clear (m_equiv
);
311 /* Add VAR and VAR's equivalence set (VAR_VR) to the equivalence
312 bitmap. If no equivalence table has been created, OBSTACK is the
313 obstack to use (NULL for the default obstack).
315 This is the central point where equivalence processing can be
319 value_range::equiv_add (const_tree var
,
320 const value_range
*var_vr
,
321 bitmap_obstack
*obstack
)
324 m_equiv
= BITMAP_ALLOC (obstack
);
325 unsigned ver
= SSA_NAME_VERSION (var
);
326 bitmap_set_bit (m_equiv
, ver
);
327 if (var_vr
&& var_vr
->m_equiv
)
328 bitmap_ior_into (m_equiv
, var_vr
->m_equiv
);
331 /* If range is a singleton, place it in RESULT and return TRUE.
332 Note: A singleton can be any gimple invariant, not just constants.
333 So, [&x, &x] counts as a singleton. */
336 value_range_base::singleton_p (tree
*result
) const
338 if (m_kind
== VR_RANGE
339 && vrp_operand_equal_p (min (), max ())
340 && is_gimple_min_invariant (min ()))
350 value_range_base::type () const
352 /* Types are only valid for VR_RANGE and VR_ANTI_RANGE, which are
353 known to have non-zero min/max. */
355 return TREE_TYPE (min ());
359 value_range_base::dump (FILE *file
) const
362 fprintf (file
, "UNDEFINED");
363 else if (m_kind
== VR_RANGE
|| m_kind
== VR_ANTI_RANGE
)
365 tree ttype
= type ();
367 print_generic_expr (file
, ttype
);
370 fprintf (file
, "%s[", (m_kind
== VR_ANTI_RANGE
) ? "~" : "");
372 if (INTEGRAL_TYPE_P (ttype
)
373 && !TYPE_UNSIGNED (ttype
)
374 && vrp_val_is_min (min ())
375 && TYPE_PRECISION (ttype
) != 1)
376 fprintf (file
, "-INF");
378 print_generic_expr (file
, min ());
380 fprintf (file
, ", ");
382 if (INTEGRAL_TYPE_P (ttype
)
383 && vrp_val_is_max (max ())
384 && TYPE_PRECISION (ttype
) != 1)
385 fprintf (file
, "+INF");
387 print_generic_expr (file
, max ());
391 else if (varying_p ())
392 fprintf (file
, "VARYING");
398 value_range::dump (FILE *file
) const
400 value_range_base::dump (file
);
401 if ((m_kind
== VR_RANGE
|| m_kind
== VR_ANTI_RANGE
)
407 fprintf (file
, " EQUIVALENCES: { ");
409 EXECUTE_IF_SET_IN_BITMAP (m_equiv
, 0, i
, bi
)
411 print_generic_expr (file
, ssa_name (i
));
416 fprintf (file
, "} (%u elements)", c
);
421 dump_value_range (FILE *file
, const value_range
*vr
)
424 fprintf (file
, "[]");
430 dump_value_range (FILE *file
, const value_range_base
*vr
)
433 fprintf (file
, "[]");
439 debug (const value_range_base
*vr
)
441 dump_value_range (stderr
, vr
);
445 debug (const value_range_base
&vr
)
447 dump_value_range (stderr
, &vr
);
451 debug (const value_range
*vr
)
453 dump_value_range (stderr
, vr
);
457 debug (const value_range
&vr
)
459 dump_value_range (stderr
, &vr
);
462 /* Return true if the SSA name NAME is live on the edge E. */
465 live_on_edge (edge e
, tree name
)
467 return (live
[e
->dest
->index
]
468 && bitmap_bit_p (live
[e
->dest
->index
], SSA_NAME_VERSION (name
)));
471 /* Location information for ASSERT_EXPRs. Each instance of this
472 structure describes an ASSERT_EXPR for an SSA name. Since a single
473 SSA name may have more than one assertion associated with it, these
474 locations are kept in a linked list attached to the corresponding
478 /* Basic block where the assertion would be inserted. */
481 /* Some assertions need to be inserted on an edge (e.g., assertions
482 generated by COND_EXPRs). In those cases, BB will be NULL. */
485 /* Pointer to the statement that generated this assertion. */
486 gimple_stmt_iterator si
;
488 /* Predicate code for the ASSERT_EXPR. Must be COMPARISON_CLASS_P. */
489 enum tree_code comp_code
;
491 /* Value being compared against. */
494 /* Expression to compare. */
497 /* Next node in the linked list. */
501 /* If bit I is present, it means that SSA name N_i has a list of
502 assertions that should be inserted in the IL. */
503 static bitmap need_assert_for
;
505 /* Array of locations lists where to insert assertions. ASSERTS_FOR[I]
506 holds a list of ASSERT_LOCUS_T nodes that describe where
507 ASSERT_EXPRs for SSA name N_I should be inserted. */
508 static assert_locus
**asserts_for
;
510 /* Return the maximum value for TYPE. */
513 vrp_val_max (const_tree type
)
515 if (!INTEGRAL_TYPE_P (type
))
518 return TYPE_MAX_VALUE (type
);
521 /* Return the minimum value for TYPE. */
524 vrp_val_min (const_tree type
)
526 if (!INTEGRAL_TYPE_P (type
))
529 return TYPE_MIN_VALUE (type
);
532 /* Return whether VAL is equal to the maximum value of its type.
533 We can't do a simple equality comparison with TYPE_MAX_VALUE because
534 C typedefs and Ada subtypes can produce types whose TYPE_MAX_VALUE
535 is not == to the integer constant with the same value in the type. */
538 vrp_val_is_max (const_tree val
)
540 tree type_max
= vrp_val_max (TREE_TYPE (val
));
541 return (val
== type_max
542 || (type_max
!= NULL_TREE
543 && operand_equal_p (val
, type_max
, 0)));
546 /* Return whether VAL is equal to the minimum value of its type. */
549 vrp_val_is_min (const_tree val
)
551 tree type_min
= vrp_val_min (TREE_TYPE (val
));
552 return (val
== type_min
553 || (type_min
!= NULL_TREE
554 && operand_equal_p (val
, type_min
, 0)));
557 /* VR_TYPE describes a range with mininum value *MIN and maximum
558 value *MAX. Restrict the range to the set of values that have
559 no bits set outside NONZERO_BITS. Update *MIN and *MAX and
560 return the new range type.
562 SGN gives the sign of the values described by the range. */
564 enum value_range_kind
565 intersect_range_with_nonzero_bits (enum value_range_kind vr_type
,
566 wide_int
*min
, wide_int
*max
,
567 const wide_int
&nonzero_bits
,
570 if (vr_type
== VR_ANTI_RANGE
)
572 /* The VR_ANTI_RANGE is equivalent to the union of the ranges
573 A: [-INF, *MIN) and B: (*MAX, +INF]. First use NONZERO_BITS
574 to create an inclusive upper bound for A and an inclusive lower
576 wide_int a_max
= wi::round_down_for_mask (*min
- 1, nonzero_bits
);
577 wide_int b_min
= wi::round_up_for_mask (*max
+ 1, nonzero_bits
);
579 /* If the calculation of A_MAX wrapped, A is effectively empty
580 and A_MAX is the highest value that satisfies NONZERO_BITS.
581 Likewise if the calculation of B_MIN wrapped, B is effectively
582 empty and B_MIN is the lowest value that satisfies NONZERO_BITS. */
583 bool a_empty
= wi::ge_p (a_max
, *min
, sgn
);
584 bool b_empty
= wi::le_p (b_min
, *max
, sgn
);
586 /* If both A and B are empty, there are no valid values. */
587 if (a_empty
&& b_empty
)
590 /* If exactly one of A or B is empty, return a VR_RANGE for the
592 if (a_empty
|| b_empty
)
596 gcc_checking_assert (wi::le_p (*min
, *max
, sgn
));
600 /* Update the VR_ANTI_RANGE bounds. */
603 gcc_checking_assert (wi::le_p (*min
, *max
, sgn
));
605 /* Now check whether the excluded range includes any values that
606 satisfy NONZERO_BITS. If not, switch to a full VR_RANGE. */
607 if (wi::round_up_for_mask (*min
, nonzero_bits
) == b_min
)
609 unsigned int precision
= min
->get_precision ();
610 *min
= wi::min_value (precision
, sgn
);
611 *max
= wi::max_value (precision
, sgn
);
615 if (vr_type
== VR_RANGE
)
617 *max
= wi::round_down_for_mask (*max
, nonzero_bits
);
619 /* Check that the range contains at least one valid value. */
620 if (wi::gt_p (*min
, *max
, sgn
))
623 *min
= wi::round_up_for_mask (*min
, nonzero_bits
);
624 gcc_checking_assert (wi::le_p (*min
, *max
, sgn
));
630 /* Set value range to the canonical form of {VRTYPE, MIN, MAX, EQUIV}.
631 This means adjusting VRTYPE, MIN and MAX representing the case of a
632 wrapping range with MAX < MIN covering [MIN, type_max] U [type_min, MAX]
633 as anti-rage ~[MAX+1, MIN-1]. Likewise for wrapping anti-ranges.
634 In corner cases where MAX+1 or MIN-1 wraps this will fall back
636 This routine exists to ease canonicalization in the case where we
637 extract ranges from var + CST op limit. */
640 value_range_base::set_and_canonicalize (enum value_range_kind kind
,
643 /* Use the canonical setters for VR_UNDEFINED and VR_VARYING. */
644 if (kind
== VR_UNDEFINED
)
649 else if (kind
== VR_VARYING
)
655 /* Nothing to canonicalize for symbolic ranges. */
656 if (TREE_CODE (min
) != INTEGER_CST
657 || TREE_CODE (max
) != INTEGER_CST
)
659 set (kind
, min
, max
);
663 /* Wrong order for min and max, to swap them and the VR type we need
665 if (tree_int_cst_lt (max
, min
))
669 /* For one bit precision if max < min, then the swapped
670 range covers all values, so for VR_RANGE it is varying and
671 for VR_ANTI_RANGE empty range, so drop to varying as well. */
672 if (TYPE_PRECISION (TREE_TYPE (min
)) == 1)
678 one
= build_int_cst (TREE_TYPE (min
), 1);
679 tmp
= int_const_binop (PLUS_EXPR
, max
, one
);
680 max
= int_const_binop (MINUS_EXPR
, min
, one
);
683 /* There's one corner case, if we had [C+1, C] before we now have
684 that again. But this represents an empty value range, so drop
685 to varying in this case. */
686 if (tree_int_cst_lt (max
, min
))
692 kind
= kind
== VR_RANGE
? VR_ANTI_RANGE
: VR_RANGE
;
695 /* Anti-ranges that can be represented as ranges should be so. */
696 if (kind
== VR_ANTI_RANGE
)
698 /* For -fstrict-enums we may receive out-of-range ranges so consider
699 values < -INF and values > INF as -INF/INF as well. */
700 tree type
= TREE_TYPE (min
);
701 bool is_min
= (INTEGRAL_TYPE_P (type
)
702 && tree_int_cst_compare (min
, TYPE_MIN_VALUE (type
)) <= 0);
703 bool is_max
= (INTEGRAL_TYPE_P (type
)
704 && tree_int_cst_compare (max
, TYPE_MAX_VALUE (type
)) >= 0);
706 if (is_min
&& is_max
)
708 /* We cannot deal with empty ranges, drop to varying.
709 ??? This could be VR_UNDEFINED instead. */
713 else if (TYPE_PRECISION (TREE_TYPE (min
)) == 1
714 && (is_min
|| is_max
))
716 /* Non-empty boolean ranges can always be represented
717 as a singleton range. */
719 min
= max
= vrp_val_max (TREE_TYPE (min
));
721 min
= max
= vrp_val_min (TREE_TYPE (min
));
725 /* As a special exception preserve non-null ranges. */
726 && !(TYPE_UNSIGNED (TREE_TYPE (min
))
727 && integer_zerop (max
)))
729 tree one
= build_int_cst (TREE_TYPE (max
), 1);
730 min
= int_const_binop (PLUS_EXPR
, max
, one
);
731 max
= vrp_val_max (TREE_TYPE (max
));
736 tree one
= build_int_cst (TREE_TYPE (min
), 1);
737 max
= int_const_binop (MINUS_EXPR
, min
, one
);
738 min
= vrp_val_min (TREE_TYPE (min
));
743 /* Do not drop [-INF(OVF), +INF(OVF)] to varying. (OVF) has to be sticky
744 to make sure VRP iteration terminates, otherwise we can get into
747 set (kind
, min
, max
);
751 value_range::set_and_canonicalize (enum value_range_kind kind
,
752 tree min
, tree max
, bitmap equiv
)
754 value_range_base::set_and_canonicalize (kind
, min
, max
);
755 if (this->kind () == VR_RANGE
|| this->kind () == VR_ANTI_RANGE
)
762 value_range_base::set (tree val
)
764 gcc_assert (TREE_CODE (val
) == SSA_NAME
|| is_gimple_min_invariant (val
));
765 if (TREE_OVERFLOW_P (val
))
766 val
= drop_tree_overflow (val
);
767 set (VR_RANGE
, val
, val
);
771 value_range::set (tree val
)
773 gcc_assert (TREE_CODE (val
) == SSA_NAME
|| is_gimple_min_invariant (val
));
774 if (TREE_OVERFLOW_P (val
))
775 val
= drop_tree_overflow (val
);
776 set (VR_RANGE
, val
, val
, NULL
);
779 /* Set value range VR to a non-NULL range of type TYPE. */
782 value_range_base::set_nonnull (tree type
)
784 tree zero
= build_int_cst (type
, 0);
785 set (VR_ANTI_RANGE
, zero
, zero
);
789 value_range::set_nonnull (tree type
)
791 tree zero
= build_int_cst (type
, 0);
792 set (VR_ANTI_RANGE
, zero
, zero
, NULL
);
795 /* Set value range VR to a NULL range of type TYPE. */
798 value_range_base::set_null (tree type
)
800 set (build_int_cst (type
, 0));
804 value_range::set_null (tree type
)
806 set (build_int_cst (type
, 0));
809 /* Return true, if VAL1 and VAL2 are equal values for VRP purposes. */
812 vrp_operand_equal_p (const_tree val1
, const_tree val2
)
816 if (!val1
|| !val2
|| !operand_equal_p (val1
, val2
, 0))
821 /* Return true, if the bitmaps B1 and B2 are equal. */
824 vrp_bitmap_equal_p (const_bitmap b1
, const_bitmap b2
)
827 || ((!b1
|| bitmap_empty_p (b1
))
828 && (!b2
|| bitmap_empty_p (b2
)))
830 && bitmap_equal_p (b1
, b2
)));
833 /* Return true if VR is [0, 0]. */
836 range_is_null (const value_range_base
*vr
)
838 return vr
->zero_p ();
842 range_is_nonnull (const value_range_base
*vr
)
844 return (vr
->kind () == VR_ANTI_RANGE
845 && vr
->min () == vr
->max ()
846 && integer_zerop (vr
->min ()));
849 /* Return true if max and min of VR are INTEGER_CST. It's not necessary
853 range_int_cst_p (const value_range_base
*vr
)
855 return (vr
->kind () == VR_RANGE
856 && TREE_CODE (vr
->min ()) == INTEGER_CST
857 && TREE_CODE (vr
->max ()) == INTEGER_CST
);
860 /* Return true if VR is a INTEGER_CST singleton. */
863 range_int_cst_singleton_p (const value_range_base
*vr
)
865 return (range_int_cst_p (vr
)
866 && tree_int_cst_equal (vr
->min (), vr
->max ()));
869 /* Return the single symbol (an SSA_NAME) contained in T if any, or NULL_TREE
870 otherwise. We only handle additive operations and set NEG to true if the
871 symbol is negated and INV to the invariant part, if any. */
874 get_single_symbol (tree t
, bool *neg
, tree
*inv
)
882 if (TREE_CODE (t
) == PLUS_EXPR
883 || TREE_CODE (t
) == POINTER_PLUS_EXPR
884 || TREE_CODE (t
) == MINUS_EXPR
)
886 if (is_gimple_min_invariant (TREE_OPERAND (t
, 0)))
888 neg_
= (TREE_CODE (t
) == MINUS_EXPR
);
889 inv_
= TREE_OPERAND (t
, 0);
890 t
= TREE_OPERAND (t
, 1);
892 else if (is_gimple_min_invariant (TREE_OPERAND (t
, 1)))
895 inv_
= TREE_OPERAND (t
, 1);
896 t
= TREE_OPERAND (t
, 0);
907 if (TREE_CODE (t
) == NEGATE_EXPR
)
909 t
= TREE_OPERAND (t
, 0);
913 if (TREE_CODE (t
) != SSA_NAME
)
916 if (inv_
&& TREE_OVERFLOW_P (inv_
))
917 inv_
= drop_tree_overflow (inv_
);
924 /* The reverse operation: build a symbolic expression with TYPE
925 from symbol SYM, negated according to NEG, and invariant INV. */
928 build_symbolic_expr (tree type
, tree sym
, bool neg
, tree inv
)
930 const bool pointer_p
= POINTER_TYPE_P (type
);
934 t
= build1 (NEGATE_EXPR
, type
, t
);
936 if (integer_zerop (inv
))
939 return build2 (pointer_p
? POINTER_PLUS_EXPR
: PLUS_EXPR
, type
, t
, inv
);
945 -2 if those are incomparable. */
947 operand_less_p (tree val
, tree val2
)
949 /* LT is folded faster than GE and others. Inline the common case. */
950 if (TREE_CODE (val
) == INTEGER_CST
&& TREE_CODE (val2
) == INTEGER_CST
)
951 return tree_int_cst_lt (val
, val2
);
956 fold_defer_overflow_warnings ();
958 tcmp
= fold_binary_to_constant (LT_EXPR
, boolean_type_node
, val
, val2
);
960 fold_undefer_and_ignore_overflow_warnings ();
963 || TREE_CODE (tcmp
) != INTEGER_CST
)
966 if (!integer_zerop (tcmp
))
973 /* Compare two values VAL1 and VAL2. Return
975 -2 if VAL1 and VAL2 cannot be compared at compile-time,
978 +1 if VAL1 > VAL2, and
981 This is similar to tree_int_cst_compare but supports pointer values
982 and values that cannot be compared at compile time.
984 If STRICT_OVERFLOW_P is not NULL, then set *STRICT_OVERFLOW_P to
985 true if the return value is only valid if we assume that signed
986 overflow is undefined. */
989 compare_values_warnv (tree val1
, tree val2
, bool *strict_overflow_p
)
994 /* Below we rely on the fact that VAL1 and VAL2 are both pointers or
996 gcc_assert (POINTER_TYPE_P (TREE_TYPE (val1
))
997 == POINTER_TYPE_P (TREE_TYPE (val2
)));
999 /* Convert the two values into the same type. This is needed because
1000 sizetype causes sign extension even for unsigned types. */
1001 val2
= fold_convert (TREE_TYPE (val1
), val2
);
1002 STRIP_USELESS_TYPE_CONVERSION (val2
);
1004 const bool overflow_undefined
1005 = INTEGRAL_TYPE_P (TREE_TYPE (val1
))
1006 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1
));
1009 tree sym1
= get_single_symbol (val1
, &neg1
, &inv1
);
1010 tree sym2
= get_single_symbol (val2
, &neg2
, &inv2
);
1012 /* If VAL1 and VAL2 are of the form '[-]NAME [+ CST]', return -1 or +1
1013 accordingly. If VAL1 and VAL2 don't use the same name, return -2. */
1016 /* Both values must use the same name with the same sign. */
1017 if (sym1
!= sym2
|| neg1
!= neg2
)
1020 /* [-]NAME + CST == [-]NAME + CST. */
1024 /* If overflow is defined we cannot simplify more. */
1025 if (!overflow_undefined
)
1028 if (strict_overflow_p
!= NULL
1029 /* Symbolic range building sets TREE_NO_WARNING to declare
1030 that overflow doesn't happen. */
1031 && (!inv1
|| !TREE_NO_WARNING (val1
))
1032 && (!inv2
|| !TREE_NO_WARNING (val2
)))
1033 *strict_overflow_p
= true;
1036 inv1
= build_int_cst (TREE_TYPE (val1
), 0);
1038 inv2
= build_int_cst (TREE_TYPE (val2
), 0);
1040 return wi::cmp (wi::to_wide (inv1
), wi::to_wide (inv2
),
1041 TYPE_SIGN (TREE_TYPE (val1
)));
1044 const bool cst1
= is_gimple_min_invariant (val1
);
1045 const bool cst2
= is_gimple_min_invariant (val2
);
1047 /* If one is of the form '[-]NAME + CST' and the other is constant, then
1048 it might be possible to say something depending on the constants. */
1049 if ((sym1
&& inv1
&& cst2
) || (sym2
&& inv2
&& cst1
))
1051 if (!overflow_undefined
)
1054 if (strict_overflow_p
!= NULL
1055 /* Symbolic range building sets TREE_NO_WARNING to declare
1056 that overflow doesn't happen. */
1057 && (!sym1
|| !TREE_NO_WARNING (val1
))
1058 && (!sym2
|| !TREE_NO_WARNING (val2
)))
1059 *strict_overflow_p
= true;
1061 const signop sgn
= TYPE_SIGN (TREE_TYPE (val1
));
1062 tree cst
= cst1
? val1
: val2
;
1063 tree inv
= cst1
? inv2
: inv1
;
1065 /* Compute the difference between the constants. If it overflows or
1066 underflows, this means that we can trivially compare the NAME with
1067 it and, consequently, the two values with each other. */
1068 wide_int diff
= wi::to_wide (cst
) - wi::to_wide (inv
);
1069 if (wi::cmp (0, wi::to_wide (inv
), sgn
)
1070 != wi::cmp (diff
, wi::to_wide (cst
), sgn
))
1072 const int res
= wi::cmp (wi::to_wide (cst
), wi::to_wide (inv
), sgn
);
1073 return cst1
? res
: -res
;
1079 /* We cannot say anything more for non-constants. */
1083 if (!POINTER_TYPE_P (TREE_TYPE (val1
)))
1085 /* We cannot compare overflowed values. */
1086 if (TREE_OVERFLOW (val1
) || TREE_OVERFLOW (val2
))
1089 if (TREE_CODE (val1
) == INTEGER_CST
1090 && TREE_CODE (val2
) == INTEGER_CST
)
1091 return tree_int_cst_compare (val1
, val2
);
1093 if (poly_int_tree_p (val1
) && poly_int_tree_p (val2
))
1095 if (known_eq (wi::to_poly_widest (val1
),
1096 wi::to_poly_widest (val2
)))
1098 if (known_lt (wi::to_poly_widest (val1
),
1099 wi::to_poly_widest (val2
)))
1101 if (known_gt (wi::to_poly_widest (val1
),
1102 wi::to_poly_widest (val2
)))
1112 /* First see if VAL1 and VAL2 are not the same. */
1113 if (val1
== val2
|| operand_equal_p (val1
, val2
, 0))
1116 /* If VAL1 is a lower address than VAL2, return -1. */
1117 if (operand_less_p (val1
, val2
) == 1)
1120 /* If VAL1 is a higher address than VAL2, return +1. */
1121 if (operand_less_p (val2
, val1
) == 1)
1124 /* If VAL1 is different than VAL2, return +2.
1125 For integer constants we either have already returned -1 or 1
1126 or they are equivalent. We still might succeed in proving
1127 something about non-trivial operands. */
1128 if (TREE_CODE (val1
) != INTEGER_CST
1129 || TREE_CODE (val2
) != INTEGER_CST
)
1131 t
= fold_binary_to_constant (NE_EXPR
, boolean_type_node
, val1
, val2
);
1132 if (t
&& integer_onep (t
))
1140 /* Compare values like compare_values_warnv. */
1143 compare_values (tree val1
, tree val2
)
1146 return compare_values_warnv (val1
, val2
, &sop
);
1150 /* Return 1 if VAL is inside value range MIN <= VAL <= MAX,
1151 0 if VAL is not inside [MIN, MAX],
1152 -2 if we cannot tell either way.
1154 Benchmark compile/20001226-1.c compilation time after changing this
1158 value_inside_range (tree val
, tree min
, tree max
)
1162 cmp1
= operand_less_p (val
, min
);
1168 cmp2
= operand_less_p (max
, val
);
1176 /* Return TRUE if *VR includes the value X. */
1179 range_includes_p (const value_range_base
*vr
, HOST_WIDE_INT x
)
1181 if (vr
->varying_p () || vr
->undefined_p ())
1183 return vr
->may_contain_p (build_int_cst (vr
->type (), x
));
1186 /* If *VR has a value range that is a single constant value return that,
1187 otherwise return NULL_TREE.
1189 ?? This actually returns TRUE for [&x, &x], so perhaps "constant"
1190 is not the best name. */
1193 value_range_constant_singleton (const value_range_base
*vr
)
1196 if (vr
->singleton_p (&result
))
1201 /* Value range wrapper for wide_int_range_set_zero_nonzero_bits.
1203 Compute MAY_BE_NONZERO and MUST_BE_NONZERO bit masks for range in VR.
1205 Return TRUE if VR was a constant range and we were able to compute
1209 vrp_set_zero_nonzero_bits (const tree expr_type
,
1210 const value_range_base
*vr
,
1211 wide_int
*may_be_nonzero
,
1212 wide_int
*must_be_nonzero
)
1214 if (!range_int_cst_p (vr
))
1216 *may_be_nonzero
= wi::minus_one (TYPE_PRECISION (expr_type
));
1217 *must_be_nonzero
= wi::zero (TYPE_PRECISION (expr_type
));
1220 wide_int_range_set_zero_nonzero_bits (TYPE_SIGN (expr_type
),
1221 wi::to_wide (vr
->min ()),
1222 wi::to_wide (vr
->max ()),
1223 *may_be_nonzero
, *must_be_nonzero
);
1227 /* Create two value-ranges in *VR0 and *VR1 from the anti-range *AR
1228 so that *VR0 U *VR1 == *AR. Returns true if that is possible,
1229 false otherwise. If *AR can be represented with a single range
1230 *VR1 will be VR_UNDEFINED. */
1233 ranges_from_anti_range (const value_range_base
*ar
,
1234 value_range_base
*vr0
, value_range_base
*vr1
)
1236 tree type
= ar
->type ();
1238 vr0
->set_undefined ();
1239 vr1
->set_undefined ();
1241 /* As a future improvement, we could handle ~[0, A] as: [-INF, -1] U
1242 [A+1, +INF]. Not sure if this helps in practice, though. */
1244 if (ar
->kind () != VR_ANTI_RANGE
1245 || TREE_CODE (ar
->min ()) != INTEGER_CST
1246 || TREE_CODE (ar
->max ()) != INTEGER_CST
1247 || !vrp_val_min (type
)
1248 || !vrp_val_max (type
))
1251 if (tree_int_cst_lt (vrp_val_min (type
), ar
->min ()))
1254 wide_int_to_tree (type
, wi::to_wide (ar
->min ()) - 1));
1255 if (tree_int_cst_lt (ar
->max (), vrp_val_max (type
)))
1257 wide_int_to_tree (type
, wi::to_wide (ar
->max ()) + 1),
1258 vrp_val_max (type
));
1259 if (vr0
->undefined_p ())
1262 vr1
->set_undefined ();
1265 return !vr0
->undefined_p ();
1268 /* Extract the components of a value range into a pair of wide ints in
1271 If the value range is anything but a VR_*RANGE of constants, the
1272 resulting wide ints are set to [-MIN, +MAX] for the type. */
1275 extract_range_into_wide_ints (const value_range_base
*vr
,
1276 signop sign
, unsigned prec
,
1277 wide_int
&wmin
, wide_int
&wmax
)
1279 gcc_assert (vr
->kind () != VR_ANTI_RANGE
|| vr
->symbolic_p ());
1280 if (range_int_cst_p (vr
))
1282 wmin
= wi::to_wide (vr
->min ());
1283 wmax
= wi::to_wide (vr
->max ());
1287 wmin
= wi::min_value (prec
, sign
);
1288 wmax
= wi::max_value (prec
, sign
);
1292 /* Value range wrapper for wide_int_range_multiplicative_op:
1294 *VR = *VR0 .CODE. *VR1. */
1297 extract_range_from_multiplicative_op (value_range_base
*vr
,
1298 enum tree_code code
,
1299 const value_range_base
*vr0
,
1300 const value_range_base
*vr1
)
1302 gcc_assert (code
== MULT_EXPR
1303 || code
== TRUNC_DIV_EXPR
1304 || code
== FLOOR_DIV_EXPR
1305 || code
== CEIL_DIV_EXPR
1306 || code
== EXACT_DIV_EXPR
1307 || code
== ROUND_DIV_EXPR
1308 || code
== RSHIFT_EXPR
1309 || code
== LSHIFT_EXPR
);
1310 gcc_assert (vr0
->kind () == VR_RANGE
1311 && vr0
->kind () == vr1
->kind ());
1313 tree type
= vr0
->type ();
1314 wide_int res_lb
, res_ub
;
1315 wide_int vr0_lb
= wi::to_wide (vr0
->min ());
1316 wide_int vr0_ub
= wi::to_wide (vr0
->max ());
1317 wide_int vr1_lb
= wi::to_wide (vr1
->min ());
1318 wide_int vr1_ub
= wi::to_wide (vr1
->max ());
1319 bool overflow_undefined
= TYPE_OVERFLOW_UNDEFINED (type
);
1320 unsigned prec
= TYPE_PRECISION (type
);
1322 if (wide_int_range_multiplicative_op (res_lb
, res_ub
,
1323 code
, TYPE_SIGN (type
), prec
,
1324 vr0_lb
, vr0_ub
, vr1_lb
, vr1_ub
,
1325 overflow_undefined
))
1326 vr
->set_and_canonicalize (VR_RANGE
,
1327 wide_int_to_tree (type
, res_lb
),
1328 wide_int_to_tree (type
, res_ub
));
1333 /* If BOUND will include a symbolic bound, adjust it accordingly,
1334 otherwise leave it as is.
