1 /* Support routines for Value Range Propagation (VRP).
2 Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010
3 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@redhat.com>.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
29 #include "basic-block.h"
30 #include "tree-flow.h"
31 #include "tree-pass.h"
32 #include "tree-dump.h"
34 #include "tree-pretty-print.h"
35 #include "gimple-pretty-print.h"
39 #include "tree-scalar-evolution.h"
40 #include "tree-ssa-propagate.h"
41 #include "tree-chrec.h"
44 /* Set of SSA names found live during the RPO traversal of the function
45 for still active basic-blocks. */
48 /* Return true if the SSA name NAME is live on the edge E. */
51 live_on_edge (edge e
, tree name
)
53 return (live
[e
->dest
->index
]
54 && TEST_BIT (live
[e
->dest
->index
], SSA_NAME_VERSION (name
)));
57 /* Local functions. */
58 static int compare_values (tree val1
, tree val2
);
59 static int compare_values_warnv (tree val1
, tree val2
, bool *);
60 static void vrp_meet (value_range_t
*, value_range_t
*);
61 static tree
vrp_evaluate_conditional_warnv_with_ops (enum tree_code
,
62 tree
, tree
, bool, bool *,
65 /* Location information for ASSERT_EXPRs. Each instance of this
66 structure describes an ASSERT_EXPR for an SSA name. Since a single
67 SSA name may have more than one assertion associated with it, these
68 locations are kept in a linked list attached to the corresponding
72 /* Basic block where the assertion would be inserted. */
75 /* Some assertions need to be inserted on an edge (e.g., assertions
76 generated by COND_EXPRs). In those cases, BB will be NULL. */
79 /* Pointer to the statement that generated this assertion. */
80 gimple_stmt_iterator si
;
82 /* Predicate code for the ASSERT_EXPR. Must be COMPARISON_CLASS_P. */
83 enum tree_code comp_code
;
85 /* Value being compared against. */
88 /* Expression to compare. */
91 /* Next node in the linked list. */
92 struct assert_locus_d
*next
;
95 typedef struct assert_locus_d
*assert_locus_t
;
97 /* If bit I is present, it means that SSA name N_i has a list of
98 assertions that should be inserted in the IL. */
99 static bitmap need_assert_for
;
101 /* Array of locations lists where to insert assertions. ASSERTS_FOR[I]
102 holds a list of ASSERT_LOCUS_T nodes that describe where
103 ASSERT_EXPRs for SSA name N_I should be inserted. */
104 static assert_locus_t
*asserts_for
;
106 /* Value range array. After propagation, VR_VALUE[I] holds the range
107 of values that SSA name N_I may take. */
108 static value_range_t
**vr_value
;
110 /* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the
111 number of executable edges we saw the last time we visited the
113 static int *vr_phi_edge_counts
;
120 static VEC (edge
, heap
) *to_remove_edges
;
121 DEF_VEC_O(switch_update
);
122 DEF_VEC_ALLOC_O(switch_update
, heap
);
123 static VEC (switch_update
, heap
) *to_update_switch_stmts
;
126 /* Return the maximum value for TYPE. */
129 vrp_val_max (const_tree type
)
131 if (!INTEGRAL_TYPE_P (type
))
134 return TYPE_MAX_VALUE (type
);
137 /* Return the minimum value for TYPE. */
140 vrp_val_min (const_tree type
)
142 if (!INTEGRAL_TYPE_P (type
))
145 return TYPE_MIN_VALUE (type
);
148 /* Return whether VAL is equal to the maximum value of its type. This
149 will be true for a positive overflow infinity. We can't do a
150 simple equality comparison with TYPE_MAX_VALUE because C typedefs
151 and Ada subtypes can produce types whose TYPE_MAX_VALUE is not ==
152 to the integer constant with the same value in the type. */
155 vrp_val_is_max (const_tree val
)
157 tree type_max
= vrp_val_max (TREE_TYPE (val
));
158 return (val
== type_max
159 || (type_max
!= NULL_TREE
160 && operand_equal_p (val
, type_max
, 0)));
163 /* Return whether VAL is equal to the minimum value of its type. This
164 will be true for a negative overflow infinity. */
167 vrp_val_is_min (const_tree val
)
169 tree type_min
= vrp_val_min (TREE_TYPE (val
));
170 return (val
== type_min
171 || (type_min
!= NULL_TREE
172 && operand_equal_p (val
, type_min
, 0)));
176 /* Return whether TYPE should use an overflow infinity distinct from
177 TYPE_{MIN,MAX}_VALUE. We use an overflow infinity value to
178 represent a signed overflow during VRP computations. An infinity
179 is distinct from a half-range, which will go from some number to
180 TYPE_{MIN,MAX}_VALUE. */
183 needs_overflow_infinity (const_tree type
)
185 return INTEGRAL_TYPE_P (type
) && !TYPE_OVERFLOW_WRAPS (type
);
188 /* Return whether TYPE can support our overflow infinity
189 representation: we use the TREE_OVERFLOW flag, which only exists
190 for constants. If TYPE doesn't support this, we don't optimize
191 cases which would require signed overflow--we drop them to
195 supports_overflow_infinity (const_tree type
)
197 tree min
= vrp_val_min (type
), max
= vrp_val_max (type
);
198 #ifdef ENABLE_CHECKING
199 gcc_assert (needs_overflow_infinity (type
));
201 return (min
!= NULL_TREE
202 && CONSTANT_CLASS_P (min
)
204 && CONSTANT_CLASS_P (max
));
207 /* VAL is the maximum or minimum value of a type. Return a
208 corresponding overflow infinity. */
211 make_overflow_infinity (tree val
)
213 #ifdef ENABLE_CHECKING
214 gcc_assert (val
!= NULL_TREE
&& CONSTANT_CLASS_P (val
));
216 val
= copy_node (val
);
217 TREE_OVERFLOW (val
) = 1;
221 /* Return a negative overflow infinity for TYPE. */
224 negative_overflow_infinity (tree type
)
226 #ifdef ENABLE_CHECKING
227 gcc_assert (supports_overflow_infinity (type
));
229 return make_overflow_infinity (vrp_val_min (type
));
232 /* Return a positive overflow infinity for TYPE. */
235 positive_overflow_infinity (tree type
)
237 #ifdef ENABLE_CHECKING
238 gcc_assert (supports_overflow_infinity (type
));
240 return make_overflow_infinity (vrp_val_max (type
));
243 /* Return whether VAL is a negative overflow infinity. */
246 is_negative_overflow_infinity (const_tree val
)
248 return (needs_overflow_infinity (TREE_TYPE (val
))
249 && CONSTANT_CLASS_P (val
)
250 && TREE_OVERFLOW (val
)
251 && vrp_val_is_min (val
));
254 /* Return whether VAL is a positive overflow infinity. */
257 is_positive_overflow_infinity (const_tree val
)
259 return (needs_overflow_infinity (TREE_TYPE (val
))
260 && CONSTANT_CLASS_P (val
)
261 && TREE_OVERFLOW (val
)
262 && vrp_val_is_max (val
));
265 /* Return whether VAL is a positive or negative overflow infinity. */
268 is_overflow_infinity (const_tree val
)
270 return (needs_overflow_infinity (TREE_TYPE (val
))
271 && CONSTANT_CLASS_P (val
)
272 && TREE_OVERFLOW (val
)
273 && (vrp_val_is_min (val
) || vrp_val_is_max (val
)));
276 /* Return whether STMT has a constant rhs that is_overflow_infinity. */
279 stmt_overflow_infinity (gimple stmt
)
281 if (is_gimple_assign (stmt
)
282 && get_gimple_rhs_class (gimple_assign_rhs_code (stmt
)) ==
284 return is_overflow_infinity (gimple_assign_rhs1 (stmt
));
288 /* If VAL is now an overflow infinity, return VAL. Otherwise, return
289 the same value with TREE_OVERFLOW clear. This can be used to avoid
290 confusing a regular value with an overflow value. */
293 avoid_overflow_infinity (tree val
)
295 if (!is_overflow_infinity (val
))
298 if (vrp_val_is_max (val
))
299 return vrp_val_max (TREE_TYPE (val
));
302 #ifdef ENABLE_CHECKING
303 gcc_assert (vrp_val_is_min (val
));
305 return vrp_val_min (TREE_TYPE (val
));
310 /* Return true if ARG is marked with the nonnull attribute in the
311 current function signature. */
314 nonnull_arg_p (const_tree arg
)
316 tree t
, attrs
, fntype
;
317 unsigned HOST_WIDE_INT arg_num
;
319 gcc_assert (TREE_CODE (arg
) == PARM_DECL
&& POINTER_TYPE_P (TREE_TYPE (arg
)));
321 /* The static chain decl is always non null. */
322 if (arg
== cfun
->static_chain_decl
)
325 fntype
= TREE_TYPE (current_function_decl
);
326 attrs
= lookup_attribute ("nonnull", TYPE_ATTRIBUTES (fntype
));
328 /* If "nonnull" wasn't specified, we know nothing about the argument. */
329 if (attrs
== NULL_TREE
)
332 /* If "nonnull" applies to all the arguments, then ARG is non-null. */
333 if (TREE_VALUE (attrs
) == NULL_TREE
)
336 /* Get the position number for ARG in the function signature. */
337 for (arg_num
= 1, t
= DECL_ARGUMENTS (current_function_decl
);
339 t
= TREE_CHAIN (t
), arg_num
++)
345 gcc_assert (t
== arg
);
347 /* Now see if ARG_NUM is mentioned in the nonnull list. */
348 for (t
= TREE_VALUE (attrs
); t
; t
= TREE_CHAIN (t
))
350 if (compare_tree_int (TREE_VALUE (t
), arg_num
) == 0)
358 /* Set value range VR to VR_VARYING. */
361 set_value_range_to_varying (value_range_t
*vr
)
363 vr
->type
= VR_VARYING
;
364 vr
->min
= vr
->max
= NULL_TREE
;
366 bitmap_clear (vr
->equiv
);
370 /* Set value range VR to {T, MIN, MAX, EQUIV}. */
373 set_value_range (value_range_t
*vr
, enum value_range_type t
, tree min
,
374 tree max
, bitmap equiv
)
376 #if defined ENABLE_CHECKING
377 /* Check the validity of the range. */
378 if (t
== VR_RANGE
|| t
== VR_ANTI_RANGE
)
382 gcc_assert (min
&& max
);
384 if (INTEGRAL_TYPE_P (TREE_TYPE (min
)) && t
== VR_ANTI_RANGE
)
385 gcc_assert (!vrp_val_is_min (min
) || !vrp_val_is_max (max
));
387 cmp
= compare_values (min
, max
);
388 gcc_assert (cmp
== 0 || cmp
== -1 || cmp
== -2);
390 if (needs_overflow_infinity (TREE_TYPE (min
)))
391 gcc_assert (!is_overflow_infinity (min
)
392 || !is_overflow_infinity (max
));
395 if (t
== VR_UNDEFINED
|| t
== VR_VARYING
)
396 gcc_assert (min
== NULL_TREE
&& max
== NULL_TREE
);
398 if (t
== VR_UNDEFINED
|| t
== VR_VARYING
)
399 gcc_assert (equiv
== NULL
|| bitmap_empty_p (equiv
));
406 /* Since updating the equivalence set involves deep copying the
407 bitmaps, only do it if absolutely necessary. */
408 if (vr
->equiv
== NULL
410 vr
->equiv
= BITMAP_ALLOC (NULL
);
412 if (equiv
!= vr
->equiv
)
414 if (equiv
&& !bitmap_empty_p (equiv
))
415 bitmap_copy (vr
->equiv
, equiv
);
417 bitmap_clear (vr
->equiv
);
422 /* Set value range VR to the canonical form of {T, MIN, MAX, EQUIV}.
423 This means adjusting T, MIN and MAX representing the case of a
424 wrapping range with MAX < MIN covering [MIN, type_max] U [type_min, MAX]
425 as anti-rage ~[MAX+1, MIN-1]. Likewise for wrapping anti-ranges.
426 In corner cases where MAX+1 or MIN-1 wraps this will fall back
428 This routine exists to ease canonicalization in the case where we
429 extract ranges from var + CST op limit. */
432 set_and_canonicalize_value_range (value_range_t
*vr
, enum value_range_type t
,
433 tree min
, tree max
, bitmap equiv
)
435 /* Nothing to canonicalize for symbolic or unknown or varying ranges. */
437 && t
!= VR_ANTI_RANGE
)
438 || TREE_CODE (min
) != INTEGER_CST
439 || TREE_CODE (max
) != INTEGER_CST
)
441 set_value_range (vr
, t
, min
, max
, equiv
);
445 /* Wrong order for min and max, to swap them and the VR type we need
447 if (tree_int_cst_lt (max
, min
))
449 tree one
= build_int_cst (TREE_TYPE (min
), 1);
450 tree tmp
= int_const_binop (PLUS_EXPR
, max
, one
, 0);
451 max
= int_const_binop (MINUS_EXPR
, min
, one
, 0);
454 /* There's one corner case, if we had [C+1, C] before we now have
455 that again. But this represents an empty value range, so drop
456 to varying in this case. */
457 if (tree_int_cst_lt (max
, min
))
459 set_value_range_to_varying (vr
);
463 t
= t
== VR_RANGE
? VR_ANTI_RANGE
: VR_RANGE
;
466 /* Anti-ranges that can be represented as ranges should be so. */
467 if (t
== VR_ANTI_RANGE
)
469 bool is_min
= vrp_val_is_min (min
);
470 bool is_max
= vrp_val_is_max (max
);
472 if (is_min
&& is_max
)
474 /* We cannot deal with empty ranges, drop to varying. */
475 set_value_range_to_varying (vr
);
479 /* As a special exception preserve non-null ranges. */
480 && !(TYPE_UNSIGNED (TREE_TYPE (min
))
481 && integer_zerop (max
)))
483 tree one
= build_int_cst (TREE_TYPE (max
), 1);
484 min
= int_const_binop (PLUS_EXPR
, max
, one
, 0);
485 max
= vrp_val_max (TREE_TYPE (max
));
490 tree one
= build_int_cst (TREE_TYPE (min
), 1);
491 max
= int_const_binop (MINUS_EXPR
, min
, one
, 0);
492 min
= vrp_val_min (TREE_TYPE (min
));
497 set_value_range (vr
, t
, min
, max
, equiv
);
500 /* Copy value range FROM into value range TO. */
503 copy_value_range (value_range_t
*to
, value_range_t
*from
)
505 set_value_range (to
, from
->type
, from
->min
, from
->max
, from
->equiv
);
508 /* Set value range VR to a single value. This function is only called
509 with values we get from statements, and exists to clear the
510 TREE_OVERFLOW flag so that we don't think we have an overflow
511 infinity when we shouldn't. */
514 set_value_range_to_value (value_range_t
*vr
, tree val
, bitmap equiv
)
516 gcc_assert (is_gimple_min_invariant (val
));
517 val
= avoid_overflow_infinity (val
);
518 set_value_range (vr
, VR_RANGE
, val
, val
, equiv
);
521 /* Set value range VR to a non-negative range of type TYPE.
522 OVERFLOW_INFINITY indicates whether to use an overflow infinity
523 rather than TYPE_MAX_VALUE; this should be true if we determine
524 that the range is nonnegative based on the assumption that signed
525 overflow does not occur. */
528 set_value_range_to_nonnegative (value_range_t
*vr
, tree type
,
529 bool overflow_infinity
)
533 if (overflow_infinity
&& !supports_overflow_infinity (type
))
535 set_value_range_to_varying (vr
);
539 zero
= build_int_cst (type
, 0);
540 set_value_range (vr
, VR_RANGE
, zero
,
542 ? positive_overflow_infinity (type
)
543 : TYPE_MAX_VALUE (type
)),
547 /* Set value range VR to a non-NULL range of type TYPE. */
550 set_value_range_to_nonnull (value_range_t
*vr
, tree type
)
552 tree zero
= build_int_cst (type
, 0);
553 set_value_range (vr
, VR_ANTI_RANGE
, zero
, zero
, vr
->equiv
);
557 /* Set value range VR to a NULL range of type TYPE. */
560 set_value_range_to_null (value_range_t
*vr
, tree type
)
562 set_value_range_to_value (vr
, build_int_cst (type
, 0), vr
->equiv
);
566 /* Set value range VR to a range of a truthvalue of type TYPE. */
569 set_value_range_to_truthvalue (value_range_t
*vr
, tree type
)
571 if (TYPE_PRECISION (type
) == 1)
572 set_value_range_to_varying (vr
);
574 set_value_range (vr
, VR_RANGE
,
575 build_int_cst (type
, 0), build_int_cst (type
, 1),
580 /* Set value range VR to VR_UNDEFINED. */
583 set_value_range_to_undefined (value_range_t
*vr
)
585 vr
->type
= VR_UNDEFINED
;
586 vr
->min
= vr
->max
= NULL_TREE
;
588 bitmap_clear (vr
->equiv
);
592 /* If abs (min) < abs (max), set VR to [-max, max], if
593 abs (min) >= abs (max), set VR to [-min, min]. */
596 abs_extent_range (value_range_t
*vr
, tree min
, tree max
)
600 gcc_assert (TREE_CODE (min
) == INTEGER_CST
);
601 gcc_assert (TREE_CODE (max
) == INTEGER_CST
);
602 gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (min
)));
603 gcc_assert (!TYPE_UNSIGNED (TREE_TYPE (min
)));
604 min
= fold_unary (ABS_EXPR
, TREE_TYPE (min
), min
);
605 max
= fold_unary (ABS_EXPR
, TREE_TYPE (max
), max
);
606 if (TREE_OVERFLOW (min
) || TREE_OVERFLOW (max
))
608 set_value_range_to_varying (vr
);
611 cmp
= compare_values (min
, max
);
613 min
= fold_unary (NEGATE_EXPR
, TREE_TYPE (min
), max
);
614 else if (cmp
== 0 || cmp
== 1)
617 min
= fold_unary (NEGATE_EXPR
, TREE_TYPE (min
), min
);
621 set_value_range_to_varying (vr
);
624 set_and_canonicalize_value_range (vr
, VR_RANGE
, min
, max
, NULL
);
628 /* Return value range information for VAR.
630 If we have no values ranges recorded (ie, VRP is not running), then
631 return NULL. Otherwise create an empty range if none existed for VAR. */
633 static value_range_t
*
634 get_value_range (const_tree var
)
638 unsigned ver
= SSA_NAME_VERSION (var
);
640 /* If we have no recorded ranges, then return NULL. */
648 /* Create a default value range. */
649 vr_value
[ver
] = vr
= XCNEW (value_range_t
);
651 /* Defer allocating the equivalence set. */
654 /* If VAR is a default definition, the variable can take any value
656 sym
= SSA_NAME_VAR (var
);
657 if (SSA_NAME_IS_DEFAULT_DEF (var
))
659 /* Try to use the "nonnull" attribute to create ~[0, 0]
660 anti-ranges for pointers. Note that this is only valid with
661 default definitions of PARM_DECLs. */
662 if (TREE_CODE (sym
) == PARM_DECL
663 && POINTER_TYPE_P (TREE_TYPE (sym
))
664 && nonnull_arg_p (sym
))
665 set_value_range_to_nonnull (vr
, TREE_TYPE (sym
));
667 set_value_range_to_varying (vr
);
673 /* Return true, if VAL1 and VAL2 are equal values for VRP purposes. */
676 vrp_operand_equal_p (const_tree val1
, const_tree val2
)
680 if (!val1
|| !val2
|| !operand_equal_p (val1
, val2
, 0))
682 if (is_overflow_infinity (val1
))
683 return is_overflow_infinity (val2
);
687 /* Return true, if the bitmaps B1 and B2 are equal. */
690 vrp_bitmap_equal_p (const_bitmap b1
, const_bitmap b2
)
694 && bitmap_equal_p (b1
, b2
)));
697 /* Update the value range and equivalence set for variable VAR to
698 NEW_VR. Return true if NEW_VR is different from VAR's previous
701 NOTE: This function assumes that NEW_VR is a temporary value range
702 object created for the sole purpose of updating VAR's range. The
703 storage used by the equivalence set from NEW_VR will be freed by
704 this function. Do not call update_value_range when NEW_VR
705 is the range object associated with another SSA name. */
708 update_value_range (const_tree var
, value_range_t
*new_vr
)
710 value_range_t
*old_vr
;
713 /* Update the value range, if necessary. */
714 old_vr
= get_value_range (var
);
715 is_new
= old_vr
->type
!= new_vr
->type
716 || !vrp_operand_equal_p (old_vr
->min
, new_vr
->min
)
717 || !vrp_operand_equal_p (old_vr
->max
, new_vr
->max
)
718 || !vrp_bitmap_equal_p (old_vr
->equiv
, new_vr
->equiv
);
721 set_value_range (old_vr
, new_vr
->type
, new_vr
->min
, new_vr
->max
,
724 BITMAP_FREE (new_vr
->equiv
);
730 /* Add VAR and VAR's equivalence set to EQUIV. This is the central
731 point where equivalence processing can be turned on/off. */
734 add_equivalence (bitmap
*equiv
, const_tree var
)
736 unsigned ver
= SSA_NAME_VERSION (var
);
737 value_range_t
*vr
= vr_value
[ver
];
740 *equiv
= BITMAP_ALLOC (NULL
);
741 bitmap_set_bit (*equiv
, ver
);
743 bitmap_ior_into (*equiv
, vr
->equiv
);
747 /* Return true if VR is ~[0, 0]. */
750 range_is_nonnull (value_range_t
*vr
)
752 return vr
->type
== VR_ANTI_RANGE
753 && integer_zerop (vr
->min
)
754 && integer_zerop (vr
->max
);
758 /* Return true if VR is [0, 0]. */
761 range_is_null (value_range_t
*vr
)
763 return vr
->type
== VR_RANGE
764 && integer_zerop (vr
->min
)
765 && integer_zerop (vr
->max
);
768 /* Return true if max and min of VR are INTEGER_CST. It's not necessary
772 range_int_cst_p (value_range_t
*vr
)
774 return (vr
->type
== VR_RANGE
775 && TREE_CODE (vr
->max
) == INTEGER_CST
776 && TREE_CODE (vr
->min
) == INTEGER_CST
777 && !TREE_OVERFLOW (vr
->max
)
778 && !TREE_OVERFLOW (vr
->min
));
781 /* Return true if VR is a INTEGER_CST singleton. */
784 range_int_cst_singleton_p (value_range_t
*vr
)
786 return (range_int_cst_p (vr
)
787 && tree_int_cst_equal (vr
->min
, vr
->max
));
790 /* Return true if value range VR involves at least one symbol. */
793 symbolic_range_p (value_range_t
*vr
)
795 return (!is_gimple_min_invariant (vr
->min
)
796 || !is_gimple_min_invariant (vr
->max
));
799 /* Return true if value range VR uses an overflow infinity. */
802 overflow_infinity_range_p (value_range_t
*vr
)
804 return (vr
->type
== VR_RANGE
805 && (is_overflow_infinity (vr
->min
)
806 || is_overflow_infinity (vr
->max
)));
809 /* Return false if we can not make a valid comparison based on VR;
810 this will be the case if it uses an overflow infinity and overflow
811 is not undefined (i.e., -fno-strict-overflow is in effect).
812 Otherwise return true, and set *STRICT_OVERFLOW_P to true if VR
813 uses an overflow infinity. */
816 usable_range_p (value_range_t
*vr
, bool *strict_overflow_p
)
818 gcc_assert (vr
->type
== VR_RANGE
);
819 if (is_overflow_infinity (vr
->min
))
821 *strict_overflow_p
= true;
822 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr
->min
)))
825 if (is_overflow_infinity (vr
->max
))
827 *strict_overflow_p
= true;
828 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr
->max
)))
835 /* Like tree_expr_nonnegative_warnv_p, but this function uses value
836 ranges obtained so far. */
839 vrp_expr_computes_nonnegative (tree expr
, bool *strict_overflow_p
)
841 return (tree_expr_nonnegative_warnv_p (expr
, strict_overflow_p
)
842 || (TREE_CODE (expr
) == SSA_NAME
843 && ssa_name_nonnegative_p (expr
)));
846 /* Return true if the result of assignment STMT is know to be non-negative.
847 If the return value is based on the assumption that signed overflow is
848 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
849 *STRICT_OVERFLOW_P.*/
852 gimple_assign_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
854 enum tree_code code
= gimple_assign_rhs_code (stmt
);
855 switch (get_gimple_rhs_class (code
))
857 case GIMPLE_UNARY_RHS
:
858 return tree_unary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt
),
859 gimple_expr_type (stmt
),
860 gimple_assign_rhs1 (stmt
),
862 case GIMPLE_BINARY_RHS
:
863 return tree_binary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt
),
864 gimple_expr_type (stmt
),
865 gimple_assign_rhs1 (stmt
),
866 gimple_assign_rhs2 (stmt
),
868 case GIMPLE_SINGLE_RHS
:
869 return tree_single_nonnegative_warnv_p (gimple_assign_rhs1 (stmt
),
871 case GIMPLE_INVALID_RHS
:
878 /* Return true if return value of call STMT is know to be non-negative.
879 If the return value is based on the assumption that signed overflow is
880 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
881 *STRICT_OVERFLOW_P.*/
884 gimple_call_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
886 tree arg0
= gimple_call_num_args (stmt
) > 0 ?
887 gimple_call_arg (stmt
, 0) : NULL_TREE
;
888 tree arg1
= gimple_call_num_args (stmt
) > 1 ?
889 gimple_call_arg (stmt
, 1) : NULL_TREE
;
891 return tree_call_nonnegative_warnv_p (gimple_expr_type (stmt
),
892 gimple_call_fndecl (stmt
),
898 /* Return true if STMT is know to to compute a non-negative value.
899 If the return value is based on the assumption that signed overflow is
900 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
901 *STRICT_OVERFLOW_P.*/
904 gimple_stmt_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
906 switch (gimple_code (stmt
))
909 return gimple_assign_nonnegative_warnv_p (stmt
, strict_overflow_p
);
911 return gimple_call_nonnegative_warnv_p (stmt
, strict_overflow_p
);
917 /* Return true if the result of assignment STMT is know to be non-zero.
918 If the return value is based on the assumption that signed overflow is
919 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
920 *STRICT_OVERFLOW_P.*/
923 gimple_assign_nonzero_warnv_p (gimple stmt
, bool *strict_overflow_p
)
925 enum tree_code code
= gimple_assign_rhs_code (stmt
);
926 switch (get_gimple_rhs_class (code
))
928 case GIMPLE_UNARY_RHS
:
929 return tree_unary_nonzero_warnv_p (gimple_assign_rhs_code (stmt
),
930 gimple_expr_type (stmt
),
931 gimple_assign_rhs1 (stmt
),
933 case GIMPLE_BINARY_RHS
:
934 return tree_binary_nonzero_warnv_p (gimple_assign_rhs_code (stmt
),
935 gimple_expr_type (stmt
),
936 gimple_assign_rhs1 (stmt
),
937 gimple_assign_rhs2 (stmt
),
939 case GIMPLE_SINGLE_RHS
:
940 return tree_single_nonzero_warnv_p (gimple_assign_rhs1 (stmt
),
942 case GIMPLE_INVALID_RHS
:
949 /* Return true if STMT is know to to compute a non-zero value.
950 If the return value is based on the assumption that signed overflow is
951 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
952 *STRICT_OVERFLOW_P.*/
955 gimple_stmt_nonzero_warnv_p (gimple stmt
, bool *strict_overflow_p
)
957 switch (gimple_code (stmt
))
960 return gimple_assign_nonzero_warnv_p (stmt
, strict_overflow_p
);
962 return gimple_alloca_call_p (stmt
);
968 /* Like tree_expr_nonzero_warnv_p, but this function uses value ranges
972 vrp_stmt_computes_nonzero (gimple stmt
, bool *strict_overflow_p
)
974 if (gimple_stmt_nonzero_warnv_p (stmt
, strict_overflow_p
))
977 /* If we have an expression of the form &X->a, then the expression
978 is nonnull if X is nonnull. */
979 if (is_gimple_assign (stmt
)
980 && gimple_assign_rhs_code (stmt
) == ADDR_EXPR
)
982 tree expr
= gimple_assign_rhs1 (stmt
);
983 tree base
= get_base_address (TREE_OPERAND (expr
, 0));
985 if (base
!= NULL_TREE
986 && TREE_CODE (base
) == INDIRECT_REF
987 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
989 value_range_t
*vr
= get_value_range (TREE_OPERAND (base
, 0));
990 if (range_is_nonnull (vr
))
998 /* Returns true if EXPR is a valid value (as expected by compare_values) --
999 a gimple invariant, or SSA_NAME +- CST. */
1002 valid_value_p (tree expr
)
1004 if (TREE_CODE (expr
) == SSA_NAME
)
1007 if (TREE_CODE (expr
) == PLUS_EXPR
1008 || TREE_CODE (expr
) == MINUS_EXPR
)
1009 return (TREE_CODE (TREE_OPERAND (expr
, 0)) == SSA_NAME
1010 && TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
);
1012 return is_gimple_min_invariant (expr
);
1018 -2 if those are incomparable. */
1020 operand_less_p (tree val
, tree val2
)
1022 /* LT is folded faster than GE and others. Inline the common case. */
1023 if (TREE_CODE (val
) == INTEGER_CST
&& TREE_CODE (val2
) == INTEGER_CST
)
1025 if (TYPE_UNSIGNED (TREE_TYPE (val
)))
1026 return INT_CST_LT_UNSIGNED (val
, val2
);
1029 if (INT_CST_LT (val
, val2
))
1037 fold_defer_overflow_warnings ();
1039 tcmp
= fold_binary_to_constant (LT_EXPR
, boolean_type_node
, val
, val2
);
1041 fold_undefer_and_ignore_overflow_warnings ();
1044 || TREE_CODE (tcmp
) != INTEGER_CST
)
1047 if (!integer_zerop (tcmp
))
1051 /* val >= val2, not considering overflow infinity. */
1052 if (is_negative_overflow_infinity (val
))
1053 return is_negative_overflow_infinity (val2
) ? 0 : 1;
1054 else if (is_positive_overflow_infinity (val2
))
1055 return is_positive_overflow_infinity (val
) ? 0 : 1;
1060 /* Compare two values VAL1 and VAL2. Return
1062 -2 if VAL1 and VAL2 cannot be compared at compile-time,
1065 +1 if VAL1 > VAL2, and
1068 This is similar to tree_int_cst_compare but supports pointer values
1069 and values that cannot be compared at compile time.
