1 /* Support routines for Value Range Propagation (VRP).
2 Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
3 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@redhat.com>.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
29 #include "basic-block.h"
30 #include "tree-flow.h"
31 #include "tree-pass.h"
32 #include "tree-dump.h"
34 #include "tree-pretty-print.h"
35 #include "gimple-pretty-print.h"
36 #include "diagnostic-core.h"
39 #include "tree-scalar-evolution.h"
40 #include "tree-ssa-propagate.h"
41 #include "tree-chrec.h"
42 #include "gimple-fold.h"
47 /* Type of value ranges. See value_range_d for a description of these
49 enum value_range_type
{ VR_UNDEFINED
, VR_RANGE
, VR_ANTI_RANGE
, VR_VARYING
};
51 /* Range of values that can be associated with an SSA_NAME after VRP
55 /* Lattice value represented by this range. */
56 enum value_range_type type
;
58 /* Minimum and maximum values represented by this range. These
59 values should be interpreted as follows:
61 - If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must
64 - If TYPE == VR_RANGE then MIN holds the minimum value and
65 MAX holds the maximum value of the range [MIN, MAX].
67 - If TYPE == ANTI_RANGE the variable is known to NOT
68 take any values in the range [MIN, MAX]. */
72 /* Set of SSA names whose value ranges are equivalent to this one.
73 This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE. */
77 typedef struct value_range_d value_range_t
;
79 /* Set of SSA names found live during the RPO traversal of the function
80 for still active basic-blocks. */
83 /* Return true if the SSA name NAME is live on the edge E. */
86 live_on_edge (edge e
, tree name
)
88 return (live
[e
->dest
->index
]
89 && TEST_BIT (live
[e
->dest
->index
], SSA_NAME_VERSION (name
)));
92 /* Local functions. */
93 static int compare_values (tree val1
, tree val2
);
94 static int compare_values_warnv (tree val1
, tree val2
, bool *);
95 static void vrp_meet (value_range_t
*, value_range_t
*);
96 static tree
vrp_evaluate_conditional_warnv_with_ops (enum tree_code
,
97 tree
, tree
, bool, bool *,
100 /* Location information for ASSERT_EXPRs. Each instance of this
101 structure describes an ASSERT_EXPR for an SSA name. Since a single
102 SSA name may have more than one assertion associated with it, these
103 locations are kept in a linked list attached to the corresponding
105 struct assert_locus_d
107 /* Basic block where the assertion would be inserted. */
110 /* Some assertions need to be inserted on an edge (e.g., assertions
111 generated by COND_EXPRs). In those cases, BB will be NULL. */
114 /* Pointer to the statement that generated this assertion. */
115 gimple_stmt_iterator si
;
117 /* Predicate code for the ASSERT_EXPR. Must be COMPARISON_CLASS_P. */
118 enum tree_code comp_code
;
120 /* Value being compared against. */
123 /* Expression to compare. */
126 /* Next node in the linked list. */
127 struct assert_locus_d
*next
;
130 typedef struct assert_locus_d
*assert_locus_t
;
132 /* If bit I is present, it means that SSA name N_i has a list of
133 assertions that should be inserted in the IL. */
134 static bitmap need_assert_for
;
136 /* Array of locations lists where to insert assertions. ASSERTS_FOR[I]
137 holds a list of ASSERT_LOCUS_T nodes that describe where
138 ASSERT_EXPRs for SSA name N_I should be inserted. */
139 static assert_locus_t
*asserts_for
;
141 /* Value range array. After propagation, VR_VALUE[I] holds the range
142 of values that SSA name N_I may take. */
143 static unsigned num_vr_values
;
144 static value_range_t
**vr_value
;
145 static bool values_propagated
;
147 /* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the
148 number of executable edges we saw the last time we visited the
150 static int *vr_phi_edge_counts
;
157 static VEC (edge
, heap
) *to_remove_edges
;
158 DEF_VEC_O(switch_update
);
159 DEF_VEC_ALLOC_O(switch_update
, heap
);
160 static VEC (switch_update
, heap
) *to_update_switch_stmts
;
163 /* Return the maximum value for TYPE. */
166 vrp_val_max (const_tree type
)
168 if (!INTEGRAL_TYPE_P (type
))
171 return TYPE_MAX_VALUE (type
);
174 /* Return the minimum value for TYPE. */
177 vrp_val_min (const_tree type
)
179 if (!INTEGRAL_TYPE_P (type
))
182 return TYPE_MIN_VALUE (type
);
185 /* Return whether VAL is equal to the maximum value of its type. This
186 will be true for a positive overflow infinity. We can't do a
187 simple equality comparison with TYPE_MAX_VALUE because C typedefs
188 and Ada subtypes can produce types whose TYPE_MAX_VALUE is not ==
189 to the integer constant with the same value in the type. */
192 vrp_val_is_max (const_tree val
)
194 tree type_max
= vrp_val_max (TREE_TYPE (val
));
195 return (val
== type_max
196 || (type_max
!= NULL_TREE
197 && operand_equal_p (val
, type_max
, 0)));
200 /* Return whether VAL is equal to the minimum value of its type. This
201 will be true for a negative overflow infinity. */
204 vrp_val_is_min (const_tree val
)
206 tree type_min
= vrp_val_min (TREE_TYPE (val
));
207 return (val
== type_min
208 || (type_min
!= NULL_TREE
209 && operand_equal_p (val
, type_min
, 0)));
213 /* Return whether TYPE should use an overflow infinity distinct from
214 TYPE_{MIN,MAX}_VALUE. We use an overflow infinity value to
215 represent a signed overflow during VRP computations. An infinity
216 is distinct from a half-range, which will go from some number to
217 TYPE_{MIN,MAX}_VALUE. */
220 needs_overflow_infinity (const_tree type
)
222 return INTEGRAL_TYPE_P (type
) && !TYPE_OVERFLOW_WRAPS (type
);
225 /* Return whether TYPE can support our overflow infinity
226 representation: we use the TREE_OVERFLOW flag, which only exists
227 for constants. If TYPE doesn't support this, we don't optimize
228 cases which would require signed overflow--we drop them to
232 supports_overflow_infinity (const_tree type
)
234 tree min
= vrp_val_min (type
), max
= vrp_val_max (type
);
235 #ifdef ENABLE_CHECKING
236 gcc_assert (needs_overflow_infinity (type
));
238 return (min
!= NULL_TREE
239 && CONSTANT_CLASS_P (min
)
241 && CONSTANT_CLASS_P (max
));
244 /* VAL is the maximum or minimum value of a type. Return a
245 corresponding overflow infinity. */
248 make_overflow_infinity (tree val
)
250 gcc_checking_assert (val
!= NULL_TREE
&& CONSTANT_CLASS_P (val
));
251 val
= copy_node (val
);
252 TREE_OVERFLOW (val
) = 1;
256 /* Return a negative overflow infinity for TYPE. */
259 negative_overflow_infinity (tree type
)
261 gcc_checking_assert (supports_overflow_infinity (type
));
262 return make_overflow_infinity (vrp_val_min (type
));
265 /* Return a positive overflow infinity for TYPE. */
268 positive_overflow_infinity (tree type
)
270 gcc_checking_assert (supports_overflow_infinity (type
));
271 return make_overflow_infinity (vrp_val_max (type
));
274 /* Return whether VAL is a negative overflow infinity. */
277 is_negative_overflow_infinity (const_tree val
)
279 return (needs_overflow_infinity (TREE_TYPE (val
))
280 && CONSTANT_CLASS_P (val
)
281 && TREE_OVERFLOW (val
)
282 && vrp_val_is_min (val
));
285 /* Return whether VAL is a positive overflow infinity. */
288 is_positive_overflow_infinity (const_tree val
)
290 return (needs_overflow_infinity (TREE_TYPE (val
))
291 && CONSTANT_CLASS_P (val
)
292 && TREE_OVERFLOW (val
)
293 && vrp_val_is_max (val
));
296 /* Return whether VAL is a positive or negative overflow infinity. */
299 is_overflow_infinity (const_tree val
)
301 return (needs_overflow_infinity (TREE_TYPE (val
))
302 && CONSTANT_CLASS_P (val
)
303 && TREE_OVERFLOW (val
)
304 && (vrp_val_is_min (val
) || vrp_val_is_max (val
)));
307 /* Return whether STMT has a constant rhs that is_overflow_infinity. */
310 stmt_overflow_infinity (gimple stmt
)
312 if (is_gimple_assign (stmt
)
313 && get_gimple_rhs_class (gimple_assign_rhs_code (stmt
)) ==
315 return is_overflow_infinity (gimple_assign_rhs1 (stmt
));
319 /* If VAL is now an overflow infinity, return VAL. Otherwise, return
320 the same value with TREE_OVERFLOW clear. This can be used to avoid
321 confusing a regular value with an overflow value. */
324 avoid_overflow_infinity (tree val
)
326 if (!is_overflow_infinity (val
))
329 if (vrp_val_is_max (val
))
330 return vrp_val_max (TREE_TYPE (val
));
333 gcc_checking_assert (vrp_val_is_min (val
));
334 return vrp_val_min (TREE_TYPE (val
));
339 /* Return true if ARG is marked with the nonnull attribute in the
340 current function signature. */
343 nonnull_arg_p (const_tree arg
)
345 tree t
, attrs
, fntype
;
346 unsigned HOST_WIDE_INT arg_num
;
348 gcc_assert (TREE_CODE (arg
) == PARM_DECL
&& POINTER_TYPE_P (TREE_TYPE (arg
)));
350 /* The static chain decl is always non null. */
351 if (arg
== cfun
->static_chain_decl
)
354 fntype
= TREE_TYPE (current_function_decl
);
355 attrs
= lookup_attribute ("nonnull", TYPE_ATTRIBUTES (fntype
));
357 /* If "nonnull" wasn't specified, we know nothing about the argument. */
358 if (attrs
== NULL_TREE
)
361 /* If "nonnull" applies to all the arguments, then ARG is non-null. */
362 if (TREE_VALUE (attrs
) == NULL_TREE
)
365 /* Get the position number for ARG in the function signature. */
366 for (arg_num
= 1, t
= DECL_ARGUMENTS (current_function_decl
);
368 t
= DECL_CHAIN (t
), arg_num
++)
374 gcc_assert (t
== arg
);
376 /* Now see if ARG_NUM is mentioned in the nonnull list. */
377 for (t
= TREE_VALUE (attrs
); t
; t
= TREE_CHAIN (t
))
379 if (compare_tree_int (TREE_VALUE (t
), arg_num
) == 0)
387 /* Set value range VR to VR_VARYING. */
390 set_value_range_to_varying (value_range_t
*vr
)
392 vr
->type
= VR_VARYING
;
393 vr
->min
= vr
->max
= NULL_TREE
;
395 bitmap_clear (vr
->equiv
);
399 /* Set value range VR to {T, MIN, MAX, EQUIV}. */
402 set_value_range (value_range_t
*vr
, enum value_range_type t
, tree min
,
403 tree max
, bitmap equiv
)
405 #if defined ENABLE_CHECKING
406 /* Check the validity of the range. */
407 if (t
== VR_RANGE
|| t
== VR_ANTI_RANGE
)
411 gcc_assert (min
&& max
);
413 if (INTEGRAL_TYPE_P (TREE_TYPE (min
)) && t
== VR_ANTI_RANGE
)
414 gcc_assert (!vrp_val_is_min (min
) || !vrp_val_is_max (max
));
416 cmp
= compare_values (min
, max
);
417 gcc_assert (cmp
== 0 || cmp
== -1 || cmp
== -2);
419 if (needs_overflow_infinity (TREE_TYPE (min
)))
420 gcc_assert (!is_overflow_infinity (min
)
421 || !is_overflow_infinity (max
));
424 if (t
== VR_UNDEFINED
|| t
== VR_VARYING
)
425 gcc_assert (min
== NULL_TREE
&& max
== NULL_TREE
);
427 if (t
== VR_UNDEFINED
|| t
== VR_VARYING
)
428 gcc_assert (equiv
== NULL
|| bitmap_empty_p (equiv
));
435 /* Since updating the equivalence set involves deep copying the
436 bitmaps, only do it if absolutely necessary. */
437 if (vr
->equiv
== NULL
439 vr
->equiv
= BITMAP_ALLOC (NULL
);
441 if (equiv
!= vr
->equiv
)
443 if (equiv
&& !bitmap_empty_p (equiv
))
444 bitmap_copy (vr
->equiv
, equiv
);
446 bitmap_clear (vr
->equiv
);
451 /* Set value range VR to the canonical form of {T, MIN, MAX, EQUIV}.
452 This means adjusting T, MIN and MAX representing the case of a
453 wrapping range with MAX < MIN covering [MIN, type_max] U [type_min, MAX]
454 as anti-rage ~[MAX+1, MIN-1]. Likewise for wrapping anti-ranges.
455 In corner cases where MAX+1 or MIN-1 wraps this will fall back
457 This routine exists to ease canonicalization in the case where we
458 extract ranges from var + CST op limit. */
461 set_and_canonicalize_value_range (value_range_t
*vr
, enum value_range_type t
,
462 tree min
, tree max
, bitmap equiv
)
464 /* Nothing to canonicalize for symbolic or unknown or varying ranges. */
466 && t
!= VR_ANTI_RANGE
)
467 || TREE_CODE (min
) != INTEGER_CST
468 || TREE_CODE (max
) != INTEGER_CST
)
470 set_value_range (vr
, t
, min
, max
, equiv
);
474 /* Wrong order for min and max, to swap them and the VR type we need
476 if (tree_int_cst_lt (max
, min
))
478 tree one
= build_int_cst (TREE_TYPE (min
), 1);
479 tree tmp
= int_const_binop (PLUS_EXPR
, max
, one
);
480 max
= int_const_binop (MINUS_EXPR
, min
, one
);
483 /* There's one corner case, if we had [C+1, C] before we now have
484 that again. But this represents an empty value range, so drop
485 to varying in this case. */
486 if (tree_int_cst_lt (max
, min
))
488 set_value_range_to_varying (vr
);
492 t
= t
== VR_RANGE
? VR_ANTI_RANGE
: VR_RANGE
;
495 /* Anti-ranges that can be represented as ranges should be so. */
496 if (t
== VR_ANTI_RANGE
)
498 bool is_min
= vrp_val_is_min (min
);
499 bool is_max
= vrp_val_is_max (max
);
501 if (is_min
&& is_max
)
503 /* We cannot deal with empty ranges, drop to varying. */
504 set_value_range_to_varying (vr
);
508 /* As a special exception preserve non-null ranges. */
509 && !(TYPE_UNSIGNED (TREE_TYPE (min
))
510 && integer_zerop (max
)))
512 tree one
= build_int_cst (TREE_TYPE (max
), 1);
513 min
= int_const_binop (PLUS_EXPR
, max
, one
);
514 max
= vrp_val_max (TREE_TYPE (max
));
519 tree one
= build_int_cst (TREE_TYPE (min
), 1);
520 max
= int_const_binop (MINUS_EXPR
, min
, one
);
521 min
= vrp_val_min (TREE_TYPE (min
));
526 set_value_range (vr
, t
, min
, max
, equiv
);
529 /* Copy value range FROM into value range TO. */
532 copy_value_range (value_range_t
*to
, value_range_t
*from
)
534 set_value_range (to
, from
->type
, from
->min
, from
->max
, from
->equiv
);
537 /* Set value range VR to a single value. This function is only called
538 with values we get from statements, and exists to clear the
539 TREE_OVERFLOW flag so that we don't think we have an overflow
540 infinity when we shouldn't. */
543 set_value_range_to_value (value_range_t
*vr
, tree val
, bitmap equiv
)
545 gcc_assert (is_gimple_min_invariant (val
));
546 val
= avoid_overflow_infinity (val
);
547 set_value_range (vr
, VR_RANGE
, val
, val
, equiv
);
550 /* Set value range VR to a non-negative range of type TYPE.
551 OVERFLOW_INFINITY indicates whether to use an overflow infinity
552 rather than TYPE_MAX_VALUE; this should be true if we determine
553 that the range is nonnegative based on the assumption that signed
554 overflow does not occur. */
557 set_value_range_to_nonnegative (value_range_t
*vr
, tree type
,
558 bool overflow_infinity
)
562 if (overflow_infinity
&& !supports_overflow_infinity (type
))
564 set_value_range_to_varying (vr
);
568 zero
= build_int_cst (type
, 0);
569 set_value_range (vr
, VR_RANGE
, zero
,
571 ? positive_overflow_infinity (type
)
572 : TYPE_MAX_VALUE (type
)),
576 /* Set value range VR to a non-NULL range of type TYPE. */
579 set_value_range_to_nonnull (value_range_t
*vr
, tree type
)
581 tree zero
= build_int_cst (type
, 0);
582 set_value_range (vr
, VR_ANTI_RANGE
, zero
, zero
, vr
->equiv
);
586 /* Set value range VR to a NULL range of type TYPE. */
589 set_value_range_to_null (value_range_t
*vr
, tree type
)
591 set_value_range_to_value (vr
, build_int_cst (type
, 0), vr
->equiv
);
595 /* Set value range VR to a range of a truthvalue of type TYPE. */
598 set_value_range_to_truthvalue (value_range_t
*vr
, tree type
)
600 if (TYPE_PRECISION (type
) == 1)
601 set_value_range_to_varying (vr
);
603 set_value_range (vr
, VR_RANGE
,
604 build_int_cst (type
, 0), build_int_cst (type
, 1),
609 /* Set value range VR to VR_UNDEFINED. */
612 set_value_range_to_undefined (value_range_t
*vr
)
614 vr
->type
= VR_UNDEFINED
;
615 vr
->min
= vr
->max
= NULL_TREE
;
617 bitmap_clear (vr
->equiv
);
621 /* If abs (min) < abs (max), set VR to [-max, max], if
622 abs (min) >= abs (max), set VR to [-min, min]. */
625 abs_extent_range (value_range_t
*vr
, tree min
, tree max
)
629 gcc_assert (TREE_CODE (min
) == INTEGER_CST
);
630 gcc_assert (TREE_CODE (max
) == INTEGER_CST
);
631 gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (min
)));
632 gcc_assert (!TYPE_UNSIGNED (TREE_TYPE (min
)));
633 min
= fold_unary (ABS_EXPR
, TREE_TYPE (min
), min
);
634 max
= fold_unary (ABS_EXPR
, TREE_TYPE (max
), max
);
635 if (TREE_OVERFLOW (min
) || TREE_OVERFLOW (max
))
637 set_value_range_to_varying (vr
);
640 cmp
= compare_values (min
, max
);
642 min
= fold_unary (NEGATE_EXPR
, TREE_TYPE (min
), max
);
643 else if (cmp
== 0 || cmp
== 1)
646 min
= fold_unary (NEGATE_EXPR
, TREE_TYPE (min
), min
);
650 set_value_range_to_varying (vr
);
653 set_and_canonicalize_value_range (vr
, VR_RANGE
, min
, max
, NULL
);
657 /* Return value range information for VAR.
659 If we have no values ranges recorded (ie, VRP is not running), then
660 return NULL. Otherwise create an empty range if none existed for VAR. */
662 static value_range_t
*
663 get_value_range (const_tree var
)
665 static const struct value_range_d vr_const_varying
666 = { VR_VARYING
, NULL_TREE
, NULL_TREE
, NULL
};
669 unsigned ver
= SSA_NAME_VERSION (var
);
671 /* If we have no recorded ranges, then return NULL. */
675 /* If we query the range for a new SSA name return an unmodifiable VARYING.
676 We should get here at most from the substitute-and-fold stage which
677 will never try to change values. */
678 if (ver
>= num_vr_values
)
679 return CONST_CAST (value_range_t
*, &vr_const_varying
);
685 /* After propagation finished do not allocate new value-ranges. */
686 if (values_propagated
)
687 return CONST_CAST (value_range_t
*, &vr_const_varying
);
689 /* Create a default value range. */
690 vr_value
[ver
] = vr
= XCNEW (value_range_t
);
692 /* Defer allocating the equivalence set. */
695 /* If VAR is a default definition of a parameter, the variable can
696 take any value in VAR's type. */
697 sym
= SSA_NAME_VAR (var
);
698 if (SSA_NAME_IS_DEFAULT_DEF (var
)
699 && TREE_CODE (sym
) == PARM_DECL
)
701 /* Try to use the "nonnull" attribute to create ~[0, 0]
702 anti-ranges for pointers. Note that this is only valid with
703 default definitions of PARM_DECLs. */
704 if (POINTER_TYPE_P (TREE_TYPE (sym
))
705 && nonnull_arg_p (sym
))
706 set_value_range_to_nonnull (vr
, TREE_TYPE (sym
));
708 set_value_range_to_varying (vr
);
714 /* Return true, if VAL1 and VAL2 are equal values for VRP purposes. */
717 vrp_operand_equal_p (const_tree val1
, const_tree val2
)
721 if (!val1
|| !val2
|| !operand_equal_p (val1
, val2
, 0))
723 if (is_overflow_infinity (val1
))
724 return is_overflow_infinity (val2
);
728 /* Return true, if the bitmaps B1 and B2 are equal. */
731 vrp_bitmap_equal_p (const_bitmap b1
, const_bitmap b2
)
734 || ((!b1
|| bitmap_empty_p (b1
))
735 && (!b2
|| bitmap_empty_p (b2
)))
737 && bitmap_equal_p (b1
, b2
)));
740 /* Update the value range and equivalence set for variable VAR to
741 NEW_VR. Return true if NEW_VR is different from VAR's previous
744 NOTE: This function assumes that NEW_VR is a temporary value range
745 object created for the sole purpose of updating VAR's range. The
746 storage used by the equivalence set from NEW_VR will be freed by
747 this function. Do not call update_value_range when NEW_VR
748 is the range object associated with another SSA name. */
751 update_value_range (const_tree var
, value_range_t
*new_vr
)
753 value_range_t
*old_vr
;
756 /* Update the value range, if necessary. */
757 old_vr
= get_value_range (var
);
758 is_new
= old_vr
->type
!= new_vr
->type
759 || !vrp_operand_equal_p (old_vr
->min
, new_vr
->min
)
760 || !vrp_operand_equal_p (old_vr
->max
, new_vr
->max
)
761 || !vrp_bitmap_equal_p (old_vr
->equiv
, new_vr
->equiv
);
764 set_value_range (old_vr
, new_vr
->type
, new_vr
->min
, new_vr
->max
,
767 BITMAP_FREE (new_vr
->equiv
);
773 /* Add VAR and VAR's equivalence set to EQUIV. This is the central
774 point where equivalence processing can be turned on/off. */
777 add_equivalence (bitmap
*equiv
, const_tree var
)
779 unsigned ver
= SSA_NAME_VERSION (var
);
780 value_range_t
*vr
= vr_value
[ver
];
783 *equiv
= BITMAP_ALLOC (NULL
);
784 bitmap_set_bit (*equiv
, ver
);
786 bitmap_ior_into (*equiv
, vr
->equiv
);
790 /* Return true if VR is ~[0, 0]. */
793 range_is_nonnull (value_range_t
*vr
)
795 return vr
->type
== VR_ANTI_RANGE
796 && integer_zerop (vr
->min
)
797 && integer_zerop (vr
->max
);
801 /* Return true if VR is [0, 0]. */
804 range_is_null (value_range_t
*vr
)
806 return vr
->type
== VR_RANGE
807 && integer_zerop (vr
->min
)
808 && integer_zerop (vr
->max
);
811 /* Return true if max and min of VR are INTEGER_CST. It's not necessary
815 range_int_cst_p (value_range_t
*vr
)
817 return (vr
->type
== VR_RANGE
818 && TREE_CODE (vr
->max
) == INTEGER_CST
819 && TREE_CODE (vr
->min
) == INTEGER_CST
820 && !TREE_OVERFLOW (vr
->max
)
821 && !TREE_OVERFLOW (vr
->min
));
824 /* Return true if VR is a INTEGER_CST singleton. */
827 range_int_cst_singleton_p (value_range_t
*vr
)
829 return (range_int_cst_p (vr
)
830 && tree_int_cst_equal (vr
->min
, vr
->max
));
833 /* Return true if value range VR involves at least one symbol. */
836 symbolic_range_p (value_range_t
*vr
)
838 return (!is_gimple_min_invariant (vr
->min
)
839 || !is_gimple_min_invariant (vr
->max
));
842 /* Return true if value range VR uses an overflow infinity. */
845 overflow_infinity_range_p (value_range_t
*vr
)
847 return (vr
->type
== VR_RANGE
848 && (is_overflow_infinity (vr
->min
)
849 || is_overflow_infinity (vr
->max
)));
852 /* Return false if we can not make a valid comparison based on VR;
853 this will be the case if it uses an overflow infinity and overflow
854 is not undefined (i.e., -fno-strict-overflow is in effect).
855 Otherwise return true, and set *STRICT_OVERFLOW_P to true if VR
856 uses an overflow infinity. */
859 usable_range_p (value_range_t
*vr
, bool *strict_overflow_p
)
861 gcc_assert (vr
->type
== VR_RANGE
);
862 if (is_overflow_infinity (vr
->min
))
864 *strict_overflow_p
= true;
865 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr
->min
)))
868 if (is_overflow_infinity (vr
->max
))
870 *strict_overflow_p
= true;
871 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr
->max
)))
878 /* Return true if the result of assignment STMT is know to be non-negative.
879 If the return value is based on the assumption that signed overflow is
880 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
881 *STRICT_OVERFLOW_P.*/
884 gimple_assign_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
886 enum tree_code code
= gimple_assign_rhs_code (stmt
);
887 switch (get_gimple_rhs_class (code
))
889 case GIMPLE_UNARY_RHS
:
890 return tree_unary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt
),
891 gimple_expr_type (stmt
),
892 gimple_assign_rhs1 (stmt
),
894 case GIMPLE_BINARY_RHS
:
895 return tree_binary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt
),
896 gimple_expr_type (stmt
),
897 gimple_assign_rhs1 (stmt
),
898 gimple_assign_rhs2 (stmt
),
900 case GIMPLE_TERNARY_RHS
:
902 case GIMPLE_SINGLE_RHS
:
903 return tree_single_nonnegative_warnv_p (gimple_assign_rhs1 (stmt
),
905 case GIMPLE_INVALID_RHS
:
912 /* Return true if return value of call STMT is know to be non-negative.
913 If the return value is based on the assumption that signed overflow is
914 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
915 *STRICT_OVERFLOW_P.*/
918 gimple_call_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
920 tree arg0
= gimple_call_num_args (stmt
) > 0 ?
921 gimple_call_arg (stmt
, 0) : NULL_TREE
;
922 tree arg1
= gimple_call_num_args (stmt
) > 1 ?
923 gimple_call_arg (stmt
, 1) : NULL_TREE
;
925 return tree_call_nonnegative_warnv_p (gimple_expr_type (stmt
),
926 gimple_call_fndecl (stmt
),
932 /* Return true if STMT is know to to compute a non-negative value.
933 If the return value is based on the assumption that signed overflow is
934 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
935 *STRICT_OVERFLOW_P.*/
938 gimple_stmt_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
940 switch (gimple_code (stmt
))
943 return gimple_assign_nonnegative_warnv_p (stmt
, strict_overflow_p
);
945 return gimple_call_nonnegative_warnv_p (stmt
, strict_overflow_p
);
951 /* Return true if the result of assignment STMT is know to be non-zero.
952 If the return value is based on the assumption that signed overflow is
953 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
954 *STRICT_OVERFLOW_P.*/
957 gimple_assign_nonzero_warnv_p (gimple stmt
, bool *strict_overflow_p
)
959 enum tree_code code
= gimple_assign_rhs_code (stmt
);
960 switch (get_gimple_rhs_class (code
))
962 case GIMPLE_UNARY_RHS
:
963 return tree_unary_nonzero_warnv_p (gimple_assign_rhs_code (stmt
),
964 gimple_expr_type (stmt
),
965 gimple_assign_rhs1 (stmt
),
967 case GIMPLE_BINARY_RHS
:
968 return tree_binary_nonzero_warnv_p (gimple_assign_rhs_code (stmt
),
969 gimple_expr_type (stmt
),
970 gimple_assign_rhs1 (stmt
),
971 gimple_assign_rhs2 (stmt
),
973 case GIMPLE_TERNARY_RHS
:
975 case GIMPLE_SINGLE_RHS
:
976 return tree_single_nonzero_warnv_p (gimple_assign_rhs1 (stmt
),
978 case GIMPLE_INVALID_RHS
:
985 /* Return true if STMT is know to to compute a non-zero value.
986 If the return value is based on the assumption that signed overflow is
987 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
988 *STRICT_OVERFLOW_P.*/
991 gimple_stmt_nonzero_warnv_p (gimple stmt
, bool *strict_overflow_p
)
993 switch (gimple_code (stmt
))
996 return gimple_assign_nonzero_warnv_p (stmt
, strict_overflow_p
);
998 return gimple_alloca_call_p (stmt
);
1004 /* Like tree_expr_nonzero_warnv_p, but this function uses value ranges
1008 vrp_stmt_computes_nonzero (gimple stmt
, bool *strict_overflow_p
)
1010 if (gimple_stmt_nonzero_warnv_p (stmt
, strict_overflow_p
))
1013 /* If we have an expression of the form &X->a, then the expression
1014 is nonnull if X is nonnull. */
1015 if (is_gimple_assign (stmt
)
1016 && gimple_assign_rhs_code (stmt
) == ADDR_EXPR
)
1018 tree expr
= gimple_assign_rhs1 (stmt
);
1019 tree base
= get_base_address (TREE_OPERAND (expr
, 0));
1021 if (base
!= NULL_TREE
1022 && TREE_CODE (base
) == MEM_REF
1023 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1025 value_range_t
*vr
= get_value_range (TREE_OPERAND (base
, 0));
1026 if (range_is_nonnull (vr
))
1034 /* Returns true if EXPR is a valid value (as expected by compare_values) --
1035 a gimple invariant, or SSA_NAME +- CST. */
1038 valid_value_p (tree expr
)
1040 if (TREE_CODE (expr
) == SSA_NAME
)
1043 if (TREE_CODE (expr
) == PLUS_EXPR
1044 || TREE_CODE (expr
) == MINUS_EXPR
)
1045 return (TREE_CODE (TREE_OPERAND (expr
, 0)) == SSA_NAME
1046 && TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
);
1048 return is_gimple_min_invariant (expr
);
1054 -2 if those are incomparable. */
1056 operand_less_p (tree val
, tree val2
)
1058 /* LT is folded faster than GE and others. Inline the common case. */
1059 if (TREE_CODE (val
) == INTEGER_CST
&& TREE_CODE (val2
) == INTEGER_CST
)
1061 if (TYPE_UNSIGNED (TREE_TYPE (val
)))
1062 return INT_CST_LT_UNSIGNED (val
, val2
);
1065 if (INT_CST_LT (val
, val2
))
1073 fold_defer_overflow_warnings ();
1075 tcmp
= fold_binary_to_constant (LT_EXPR
, boolean_type_node
, val
, val2
);
1077 fold_undefer_and_ignore_overflow_warnings ();
1080 || TREE_CODE (tcmp
) != INTEGER_CST
)
1083 if (!integer_zerop (tcmp
))
1087 /* val >= val2, not considering overflow infinity. */
1088 if (is_negative_overflow_infinity (val
))
1089 return is_negative_overflow_infinity (val2
) ? 0 : 1;
1090 else if (is_positive_overflow_infinity (val2
))
1091 return is_positive_overflow_infinity (val
) ? 0 : 1;
1096 /* Compare two values VAL1 and VAL2. Return
1098 -2 if VAL1 and VAL2 cannot be compared at compile-time,
1101 +1 if VAL1 > VAL2, and
1104 This is similar to tree_int_cst_compare but supports pointer values
1105 and values that cannot be compared at compile time.