1336 CODE is the original operation that combined the bounds (PLUS_EXPR
1339 TYPE is the type of the original operation.
1341 SYM_OPn is the symbolic for OPn if it has a symbolic.
1343 NEG_OPn is TRUE if the OPn was negated. */
1346 adjust_symbolic_bound (tree
&bound
, enum tree_code code
, tree type
,
1347 tree sym_op0
, tree sym_op1
,
1348 bool neg_op0
, bool neg_op1
)
1350 bool minus_p
= (code
== MINUS_EXPR
);
1351 /* If the result bound is constant, we're done; otherwise, build the
1352 symbolic lower bound. */
1353 if (sym_op0
== sym_op1
)
1356 bound
= build_symbolic_expr (type
, sym_op0
,
1360 /* We may not negate if that might introduce
1361 undefined overflow. */
1364 || TYPE_OVERFLOW_WRAPS (type
))
1365 bound
= build_symbolic_expr (type
, sym_op1
,
1366 neg_op1
^ minus_p
, bound
);
1372 /* Combine OP1 and OP1, which are two parts of a bound, into one wide
1373 int bound according to CODE. CODE is the operation combining the
1374 bound (either a PLUS_EXPR or a MINUS_EXPR).
1376 TYPE is the type of the combine operation.
1378 WI is the wide int to store the result.
1380 OVF is -1 if an underflow occurred, +1 if an overflow occurred or 0
1381 if over/underflow occurred. */
1384 combine_bound (enum tree_code code
, wide_int
&wi
, wi::overflow_type
&ovf
,
1385 tree type
, tree op0
, tree op1
)
1387 bool minus_p
= (code
== MINUS_EXPR
);
1388 const signop sgn
= TYPE_SIGN (type
);
1389 const unsigned int prec
= TYPE_PRECISION (type
);
1391 /* Combine the bounds, if any. */
1395 wi
= wi::sub (wi::to_wide (op0
), wi::to_wide (op1
), sgn
, &ovf
);
1397 wi
= wi::add (wi::to_wide (op0
), wi::to_wide (op1
), sgn
, &ovf
);
1400 wi
= wi::to_wide (op0
);
1404 wi
= wi::neg (wi::to_wide (op1
), &ovf
);
1406 wi
= wi::to_wide (op1
);
1409 wi
= wi::shwi (0, prec
);
1412 /* Given a range in [WMIN, WMAX], adjust it for possible overflow and
1413 put the result in VR.
1415 TYPE is the type of the range.
1417 MIN_OVF and MAX_OVF indicate what type of overflow, if any,
1418 occurred while originally calculating WMIN or WMAX. -1 indicates
1419 underflow. +1 indicates overflow. 0 indicates neither. */
1422 set_value_range_with_overflow (value_range_kind
&kind
, tree
&min
, tree
&max
,
1424 const wide_int
&wmin
, const wide_int
&wmax
,
1425 wi::overflow_type min_ovf
,
1426 wi::overflow_type max_ovf
)
1428 const signop sgn
= TYPE_SIGN (type
);
1429 const unsigned int prec
= TYPE_PRECISION (type
);
1431 /* For one bit precision if max < min, then the swapped
1432 range covers all values. */
1433 if (prec
== 1 && wi::lt_p (wmax
, wmin
, sgn
))
1439 if (TYPE_OVERFLOW_WRAPS (type
))
1441 /* If overflow wraps, truncate the values and adjust the
1442 range kind and bounds appropriately. */
1443 wide_int tmin
= wide_int::from (wmin
, prec
, sgn
);
1444 wide_int tmax
= wide_int::from (wmax
, prec
, sgn
);
1445 if ((min_ovf
!= wi::OVF_NONE
) == (max_ovf
!= wi::OVF_NONE
))
1447 /* If the limits are swapped, we wrapped around and cover
1448 the entire range. We have a similar check at the end of
1449 extract_range_from_binary_expr. */
1450 if (wi::gt_p (tmin
, tmax
, sgn
))
1455 /* No overflow or both overflow or underflow. The
1456 range kind stays VR_RANGE. */
1457 min
= wide_int_to_tree (type
, tmin
);
1458 max
= wide_int_to_tree (type
, tmax
);
1462 else if ((min_ovf
== wi::OVF_UNDERFLOW
&& max_ovf
== wi::OVF_NONE
)
1463 || (max_ovf
== wi::OVF_OVERFLOW
&& min_ovf
== wi::OVF_NONE
))
1465 /* Min underflow or max overflow. The range kind
1466 changes to VR_ANTI_RANGE. */
1467 bool covers
= false;
1468 wide_int tem
= tmin
;
1470 if (wi::cmp (tmin
, tmax
, sgn
) < 0)
1473 if (wi::cmp (tmax
, tem
, sgn
) > 0)
1475 /* If the anti-range would cover nothing, drop to varying.
1476 Likewise if the anti-range bounds are outside of the
1478 if (covers
|| wi::cmp (tmin
, tmax
, sgn
) > 0)
1483 kind
= VR_ANTI_RANGE
;
1484 min
= wide_int_to_tree (type
, tmin
);
1485 max
= wide_int_to_tree (type
, tmax
);
1490 /* Other underflow and/or overflow, drop to VR_VARYING. */
1497 /* If overflow does not wrap, saturate to the types min/max
1499 wide_int type_min
= wi::min_value (prec
, sgn
);
1500 wide_int type_max
= wi::max_value (prec
, sgn
);
1502 if (min_ovf
== wi::OVF_UNDERFLOW
)
1503 min
= wide_int_to_tree (type
, type_min
);
1504 else if (min_ovf
== wi::OVF_OVERFLOW
)
1505 min
= wide_int_to_tree (type
, type_max
);
1507 min
= wide_int_to_tree (type
, wmin
);
1509 if (max_ovf
== wi::OVF_UNDERFLOW
)
1510 max
= wide_int_to_tree (type
, type_min
);
1511 else if (max_ovf
== wi::OVF_OVERFLOW
)
1512 max
= wide_int_to_tree (type
, type_max
);
1514 max
= wide_int_to_tree (type
, wmax
);
1518 /* Extract range information from a binary operation CODE based on
1519 the ranges of each of its operands *VR0 and *VR1 with resulting
1520 type EXPR_TYPE. The resulting range is stored in *VR. */
1523 extract_range_from_binary_expr (value_range_base
*vr
,
1524 enum tree_code code
, tree expr_type
,
1525 const value_range_base
*vr0_
,
1526 const value_range_base
*vr1_
)
1528 signop sign
= TYPE_SIGN (expr_type
);
1529 unsigned int prec
= TYPE_PRECISION (expr_type
);
1530 value_range_base vr0
= *vr0_
, vr1
= *vr1_
;
1531 value_range_base vrtem0
, vrtem1
;
1532 enum value_range_kind type
;
1533 tree min
= NULL_TREE
, max
= NULL_TREE
;
1536 if (!INTEGRAL_TYPE_P (expr_type
)
1537 && !POINTER_TYPE_P (expr_type
))
1543 /* Not all binary expressions can be applied to ranges in a
1544 meaningful way. Handle only arithmetic operations. */
1545 if (code
!= PLUS_EXPR
1546 && code
!= MINUS_EXPR
1547 && code
!= POINTER_PLUS_EXPR
1548 && code
!= MULT_EXPR
1549 && code
!= TRUNC_DIV_EXPR
1550 && code
!= FLOOR_DIV_EXPR
1551 && code
!= CEIL_DIV_EXPR
1552 && code
!= EXACT_DIV_EXPR
1553 && code
!= ROUND_DIV_EXPR
1554 && code
!= TRUNC_MOD_EXPR
1555 && code
!= RSHIFT_EXPR
1556 && code
!= LSHIFT_EXPR
1559 && code
!= BIT_AND_EXPR
1560 && code
!= BIT_IOR_EXPR
1561 && code
!= BIT_XOR_EXPR
)
1567 /* If both ranges are UNDEFINED, so is the result. */
1568 if (vr0
.undefined_p () && vr1
.undefined_p ())
1570 vr
->set_undefined ();
1573 /* If one of the ranges is UNDEFINED drop it to VARYING for the following
1574 code. At some point we may want to special-case operations that
1575 have UNDEFINED result for all or some value-ranges of the not UNDEFINED
1577 else if (vr0
.undefined_p ())
1579 else if (vr1
.undefined_p ())
1582 /* We get imprecise results from ranges_from_anti_range when
1583 code is EXACT_DIV_EXPR. We could mask out bits in the resulting
1584 range, but then we also need to hack up vrp_union. It's just
1585 easier to special case when vr0 is ~[0,0] for EXACT_DIV_EXPR. */
1586 if (code
== EXACT_DIV_EXPR
&& range_is_nonnull (&vr0
))
1588 vr
->set_nonnull (expr_type
);
1592 /* Now canonicalize anti-ranges to ranges when they are not symbolic
1593 and express ~[] op X as ([]' op X) U ([]'' op X). */
1594 if (vr0
.kind () == VR_ANTI_RANGE
1595 && ranges_from_anti_range (&vr0
, &vrtem0
, &vrtem1
))
1597 extract_range_from_binary_expr (vr
, code
, expr_type
, &vrtem0
, vr1_
);
1598 if (!vrtem1
.undefined_p ())
1600 value_range_base vrres
;
1601 extract_range_from_binary_expr (&vrres
, code
, expr_type
,
1603 vr
->union_ (&vrres
);
1607 /* Likewise for X op ~[]. */
1608 if (vr1
.kind () == VR_ANTI_RANGE
1609 && ranges_from_anti_range (&vr1
, &vrtem0
, &vrtem1
))
1611 extract_range_from_binary_expr (vr
, code
, expr_type
, vr0_
, &vrtem0
);
1612 if (!vrtem1
.undefined_p ())
1614 value_range_base vrres
;
1615 extract_range_from_binary_expr (&vrres
, code
, expr_type
,
1617 vr
->union_ (&vrres
);
1622 /* The type of the resulting value range defaults to VR0.TYPE. */
1625 /* Refuse to operate on VARYING ranges, ranges of different kinds
1626 and symbolic ranges. As an exception, we allow BIT_{AND,IOR}
1627 because we may be able to derive a useful range even if one of
1628 the operands is VR_VARYING or symbolic range. Similarly for
1629 divisions, MIN/MAX and PLUS/MINUS.
1631 TODO, we may be able to derive anti-ranges in some cases. */
1632 if (code
!= BIT_AND_EXPR
1633 && code
!= BIT_IOR_EXPR
1634 && code
!= TRUNC_DIV_EXPR
1635 && code
!= FLOOR_DIV_EXPR
1636 && code
!= CEIL_DIV_EXPR
1637 && code
!= EXACT_DIV_EXPR
1638 && code
!= ROUND_DIV_EXPR
1639 && code
!= TRUNC_MOD_EXPR
1642 && code
!= PLUS_EXPR
1643 && code
!= MINUS_EXPR
1644 && code
!= RSHIFT_EXPR
1645 && code
!= POINTER_PLUS_EXPR
1646 && (vr0
.varying_p ()
1648 || vr0
.kind () != vr1
.kind ()
1649 || vr0
.symbolic_p ()
1650 || vr1
.symbolic_p ()))
1656 /* Now evaluate the expression to determine the new range. */
1657 if (POINTER_TYPE_P (expr_type
))
1659 if (code
== MIN_EXPR
|| code
== MAX_EXPR
)
1661 /* For MIN/MAX expressions with pointers, we only care about
1662 nullness, if both are non null, then the result is nonnull.
1663 If both are null, then the result is null. Otherwise they
1665 if (!range_includes_zero_p (&vr0
) && !range_includes_zero_p (&vr1
))
1666 vr
->set_nonnull (expr_type
);
1667 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
1668 vr
->set_null (expr_type
);
1672 else if (code
== POINTER_PLUS_EXPR
)
1674 /* For pointer types, we are really only interested in asserting
1675 whether the expression evaluates to non-NULL.
1676 With -fno-delete-null-pointer-checks we need to be more
1677 conservative. As some object might reside at address 0,
1678 then some offset could be added to it and the same offset
1679 subtracted again and the result would be NULL.
1681 static int a[12]; where &a[0] is NULL and
1684 ptr will be NULL here, even when there is POINTER_PLUS_EXPR
1685 where the first range doesn't include zero and the second one
1686 doesn't either. As the second operand is sizetype (unsigned),
1687 consider all ranges where the MSB could be set as possible
1688 subtractions where the result might be NULL. */
1689 if ((!range_includes_zero_p (&vr0
)
1690 || !range_includes_zero_p (&vr1
))
1691 && !TYPE_OVERFLOW_WRAPS (expr_type
)
1692 && (flag_delete_null_pointer_checks
1693 || (range_int_cst_p (&vr1
)
1694 && !tree_int_cst_sign_bit (vr1
.max ()))))
1695 vr
->set_nonnull (expr_type
);
1696 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
1697 vr
->set_null (expr_type
);
1701 else if (code
== BIT_AND_EXPR
)
1703 /* For pointer types, we are really only interested in asserting
1704 whether the expression evaluates to non-NULL. */
1705 if (!range_includes_zero_p (&vr0
) && !range_includes_zero_p (&vr1
))
1706 vr
->set_nonnull (expr_type
);
1707 else if (range_is_null (&vr0
) || range_is_null (&vr1
))
1708 vr
->set_null (expr_type
);
1718 /* For integer ranges, apply the operation to each end of the
1719 range and see what we end up with. */
1720 if (code
== PLUS_EXPR
|| code
== MINUS_EXPR
)
1722 /* This will normalize things such that calculating
1723 [0,0] - VR_VARYING is not dropped to varying, but is
1724 calculated as [MIN+1, MAX]. */
1725 if (vr0
.varying_p ())
1726 vr0
.set (VR_RANGE
, vrp_val_min (expr_type
), vrp_val_max (expr_type
));
1727 if (vr1
.varying_p ())
1728 vr1
.set (VR_RANGE
, vrp_val_min (expr_type
), vrp_val_max (expr_type
));
1730 const bool minus_p
= (code
== MINUS_EXPR
);
1731 tree min_op0
= vr0
.min ();
1732 tree min_op1
= minus_p
? vr1
.max () : vr1
.min ();
1733 tree max_op0
= vr0
.max ();
1734 tree max_op1
= minus_p
? vr1
.min () : vr1
.max ();
1735 tree sym_min_op0
= NULL_TREE
;
1736 tree sym_min_op1
= NULL_TREE
;
1737 tree sym_max_op0
= NULL_TREE
;
1738 tree sym_max_op1
= NULL_TREE
;
1739 bool neg_min_op0
, neg_min_op1
, neg_max_op0
, neg_max_op1
;
1741 neg_min_op0
= neg_min_op1
= neg_max_op0
= neg_max_op1
= false;
1743 /* If we have a PLUS or MINUS with two VR_RANGEs, either constant or
1744 single-symbolic ranges, try to compute the precise resulting range,
1745 but only if we know that this resulting range will also be constant
1746 or single-symbolic. */
1747 if (vr0
.kind () == VR_RANGE
&& vr1
.kind () == VR_RANGE
1748 && (TREE_CODE (min_op0
) == INTEGER_CST
1750 = get_single_symbol (min_op0
, &neg_min_op0
, &min_op0
)))
1751 && (TREE_CODE (min_op1
) == INTEGER_CST
1753 = get_single_symbol (min_op1
, &neg_min_op1
, &min_op1
)))
1754 && (!(sym_min_op0
&& sym_min_op1
)
1755 || (sym_min_op0
== sym_min_op1
1756 && neg_min_op0
== (minus_p
? neg_min_op1
: !neg_min_op1
)))
1757 && (TREE_CODE (max_op0
) == INTEGER_CST
1759 = get_single_symbol (max_op0
, &neg_max_op0
, &max_op0
)))
1760 && (TREE_CODE (max_op1
) == INTEGER_CST
1762 = get_single_symbol (max_op1
, &neg_max_op1
, &max_op1
)))
1763 && (!(sym_max_op0
&& sym_max_op1
)
1764 || (sym_max_op0
== sym_max_op1
1765 && neg_max_op0
== (minus_p
? neg_max_op1
: !neg_max_op1
))))
1767 wide_int wmin
, wmax
;
1768 wi::overflow_type min_ovf
= wi::OVF_NONE
;
1769 wi::overflow_type max_ovf
= wi::OVF_NONE
;
1771 /* Build the bounds. */
1772 combine_bound (code
, wmin
, min_ovf
, expr_type
, min_op0
, min_op1
);
1773 combine_bound (code
, wmax
, max_ovf
, expr_type
, max_op0
, max_op1
);
1775 /* If we have overflow for the constant part and the resulting
1776 range will be symbolic, drop to VR_VARYING. */
1777 if (((bool)min_ovf
&& sym_min_op0
!= sym_min_op1
)
1778 || ((bool)max_ovf
&& sym_max_op0
!= sym_max_op1
))
1784 /* Adjust the range for possible overflow. */
1787 set_value_range_with_overflow (type
, min
, max
, expr_type
,
1788 wmin
, wmax
, min_ovf
, max_ovf
);
1789 if (type
== VR_VARYING
)
1795 /* Build the symbolic bounds if needed. */
1796 adjust_symbolic_bound (min
, code
, expr_type
,
1797 sym_min_op0
, sym_min_op1
,
1798 neg_min_op0
, neg_min_op1
);
1799 adjust_symbolic_bound (max
, code
, expr_type
,
1800 sym_max_op0
, sym_max_op1
,
1801 neg_max_op0
, neg_max_op1
);
1805 /* For other cases, for example if we have a PLUS_EXPR with two
1806 VR_ANTI_RANGEs, drop to VR_VARYING. It would take more effort
1807 to compute a precise range for such a case.
1808 ??? General even mixed range kind operations can be expressed
1809 by for example transforming ~[3, 5] + [1, 2] to range-only
1810 operations and a union primitive:
1811 [-INF, 2] + [1, 2] U [5, +INF] + [1, 2]
1812 [-INF+1, 4] U [6, +INF(OVF)]
1813 though usually the union is not exactly representable with
1814 a single range or anti-range as the above is
1815 [-INF+1, +INF(OVF)] intersected with ~[5, 5]
1816 but one could use a scheme similar to equivalences for this. */
1821 else if (code
== MIN_EXPR
1822 || code
== MAX_EXPR
)
1824 wide_int wmin
, wmax
;
1825 wide_int vr0_min
, vr0_max
;
1826 wide_int vr1_min
, vr1_max
;
1827 extract_range_into_wide_ints (&vr0
, sign
, prec
, vr0_min
, vr0_max
);
1828 extract_range_into_wide_ints (&vr1
, sign
, prec
, vr1_min
, vr1_max
);
1829 if (wide_int_range_min_max (wmin
, wmax
, code
, sign
, prec
,
1830 vr0_min
, vr0_max
, vr1_min
, vr1_max
))
1831 vr
->set (VR_RANGE
, wide_int_to_tree (expr_type
, wmin
),
1832 wide_int_to_tree (expr_type
, wmax
));
1837 else if (code
== MULT_EXPR
)
1839 if (!range_int_cst_p (&vr0
)
1840 || !range_int_cst_p (&vr1
))
1845 extract_range_from_multiplicative_op (vr
, code
, &vr0
, &vr1
);
1848 else if (code
== RSHIFT_EXPR
1849 || code
== LSHIFT_EXPR
)
1851 if (range_int_cst_p (&vr1
)
1852 && !wide_int_range_shift_undefined_p
1853 (TYPE_SIGN (TREE_TYPE (vr1
.min ())),
1855 wi::to_wide (vr1
.min ()),
1856 wi::to_wide (vr1
.max ())))
1858 if (code
== RSHIFT_EXPR
)
1860 /* Even if vr0 is VARYING or otherwise not usable, we can derive
1861 useful ranges just from the shift count. E.g.
1862 x >> 63 for signed 64-bit x is always [-1, 0]. */
1863 if (vr0
.kind () != VR_RANGE
|| vr0
.symbolic_p ())
1864 vr0
.set (VR_RANGE
, vrp_val_min (expr_type
),
1865 vrp_val_max (expr_type
));
1866 extract_range_from_multiplicative_op (vr
, code
, &vr0
, &vr1
);
1869 else if (code
== LSHIFT_EXPR
1870 && range_int_cst_p (&vr0
))
1872 wide_int res_lb
, res_ub
;
1873 if (wide_int_range_lshift (res_lb
, res_ub
, sign
, prec
,
1874 wi::to_wide (vr0
.min ()),
1875 wi::to_wide (vr0
.max ()),
1876 wi::to_wide (vr1
.min ()),
1877 wi::to_wide (vr1
.max ()),
1878 TYPE_OVERFLOW_UNDEFINED (expr_type
)))
1880 min
= wide_int_to_tree (expr_type
, res_lb
);
1881 max
= wide_int_to_tree (expr_type
, res_ub
);
1882 vr
->set_and_canonicalize (VR_RANGE
, min
, max
);
1890 else if (code
== TRUNC_DIV_EXPR
1891 || code
== FLOOR_DIV_EXPR
1892 || code
== CEIL_DIV_EXPR
1893 || code
== EXACT_DIV_EXPR
1894 || code
== ROUND_DIV_EXPR
)
1896 wide_int dividend_min
, dividend_max
, divisor_min
, divisor_max
;
1897 wide_int wmin
, wmax
, extra_min
, extra_max
;
1900 /* Special case explicit division by zero as undefined. */
1901 if (range_is_null (&vr1
))
1903 vr
->set_undefined ();
1907 /* First, normalize ranges into constants we can handle. Note
1908 that VR_ANTI_RANGE's of constants were already normalized
1909 before arriving here.
1911 NOTE: As a future improvement, we may be able to do better
1912 with mixed symbolic (anti-)ranges like [0, A]. See note in
1913 ranges_from_anti_range. */
1914 extract_range_into_wide_ints (&vr0
, sign
, prec
,
1915 dividend_min
, dividend_max
);
1916 extract_range_into_wide_ints (&vr1
, sign
, prec
,
1917 divisor_min
, divisor_max
);
1918 if (!wide_int_range_div (wmin
, wmax
, code
, sign
, prec
,
1919 dividend_min
, dividend_max
,
1920 divisor_min
, divisor_max
,
1921 TYPE_OVERFLOW_UNDEFINED (expr_type
),
1922 extra_range_p
, extra_min
, extra_max
))
1927 vr
->set (VR_RANGE
, wide_int_to_tree (expr_type
, wmin
),
1928 wide_int_to_tree (expr_type
, wmax
));
1932 extra_range (VR_RANGE
, wide_int_to_tree (expr_type
, extra_min
),
1933 wide_int_to_tree (expr_type
, extra_max
));
1934 vr
->union_ (&extra_range
);
1938 else if (code
== TRUNC_MOD_EXPR
)
1940 if (range_is_null (&vr1
))
1942 vr
->set_undefined ();
1945 wide_int wmin
, wmax
, tmp
;
1946 wide_int vr0_min
, vr0_max
, vr1_min
, vr1_max
;
1947 extract_range_into_wide_ints (&vr0
, sign
, prec
, vr0_min
, vr0_max
);
1948 extract_range_into_wide_ints (&vr1
, sign
, prec
, vr1_min
, vr1_max
);
1949 wide_int_range_trunc_mod (wmin
, wmax
, sign
, prec
,
1950 vr0_min
, vr0_max
, vr1_min
, vr1_max
);
1951 min
= wide_int_to_tree (expr_type
, wmin
);
1952 max
= wide_int_to_tree (expr_type
, wmax
);
1953 vr
->set (VR_RANGE
, min
, max
);
1956 else if (code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
)
1958 wide_int may_be_nonzero0
, may_be_nonzero1
;
1959 wide_int must_be_nonzero0
, must_be_nonzero1
;
1960 wide_int wmin
, wmax
;
1961 wide_int vr0_min
, vr0_max
, vr1_min
, vr1_max
;
1962 vrp_set_zero_nonzero_bits (expr_type
, &vr0
,
1963 &may_be_nonzero0
, &must_be_nonzero0
);
1964 vrp_set_zero_nonzero_bits (expr_type
, &vr1
,
1965 &may_be_nonzero1
, &must_be_nonzero1
);
1966 extract_range_into_wide_ints (&vr0
, sign
, prec
, vr0_min
, vr0_max
);
1967 extract_range_into_wide_ints (&vr1
, sign
, prec
, vr1_min
, vr1_max
);
1968 if (code
== BIT_AND_EXPR
)
1970 if (wide_int_range_bit_and (wmin
, wmax
, sign
, prec
,
1978 min
= wide_int_to_tree (expr_type
, wmin
);
1979 max
= wide_int_to_tree (expr_type
, wmax
);
1980 vr
->set (VR_RANGE
, min
, max
);
1986 else if (code
== BIT_IOR_EXPR
)
1988 if (wide_int_range_bit_ior (wmin
, wmax
, sign
,
1996 min
= wide_int_to_tree (expr_type
, wmin
);
1997 max
= wide_int_to_tree (expr_type
, wmax
);
1998 vr
->set (VR_RANGE
, min
, max
);
2004 else if (code
== BIT_XOR_EXPR
)
2006 if (wide_int_range_bit_xor (wmin
, wmax
, sign
, prec
,
2012 min
= wide_int_to_tree (expr_type
, wmin
);
2013 max
= wide_int_to_tree (expr_type
, wmax
);
2014 vr
->set (VR_RANGE
, min
, max
);
2024 /* If either MIN or MAX overflowed, then set the resulting range to
2026 if (min
== NULL_TREE
2027 || TREE_OVERFLOW_P (min
)
2029 || TREE_OVERFLOW_P (max
))
2035 /* We punt for [-INF, +INF].