1071 If STRICT_OVERFLOW_P is not NULL, then set *STRICT_OVERFLOW_P to
1072 true if the return value is only valid if we assume that signed
1073 overflow is undefined. */
1076 compare_values_warnv (tree val1
, tree val2
, bool *strict_overflow_p
)
1081 /* Below we rely on the fact that VAL1 and VAL2 are both pointers or
1083 gcc_assert (POINTER_TYPE_P (TREE_TYPE (val1
))
1084 == POINTER_TYPE_P (TREE_TYPE (val2
)));
1085 /* Convert the two values into the same type. This is needed because
1086 sizetype causes sign extension even for unsigned types. */
1087 val2
= fold_convert (TREE_TYPE (val1
), val2
);
1088 STRIP_USELESS_TYPE_CONVERSION (val2
);
1090 if ((TREE_CODE (val1
) == SSA_NAME
1091 || TREE_CODE (val1
) == PLUS_EXPR
1092 || TREE_CODE (val1
) == MINUS_EXPR
)
1093 && (TREE_CODE (val2
) == SSA_NAME
1094 || TREE_CODE (val2
) == PLUS_EXPR
1095 || TREE_CODE (val2
) == MINUS_EXPR
))
1097 tree n1
, c1
, n2
, c2
;
1098 enum tree_code code1
, code2
;
1100 /* If VAL1 and VAL2 are of the form 'NAME [+-] CST' or 'NAME',
1101 return -1 or +1 accordingly. If VAL1 and VAL2 don't use the
1102 same name, return -2. */
1103 if (TREE_CODE (val1
) == SSA_NAME
)
1111 code1
= TREE_CODE (val1
);
1112 n1
= TREE_OPERAND (val1
, 0);
1113 c1
= TREE_OPERAND (val1
, 1);
1114 if (tree_int_cst_sgn (c1
) == -1)
1116 if (is_negative_overflow_infinity (c1
))
1118 c1
= fold_unary_to_constant (NEGATE_EXPR
, TREE_TYPE (c1
), c1
);
1121 code1
= code1
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
;
1125 if (TREE_CODE (val2
) == SSA_NAME
)
1133 code2
= TREE_CODE (val2
);
1134 n2
= TREE_OPERAND (val2
, 0);
1135 c2
= TREE_OPERAND (val2
, 1);
1136 if (tree_int_cst_sgn (c2
) == -1)
1138 if (is_negative_overflow_infinity (c2
))
1140 c2
= fold_unary_to_constant (NEGATE_EXPR
, TREE_TYPE (c2
), c2
);
1143 code2
= code2
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
;
1147 /* Both values must use the same name. */
1151 if (code1
== SSA_NAME
1152 && code2
== SSA_NAME
)
1156 /* If overflow is defined we cannot simplify more. */
1157 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1
)))
1160 if (strict_overflow_p
!= NULL
1161 && (code1
== SSA_NAME
|| !TREE_NO_WARNING (val1
))
1162 && (code2
== SSA_NAME
|| !TREE_NO_WARNING (val2
)))
1163 *strict_overflow_p
= true;
1165 if (code1
== SSA_NAME
)
1167 if (code2
== PLUS_EXPR
)
1168 /* NAME < NAME + CST */
1170 else if (code2
== MINUS_EXPR
)
1171 /* NAME > NAME - CST */
1174 else if (code1
== PLUS_EXPR
)
1176 if (code2
== SSA_NAME
)
1177 /* NAME + CST > NAME */
1179 else if (code2
== PLUS_EXPR
)
1180 /* NAME + CST1 > NAME + CST2, if CST1 > CST2 */
1181 return compare_values_warnv (c1
, c2
, strict_overflow_p
);
1182 else if (code2
== MINUS_EXPR
)
1183 /* NAME + CST1 > NAME - CST2 */
1186 else if (code1
== MINUS_EXPR
)
1188 if (code2
== SSA_NAME
)
1189 /* NAME - CST < NAME */
1191 else if (code2
== PLUS_EXPR
)
1192 /* NAME - CST1 < NAME + CST2 */
1194 else if (code2
== MINUS_EXPR
)
1195 /* NAME - CST1 > NAME - CST2, if CST1 < CST2. Notice that
1196 C1 and C2 are swapped in the call to compare_values. */
1197 return compare_values_warnv (c2
, c1
, strict_overflow_p
);
1203 /* We cannot compare non-constants. */
1204 if (!is_gimple_min_invariant (val1
) || !is_gimple_min_invariant (val2
))
1207 if (!POINTER_TYPE_P (TREE_TYPE (val1
)))
1209 /* We cannot compare overflowed values, except for overflow
1211 if (TREE_OVERFLOW (val1
) || TREE_OVERFLOW (val2
))
1213 if (strict_overflow_p
!= NULL
)
1214 *strict_overflow_p
= true;
1215 if (is_negative_overflow_infinity (val1
))
1216 return is_negative_overflow_infinity (val2
) ? 0 : -1;
1217 else if (is_negative_overflow_infinity (val2
))
1219 else if (is_positive_overflow_infinity (val1
))
1220 return is_positive_overflow_infinity (val2
) ? 0 : 1;
1221 else if (is_positive_overflow_infinity (val2
))
1226 return tree_int_cst_compare (val1
, val2
);
1232 /* First see if VAL1 and VAL2 are not the same. */
1233 if (val1
== val2
|| operand_equal_p (val1
, val2
, 0))
1236 /* If VAL1 is a lower address than VAL2, return -1. */
1237 if (operand_less_p (val1
, val2
) == 1)
1240 /* If VAL1 is a higher address than VAL2, return +1. */
1241 if (operand_less_p (val2
, val1
) == 1)
1244 /* If VAL1 is different than VAL2, return +2.
1245 For integer constants we either have already returned -1 or 1
1246 or they are equivalent. We still might succeed in proving
1247 something about non-trivial operands. */
1248 if (TREE_CODE (val1
) != INTEGER_CST
1249 || TREE_CODE (val2
) != INTEGER_CST
)
1251 t
= fold_binary_to_constant (NE_EXPR
, boolean_type_node
, val1
, val2
);
1252 if (t
&& integer_onep (t
))
1260 /* Compare values like compare_values_warnv, but treat comparisons of
1261 nonconstants which rely on undefined overflow as incomparable. */
1264 compare_values (tree val1
, tree val2
)
1270 ret
= compare_values_warnv (val1
, val2
, &sop
);
1272 && (!is_gimple_min_invariant (val1
) || !is_gimple_min_invariant (val2
)))
1278 /* Return 1 if VAL is inside value range VR (VR->MIN <= VAL <= VR->MAX),
1279 0 if VAL is not inside VR,
1280 -2 if we cannot tell either way.
1282 FIXME, the current semantics of this functions are a bit quirky
1283 when taken in the context of VRP. In here we do not care
1284 about VR's type. If VR is the anti-range ~[3, 5] the call
1285 value_inside_range (4, VR) will return 1.
1287 This is counter-intuitive in a strict sense, but the callers
1288 currently expect this. They are calling the function
1289 merely to determine whether VR->MIN <= VAL <= VR->MAX. The
1290 callers are applying the VR_RANGE/VR_ANTI_RANGE semantics
1293 This also applies to value_ranges_intersect_p and
1294 range_includes_zero_p. The semantics of VR_RANGE and
1295 VR_ANTI_RANGE should be encoded here, but that also means
1296 adapting the users of these functions to the new semantics.
1298 Benchmark compile/20001226-1.c compilation time after changing this
1302 value_inside_range (tree val
, value_range_t
* vr
)
1306 cmp1
= operand_less_p (val
, vr
->min
);
1312 cmp2
= operand_less_p (vr
->max
, val
);
1320 /* Return true if value ranges VR0 and VR1 have a non-empty
1323 Benchmark compile/20001226-1.c compilation time after changing this
1328 value_ranges_intersect_p (value_range_t
*vr0
, value_range_t
*vr1
)
1330 /* The value ranges do not intersect if the maximum of the first range is
1331 less than the minimum of the second range or vice versa.
1332 When those relations are unknown, we can't do any better. */
1333 if (operand_less_p (vr0
->max
, vr1
->min
) != 0)
1335 if (operand_less_p (vr1
->max
, vr0
->min
) != 0)
1341 /* Return true if VR includes the value zero, false otherwise. FIXME,
1342 currently this will return false for an anti-range like ~[-4, 3].
1343 This will be wrong when the semantics of value_inside_range are
1344 modified (currently the users of this function expect these
1348 range_includes_zero_p (value_range_t
*vr
)
1352 gcc_assert (vr
->type
!= VR_UNDEFINED
1353 && vr
->type
!= VR_VARYING
1354 && !symbolic_range_p (vr
));
1356 zero
= build_int_cst (TREE_TYPE (vr
->min
), 0);
1357 return (value_inside_range (zero
, vr
) == 1);
1360 /* Return true if T, an SSA_NAME, is known to be nonnegative. Return
1361 false otherwise or if no value range information is available. */
1364 ssa_name_nonnegative_p (const_tree t
)
1366 value_range_t
*vr
= get_value_range (t
);
1368 if (INTEGRAL_TYPE_P (t
)
1369 && TYPE_UNSIGNED (t
))
1375 /* Testing for VR_ANTI_RANGE is not useful here as any anti-range
1376 which would return a useful value should be encoded as a VR_RANGE. */
1377 if (vr
->type
== VR_RANGE
)
1379 int result
= compare_values (vr
->min
, integer_zero_node
);
1381 return (result
== 0 || result
== 1);
1386 /* If OP has a value range with a single constant value return that,
1387 otherwise return NULL_TREE. This returns OP itself if OP is a
1391 op_with_constant_singleton_value_range (tree op
)
1395 if (is_gimple_min_invariant (op
))
1398 if (TREE_CODE (op
) != SSA_NAME
)
1401 vr
= get_value_range (op
);
1402 if (vr
->type
== VR_RANGE
1403 && operand_equal_p (vr
->min
, vr
->max
, 0)
1404 && is_gimple_min_invariant (vr
->min
))
1411 /* Extract value range information from an ASSERT_EXPR EXPR and store
1415 extract_range_from_assert (value_range_t
*vr_p
, tree expr
)
1417 tree var
, cond
, limit
, min
, max
, type
;
1418 value_range_t
*var_vr
, *limit_vr
;
1419 enum tree_code cond_code
;
1421 var
= ASSERT_EXPR_VAR (expr
);
1422 cond
= ASSERT_EXPR_COND (expr
);
1424 gcc_assert (COMPARISON_CLASS_P (cond
));
1426 /* Find VAR in the ASSERT_EXPR conditional. */
1427 if (var
== TREE_OPERAND (cond
, 0)
1428 || TREE_CODE (TREE_OPERAND (cond
, 0)) == PLUS_EXPR
1429 || TREE_CODE (TREE_OPERAND (cond
, 0)) == NOP_EXPR
)
1431 /* If the predicate is of the form VAR COMP LIMIT, then we just
1432 take LIMIT from the RHS and use the same comparison code. */
1433 cond_code
= TREE_CODE (cond
);
1434 limit
= TREE_OPERAND (cond
, 1);
1435 cond
= TREE_OPERAND (cond
, 0);
1439 /* If the predicate is of the form LIMIT COMP VAR, then we need
1440 to flip around the comparison code to create the proper range
1442 cond_code
= swap_tree_comparison (TREE_CODE (cond
));
1443 limit
= TREE_OPERAND (cond
, 0);
1444 cond
= TREE_OPERAND (cond
, 1);
1447 limit
= avoid_overflow_infinity (limit
);
1449 type
= TREE_TYPE (limit
);
1450 gcc_assert (limit
!= var
);
1452 /* For pointer arithmetic, we only keep track of pointer equality
1454 if (POINTER_TYPE_P (type
) && cond_code
!= NE_EXPR
&& cond_code
!= EQ_EXPR
)
1456 set_value_range_to_varying (vr_p
);
1460 /* If LIMIT is another SSA name and LIMIT has a range of its own,
1461 try to use LIMIT's range to avoid creating symbolic ranges
1463 limit_vr
= (TREE_CODE (limit
) == SSA_NAME
) ? get_value_range (limit
) : NULL
;
1465 /* LIMIT's range is only interesting if it has any useful information. */
1467 && (limit_vr
->type
== VR_UNDEFINED
1468 || limit_vr
->type
== VR_VARYING
1469 || symbolic_range_p (limit_vr
)))
1472 /* Initially, the new range has the same set of equivalences of
1473 VAR's range. This will be revised before returning the final
1474 value. Since assertions may be chained via mutually exclusive
1475 predicates, we will need to trim the set of equivalences before
1477 gcc_assert (vr_p
->equiv
== NULL
);
1478 add_equivalence (&vr_p
->equiv
, var
);
1480 /* Extract a new range based on the asserted comparison for VAR and
1481 LIMIT's value range. Notice that if LIMIT has an anti-range, we
1482 will only use it for equality comparisons (EQ_EXPR). For any
1483 other kind of assertion, we cannot derive a range from LIMIT's
1484 anti-range that can be used to describe the new range. For
1485 instance, ASSERT_EXPR <x_2, x_2 <= b_4>. If b_4 is ~[2, 10],
1486 then b_4 takes on the ranges [-INF, 1] and [11, +INF]. There is
1487 no single range for x_2 that could describe LE_EXPR, so we might
1488 as well build the range [b_4, +INF] for it.
1489 One special case we handle is extracting a range from a
1490 range test encoded as (unsigned)var + CST <= limit. */
1491 if (TREE_CODE (cond
) == NOP_EXPR
1492 || TREE_CODE (cond
) == PLUS_EXPR
)
1494 if (TREE_CODE (cond
) == PLUS_EXPR
)
1496 min
= fold_build1 (NEGATE_EXPR
, TREE_TYPE (TREE_OPERAND (cond
, 1)),
1497 TREE_OPERAND (cond
, 1));
1498 max
= int_const_binop (PLUS_EXPR
, limit
, min
, 0);
1499 cond
= TREE_OPERAND (cond
, 0);
1503 min
= build_int_cst (TREE_TYPE (var
), 0);
1507 /* Make sure to not set TREE_OVERFLOW on the final type
1508 conversion. We are willingly interpreting large positive
1509 unsigned values as negative singed values here. */
1510 min
= force_fit_type_double (TREE_TYPE (var
), TREE_INT_CST_LOW (min
),
1511 TREE_INT_CST_HIGH (min
), 0, false);
1512 max
= force_fit_type_double (TREE_TYPE (var
), TREE_INT_CST_LOW (max
),
1513 TREE_INT_CST_HIGH (max
), 0, false);
1515 /* We can transform a max, min range to an anti-range or
1516 vice-versa. Use set_and_canonicalize_value_range which does
1518 if (cond_code
== LE_EXPR
)
1519 set_and_canonicalize_value_range (vr_p
, VR_RANGE
,
1520 min
, max
, vr_p
->equiv
);
1521 else if (cond_code
== GT_EXPR
)
1522 set_and_canonicalize_value_range (vr_p
, VR_ANTI_RANGE
,
1523 min
, max
, vr_p
->equiv
);
1527 else if (cond_code
== EQ_EXPR
)
1529 enum value_range_type range_type
;
1533 range_type
= limit_vr
->type
;
1534 min
= limit_vr
->min
;
1535 max
= limit_vr
->max
;
1539 range_type
= VR_RANGE
;
1544 set_value_range (vr_p
, range_type
, min
, max
, vr_p
->equiv
);
1546 /* When asserting the equality VAR == LIMIT and LIMIT is another
1547 SSA name, the new range will also inherit the equivalence set
1549 if (TREE_CODE (limit
) == SSA_NAME
)
1550 add_equivalence (&vr_p
->equiv
, limit
);
1552 else if (cond_code
== NE_EXPR
)
1554 /* As described above, when LIMIT's range is an anti-range and
1555 this assertion is an inequality (NE_EXPR), then we cannot
1556 derive anything from the anti-range. For instance, if
1557 LIMIT's range was ~[0, 0], the assertion 'VAR != LIMIT' does
1558 not imply that VAR's range is [0, 0]. So, in the case of
1559 anti-ranges, we just assert the inequality using LIMIT and
1562 If LIMIT_VR is a range, we can only use it to build a new
1563 anti-range if LIMIT_VR is a single-valued range. For
1564 instance, if LIMIT_VR is [0, 1], the predicate
1565 VAR != [0, 1] does not mean that VAR's range is ~[0, 1].
1566 Rather, it means that for value 0 VAR should be ~[0, 0]
1567 and for value 1, VAR should be ~[1, 1]. We cannot
1568 represent these ranges.
1570 The only situation in which we can build a valid
1571 anti-range is when LIMIT_VR is a single-valued range
1572 (i.e., LIMIT_VR->MIN == LIMIT_VR->MAX). In that case,
1573 build the anti-range ~[LIMIT_VR->MIN, LIMIT_VR->MAX]. */
1575 && limit_vr
->type
== VR_RANGE
1576 && compare_values (limit_vr
->min
, limit_vr
->max
) == 0)
1578 min
= limit_vr
->min
;
1579 max
= limit_vr
->max
;
1583 /* In any other case, we cannot use LIMIT's range to build a
1584 valid anti-range. */
1588 /* If MIN and MAX cover the whole range for their type, then
1589 just use the original LIMIT. */
1590 if (INTEGRAL_TYPE_P (type
)
1591 && vrp_val_is_min (min
)
1592 && vrp_val_is_max (max
))
1595 set_value_range (vr_p
, VR_ANTI_RANGE
, min
, max
, vr_p
->equiv
);
1597 else if (cond_code
== LE_EXPR
|| cond_code
== LT_EXPR
)
1599 min
= TYPE_MIN_VALUE (type
);
1601 if (limit_vr
== NULL
|| limit_vr
->type
== VR_ANTI_RANGE
)
1605 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1606 range [MIN, N2] for LE_EXPR and [MIN, N2 - 1] for
1608 max
= limit_vr
->max
;
1611 /* If the maximum value forces us to be out of bounds, simply punt.
1612 It would be pointless to try and do anything more since this
1613 all should be optimized away above us. */
1614 if ((cond_code
== LT_EXPR
1615 && compare_values (max
, min
) == 0)
1616 || (CONSTANT_CLASS_P (max
) && TREE_OVERFLOW (max
)))
1617 set_value_range_to_varying (vr_p
);
1620 /* For LT_EXPR, we create the range [MIN, MAX - 1]. */
1621 if (cond_code
== LT_EXPR
)
1623 tree one
= build_int_cst (type
, 1);
1624 max
= fold_build2 (MINUS_EXPR
, type
, max
, one
);
1626 TREE_NO_WARNING (max
) = 1;
1629 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1632 else if (cond_code
== GE_EXPR
|| cond_code
== GT_EXPR
)
1634 max
= TYPE_MAX_VALUE (type
);
1636 if (limit_vr
== NULL
|| limit_vr
->type
== VR_ANTI_RANGE
)
1640 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1641 range [N1, MAX] for GE_EXPR and [N1 + 1, MAX] for
1643 min
= limit_vr
->min
;
1646 /* If the minimum value forces us to be out of bounds, simply punt.
1647 It would be pointless to try and do anything more since this
1648 all should be optimized away above us. */
1649 if ((cond_code
== GT_EXPR
1650 && compare_values (min
, max
) == 0)
1651 || (CONSTANT_CLASS_P (min
) && TREE_OVERFLOW (min
)))
1652 set_value_range_to_varying (vr_p
);
1655 /* For GT_EXPR, we create the range [MIN + 1, MAX]. */
1656 if (cond_code
== GT_EXPR
)
1658 tree one
= build_int_cst (type
, 1);
1659 min
= fold_build2 (PLUS_EXPR
, type
, min
, one
);
1661 TREE_NO_WARNING (min
) = 1;
1664 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1670 /* If VAR already had a known range, it may happen that the new
1671 range we have computed and VAR's range are not compatible. For
1675 p_6 = ASSERT_EXPR <p_5, p_5 == NULL>;
1677 p_8 = ASSERT_EXPR <p_6, p_6 != NULL>;
1679 While the above comes from a faulty program, it will cause an ICE
1680 later because p_8 and p_6 will have incompatible ranges and at
1681 the same time will be considered equivalent. A similar situation
1685 i_6 = ASSERT_EXPR <i_5, i_5 > 10>;
1687 i_7 = ASSERT_EXPR <i_6, i_6 < 5>;
1689 Again i_6 and i_7 will have incompatible ranges. It would be
1690 pointless to try and do anything with i_7's range because
1691 anything dominated by 'if (i_5 < 5)' will be optimized away.
1692 Note, due to the wa in which simulation proceeds, the statement
1693 i_7 = ASSERT_EXPR <...> we would never be visited because the
1694 conditional 'if (i_5 < 5)' always evaluates to false. However,
1695 this extra check does not hurt and may protect against future
1696 changes to VRP that may get into a situation similar to the
1697 NULL pointer dereference example.
1699 Note that these compatibility tests are only needed when dealing
1700 with ranges or a mix of range and anti-range. If VAR_VR and VR_P
1701 are both anti-ranges, they will always be compatible, because two
1702 anti-ranges will always have a non-empty intersection. */
1704 var_vr
= get_value_range (var
);
1706 /* We may need to make adjustments when VR_P and VAR_VR are numeric
1707 ranges or anti-ranges. */
1708 if (vr_p
->type
== VR_VARYING
1709 || vr_p
->type
== VR_UNDEFINED
1710 || var_vr
->type
== VR_VARYING
1711 || var_vr
->type
== VR_UNDEFINED
1712 || symbolic_range_p (vr_p
)
1713 || symbolic_range_p (var_vr
))
1716 if (var_vr
->type
== VR_RANGE
&& vr_p
->type
== VR_RANGE
)
1718 /* If the two ranges have a non-empty intersection, we can
1719 refine the resulting range. Since the assert expression
1720 creates an equivalency and at the same time it asserts a
1721 predicate, we can take the intersection of the two ranges to
1722 get better precision. */
1723 if (value_ranges_intersect_p (var_vr
, vr_p
))
1725 /* Use the larger of the two minimums. */
1726 if (compare_values (vr_p
->min
, var_vr
->min
) == -1)
1731 /* Use the smaller of the two maximums. */
1732 if (compare_values (vr_p
->max
, var_vr
->max
) == 1)
1737 set_value_range (vr_p
, vr_p
->type
, min
, max
, vr_p
->equiv
);
1741 /* The two ranges do not intersect, set the new range to
1742 VARYING, because we will not be able to do anything
1743 meaningful with it. */
1744 set_value_range_to_varying (vr_p
);
1747 else if ((var_vr
->type
== VR_RANGE
&& vr_p
->type
== VR_ANTI_RANGE
)
1748 || (var_vr
->type
== VR_ANTI_RANGE
&& vr_p
->type
== VR_RANGE
))
1750 /* A range and an anti-range will cancel each other only if
1751 their ends are the same. For instance, in the example above,
1752 p_8's range ~[0, 0] and p_6's range [0, 0] are incompatible,
1753 so VR_P should be set to VR_VARYING. */
1754 if (compare_values (var_vr
->min
, vr_p
->min
) == 0
1755 && compare_values (var_vr
->max
, vr_p
->max
) == 0)
1756 set_value_range_to_varying (vr_p
);
1759 tree min
, max
, anti_min
, anti_max
, real_min
, real_max
;
1762 /* We want to compute the logical AND of the two ranges;
1763 there are three cases to consider.
1766 1. The VR_ANTI_RANGE range is completely within the
1767 VR_RANGE and the endpoints of the ranges are
1768 different. In that case the resulting range
1769 should be whichever range is more precise.
1770 Typically that will be the VR_RANGE.
1772 2. The VR_ANTI_RANGE is completely disjoint from
1773 the VR_RANGE. In this case the resulting range
1774 should be the VR_RANGE.
1776 3. There is some overlap between the VR_ANTI_RANGE
1779 3a. If the high limit of the VR_ANTI_RANGE resides
1780 within the VR_RANGE, then the result is a new
1781 VR_RANGE starting at the high limit of the
1782 VR_ANTI_RANGE + 1 and extending to the
1783 high limit of the original VR_RANGE.
1785 3b. If the low limit of the VR_ANTI_RANGE resides
1786 within the VR_RANGE, then the result is a new
1787 VR_RANGE starting at the low limit of the original
1788 VR_RANGE and extending to the low limit of the
1789 VR_ANTI_RANGE - 1. */
1790 if (vr_p
->type
== VR_ANTI_RANGE
)
1792 anti_min
= vr_p
->min
;
1793 anti_max
= vr_p
->max
;
1794 real_min
= var_vr
->min
;
1795 real_max
= var_vr
->max
;
1799 anti_min
= var_vr
->min
;
1800 anti_max
= var_vr
->max
;
1801 real_min
= vr_p
->min
;
1802 real_max
= vr_p
->max
;
1806 /* Case 1, VR_ANTI_RANGE completely within VR_RANGE,
1807 not including any endpoints. */
1808 if (compare_values (anti_max
, real_max
) == -1
1809 && compare_values (anti_min
, real_min
) == 1)
1811 /* If the range is covering the whole valid range of
1812 the type keep the anti-range. */
1813 if (!vrp_val_is_min (real_min
)
1814 || !vrp_val_is_max (real_max
))
1815 set_value_range (vr_p
, VR_RANGE
, real_min
,
1816 real_max
, vr_p
->equiv
);
1818 /* Case 2, VR_ANTI_RANGE completely disjoint from
1820 else if (compare_values (anti_min
, real_max
) == 1
1821 || compare_values (anti_max
, real_min
) == -1)
1823 set_value_range (vr_p
, VR_RANGE
, real_min
,
1824 real_max
, vr_p
->equiv
);
1826 /* Case 3a, the anti-range extends into the low
1827 part of the real range. Thus creating a new
1828 low for the real range. */
1829 else if (((cmp
= compare_values (anti_max
, real_min
)) == 1
1831 && compare_values (anti_max
, real_max
) == -1)
1833 gcc_assert (!is_positive_overflow_infinity (anti_max
));
1834 if (needs_overflow_infinity (TREE_TYPE (anti_max
))
1835 && vrp_val_is_max (anti_max
))
1837 if (!supports_overflow_infinity (TREE_TYPE (var_vr
->min
)))
1839 set_value_range_to_varying (vr_p
);
1842 min
= positive_overflow_infinity (TREE_TYPE (var_vr
->min
));
1844 else if (!POINTER_TYPE_P (TREE_TYPE (var_vr
->min
)))
1845 min
= fold_build2 (PLUS_EXPR
, TREE_TYPE (var_vr
->min
),
1847 build_int_cst (TREE_TYPE (var_vr
->min
), 1));
1849 min
= fold_build2 (POINTER_PLUS_EXPR
, TREE_TYPE (var_vr
->min
),
1850 anti_max
, size_int (1));
1852 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1854 /* Case 3b, the anti-range extends into the high
1855 part of the real range. Thus creating a new
1856 higher for the real range. */
1857 else if (compare_values (anti_min
, real_min
) == 1
1858 && ((cmp
= compare_values (anti_min
, real_max
)) == -1
1861 gcc_assert (!is_negative_overflow_infinity (anti_min
));
1862 if (needs_overflow_infinity (TREE_TYPE (anti_min
))
1863 && vrp_val_is_min (anti_min
))
1865 if (!supports_overflow_infinity (TREE_TYPE (var_vr
->min
)))
1867 set_value_range_to_varying (vr_p
);
1870 max
= negative_overflow_infinity (TREE_TYPE (var_vr
->min
));
1872 else if (!POINTER_TYPE_P (TREE_TYPE (var_vr
->min
)))
1873 max
= fold_build2 (MINUS_EXPR
, TREE_TYPE (var_vr
->min
),
1875 build_int_cst (TREE_TYPE (var_vr
->min
), 1));
1877 max
= fold_build2 (POINTER_PLUS_EXPR
, TREE_TYPE (var_vr
->min
),
1881 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1888 /* Extract range information from SSA name VAR and store it in VR. If
1889 VAR has an interesting range, use it. Otherwise, create the
1890 range [VAR, VAR] and return it. This is useful in situations where
1891 we may have conditionals testing values of VARYING names. For
1898 Even if y_5 is deemed VARYING, we can determine that x_3 > y_5 is
1902 extract_range_from_ssa_name (value_range_t
*vr
, tree var
)
1904 value_range_t
*var_vr
= get_value_range (var
);
1906 if (var_vr
->type
!= VR_UNDEFINED
&& var_vr
->type
!= VR_VARYING
)
1907 copy_value_range (vr
, var_vr
);
1909 set_value_range (vr
, VR_RANGE
, var
, var
, NULL
);
1911 add_equivalence (&vr
->equiv
, var
);
1915 /* Wrapper around int_const_binop. If the operation overflows and we
1916 are not using wrapping arithmetic, then adjust the result to be
1917 -INF or +INF depending on CODE, VAL1 and VAL2. This can return
1918 NULL_TREE if we need to use an overflow infinity representation but
1919 the type does not support it. */
1922 vrp_int_const_binop (enum tree_code code
, tree val1
, tree val2
)
1926 res
= int_const_binop (code
, val1
, val2
, 0);
1928 /* If we are using unsigned arithmetic, operate symbolically
1929 on -INF and +INF as int_const_binop only handles signed overflow. */
1930 if (TYPE_UNSIGNED (TREE_TYPE (val1
)))
1932 int checkz
= compare_values (res
, val1
);
1933 bool overflow
= false;
1935 /* Ensure that res = val1 [+*] val2 >= val1
1936 or that res = val1 - val2 <= val1. */
1937 if ((code
== PLUS_EXPR
1938 && !(checkz
== 1 || checkz
== 0))
1939 || (code
== MINUS_EXPR
1940 && !(checkz
== 0 || checkz
== -1)))
1944 /* Checking for multiplication overflow is done by dividing the
1945 output of the multiplication by the first input of the
1946 multiplication. If the result of that division operation is
1947 not equal to the second input of the multiplication, then the
1948 multiplication overflowed. */
1949 else if (code
== MULT_EXPR
&& !integer_zerop (val1
))
1951 tree tmp
= int_const_binop (TRUNC_DIV_EXPR
,
1954 int check
= compare_values (tmp
, val2
);
1962 res
= copy_node (res
);
1963 TREE_OVERFLOW (res
) = 1;
1967 else if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (val1
)))
1968 /* If the singed operation wraps then int_const_binop has done
1969 everything we want. */
1971 else if ((TREE_OVERFLOW (res
)
1972 && !TREE_OVERFLOW (val1
)
1973 && !TREE_OVERFLOW (val2
))
1974 || is_overflow_infinity (val1
)
1975 || is_overflow_infinity (val2
))
1977 /* If the operation overflowed but neither VAL1 nor VAL2 are
1978 overflown, return -INF or +INF depending on the operation
1979 and the combination of signs of the operands. */
1980 int sgn1
= tree_int_cst_sgn (val1
);
1981 int sgn2
= tree_int_cst_sgn (val2
);
1983 if (needs_overflow_infinity (TREE_TYPE (res
))
1984 && !supports_overflow_infinity (TREE_TYPE (res
)))
1987 /* We have to punt on adding infinities of different signs,
1988 since we can't tell what the sign of the result should be.