1107 If STRICT_OVERFLOW_P is not NULL, then set *STRICT_OVERFLOW_P to
1108 true if the return value is only valid if we assume that signed
1109 overflow is undefined. */
1112 compare_values_warnv (tree val1
, tree val2
, bool *strict_overflow_p
)
1117 /* Below we rely on the fact that VAL1 and VAL2 are both pointers or
1119 gcc_assert (POINTER_TYPE_P (TREE_TYPE (val1
))
1120 == POINTER_TYPE_P (TREE_TYPE (val2
)));
1121 /* Convert the two values into the same type. This is needed because
1122 sizetype causes sign extension even for unsigned types. */
1123 val2
= fold_convert (TREE_TYPE (val1
), val2
);
1124 STRIP_USELESS_TYPE_CONVERSION (val2
);
1126 if ((TREE_CODE (val1
) == SSA_NAME
1127 || TREE_CODE (val1
) == PLUS_EXPR
1128 || TREE_CODE (val1
) == MINUS_EXPR
)
1129 && (TREE_CODE (val2
) == SSA_NAME
1130 || TREE_CODE (val2
) == PLUS_EXPR
1131 || TREE_CODE (val2
) == MINUS_EXPR
))
1133 tree n1
, c1
, n2
, c2
;
1134 enum tree_code code1
, code2
;
1136 /* If VAL1 and VAL2 are of the form 'NAME [+-] CST' or 'NAME',
1137 return -1 or +1 accordingly. If VAL1 and VAL2 don't use the
1138 same name, return -2. */
1139 if (TREE_CODE (val1
) == SSA_NAME
)
1147 code1
= TREE_CODE (val1
);
1148 n1
= TREE_OPERAND (val1
, 0);
1149 c1
= TREE_OPERAND (val1
, 1);
1150 if (tree_int_cst_sgn (c1
) == -1)
1152 if (is_negative_overflow_infinity (c1
))
1154 c1
= fold_unary_to_constant (NEGATE_EXPR
, TREE_TYPE (c1
), c1
);
1157 code1
= code1
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
;
1161 if (TREE_CODE (val2
) == SSA_NAME
)
1169 code2
= TREE_CODE (val2
);
1170 n2
= TREE_OPERAND (val2
, 0);
1171 c2
= TREE_OPERAND (val2
, 1);
1172 if (tree_int_cst_sgn (c2
) == -1)
1174 if (is_negative_overflow_infinity (c2
))
1176 c2
= fold_unary_to_constant (NEGATE_EXPR
, TREE_TYPE (c2
), c2
);
1179 code2
= code2
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
;
1183 /* Both values must use the same name. */
1187 if (code1
== SSA_NAME
1188 && code2
== SSA_NAME
)
1192 /* If overflow is defined we cannot simplify more. */
1193 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1
)))
1196 if (strict_overflow_p
!= NULL
1197 && (code1
== SSA_NAME
|| !TREE_NO_WARNING (val1
))
1198 && (code2
== SSA_NAME
|| !TREE_NO_WARNING (val2
)))
1199 *strict_overflow_p
= true;
1201 if (code1
== SSA_NAME
)
1203 if (code2
== PLUS_EXPR
)
1204 /* NAME < NAME + CST */
1206 else if (code2
== MINUS_EXPR
)
1207 /* NAME > NAME - CST */
1210 else if (code1
== PLUS_EXPR
)
1212 if (code2
== SSA_NAME
)
1213 /* NAME + CST > NAME */
1215 else if (code2
== PLUS_EXPR
)
1216 /* NAME + CST1 > NAME + CST2, if CST1 > CST2 */
1217 return compare_values_warnv (c1
, c2
, strict_overflow_p
);
1218 else if (code2
== MINUS_EXPR
)
1219 /* NAME + CST1 > NAME - CST2 */
1222 else if (code1
== MINUS_EXPR
)
1224 if (code2
== SSA_NAME
)
1225 /* NAME - CST < NAME */
1227 else if (code2
== PLUS_EXPR
)
1228 /* NAME - CST1 < NAME + CST2 */
1230 else if (code2
== MINUS_EXPR
)
1231 /* NAME - CST1 > NAME - CST2, if CST1 < CST2. Notice that
1232 C1 and C2 are swapped in the call to compare_values. */
1233 return compare_values_warnv (c2
, c1
, strict_overflow_p
);
1239 /* We cannot compare non-constants. */
1240 if (!is_gimple_min_invariant (val1
) || !is_gimple_min_invariant (val2
))
1243 if (!POINTER_TYPE_P (TREE_TYPE (val1
)))
1245 /* We cannot compare overflowed values, except for overflow
1247 if (TREE_OVERFLOW (val1
) || TREE_OVERFLOW (val2
))
1249 if (strict_overflow_p
!= NULL
)
1250 *strict_overflow_p
= true;
1251 if (is_negative_overflow_infinity (val1
))
1252 return is_negative_overflow_infinity (val2
) ? 0 : -1;
1253 else if (is_negative_overflow_infinity (val2
))
1255 else if (is_positive_overflow_infinity (val1
))
1256 return is_positive_overflow_infinity (val2
) ? 0 : 1;
1257 else if (is_positive_overflow_infinity (val2
))
1262 return tree_int_cst_compare (val1
, val2
);
1268 /* First see if VAL1 and VAL2 are not the same. */
1269 if (val1
== val2
|| operand_equal_p (val1
, val2
, 0))
1272 /* If VAL1 is a lower address than VAL2, return -1. */
1273 if (operand_less_p (val1
, val2
) == 1)
1276 /* If VAL1 is a higher address than VAL2, return +1. */
1277 if (operand_less_p (val2
, val1
) == 1)
1280 /* If VAL1 is different than VAL2, return +2.
1281 For integer constants we either have already returned -1 or 1
1282 or they are equivalent. We still might succeed in proving
1283 something about non-trivial operands. */
1284 if (TREE_CODE (val1
) != INTEGER_CST
1285 || TREE_CODE (val2
) != INTEGER_CST
)
1287 t
= fold_binary_to_constant (NE_EXPR
, boolean_type_node
, val1
, val2
);
1288 if (t
&& integer_onep (t
))
1296 /* Compare values like compare_values_warnv, but treat comparisons of
1297 nonconstants which rely on undefined overflow as incomparable. */
1300 compare_values (tree val1
, tree val2
)
1306 ret
= compare_values_warnv (val1
, val2
, &sop
);
1308 && (!is_gimple_min_invariant (val1
) || !is_gimple_min_invariant (val2
)))
1314 /* Return 1 if VAL is inside value range VR (VR->MIN <= VAL <= VR->MAX),
1315 0 if VAL is not inside VR,
1316 -2 if we cannot tell either way.
1318 FIXME, the current semantics of this functions are a bit quirky
1319 when taken in the context of VRP. In here we do not care
1320 about VR's type. If VR is the anti-range ~[3, 5] the call
1321 value_inside_range (4, VR) will return 1.
1323 This is counter-intuitive in a strict sense, but the callers
1324 currently expect this. They are calling the function
1325 merely to determine whether VR->MIN <= VAL <= VR->MAX. The
1326 callers are applying the VR_RANGE/VR_ANTI_RANGE semantics
1329 This also applies to value_ranges_intersect_p and
1330 range_includes_zero_p. The semantics of VR_RANGE and
1331 VR_ANTI_RANGE should be encoded here, but that also means
1332 adapting the users of these functions to the new semantics.
1334 Benchmark compile/20001226-1.c compilation time after changing this
1338 value_inside_range (tree val
, value_range_t
* vr
)
1342 cmp1
= operand_less_p (val
, vr
->min
);
1348 cmp2
= operand_less_p (vr
->max
, val
);
1356 /* Return true if value ranges VR0 and VR1 have a non-empty
1359 Benchmark compile/20001226-1.c compilation time after changing this
1364 value_ranges_intersect_p (value_range_t
*vr0
, value_range_t
*vr1
)
1366 /* The value ranges do not intersect if the maximum of the first range is
1367 less than the minimum of the second range or vice versa.
1368 When those relations are unknown, we can't do any better. */
1369 if (operand_less_p (vr0
->max
, vr1
->min
) != 0)
1371 if (operand_less_p (vr1
->max
, vr0
->min
) != 0)
1377 /* Return true if VR includes the value zero, false otherwise. FIXME,
1378 currently this will return false for an anti-range like ~[-4, 3].
1379 This will be wrong when the semantics of value_inside_range are
1380 modified (currently the users of this function expect these
1384 range_includes_zero_p (value_range_t
*vr
)
1388 gcc_assert (vr
->type
!= VR_UNDEFINED
1389 && vr
->type
!= VR_VARYING
1390 && !symbolic_range_p (vr
));
1392 zero
= build_int_cst (TREE_TYPE (vr
->min
), 0);
1393 return (value_inside_range (zero
, vr
) == 1);
1396 /* Return true if *VR is know to only contain nonnegative values. */
1399 value_range_nonnegative_p (value_range_t
*vr
)
1401 if (vr
->type
== VR_RANGE
)
1403 int result
= compare_values (vr
->min
, integer_zero_node
);
1404 return (result
== 0 || result
== 1);
1406 else if (vr
->type
== VR_ANTI_RANGE
)
1408 int result
= compare_values (vr
->max
, integer_zero_node
);
1409 return result
== -1;
1415 /* Return true if T, an SSA_NAME, is known to be nonnegative. Return
1416 false otherwise or if no value range information is available. */
1419 ssa_name_nonnegative_p (const_tree t
)
1421 value_range_t
*vr
= get_value_range (t
);
1423 if (INTEGRAL_TYPE_P (t
)
1424 && TYPE_UNSIGNED (t
))
1430 return value_range_nonnegative_p (vr
);
1433 /* If *VR has a value rante that is a single constant value return that,
1434 otherwise return NULL_TREE. */
1437 value_range_constant_singleton (value_range_t
*vr
)
1439 if (vr
->type
== VR_RANGE
1440 && operand_equal_p (vr
->min
, vr
->max
, 0)
1441 && is_gimple_min_invariant (vr
->min
))
1447 /* If OP has a value range with a single constant value return that,
1448 otherwise return NULL_TREE. This returns OP itself if OP is a
1452 op_with_constant_singleton_value_range (tree op
)
1454 if (is_gimple_min_invariant (op
))
1457 if (TREE_CODE (op
) != SSA_NAME
)
1460 return value_range_constant_singleton (get_value_range (op
));
1463 /* Return true if op is in a boolean [0, 1] value-range. */
1466 op_with_boolean_value_range_p (tree op
)
1470 if (TYPE_PRECISION (TREE_TYPE (op
)) == 1)
1473 if (integer_zerop (op
)
1474 || integer_onep (op
))
1477 if (TREE_CODE (op
) != SSA_NAME
)
1480 vr
= get_value_range (op
);
1481 return (vr
->type
== VR_RANGE
1482 && integer_zerop (vr
->min
)
1483 && integer_onep (vr
->max
));
1486 /* Extract value range information from an ASSERT_EXPR EXPR and store
1490 extract_range_from_assert (value_range_t
*vr_p
, tree expr
)
1492 tree var
, cond
, limit
, min
, max
, type
;
1493 value_range_t
*var_vr
, *limit_vr
;
1494 enum tree_code cond_code
;
1496 var
= ASSERT_EXPR_VAR (expr
);
1497 cond
= ASSERT_EXPR_COND (expr
);
1499 gcc_assert (COMPARISON_CLASS_P (cond
));
1501 /* Find VAR in the ASSERT_EXPR conditional. */
1502 if (var
== TREE_OPERAND (cond
, 0)
1503 || TREE_CODE (TREE_OPERAND (cond
, 0)) == PLUS_EXPR
1504 || TREE_CODE (TREE_OPERAND (cond
, 0)) == NOP_EXPR
)
1506 /* If the predicate is of the form VAR COMP LIMIT, then we just
1507 take LIMIT from the RHS and use the same comparison code. */
1508 cond_code
= TREE_CODE (cond
);
1509 limit
= TREE_OPERAND (cond
, 1);
1510 cond
= TREE_OPERAND (cond
, 0);
1514 /* If the predicate is of the form LIMIT COMP VAR, then we need
1515 to flip around the comparison code to create the proper range
1517 cond_code
= swap_tree_comparison (TREE_CODE (cond
));
1518 limit
= TREE_OPERAND (cond
, 0);
1519 cond
= TREE_OPERAND (cond
, 1);
1522 limit
= avoid_overflow_infinity (limit
);
1524 type
= TREE_TYPE (limit
);
1525 gcc_assert (limit
!= var
);
1527 /* For pointer arithmetic, we only keep track of pointer equality
1529 if (POINTER_TYPE_P (type
) && cond_code
!= NE_EXPR
&& cond_code
!= EQ_EXPR
)
1531 set_value_range_to_varying (vr_p
);
1535 /* If LIMIT is another SSA name and LIMIT has a range of its own,
1536 try to use LIMIT's range to avoid creating symbolic ranges
1538 limit_vr
= (TREE_CODE (limit
) == SSA_NAME
) ? get_value_range (limit
) : NULL
;
1540 /* LIMIT's range is only interesting if it has any useful information. */
1542 && (limit_vr
->type
== VR_UNDEFINED
1543 || limit_vr
->type
== VR_VARYING
1544 || symbolic_range_p (limit_vr
)))
1547 /* Initially, the new range has the same set of equivalences of
1548 VAR's range. This will be revised before returning the final
1549 value. Since assertions may be chained via mutually exclusive
1550 predicates, we will need to trim the set of equivalences before
1552 gcc_assert (vr_p
->equiv
== NULL
);
1553 add_equivalence (&vr_p
->equiv
, var
);
1555 /* Extract a new range based on the asserted comparison for VAR and
1556 LIMIT's value range. Notice that if LIMIT has an anti-range, we
1557 will only use it for equality comparisons (EQ_EXPR). For any
1558 other kind of assertion, we cannot derive a range from LIMIT's
1559 anti-range that can be used to describe the new range. For
1560 instance, ASSERT_EXPR <x_2, x_2 <= b_4>. If b_4 is ~[2, 10],
1561 then b_4 takes on the ranges [-INF, 1] and [11, +INF]. There is
1562 no single range for x_2 that could describe LE_EXPR, so we might
1563 as well build the range [b_4, +INF] for it.
1564 One special case we handle is extracting a range from a
1565 range test encoded as (unsigned)var + CST <= limit. */
1566 if (TREE_CODE (cond
) == NOP_EXPR
1567 || TREE_CODE (cond
) == PLUS_EXPR
)
1569 if (TREE_CODE (cond
) == PLUS_EXPR
)
1571 min
= fold_build1 (NEGATE_EXPR
, TREE_TYPE (TREE_OPERAND (cond
, 1)),
1572 TREE_OPERAND (cond
, 1));
1573 max
= int_const_binop (PLUS_EXPR
, limit
, min
);
1574 cond
= TREE_OPERAND (cond
, 0);
1578 min
= build_int_cst (TREE_TYPE (var
), 0);
1582 /* Make sure to not set TREE_OVERFLOW on the final type
1583 conversion. We are willingly interpreting large positive
1584 unsigned values as negative singed values here. */
1585 min
= force_fit_type_double (TREE_TYPE (var
), tree_to_double_int (min
),
1587 max
= force_fit_type_double (TREE_TYPE (var
), tree_to_double_int (max
),
1590 /* We can transform a max, min range to an anti-range or
1591 vice-versa. Use set_and_canonicalize_value_range which does
1593 if (cond_code
== LE_EXPR
)
1594 set_and_canonicalize_value_range (vr_p
, VR_RANGE
,
1595 min
, max
, vr_p
->equiv
);
1596 else if (cond_code
== GT_EXPR
)
1597 set_and_canonicalize_value_range (vr_p
, VR_ANTI_RANGE
,
1598 min
, max
, vr_p
->equiv
);
1602 else if (cond_code
== EQ_EXPR
)
1604 enum value_range_type range_type
;
1608 range_type
= limit_vr
->type
;
1609 min
= limit_vr
->min
;
1610 max
= limit_vr
->max
;
1614 range_type
= VR_RANGE
;
1619 set_value_range (vr_p
, range_type
, min
, max
, vr_p
->equiv
);
1621 /* When asserting the equality VAR == LIMIT and LIMIT is another
1622 SSA name, the new range will also inherit the equivalence set
1624 if (TREE_CODE (limit
) == SSA_NAME
)
1625 add_equivalence (&vr_p
->equiv
, limit
);
1627 else if (cond_code
== NE_EXPR
)
1629 /* As described above, when LIMIT's range is an anti-range and
1630 this assertion is an inequality (NE_EXPR), then we cannot
1631 derive anything from the anti-range. For instance, if
1632 LIMIT's range was ~[0, 0], the assertion 'VAR != LIMIT' does
1633 not imply that VAR's range is [0, 0]. So, in the case of
1634 anti-ranges, we just assert the inequality using LIMIT and
1637 If LIMIT_VR is a range, we can only use it to build a new
1638 anti-range if LIMIT_VR is a single-valued range. For
1639 instance, if LIMIT_VR is [0, 1], the predicate
1640 VAR != [0, 1] does not mean that VAR's range is ~[0, 1].
1641 Rather, it means that for value 0 VAR should be ~[0, 0]
1642 and for value 1, VAR should be ~[1, 1]. We cannot
1643 represent these ranges.
1645 The only situation in which we can build a valid
1646 anti-range is when LIMIT_VR is a single-valued range
1647 (i.e., LIMIT_VR->MIN == LIMIT_VR->MAX). In that case,
1648 build the anti-range ~[LIMIT_VR->MIN, LIMIT_VR->MAX]. */
1650 && limit_vr
->type
== VR_RANGE
1651 && compare_values (limit_vr
->min
, limit_vr
->max
) == 0)
1653 min
= limit_vr
->min
;
1654 max
= limit_vr
->max
;
1658 /* In any other case, we cannot use LIMIT's range to build a
1659 valid anti-range. */
1663 /* If MIN and MAX cover the whole range for their type, then
1664 just use the original LIMIT. */
1665 if (INTEGRAL_TYPE_P (type
)
1666 && vrp_val_is_min (min
)
1667 && vrp_val_is_max (max
))
1670 set_value_range (vr_p
, VR_ANTI_RANGE
, min
, max
, vr_p
->equiv
);
1672 else if (cond_code
== LE_EXPR
|| cond_code
== LT_EXPR
)
1674 min
= TYPE_MIN_VALUE (type
);
1676 if (limit_vr
== NULL
|| limit_vr
->type
== VR_ANTI_RANGE
)
1680 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1681 range [MIN, N2] for LE_EXPR and [MIN, N2 - 1] for
1683 max
= limit_vr
->max
;
1686 /* If the maximum value forces us to be out of bounds, simply punt.
1687 It would be pointless to try and do anything more since this
1688 all should be optimized away above us. */
1689 if ((cond_code
== LT_EXPR
1690 && compare_values (max
, min
) == 0)
1691 || (CONSTANT_CLASS_P (max
) && TREE_OVERFLOW (max
)))
1692 set_value_range_to_varying (vr_p
);
1695 /* For LT_EXPR, we create the range [MIN, MAX - 1]. */
1696 if (cond_code
== LT_EXPR
)
1698 tree one
= build_int_cst (type
, 1);
1699 max
= fold_build2 (MINUS_EXPR
, type
, max
, one
);
1701 TREE_NO_WARNING (max
) = 1;
1704 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1707 else if (cond_code
== GE_EXPR
|| cond_code
== GT_EXPR
)
1709 max
= TYPE_MAX_VALUE (type
);
1711 if (limit_vr
== NULL
|| limit_vr
->type
== VR_ANTI_RANGE
)
1715 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1716 range [N1, MAX] for GE_EXPR and [N1 + 1, MAX] for
1718 min
= limit_vr
->min
;
1721 /* If the minimum value forces us to be out of bounds, simply punt.
1722 It would be pointless to try and do anything more since this
1723 all should be optimized away above us. */
1724 if ((cond_code
== GT_EXPR
1725 && compare_values (min
, max
) == 0)
1726 || (CONSTANT_CLASS_P (min
) && TREE_OVERFLOW (min
)))
1727 set_value_range_to_varying (vr_p
);
1730 /* For GT_EXPR, we create the range [MIN + 1, MAX]. */
1731 if (cond_code
== GT_EXPR
)
1733 tree one
= build_int_cst (type
, 1);
1734 min
= fold_build2 (PLUS_EXPR
, type
, min
, one
);
1736 TREE_NO_WARNING (min
) = 1;
1739 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1745 /* If VAR already had a known range, it may happen that the new
1746 range we have computed and VAR's range are not compatible. For
1750 p_6 = ASSERT_EXPR <p_5, p_5 == NULL>;
1752 p_8 = ASSERT_EXPR <p_6, p_6 != NULL>;
1754 While the above comes from a faulty program, it will cause an ICE
1755 later because p_8 and p_6 will have incompatible ranges and at
1756 the same time will be considered equivalent. A similar situation
1760 i_6 = ASSERT_EXPR <i_5, i_5 > 10>;
1762 i_7 = ASSERT_EXPR <i_6, i_6 < 5>;
1764 Again i_6 and i_7 will have incompatible ranges. It would be
1765 pointless to try and do anything with i_7's range because
1766 anything dominated by 'if (i_5 < 5)' will be optimized away.
1767 Note, due to the wa in which simulation proceeds, the statement
1768 i_7 = ASSERT_EXPR <...> we would never be visited because the
1769 conditional 'if (i_5 < 5)' always evaluates to false. However,
1770 this extra check does not hurt and may protect against future
1771 changes to VRP that may get into a situation similar to the
1772 NULL pointer dereference example.
1774 Note that these compatibility tests are only needed when dealing
1775 with ranges or a mix of range and anti-range. If VAR_VR and VR_P
1776 are both anti-ranges, they will always be compatible, because two
1777 anti-ranges will always have a non-empty intersection. */
1779 var_vr
= get_value_range (var
);
1781 /* We may need to make adjustments when VR_P and VAR_VR are numeric
1782 ranges or anti-ranges. */
1783 if (vr_p
->type
== VR_VARYING
1784 || vr_p
->type
== VR_UNDEFINED
1785 || var_vr
->type
== VR_VARYING
1786 || var_vr
->type
== VR_UNDEFINED
1787 || symbolic_range_p (vr_p
)
1788 || symbolic_range_p (var_vr
))
1791 if (var_vr
->type
== VR_RANGE
&& vr_p
->type
== VR_RANGE
)
1793 /* If the two ranges have a non-empty intersection, we can
1794 refine the resulting range. Since the assert expression
1795 creates an equivalency and at the same time it asserts a
1796 predicate, we can take the intersection of the two ranges to
1797 get better precision. */
1798 if (value_ranges_intersect_p (var_vr
, vr_p
))
1800 /* Use the larger of the two minimums. */
1801 if (compare_values (vr_p
->min
, var_vr
->min
) == -1)
1806 /* Use the smaller of the two maximums. */
1807 if (compare_values (vr_p
->max
, var_vr
->max
) == 1)
1812 set_value_range (vr_p
, vr_p
->type
, min
, max
, vr_p
->equiv
);
1816 /* The two ranges do not intersect, set the new range to
1817 VARYING, because we will not be able to do anything
1818 meaningful with it. */
1819 set_value_range_to_varying (vr_p
);
1822 else if ((var_vr
->type
== VR_RANGE
&& vr_p
->type
== VR_ANTI_RANGE
)
1823 || (var_vr
->type
== VR_ANTI_RANGE
&& vr_p
->type
== VR_RANGE
))
1825 /* A range and an anti-range will cancel each other only if
1826 their ends are the same. For instance, in the example above,
1827 p_8's range ~[0, 0] and p_6's range [0, 0] are incompatible,
1828 so VR_P should be set to VR_VARYING. */
1829 if (compare_values (var_vr
->min
, vr_p
->min
) == 0
1830 && compare_values (var_vr
->max
, vr_p
->max
) == 0)
1831 set_value_range_to_varying (vr_p
);
1834 tree min
, max
, anti_min
, anti_max
, real_min
, real_max
;
1837 /* We want to compute the logical AND of the two ranges;
1838 there are three cases to consider.
1841 1. The VR_ANTI_RANGE range is completely within the
1842 VR_RANGE and the endpoints of the ranges are
1843 different. In that case the resulting range
1844 should be whichever range is more precise.
1845 Typically that will be the VR_RANGE.
1847 2. The VR_ANTI_RANGE is completely disjoint from
1848 the VR_RANGE. In this case the resulting range
1849 should be the VR_RANGE.
1851 3. There is some overlap between the VR_ANTI_RANGE
1854 3a. If the high limit of the VR_ANTI_RANGE resides
1855 within the VR_RANGE, then the result is a new
1856 VR_RANGE starting at the high limit of the
1857 VR_ANTI_RANGE + 1 and extending to the
1858 high limit of the original VR_RANGE.
1860 3b. If the low limit of the VR_ANTI_RANGE resides
1861 within the VR_RANGE, then the result is a new
1862 VR_RANGE starting at the low limit of the original
1863 VR_RANGE and extending to the low limit of the
1864 VR_ANTI_RANGE - 1. */
1865 if (vr_p
->type
== VR_ANTI_RANGE
)
1867 anti_min
= vr_p
->min
;
1868 anti_max
= vr_p
->max
;
1869 real_min
= var_vr
->min
;
1870 real_max
= var_vr
->max
;
1874 anti_min
= var_vr
->min
;
1875 anti_max
= var_vr
->max
;
1876 real_min
= vr_p
->min
;
1877 real_max
= vr_p
->max
;
1881 /* Case 1, VR_ANTI_RANGE completely within VR_RANGE,
1882 not including any endpoints. */
1883 if (compare_values (anti_max
, real_max
) == -1
1884 && compare_values (anti_min
, real_min
) == 1)
1886 /* If the range is covering the whole valid range of
1887 the type keep the anti-range. */
1888 if (!vrp_val_is_min (real_min
)
1889 || !vrp_val_is_max (real_max
))
1890 set_value_range (vr_p
, VR_RANGE
, real_min
,
1891 real_max
, vr_p
->equiv
);
1893 /* Case 2, VR_ANTI_RANGE completely disjoint from
1895 else if (compare_values (anti_min
, real_max
) == 1
1896 || compare_values (anti_max
, real_min
) == -1)
1898 set_value_range (vr_p
, VR_RANGE
, real_min
,
1899 real_max
, vr_p
->equiv
);
1901 /* Case 3a, the anti-range extends into the low
1902 part of the real range. Thus creating a new
1903 low for the real range. */
1904 else if (((cmp
= compare_values (anti_max
, real_min
)) == 1
1906 && compare_values (anti_max
, real_max
) == -1)
1908 gcc_assert (!is_positive_overflow_infinity (anti_max
));
1909 if (needs_overflow_infinity (TREE_TYPE (anti_max
))
1910 && vrp_val_is_max (anti_max
))
1912 if (!supports_overflow_infinity (TREE_TYPE (var_vr
->min
)))
1914 set_value_range_to_varying (vr_p
);
1917 min
= positive_overflow_infinity (TREE_TYPE (var_vr
->min
));
1919 else if (!POINTER_TYPE_P (TREE_TYPE (var_vr
->min
)))
1920 min
= fold_build2 (PLUS_EXPR
, TREE_TYPE (var_vr
->min
),
1922 build_int_cst (TREE_TYPE (var_vr
->min
), 1));
1924 min
= fold_build_pointer_plus_hwi (anti_max
, 1);
1926 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1928 /* Case 3b, the anti-range extends into the high
1929 part of the real range. Thus creating a new
1930 higher for the real range. */
1931 else if (compare_values (anti_min
, real_min
) == 1
1932 && ((cmp
= compare_values (anti_min
, real_max
)) == -1
1935 gcc_assert (!is_negative_overflow_infinity (anti_min
));
1936 if (needs_overflow_infinity (TREE_TYPE (anti_min
))
1937 && vrp_val_is_min (anti_min
))
1939 if (!supports_overflow_infinity (TREE_TYPE (var_vr
->min
)))
1941 set_value_range_to_varying (vr_p
);
1944 max
= negative_overflow_infinity (TREE_TYPE (var_vr
->min
));
1946 else if (!POINTER_TYPE_P (TREE_TYPE (var_vr
->min
)))
1947 max
= fold_build2 (MINUS_EXPR
, TREE_TYPE (var_vr
->min
),
1949 build_int_cst (TREE_TYPE (var_vr
->min
), 1));
1951 max
= fold_build_pointer_plus_hwi (anti_min
, -1);
1953 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1960 /* Extract range information from SSA name VAR and store it in VR. If
1961 VAR has an interesting range, use it. Otherwise, create the
1962 range [VAR, VAR] and return it. This is useful in situations where
1963 we may have conditionals testing values of VARYING names. For
1970 Even if y_5 is deemed VARYING, we can determine that x_3 > y_5 is
1974 extract_range_from_ssa_name (value_range_t
*vr
, tree var
)
1976 value_range_t
*var_vr
= get_value_range (var
);
1978 if (var_vr
->type
!= VR_UNDEFINED
&& var_vr
->type
!= VR_VARYING
)
1979 copy_value_range (vr
, var_vr
);
1981 set_value_range (vr
, VR_RANGE
, var
, var
, NULL
);
1983 add_equivalence (&vr
->equiv
, var
);
1987 /* Wrapper around int_const_binop. If the operation overflows and we
1988 are not using wrapping arithmetic, then adjust the result to be
1989 -INF or +INF depending on CODE, VAL1 and VAL2. This can return
1990 NULL_TREE if we need to use an overflow infinity representation but
1991 the type does not support it. */
1994 vrp_int_const_binop (enum tree_code code
, tree val1
, tree val2
)
1998 res
= int_const_binop (code
, val1
, val2
);
2000 /* If we are using unsigned arithmetic, operate symbolically
2001 on -INF and +INF as int_const_binop only handles signed overflow. */
2002 if (TYPE_UNSIGNED (TREE_TYPE (val1
)))
2004 int checkz
= compare_values (res
, val1
);
2005 bool overflow
= false;
2007 /* Ensure that res = val1 [+*] val2 >= val1
2008 or that res = val1 - val2 <= val1. */
2009 if ((code
== PLUS_EXPR
2010 && !(checkz
== 1 || checkz
== 0))
2011 || (code
== MINUS_EXPR
2012 && !(checkz
== 0 || checkz
== -1)))
2016 /* Checking for multiplication overflow is done by dividing the
2017 output of the multiplication by the first input of the
2018 multiplication. If the result of that division operation is
2019 not equal to the second input of the multiplication, then the
2020 multiplication overflowed. */
2021 else if (code
== MULT_EXPR
&& !integer_zerop (val1
))
2023 tree tmp
= int_const_binop (TRUNC_DIV_EXPR
,
2026 int check
= compare_values (tmp
, val2
);
2034 res
= copy_node (res
);
2035 TREE_OVERFLOW (res
) = 1;
2039 else if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (val1
)))
2040 /* If the singed operation wraps then int_const_binop has done
2041 everything we want. */
2043 else if ((TREE_OVERFLOW (res
)
2044 && !TREE_OVERFLOW (val1
)
2045 && !TREE_OVERFLOW (val2
))
2046 || is_overflow_infinity (val1
)
2047 || is_overflow_infinity (val2
))
2049 /* If the operation overflowed but neither VAL1 nor VAL2 are
2050 overflown, return -INF or +INF depending on the operation
2051 and the combination of signs of the operands. */
2052 int sgn1
= tree_int_cst_sgn (val1
);
2053 int sgn2
= tree_int_cst_sgn (val2
);
2055 if (needs_overflow_infinity (TREE_TYPE (res
))
2056 && !supports_overflow_infinity (TREE_TYPE (res
)))
2059 /* We have to punt on adding infinities of different signs,
2060 since we can't tell what the sign of the result should be.