2036 We learn nothing when we have INF on both sides.
2037 Note that we do accept [-INF, -INF] and [+INF, +INF]. */
2038 if (vrp_val_is_min (min
) && vrp_val_is_max (max
))
2044 cmp
= compare_values (min
, max
);
2045 if (cmp
== -2 || cmp
== 1)
2047 /* If the new range has its limits swapped around (MIN > MAX),
2048 then the operation caused one of them to wrap around, mark
2049 the new range VARYING. */
2053 vr
->set (type
, min
, max
);
2056 /* Extract range information from a unary operation CODE based on
2057 the range of its operand *VR0 with type OP0_TYPE with resulting type TYPE.
2058 The resulting range is stored in *VR. */
2061 extract_range_from_unary_expr (value_range_base
*vr
,
2062 enum tree_code code
, tree type
,
2063 const value_range_base
*vr0_
, tree op0_type
)
2065 signop sign
= TYPE_SIGN (type
);
2066 unsigned int prec
= TYPE_PRECISION (type
);
2067 value_range_base vr0
= *vr0_
;
2068 value_range_base vrtem0
, vrtem1
;
2070 /* VRP only operates on integral and pointer types. */
2071 if (!(INTEGRAL_TYPE_P (op0_type
)
2072 || POINTER_TYPE_P (op0_type
))
2073 || !(INTEGRAL_TYPE_P (type
)
2074 || POINTER_TYPE_P (type
)))
2080 /* If VR0 is UNDEFINED, so is the result. */
2081 if (vr0
.undefined_p ())
2083 vr
->set_undefined ();
2087 /* Handle operations that we express in terms of others. */
2088 if (code
== PAREN_EXPR
)
2090 /* PAREN_EXPR and OBJ_TYPE_REF are simple copies. */
2094 else if (code
== NEGATE_EXPR
)
2096 /* -X is simply 0 - X, so re-use existing code that also handles
2097 anti-ranges fine. */
2098 value_range_base zero
;
2099 zero
.set (build_int_cst (type
, 0));
2100 extract_range_from_binary_expr (vr
, MINUS_EXPR
, type
, &zero
, &vr0
);
2103 else if (code
== BIT_NOT_EXPR
)
2105 /* ~X is simply -1 - X, so re-use existing code that also handles
2106 anti-ranges fine. */
2107 value_range_base minusone
;
2108 minusone
.set (build_int_cst (type
, -1));
2109 extract_range_from_binary_expr (vr
, MINUS_EXPR
, type
, &minusone
, &vr0
);
2113 /* Now canonicalize anti-ranges to ranges when they are not symbolic
2114 and express op ~[] as (op []') U (op []''). */
2115 if (vr0
.kind () == VR_ANTI_RANGE
2116 && ranges_from_anti_range (&vr0
, &vrtem0
, &vrtem1
))
2118 extract_range_from_unary_expr (vr
, code
, type
, &vrtem0
, op0_type
);
2119 if (!vrtem1
.undefined_p ())
2121 value_range_base vrres
;
2122 extract_range_from_unary_expr (&vrres
, code
, type
,
2124 vr
->union_ (&vrres
);
2129 if (CONVERT_EXPR_CODE_P (code
))
2131 tree inner_type
= op0_type
;
2132 tree outer_type
= type
;
2134 /* If the expression involves a pointer, we are only interested in
2135 determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]).
2137 This may lose precision when converting (char *)~[0,2] to
2138 int, because we'll forget that the pointer can also not be 1
2139 or 2. In practice we don't care, as this is some idiot
2140 storing a magic constant to a pointer. */
2141 if (POINTER_TYPE_P (type
) || POINTER_TYPE_P (op0_type
))
2143 if (!range_includes_zero_p (&vr0
))
2144 vr
->set_nonnull (type
);
2145 else if (range_is_null (&vr0
))
2146 vr
->set_null (type
);
2152 /* The POINTER_TYPE_P code above will have dealt with all
2153 pointer anti-ranges. Any remaining anti-ranges at this point
2154 will be integer conversions from SSA names that will be
2155 normalized into VARYING. For instance: ~[x_55, x_55]. */
2156 gcc_assert (vr0
.kind () != VR_ANTI_RANGE
2157 || TREE_CODE (vr0
.min ()) != INTEGER_CST
);
2159 /* NOTES: Previously we were returning VARYING for all symbolics, but
2160 we can do better by treating them as [-MIN, +MAX]. For
2161 example, converting [SYM, SYM] from INT to LONG UNSIGNED,
2162 we can return: ~[0x8000000, 0xffffffff7fffffff].
2164 We were also failing to convert ~[0,0] from char* to unsigned,
2165 instead choosing to return VR_VARYING. Now we return ~[0,0]. */
2166 wide_int vr0_min
, vr0_max
, wmin
, wmax
;
2167 signop inner_sign
= TYPE_SIGN (inner_type
);
2168 signop outer_sign
= TYPE_SIGN (outer_type
);
2169 unsigned inner_prec
= TYPE_PRECISION (inner_type
);
2170 unsigned outer_prec
= TYPE_PRECISION (outer_type
);
2171 extract_range_into_wide_ints (&vr0
, inner_sign
, inner_prec
,
2173 if (wide_int_range_convert (wmin
, wmax
,
2174 inner_sign
, inner_prec
,
2175 outer_sign
, outer_prec
,
2178 tree min
= wide_int_to_tree (outer_type
, wmin
);
2179 tree max
= wide_int_to_tree (outer_type
, wmax
);
2180 vr
->set_and_canonicalize (VR_RANGE
, min
, max
);
2186 else if (code
== ABS_EXPR
)
2188 wide_int wmin
, wmax
;
2189 wide_int vr0_min
, vr0_max
;
2190 extract_range_into_wide_ints (&vr0
, sign
, prec
, vr0_min
, vr0_max
);
2191 if (wide_int_range_abs (wmin
, wmax
, sign
, prec
, vr0_min
, vr0_max
,
2192 TYPE_OVERFLOW_UNDEFINED (type
)))
2193 vr
->set (VR_RANGE
, wide_int_to_tree (type
, wmin
),
2194 wide_int_to_tree (type
, wmax
));
2199 else if (code
== ABSU_EXPR
)
2201 wide_int wmin
, wmax
;
2202 wide_int vr0_min
, vr0_max
;
2203 extract_range_into_wide_ints (&vr0
, SIGNED
, prec
, vr0_min
, vr0_max
);
2204 wide_int_range_absu (wmin
, wmax
, prec
, vr0_min
, vr0_max
);
2205 vr
->set (VR_RANGE
, wide_int_to_tree (type
, wmin
),
2206 wide_int_to_tree (type
, wmax
));
2210 /* For unhandled operations fall back to varying. */
2215 /* Given a COND_EXPR COND of the form 'V OP W', and an SSA name V,
2216 create a new SSA name N and return the assertion assignment
2217 'N = ASSERT_EXPR <V, V OP W>'. */
2220 build_assert_expr_for (tree cond
, tree v
)
2225 gcc_assert (TREE_CODE (v
) == SSA_NAME
2226 && COMPARISON_CLASS_P (cond
));
2228 a
= build2 (ASSERT_EXPR
, TREE_TYPE (v
), v
, cond
);
2229 assertion
= gimple_build_assign (NULL_TREE
, a
);
2231 /* The new ASSERT_EXPR, creates a new SSA name that replaces the
2232 operand of the ASSERT_EXPR. Create it so the new name and the old one
2233 are registered in the replacement table so that we can fix the SSA web
2234 after adding all the ASSERT_EXPRs. */
2235 tree new_def
= create_new_def_for (v
, assertion
, NULL
);
2236 /* Make sure we preserve abnormalness throughout an ASSERT_EXPR chain
2237 given we have to be able to fully propagate those out to re-create
2238 valid SSA when removing the asserts. */
2239 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (v
))
2240 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_def
) = 1;
2246 /* Return false if EXPR is a predicate expression involving floating
2250 fp_predicate (gimple
*stmt
)
2252 GIMPLE_CHECK (stmt
, GIMPLE_COND
);
2254 return FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (stmt
)));
2257 /* If the range of values taken by OP can be inferred after STMT executes,
2258 return the comparison code (COMP_CODE_P) and value (VAL_P) that
2259 describes the inferred range. Return true if a range could be
2263 infer_value_range (gimple
*stmt
, tree op
, tree_code
*comp_code_p
, tree
*val_p
)
2266 *comp_code_p
= ERROR_MARK
;
2268 /* Do not attempt to infer anything in names that flow through
2270 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op
))
2273 /* If STMT is the last statement of a basic block with no normal
2274 successors, there is no point inferring anything about any of its
2275 operands. We would not be able to find a proper insertion point
2276 for the assertion, anyway. */
2277 if (stmt_ends_bb_p (stmt
))
2282 FOR_EACH_EDGE (e
, ei
, gimple_bb (stmt
)->succs
)
2283 if (!(e
->flags
& (EDGE_ABNORMAL
|EDGE_EH
)))
2289 if (infer_nonnull_range (stmt
, op
))
2291 *val_p
= build_int_cst (TREE_TYPE (op
), 0);
2292 *comp_code_p
= NE_EXPR
;
2300 void dump_asserts_for (FILE *, tree
);
2301 void debug_asserts_for (tree
);
2302 void dump_all_asserts (FILE *);
2303 void debug_all_asserts (void);
2305 /* Dump all the registered assertions for NAME to FILE. */
2308 dump_asserts_for (FILE *file
, tree name
)
2312 fprintf (file
, "Assertions to be inserted for ");
2313 print_generic_expr (file
, name
);
2314 fprintf (file
, "\n");
2316 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
2319 fprintf (file
, "\t");
2320 print_gimple_stmt (file
, gsi_stmt (loc
->si
), 0);
2321 fprintf (file
, "\n\tBB #%d", loc
->bb
->index
);
2324 fprintf (file
, "\n\tEDGE %d->%d", loc
->e
->src
->index
,
2325 loc
->e
->dest
->index
);
2326 dump_edge_info (file
, loc
->e
, dump_flags
, 0);
2328 fprintf (file
, "\n\tPREDICATE: ");
2329 print_generic_expr (file
, loc
->expr
);
2330 fprintf (file
, " %s ", get_tree_code_name (loc
->comp_code
));
2331 print_generic_expr (file
, loc
->val
);
2332 fprintf (file
, "\n\n");
2336 fprintf (file
, "\n");
2340 /* Dump all the registered assertions for NAME to stderr. */
2343 debug_asserts_for (tree name
)
2345 dump_asserts_for (stderr
, name
);
2349 /* Dump all the registered assertions for all the names to FILE. */
2352 dump_all_asserts (FILE *file
)
2357 fprintf (file
, "\nASSERT_EXPRs to be inserted\n\n");
2358 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
2359 dump_asserts_for (file
, ssa_name (i
));
2360 fprintf (file
, "\n");
2364 /* Dump all the registered assertions for all the names to stderr. */
2367 debug_all_asserts (void)
2369 dump_all_asserts (stderr
);
2372 /* Push the assert info for NAME, EXPR, COMP_CODE and VAL to ASSERTS. */
2375 add_assert_info (vec
<assert_info
> &asserts
,
2376 tree name
, tree expr
, enum tree_code comp_code
, tree val
)
2379 info
.comp_code
= comp_code
;
2381 if (TREE_OVERFLOW_P (val
))
2382 val
= drop_tree_overflow (val
);
2385 asserts
.safe_push (info
);
2386 if (dump_enabled_p ())
2387 dump_printf (MSG_NOTE
| MSG_PRIORITY_INTERNALS
,
2388 "Adding assert for %T from %T %s %T\n",
2389 name
, expr
, op_symbol_code (comp_code
), val
);
2392 /* If NAME doesn't have an ASSERT_EXPR registered for asserting
2393 'EXPR COMP_CODE VAL' at a location that dominates block BB or
2394 E->DEST, then register this location as a possible insertion point
2395 for ASSERT_EXPR <NAME, EXPR COMP_CODE VAL>.
2397 BB, E and SI provide the exact insertion point for the new
2398 ASSERT_EXPR. If BB is NULL, then the ASSERT_EXPR is to be inserted
2399 on edge E. Otherwise, if E is NULL, the ASSERT_EXPR is inserted on
2400 BB. If SI points to a COND_EXPR or a SWITCH_EXPR statement, then E
2401 must not be NULL. */
2404 register_new_assert_for (tree name
, tree expr
,
2405 enum tree_code comp_code
,
2409 gimple_stmt_iterator si
)
2411 assert_locus
*n
, *loc
, *last_loc
;
2412 basic_block dest_bb
;
2414 gcc_checking_assert (bb
== NULL
|| e
== NULL
);
2417 gcc_checking_assert (gimple_code (gsi_stmt (si
)) != GIMPLE_COND
2418 && gimple_code (gsi_stmt (si
)) != GIMPLE_SWITCH
);
2420 /* Never build an assert comparing against an integer constant with
2421 TREE_OVERFLOW set. This confuses our undefined overflow warning
2423 if (TREE_OVERFLOW_P (val
))
2424 val
= drop_tree_overflow (val
);
2426 /* The new assertion A will be inserted at BB or E. We need to
2427 determine if the new location is dominated by a previously
2428 registered location for A. If we are doing an edge insertion,
2429 assume that A will be inserted at E->DEST. Note that this is not
2432 If E is a critical edge, it will be split. But even if E is
2433 split, the new block will dominate the same set of blocks that
2436 The reverse, however, is not true, blocks dominated by E->DEST
2437 will not be dominated by the new block created to split E. So,
2438 if the insertion location is on a critical edge, we will not use
2439 the new location to move another assertion previously registered
2440 at a block dominated by E->DEST. */
2441 dest_bb
= (bb
) ? bb
: e
->dest
;
2443 /* If NAME already has an ASSERT_EXPR registered for COMP_CODE and
2444 VAL at a block dominating DEST_BB, then we don't need to insert a new
2445 one. Similarly, if the same assertion already exists at a block
2446 dominated by DEST_BB and the new location is not on a critical
2447 edge, then update the existing location for the assertion (i.e.,
2448 move the assertion up in the dominance tree).
2450 Note, this is implemented as a simple linked list because there
2451 should not be more than a handful of assertions registered per
2452 name. If this becomes a performance problem, a table hashed by
2453 COMP_CODE and VAL could be implemented. */
2454 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
2458 if (loc
->comp_code
== comp_code
2460 || operand_equal_p (loc
->val
, val
, 0))
2461 && (loc
->expr
== expr
2462 || operand_equal_p (loc
->expr
, expr
, 0)))
2464 /* If E is not a critical edge and DEST_BB
2465 dominates the existing location for the assertion, move
2466 the assertion up in the dominance tree by updating its
2467 location information. */
2468 if ((e
== NULL
|| !EDGE_CRITICAL_P (e
))
2469 && dominated_by_p (CDI_DOMINATORS
, loc
->bb
, dest_bb
))
2478 /* Update the last node of the list and move to the next one. */
2483 /* If we didn't find an assertion already registered for
2484 NAME COMP_CODE VAL, add a new one at the end of the list of
2485 assertions associated with NAME. */
2486 n
= XNEW (struct assert_locus
);
2490 n
->comp_code
= comp_code
;
2498 asserts_for
[SSA_NAME_VERSION (name
)] = n
;
2500 bitmap_set_bit (need_assert_for
, SSA_NAME_VERSION (name
));
2503 /* (COND_OP0 COND_CODE COND_OP1) is a predicate which uses NAME.
2504 Extract a suitable test code and value and store them into *CODE_P and
2505 *VAL_P so the predicate is normalized to NAME *CODE_P *VAL_P.
2507 If no extraction was possible, return FALSE, otherwise return TRUE.
2509 If INVERT is true, then we invert the result stored into *CODE_P. */
2512 extract_code_and_val_from_cond_with_ops (tree name
, enum tree_code cond_code
,
2513 tree cond_op0
, tree cond_op1
,
2514 bool invert
, enum tree_code
*code_p
,
2517 enum tree_code comp_code
;
2520 /* Otherwise, we have a comparison of the form NAME COMP VAL
2521 or VAL COMP NAME. */
2522 if (name
== cond_op1
)
2524 /* If the predicate is of the form VAL COMP NAME, flip
2525 COMP around because we need to register NAME as the
2526 first operand in the predicate. */
2527 comp_code
= swap_tree_comparison (cond_code
);
2530 else if (name
== cond_op0
)
2532 /* The comparison is of the form NAME COMP VAL, so the
2533 comparison code remains unchanged. */
2534 comp_code
= cond_code
;
2540 /* Invert the comparison code as necessary. */
2542 comp_code
= invert_tree_comparison (comp_code
, 0);
2544 /* VRP only handles integral and pointer types. */
2545 if (! INTEGRAL_TYPE_P (TREE_TYPE (val
))
2546 && ! POINTER_TYPE_P (TREE_TYPE (val
)))
2549 /* Do not register always-false predicates.
2550 FIXME: this works around a limitation in fold() when dealing with
2551 enumerations. Given 'enum { N1, N2 } x;', fold will not
2552 fold 'if (x > N2)' to 'if (0)'. */
2553 if ((comp_code
== GT_EXPR
|| comp_code
== LT_EXPR
)
2554 && INTEGRAL_TYPE_P (TREE_TYPE (val
)))
2556 tree min
= TYPE_MIN_VALUE (TREE_TYPE (val
));
2557 tree max
= TYPE_MAX_VALUE (TREE_TYPE (val
));
2559 if (comp_code
== GT_EXPR
2561 || compare_values (val
, max
) == 0))
2564 if (comp_code
== LT_EXPR
2566 || compare_values (val
, min
) == 0))
2569 *code_p
= comp_code
;
2574 /* Find out smallest RES where RES > VAL && (RES & MASK) == RES, if any
2575 (otherwise return VAL). VAL and MASK must be zero-extended for
2576 precision PREC. If SGNBIT is non-zero, first xor VAL with SGNBIT
2577 (to transform signed values into unsigned) and at the end xor
2581 masked_increment (const wide_int
&val_in
, const wide_int
&mask
,
2582 const wide_int
&sgnbit
, unsigned int prec
)
2584 wide_int bit
= wi::one (prec
), res
;
2587 wide_int val
= val_in
^ sgnbit
;
2588 for (i
= 0; i
< prec
; i
++, bit
+= bit
)
2591 if ((res
& bit
) == 0)
2594 res
= wi::bit_and_not (val
+ bit
, res
);
2596 if (wi::gtu_p (res
, val
))
2597 return res
^ sgnbit
;
2599 return val
^ sgnbit
;
2602 /* Helper for overflow_comparison_p
2604 OP0 CODE OP1 is a comparison. Examine the comparison and potentially
2605 OP1's defining statement to see if it ultimately has the form
2606 OP0 CODE (OP0 PLUS INTEGER_CST)
2608 If so, return TRUE indicating this is an overflow test and store into
2609 *NEW_CST an updated constant that can be used in a narrowed range test.
2611 REVERSED indicates if the comparison was originally:
2615 This affects how we build the updated constant. */
2618 overflow_comparison_p_1 (enum tree_code code
, tree op0
, tree op1
,
2619 bool follow_assert_exprs
, bool reversed
, tree
*new_cst
)
2621 /* See if this is a relational operation between two SSA_NAMES with
2622 unsigned, overflow wrapping values. If so, check it more deeply. */
2623 if ((code
== LT_EXPR
|| code
== LE_EXPR
2624 || code
== GE_EXPR
|| code
== GT_EXPR
)
2625 && TREE_CODE (op0
) == SSA_NAME
2626 && TREE_CODE (op1
) == SSA_NAME
2627 && INTEGRAL_TYPE_P (TREE_TYPE (op0
))
2628 && TYPE_UNSIGNED (TREE_TYPE (op0
))
2629 && TYPE_OVERFLOW_WRAPS (TREE_TYPE (op0
)))
2631 gimple
*op1_def
= SSA_NAME_DEF_STMT (op1
);
2633 /* If requested, follow any ASSERT_EXPRs backwards for OP1. */
2634 if (follow_assert_exprs
)
2636 while (gimple_assign_single_p (op1_def
)
2637 && TREE_CODE (gimple_assign_rhs1 (op1_def
)) == ASSERT_EXPR
)
2639 op1
= TREE_OPERAND (gimple_assign_rhs1 (op1_def
), 0);
2640 if (TREE_CODE (op1
) != SSA_NAME
)
2642 op1_def
= SSA_NAME_DEF_STMT (op1
);
2646 /* Now look at the defining statement of OP1 to see if it adds
2647 or subtracts a nonzero constant from another operand. */
2649 && is_gimple_assign (op1_def
)
2650 && gimple_assign_rhs_code (op1_def
) == PLUS_EXPR
2651 && TREE_CODE (gimple_assign_rhs2 (op1_def
)) == INTEGER_CST
2652 && !integer_zerop (gimple_assign_rhs2 (op1_def
)))
2654 tree target
= gimple_assign_rhs1 (op1_def
);
2656 /* If requested, follow ASSERT_EXPRs backwards for op0 looking
2657 for one where TARGET appears on the RHS. */
2658 if (follow_assert_exprs
)
2660 /* Now see if that "other operand" is op0, following the chain
2661 of ASSERT_EXPRs if necessary. */
2662 gimple
*op0_def
= SSA_NAME_DEF_STMT (op0
);
2663 while (op0
!= target
2664 && gimple_assign_single_p (op0_def
)
2665 && TREE_CODE (gimple_assign_rhs1 (op0_def
)) == ASSERT_EXPR
)
2667 op0
= TREE_OPERAND (gimple_assign_rhs1 (op0_def
), 0);
2668 if (TREE_CODE (op0
) != SSA_NAME
)
2670 op0_def
= SSA_NAME_DEF_STMT (op0
);
2674 /* If we did not find our target SSA_NAME, then this is not
2675 an overflow test. */
2679 tree type
= TREE_TYPE (op0
);
2680 wide_int max
= wi::max_value (TYPE_PRECISION (type
), UNSIGNED
);
2681 tree inc
= gimple_assign_rhs2 (op1_def
);
2683 *new_cst
= wide_int_to_tree (type
, max
+ wi::to_wide (inc
));
2685 *new_cst
= wide_int_to_tree (type
, max
- wi::to_wide (inc
));
2692 /* OP0 CODE OP1 is a comparison. Examine the comparison and potentially
2693 OP1's defining statement to see if it ultimately has the form
2694 OP0 CODE (OP0 PLUS INTEGER_CST)
2696 If so, return TRUE indicating this is an overflow test and store into
2697 *NEW_CST an updated constant that can be used in a narrowed range test.
2699 These statements are left as-is in the IL to facilitate discovery of
2700 {ADD,SUB}_OVERFLOW sequences later in the optimizer pipeline. But
2701 the alternate range representation is often useful within VRP. */
2704 overflow_comparison_p (tree_code code
, tree name
, tree val
,
2705 bool use_equiv_p
, tree
*new_cst
)
2707 if (overflow_comparison_p_1 (code
, name
, val
, use_equiv_p
, false, new_cst
))
2709 return overflow_comparison_p_1 (swap_tree_comparison (code
), val
, name
,
2710 use_equiv_p
, true, new_cst
);
2714 /* Try to register an edge assertion for SSA name NAME on edge E for
2715 the condition COND contributing to the conditional jump pointed to by BSI.
2716 Invert the condition COND if INVERT is true. */
2719 register_edge_assert_for_2 (tree name
, edge e
,
2720 enum tree_code cond_code
,
2721 tree cond_op0
, tree cond_op1
, bool invert
,
2722 vec
<assert_info
> &asserts
)
2725 enum tree_code comp_code
;
2727 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
2730 invert
, &comp_code
, &val
))
2733 /* Queue the assert. */
2735 if (overflow_comparison_p (comp_code
, name
, val
, false, &x
))
2737 enum tree_code new_code
= ((comp_code
== GT_EXPR
|| comp_code
== GE_EXPR
)
2738 ? GT_EXPR
: LE_EXPR
);
2739 add_assert_info (asserts
, name
, name
, new_code
, x
);
2741 add_assert_info (asserts
, name
, name
, comp_code
, val
);
2743 /* In the case of NAME <= CST and NAME being defined as
2744 NAME = (unsigned) NAME2 + CST2 we can assert NAME2 >= -CST2
2745 and NAME2 <= CST - CST2. We can do the same for NAME > CST.
2746 This catches range and anti-range tests. */
2747 if ((comp_code
== LE_EXPR
2748 || comp_code
== GT_EXPR
)
2749 && TREE_CODE (val
) == INTEGER_CST
2750 && TYPE_UNSIGNED (TREE_TYPE (val
)))
2752 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
2753 tree cst2
= NULL_TREE
, name2
= NULL_TREE
, name3
= NULL_TREE
;
2755 /* Extract CST2 from the (optional) addition. */
2756 if (is_gimple_assign (def_stmt
)
2757 && gimple_assign_rhs_code (def_stmt
) == PLUS_EXPR
)
2759 name2
= gimple_assign_rhs1 (def_stmt
);
2760 cst2
= gimple_assign_rhs2 (def_stmt
);
2761 if (TREE_CODE (name2
) == SSA_NAME
2762 && TREE_CODE (cst2
) == INTEGER_CST
)
2763 def_stmt
= SSA_NAME_DEF_STMT (name2
);
2766 /* Extract NAME2 from the (optional) sign-changing cast. */
2767 if (gimple_assign_cast_p (def_stmt
))
2769 if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
))
2770 && ! TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))
2771 && (TYPE_PRECISION (gimple_expr_type (def_stmt
))
2772 == TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))))
2773 name3
= gimple_assign_rhs1 (def_stmt
);
2776 /* If name3 is used later, create an ASSERT_EXPR for it. */
2777 if (name3
!= NULL_TREE
2778 && TREE_CODE (name3
) == SSA_NAME
2779 && (cst2
== NULL_TREE
2780 || TREE_CODE (cst2
) == INTEGER_CST
)
2781 && INTEGRAL_TYPE_P (TREE_TYPE (name3
)))
2785 /* Build an expression for the range test. */
2786 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), name3
);
2787 if (cst2
!= NULL_TREE
)
2788 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
2789 add_assert_info (asserts
, name3
, tmp
, comp_code
, val
);
2792 /* If name2 is used later, create an ASSERT_EXPR for it. */
2793 if (name2
!= NULL_TREE
2794 && TREE_CODE (name2
) == SSA_NAME
2795 && TREE_CODE (cst2
) == INTEGER_CST
2796 && INTEGRAL_TYPE_P (TREE_TYPE (name2
)))
2800 /* Build an expression for the range test. */
2802 if (TREE_TYPE (name
) != TREE_TYPE (name2
))
2803 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), tmp
);
2804 if (cst2
!= NULL_TREE
)
2805 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
2806 add_assert_info (asserts
, name2
, tmp
, comp_code
, val
);
2810 /* In the case of post-in/decrement tests like if (i++) ... and uses
2811 of the in/decremented value on the edge the extra name we want to
2812 assert for is not on the def chain of the name compared. Instead
2813 it is in the set of use stmts.