1989 Likewise for subtracting infinities of the same sign. */
1990 if (((code
== PLUS_EXPR
&& sgn1
!= sgn2
)
1991 || (code
== MINUS_EXPR
&& sgn1
== sgn2
))
1992 && is_overflow_infinity (val1
)
1993 && is_overflow_infinity (val2
))
1996 /* Don't try to handle division or shifting of infinities. */
1997 if ((code
== TRUNC_DIV_EXPR
1998 || code
== FLOOR_DIV_EXPR
1999 || code
== CEIL_DIV_EXPR
2000 || code
== EXACT_DIV_EXPR
2001 || code
== ROUND_DIV_EXPR
2002 || code
== RSHIFT_EXPR
)
2003 && (is_overflow_infinity (val1
)
2004 || is_overflow_infinity (val2
)))
2007 /* Notice that we only need to handle the restricted set of
2008 operations handled by extract_range_from_binary_expr.
2009 Among them, only multiplication, addition and subtraction
2010 can yield overflow without overflown operands because we
2011 are working with integral types only... except in the
2012 case VAL1 = -INF and VAL2 = -1 which overflows to +INF
2013 for division too. */
2015 /* For multiplication, the sign of the overflow is given
2016 by the comparison of the signs of the operands. */
2017 if ((code
== MULT_EXPR
&& sgn1
== sgn2
)
2018 /* For addition, the operands must be of the same sign
2019 to yield an overflow. Its sign is therefore that
2020 of one of the operands, for example the first. For
2021 infinite operands X + -INF is negative, not positive. */
2022 || (code
== PLUS_EXPR
2024 ? !is_negative_overflow_infinity (val2
)
2025 : is_positive_overflow_infinity (val2
)))
2026 /* For subtraction, non-infinite operands must be of
2027 different signs to yield an overflow. Its sign is
2028 therefore that of the first operand or the opposite of
2029 that of the second operand. A first operand of 0 counts
2030 as positive here, for the corner case 0 - (-INF), which
2031 overflows, but must yield +INF. For infinite operands 0
2032 - INF is negative, not positive. */
2033 || (code
== MINUS_EXPR
2035 ? !is_positive_overflow_infinity (val2
)
2036 : is_negative_overflow_infinity (val2
)))
2037 /* We only get in here with positive shift count, so the
2038 overflow direction is the same as the sign of val1.
2039 Actually rshift does not overflow at all, but we only
2040 handle the case of shifting overflowed -INF and +INF. */
2041 || (code
== RSHIFT_EXPR
2043 /* For division, the only case is -INF / -1 = +INF. */
2044 || code
== TRUNC_DIV_EXPR
2045 || code
== FLOOR_DIV_EXPR
2046 || code
== CEIL_DIV_EXPR
2047 || code
== EXACT_DIV_EXPR
2048 || code
== ROUND_DIV_EXPR
)
2049 return (needs_overflow_infinity (TREE_TYPE (res
))
2050 ? positive_overflow_infinity (TREE_TYPE (res
))
2051 : TYPE_MAX_VALUE (TREE_TYPE (res
)));
2053 return (needs_overflow_infinity (TREE_TYPE (res
))
2054 ? negative_overflow_infinity (TREE_TYPE (res
))
2055 : TYPE_MIN_VALUE (TREE_TYPE (res
)));
2062 /* Extract range information from a binary expression EXPR based on
2063 the ranges of each of its operands and the expression code. */
2066 extract_range_from_binary_expr (value_range_t
*vr
,
2067 enum tree_code code
,
2068 tree expr_type
, tree op0
, tree op1
)
2070 enum value_range_type type
;
2073 value_range_t vr0
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
2074 value_range_t vr1
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
2076 /* Not all binary expressions can be applied to ranges in a
2077 meaningful way. Handle only arithmetic operations. */
2078 if (code
!= PLUS_EXPR
2079 && code
!= MINUS_EXPR
2080 && code
!= POINTER_PLUS_EXPR
2081 && code
!= MULT_EXPR
2082 && code
!= TRUNC_DIV_EXPR
2083 && code
!= FLOOR_DIV_EXPR
2084 && code
!= CEIL_DIV_EXPR
2085 && code
!= EXACT_DIV_EXPR
2086 && code
!= ROUND_DIV_EXPR
2087 && code
!= TRUNC_MOD_EXPR
2088 && code
!= RSHIFT_EXPR
2091 && code
!= BIT_AND_EXPR
2092 && code
!= BIT_IOR_EXPR
2093 && code
!= TRUTH_AND_EXPR
2094 && code
!= TRUTH_OR_EXPR
)
2096 /* We can still do constant propagation here. */
2097 tree const_op0
= op_with_constant_singleton_value_range (op0
);
2098 tree const_op1
= op_with_constant_singleton_value_range (op1
);
2099 if (const_op0
|| const_op1
)
2101 tree tem
= fold_binary (code
, expr_type
,
2102 const_op0
? const_op0
: op0
,
2103 const_op1
? const_op1
: op1
);
2105 && is_gimple_min_invariant (tem
)
2106 && !is_overflow_infinity (tem
))
2108 set_value_range (vr
, VR_RANGE
, tem
, tem
, NULL
);
2112 set_value_range_to_varying (vr
);
2116 /* Get value ranges for each operand. For constant operands, create
2117 a new value range with the operand to simplify processing. */
2118 if (TREE_CODE (op0
) == SSA_NAME
)
2119 vr0
= *(get_value_range (op0
));
2120 else if (is_gimple_min_invariant (op0
))
2121 set_value_range_to_value (&vr0
, op0
, NULL
);
2123 set_value_range_to_varying (&vr0
);
2125 if (TREE_CODE (op1
) == SSA_NAME
)
2126 vr1
= *(get_value_range (op1
));
2127 else if (is_gimple_min_invariant (op1
))
2128 set_value_range_to_value (&vr1
, op1
, NULL
);
2130 set_value_range_to_varying (&vr1
);
2132 /* If either range is UNDEFINED, so is the result. */
2133 if (vr0
.type
== VR_UNDEFINED
|| vr1
.type
== VR_UNDEFINED
)
2135 set_value_range_to_undefined (vr
);
2139 /* The type of the resulting value range defaults to VR0.TYPE. */
2142 /* Refuse to operate on VARYING ranges, ranges of different kinds
2143 and symbolic ranges. As an exception, we allow BIT_AND_EXPR
2144 because we may be able to derive a useful range even if one of
2145 the operands is VR_VARYING or symbolic range. Similarly for
2146 divisions. TODO, we may be able to derive anti-ranges in
2148 if (code
!= BIT_AND_EXPR
2149 && code
!= TRUTH_AND_EXPR
2150 && code
!= TRUTH_OR_EXPR
2151 && code
!= TRUNC_DIV_EXPR
2152 && code
!= FLOOR_DIV_EXPR
2153 && code
!= CEIL_DIV_EXPR
2154 && code
!= EXACT_DIV_EXPR
2155 && code
!= ROUND_DIV_EXPR
2156 && code
!= TRUNC_MOD_EXPR
2157 && (vr0
.type
== VR_VARYING
2158 || vr1
.type
== VR_VARYING
2159 || vr0
.type
!= vr1
.type
2160 || symbolic_range_p (&vr0
)
2161 || symbolic_range_p (&vr1
)))
2163 set_value_range_to_varying (vr
);
2167 /* Now evaluate the expression to determine the new range. */
2168 if (POINTER_TYPE_P (expr_type
)
2169 || POINTER_TYPE_P (TREE_TYPE (op0
))
2170 || POINTER_TYPE_P (TREE_TYPE (op1
)))
2172 if (code
== MIN_EXPR
|| code
== MAX_EXPR
)
2174 /* For MIN/MAX expressions with pointers, we only care about
2175 nullness, if both are non null, then the result is nonnull.
2176 If both are null, then the result is null. Otherwise they
2178 if (range_is_nonnull (&vr0
) && range_is_nonnull (&vr1
))
2179 set_value_range_to_nonnull (vr
, expr_type
);
2180 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
2181 set_value_range_to_null (vr
, expr_type
);
2183 set_value_range_to_varying (vr
);
2187 gcc_assert (code
== POINTER_PLUS_EXPR
);
2188 /* For pointer types, we are really only interested in asserting
2189 whether the expression evaluates to non-NULL. */
2190 if (range_is_nonnull (&vr0
) || range_is_nonnull (&vr1
))
2191 set_value_range_to_nonnull (vr
, expr_type
);
2192 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
2193 set_value_range_to_null (vr
, expr_type
);
2195 set_value_range_to_varying (vr
);
2200 /* For integer ranges, apply the operation to each end of the
2201 range and see what we end up with. */
2202 if (code
== TRUTH_AND_EXPR
2203 || code
== TRUTH_OR_EXPR
)
2205 /* If one of the operands is zero, we know that the whole
2206 expression evaluates zero. */
2207 if (code
== TRUTH_AND_EXPR
2208 && ((vr0
.type
== VR_RANGE
2209 && integer_zerop (vr0
.min
)
2210 && integer_zerop (vr0
.max
))
2211 || (vr1
.type
== VR_RANGE
2212 && integer_zerop (vr1
.min
)
2213 && integer_zerop (vr1
.max
))))
2216 min
= max
= build_int_cst (expr_type
, 0);
2218 /* If one of the operands is one, we know that the whole
2219 expression evaluates one. */
2220 else if (code
== TRUTH_OR_EXPR
2221 && ((vr0
.type
== VR_RANGE
2222 && integer_onep (vr0
.min
)
2223 && integer_onep (vr0
.max
))
2224 || (vr1
.type
== VR_RANGE
2225 && integer_onep (vr1
.min
)
2226 && integer_onep (vr1
.max
))))
2229 min
= max
= build_int_cst (expr_type
, 1);
2231 else if (vr0
.type
!= VR_VARYING
2232 && vr1
.type
!= VR_VARYING
2233 && vr0
.type
== vr1
.type
2234 && !symbolic_range_p (&vr0
)
2235 && !overflow_infinity_range_p (&vr0
)
2236 && !symbolic_range_p (&vr1
)
2237 && !overflow_infinity_range_p (&vr1
))
2239 /* Boolean expressions cannot be folded with int_const_binop. */
2240 min
= fold_binary (code
, expr_type
, vr0
.min
, vr1
.min
);
2241 max
= fold_binary (code
, expr_type
, vr0
.max
, vr1
.max
);
2245 /* The result of a TRUTH_*_EXPR is always true or false. */
2246 set_value_range_to_truthvalue (vr
, expr_type
);
2250 else if (code
== PLUS_EXPR
2252 || code
== MAX_EXPR
)
2254 /* If we have a PLUS_EXPR with two VR_ANTI_RANGEs, drop to
2255 VR_VARYING. It would take more effort to compute a precise
2256 range for such a case. For example, if we have op0 == 1 and
2257 op1 == -1 with their ranges both being ~[0,0], we would have
2258 op0 + op1 == 0, so we cannot claim that the sum is in ~[0,0].
2259 Note that we are guaranteed to have vr0.type == vr1.type at
2261 if (code
== PLUS_EXPR
&& vr0
.type
== VR_ANTI_RANGE
)
2263 set_value_range_to_varying (vr
);
2267 /* For operations that make the resulting range directly
2268 proportional to the original ranges, apply the operation to
2269 the same end of each range. */
2270 min
= vrp_int_const_binop (code
, vr0
.min
, vr1
.min
);
2271 max
= vrp_int_const_binop (code
, vr0
.max
, vr1
.max
);
2273 /* If both additions overflowed the range kind is still correct.
2274 This happens regularly with subtracting something in unsigned
2276 ??? See PR30318 for all the cases we do not handle. */
2277 if (code
== PLUS_EXPR
2278 && (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2279 && (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2281 min
= build_int_cst_wide (TREE_TYPE (min
),
2282 TREE_INT_CST_LOW (min
),
2283 TREE_INT_CST_HIGH (min
));
2284 max
= build_int_cst_wide (TREE_TYPE (max
),
2285 TREE_INT_CST_LOW (max
),
2286 TREE_INT_CST_HIGH (max
));
2289 else if (code
== MULT_EXPR
2290 || code
== TRUNC_DIV_EXPR
2291 || code
== FLOOR_DIV_EXPR
2292 || code
== CEIL_DIV_EXPR
2293 || code
== EXACT_DIV_EXPR
2294 || code
== ROUND_DIV_EXPR
2295 || code
== RSHIFT_EXPR
)
2301 /* If we have an unsigned MULT_EXPR with two VR_ANTI_RANGEs,
2302 drop to VR_VARYING. It would take more effort to compute a
2303 precise range for such a case. For example, if we have
2304 op0 == 65536 and op1 == 65536 with their ranges both being
2305 ~[0,0] on a 32-bit machine, we would have op0 * op1 == 0, so
2306 we cannot claim that the product is in ~[0,0]. Note that we
2307 are guaranteed to have vr0.type == vr1.type at this
2309 if (code
== MULT_EXPR
2310 && vr0
.type
== VR_ANTI_RANGE
2311 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0
)))
2313 set_value_range_to_varying (vr
);
2317 /* If we have a RSHIFT_EXPR with any shift values outside [0..prec-1],
2318 then drop to VR_VARYING. Outside of this range we get undefined
2319 behavior from the shift operation. We cannot even trust
2320 SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl
2321 shifts, and the operation at the tree level may be widened. */
2322 if (code
== RSHIFT_EXPR
)
2324 if (vr1
.type
== VR_ANTI_RANGE
2325 || !vrp_expr_computes_nonnegative (op1
, &sop
)
2327 (build_int_cst (TREE_TYPE (vr1
.max
),
2328 TYPE_PRECISION (expr_type
) - 1),
2331 set_value_range_to_varying (vr
);
2336 else if ((code
== TRUNC_DIV_EXPR
2337 || code
== FLOOR_DIV_EXPR
2338 || code
== CEIL_DIV_EXPR
2339 || code
== EXACT_DIV_EXPR
2340 || code
== ROUND_DIV_EXPR
)
2341 && (vr0
.type
!= VR_RANGE
|| symbolic_range_p (&vr0
)))
2343 /* For division, if op1 has VR_RANGE but op0 does not, something
2344 can be deduced just from that range. Say [min, max] / [4, max]
2345 gives [min / 4, max / 4] range. */
2346 if (vr1
.type
== VR_RANGE
2347 && !symbolic_range_p (&vr1
)
2348 && !range_includes_zero_p (&vr1
))
2350 vr0
.type
= type
= VR_RANGE
;
2351 vr0
.min
= vrp_val_min (TREE_TYPE (op0
));
2352 vr0
.max
= vrp_val_max (TREE_TYPE (op1
));
2356 set_value_range_to_varying (vr
);
2361 /* For divisions, if op0 is VR_RANGE, we can deduce a range
2362 even if op1 is VR_VARYING, VR_ANTI_RANGE, symbolic or can
2364 if ((code
== TRUNC_DIV_EXPR
2365 || code
== FLOOR_DIV_EXPR
2366 || code
== CEIL_DIV_EXPR
2367 || code
== EXACT_DIV_EXPR
2368 || code
== ROUND_DIV_EXPR
)
2369 && vr0
.type
== VR_RANGE
2370 && (vr1
.type
!= VR_RANGE
2371 || symbolic_range_p (&vr1
)
2372 || range_includes_zero_p (&vr1
)))
2374 tree zero
= build_int_cst (TREE_TYPE (vr0
.min
), 0);
2380 if (vrp_expr_computes_nonnegative (op1
, &sop
) && !sop
)
2382 /* For unsigned division or when divisor is known
2383 to be non-negative, the range has to cover
2384 all numbers from 0 to max for positive max
2385 and all numbers from min to 0 for negative min. */
2386 cmp
= compare_values (vr0
.max
, zero
);
2389 else if (cmp
== 0 || cmp
== 1)
2393 cmp
= compare_values (vr0
.min
, zero
);
2396 else if (cmp
== 0 || cmp
== -1)
2403 /* Otherwise the range is -max .. max or min .. -min
2404 depending on which bound is bigger in absolute value,
2405 as the division can change the sign. */
2406 abs_extent_range (vr
, vr0
.min
, vr0
.max
);
2409 if (type
== VR_VARYING
)
2411 set_value_range_to_varying (vr
);
2416 /* Multiplications and divisions are a bit tricky to handle,
2417 depending on the mix of signs we have in the two ranges, we
2418 need to operate on different values to get the minimum and
2419 maximum values for the new range. One approach is to figure
2420 out all the variations of range combinations and do the
2423 However, this involves several calls to compare_values and it
2424 is pretty convoluted. It's simpler to do the 4 operations
2425 (MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
2426 MAX1) and then figure the smallest and largest values to form
2430 gcc_assert ((vr0
.type
== VR_RANGE
2431 || (code
== MULT_EXPR
&& vr0
.type
== VR_ANTI_RANGE
))
2432 && vr0
.type
== vr1
.type
);
2434 /* Compute the 4 cross operations. */
2436 val
[0] = vrp_int_const_binop (code
, vr0
.min
, vr1
.min
);
2437 if (val
[0] == NULL_TREE
)
2440 if (vr1
.max
== vr1
.min
)
2444 val
[1] = vrp_int_const_binop (code
, vr0
.min
, vr1
.max
);
2445 if (val
[1] == NULL_TREE
)
2449 if (vr0
.max
== vr0
.min
)
2453 val
[2] = vrp_int_const_binop (code
, vr0
.max
, vr1
.min
);
2454 if (val
[2] == NULL_TREE
)
2458 if (vr0
.min
== vr0
.max
|| vr1
.min
== vr1
.max
)
2462 val
[3] = vrp_int_const_binop (code
, vr0
.max
, vr1
.max
);
2463 if (val
[3] == NULL_TREE
)
2469 set_value_range_to_varying (vr
);
2473 /* Set MIN to the minimum of VAL[i] and MAX to the maximum
2477 for (i
= 1; i
< 4; i
++)
2479 if (!is_gimple_min_invariant (min
)
2480 || (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2481 || !is_gimple_min_invariant (max
)
2482 || (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2487 if (!is_gimple_min_invariant (val
[i
])
2488 || (TREE_OVERFLOW (val
[i
])
2489 && !is_overflow_infinity (val
[i
])))
2491 /* If we found an overflowed value, set MIN and MAX
2492 to it so that we set the resulting range to
2498 if (compare_values (val
[i
], min
) == -1)
2501 if (compare_values (val
[i
], max
) == 1)
2507 else if (code
== TRUNC_MOD_EXPR
)
2510 if (vr1
.type
!= VR_RANGE
2511 || symbolic_range_p (&vr1
)
2512 || range_includes_zero_p (&vr1
)
2513 || vrp_val_is_min (vr1
.min
))
2515 set_value_range_to_varying (vr
);
2519 /* Compute MAX <|vr1.min|, |vr1.max|> - 1. */
2520 max
= fold_unary_to_constant (ABS_EXPR
, TREE_TYPE (vr1
.min
), vr1
.min
);
2521 if (tree_int_cst_lt (max
, vr1
.max
))
2523 max
= int_const_binop (MINUS_EXPR
, max
, integer_one_node
, 0);
2524 /* If the dividend is non-negative the modulus will be
2525 non-negative as well. */
2526 if (TYPE_UNSIGNED (TREE_TYPE (max
))
2527 || (vrp_expr_computes_nonnegative (op0
, &sop
) && !sop
))
2528 min
= build_int_cst (TREE_TYPE (max
), 0);
2530 min
= fold_unary_to_constant (NEGATE_EXPR
, TREE_TYPE (max
), max
);
2532 else if (code
== MINUS_EXPR
)
2534 /* If we have a MINUS_EXPR with two VR_ANTI_RANGEs, drop to
2535 VR_VARYING. It would take more effort to compute a precise
2536 range for such a case. For example, if we have op0 == 1 and
2537 op1 == 1 with their ranges both being ~[0,0], we would have
2538 op0 - op1 == 0, so we cannot claim that the difference is in
2539 ~[0,0]. Note that we are guaranteed to have
2540 vr0.type == vr1.type at this point. */
2541 if (vr0
.type
== VR_ANTI_RANGE
)
2543 set_value_range_to_varying (vr
);
2547 /* For MINUS_EXPR, apply the operation to the opposite ends of
2549 min
= vrp_int_const_binop (code
, vr0
.min
, vr1
.max
);
2550 max
= vrp_int_const_binop (code
, vr0
.max
, vr1
.min
);
2552 else if (code
== BIT_AND_EXPR
)
2554 bool vr0_int_cst_singleton_p
, vr1_int_cst_singleton_p
;
2556 vr0_int_cst_singleton_p
= range_int_cst_singleton_p (&vr0
);
2557 vr1_int_cst_singleton_p
= range_int_cst_singleton_p (&vr1
);
2559 if (vr0_int_cst_singleton_p
&& vr1_int_cst_singleton_p
)
2560 min
= max
= int_const_binop (code
, vr0
.max
, vr1
.max
, 0);
2561 else if (vr0_int_cst_singleton_p
2562 && tree_int_cst_sgn (vr0
.max
) >= 0)
2564 min
= build_int_cst (expr_type
, 0);
2567 else if (vr1_int_cst_singleton_p
2568 && tree_int_cst_sgn (vr1
.max
) >= 0)
2571 min
= build_int_cst (expr_type
, 0);
2576 set_value_range_to_varying (vr
);
2580 else if (code
== BIT_IOR_EXPR
)
2582 if (range_int_cst_p (&vr0
)
2583 && range_int_cst_p (&vr1
)
2584 && tree_int_cst_sgn (vr0
.min
) >= 0
2585 && tree_int_cst_sgn (vr1
.min
) >= 0)
2587 double_int vr0_max
= tree_to_double_int (vr0
.max
);
2588 double_int vr1_max
= tree_to_double_int (vr1
.max
);
2591 /* Set all bits to the right of the most significant one to 1.
2592 For example, [0, 4] | [4, 4] = [4, 7]. */
2593 ior_max
.low
= vr0_max
.low
| vr1_max
.low
;
2594 ior_max
.high
= vr0_max
.high
| vr1_max
.high
;
2595 if (ior_max
.high
!= 0)
2597 ior_max
.low
= ~(unsigned HOST_WIDE_INT
)0u;
2598 ior_max
.high
|= ((HOST_WIDE_INT
) 1
2599 << floor_log2 (ior_max
.high
)) - 1;
2601 else if (ior_max
.low
!= 0)
2602 ior_max
.low
|= ((unsigned HOST_WIDE_INT
) 1u
2603 << floor_log2 (ior_max
.low
)) - 1;
2605 /* Both of these endpoints are conservative. */
2606 min
= vrp_int_const_binop (MAX_EXPR
, vr0
.min
, vr1
.min
);
2607 max
= double_int_to_tree (expr_type
, ior_max
);
2611 set_value_range_to_varying (vr
);
2618 /* If either MIN or MAX overflowed, then set the resulting range to
2619 VARYING. But we do accept an overflow infinity
2621 if (min
== NULL_TREE
2622 || !is_gimple_min_invariant (min
)
2623 || (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2625 || !is_gimple_min_invariant (max
)
2626 || (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2628 set_value_range_to_varying (vr
);
2634 2) [-INF, +-INF(OVF)]
2635 3) [+-INF(OVF), +INF]
2636 4) [+-INF(OVF), +-INF(OVF)]