2061 Likewise for subtracting infinities of the same sign. */
2062 if (((code
== PLUS_EXPR
&& sgn1
!= sgn2
)
2063 || (code
== MINUS_EXPR
&& sgn1
== sgn2
))
2064 && is_overflow_infinity (val1
)
2065 && is_overflow_infinity (val2
))
2068 /* Don't try to handle division or shifting of infinities. */
2069 if ((code
== TRUNC_DIV_EXPR
2070 || code
== FLOOR_DIV_EXPR
2071 || code
== CEIL_DIV_EXPR
2072 || code
== EXACT_DIV_EXPR
2073 || code
== ROUND_DIV_EXPR
2074 || code
== RSHIFT_EXPR
)
2075 && (is_overflow_infinity (val1
)
2076 || is_overflow_infinity (val2
)))
2079 /* Notice that we only need to handle the restricted set of
2080 operations handled by extract_range_from_binary_expr.
2081 Among them, only multiplication, addition and subtraction
2082 can yield overflow without overflown operands because we
2083 are working with integral types only... except in the
2084 case VAL1 = -INF and VAL2 = -1 which overflows to +INF
2085 for division too. */
2087 /* For multiplication, the sign of the overflow is given
2088 by the comparison of the signs of the operands. */
2089 if ((code
== MULT_EXPR
&& sgn1
== sgn2
)
2090 /* For addition, the operands must be of the same sign
2091 to yield an overflow. Its sign is therefore that
2092 of one of the operands, for example the first. For
2093 infinite operands X + -INF is negative, not positive. */
2094 || (code
== PLUS_EXPR
2096 ? !is_negative_overflow_infinity (val2
)
2097 : is_positive_overflow_infinity (val2
)))
2098 /* For subtraction, non-infinite operands must be of
2099 different signs to yield an overflow. Its sign is
2100 therefore that of the first operand or the opposite of
2101 that of the second operand. A first operand of 0 counts
2102 as positive here, for the corner case 0 - (-INF), which
2103 overflows, but must yield +INF. For infinite operands 0
2104 - INF is negative, not positive. */
2105 || (code
== MINUS_EXPR
2107 ? !is_positive_overflow_infinity (val2
)
2108 : is_negative_overflow_infinity (val2
)))
2109 /* We only get in here with positive shift count, so the
2110 overflow direction is the same as the sign of val1.
2111 Actually rshift does not overflow at all, but we only
2112 handle the case of shifting overflowed -INF and +INF. */
2113 || (code
== RSHIFT_EXPR
2115 /* For division, the only case is -INF / -1 = +INF. */
2116 || code
== TRUNC_DIV_EXPR
2117 || code
== FLOOR_DIV_EXPR
2118 || code
== CEIL_DIV_EXPR
2119 || code
== EXACT_DIV_EXPR
2120 || code
== ROUND_DIV_EXPR
)
2121 return (needs_overflow_infinity (TREE_TYPE (res
))
2122 ? positive_overflow_infinity (TREE_TYPE (res
))
2123 : TYPE_MAX_VALUE (TREE_TYPE (res
)));
2125 return (needs_overflow_infinity (TREE_TYPE (res
))
2126 ? negative_overflow_infinity (TREE_TYPE (res
))
2127 : TYPE_MIN_VALUE (TREE_TYPE (res
)));
2134 /* For range VR compute two double_int bitmasks. In *MAY_BE_NONZERO
2135 bitmask if some bit is unset, it means for all numbers in the range
2136 the bit is 0, otherwise it might be 0 or 1. In *MUST_BE_NONZERO
2137 bitmask if some bit is set, it means for all numbers in the range
2138 the bit is 1, otherwise it might be 0 or 1. */
2141 zero_nonzero_bits_from_vr (value_range_t
*vr
,
2142 double_int
*may_be_nonzero
,
2143 double_int
*must_be_nonzero
)
2145 *may_be_nonzero
= double_int_minus_one
;
2146 *must_be_nonzero
= double_int_zero
;
2147 if (!range_int_cst_p (vr
))
2150 if (range_int_cst_singleton_p (vr
))
2152 *may_be_nonzero
= tree_to_double_int (vr
->min
);
2153 *must_be_nonzero
= *may_be_nonzero
;
2155 else if (tree_int_cst_sgn (vr
->min
) >= 0
2156 || tree_int_cst_sgn (vr
->max
) < 0)
2158 double_int dmin
= tree_to_double_int (vr
->min
);
2159 double_int dmax
= tree_to_double_int (vr
->max
);
2160 double_int xor_mask
= double_int_xor (dmin
, dmax
);
2161 *may_be_nonzero
= double_int_ior (dmin
, dmax
);
2162 *must_be_nonzero
= double_int_and (dmin
, dmax
);
2163 if (xor_mask
.high
!= 0)
2165 unsigned HOST_WIDE_INT mask
2166 = ((unsigned HOST_WIDE_INT
) 1
2167 << floor_log2 (xor_mask
.high
)) - 1;
2168 may_be_nonzero
->low
= ALL_ONES
;
2169 may_be_nonzero
->high
|= mask
;
2170 must_be_nonzero
->low
= 0;
2171 must_be_nonzero
->high
&= ~mask
;
2173 else if (xor_mask
.low
!= 0)
2175 unsigned HOST_WIDE_INT mask
2176 = ((unsigned HOST_WIDE_INT
) 1
2177 << floor_log2 (xor_mask
.low
)) - 1;
2178 may_be_nonzero
->low
|= mask
;
2179 must_be_nonzero
->low
&= ~mask
;
2187 /* Extract range information from a binary operation CODE based on
2188 the ranges of each of its operands, *VR0 and *VR1 with resulting
2189 type EXPR_TYPE. The resulting range is stored in *VR. */
2192 extract_range_from_binary_expr_1 (value_range_t
*vr
,
2193 enum tree_code code
, tree expr_type
,
2194 value_range_t
*vr0_
, value_range_t
*vr1_
)
2196 value_range_t vr0
= *vr0_
, vr1
= *vr1_
;
2197 enum value_range_type type
;
2201 /* Not all binary expressions can be applied to ranges in a
2202 meaningful way. Handle only arithmetic operations. */
2203 if (code
!= PLUS_EXPR
2204 && code
!= MINUS_EXPR
2205 && code
!= POINTER_PLUS_EXPR
2206 && code
!= MULT_EXPR
2207 && code
!= TRUNC_DIV_EXPR
2208 && code
!= FLOOR_DIV_EXPR
2209 && code
!= CEIL_DIV_EXPR
2210 && code
!= EXACT_DIV_EXPR
2211 && code
!= ROUND_DIV_EXPR
2212 && code
!= TRUNC_MOD_EXPR
2213 && code
!= RSHIFT_EXPR
2216 && code
!= BIT_AND_EXPR
2217 && code
!= BIT_IOR_EXPR
2218 && code
!= BIT_XOR_EXPR
)
2220 set_value_range_to_varying (vr
);
2224 /* If both ranges are UNDEFINED, so is the result. */
2225 if (vr0
.type
== VR_UNDEFINED
&& vr1
.type
== VR_UNDEFINED
)
2227 set_value_range_to_undefined (vr
);
2230 /* If one of the ranges is UNDEFINED drop it to VARYING for the following
2231 code. At some point we may want to special-case operations that
2232 have UNDEFINED result for all or some value-ranges of the not UNDEFINED
2234 else if (vr0
.type
== VR_UNDEFINED
)
2235 set_value_range_to_varying (&vr0
);
2236 else if (vr1
.type
== VR_UNDEFINED
)
2237 set_value_range_to_varying (&vr1
);
2239 /* The type of the resulting value range defaults to VR0.TYPE. */
2242 /* Refuse to operate on VARYING ranges, ranges of different kinds
2243 and symbolic ranges. As an exception, we allow BIT_AND_EXPR
2244 because we may be able to derive a useful range even if one of
2245 the operands is VR_VARYING or symbolic range. Similarly for
2246 divisions. TODO, we may be able to derive anti-ranges in
2248 if (code
!= BIT_AND_EXPR
2249 && code
!= BIT_IOR_EXPR
2250 && code
!= TRUNC_DIV_EXPR
2251 && code
!= FLOOR_DIV_EXPR
2252 && code
!= CEIL_DIV_EXPR
2253 && code
!= EXACT_DIV_EXPR
2254 && code
!= ROUND_DIV_EXPR
2255 && code
!= TRUNC_MOD_EXPR
2256 && (vr0
.type
== VR_VARYING
2257 || vr1
.type
== VR_VARYING
2258 || vr0
.type
!= vr1
.type
2259 || symbolic_range_p (&vr0
)
2260 || symbolic_range_p (&vr1
)))
2262 set_value_range_to_varying (vr
);
2266 /* Now evaluate the expression to determine the new range. */
2267 if (POINTER_TYPE_P (expr_type
))
2269 if (code
== MIN_EXPR
|| code
== MAX_EXPR
)
2271 /* For MIN/MAX expressions with pointers, we only care about
2272 nullness, if both are non null, then the result is nonnull.
2273 If both are null, then the result is null. Otherwise they
2275 if (range_is_nonnull (&vr0
) && range_is_nonnull (&vr1
))
2276 set_value_range_to_nonnull (vr
, expr_type
);
2277 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
2278 set_value_range_to_null (vr
, expr_type
);
2280 set_value_range_to_varying (vr
);
2282 else if (code
== POINTER_PLUS_EXPR
)
2284 /* For pointer types, we are really only interested in asserting
2285 whether the expression evaluates to non-NULL. */
2286 if (range_is_nonnull (&vr0
) || range_is_nonnull (&vr1
))
2287 set_value_range_to_nonnull (vr
, expr_type
);
2288 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
2289 set_value_range_to_null (vr
, expr_type
);
2291 set_value_range_to_varying (vr
);
2293 else if (code
== BIT_AND_EXPR
)
2295 /* For pointer types, we are really only interested in asserting
2296 whether the expression evaluates to non-NULL. */
2297 if (range_is_nonnull (&vr0
) && range_is_nonnull (&vr1
))
2298 set_value_range_to_nonnull (vr
, expr_type
);
2299 else if (range_is_null (&vr0
) || range_is_null (&vr1
))
2300 set_value_range_to_null (vr
, expr_type
);
2302 set_value_range_to_varying (vr
);
2305 set_value_range_to_varying (vr
);
2310 /* For integer ranges, apply the operation to each end of the
2311 range and see what we end up with. */
2312 if (code
== PLUS_EXPR
2314 || code
== MAX_EXPR
)
2316 /* If we have a PLUS_EXPR with two VR_ANTI_RANGEs, drop to
2317 VR_VARYING. It would take more effort to compute a precise
2318 range for such a case. For example, if we have op0 == 1 and
2319 op1 == -1 with their ranges both being ~[0,0], we would have
2320 op0 + op1 == 0, so we cannot claim that the sum is in ~[0,0].
2321 Note that we are guaranteed to have vr0.type == vr1.type at
2323 if (vr0
.type
== VR_ANTI_RANGE
)
2325 if (code
== PLUS_EXPR
)
2327 set_value_range_to_varying (vr
);
2330 /* For MIN_EXPR and MAX_EXPR with two VR_ANTI_RANGEs,
2331 the resulting VR_ANTI_RANGE is the same - intersection
2332 of the two ranges. */
2333 min
= vrp_int_const_binop (MAX_EXPR
, vr0
.min
, vr1
.min
);
2334 max
= vrp_int_const_binop (MIN_EXPR
, vr0
.max
, vr1
.max
);
2338 /* For operations that make the resulting range directly
2339 proportional to the original ranges, apply the operation to
2340 the same end of each range. */
2341 min
= vrp_int_const_binop (code
, vr0
.min
, vr1
.min
);
2342 max
= vrp_int_const_binop (code
, vr0
.max
, vr1
.max
);
2345 /* If both additions overflowed the range kind is still correct.
2346 This happens regularly with subtracting something in unsigned
2348 ??? See PR30318 for all the cases we do not handle. */
2349 if (code
== PLUS_EXPR
2350 && (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2351 && (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2353 min
= build_int_cst_wide (TREE_TYPE (min
),
2354 TREE_INT_CST_LOW (min
),
2355 TREE_INT_CST_HIGH (min
));
2356 max
= build_int_cst_wide (TREE_TYPE (max
),
2357 TREE_INT_CST_LOW (max
),
2358 TREE_INT_CST_HIGH (max
));
2361 else if (code
== MULT_EXPR
2362 || code
== TRUNC_DIV_EXPR
2363 || code
== FLOOR_DIV_EXPR
2364 || code
== CEIL_DIV_EXPR
2365 || code
== EXACT_DIV_EXPR
2366 || code
== ROUND_DIV_EXPR
2367 || code
== RSHIFT_EXPR
)
2373 /* If we have an unsigned MULT_EXPR with two VR_ANTI_RANGEs,
2374 drop to VR_VARYING. It would take more effort to compute a
2375 precise range for such a case. For example, if we have
2376 op0 == 65536 and op1 == 65536 with their ranges both being
2377 ~[0,0] on a 32-bit machine, we would have op0 * op1 == 0, so
2378 we cannot claim that the product is in ~[0,0]. Note that we
2379 are guaranteed to have vr0.type == vr1.type at this
2381 if (code
== MULT_EXPR
2382 && vr0
.type
== VR_ANTI_RANGE
2383 && !TYPE_OVERFLOW_UNDEFINED (expr_type
))
2385 set_value_range_to_varying (vr
);
2389 /* If we have a RSHIFT_EXPR with any shift values outside [0..prec-1],
2390 then drop to VR_VARYING. Outside of this range we get undefined
2391 behavior from the shift operation. We cannot even trust
2392 SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl
2393 shifts, and the operation at the tree level may be widened. */
2394 if (code
== RSHIFT_EXPR
)
2396 if (vr1
.type
!= VR_RANGE
2397 || !value_range_nonnegative_p (&vr1
)
2398 || TREE_CODE (vr1
.max
) != INTEGER_CST
2399 || compare_tree_int (vr1
.max
,
2400 TYPE_PRECISION (expr_type
) - 1) == 1)
2402 set_value_range_to_varying (vr
);
2407 else if ((code
== TRUNC_DIV_EXPR
2408 || code
== FLOOR_DIV_EXPR
2409 || code
== CEIL_DIV_EXPR
2410 || code
== EXACT_DIV_EXPR
2411 || code
== ROUND_DIV_EXPR
)
2412 && (vr0
.type
!= VR_RANGE
|| symbolic_range_p (&vr0
)))
2414 /* For division, if op1 has VR_RANGE but op0 does not, something
2415 can be deduced just from that range. Say [min, max] / [4, max]
2416 gives [min / 4, max / 4] range. */
2417 if (vr1
.type
== VR_RANGE
2418 && !symbolic_range_p (&vr1
)
2419 && !range_includes_zero_p (&vr1
))
2421 vr0
.type
= type
= VR_RANGE
;
2422 vr0
.min
= vrp_val_min (expr_type
);
2423 vr0
.max
= vrp_val_max (expr_type
);
2427 set_value_range_to_varying (vr
);
2432 /* For divisions, if flag_non_call_exceptions is true, we must
2433 not eliminate a division by zero. */
2434 if ((code
== TRUNC_DIV_EXPR
2435 || code
== FLOOR_DIV_EXPR
2436 || code
== CEIL_DIV_EXPR
2437 || code
== EXACT_DIV_EXPR
2438 || code
== ROUND_DIV_EXPR
)
2439 && cfun
->can_throw_non_call_exceptions
2440 && (vr1
.type
!= VR_RANGE
2441 || symbolic_range_p (&vr1
)
2442 || range_includes_zero_p (&vr1
)))
2444 set_value_range_to_varying (vr
);
2448 /* For divisions, if op0 is VR_RANGE, we can deduce a range
2449 even if op1 is VR_VARYING, VR_ANTI_RANGE, symbolic or can
2451 if ((code
== TRUNC_DIV_EXPR
2452 || code
== FLOOR_DIV_EXPR
2453 || code
== CEIL_DIV_EXPR
2454 || code
== EXACT_DIV_EXPR
2455 || code
== ROUND_DIV_EXPR
)
2456 && vr0
.type
== VR_RANGE
2457 && (vr1
.type
!= VR_RANGE
2458 || symbolic_range_p (&vr1
)
2459 || range_includes_zero_p (&vr1
)))
2461 tree zero
= build_int_cst (TREE_TYPE (vr0
.min
), 0);
2467 if (TYPE_UNSIGNED (expr_type
)
2468 || value_range_nonnegative_p (&vr1
))
2470 /* For unsigned division or when divisor is known
2471 to be non-negative, the range has to cover
2472 all numbers from 0 to max for positive max
2473 and all numbers from min to 0 for negative min. */
2474 cmp
= compare_values (vr0
.max
, zero
);
2477 else if (cmp
== 0 || cmp
== 1)
2481 cmp
= compare_values (vr0
.min
, zero
);
2484 else if (cmp
== 0 || cmp
== -1)
2491 /* Otherwise the range is -max .. max or min .. -min
2492 depending on which bound is bigger in absolute value,
2493 as the division can change the sign. */
2494 abs_extent_range (vr
, vr0
.min
, vr0
.max
);
2497 if (type
== VR_VARYING
)
2499 set_value_range_to_varying (vr
);
2504 /* Multiplications and divisions are a bit tricky to handle,
2505 depending on the mix of signs we have in the two ranges, we
2506 need to operate on different values to get the minimum and
2507 maximum values for the new range. One approach is to figure
2508 out all the variations of range combinations and do the
2511 However, this involves several calls to compare_values and it
2512 is pretty convoluted. It's simpler to do the 4 operations
2513 (MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
2514 MAX1) and then figure the smallest and largest values to form
2518 gcc_assert ((vr0
.type
== VR_RANGE
2519 || (code
== MULT_EXPR
&& vr0
.type
== VR_ANTI_RANGE
))
2520 && vr0
.type
== vr1
.type
);
2522 /* Compute the 4 cross operations. */
2524 val
[0] = vrp_int_const_binop (code
, vr0
.min
, vr1
.min
);
2525 if (val
[0] == NULL_TREE
)
2528 if (vr1
.max
== vr1
.min
)
2532 val
[1] = vrp_int_const_binop (code
, vr0
.min
, vr1
.max
);
2533 if (val
[1] == NULL_TREE
)
2537 if (vr0
.max
== vr0
.min
)
2541 val
[2] = vrp_int_const_binop (code
, vr0
.max
, vr1
.min
);
2542 if (val
[2] == NULL_TREE
)
2546 if (vr0
.min
== vr0
.max
|| vr1
.min
== vr1
.max
)
2550 val
[3] = vrp_int_const_binop (code
, vr0
.max
, vr1
.max
);
2551 if (val
[3] == NULL_TREE
)
2557 set_value_range_to_varying (vr
);
2561 /* Set MIN to the minimum of VAL[i] and MAX to the maximum
2565 for (i
= 1; i
< 4; i
++)
2567 if (!is_gimple_min_invariant (min
)
2568 || (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2569 || !is_gimple_min_invariant (max
)
2570 || (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2575 if (!is_gimple_min_invariant (val
[i
])
2576 || (TREE_OVERFLOW (val
[i
])
2577 && !is_overflow_infinity (val
[i
])))
2579 /* If we found an overflowed value, set MIN and MAX
2580 to it so that we set the resulting range to
2586 if (compare_values (val
[i
], min
) == -1)
2589 if (compare_values (val
[i
], max
) == 1)
2595 else if (code
== TRUNC_MOD_EXPR
)
2597 if (vr1
.type
!= VR_RANGE
2598 || symbolic_range_p (&vr1
)
2599 || range_includes_zero_p (&vr1
)
2600 || vrp_val_is_min (vr1
.min
))
2602 set_value_range_to_varying (vr
);
2606 /* Compute MAX <|vr1.min|, |vr1.max|> - 1. */
2607 max
= fold_unary_to_constant (ABS_EXPR
, expr_type
, vr1
.min
);
2608 if (tree_int_cst_lt (max
, vr1
.max
))
2610 max
= int_const_binop (MINUS_EXPR
, max
, integer_one_node
);
2611 /* If the dividend is non-negative the modulus will be
2612 non-negative as well. */
2613 if (TYPE_UNSIGNED (expr_type
)
2614 || value_range_nonnegative_p (&vr0
))
2615 min
= build_int_cst (TREE_TYPE (max
), 0);
2617 min
= fold_unary_to_constant (NEGATE_EXPR
, expr_type
, max
);
2619 else if (code
== MINUS_EXPR
)
2621 /* If we have a MINUS_EXPR with two VR_ANTI_RANGEs, drop to
2622 VR_VARYING. It would take more effort to compute a precise
2623 range for such a case. For example, if we have op0 == 1 and
2624 op1 == 1 with their ranges both being ~[0,0], we would have
2625 op0 - op1 == 0, so we cannot claim that the difference is in
2626 ~[0,0]. Note that we are guaranteed to have
2627 vr0.type == vr1.type at this point. */
2628 if (vr0
.type
== VR_ANTI_RANGE
)
2630 set_value_range_to_varying (vr
);
2634 /* For MINUS_EXPR, apply the operation to the opposite ends of
2636 min
= vrp_int_const_binop (code
, vr0
.min
, vr1
.max
);
2637 max
= vrp_int_const_binop (code
, vr0
.max
, vr1
.min
);
2639 else if (code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
)
2641 bool int_cst_range0
, int_cst_range1
;
2642 double_int may_be_nonzero0
, may_be_nonzero1
;
2643 double_int must_be_nonzero0
, must_be_nonzero1
;
2645 int_cst_range0
= zero_nonzero_bits_from_vr (&vr0
, &may_be_nonzero0
,
2647 int_cst_range1
= zero_nonzero_bits_from_vr (&vr1
, &may_be_nonzero1
,
2651 if (code
== BIT_AND_EXPR
)
2654 min
= double_int_to_tree (expr_type
,
2655 double_int_and (must_be_nonzero0
,
2657 dmax
= double_int_and (may_be_nonzero0
, may_be_nonzero1
);
2658 /* If both input ranges contain only negative values we can
2659 truncate the result range maximum to the minimum of the
2660 input range maxima. */
2661 if (int_cst_range0
&& int_cst_range1
2662 && tree_int_cst_sgn (vr0
.max
) < 0
2663 && tree_int_cst_sgn (vr1
.max
) < 0)
2665 dmax
= double_int_min (dmax
, tree_to_double_int (vr0
.max
),
2666 TYPE_UNSIGNED (expr_type
));
2667 dmax
= double_int_min (dmax
, tree_to_double_int (vr1
.max
),
2668 TYPE_UNSIGNED (expr_type
));
2670 /* If either input range contains only non-negative values
2671 we can truncate the result range maximum to the respective
2672 maximum of the input range. */
2673 if (int_cst_range0
&& tree_int_cst_sgn (vr0
.min
) >= 0)
2674 dmax
= double_int_min (dmax
, tree_to_double_int (vr0
.max
),
2675 TYPE_UNSIGNED (expr_type
));
2676 if (int_cst_range1
&& tree_int_cst_sgn (vr1
.min
) >= 0)
2677 dmax
= double_int_min (dmax
, tree_to_double_int (vr1
.max
),
2678 TYPE_UNSIGNED (expr_type
));
2679 max
= double_int_to_tree (expr_type
, dmax
);
2681 else if (code
== BIT_IOR_EXPR
)
2684 max
= double_int_to_tree (expr_type
,
2685 double_int_ior (may_be_nonzero0
,
2687 dmin
= double_int_ior (must_be_nonzero0
, must_be_nonzero1
);
2688 /* If the input ranges contain only positive values we can
2689 truncate the minimum of the result range to the maximum
2690 of the input range minima. */
2691 if (int_cst_range0
&& int_cst_range1
2692 && tree_int_cst_sgn (vr0
.min
) >= 0
2693 && tree_int_cst_sgn (vr1
.min
) >= 0)
2695 dmin
= double_int_max (dmin
, tree_to_double_int (vr0
.min
),
2696 TYPE_UNSIGNED (expr_type
));
2697 dmin
= double_int_max (dmin
, tree_to_double_int (vr1
.min
),
2698 TYPE_UNSIGNED (expr_type
));
2700 /* If either input range contains only negative values
2701 we can truncate the minimum of the result range to the
2702 respective minimum range. */
2703 if (int_cst_range0
&& tree_int_cst_sgn (vr0
.max
) < 0)
2704 dmin
= double_int_max (dmin
, tree_to_double_int (vr0
.min
),
2705 TYPE_UNSIGNED (expr_type
));
2706 if (int_cst_range1
&& tree_int_cst_sgn (vr1
.max
) < 0)
2707 dmin
= double_int_max (dmin
, tree_to_double_int (vr1
.min
),
2708 TYPE_UNSIGNED (expr_type
));
2709 min
= double_int_to_tree (expr_type
, dmin
);
2711 else if (code
== BIT_XOR_EXPR
)
2713 double_int result_zero_bits
, result_one_bits
;
2715 = double_int_ior (double_int_and (must_be_nonzero0
,
2718 (double_int_ior (may_be_nonzero0
,
2721 = double_int_ior (double_int_and
2723 double_int_not (may_be_nonzero1
)),
2726 double_int_not (may_be_nonzero0
)));
2727 max
= double_int_to_tree (expr_type
,
2728 double_int_not (result_zero_bits
));
2729 min
= double_int_to_tree (expr_type
, result_one_bits
);
2730 /* If the range has all positive or all negative values the
2731 result is better than VARYING. */
2732 if (tree_int_cst_sgn (min
) < 0
2733 || tree_int_cst_sgn (max
) >= 0)
2736 max
= min
= NULL_TREE
;
2740 set_value_range_to_varying (vr
);
2747 /* If either MIN or MAX overflowed, then set the resulting range to
2748 VARYING. But we do accept an overflow infinity
2750 if (min
== NULL_TREE
2751 || !is_gimple_min_invariant (min
)
2752 || (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2754 || !is_gimple_min_invariant (max
)
2755 || (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2757 set_value_range_to_varying (vr
);
2763 2) [-INF, +-INF(OVF)]
2764 3) [+-INF(OVF), +INF]
2765 4) [+-INF(OVF), +-INF(OVF)]
2766 We learn nothing when we have INF and INF(OVF) on both sides.
2767 Note that we do accept [-INF, -INF] and [+INF, +INF] without
2769 if ((vrp_val_is_min (min
) || is_overflow_infinity (min
))
2770 && (vrp_val_is_max (max
) || is_overflow_infinity (max
)))
2772 set_value_range_to_varying (vr
);
2776 cmp
= compare_values (min
, max
);
2777 if (cmp
== -2 || cmp
== 1)
2779 /* If the new range has its limits swapped around (MIN > MAX),
2780 then the operation caused one of them to wrap around, mark
2781 the new range VARYING. */
2782 set_value_range_to_varying (vr
);
2785 set_value_range (vr
, type
, min
, max
, NULL
);
2788 /* Extract range information from a binary expression OP0 CODE OP1 based on
2789 the ranges of each of its operands with resulting type EXPR_TYPE.
2790 The resulting range is stored in *VR. */
2793 extract_range_from_binary_expr (value_range_t
*vr
,
2794 enum tree_code code
,
2795 tree expr_type
, tree op0
, tree op1
)
2797 value_range_t vr0
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
2798 value_range_t vr1
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
2800 /* Get value ranges for each operand. For constant operands, create
2801 a new value range with the operand to simplify processing. */
2802 if (TREE_CODE (op0
) == SSA_NAME
)
2803 vr0
= *(get_value_range (op0
));
2804 else if (is_gimple_min_invariant (op0
))
2805 set_value_range_to_value (&vr0
, op0
, NULL
);
2807 set_value_range_to_varying (&vr0
);
2809 if (TREE_CODE (op1
) == SSA_NAME
)
2810 vr1
= *(get_value_range (op1
));
2811 else if (is_gimple_min_invariant (op1
))
2812 set_value_range_to_value (&vr1
, op1
, NULL
);
2814 set_value_range_to_varying (&vr1
);
2816 extract_range_from_binary_expr_1 (vr
, code
, expr_type
, &vr0
, &vr1
);
2819 /* Extract range information from a unary operation CODE based on
2820 the range of its operand *VR0 with type OP0_TYPE with resulting type TYPE.