2814 Similar cases happen for conversions that were simplified through
2815 fold_{sign_changed,widened}_comparison. */
2816 if ((comp_code
== NE_EXPR
2817 || comp_code
== EQ_EXPR
)
2818 && TREE_CODE (val
) == INTEGER_CST
)
2820 imm_use_iterator ui
;
2822 FOR_EACH_IMM_USE_STMT (use_stmt
, ui
, name
)
2824 if (!is_gimple_assign (use_stmt
))
2827 /* Cut off to use-stmts that are dominating the predecessor. */
2828 if (!dominated_by_p (CDI_DOMINATORS
, e
->src
, gimple_bb (use_stmt
)))
2831 tree name2
= gimple_assign_lhs (use_stmt
);
2832 if (TREE_CODE (name2
) != SSA_NAME
)
2835 enum tree_code code
= gimple_assign_rhs_code (use_stmt
);
2837 if (code
== PLUS_EXPR
2838 || code
== MINUS_EXPR
)
2840 cst
= gimple_assign_rhs2 (use_stmt
);
2841 if (TREE_CODE (cst
) != INTEGER_CST
)
2843 cst
= int_const_binop (code
, val
, cst
);
2845 else if (CONVERT_EXPR_CODE_P (code
))
2847 /* For truncating conversions we cannot record
2849 if (comp_code
== NE_EXPR
2850 && (TYPE_PRECISION (TREE_TYPE (name2
))
2851 < TYPE_PRECISION (TREE_TYPE (name
))))
2853 cst
= fold_convert (TREE_TYPE (name2
), val
);
2858 if (TREE_OVERFLOW_P (cst
))
2859 cst
= drop_tree_overflow (cst
);
2860 add_assert_info (asserts
, name2
, name2
, comp_code
, cst
);
2864 if (TREE_CODE_CLASS (comp_code
) == tcc_comparison
2865 && TREE_CODE (val
) == INTEGER_CST
)
2867 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
2868 tree name2
= NULL_TREE
, names
[2], cst2
= NULL_TREE
;
2869 tree val2
= NULL_TREE
;
2870 unsigned int prec
= TYPE_PRECISION (TREE_TYPE (val
));
2871 wide_int mask
= wi::zero (prec
);
2872 unsigned int nprec
= prec
;
2873 enum tree_code rhs_code
= ERROR_MARK
;
2875 if (is_gimple_assign (def_stmt
))
2876 rhs_code
= gimple_assign_rhs_code (def_stmt
);
2878 /* In the case of NAME != CST1 where NAME = A +- CST2 we can
2879 assert that A != CST1 -+ CST2. */
2880 if ((comp_code
== EQ_EXPR
|| comp_code
== NE_EXPR
)
2881 && (rhs_code
== PLUS_EXPR
|| rhs_code
== MINUS_EXPR
))
2883 tree op0
= gimple_assign_rhs1 (def_stmt
);
2884 tree op1
= gimple_assign_rhs2 (def_stmt
);
2885 if (TREE_CODE (op0
) == SSA_NAME
2886 && TREE_CODE (op1
) == INTEGER_CST
)
2888 enum tree_code reverse_op
= (rhs_code
== PLUS_EXPR
2889 ? MINUS_EXPR
: PLUS_EXPR
);
2890 op1
= int_const_binop (reverse_op
, val
, op1
);
2891 if (TREE_OVERFLOW (op1
))
2892 op1
= drop_tree_overflow (op1
);
2893 add_assert_info (asserts
, op0
, op0
, comp_code
, op1
);
2897 /* Add asserts for NAME cmp CST and NAME being defined
2898 as NAME = (int) NAME2. */
2899 if (!TYPE_UNSIGNED (TREE_TYPE (val
))
2900 && (comp_code
== LE_EXPR
|| comp_code
== LT_EXPR
2901 || comp_code
== GT_EXPR
|| comp_code
== GE_EXPR
)
2902 && gimple_assign_cast_p (def_stmt
))
2904 name2
= gimple_assign_rhs1 (def_stmt
);
2905 if (CONVERT_EXPR_CODE_P (rhs_code
)
2906 && TREE_CODE (name2
) == SSA_NAME
2907 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
2908 && TYPE_UNSIGNED (TREE_TYPE (name2
))
2909 && prec
== TYPE_PRECISION (TREE_TYPE (name2
))
2910 && (comp_code
== LE_EXPR
|| comp_code
== GT_EXPR
2911 || !tree_int_cst_equal (val
,
2912 TYPE_MIN_VALUE (TREE_TYPE (val
)))))
2915 enum tree_code new_comp_code
= comp_code
;
2917 cst
= fold_convert (TREE_TYPE (name2
),
2918 TYPE_MIN_VALUE (TREE_TYPE (val
)));
2919 /* Build an expression for the range test. */
2920 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name2
), name2
, cst
);
2921 cst
= fold_build2 (PLUS_EXPR
, TREE_TYPE (name2
), cst
,
2922 fold_convert (TREE_TYPE (name2
), val
));
2923 if (comp_code
== LT_EXPR
|| comp_code
== GE_EXPR
)
2925 new_comp_code
= comp_code
== LT_EXPR
? LE_EXPR
: GT_EXPR
;
2926 cst
= fold_build2 (MINUS_EXPR
, TREE_TYPE (name2
), cst
,
2927 build_int_cst (TREE_TYPE (name2
), 1));
2929 add_assert_info (asserts
, name2
, tmp
, new_comp_code
, cst
);
2933 /* Add asserts for NAME cmp CST and NAME being defined as
2934 NAME = NAME2 >> CST2.
2936 Extract CST2 from the right shift. */
2937 if (rhs_code
== RSHIFT_EXPR
)
2939 name2
= gimple_assign_rhs1 (def_stmt
);
2940 cst2
= gimple_assign_rhs2 (def_stmt
);
2941 if (TREE_CODE (name2
) == SSA_NAME
2942 && tree_fits_uhwi_p (cst2
)
2943 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
2944 && IN_RANGE (tree_to_uhwi (cst2
), 1, prec
- 1)
2945 && type_has_mode_precision_p (TREE_TYPE (val
)))
2947 mask
= wi::mask (tree_to_uhwi (cst2
), false, prec
);
2948 val2
= fold_binary (LSHIFT_EXPR
, TREE_TYPE (val
), val
, cst2
);
2951 if (val2
!= NULL_TREE
2952 && TREE_CODE (val2
) == INTEGER_CST
2953 && simple_cst_equal (fold_build2 (RSHIFT_EXPR
,
2957 enum tree_code new_comp_code
= comp_code
;
2961 if (comp_code
== EQ_EXPR
|| comp_code
== NE_EXPR
)
2963 if (!TYPE_UNSIGNED (TREE_TYPE (val
)))
2965 tree type
= build_nonstandard_integer_type (prec
, 1);
2966 tmp
= build1 (NOP_EXPR
, type
, name2
);
2967 val2
= fold_convert (type
, val2
);
2969 tmp
= fold_build2 (MINUS_EXPR
, TREE_TYPE (tmp
), tmp
, val2
);
2970 new_val
= wide_int_to_tree (TREE_TYPE (tmp
), mask
);
2971 new_comp_code
= comp_code
== EQ_EXPR
? LE_EXPR
: GT_EXPR
;
2973 else if (comp_code
== LT_EXPR
|| comp_code
== GE_EXPR
)
2976 = wi::min_value (prec
, TYPE_SIGN (TREE_TYPE (val
)));
2978 if (minval
== wi::to_wide (new_val
))
2979 new_val
= NULL_TREE
;
2984 = wi::max_value (prec
, TYPE_SIGN (TREE_TYPE (val
)));
2985 mask
|= wi::to_wide (val2
);
2986 if (wi::eq_p (mask
, maxval
))
2987 new_val
= NULL_TREE
;
2989 new_val
= wide_int_to_tree (TREE_TYPE (val2
), mask
);
2993 add_assert_info (asserts
, name2
, tmp
, new_comp_code
, new_val
);
2996 /* If we have a conversion that doesn't change the value of the source
2997 simply register the same assert for it. */
2998 if (CONVERT_EXPR_CODE_P (rhs_code
))
3000 wide_int rmin
, rmax
;
3001 tree rhs1
= gimple_assign_rhs1 (def_stmt
);
3002 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
3003 && TREE_CODE (rhs1
) == SSA_NAME
3004 /* Make sure the relation preserves the upper/lower boundary of
3005 the range conservatively. */
3006 && (comp_code
== NE_EXPR
3007 || comp_code
== EQ_EXPR
3008 || (TYPE_SIGN (TREE_TYPE (name
))
3009 == TYPE_SIGN (TREE_TYPE (rhs1
)))
3010 || ((comp_code
== LE_EXPR
3011 || comp_code
== LT_EXPR
)
3012 && !TYPE_UNSIGNED (TREE_TYPE (rhs1
)))
3013 || ((comp_code
== GE_EXPR
3014 || comp_code
== GT_EXPR
)
3015 && TYPE_UNSIGNED (TREE_TYPE (rhs1
))))
3016 /* And the conversion does not alter the value we compare
3017 against and all values in rhs1 can be represented in
3018 the converted to type. */
3019 && int_fits_type_p (val
, TREE_TYPE (rhs1
))
3020 && ((TYPE_PRECISION (TREE_TYPE (name
))
3021 > TYPE_PRECISION (TREE_TYPE (rhs1
)))
3022 || (get_range_info (rhs1
, &rmin
, &rmax
) == VR_RANGE
3023 && wi::fits_to_tree_p (rmin
, TREE_TYPE (name
))
3024 && wi::fits_to_tree_p (rmax
, TREE_TYPE (name
)))))
3025 add_assert_info (asserts
, rhs1
, rhs1
,
3026 comp_code
, fold_convert (TREE_TYPE (rhs1
), val
));
3029 /* Add asserts for NAME cmp CST and NAME being defined as
3030 NAME = NAME2 & CST2.
3032 Extract CST2 from the and.
3035 NAME = (unsigned) NAME2;
3036 casts where NAME's type is unsigned and has smaller precision
3037 than NAME2's type as if it was NAME = NAME2 & MASK. */
3038 names
[0] = NULL_TREE
;
3039 names
[1] = NULL_TREE
;
3041 if (rhs_code
== BIT_AND_EXPR
3042 || (CONVERT_EXPR_CODE_P (rhs_code
)
3043 && INTEGRAL_TYPE_P (TREE_TYPE (val
))
3044 && TYPE_UNSIGNED (TREE_TYPE (val
))
3045 && TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))
3048 name2
= gimple_assign_rhs1 (def_stmt
);
3049 if (rhs_code
== BIT_AND_EXPR
)
3050 cst2
= gimple_assign_rhs2 (def_stmt
);
3053 cst2
= TYPE_MAX_VALUE (TREE_TYPE (val
));
3054 nprec
= TYPE_PRECISION (TREE_TYPE (name2
));
3056 if (TREE_CODE (name2
) == SSA_NAME
3057 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
3058 && TREE_CODE (cst2
) == INTEGER_CST
3059 && !integer_zerop (cst2
)
3061 || TYPE_UNSIGNED (TREE_TYPE (val
))))
3063 gimple
*def_stmt2
= SSA_NAME_DEF_STMT (name2
);
3064 if (gimple_assign_cast_p (def_stmt2
))
3066 names
[1] = gimple_assign_rhs1 (def_stmt2
);
3067 if (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt2
))
3068 || TREE_CODE (names
[1]) != SSA_NAME
3069 || !INTEGRAL_TYPE_P (TREE_TYPE (names
[1]))
3070 || (TYPE_PRECISION (TREE_TYPE (name2
))
3071 != TYPE_PRECISION (TREE_TYPE (names
[1]))))
3072 names
[1] = NULL_TREE
;
3077 if (names
[0] || names
[1])
3079 wide_int minv
, maxv
, valv
, cst2v
;
3080 wide_int tem
, sgnbit
;
3081 bool valid_p
= false, valn
, cst2n
;
3082 enum tree_code ccode
= comp_code
;
3084 valv
= wide_int::from (wi::to_wide (val
), nprec
, UNSIGNED
);
3085 cst2v
= wide_int::from (wi::to_wide (cst2
), nprec
, UNSIGNED
);
3086 valn
= wi::neg_p (valv
, TYPE_SIGN (TREE_TYPE (val
)));
3087 cst2n
= wi::neg_p (cst2v
, TYPE_SIGN (TREE_TYPE (val
)));
3088 /* If CST2 doesn't have most significant bit set,
3089 but VAL is negative, we have comparison like
3090 if ((x & 0x123) > -4) (always true). Just give up. */
3094 sgnbit
= wi::set_bit_in_zero (nprec
- 1, nprec
);
3096 sgnbit
= wi::zero (nprec
);
3097 minv
= valv
& cst2v
;
3101 /* Minimum unsigned value for equality is VAL & CST2
3102 (should be equal to VAL, otherwise we probably should
3103 have folded the comparison into false) and
3104 maximum unsigned value is VAL | ~CST2. */
3105 maxv
= valv
| ~cst2v
;
3110 tem
= valv
| ~cst2v
;
3111 /* If VAL is 0, handle (X & CST2) != 0 as (X & CST2) > 0U. */
3115 sgnbit
= wi::zero (nprec
);
3118 /* If (VAL | ~CST2) is all ones, handle it as
3119 (X & CST2) < VAL. */
3124 sgnbit
= wi::zero (nprec
);
3127 if (!cst2n
&& wi::neg_p (cst2v
))
3128 sgnbit
= wi::set_bit_in_zero (nprec
- 1, nprec
);
3137 if (tem
== wi::mask (nprec
- 1, false, nprec
))
3143 sgnbit
= wi::zero (nprec
);
3148 /* Minimum unsigned value for >= if (VAL & CST2) == VAL
3149 is VAL and maximum unsigned value is ~0. For signed
3150 comparison, if CST2 doesn't have most significant bit
3151 set, handle it similarly. If CST2 has MSB set,
3152 the minimum is the same, and maximum is ~0U/2. */
3155 /* If (VAL & CST2) != VAL, X & CST2 can't be equal to
3157 minv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
3161 maxv
= wi::mask (nprec
- (cst2n
? 1 : 0), false, nprec
);
3167 /* Find out smallest MINV where MINV > VAL
3168 && (MINV & CST2) == MINV, if any. If VAL is signed and
3169 CST2 has MSB set, compute it biased by 1 << (nprec - 1). */
3170 minv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
3173 maxv
= wi::mask (nprec
- (cst2n
? 1 : 0), false, nprec
);
3178 /* Minimum unsigned value for <= is 0 and maximum
3179 unsigned value is VAL | ~CST2 if (VAL & CST2) == VAL.
3180 Otherwise, find smallest VAL2 where VAL2 > VAL
3181 && (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2
3183 For signed comparison, if CST2 doesn't have most
3184 significant bit set, handle it similarly. If CST2 has
3185 MSB set, the maximum is the same and minimum is INT_MIN. */
3190 maxv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
3202 /* Minimum unsigned value for < is 0 and maximum
3203 unsigned value is (VAL-1) | ~CST2 if (VAL & CST2) == VAL.
3204 Otherwise, find smallest VAL2 where VAL2 > VAL
3205 && (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2
3207 For signed comparison, if CST2 doesn't have most
3208 significant bit set, handle it similarly. If CST2 has
3209 MSB set, the maximum is the same and minimum is INT_MIN. */
3218 maxv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
3232 && (maxv
- minv
) != -1)
3234 tree tmp
, new_val
, type
;
3237 for (i
= 0; i
< 2; i
++)
3240 wide_int maxv2
= maxv
;
3242 type
= TREE_TYPE (names
[i
]);
3243 if (!TYPE_UNSIGNED (type
))
3245 type
= build_nonstandard_integer_type (nprec
, 1);
3246 tmp
= build1 (NOP_EXPR
, type
, names
[i
]);
3250 tmp
= build2 (PLUS_EXPR
, type
, tmp
,
3251 wide_int_to_tree (type
, -minv
));
3252 maxv2
= maxv
- minv
;
3254 new_val
= wide_int_to_tree (type
, maxv2
);
3255 add_assert_info (asserts
, names
[i
], tmp
, LE_EXPR
, new_val
);
3262 /* OP is an operand of a truth value expression which is known to have
3263 a particular value. Register any asserts for OP and for any
3264 operands in OP's defining statement.
3266 If CODE is EQ_EXPR, then we want to register OP is zero (false),
3267 if CODE is NE_EXPR, then we want to register OP is nonzero (true). */
3270 register_edge_assert_for_1 (tree op
, enum tree_code code
,
3271 edge e
, vec
<assert_info
> &asserts
)
3275 enum tree_code rhs_code
;
3277 /* We only care about SSA_NAMEs. */
3278 if (TREE_CODE (op
) != SSA_NAME
)
3281 /* We know that OP will have a zero or nonzero value. */
3282 val
= build_int_cst (TREE_TYPE (op
), 0);
3283 add_assert_info (asserts
, op
, op
, code
, val
);
3285 /* Now look at how OP is set. If it's set from a comparison,
3286 a truth operation or some bit operations, then we may be able
3287 to register information about the operands of that assignment. */
3288 op_def
= SSA_NAME_DEF_STMT (op
);
3289 if (gimple_code (op_def
) != GIMPLE_ASSIGN
)
3292 rhs_code
= gimple_assign_rhs_code (op_def
);
3294 if (TREE_CODE_CLASS (rhs_code
) == tcc_comparison
)
3296 bool invert
= (code
== EQ_EXPR
? true : false);
3297 tree op0
= gimple_assign_rhs1 (op_def
);
3298 tree op1
= gimple_assign_rhs2 (op_def
);
3300 if (TREE_CODE (op0
) == SSA_NAME
)
3301 register_edge_assert_for_2 (op0
, e
, rhs_code
, op0
, op1
, invert
, asserts
);
3302 if (TREE_CODE (op1
) == SSA_NAME
)
3303 register_edge_assert_for_2 (op1
, e
, rhs_code
, op0
, op1
, invert
, asserts
);
3305 else if ((code
== NE_EXPR
3306 && gimple_assign_rhs_code (op_def
) == BIT_AND_EXPR
)
3308 && gimple_assign_rhs_code (op_def
) == BIT_IOR_EXPR
))
3310 /* Recurse on each operand. */
3311 tree op0
= gimple_assign_rhs1 (op_def
);
3312 tree op1
= gimple_assign_rhs2 (op_def
);
3313 if (TREE_CODE (op0
) == SSA_NAME
3314 && has_single_use (op0
))
3315 register_edge_assert_for_1 (op0
, code
, e
, asserts
);
3316 if (TREE_CODE (op1
) == SSA_NAME
3317 && has_single_use (op1
))
3318 register_edge_assert_for_1 (op1
, code
, e
, asserts
);
3320 else if (gimple_assign_rhs_code (op_def
) == BIT_NOT_EXPR
3321 && TYPE_PRECISION (TREE_TYPE (gimple_assign_lhs (op_def
))) == 1)
3323 /* Recurse, flipping CODE. */
3324 code
= invert_tree_comparison (code
, false);
3325 register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
), code
, e
, asserts
);
3327 else if (gimple_assign_rhs_code (op_def
) == SSA_NAME
)
3329 /* Recurse through the copy. */
3330 register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
), code
, e
, asserts
);
3332 else if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (op_def
)))
3334 /* Recurse through the type conversion, unless it is a narrowing
3335 conversion or conversion from non-integral type. */
3336 tree rhs
= gimple_assign_rhs1 (op_def
);
3337 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs
))
3338 && (TYPE_PRECISION (TREE_TYPE (rhs
))
3339 <= TYPE_PRECISION (TREE_TYPE (op
))))
3340 register_edge_assert_for_1 (rhs
, code
, e
, asserts
);
3344 /* Check if comparison
3345 NAME COND_OP INTEGER_CST
3347 (X & 11...100..0) COND_OP XX...X00...0
3348 Such comparison can yield assertions like
3351 in case of COND_OP being EQ_EXPR or
3354 in case of NE_EXPR. */
3357 is_masked_range_test (tree name
, tree valt
, enum tree_code cond_code
,
3358 tree
*new_name
, tree
*low
, enum tree_code
*low_code
,
3359 tree
*high
, enum tree_code
*high_code
)
3361 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
3363 if (!is_gimple_assign (def_stmt
)
3364 || gimple_assign_rhs_code (def_stmt
) != BIT_AND_EXPR
)
3367 tree t
= gimple_assign_rhs1 (def_stmt
);
3368 tree maskt
= gimple_assign_rhs2 (def_stmt
);
3369 if (TREE_CODE (t
) != SSA_NAME
|| TREE_CODE (maskt
) != INTEGER_CST
)
3372 wi::tree_to_wide_ref mask
= wi::to_wide (maskt
);
3373 wide_int inv_mask
= ~mask
;
3374 /* Must have been removed by now so don't bother optimizing. */
3375 if (mask
== 0 || inv_mask
== 0)
3378 /* Assume VALT is INTEGER_CST. */
3379 wi::tree_to_wide_ref val
= wi::to_wide (valt
);
3381 if ((inv_mask
& (inv_mask
+ 1)) != 0
3382 || (val
& mask
) != val
)
3385 bool is_range
= cond_code
== EQ_EXPR
;
3387 tree type
= TREE_TYPE (t
);
3388 wide_int min
= wi::min_value (type
),
3389 max
= wi::max_value (type
);
3393 *low_code
= val
== min
? ERROR_MARK
: GE_EXPR
;
3394 *high_code
= val
== max
? ERROR_MARK
: LE_EXPR
;
3398 /* We can still generate assertion if one of alternatives
3399 is known to always be false. */
3402 *low_code
= (enum tree_code
) 0;
3403 *high_code
= GT_EXPR
;
3405 else if ((val
| inv_mask
) == max
)
3407 *low_code
= LT_EXPR
;
3408 *high_code
= (enum tree_code
) 0;
3415 *low
= wide_int_to_tree (type
, val
);
3416 *high
= wide_int_to_tree (type
, val
| inv_mask
);
3421 /* Try to register an edge assertion for SSA name NAME on edge E for
3422 the condition COND contributing to the conditional jump pointed to by
3426 register_edge_assert_for (tree name
, edge e
,
3427 enum tree_code cond_code
, tree cond_op0
,
3428 tree cond_op1
, vec
<assert_info
> &asserts
)
3431 enum tree_code comp_code
;
3432 bool is_else_edge
= (e
->flags
& EDGE_FALSE_VALUE
) != 0;
3434 /* Do not attempt to infer anything in names that flow through
3436 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name
))
3439 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
3445 /* Register ASSERT_EXPRs for name. */
3446 register_edge_assert_for_2 (name
, e
, cond_code
, cond_op0
,
3447 cond_op1
, is_else_edge
, asserts
);
3450 /* If COND is effectively an equality test of an SSA_NAME against
3451 the value zero or one, then we may be able to assert values
3452 for SSA_NAMEs which flow into COND. */
3454 /* In the case of NAME == 1 or NAME != 0, for BIT_AND_EXPR defining
3455 statement of NAME we can assert both operands of the BIT_AND_EXPR
3456 have nonzero value. */
3457 if (((comp_code
== EQ_EXPR
&& integer_onep (val
))
3458 || (comp_code
== NE_EXPR
&& integer_zerop (val
))))
3460 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
3462 if (is_gimple_assign (def_stmt
)
3463 && gimple_assign_rhs_code (def_stmt
) == BIT_AND_EXPR
)
3465 tree op0
= gimple_assign_rhs1 (def_stmt
);
3466 tree op1
= gimple_assign_rhs2 (def_stmt
);
3467 register_edge_assert_for_1 (op0
, NE_EXPR
, e
, asserts
);
3468 register_edge_assert_for_1 (op1
, NE_EXPR
, e
, asserts
);
3472 /* In the case of NAME == 0 or NAME != 1, for BIT_IOR_EXPR defining
3473 statement of NAME we can assert both operands of the BIT_IOR_EXPR
3475 if (((comp_code
== EQ_EXPR
&& integer_zerop (val
))
3476 || (comp_code
== NE_EXPR
&& integer_onep (val
))))
3478 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
3480 /* For BIT_IOR_EXPR only if NAME == 0 both operands have
3481 necessarily zero value, or if type-precision is one. */
3482 if (is_gimple_assign (def_stmt
)
3483 && (gimple_assign_rhs_code (def_stmt
) == BIT_IOR_EXPR
3484 && (TYPE_PRECISION (TREE_TYPE (name
)) == 1
3485 || comp_code
== EQ_EXPR
)))
3487 tree op0
= gimple_assign_rhs1 (def_stmt
);
3488 tree op1
= gimple_assign_rhs2 (def_stmt
);
3489 register_edge_assert_for_1 (op0
, EQ_EXPR
, e
, asserts
);
3490 register_edge_assert_for_1 (op1
, EQ_EXPR
, e
, asserts
);
3494 /* Sometimes we can infer ranges from (NAME & MASK) == VALUE. */
3495 if ((comp_code
== EQ_EXPR
|| comp_code
== NE_EXPR
)
3496 && TREE_CODE (val
) == INTEGER_CST
)
3498 enum tree_code low_code
, high_code
;
3500 if (is_masked_range_test (name
, val
, comp_code
, &name
, &low
,
3501 &low_code
, &high
, &high_code
))
3503 if (low_code
!= ERROR_MARK
)
3504 register_edge_assert_for_2 (name
, e
, low_code
, name
,
3505 low
, /*invert*/false, asserts
);
3506 if (high_code
!= ERROR_MARK
)
3507 register_edge_assert_for_2 (name
, e
, high_code
, name
,
3508 high
, /*invert*/false, asserts
);
3513 /* Finish found ASSERTS for E and register them at GSI. */
3516 finish_register_edge_assert_for (edge e
, gimple_stmt_iterator gsi
,
3517 vec
<assert_info
> &asserts
)
3519 for (unsigned i
= 0; i
< asserts
.length (); ++i
)
3520 /* Only register an ASSERT_EXPR if NAME was found in the sub-graph
3521 reachable from E. */
3522 if (live_on_edge (e
, asserts
[i
].name
))
3523 register_new_assert_for (asserts
[i
].name
, asserts
[i
].expr
,
3524 asserts
[i
].comp_code
, asserts
[i
].val
,
3530 /* Determine whether the outgoing edges of BB should receive an
3531 ASSERT_EXPR for each of the operands of BB's LAST statement.
3532 The last statement of BB must be a COND_EXPR.
3534 If any of the sub-graphs rooted at BB have an interesting use of
3535 the predicate operands, an assert location node is added to the
3536 list of assertions for the corresponding operands. */
3539 find_conditional_asserts (basic_block bb
, gcond
*last
)
3541 gimple_stmt_iterator bsi
;
3547 bsi
= gsi_for_stmt (last
);
3549 /* Look for uses of the operands in each of the sub-graphs
3550 rooted at BB. We need to check each of the outgoing edges
3551 separately, so that we know what kind of ASSERT_EXPR to
3553 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
3558 /* Register the necessary assertions for each operand in the
3559 conditional predicate. */
3560 auto_vec
<assert_info
, 8> asserts
;
3561 FOR_EACH_SSA_TREE_OPERAND (op
, last
, iter
, SSA_OP_USE
)
3562 register_edge_assert_for (op
, e
,
3563 gimple_cond_code (last
),
3564 gimple_cond_lhs (last
),
3565 gimple_cond_rhs (last
), asserts
);
3566 finish_register_edge_assert_for (e
, bsi
, asserts
);
3576 /* Compare two case labels sorting first by the destination bb index
3577 and then by the case value. */
3580 compare_case_labels (const void *p1
, const void *p2
)
3582 const struct case_info
*ci1
= (const struct case_info
*) p1
;
3583 const struct case_info
*ci2
= (const struct case_info
*) p2
;
3584 int idx1
= ci1
->bb
->index
;
3585 int idx2
= ci2
->bb
->index
;
3589 else if (idx1
== idx2
)
3591 /* Make sure the default label is first in a group. */
3592 if (!CASE_LOW (ci1
->expr
))
3594 else if (!CASE_LOW (ci2
->expr
))
3597 return tree_int_cst_compare (CASE_LOW (ci1
->expr
),
3598 CASE_LOW (ci2
->expr
));