2637 We learn nothing when we have INF and INF(OVF) on both sides.
2638 Note that we do accept [-INF, -INF] and [+INF, +INF] without
2640 if ((vrp_val_is_min (min
) || is_overflow_infinity (min
))
2641 && (vrp_val_is_max (max
) || is_overflow_infinity (max
)))
2643 set_value_range_to_varying (vr
);
2647 cmp
= compare_values (min
, max
);
2648 if (cmp
== -2 || cmp
== 1)
2650 /* If the new range has its limits swapped around (MIN > MAX),
2651 then the operation caused one of them to wrap around, mark
2652 the new range VARYING. */
2653 set_value_range_to_varying (vr
);
2656 set_value_range (vr
, type
, min
, max
, NULL
);
2660 /* Extract range information from a unary expression EXPR based on
2661 the range of its operand and the expression code. */
2664 extract_range_from_unary_expr (value_range_t
*vr
, enum tree_code code
,
2665 tree type
, tree op0
)
2669 value_range_t vr0
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
2671 /* Refuse to operate on certain unary expressions for which we
2672 cannot easily determine a resulting range. */
2673 if (code
== FIX_TRUNC_EXPR
2674 || code
== FLOAT_EXPR
2675 || code
== BIT_NOT_EXPR
2676 || code
== CONJ_EXPR
)
2678 /* We can still do constant propagation here. */
2679 if ((op0
= op_with_constant_singleton_value_range (op0
)) != NULL_TREE
)
2681 tree tem
= fold_unary (code
, type
, op0
);
2683 && is_gimple_min_invariant (tem
)
2684 && !is_overflow_infinity (tem
))
2686 set_value_range (vr
, VR_RANGE
, tem
, tem
, NULL
);
2690 set_value_range_to_varying (vr
);
2694 /* Get value ranges for the operand. For constant operands, create
2695 a new value range with the operand to simplify processing. */
2696 if (TREE_CODE (op0
) == SSA_NAME
)
2697 vr0
= *(get_value_range (op0
));
2698 else if (is_gimple_min_invariant (op0
))
2699 set_value_range_to_value (&vr0
, op0
, NULL
);
2701 set_value_range_to_varying (&vr0
);
2703 /* If VR0 is UNDEFINED, so is the result. */
2704 if (vr0
.type
== VR_UNDEFINED
)
2706 set_value_range_to_undefined (vr
);
2710 /* Refuse to operate on symbolic ranges, or if neither operand is
2711 a pointer or integral type. */
2712 if ((!INTEGRAL_TYPE_P (TREE_TYPE (op0
))
2713 && !POINTER_TYPE_P (TREE_TYPE (op0
)))
2714 || (vr0
.type
!= VR_VARYING
2715 && symbolic_range_p (&vr0
)))
2717 set_value_range_to_varying (vr
);
2721 /* If the expression involves pointers, we are only interested in
2722 determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */
2723 if (POINTER_TYPE_P (type
) || POINTER_TYPE_P (TREE_TYPE (op0
)))
2728 if (range_is_nonnull (&vr0
)
2729 || (tree_unary_nonzero_warnv_p (code
, type
, op0
, &sop
)
2731 set_value_range_to_nonnull (vr
, type
);
2732 else if (range_is_null (&vr0
))
2733 set_value_range_to_null (vr
, type
);
2735 set_value_range_to_varying (vr
);
2740 /* Handle unary expressions on integer ranges. */
2741 if (CONVERT_EXPR_CODE_P (code
)
2742 && INTEGRAL_TYPE_P (type
)
2743 && INTEGRAL_TYPE_P (TREE_TYPE (op0
)))
2745 tree inner_type
= TREE_TYPE (op0
);
2746 tree outer_type
= type
;
2748 /* If VR0 is varying and we increase the type precision, assume
2749 a full range for the following transformation. */
2750 if (vr0
.type
== VR_VARYING
2751 && TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
))
2753 vr0
.type
= VR_RANGE
;
2754 vr0
.min
= TYPE_MIN_VALUE (inner_type
);
2755 vr0
.max
= TYPE_MAX_VALUE (inner_type
);
2758 /* If VR0 is a constant range or anti-range and the conversion is
2759 not truncating we can convert the min and max values and
2760 canonicalize the resulting range. Otherwise we can do the
2761 conversion if the size of the range is less than what the
2762 precision of the target type can represent and the range is
2763 not an anti-range. */
2764 if ((vr0
.type
== VR_RANGE
2765 || vr0
.type
== VR_ANTI_RANGE
)
2766 && TREE_CODE (vr0
.min
) == INTEGER_CST
2767 && TREE_CODE (vr0
.max
) == INTEGER_CST
2768 && (!is_overflow_infinity (vr0
.min
)
2769 || (vr0
.type
== VR_RANGE
2770 && TYPE_PRECISION (outer_type
) > TYPE_PRECISION (inner_type
)
2771 && needs_overflow_infinity (outer_type
)
2772 && supports_overflow_infinity (outer_type
)))
2773 && (!is_overflow_infinity (vr0
.max
)
2774 || (vr0
.type
== VR_RANGE
2775 && TYPE_PRECISION (outer_type
) > TYPE_PRECISION (inner_type
)
2776 && needs_overflow_infinity (outer_type
)
2777 && supports_overflow_infinity (outer_type
)))
2778 && (TYPE_PRECISION (outer_type
) >= TYPE_PRECISION (inner_type
)
2779 || (vr0
.type
== VR_RANGE
2780 && integer_zerop (int_const_binop (RSHIFT_EXPR
,
2781 int_const_binop (MINUS_EXPR
, vr0
.max
, vr0
.min
, 0),
2782 size_int (TYPE_PRECISION (outer_type
)), 0)))))
2784 tree new_min
, new_max
;
2785 new_min
= force_fit_type_double (outer_type
,
2786 TREE_INT_CST_LOW (vr0
.min
),
2787 TREE_INT_CST_HIGH (vr0
.min
), 0, 0);
2788 new_max
= force_fit_type_double (outer_type
,
2789 TREE_INT_CST_LOW (vr0
.max
),
2790 TREE_INT_CST_HIGH (vr0
.max
), 0, 0);
2791 if (is_overflow_infinity (vr0
.min
))
2792 new_min
= negative_overflow_infinity (outer_type
);
2793 if (is_overflow_infinity (vr0
.max
))
2794 new_max
= positive_overflow_infinity (outer_type
);
2795 set_and_canonicalize_value_range (vr
, vr0
.type
,
2796 new_min
, new_max
, NULL
);
2800 set_value_range_to_varying (vr
);
2804 /* Conversion of a VR_VARYING value to a wider type can result
2805 in a usable range. So wait until after we've handled conversions
2806 before dropping the result to VR_VARYING if we had a source
2807 operand that is VR_VARYING. */
2808 if (vr0
.type
== VR_VARYING
)
2810 set_value_range_to_varying (vr
);
2814 /* Apply the operation to each end of the range and see what we end
2816 if (code
== NEGATE_EXPR
2817 && !TYPE_UNSIGNED (type
))
2819 /* NEGATE_EXPR flips the range around. We need to treat
2820 TYPE_MIN_VALUE specially. */
2821 if (is_positive_overflow_infinity (vr0
.max
))
2822 min
= negative_overflow_infinity (type
);
2823 else if (is_negative_overflow_infinity (vr0
.max
))
2824 min
= positive_overflow_infinity (type
);
2825 else if (!vrp_val_is_min (vr0
.max
))
2826 min
= fold_unary_to_constant (code
, type
, vr0
.max
);
2827 else if (needs_overflow_infinity (type
))
2829 if (supports_overflow_infinity (type
)
2830 && !is_overflow_infinity (vr0
.min
)
2831 && !vrp_val_is_min (vr0
.min
))
2832 min
= positive_overflow_infinity (type
);
2835 set_value_range_to_varying (vr
);
2840 min
= TYPE_MIN_VALUE (type
);
2842 if (is_positive_overflow_infinity (vr0
.min
))
2843 max
= negative_overflow_infinity (type
);
2844 else if (is_negative_overflow_infinity (vr0
.min
))
2845 max
= positive_overflow_infinity (type
);
2846 else if (!vrp_val_is_min (vr0
.min
))
2847 max
= fold_unary_to_constant (code
, type
, vr0
.min
);
2848 else if (needs_overflow_infinity (type
))
2850 if (supports_overflow_infinity (type
))
2851 max
= positive_overflow_infinity (type
);
2854 set_value_range_to_varying (vr
);
2859 max
= TYPE_MIN_VALUE (type
);
2861 else if (code
== NEGATE_EXPR
2862 && TYPE_UNSIGNED (type
))
2864 if (!range_includes_zero_p (&vr0
))
2866 max
= fold_unary_to_constant (code
, type
, vr0
.min
);
2867 min
= fold_unary_to_constant (code
, type
, vr0
.max
);
2871 if (range_is_null (&vr0
))
2872 set_value_range_to_null (vr
, type
);
2874 set_value_range_to_varying (vr
);
2878 else if (code
== ABS_EXPR
2879 && !TYPE_UNSIGNED (type
))
2881 /* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a
2883 if (!TYPE_OVERFLOW_UNDEFINED (type
)
2884 && ((vr0
.type
== VR_RANGE
2885 && vrp_val_is_min (vr0
.min
))
2886 || (vr0
.type
== VR_ANTI_RANGE
2887 && !vrp_val_is_min (vr0
.min
)
2888 && !range_includes_zero_p (&vr0
))))
2890 set_value_range_to_varying (vr
);
2894 /* ABS_EXPR may flip the range around, if the original range
2895 included negative values. */
2896 if (is_overflow_infinity (vr0
.min
))
2897 min
= positive_overflow_infinity (type
);
2898 else if (!vrp_val_is_min (vr0
.min
))
2899 min
= fold_unary_to_constant (code
, type
, vr0
.min
);
2900 else if (!needs_overflow_infinity (type
))
2901 min
= TYPE_MAX_VALUE (type
);
2902 else if (supports_overflow_infinity (type
))
2903 min
= positive_overflow_infinity (type
);
2906 set_value_range_to_varying (vr
);
2910 if (is_overflow_infinity (vr0
.max
))
2911 max
= positive_overflow_infinity (type
);
2912 else if (!vrp_val_is_min (vr0
.max
))
2913 max
= fold_unary_to_constant (code
, type
, vr0
.max
);
2914 else if (!needs_overflow_infinity (type
))
2915 max
= TYPE_MAX_VALUE (type
);
2916 else if (supports_overflow_infinity (type
)
2917 /* We shouldn't generate [+INF, +INF] as set_value_range
2918 doesn't like this and ICEs. */
2919 && !is_positive_overflow_infinity (min
))
2920 max
= positive_overflow_infinity (type
);
2923 set_value_range_to_varying (vr
);
2927 cmp
= compare_values (min
, max
);
2929 /* If a VR_ANTI_RANGEs contains zero, then we have
2930 ~[-INF, min(MIN, MAX)]. */
2931 if (vr0
.type
== VR_ANTI_RANGE
)
2933 if (range_includes_zero_p (&vr0
))
2935 /* Take the lower of the two values. */
2939 /* Create ~[-INF, min (abs(MIN), abs(MAX))]
2940 or ~[-INF + 1, min (abs(MIN), abs(MAX))] when
2941 flag_wrapv is set and the original anti-range doesn't include
2942 TYPE_MIN_VALUE, remember -TYPE_MIN_VALUE = TYPE_MIN_VALUE. */
2943 if (TYPE_OVERFLOW_WRAPS (type
))
2945 tree type_min_value
= TYPE_MIN_VALUE (type
);
2947 min
= (vr0
.min
!= type_min_value
2948 ? int_const_binop (PLUS_EXPR
, type_min_value
,
2949 integer_one_node
, 0)
2954 if (overflow_infinity_range_p (&vr0
))
2955 min
= negative_overflow_infinity (type
);
2957 min
= TYPE_MIN_VALUE (type
);
2962 /* All else has failed, so create the range [0, INF], even for
2963 flag_wrapv since TYPE_MIN_VALUE is in the original
2965 vr0
.type
= VR_RANGE
;
2966 min
= build_int_cst (type
, 0);
2967 if (needs_overflow_infinity (type
))
2969 if (supports_overflow_infinity (type
))
2970 max
= positive_overflow_infinity (type
);
2973 set_value_range_to_varying (vr
);
2978 max
= TYPE_MAX_VALUE (type
);
2982 /* If the range contains zero then we know that the minimum value in the
2983 range will be zero. */
2984 else if (range_includes_zero_p (&vr0
))
2988 min
= build_int_cst (type
, 0);
2992 /* If the range was reversed, swap MIN and MAX. */
3003 /* Otherwise, operate on each end of the range. */
3004 min
= fold_unary_to_constant (code
, type
, vr0
.min
);
3005 max
= fold_unary_to_constant (code
, type
, vr0
.max
);
3007 if (needs_overflow_infinity (type
))
3009 gcc_assert (code
!= NEGATE_EXPR
&& code
!= ABS_EXPR
);
3011 /* If both sides have overflowed, we don't know
3013 if ((is_overflow_infinity (vr0
.min
)
3014 || TREE_OVERFLOW (min
))
3015 && (is_overflow_infinity (vr0
.max
)
3016 || TREE_OVERFLOW (max
)))
3018 set_value_range_to_varying (vr
);
3022 if (is_overflow_infinity (vr0
.min
))
3024 else if (TREE_OVERFLOW (min
))
3026 if (supports_overflow_infinity (type
))
3027 min
= (tree_int_cst_sgn (min
) >= 0
3028 ? positive_overflow_infinity (TREE_TYPE (min
))
3029 : negative_overflow_infinity (TREE_TYPE (min
)));
3032 set_value_range_to_varying (vr
);
3037 if (is_overflow_infinity (vr0
.max
))
3039 else if (TREE_OVERFLOW (max
))
3041 if (supports_overflow_infinity (type
))
3042 max
= (tree_int_cst_sgn (max
) >= 0
3043 ? positive_overflow_infinity (TREE_TYPE (max
))
3044 : negative_overflow_infinity (TREE_TYPE (max
)));
3047 set_value_range_to_varying (vr
);
3054 cmp
= compare_values (min
, max
);
3055 if (cmp
== -2 || cmp
== 1)
3057 /* If the new range has its limits swapped around (MIN > MAX),
3058 then the operation caused one of them to wrap around, mark
3059 the new range VARYING. */
3060 set_value_range_to_varying (vr
);
3063 set_value_range (vr
, vr0
.type
, min
, max
, NULL
);
3067 /* Extract range information from a conditional expression EXPR based on
3068 the ranges of each of its operands and the expression code. */
3071 extract_range_from_cond_expr (value_range_t
*vr
, tree expr
)
3074 value_range_t vr0
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3075 value_range_t vr1
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3077 /* Get value ranges for each operand. For constant operands, create
3078 a new value range with the operand to simplify processing. */
3079 op0
= COND_EXPR_THEN (expr
);
3080 if (TREE_CODE (op0
) == SSA_NAME
)
3081 vr0
= *(get_value_range (op0
));
3082 else if (is_gimple_min_invariant (op0
))
3083 set_value_range_to_value (&vr0
, op0
, NULL
);
3085 set_value_range_to_varying (&vr0
);
3087 op1
= COND_EXPR_ELSE (expr
);
3088 if (TREE_CODE (op1
) == SSA_NAME
)
3089 vr1
= *(get_value_range (op1
));
3090 else if (is_gimple_min_invariant (op1
))
3091 set_value_range_to_value (&vr1
, op1
, NULL
);
3093 set_value_range_to_varying (&vr1
);
3095 /* The resulting value range is the union of the operand ranges */
3096 vrp_meet (&vr0
, &vr1
);
3097 copy_value_range (vr
, &vr0
);
3101 /* Extract range information from a comparison expression EXPR based
3102 on the range of its operand and the expression code. */
3105 extract_range_from_comparison (value_range_t
*vr
, enum tree_code code
,
3106 tree type
, tree op0
, tree op1
)
3111 val
= vrp_evaluate_conditional_warnv_with_ops (code
, op0
, op1
, false, &sop
,
3114 /* A disadvantage of using a special infinity as an overflow
3115 representation is that we lose the ability to record overflow
3116 when we don't have an infinity. So we have to ignore a result
3117 which relies on overflow. */
3119 if (val
&& !is_overflow_infinity (val
) && !sop
)
3121 /* Since this expression was found on the RHS of an assignment,
3122 its type may be different from _Bool. Convert VAL to EXPR's
3124 val
= fold_convert (type
, val
);
3125 if (is_gimple_min_invariant (val
))
3126 set_value_range_to_value (vr
, val
, vr
->equiv
);
3128 set_value_range (vr
, VR_RANGE
, val
, val
, vr
->equiv
);
3131 /* The result of a comparison is always true or false. */
3132 set_value_range_to_truthvalue (vr
, type
);
3135 /* Try to derive a nonnegative or nonzero range out of STMT relying
3136 primarily on generic routines in fold in conjunction with range data.
3137 Store the result in *VR */
3140 extract_range_basic (value_range_t
*vr
, gimple stmt
)
3143 tree type
= gimple_expr_type (stmt
);
3145 if (INTEGRAL_TYPE_P (type
)
3146 && gimple_stmt_nonnegative_warnv_p (stmt
, &sop
))
3147 set_value_range_to_nonnegative (vr
, type
,
3148 sop
|| stmt_overflow_infinity (stmt
));
3149 else if (vrp_stmt_computes_nonzero (stmt
, &sop
)
3151 set_value_range_to_nonnull (vr
, type
);
3153 set_value_range_to_varying (vr
);
3157 /* Try to compute a useful range out of assignment STMT and store it
3161 extract_range_from_assignment (value_range_t
*vr
, gimple stmt
)
3163 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3165 if (code
== ASSERT_EXPR
)
3166 extract_range_from_assert (vr
, gimple_assign_rhs1 (stmt
));
3167 else if (code
== SSA_NAME
)
3168 extract_range_from_ssa_name (vr
, gimple_assign_rhs1 (stmt
));
3169 else if (TREE_CODE_CLASS (code
) == tcc_binary
3170 || code
== TRUTH_AND_EXPR
3171 || code
== TRUTH_OR_EXPR
3172 || code
== TRUTH_XOR_EXPR
)
3173 extract_range_from_binary_expr (vr
, gimple_assign_rhs_code (stmt
),
3174 gimple_expr_type (stmt
),
3175 gimple_assign_rhs1 (stmt
),
3176 gimple_assign_rhs2 (stmt
));
3177 else if (TREE_CODE_CLASS (code
) == tcc_unary
)
3178 extract_range_from_unary_expr (vr
, gimple_assign_rhs_code (stmt
),
3179 gimple_expr_type (stmt
),
3180 gimple_assign_rhs1 (stmt
));
3181 else if (code
== COND_EXPR
)
3182 extract_range_from_cond_expr (vr
, gimple_assign_rhs1 (stmt
));
3183 else if (TREE_CODE_CLASS (code
) == tcc_comparison
)
3184 extract_range_from_comparison (vr
, gimple_assign_rhs_code (stmt
),
3185 gimple_expr_type (stmt
),
3186 gimple_assign_rhs1 (stmt
),
3187 gimple_assign_rhs2 (stmt
));
3188 else if (get_gimple_rhs_class (code
) == GIMPLE_SINGLE_RHS
3189 && is_gimple_min_invariant (gimple_assign_rhs1 (stmt
)))
3190 set_value_range_to_value (vr
, gimple_assign_rhs1 (stmt
), NULL
);
3192 set_value_range_to_varying (vr
);
3194 if (vr
->type
== VR_VARYING
)
3195 extract_range_basic (vr
, stmt
);
3198 /* Given a range VR, a LOOP and a variable VAR, determine whether it
3199 would be profitable to adjust VR using scalar evolution information
3200 for VAR. If so, update VR with the new limits. */
3203 adjust_range_with_scev (value_range_t
*vr
, struct loop
*loop
,
3204 gimple stmt
, tree var
)
3206 tree init
, step
, chrec
, tmin
, tmax
, min
, max
, type
, tem
;
3207 enum ev_direction dir
;
3209 /* TODO. Don't adjust anti-ranges. An anti-range may provide
3210 better opportunities than a regular range, but I'm not sure. */
3211 if (vr
->type
== VR_ANTI_RANGE
)
3214 chrec
= instantiate_parameters (loop
, analyze_scalar_evolution (loop
, var
));
3216 /* Like in PR19590, scev can return a constant function. */
3217 if (is_gimple_min_invariant (chrec
))
3219 set_value_range_to_value (vr
, chrec
, vr
->equiv
);
3223 if (TREE_CODE (chrec
) != POLYNOMIAL_CHREC
)
3226 init
= initial_condition_in_loop_num (chrec
, loop
->num
);
3227 tem
= op_with_constant_singleton_value_range (init
);
3230 step
= evolution_part_in_loop_num (chrec
, loop
->num
);
3231 tem
= op_with_constant_singleton_value_range (step
);
3235 /* If STEP is symbolic, we can't know whether INIT will be the
3236 minimum or maximum value in the range. Also, unless INIT is
3237 a simple expression, compare_values and possibly other functions
3238 in tree-vrp won't be able to handle it. */
3239 if (step
== NULL_TREE
3240 || !is_gimple_min_invariant (step
)
3241 || !valid_value_p (init
))
3244 dir
= scev_direction (chrec
);
3245 if (/* Do not adjust ranges if we do not know whether the iv increases
3246 or decreases, ... */
3247 dir
== EV_DIR_UNKNOWN
3248 /* ... or if it may wrap. */
3249 || scev_probably_wraps_p (init
, step
, stmt
, get_chrec_loop (chrec
),
3253 /* We use TYPE_MIN_VALUE and TYPE_MAX_VALUE here instead of
3254 negative_overflow_infinity and positive_overflow_infinity,
3255 because we have concluded that the loop probably does not
3258 type
= TREE_TYPE (var
);
3259 if (POINTER_TYPE_P (type
) || !TYPE_MIN_VALUE (type
))
3260 tmin
= lower_bound_in_type (type
, type
);
3262 tmin
= TYPE_MIN_VALUE (type
);
3263 if (POINTER_TYPE_P (type
) || !TYPE_MAX_VALUE (type
))
3264 tmax
= upper_bound_in_type (type
, type
);
3266 tmax
= TYPE_MAX_VALUE (type
);
3268 if (vr
->type
== VR_VARYING
|| vr
->type
== VR_UNDEFINED
)
3273 /* For VARYING or UNDEFINED ranges, just about anything we get
3274 from scalar evolutions should be better. */
3276 if (dir
== EV_DIR_DECREASES
)
3281 /* If we would create an invalid range, then just assume we
3282 know absolutely nothing. This may be over-conservative,
3283 but it's clearly safe, and should happen only in unreachable
3284 parts of code, or for invalid programs. */
3285 if (compare_values (min
, max
) == 1)
3288 set_value_range (vr
, VR_RANGE
, min
, max
, vr
->equiv
);
3290 else if (vr
->type
== VR_RANGE
)
3295 if (dir
== EV_DIR_DECREASES
)
3297 /* INIT is the maximum value. If INIT is lower than VR->MAX
3298 but no smaller than VR->MIN, set VR->MAX to INIT. */
3299 if (compare_values (init
, max
) == -1)
3303 /* If we just created an invalid range with the minimum
3304 greater than the maximum, we fail conservatively.
3305 This should happen only in unreachable
3306 parts of code, or for invalid programs. */
3307 if (compare_values (min
, max
) == 1)
3311 /* According to the loop information, the variable does not
3312 overflow. If we think it does, probably because of an
3313 overflow due to arithmetic on a different INF value,
3315 if (is_negative_overflow_infinity (min
))
3320 /* If INIT is bigger than VR->MIN, set VR->MIN to INIT. */
3321 if (compare_values (init
, min
) == 1)
3325 /* Again, avoid creating invalid range by failing. */
3326 if (compare_values (min
, max
) == 1)
3330 if (is_positive_overflow_infinity (max
))
3334 set_value_range (vr
, VR_RANGE
, min
, max
, vr
->equiv
);
3338 /* Return true if VAR may overflow at STMT. This checks any available
3339 loop information to see if we can determine that VAR does not
3343 vrp_var_may_overflow (tree var
, gimple stmt
)
3346 tree chrec
, init
, step
;
3348 if (current_loops
== NULL
)
3351 l
= loop_containing_stmt (stmt
);
3356 chrec
= instantiate_parameters (l
, analyze_scalar_evolution (l
, var
));
3357 if (TREE_CODE (chrec
) != POLYNOMIAL_CHREC
)
3360 init
= initial_condition_in_loop_num (chrec
, l
->num
);
3361 step
= evolution_part_in_loop_num (chrec
, l
->num
);
3363 if (step
== NULL_TREE
3364 || !is_gimple_min_invariant (step
)
3365 || !valid_value_p (init
))
3368 /* If we get here, we know something useful about VAR based on the
3369 loop information. If it wraps, it may overflow. */
3371 if (scev_probably_wraps_p (init
, step
, stmt
, get_chrec_loop (chrec
),
3375 if (dump_file
&& (dump_flags
& TDF_DETAILS
) != 0)
3377 print_generic_expr (dump_file
, var
, 0);
3378 fprintf (dump_file
, ": loop information indicates does not overflow\n");
3385 /* Given two numeric value ranges VR0, VR1 and a comparison code COMP:
3387 - Return BOOLEAN_TRUE_NODE if VR0 COMP VR1 always returns true for
3388 all the values in the ranges.
3390 - Return BOOLEAN_FALSE_NODE if the comparison always returns false.
3392 - Return NULL_TREE if it is not always possible to determine the
3393 value of the comparison.