2821 The The resulting range is stored in *VR. */
2824 extract_range_from_unary_expr_1 (value_range_t
*vr
,
2825 enum tree_code code
, tree type
,
2826 value_range_t
*vr0_
, tree op0_type
)
2828 value_range_t vr0
= *vr0_
;
2832 /* If VR0 is UNDEFINED, so is the result. */
2833 if (vr0
.type
== VR_UNDEFINED
)
2835 set_value_range_to_undefined (vr
);
2839 /* Refuse to operate on certain unary expressions for which we
2840 cannot easily determine a resulting range. */
2841 if (code
== FIX_TRUNC_EXPR
2842 || code
== FLOAT_EXPR
2843 || code
== CONJ_EXPR
)
2845 set_value_range_to_varying (vr
);
2849 /* Refuse to operate on symbolic ranges, or if neither operand is
2850 a pointer or integral type. */
2851 if ((!INTEGRAL_TYPE_P (op0_type
)
2852 && !POINTER_TYPE_P (op0_type
))
2853 || (vr0
.type
!= VR_VARYING
2854 && symbolic_range_p (&vr0
)))
2856 set_value_range_to_varying (vr
);
2860 /* If the expression involves pointers, we are only interested in
2861 determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */
2862 if (POINTER_TYPE_P (type
) || POINTER_TYPE_P (op0_type
))
2864 if (range_is_nonnull (&vr0
))
2865 set_value_range_to_nonnull (vr
, type
);
2866 else if (range_is_null (&vr0
))
2867 set_value_range_to_null (vr
, type
);
2869 set_value_range_to_varying (vr
);
2873 /* Handle unary expressions on integer ranges. */
2874 if (CONVERT_EXPR_CODE_P (code
)
2875 && INTEGRAL_TYPE_P (type
)
2876 && INTEGRAL_TYPE_P (op0_type
))
2878 tree inner_type
= op0_type
;
2879 tree outer_type
= type
;
2881 /* If VR0 is varying and we increase the type precision, assume
2882 a full range for the following transformation. */
2883 if (vr0
.type
== VR_VARYING
2884 && TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
))
2886 vr0
.type
= VR_RANGE
;
2887 vr0
.min
= TYPE_MIN_VALUE (inner_type
);
2888 vr0
.max
= TYPE_MAX_VALUE (inner_type
);
2891 /* If VR0 is a constant range or anti-range and the conversion is
2892 not truncating we can convert the min and max values and
2893 canonicalize the resulting range. Otherwise we can do the
2894 conversion if the size of the range is less than what the
2895 precision of the target type can represent and the range is
2896 not an anti-range. */
2897 if ((vr0
.type
== VR_RANGE
2898 || vr0
.type
== VR_ANTI_RANGE
)
2899 && TREE_CODE (vr0
.min
) == INTEGER_CST
2900 && TREE_CODE (vr0
.max
) == INTEGER_CST
2901 && (!is_overflow_infinity (vr0
.min
)
2902 || (vr0
.type
== VR_RANGE
2903 && TYPE_PRECISION (outer_type
) > TYPE_PRECISION (inner_type
)
2904 && needs_overflow_infinity (outer_type
)
2905 && supports_overflow_infinity (outer_type
)))
2906 && (!is_overflow_infinity (vr0
.max
)
2907 || (vr0
.type
== VR_RANGE
2908 && TYPE_PRECISION (outer_type
) > TYPE_PRECISION (inner_type
)
2909 && needs_overflow_infinity (outer_type
)
2910 && supports_overflow_infinity (outer_type
)))
2911 && (TYPE_PRECISION (outer_type
) >= TYPE_PRECISION (inner_type
)
2912 || (vr0
.type
== VR_RANGE
2913 && integer_zerop (int_const_binop (RSHIFT_EXPR
,
2914 int_const_binop (MINUS_EXPR
, vr0
.max
, vr0
.min
),
2915 size_int (TYPE_PRECISION (outer_type
)))))))
2917 tree new_min
, new_max
;
2918 new_min
= force_fit_type_double (outer_type
,
2919 tree_to_double_int (vr0
.min
),
2921 new_max
= force_fit_type_double (outer_type
,
2922 tree_to_double_int (vr0
.max
),
2924 if (is_overflow_infinity (vr0
.min
))
2925 new_min
= negative_overflow_infinity (outer_type
);
2926 if (is_overflow_infinity (vr0
.max
))
2927 new_max
= positive_overflow_infinity (outer_type
);
2928 set_and_canonicalize_value_range (vr
, vr0
.type
,
2929 new_min
, new_max
, NULL
);
2933 set_value_range_to_varying (vr
);
2937 /* Conversion of a VR_VARYING value to a wider type can result
2938 in a usable range. So wait until after we've handled conversions
2939 before dropping the result to VR_VARYING if we had a source
2940 operand that is VR_VARYING. */
2941 if (vr0
.type
== VR_VARYING
)
2943 set_value_range_to_varying (vr
);
2947 /* Apply the operation to each end of the range and see what we end
2949 if (code
== NEGATE_EXPR
)
2951 /* -X is simply 0 - X, so re-use existing code that also handles
2952 anti-ranges fine. */
2953 value_range_t zero
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
2954 set_value_range_to_value (&zero
, build_int_cst (type
, 0), NULL
);
2955 extract_range_from_binary_expr_1 (vr
, MINUS_EXPR
, type
, &zero
, &vr0
);
2958 else if (code
== ABS_EXPR
2959 && !TYPE_UNSIGNED (type
))
2961 /* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a
2963 if (!TYPE_OVERFLOW_UNDEFINED (type
)
2964 && ((vr0
.type
== VR_RANGE
2965 && vrp_val_is_min (vr0
.min
))
2966 || (vr0
.type
== VR_ANTI_RANGE
2967 && !vrp_val_is_min (vr0
.min
)
2968 && !range_includes_zero_p (&vr0
))))
2970 set_value_range_to_varying (vr
);
2974 /* ABS_EXPR may flip the range around, if the original range
2975 included negative values. */
2976 if (is_overflow_infinity (vr0
.min
))
2977 min
= positive_overflow_infinity (type
);
2978 else if (!vrp_val_is_min (vr0
.min
))
2979 min
= fold_unary_to_constant (code
, type
, vr0
.min
);
2980 else if (!needs_overflow_infinity (type
))
2981 min
= TYPE_MAX_VALUE (type
);
2982 else if (supports_overflow_infinity (type
))
2983 min
= positive_overflow_infinity (type
);
2986 set_value_range_to_varying (vr
);
2990 if (is_overflow_infinity (vr0
.max
))
2991 max
= positive_overflow_infinity (type
);
2992 else if (!vrp_val_is_min (vr0
.max
))
2993 max
= fold_unary_to_constant (code
, type
, vr0
.max
);
2994 else if (!needs_overflow_infinity (type
))
2995 max
= TYPE_MAX_VALUE (type
);
2996 else if (supports_overflow_infinity (type
)
2997 /* We shouldn't generate [+INF, +INF] as set_value_range
2998 doesn't like this and ICEs. */
2999 && !is_positive_overflow_infinity (min
))
3000 max
= positive_overflow_infinity (type
);
3003 set_value_range_to_varying (vr
);
3007 cmp
= compare_values (min
, max
);
3009 /* If a VR_ANTI_RANGEs contains zero, then we have
3010 ~[-INF, min(MIN, MAX)]. */
3011 if (vr0
.type
== VR_ANTI_RANGE
)
3013 if (range_includes_zero_p (&vr0
))
3015 /* Take the lower of the two values. */
3019 /* Create ~[-INF, min (abs(MIN), abs(MAX))]
3020 or ~[-INF + 1, min (abs(MIN), abs(MAX))] when
3021 flag_wrapv is set and the original anti-range doesn't include
3022 TYPE_MIN_VALUE, remember -TYPE_MIN_VALUE = TYPE_MIN_VALUE. */
3023 if (TYPE_OVERFLOW_WRAPS (type
))
3025 tree type_min_value
= TYPE_MIN_VALUE (type
);
3027 min
= (vr0
.min
!= type_min_value
3028 ? int_const_binop (PLUS_EXPR
, type_min_value
,
3034 if (overflow_infinity_range_p (&vr0
))
3035 min
= negative_overflow_infinity (type
);
3037 min
= TYPE_MIN_VALUE (type
);
3042 /* All else has failed, so create the range [0, INF], even for
3043 flag_wrapv since TYPE_MIN_VALUE is in the original
3045 vr0
.type
= VR_RANGE
;
3046 min
= build_int_cst (type
, 0);
3047 if (needs_overflow_infinity (type
))
3049 if (supports_overflow_infinity (type
))
3050 max
= positive_overflow_infinity (type
);
3053 set_value_range_to_varying (vr
);
3058 max
= TYPE_MAX_VALUE (type
);
3062 /* If the range contains zero then we know that the minimum value in the
3063 range will be zero. */
3064 else if (range_includes_zero_p (&vr0
))
3068 min
= build_int_cst (type
, 0);
3072 /* If the range was reversed, swap MIN and MAX. */
3081 else if (code
== BIT_NOT_EXPR
)
3083 /* ~X is simply -1 - X, so re-use existing code that also handles
3084 anti-ranges fine. */
3085 value_range_t minusone
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3086 set_value_range_to_value (&minusone
, build_int_cst (type
, -1), NULL
);
3087 extract_range_from_binary_expr_1 (vr
, MINUS_EXPR
,
3088 type
, &minusone
, &vr0
);
3093 /* Otherwise, operate on each end of the range. */
3094 min
= fold_unary_to_constant (code
, type
, vr0
.min
);
3095 max
= fold_unary_to_constant (code
, type
, vr0
.max
);
3097 if (needs_overflow_infinity (type
))
3099 gcc_assert (code
!= NEGATE_EXPR
&& code
!= ABS_EXPR
);
3101 /* If both sides have overflowed, we don't know
3103 if ((is_overflow_infinity (vr0
.min
)
3104 || TREE_OVERFLOW (min
))
3105 && (is_overflow_infinity (vr0
.max
)
3106 || TREE_OVERFLOW (max
)))
3108 set_value_range_to_varying (vr
);
3112 if (is_overflow_infinity (vr0
.min
))
3114 else if (TREE_OVERFLOW (min
))
3116 if (supports_overflow_infinity (type
))
3117 min
= (tree_int_cst_sgn (min
) >= 0
3118 ? positive_overflow_infinity (TREE_TYPE (min
))
3119 : negative_overflow_infinity (TREE_TYPE (min
)));
3122 set_value_range_to_varying (vr
);
3127 if (is_overflow_infinity (vr0
.max
))
3129 else if (TREE_OVERFLOW (max
))
3131 if (supports_overflow_infinity (type
))
3132 max
= (tree_int_cst_sgn (max
) >= 0
3133 ? positive_overflow_infinity (TREE_TYPE (max
))
3134 : negative_overflow_infinity (TREE_TYPE (max
)));
3137 set_value_range_to_varying (vr
);
3144 cmp
= compare_values (min
, max
);
3145 if (cmp
== -2 || cmp
== 1)
3147 /* If the new range has its limits swapped around (MIN > MAX),
3148 then the operation caused one of them to wrap around, mark
3149 the new range VARYING. */
3150 set_value_range_to_varying (vr
);
3153 set_value_range (vr
, vr0
.type
, min
, max
, NULL
);
3157 /* Extract range information from a unary expression CODE OP0 based on
3158 the range of its operand with resulting type TYPE.
3159 The resulting range is stored in *VR. */
3162 extract_range_from_unary_expr (value_range_t
*vr
, enum tree_code code
,
3163 tree type
, tree op0
)
3165 value_range_t vr0
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3167 /* Get value ranges for the operand. For constant operands, create
3168 a new value range with the operand to simplify processing. */
3169 if (TREE_CODE (op0
) == SSA_NAME
)
3170 vr0
= *(get_value_range (op0
));
3171 else if (is_gimple_min_invariant (op0
))
3172 set_value_range_to_value (&vr0
, op0
, NULL
);
3174 set_value_range_to_varying (&vr0
);
3176 extract_range_from_unary_expr_1 (vr
, code
, type
, &vr0
, TREE_TYPE (op0
));
3180 /* Extract range information from a conditional expression EXPR based on
3181 the ranges of each of its operands and the expression code. */
3184 extract_range_from_cond_expr (value_range_t
*vr
, tree expr
)
3187 value_range_t vr0
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3188 value_range_t vr1
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3190 /* Get value ranges for each operand. For constant operands, create
3191 a new value range with the operand to simplify processing. */
3192 op0
= COND_EXPR_THEN (expr
);
3193 if (TREE_CODE (op0
) == SSA_NAME
)
3194 vr0
= *(get_value_range (op0
));
3195 else if (is_gimple_min_invariant (op0
))
3196 set_value_range_to_value (&vr0
, op0
, NULL
);
3198 set_value_range_to_varying (&vr0
);
3200 op1
= COND_EXPR_ELSE (expr
);
3201 if (TREE_CODE (op1
) == SSA_NAME
)
3202 vr1
= *(get_value_range (op1
));
3203 else if (is_gimple_min_invariant (op1
))
3204 set_value_range_to_value (&vr1
, op1
, NULL
);
3206 set_value_range_to_varying (&vr1
);
3208 /* The resulting value range is the union of the operand ranges */
3209 vrp_meet (&vr0
, &vr1
);
3210 copy_value_range (vr
, &vr0
);
3214 /* Extract range information from a comparison expression EXPR based
3215 on the range of its operand and the expression code. */
3218 extract_range_from_comparison (value_range_t
*vr
, enum tree_code code
,
3219 tree type
, tree op0
, tree op1
)
3224 val
= vrp_evaluate_conditional_warnv_with_ops (code
, op0
, op1
, false, &sop
,
3227 /* A disadvantage of using a special infinity as an overflow
3228 representation is that we lose the ability to record overflow
3229 when we don't have an infinity. So we have to ignore a result
3230 which relies on overflow. */
3232 if (val
&& !is_overflow_infinity (val
) && !sop
)
3234 /* Since this expression was found on the RHS of an assignment,
3235 its type may be different from _Bool. Convert VAL to EXPR's
3237 val
= fold_convert (type
, val
);
3238 if (is_gimple_min_invariant (val
))
3239 set_value_range_to_value (vr
, val
, vr
->equiv
);
3241 set_value_range (vr
, VR_RANGE
, val
, val
, vr
->equiv
);
3244 /* The result of a comparison is always true or false. */
3245 set_value_range_to_truthvalue (vr
, type
);
3248 /* Try to derive a nonnegative or nonzero range out of STMT relying
3249 primarily on generic routines in fold in conjunction with range data.
3250 Store the result in *VR */
3253 extract_range_basic (value_range_t
*vr
, gimple stmt
)
3256 tree type
= gimple_expr_type (stmt
);
3258 if (INTEGRAL_TYPE_P (type
)
3259 && gimple_stmt_nonnegative_warnv_p (stmt
, &sop
))
3260 set_value_range_to_nonnegative (vr
, type
,
3261 sop
|| stmt_overflow_infinity (stmt
));
3262 else if (vrp_stmt_computes_nonzero (stmt
, &sop
)
3264 set_value_range_to_nonnull (vr
, type
);
3266 set_value_range_to_varying (vr
);
3270 /* Try to compute a useful range out of assignment STMT and store it
3274 extract_range_from_assignment (value_range_t
*vr
, gimple stmt
)
3276 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3278 if (code
== ASSERT_EXPR
)
3279 extract_range_from_assert (vr
, gimple_assign_rhs1 (stmt
));
3280 else if (code
== SSA_NAME
)
3281 extract_range_from_ssa_name (vr
, gimple_assign_rhs1 (stmt
));
3282 else if (TREE_CODE_CLASS (code
) == tcc_binary
)
3283 extract_range_from_binary_expr (vr
, gimple_assign_rhs_code (stmt
),
3284 gimple_expr_type (stmt
),
3285 gimple_assign_rhs1 (stmt
),
3286 gimple_assign_rhs2 (stmt
));
3287 else if (TREE_CODE_CLASS (code
) == tcc_unary
)
3288 extract_range_from_unary_expr (vr
, gimple_assign_rhs_code (stmt
),
3289 gimple_expr_type (stmt
),
3290 gimple_assign_rhs1 (stmt
));
3291 else if (code
== COND_EXPR
)
3292 extract_range_from_cond_expr (vr
, gimple_assign_rhs1 (stmt
));
3293 else if (TREE_CODE_CLASS (code
) == tcc_comparison
)
3294 extract_range_from_comparison (vr
, gimple_assign_rhs_code (stmt
),
3295 gimple_expr_type (stmt
),
3296 gimple_assign_rhs1 (stmt
),
3297 gimple_assign_rhs2 (stmt
));
3298 else if (get_gimple_rhs_class (code
) == GIMPLE_SINGLE_RHS
3299 && is_gimple_min_invariant (gimple_assign_rhs1 (stmt
)))
3300 set_value_range_to_value (vr
, gimple_assign_rhs1 (stmt
), NULL
);
3302 set_value_range_to_varying (vr
);
3304 if (vr
->type
== VR_VARYING
)
3305 extract_range_basic (vr
, stmt
);
3308 /* Given a range VR, a LOOP and a variable VAR, determine whether it
3309 would be profitable to adjust VR using scalar evolution information
3310 for VAR. If so, update VR with the new limits. */
3313 adjust_range_with_scev (value_range_t
*vr
, struct loop
*loop
,
3314 gimple stmt
, tree var
)
3316 tree init
, step
, chrec
, tmin
, tmax
, min
, max
, type
, tem
;
3317 enum ev_direction dir
;
3319 /* TODO. Don't adjust anti-ranges. An anti-range may provide
3320 better opportunities than a regular range, but I'm not sure. */
3321 if (vr
->type
== VR_ANTI_RANGE
)
3324 chrec
= instantiate_parameters (loop
, analyze_scalar_evolution (loop
, var
));
3326 /* Like in PR19590, scev can return a constant function. */
3327 if (is_gimple_min_invariant (chrec
))
3329 set_value_range_to_value (vr
, chrec
, vr
->equiv
);
3333 if (TREE_CODE (chrec
) != POLYNOMIAL_CHREC
)
3336 init
= initial_condition_in_loop_num (chrec
, loop
->num
);
3337 tem
= op_with_constant_singleton_value_range (init
);
3340 step
= evolution_part_in_loop_num (chrec
, loop
->num
);
3341 tem
= op_with_constant_singleton_value_range (step
);
3345 /* If STEP is symbolic, we can't know whether INIT will be the
3346 minimum or maximum value in the range. Also, unless INIT is
3347 a simple expression, compare_values and possibly other functions
3348 in tree-vrp won't be able to handle it. */
3349 if (step
== NULL_TREE
3350 || !is_gimple_min_invariant (step
)
3351 || !valid_value_p (init
))
3354 dir
= scev_direction (chrec
);
3355 if (/* Do not adjust ranges if we do not know whether the iv increases
3356 or decreases, ... */
3357 dir
== EV_DIR_UNKNOWN
3358 /* ... or if it may wrap. */
3359 || scev_probably_wraps_p (init
, step
, stmt
, get_chrec_loop (chrec
),
3363 /* We use TYPE_MIN_VALUE and TYPE_MAX_VALUE here instead of
3364 negative_overflow_infinity and positive_overflow_infinity,
3365 because we have concluded that the loop probably does not
3368 type
= TREE_TYPE (var
);
3369 if (POINTER_TYPE_P (type
) || !TYPE_MIN_VALUE (type
))
3370 tmin
= lower_bound_in_type (type
, type
);
3372 tmin
= TYPE_MIN_VALUE (type
);
3373 if (POINTER_TYPE_P (type
) || !TYPE_MAX_VALUE (type
))
3374 tmax
= upper_bound_in_type (type
, type
);
3376 tmax
= TYPE_MAX_VALUE (type
);
3378 /* Try to use estimated number of iterations for the loop to constrain the
3379 final value in the evolution. */
3380 if (TREE_CODE (step
) == INTEGER_CST
3381 && is_gimple_val (init
)
3382 && (TREE_CODE (init
) != SSA_NAME
3383 || get_value_range (init
)->type
== VR_RANGE
))
3387 if (estimated_loop_iterations (loop
, true, &nit
))
3389 value_range_t maxvr
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
3391 bool unsigned_p
= TYPE_UNSIGNED (TREE_TYPE (step
));
3394 dtmp
= double_int_mul_with_sign (tree_to_double_int (step
), nit
,
3395 unsigned_p
, &overflow
);
3396 /* If the multiplication overflowed we can't do a meaningful
3397 adjustment. Likewise if the result doesn't fit in the type
3398 of the induction variable. For a signed type we have to
3399 check whether the result has the expected signedness which
3400 is that of the step as number of iterations is unsigned. */
3402 && double_int_fits_to_tree_p (TREE_TYPE (init
), dtmp
)
3404 || ((dtmp
.high
^ TREE_INT_CST_HIGH (step
)) >= 0)))
3406 tem
= double_int_to_tree (TREE_TYPE (init
), dtmp
);
3407 extract_range_from_binary_expr (&maxvr
, PLUS_EXPR
,
3408 TREE_TYPE (init
), init
, tem
);
3409 /* Likewise if the addition did. */
3410 if (maxvr
.type
== VR_RANGE
)
3419 if (vr
->type
== VR_VARYING
|| vr
->type
== VR_UNDEFINED
)
3424 /* For VARYING or UNDEFINED ranges, just about anything we get
3425 from scalar evolutions should be better. */
3427 if (dir
== EV_DIR_DECREASES
)
3432 /* If we would create an invalid range, then just assume we
3433 know absolutely nothing. This may be over-conservative,
3434 but it's clearly safe, and should happen only in unreachable
3435 parts of code, or for invalid programs. */
3436 if (compare_values (min
, max
) == 1)
3439 set_value_range (vr
, VR_RANGE
, min
, max
, vr
->equiv
);
3441 else if (vr
->type
== VR_RANGE
)
3446 if (dir
== EV_DIR_DECREASES
)
3448 /* INIT is the maximum value. If INIT is lower than VR->MAX
3449 but no smaller than VR->MIN, set VR->MAX to INIT. */
3450 if (compare_values (init
, max
) == -1)
3453 /* According to the loop information, the variable does not
3454 overflow. If we think it does, probably because of an
3455 overflow due to arithmetic on a different INF value,
3457 if (is_negative_overflow_infinity (min
)
3458 || compare_values (min
, tmin
) == -1)
3464 /* If INIT is bigger than VR->MIN, set VR->MIN to INIT. */
3465 if (compare_values (init
, min
) == 1)
3468 if (is_positive_overflow_infinity (max
)
3469 || compare_values (tmax
, max
) == -1)
3473 /* If we just created an invalid range with the minimum
3474 greater than the maximum, we fail conservatively.
3475 This should happen only in unreachable
3476 parts of code, or for invalid programs. */
3477 if (compare_values (min
, max
) == 1)
3480 set_value_range (vr
, VR_RANGE
, min
, max
, vr
->equiv
);
3484 /* Return true if VAR may overflow at STMT. This checks any available
3485 loop information to see if we can determine that VAR does not
3489 vrp_var_may_overflow (tree var
, gimple stmt
)
3492 tree chrec
, init
, step
;
3494 if (current_loops
== NULL
)
3497 l
= loop_containing_stmt (stmt
);
3502 chrec
= instantiate_parameters (l
, analyze_scalar_evolution (l
, var
));
3503 if (TREE_CODE (chrec
) != POLYNOMIAL_CHREC
)
3506 init
= initial_condition_in_loop_num (chrec
, l
->num
);
3507 step
= evolution_part_in_loop_num (chrec
, l
->num
);
3509 if (step
== NULL_TREE
3510 || !is_gimple_min_invariant (step
)
3511 || !valid_value_p (init
))
3514 /* If we get here, we know something useful about VAR based on the
3515 loop information. If it wraps, it may overflow. */
3517 if (scev_probably_wraps_p (init
, step
, stmt
, get_chrec_loop (chrec
),
3521 if (dump_file
&& (dump_flags
& TDF_DETAILS
) != 0)
3523 print_generic_expr (dump_file
, var
, 0);
3524 fprintf (dump_file
, ": loop information indicates does not overflow\n");
3531 /* Given two numeric value ranges VR0, VR1 and a comparison code COMP:
3533 - Return BOOLEAN_TRUE_NODE if VR0 COMP VR1 always returns true for
3534 all the values in the ranges.
3536 - Return BOOLEAN_FALSE_NODE if the comparison always returns false.
3538 - Return NULL_TREE if it is not always possible to determine the
3539 value of the comparison.
3541 Also set *STRICT_OVERFLOW_P to indicate whether a range with an
3542 overflow infinity was used in the test. */
3546 compare_ranges (enum tree_code comp
, value_range_t
*vr0
, value_range_t
*vr1
,
3547 bool *strict_overflow_p
)
3549 /* VARYING or UNDEFINED ranges cannot be compared. */
3550 if (vr0
->type
== VR_VARYING
3551 || vr0
->type
== VR_UNDEFINED
3552 || vr1
->type
== VR_VARYING
3553 || vr1
->type
== VR_UNDEFINED
)
3556 /* Anti-ranges need to be handled separately. */
3557 if (vr0
->type
== VR_ANTI_RANGE
|| vr1
->type
== VR_ANTI_RANGE
)
3559 /* If both are anti-ranges, then we cannot compute any
3561 if (vr0
->type
== VR_ANTI_RANGE
&& vr1
->type
== VR_ANTI_RANGE
)
3564 /* These comparisons are never statically computable. */
3571 /* Equality can be computed only between a range and an
3572 anti-range. ~[VAL1, VAL2] == [VAL1, VAL2] is always false. */
3573 if (vr0
->type
== VR_RANGE
)
3575 /* To simplify processing, make VR0 the anti-range. */
3576 value_range_t
*tmp
= vr0
;
3581 gcc_assert (comp
== NE_EXPR
|| comp
== EQ_EXPR
);
3583 if (compare_values_warnv (vr0
->min
, vr1
->min
, strict_overflow_p
) == 0
3584 && compare_values_warnv (vr0
->max
, vr1
->max
, strict_overflow_p
) == 0)
3585 return (comp
== NE_EXPR
) ? boolean_true_node
: boolean_false_node
;
3590 if (!usable_range_p (vr0
, strict_overflow_p
)
3591 || !usable_range_p (vr1
, strict_overflow_p
))
3594 /* Simplify processing. If COMP is GT_EXPR or GE_EXPR, switch the
3595 operands around and change the comparison code. */
3596 if (comp
== GT_EXPR
|| comp
== GE_EXPR
)
3599 comp
= (comp
== GT_EXPR
) ? LT_EXPR
: LE_EXPR
;
3605 if (comp
== EQ_EXPR
)
3607 /* Equality may only be computed if both ranges represent
3608 exactly one value. */
3609 if (compare_values_warnv (vr0
->min
, vr0
->max
, strict_overflow_p
) == 0
3610 && compare_values_warnv (vr1
->min
, vr1
->max
, strict_overflow_p
) == 0)
3612 int cmp_min
= compare_values_warnv (vr0
->min
, vr1
->min
,
3614 int cmp_max
= compare_values_warnv (vr0
->max
, vr1
->max
,
3616 if (cmp_min
== 0 && cmp_max
== 0)
3617 return boolean_true_node
;
3618 else if (cmp_min
!= -2 && cmp_max
!= -2)
3619 return boolean_false_node
;
3621 /* If [V0_MIN, V1_MAX] < [V1_MIN, V1_MAX] then V0 != V1. */
3622 else if (compare_values_warnv (vr0
->min
, vr1
->max
,
3623 strict_overflow_p
) == 1
3624 || compare_values_warnv (vr1
->min
, vr0
->max
,
3625 strict_overflow_p
) == 1)
3626 return boolean_false_node
;
3630 else if (comp
== NE_EXPR
)
3634 /* If VR0 is completely to the left or completely to the right
3635 of VR1, they are always different. Notice that we need to
3636 make sure that both comparisons yield similar results to
3637 avoid comparing values that cannot be compared at
3639 cmp1
= compare_values_warnv (vr0
->max
, vr1
->min
, strict_overflow_p
);
3640 cmp2
= compare_values_warnv (vr0
->min
, vr1
->max
, strict_overflow_p
);
3641 if ((cmp1
== -1 && cmp2
== -1) || (cmp1
== 1 && cmp2
== 1))
3642 return boolean_true_node
;
3644 /* If VR0 and VR1 represent a single value and are identical,
3646 else if (compare_values_warnv (vr0
->min
, vr0
->max
,
3647 strict_overflow_p
) == 0
3648 && compare_values_warnv (vr1
->min
, vr1
->max
,
3649 strict_overflow_p
) == 0
3650 && compare_values_warnv (vr0
->min
, vr1
->min
,
3651 strict_overflow_p
) == 0
3652 && compare_values_warnv (vr0
->max
, vr1
->max
,
3653 strict_overflow_p
) == 0)
3654 return boolean_false_node
;
3656 /* Otherwise, they may or may not be different. */
3660 else if (comp
== LT_EXPR
|| comp
== LE_EXPR
)
3664 /* If VR0 is to the left of VR1, return true. */
3665 tst
= compare_values_warnv (vr0
->max
, vr1
->min
, strict_overflow_p
);
3666 if ((comp
== LT_EXPR
&& tst
== -1)
3667 || (comp
== LE_EXPR
&& (tst
== -1 || tst
== 0)))
3669 if (overflow_infinity_range_p (vr0
)
3670 || overflow_infinity_range_p (vr1
))
3671 *strict_overflow_p
= true;
3672 return boolean_true_node
;
3675 /* If VR0 is to the right of VR1, return false. */
3676 tst
= compare_values_warnv (vr0
->min
, vr1
->max
, strict_overflow_p
);
3677 if ((comp
== LT_EXPR
&& (tst
== 0 || tst
== 1))
3678 || (comp
== LE_EXPR
&& tst
== 1))
3680 if (overflow_infinity_range_p (vr0
)
3681 || overflow_infinity_range_p (vr1
))
3682 *strict_overflow_p
= true;
3683 return boolean_false_node
;
3686 /* Otherwise, we don't know. */
3694 /* Given a value range VR, a value VAL and a comparison code COMP, return
3695 BOOLEAN_TRUE_NODE if VR COMP VAL always returns true for all the
3696 values in VR. Return BOOLEAN_FALSE_NODE if the comparison
3697 always returns false. Return NULL_TREE if it is not always
3698 possible to determine the value of the comparison. Also set
3699 *STRICT_OVERFLOW_P to indicate whether a range with an overflow
3700 infinity was used in the test. */
3703 compare_range_with_value (enum tree_code comp
, value_range_t
*vr
, tree val
,
3704 bool *strict_overflow_p
)
3706 if (vr
->type
== VR_VARYING
|| vr
->type
== VR_UNDEFINED
)
3709 /* Anti-ranges need to be handled separately. */
3710 if (vr
->type
== VR_ANTI_RANGE
)
3712 /* For anti-ranges, the only predicates that we can compute at
3713 compile time are equality and inequality. */
3720 /* ~[VAL_1, VAL_2] OP VAL is known if VAL_1 <= VAL <= VAL_2. */
3721 if (value_inside_range (val
, vr
) == 1)
3722 return (comp
== NE_EXPR
) ? boolean_true_node
: boolean_false_node
;
3727 if (!usable_range_p (vr
, strict_overflow_p
))
3730 if (comp
== EQ_EXPR
)
3732 /* EQ_EXPR may only be computed if VR represents exactly
3734 if (compare_values_warnv (vr
->min
, vr
->max
, strict_overflow_p
) == 0)
3736 int cmp
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
3738 return boolean_true_node
;
3739 else if (cmp
== -1 || cmp
== 1 || cmp
== 2)
3740 return boolean_false_node
;
3742 else if (compare_values_warnv (val
, vr
->min
, strict_overflow_p
) == -1
3743 || compare_values_warnv (vr
->max
, val
, strict_overflow_p
) == -1)
3744 return boolean_false_node
;
3748 else if (comp
== NE_EXPR
)
3750 /* If VAL is not inside VR, then they are always different. */
3751 if (compare_values_warnv (vr
->max
, val
, strict_overflow_p
) == -1
3752 || compare_values_warnv (vr
->min
, val
, strict_overflow_p
) == 1)
3753 return boolean_true_node
;
3755 /* If VR represents exactly one value equal to VAL, then return
3757 if (compare_values_warnv (vr
->min
, vr
->max
, strict_overflow_p
) == 0
3758 && compare_values_warnv (vr
->min
, val
, strict_overflow_p
) == 0)
3759 return boolean_false_node
;
3761 /* Otherwise, they may or may not be different. */
3764 else if (comp
== LT_EXPR
|| comp
== LE_EXPR
)
3768 /* If VR is to the left of VAL, return true. */
3769 tst
= compare_values_warnv (vr
->max
, val
, strict_overflow_p
);
3770 if ((comp
== LT_EXPR
&& tst
== -1)
3771 || (comp
== LE_EXPR
&& (tst
== -1 || tst
== 0)))
3773 if (overflow_infinity_range_p (vr
))
3774 *strict_overflow_p
= true;
3775 return boolean_true_node
;
3778 /* If VR is to the right of VAL, return false. */
3779 tst
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
3780 if ((comp
== LT_EXPR
&& (tst
== 0 || tst
== 1))
3781 || (comp
== LE_EXPR
&& tst
== 1))
3783 if (overflow_infinity_range_p (vr
))
3784 *strict_overflow_p
= true;
3785 return boolean_false_node
;
3788 /* Otherwise, we don't know. */
3791 else if (comp
== GT_EXPR
|| comp
== GE_EXPR
)
3795 /* If VR is to the right of VAL, return true. */
3796 tst
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
3797 if ((comp
== GT_EXPR
&& tst
== 1)
3798 || (comp
== GE_EXPR
&& (tst
== 0 || tst
== 1)))
3800 if (overflow_infinity_range_p (vr
))
3801 *strict_overflow_p
= true;
3802 return boolean_true_node
;
3805 /* If VR is to the left of VAL, return false. */
3806 tst
= compare_values_warnv (vr
->max
, val
, strict_overflow_p
);
3807 if ((comp
== GT_EXPR
&& (tst
== -1 || tst
== 0))
3808 || (comp
== GE_EXPR
&& tst
== -1))
3810 if (overflow_infinity_range_p (vr
))
3811 *strict_overflow_p
= true;
3812 return boolean_false_node
;
3815 /* Otherwise, we don't know. */
3823 /* Debugging dumps. */
3825 void dump_value_range (FILE *, value_range_t
*);
3826 void debug_value_range (value_range_t
*);
3827 void dump_all_value_ranges (FILE *);
3828 void debug_all_value_ranges (void);
3829 void dump_vr_equiv (FILE *, bitmap
);
3830 void debug_vr_equiv (bitmap
);
3833 /* Dump value range VR to FILE. */
3836 dump_value_range (FILE *file
, value_range_t
*vr
)
3839 fprintf (file
, "[]");
3840 else if (vr
->type
== VR_UNDEFINED
)
3841 fprintf (file
, "UNDEFINED");
3842 else if (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
)
3844 tree type
= TREE_TYPE (vr
->min
);
3846 fprintf (file
, "%s[", (vr
->type
== VR_ANTI_RANGE
) ? "~" : "");
3848 if (is_negative_overflow_infinity (vr
->min
))
3849 fprintf (file
, "-INF(OVF)");
3850 else if (INTEGRAL_TYPE_P (type
)
3851 && !TYPE_UNSIGNED (type
)
3852 && vrp_val_is_min (vr
->min
))
3853 fprintf (file
, "-INF");
3855 print_generic_expr (file
, vr
->min
, 0);
3857 fprintf (file
, ", ");
3859 if (is_positive_overflow_infinity (vr
->max
))
3860 fprintf (file
, "+INF(OVF)");
3861 else if (INTEGRAL_TYPE_P (type
)
3862 && vrp_val_is_max (vr
->max
))
3863 fprintf (file
, "+INF");
3865 print_generic_expr (file
, vr
->max
, 0);
3867 fprintf (file
, "]");
3874 fprintf (file
, " EQUIVALENCES: { ");
3876 EXECUTE_IF_SET_IN_BITMAP (vr
->equiv
, 0, i
, bi
)
3878 print_generic_expr (file
, ssa_name (i
), 0);
3879 fprintf (file
, " ");
3883 fprintf (file
, "} (%u elements)", c
);
3886 else if (vr
->type
== VR_VARYING
)
3887 fprintf (file
, "VARYING");
3889 fprintf (file
, "INVALID RANGE");
3893 /* Dump value range VR to stderr. */
3896 debug_value_range (value_range_t
*vr
)
3898 dump_value_range (stderr
, vr
);
3899 fprintf (stderr
, "\n");
3903 /* Dump value ranges of all SSA_NAMEs to FILE. */
3906 dump_all_value_ranges (FILE *file
)
3910 for (i
= 0; i
< num_vr_values
; i
++)
3914 print_generic_expr (file
, ssa_name (i
), 0);
3915 fprintf (file
, ": ");
3916 dump_value_range (file
, vr_value
[i
]);
3917 fprintf (file
, "\n");
3921 fprintf (file
, "\n");
3925 /* Dump all value ranges to stderr. */
3928 debug_all_value_ranges (void)
3930 dump_all_value_ranges (stderr
);
3934 /* Given a COND_EXPR COND of the form 'V OP W', and an SSA name V,
3935 create a new SSA name N and return the assertion assignment
3936 'V = ASSERT_EXPR <V, V OP W>'. */
3939 build_assert_expr_for (tree cond
, tree v
)
3944 gcc_assert (TREE_CODE (v
) == SSA_NAME
);
3945 n
= duplicate_ssa_name (v
, NULL
);
3947 if (COMPARISON_CLASS_P (cond
))
3949 tree a
= build2 (ASSERT_EXPR
, TREE_TYPE (v
), v
, cond
);
3950 assertion
= gimple_build_assign (n
, a
);
3952 else if (TREE_CODE (cond
) == SSA_NAME
)
3954 /* Given V, build the assignment N = true. */
3955 gcc_assert (v
== cond
);
3956 assertion
= gimple_build_assign (n
, boolean_true_node
);
3961 SSA_NAME_DEF_STMT (n
) = assertion
;
3963 /* The new ASSERT_EXPR, creates a new SSA name that replaces the
3964 operand of the ASSERT_EXPR. Register the new name and the old one
3965 in the replacement table so that we can fix the SSA web after
3966 adding all the ASSERT_EXPRs. */
3967 register_new_name_mapping (n
, v
);
3973 /* Return false if EXPR is a predicate expression involving floating
3977 fp_predicate (gimple stmt
)
3979 GIMPLE_CHECK (stmt
, GIMPLE_COND
);
3981 return FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (stmt
)));
3985 /* If the range of values taken by OP can be inferred after STMT executes,
3986 return the comparison code (COMP_CODE_P) and value (VAL_P) that
3987 describes the inferred range. Return true if a range could be
3991 infer_value_range (gimple stmt
, tree op
, enum tree_code
*comp_code_p
, tree
*val_p
)
3994 *comp_code_p
= ERROR_MARK
;
3996 /* Do not attempt to infer anything in names that flow through
3998 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op
))
4001 /* Similarly, don't infer anything from statements that may throw
4003 if (stmt_could_throw_p (stmt
))
4006 /* If STMT is the last statement of a basic block with no
4007 successors, there is no point inferring anything about any of its
4008 operands. We would not be able to find a proper insertion point
4009 for the assertion, anyway. */
4010 if (stmt_ends_bb_p (stmt
) && EDGE_COUNT (gimple_bb (stmt
)->succs
) == 0)
4013 /* We can only assume that a pointer dereference will yield
4014 non-NULL if -fdelete-null-pointer-checks is enabled. */
4015 if (flag_delete_null_pointer_checks
4016 && POINTER_TYPE_P (TREE_TYPE (op
))
4017 && gimple_code (stmt
) != GIMPLE_ASM
)
4019 unsigned num_uses
, num_loads
, num_stores
;
4021 count_uses_and_derefs (op
, stmt
, &num_uses
, &num_loads
, &num_stores
);
4022 if (num_loads
+ num_stores
> 0)
4024 *val_p
= build_int_cst (TREE_TYPE (op
), 0);
4025 *comp_code_p
= NE_EXPR
;
4034 void dump_asserts_for (FILE *, tree
);
4035 void debug_asserts_for (tree
);
4036 void dump_all_asserts (FILE *);
4037 void debug_all_asserts (void);
4039 /* Dump all the registered assertions for NAME to FILE. */
4042 dump_asserts_for (FILE *file
, tree name
)
4046 fprintf (file
, "Assertions to be inserted for ");
4047 print_generic_expr (file
, name
, 0);
4048 fprintf (file
, "\n");
4050 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
4053 fprintf (file
, "\t");
4054 print_gimple_stmt (file
, gsi_stmt (loc
->si
), 0, 0);
4055 fprintf (file
, "\n\tBB #%d", loc
->bb
->index
);
4058 fprintf (file
, "\n\tEDGE %d->%d", loc
->e
->src
->index
,
4059 loc
->e
->dest
->index
);
4060 dump_edge_info (file
, loc
->e
, 0);
4062 fprintf (file
, "\n\tPREDICATE: ");
4063 print_generic_expr (file
, name
, 0);
4064 fprintf (file
, " %s ", tree_code_name
[(int)loc
->comp_code
]);
4065 print_generic_expr (file
, loc
->val
, 0);
4066 fprintf (file
, "\n\n");
4070 fprintf (file
, "\n");
4074 /* Dump all the registered assertions for NAME to stderr. */
4077 debug_asserts_for (tree name
)
4079 dump_asserts_for (stderr
, name
);
4083 /* Dump all the registered assertions for all the names to FILE. */
4086 dump_all_asserts (FILE *file
)
4091 fprintf (file
, "\nASSERT_EXPRs to be inserted\n\n");
4092 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
4093 dump_asserts_for (file
, ssa_name (i
));
4094 fprintf (file
, "\n");
4098 /* Dump all the registered assertions for all the names to stderr. */
4101 debug_all_asserts (void)
4103 dump_all_asserts (stderr
);
4107 /* If NAME doesn't have an ASSERT_EXPR registered for asserting
4108 'EXPR COMP_CODE VAL' at a location that dominates block BB or
4109 E->DEST, then register this location as a possible insertion point
4110 for ASSERT_EXPR <NAME, EXPR COMP_CODE VAL>.