3604 /* Determine whether the outgoing edges of BB should receive an
3605 ASSERT_EXPR for each of the operands of BB's LAST statement.
3606 The last statement of BB must be a SWITCH_EXPR.
3608 If any of the sub-graphs rooted at BB have an interesting use of
3609 the predicate operands, an assert location node is added to the
3610 list of assertions for the corresponding operands. */
3613 find_switch_asserts (basic_block bb
, gswitch
*last
)
3615 gimple_stmt_iterator bsi
;
3618 struct case_info
*ci
;
3619 size_t n
= gimple_switch_num_labels (last
);
3620 #if GCC_VERSION >= 4000
3623 /* Work around GCC 3.4 bug (PR 37086). */
3624 volatile unsigned int idx
;
3627 bsi
= gsi_for_stmt (last
);
3628 op
= gimple_switch_index (last
);
3629 if (TREE_CODE (op
) != SSA_NAME
)
3632 /* Build a vector of case labels sorted by destination label. */
3633 ci
= XNEWVEC (struct case_info
, n
);
3634 for (idx
= 0; idx
< n
; ++idx
)
3636 ci
[idx
].expr
= gimple_switch_label (last
, idx
);
3637 ci
[idx
].bb
= label_to_block (cfun
, CASE_LABEL (ci
[idx
].expr
));
3639 edge default_edge
= find_edge (bb
, ci
[0].bb
);
3640 qsort (ci
, n
, sizeof (struct case_info
), compare_case_labels
);
3642 for (idx
= 0; idx
< n
; ++idx
)
3645 tree cl
= ci
[idx
].expr
;
3646 basic_block cbb
= ci
[idx
].bb
;
3648 min
= CASE_LOW (cl
);
3649 max
= CASE_HIGH (cl
);
3651 /* If there are multiple case labels with the same destination
3652 we need to combine them to a single value range for the edge. */
3653 if (idx
+ 1 < n
&& cbb
== ci
[idx
+ 1].bb
)
3655 /* Skip labels until the last of the group. */
3658 } while (idx
< n
&& cbb
== ci
[idx
].bb
);
3661 /* Pick up the maximum of the case label range. */
3662 if (CASE_HIGH (ci
[idx
].expr
))
3663 max
= CASE_HIGH (ci
[idx
].expr
);
3665 max
= CASE_LOW (ci
[idx
].expr
);
3668 /* Can't extract a useful assertion out of a range that includes the
3670 if (min
== NULL_TREE
)
3673 /* Find the edge to register the assert expr on. */
3674 e
= find_edge (bb
, cbb
);
3676 /* Register the necessary assertions for the operand in the
3678 auto_vec
<assert_info
, 8> asserts
;
3679 register_edge_assert_for (op
, e
,
3680 max
? GE_EXPR
: EQ_EXPR
,
3681 op
, fold_convert (TREE_TYPE (op
), min
),
3684 register_edge_assert_for (op
, e
, LE_EXPR
, op
,
3685 fold_convert (TREE_TYPE (op
), max
),
3687 finish_register_edge_assert_for (e
, bsi
, asserts
);
3692 if (!live_on_edge (default_edge
, op
))
3695 /* Now register along the default label assertions that correspond to the
3696 anti-range of each label. */
3697 int insertion_limit
= PARAM_VALUE (PARAM_MAX_VRP_SWITCH_ASSERTIONS
);
3698 if (insertion_limit
== 0)
3701 /* We can't do this if the default case shares a label with another case. */
3702 tree default_cl
= gimple_switch_default_label (last
);
3703 for (idx
= 1; idx
< n
; idx
++)
3706 tree cl
= gimple_switch_label (last
, idx
);
3707 if (CASE_LABEL (cl
) == CASE_LABEL (default_cl
))
3710 min
= CASE_LOW (cl
);
3711 max
= CASE_HIGH (cl
);
3713 /* Combine contiguous case ranges to reduce the number of assertions
3715 for (idx
= idx
+ 1; idx
< n
; idx
++)
3717 tree next_min
, next_max
;
3718 tree next_cl
= gimple_switch_label (last
, idx
);
3719 if (CASE_LABEL (next_cl
) == CASE_LABEL (default_cl
))
3722 next_min
= CASE_LOW (next_cl
);
3723 next_max
= CASE_HIGH (next_cl
);
3725 wide_int difference
= (wi::to_wide (next_min
)
3726 - wi::to_wide (max
? max
: min
));
3727 if (wi::eq_p (difference
, 1))
3728 max
= next_max
? next_max
: next_min
;
3734 if (max
== NULL_TREE
)
3736 /* Register the assertion OP != MIN. */
3737 auto_vec
<assert_info
, 8> asserts
;
3738 min
= fold_convert (TREE_TYPE (op
), min
);
3739 register_edge_assert_for (op
, default_edge
, NE_EXPR
, op
, min
,
3741 finish_register_edge_assert_for (default_edge
, bsi
, asserts
);
3745 /* Register the assertion (unsigned)OP - MIN > (MAX - MIN),
3746 which will give OP the anti-range ~[MIN,MAX]. */
3747 tree uop
= fold_convert (unsigned_type_for (TREE_TYPE (op
)), op
);
3748 min
= fold_convert (TREE_TYPE (uop
), min
);
3749 max
= fold_convert (TREE_TYPE (uop
), max
);
3751 tree lhs
= fold_build2 (MINUS_EXPR
, TREE_TYPE (uop
), uop
, min
);
3752 tree rhs
= int_const_binop (MINUS_EXPR
, max
, min
);
3753 register_new_assert_for (op
, lhs
, GT_EXPR
, rhs
,
3754 NULL
, default_edge
, bsi
);
3757 if (--insertion_limit
== 0)
3763 /* Traverse all the statements in block BB looking for statements that
3764 may generate useful assertions for the SSA names in their operand.
3765 If a statement produces a useful assertion A for name N_i, then the
3766 list of assertions already generated for N_i is scanned to
3767 determine if A is actually needed.
3769 If N_i already had the assertion A at a location dominating the
3770 current location, then nothing needs to be done. Otherwise, the
3771 new location for A is recorded instead.
3773 1- For every statement S in BB, all the variables used by S are
3774 added to bitmap FOUND_IN_SUBGRAPH.
3776 2- If statement S uses an operand N in a way that exposes a known
3777 value range for N, then if N was not already generated by an
3778 ASSERT_EXPR, create a new assert location for N. For instance,
3779 if N is a pointer and the statement dereferences it, we can
3780 assume that N is not NULL.
3782 3- COND_EXPRs are a special case of #2. We can derive range
3783 information from the predicate but need to insert different
3784 ASSERT_EXPRs for each of the sub-graphs rooted at the
3785 conditional block. If the last statement of BB is a conditional
3786 expression of the form 'X op Y', then
3788 a) Remove X and Y from the set FOUND_IN_SUBGRAPH.
3790 b) If the conditional is the only entry point to the sub-graph
3791 corresponding to the THEN_CLAUSE, recurse into it. On
3792 return, if X and/or Y are marked in FOUND_IN_SUBGRAPH, then
3793 an ASSERT_EXPR is added for the corresponding variable.
3795 c) Repeat step (b) on the ELSE_CLAUSE.
3797 d) Mark X and Y in FOUND_IN_SUBGRAPH.
3806 In this case, an assertion on the THEN clause is useful to
3807 determine that 'a' is always 9 on that edge. However, an assertion
3808 on the ELSE clause would be unnecessary.
3810 4- If BB does not end in a conditional expression, then we recurse
3811 into BB's dominator children.
3813 At the end of the recursive traversal, every SSA name will have a
3814 list of locations where ASSERT_EXPRs should be added. When a new
3815 location for name N is found, it is registered by calling
3816 register_new_assert_for. That function keeps track of all the
3817 registered assertions to prevent adding unnecessary assertions.
3818 For instance, if a pointer P_4 is dereferenced more than once in a
3819 dominator tree, only the location dominating all the dereference of
3820 P_4 will receive an ASSERT_EXPR. */
3823 find_assert_locations_1 (basic_block bb
, sbitmap live
)
3827 last
= last_stmt (bb
);
3829 /* If BB's last statement is a conditional statement involving integer
3830 operands, determine if we need to add ASSERT_EXPRs. */
3832 && gimple_code (last
) == GIMPLE_COND
3833 && !fp_predicate (last
)
3834 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
3835 find_conditional_asserts (bb
, as_a
<gcond
*> (last
));
3837 /* If BB's last statement is a switch statement involving integer
3838 operands, determine if we need to add ASSERT_EXPRs. */
3840 && gimple_code (last
) == GIMPLE_SWITCH
3841 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
3842 find_switch_asserts (bb
, as_a
<gswitch
*> (last
));
3844 /* Traverse all the statements in BB marking used names and looking
3845 for statements that may infer assertions for their used operands. */
3846 for (gimple_stmt_iterator si
= gsi_last_bb (bb
); !gsi_end_p (si
);
3853 stmt
= gsi_stmt (si
);
3855 if (is_gimple_debug (stmt
))
3858 /* See if we can derive an assertion for any of STMT's operands. */
3859 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_USE
)
3862 enum tree_code comp_code
;
3864 /* If op is not live beyond this stmt, do not bother to insert
3866 if (!bitmap_bit_p (live
, SSA_NAME_VERSION (op
)))
3869 /* If OP is used in such a way that we can infer a value
3870 range for it, and we don't find a previous assertion for
3871 it, create a new assertion location node for OP. */
3872 if (infer_value_range (stmt
, op
, &comp_code
, &value
))
3874 /* If we are able to infer a nonzero value range for OP,
3875 then walk backwards through the use-def chain to see if OP
3876 was set via a typecast.
3878 If so, then we can also infer a nonzero value range
3879 for the operand of the NOP_EXPR. */
3880 if (comp_code
== NE_EXPR
&& integer_zerop (value
))
3883 gimple
*def_stmt
= SSA_NAME_DEF_STMT (t
);
3885 while (is_gimple_assign (def_stmt
)
3886 && CONVERT_EXPR_CODE_P
3887 (gimple_assign_rhs_code (def_stmt
))
3889 (gimple_assign_rhs1 (def_stmt
)) == SSA_NAME
3891 (TREE_TYPE (gimple_assign_rhs1 (def_stmt
))))
3893 t
= gimple_assign_rhs1 (def_stmt
);
3894 def_stmt
= SSA_NAME_DEF_STMT (t
);
3896 /* Note we want to register the assert for the
3897 operand of the NOP_EXPR after SI, not after the
3899 if (bitmap_bit_p (live
, SSA_NAME_VERSION (t
)))
3900 register_new_assert_for (t
, t
, comp_code
, value
,
3905 register_new_assert_for (op
, op
, comp_code
, value
, bb
, NULL
, si
);
3910 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_USE
)
3911 bitmap_set_bit (live
, SSA_NAME_VERSION (op
));
3912 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_DEF
)
3913 bitmap_clear_bit (live
, SSA_NAME_VERSION (op
));
3916 /* Traverse all PHI nodes in BB, updating live. */
3917 for (gphi_iterator si
= gsi_start_phis (bb
); !gsi_end_p (si
);
3920 use_operand_p arg_p
;
3922 gphi
*phi
= si
.phi ();
3923 tree res
= gimple_phi_result (phi
);
3925 if (virtual_operand_p (res
))
3928 FOR_EACH_PHI_ARG (arg_p
, phi
, i
, SSA_OP_USE
)
3930 tree arg
= USE_FROM_PTR (arg_p
);
3931 if (TREE_CODE (arg
) == SSA_NAME
)
3932 bitmap_set_bit (live
, SSA_NAME_VERSION (arg
));
3935 bitmap_clear_bit (live
, SSA_NAME_VERSION (res
));
3939 /* Do an RPO walk over the function computing SSA name liveness
3940 on-the-fly and deciding on assert expressions to insert. */
3943 find_assert_locations (void)
3945 int *rpo
= XNEWVEC (int, last_basic_block_for_fn (cfun
));
3946 int *bb_rpo
= XNEWVEC (int, last_basic_block_for_fn (cfun
));
3947 int *last_rpo
= XCNEWVEC (int, last_basic_block_for_fn (cfun
));
3950 live
= XCNEWVEC (sbitmap
, last_basic_block_for_fn (cfun
));
3951 rpo_cnt
= pre_and_rev_post_order_compute (NULL
, rpo
, false);
3952 for (i
= 0; i
< rpo_cnt
; ++i
)
3955 /* Pre-seed loop latch liveness from loop header PHI nodes. Due to
3956 the order we compute liveness and insert asserts we otherwise
3957 fail to insert asserts into the loop latch. */
3959 FOR_EACH_LOOP (loop
, 0)
3961 i
= loop
->latch
->index
;
3962 unsigned int j
= single_succ_edge (loop
->latch
)->dest_idx
;
3963 for (gphi_iterator gsi
= gsi_start_phis (loop
->header
);
3964 !gsi_end_p (gsi
); gsi_next (&gsi
))
3966 gphi
*phi
= gsi
.phi ();
3967 if (virtual_operand_p (gimple_phi_result (phi
)))
3969 tree arg
= gimple_phi_arg_def (phi
, j
);
3970 if (TREE_CODE (arg
) == SSA_NAME
)
3972 if (live
[i
] == NULL
)
3974 live
[i
] = sbitmap_alloc (num_ssa_names
);
3975 bitmap_clear (live
[i
]);
3977 bitmap_set_bit (live
[i
], SSA_NAME_VERSION (arg
));
3982 for (i
= rpo_cnt
- 1; i
>= 0; --i
)
3984 basic_block bb
= BASIC_BLOCK_FOR_FN (cfun
, rpo
[i
]);
3990 live
[rpo
[i
]] = sbitmap_alloc (num_ssa_names
);
3991 bitmap_clear (live
[rpo
[i
]]);
3994 /* Process BB and update the live information with uses in
3996 find_assert_locations_1 (bb
, live
[rpo
[i
]]);
3998 /* Merge liveness into the predecessor blocks and free it. */
3999 if (!bitmap_empty_p (live
[rpo
[i
]]))
4002 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
4004 int pred
= e
->src
->index
;
4005 if ((e
->flags
& EDGE_DFS_BACK
) || pred
== ENTRY_BLOCK
)
4010 live
[pred
] = sbitmap_alloc (num_ssa_names
);
4011 bitmap_clear (live
[pred
]);
4013 bitmap_ior (live
[pred
], live
[pred
], live
[rpo
[i
]]);
4015 if (bb_rpo
[pred
] < pred_rpo
)
4016 pred_rpo
= bb_rpo
[pred
];
4019 /* Record the RPO number of the last visited block that needs
4020 live information from this block. */
4021 last_rpo
[rpo
[i
]] = pred_rpo
;
4025 sbitmap_free (live
[rpo
[i
]]);
4026 live
[rpo
[i
]] = NULL
;
4029 /* We can free all successors live bitmaps if all their
4030 predecessors have been visited already. */
4031 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4032 if (last_rpo
[e
->dest
->index
] == i
4033 && live
[e
->dest
->index
])
4035 sbitmap_free (live
[e
->dest
->index
]);
4036 live
[e
->dest
->index
] = NULL
;
4041 XDELETEVEC (bb_rpo
);
4042 XDELETEVEC (last_rpo
);
4043 for (i
= 0; i
< last_basic_block_for_fn (cfun
); ++i
)
4045 sbitmap_free (live
[i
]);
4049 /* Create an ASSERT_EXPR for NAME and insert it in the location
4050 indicated by LOC. Return true if we made any edge insertions. */
4053 process_assert_insertions_for (tree name
, assert_locus
*loc
)
4055 /* Build the comparison expression NAME_i COMP_CODE VAL. */
4058 gimple
*assert_stmt
;
4062 /* If we have X <=> X do not insert an assert expr for that. */
4063 if (loc
->expr
== loc
->val
)
4066 cond
= build2 (loc
->comp_code
, boolean_type_node
, loc
->expr
, loc
->val
);
4067 assert_stmt
= build_assert_expr_for (cond
, name
);
4070 /* We have been asked to insert the assertion on an edge. This
4071 is used only by COND_EXPR and SWITCH_EXPR assertions. */
4072 gcc_checking_assert (gimple_code (gsi_stmt (loc
->si
)) == GIMPLE_COND
4073 || (gimple_code (gsi_stmt (loc
->si
))
4076 gsi_insert_on_edge (loc
->e
, assert_stmt
);
4080 /* If the stmt iterator points at the end then this is an insertion
4081 at the beginning of a block. */
4082 if (gsi_end_p (loc
->si
))
4084 gimple_stmt_iterator si
= gsi_after_labels (loc
->bb
);
4085 gsi_insert_before (&si
, assert_stmt
, GSI_SAME_STMT
);
4089 /* Otherwise, we can insert right after LOC->SI iff the
4090 statement must not be the last statement in the block. */
4091 stmt
= gsi_stmt (loc
->si
);
4092 if (!stmt_ends_bb_p (stmt
))
4094 gsi_insert_after (&loc
->si
, assert_stmt
, GSI_SAME_STMT
);
4098 /* If STMT must be the last statement in BB, we can only insert new
4099 assertions on the non-abnormal edge out of BB. Note that since
4100 STMT is not control flow, there may only be one non-abnormal/eh edge
4102 FOR_EACH_EDGE (e
, ei
, loc
->bb
->succs
)
4103 if (!(e
->flags
& (EDGE_ABNORMAL
|EDGE_EH
)))
4105 gsi_insert_on_edge (e
, assert_stmt
);
4112 /* Qsort helper for sorting assert locations. If stable is true, don't
4113 use iterative_hash_expr because it can be unstable for -fcompare-debug,
4114 on the other side some pointers might be NULL. */
4116 template <bool stable
>
4118 compare_assert_loc (const void *pa
, const void *pb
)
4120 assert_locus
* const a
= *(assert_locus
* const *)pa
;
4121 assert_locus
* const b
= *(assert_locus
* const *)pb
;
4123 /* If stable, some asserts might be optimized away already, sort
4133 if (a
->e
== NULL
&& b
->e
!= NULL
)
4135 else if (a
->e
!= NULL
&& b
->e
== NULL
)
4138 /* After the above checks, we know that (a->e == NULL) == (b->e == NULL),
4139 no need to test both a->e and b->e. */
4141 /* Sort after destination index. */
4144 else if (a
->e
->dest
->index
> b
->e
->dest
->index
)
4146 else if (a
->e
->dest
->index
< b
->e
->dest
->index
)
4149 /* Sort after comp_code. */
4150 if (a
->comp_code
> b
->comp_code
)
4152 else if (a
->comp_code
< b
->comp_code
)
4157 /* E.g. if a->val is ADDR_EXPR of a VAR_DECL, iterative_hash_expr
4158 uses DECL_UID of the VAR_DECL, so sorting might differ between
4159 -g and -g0. When doing the removal of redundant assert exprs
4160 and commonization to successors, this does not matter, but for
4161 the final sort needs to be stable. */
4169 ha
= iterative_hash_expr (a
->expr
, iterative_hash_expr (a
->val
, 0));
4170 hb
= iterative_hash_expr (b
->expr
, iterative_hash_expr (b
->val
, 0));
4173 /* Break the tie using hashing and source/bb index. */
4175 return (a
->e
!= NULL
4176 ? a
->e
->src
->index
- b
->e
->src
->index
4177 : a
->bb
->index
- b
->bb
->index
);
4178 return ha
> hb
? 1 : -1;
4181 /* Process all the insertions registered for every name N_i registered
4182 in NEED_ASSERT_FOR. The list of assertions to be inserted are
4183 found in ASSERTS_FOR[i]. */
4186 process_assert_insertions (void)
4190 bool update_edges_p
= false;
4191 int num_asserts
= 0;
4193 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4194 dump_all_asserts (dump_file
);
4196 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
4198 assert_locus
*loc
= asserts_for
[i
];
4201 auto_vec
<assert_locus
*, 16> asserts
;
4202 for (; loc
; loc
= loc
->next
)
4203 asserts
.safe_push (loc
);
4204 asserts
.qsort (compare_assert_loc
<false>);
4206 /* Push down common asserts to successors and remove redundant ones. */
4208 assert_locus
*common
= NULL
;
4209 unsigned commonj
= 0;
4210 for (unsigned j
= 0; j
< asserts
.length (); ++j
)
4216 || loc
->e
->dest
!= common
->e
->dest
4217 || loc
->comp_code
!= common
->comp_code
4218 || ! operand_equal_p (loc
->val
, common
->val
, 0)
4219 || ! operand_equal_p (loc
->expr
, common
->expr
, 0))
4225 else if (loc
->e
== asserts
[j
-1]->e
)
4227 /* Remove duplicate asserts. */
4228 if (commonj
== j
- 1)
4233 free (asserts
[j
-1]);
4234 asserts
[j
-1] = NULL
;
4239 if (EDGE_COUNT (common
->e
->dest
->preds
) == ecnt
)
4241 /* We have the same assertion on all incoming edges of a BB.
4242 Insert it at the beginning of that block. */
4243 loc
->bb
= loc
->e
->dest
;
4245 loc
->si
= gsi_none ();
4247 /* Clear asserts commoned. */
4248 for (; commonj
!= j
; ++commonj
)
4249 if (asserts
[commonj
])
4251 free (asserts
[commonj
]);
4252 asserts
[commonj
] = NULL
;
4258 /* The asserts vector sorting above might be unstable for
4259 -fcompare-debug, sort again to ensure a stable sort. */
4260 asserts
.qsort (compare_assert_loc
<true>);
4261 for (unsigned j
= 0; j
< asserts
.length (); ++j
)
4266 update_edges_p
|= process_assert_insertions_for (ssa_name (i
), loc
);
4273 gsi_commit_edge_inserts ();
4275 statistics_counter_event (cfun
, "Number of ASSERT_EXPR expressions inserted",
4280 /* Traverse the flowgraph looking for conditional jumps to insert range
4281 expressions. These range expressions are meant to provide information
4282 to optimizations that need to reason in terms of value ranges. They
4283 will not be expanded into RTL. For instance, given:
4292 this pass will transform the code into:
4298 x = ASSERT_EXPR <x, x < y>
4303 y = ASSERT_EXPR <y, x >= y>
4307 The idea is that once copy and constant propagation have run, other
4308 optimizations will be able to determine what ranges of values can 'x'
4309 take in different paths of the code, simply by checking the reaching
4310 definition of 'x'. */
4313 insert_range_assertions (void)
4315 need_assert_for
= BITMAP_ALLOC (NULL
);
4316 asserts_for
= XCNEWVEC (assert_locus
*, num_ssa_names
);
4318 calculate_dominance_info (CDI_DOMINATORS
);
4320 find_assert_locations ();
4321 if (!bitmap_empty_p (need_assert_for
))
4323 process_assert_insertions ();
4324 update_ssa (TODO_update_ssa_no_phi
);
4327 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4329 fprintf (dump_file
, "\nSSA form after inserting ASSERT_EXPRs\n");
4330 dump_function_to_file (current_function_decl
, dump_file
, dump_flags
);
4334 BITMAP_FREE (need_assert_for
);
4337 class vrp_prop
: public ssa_propagation_engine
4340 enum ssa_prop_result
visit_stmt (gimple
*, edge
*, tree
*) FINAL OVERRIDE
;
4341 enum ssa_prop_result
visit_phi (gphi
*) FINAL OVERRIDE
;
4343 void vrp_initialize (void);
4344 void vrp_finalize (bool);
4345 void check_all_array_refs (void);
4346 void check_array_ref (location_t
, tree
, bool);
4347 void check_mem_ref (location_t
, tree
, bool);
4348 void search_for_addr_array (tree
, location_t
);
4350 class vr_values vr_values
;
4351 /* Temporary delegator to minimize code churn. */
4352 value_range
*get_value_range (const_tree op
)
4353 { return vr_values
.get_value_range (op
); }
4354 void set_defs_to_varying (gimple
*stmt
)
4355 { return vr_values
.set_defs_to_varying (stmt
); }
4356 void extract_range_from_stmt (gimple
*stmt
, edge
*taken_edge_p
,
4357 tree
*output_p
, value_range
*vr
)
4358 { vr_values
.extract_range_from_stmt (stmt
, taken_edge_p
, output_p
, vr
); }
4359 bool update_value_range (const_tree op
, value_range
*vr
)
4360 { return vr_values
.update_value_range (op
, vr
); }
4361 void extract_range_basic (value_range
*vr
, gimple
*stmt
)
4362 { vr_values
.extract_range_basic (vr
, stmt
); }
4363 void extract_range_from_phi_node (gphi
*phi
, value_range
*vr
)
4364 { vr_values
.extract_range_from_phi_node (phi
, vr
); }
4366 /* Checks one ARRAY_REF in REF, located at LOCUS. Ignores flexible arrays
4367 and "struct" hacks. If VRP can determine that the
4368 array subscript is a constant, check if it is outside valid
4369 range. If the array subscript is a RANGE, warn if it is
4370 non-overlapping with valid range.
4371 IGNORE_OFF_BY_ONE is true if the ARRAY_REF is inside a ADDR_EXPR. */
4374 vrp_prop::check_array_ref (location_t location
, tree ref
,
4375 bool ignore_off_by_one
)
4377 const value_range
*vr
= NULL
;
4378 tree low_sub
, up_sub
;
4379 tree low_bound
, up_bound
, up_bound_p1
;
4381 if (TREE_NO_WARNING (ref
))
4384 low_sub
= up_sub
= TREE_OPERAND (ref
, 1);
4385 up_bound
= array_ref_up_bound (ref
);
4388 || TREE_CODE (up_bound
) != INTEGER_CST
4389 || (warn_array_bounds
< 2
4390 && array_at_struct_end_p (ref
)))
4392 /* Accesses to trailing arrays via pointers may access storage
4393 beyond the types array bounds. For such arrays, or for flexible
4394 array members, as well as for other arrays of an unknown size,
4395 replace the upper bound with a more permissive one that assumes
4396 the size of the largest object is PTRDIFF_MAX. */
4397 tree eltsize
= array_ref_element_size (ref
);
4399 if (TREE_CODE (eltsize
) != INTEGER_CST
4400 || integer_zerop (eltsize
))
4402 up_bound
= NULL_TREE
;
4403 up_bound_p1
= NULL_TREE
;
4407 tree maxbound
= TYPE_MAX_VALUE (ptrdiff_type_node
);
4408 tree arg
= TREE_OPERAND (ref
, 0);
4411 if (get_addr_base_and_unit_offset (arg
, &off
) && known_gt (off
, 0))
4412 maxbound
= wide_int_to_tree (sizetype
,
4413 wi::sub (wi::to_wide (maxbound
),
4416 maxbound
= fold_convert (sizetype
, maxbound
);
4418 up_bound_p1
= int_const_binop (TRUNC_DIV_EXPR
, maxbound
, eltsize
);
4420 up_bound
= int_const_binop (MINUS_EXPR
, up_bound_p1
,
4421 build_int_cst (ptrdiff_type_node
, 1));
4425 up_bound_p1
= int_const_binop (PLUS_EXPR
, up_bound
,
4426 build_int_cst (TREE_TYPE (up_bound
), 1));
4428 low_bound
= array_ref_low_bound (ref
);
4430 tree artype
= TREE_TYPE (TREE_OPERAND (ref
, 0));
4432 bool warned
= false;
4435 if (up_bound
&& tree_int_cst_equal (low_bound
, up_bound_p1
))
4436 warned
= warning_at (location
, OPT_Warray_bounds
,
4437 "array subscript %E is above array bounds of %qT",
4440 if (TREE_CODE (low_sub
) == SSA_NAME
)
4442 vr
= get_value_range (low_sub
);
4443 if (!vr
->undefined_p () && !vr
->varying_p ())
4445 low_sub
= vr
->kind () == VR_RANGE
? vr
->max () : vr
->min ();
4446 up_sub
= vr
->kind () == VR_RANGE
? vr
->min () : vr
->max ();
4450 if (vr
&& vr
->kind () == VR_ANTI_RANGE
)
4453 && TREE_CODE (up_sub
) == INTEGER_CST
4454 && (ignore_off_by_one
4455 ? tree_int_cst_lt (up_bound
, up_sub
)
4456 : tree_int_cst_le (up_bound
, up_sub
))
4457 && TREE_CODE (low_sub
) == INTEGER_CST
4458 && tree_int_cst_le (low_sub
, low_bound
))
4459 warned
= warning_at (location
, OPT_Warray_bounds
,
4460 "array subscript [%E, %E] is outside "
4461 "array bounds of %qT",
4462 low_sub
, up_sub
, artype
);
4465 && TREE_CODE (up_sub
) == INTEGER_CST
4466 && (ignore_off_by_one
4467 ? !tree_int_cst_le (up_sub
, up_bound_p1
)
4468 : !tree_int_cst_le (up_sub
, up_bound
)))
4470 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4472 fprintf (dump_file
, "Array bound warning for ");
4473 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, ref
);
4474 fprintf (dump_file
, "\n");
4476 warned
= warning_at (location
, OPT_Warray_bounds
,
4477 "array subscript %E is above array bounds of %qT",
4480 else if (TREE_CODE (low_sub
) == INTEGER_CST
4481 && tree_int_cst_lt (low_sub
, low_bound
))
4483 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4485 fprintf (dump_file
, "Array bound warning for ");
4486 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, ref
);
4487 fprintf (dump_file
, "\n");
4489 warned
= warning_at (location
, OPT_Warray_bounds
,
4490 "array subscript %E is below array bounds of %qT",
4496 ref
= TREE_OPERAND (ref
, 0);
4499 inform (DECL_SOURCE_LOCATION (ref
), "while referencing %qD", ref
);
4501 TREE_NO_WARNING (ref
) = 1;
4505 /* Checks one MEM_REF in REF, located at LOCATION, for out-of-bounds
4506 references to string constants. If VRP can determine that the array
4507 subscript is a constant, check if it is outside valid range.