3395 Also set *STRICT_OVERFLOW_P to indicate whether a range with an
3396 overflow infinity was used in the test. */
3400 compare_ranges (enum tree_code comp
, value_range_t
*vr0
, value_range_t
*vr1
,
3401 bool *strict_overflow_p
)
3403 /* VARYING or UNDEFINED ranges cannot be compared. */
3404 if (vr0
->type
== VR_VARYING
3405 || vr0
->type
== VR_UNDEFINED
3406 || vr1
->type
== VR_VARYING
3407 || vr1
->type
== VR_UNDEFINED
)
3410 /* Anti-ranges need to be handled separately. */
3411 if (vr0
->type
== VR_ANTI_RANGE
|| vr1
->type
== VR_ANTI_RANGE
)
3413 /* If both are anti-ranges, then we cannot compute any
3415 if (vr0
->type
== VR_ANTI_RANGE
&& vr1
->type
== VR_ANTI_RANGE
)
3418 /* These comparisons are never statically computable. */
3425 /* Equality can be computed only between a range and an
3426 anti-range. ~[VAL1, VAL2] == [VAL1, VAL2] is always false. */
3427 if (vr0
->type
== VR_RANGE
)
3429 /* To simplify processing, make VR0 the anti-range. */
3430 value_range_t
*tmp
= vr0
;
3435 gcc_assert (comp
== NE_EXPR
|| comp
== EQ_EXPR
);
3437 if (compare_values_warnv (vr0
->min
, vr1
->min
, strict_overflow_p
) == 0
3438 && compare_values_warnv (vr0
->max
, vr1
->max
, strict_overflow_p
) == 0)
3439 return (comp
== NE_EXPR
) ? boolean_true_node
: boolean_false_node
;
3444 if (!usable_range_p (vr0
, strict_overflow_p
)
3445 || !usable_range_p (vr1
, strict_overflow_p
))
3448 /* Simplify processing. If COMP is GT_EXPR or GE_EXPR, switch the
3449 operands around and change the comparison code. */
3450 if (comp
== GT_EXPR
|| comp
== GE_EXPR
)
3453 comp
= (comp
== GT_EXPR
) ? LT_EXPR
: LE_EXPR
;
3459 if (comp
== EQ_EXPR
)
3461 /* Equality may only be computed if both ranges represent
3462 exactly one value. */
3463 if (compare_values_warnv (vr0
->min
, vr0
->max
, strict_overflow_p
) == 0
3464 && compare_values_warnv (vr1
->min
, vr1
->max
, strict_overflow_p
) == 0)
3466 int cmp_min
= compare_values_warnv (vr0
->min
, vr1
->min
,
3468 int cmp_max
= compare_values_warnv (vr0
->max
, vr1
->max
,
3470 if (cmp_min
== 0 && cmp_max
== 0)
3471 return boolean_true_node
;
3472 else if (cmp_min
!= -2 && cmp_max
!= -2)
3473 return boolean_false_node
;
3475 /* If [V0_MIN, V1_MAX] < [V1_MIN, V1_MAX] then V0 != V1. */
3476 else if (compare_values_warnv (vr0
->min
, vr1
->max
,
3477 strict_overflow_p
) == 1
3478 || compare_values_warnv (vr1
->min
, vr0
->max
,
3479 strict_overflow_p
) == 1)
3480 return boolean_false_node
;
3484 else if (comp
== NE_EXPR
)
3488 /* If VR0 is completely to the left or completely to the right
3489 of VR1, they are always different. Notice that we need to
3490 make sure that both comparisons yield similar results to
3491 avoid comparing values that cannot be compared at
3493 cmp1
= compare_values_warnv (vr0
->max
, vr1
->min
, strict_overflow_p
);
3494 cmp2
= compare_values_warnv (vr0
->min
, vr1
->max
, strict_overflow_p
);
3495 if ((cmp1
== -1 && cmp2
== -1) || (cmp1
== 1 && cmp2
== 1))
3496 return boolean_true_node
;
3498 /* If VR0 and VR1 represent a single value and are identical,
3500 else if (compare_values_warnv (vr0
->min
, vr0
->max
,
3501 strict_overflow_p
) == 0
3502 && compare_values_warnv (vr1
->min
, vr1
->max
,
3503 strict_overflow_p
) == 0
3504 && compare_values_warnv (vr0
->min
, vr1
->min
,
3505 strict_overflow_p
) == 0
3506 && compare_values_warnv (vr0
->max
, vr1
->max
,
3507 strict_overflow_p
) == 0)
3508 return boolean_false_node
;
3510 /* Otherwise, they may or may not be different. */
3514 else if (comp
== LT_EXPR
|| comp
== LE_EXPR
)
3518 /* If VR0 is to the left of VR1, return true. */
3519 tst
= compare_values_warnv (vr0
->max
, vr1
->min
, strict_overflow_p
);
3520 if ((comp
== LT_EXPR
&& tst
== -1)
3521 || (comp
== LE_EXPR
&& (tst
== -1 || tst
== 0)))
3523 if (overflow_infinity_range_p (vr0
)
3524 || overflow_infinity_range_p (vr1
))
3525 *strict_overflow_p
= true;
3526 return boolean_true_node
;
3529 /* If VR0 is to the right of VR1, return false. */
3530 tst
= compare_values_warnv (vr0
->min
, vr1
->max
, strict_overflow_p
);
3531 if ((comp
== LT_EXPR
&& (tst
== 0 || tst
== 1))
3532 || (comp
== LE_EXPR
&& tst
== 1))
3534 if (overflow_infinity_range_p (vr0
)
3535 || overflow_infinity_range_p (vr1
))
3536 *strict_overflow_p
= true;
3537 return boolean_false_node
;
3540 /* Otherwise, we don't know. */
3548 /* Given a value range VR, a value VAL and a comparison code COMP, return
3549 BOOLEAN_TRUE_NODE if VR COMP VAL always returns true for all the
3550 values in VR. Return BOOLEAN_FALSE_NODE if the comparison
3551 always returns false. Return NULL_TREE if it is not always
3552 possible to determine the value of the comparison. Also set
3553 *STRICT_OVERFLOW_P to indicate whether a range with an overflow
3554 infinity was used in the test. */
3557 compare_range_with_value (enum tree_code comp
, value_range_t
*vr
, tree val
,
3558 bool *strict_overflow_p
)
3560 if (vr
->type
== VR_VARYING
|| vr
->type
== VR_UNDEFINED
)
3563 /* Anti-ranges need to be handled separately. */
3564 if (vr
->type
== VR_ANTI_RANGE
)
3566 /* For anti-ranges, the only predicates that we can compute at
3567 compile time are equality and inequality. */
3574 /* ~[VAL_1, VAL_2] OP VAL is known if VAL_1 <= VAL <= VAL_2. */
3575 if (value_inside_range (val
, vr
) == 1)
3576 return (comp
== NE_EXPR
) ? boolean_true_node
: boolean_false_node
;
3581 if (!usable_range_p (vr
, strict_overflow_p
))
3584 if (comp
== EQ_EXPR
)
3586 /* EQ_EXPR may only be computed if VR represents exactly
3588 if (compare_values_warnv (vr
->min
, vr
->max
, strict_overflow_p
) == 0)
3590 int cmp
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
3592 return boolean_true_node
;
3593 else if (cmp
== -1 || cmp
== 1 || cmp
== 2)
3594 return boolean_false_node
;
3596 else if (compare_values_warnv (val
, vr
->min
, strict_overflow_p
) == -1
3597 || compare_values_warnv (vr
->max
, val
, strict_overflow_p
) == -1)
3598 return boolean_false_node
;
3602 else if (comp
== NE_EXPR
)
3604 /* If VAL is not inside VR, then they are always different. */
3605 if (compare_values_warnv (vr
->max
, val
, strict_overflow_p
) == -1
3606 || compare_values_warnv (vr
->min
, val
, strict_overflow_p
) == 1)
3607 return boolean_true_node
;
3609 /* If VR represents exactly one value equal to VAL, then return
3611 if (compare_values_warnv (vr
->min
, vr
->max
, strict_overflow_p
) == 0
3612 && compare_values_warnv (vr
->min
, val
, strict_overflow_p
) == 0)
3613 return boolean_false_node
;
3615 /* Otherwise, they may or may not be different. */
3618 else if (comp
== LT_EXPR
|| comp
== LE_EXPR
)
3622 /* If VR is to the left of VAL, return true. */
3623 tst
= compare_values_warnv (vr
->max
, val
, strict_overflow_p
);
3624 if ((comp
== LT_EXPR
&& tst
== -1)
3625 || (comp
== LE_EXPR
&& (tst
== -1 || tst
== 0)))
3627 if (overflow_infinity_range_p (vr
))
3628 *strict_overflow_p
= true;
3629 return boolean_true_node
;
3632 /* If VR is to the right of VAL, return false. */
3633 tst
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
3634 if ((comp
== LT_EXPR
&& (tst
== 0 || tst
== 1))
3635 || (comp
== LE_EXPR
&& tst
== 1))
3637 if (overflow_infinity_range_p (vr
))
3638 *strict_overflow_p
= true;
3639 return boolean_false_node
;
3642 /* Otherwise, we don't know. */
3645 else if (comp
== GT_EXPR
|| comp
== GE_EXPR
)
3649 /* If VR is to the right of VAL, return true. */
3650 tst
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
3651 if ((comp
== GT_EXPR
&& tst
== 1)
3652 || (comp
== GE_EXPR
&& (tst
== 0 || tst
== 1)))
3654 if (overflow_infinity_range_p (vr
))
3655 *strict_overflow_p
= true;
3656 return boolean_true_node
;
3659 /* If VR is to the left of VAL, return false. */
3660 tst
= compare_values_warnv (vr
->max
, val
, strict_overflow_p
);
3661 if ((comp
== GT_EXPR
&& (tst
== -1 || tst
== 0))
3662 || (comp
== GE_EXPR
&& tst
== -1))
3664 if (overflow_infinity_range_p (vr
))
3665 *strict_overflow_p
= true;
3666 return boolean_false_node
;
3669 /* Otherwise, we don't know. */
3677 /* Debugging dumps. */
3679 void dump_value_range (FILE *, value_range_t
*);
3680 void debug_value_range (value_range_t
*);
3681 void dump_all_value_ranges (FILE *);
3682 void debug_all_value_ranges (void);
3683 void dump_vr_equiv (FILE *, bitmap
);
3684 void debug_vr_equiv (bitmap
);
3687 /* Dump value range VR to FILE. */
3690 dump_value_range (FILE *file
, value_range_t
*vr
)
3693 fprintf (file
, "[]");
3694 else if (vr
->type
== VR_UNDEFINED
)
3695 fprintf (file
, "UNDEFINED");
3696 else if (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
)
3698 tree type
= TREE_TYPE (vr
->min
);
3700 fprintf (file
, "%s[", (vr
->type
== VR_ANTI_RANGE
) ? "~" : "");
3702 if (is_negative_overflow_infinity (vr
->min
))
3703 fprintf (file
, "-INF(OVF)");
3704 else if (INTEGRAL_TYPE_P (type
)
3705 && !TYPE_UNSIGNED (type
)
3706 && vrp_val_is_min (vr
->min
))
3707 fprintf (file
, "-INF");
3709 print_generic_expr (file
, vr
->min
, 0);
3711 fprintf (file
, ", ");
3713 if (is_positive_overflow_infinity (vr
->max
))
3714 fprintf (file
, "+INF(OVF)");
3715 else if (INTEGRAL_TYPE_P (type
)
3716 && vrp_val_is_max (vr
->max
))
3717 fprintf (file
, "+INF");
3719 print_generic_expr (file
, vr
->max
, 0);
3721 fprintf (file
, "]");
3728 fprintf (file
, " EQUIVALENCES: { ");
3730 EXECUTE_IF_SET_IN_BITMAP (vr
->equiv
, 0, i
, bi
)
3732 print_generic_expr (file
, ssa_name (i
), 0);
3733 fprintf (file
, " ");
3737 fprintf (file
, "} (%u elements)", c
);
3740 else if (vr
->type
== VR_VARYING
)
3741 fprintf (file
, "VARYING");
3743 fprintf (file
, "INVALID RANGE");
3747 /* Dump value range VR to stderr. */
3750 debug_value_range (value_range_t
*vr
)
3752 dump_value_range (stderr
, vr
);
3753 fprintf (stderr
, "\n");
3757 /* Dump value ranges of all SSA_NAMEs to FILE. */
3760 dump_all_value_ranges (FILE *file
)
3764 for (i
= 0; i
< num_ssa_names
; i
++)
3768 print_generic_expr (file
, ssa_name (i
), 0);
3769 fprintf (file
, ": ");
3770 dump_value_range (file
, vr_value
[i
]);
3771 fprintf (file
, "\n");
3775 fprintf (file
, "\n");
3779 /* Dump all value ranges to stderr. */
3782 debug_all_value_ranges (void)
3784 dump_all_value_ranges (stderr
);
3788 /* Given a COND_EXPR COND of the form 'V OP W', and an SSA name V,
3789 create a new SSA name N and return the assertion assignment
3790 'V = ASSERT_EXPR <V, V OP W>'. */
3793 build_assert_expr_for (tree cond
, tree v
)
3798 gcc_assert (TREE_CODE (v
) == SSA_NAME
);
3799 n
= duplicate_ssa_name (v
, NULL
);
3801 if (COMPARISON_CLASS_P (cond
))
3803 tree a
= build2 (ASSERT_EXPR
, TREE_TYPE (v
), v
, cond
);
3804 assertion
= gimple_build_assign (n
, a
);
3806 else if (TREE_CODE (cond
) == TRUTH_NOT_EXPR
)
3808 /* Given !V, build the assignment N = false. */
3809 tree op0
= TREE_OPERAND (cond
, 0);
3810 gcc_assert (op0
== v
);
3811 assertion
= gimple_build_assign (n
, boolean_false_node
);
3813 else if (TREE_CODE (cond
) == SSA_NAME
)
3815 /* Given V, build the assignment N = true. */
3816 gcc_assert (v
== cond
);
3817 assertion
= gimple_build_assign (n
, boolean_true_node
);
3822 SSA_NAME_DEF_STMT (n
) = assertion
;
3824 /* The new ASSERT_EXPR, creates a new SSA name that replaces the
3825 operand of the ASSERT_EXPR. Register the new name and the old one
3826 in the replacement table so that we can fix the SSA web after
3827 adding all the ASSERT_EXPRs. */
3828 register_new_name_mapping (n
, v
);
3834 /* Return false if EXPR is a predicate expression involving floating
3838 fp_predicate (gimple stmt
)
3840 GIMPLE_CHECK (stmt
, GIMPLE_COND
);
3842 return FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (stmt
)));
3846 /* If the range of values taken by OP can be inferred after STMT executes,
3847 return the comparison code (COMP_CODE_P) and value (VAL_P) that
3848 describes the inferred range. Return true if a range could be
3852 infer_value_range (gimple stmt
, tree op
, enum tree_code
*comp_code_p
, tree
*val_p
)
3855 *comp_code_p
= ERROR_MARK
;
3857 /* Do not attempt to infer anything in names that flow through
3859 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op
))
3862 /* Similarly, don't infer anything from statements that may throw
3864 if (stmt_could_throw_p (stmt
))
3867 /* If STMT is the last statement of a basic block with no
3868 successors, there is no point inferring anything about any of its
3869 operands. We would not be able to find a proper insertion point
3870 for the assertion, anyway. */
3871 if (stmt_ends_bb_p (stmt
) && EDGE_COUNT (gimple_bb (stmt
)->succs
) == 0)
3874 /* We can only assume that a pointer dereference will yield
3875 non-NULL if -fdelete-null-pointer-checks is enabled. */
3876 if (flag_delete_null_pointer_checks
3877 && POINTER_TYPE_P (TREE_TYPE (op
))
3878 && gimple_code (stmt
) != GIMPLE_ASM
)
3880 unsigned num_uses
, num_loads
, num_stores
;
3882 count_uses_and_derefs (op
, stmt
, &num_uses
, &num_loads
, &num_stores
);
3883 if (num_loads
+ num_stores
> 0)
3885 *val_p
= build_int_cst (TREE_TYPE (op
), 0);
3886 *comp_code_p
= NE_EXPR
;
3895 void dump_asserts_for (FILE *, tree
);
3896 void debug_asserts_for (tree
);
3897 void dump_all_asserts (FILE *);
3898 void debug_all_asserts (void);
3900 /* Dump all the registered assertions for NAME to FILE. */
3903 dump_asserts_for (FILE *file
, tree name
)
3907 fprintf (file
, "Assertions to be inserted for ");
3908 print_generic_expr (file
, name
, 0);
3909 fprintf (file
, "\n");
3911 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
3914 fprintf (file
, "\t");
3915 print_gimple_stmt (file
, gsi_stmt (loc
->si
), 0, 0);
3916 fprintf (file
, "\n\tBB #%d", loc
->bb
->index
);
3919 fprintf (file
, "\n\tEDGE %d->%d", loc
->e
->src
->index
,
3920 loc
->e
->dest
->index
);
3921 dump_edge_info (file
, loc
->e
, 0);
3923 fprintf (file
, "\n\tPREDICATE: ");
3924 print_generic_expr (file
, name
, 0);
3925 fprintf (file
, " %s ", tree_code_name
[(int)loc
->comp_code
]);
3926 print_generic_expr (file
, loc
->val
, 0);
3927 fprintf (file
, "\n\n");
3931 fprintf (file
, "\n");
3935 /* Dump all the registered assertions for NAME to stderr. */
3938 debug_asserts_for (tree name
)
3940 dump_asserts_for (stderr
, name
);
3944 /* Dump all the registered assertions for all the names to FILE. */
3947 dump_all_asserts (FILE *file
)
3952 fprintf (file
, "\nASSERT_EXPRs to be inserted\n\n");
3953 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
3954 dump_asserts_for (file
, ssa_name (i
));
3955 fprintf (file
, "\n");
3959 /* Dump all the registered assertions for all the names to stderr. */
3962 debug_all_asserts (void)
3964 dump_all_asserts (stderr
);
3968 /* If NAME doesn't have an ASSERT_EXPR registered for asserting
3969 'EXPR COMP_CODE VAL' at a location that dominates block BB or
3970 E->DEST, then register this location as a possible insertion point
3971 for ASSERT_EXPR <NAME, EXPR COMP_CODE VAL>.
3973 BB, E and SI provide the exact insertion point for the new
3974 ASSERT_EXPR. If BB is NULL, then the ASSERT_EXPR is to be inserted
3975 on edge E. Otherwise, if E is NULL, the ASSERT_EXPR is inserted on
3976 BB. If SI points to a COND_EXPR or a SWITCH_EXPR statement, then E
3977 must not be NULL. */
3980 register_new_assert_for (tree name
, tree expr
,
3981 enum tree_code comp_code
,
3985 gimple_stmt_iterator si
)
3987 assert_locus_t n
, loc
, last_loc
;
3988 basic_block dest_bb
;
3990 #if defined ENABLE_CHECKING
3991 gcc_assert (bb
== NULL
|| e
== NULL
);
3994 gcc_assert (gimple_code (gsi_stmt (si
)) != GIMPLE_COND
3995 && gimple_code (gsi_stmt (si
)) != GIMPLE_SWITCH
);
3998 /* Never build an assert comparing against an integer constant with
3999 TREE_OVERFLOW set. This confuses our undefined overflow warning
4001 if (TREE_CODE (val
) == INTEGER_CST
4002 && TREE_OVERFLOW (val
))
4003 val
= build_int_cst_wide (TREE_TYPE (val
),
4004 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
));
4006 /* The new assertion A will be inserted at BB or E. We need to
4007 determine if the new location is dominated by a previously
4008 registered location for A. If we are doing an edge insertion,
4009 assume that A will be inserted at E->DEST. Note that this is not
4012 If E is a critical edge, it will be split. But even if E is
4013 split, the new block will dominate the same set of blocks that
4016 The reverse, however, is not true, blocks dominated by E->DEST
4017 will not be dominated by the new block created to split E. So,
4018 if the insertion location is on a critical edge, we will not use
4019 the new location to move another assertion previously registered
4020 at a block dominated by E->DEST. */
4021 dest_bb
= (bb
) ? bb
: e
->dest
;
4023 /* If NAME already has an ASSERT_EXPR registered for COMP_CODE and
4024 VAL at a block dominating DEST_BB, then we don't need to insert a new
4025 one. Similarly, if the same assertion already exists at a block
4026 dominated by DEST_BB and the new location is not on a critical
4027 edge, then update the existing location for the assertion (i.e.,
4028 move the assertion up in the dominance tree).
4030 Note, this is implemented as a simple linked list because there
4031 should not be more than a handful of assertions registered per
4032 name. If this becomes a performance problem, a table hashed by
4033 COMP_CODE and VAL could be implemented. */
4034 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
4038 if (loc
->comp_code
== comp_code
4040 || operand_equal_p (loc
->val
, val
, 0))
4041 && (loc
->expr
== expr
4042 || operand_equal_p (loc
->expr
, expr
, 0)))
4044 /* If the assertion NAME COMP_CODE VAL has already been
4045 registered at a basic block that dominates DEST_BB, then
4046 we don't need to insert the same assertion again. Note
4047 that we don't check strict dominance here to avoid
4048 replicating the same assertion inside the same basic
4049 block more than once (e.g., when a pointer is
4050 dereferenced several times inside a block).
4052 An exception to this rule are edge insertions. If the
4053 new assertion is to be inserted on edge E, then it will
4054 dominate all the other insertions that we may want to
4055 insert in DEST_BB. So, if we are doing an edge
4056 insertion, don't do this dominance check. */
4058 && dominated_by_p (CDI_DOMINATORS
, dest_bb
, loc
->bb
))
4061 /* Otherwise, if E is not a critical edge and DEST_BB
4062 dominates the existing location for the assertion, move
4063 the assertion up in the dominance tree by updating its
4064 location information. */
4065 if ((e
== NULL
|| !EDGE_CRITICAL_P (e
))
4066 && dominated_by_p (CDI_DOMINATORS
, loc
->bb
, dest_bb
))
4075 /* Update the last node of the list and move to the next one. */
4080 /* If we didn't find an assertion already registered for
4081 NAME COMP_CODE VAL, add a new one at the end of the list of
4082 assertions associated with NAME. */
4083 n
= XNEW (struct assert_locus_d
);
4087 n
->comp_code
= comp_code
;
4095 asserts_for
[SSA_NAME_VERSION (name
)] = n
;
4097 bitmap_set_bit (need_assert_for
, SSA_NAME_VERSION (name
));
4100 /* (COND_OP0 COND_CODE COND_OP1) is a predicate which uses NAME.
4101 Extract a suitable test code and value and store them into *CODE_P and
4102 *VAL_P so the predicate is normalized to NAME *CODE_P *VAL_P.
4104 If no extraction was possible, return FALSE, otherwise return TRUE.
4106 If INVERT is true, then we invert the result stored into *CODE_P. */
4109 extract_code_and_val_from_cond_with_ops (tree name
, enum tree_code cond_code
,
4110 tree cond_op0
, tree cond_op1
,
4111 bool invert
, enum tree_code
*code_p
,
4114 enum tree_code comp_code
;
4117 /* Otherwise, we have a comparison of the form NAME COMP VAL
4118 or VAL COMP NAME. */
4119 if (name
== cond_op1
)
4121 /* If the predicate is of the form VAL COMP NAME, flip
4122 COMP around because we need to register NAME as the
4123 first operand in the predicate. */
4124 comp_code
= swap_tree_comparison (cond_code
);
4129 /* The comparison is of the form NAME COMP VAL, so the
4130 comparison code remains unchanged. */
4131 comp_code
= cond_code
;
4135 /* Invert the comparison code as necessary. */
4137 comp_code
= invert_tree_comparison (comp_code
, 0);
4139 /* VRP does not handle float types. */
4140 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (val
)))
4143 /* Do not register always-false predicates.
4144 FIXME: this works around a limitation in fold() when dealing with
4145 enumerations. Given 'enum { N1, N2 } x;', fold will not
4146 fold 'if (x > N2)' to 'if (0)'. */
4147 if ((comp_code
== GT_EXPR
|| comp_code
== LT_EXPR
)
4148 && INTEGRAL_TYPE_P (TREE_TYPE (val
)))
4150 tree min
= TYPE_MIN_VALUE (TREE_TYPE (val
));
4151 tree max
= TYPE_MAX_VALUE (TREE_TYPE (val
));
4153 if (comp_code
== GT_EXPR
4155 || compare_values (val
, max
) == 0))
4158 if (comp_code
== LT_EXPR
4160 || compare_values (val
, min
) == 0))
4163 *code_p
= comp_code
;
4168 /* Try to register an edge assertion for SSA name NAME on edge E for
4169 the condition COND contributing to the conditional jump pointed to by BSI.
4170 Invert the condition COND if INVERT is true.
4171 Return true if an assertion for NAME could be registered. */
4174 register_edge_assert_for_2 (tree name
, edge e
, gimple_stmt_iterator bsi
,
4175 enum tree_code cond_code
,
4176 tree cond_op0
, tree cond_op1
, bool invert
)
4179 enum tree_code comp_code
;
4180 bool retval
= false;
4182 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
4185 invert
, &comp_code
, &val
))
4188 /* Only register an ASSERT_EXPR if NAME was found in the sub-graph
4189 reachable from E. */
4190 if (live_on_edge (e
, name
)
4191 && !has_single_use (name
))
4193 register_new_assert_for (name
, name
, comp_code
, val
, NULL
, e
, bsi
);
4197 /* In the case of NAME <= CST and NAME being defined as
4198 NAME = (unsigned) NAME2 + CST2 we can assert NAME2 >= -CST2
4199 and NAME2 <= CST - CST2. We can do the same for NAME > CST.
4200 This catches range and anti-range tests. */
4201 if ((comp_code
== LE_EXPR
4202 || comp_code
== GT_EXPR
)
4203 && TREE_CODE (val
) == INTEGER_CST
4204 && TYPE_UNSIGNED (TREE_TYPE (val
)))
4206 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
4207 tree cst2
= NULL_TREE
, name2
= NULL_TREE
, name3
= NULL_TREE
;
4209 /* Extract CST2 from the (optional) addition. */
4210 if (is_gimple_assign (def_stmt
)
4211 && gimple_assign_rhs_code (def_stmt
) == PLUS_EXPR
)
4213 name2
= gimple_assign_rhs1 (def_stmt
);
4214 cst2
= gimple_assign_rhs2 (def_stmt
);
4215 if (TREE_CODE (name2
) == SSA_NAME
4216 && TREE_CODE (cst2
) == INTEGER_CST
)
4217 def_stmt
= SSA_NAME_DEF_STMT (name2
);
4220 /* Extract NAME2 from the (optional) sign-changing cast. */
4221 if (gimple_assign_cast_p (def_stmt
))
4223 if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
))
4224 && ! TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))
4225 && (TYPE_PRECISION (gimple_expr_type (def_stmt
))
4226 == TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))))
4227 name3
= gimple_assign_rhs1 (def_stmt
);
4230 /* If name3 is used later, create an ASSERT_EXPR for it. */
4231 if (name3
!= NULL_TREE
4232 && TREE_CODE (name3
) == SSA_NAME
4233 && (cst2
== NULL_TREE
4234 || TREE_CODE (cst2
) == INTEGER_CST
)
4235 && INTEGRAL_TYPE_P (TREE_TYPE (name3
))
4236 && live_on_edge (e
, name3
)
4237 && !has_single_use (name3
))
4241 /* Build an expression for the range test. */
4242 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), name3
);
4243 if (cst2
!= NULL_TREE
)
4244 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
4248 fprintf (dump_file
, "Adding assert for ");
4249 print_generic_expr (dump_file
, name3
, 0);
4250 fprintf (dump_file
, " from ");
4251 print_generic_expr (dump_file
, tmp
, 0);
4252 fprintf (dump_file
, "\n");
4255 register_new_assert_for (name3
, tmp
, comp_code
, val
, NULL
, e
, bsi
);
4260 /* If name2 is used later, create an ASSERT_EXPR for it. */
4261 if (name2
!= NULL_TREE
4262 && TREE_CODE (name2
) == SSA_NAME
4263 && TREE_CODE (cst2
) == INTEGER_CST
4264 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
4265 && live_on_edge (e
, name2
)
4266 && !has_single_use (name2
))
4270 /* Build an expression for the range test. */
4272 if (TREE_TYPE (name
) != TREE_TYPE (name2
))
4273 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), tmp
);
4274 if (cst2
!= NULL_TREE
)
4275 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
4279 fprintf (dump_file
, "Adding assert for ");
4280 print_generic_expr (dump_file
, name2
, 0);
4281 fprintf (dump_file
, " from ");
4282 print_generic_expr (dump_file
, tmp
, 0);
4283 fprintf (dump_file
, "\n");
4286 register_new_assert_for (name2
, tmp
, comp_code
, val
, NULL
, e
, bsi
);
4295 /* OP is an operand of a truth value expression which is known to have
4296 a particular value. Register any asserts for OP and for any
4297 operands in OP's defining statement.
4299 If CODE is EQ_EXPR, then we want to register OP is zero (false),
4300 if CODE is NE_EXPR, then we want to register OP is nonzero (true). */
4303 register_edge_assert_for_1 (tree op
, enum tree_code code
,
4304 edge e
, gimple_stmt_iterator bsi
)
4306 bool retval
= false;
4309 enum tree_code rhs_code
;
4311 /* We only care about SSA_NAMEs. */
4312 if (TREE_CODE (op
) != SSA_NAME
)
4315 /* We know that OP will have a zero or nonzero value. If OP is used
4316 more than once go ahead and register an assert for OP.
4318 The FOUND_IN_SUBGRAPH support is not helpful in this situation as
4319 it will always be set for OP (because OP is used in a COND_EXPR in
4321 if (!has_single_use (op
))
4323 val
= build_int_cst (TREE_TYPE (op
), 0);
4324 register_new_assert_for (op
, op
, code
, val
, NULL
, e
, bsi
);
4328 /* Now look at how OP is set. If it's set from a comparison,
4329 a truth operation or some bit operations, then we may be able
4330 to register information about the operands of that assignment. */
4331 op_def
= SSA_NAME_DEF_STMT (op
);
4332 if (gimple_code (op_def
) != GIMPLE_ASSIGN
)
4335 rhs_code
= gimple_assign_rhs_code (op_def
);
4337 if (TREE_CODE_CLASS (rhs_code
) == tcc_comparison
)
4339 bool invert
= (code
== EQ_EXPR
? true : false);
4340 tree op0
= gimple_assign_rhs1 (op_def
);
4341 tree op1
= gimple_assign_rhs2 (op_def
);
4343 if (TREE_CODE (op0
) == SSA_NAME
)
4344 retval
|= register_edge_assert_for_2 (op0
, e
, bsi
, rhs_code
, op0
, op1
,
4346 if (TREE_CODE (op1
) == SSA_NAME
)
4347 retval
|= register_edge_assert_for_2 (op1
, e
, bsi
, rhs_code
, op0
, op1
,
4350 else if ((code
== NE_EXPR
4351 && (gimple_assign_rhs_code (op_def
) == TRUTH_AND_EXPR
4352 || gimple_assign_rhs_code (op_def
) == BIT_AND_EXPR
))
4354 && (gimple_assign_rhs_code (op_def
) == TRUTH_OR_EXPR
4355 || gimple_assign_rhs_code (op_def
) == BIT_IOR_EXPR
)))
4357 /* Recurse on each operand. */
4358 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4360 retval
|= register_edge_assert_for_1 (gimple_assign_rhs2 (op_def
),
4363 else if (gimple_assign_rhs_code (op_def
) == TRUTH_NOT_EXPR
)
4365 /* Recurse, flipping CODE. */
4366 code
= invert_tree_comparison (code
, false);
4367 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4370 else if (gimple_assign_rhs_code (op_def
) == SSA_NAME
)
4372 /* Recurse through the copy. */
4373 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4376 else if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (op_def
)))
4378 /* Recurse through the type conversion. */
4379 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4386 /* Try to register an edge assertion for SSA name NAME on edge E for
4387 the condition COND contributing to the conditional jump pointed to by SI.
4388 Return true if an assertion for NAME could be registered. */
4391 register_edge_assert_for (tree name
, edge e
, gimple_stmt_iterator si
,
4392 enum tree_code cond_code
, tree cond_op0
,
4396 enum tree_code comp_code
;
4397 bool retval
= false;
4398 bool is_else_edge
= (e
->flags
& EDGE_FALSE_VALUE
) != 0;
4400 /* Do not attempt to infer anything in names that flow through
4402 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name
))
4405 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
4411 /* Register ASSERT_EXPRs for name. */
4412 retval
|= register_edge_assert_for_2 (name
, e
, si
, cond_code
, cond_op0
,
4413 cond_op1
, is_else_edge
);
4416 /* If COND is effectively an equality test of an SSA_NAME against
4417 the value zero or one, then we may be able to assert values
4418 for SSA_NAMEs which flow into COND. */
4420 /* In the case of NAME == 1 or NAME != 0, for TRUTH_AND_EXPR defining
4421 statement of NAME we can assert both operands of the TRUTH_AND_EXPR
4422 have nonzero value. */
4423 if (((comp_code
== EQ_EXPR
&& integer_onep (val
))
4424 || (comp_code
== NE_EXPR
&& integer_zerop (val
))))
4426 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
4428 if (is_gimple_assign (def_stmt
)
4429 && (gimple_assign_rhs_code (def_stmt
) == TRUTH_AND_EXPR
4430 || gimple_assign_rhs_code (def_stmt
) == BIT_AND_EXPR
))
4432 tree op0
= gimple_assign_rhs1 (def_stmt
);
4433 tree op1
= gimple_assign_rhs2 (def_stmt
);
4434 retval
|= register_edge_assert_for_1 (op0
, NE_EXPR
, e
, si
);
4435 retval
|= register_edge_assert_for_1 (op1
, NE_EXPR
, e
, si
);
4439 /* In the case of NAME == 0 or NAME != 1, for TRUTH_OR_EXPR defining
4440 statement of NAME we can assert both operands of the TRUTH_OR_EXPR
4442 if (((comp_code
== EQ_EXPR
&& integer_zerop (val
))
4443 || (comp_code
== NE_EXPR
&& integer_onep (val
))))
4445 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
4447 if (is_gimple_assign (def_stmt
)
4448 && (gimple_assign_rhs_code (def_stmt
) == TRUTH_OR_EXPR
4449 /* For BIT_IOR_EXPR only if NAME == 0 both operands have
4450 necessarily zero value. */
4451 || (comp_code
== EQ_EXPR
4452 && (gimple_assign_rhs_code (def_stmt
) == BIT_IOR_EXPR
))))
4454 tree op0
= gimple_assign_rhs1 (def_stmt
);
4455 tree op1
= gimple_assign_rhs2 (def_stmt
);
4456 retval
|= register_edge_assert_for_1 (op0
, EQ_EXPR
, e
, si
);
4457 retval
|= register_edge_assert_for_1 (op1
, EQ_EXPR
, e
, si
);
4465 /* Determine whether the outgoing edges of BB should receive an
4466 ASSERT_EXPR for each of the operands of BB's LAST statement.
4467 The last statement of BB must be a COND_EXPR.
4469 If any of the sub-graphs rooted at BB have an interesting use of
4470 the predicate operands, an assert location node is added to the
4471 list of assertions for the corresponding operands. */
4474 find_conditional_asserts (basic_block bb
, gimple last
)
4477 gimple_stmt_iterator bsi
;
4483 need_assert
= false;
4484 bsi
= gsi_for_stmt (last
);
4486 /* Look for uses of the operands in each of the sub-graphs
4487 rooted at BB. We need to check each of the outgoing edges
4488 separately, so that we know what kind of ASSERT_EXPR to
4490 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4495 /* Register the necessary assertions for each operand in the
4496 conditional predicate. */
4497 FOR_EACH_SSA_TREE_OPERAND (op
, last
, iter
, SSA_OP_USE
)
4499 need_assert
|= register_edge_assert_for (op
, e
, bsi
,
4500 gimple_cond_code (last
),
4501 gimple_cond_lhs (last
),
4502 gimple_cond_rhs (last
));
4509 /* Compare two case labels sorting first by the destination label uid
4510 and then by the case value. */
4513 compare_case_labels (const void *p1
, const void *p2
)
4515 const_tree
const case1
= *(const_tree
const*)p1
;
4516 const_tree
const case2
= *(const_tree
const*)p2
;
4517 unsigned int uid1
= DECL_UID (CASE_LABEL (case1
));
4518 unsigned int uid2
= DECL_UID (CASE_LABEL (case2
));
4522 else if (uid1
== uid2
)
4524 /* Make sure the default label is first in a group. */
4525 if (!CASE_LOW (case1
))
4527 else if (!CASE_LOW (case2
))
4530 return tree_int_cst_compare (CASE_LOW (case1
), CASE_LOW (case2
));
4536 /* Determine whether the outgoing edges of BB should receive an
4537 ASSERT_EXPR for each of the operands of BB's LAST statement.
4538 The last statement of BB must be a SWITCH_EXPR.
4540 If any of the sub-graphs rooted at BB have an interesting use of
4541 the predicate operands, an assert location node is added to the
4542 list of assertions for the corresponding operands. */
4545 find_switch_asserts (basic_block bb
, gimple last
)
4548 gimple_stmt_iterator bsi
;
4552 size_t n
= gimple_switch_num_labels(last
);
4553 #if GCC_VERSION >= 4000
4556 /* Work around GCC 3.4 bug (PR 37086). */
4557 volatile unsigned int idx
;
4560 need_assert
= false;
4561 bsi
= gsi_for_stmt (last
);
4562 op
= gimple_switch_index (last
);
4563 if (TREE_CODE (op
) != SSA_NAME
)
4566 /* Build a vector of case labels sorted by destination label. */
4567 vec2
= make_tree_vec (n
);
4568 for (idx
= 0; idx
< n
; ++idx
)
4569 TREE_VEC_ELT (vec2
, idx
) = gimple_switch_label (last
, idx
);
4570 qsort (&TREE_VEC_ELT (vec2
, 0), n
, sizeof (tree
), compare_case_labels
);
4572 for (idx
= 0; idx
< n
; ++idx
)
4575 tree cl
= TREE_VEC_ELT (vec2
, idx
);
4577 min
= CASE_LOW (cl
);
4578 max
= CASE_HIGH (cl
);
4580 /* If there are multiple case labels with the same destination
4581 we need to combine them to a single value range for the edge. */
4583 && CASE_LABEL (cl
) == CASE_LABEL (TREE_VEC_ELT (vec2
, idx
+ 1)))
4585 /* Skip labels until the last of the group. */
4589 && CASE_LABEL (cl
) == CASE_LABEL (TREE_VEC_ELT (vec2
, idx
)));
4592 /* Pick up the maximum of the case label range. */
4593 if (CASE_HIGH (TREE_VEC_ELT (vec2
, idx
)))
4594 max
= CASE_HIGH (TREE_VEC_ELT (vec2
, idx
));
4596 max
= CASE_LOW (TREE_VEC_ELT (vec2
, idx
));
4599 /* Nothing to do if the range includes the default label until we
4600 can register anti-ranges. */
4601 if (min
== NULL_TREE
)
4604 /* Find the edge to register the assert expr on. */
4605 e
= find_edge (bb
, label_to_block (CASE_LABEL (cl
)));
4607 /* Register the necessary assertions for the operand in the
4609 need_assert
|= register_edge_assert_for (op
, e
, bsi
,
4610 max
? GE_EXPR
: EQ_EXPR
,
4612 fold_convert (TREE_TYPE (op
),
4616 need_assert
|= register_edge_assert_for (op
, e
, bsi
, LE_EXPR
,
4618 fold_convert (TREE_TYPE (op
),
4627 /* Traverse all the statements in block BB looking for statements that
4628 may generate useful assertions for the SSA names in their operand.