4112 BB, E and SI provide the exact insertion point for the new
4113 ASSERT_EXPR. If BB is NULL, then the ASSERT_EXPR is to be inserted
4114 on edge E. Otherwise, if E is NULL, the ASSERT_EXPR is inserted on
4115 BB. If SI points to a COND_EXPR or a SWITCH_EXPR statement, then E
4116 must not be NULL. */
4119 register_new_assert_for (tree name
, tree expr
,
4120 enum tree_code comp_code
,
4124 gimple_stmt_iterator si
)
4126 assert_locus_t n
, loc
, last_loc
;
4127 basic_block dest_bb
;
4129 gcc_checking_assert (bb
== NULL
|| e
== NULL
);
4132 gcc_checking_assert (gimple_code (gsi_stmt (si
)) != GIMPLE_COND
4133 && gimple_code (gsi_stmt (si
)) != GIMPLE_SWITCH
);
4135 /* Never build an assert comparing against an integer constant with
4136 TREE_OVERFLOW set. This confuses our undefined overflow warning
4138 if (TREE_CODE (val
) == INTEGER_CST
4139 && TREE_OVERFLOW (val
))
4140 val
= build_int_cst_wide (TREE_TYPE (val
),
4141 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
));
4143 /* The new assertion A will be inserted at BB or E. We need to
4144 determine if the new location is dominated by a previously
4145 registered location for A. If we are doing an edge insertion,
4146 assume that A will be inserted at E->DEST. Note that this is not
4149 If E is a critical edge, it will be split. But even if E is
4150 split, the new block will dominate the same set of blocks that
4153 The reverse, however, is not true, blocks dominated by E->DEST
4154 will not be dominated by the new block created to split E. So,
4155 if the insertion location is on a critical edge, we will not use
4156 the new location to move another assertion previously registered
4157 at a block dominated by E->DEST. */
4158 dest_bb
= (bb
) ? bb
: e
->dest
;
4160 /* If NAME already has an ASSERT_EXPR registered for COMP_CODE and
4161 VAL at a block dominating DEST_BB, then we don't need to insert a new
4162 one. Similarly, if the same assertion already exists at a block
4163 dominated by DEST_BB and the new location is not on a critical
4164 edge, then update the existing location for the assertion (i.e.,
4165 move the assertion up in the dominance tree).
4167 Note, this is implemented as a simple linked list because there
4168 should not be more than a handful of assertions registered per
4169 name. If this becomes a performance problem, a table hashed by
4170 COMP_CODE and VAL could be implemented. */
4171 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
4175 if (loc
->comp_code
== comp_code
4177 || operand_equal_p (loc
->val
, val
, 0))
4178 && (loc
->expr
== expr
4179 || operand_equal_p (loc
->expr
, expr
, 0)))
4181 /* If the assertion NAME COMP_CODE VAL has already been
4182 registered at a basic block that dominates DEST_BB, then
4183 we don't need to insert the same assertion again. Note
4184 that we don't check strict dominance here to avoid
4185 replicating the same assertion inside the same basic
4186 block more than once (e.g., when a pointer is
4187 dereferenced several times inside a block).
4189 An exception to this rule are edge insertions. If the
4190 new assertion is to be inserted on edge E, then it will
4191 dominate all the other insertions that we may want to
4192 insert in DEST_BB. So, if we are doing an edge
4193 insertion, don't do this dominance check. */
4195 && dominated_by_p (CDI_DOMINATORS
, dest_bb
, loc
->bb
))
4198 /* Otherwise, if E is not a critical edge and DEST_BB
4199 dominates the existing location for the assertion, move
4200 the assertion up in the dominance tree by updating its
4201 location information. */
4202 if ((e
== NULL
|| !EDGE_CRITICAL_P (e
))
4203 && dominated_by_p (CDI_DOMINATORS
, loc
->bb
, dest_bb
))
4212 /* Update the last node of the list and move to the next one. */
4217 /* If we didn't find an assertion already registered for
4218 NAME COMP_CODE VAL, add a new one at the end of the list of
4219 assertions associated with NAME. */
4220 n
= XNEW (struct assert_locus_d
);
4224 n
->comp_code
= comp_code
;
4232 asserts_for
[SSA_NAME_VERSION (name
)] = n
;
4234 bitmap_set_bit (need_assert_for
, SSA_NAME_VERSION (name
));
4237 /* (COND_OP0 COND_CODE COND_OP1) is a predicate which uses NAME.
4238 Extract a suitable test code and value and store them into *CODE_P and
4239 *VAL_P so the predicate is normalized to NAME *CODE_P *VAL_P.
4241 If no extraction was possible, return FALSE, otherwise return TRUE.
4243 If INVERT is true, then we invert the result stored into *CODE_P. */
4246 extract_code_and_val_from_cond_with_ops (tree name
, enum tree_code cond_code
,
4247 tree cond_op0
, tree cond_op1
,
4248 bool invert
, enum tree_code
*code_p
,
4251 enum tree_code comp_code
;
4254 /* Otherwise, we have a comparison of the form NAME COMP VAL
4255 or VAL COMP NAME. */
4256 if (name
== cond_op1
)
4258 /* If the predicate is of the form VAL COMP NAME, flip
4259 COMP around because we need to register NAME as the
4260 first operand in the predicate. */
4261 comp_code
= swap_tree_comparison (cond_code
);
4266 /* The comparison is of the form NAME COMP VAL, so the
4267 comparison code remains unchanged. */
4268 comp_code
= cond_code
;
4272 /* Invert the comparison code as necessary. */
4274 comp_code
= invert_tree_comparison (comp_code
, 0);
4276 /* VRP does not handle float types. */
4277 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (val
)))
4280 /* Do not register always-false predicates.
4281 FIXME: this works around a limitation in fold() when dealing with
4282 enumerations. Given 'enum { N1, N2 } x;', fold will not
4283 fold 'if (x > N2)' to 'if (0)'. */
4284 if ((comp_code
== GT_EXPR
|| comp_code
== LT_EXPR
)
4285 && INTEGRAL_TYPE_P (TREE_TYPE (val
)))
4287 tree min
= TYPE_MIN_VALUE (TREE_TYPE (val
));
4288 tree max
= TYPE_MAX_VALUE (TREE_TYPE (val
));
4290 if (comp_code
== GT_EXPR
4292 || compare_values (val
, max
) == 0))
4295 if (comp_code
== LT_EXPR
4297 || compare_values (val
, min
) == 0))
4300 *code_p
= comp_code
;
4305 /* Try to register an edge assertion for SSA name NAME on edge E for
4306 the condition COND contributing to the conditional jump pointed to by BSI.
4307 Invert the condition COND if INVERT is true.
4308 Return true if an assertion for NAME could be registered. */
4311 register_edge_assert_for_2 (tree name
, edge e
, gimple_stmt_iterator bsi
,
4312 enum tree_code cond_code
,
4313 tree cond_op0
, tree cond_op1
, bool invert
)
4316 enum tree_code comp_code
;
4317 bool retval
= false;
4319 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
4322 invert
, &comp_code
, &val
))
4325 /* Only register an ASSERT_EXPR if NAME was found in the sub-graph
4326 reachable from E. */
4327 if (live_on_edge (e
, name
)
4328 && !has_single_use (name
))
4330 register_new_assert_for (name
, name
, comp_code
, val
, NULL
, e
, bsi
);
4334 /* In the case of NAME <= CST and NAME being defined as
4335 NAME = (unsigned) NAME2 + CST2 we can assert NAME2 >= -CST2
4336 and NAME2 <= CST - CST2. We can do the same for NAME > CST.
4337 This catches range and anti-range tests. */
4338 if ((comp_code
== LE_EXPR
4339 || comp_code
== GT_EXPR
)
4340 && TREE_CODE (val
) == INTEGER_CST
4341 && TYPE_UNSIGNED (TREE_TYPE (val
)))
4343 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
4344 tree cst2
= NULL_TREE
, name2
= NULL_TREE
, name3
= NULL_TREE
;
4346 /* Extract CST2 from the (optional) addition. */
4347 if (is_gimple_assign (def_stmt
)
4348 && gimple_assign_rhs_code (def_stmt
) == PLUS_EXPR
)
4350 name2
= gimple_assign_rhs1 (def_stmt
);
4351 cst2
= gimple_assign_rhs2 (def_stmt
);
4352 if (TREE_CODE (name2
) == SSA_NAME
4353 && TREE_CODE (cst2
) == INTEGER_CST
)
4354 def_stmt
= SSA_NAME_DEF_STMT (name2
);
4357 /* Extract NAME2 from the (optional) sign-changing cast. */
4358 if (gimple_assign_cast_p (def_stmt
))
4360 if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
))
4361 && ! TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))
4362 && (TYPE_PRECISION (gimple_expr_type (def_stmt
))
4363 == TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))))
4364 name3
= gimple_assign_rhs1 (def_stmt
);
4367 /* If name3 is used later, create an ASSERT_EXPR for it. */
4368 if (name3
!= NULL_TREE
4369 && TREE_CODE (name3
) == SSA_NAME
4370 && (cst2
== NULL_TREE
4371 || TREE_CODE (cst2
) == INTEGER_CST
)
4372 && INTEGRAL_TYPE_P (TREE_TYPE (name3
))
4373 && live_on_edge (e
, name3
)
4374 && !has_single_use (name3
))
4378 /* Build an expression for the range test. */
4379 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), name3
);
4380 if (cst2
!= NULL_TREE
)
4381 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
4385 fprintf (dump_file
, "Adding assert for ");
4386 print_generic_expr (dump_file
, name3
, 0);
4387 fprintf (dump_file
, " from ");
4388 print_generic_expr (dump_file
, tmp
, 0);
4389 fprintf (dump_file
, "\n");
4392 register_new_assert_for (name3
, tmp
, comp_code
, val
, NULL
, e
, bsi
);
4397 /* If name2 is used later, create an ASSERT_EXPR for it. */
4398 if (name2
!= NULL_TREE
4399 && TREE_CODE (name2
) == SSA_NAME
4400 && TREE_CODE (cst2
) == INTEGER_CST
4401 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
4402 && live_on_edge (e
, name2
)
4403 && !has_single_use (name2
))
4407 /* Build an expression for the range test. */
4409 if (TREE_TYPE (name
) != TREE_TYPE (name2
))
4410 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), tmp
);
4411 if (cst2
!= NULL_TREE
)
4412 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
4416 fprintf (dump_file
, "Adding assert for ");
4417 print_generic_expr (dump_file
, name2
, 0);
4418 fprintf (dump_file
, " from ");
4419 print_generic_expr (dump_file
, tmp
, 0);
4420 fprintf (dump_file
, "\n");
4423 register_new_assert_for (name2
, tmp
, comp_code
, val
, NULL
, e
, bsi
);
4432 /* OP is an operand of a truth value expression which is known to have
4433 a particular value. Register any asserts for OP and for any
4434 operands in OP's defining statement.
4436 If CODE is EQ_EXPR, then we want to register OP is zero (false),
4437 if CODE is NE_EXPR, then we want to register OP is nonzero (true). */
4440 register_edge_assert_for_1 (tree op
, enum tree_code code
,
4441 edge e
, gimple_stmt_iterator bsi
)
4443 bool retval
= false;
4446 enum tree_code rhs_code
;
4448 /* We only care about SSA_NAMEs. */
4449 if (TREE_CODE (op
) != SSA_NAME
)
4452 /* We know that OP will have a zero or nonzero value. If OP is used
4453 more than once go ahead and register an assert for OP.
4455 The FOUND_IN_SUBGRAPH support is not helpful in this situation as
4456 it will always be set for OP (because OP is used in a COND_EXPR in
4458 if (!has_single_use (op
))
4460 val
= build_int_cst (TREE_TYPE (op
), 0);
4461 register_new_assert_for (op
, op
, code
, val
, NULL
, e
, bsi
);
4465 /* Now look at how OP is set. If it's set from a comparison,
4466 a truth operation or some bit operations, then we may be able
4467 to register information about the operands of that assignment. */
4468 op_def
= SSA_NAME_DEF_STMT (op
);
4469 if (gimple_code (op_def
) != GIMPLE_ASSIGN
)
4472 rhs_code
= gimple_assign_rhs_code (op_def
);
4474 if (TREE_CODE_CLASS (rhs_code
) == tcc_comparison
)
4476 bool invert
= (code
== EQ_EXPR
? true : false);
4477 tree op0
= gimple_assign_rhs1 (op_def
);
4478 tree op1
= gimple_assign_rhs2 (op_def
);
4480 if (TREE_CODE (op0
) == SSA_NAME
)
4481 retval
|= register_edge_assert_for_2 (op0
, e
, bsi
, rhs_code
, op0
, op1
,
4483 if (TREE_CODE (op1
) == SSA_NAME
)
4484 retval
|= register_edge_assert_for_2 (op1
, e
, bsi
, rhs_code
, op0
, op1
,
4487 else if ((code
== NE_EXPR
4488 && gimple_assign_rhs_code (op_def
) == BIT_AND_EXPR
)
4490 && gimple_assign_rhs_code (op_def
) == BIT_IOR_EXPR
))
4492 /* Recurse on each operand. */
4493 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4495 retval
|= register_edge_assert_for_1 (gimple_assign_rhs2 (op_def
),
4498 else if (gimple_assign_rhs_code (op_def
) == BIT_NOT_EXPR
4499 && TYPE_PRECISION (TREE_TYPE (gimple_assign_lhs (op_def
))) == 1)
4501 /* Recurse, flipping CODE. */
4502 code
= invert_tree_comparison (code
, false);
4503 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4506 else if (gimple_assign_rhs_code (op_def
) == SSA_NAME
)
4508 /* Recurse through the copy. */
4509 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4512 else if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (op_def
)))
4514 /* Recurse through the type conversion. */
4515 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
4522 /* Try to register an edge assertion for SSA name NAME on edge E for
4523 the condition COND contributing to the conditional jump pointed to by SI.
4524 Return true if an assertion for NAME could be registered. */
4527 register_edge_assert_for (tree name
, edge e
, gimple_stmt_iterator si
,
4528 enum tree_code cond_code
, tree cond_op0
,
4532 enum tree_code comp_code
;
4533 bool retval
= false;
4534 bool is_else_edge
= (e
->flags
& EDGE_FALSE_VALUE
) != 0;
4536 /* Do not attempt to infer anything in names that flow through
4538 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name
))
4541 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
4547 /* Register ASSERT_EXPRs for name. */
4548 retval
|= register_edge_assert_for_2 (name
, e
, si
, cond_code
, cond_op0
,
4549 cond_op1
, is_else_edge
);
4552 /* If COND is effectively an equality test of an SSA_NAME against
4553 the value zero or one, then we may be able to assert values
4554 for SSA_NAMEs which flow into COND. */
4556 /* In the case of NAME == 1 or NAME != 0, for BIT_AND_EXPR defining
4557 statement of NAME we can assert both operands of the BIT_AND_EXPR
4558 have nonzero value. */
4559 if (((comp_code
== EQ_EXPR
&& integer_onep (val
))
4560 || (comp_code
== NE_EXPR
&& integer_zerop (val
))))
4562 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
4564 if (is_gimple_assign (def_stmt
)
4565 && gimple_assign_rhs_code (def_stmt
) == BIT_AND_EXPR
)
4567 tree op0
= gimple_assign_rhs1 (def_stmt
);
4568 tree op1
= gimple_assign_rhs2 (def_stmt
);
4569 retval
|= register_edge_assert_for_1 (op0
, NE_EXPR
, e
, si
);
4570 retval
|= register_edge_assert_for_1 (op1
, NE_EXPR
, e
, si
);
4574 /* In the case of NAME == 0 or NAME != 1, for BIT_IOR_EXPR defining
4575 statement of NAME we can assert both operands of the BIT_IOR_EXPR
4577 if (((comp_code
== EQ_EXPR
&& integer_zerop (val
))
4578 || (comp_code
== NE_EXPR
&& integer_onep (val
))))
4580 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
4582 /* For BIT_IOR_EXPR only if NAME == 0 both operands have
4583 necessarily zero value, or if type-precision is one. */
4584 if (is_gimple_assign (def_stmt
)
4585 && (gimple_assign_rhs_code (def_stmt
) == BIT_IOR_EXPR
4586 && (TYPE_PRECISION (TREE_TYPE (name
)) == 1
4587 || comp_code
== EQ_EXPR
)))
4589 tree op0
= gimple_assign_rhs1 (def_stmt
);
4590 tree op1
= gimple_assign_rhs2 (def_stmt
);
4591 retval
|= register_edge_assert_for_1 (op0
, EQ_EXPR
, e
, si
);
4592 retval
|= register_edge_assert_for_1 (op1
, EQ_EXPR
, e
, si
);
4600 /* Determine whether the outgoing edges of BB should receive an
4601 ASSERT_EXPR for each of the operands of BB's LAST statement.
4602 The last statement of BB must be a COND_EXPR.
4604 If any of the sub-graphs rooted at BB have an interesting use of
4605 the predicate operands, an assert location node is added to the
4606 list of assertions for the corresponding operands. */
4609 find_conditional_asserts (basic_block bb
, gimple last
)
4612 gimple_stmt_iterator bsi
;
4618 need_assert
= false;
4619 bsi
= gsi_for_stmt (last
);
4621 /* Look for uses of the operands in each of the sub-graphs
4622 rooted at BB. We need to check each of the outgoing edges
4623 separately, so that we know what kind of ASSERT_EXPR to
4625 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4630 /* Register the necessary assertions for each operand in the
4631 conditional predicate. */
4632 FOR_EACH_SSA_TREE_OPERAND (op
, last
, iter
, SSA_OP_USE
)
4634 need_assert
|= register_edge_assert_for (op
, e
, bsi
,
4635 gimple_cond_code (last
),
4636 gimple_cond_lhs (last
),
4637 gimple_cond_rhs (last
));
4650 /* Compare two case labels sorting first by the destination bb index
4651 and then by the case value. */
4654 compare_case_labels (const void *p1
, const void *p2
)
4656 const struct case_info
*ci1
= (const struct case_info
*) p1
;
4657 const struct case_info
*ci2
= (const struct case_info
*) p2
;
4658 int idx1
= ci1
->bb
->index
;
4659 int idx2
= ci2
->bb
->index
;
4663 else if (idx1
== idx2
)
4665 /* Make sure the default label is first in a group. */
4666 if (!CASE_LOW (ci1
->expr
))
4668 else if (!CASE_LOW (ci2
->expr
))
4671 return tree_int_cst_compare (CASE_LOW (ci1
->expr
),
4672 CASE_LOW (ci2
->expr
));
4678 /* Determine whether the outgoing edges of BB should receive an
4679 ASSERT_EXPR for each of the operands of BB's LAST statement.
4680 The last statement of BB must be a SWITCH_EXPR.
4682 If any of the sub-graphs rooted at BB have an interesting use of
4683 the predicate operands, an assert location node is added to the
4684 list of assertions for the corresponding operands. */
4687 find_switch_asserts (basic_block bb
, gimple last
)
4690 gimple_stmt_iterator bsi
;
4693 struct case_info
*ci
;
4694 size_t n
= gimple_switch_num_labels (last
);
4695 #if GCC_VERSION >= 4000
4698 /* Work around GCC 3.4 bug (PR 37086). */
4699 volatile unsigned int idx
;
4702 need_assert
= false;
4703 bsi
= gsi_for_stmt (last
);
4704 op
= gimple_switch_index (last
);
4705 if (TREE_CODE (op
) != SSA_NAME
)
4708 /* Build a vector of case labels sorted by destination label. */
4709 ci
= XNEWVEC (struct case_info
, n
);
4710 for (idx
= 0; idx
< n
; ++idx
)
4712 ci
[idx
].expr
= gimple_switch_label (last
, idx
);
4713 ci
[idx
].bb
= label_to_block (CASE_LABEL (ci
[idx
].expr
));
4715 qsort (ci
, n
, sizeof (struct case_info
), compare_case_labels
);
4717 for (idx
= 0; idx
< n
; ++idx
)
4720 tree cl
= ci
[idx
].expr
;
4721 basic_block cbb
= ci
[idx
].bb
;
4723 min
= CASE_LOW (cl
);
4724 max
= CASE_HIGH (cl
);
4726 /* If there are multiple case labels with the same destination
4727 we need to combine them to a single value range for the edge. */
4728 if (idx
+ 1 < n
&& cbb
== ci
[idx
+ 1].bb
)
4730 /* Skip labels until the last of the group. */
4733 } while (idx
< n
&& cbb
== ci
[idx
].bb
);
4736 /* Pick up the maximum of the case label range. */
4737 if (CASE_HIGH (ci
[idx
].expr
))
4738 max
= CASE_HIGH (ci
[idx
].expr
);
4740 max
= CASE_LOW (ci
[idx
].expr
);
4743 /* Nothing to do if the range includes the default label until we
4744 can register anti-ranges. */
4745 if (min
== NULL_TREE
)
4748 /* Find the edge to register the assert expr on. */
4749 e
= find_edge (bb
, cbb
);
4751 /* Register the necessary assertions for the operand in the
4753 need_assert
|= register_edge_assert_for (op
, e
, bsi
,
4754 max
? GE_EXPR
: EQ_EXPR
,
4756 fold_convert (TREE_TYPE (op
),
4760 need_assert
|= register_edge_assert_for (op
, e
, bsi
, LE_EXPR
,
4762 fold_convert (TREE_TYPE (op
),
4772 /* Traverse all the statements in block BB looking for statements that
4773 may generate useful assertions for the SSA names in their operand.
4774 If a statement produces a useful assertion A for name N_i, then the
4775 list of assertions already generated for N_i is scanned to
4776 determine if A is actually needed.
4778 If N_i already had the assertion A at a location dominating the
4779 current location, then nothing needs to be done. Otherwise, the
4780 new location for A is recorded instead.
4782 1- For every statement S in BB, all the variables used by S are
4783 added to bitmap FOUND_IN_SUBGRAPH.
4785 2- If statement S uses an operand N in a way that exposes a known
4786 value range for N, then if N was not already generated by an
4787 ASSERT_EXPR, create a new assert location for N. For instance,
4788 if N is a pointer and the statement dereferences it, we can
4789 assume that N is not NULL.
4791 3- COND_EXPRs are a special case of #2. We can derive range
4792 information from the predicate but need to insert different
4793 ASSERT_EXPRs for each of the sub-graphs rooted at the
4794 conditional block. If the last statement of BB is a conditional
4795 expression of the form 'X op Y', then
4797 a) Remove X and Y from the set FOUND_IN_SUBGRAPH.
4799 b) If the conditional is the only entry point to the sub-graph
4800 corresponding to the THEN_CLAUSE, recurse into it. On
4801 return, if X and/or Y are marked in FOUND_IN_SUBGRAPH, then
4802 an ASSERT_EXPR is added for the corresponding variable.
4804 c) Repeat step (b) on the ELSE_CLAUSE.
4806 d) Mark X and Y in FOUND_IN_SUBGRAPH.
4815 In this case, an assertion on the THEN clause is useful to
4816 determine that 'a' is always 9 on that edge. However, an assertion
4817 on the ELSE clause would be unnecessary.
4819 4- If BB does not end in a conditional expression, then we recurse
4820 into BB's dominator children.
4822 At the end of the recursive traversal, every SSA name will have a
4823 list of locations where ASSERT_EXPRs should be added. When a new
4824 location for name N is found, it is registered by calling
4825 register_new_assert_for. That function keeps track of all the
4826 registered assertions to prevent adding unnecessary assertions.
4827 For instance, if a pointer P_4 is dereferenced more than once in a
4828 dominator tree, only the location dominating all the dereference of
4829 P_4 will receive an ASSERT_EXPR.
4831 If this function returns true, then it means that there are names
4832 for which we need to generate ASSERT_EXPRs. Those assertions are
4833 inserted by process_assert_insertions. */
4836 find_assert_locations_1 (basic_block bb
, sbitmap live
)
4838 gimple_stmt_iterator si
;
4843 need_assert
= false;
4844 last
= last_stmt (bb
);
4846 /* If BB's last statement is a conditional statement involving integer
4847 operands, determine if we need to add ASSERT_EXPRs. */
4849 && gimple_code (last
) == GIMPLE_COND
4850 && !fp_predicate (last
)
4851 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
4852 need_assert
|= find_conditional_asserts (bb
, last
);
4854 /* If BB's last statement is a switch statement involving integer
4855 operands, determine if we need to add ASSERT_EXPRs. */
4857 && gimple_code (last
) == GIMPLE_SWITCH
4858 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
4859 need_assert
|= find_switch_asserts (bb
, last
);
4861 /* Traverse all the statements in BB marking used names and looking
4862 for statements that may infer assertions for their used operands. */
4863 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
4869 stmt
= gsi_stmt (si
);
4871 if (is_gimple_debug (stmt
))
4874 /* See if we can derive an assertion for any of STMT's operands. */
4875 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_USE
)
4878 enum tree_code comp_code
;
4880 /* Mark OP in our live bitmap. */
4881 SET_BIT (live
, SSA_NAME_VERSION (op
));
4883 /* If OP is used in such a way that we can infer a value
4884 range for it, and we don't find a previous assertion for
4885 it, create a new assertion location node for OP. */
4886 if (infer_value_range (stmt
, op
, &comp_code
, &value
))
4888 /* If we are able to infer a nonzero value range for OP,
4889 then walk backwards through the use-def chain to see if OP
4890 was set via a typecast.