4508 If the array subscript is a RANGE, warn if it is non-overlapping
4510 IGNORE_OFF_BY_ONE is true if the MEM_REF is inside an ADDR_EXPR
4511 (used to allow one-past-the-end indices for code that takes
4512 the address of the just-past-the-end element of an array). */
4515 vrp_prop::check_mem_ref (location_t location
, tree ref
,
4516 bool ignore_off_by_one
)
4518 if (TREE_NO_WARNING (ref
))
4521 tree arg
= TREE_OPERAND (ref
, 0);
4522 /* The constant and variable offset of the reference. */
4523 tree cstoff
= TREE_OPERAND (ref
, 1);
4524 tree varoff
= NULL_TREE
;
4526 const offset_int maxobjsize
= tree_to_shwi (max_object_size ());
4528 /* The array or string constant bounds in bytes. Initially set
4529 to [-MAXOBJSIZE - 1, MAXOBJSIZE] until a tighter bound is
4531 offset_int arrbounds
[2] = { -maxobjsize
- 1, maxobjsize
};
4533 /* The minimum and maximum intermediate offset. For a reference
4534 to be valid, not only does the final offset/subscript must be
4535 in bounds but all intermediate offsets should be as well.
4536 GCC may be able to deal gracefully with such out-of-bounds
4537 offsets so the checking is only enbaled at -Warray-bounds=2
4538 where it may help detect bugs in uses of the intermediate
4539 offsets that could otherwise not be detectable. */
4540 offset_int ioff
= wi::to_offset (fold_convert (ptrdiff_type_node
, cstoff
));
4541 offset_int extrema
[2] = { 0, wi::abs (ioff
) };
4543 /* The range of the byte offset into the reference. */
4544 offset_int offrange
[2] = { 0, 0 };
4546 const value_range
*vr
= NULL
;
4548 /* Determine the offsets and increment OFFRANGE for the bounds of each.
4549 The loop computes the the range of the final offset for expressions
4550 such as (A + i0 + ... + iN)[CSTOFF] where i0 through iN are SSA_NAMEs
4552 while (TREE_CODE (arg
) == SSA_NAME
)
4554 gimple
*def
= SSA_NAME_DEF_STMT (arg
);
4555 if (!is_gimple_assign (def
))
4558 tree_code code
= gimple_assign_rhs_code (def
);
4559 if (code
== POINTER_PLUS_EXPR
)
4561 arg
= gimple_assign_rhs1 (def
);
4562 varoff
= gimple_assign_rhs2 (def
);
4564 else if (code
== ASSERT_EXPR
)
4566 arg
= TREE_OPERAND (gimple_assign_rhs1 (def
), 0);
4572 /* VAROFF should always be a SSA_NAME here (and not even
4573 INTEGER_CST) but there's no point in taking chances. */
4574 if (TREE_CODE (varoff
) != SSA_NAME
)
4577 vr
= get_value_range (varoff
);
4578 if (!vr
|| vr
->undefined_p () || vr
->varying_p ())
4581 if (!vr
->constant_p ())
4584 if (vr
->kind () == VR_RANGE
)
4586 if (tree_int_cst_lt (vr
->min (), vr
->max ()))
4589 = wi::to_offset (fold_convert (ptrdiff_type_node
, vr
->min ()));
4591 = wi::to_offset (fold_convert (ptrdiff_type_node
, vr
->max ()));
4605 /* Conservatively add [-MAXOBJSIZE -1, MAXOBJSIZE]
4607 offrange
[0] += arrbounds
[0];
4608 offrange
[1] += arrbounds
[1];
4613 /* For an anti-range, analogously to the above, conservatively
4614 add [-MAXOBJSIZE -1, MAXOBJSIZE] to OFFRANGE. */
4615 offrange
[0] += arrbounds
[0];
4616 offrange
[1] += arrbounds
[1];
4619 /* Keep track of the minimum and maximum offset. */
4620 if (offrange
[1] < 0 && offrange
[1] < extrema
[0])
4621 extrema
[0] = offrange
[1];
4622 if (offrange
[0] > 0 && offrange
[0] > extrema
[1])
4623 extrema
[1] = offrange
[0];
4625 if (offrange
[0] < arrbounds
[0])
4626 offrange
[0] = arrbounds
[0];
4628 if (offrange
[1] > arrbounds
[1])
4629 offrange
[1] = arrbounds
[1];
4632 if (TREE_CODE (arg
) == ADDR_EXPR
)
4634 arg
= TREE_OPERAND (arg
, 0);
4635 if (TREE_CODE (arg
) != STRING_CST
4636 && TREE_CODE (arg
) != VAR_DECL
)
4642 /* The type of the object being referred to. It can be an array,
4643 string literal, or a non-array type when the MEM_REF represents
4644 a reference/subscript via a pointer to an object that is not
4645 an element of an array. References to members of structs and
4646 unions are excluded because MEM_REF doesn't make it possible
4647 to identify the member where the reference originated.
4648 Incomplete types are excluded as well because their size is
4650 tree reftype
= TREE_TYPE (arg
);
4651 if (POINTER_TYPE_P (reftype
)
4652 || !COMPLETE_TYPE_P (reftype
)
4653 || TREE_CODE (TYPE_SIZE_UNIT (reftype
)) != INTEGER_CST
4654 || RECORD_OR_UNION_TYPE_P (reftype
))
4658 if (TREE_CODE (reftype
) == ARRAY_TYPE
)
4660 eltsize
= wi::to_offset (TYPE_SIZE_UNIT (TREE_TYPE (reftype
)));
4662 if (tree dom
= TYPE_DOMAIN (reftype
))
4664 tree bnds
[] = { TYPE_MIN_VALUE (dom
), TYPE_MAX_VALUE (dom
) };
4665 if (array_at_struct_end_p (arg
)
4666 || !bnds
[0] || !bnds
[1])
4669 arrbounds
[1] = wi::lrshift (maxobjsize
, wi::floor_log2 (eltsize
));
4673 arrbounds
[0] = wi::to_offset (bnds
[0]) * eltsize
;
4674 arrbounds
[1] = (wi::to_offset (bnds
[1]) + 1) * eltsize
;
4680 arrbounds
[1] = wi::lrshift (maxobjsize
, wi::floor_log2 (eltsize
));
4683 if (TREE_CODE (ref
) == MEM_REF
)
4685 /* For MEM_REF determine a tighter bound of the non-array
4687 tree eltype
= TREE_TYPE (reftype
);
4688 while (TREE_CODE (eltype
) == ARRAY_TYPE
)
4689 eltype
= TREE_TYPE (eltype
);
4690 eltsize
= wi::to_offset (TYPE_SIZE_UNIT (eltype
));
4697 arrbounds
[1] = wi::to_offset (TYPE_SIZE_UNIT (reftype
));
4700 offrange
[0] += ioff
;
4701 offrange
[1] += ioff
;
4703 /* Compute the more permissive upper bound when IGNORE_OFF_BY_ONE
4704 is set (when taking the address of the one-past-last element
4705 of an array) but always use the stricter bound in diagnostics. */
4706 offset_int ubound
= arrbounds
[1];
4707 if (ignore_off_by_one
)
4710 if (offrange
[0] >= ubound
|| offrange
[1] < arrbounds
[0])
4712 /* Treat a reference to a non-array object as one to an array
4713 of a single element. */
4714 if (TREE_CODE (reftype
) != ARRAY_TYPE
)
4715 reftype
= build_array_type_nelts (reftype
, 1);
4717 if (TREE_CODE (ref
) == MEM_REF
)
4719 /* Extract the element type out of MEM_REF and use its size
4720 to compute the index to print in the diagnostic; arrays
4721 in MEM_REF don't mean anything. */
4722 tree type
= TREE_TYPE (ref
);
4723 while (TREE_CODE (type
) == ARRAY_TYPE
)
4724 type
= TREE_TYPE (type
);
4725 tree size
= TYPE_SIZE_UNIT (type
);
4726 offrange
[0] = offrange
[0] / wi::to_offset (size
);
4727 offrange
[1] = offrange
[1] / wi::to_offset (size
);
4731 /* For anything other than MEM_REF, compute the index to
4732 print in the diagnostic as the offset over element size. */
4733 offrange
[0] = offrange
[0] / eltsize
;
4734 offrange
[1] = offrange
[1] / eltsize
;
4738 if (offrange
[0] == offrange
[1])
4739 warned
= warning_at (location
, OPT_Warray_bounds
,
4740 "array subscript %wi is outside array bounds "
4742 offrange
[0].to_shwi (), reftype
);
4744 warned
= warning_at (location
, OPT_Warray_bounds
,
4745 "array subscript [%wi, %wi] is outside "
4746 "array bounds of %qT",
4747 offrange
[0].to_shwi (),
4748 offrange
[1].to_shwi (), reftype
);
4749 if (warned
&& DECL_P (arg
))
4750 inform (DECL_SOURCE_LOCATION (arg
), "while referencing %qD", arg
);
4752 TREE_NO_WARNING (ref
) = 1;
4756 if (warn_array_bounds
< 2)
4759 /* At level 2 check also intermediate offsets. */
4761 if (extrema
[i
] < -arrbounds
[1] || extrema
[i
= 1] > ubound
)
4763 HOST_WIDE_INT tmpidx
= extrema
[i
].to_shwi () / eltsize
.to_shwi ();
4765 warning_at (location
, OPT_Warray_bounds
,
4766 "intermediate array offset %wi is outside array bounds "
4769 TREE_NO_WARNING (ref
) = 1;
4773 /* Searches if the expr T, located at LOCATION computes
4774 address of an ARRAY_REF, and call check_array_ref on it. */
4777 vrp_prop::search_for_addr_array (tree t
, location_t location
)
4779 /* Check each ARRAY_REF and MEM_REF in the reference chain. */
4782 if (TREE_CODE (t
) == ARRAY_REF
)
4783 check_array_ref (location
, t
, true /*ignore_off_by_one*/);
4784 else if (TREE_CODE (t
) == MEM_REF
)
4785 check_mem_ref (location
, t
, true /*ignore_off_by_one*/);
4787 t
= TREE_OPERAND (t
, 0);
4789 while (handled_component_p (t
) || TREE_CODE (t
) == MEM_REF
);
4791 if (TREE_CODE (t
) != MEM_REF
4792 || TREE_CODE (TREE_OPERAND (t
, 0)) != ADDR_EXPR
4793 || TREE_NO_WARNING (t
))
4796 tree tem
= TREE_OPERAND (TREE_OPERAND (t
, 0), 0);
4797 tree low_bound
, up_bound
, el_sz
;
4798 if (TREE_CODE (TREE_TYPE (tem
)) != ARRAY_TYPE
4799 || TREE_CODE (TREE_TYPE (TREE_TYPE (tem
))) == ARRAY_TYPE
4800 || !TYPE_DOMAIN (TREE_TYPE (tem
)))
4803 low_bound
= TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (tem
)));
4804 up_bound
= TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (tem
)));
4805 el_sz
= TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (tem
)));
4807 || TREE_CODE (low_bound
) != INTEGER_CST
4809 || TREE_CODE (up_bound
) != INTEGER_CST
4811 || TREE_CODE (el_sz
) != INTEGER_CST
)
4815 if (!mem_ref_offset (t
).is_constant (&idx
))
4818 bool warned
= false;
4819 idx
= wi::sdiv_trunc (idx
, wi::to_offset (el_sz
));
4822 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4824 fprintf (dump_file
, "Array bound warning for ");
4825 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, t
);
4826 fprintf (dump_file
, "\n");
4828 warned
= warning_at (location
, OPT_Warray_bounds
,
4829 "array subscript %wi is below "
4830 "array bounds of %qT",
4831 idx
.to_shwi (), TREE_TYPE (tem
));
4833 else if (idx
> (wi::to_offset (up_bound
)
4834 - wi::to_offset (low_bound
) + 1))
4836 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4838 fprintf (dump_file
, "Array bound warning for ");
4839 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, t
);
4840 fprintf (dump_file
, "\n");
4842 warned
= warning_at (location
, OPT_Warray_bounds
,
4843 "array subscript %wu is above "
4844 "array bounds of %qT",
4845 idx
.to_uhwi (), TREE_TYPE (tem
));
4851 inform (DECL_SOURCE_LOCATION (t
), "while referencing %qD", t
);
4853 TREE_NO_WARNING (t
) = 1;
4857 /* walk_tree() callback that checks if *TP is
4858 an ARRAY_REF inside an ADDR_EXPR (in which an array
4859 subscript one outside the valid range is allowed). Call
4860 check_array_ref for each ARRAY_REF found. The location is
4864 check_array_bounds (tree
*tp
, int *walk_subtree
, void *data
)
4867 struct walk_stmt_info
*wi
= (struct walk_stmt_info
*) data
;
4868 location_t location
;
4870 if (EXPR_HAS_LOCATION (t
))
4871 location
= EXPR_LOCATION (t
);
4873 location
= gimple_location (wi
->stmt
);
4875 *walk_subtree
= TRUE
;
4877 vrp_prop
*vrp_prop
= (class vrp_prop
*)wi
->info
;
4878 if (TREE_CODE (t
) == ARRAY_REF
)
4879 vrp_prop
->check_array_ref (location
, t
, false /*ignore_off_by_one*/);
4880 else if (TREE_CODE (t
) == MEM_REF
)
4881 vrp_prop
->check_mem_ref (location
, t
, false /*ignore_off_by_one*/);
4882 else if (TREE_CODE (t
) == ADDR_EXPR
)
4884 vrp_prop
->search_for_addr_array (t
, location
);
4885 *walk_subtree
= FALSE
;
4891 /* A dom_walker subclass for use by vrp_prop::check_all_array_refs,
4892 to walk over all statements of all reachable BBs and call
4893 check_array_bounds on them. */
4895 class check_array_bounds_dom_walker
: public dom_walker
4898 check_array_bounds_dom_walker (vrp_prop
*prop
)
4899 : dom_walker (CDI_DOMINATORS
,
4900 /* Discover non-executable edges, preserving EDGE_EXECUTABLE
4901 flags, so that we can merge in information on
4902 non-executable edges from vrp_folder . */
4903 REACHABLE_BLOCKS_PRESERVING_FLAGS
),
4905 ~check_array_bounds_dom_walker () {}
4907 edge
before_dom_children (basic_block
) FINAL OVERRIDE
;
4913 /* Implementation of dom_walker::before_dom_children.
4915 Walk over all statements of BB and call check_array_bounds on them,
4916 and determine if there's a unique successor edge. */
4919 check_array_bounds_dom_walker::before_dom_children (basic_block bb
)
4921 gimple_stmt_iterator si
;
4922 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
4924 gimple
*stmt
= gsi_stmt (si
);
4925 struct walk_stmt_info wi
;
4926 if (!gimple_has_location (stmt
)
4927 || is_gimple_debug (stmt
))
4930 memset (&wi
, 0, sizeof (wi
));
4934 walk_gimple_op (stmt
, check_array_bounds
, &wi
);
4937 /* Determine if there's a unique successor edge, and if so, return
4938 that back to dom_walker, ensuring that we don't visit blocks that
4939 became unreachable during the VRP propagation
4940 (PR tree-optimization/83312). */
4941 return find_taken_edge (bb
, NULL_TREE
);
4944 /* Walk over all statements of all reachable BBs and call check_array_bounds
4948 vrp_prop::check_all_array_refs ()
4950 check_array_bounds_dom_walker
w (this);
4951 w
.walk (ENTRY_BLOCK_PTR_FOR_FN (cfun
));
4954 /* Return true if all imm uses of VAR are either in STMT, or
4955 feed (optionally through a chain of single imm uses) GIMPLE_COND
4956 in basic block COND_BB. */
4959 all_imm_uses_in_stmt_or_feed_cond (tree var
, gimple
*stmt
, basic_block cond_bb
)
4961 use_operand_p use_p
, use2_p
;
4962 imm_use_iterator iter
;
4964 FOR_EACH_IMM_USE_FAST (use_p
, iter
, var
)
4965 if (USE_STMT (use_p
) != stmt
)
4967 gimple
*use_stmt
= USE_STMT (use_p
), *use_stmt2
;
4968 if (is_gimple_debug (use_stmt
))
4970 while (is_gimple_assign (use_stmt
)
4971 && TREE_CODE (gimple_assign_lhs (use_stmt
)) == SSA_NAME
4972 && single_imm_use (gimple_assign_lhs (use_stmt
),
4973 &use2_p
, &use_stmt2
))
4974 use_stmt
= use_stmt2
;
4975 if (gimple_code (use_stmt
) != GIMPLE_COND
4976 || gimple_bb (use_stmt
) != cond_bb
)
4989 __builtin_unreachable ();
4991 x_5 = ASSERT_EXPR <x_3, ...>;
4992 If x_3 has no other immediate uses (checked by caller),
4993 var is the x_3 var from ASSERT_EXPR, we can clear low 5 bits
4994 from the non-zero bitmask. */
4997 maybe_set_nonzero_bits (edge e
, tree var
)
4999 basic_block cond_bb
= e
->src
;
5000 gimple
*stmt
= last_stmt (cond_bb
);
5004 || gimple_code (stmt
) != GIMPLE_COND
5005 || gimple_cond_code (stmt
) != ((e
->flags
& EDGE_TRUE_VALUE
)
5006 ? EQ_EXPR
: NE_EXPR
)
5007 || TREE_CODE (gimple_cond_lhs (stmt
)) != SSA_NAME
5008 || !integer_zerop (gimple_cond_rhs (stmt
)))
5011 stmt
= SSA_NAME_DEF_STMT (gimple_cond_lhs (stmt
));
5012 if (!is_gimple_assign (stmt
)
5013 || gimple_assign_rhs_code (stmt
) != BIT_AND_EXPR
5014 || TREE_CODE (gimple_assign_rhs2 (stmt
)) != INTEGER_CST
)
5016 if (gimple_assign_rhs1 (stmt
) != var
)
5020 if (TREE_CODE (gimple_assign_rhs1 (stmt
)) != SSA_NAME
)
5022 stmt2
= SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt
));
5023 if (!gimple_assign_cast_p (stmt2
)
5024 || gimple_assign_rhs1 (stmt2
) != var
5025 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt2
))
5026 || (TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (stmt
)))
5027 != TYPE_PRECISION (TREE_TYPE (var
))))
5030 cst
= gimple_assign_rhs2 (stmt
);
5031 set_nonzero_bits (var
, wi::bit_and_not (get_nonzero_bits (var
),
5032 wi::to_wide (cst
)));
5035 /* Convert range assertion expressions into the implied copies and
5036 copy propagate away the copies. Doing the trivial copy propagation
5037 here avoids the need to run the full copy propagation pass after
5040 FIXME, this will eventually lead to copy propagation removing the
5041 names that had useful range information attached to them. For
5042 instance, if we had the assertion N_i = ASSERT_EXPR <N_j, N_j > 3>,
5043 then N_i will have the range [3, +INF].
5045 However, by converting the assertion into the implied copy
5046 operation N_i = N_j, we will then copy-propagate N_j into the uses
5047 of N_i and lose the range information. We may want to hold on to
5048 ASSERT_EXPRs a little while longer as the ranges could be used in
5049 things like jump threading.
5051 The problem with keeping ASSERT_EXPRs around is that passes after
5052 VRP need to handle them appropriately.
5054 Another approach would be to make the range information a first
5055 class property of the SSA_NAME so that it can be queried from
5056 any pass. This is made somewhat more complex by the need for
5057 multiple ranges to be associated with one SSA_NAME. */
5060 remove_range_assertions (void)
5063 gimple_stmt_iterator si
;
5064 /* 1 if looking at ASSERT_EXPRs immediately at the beginning of
5065 a basic block preceeded by GIMPLE_COND branching to it and
5066 __builtin_trap, -1 if not yet checked, 0 otherwise. */
5069 /* Note that the BSI iterator bump happens at the bottom of the
5070 loop and no bump is necessary if we're removing the statement
5071 referenced by the current BSI. */
5072 FOR_EACH_BB_FN (bb
, cfun
)
5073 for (si
= gsi_after_labels (bb
), is_unreachable
= -1; !gsi_end_p (si
);)
5075 gimple
*stmt
= gsi_stmt (si
);
5077 if (is_gimple_assign (stmt
)
5078 && gimple_assign_rhs_code (stmt
) == ASSERT_EXPR
)
5080 tree lhs
= gimple_assign_lhs (stmt
);
5081 tree rhs
= gimple_assign_rhs1 (stmt
);
5084 var
= ASSERT_EXPR_VAR (rhs
);
5086 if (TREE_CODE (var
) == SSA_NAME
5087 && !POINTER_TYPE_P (TREE_TYPE (lhs
))
5088 && SSA_NAME_RANGE_INFO (lhs
))
5090 if (is_unreachable
== -1)
5093 if (single_pred_p (bb
)
5094 && assert_unreachable_fallthru_edge_p
5095 (single_pred_edge (bb
)))
5099 if (x_7 >= 10 && x_7 < 20)
5100 __builtin_unreachable ();
5101 x_8 = ASSERT_EXPR <x_7, ...>;
5102 if the only uses of x_7 are in the ASSERT_EXPR and
5103 in the condition. In that case, we can copy the
5104 range info from x_8 computed in this pass also
5107 && all_imm_uses_in_stmt_or_feed_cond (var
, stmt
,
5110 set_range_info (var
, SSA_NAME_RANGE_TYPE (lhs
),
5111 SSA_NAME_RANGE_INFO (lhs
)->get_min (),
5112 SSA_NAME_RANGE_INFO (lhs
)->get_max ());
5113 maybe_set_nonzero_bits (single_pred_edge (bb
), var
);
5117 /* Propagate the RHS into every use of the LHS. For SSA names
5118 also propagate abnormals as it merely restores the original
5119 IL in this case (an replace_uses_by would assert). */
5120 if (TREE_CODE (var
) == SSA_NAME
)
5122 imm_use_iterator iter
;
5123 use_operand_p use_p
;
5125 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, lhs
)
5126 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
5127 SET_USE (use_p
, var
);
5130 replace_uses_by (lhs
, var
);
5132 /* And finally, remove the copy, it is not needed. */
5133 gsi_remove (&si
, true);
5134 release_defs (stmt
);
5138 if (!is_gimple_debug (gsi_stmt (si
)))
5145 /* Return true if STMT is interesting for VRP. */
5148 stmt_interesting_for_vrp (gimple
*stmt
)
5150 if (gimple_code (stmt
) == GIMPLE_PHI
)
5152 tree res
= gimple_phi_result (stmt
);
5153 return (!virtual_operand_p (res
)
5154 && (INTEGRAL_TYPE_P (TREE_TYPE (res
))
5155 || POINTER_TYPE_P (TREE_TYPE (res
))));
5157 else if (is_gimple_assign (stmt
) || is_gimple_call (stmt
))
5159 tree lhs
= gimple_get_lhs (stmt
);
5161 /* In general, assignments with virtual operands are not useful
5162 for deriving ranges, with the obvious exception of calls to
5163 builtin functions. */
5164 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
5165 && (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
5166 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
5167 && (is_gimple_call (stmt
)
5168 || !gimple_vuse (stmt
)))
5170 else if (is_gimple_call (stmt
) && gimple_call_internal_p (stmt
))
5171 switch (gimple_call_internal_fn (stmt
))
5173 case IFN_ADD_OVERFLOW
:
5174 case IFN_SUB_OVERFLOW
:
5175 case IFN_MUL_OVERFLOW
:
5176 case IFN_ATOMIC_COMPARE_EXCHANGE
:
5177 /* These internal calls return _Complex integer type,
5178 but are interesting to VRP nevertheless. */
5179 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
)
5186 else if (gimple_code (stmt
) == GIMPLE_COND
5187 || gimple_code (stmt
) == GIMPLE_SWITCH
)
5193 /* Initialization required by ssa_propagate engine. */
5196 vrp_prop::vrp_initialize ()
5200 FOR_EACH_BB_FN (bb
, cfun
)
5202 for (gphi_iterator si
= gsi_start_phis (bb
); !gsi_end_p (si
);
5205 gphi
*phi
= si
.phi ();
5206 if (!stmt_interesting_for_vrp (phi
))
5208 tree lhs
= PHI_RESULT (phi
);
5209 get_value_range (lhs
)->set_varying ();
5210 prop_set_simulate_again (phi
, false);
5213 prop_set_simulate_again (phi
, true);
5216 for (gimple_stmt_iterator si
= gsi_start_bb (bb
); !gsi_end_p (si
);
5219 gimple
*stmt
= gsi_stmt (si
);
5221 /* If the statement is a control insn, then we do not
5222 want to avoid simulating the statement once. Failure
5223 to do so means that those edges will never get added. */
5224 if (stmt_ends_bb_p (stmt
))
5225 prop_set_simulate_again (stmt
, true);
5226 else if (!stmt_interesting_for_vrp (stmt
))
5228 set_defs_to_varying (stmt
);
5229 prop_set_simulate_again (stmt
, false);
5232 prop_set_simulate_again (stmt
, true);
5237 /* Searches the case label vector VEC for the index *IDX of the CASE_LABEL
5238 that includes the value VAL. The search is restricted to the range
5239 [START_IDX, n - 1] where n is the size of VEC.
5241 If there is a CASE_LABEL for VAL, its index is placed in IDX and true is
5244 If there is no CASE_LABEL for VAL and there is one that is larger than VAL,
5245 it is placed in IDX and false is returned.
5247 If VAL is larger than any CASE_LABEL, n is placed on IDX and false is
5251 find_case_label_index (gswitch
*stmt
, size_t start_idx
, tree val
, size_t *idx
)
5253 size_t n
= gimple_switch_num_labels (stmt
);
5256 /* Find case label for minimum of the value range or the next one.
5257 At each iteration we are searching in [low, high - 1]. */
5259 for (low
= start_idx
, high
= n
; high
!= low
; )
5263 /* Note that i != high, so we never ask for n. */
5264 size_t i
= (high
+ low
) / 2;
5265 t
= gimple_switch_label (stmt
, i
);
5267 /* Cache the result of comparing CASE_LOW and val. */
5268 cmp
= tree_int_cst_compare (CASE_LOW (t
), val
);
5272 /* Ranges cannot be empty. */
5281 if (CASE_HIGH (t
) != NULL
5282 && tree_int_cst_compare (CASE_HIGH (t
), val
) >= 0)
5294 /* Searches the case label vector VEC for the range of CASE_LABELs that is used
5295 for values between MIN and MAX. The first index is placed in MIN_IDX. The
5296 last index is placed in MAX_IDX. If the range of CASE_LABELs is empty
5297 then MAX_IDX < MIN_IDX.