4629 If a statement produces a useful assertion A for name N_i, then the
4630 list of assertions already generated for N_i is scanned to
4631 determine if A is actually needed.
4633 If N_i already had the assertion A at a location dominating the
4634 current location, then nothing needs to be done. Otherwise, the
4635 new location for A is recorded instead.
4637 1- For every statement S in BB, all the variables used by S are
4638 added to bitmap FOUND_IN_SUBGRAPH.
4640 2- If statement S uses an operand N in a way that exposes a known
4641 value range for N, then if N was not already generated by an
4642 ASSERT_EXPR, create a new assert location for N. For instance,
4643 if N is a pointer and the statement dereferences it, we can
4644 assume that N is not NULL.
4646 3- COND_EXPRs are a special case of #2. We can derive range
4647 information from the predicate but need to insert different
4648 ASSERT_EXPRs for each of the sub-graphs rooted at the
4649 conditional block. If the last statement of BB is a conditional
4650 expression of the form 'X op Y', then
4652 a) Remove X and Y from the set FOUND_IN_SUBGRAPH.
4654 b) If the conditional is the only entry point to the sub-graph
4655 corresponding to the THEN_CLAUSE, recurse into it. On
4656 return, if X and/or Y are marked in FOUND_IN_SUBGRAPH, then
4657 an ASSERT_EXPR is added for the corresponding variable.
4659 c) Repeat step (b) on the ELSE_CLAUSE.
4661 d) Mark X and Y in FOUND_IN_SUBGRAPH.
4670 In this case, an assertion on the THEN clause is useful to
4671 determine that 'a' is always 9 on that edge. However, an assertion
4672 on the ELSE clause would be unnecessary.
4674 4- If BB does not end in a conditional expression, then we recurse
4675 into BB's dominator children.
4677 At the end of the recursive traversal, every SSA name will have a
4678 list of locations where ASSERT_EXPRs should be added. When a new
4679 location for name N is found, it is registered by calling
4680 register_new_assert_for. That function keeps track of all the
4681 registered assertions to prevent adding unnecessary assertions.
4682 For instance, if a pointer P_4 is dereferenced more than once in a
4683 dominator tree, only the location dominating all the dereference of
4684 P_4 will receive an ASSERT_EXPR.
4686 If this function returns true, then it means that there are names
4687 for which we need to generate ASSERT_EXPRs. Those assertions are
4688 inserted by process_assert_insertions. */
4691 find_assert_locations_1 (basic_block bb
, sbitmap live
)
4693 gimple_stmt_iterator si
;
4698 need_assert
= false;
4699 last
= last_stmt (bb
);
4701 /* If BB's last statement is a conditional statement involving integer
4702 operands, determine if we need to add ASSERT_EXPRs. */
4704 && gimple_code (last
) == GIMPLE_COND
4705 && !fp_predicate (last
)
4706 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
4707 need_assert
|= find_conditional_asserts (bb
, last
);
4709 /* If BB's last statement is a switch statement involving integer
4710 operands, determine if we need to add ASSERT_EXPRs. */
4712 && gimple_code (last
) == GIMPLE_SWITCH
4713 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
4714 need_assert
|= find_switch_asserts (bb
, last
);
4716 /* Traverse all the statements in BB marking used names and looking
4717 for statements that may infer assertions for their used operands. */
4718 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
4724 stmt
= gsi_stmt (si
);
4726 if (is_gimple_debug (stmt
))
4729 /* See if we can derive an assertion for any of STMT's operands. */
4730 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_USE
)
4733 enum tree_code comp_code
;
4735 /* Mark OP in our live bitmap. */
4736 SET_BIT (live
, SSA_NAME_VERSION (op
));
4738 /* If OP is used in such a way that we can infer a value
4739 range for it, and we don't find a previous assertion for
4740 it, create a new assertion location node for OP. */
4741 if (infer_value_range (stmt
, op
, &comp_code
, &value
))
4743 /* If we are able to infer a nonzero value range for OP,
4744 then walk backwards through the use-def chain to see if OP
4745 was set via a typecast.
4747 If so, then we can also infer a nonzero value range
4748 for the operand of the NOP_EXPR. */
4749 if (comp_code
== NE_EXPR
&& integer_zerop (value
))
4752 gimple def_stmt
= SSA_NAME_DEF_STMT (t
);
4754 while (is_gimple_assign (def_stmt
)
4755 && gimple_assign_rhs_code (def_stmt
) == NOP_EXPR
4757 (gimple_assign_rhs1 (def_stmt
)) == SSA_NAME
4759 (TREE_TYPE (gimple_assign_rhs1 (def_stmt
))))
4761 t
= gimple_assign_rhs1 (def_stmt
);
4762 def_stmt
= SSA_NAME_DEF_STMT (t
);
4764 /* Note we want to register the assert for the
4765 operand of the NOP_EXPR after SI, not after the
4767 if (! has_single_use (t
))
4769 register_new_assert_for (t
, t
, comp_code
, value
,
4776 /* If OP is used only once, namely in this STMT, don't
4777 bother creating an ASSERT_EXPR for it. Such an
4778 ASSERT_EXPR would do nothing but increase compile time. */
4779 if (!has_single_use (op
))
4781 register_new_assert_for (op
, op
, comp_code
, value
,
4789 /* Traverse all PHI nodes in BB marking used operands. */
4790 for (si
= gsi_start_phis (bb
); !gsi_end_p(si
); gsi_next (&si
))
4792 use_operand_p arg_p
;
4794 phi
= gsi_stmt (si
);
4796 FOR_EACH_PHI_ARG (arg_p
, phi
, i
, SSA_OP_USE
)
4798 tree arg
= USE_FROM_PTR (arg_p
);
4799 if (TREE_CODE (arg
) == SSA_NAME
)
4800 SET_BIT (live
, SSA_NAME_VERSION (arg
));
4807 /* Do an RPO walk over the function computing SSA name liveness
4808 on-the-fly and deciding on assert expressions to insert.
4809 Returns true if there are assert expressions to be inserted. */
4812 find_assert_locations (void)
4814 int *rpo
= XCNEWVEC (int, last_basic_block
+ NUM_FIXED_BLOCKS
);
4815 int *bb_rpo
= XCNEWVEC (int, last_basic_block
+ NUM_FIXED_BLOCKS
);
4816 int *last_rpo
= XCNEWVEC (int, last_basic_block
+ NUM_FIXED_BLOCKS
);
4820 live
= XCNEWVEC (sbitmap
, last_basic_block
+ NUM_FIXED_BLOCKS
);
4821 rpo_cnt
= pre_and_rev_post_order_compute (NULL
, rpo
, false);
4822 for (i
= 0; i
< rpo_cnt
; ++i
)
4825 need_asserts
= false;
4826 for (i
= rpo_cnt
-1; i
>= 0; --i
)
4828 basic_block bb
= BASIC_BLOCK (rpo
[i
]);
4834 live
[rpo
[i
]] = sbitmap_alloc (num_ssa_names
);
4835 sbitmap_zero (live
[rpo
[i
]]);
4838 /* Process BB and update the live information with uses in
4840 need_asserts
|= find_assert_locations_1 (bb
, live
[rpo
[i
]]);
4842 /* Merge liveness into the predecessor blocks and free it. */
4843 if (!sbitmap_empty_p (live
[rpo
[i
]]))
4846 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
4848 int pred
= e
->src
->index
;
4849 if (e
->flags
& EDGE_DFS_BACK
)
4854 live
[pred
] = sbitmap_alloc (num_ssa_names
);
4855 sbitmap_zero (live
[pred
]);
4857 sbitmap_a_or_b (live
[pred
], live
[pred
], live
[rpo
[i
]]);
4859 if (bb_rpo
[pred
] < pred_rpo
)
4860 pred_rpo
= bb_rpo
[pred
];
4863 /* Record the RPO number of the last visited block that needs
4864 live information from this block. */
4865 last_rpo
[rpo
[i
]] = pred_rpo
;
4869 sbitmap_free (live
[rpo
[i
]]);
4870 live
[rpo
[i
]] = NULL
;
4873 /* We can free all successors live bitmaps if all their
4874 predecessors have been visited already. */
4875 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4876 if (last_rpo
[e
->dest
->index
] == i
4877 && live
[e
->dest
->index
])
4879 sbitmap_free (live
[e
->dest
->index
]);
4880 live
[e
->dest
->index
] = NULL
;
4885 XDELETEVEC (bb_rpo
);
4886 XDELETEVEC (last_rpo
);
4887 for (i
= 0; i
< last_basic_block
+ NUM_FIXED_BLOCKS
; ++i
)
4889 sbitmap_free (live
[i
]);
4892 return need_asserts
;
4895 /* Create an ASSERT_EXPR for NAME and insert it in the location
4896 indicated by LOC. Return true if we made any edge insertions. */
4899 process_assert_insertions_for (tree name
, assert_locus_t loc
)
4901 /* Build the comparison expression NAME_i COMP_CODE VAL. */
4908 /* If we have X <=> X do not insert an assert expr for that. */
4909 if (loc
->expr
== loc
->val
)
4912 cond
= build2 (loc
->comp_code
, boolean_type_node
, loc
->expr
, loc
->val
);
4913 assert_stmt
= build_assert_expr_for (cond
, name
);
4916 /* We have been asked to insert the assertion on an edge. This
4917 is used only by COND_EXPR and SWITCH_EXPR assertions. */
4918 #if defined ENABLE_CHECKING
4919 gcc_assert (gimple_code (gsi_stmt (loc
->si
)) == GIMPLE_COND
4920 || gimple_code (gsi_stmt (loc
->si
)) == GIMPLE_SWITCH
);
4923 gsi_insert_on_edge (loc
->e
, assert_stmt
);
4927 /* Otherwise, we can insert right after LOC->SI iff the
4928 statement must not be the last statement in the block. */
4929 stmt
= gsi_stmt (loc
->si
);
4930 if (!stmt_ends_bb_p (stmt
))
4932 gsi_insert_after (&loc
->si
, assert_stmt
, GSI_SAME_STMT
);
4936 /* If STMT must be the last statement in BB, we can only insert new
4937 assertions on the non-abnormal edge out of BB. Note that since
4938 STMT is not control flow, there may only be one non-abnormal edge
4940 FOR_EACH_EDGE (e
, ei
, loc
->bb
->succs
)
4941 if (!(e
->flags
& EDGE_ABNORMAL
))
4943 gsi_insert_on_edge (e
, assert_stmt
);
4951 /* Process all the insertions registered for every name N_i registered
4952 in NEED_ASSERT_FOR. The list of assertions to be inserted are
4953 found in ASSERTS_FOR[i]. */
4956 process_assert_insertions (void)
4960 bool update_edges_p
= false;
4961 int num_asserts
= 0;
4963 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4964 dump_all_asserts (dump_file
);
4966 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
4968 assert_locus_t loc
= asserts_for
[i
];
4973 assert_locus_t next
= loc
->next
;
4974 update_edges_p
|= process_assert_insertions_for (ssa_name (i
), loc
);
4982 gsi_commit_edge_inserts ();
4984 statistics_counter_event (cfun
, "Number of ASSERT_EXPR expressions inserted",
4989 /* Traverse the flowgraph looking for conditional jumps to insert range
4990 expressions. These range expressions are meant to provide information
4991 to optimizations that need to reason in terms of value ranges. They
4992 will not be expanded into RTL. For instance, given:
5001 this pass will transform the code into:
5007 x = ASSERT_EXPR <x, x < y>
5012 y = ASSERT_EXPR <y, x <= y>
5016 The idea is that once copy and constant propagation have run, other
5017 optimizations will be able to determine what ranges of values can 'x'
5018 take in different paths of the code, simply by checking the reaching
5019 definition of 'x'. */
5022 insert_range_assertions (void)
5024 need_assert_for
= BITMAP_ALLOC (NULL
);
5025 asserts_for
= XCNEWVEC (assert_locus_t
, num_ssa_names
);
5027 calculate_dominance_info (CDI_DOMINATORS
);
5029 if (find_assert_locations ())
5031 process_assert_insertions ();
5032 update_ssa (TODO_update_ssa_no_phi
);
5035 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5037 fprintf (dump_file
, "\nSSA form after inserting ASSERT_EXPRs\n");
5038 dump_function_to_file (current_function_decl
, dump_file
, dump_flags
);
5042 BITMAP_FREE (need_assert_for
);
5045 /* Checks one ARRAY_REF in REF, located at LOCUS. Ignores flexible arrays
5046 and "struct" hacks. If VRP can determine that the
5047 array subscript is a constant, check if it is outside valid
5048 range. If the array subscript is a RANGE, warn if it is
5049 non-overlapping with valid range.
5050 IGNORE_OFF_BY_ONE is true if the ARRAY_REF is inside a ADDR_EXPR. */
5053 check_array_ref (location_t location
, tree ref
, bool ignore_off_by_one
)
5055 value_range_t
* vr
= NULL
;
5056 tree low_sub
, up_sub
;
5057 tree low_bound
, up_bound
, up_bound_p1
;
5060 if (TREE_NO_WARNING (ref
))
5063 low_sub
= up_sub
= TREE_OPERAND (ref
, 1);
5064 up_bound
= array_ref_up_bound (ref
);
5066 /* Can not check flexible arrays. */
5068 || TREE_CODE (up_bound
) != INTEGER_CST
)
5071 /* Accesses to trailing arrays via pointers may access storage
5072 beyond the types array bounds. */
5073 base
= get_base_address (ref
);
5075 && INDIRECT_REF_P (base
))
5077 tree cref
, next
= NULL_TREE
;
5079 if (TREE_CODE (TREE_OPERAND (ref
, 0)) != COMPONENT_REF
)
5082 cref
= TREE_OPERAND (ref
, 0);
5083 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (cref
, 0))) == RECORD_TYPE
)
5084 for (next
= TREE_CHAIN (TREE_OPERAND (cref
, 1));
5085 next
&& TREE_CODE (next
) != FIELD_DECL
;
5086 next
= TREE_CHAIN (next
))
5089 /* If this is the last field in a struct type or a field in a
5090 union type do not warn. */
5095 low_bound
= array_ref_low_bound (ref
);
5096 up_bound_p1
= int_const_binop (PLUS_EXPR
, up_bound
, integer_one_node
, 0);
5098 if (TREE_CODE (low_sub
) == SSA_NAME
)
5100 vr
= get_value_range (low_sub
);
5101 if (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
)
5103 low_sub
= vr
->type
== VR_RANGE
? vr
->max
: vr
->min
;
5104 up_sub
= vr
->type
== VR_RANGE
? vr
->min
: vr
->max
;
5108 if (vr
&& vr
->type
== VR_ANTI_RANGE
)
5110 if (TREE_CODE (up_sub
) == INTEGER_CST
5111 && tree_int_cst_lt (up_bound
, up_sub
)
5112 && TREE_CODE (low_sub
) == INTEGER_CST
5113 && tree_int_cst_lt (low_sub
, low_bound
))
5115 warning_at (location
, OPT_Warray_bounds
,
5116 "array subscript is outside array bounds");
5117 TREE_NO_WARNING (ref
) = 1;
5120 else if (TREE_CODE (up_sub
) == INTEGER_CST
5121 && (ignore_off_by_one
5122 ? (tree_int_cst_lt (up_bound
, up_sub
)
5123 && !tree_int_cst_equal (up_bound_p1
, up_sub
))
5124 : (tree_int_cst_lt (up_bound
, up_sub
)
5125 || tree_int_cst_equal (up_bound_p1
, up_sub
))))
5127 warning_at (location
, OPT_Warray_bounds
,
5128 "array subscript is above array bounds");
5129 TREE_NO_WARNING (ref
) = 1;
5131 else if (TREE_CODE (low_sub
) == INTEGER_CST
5132 && tree_int_cst_lt (low_sub
, low_bound
))
5134 warning_at (location
, OPT_Warray_bounds
,
5135 "array subscript is below array bounds");
5136 TREE_NO_WARNING (ref
) = 1;
5140 /* Searches if the expr T, located at LOCATION computes
5141 address of an ARRAY_REF, and call check_array_ref on it. */
5144 search_for_addr_array (tree t
, location_t location
)
5146 while (TREE_CODE (t
) == SSA_NAME
)
5148 gimple g
= SSA_NAME_DEF_STMT (t
);
5150 if (gimple_code (g
) != GIMPLE_ASSIGN
)
5153 if (get_gimple_rhs_class (gimple_assign_rhs_code (g
))
5154 != GIMPLE_SINGLE_RHS
)
5157 t
= gimple_assign_rhs1 (g
);
5161 /* We are only interested in addresses of ARRAY_REF's. */
5162 if (TREE_CODE (t
) != ADDR_EXPR
)
5165 /* Check each ARRAY_REFs in the reference chain. */
5168 if (TREE_CODE (t
) == ARRAY_REF
)
5169 check_array_ref (location
, t
, true /*ignore_off_by_one*/);
5171 t
= TREE_OPERAND (t
, 0);
5173 while (handled_component_p (t
));
5176 /* walk_tree() callback that checks if *TP is
5177 an ARRAY_REF inside an ADDR_EXPR (in which an array
5178 subscript one outside the valid range is allowed). Call
5179 check_array_ref for each ARRAY_REF found. The location is
5183 check_array_bounds (tree
*tp
, int *walk_subtree
, void *data
)
5186 struct walk_stmt_info
*wi
= (struct walk_stmt_info
*) data
;
5187 location_t location
;
5189 if (EXPR_HAS_LOCATION (t
))
5190 location
= EXPR_LOCATION (t
);
5193 location_t
*locp
= (location_t
*) wi
->info
;
5197 *walk_subtree
= TRUE
;
5199 if (TREE_CODE (t
) == ARRAY_REF
)
5200 check_array_ref (location
, t
, false /*ignore_off_by_one*/);
5202 if (TREE_CODE (t
) == INDIRECT_REF
5203 || (TREE_CODE (t
) == RETURN_EXPR
&& TREE_OPERAND (t
, 0)))
5204 search_for_addr_array (TREE_OPERAND (t
, 0), location
);
5206 if (TREE_CODE (t
) == ADDR_EXPR
)
5207 *walk_subtree
= FALSE
;
5212 /* Walk over all statements of all reachable BBs and call check_array_bounds
5216 check_all_array_refs (void)
5219 gimple_stmt_iterator si
;
5225 bool executable
= false;
5227 /* Skip blocks that were found to be unreachable. */
5228 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
5229 executable
|= !!(e
->flags
& EDGE_EXECUTABLE
);
5233 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
5235 gimple stmt
= gsi_stmt (si
);
5236 struct walk_stmt_info wi
;
5237 if (!gimple_has_location (stmt
))
5240 if (is_gimple_call (stmt
))
5243 size_t n
= gimple_call_num_args (stmt
);
5244 for (i
= 0; i
< n
; i
++)
5246 tree arg
= gimple_call_arg (stmt
, i
);
5247 search_for_addr_array (arg
, gimple_location (stmt
));
5252 memset (&wi
, 0, sizeof (wi
));
5253 wi
.info
= CONST_CAST (void *, (const void *)
5254 gimple_location_ptr (stmt
));
5256 walk_gimple_op (gsi_stmt (si
),
5264 /* Convert range assertion expressions into the implied copies and
5265 copy propagate away the copies. Doing the trivial copy propagation
5266 here avoids the need to run the full copy propagation pass after
5269 FIXME, this will eventually lead to copy propagation removing the
5270 names that had useful range information attached to them. For
5271 instance, if we had the assertion N_i = ASSERT_EXPR <N_j, N_j > 3>,
5272 then N_i will have the range [3, +INF].
5274 However, by converting the assertion into the implied copy
5275 operation N_i = N_j, we will then copy-propagate N_j into the uses
5276 of N_i and lose the range information. We may want to hold on to
5277 ASSERT_EXPRs a little while longer as the ranges could be used in
5278 things like jump threading.
5280 The problem with keeping ASSERT_EXPRs around is that passes after
5281 VRP need to handle them appropriately.
5283 Another approach would be to make the range information a first
5284 class property of the SSA_NAME so that it can be queried from
5285 any pass. This is made somewhat more complex by the need for
5286 multiple ranges to be associated with one SSA_NAME. */
5289 remove_range_assertions (void)
5292 gimple_stmt_iterator si
;
5294 /* Note that the BSI iterator bump happens at the bottom of the
5295 loop and no bump is necessary if we're removing the statement
5296 referenced by the current BSI. */
5298 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
);)
5300 gimple stmt
= gsi_stmt (si
);
5303 if (is_gimple_assign (stmt
)
5304 && gimple_assign_rhs_code (stmt
) == ASSERT_EXPR
)
5306 tree rhs
= gimple_assign_rhs1 (stmt
);
5308 tree cond
= fold (ASSERT_EXPR_COND (rhs
));
5309 use_operand_p use_p
;
5310 imm_use_iterator iter
;
5312 gcc_assert (cond
!= boolean_false_node
);
5314 /* Propagate the RHS into every use of the LHS. */
5315 var
= ASSERT_EXPR_VAR (rhs
);
5316 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
,
5317 gimple_assign_lhs (stmt
))
5318 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
5320 SET_USE (use_p
, var
);
5321 gcc_assert (TREE_CODE (var
) == SSA_NAME
);
5324 /* And finally, remove the copy, it is not needed. */
5325 gsi_remove (&si
, true);
5326 release_defs (stmt
);
5334 /* Return true if STMT is interesting for VRP. */
5337 stmt_interesting_for_vrp (gimple stmt
)
5339 if (gimple_code (stmt
) == GIMPLE_PHI
5340 && is_gimple_reg (gimple_phi_result (stmt
))
5341 && (INTEGRAL_TYPE_P (TREE_TYPE (gimple_phi_result (stmt
)))
5342 || POINTER_TYPE_P (TREE_TYPE (gimple_phi_result (stmt
)))))
5344 else if (is_gimple_assign (stmt
) || is_gimple_call (stmt
))
5346 tree lhs
= gimple_get_lhs (stmt
);
5348 /* In general, assignments with virtual operands are not useful
5349 for deriving ranges, with the obvious exception of calls to
5350 builtin functions. */
5351 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
5352 && (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
5353 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
5354 && ((is_gimple_call (stmt
)
5355 && gimple_call_fndecl (stmt
) != NULL_TREE
5356 && DECL_IS_BUILTIN (gimple_call_fndecl (stmt
)))
5357 || !gimple_vuse (stmt
)))
5360 else if (gimple_code (stmt
) == GIMPLE_COND
5361 || gimple_code (stmt
) == GIMPLE_SWITCH
)
5368 /* Initialize local data structures for VRP. */
5371 vrp_initialize (void)
5375 vr_value
= XCNEWVEC (value_range_t
*, num_ssa_names
);
5376 vr_phi_edge_counts
= XCNEWVEC (int, num_ssa_names
);
5380 gimple_stmt_iterator si
;
5382 for (si
= gsi_start_phis (bb
); !gsi_end_p (si
); gsi_next (&si
))
5384 gimple phi
= gsi_stmt (si
);
5385 if (!stmt_interesting_for_vrp (phi
))
5387 tree lhs
= PHI_RESULT (phi
);
5388 set_value_range_to_varying (get_value_range (lhs
));
5389 prop_set_simulate_again (phi
, false);
5392 prop_set_simulate_again (phi
, true);
5395 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
5397 gimple stmt
= gsi_stmt (si
);
5399 /* If the statement is a control insn, then we do not
5400 want to avoid simulating the statement once. Failure
5401 to do so means that those edges will never get added. */
5402 if (stmt_ends_bb_p (stmt
))
5403 prop_set_simulate_again (stmt
, true);
5404 else if (!stmt_interesting_for_vrp (stmt
))
5408 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, i
, SSA_OP_DEF
)
5409 set_value_range_to_varying (get_value_range (def
));
5410 prop_set_simulate_again (stmt
, false);
5413 prop_set_simulate_again (stmt
, true);
5419 /* Visit assignment STMT. If it produces an interesting range, record
5420 the SSA name in *OUTPUT_P. */
5422 static enum ssa_prop_result
5423 vrp_visit_assignment_or_call (gimple stmt
, tree
*output_p
)
5427 enum gimple_code code
= gimple_code (stmt
);
5428 lhs
= gimple_get_lhs (stmt
);
5430 /* We only keep track of ranges in integral and pointer types. */
5431 if (TREE_CODE (lhs
) == SSA_NAME
5432 && ((INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
5433 /* It is valid to have NULL MIN/MAX values on a type. See
5434 build_range_type. */
5435 && TYPE_MIN_VALUE (TREE_TYPE (lhs
))
5436 && TYPE_MAX_VALUE (TREE_TYPE (lhs
)))
5437 || POINTER_TYPE_P (TREE_TYPE (lhs
))))
5439 value_range_t new_vr
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
5441 if (code
== GIMPLE_CALL
)
5442 extract_range_basic (&new_vr
, stmt
);
5444 extract_range_from_assignment (&new_vr
, stmt
);
5446 if (update_value_range (lhs
, &new_vr
))
5450 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5452 fprintf (dump_file
, "Found new range for ");
5453 print_generic_expr (dump_file
, lhs
, 0);
5454 fprintf (dump_file
, ": ");
5455 dump_value_range (dump_file
, &new_vr
);
5456 fprintf (dump_file
, "\n\n");
5459 if (new_vr
.type
== VR_VARYING
)
5460 return SSA_PROP_VARYING
;
5462 return SSA_PROP_INTERESTING
;
5465 return SSA_PROP_NOT_INTERESTING
;
5468 /* Every other statement produces no useful ranges. */
5469 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_DEF
)
5470 set_value_range_to_varying (get_value_range (def
));
5472 return SSA_PROP_VARYING
;
5475 /* Helper that gets the value range of the SSA_NAME with version I
5476 or a symbolic range containing the SSA_NAME only if the value range
5477 is varying or undefined. */
5479 static inline value_range_t
5480 get_vr_for_comparison (int i
)
5482 value_range_t vr
= *(vr_value
[i
]);
5484 /* If name N_i does not have a valid range, use N_i as its own
5485 range. This allows us to compare against names that may
5486 have N_i in their ranges. */
5487 if (vr
.type
== VR_VARYING
|| vr
.type
== VR_UNDEFINED
)
5490 vr
.min
= ssa_name (i
);
5491 vr
.max
= ssa_name (i
);
5497 /* Compare all the value ranges for names equivalent to VAR with VAL
5498 using comparison code COMP. Return the same value returned by
5499 compare_range_with_value, including the setting of
5500 *STRICT_OVERFLOW_P. */
5503 compare_name_with_value (enum tree_code comp
, tree var
, tree val
,
5504 bool *strict_overflow_p
)
5510 int used_strict_overflow
;
5512 value_range_t equiv_vr
;
5514 /* Get the set of equivalences for VAR. */
5515 e
= get_value_range (var
)->equiv
;
5517 /* Start at -1. Set it to 0 if we do a comparison without relying
5518 on overflow, or 1 if all comparisons rely on overflow. */
5519 used_strict_overflow
= -1;
5521 /* Compare vars' value range with val. */
5522 equiv_vr
= get_vr_for_comparison (SSA_NAME_VERSION (var
));
5524 retval
= compare_range_with_value (comp
, &equiv_vr
, val
, &sop
);
5526 used_strict_overflow
= sop
? 1 : 0;
5528 /* If the equiv set is empty we have done all work we need to do. */
5532 && used_strict_overflow
> 0)
5533 *strict_overflow_p
= true;
5537 EXECUTE_IF_SET_IN_BITMAP (e
, 0, i
, bi
)
5539 equiv_vr
= get_vr_for_comparison (i
);
5541 t
= compare_range_with_value (comp
, &equiv_vr
, val
, &sop
);
5544 /* If we get different answers from different members
5545 of the equivalence set this check must be in a dead
5546 code region. Folding it to a trap representation
5547 would be correct here. For now just return don't-know. */
5557 used_strict_overflow
= 0;
5558 else if (used_strict_overflow
< 0)
5559 used_strict_overflow
= 1;
5564 && used_strict_overflow
> 0)
5565 *strict_overflow_p
= true;
5571 /* Given a comparison code COMP and names N1 and N2, compare all the
5572 ranges equivalent to N1 against all the ranges equivalent to N2
5573 to determine the value of N1 COMP N2. Return the same value
5574 returned by compare_ranges. Set *STRICT_OVERFLOW_P to indicate
5575 whether we relied on an overflow infinity in the comparison. */
5579 compare_names (enum tree_code comp
, tree n1
, tree n2
,
5580 bool *strict_overflow_p
)
5584 bitmap_iterator bi1
, bi2
;
5586 int used_strict_overflow
;
5587 static bitmap_obstack
*s_obstack
= NULL
;
5588 static bitmap s_e1
= NULL
, s_e2
= NULL
;
5590 /* Compare the ranges of every name equivalent to N1 against the
5591 ranges of every name equivalent to N2. */
5592 e1
= get_value_range (n1
)->equiv
;
5593 e2
= get_value_range (n2
)->equiv
;
5595 /* Use the fake bitmaps if e1 or e2 are not available. */
5596 if (s_obstack
== NULL
)
5598 s_obstack
= XNEW (bitmap_obstack
);
5599 bitmap_obstack_initialize (s_obstack
);
5600 s_e1
= BITMAP_ALLOC (s_obstack
);
5601 s_e2
= BITMAP_ALLOC (s_obstack
);
5608 /* Add N1 and N2 to their own set of equivalences to avoid
5609 duplicating the body of the loop just to check N1 and N2
5611 bitmap_set_bit (e1
, SSA_NAME_VERSION (n1
));
5612 bitmap_set_bit (e2
, SSA_NAME_VERSION (n2
));
5614 /* If the equivalence sets have a common intersection, then the two
5615 names can be compared without checking their ranges. */
5616 if (bitmap_intersect_p (e1
, e2
))
5618 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5619 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5621 return (comp
== EQ_EXPR
|| comp
== GE_EXPR
|| comp
== LE_EXPR
)
5623 : boolean_false_node
;
5626 /* Start at -1. Set it to 0 if we do a comparison without relying
5627 on overflow, or 1 if all comparisons rely on overflow. */
5628 used_strict_overflow
= -1;
5630 /* Otherwise, compare all the equivalent ranges. First, add N1 and
5631 N2 to their own set of equivalences to avoid duplicating the body
5632 of the loop just to check N1 and N2 ranges. */
5633 EXECUTE_IF_SET_IN_BITMAP (e1
, 0, i1
, bi1
)
5635 value_range_t vr1
= get_vr_for_comparison (i1
);
5637 t
= retval
= NULL_TREE
;
5638 EXECUTE_IF_SET_IN_BITMAP (e2
, 0, i2
, bi2
)
5642 value_range_t vr2
= get_vr_for_comparison (i2
);
5644 t
= compare_ranges (comp
, &vr1
, &vr2
, &sop
);
5647 /* If we get different answers from different members
5648 of the equivalence set this check must be in a dead
5649 code region. Folding it to a trap representation
5650 would be correct here. For now just return don't-know. */
5654 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5655 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5661 used_strict_overflow
= 0;
5662 else if (used_strict_overflow
< 0)
5663 used_strict_overflow
= 1;
5669 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5670 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5671 if (used_strict_overflow
> 0)
5672 *strict_overflow_p
= true;
5677 /* None of the equivalent ranges are useful in computing this
5679 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5680 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5684 /* Helper function for vrp_evaluate_conditional_warnv. */
5687 vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code code
,
5689 bool * strict_overflow_p
)
5691 value_range_t
*vr0
, *vr1
;
5693 vr0
= (TREE_CODE (op0
) == SSA_NAME
) ? get_value_range (op0
) : NULL
;
5694 vr1
= (TREE_CODE (op1
) == SSA_NAME
) ? get_value_range (op1
) : NULL
;
5697 return compare_ranges (code
, vr0
, vr1
, strict_overflow_p
);
5698 else if (vr0
&& vr1
== NULL
)
5699 return compare_range_with_value (code
, vr0
, op1
, strict_overflow_p
);
5700 else if (vr0
== NULL
&& vr1
)
5701 return (compare_range_with_value
5702 (swap_tree_comparison (code
), vr1
, op0
, strict_overflow_p
));
5706 /* Helper function for vrp_evaluate_conditional_warnv. */
5709 vrp_evaluate_conditional_warnv_with_ops (enum tree_code code
, tree op0
,
5710 tree op1
, bool use_equiv_p
,
5711 bool *strict_overflow_p
, bool *only_ranges
)
5715 *only_ranges
= true;
5717 /* We only deal with integral and pointer types. */
5718 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0
))
5719 && !POINTER_TYPE_P (TREE_TYPE (op0
)))
5725 && (ret
= vrp_evaluate_conditional_warnv_with_ops_using_ranges
5726 (code
, op0
, op1
, strict_overflow_p
)))
5728 *only_ranges
= false;
5729 if (TREE_CODE (op0
) == SSA_NAME
&& TREE_CODE (op1
) == SSA_NAME
)
5730 return compare_names (code
, op0
, op1
, strict_overflow_p
);
5731 else if (TREE_CODE (op0
) == SSA_NAME
)
5732 return compare_name_with_value (code
, op0
, op1
, strict_overflow_p
);
5733 else if (TREE_CODE (op1
) == SSA_NAME
)
5734 return (compare_name_with_value
5735 (swap_tree_comparison (code
), op1
, op0
, strict_overflow_p
));
5738 return vrp_evaluate_conditional_warnv_with_ops_using_ranges (code
, op0
, op1
,
5743 /* Given (CODE OP0 OP1) within STMT, try to simplify it based on value range
5744 information. Return NULL if the conditional can not be evaluated.