4892 If so, then we can also infer a nonzero value range
4893 for the operand of the NOP_EXPR. */
4894 if (comp_code
== NE_EXPR
&& integer_zerop (value
))
4897 gimple def_stmt
= SSA_NAME_DEF_STMT (t
);
4899 while (is_gimple_assign (def_stmt
)
4900 && gimple_assign_rhs_code (def_stmt
) == NOP_EXPR
4902 (gimple_assign_rhs1 (def_stmt
)) == SSA_NAME
4904 (TREE_TYPE (gimple_assign_rhs1 (def_stmt
))))
4906 t
= gimple_assign_rhs1 (def_stmt
);
4907 def_stmt
= SSA_NAME_DEF_STMT (t
);
4909 /* Note we want to register the assert for the
4910 operand of the NOP_EXPR after SI, not after the
4912 if (! has_single_use (t
))
4914 register_new_assert_for (t
, t
, comp_code
, value
,
4921 /* If OP is used only once, namely in this STMT, don't
4922 bother creating an ASSERT_EXPR for it. Such an
4923 ASSERT_EXPR would do nothing but increase compile time. */
4924 if (!has_single_use (op
))
4926 register_new_assert_for (op
, op
, comp_code
, value
,
4934 /* Traverse all PHI nodes in BB marking used operands. */
4935 for (si
= gsi_start_phis (bb
); !gsi_end_p(si
); gsi_next (&si
))
4937 use_operand_p arg_p
;
4939 phi
= gsi_stmt (si
);
4941 FOR_EACH_PHI_ARG (arg_p
, phi
, i
, SSA_OP_USE
)
4943 tree arg
= USE_FROM_PTR (arg_p
);
4944 if (TREE_CODE (arg
) == SSA_NAME
)
4945 SET_BIT (live
, SSA_NAME_VERSION (arg
));
4952 /* Do an RPO walk over the function computing SSA name liveness
4953 on-the-fly and deciding on assert expressions to insert.
4954 Returns true if there are assert expressions to be inserted. */
4957 find_assert_locations (void)
4959 int *rpo
= XCNEWVEC (int, last_basic_block
+ NUM_FIXED_BLOCKS
);
4960 int *bb_rpo
= XCNEWVEC (int, last_basic_block
+ NUM_FIXED_BLOCKS
);
4961 int *last_rpo
= XCNEWVEC (int, last_basic_block
+ NUM_FIXED_BLOCKS
);
4965 live
= XCNEWVEC (sbitmap
, last_basic_block
+ NUM_FIXED_BLOCKS
);
4966 rpo_cnt
= pre_and_rev_post_order_compute (NULL
, rpo
, false);
4967 for (i
= 0; i
< rpo_cnt
; ++i
)
4970 need_asserts
= false;
4971 for (i
= rpo_cnt
-1; i
>= 0; --i
)
4973 basic_block bb
= BASIC_BLOCK (rpo
[i
]);
4979 live
[rpo
[i
]] = sbitmap_alloc (num_ssa_names
);
4980 sbitmap_zero (live
[rpo
[i
]]);
4983 /* Process BB and update the live information with uses in
4985 need_asserts
|= find_assert_locations_1 (bb
, live
[rpo
[i
]]);
4987 /* Merge liveness into the predecessor blocks and free it. */
4988 if (!sbitmap_empty_p (live
[rpo
[i
]]))
4991 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
4993 int pred
= e
->src
->index
;
4994 if (e
->flags
& EDGE_DFS_BACK
)
4999 live
[pred
] = sbitmap_alloc (num_ssa_names
);
5000 sbitmap_zero (live
[pred
]);
5002 sbitmap_a_or_b (live
[pred
], live
[pred
], live
[rpo
[i
]]);
5004 if (bb_rpo
[pred
] < pred_rpo
)
5005 pred_rpo
= bb_rpo
[pred
];
5008 /* Record the RPO number of the last visited block that needs
5009 live information from this block. */
5010 last_rpo
[rpo
[i
]] = pred_rpo
;
5014 sbitmap_free (live
[rpo
[i
]]);
5015 live
[rpo
[i
]] = NULL
;
5018 /* We can free all successors live bitmaps if all their
5019 predecessors have been visited already. */
5020 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5021 if (last_rpo
[e
->dest
->index
] == i
5022 && live
[e
->dest
->index
])
5024 sbitmap_free (live
[e
->dest
->index
]);
5025 live
[e
->dest
->index
] = NULL
;
5030 XDELETEVEC (bb_rpo
);
5031 XDELETEVEC (last_rpo
);
5032 for (i
= 0; i
< last_basic_block
+ NUM_FIXED_BLOCKS
; ++i
)
5034 sbitmap_free (live
[i
]);
5037 return need_asserts
;
5040 /* Create an ASSERT_EXPR for NAME and insert it in the location
5041 indicated by LOC. Return true if we made any edge insertions. */
5044 process_assert_insertions_for (tree name
, assert_locus_t loc
)
5046 /* Build the comparison expression NAME_i COMP_CODE VAL. */
5053 /* If we have X <=> X do not insert an assert expr for that. */
5054 if (loc
->expr
== loc
->val
)
5057 cond
= build2 (loc
->comp_code
, boolean_type_node
, loc
->expr
, loc
->val
);
5058 assert_stmt
= build_assert_expr_for (cond
, name
);
5061 /* We have been asked to insert the assertion on an edge. This
5062 is used only by COND_EXPR and SWITCH_EXPR assertions. */
5063 gcc_checking_assert (gimple_code (gsi_stmt (loc
->si
)) == GIMPLE_COND
5064 || (gimple_code (gsi_stmt (loc
->si
))
5067 gsi_insert_on_edge (loc
->e
, assert_stmt
);
5071 /* Otherwise, we can insert right after LOC->SI iff the
5072 statement must not be the last statement in the block. */
5073 stmt
= gsi_stmt (loc
->si
);
5074 if (!stmt_ends_bb_p (stmt
))
5076 gsi_insert_after (&loc
->si
, assert_stmt
, GSI_SAME_STMT
);
5080 /* If STMT must be the last statement in BB, we can only insert new
5081 assertions on the non-abnormal edge out of BB. Note that since
5082 STMT is not control flow, there may only be one non-abnormal edge
5084 FOR_EACH_EDGE (e
, ei
, loc
->bb
->succs
)
5085 if (!(e
->flags
& EDGE_ABNORMAL
))
5087 gsi_insert_on_edge (e
, assert_stmt
);
5095 /* Process all the insertions registered for every name N_i registered
5096 in NEED_ASSERT_FOR. The list of assertions to be inserted are
5097 found in ASSERTS_FOR[i]. */
5100 process_assert_insertions (void)
5104 bool update_edges_p
= false;
5105 int num_asserts
= 0;
5107 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5108 dump_all_asserts (dump_file
);
5110 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
5112 assert_locus_t loc
= asserts_for
[i
];
5117 assert_locus_t next
= loc
->next
;
5118 update_edges_p
|= process_assert_insertions_for (ssa_name (i
), loc
);
5126 gsi_commit_edge_inserts ();
5128 statistics_counter_event (cfun
, "Number of ASSERT_EXPR expressions inserted",
5133 /* Traverse the flowgraph looking for conditional jumps to insert range
5134 expressions. These range expressions are meant to provide information
5135 to optimizations that need to reason in terms of value ranges. They
5136 will not be expanded into RTL. For instance, given:
5145 this pass will transform the code into:
5151 x = ASSERT_EXPR <x, x < y>
5156 y = ASSERT_EXPR <y, x <= y>
5160 The idea is that once copy and constant propagation have run, other
5161 optimizations will be able to determine what ranges of values can 'x'
5162 take in different paths of the code, simply by checking the reaching
5163 definition of 'x'. */
5166 insert_range_assertions (void)
5168 need_assert_for
= BITMAP_ALLOC (NULL
);
5169 asserts_for
= XCNEWVEC (assert_locus_t
, num_ssa_names
);
5171 calculate_dominance_info (CDI_DOMINATORS
);
5173 if (find_assert_locations ())
5175 process_assert_insertions ();
5176 update_ssa (TODO_update_ssa_no_phi
);
5179 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5181 fprintf (dump_file
, "\nSSA form after inserting ASSERT_EXPRs\n");
5182 dump_function_to_file (current_function_decl
, dump_file
, dump_flags
);
5186 BITMAP_FREE (need_assert_for
);
5189 /* Checks one ARRAY_REF in REF, located at LOCUS. Ignores flexible arrays
5190 and "struct" hacks. If VRP can determine that the
5191 array subscript is a constant, check if it is outside valid
5192 range. If the array subscript is a RANGE, warn if it is
5193 non-overlapping with valid range.
5194 IGNORE_OFF_BY_ONE is true if the ARRAY_REF is inside a ADDR_EXPR. */
5197 check_array_ref (location_t location
, tree ref
, bool ignore_off_by_one
)
5199 value_range_t
* vr
= NULL
;
5200 tree low_sub
, up_sub
;
5201 tree low_bound
, up_bound
, up_bound_p1
;
5204 if (TREE_NO_WARNING (ref
))
5207 low_sub
= up_sub
= TREE_OPERAND (ref
, 1);
5208 up_bound
= array_ref_up_bound (ref
);
5210 /* Can not check flexible arrays. */
5212 || TREE_CODE (up_bound
) != INTEGER_CST
)
5215 /* Accesses to trailing arrays via pointers may access storage
5216 beyond the types array bounds. */
5217 base
= get_base_address (ref
);
5218 if (base
&& TREE_CODE (base
) == MEM_REF
)
5220 tree cref
, next
= NULL_TREE
;
5222 if (TREE_CODE (TREE_OPERAND (ref
, 0)) != COMPONENT_REF
)
5225 cref
= TREE_OPERAND (ref
, 0);
5226 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (cref
, 0))) == RECORD_TYPE
)
5227 for (next
= DECL_CHAIN (TREE_OPERAND (cref
, 1));
5228 next
&& TREE_CODE (next
) != FIELD_DECL
;
5229 next
= DECL_CHAIN (next
))
5232 /* If this is the last field in a struct type or a field in a
5233 union type do not warn. */
5238 low_bound
= array_ref_low_bound (ref
);
5239 up_bound_p1
= int_const_binop (PLUS_EXPR
, up_bound
, integer_one_node
);
5241 if (TREE_CODE (low_sub
) == SSA_NAME
)
5243 vr
= get_value_range (low_sub
);
5244 if (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
)
5246 low_sub
= vr
->type
== VR_RANGE
? vr
->max
: vr
->min
;
5247 up_sub
= vr
->type
== VR_RANGE
? vr
->min
: vr
->max
;
5251 if (vr
&& vr
->type
== VR_ANTI_RANGE
)
5253 if (TREE_CODE (up_sub
) == INTEGER_CST
5254 && tree_int_cst_lt (up_bound
, up_sub
)
5255 && TREE_CODE (low_sub
) == INTEGER_CST
5256 && tree_int_cst_lt (low_sub
, low_bound
))
5258 warning_at (location
, OPT_Warray_bounds
,
5259 "array subscript is outside array bounds");
5260 TREE_NO_WARNING (ref
) = 1;
5263 else if (TREE_CODE (up_sub
) == INTEGER_CST
5264 && (ignore_off_by_one
5265 ? (tree_int_cst_lt (up_bound
, up_sub
)
5266 && !tree_int_cst_equal (up_bound_p1
, up_sub
))
5267 : (tree_int_cst_lt (up_bound
, up_sub
)
5268 || tree_int_cst_equal (up_bound_p1
, up_sub
))))
5270 warning_at (location
, OPT_Warray_bounds
,
5271 "array subscript is above array bounds");
5272 TREE_NO_WARNING (ref
) = 1;
5274 else if (TREE_CODE (low_sub
) == INTEGER_CST
5275 && tree_int_cst_lt (low_sub
, low_bound
))
5277 warning_at (location
, OPT_Warray_bounds
,
5278 "array subscript is below array bounds");
5279 TREE_NO_WARNING (ref
) = 1;
5283 /* Searches if the expr T, located at LOCATION computes
5284 address of an ARRAY_REF, and call check_array_ref on it. */
5287 search_for_addr_array (tree t
, location_t location
)
5289 while (TREE_CODE (t
) == SSA_NAME
)
5291 gimple g
= SSA_NAME_DEF_STMT (t
);
5293 if (gimple_code (g
) != GIMPLE_ASSIGN
)
5296 if (get_gimple_rhs_class (gimple_assign_rhs_code (g
))
5297 != GIMPLE_SINGLE_RHS
)
5300 t
= gimple_assign_rhs1 (g
);
5304 /* We are only interested in addresses of ARRAY_REF's. */
5305 if (TREE_CODE (t
) != ADDR_EXPR
)
5308 /* Check each ARRAY_REFs in the reference chain. */
5311 if (TREE_CODE (t
) == ARRAY_REF
)
5312 check_array_ref (location
, t
, true /*ignore_off_by_one*/);
5314 t
= TREE_OPERAND (t
, 0);
5316 while (handled_component_p (t
));
5318 if (TREE_CODE (t
) == MEM_REF
5319 && TREE_CODE (TREE_OPERAND (t
, 0)) == ADDR_EXPR
5320 && !TREE_NO_WARNING (t
))
5322 tree tem
= TREE_OPERAND (TREE_OPERAND (t
, 0), 0);
5323 tree low_bound
, up_bound
, el_sz
;
5325 if (TREE_CODE (TREE_TYPE (tem
)) != ARRAY_TYPE
5326 || TREE_CODE (TREE_TYPE (TREE_TYPE (tem
))) == ARRAY_TYPE
5327 || !TYPE_DOMAIN (TREE_TYPE (tem
)))
5330 low_bound
= TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (tem
)));
5331 up_bound
= TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (tem
)));
5332 el_sz
= TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (tem
)));
5334 || TREE_CODE (low_bound
) != INTEGER_CST
5336 || TREE_CODE (up_bound
) != INTEGER_CST
5338 || TREE_CODE (el_sz
) != INTEGER_CST
)
5341 idx
= mem_ref_offset (t
);
5342 idx
= double_int_sdiv (idx
, tree_to_double_int (el_sz
), TRUNC_DIV_EXPR
);
5343 if (double_int_scmp (idx
, double_int_zero
) < 0)
5345 warning_at (location
, OPT_Warray_bounds
,
5346 "array subscript is below array bounds");
5347 TREE_NO_WARNING (t
) = 1;
5349 else if (double_int_scmp (idx
,
5352 (tree_to_double_int (up_bound
),
5354 (tree_to_double_int (low_bound
))),
5355 double_int_one
)) > 0)
5357 warning_at (location
, OPT_Warray_bounds
,
5358 "array subscript is above array bounds");
5359 TREE_NO_WARNING (t
) = 1;
5364 /* walk_tree() callback that checks if *TP is
5365 an ARRAY_REF inside an ADDR_EXPR (in which an array
5366 subscript one outside the valid range is allowed). Call
5367 check_array_ref for each ARRAY_REF found. The location is
5371 check_array_bounds (tree
*tp
, int *walk_subtree
, void *data
)
5374 struct walk_stmt_info
*wi
= (struct walk_stmt_info
*) data
;
5375 location_t location
;
5377 if (EXPR_HAS_LOCATION (t
))
5378 location
= EXPR_LOCATION (t
);
5381 location_t
*locp
= (location_t
*) wi
->info
;
5385 *walk_subtree
= TRUE
;
5387 if (TREE_CODE (t
) == ARRAY_REF
)
5388 check_array_ref (location
, t
, false /*ignore_off_by_one*/);
5390 if (TREE_CODE (t
) == MEM_REF
5391 || (TREE_CODE (t
) == RETURN_EXPR
&& TREE_OPERAND (t
, 0)))
5392 search_for_addr_array (TREE_OPERAND (t
, 0), location
);
5394 if (TREE_CODE (t
) == ADDR_EXPR
)
5395 *walk_subtree
= FALSE
;
5400 /* Walk over all statements of all reachable BBs and call check_array_bounds
5404 check_all_array_refs (void)
5407 gimple_stmt_iterator si
;
5413 bool executable
= false;
5415 /* Skip blocks that were found to be unreachable. */
5416 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
5417 executable
|= !!(e
->flags
& EDGE_EXECUTABLE
);
5421 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
5423 gimple stmt
= gsi_stmt (si
);
5424 struct walk_stmt_info wi
;
5425 if (!gimple_has_location (stmt
))
5428 if (is_gimple_call (stmt
))
5431 size_t n
= gimple_call_num_args (stmt
);
5432 for (i
= 0; i
< n
; i
++)
5434 tree arg
= gimple_call_arg (stmt
, i
);
5435 search_for_addr_array (arg
, gimple_location (stmt
));
5440 memset (&wi
, 0, sizeof (wi
));
5441 wi
.info
= CONST_CAST (void *, (const void *)
5442 gimple_location_ptr (stmt
));
5444 walk_gimple_op (gsi_stmt (si
),
5452 /* Convert range assertion expressions into the implied copies and
5453 copy propagate away the copies. Doing the trivial copy propagation
5454 here avoids the need to run the full copy propagation pass after
5457 FIXME, this will eventually lead to copy propagation removing the
5458 names that had useful range information attached to them. For
5459 instance, if we had the assertion N_i = ASSERT_EXPR <N_j, N_j > 3>,
5460 then N_i will have the range [3, +INF].
5462 However, by converting the assertion into the implied copy
5463 operation N_i = N_j, we will then copy-propagate N_j into the uses
5464 of N_i and lose the range information. We may want to hold on to
5465 ASSERT_EXPRs a little while longer as the ranges could be used in
5466 things like jump threading.
5468 The problem with keeping ASSERT_EXPRs around is that passes after
5469 VRP need to handle them appropriately.
5471 Another approach would be to make the range information a first
5472 class property of the SSA_NAME so that it can be queried from
5473 any pass. This is made somewhat more complex by the need for
5474 multiple ranges to be associated with one SSA_NAME. */
5477 remove_range_assertions (void)
5480 gimple_stmt_iterator si
;
5482 /* Note that the BSI iterator bump happens at the bottom of the
5483 loop and no bump is necessary if we're removing the statement
5484 referenced by the current BSI. */
5486 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
);)
5488 gimple stmt
= gsi_stmt (si
);
5491 if (is_gimple_assign (stmt
)
5492 && gimple_assign_rhs_code (stmt
) == ASSERT_EXPR
)
5494 tree rhs
= gimple_assign_rhs1 (stmt
);
5496 tree cond
= fold (ASSERT_EXPR_COND (rhs
));
5497 use_operand_p use_p
;
5498 imm_use_iterator iter
;
5500 gcc_assert (cond
!= boolean_false_node
);
5502 /* Propagate the RHS into every use of the LHS. */
5503 var
= ASSERT_EXPR_VAR (rhs
);
5504 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
,
5505 gimple_assign_lhs (stmt
))
5506 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
5508 SET_USE (use_p
, var
);
5509 gcc_assert (TREE_CODE (var
) == SSA_NAME
);
5512 /* And finally, remove the copy, it is not needed. */
5513 gsi_remove (&si
, true);
5514 release_defs (stmt
);
5522 /* Return true if STMT is interesting for VRP. */
5525 stmt_interesting_for_vrp (gimple stmt
)
5527 if (gimple_code (stmt
) == GIMPLE_PHI
5528 && is_gimple_reg (gimple_phi_result (stmt
))
5529 && (INTEGRAL_TYPE_P (TREE_TYPE (gimple_phi_result (stmt
)))
5530 || POINTER_TYPE_P (TREE_TYPE (gimple_phi_result (stmt
)))))
5532 else if (is_gimple_assign (stmt
) || is_gimple_call (stmt
))
5534 tree lhs
= gimple_get_lhs (stmt
);
5536 /* In general, assignments with virtual operands are not useful
5537 for deriving ranges, with the obvious exception of calls to
5538 builtin functions. */
5539 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
5540 && (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
5541 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
5542 && ((is_gimple_call (stmt
)
5543 && gimple_call_fndecl (stmt
) != NULL_TREE
5544 && DECL_BUILT_IN (gimple_call_fndecl (stmt
)))
5545 || !gimple_vuse (stmt
)))
5548 else if (gimple_code (stmt
) == GIMPLE_COND
5549 || gimple_code (stmt
) == GIMPLE_SWITCH
)
5556 /* Initialize local data structures for VRP. */
5559 vrp_initialize (void)
5563 values_propagated
= false;
5564 num_vr_values
= num_ssa_names
;
5565 vr_value
= XCNEWVEC (value_range_t
*, num_vr_values
);
5566 vr_phi_edge_counts
= XCNEWVEC (int, num_ssa_names
);
5570 gimple_stmt_iterator si
;
5572 for (si
= gsi_start_phis (bb
); !gsi_end_p (si
); gsi_next (&si
))
5574 gimple phi
= gsi_stmt (si
);
5575 if (!stmt_interesting_for_vrp (phi
))
5577 tree lhs
= PHI_RESULT (phi
);
5578 set_value_range_to_varying (get_value_range (lhs
));
5579 prop_set_simulate_again (phi
, false);
5582 prop_set_simulate_again (phi
, true);
5585 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
5587 gimple stmt
= gsi_stmt (si
);
5589 /* If the statement is a control insn, then we do not
5590 want to avoid simulating the statement once. Failure
5591 to do so means that those edges will never get added. */
5592 if (stmt_ends_bb_p (stmt
))
5593 prop_set_simulate_again (stmt
, true);
5594 else if (!stmt_interesting_for_vrp (stmt
))
5598 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, i
, SSA_OP_DEF
)
5599 set_value_range_to_varying (get_value_range (def
));
5600 prop_set_simulate_again (stmt
, false);
5603 prop_set_simulate_again (stmt
, true);
5608 /* Return the singleton value-range for NAME or NAME. */
5611 vrp_valueize (tree name
)
5613 if (TREE_CODE (name
) == SSA_NAME
)
5615 value_range_t
*vr
= get_value_range (name
);
5616 if (vr
->type
== VR_RANGE
5617 && (vr
->min
== vr
->max
5618 || operand_equal_p (vr
->min
, vr
->max
, 0)))
5624 /* Visit assignment STMT. If it produces an interesting range, record
5625 the SSA name in *OUTPUT_P. */
5627 static enum ssa_prop_result
5628 vrp_visit_assignment_or_call (gimple stmt
, tree
*output_p
)
5632 enum gimple_code code
= gimple_code (stmt
);
5633 lhs
= gimple_get_lhs (stmt
);
5635 /* We only keep track of ranges in integral and pointer types. */
5636 if (TREE_CODE (lhs
) == SSA_NAME
5637 && ((INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
5638 /* It is valid to have NULL MIN/MAX values on a type. See
5639 build_range_type. */
5640 && TYPE_MIN_VALUE (TREE_TYPE (lhs
))
5641 && TYPE_MAX_VALUE (TREE_TYPE (lhs
)))
5642 || POINTER_TYPE_P (TREE_TYPE (lhs
))))
5644 value_range_t new_vr
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
5646 /* Try folding the statement to a constant first. */
5647 tree tem
= gimple_fold_stmt_to_constant (stmt
, vrp_valueize
);
5648 if (tem
&& !is_overflow_infinity (tem
))
5649 set_value_range (&new_vr
, VR_RANGE
, tem
, tem
, NULL
);
5650 /* Then dispatch to value-range extracting functions. */
5651 else if (code
== GIMPLE_CALL
)
5652 extract_range_basic (&new_vr
, stmt
);
5654 extract_range_from_assignment (&new_vr
, stmt
);
5656 if (update_value_range (lhs
, &new_vr
))
5660 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
5662 fprintf (dump_file
, "Found new range for ");
5663 print_generic_expr (dump_file
, lhs
, 0);
5664 fprintf (dump_file
, ": ");
5665 dump_value_range (dump_file
, &new_vr
);
5666 fprintf (dump_file
, "\n\n");
5669 if (new_vr
.type
== VR_VARYING
)
5670 return SSA_PROP_VARYING
;
5672 return SSA_PROP_INTERESTING
;
5675 return SSA_PROP_NOT_INTERESTING
;
5678 /* Every other statement produces no useful ranges. */
5679 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_DEF
)
5680 set_value_range_to_varying (get_value_range (def
));
5682 return SSA_PROP_VARYING
;
5685 /* Helper that gets the value range of the SSA_NAME with version I
5686 or a symbolic range containing the SSA_NAME only if the value range
5687 is varying or undefined. */
5689 static inline value_range_t
5690 get_vr_for_comparison (int i
)
5692 value_range_t vr
= *get_value_range (ssa_name (i
));
5694 /* If name N_i does not have a valid range, use N_i as its own
5695 range. This allows us to compare against names that may
5696 have N_i in their ranges. */
5697 if (vr
.type
== VR_VARYING
|| vr
.type
== VR_UNDEFINED
)
5700 vr
.min
= ssa_name (i
);
5701 vr
.max
= ssa_name (i
);
5707 /* Compare all the value ranges for names equivalent to VAR with VAL
5708 using comparison code COMP. Return the same value returned by
5709 compare_range_with_value, including the setting of
5710 *STRICT_OVERFLOW_P. */
5713 compare_name_with_value (enum tree_code comp
, tree var
, tree val
,
5714 bool *strict_overflow_p
)
5720 int used_strict_overflow
;
5722 value_range_t equiv_vr
;
5724 /* Get the set of equivalences for VAR. */
5725 e
= get_value_range (var
)->equiv
;
5727 /* Start at -1. Set it to 0 if we do a comparison without relying
5728 on overflow, or 1 if all comparisons rely on overflow. */
5729 used_strict_overflow
= -1;
5731 /* Compare vars' value range with val. */
5732 equiv_vr
= get_vr_for_comparison (SSA_NAME_VERSION (var
));
5734 retval
= compare_range_with_value (comp
, &equiv_vr
, val
, &sop
);
5736 used_strict_overflow
= sop
? 1 : 0;
5738 /* If the equiv set is empty we have done all work we need to do. */
5742 && used_strict_overflow
> 0)
5743 *strict_overflow_p
= true;
5747 EXECUTE_IF_SET_IN_BITMAP (e
, 0, i
, bi
)
5749 equiv_vr
= get_vr_for_comparison (i
);
5751 t
= compare_range_with_value (comp
, &equiv_vr
, val
, &sop
);
5754 /* If we get different answers from different members
5755 of the equivalence set this check must be in a dead
5756 code region. Folding it to a trap representation
5757 would be correct here. For now just return don't-know. */
5767 used_strict_overflow
= 0;
5768 else if (used_strict_overflow
< 0)
5769 used_strict_overflow
= 1;
5774 && used_strict_overflow
> 0)
5775 *strict_overflow_p
= true;
5781 /* Given a comparison code COMP and names N1 and N2, compare all the
5782 ranges equivalent to N1 against all the ranges equivalent to N2
5783 to determine the value of N1 COMP N2. Return the same value
5784 returned by compare_ranges. Set *STRICT_OVERFLOW_P to indicate
5785 whether we relied on an overflow infinity in the comparison. */
5789 compare_names (enum tree_code comp
, tree n1
, tree n2
,
5790 bool *strict_overflow_p
)
5794 bitmap_iterator bi1
, bi2
;
5796 int used_strict_overflow
;
5797 static bitmap_obstack
*s_obstack
= NULL
;
5798 static bitmap s_e1
= NULL
, s_e2
= NULL
;
5800 /* Compare the ranges of every name equivalent to N1 against the
5801 ranges of every name equivalent to N2. */
5802 e1
= get_value_range (n1
)->equiv
;
5803 e2
= get_value_range (n2
)->equiv
;
5805 /* Use the fake bitmaps if e1 or e2 are not available. */
5806 if (s_obstack
== NULL
)
5808 s_obstack
= XNEW (bitmap_obstack
);
5809 bitmap_obstack_initialize (s_obstack
);
5810 s_e1
= BITMAP_ALLOC (s_obstack
);
5811 s_e2
= BITMAP_ALLOC (s_obstack
);
5818 /* Add N1 and N2 to their own set of equivalences to avoid
5819 duplicating the body of the loop just to check N1 and N2
5821 bitmap_set_bit (e1
, SSA_NAME_VERSION (n1
));
5822 bitmap_set_bit (e2
, SSA_NAME_VERSION (n2
));
5824 /* If the equivalence sets have a common intersection, then the two
5825 names can be compared without checking their ranges. */
5826 if (bitmap_intersect_p (e1
, e2
))
5828 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5829 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5831 return (comp
== EQ_EXPR
|| comp
== GE_EXPR
|| comp
== LE_EXPR
)
5833 : boolean_false_node
;
5836 /* Start at -1. Set it to 0 if we do a comparison without relying
5837 on overflow, or 1 if all comparisons rely on overflow. */
5838 used_strict_overflow
= -1;
5840 /* Otherwise, compare all the equivalent ranges. First, add N1 and
5841 N2 to their own set of equivalences to avoid duplicating the body
5842 of the loop just to check N1 and N2 ranges. */
5843 EXECUTE_IF_SET_IN_BITMAP (e1
, 0, i1
, bi1
)
5845 value_range_t vr1
= get_vr_for_comparison (i1
);
5847 t
= retval
= NULL_TREE
;
5848 EXECUTE_IF_SET_IN_BITMAP (e2
, 0, i2
, bi2
)
5852 value_range_t vr2
= get_vr_for_comparison (i2
);
5854 t
= compare_ranges (comp
, &vr1
, &vr2
, &sop
);
5857 /* If we get different answers from different members
5858 of the equivalence set this check must be in a dead
5859 code region. Folding it to a trap representation
5860 would be correct here. For now just return don't-know. */
5864 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5865 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5871 used_strict_overflow
= 0;
5872 else if (used_strict_overflow
< 0)
5873 used_strict_overflow
= 1;
5879 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5880 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5881 if (used_strict_overflow
> 0)
5882 *strict_overflow_p
= true;
5887 /* None of the equivalent ranges are useful in computing this
5889 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
5890 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
5894 /* Helper function for vrp_evaluate_conditional_warnv. */
5897 vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code code
,
5899 bool * strict_overflow_p
)
5901 value_range_t
*vr0
, *vr1
;
5903 vr0
= (TREE_CODE (op0
) == SSA_NAME
) ? get_value_range (op0
) : NULL
;
5904 vr1
= (TREE_CODE (op1
) == SSA_NAME
) ? get_value_range (op1
) : NULL
;
5907 return compare_ranges (code
, vr0
, vr1
, strict_overflow_p
);
5908 else if (vr0
&& vr1
== NULL
)
5909 return compare_range_with_value (code
, vr0
, op1
, strict_overflow_p
);
5910 else if (vr0
== NULL
&& vr1
)
5911 return (compare_range_with_value
5912 (swap_tree_comparison (code
), vr1
, op0
, strict_overflow_p
));
5916 /* Helper function for vrp_evaluate_conditional_warnv. */
5919 vrp_evaluate_conditional_warnv_with_ops (enum tree_code code
, tree op0
,
5920 tree op1
, bool use_equiv_p
,
5921 bool *strict_overflow_p
, bool *only_ranges
)
5925 *only_ranges
= true;
5927 /* We only deal with integral and pointer types. */
5928 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0
))
5929 && !POINTER_TYPE_P (TREE_TYPE (op0
)))
5935 && (ret
= vrp_evaluate_conditional_warnv_with_ops_using_ranges
5936 (code
, op0
, op1
, strict_overflow_p
)))
5938 *only_ranges
= false;
5939 if (TREE_CODE (op0
) == SSA_NAME
&& TREE_CODE (op1
) == SSA_NAME
)
5940 return compare_names (code
, op0
, op1
, strict_overflow_p
);
5941 else if (TREE_CODE (op0
) == SSA_NAME
)
5942 return compare_name_with_value (code
, op0
, op1
, strict_overflow_p
);
5943 else if (TREE_CODE (op1
) == SSA_NAME
)
5944 return (compare_name_with_value
5945 (swap_tree_comparison (code
), op1
, op0
, strict_overflow_p
));
5948 return vrp_evaluate_conditional_warnv_with_ops_using_ranges (code
, op0
, op1
,
5953 /* Given (CODE OP0 OP1) within STMT, try to simplify it based on value range
5954 information. Return NULL if the conditional can not be evaluated.