5298 Returns true if the default label is not needed. */
5301 find_case_label_range (gswitch
*stmt
, tree min
, tree max
, size_t *min_idx
,
5305 bool min_take_default
= !find_case_label_index (stmt
, 1, min
, &i
);
5306 bool max_take_default
= !find_case_label_index (stmt
, i
, max
, &j
);
5310 && max_take_default
)
5312 /* Only the default case label reached.
5313 Return an empty range. */
5320 bool take_default
= min_take_default
|| max_take_default
;
5324 if (max_take_default
)
5327 /* If the case label range is continuous, we do not need
5328 the default case label. Verify that. */
5329 high
= CASE_LOW (gimple_switch_label (stmt
, i
));
5330 if (CASE_HIGH (gimple_switch_label (stmt
, i
)))
5331 high
= CASE_HIGH (gimple_switch_label (stmt
, i
));
5332 for (k
= i
+ 1; k
<= j
; ++k
)
5334 low
= CASE_LOW (gimple_switch_label (stmt
, k
));
5335 if (!integer_onep (int_const_binop (MINUS_EXPR
, low
, high
)))
5337 take_default
= true;
5341 if (CASE_HIGH (gimple_switch_label (stmt
, k
)))
5342 high
= CASE_HIGH (gimple_switch_label (stmt
, k
));
5347 return !take_default
;
5351 /* Evaluate statement STMT. If the statement produces a useful range,
5352 return SSA_PROP_INTERESTING and record the SSA name with the
5353 interesting range into *OUTPUT_P.
5355 If STMT is a conditional branch and we can determine its truth
5356 value, the taken edge is recorded in *TAKEN_EDGE_P.
5358 If STMT produces a varying value, return SSA_PROP_VARYING. */
5360 enum ssa_prop_result
5361 vrp_prop::visit_stmt (gimple
*stmt
, edge
*taken_edge_p
, tree
*output_p
)
5363 tree lhs
= gimple_get_lhs (stmt
);
5365 extract_range_from_stmt (stmt
, taken_edge_p
, output_p
, &vr
);
5369 if (update_value_range (*output_p
, &vr
))
5371 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5373 fprintf (dump_file
, "Found new range for ");
5374 print_generic_expr (dump_file
, *output_p
);
5375 fprintf (dump_file
, ": ");
5376 dump_value_range (dump_file
, &vr
);
5377 fprintf (dump_file
, "\n");
5380 if (vr
.varying_p ())
5381 return SSA_PROP_VARYING
;
5383 return SSA_PROP_INTERESTING
;
5385 return SSA_PROP_NOT_INTERESTING
;
5388 if (is_gimple_call (stmt
) && gimple_call_internal_p (stmt
))
5389 switch (gimple_call_internal_fn (stmt
))
5391 case IFN_ADD_OVERFLOW
:
5392 case IFN_SUB_OVERFLOW
:
5393 case IFN_MUL_OVERFLOW
:
5394 case IFN_ATOMIC_COMPARE_EXCHANGE
:
5395 /* These internal calls return _Complex integer type,
5396 which VRP does not track, but the immediate uses
5397 thereof might be interesting. */
5398 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
)
5400 imm_use_iterator iter
;
5401 use_operand_p use_p
;
5402 enum ssa_prop_result res
= SSA_PROP_VARYING
;
5404 get_value_range (lhs
)->set_varying ();
5406 FOR_EACH_IMM_USE_FAST (use_p
, iter
, lhs
)
5408 gimple
*use_stmt
= USE_STMT (use_p
);
5409 if (!is_gimple_assign (use_stmt
))
5411 enum tree_code rhs_code
= gimple_assign_rhs_code (use_stmt
);
5412 if (rhs_code
!= REALPART_EXPR
&& rhs_code
!= IMAGPART_EXPR
)
5414 tree rhs1
= gimple_assign_rhs1 (use_stmt
);
5415 tree use_lhs
= gimple_assign_lhs (use_stmt
);
5416 if (TREE_CODE (rhs1
) != rhs_code
5417 || TREE_OPERAND (rhs1
, 0) != lhs
5418 || TREE_CODE (use_lhs
) != SSA_NAME
5419 || !stmt_interesting_for_vrp (use_stmt
)
5420 || (!INTEGRAL_TYPE_P (TREE_TYPE (use_lhs
))
5421 || !TYPE_MIN_VALUE (TREE_TYPE (use_lhs
))
5422 || !TYPE_MAX_VALUE (TREE_TYPE (use_lhs
))))
5425 /* If there is a change in the value range for any of the
5426 REALPART_EXPR/IMAGPART_EXPR immediate uses, return
5427 SSA_PROP_INTERESTING. If there are any REALPART_EXPR
5428 or IMAGPART_EXPR immediate uses, but none of them have
5429 a change in their value ranges, return
5430 SSA_PROP_NOT_INTERESTING. If there are no
5431 {REAL,IMAG}PART_EXPR uses at all,
5432 return SSA_PROP_VARYING. */
5434 extract_range_basic (&new_vr
, use_stmt
);
5435 const value_range
*old_vr
= get_value_range (use_lhs
);
5436 if (!old_vr
->equal_p (new_vr
, /*ignore_equivs=*/false))
5437 res
= SSA_PROP_INTERESTING
;
5439 res
= SSA_PROP_NOT_INTERESTING
;
5440 new_vr
.equiv_clear ();
5441 if (res
== SSA_PROP_INTERESTING
)
5455 /* All other statements produce nothing of interest for VRP, so mark
5456 their outputs varying and prevent further simulation. */
5457 set_defs_to_varying (stmt
);
5459 return (*taken_edge_p
) ? SSA_PROP_INTERESTING
: SSA_PROP_VARYING
;
5462 /* Union the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and
5463 { VR1TYPE, VR0MIN, VR0MAX } and store the result
5464 in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest
5465 possible such range. The resulting range is not canonicalized. */
5468 union_ranges (enum value_range_kind
*vr0type
,
5469 tree
*vr0min
, tree
*vr0max
,
5470 enum value_range_kind vr1type
,
5471 tree vr1min
, tree vr1max
)
5473 bool mineq
= vrp_operand_equal_p (*vr0min
, vr1min
);
5474 bool maxeq
= vrp_operand_equal_p (*vr0max
, vr1max
);
5476 /* [] is vr0, () is vr1 in the following classification comments. */
5480 if (*vr0type
== vr1type
)
5481 /* Nothing to do for equal ranges. */
5483 else if ((*vr0type
== VR_RANGE
5484 && vr1type
== VR_ANTI_RANGE
)
5485 || (*vr0type
== VR_ANTI_RANGE
5486 && vr1type
== VR_RANGE
))
5488 /* For anti-range with range union the result is varying. */
5494 else if (operand_less_p (*vr0max
, vr1min
) == 1
5495 || operand_less_p (vr1max
, *vr0min
) == 1)
5497 /* [ ] ( ) or ( ) [ ]
5498 If the ranges have an empty intersection, result of the union
5499 operation is the anti-range or if both are anti-ranges
5501 if (*vr0type
== VR_ANTI_RANGE
5502 && vr1type
== VR_ANTI_RANGE
)
5504 else if (*vr0type
== VR_ANTI_RANGE
5505 && vr1type
== VR_RANGE
)
5507 else if (*vr0type
== VR_RANGE
5508 && vr1type
== VR_ANTI_RANGE
)
5514 else if (*vr0type
== VR_RANGE
5515 && vr1type
== VR_RANGE
)
5517 /* The result is the convex hull of both ranges. */
5518 if (operand_less_p (*vr0max
, vr1min
) == 1)
5520 /* If the result can be an anti-range, create one. */
5521 if (TREE_CODE (*vr0max
) == INTEGER_CST
5522 && TREE_CODE (vr1min
) == INTEGER_CST
5523 && vrp_val_is_min (*vr0min
)
5524 && vrp_val_is_max (vr1max
))
5526 tree min
= int_const_binop (PLUS_EXPR
,
5528 build_int_cst (TREE_TYPE (*vr0max
), 1));
5529 tree max
= int_const_binop (MINUS_EXPR
,
5531 build_int_cst (TREE_TYPE (vr1min
), 1));
5532 if (!operand_less_p (max
, min
))
5534 *vr0type
= VR_ANTI_RANGE
;
5546 /* If the result can be an anti-range, create one. */
5547 if (TREE_CODE (vr1max
) == INTEGER_CST
5548 && TREE_CODE (*vr0min
) == INTEGER_CST
5549 && vrp_val_is_min (vr1min
)
5550 && vrp_val_is_max (*vr0max
))
5552 tree min
= int_const_binop (PLUS_EXPR
,
5554 build_int_cst (TREE_TYPE (vr1max
), 1));
5555 tree max
= int_const_binop (MINUS_EXPR
,
5557 build_int_cst (TREE_TYPE (*vr0min
), 1));
5558 if (!operand_less_p (max
, min
))
5560 *vr0type
= VR_ANTI_RANGE
;
5574 else if ((maxeq
|| operand_less_p (vr1max
, *vr0max
) == 1)
5575 && (mineq
|| operand_less_p (*vr0min
, vr1min
) == 1))
5577 /* [ ( ) ] or [( ) ] or [ ( )] */
5578 if (*vr0type
== VR_RANGE
5579 && vr1type
== VR_RANGE
)
5581 else if (*vr0type
== VR_ANTI_RANGE
5582 && vr1type
== VR_ANTI_RANGE
)
5588 else if (*vr0type
== VR_ANTI_RANGE
5589 && vr1type
== VR_RANGE
)
5591 /* Arbitrarily choose the right or left gap. */
5592 if (!mineq
&& TREE_CODE (vr1min
) == INTEGER_CST
)
5593 *vr0max
= int_const_binop (MINUS_EXPR
, vr1min
,
5594 build_int_cst (TREE_TYPE (vr1min
), 1));
5595 else if (!maxeq
&& TREE_CODE (vr1max
) == INTEGER_CST
)
5596 *vr0min
= int_const_binop (PLUS_EXPR
, vr1max
,
5597 build_int_cst (TREE_TYPE (vr1max
), 1));
5601 else if (*vr0type
== VR_RANGE
5602 && vr1type
== VR_ANTI_RANGE
)
5603 /* The result covers everything. */
5608 else if ((maxeq
|| operand_less_p (*vr0max
, vr1max
) == 1)
5609 && (mineq
|| operand_less_p (vr1min
, *vr0min
) == 1))
5611 /* ( [ ] ) or ([ ] ) or ( [ ]) */
5612 if (*vr0type
== VR_RANGE
5613 && vr1type
== VR_RANGE
)
5619 else if (*vr0type
== VR_ANTI_RANGE
5620 && vr1type
== VR_ANTI_RANGE
)
5622 else if (*vr0type
== VR_RANGE
5623 && vr1type
== VR_ANTI_RANGE
)
5625 *vr0type
= VR_ANTI_RANGE
;
5626 if (!mineq
&& TREE_CODE (*vr0min
) == INTEGER_CST
)
5628 *vr0max
= int_const_binop (MINUS_EXPR
, *vr0min
,
5629 build_int_cst (TREE_TYPE (*vr0min
), 1));
5632 else if (!maxeq
&& TREE_CODE (*vr0max
) == INTEGER_CST
)
5634 *vr0min
= int_const_binop (PLUS_EXPR
, *vr0max
,
5635 build_int_cst (TREE_TYPE (*vr0max
), 1));
5641 else if (*vr0type
== VR_ANTI_RANGE
5642 && vr1type
== VR_RANGE
)
5643 /* The result covers everything. */
5648 else if ((operand_less_p (vr1min
, *vr0max
) == 1
5649 || operand_equal_p (vr1min
, *vr0max
, 0))
5650 && operand_less_p (*vr0min
, vr1min
) == 1
5651 && operand_less_p (*vr0max
, vr1max
) == 1)
5653 /* [ ( ] ) or [ ]( ) */
5654 if (*vr0type
== VR_RANGE
5655 && vr1type
== VR_RANGE
)
5657 else if (*vr0type
== VR_ANTI_RANGE
5658 && vr1type
== VR_ANTI_RANGE
)
5660 else if (*vr0type
== VR_ANTI_RANGE
5661 && vr1type
== VR_RANGE
)
5663 if (TREE_CODE (vr1min
) == INTEGER_CST
)
5664 *vr0max
= int_const_binop (MINUS_EXPR
, vr1min
,
5665 build_int_cst (TREE_TYPE (vr1min
), 1));
5669 else if (*vr0type
== VR_RANGE
5670 && vr1type
== VR_ANTI_RANGE
)
5672 if (TREE_CODE (*vr0max
) == INTEGER_CST
)
5675 *vr0min
= int_const_binop (PLUS_EXPR
, *vr0max
,
5676 build_int_cst (TREE_TYPE (*vr0max
), 1));
5685 else if ((operand_less_p (*vr0min
, vr1max
) == 1
5686 || operand_equal_p (*vr0min
, vr1max
, 0))
5687 && operand_less_p (vr1min
, *vr0min
) == 1
5688 && operand_less_p (vr1max
, *vr0max
) == 1)
5690 /* ( [ ) ] or ( )[ ] */
5691 if (*vr0type
== VR_RANGE
5692 && vr1type
== VR_RANGE
)
5694 else if (*vr0type
== VR_ANTI_RANGE
5695 && vr1type
== VR_ANTI_RANGE
)
5697 else if (*vr0type
== VR_ANTI_RANGE
5698 && vr1type
== VR_RANGE
)
5700 if (TREE_CODE (vr1max
) == INTEGER_CST
)
5701 *vr0min
= int_const_binop (PLUS_EXPR
, vr1max
,
5702 build_int_cst (TREE_TYPE (vr1max
), 1));
5706 else if (*vr0type
== VR_RANGE
5707 && vr1type
== VR_ANTI_RANGE
)
5709 if (TREE_CODE (*vr0min
) == INTEGER_CST
)
5712 *vr0max
= int_const_binop (MINUS_EXPR
, *vr0min
,
5713 build_int_cst (TREE_TYPE (*vr0min
), 1));
5728 *vr0type
= VR_VARYING
;
5729 *vr0min
= NULL_TREE
;
5730 *vr0max
= NULL_TREE
;
5733 /* Intersect the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and
5734 { VR1TYPE, VR0MIN, VR0MAX } and store the result
5735 in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest
5736 possible such range. The resulting range is not canonicalized. */
5739 intersect_ranges (enum value_range_kind
*vr0type
,
5740 tree
*vr0min
, tree
*vr0max
,
5741 enum value_range_kind vr1type
,
5742 tree vr1min
, tree vr1max
)
5744 bool mineq
= vrp_operand_equal_p (*vr0min
, vr1min
);
5745 bool maxeq
= vrp_operand_equal_p (*vr0max
, vr1max
);
5747 /* [] is vr0, () is vr1 in the following classification comments. */
5751 if (*vr0type
== vr1type
)
5752 /* Nothing to do for equal ranges. */
5754 else if ((*vr0type
== VR_RANGE
5755 && vr1type
== VR_ANTI_RANGE
)
5756 || (*vr0type
== VR_ANTI_RANGE
5757 && vr1type
== VR_RANGE
))
5759 /* For anti-range with range intersection the result is empty. */
5760 *vr0type
= VR_UNDEFINED
;
5761 *vr0min
= NULL_TREE
;
5762 *vr0max
= NULL_TREE
;
5767 else if (operand_less_p (*vr0max
, vr1min
) == 1
5768 || operand_less_p (vr1max
, *vr0min
) == 1)
5770 /* [ ] ( ) or ( ) [ ]
5771 If the ranges have an empty intersection, the result of the
5772 intersect operation is the range for intersecting an
5773 anti-range with a range or empty when intersecting two ranges. */
5774 if (*vr0type
== VR_RANGE
5775 && vr1type
== VR_ANTI_RANGE
)
5777 else if (*vr0type
== VR_ANTI_RANGE
5778 && vr1type
== VR_RANGE
)
5784 else if (*vr0type
== VR_RANGE
5785 && vr1type
== VR_RANGE
)
5787 *vr0type
= VR_UNDEFINED
;
5788 *vr0min
= NULL_TREE
;
5789 *vr0max
= NULL_TREE
;
5791 else if (*vr0type
== VR_ANTI_RANGE
5792 && vr1type
== VR_ANTI_RANGE
)
5794 /* If the anti-ranges are adjacent to each other merge them. */
5795 if (TREE_CODE (*vr0max
) == INTEGER_CST
5796 && TREE_CODE (vr1min
) == INTEGER_CST
5797 && operand_less_p (*vr0max
, vr1min
) == 1
5798 && integer_onep (int_const_binop (MINUS_EXPR
,
5801 else if (TREE_CODE (vr1max
) == INTEGER_CST
5802 && TREE_CODE (*vr0min
) == INTEGER_CST
5803 && operand_less_p (vr1max
, *vr0min
) == 1
5804 && integer_onep (int_const_binop (MINUS_EXPR
,
5807 /* Else arbitrarily take VR0. */
5810 else if ((maxeq
|| operand_less_p (vr1max
, *vr0max
) == 1)
5811 && (mineq
|| operand_less_p (*vr0min
, vr1min
) == 1))
5813 /* [ ( ) ] or [( ) ] or [ ( )] */
5814 if (*vr0type
== VR_RANGE
5815 && vr1type
== VR_RANGE
)
5817 /* If both are ranges the result is the inner one. */
5822 else if (*vr0type
== VR_RANGE
5823 && vr1type
== VR_ANTI_RANGE
)
5825 /* Choose the right gap if the left one is empty. */
5828 if (TREE_CODE (vr1max
) != INTEGER_CST
)
5830 else if (TYPE_PRECISION (TREE_TYPE (vr1max
)) == 1
5831 && !TYPE_UNSIGNED (TREE_TYPE (vr1max
)))
5833 = int_const_binop (MINUS_EXPR
, vr1max
,
5834 build_int_cst (TREE_TYPE (vr1max
), -1));
5837 = int_const_binop (PLUS_EXPR
, vr1max
,
5838 build_int_cst (TREE_TYPE (vr1max
), 1));
5840 /* Choose the left gap if the right one is empty. */
5843 if (TREE_CODE (vr1min
) != INTEGER_CST
)
5845 else if (TYPE_PRECISION (TREE_TYPE (vr1min
)) == 1
5846 && !TYPE_UNSIGNED (TREE_TYPE (vr1min
)))
5848 = int_const_binop (PLUS_EXPR
, vr1min
,
5849 build_int_cst (TREE_TYPE (vr1min
), -1));
5852 = int_const_binop (MINUS_EXPR
, vr1min
,
5853 build_int_cst (TREE_TYPE (vr1min
), 1));
5855 /* Choose the anti-range if the range is effectively varying. */
5856 else if (vrp_val_is_min (*vr0min
)
5857 && vrp_val_is_max (*vr0max
))
5863 /* Else choose the range. */
5865 else if (*vr0type
== VR_ANTI_RANGE
5866 && vr1type
== VR_ANTI_RANGE
)
5867 /* If both are anti-ranges the result is the outer one. */
5869 else if (*vr0type
== VR_ANTI_RANGE
5870 && vr1type
== VR_RANGE
)
5872 /* The intersection is empty. */
5873 *vr0type
= VR_UNDEFINED
;
5874 *vr0min
= NULL_TREE
;
5875 *vr0max
= NULL_TREE
;
5880 else if ((maxeq
|| operand_less_p (*vr0max
, vr1max
) == 1)
5881 && (mineq
|| operand_less_p (vr1min
, *vr0min
) == 1))
5883 /* ( [ ] ) or ([ ] ) or ( [ ]) */
5884 if (*vr0type
== VR_RANGE
5885 && vr1type
== VR_RANGE
)
5886 /* Choose the inner range. */
5888 else if (*vr0type
== VR_ANTI_RANGE
5889 && vr1type
== VR_RANGE
)
5891 /* Choose the right gap if the left is empty. */
5894 *vr0type
= VR_RANGE
;
5895 if (TREE_CODE (*vr0max
) != INTEGER_CST
)
5897 else if (TYPE_PRECISION (TREE_TYPE (*vr0max
)) == 1
5898 && !TYPE_UNSIGNED (TREE_TYPE (*vr0max
)))
5900 = int_const_binop (MINUS_EXPR
, *vr0max
,
5901 build_int_cst (TREE_TYPE (*vr0max
), -1));
5904 = int_const_binop (PLUS_EXPR
, *vr0max
,
5905 build_int_cst (TREE_TYPE (*vr0max
), 1));
5908 /* Choose the left gap if the right is empty. */
5911 *vr0type
= VR_RANGE
;
5912 if (TREE_CODE (*vr0min
) != INTEGER_CST
)
5914 else if (TYPE_PRECISION (TREE_TYPE (*vr0min
)) == 1
5915 && !TYPE_UNSIGNED (TREE_TYPE (*vr0min
)))
5917 = int_const_binop (PLUS_EXPR
, *vr0min
,
5918 build_int_cst (TREE_TYPE (*vr0min
), -1));
5921 = int_const_binop (MINUS_EXPR
, *vr0min
,
5922 build_int_cst (TREE_TYPE (*vr0min
), 1));
5925 /* Choose the anti-range if the range is effectively varying. */
5926 else if (vrp_val_is_min (vr1min
)
5927 && vrp_val_is_max (vr1max
))
5929 /* Choose the anti-range if it is ~[0,0], that range is special
5930 enough to special case when vr1's range is relatively wide.
5931 At least for types bigger than int - this covers pointers
5932 and arguments to functions like ctz. */
5933 else if (*vr0min
== *vr0max
5934 && integer_zerop (*vr0min
)
5935 && ((TYPE_PRECISION (TREE_TYPE (*vr0min
))
5936 >= TYPE_PRECISION (integer_type_node
))
5937 || POINTER_TYPE_P (TREE_TYPE (*vr0min
)))
5938 && TREE_CODE (vr1max
) == INTEGER_CST
5939 && TREE_CODE (vr1min
) == INTEGER_CST
5940 && (wi::clz (wi::to_wide (vr1max
) - wi::to_wide (vr1min
))
5941 < TYPE_PRECISION (TREE_TYPE (*vr0min
)) / 2))
5943 /* Else choose the range. */
5951 else if (*vr0type
== VR_ANTI_RANGE
5952 && vr1type
== VR_ANTI_RANGE
)
5954 /* If both are anti-ranges the result is the outer one. */
5959 else if (vr1type
== VR_ANTI_RANGE
5960 && *vr0type
== VR_RANGE
)
5962 /* The intersection is empty. */
5963 *vr0type
= VR_UNDEFINED
;
5964 *vr0min
= NULL_TREE
;
5965 *vr0max
= NULL_TREE
;
5970 else if ((operand_less_p (vr1min
, *vr0max
) == 1
5971 || operand_equal_p (vr1min
, *vr0max
, 0))
5972 && operand_less_p (*vr0min
, vr1min
) == 1)
5974 /* [ ( ] ) or [ ]( ) */
5975 if (*vr0type
== VR_ANTI_RANGE
5976 && vr1type
== VR_ANTI_RANGE
)
5978 else if (*vr0type
== VR_RANGE
5979 && vr1type
== VR_RANGE
)
5981 else if (*vr0type
== VR_RANGE
5982 && vr1type
== VR_ANTI_RANGE
)
5984 if (TREE_CODE (vr1min
) == INTEGER_CST
)
5985 *vr0max
= int_const_binop (MINUS_EXPR
, vr1min
,
5986 build_int_cst (TREE_TYPE (vr1min
), 1));
5990 else if (*vr0type
== VR_ANTI_RANGE
5991 && vr1type
== VR_RANGE
)
5993 *vr0type
= VR_RANGE
;
5994 if (TREE_CODE (*vr0max
) == INTEGER_CST
)
5995 *vr0min
= int_const_binop (PLUS_EXPR
, *vr0max
,
5996 build_int_cst (TREE_TYPE (*vr0max
), 1));
6004 else if ((operand_less_p (*vr0min
, vr1max
) == 1
6005 || operand_equal_p (*vr0min
, vr1max
, 0))
6006 && operand_less_p (vr1min
, *vr0min
) == 1)
6008 /* ( [ ) ] or ( )[ ] */
6009 if (*vr0type
== VR_ANTI_RANGE
6010 && vr1type
== VR_ANTI_RANGE
)
6012 else if (*vr0type
== VR_RANGE
6013 && vr1type
== VR_RANGE
)
6015 else if (*vr0type
== VR_RANGE
6016 && vr1type
== VR_ANTI_RANGE
)
6018 if (TREE_CODE (vr1max
) == INTEGER_CST
)
6019 *vr0min
= int_const_binop (PLUS_EXPR
, vr1max
,
6020 build_int_cst (TREE_TYPE (vr1max
), 1));
6024 else if (*vr0type
== VR_ANTI_RANGE
6025 && vr1type
== VR_RANGE
)
6027 *vr0type
= VR_RANGE
;
6028 if (TREE_CODE (*vr0min
) == INTEGER_CST
)
6029 *vr0max
= int_const_binop (MINUS_EXPR
, *vr0min
,
6030 build_int_cst (TREE_TYPE (*vr0min
), 1));
6039 /* As a fallback simply use { *VRTYPE, *VR0MIN, *VR0MAX } as
6040 result for the intersection. That's always a conservative
6041 correct estimate unless VR1 is a constant singleton range
6042 in which case we choose that. */
6043 if (vr1type
== VR_RANGE
6044 && is_gimple_min_invariant (vr1min
)
6045 && vrp_operand_equal_p (vr1min
, vr1max
))
6054 /* Intersect the two value-ranges *VR0 and *VR1 and store the result
6055 in *VR0. This may not be the smallest possible such range. */
6058 value_range::intersect_helper (value_range
*vr0
, const value_range
*vr1
)
6060 /* If either range is VR_VARYING the other one wins. */
6061 if (vr1
->varying_p ())
6063 if (vr0
->varying_p ())
6065 vr0
->deep_copy (vr1
);
6069 /* When either range is VR_UNDEFINED the resulting range is
6070 VR_UNDEFINED, too. */
6071 if (vr0
->undefined_p ())
6073 if (vr1
->undefined_p ())
6075 vr0
->set_undefined ();
6079 value_range_kind vr0type
= vr0
->kind ();
6080 tree vr0min
= vr0
->min ();
6081 tree vr0max
= vr0
->max ();
6082 intersect_ranges (&vr0type
, &vr0min
, &vr0max
,
6083 vr1
->kind (), vr1
->min (), vr1
->max ());
6084 /* Make sure to canonicalize the result though as the inversion of a
6085 VR_RANGE can still be a VR_RANGE. Work on a temporary so we can
6086 fall back to vr0 when this turns things to varying. */
6088 tem
.set_and_canonicalize (vr0type
, vr0min
, vr0max
);
6089 /* If that failed, use the saved original VR0. */
6090 if (tem
.varying_p ())
6092 vr0
->update (tem
.kind (), tem
.min (), tem
.max ());
6094 /* If the result is VR_UNDEFINED there is no need to mess with
6095 the equivalencies. */
6096 if (vr0
->undefined_p ())
6099 /* The resulting set of equivalences for range intersection is the union of
6101 if (vr0
->m_equiv
&& vr1
->m_equiv
&& vr0
->m_equiv
!= vr1
->m_equiv
)
6102 bitmap_ior_into (vr0
->m_equiv
, vr1
->m_equiv
);
6103 else if (vr1
->m_equiv
&& !vr0
->m_equiv
)
6105 /* All equivalence bitmaps are allocated from the same obstack. So
6106 we can use the obstack associated with VR to allocate vr0->equiv. */
6107 vr0
->m_equiv
= BITMAP_ALLOC (vr1
->m_equiv
->obstack
);
6108 bitmap_copy (m_equiv
, vr1
->m_equiv
);
6113 value_range::intersect (const value_range
*other
)
6115 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6117 fprintf (dump_file
, "Intersecting\n ");
6118 dump_value_range (dump_file
, this);
6119 fprintf (dump_file
, "\nand\n ");
6120 dump_value_range (dump_file
, other
);
6121 fprintf (dump_file
, "\n");
6123 intersect_helper (this, other
);
6124 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6126 fprintf (dump_file
, "to\n ");
6127 dump_value_range (dump_file
, this);
6128 fprintf (dump_file
, "\n");
6132 /* Helper for meet operation for value ranges. Given two value ranges VR0 and
6133 VR1, return a range that contains both VR0 and VR1. This may not be the
6134 smallest possible such range. */
6137 value_range_base::union_helper (const value_range_base
*vr0
,
6138 const value_range_base
*vr1
)
6140 /* VR0 has the resulting range if VR1 is undefined or VR0 is varying. */
6141 if (vr1
->undefined_p ()
6142 || vr0
->varying_p ())
6145 /* VR1 has the resulting range if VR0 is undefined or VR1 is varying. */
6146 if (vr0
->undefined_p ()
6147 || vr1
->varying_p ())
6150 value_range_kind vr0type
= vr0
->kind ();
6151 tree vr0min
= vr0
->min ();
6152 tree vr0max
= vr0
->max ();
6153 union_ranges (&vr0type
, &vr0min
, &vr0max
,
6154 vr1
->kind (), vr1
->min (), vr1
->max ());
6156 /* Work on a temporary so we can still use vr0 when union returns varying. */
6158 tem
.set_and_canonicalize (vr0type
, vr0min
, vr0max
);
6160 /* Failed to find an efficient meet. Before giving up and setting
6161 the result to VARYING, see if we can at least derive a useful
6163 if (tem
.varying_p ()
6164 && range_includes_zero_p (vr0
) == 0
6165 && range_includes_zero_p (vr1
) == 0)
6167 tem
.set_nonnull (vr0
->type ());
6175 /* Meet operation for value ranges. Given two value ranges VR0 and
6176 VR1, store in VR0 a range that contains both VR0 and VR1. This
6177 may not be the smallest possible such range. */
6180 value_range_base::union_ (const value_range_base
*other
)
6182 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6184 fprintf (dump_file
, "Meeting\n ");
6185 dump_value_range (dump_file
, this);
6186 fprintf (dump_file
, "\nand\n ");
6187 dump_value_range (dump_file
, other
);
6188 fprintf (dump_file
, "\n");
6191 *this = union_helper (this, other
);
6193 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6195 fprintf (dump_file
, "to\n ");
6196 dump_value_range (dump_file
, this);
6197 fprintf (dump_file
, "\n");
6202 value_range::union_ (const value_range
*other
)
6204 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6206 fprintf (dump_file
, "Meeting\n ");
6207 dump_value_range (dump_file
, this);
6208 fprintf (dump_file
, "\nand\n ");
6209 dump_value_range (dump_file
, other
);
6210 fprintf (dump_file
, "\n");
6213 /* If THIS is undefined we want to pick up equivalences from OTHER.