5745 The ranges of all the names equivalent with the operands in COND
5746 will be used when trying to compute the value. If the result is
5747 based on undefined signed overflow, issue a warning if
5751 vrp_evaluate_conditional (enum tree_code code
, tree op0
, tree op1
, gimple stmt
)
5757 /* Some passes and foldings leak constants with overflow flag set
5758 into the IL. Avoid doing wrong things with these and bail out. */
5759 if ((TREE_CODE (op0
) == INTEGER_CST
5760 && TREE_OVERFLOW (op0
))
5761 || (TREE_CODE (op1
) == INTEGER_CST
5762 && TREE_OVERFLOW (op1
)))
5766 ret
= vrp_evaluate_conditional_warnv_with_ops (code
, op0
, op1
, true, &sop
,
5771 enum warn_strict_overflow_code wc
;
5772 const char* warnmsg
;
5774 if (is_gimple_min_invariant (ret
))
5776 wc
= WARN_STRICT_OVERFLOW_CONDITIONAL
;
5777 warnmsg
= G_("assuming signed overflow does not occur when "
5778 "simplifying conditional to constant");
5782 wc
= WARN_STRICT_OVERFLOW_COMPARISON
;
5783 warnmsg
= G_("assuming signed overflow does not occur when "
5784 "simplifying conditional");
5787 if (issue_strict_overflow_warning (wc
))
5789 location_t location
;
5791 if (!gimple_has_location (stmt
))
5792 location
= input_location
;
5794 location
= gimple_location (stmt
);
5795 warning_at (location
, OPT_Wstrict_overflow
, "%s", warnmsg
);
5799 if (warn_type_limits
5800 && ret
&& only_ranges
5801 && TREE_CODE_CLASS (code
) == tcc_comparison
5802 && TREE_CODE (op0
) == SSA_NAME
)
5804 /* If the comparison is being folded and the operand on the LHS
5805 is being compared against a constant value that is outside of
5806 the natural range of OP0's type, then the predicate will
5807 always fold regardless of the value of OP0. If -Wtype-limits
5808 was specified, emit a warning. */
5809 tree type
= TREE_TYPE (op0
);
5810 value_range_t
*vr0
= get_value_range (op0
);
5812 if (vr0
->type
!= VR_VARYING
5813 && INTEGRAL_TYPE_P (type
)
5814 && vrp_val_is_min (vr0
->min
)
5815 && vrp_val_is_max (vr0
->max
)
5816 && is_gimple_min_invariant (op1
))
5818 location_t location
;
5820 if (!gimple_has_location (stmt
))
5821 location
= input_location
;
5823 location
= gimple_location (stmt
);
5825 warning_at (location
, OPT_Wtype_limits
,
5827 ? G_("comparison always false "
5828 "due to limited range of data type")
5829 : G_("comparison always true "
5830 "due to limited range of data type"));
5838 /* Visit conditional statement STMT. If we can determine which edge
5839 will be taken out of STMT's basic block, record it in
5840 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
5841 SSA_PROP_VARYING. */
5843 static enum ssa_prop_result
5844 vrp_visit_cond_stmt (gimple stmt
, edge
*taken_edge_p
)
5849 *taken_edge_p
= NULL
;
5851 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5856 fprintf (dump_file
, "\nVisiting conditional with predicate: ");
5857 print_gimple_stmt (dump_file
, stmt
, 0, 0);
5858 fprintf (dump_file
, "\nWith known ranges\n");
5860 FOR_EACH_SSA_TREE_OPERAND (use
, stmt
, i
, SSA_OP_USE
)
5862 fprintf (dump_file
, "\t");
5863 print_generic_expr (dump_file
, use
, 0);
5864 fprintf (dump_file
, ": ");
5865 dump_value_range (dump_file
, vr_value
[SSA_NAME_VERSION (use
)]);
5868 fprintf (dump_file
, "\n");
5871 /* Compute the value of the predicate COND by checking the known
5872 ranges of each of its operands.
5874 Note that we cannot evaluate all the equivalent ranges here
5875 because those ranges may not yet be final and with the current
5876 propagation strategy, we cannot determine when the value ranges
5877 of the names in the equivalence set have changed.
5879 For instance, given the following code fragment
5883 i_14 = ASSERT_EXPR <i_5, i_5 != 0>
5887 Assume that on the first visit to i_14, i_5 has the temporary
5888 range [8, 8] because the second argument to the PHI function is
5889 not yet executable. We derive the range ~[0, 0] for i_14 and the
5890 equivalence set { i_5 }. So, when we visit 'if (i_14 == 1)' for
5891 the first time, since i_14 is equivalent to the range [8, 8], we
5892 determine that the predicate is always false.
5894 On the next round of propagation, i_13 is determined to be
5895 VARYING, which causes i_5 to drop down to VARYING. So, another
5896 visit to i_14 is scheduled. In this second visit, we compute the
5897 exact same range and equivalence set for i_14, namely ~[0, 0] and
5898 { i_5 }. But we did not have the previous range for i_5
5899 registered, so vrp_visit_assignment thinks that the range for
5900 i_14 has not changed. Therefore, the predicate 'if (i_14 == 1)'
5901 is not visited again, which stops propagation from visiting
5902 statements in the THEN clause of that if().
5904 To properly fix this we would need to keep the previous range
5905 value for the names in the equivalence set. This way we would've
5906 discovered that from one visit to the other i_5 changed from
5907 range [8, 8] to VR_VARYING.
5909 However, fixing this apparent limitation may not be worth the
5910 additional checking. Testing on several code bases (GCC, DLV,
5911 MICO, TRAMP3D and SPEC2000) showed that doing this results in
5912 4 more predicates folded in SPEC. */
5915 val
= vrp_evaluate_conditional_warnv_with_ops (gimple_cond_code (stmt
),
5916 gimple_cond_lhs (stmt
),
5917 gimple_cond_rhs (stmt
),
5922 *taken_edge_p
= find_taken_edge (gimple_bb (stmt
), val
);
5925 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5927 "\nIgnoring predicate evaluation because "
5928 "it assumes that signed overflow is undefined");
5933 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5935 fprintf (dump_file
, "\nPredicate evaluates to: ");
5936 if (val
== NULL_TREE
)
5937 fprintf (dump_file
, "DON'T KNOW\n");
5939 print_generic_stmt (dump_file
, val
, 0);
5942 return (*taken_edge_p
) ? SSA_PROP_INTERESTING
: SSA_PROP_VARYING
;
5945 /* Searches the case label vector VEC for the index *IDX of the CASE_LABEL
5946 that includes the value VAL. The search is restricted to the range
5947 [START_IDX, n - 1] where n is the size of VEC.
5949 If there is a CASE_LABEL for VAL, its index is placed in IDX and true is
5952 If there is no CASE_LABEL for VAL and there is one that is larger than VAL,
5953 it is placed in IDX and false is returned.
5955 If VAL is larger than any CASE_LABEL, n is placed on IDX and false is
5959 find_case_label_index (gimple stmt
, size_t start_idx
, tree val
, size_t *idx
)
5961 size_t n
= gimple_switch_num_labels (stmt
);
5964 /* Find case label for minimum of the value range or the next one.
5965 At each iteration we are searching in [low, high - 1]. */
5967 for (low
= start_idx
, high
= n
; high
!= low
; )
5971 /* Note that i != high, so we never ask for n. */
5972 size_t i
= (high
+ low
) / 2;
5973 t
= gimple_switch_label (stmt
, i
);
5975 /* Cache the result of comparing CASE_LOW and val. */
5976 cmp
= tree_int_cst_compare (CASE_LOW (t
), val
);
5980 /* Ranges cannot be empty. */
5989 if (CASE_HIGH (t
) != NULL
5990 && tree_int_cst_compare (CASE_HIGH (t
), val
) >= 0)
6002 /* Searches the case label vector VEC for the range of CASE_LABELs that is used
6003 for values between MIN and MAX. The first index is placed in MIN_IDX. The
6004 last index is placed in MAX_IDX. If the range of CASE_LABELs is empty
6005 then MAX_IDX < MIN_IDX.
6006 Returns true if the default label is not needed. */
6009 find_case_label_range (gimple stmt
, tree min
, tree max
, size_t *min_idx
,
6013 bool min_take_default
= !find_case_label_index (stmt
, 1, min
, &i
);
6014 bool max_take_default
= !find_case_label_index (stmt
, i
, max
, &j
);
6018 && max_take_default
)
6020 /* Only the default case label reached.
6021 Return an empty range. */
6028 bool take_default
= min_take_default
|| max_take_default
;
6032 if (max_take_default
)
6035 /* If the case label range is continuous, we do not need
6036 the default case label. Verify that. */
6037 high
= CASE_LOW (gimple_switch_label (stmt
, i
));
6038 if (CASE_HIGH (gimple_switch_label (stmt
, i
)))
6039 high
= CASE_HIGH (gimple_switch_label (stmt
, i
));
6040 for (k
= i
+ 1; k
<= j
; ++k
)
6042 low
= CASE_LOW (gimple_switch_label (stmt
, k
));
6043 if (!integer_onep (int_const_binop (MINUS_EXPR
, low
, high
, 0)))
6045 take_default
= true;
6049 if (CASE_HIGH (gimple_switch_label (stmt
, k
)))
6050 high
= CASE_HIGH (gimple_switch_label (stmt
, k
));
6055 return !take_default
;
6059 /* Visit switch statement STMT. If we can determine which edge
6060 will be taken out of STMT's basic block, record it in
6061 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
6062 SSA_PROP_VARYING. */
6064 static enum ssa_prop_result
6065 vrp_visit_switch_stmt (gimple stmt
, edge
*taken_edge_p
)
6069 size_t i
= 0, j
= 0;
6072 *taken_edge_p
= NULL
;
6073 op
= gimple_switch_index (stmt
);
6074 if (TREE_CODE (op
) != SSA_NAME
)
6075 return SSA_PROP_VARYING
;
6077 vr
= get_value_range (op
);
6078 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6080 fprintf (dump_file
, "\nVisiting switch expression with operand ");
6081 print_generic_expr (dump_file
, op
, 0);
6082 fprintf (dump_file
, " with known range ");
6083 dump_value_range (dump_file
, vr
);
6084 fprintf (dump_file
, "\n");
6087 if (vr
->type
!= VR_RANGE
6088 || symbolic_range_p (vr
))
6089 return SSA_PROP_VARYING
;
6091 /* Find the single edge that is taken from the switch expression. */
6092 take_default
= !find_case_label_range (stmt
, vr
->min
, vr
->max
, &i
, &j
);
6094 /* Check if the range spans no CASE_LABEL. If so, we only reach the default
6098 gcc_assert (take_default
);
6099 val
= gimple_switch_default_label (stmt
);
6103 /* Check if labels with index i to j and maybe the default label
6104 are all reaching the same label. */
6106 val
= gimple_switch_label (stmt
, i
);
6108 && CASE_LABEL (gimple_switch_default_label (stmt
))
6109 != CASE_LABEL (val
))
6111 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6112 fprintf (dump_file
, " not a single destination for this "
6114 return SSA_PROP_VARYING
;
6116 for (++i
; i
<= j
; ++i
)
6118 if (CASE_LABEL (gimple_switch_label (stmt
, i
)) != CASE_LABEL (val
))
6120 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6121 fprintf (dump_file
, " not a single destination for this "
6123 return SSA_PROP_VARYING
;
6128 *taken_edge_p
= find_edge (gimple_bb (stmt
),
6129 label_to_block (CASE_LABEL (val
)));
6131 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6133 fprintf (dump_file
, " will take edge to ");
6134 print_generic_stmt (dump_file
, CASE_LABEL (val
), 0);
6137 return SSA_PROP_INTERESTING
;
6141 /* Evaluate statement STMT. If the statement produces a useful range,
6142 return SSA_PROP_INTERESTING and record the SSA name with the
6143 interesting range into *OUTPUT_P.
6145 If STMT is a conditional branch and we can determine its truth
6146 value, the taken edge is recorded in *TAKEN_EDGE_P.
6148 If STMT produces a varying value, return SSA_PROP_VARYING. */
6150 static enum ssa_prop_result
6151 vrp_visit_stmt (gimple stmt
, edge
*taken_edge_p
, tree
*output_p
)
6156 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6158 fprintf (dump_file
, "\nVisiting statement:\n");
6159 print_gimple_stmt (dump_file
, stmt
, 0, dump_flags
);
6160 fprintf (dump_file
, "\n");
6163 if (!stmt_interesting_for_vrp (stmt
))
6164 gcc_assert (stmt_ends_bb_p (stmt
));
6165 else if (is_gimple_assign (stmt
) || is_gimple_call (stmt
))
6167 /* In general, assignments with virtual operands are not useful
6168 for deriving ranges, with the obvious exception of calls to
6169 builtin functions. */
6171 if ((is_gimple_call (stmt
)
6172 && gimple_call_fndecl (stmt
) != NULL_TREE
6173 && DECL_IS_BUILTIN (gimple_call_fndecl (stmt
)))
6174 || !gimple_vuse (stmt
))
6175 return vrp_visit_assignment_or_call (stmt
, output_p
);
6177 else if (gimple_code (stmt
) == GIMPLE_COND
)
6178 return vrp_visit_cond_stmt (stmt
, taken_edge_p
);
6179 else if (gimple_code (stmt
) == GIMPLE_SWITCH
)
6180 return vrp_visit_switch_stmt (stmt
, taken_edge_p
);
6182 /* All other statements produce nothing of interest for VRP, so mark
6183 their outputs varying and prevent further simulation. */
6184 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_DEF
)
6185 set_value_range_to_varying (get_value_range (def
));
6187 return SSA_PROP_VARYING
;
6191 /* Meet operation for value ranges. Given two value ranges VR0 and
6192 VR1, store in VR0 a range that contains both VR0 and VR1. This
6193 may not be the smallest possible such range. */
6196 vrp_meet (value_range_t
*vr0
, value_range_t
*vr1
)
6198 if (vr0
->type
== VR_UNDEFINED
)
6200 copy_value_range (vr0
, vr1
);
6204 if (vr1
->type
== VR_UNDEFINED
)
6206 /* Nothing to do. VR0 already has the resulting range. */
6210 if (vr0
->type
== VR_VARYING
)
6212 /* Nothing to do. VR0 already has the resulting range. */
6216 if (vr1
->type
== VR_VARYING
)
6218 set_value_range_to_varying (vr0
);
6222 if (vr0
->type
== VR_RANGE
&& vr1
->type
== VR_RANGE
)
6227 /* Compute the convex hull of the ranges. The lower limit of
6228 the new range is the minimum of the two ranges. If they
6229 cannot be compared, then give up. */
6230 cmp
= compare_values (vr0
->min
, vr1
->min
);
6231 if (cmp
== 0 || cmp
== 1)
6238 /* Similarly, the upper limit of the new range is the maximum
6239 of the two ranges. If they cannot be compared, then
6241 cmp
= compare_values (vr0
->max
, vr1
->max
);
6242 if (cmp
== 0 || cmp
== -1)
6249 /* Check for useless ranges. */
6250 if (INTEGRAL_TYPE_P (TREE_TYPE (min
))
6251 && ((vrp_val_is_min (min
) || is_overflow_infinity (min
))
6252 && (vrp_val_is_max (max
) || is_overflow_infinity (max
))))
6255 /* The resulting set of equivalences is the intersection of
6257 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
6258 bitmap_and_into (vr0
->equiv
, vr1
->equiv
);
6259 else if (vr0
->equiv
&& !vr1
->equiv
)
6260 bitmap_clear (vr0
->equiv
);
6262 set_value_range (vr0
, vr0
->type
, min
, max
, vr0
->equiv
);
6264 else if (vr0
->type
== VR_ANTI_RANGE
&& vr1
->type
== VR_ANTI_RANGE
)
6266 /* Two anti-ranges meet only if their complements intersect.
6267 Only handle the case of identical ranges. */
6268 if (compare_values (vr0
->min
, vr1
->min
) == 0
6269 && compare_values (vr0
->max
, vr1
->max
) == 0
6270 && compare_values (vr0
->min
, vr0
->max
) == 0)
6272 /* The resulting set of equivalences is the intersection of
6274 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
6275 bitmap_and_into (vr0
->equiv
, vr1
->equiv
);
6276 else if (vr0
->equiv
&& !vr1
->equiv
)
6277 bitmap_clear (vr0
->equiv
);
6282 else if (vr0
->type
== VR_ANTI_RANGE
|| vr1
->type
== VR_ANTI_RANGE
)
6284 /* For a numeric range [VAL1, VAL2] and an anti-range ~[VAL3, VAL4],
6285 only handle the case where the ranges have an empty intersection.
6286 The result of the meet operation is the anti-range. */
6287 if (!symbolic_range_p (vr0
)
6288 && !symbolic_range_p (vr1
)
6289 && !value_ranges_intersect_p (vr0
, vr1
))
6291 /* Copy most of VR1 into VR0. Don't copy VR1's equivalence
6292 set. We need to compute the intersection of the two
6293 equivalence sets. */
6294 if (vr1
->type
== VR_ANTI_RANGE
)
6295 set_value_range (vr0
, vr1
->type
, vr1
->min
, vr1
->max
, vr0
->equiv
);
6297 /* The resulting set of equivalences is the intersection of
6299 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
6300 bitmap_and_into (vr0
->equiv
, vr1
->equiv
);
6301 else if (vr0
->equiv
&& !vr1
->equiv
)
6302 bitmap_clear (vr0
->equiv
);
6313 /* Failed to find an efficient meet. Before giving up and setting
6314 the result to VARYING, see if we can at least derive a useful
6315 anti-range. FIXME, all this nonsense about distinguishing
6316 anti-ranges from ranges is necessary because of the odd
6317 semantics of range_includes_zero_p and friends. */
6318 if (!symbolic_range_p (vr0
)
6319 && ((vr0
->type
== VR_RANGE
&& !range_includes_zero_p (vr0
))
6320 || (vr0
->type
== VR_ANTI_RANGE
&& range_includes_zero_p (vr0
)))
6321 && !symbolic_range_p (vr1
)
6322 && ((vr1
->type
== VR_RANGE
&& !range_includes_zero_p (vr1
))
6323 || (vr1
->type
== VR_ANTI_RANGE
&& range_includes_zero_p (vr1
))))
6325 set_value_range_to_nonnull (vr0
, TREE_TYPE (vr0
->min
));
6327 /* Since this meet operation did not result from the meeting of
6328 two equivalent names, VR0 cannot have any equivalences. */
6330 bitmap_clear (vr0
->equiv
);
6333 set_value_range_to_varying (vr0
);
6337 /* Visit all arguments for PHI node PHI that flow through executable
6338 edges. If a valid value range can be derived from all the incoming
6339 value ranges, set a new range for the LHS of PHI. */
6341 static enum ssa_prop_result
6342 vrp_visit_phi_node (gimple phi
)
6345 tree lhs
= PHI_RESULT (phi
);
6346 value_range_t
*lhs_vr
= get_value_range (lhs
);
6347 value_range_t vr_result
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
6348 int edges
, old_edges
;
6351 copy_value_range (&vr_result
, lhs_vr
);
6353 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6355 fprintf (dump_file
, "\nVisiting PHI node: ");
6356 print_gimple_stmt (dump_file
, phi
, 0, dump_flags
);
6360 for (i
= 0; i
< gimple_phi_num_args (phi
); i
++)
6362 edge e
= gimple_phi_arg_edge (phi
, i
);
6364 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6367 "\n Argument #%d (%d -> %d %sexecutable)\n",
6368 (int) i
, e
->src
->index
, e
->dest
->index
,
6369 (e
->flags
& EDGE_EXECUTABLE
) ? "" : "not ");
6372 if (e
->flags
& EDGE_EXECUTABLE
)
6374 tree arg
= PHI_ARG_DEF (phi
, i
);
6375 value_range_t vr_arg
;
6379 if (TREE_CODE (arg
) == SSA_NAME
)
6381 vr_arg
= *(get_value_range (arg
));
6385 if (is_overflow_infinity (arg
))
6387 arg
= copy_node (arg
);
6388 TREE_OVERFLOW (arg
) = 0;
6391 vr_arg
.type
= VR_RANGE
;
6394 vr_arg
.equiv
= NULL
;
6397 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6399 fprintf (dump_file
, "\t");
6400 print_generic_expr (dump_file
, arg
, dump_flags
);
6401 fprintf (dump_file
, "\n\tValue: ");
6402 dump_value_range (dump_file
, &vr_arg
);
6403 fprintf (dump_file
, "\n");
6406 vrp_meet (&vr_result
, &vr_arg
);
6408 if (vr_result
.type
== VR_VARYING
)
6413 /* If this is a loop PHI node SCEV may known more about its
6416 && (l
= loop_containing_stmt (phi
))
6417 && l
->header
== gimple_bb (phi
))
6418 adjust_range_with_scev (&vr_result
, l
, phi
, lhs
);
6420 if (vr_result
.type
== VR_VARYING
)
6423 old_edges
= vr_phi_edge_counts
[SSA_NAME_VERSION (lhs
)];
6424 vr_phi_edge_counts
[SSA_NAME_VERSION (lhs
)] = edges
;
6426 /* To prevent infinite iterations in the algorithm, derive ranges
6427 when the new value is slightly bigger or smaller than the
6428 previous one. We don't do this if we have seen a new executable
6429 edge; this helps us avoid an overflow infinity for conditionals
6430 which are not in a loop. */
6431 if (lhs_vr
->type
== VR_RANGE
&& vr_result
.type
== VR_RANGE
6432 && edges
<= old_edges
)
6434 if (!POINTER_TYPE_P (TREE_TYPE (lhs
)))
6436 int cmp_min
= compare_values (lhs_vr
->min
, vr_result
.min
);
6437 int cmp_max
= compare_values (lhs_vr
->max
, vr_result
.max
);
6439 /* If the new minimum is smaller or larger than the previous
6440 one, go all the way to -INF. In the first case, to avoid
6441 iterating millions of times to reach -INF, and in the
6442 other case to avoid infinite bouncing between different
6444 if (cmp_min
> 0 || cmp_min
< 0)
6446 /* If we will end up with a (-INF, +INF) range, set it to
6447 VARYING. Same if the previous max value was invalid for
6448 the type and we'd end up with vr_result.min > vr_result.max. */
6449 if (vrp_val_is_max (vr_result
.max
)
6450 || compare_values (TYPE_MIN_VALUE (TREE_TYPE (vr_result
.min
)),
6454 if (!needs_overflow_infinity (TREE_TYPE (vr_result
.min
))
6455 || !vrp_var_may_overflow (lhs
, phi
))
6456 vr_result
.min
= TYPE_MIN_VALUE (TREE_TYPE (vr_result
.min
));
6457 else if (supports_overflow_infinity (TREE_TYPE (vr_result
.min
)))
6459 negative_overflow_infinity (TREE_TYPE (vr_result
.min
));
6464 /* Similarly, if the new maximum is smaller or larger than
6465 the previous one, go all the way to +INF. */
6466 if (cmp_max
< 0 || cmp_max
> 0)
6468 /* If we will end up with a (-INF, +INF) range, set it to
6469 VARYING. Same if the previous min value was invalid for
6470 the type and we'd end up with vr_result.max < vr_result.min. */
6471 if (vrp_val_is_min (vr_result
.min
)
6472 || compare_values (TYPE_MAX_VALUE (TREE_TYPE (vr_result
.max
)),
6476 if (!needs_overflow_infinity (TREE_TYPE (vr_result
.max
))
6477 || !vrp_var_may_overflow (lhs
, phi
))
6478 vr_result
.max
= TYPE_MAX_VALUE (TREE_TYPE (vr_result
.max
));
6479 else if (supports_overflow_infinity (TREE_TYPE (vr_result
.max
)))
6481 positive_overflow_infinity (TREE_TYPE (vr_result
.max
));
6488 /* If the new range is different than the previous value, keep
6490 if (update_value_range (lhs
, &vr_result
))
6492 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6494 fprintf (dump_file
, "Found new range for ");
6495 print_generic_expr (dump_file
, lhs
, 0);
6496 fprintf (dump_file
, ": ");
6497 dump_value_range (dump_file
, &vr_result
);
6498 fprintf (dump_file
, "\n\n");
6501 return SSA_PROP_INTERESTING
;
6504 /* Nothing changed, don't add outgoing edges. */
6505 return SSA_PROP_NOT_INTERESTING
;
6507 /* No match found. Set the LHS to VARYING. */
6509 set_value_range_to_varying (lhs_vr
);
6510 return SSA_PROP_VARYING
;
6513 /* Simplify boolean operations if the source is known
6514 to be already a boolean. */
6516 simplify_truth_ops_using_ranges (gimple_stmt_iterator
*gsi
, gimple stmt
)
6518 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
6523 bool need_conversion
;
6525 op0
= gimple_assign_rhs1 (stmt
);
6526 if (TYPE_PRECISION (TREE_TYPE (op0
)) != 1)
6528 if (TREE_CODE (op0
) != SSA_NAME
)
6530 vr
= get_value_range (op0
);
6532 val
= compare_range_with_value (GE_EXPR
, vr
, integer_zero_node
, &sop
);
6533 if (!val
|| !integer_onep (val
))
6536 val
= compare_range_with_value (LE_EXPR
, vr
, integer_one_node
, &sop
);
6537 if (!val
|| !integer_onep (val
))
6541 if (rhs_code
== TRUTH_NOT_EXPR
)
6544 op1
= build_int_cst (TREE_TYPE (op0
), 1);
6548 op1
= gimple_assign_rhs2 (stmt
);
6550 /* Reduce number of cases to handle. */
6551 if (is_gimple_min_invariant (op1
))
6553 /* Exclude anything that should have been already folded. */
6554 if (rhs_code
!= EQ_EXPR
6555 && rhs_code
!= NE_EXPR
6556 && rhs_code
!= TRUTH_XOR_EXPR
)
6559 if (!integer_zerop (op1
)
6560 && !integer_onep (op1
)
6561 && !integer_all_onesp (op1
))
6564 /* Limit the number of cases we have to consider. */
6565 if (rhs_code
== EQ_EXPR
)
6568 op1
= fold_unary (TRUTH_NOT_EXPR
, TREE_TYPE (op1
), op1
);
6573 /* Punt on A == B as there is no BIT_XNOR_EXPR. */
6574 if (rhs_code
== EQ_EXPR
)
6577 if (TYPE_PRECISION (TREE_TYPE (op1
)) != 1)
6579 vr
= get_value_range (op1
);
6580 val
= compare_range_with_value (GE_EXPR
, vr
, integer_zero_node
, &sop
);
6581 if (!val
|| !integer_onep (val
))
6584 val
= compare_range_with_value (LE_EXPR
, vr
, integer_one_node
, &sop
);
6585 if (!val
|| !integer_onep (val
))
6591 if (sop
&& issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
6593 location_t location
;
6595 if (!gimple_has_location (stmt
))
6596 location
= input_location
;
6598 location
= gimple_location (stmt
);
6600 if (rhs_code
== TRUTH_AND_EXPR
|| rhs_code
== TRUTH_OR_EXPR
)
6601 warning_at (location
, OPT_Wstrict_overflow
,
6602 _("assuming signed overflow does not occur when "
6603 "simplifying && or || to & or |"));
6605 warning_at (location
, OPT_Wstrict_overflow
,
6606 _("assuming signed overflow does not occur when "
6607 "simplifying ==, != or ! to identity or ^"));
6611 !useless_type_conversion_p (TREE_TYPE (gimple_assign_lhs (stmt
)),
6614 /* Make sure to not sign-extend -1 as a boolean value. */
6616 && !TYPE_UNSIGNED (TREE_TYPE (op0
))
6617 && TYPE_PRECISION (TREE_TYPE (op0
)) == 1)
6622 case TRUTH_AND_EXPR
:
6623 rhs_code
= BIT_AND_EXPR
;
6626 rhs_code
= BIT_IOR_EXPR
;
6628 case TRUTH_XOR_EXPR
:
6630 if (integer_zerop (op1
))
6632 gimple_assign_set_rhs_with_ops (gsi
,
6633 need_conversion
? NOP_EXPR
: SSA_NAME
,
6635 update_stmt (gsi_stmt (*gsi
));
6639 rhs_code
= BIT_XOR_EXPR
;
6645 if (need_conversion
)
6648 gimple_assign_set_rhs_with_ops (gsi
, rhs_code
, op0
, op1
);
6649 update_stmt (gsi_stmt (*gsi
));
6653 /* Simplify a division or modulo operator to a right shift or
6654 bitwise and if the first operand is unsigned or is greater
6655 than zero and the second operand is an exact power of two. */
6658 simplify_div_or_mod_using_ranges (gimple stmt
)
6660 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
6662 tree op0
= gimple_assign_rhs1 (stmt
);
6663 tree op1
= gimple_assign_rhs2 (stmt
);
6664 value_range_t
*vr
= get_value_range (gimple_assign_rhs1 (stmt
));
6666 if (TYPE_UNSIGNED (TREE_TYPE (op0
)))
6668 val
= integer_one_node
;
6674 val
= compare_range_with_value (GE_EXPR
, vr
, integer_zero_node
, &sop
);
6678 && integer_onep (val
)
6679 && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
6681 location_t location
;
6683 if (!gimple_has_location (stmt
))
6684 location
= input_location
;
6686 location
= gimple_location (stmt
);
6687 warning_at (location
, OPT_Wstrict_overflow
,
6688 "assuming signed overflow does not occur when "
6689 "simplifying %</%> or %<%%%> to %<>>%> or %<&%>");
6693 if (val
&& integer_onep (val
))
6697 if (rhs_code
== TRUNC_DIV_EXPR
)
6699 t
= build_int_cst (NULL_TREE
, tree_log2 (op1
));
6700 gimple_assign_set_rhs_code (stmt
, RSHIFT_EXPR
);
6701 gimple_assign_set_rhs1 (stmt
, op0
);
6702 gimple_assign_set_rhs2 (stmt
, t
);
6706 t
= build_int_cst (TREE_TYPE (op1
), 1);
6707 t
= int_const_binop (MINUS_EXPR
, op1
, t
, 0);
6708 t
= fold_convert (TREE_TYPE (op0
), t
);
6710 gimple_assign_set_rhs_code (stmt
, BIT_AND_EXPR
);
6711 gimple_assign_set_rhs1 (stmt
, op0
);
6712 gimple_assign_set_rhs2 (stmt
, t
);
6722 /* If the operand to an ABS_EXPR is >= 0, then eliminate the
6723 ABS_EXPR. If the operand is <= 0, then simplify the
6724 ABS_EXPR into a NEGATE_EXPR. */
6727 simplify_abs_using_ranges (gimple stmt
)
6730 tree op
= gimple_assign_rhs1 (stmt
);
6731 tree type
= TREE_TYPE (op
);
6732 value_range_t
*vr
= get_value_range (op
);
6734 if (TYPE_UNSIGNED (type
))
6736 val
= integer_zero_node
;
6742 val
= compare_range_with_value (LE_EXPR
, vr
, integer_zero_node
, &sop
);
6746 val
= compare_range_with_value (GE_EXPR
, vr
, integer_zero_node
,
6751 if (integer_zerop (val
))
6752 val
= integer_one_node
;
6753 else if (integer_onep (val
))
6754 val
= integer_zero_node
;
6759 && (integer_onep (val
) || integer_zerop (val
)))
6761 if (sop
&& issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
6763 location_t location
;
6765 if (!gimple_has_location (stmt
))
6766 location
= input_location
;
6768 location
= gimple_location (stmt
);
6769 warning_at (location
, OPT_Wstrict_overflow
,
6770 "assuming signed overflow does not occur when "
6771 "simplifying %<abs (X)%> to %<X%> or %<-X%>");
6774 gimple_assign_set_rhs1 (stmt
, op
);
6775 if (integer_onep (val
))
6776 gimple_assign_set_rhs_code (stmt
, NEGATE_EXPR
);
6778 gimple_assign_set_rhs_code (stmt
, SSA_NAME
);
6787 /* We are comparing trees OP0 and OP1 using COND_CODE. OP0 has
6788 a known value range VR.