5955 The ranges of all the names equivalent with the operands in COND
5956 will be used when trying to compute the value. If the result is
5957 based on undefined signed overflow, issue a warning if
5961 vrp_evaluate_conditional (enum tree_code code
, tree op0
, tree op1
, gimple stmt
)
5967 /* Some passes and foldings leak constants with overflow flag set
5968 into the IL. Avoid doing wrong things with these and bail out. */
5969 if ((TREE_CODE (op0
) == INTEGER_CST
5970 && TREE_OVERFLOW (op0
))
5971 || (TREE_CODE (op1
) == INTEGER_CST
5972 && TREE_OVERFLOW (op1
)))
5976 ret
= vrp_evaluate_conditional_warnv_with_ops (code
, op0
, op1
, true, &sop
,
5981 enum warn_strict_overflow_code wc
;
5982 const char* warnmsg
;
5984 if (is_gimple_min_invariant (ret
))
5986 wc
= WARN_STRICT_OVERFLOW_CONDITIONAL
;
5987 warnmsg
= G_("assuming signed overflow does not occur when "
5988 "simplifying conditional to constant");
5992 wc
= WARN_STRICT_OVERFLOW_COMPARISON
;
5993 warnmsg
= G_("assuming signed overflow does not occur when "
5994 "simplifying conditional");
5997 if (issue_strict_overflow_warning (wc
))
5999 location_t location
;
6001 if (!gimple_has_location (stmt
))
6002 location
= input_location
;
6004 location
= gimple_location (stmt
);
6005 warning_at (location
, OPT_Wstrict_overflow
, "%s", warnmsg
);
6009 if (warn_type_limits
6010 && ret
&& only_ranges
6011 && TREE_CODE_CLASS (code
) == tcc_comparison
6012 && TREE_CODE (op0
) == SSA_NAME
)
6014 /* If the comparison is being folded and the operand on the LHS
6015 is being compared against a constant value that is outside of
6016 the natural range of OP0's type, then the predicate will
6017 always fold regardless of the value of OP0. If -Wtype-limits
6018 was specified, emit a warning. */
6019 tree type
= TREE_TYPE (op0
);
6020 value_range_t
*vr0
= get_value_range (op0
);
6022 if (vr0
->type
!= VR_VARYING
6023 && INTEGRAL_TYPE_P (type
)
6024 && vrp_val_is_min (vr0
->min
)
6025 && vrp_val_is_max (vr0
->max
)
6026 && is_gimple_min_invariant (op1
))
6028 location_t location
;
6030 if (!gimple_has_location (stmt
))
6031 location
= input_location
;
6033 location
= gimple_location (stmt
);
6035 warning_at (location
, OPT_Wtype_limits
,
6037 ? G_("comparison always false "
6038 "due to limited range of data type")
6039 : G_("comparison always true "
6040 "due to limited range of data type"));
6048 /* Visit conditional statement STMT. If we can determine which edge
6049 will be taken out of STMT's basic block, record it in
6050 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
6051 SSA_PROP_VARYING. */
6053 static enum ssa_prop_result
6054 vrp_visit_cond_stmt (gimple stmt
, edge
*taken_edge_p
)
6059 *taken_edge_p
= NULL
;
6061 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6066 fprintf (dump_file
, "\nVisiting conditional with predicate: ");
6067 print_gimple_stmt (dump_file
, stmt
, 0, 0);
6068 fprintf (dump_file
, "\nWith known ranges\n");
6070 FOR_EACH_SSA_TREE_OPERAND (use
, stmt
, i
, SSA_OP_USE
)
6072 fprintf (dump_file
, "\t");
6073 print_generic_expr (dump_file
, use
, 0);
6074 fprintf (dump_file
, ": ");
6075 dump_value_range (dump_file
, vr_value
[SSA_NAME_VERSION (use
)]);
6078 fprintf (dump_file
, "\n");
6081 /* Compute the value of the predicate COND by checking the known
6082 ranges of each of its operands.
6084 Note that we cannot evaluate all the equivalent ranges here
6085 because those ranges may not yet be final and with the current
6086 propagation strategy, we cannot determine when the value ranges
6087 of the names in the equivalence set have changed.
6089 For instance, given the following code fragment
6093 i_14 = ASSERT_EXPR <i_5, i_5 != 0>
6097 Assume that on the first visit to i_14, i_5 has the temporary
6098 range [8, 8] because the second argument to the PHI function is
6099 not yet executable. We derive the range ~[0, 0] for i_14 and the
6100 equivalence set { i_5 }. So, when we visit 'if (i_14 == 1)' for
6101 the first time, since i_14 is equivalent to the range [8, 8], we
6102 determine that the predicate is always false.
6104 On the next round of propagation, i_13 is determined to be
6105 VARYING, which causes i_5 to drop down to VARYING. So, another
6106 visit to i_14 is scheduled. In this second visit, we compute the
6107 exact same range and equivalence set for i_14, namely ~[0, 0] and
6108 { i_5 }. But we did not have the previous range for i_5
6109 registered, so vrp_visit_assignment thinks that the range for
6110 i_14 has not changed. Therefore, the predicate 'if (i_14 == 1)'
6111 is not visited again, which stops propagation from visiting
6112 statements in the THEN clause of that if().
6114 To properly fix this we would need to keep the previous range
6115 value for the names in the equivalence set. This way we would've
6116 discovered that from one visit to the other i_5 changed from
6117 range [8, 8] to VR_VARYING.
6119 However, fixing this apparent limitation may not be worth the
6120 additional checking. Testing on several code bases (GCC, DLV,
6121 MICO, TRAMP3D and SPEC2000) showed that doing this results in
6122 4 more predicates folded in SPEC. */
6125 val
= vrp_evaluate_conditional_warnv_with_ops (gimple_cond_code (stmt
),
6126 gimple_cond_lhs (stmt
),
6127 gimple_cond_rhs (stmt
),
6132 *taken_edge_p
= find_taken_edge (gimple_bb (stmt
), val
);
6135 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6137 "\nIgnoring predicate evaluation because "
6138 "it assumes that signed overflow is undefined");
6143 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6145 fprintf (dump_file
, "\nPredicate evaluates to: ");
6146 if (val
== NULL_TREE
)
6147 fprintf (dump_file
, "DON'T KNOW\n");
6149 print_generic_stmt (dump_file
, val
, 0);
6152 return (*taken_edge_p
) ? SSA_PROP_INTERESTING
: SSA_PROP_VARYING
;
6155 /* Searches the case label vector VEC for the index *IDX of the CASE_LABEL
6156 that includes the value VAL. The search is restricted to the range
6157 [START_IDX, n - 1] where n is the size of VEC.
6159 If there is a CASE_LABEL for VAL, its index is placed in IDX and true is
6162 If there is no CASE_LABEL for VAL and there is one that is larger than VAL,
6163 it is placed in IDX and false is returned.
6165 If VAL is larger than any CASE_LABEL, n is placed on IDX and false is
6169 find_case_label_index (gimple stmt
, size_t start_idx
, tree val
, size_t *idx
)
6171 size_t n
= gimple_switch_num_labels (stmt
);
6174 /* Find case label for minimum of the value range or the next one.
6175 At each iteration we are searching in [low, high - 1]. */
6177 for (low
= start_idx
, high
= n
; high
!= low
; )
6181 /* Note that i != high, so we never ask for n. */
6182 size_t i
= (high
+ low
) / 2;
6183 t
= gimple_switch_label (stmt
, i
);
6185 /* Cache the result of comparing CASE_LOW and val. */
6186 cmp
= tree_int_cst_compare (CASE_LOW (t
), val
);
6190 /* Ranges cannot be empty. */
6199 if (CASE_HIGH (t
) != NULL
6200 && tree_int_cst_compare (CASE_HIGH (t
), val
) >= 0)
6212 /* Searches the case label vector VEC for the range of CASE_LABELs that is used
6213 for values between MIN and MAX. The first index is placed in MIN_IDX. The
6214 last index is placed in MAX_IDX. If the range of CASE_LABELs is empty
6215 then MAX_IDX < MIN_IDX.
6216 Returns true if the default label is not needed. */
6219 find_case_label_range (gimple stmt
, tree min
, tree max
, size_t *min_idx
,
6223 bool min_take_default
= !find_case_label_index (stmt
, 1, min
, &i
);
6224 bool max_take_default
= !find_case_label_index (stmt
, i
, max
, &j
);
6228 && max_take_default
)
6230 /* Only the default case label reached.
6231 Return an empty range. */
6238 bool take_default
= min_take_default
|| max_take_default
;
6242 if (max_take_default
)
6245 /* If the case label range is continuous, we do not need
6246 the default case label. Verify that. */
6247 high
= CASE_LOW (gimple_switch_label (stmt
, i
));
6248 if (CASE_HIGH (gimple_switch_label (stmt
, i
)))
6249 high
= CASE_HIGH (gimple_switch_label (stmt
, i
));
6250 for (k
= i
+ 1; k
<= j
; ++k
)
6252 low
= CASE_LOW (gimple_switch_label (stmt
, k
));
6253 if (!integer_onep (int_const_binop (MINUS_EXPR
, low
, high
)))
6255 take_default
= true;
6259 if (CASE_HIGH (gimple_switch_label (stmt
, k
)))
6260 high
= CASE_HIGH (gimple_switch_label (stmt
, k
));
6265 return !take_default
;
6269 /* Visit switch statement STMT. If we can determine which edge
6270 will be taken out of STMT's basic block, record it in
6271 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
6272 SSA_PROP_VARYING. */
6274 static enum ssa_prop_result
6275 vrp_visit_switch_stmt (gimple stmt
, edge
*taken_edge_p
)
6279 size_t i
= 0, j
= 0;
6282 *taken_edge_p
= NULL
;
6283 op
= gimple_switch_index (stmt
);
6284 if (TREE_CODE (op
) != SSA_NAME
)
6285 return SSA_PROP_VARYING
;
6287 vr
= get_value_range (op
);
6288 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6290 fprintf (dump_file
, "\nVisiting switch expression with operand ");
6291 print_generic_expr (dump_file
, op
, 0);
6292 fprintf (dump_file
, " with known range ");
6293 dump_value_range (dump_file
, vr
);
6294 fprintf (dump_file
, "\n");
6297 if (vr
->type
!= VR_RANGE
6298 || symbolic_range_p (vr
))
6299 return SSA_PROP_VARYING
;
6301 /* Find the single edge that is taken from the switch expression. */
6302 take_default
= !find_case_label_range (stmt
, vr
->min
, vr
->max
, &i
, &j
);
6304 /* Check if the range spans no CASE_LABEL. If so, we only reach the default
6308 gcc_assert (take_default
);
6309 val
= gimple_switch_default_label (stmt
);
6313 /* Check if labels with index i to j and maybe the default label
6314 are all reaching the same label. */
6316 val
= gimple_switch_label (stmt
, i
);
6318 && CASE_LABEL (gimple_switch_default_label (stmt
))
6319 != CASE_LABEL (val
))
6321 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6322 fprintf (dump_file
, " not a single destination for this "
6324 return SSA_PROP_VARYING
;
6326 for (++i
; i
<= j
; ++i
)
6328 if (CASE_LABEL (gimple_switch_label (stmt
, i
)) != CASE_LABEL (val
))
6330 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6331 fprintf (dump_file
, " not a single destination for this "
6333 return SSA_PROP_VARYING
;
6338 *taken_edge_p
= find_edge (gimple_bb (stmt
),
6339 label_to_block (CASE_LABEL (val
)));
6341 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6343 fprintf (dump_file
, " will take edge to ");
6344 print_generic_stmt (dump_file
, CASE_LABEL (val
), 0);
6347 return SSA_PROP_INTERESTING
;
6351 /* Evaluate statement STMT. If the statement produces a useful range,
6352 return SSA_PROP_INTERESTING and record the SSA name with the
6353 interesting range into *OUTPUT_P.
6355 If STMT is a conditional branch and we can determine its truth
6356 value, the taken edge is recorded in *TAKEN_EDGE_P.
6358 If STMT produces a varying value, return SSA_PROP_VARYING. */
6360 static enum ssa_prop_result
6361 vrp_visit_stmt (gimple stmt
, edge
*taken_edge_p
, tree
*output_p
)
6366 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6368 fprintf (dump_file
, "\nVisiting statement:\n");
6369 print_gimple_stmt (dump_file
, stmt
, 0, dump_flags
);
6370 fprintf (dump_file
, "\n");
6373 if (!stmt_interesting_for_vrp (stmt
))
6374 gcc_assert (stmt_ends_bb_p (stmt
));
6375 else if (is_gimple_assign (stmt
) || is_gimple_call (stmt
))
6377 /* In general, assignments with virtual operands are not useful
6378 for deriving ranges, with the obvious exception of calls to
6379 builtin functions. */
6380 if ((is_gimple_call (stmt
)
6381 && gimple_call_fndecl (stmt
) != NULL_TREE
6382 && DECL_BUILT_IN (gimple_call_fndecl (stmt
)))
6383 || !gimple_vuse (stmt
))
6384 return vrp_visit_assignment_or_call (stmt
, output_p
);
6386 else if (gimple_code (stmt
) == GIMPLE_COND
)
6387 return vrp_visit_cond_stmt (stmt
, taken_edge_p
);
6388 else if (gimple_code (stmt
) == GIMPLE_SWITCH
)
6389 return vrp_visit_switch_stmt (stmt
, taken_edge_p
);
6391 /* All other statements produce nothing of interest for VRP, so mark
6392 their outputs varying and prevent further simulation. */
6393 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_DEF
)
6394 set_value_range_to_varying (get_value_range (def
));
6396 return SSA_PROP_VARYING
;
6400 /* Meet operation for value ranges. Given two value ranges VR0 and
6401 VR1, store in VR0 a range that contains both VR0 and VR1. This
6402 may not be the smallest possible such range. */
6405 vrp_meet (value_range_t
*vr0
, value_range_t
*vr1
)
6407 if (vr0
->type
== VR_UNDEFINED
)
6409 copy_value_range (vr0
, vr1
);
6413 if (vr1
->type
== VR_UNDEFINED
)
6415 /* Nothing to do. VR0 already has the resulting range. */
6419 if (vr0
->type
== VR_VARYING
)
6421 /* Nothing to do. VR0 already has the resulting range. */
6425 if (vr1
->type
== VR_VARYING
)
6427 set_value_range_to_varying (vr0
);
6431 if (vr0
->type
== VR_RANGE
&& vr1
->type
== VR_RANGE
)
6436 /* Compute the convex hull of the ranges. The lower limit of
6437 the new range is the minimum of the two ranges. If they
6438 cannot be compared, then give up. */
6439 cmp
= compare_values (vr0
->min
, vr1
->min
);
6440 if (cmp
== 0 || cmp
== 1)
6447 /* Similarly, the upper limit of the new range is the maximum
6448 of the two ranges. If they cannot be compared, then
6450 cmp
= compare_values (vr0
->max
, vr1
->max
);
6451 if (cmp
== 0 || cmp
== -1)
6458 /* Check for useless ranges. */
6459 if (INTEGRAL_TYPE_P (TREE_TYPE (min
))
6460 && ((vrp_val_is_min (min
) || is_overflow_infinity (min
))
6461 && (vrp_val_is_max (max
) || is_overflow_infinity (max
))))
6464 /* The resulting set of equivalences is the intersection of
6466 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
6467 bitmap_and_into (vr0
->equiv
, vr1
->equiv
);
6468 else if (vr0
->equiv
&& !vr1
->equiv
)
6469 bitmap_clear (vr0
->equiv
);
6471 set_value_range (vr0
, vr0
->type
, min
, max
, vr0
->equiv
);
6473 else if (vr0
->type
== VR_ANTI_RANGE
&& vr1
->type
== VR_ANTI_RANGE
)
6475 /* Two anti-ranges meet only if their complements intersect.
6476 Only handle the case of identical ranges. */
6477 if (compare_values (vr0
->min
, vr1
->min
) == 0
6478 && compare_values (vr0
->max
, vr1
->max
) == 0
6479 && compare_values (vr0
->min
, vr0
->max
) == 0)
6481 /* The resulting set of equivalences is the intersection of
6483 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
6484 bitmap_and_into (vr0
->equiv
, vr1
->equiv
);
6485 else if (vr0
->equiv
&& !vr1
->equiv
)
6486 bitmap_clear (vr0
->equiv
);
6491 else if (vr0
->type
== VR_ANTI_RANGE
|| vr1
->type
== VR_ANTI_RANGE
)
6493 /* For a numeric range [VAL1, VAL2] and an anti-range ~[VAL3, VAL4],
6494 only handle the case where the ranges have an empty intersection.
6495 The result of the meet operation is the anti-range. */
6496 if (!symbolic_range_p (vr0
)
6497 && !symbolic_range_p (vr1
)
6498 && !value_ranges_intersect_p (vr0
, vr1
))
6500 /* Copy most of VR1 into VR0. Don't copy VR1's equivalence
6501 set. We need to compute the intersection of the two
6502 equivalence sets. */
6503 if (vr1
->type
== VR_ANTI_RANGE
)
6504 set_value_range (vr0
, vr1
->type
, vr1
->min
, vr1
->max
, vr0
->equiv
);
6506 /* The resulting set of equivalences is the intersection of
6508 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
6509 bitmap_and_into (vr0
->equiv
, vr1
->equiv
);
6510 else if (vr0
->equiv
&& !vr1
->equiv
)
6511 bitmap_clear (vr0
->equiv
);
6522 /* Failed to find an efficient meet. Before giving up and setting
6523 the result to VARYING, see if we can at least derive a useful
6524 anti-range. FIXME, all this nonsense about distinguishing
6525 anti-ranges from ranges is necessary because of the odd
6526 semantics of range_includes_zero_p and friends. */
6527 if (!symbolic_range_p (vr0
)
6528 && ((vr0
->type
== VR_RANGE
&& !range_includes_zero_p (vr0
))
6529 || (vr0
->type
== VR_ANTI_RANGE
&& range_includes_zero_p (vr0
)))
6530 && !symbolic_range_p (vr1
)
6531 && ((vr1
->type
== VR_RANGE
&& !range_includes_zero_p (vr1
))
6532 || (vr1
->type
== VR_ANTI_RANGE
&& range_includes_zero_p (vr1
))))
6534 set_value_range_to_nonnull (vr0
, TREE_TYPE (vr0
->min
));
6536 /* Since this meet operation did not result from the meeting of
6537 two equivalent names, VR0 cannot have any equivalences. */
6539 bitmap_clear (vr0
->equiv
);
6542 set_value_range_to_varying (vr0
);
6546 /* Visit all arguments for PHI node PHI that flow through executable
6547 edges. If a valid value range can be derived from all the incoming
6548 value ranges, set a new range for the LHS of PHI. */
6550 static enum ssa_prop_result
6551 vrp_visit_phi_node (gimple phi
)
6554 tree lhs
= PHI_RESULT (phi
);
6555 value_range_t
*lhs_vr
= get_value_range (lhs
);
6556 value_range_t vr_result
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
6557 int edges
, old_edges
;
6560 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6562 fprintf (dump_file
, "\nVisiting PHI node: ");
6563 print_gimple_stmt (dump_file
, phi
, 0, dump_flags
);
6567 for (i
= 0; i
< gimple_phi_num_args (phi
); i
++)
6569 edge e
= gimple_phi_arg_edge (phi
, i
);
6571 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6574 "\n Argument #%d (%d -> %d %sexecutable)\n",
6575 (int) i
, e
->src
->index
, e
->dest
->index
,
6576 (e
->flags
& EDGE_EXECUTABLE
) ? "" : "not ");
6579 if (e
->flags
& EDGE_EXECUTABLE
)
6581 tree arg
= PHI_ARG_DEF (phi
, i
);
6582 value_range_t vr_arg
;
6586 if (TREE_CODE (arg
) == SSA_NAME
)
6588 vr_arg
= *(get_value_range (arg
));
6592 if (is_overflow_infinity (arg
))
6594 arg
= copy_node (arg
);
6595 TREE_OVERFLOW (arg
) = 0;
6598 vr_arg
.type
= VR_RANGE
;
6601 vr_arg
.equiv
= NULL
;
6604 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6606 fprintf (dump_file
, "\t");
6607 print_generic_expr (dump_file
, arg
, dump_flags
);
6608 fprintf (dump_file
, "\n\tValue: ");
6609 dump_value_range (dump_file
, &vr_arg
);
6610 fprintf (dump_file
, "\n");
6613 vrp_meet (&vr_result
, &vr_arg
);
6615 if (vr_result
.type
== VR_VARYING
)
6620 if (vr_result
.type
== VR_VARYING
)
6622 else if (vr_result
.type
== VR_UNDEFINED
)
6625 old_edges
= vr_phi_edge_counts
[SSA_NAME_VERSION (lhs
)];
6626 vr_phi_edge_counts
[SSA_NAME_VERSION (lhs
)] = edges
;
6628 /* To prevent infinite iterations in the algorithm, derive ranges
6629 when the new value is slightly bigger or smaller than the
6630 previous one. We don't do this if we have seen a new executable
6631 edge; this helps us avoid an overflow infinity for conditionals
6632 which are not in a loop. */
6634 && gimple_phi_num_args (phi
) > 1
6635 && edges
== old_edges
)
6637 int cmp_min
= compare_values (lhs_vr
->min
, vr_result
.min
);
6638 int cmp_max
= compare_values (lhs_vr
->max
, vr_result
.max
);
6640 /* For non VR_RANGE or for pointers fall back to varying if
6641 the range changed. */
6642 if ((lhs_vr
->type
!= VR_RANGE
|| vr_result
.type
!= VR_RANGE
6643 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
6644 && (cmp_min
!= 0 || cmp_max
!= 0))
6647 /* If the new minimum is smaller or larger than the previous
6648 one, go all the way to -INF. In the first case, to avoid
6649 iterating millions of times to reach -INF, and in the
6650 other case to avoid infinite bouncing between different
6652 if (cmp_min
> 0 || cmp_min
< 0)
6654 if (!needs_overflow_infinity (TREE_TYPE (vr_result
.min
))
6655 || !vrp_var_may_overflow (lhs
, phi
))
6656 vr_result
.min
= TYPE_MIN_VALUE (TREE_TYPE (vr_result
.min
));
6657 else if (supports_overflow_infinity (TREE_TYPE (vr_result
.min
)))
6659 negative_overflow_infinity (TREE_TYPE (vr_result
.min
));
6662 /* Similarly, if the new maximum is smaller or larger than
6663 the previous one, go all the way to +INF. */
6664 if (cmp_max
< 0 || cmp_max
> 0)
6666 if (!needs_overflow_infinity (TREE_TYPE (vr_result
.max
))
6667 || !vrp_var_may_overflow (lhs
, phi
))
6668 vr_result
.max
= TYPE_MAX_VALUE (TREE_TYPE (vr_result
.max
));
6669 else if (supports_overflow_infinity (TREE_TYPE (vr_result
.max
)))
6671 positive_overflow_infinity (TREE_TYPE (vr_result
.max
));
6674 /* If we dropped either bound to +-INF then if this is a loop
6675 PHI node SCEV may known more about its value-range. */
6676 if ((cmp_min
> 0 || cmp_min
< 0
6677 || cmp_max
< 0 || cmp_max
> 0)
6679 && (l
= loop_containing_stmt (phi
))
6680 && l
->header
== gimple_bb (phi
))
6681 adjust_range_with_scev (&vr_result
, l
, phi
, lhs
);
6683 /* If we will end up with a (-INF, +INF) range, set it to
6684 VARYING. Same if the previous max value was invalid for
6685 the type and we end up with vr_result.min > vr_result.max. */
6686 if ((vrp_val_is_max (vr_result
.max
)
6687 && vrp_val_is_min (vr_result
.min
))
6688 || compare_values (vr_result
.min
,
6693 /* If the new range is different than the previous value, keep
6696 if (update_value_range (lhs
, &vr_result
))
6698 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6700 fprintf (dump_file
, "Found new range for ");
6701 print_generic_expr (dump_file
, lhs
, 0);
6702 fprintf (dump_file
, ": ");
6703 dump_value_range (dump_file
, &vr_result
);
6704 fprintf (dump_file
, "\n\n");
6707 return SSA_PROP_INTERESTING
;
6710 /* Nothing changed, don't add outgoing edges. */
6711 return SSA_PROP_NOT_INTERESTING
;
6713 /* No match found. Set the LHS to VARYING. */
6715 set_value_range_to_varying (lhs_vr
);
6716 return SSA_PROP_VARYING
;
6719 /* Simplify boolean operations if the source is known
6720 to be already a boolean. */
6722 simplify_truth_ops_using_ranges (gimple_stmt_iterator
*gsi
, gimple stmt
)
6724 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
6726 bool need_conversion
;
6728 /* We handle only !=/== case here. */
6729 gcc_assert (rhs_code
== EQ_EXPR
|| rhs_code
== NE_EXPR
);
6731 op0
= gimple_assign_rhs1 (stmt
);
6732 if (!op_with_boolean_value_range_p (op0
))
6735 op1
= gimple_assign_rhs2 (stmt
);
6736 if (!op_with_boolean_value_range_p (op1
))
6739 /* Reduce number of cases to handle to NE_EXPR. As there is no
6740 BIT_XNOR_EXPR we cannot replace A == B with a single statement. */
6741 if (rhs_code
== EQ_EXPR
)
6743 if (TREE_CODE (op1
) == INTEGER_CST
)
6744 op1
= int_const_binop (BIT_XOR_EXPR
, op1
, integer_one_node
);
6749 lhs
= gimple_assign_lhs (stmt
);
6751 = !useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (op0
));
6753 /* Make sure to not sign-extend a 1-bit 1 when converting the result. */
6755 && !TYPE_UNSIGNED (TREE_TYPE (op0
))
6756 && TYPE_PRECISION (TREE_TYPE (op0
)) == 1
6757 && TYPE_PRECISION (TREE_TYPE (lhs
)) > 1)
6760 /* For A != 0 we can substitute A itself. */
6761 if (integer_zerop (op1
))
6762 gimple_assign_set_rhs_with_ops (gsi
,
6764 ? NOP_EXPR
: TREE_CODE (op0
),
6766 /* For A != B we substitute A ^ B. Either with conversion. */
6767 else if (need_conversion
)
6770 tree tem
= create_tmp_reg (TREE_TYPE (op0
), NULL
);
6771 newop
= gimple_build_assign_with_ops (BIT_XOR_EXPR
, tem
, op0
, op1
);
6772 tem
= make_ssa_name (tem
, newop
);
6773 gimple_assign_set_lhs (newop
, tem
);
6774 gsi_insert_before (gsi
, newop
, GSI_SAME_STMT
);
6775 update_stmt (newop
);
6776 gimple_assign_set_rhs_with_ops (gsi
, NOP_EXPR
, tem
, NULL_TREE
);
6780 gimple_assign_set_rhs_with_ops (gsi
, BIT_XOR_EXPR
, op0
, op1
);
6781 update_stmt (gsi_stmt (*gsi
));
6786 /* Simplify a division or modulo operator to a right shift or
6787 bitwise and if the first operand is unsigned or is greater
6788 than zero and the second operand is an exact power of two. */
6791 simplify_div_or_mod_using_ranges (gimple stmt
)
6793 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
6795 tree op0
= gimple_assign_rhs1 (stmt
);
6796 tree op1
= gimple_assign_rhs2 (stmt
);
6797 value_range_t
*vr
= get_value_range (gimple_assign_rhs1 (stmt
));
6799 if (TYPE_UNSIGNED (TREE_TYPE (op0
)))
6801 val
= integer_one_node
;
6807 val
= compare_range_with_value (GE_EXPR
, vr
, integer_zero_node
, &sop
);
6811 && integer_onep (val
)
6812 && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
6814 location_t location
;
6816 if (!gimple_has_location (stmt
))
6817 location
= input_location
;
6819 location
= gimple_location (stmt
);
6820 warning_at (location
, OPT_Wstrict_overflow
,
6821 "assuming signed overflow does not occur when "
6822 "simplifying %</%> or %<%%%> to %<>>%> or %<&%>");
6826 if (val
&& integer_onep (val
))
6830 if (rhs_code
== TRUNC_DIV_EXPR
)
6832 t
= build_int_cst (integer_type_node
, tree_log2 (op1
));
6833 gimple_assign_set_rhs_code (stmt
, RSHIFT_EXPR
);
6834 gimple_assign_set_rhs1 (stmt
, op0
);
6835 gimple_assign_set_rhs2 (stmt
, t
);
6839 t
= build_int_cst (TREE_TYPE (op1
), 1);
6840 t
= int_const_binop (MINUS_EXPR
, op1
, t
);
6841 t
= fold_convert (TREE_TYPE (op0
), t
);
6843 gimple_assign_set_rhs_code (stmt
, BIT_AND_EXPR
);
6844 gimple_assign_set_rhs1 (stmt
, op0
);
6845 gimple_assign_set_rhs2 (stmt
, t
);
6855 /* If the operand to an ABS_EXPR is >= 0, then eliminate the
6856 ABS_EXPR. If the operand is <= 0, then simplify the
6857 ABS_EXPR into a NEGATE_EXPR. */
6860 simplify_abs_using_ranges (gimple stmt
)
6863 tree op
= gimple_assign_rhs1 (stmt
);
6864 tree type
= TREE_TYPE (op
);
6865 value_range_t
*vr
= get_value_range (op
);
6867 if (TYPE_UNSIGNED (type
))
6869 val
= integer_zero_node
;
6875 val
= compare_range_with_value (LE_EXPR
, vr
, integer_zero_node
, &sop
);
6879 val
= compare_range_with_value (GE_EXPR
, vr
, integer_zero_node
,
6884 if (integer_zerop (val
))
6885 val
= integer_one_node
;
6886 else if (integer_onep (val
))
6887 val
= integer_zero_node
;
6892 && (integer_onep (val
) || integer_zerop (val
)))
6894 if (sop
&& issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
6896 location_t location
;
6898 if (!gimple_has_location (stmt
))
6899 location
= input_location
;
6901 location
= gimple_location (stmt
);
6902 warning_at (location
, OPT_Wstrict_overflow
,
6903 "assuming signed overflow does not occur when "
6904 "simplifying %<abs (X)%> to %<X%> or %<-X%>");
6907 gimple_assign_set_rhs1 (stmt
, op
);
6908 if (integer_onep (val
))
6909 gimple_assign_set_rhs_code (stmt
, NEGATE_EXPR
);
6911 gimple_assign_set_rhs_code (stmt
, SSA_NAME
);
6920 /* Optimize away redundant BIT_AND_EXPR and BIT_IOR_EXPR.