6214 Just special-case this here rather than trying to fixup after the fact. */
6215 if (this->undefined_p ())
6216 this->deep_copy (other
);
6219 value_range_base tem
= union_helper (this, other
);
6220 this->update (tem
.kind (), tem
.min (), tem
.max ());
6222 /* The resulting set of equivalences is always the intersection of
6224 if (this->m_equiv
&& other
->m_equiv
&& this->m_equiv
!= other
->m_equiv
)
6225 bitmap_and_into (this->m_equiv
, other
->m_equiv
);
6226 else if (this->m_equiv
&& !other
->m_equiv
)
6227 bitmap_clear (this->m_equiv
);
6230 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6232 fprintf (dump_file
, "to\n ");
6233 dump_value_range (dump_file
, this);
6234 fprintf (dump_file
, "\n");
6238 /* Visit all arguments for PHI node PHI that flow through executable
6239 edges. If a valid value range can be derived from all the incoming
6240 value ranges, set a new range for the LHS of PHI. */
6242 enum ssa_prop_result
6243 vrp_prop::visit_phi (gphi
*phi
)
6245 tree lhs
= PHI_RESULT (phi
);
6246 value_range vr_result
;
6247 extract_range_from_phi_node (phi
, &vr_result
);
6248 if (update_value_range (lhs
, &vr_result
))
6250 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6252 fprintf (dump_file
, "Found new range for ");
6253 print_generic_expr (dump_file
, lhs
);
6254 fprintf (dump_file
, ": ");
6255 dump_value_range (dump_file
, &vr_result
);
6256 fprintf (dump_file
, "\n");
6259 if (vr_result
.varying_p ())
6260 return SSA_PROP_VARYING
;
6262 return SSA_PROP_INTERESTING
;
6265 /* Nothing changed, don't add outgoing edges. */
6266 return SSA_PROP_NOT_INTERESTING
;
6269 class vrp_folder
: public substitute_and_fold_engine
6272 tree
get_value (tree
) FINAL OVERRIDE
;
6273 bool fold_stmt (gimple_stmt_iterator
*) FINAL OVERRIDE
;
6274 bool fold_predicate_in (gimple_stmt_iterator
*);
6276 class vr_values
*vr_values
;
6279 tree
vrp_evaluate_conditional (tree_code code
, tree op0
,
6280 tree op1
, gimple
*stmt
)
6281 { return vr_values
->vrp_evaluate_conditional (code
, op0
, op1
, stmt
); }
6282 bool simplify_stmt_using_ranges (gimple_stmt_iterator
*gsi
)
6283 { return vr_values
->simplify_stmt_using_ranges (gsi
); }
6284 tree
op_with_constant_singleton_value_range (tree op
)
6285 { return vr_values
->op_with_constant_singleton_value_range (op
); }
6288 /* If the statement pointed by SI has a predicate whose value can be
6289 computed using the value range information computed by VRP, compute
6290 its value and return true. Otherwise, return false. */
6293 vrp_folder::fold_predicate_in (gimple_stmt_iterator
*si
)
6295 bool assignment_p
= false;
6297 gimple
*stmt
= gsi_stmt (*si
);
6299 if (is_gimple_assign (stmt
)
6300 && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt
)) == tcc_comparison
)
6302 assignment_p
= true;
6303 val
= vrp_evaluate_conditional (gimple_assign_rhs_code (stmt
),
6304 gimple_assign_rhs1 (stmt
),
6305 gimple_assign_rhs2 (stmt
),
6308 else if (gcond
*cond_stmt
= dyn_cast
<gcond
*> (stmt
))
6309 val
= vrp_evaluate_conditional (gimple_cond_code (cond_stmt
),
6310 gimple_cond_lhs (cond_stmt
),
6311 gimple_cond_rhs (cond_stmt
),
6319 val
= fold_convert (gimple_expr_type (stmt
), val
);
6323 fprintf (dump_file
, "Folding predicate ");
6324 print_gimple_expr (dump_file
, stmt
, 0);
6325 fprintf (dump_file
, " to ");
6326 print_generic_expr (dump_file
, val
);
6327 fprintf (dump_file
, "\n");
6330 if (is_gimple_assign (stmt
))
6331 gimple_assign_set_rhs_from_tree (si
, val
);
6334 gcc_assert (gimple_code (stmt
) == GIMPLE_COND
);
6335 gcond
*cond_stmt
= as_a
<gcond
*> (stmt
);
6336 if (integer_zerop (val
))
6337 gimple_cond_make_false (cond_stmt
);
6338 else if (integer_onep (val
))
6339 gimple_cond_make_true (cond_stmt
);
6350 /* Callback for substitute_and_fold folding the stmt at *SI. */
6353 vrp_folder::fold_stmt (gimple_stmt_iterator
*si
)
6355 if (fold_predicate_in (si
))
6358 return simplify_stmt_using_ranges (si
);
6361 /* If OP has a value range with a single constant value return that,
6362 otherwise return NULL_TREE. This returns OP itself if OP is a
6365 Implemented as a pure wrapper right now, but this will change. */
6368 vrp_folder::get_value (tree op
)
6370 return op_with_constant_singleton_value_range (op
);
6373 /* Return the LHS of any ASSERT_EXPR where OP appears as the first
6374 argument to the ASSERT_EXPR and in which the ASSERT_EXPR dominates
6375 BB. If no such ASSERT_EXPR is found, return OP. */
6378 lhs_of_dominating_assert (tree op
, basic_block bb
, gimple
*stmt
)
6380 imm_use_iterator imm_iter
;
6382 use_operand_p use_p
;
6384 if (TREE_CODE (op
) == SSA_NAME
)
6386 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, op
)
6388 use_stmt
= USE_STMT (use_p
);
6389 if (use_stmt
!= stmt
6390 && gimple_assign_single_p (use_stmt
)
6391 && TREE_CODE (gimple_assign_rhs1 (use_stmt
)) == ASSERT_EXPR
6392 && TREE_OPERAND (gimple_assign_rhs1 (use_stmt
), 0) == op
6393 && dominated_by_p (CDI_DOMINATORS
, bb
, gimple_bb (use_stmt
)))
6394 return gimple_assign_lhs (use_stmt
);
6401 static class vr_values
*x_vr_values
;
6403 /* A trivial wrapper so that we can present the generic jump threading
6404 code with a simple API for simplifying statements. STMT is the
6405 statement we want to simplify, WITHIN_STMT provides the location
6406 for any overflow warnings. */
6409 simplify_stmt_for_jump_threading (gimple
*stmt
, gimple
*within_stmt
,
6410 class avail_exprs_stack
*avail_exprs_stack ATTRIBUTE_UNUSED
,
6413 /* First see if the conditional is in the hash table. */
6414 tree cached_lhs
= avail_exprs_stack
->lookup_avail_expr (stmt
, false, true);
6415 if (cached_lhs
&& is_gimple_min_invariant (cached_lhs
))
6418 vr_values
*vr_values
= x_vr_values
;
6419 if (gcond
*cond_stmt
= dyn_cast
<gcond
*> (stmt
))
6421 tree op0
= gimple_cond_lhs (cond_stmt
);
6422 op0
= lhs_of_dominating_assert (op0
, bb
, stmt
);
6424 tree op1
= gimple_cond_rhs (cond_stmt
);
6425 op1
= lhs_of_dominating_assert (op1
, bb
, stmt
);
6427 return vr_values
->vrp_evaluate_conditional (gimple_cond_code (cond_stmt
),
6428 op0
, op1
, within_stmt
);
6431 /* We simplify a switch statement by trying to determine which case label
6432 will be taken. If we are successful then we return the corresponding
6434 if (gswitch
*switch_stmt
= dyn_cast
<gswitch
*> (stmt
))
6436 tree op
= gimple_switch_index (switch_stmt
);
6437 if (TREE_CODE (op
) != SSA_NAME
)
6440 op
= lhs_of_dominating_assert (op
, bb
, stmt
);
6442 const value_range
*vr
= vr_values
->get_value_range (op
);
6443 if (vr
->undefined_p ()
6445 || vr
->symbolic_p ())
6448 if (vr
->kind () == VR_RANGE
)
6451 /* Get the range of labels that contain a part of the operand's
6453 find_case_label_range (switch_stmt
, vr
->min (), vr
->max (), &i
, &j
);
6455 /* Is there only one such label? */
6458 tree label
= gimple_switch_label (switch_stmt
, i
);
6460 /* The i'th label will be taken only if the value range of the
6461 operand is entirely within the bounds of this label. */
6462 if (CASE_HIGH (label
) != NULL_TREE
6463 ? (tree_int_cst_compare (CASE_LOW (label
), vr
->min ()) <= 0
6464 && tree_int_cst_compare (CASE_HIGH (label
),
6466 : (tree_int_cst_equal (CASE_LOW (label
), vr
->min ())
6467 && tree_int_cst_equal (vr
->min (), vr
->max ())))
6471 /* If there are no such labels then the default label will be
6474 return gimple_switch_label (switch_stmt
, 0);
6477 if (vr
->kind () == VR_ANTI_RANGE
)
6479 unsigned n
= gimple_switch_num_labels (switch_stmt
);
6480 tree min_label
= gimple_switch_label (switch_stmt
, 1);
6481 tree max_label
= gimple_switch_label (switch_stmt
, n
- 1);
6483 /* The default label will be taken only if the anti-range of the
6484 operand is entirely outside the bounds of all the (non-default)
6486 if (tree_int_cst_compare (vr
->min (), CASE_LOW (min_label
)) <= 0
6487 && (CASE_HIGH (max_label
) != NULL_TREE
6488 ? tree_int_cst_compare (vr
->max (),
6489 CASE_HIGH (max_label
)) >= 0
6490 : tree_int_cst_compare (vr
->max (),
6491 CASE_LOW (max_label
)) >= 0))
6492 return gimple_switch_label (switch_stmt
, 0);
6498 if (gassign
*assign_stmt
= dyn_cast
<gassign
*> (stmt
))
6500 tree lhs
= gimple_assign_lhs (assign_stmt
);
6501 if (TREE_CODE (lhs
) == SSA_NAME
6502 && (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
6503 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
6504 && stmt_interesting_for_vrp (stmt
))
6509 vr_values
->extract_range_from_stmt (stmt
, &dummy_e
,
6510 &dummy_tree
, &new_vr
);
6512 if (new_vr
.singleton_p (&singleton
))
6520 class vrp_dom_walker
: public dom_walker
6523 vrp_dom_walker (cdi_direction direction
,
6524 class const_and_copies
*const_and_copies
,
6525 class avail_exprs_stack
*avail_exprs_stack
)
6526 : dom_walker (direction
, REACHABLE_BLOCKS
),
6527 m_const_and_copies (const_and_copies
),
6528 m_avail_exprs_stack (avail_exprs_stack
),
6529 m_dummy_cond (NULL
) {}
6531 virtual edge
before_dom_children (basic_block
);
6532 virtual void after_dom_children (basic_block
);
6534 class vr_values
*vr_values
;
6537 class const_and_copies
*m_const_and_copies
;
6538 class avail_exprs_stack
*m_avail_exprs_stack
;
6540 gcond
*m_dummy_cond
;
6544 /* Called before processing dominator children of BB. We want to look
6545 at ASSERT_EXPRs and record information from them in the appropriate
6548 We could look at other statements here. It's not seen as likely
6549 to significantly increase the jump threads we discover. */
6552 vrp_dom_walker::before_dom_children (basic_block bb
)
6554 gimple_stmt_iterator gsi
;
6556 m_avail_exprs_stack
->push_marker ();
6557 m_const_and_copies
->push_marker ();
6558 for (gsi
= gsi_start_nondebug_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6560 gimple
*stmt
= gsi_stmt (gsi
);
6561 if (gimple_assign_single_p (stmt
)
6562 && TREE_CODE (gimple_assign_rhs1 (stmt
)) == ASSERT_EXPR
)
6564 tree rhs1
= gimple_assign_rhs1 (stmt
);
6565 tree cond
= TREE_OPERAND (rhs1
, 1);
6566 tree inverted
= invert_truthvalue (cond
);
6567 vec
<cond_equivalence
> p
;
6569 record_conditions (&p
, cond
, inverted
);
6570 for (unsigned int i
= 0; i
< p
.length (); i
++)
6571 m_avail_exprs_stack
->record_cond (&p
[i
]);
6573 tree lhs
= gimple_assign_lhs (stmt
);
6574 m_const_and_copies
->record_const_or_copy (lhs
,
6575 TREE_OPERAND (rhs1
, 0));
6584 /* Called after processing dominator children of BB. This is where we
6585 actually call into the threader. */
6587 vrp_dom_walker::after_dom_children (basic_block bb
)
6590 m_dummy_cond
= gimple_build_cond (NE_EXPR
,
6591 integer_zero_node
, integer_zero_node
,
6594 x_vr_values
= vr_values
;
6595 thread_outgoing_edges (bb
, m_dummy_cond
, m_const_and_copies
,
6596 m_avail_exprs_stack
, NULL
,
6597 simplify_stmt_for_jump_threading
);
6600 m_avail_exprs_stack
->pop_to_marker ();
6601 m_const_and_copies
->pop_to_marker ();
6604 /* Blocks which have more than one predecessor and more than
6605 one successor present jump threading opportunities, i.e.,
6606 when the block is reached from a specific predecessor, we
6607 may be able to determine which of the outgoing edges will
6608 be traversed. When this optimization applies, we are able
6609 to avoid conditionals at runtime and we may expose secondary
6610 optimization opportunities.
6612 This routine is effectively a driver for the generic jump
6613 threading code. It basically just presents the generic code
6614 with edges that may be suitable for jump threading.
6616 Unlike DOM, we do not iterate VRP if jump threading was successful.
6617 While iterating may expose new opportunities for VRP, it is expected
6618 those opportunities would be very limited and the compile time cost
6619 to expose those opportunities would be significant.
6621 As jump threading opportunities are discovered, they are registered
6622 for later realization. */
6625 identify_jump_threads (class vr_values
*vr_values
)
6627 /* Ugh. When substituting values earlier in this pass we can
6628 wipe the dominance information. So rebuild the dominator
6629 information as we need it within the jump threading code. */
6630 calculate_dominance_info (CDI_DOMINATORS
);
6632 /* We do not allow VRP information to be used for jump threading
6633 across a back edge in the CFG. Otherwise it becomes too
6634 difficult to avoid eliminating loop exit tests. Of course
6635 EDGE_DFS_BACK is not accurate at this time so we have to
6637 mark_dfs_back_edges ();
6639 /* Allocate our unwinder stack to unwind any temporary equivalences
6640 that might be recorded. */
6641 const_and_copies
*equiv_stack
= new const_and_copies ();
6643 hash_table
<expr_elt_hasher
> *avail_exprs
6644 = new hash_table
<expr_elt_hasher
> (1024);
6645 avail_exprs_stack
*avail_exprs_stack
6646 = new class avail_exprs_stack (avail_exprs
);
6648 vrp_dom_walker
walker (CDI_DOMINATORS
, equiv_stack
, avail_exprs_stack
);
6649 walker
.vr_values
= vr_values
;
6650 walker
.walk (cfun
->cfg
->x_entry_block_ptr
);
6652 /* We do not actually update the CFG or SSA graphs at this point as
6653 ASSERT_EXPRs are still in the IL and cfg cleanup code does not yet
6654 handle ASSERT_EXPRs gracefully. */
6657 delete avail_exprs_stack
;
6660 /* Traverse all the blocks folding conditionals with known ranges. */
6663 vrp_prop::vrp_finalize (bool warn_array_bounds_p
)
6667 /* We have completed propagating through the lattice. */
6668 vr_values
.set_lattice_propagation_complete ();
6672 fprintf (dump_file
, "\nValue ranges after VRP:\n\n");
6673 vr_values
.dump_all_value_ranges (dump_file
);
6674 fprintf (dump_file
, "\n");
6677 /* Set value range to non pointer SSA_NAMEs. */
6678 for (i
= 0; i
< num_ssa_names
; i
++)
6680 tree name
= ssa_name (i
);
6684 const value_range
*vr
= get_value_range (name
);
6685 if (!name
|| !vr
->constant_p ())
6688 if (POINTER_TYPE_P (TREE_TYPE (name
))
6689 && range_includes_zero_p (vr
) == 0)
6690 set_ptr_nonnull (name
);
6691 else if (!POINTER_TYPE_P (TREE_TYPE (name
)))
6692 set_range_info (name
, *vr
);
6695 /* If we're checking array refs, we want to merge information on
6696 the executability of each edge between vrp_folder and the
6697 check_array_bounds_dom_walker: each can clear the
6698 EDGE_EXECUTABLE flag on edges, in different ways.
6700 Hence, if we're going to call check_all_array_refs, set
6701 the flag on every edge now, rather than in
6702 check_array_bounds_dom_walker's ctor; vrp_folder may clear
6703 it from some edges. */
6704 if (warn_array_bounds
&& warn_array_bounds_p
)
6705 set_all_edges_as_executable (cfun
);
6707 class vrp_folder vrp_folder
;
6708 vrp_folder
.vr_values
= &vr_values
;
6709 vrp_folder
.substitute_and_fold ();
6711 if (warn_array_bounds
&& warn_array_bounds_p
)
6712 check_all_array_refs ();
6715 /* Main entry point to VRP (Value Range Propagation). This pass is
6716 loosely based on J. R. C. Patterson, ``Accurate Static Branch
6717 Prediction by Value Range Propagation,'' in SIGPLAN Conference on
6718 Programming Language Design and Implementation, pp. 67-78, 1995.
6719 Also available at http://citeseer.ist.psu.edu/patterson95accurate.html
6721 This is essentially an SSA-CCP pass modified to deal with ranges
6722 instead of constants.
6724 While propagating ranges, we may find that two or more SSA name
6725 have equivalent, though distinct ranges. For instance,
6728 2 p_4 = ASSERT_EXPR <p_3, p_3 != 0>
6730 4 p_5 = ASSERT_EXPR <p_4, p_4 == q_2>;
6734 In the code above, pointer p_5 has range [q_2, q_2], but from the
6735 code we can also determine that p_5 cannot be NULL and, if q_2 had
6736 a non-varying range, p_5's range should also be compatible with it.
6738 These equivalences are created by two expressions: ASSERT_EXPR and
6739 copy operations. Since p_5 is an assertion on p_4, and p_4 was the
6740 result of another assertion, then we can use the fact that p_5 and
6741 p_4 are equivalent when evaluating p_5's range.
6743 Together with value ranges, we also propagate these equivalences
6744 between names so that we can take advantage of information from
6745 multiple ranges when doing final replacement. Note that this
6746 equivalency relation is transitive but not symmetric.
6748 In the example above, p_5 is equivalent to p_4, q_2 and p_3, but we
6749 cannot assert that q_2 is equivalent to p_5 because q_2 may be used
6750 in contexts where that assertion does not hold (e.g., in line 6).
6752 TODO, the main difference between this pass and Patterson's is that
6753 we do not propagate edge probabilities. We only compute whether
6754 edges can be taken or not. That is, instead of having a spectrum
6755 of jump probabilities between 0 and 1, we only deal with 0, 1 and
6756 DON'T KNOW. In the future, it may be worthwhile to propagate
6757 probabilities to aid branch prediction. */
6760 execute_vrp (bool warn_array_bounds_p
)
6763 loop_optimizer_init (LOOPS_NORMAL
| LOOPS_HAVE_RECORDED_EXITS
);
6764 rewrite_into_loop_closed_ssa (NULL
, TODO_update_ssa
);
6767 /* ??? This ends up using stale EDGE_DFS_BACK for liveness computation.
6768 Inserting assertions may split edges which will invalidate
6770 insert_range_assertions ();
6772 threadedge_initialize_values ();
6774 /* For visiting PHI nodes we need EDGE_DFS_BACK computed. */
6775 mark_dfs_back_edges ();
6777 class vrp_prop vrp_prop
;
6778 vrp_prop
.vrp_initialize ();
6779 vrp_prop
.ssa_propagate ();
6780 vrp_prop
.vrp_finalize (warn_array_bounds_p
);
6782 /* We must identify jump threading opportunities before we release
6783 the datastructures built by VRP. */
6784 identify_jump_threads (&vrp_prop
.vr_values
);
6786 /* A comparison of an SSA_NAME against a constant where the SSA_NAME
6787 was set by a type conversion can often be rewritten to use the
6788 RHS of the type conversion.
6790 However, doing so inhibits jump threading through the comparison.
6791 So that transformation is not performed until after jump threading
6794 FOR_EACH_BB_FN (bb
, cfun
)
6796 gimple
*last
= last_stmt (bb
);
6797 if (last
&& gimple_code (last
) == GIMPLE_COND
)
6798 vrp_prop
.vr_values
.simplify_cond_using_ranges_2 (as_a
<gcond
*> (last
));
6801 free_numbers_of_iterations_estimates (cfun
);
6803 /* ASSERT_EXPRs must be removed before finalizing jump threads
6804 as finalizing jump threads calls the CFG cleanup code which
6805 does not properly handle ASSERT_EXPRs. */
6806 remove_range_assertions ();
6808 /* If we exposed any new variables, go ahead and put them into
6809 SSA form now, before we handle jump threading. This simplifies
6810 interactions between rewriting of _DECL nodes into SSA form
6811 and rewriting SSA_NAME nodes into SSA form after block
6812 duplication and CFG manipulation. */
6813 update_ssa (TODO_update_ssa
);
6815 /* We identified all the jump threading opportunities earlier, but could
6816 not transform the CFG at that time. This routine transforms the
6817 CFG and arranges for the dominator tree to be rebuilt if necessary.
6819 Note the SSA graph update will occur during the normal TODO
6820 processing by the pass manager. */
6821 thread_through_all_blocks (false);
6823 vrp_prop
.vr_values
.cleanup_edges_and_switches ();
6824 threadedge_finalize_values ();
6827 loop_optimizer_finalize ();
6833 const pass_data pass_data_vrp
=
6835 GIMPLE_PASS
, /* type */
6837 OPTGROUP_NONE
, /* optinfo_flags */
6838 TV_TREE_VRP
, /* tv_id */
6839 PROP_ssa
, /* properties_required */
6840 0, /* properties_provided */
6841 0, /* properties_destroyed */
6842 0, /* todo_flags_start */
6843 ( TODO_cleanup_cfg
| TODO_update_ssa
), /* todo_flags_finish */
6846 class pass_vrp
: public gimple_opt_pass
6849 pass_vrp (gcc::context
*ctxt
)
6850 : gimple_opt_pass (pass_data_vrp
, ctxt
), warn_array_bounds_p (false)
6853 /* opt_pass methods: */
6854 opt_pass
* clone () { return new pass_vrp (m_ctxt
); }
6855 void set_pass_param (unsigned int n
, bool param
)
6857 gcc_assert (n
== 0);
6858 warn_array_bounds_p
= param
;
6860 virtual bool gate (function
*) { return flag_tree_vrp
!= 0; }
6861 virtual unsigned int execute (function
*)
6862 { return execute_vrp (warn_array_bounds_p
); }
6865 bool warn_array_bounds_p
;
6866 }; // class pass_vrp
6871 make_pass_vrp (gcc::context
*ctxt
)
6873 return new pass_vrp (ctxt
);
6877 /* Worker for determine_value_range. */
6880 determine_value_range_1 (value_range_base
*vr
, tree expr
)
6882 if (BINARY_CLASS_P (expr
))
6884 value_range_base vr0
, vr1
;
6885 determine_value_range_1 (&vr0
, TREE_OPERAND (expr
, 0));
6886 determine_value_range_1 (&vr1
, TREE_OPERAND (expr
, 1));
6887 extract_range_from_binary_expr (vr
, TREE_CODE (expr
), TREE_TYPE (expr
),
6890 else if (UNARY_CLASS_P (expr
))
6892 value_range_base vr0
;
6893 determine_value_range_1 (&vr0
, TREE_OPERAND (expr
, 0));
6894 extract_range_from_unary_expr (vr
, TREE_CODE (expr
), TREE_TYPE (expr
),
6895 &vr0
, TREE_TYPE (TREE_OPERAND (expr
, 0)));
6897 else if (TREE_CODE (expr
) == INTEGER_CST
)
6901 value_range_kind kind
;
6903 /* For SSA names try to extract range info computed by VRP. Otherwise
6904 fall back to varying. */
6905 if (TREE_CODE (expr
) == SSA_NAME
6906 && INTEGRAL_TYPE_P (TREE_TYPE (expr
))
6907 && (kind
= get_range_info (expr
, &min
, &max
)) != VR_VARYING
)
6908 vr
->set (kind
, wide_int_to_tree (TREE_TYPE (expr
), min
),
6909 wide_int_to_tree (TREE_TYPE (expr
), max
));
6915 /* Compute a value-range for EXPR and set it in *MIN and *MAX. Return
6916 the determined range type. */
6919 determine_value_range (tree expr
, wide_int
*min
, wide_int
*max
)
6921 value_range_base vr
;
6922 determine_value_range_1 (&vr
, expr
);
6923 if (vr
.constant_p ())
6925 *min
= wi::to_wide (vr
.min ());
6926 *max
= wi::to_wide (vr
.max ());