6790 If there is one and only one value which will satisfy the
6791 conditional, then return that value. Else return NULL. */
6794 test_for_singularity (enum tree_code cond_code
, tree op0
,
6795 tree op1
, value_range_t
*vr
)
6800 /* Extract minimum/maximum values which satisfy the
6801 the conditional as it was written. */
6802 if (cond_code
== LE_EXPR
|| cond_code
== LT_EXPR
)
6804 /* This should not be negative infinity; there is no overflow
6806 min
= TYPE_MIN_VALUE (TREE_TYPE (op0
));
6809 if (cond_code
== LT_EXPR
&& !is_overflow_infinity (max
))
6811 tree one
= build_int_cst (TREE_TYPE (op0
), 1);
6812 max
= fold_build2 (MINUS_EXPR
, TREE_TYPE (op0
), max
, one
);
6814 TREE_NO_WARNING (max
) = 1;
6817 else if (cond_code
== GE_EXPR
|| cond_code
== GT_EXPR
)
6819 /* This should not be positive infinity; there is no overflow
6821 max
= TYPE_MAX_VALUE (TREE_TYPE (op0
));
6824 if (cond_code
== GT_EXPR
&& !is_overflow_infinity (min
))
6826 tree one
= build_int_cst (TREE_TYPE (op0
), 1);
6827 min
= fold_build2 (PLUS_EXPR
, TREE_TYPE (op0
), min
, one
);
6829 TREE_NO_WARNING (min
) = 1;
6833 /* Now refine the minimum and maximum values using any
6834 value range information we have for op0. */
6837 if (compare_values (vr
->min
, min
) == 1)
6839 if (compare_values (vr
->max
, max
) == -1)
6842 /* If the new min/max values have converged to a single value,
6843 then there is only one value which can satisfy the condition,
6844 return that value. */
6845 if (operand_equal_p (min
, max
, 0) && is_gimple_min_invariant (min
))
6851 /* Simplify a conditional using a relational operator to an equality
6852 test if the range information indicates only one value can satisfy
6853 the original conditional. */
6856 simplify_cond_using_ranges (gimple stmt
)
6858 tree op0
= gimple_cond_lhs (stmt
);
6859 tree op1
= gimple_cond_rhs (stmt
);
6860 enum tree_code cond_code
= gimple_cond_code (stmt
);
6862 if (cond_code
!= NE_EXPR
6863 && cond_code
!= EQ_EXPR
6864 && TREE_CODE (op0
) == SSA_NAME
6865 && INTEGRAL_TYPE_P (TREE_TYPE (op0
))
6866 && is_gimple_min_invariant (op1
))
6868 value_range_t
*vr
= get_value_range (op0
);
6870 /* If we have range information for OP0, then we might be
6871 able to simplify this conditional. */
6872 if (vr
->type
== VR_RANGE
)
6874 tree new_tree
= test_for_singularity (cond_code
, op0
, op1
, vr
);
6880 fprintf (dump_file
, "Simplified relational ");
6881 print_gimple_stmt (dump_file
, stmt
, 0, 0);
6882 fprintf (dump_file
, " into ");
6885 gimple_cond_set_code (stmt
, EQ_EXPR
);
6886 gimple_cond_set_lhs (stmt
, op0
);
6887 gimple_cond_set_rhs (stmt
, new_tree
);
6893 print_gimple_stmt (dump_file
, stmt
, 0, 0);
6894 fprintf (dump_file
, "\n");
6900 /* Try again after inverting the condition. We only deal
6901 with integral types here, so no need to worry about
6902 issues with inverting FP comparisons. */
6903 cond_code
= invert_tree_comparison (cond_code
, false);
6904 new_tree
= test_for_singularity (cond_code
, op0
, op1
, vr
);
6910 fprintf (dump_file
, "Simplified relational ");
6911 print_gimple_stmt (dump_file
, stmt
, 0, 0);
6912 fprintf (dump_file
, " into ");
6915 gimple_cond_set_code (stmt
, NE_EXPR
);
6916 gimple_cond_set_lhs (stmt
, op0
);
6917 gimple_cond_set_rhs (stmt
, new_tree
);
6923 print_gimple_stmt (dump_file
, stmt
, 0, 0);
6924 fprintf (dump_file
, "\n");
6935 /* Simplify a switch statement using the value range of the switch
6939 simplify_switch_using_ranges (gimple stmt
)
6941 tree op
= gimple_switch_index (stmt
);
6946 size_t i
= 0, j
= 0, n
, n2
;
6950 if (TREE_CODE (op
) == SSA_NAME
)
6952 vr
= get_value_range (op
);
6954 /* We can only handle integer ranges. */
6955 if (vr
->type
!= VR_RANGE
6956 || symbolic_range_p (vr
))
6959 /* Find case label for min/max of the value range. */
6960 take_default
= !find_case_label_range (stmt
, vr
->min
, vr
->max
, &i
, &j
);
6962 else if (TREE_CODE (op
) == INTEGER_CST
)
6964 take_default
= !find_case_label_index (stmt
, 1, op
, &i
);
6978 n
= gimple_switch_num_labels (stmt
);
6980 /* Bail out if this is just all edges taken. */
6986 /* Build a new vector of taken case labels. */
6987 vec2
= make_tree_vec (j
- i
+ 1 + (int)take_default
);
6990 /* Add the default edge, if necessary. */
6992 TREE_VEC_ELT (vec2
, n2
++) = gimple_switch_default_label (stmt
);
6994 for (; i
<= j
; ++i
, ++n2
)
6995 TREE_VEC_ELT (vec2
, n2
) = gimple_switch_label (stmt
, i
);
6997 /* Mark needed edges. */
6998 for (i
= 0; i
< n2
; ++i
)
7000 e
= find_edge (gimple_bb (stmt
),
7001 label_to_block (CASE_LABEL (TREE_VEC_ELT (vec2
, i
))));
7002 e
->aux
= (void *)-1;
7005 /* Queue not needed edges for later removal. */
7006 FOR_EACH_EDGE (e
, ei
, gimple_bb (stmt
)->succs
)
7008 if (e
->aux
== (void *)-1)
7014 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7016 fprintf (dump_file
, "removing unreachable case label\n");
7018 VEC_safe_push (edge
, heap
, to_remove_edges
, e
);
7019 e
->flags
&= ~EDGE_EXECUTABLE
;
7022 /* And queue an update for the stmt. */
7025 VEC_safe_push (switch_update
, heap
, to_update_switch_stmts
, &su
);
7029 /* Simplify STMT using ranges if possible. */
7032 simplify_stmt_using_ranges (gimple_stmt_iterator
*gsi
)
7034 gimple stmt
= gsi_stmt (*gsi
);
7035 if (is_gimple_assign (stmt
))
7037 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
7043 case TRUTH_NOT_EXPR
:
7044 case TRUTH_AND_EXPR
:
7046 case TRUTH_XOR_EXPR
:
7047 /* Transform EQ_EXPR, NE_EXPR, TRUTH_NOT_EXPR into BIT_XOR_EXPR
7048 or identity if the RHS is zero or one, and the LHS are known
7049 to be boolean values. Transform all TRUTH_*_EXPR into
7050 BIT_*_EXPR if both arguments are known to be boolean values. */
7051 if (INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt
))))
7052 return simplify_truth_ops_using_ranges (gsi
, stmt
);
7055 /* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
7056 and BIT_AND_EXPR respectively if the first operand is greater
7057 than zero and the second operand is an exact power of two. */
7058 case TRUNC_DIV_EXPR
:
7059 case TRUNC_MOD_EXPR
:
7060 if (INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt
)))
7061 && integer_pow2p (gimple_assign_rhs2 (stmt
)))
7062 return simplify_div_or_mod_using_ranges (stmt
);
7065 /* Transform ABS (X) into X or -X as appropriate. */
7067 if (TREE_CODE (gimple_assign_rhs1 (stmt
)) == SSA_NAME
7068 && INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt
))))
7069 return simplify_abs_using_ranges (stmt
);
7076 else if (gimple_code (stmt
) == GIMPLE_COND
)
7077 return simplify_cond_using_ranges (stmt
);
7078 else if (gimple_code (stmt
) == GIMPLE_SWITCH
)
7079 return simplify_switch_using_ranges (stmt
);
7084 /* If the statement pointed by SI has a predicate whose value can be
7085 computed using the value range information computed by VRP, compute
7086 its value and return true. Otherwise, return false. */
7089 fold_predicate_in (gimple_stmt_iterator
*si
)
7091 bool assignment_p
= false;
7093 gimple stmt
= gsi_stmt (*si
);
7095 if (is_gimple_assign (stmt
)
7096 && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt
)) == tcc_comparison
)
7098 assignment_p
= true;
7099 val
= vrp_evaluate_conditional (gimple_assign_rhs_code (stmt
),
7100 gimple_assign_rhs1 (stmt
),
7101 gimple_assign_rhs2 (stmt
),
7104 else if (gimple_code (stmt
) == GIMPLE_COND
)
7105 val
= vrp_evaluate_conditional (gimple_cond_code (stmt
),
7106 gimple_cond_lhs (stmt
),
7107 gimple_cond_rhs (stmt
),
7115 val
= fold_convert (gimple_expr_type (stmt
), val
);
7119 fprintf (dump_file
, "Folding predicate ");
7120 print_gimple_expr (dump_file
, stmt
, 0, 0);
7121 fprintf (dump_file
, " to ");
7122 print_generic_expr (dump_file
, val
, 0);
7123 fprintf (dump_file
, "\n");
7126 if (is_gimple_assign (stmt
))
7127 gimple_assign_set_rhs_from_tree (si
, val
);
7130 gcc_assert (gimple_code (stmt
) == GIMPLE_COND
);
7131 if (integer_zerop (val
))
7132 gimple_cond_make_false (stmt
);
7133 else if (integer_onep (val
))
7134 gimple_cond_make_true (stmt
);
7145 /* Callback for substitute_and_fold folding the stmt at *SI. */
7148 vrp_fold_stmt (gimple_stmt_iterator
*si
)
7150 if (fold_predicate_in (si
))
7153 return simplify_stmt_using_ranges (si
);
7156 /* Stack of dest,src equivalency pairs that need to be restored after
7157 each attempt to thread a block's incoming edge to an outgoing edge.
7159 A NULL entry is used to mark the end of pairs which need to be
7161 static VEC(tree
,heap
) *stack
;
7163 /* A trivial wrapper so that we can present the generic jump threading
7164 code with a simple API for simplifying statements. STMT is the
7165 statement we want to simplify, WITHIN_STMT provides the location
7166 for any overflow warnings. */
7169 simplify_stmt_for_jump_threading (gimple stmt
, gimple within_stmt
)
7171 /* We only use VRP information to simplify conditionals. This is
7172 overly conservative, but it's unclear if doing more would be
7173 worth the compile time cost. */
7174 if (gimple_code (stmt
) != GIMPLE_COND
)
7177 return vrp_evaluate_conditional (gimple_cond_code (stmt
),
7178 gimple_cond_lhs (stmt
),
7179 gimple_cond_rhs (stmt
), within_stmt
);
7182 /* Blocks which have more than one predecessor and more than
7183 one successor present jump threading opportunities, i.e.,
7184 when the block is reached from a specific predecessor, we
7185 may be able to determine which of the outgoing edges will
7186 be traversed. When this optimization applies, we are able
7187 to avoid conditionals at runtime and we may expose secondary
7188 optimization opportunities.
7190 This routine is effectively a driver for the generic jump
7191 threading code. It basically just presents the generic code
7192 with edges that may be suitable for jump threading.
7194 Unlike DOM, we do not iterate VRP if jump threading was successful.
7195 While iterating may expose new opportunities for VRP, it is expected
7196 those opportunities would be very limited and the compile time cost
7197 to expose those opportunities would be significant.
7199 As jump threading opportunities are discovered, they are registered
7200 for later realization. */
7203 identify_jump_threads (void)
7210 /* Ugh. When substituting values earlier in this pass we can
7211 wipe the dominance information. So rebuild the dominator
7212 information as we need it within the jump threading code. */
7213 calculate_dominance_info (CDI_DOMINATORS
);
7215 /* We do not allow VRP information to be used for jump threading
7216 across a back edge in the CFG. Otherwise it becomes too
7217 difficult to avoid eliminating loop exit tests. Of course
7218 EDGE_DFS_BACK is not accurate at this time so we have to
7220 mark_dfs_back_edges ();
7222 /* Do not thread across edges we are about to remove. Just marking
7223 them as EDGE_DFS_BACK will do. */
7224 for (i
= 0; VEC_iterate (edge
, to_remove_edges
, i
, e
); ++i
)
7225 e
->flags
|= EDGE_DFS_BACK
;
7227 /* Allocate our unwinder stack to unwind any temporary equivalences
7228 that might be recorded. */
7229 stack
= VEC_alloc (tree
, heap
, 20);
7231 /* To avoid lots of silly node creation, we create a single
7232 conditional and just modify it in-place when attempting to
7234 dummy
= gimple_build_cond (EQ_EXPR
,
7235 integer_zero_node
, integer_zero_node
,
7238 /* Walk through all the blocks finding those which present a
7239 potential jump threading opportunity. We could set this up
7240 as a dominator walker and record data during the walk, but
7241 I doubt it's worth the effort for the classes of jump
7242 threading opportunities we are trying to identify at this
7243 point in compilation. */
7248 /* If the generic jump threading code does not find this block
7249 interesting, then there is nothing to do. */
7250 if (! potentially_threadable_block (bb
))
7253 /* We only care about blocks ending in a COND_EXPR. While there
7254 may be some value in handling SWITCH_EXPR here, I doubt it's
7255 terribly important. */
7256 last
= gsi_stmt (gsi_last_bb (bb
));
7257 if (gimple_code (last
) != GIMPLE_COND
)
7260 /* We're basically looking for any kind of conditional with
7261 integral type arguments. */
7262 if (TREE_CODE (gimple_cond_lhs (last
)) == SSA_NAME
7263 && INTEGRAL_TYPE_P (TREE_TYPE (gimple_cond_lhs (last
)))
7264 && (TREE_CODE (gimple_cond_rhs (last
)) == SSA_NAME
7265 || is_gimple_min_invariant (gimple_cond_rhs (last
)))
7266 && INTEGRAL_TYPE_P (TREE_TYPE (gimple_cond_rhs (last
))))
7270 /* We've got a block with multiple predecessors and multiple
7271 successors which also ends in a suitable conditional. For
7272 each predecessor, see if we can thread it to a specific
7274 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
7276 /* Do not thread across back edges or abnormal edges
7278 if (e
->flags
& (EDGE_DFS_BACK
| EDGE_COMPLEX
))
7281 thread_across_edge (dummy
, e
, true, &stack
,
7282 simplify_stmt_for_jump_threading
);
7287 /* We do not actually update the CFG or SSA graphs at this point as
7288 ASSERT_EXPRs are still in the IL and cfg cleanup code does not yet
7289 handle ASSERT_EXPRs gracefully. */
7292 /* We identified all the jump threading opportunities earlier, but could
7293 not transform the CFG at that time. This routine transforms the
7294 CFG and arranges for the dominator tree to be rebuilt if necessary.
7296 Note the SSA graph update will occur during the normal TODO
7297 processing by the pass manager. */
7299 finalize_jump_threads (void)
7301 thread_through_all_blocks (false);
7302 VEC_free (tree
, heap
, stack
);
7306 /* Traverse all the blocks folding conditionals with known ranges. */
7312 prop_value_t
*single_val_range
;
7313 bool do_value_subst_p
;
7317 fprintf (dump_file
, "\nValue ranges after VRP:\n\n");
7318 dump_all_value_ranges (dump_file
);
7319 fprintf (dump_file
, "\n");
7322 /* We may have ended with ranges that have exactly one value. Those
7323 values can be substituted as any other const propagated
7324 value using substitute_and_fold. */
7325 single_val_range
= XCNEWVEC (prop_value_t
, num_ssa_names
);
7327 do_value_subst_p
= false;
7328 for (i
= 0; i
< num_ssa_names
; i
++)
7330 && vr_value
[i
]->type
== VR_RANGE
7331 && vr_value
[i
]->min
== vr_value
[i
]->max
7332 && is_gimple_min_invariant (vr_value
[i
]->min
))
7334 single_val_range
[i
].value
= vr_value
[i
]->min
;
7335 do_value_subst_p
= true;
7338 if (!do_value_subst_p
)
7340 /* We found no single-valued ranges, don't waste time trying to
7341 do single value substitution in substitute_and_fold. */
7342 free (single_val_range
);
7343 single_val_range
= NULL
;
7346 substitute_and_fold (single_val_range
, vrp_fold_stmt
, false);
7348 if (warn_array_bounds
)
7349 check_all_array_refs ();
7351 /* We must identify jump threading opportunities before we release
7352 the datastructures built by VRP. */
7353 identify_jump_threads ();
7355 /* Free allocated memory. */
7356 for (i
= 0; i
< num_ssa_names
; i
++)
7359 BITMAP_FREE (vr_value
[i
]->equiv
);
7363 free (single_val_range
);
7365 free (vr_phi_edge_counts
);
7367 /* So that we can distinguish between VRP data being available
7368 and not available. */
7370 vr_phi_edge_counts
= NULL
;
7374 /* Main entry point to VRP (Value Range Propagation). This pass is
7375 loosely based on J. R. C. Patterson, ``Accurate Static Branch
7376 Prediction by Value Range Propagation,'' in SIGPLAN Conference on
7377 Programming Language Design and Implementation, pp. 67-78, 1995.
7378 Also available at http://citeseer.ist.psu.edu/patterson95accurate.html
7380 This is essentially an SSA-CCP pass modified to deal with ranges
7381 instead of constants.
7383 While propagating ranges, we may find that two or more SSA name
7384 have equivalent, though distinct ranges. For instance,
7387 2 p_4 = ASSERT_EXPR <p_3, p_3 != 0>
7389 4 p_5 = ASSERT_EXPR <p_4, p_4 == q_2>;
7393 In the code above, pointer p_5 has range [q_2, q_2], but from the
7394 code we can also determine that p_5 cannot be NULL and, if q_2 had
7395 a non-varying range, p_5's range should also be compatible with it.
7397 These equivalences are created by two expressions: ASSERT_EXPR and
7398 copy operations. Since p_5 is an assertion on p_4, and p_4 was the
7399 result of another assertion, then we can use the fact that p_5 and
7400 p_4 are equivalent when evaluating p_5's range.
7402 Together with value ranges, we also propagate these equivalences
7403 between names so that we can take advantage of information from
7404 multiple ranges when doing final replacement. Note that this
7405 equivalency relation is transitive but not symmetric.
7407 In the example above, p_5 is equivalent to p_4, q_2 and p_3, but we
7408 cannot assert that q_2 is equivalent to p_5 because q_2 may be used
7409 in contexts where that assertion does not hold (e.g., in line 6).
7411 TODO, the main difference between this pass and Patterson's is that
7412 we do not propagate edge probabilities. We only compute whether
7413 edges can be taken or not. That is, instead of having a spectrum
7414 of jump probabilities between 0 and 1, we only deal with 0, 1 and
7415 DON'T KNOW. In the future, it may be worthwhile to propagate
7416 probabilities to aid branch prediction. */
7425 loop_optimizer_init (LOOPS_NORMAL
| LOOPS_HAVE_RECORDED_EXITS
);
7426 rewrite_into_loop_closed_ssa (NULL
, TODO_update_ssa
);
7429 insert_range_assertions ();
7431 to_remove_edges
= VEC_alloc (edge
, heap
, 10);
7432 to_update_switch_stmts
= VEC_alloc (switch_update
, heap
, 5);
7433 threadedge_initialize_values ();
7436 ssa_propagate (vrp_visit_stmt
, vrp_visit_phi_node
);
7439 /* ASSERT_EXPRs must be removed before finalizing jump threads
7440 as finalizing jump threads calls the CFG cleanup code which
7441 does not properly handle ASSERT_EXPRs. */
7442 remove_range_assertions ();
7444 /* If we exposed any new variables, go ahead and put them into
7445 SSA form now, before we handle jump threading. This simplifies
7446 interactions between rewriting of _DECL nodes into SSA form
7447 and rewriting SSA_NAME nodes into SSA form after block
7448 duplication and CFG manipulation. */
7449 update_ssa (TODO_update_ssa
);
7451 finalize_jump_threads ();
7453 /* Remove dead edges from SWITCH_EXPR optimization. This leaves the
7454 CFG in a broken state and requires a cfg_cleanup run. */
7455 for (i
= 0; VEC_iterate (edge
, to_remove_edges
, i
, e
); ++i
)
7457 /* Update SWITCH_EXPR case label vector. */
7458 for (i
= 0; VEC_iterate (switch_update
, to_update_switch_stmts
, i
, su
); ++i
)
7461 size_t n
= TREE_VEC_LENGTH (su
->vec
);
7463 gimple_switch_set_num_labels (su
->stmt
, n
);
7464 for (j
= 0; j
< n
; j
++)
7465 gimple_switch_set_label (su
->stmt
, j
, TREE_VEC_ELT (su
->vec
, j
));
7466 /* As we may have replaced the default label with a regular one
7467 make sure to make it a real default label again. This ensures
7468 optimal expansion. */
7469 label
= gimple_switch_default_label (su
->stmt
);
7470 CASE_LOW (label
) = NULL_TREE
;
7471 CASE_HIGH (label
) = NULL_TREE
;
7474 if (VEC_length (edge
, to_remove_edges
) > 0)
7475 free_dominance_info (CDI_DOMINATORS
);
7477 VEC_free (edge
, heap
, to_remove_edges
);
7478 VEC_free (switch_update
, heap
, to_update_switch_stmts
);
7479 threadedge_finalize_values ();
7482 loop_optimizer_finalize ();
7489 return flag_tree_vrp
!= 0;
7492 struct gimple_opt_pass pass_vrp
=
7497 gate_vrp
, /* gate */
7498 execute_vrp
, /* execute */
7501 0, /* static_pass_number */
7502 TV_TREE_VRP
, /* tv_id */
7503 PROP_ssa
, /* properties_required */
7504 0, /* properties_provided */
7505 0, /* properties_destroyed */
7506 0, /* todo_flags_start */
7511 | TODO_update_ssa
/* todo_flags_finish */