6921 If all the bits that are being cleared by & are already
6922 known to be zero from VR, or all the bits that are being
6923 set by | are already known to be one from VR, the bit
6924 operation is redundant. */
6927 simplify_bit_ops_using_ranges (gimple_stmt_iterator
*gsi
, gimple stmt
)
6929 tree op0
= gimple_assign_rhs1 (stmt
);
6930 tree op1
= gimple_assign_rhs2 (stmt
);
6931 tree op
= NULL_TREE
;
6932 value_range_t vr0
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
6933 value_range_t vr1
= { VR_UNDEFINED
, NULL_TREE
, NULL_TREE
, NULL
};
6934 double_int may_be_nonzero0
, may_be_nonzero1
;
6935 double_int must_be_nonzero0
, must_be_nonzero1
;
6938 if (TREE_CODE (op0
) == SSA_NAME
)
6939 vr0
= *(get_value_range (op0
));
6940 else if (is_gimple_min_invariant (op0
))
6941 set_value_range_to_value (&vr0
, op0
, NULL
);
6945 if (TREE_CODE (op1
) == SSA_NAME
)
6946 vr1
= *(get_value_range (op1
));
6947 else if (is_gimple_min_invariant (op1
))
6948 set_value_range_to_value (&vr1
, op1
, NULL
);
6952 if (!zero_nonzero_bits_from_vr (&vr0
, &may_be_nonzero0
, &must_be_nonzero0
))
6954 if (!zero_nonzero_bits_from_vr (&vr1
, &may_be_nonzero1
, &must_be_nonzero1
))
6957 switch (gimple_assign_rhs_code (stmt
))
6960 mask
= double_int_and_not (may_be_nonzero0
, must_be_nonzero1
);
6961 if (double_int_zero_p (mask
))
6966 mask
= double_int_and_not (may_be_nonzero1
, must_be_nonzero0
);
6967 if (double_int_zero_p (mask
))
6974 mask
= double_int_and_not (may_be_nonzero0
, must_be_nonzero1
);
6975 if (double_int_zero_p (mask
))
6980 mask
= double_int_and_not (may_be_nonzero1
, must_be_nonzero0
);
6981 if (double_int_zero_p (mask
))
6991 if (op
== NULL_TREE
)
6994 gimple_assign_set_rhs_with_ops (gsi
, TREE_CODE (op
), op
, NULL
);
6995 update_stmt (gsi_stmt (*gsi
));
6999 /* We are comparing trees OP0 and OP1 using COND_CODE. OP0 has
7000 a known value range VR.
7002 If there is one and only one value which will satisfy the
7003 conditional, then return that value. Else return NULL. */
7006 test_for_singularity (enum tree_code cond_code
, tree op0
,
7007 tree op1
, value_range_t
*vr
)
7012 /* Extract minimum/maximum values which satisfy the
7013 the conditional as it was written. */
7014 if (cond_code
== LE_EXPR
|| cond_code
== LT_EXPR
)
7016 /* This should not be negative infinity; there is no overflow
7018 min
= TYPE_MIN_VALUE (TREE_TYPE (op0
));
7021 if (cond_code
== LT_EXPR
&& !is_overflow_infinity (max
))
7023 tree one
= build_int_cst (TREE_TYPE (op0
), 1);
7024 max
= fold_build2 (MINUS_EXPR
, TREE_TYPE (op0
), max
, one
);
7026 TREE_NO_WARNING (max
) = 1;
7029 else if (cond_code
== GE_EXPR
|| cond_code
== GT_EXPR
)
7031 /* This should not be positive infinity; there is no overflow
7033 max
= TYPE_MAX_VALUE (TREE_TYPE (op0
));
7036 if (cond_code
== GT_EXPR
&& !is_overflow_infinity (min
))
7038 tree one
= build_int_cst (TREE_TYPE (op0
), 1);
7039 min
= fold_build2 (PLUS_EXPR
, TREE_TYPE (op0
), min
, one
);
7041 TREE_NO_WARNING (min
) = 1;
7045 /* Now refine the minimum and maximum values using any
7046 value range information we have for op0. */
7049 if (compare_values (vr
->min
, min
) == 1)
7051 if (compare_values (vr
->max
, max
) == -1)
7054 /* If the new min/max values have converged to a single value,
7055 then there is only one value which can satisfy the condition,
7056 return that value. */
7057 if (operand_equal_p (min
, max
, 0) && is_gimple_min_invariant (min
))
7063 /* Simplify a conditional using a relational operator to an equality
7064 test if the range information indicates only one value can satisfy
7065 the original conditional. */
7068 simplify_cond_using_ranges (gimple stmt
)
7070 tree op0
= gimple_cond_lhs (stmt
);
7071 tree op1
= gimple_cond_rhs (stmt
);
7072 enum tree_code cond_code
= gimple_cond_code (stmt
);
7074 if (cond_code
!= NE_EXPR
7075 && cond_code
!= EQ_EXPR
7076 && TREE_CODE (op0
) == SSA_NAME
7077 && INTEGRAL_TYPE_P (TREE_TYPE (op0
))
7078 && is_gimple_min_invariant (op1
))
7080 value_range_t
*vr
= get_value_range (op0
);
7082 /* If we have range information for OP0, then we might be
7083 able to simplify this conditional. */
7084 if (vr
->type
== VR_RANGE
)
7086 tree new_tree
= test_for_singularity (cond_code
, op0
, op1
, vr
);
7092 fprintf (dump_file
, "Simplified relational ");
7093 print_gimple_stmt (dump_file
, stmt
, 0, 0);
7094 fprintf (dump_file
, " into ");
7097 gimple_cond_set_code (stmt
, EQ_EXPR
);
7098 gimple_cond_set_lhs (stmt
, op0
);
7099 gimple_cond_set_rhs (stmt
, new_tree
);
7105 print_gimple_stmt (dump_file
, stmt
, 0, 0);
7106 fprintf (dump_file
, "\n");
7112 /* Try again after inverting the condition. We only deal
7113 with integral types here, so no need to worry about
7114 issues with inverting FP comparisons. */
7115 cond_code
= invert_tree_comparison (cond_code
, false);
7116 new_tree
= test_for_singularity (cond_code
, op0
, op1
, vr
);
7122 fprintf (dump_file
, "Simplified relational ");
7123 print_gimple_stmt (dump_file
, stmt
, 0, 0);
7124 fprintf (dump_file
, " into ");
7127 gimple_cond_set_code (stmt
, NE_EXPR
);
7128 gimple_cond_set_lhs (stmt
, op0
);
7129 gimple_cond_set_rhs (stmt
, new_tree
);
7135 print_gimple_stmt (dump_file
, stmt
, 0, 0);
7136 fprintf (dump_file
, "\n");
7147 /* Simplify a switch statement using the value range of the switch
7151 simplify_switch_using_ranges (gimple stmt
)
7153 tree op
= gimple_switch_index (stmt
);
7158 size_t i
= 0, j
= 0, n
, n2
;
7162 if (TREE_CODE (op
) == SSA_NAME
)
7164 vr
= get_value_range (op
);
7166 /* We can only handle integer ranges. */
7167 if (vr
->type
!= VR_RANGE
7168 || symbolic_range_p (vr
))
7171 /* Find case label for min/max of the value range. */
7172 take_default
= !find_case_label_range (stmt
, vr
->min
, vr
->max
, &i
, &j
);
7174 else if (TREE_CODE (op
) == INTEGER_CST
)
7176 take_default
= !find_case_label_index (stmt
, 1, op
, &i
);
7190 n
= gimple_switch_num_labels (stmt
);
7192 /* Bail out if this is just all edges taken. */
7198 /* Build a new vector of taken case labels. */
7199 vec2
= make_tree_vec (j
- i
+ 1 + (int)take_default
);
7202 /* Add the default edge, if necessary. */
7204 TREE_VEC_ELT (vec2
, n2
++) = gimple_switch_default_label (stmt
);
7206 for (; i
<= j
; ++i
, ++n2
)
7207 TREE_VEC_ELT (vec2
, n2
) = gimple_switch_label (stmt
, i
);
7209 /* Mark needed edges. */
7210 for (i
= 0; i
< n2
; ++i
)
7212 e
= find_edge (gimple_bb (stmt
),
7213 label_to_block (CASE_LABEL (TREE_VEC_ELT (vec2
, i
))));
7214 e
->aux
= (void *)-1;
7217 /* Queue not needed edges for later removal. */
7218 FOR_EACH_EDGE (e
, ei
, gimple_bb (stmt
)->succs
)
7220 if (e
->aux
== (void *)-1)
7226 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7228 fprintf (dump_file
, "removing unreachable case label\n");
7230 VEC_safe_push (edge
, heap
, to_remove_edges
, e
);
7231 e
->flags
&= ~EDGE_EXECUTABLE
;
7234 /* And queue an update for the stmt. */
7237 VEC_safe_push (switch_update
, heap
, to_update_switch_stmts
, &su
);
7241 /* Simplify an integral conversion from an SSA name in STMT. */
7244 simplify_conversion_using_ranges (gimple stmt
)
7246 tree innerop
, middleop
, finaltype
;
7248 value_range_t
*innervr
;
7249 double_int innermin
, innermax
, middlemin
, middlemax
;
7251 finaltype
= TREE_TYPE (gimple_assign_lhs (stmt
));
7252 if (!INTEGRAL_TYPE_P (finaltype
))
7254 middleop
= gimple_assign_rhs1 (stmt
);
7255 def_stmt
= SSA_NAME_DEF_STMT (middleop
);
7256 if (!is_gimple_assign (def_stmt
)
7257 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
)))
7259 innerop
= gimple_assign_rhs1 (def_stmt
);
7260 if (TREE_CODE (innerop
) != SSA_NAME
)
7263 /* Get the value-range of the inner operand. */
7264 innervr
= get_value_range (innerop
);
7265 if (innervr
->type
!= VR_RANGE
7266 || TREE_CODE (innervr
->min
) != INTEGER_CST
7267 || TREE_CODE (innervr
->max
) != INTEGER_CST
)
7270 /* Simulate the conversion chain to check if the result is equal if
7271 the middle conversion is removed. */
7272 innermin
= tree_to_double_int (innervr
->min
);
7273 innermax
= tree_to_double_int (innervr
->max
);
7274 middlemin
= double_int_ext (innermin
, TYPE_PRECISION (TREE_TYPE (middleop
)),
7275 TYPE_UNSIGNED (TREE_TYPE (middleop
)));
7276 middlemax
= double_int_ext (innermax
, TYPE_PRECISION (TREE_TYPE (middleop
)),
7277 TYPE_UNSIGNED (TREE_TYPE (middleop
)));
7278 /* If the middle values do not represent a proper range fail. */
7279 if (double_int_cmp (middlemin
, middlemax
,
7280 TYPE_UNSIGNED (TREE_TYPE (middleop
))) > 0)
7282 if (!double_int_equal_p (double_int_ext (middlemin
,
7283 TYPE_PRECISION (finaltype
),
7284 TYPE_UNSIGNED (finaltype
)),
7285 double_int_ext (innermin
,
7286 TYPE_PRECISION (finaltype
),
7287 TYPE_UNSIGNED (finaltype
)))
7288 || !double_int_equal_p (double_int_ext (middlemax
,
7289 TYPE_PRECISION (finaltype
),
7290 TYPE_UNSIGNED (finaltype
)),
7291 double_int_ext (innermax
,
7292 TYPE_PRECISION (finaltype
),
7293 TYPE_UNSIGNED (finaltype
))))
7296 gimple_assign_set_rhs1 (stmt
, innerop
);
7301 /* Return whether the value range *VR fits in an integer type specified
7302 by PRECISION and UNSIGNED_P. */
7305 range_fits_type_p (value_range_t
*vr
, unsigned precision
, bool unsigned_p
)
7308 unsigned src_precision
;
7311 /* We can only handle integral and pointer types. */
7312 src_type
= TREE_TYPE (vr
->min
);
7313 if (!INTEGRAL_TYPE_P (src_type
)
7314 && !POINTER_TYPE_P (src_type
))
7317 /* An extension is always fine, so is an identity transform. */
7318 src_precision
= TYPE_PRECISION (TREE_TYPE (vr
->min
));
7319 if (src_precision
< precision
7320 || (src_precision
== precision
7321 && TYPE_UNSIGNED (src_type
) == unsigned_p
))
7324 /* Now we can only handle ranges with constant bounds. */
7325 if (vr
->type
!= VR_RANGE
7326 || TREE_CODE (vr
->min
) != INTEGER_CST
7327 || TREE_CODE (vr
->max
) != INTEGER_CST
)
7330 /* For precision-preserving sign-changes the MSB of the double-int
7332 if (src_precision
== precision
7333 && (TREE_INT_CST_HIGH (vr
->min
) | TREE_INT_CST_HIGH (vr
->max
)) < 0)
7336 /* Then we can perform the conversion on both ends and compare
7337 the result for equality. */
7338 tem
= double_int_ext (tree_to_double_int (vr
->min
), precision
, unsigned_p
);
7339 if (!double_int_equal_p (tree_to_double_int (vr
->min
), tem
))
7341 tem
= double_int_ext (tree_to_double_int (vr
->max
), precision
, unsigned_p
);
7342 if (!double_int_equal_p (tree_to_double_int (vr
->max
), tem
))
7348 /* Simplify a conversion from integral SSA name to float in STMT. */
7351 simplify_float_conversion_using_ranges (gimple_stmt_iterator
*gsi
, gimple stmt
)
7353 tree rhs1
= gimple_assign_rhs1 (stmt
);
7354 value_range_t
*vr
= get_value_range (rhs1
);
7355 enum machine_mode fltmode
= TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt
)));
7356 enum machine_mode mode
;
7360 /* We can only handle constant ranges. */
7361 if (vr
->type
!= VR_RANGE
7362 || TREE_CODE (vr
->min
) != INTEGER_CST
7363 || TREE_CODE (vr
->max
) != INTEGER_CST
)
7366 /* First check if we can use a signed type in place of an unsigned. */
7367 if (TYPE_UNSIGNED (TREE_TYPE (rhs1
))
7368 && (can_float_p (fltmode
, TYPE_MODE (TREE_TYPE (rhs1
)), 0)
7369 != CODE_FOR_nothing
)
7370 && range_fits_type_p (vr
, GET_MODE_PRECISION
7371 (TYPE_MODE (TREE_TYPE (rhs1
))), 0))
7372 mode
= TYPE_MODE (TREE_TYPE (rhs1
));
7373 /* If we can do the conversion in the current input mode do nothing. */
7374 else if (can_float_p (fltmode
, TYPE_MODE (TREE_TYPE (rhs1
)),
7375 TYPE_UNSIGNED (TREE_TYPE (rhs1
))))
7377 /* Otherwise search for a mode we can use, starting from the narrowest
7378 integer mode available. */
7381 mode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
7384 /* If we cannot do a signed conversion to float from mode
7385 or if the value-range does not fit in the signed type
7386 try with a wider mode. */
7387 if (can_float_p (fltmode
, mode
, 0) != CODE_FOR_nothing
7388 && range_fits_type_p (vr
, GET_MODE_PRECISION (mode
), 0))
7391 mode
= GET_MODE_WIDER_MODE (mode
);
7392 /* But do not widen the input. Instead leave that to the
7393 optabs expansion code. */
7394 if (GET_MODE_PRECISION (mode
) > TYPE_PRECISION (TREE_TYPE (rhs1
)))
7397 while (mode
!= VOIDmode
);
7398 if (mode
== VOIDmode
)
7402 /* It works, insert a truncation or sign-change before the
7403 float conversion. */
7404 tem
= create_tmp_var (build_nonstandard_integer_type
7405 (GET_MODE_PRECISION (mode
), 0), NULL
);
7406 conv
= gimple_build_assign_with_ops (NOP_EXPR
, tem
, rhs1
, NULL_TREE
);
7407 tem
= make_ssa_name (tem
, conv
);
7408 gimple_assign_set_lhs (conv
, tem
);
7409 gsi_insert_before (gsi
, conv
, GSI_SAME_STMT
);
7410 gimple_assign_set_rhs1 (stmt
, tem
);
7416 /* Simplify STMT using ranges if possible. */
7419 simplify_stmt_using_ranges (gimple_stmt_iterator
*gsi
)
7421 gimple stmt
= gsi_stmt (*gsi
);
7422 if (is_gimple_assign (stmt
))
7424 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
7425 tree rhs1
= gimple_assign_rhs1 (stmt
);
7431 /* Transform EQ_EXPR, NE_EXPR into BIT_XOR_EXPR or identity
7432 if the RHS is zero or one, and the LHS are known to be boolean
7434 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
7435 return simplify_truth_ops_using_ranges (gsi
, stmt
);
7438 /* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
7439 and BIT_AND_EXPR respectively if the first operand is greater
7440 than zero and the second operand is an exact power of two. */
7441 case TRUNC_DIV_EXPR
:
7442 case TRUNC_MOD_EXPR
:
7443 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
7444 && integer_pow2p (gimple_assign_rhs2 (stmt
)))
7445 return simplify_div_or_mod_using_ranges (stmt
);
7448 /* Transform ABS (X) into X or -X as appropriate. */
7450 if (TREE_CODE (rhs1
) == SSA_NAME
7451 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
7452 return simplify_abs_using_ranges (stmt
);
7457 /* Optimize away BIT_AND_EXPR and BIT_IOR_EXPR
7458 if all the bits being cleared are already cleared or
7459 all the bits being set are already set. */
7460 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
7461 return simplify_bit_ops_using_ranges (gsi
, stmt
);
7465 if (TREE_CODE (rhs1
) == SSA_NAME
7466 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
7467 return simplify_conversion_using_ranges (stmt
);
7471 if (TREE_CODE (rhs1
) == SSA_NAME
7472 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
7473 return simplify_float_conversion_using_ranges (gsi
, stmt
);
7480 else if (gimple_code (stmt
) == GIMPLE_COND
)
7481 return simplify_cond_using_ranges (stmt
);
7482 else if (gimple_code (stmt
) == GIMPLE_SWITCH
)
7483 return simplify_switch_using_ranges (stmt
);
7488 /* If the statement pointed by SI has a predicate whose value can be
7489 computed using the value range information computed by VRP, compute
7490 its value and return true. Otherwise, return false. */
7493 fold_predicate_in (gimple_stmt_iterator
*si
)
7495 bool assignment_p
= false;
7497 gimple stmt
= gsi_stmt (*si
);
7499 if (is_gimple_assign (stmt
)
7500 && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt
)) == tcc_comparison
)
7502 assignment_p
= true;
7503 val
= vrp_evaluate_conditional (gimple_assign_rhs_code (stmt
),
7504 gimple_assign_rhs1 (stmt
),
7505 gimple_assign_rhs2 (stmt
),
7508 else if (gimple_code (stmt
) == GIMPLE_COND
)
7509 val
= vrp_evaluate_conditional (gimple_cond_code (stmt
),
7510 gimple_cond_lhs (stmt
),
7511 gimple_cond_rhs (stmt
),
7519 val
= fold_convert (gimple_expr_type (stmt
), val
);
7523 fprintf (dump_file
, "Folding predicate ");
7524 print_gimple_expr (dump_file
, stmt
, 0, 0);
7525 fprintf (dump_file
, " to ");
7526 print_generic_expr (dump_file
, val
, 0);
7527 fprintf (dump_file
, "\n");
7530 if (is_gimple_assign (stmt
))
7531 gimple_assign_set_rhs_from_tree (si
, val
);
7534 gcc_assert (gimple_code (stmt
) == GIMPLE_COND
);
7535 if (integer_zerop (val
))
7536 gimple_cond_make_false (stmt
);
7537 else if (integer_onep (val
))
7538 gimple_cond_make_true (stmt
);
7549 /* Callback for substitute_and_fold folding the stmt at *SI. */
7552 vrp_fold_stmt (gimple_stmt_iterator
*si
)
7554 if (fold_predicate_in (si
))
7557 return simplify_stmt_using_ranges (si
);
7560 /* Stack of dest,src equivalency pairs that need to be restored after
7561 each attempt to thread a block's incoming edge to an outgoing edge.
7563 A NULL entry is used to mark the end of pairs which need to be
7565 static VEC(tree
,heap
) *stack
;
7567 /* A trivial wrapper so that we can present the generic jump threading
7568 code with a simple API for simplifying statements. STMT is the
7569 statement we want to simplify, WITHIN_STMT provides the location
7570 for any overflow warnings. */
7573 simplify_stmt_for_jump_threading (gimple stmt
, gimple within_stmt
)
7575 /* We only use VRP information to simplify conditionals. This is
7576 overly conservative, but it's unclear if doing more would be
7577 worth the compile time cost. */
7578 if (gimple_code (stmt
) != GIMPLE_COND
)
7581 return vrp_evaluate_conditional (gimple_cond_code (stmt
),
7582 gimple_cond_lhs (stmt
),
7583 gimple_cond_rhs (stmt
), within_stmt
);
7586 /* Blocks which have more than one predecessor and more than
7587 one successor present jump threading opportunities, i.e.,
7588 when the block is reached from a specific predecessor, we
7589 may be able to determine which of the outgoing edges will
7590 be traversed. When this optimization applies, we are able
7591 to avoid conditionals at runtime and we may expose secondary
7592 optimization opportunities.
7594 This routine is effectively a driver for the generic jump
7595 threading code. It basically just presents the generic code
7596 with edges that may be suitable for jump threading.
7598 Unlike DOM, we do not iterate VRP if jump threading was successful.
7599 While iterating may expose new opportunities for VRP, it is expected
7600 those opportunities would be very limited and the compile time cost
7601 to expose those opportunities would be significant.
7603 As jump threading opportunities are discovered, they are registered
7604 for later realization. */
7607 identify_jump_threads (void)
7614 /* Ugh. When substituting values earlier in this pass we can
7615 wipe the dominance information. So rebuild the dominator
7616 information as we need it within the jump threading code. */
7617 calculate_dominance_info (CDI_DOMINATORS
);
7619 /* We do not allow VRP information to be used for jump threading
7620 across a back edge in the CFG. Otherwise it becomes too
7621 difficult to avoid eliminating loop exit tests. Of course
7622 EDGE_DFS_BACK is not accurate at this time so we have to
7624 mark_dfs_back_edges ();
7626 /* Do not thread across edges we are about to remove. Just marking
7627 them as EDGE_DFS_BACK will do. */
7628 FOR_EACH_VEC_ELT (edge
, to_remove_edges
, i
, e
)
7629 e
->flags
|= EDGE_DFS_BACK
;
7631 /* Allocate our unwinder stack to unwind any temporary equivalences
7632 that might be recorded. */
7633 stack
= VEC_alloc (tree
, heap
, 20);
7635 /* To avoid lots of silly node creation, we create a single
7636 conditional and just modify it in-place when attempting to
7638 dummy
= gimple_build_cond (EQ_EXPR
,
7639 integer_zero_node
, integer_zero_node
,
7642 /* Walk through all the blocks finding those which present a
7643 potential jump threading opportunity. We could set this up
7644 as a dominator walker and record data during the walk, but
7645 I doubt it's worth the effort for the classes of jump
7646 threading opportunities we are trying to identify at this
7647 point in compilation. */
7652 /* If the generic jump threading code does not find this block
7653 interesting, then there is nothing to do. */
7654 if (! potentially_threadable_block (bb
))
7657 /* We only care about blocks ending in a COND_EXPR. While there
7658 may be some value in handling SWITCH_EXPR here, I doubt it's
7659 terribly important. */
7660 last
= gsi_stmt (gsi_last_bb (bb
));
7662 /* We're basically looking for a switch or any kind of conditional with
7663 integral or pointer type arguments. Note the type of the second
7664 argument will be the same as the first argument, so no need to
7665 check it explicitly. */
7666 if (gimple_code (last
) == GIMPLE_SWITCH
7667 || (gimple_code (last
) == GIMPLE_COND
7668 && TREE_CODE (gimple_cond_lhs (last
)) == SSA_NAME
7669 && (INTEGRAL_TYPE_P (TREE_TYPE (gimple_cond_lhs (last
)))
7670 || POINTER_TYPE_P (TREE_TYPE (gimple_cond_lhs (last
))))
7671 && (TREE_CODE (gimple_cond_rhs (last
)) == SSA_NAME
7672 || is_gimple_min_invariant (gimple_cond_rhs (last
)))))
7676 /* We've got a block with multiple predecessors and multiple
7677 successors which also ends in a suitable conditional or
7678 switch statement. For each predecessor, see if we can thread
7679 it to a specific successor. */
7680 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
7682 /* Do not thread across back edges or abnormal edges
7684 if (e
->flags
& (EDGE_DFS_BACK
| EDGE_COMPLEX
))
7687 thread_across_edge (dummy
, e
, true, &stack
,
7688 simplify_stmt_for_jump_threading
);
7693 /* We do not actually update the CFG or SSA graphs at this point as
7694 ASSERT_EXPRs are still in the IL and cfg cleanup code does not yet
7695 handle ASSERT_EXPRs gracefully. */
7698 /* We identified all the jump threading opportunities earlier, but could
7699 not transform the CFG at that time. This routine transforms the
7700 CFG and arranges for the dominator tree to be rebuilt if necessary.
7702 Note the SSA graph update will occur during the normal TODO
7703 processing by the pass manager. */
7705 finalize_jump_threads (void)
7707 thread_through_all_blocks (false);
7708 VEC_free (tree
, heap
, stack
);
7712 /* Traverse all the blocks folding conditionals with known ranges. */
7719 values_propagated
= true;
7723 fprintf (dump_file
, "\nValue ranges after VRP:\n\n");
7724 dump_all_value_ranges (dump_file
);
7725 fprintf (dump_file
, "\n");
7728 substitute_and_fold (op_with_constant_singleton_value_range
,
7729 vrp_fold_stmt
, false);
7731 if (warn_array_bounds
)
7732 check_all_array_refs ();
7734 /* We must identify jump threading opportunities before we release
7735 the datastructures built by VRP. */
7736 identify_jump_threads ();
7738 /* Free allocated memory. */
7739 for (i
= 0; i
< num_vr_values
; i
++)
7742 BITMAP_FREE (vr_value
[i
]->equiv
);
7747 free (vr_phi_edge_counts
);
7749 /* So that we can distinguish between VRP data being available
7750 and not available. */
7752 vr_phi_edge_counts
= NULL
;
7756 /* Main entry point to VRP (Value Range Propagation). This pass is
7757 loosely based on J. R. C. Patterson, ``Accurate Static Branch
7758 Prediction by Value Range Propagation,'' in SIGPLAN Conference on
7759 Programming Language Design and Implementation, pp. 67-78, 1995.
7760 Also available at http://citeseer.ist.psu.edu/patterson95accurate.html
7762 This is essentially an SSA-CCP pass modified to deal with ranges
7763 instead of constants.
7765 While propagating ranges, we may find that two or more SSA name
7766 have equivalent, though distinct ranges. For instance,
7769 2 p_4 = ASSERT_EXPR <p_3, p_3 != 0>
7771 4 p_5 = ASSERT_EXPR <p_4, p_4 == q_2>;
7775 In the code above, pointer p_5 has range [q_2, q_2], but from the
7776 code we can also determine that p_5 cannot be NULL and, if q_2 had
7777 a non-varying range, p_5's range should also be compatible with it.
7779 These equivalences are created by two expressions: ASSERT_EXPR and
7780 copy operations. Since p_5 is an assertion on p_4, and p_4 was the
7781 result of another assertion, then we can use the fact that p_5 and
7782 p_4 are equivalent when evaluating p_5's range.
7784 Together with value ranges, we also propagate these equivalences
7785 between names so that we can take advantage of information from
7786 multiple ranges when doing final replacement. Note that this
7787 equivalency relation is transitive but not symmetric.
7789 In the example above, p_5 is equivalent to p_4, q_2 and p_3, but we
7790 cannot assert that q_2 is equivalent to p_5 because q_2 may be used
7791 in contexts where that assertion does not hold (e.g., in line 6).
7793 TODO, the main difference between this pass and Patterson's is that
7794 we do not propagate edge probabilities. We only compute whether
7795 edges can be taken or not. That is, instead of having a spectrum
7796 of jump probabilities between 0 and 1, we only deal with 0, 1 and
7797 DON'T KNOW. In the future, it may be worthwhile to propagate
7798 probabilities to aid branch prediction. */
7807 loop_optimizer_init (LOOPS_NORMAL
| LOOPS_HAVE_RECORDED_EXITS
);
7808 rewrite_into_loop_closed_ssa (NULL
, TODO_update_ssa
);
7811 insert_range_assertions ();
7813 /* Estimate number of iterations - but do not use undefined behavior
7814 for this. We can't do this lazily as other functions may compute
7815 this using undefined behavior. */
7816 free_numbers_of_iterations_estimates ();
7817 estimate_numbers_of_iterations (false);
7819 to_remove_edges
= VEC_alloc (edge
, heap
, 10);
7820 to_update_switch_stmts
= VEC_alloc (switch_update
, heap
, 5);
7821 threadedge_initialize_values ();
7824 ssa_propagate (vrp_visit_stmt
, vrp_visit_phi_node
);
7827 free_numbers_of_iterations_estimates ();
7829 /* ASSERT_EXPRs must be removed before finalizing jump threads
7830 as finalizing jump threads calls the CFG cleanup code which
7831 does not properly handle ASSERT_EXPRs. */
7832 remove_range_assertions ();
7834 /* If we exposed any new variables, go ahead and put them into
7835 SSA form now, before we handle jump threading. This simplifies
7836 interactions between rewriting of _DECL nodes into SSA form
7837 and rewriting SSA_NAME nodes into SSA form after block
7838 duplication and CFG manipulation. */
7839 update_ssa (TODO_update_ssa
);
7841 finalize_jump_threads ();
7843 /* Remove dead edges from SWITCH_EXPR optimization. This leaves the
7844 CFG in a broken state and requires a cfg_cleanup run. */
7845 FOR_EACH_VEC_ELT (edge
, to_remove_edges
, i
, e
)
7847 /* Update SWITCH_EXPR case label vector. */
7848 FOR_EACH_VEC_ELT (switch_update
, to_update_switch_stmts
, i
, su
)
7851 size_t n
= TREE_VEC_LENGTH (su
->vec
);
7853 gimple_switch_set_num_labels (su
->stmt
, n
);
7854 for (j
= 0; j
< n
; j
++)
7855 gimple_switch_set_label (su
->stmt
, j
, TREE_VEC_ELT (su
->vec
, j
));
7856 /* As we may have replaced the default label with a regular one
7857 make sure to make it a real default label again. This ensures
7858 optimal expansion. */
7859 label
= gimple_switch_default_label (su
->stmt
);
7860 CASE_LOW (label
) = NULL_TREE
;
7861 CASE_HIGH (label
) = NULL_TREE
;
7864 if (VEC_length (edge
, to_remove_edges
) > 0)
7865 free_dominance_info (CDI_DOMINATORS
);
7867 VEC_free (edge
, heap
, to_remove_edges
);
7868 VEC_free (switch_update
, heap
, to_update_switch_stmts
);
7869 threadedge_finalize_values ();
7872 loop_optimizer_finalize ();
7879 return flag_tree_vrp
!= 0;
7882 struct gimple_opt_pass pass_vrp
=
7887 gate_vrp
, /* gate */
7888 execute_vrp
, /* execute */
7891 0, /* static_pass_number */
7892 TV_TREE_VRP
, /* tv_id */
7893 PROP_ssa
, /* properties_required */
7894 0, /* properties_provided */
7895 0, /* properties_destroyed */
7896 0, /* todo_flags_start */
7901 | TODO_ggc_collect
/* todo_flags_finish */