1 /* Support routines for Value Range Propagation (VRP).
2 Copyright (C) 2005-2013 Free Software Foundation, Inc.
3 Contributed by Diego Novillo <dnovillo@redhat.com>.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
27 #include "stor-layout.h"
29 #include "basic-block.h"
30 #include "tree-ssa-alias.h"
31 #include "internal-fn.h"
32 #include "gimple-fold.h"
34 #include "gimple-expr.h"
37 #include "gimple-iterator.h"
38 #include "gimple-walk.h"
39 #include "gimple-ssa.h"
41 #include "tree-phinodes.h"
42 #include "ssa-iterators.h"
43 #include "stringpool.h"
44 #include "tree-ssanames.h"
45 #include "tree-ssa-loop-manip.h"
46 #include "tree-ssa-loop-niter.h"
47 #include "tree-ssa-loop.h"
48 #include "tree-into-ssa.h"
50 #include "tree-pass.h"
51 #include "tree-dump.h"
52 #include "gimple-pretty-print.h"
53 #include "diagnostic-core.h"
56 #include "tree-scalar-evolution.h"
57 #include "tree-ssa-propagate.h"
58 #include "tree-chrec.h"
59 #include "tree-ssa-threadupdate.h"
62 #include "tree-ssa-threadedge.h"
66 /* Range of values that can be associated with an SSA_NAME after VRP
70 /* Lattice value represented by this range. */
71 enum value_range_type type
;
73 /* Minimum and maximum values represented by this range. These
74 values should be interpreted as follows:
76 - If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must
79 - If TYPE == VR_RANGE then MIN holds the minimum value and
80 MAX holds the maximum value of the range [MIN, MAX].
82 - If TYPE == ANTI_RANGE the variable is known to NOT
83 take any values in the range [MIN, MAX]. */
87 /* Set of SSA names whose value ranges are equivalent to this one.
88 This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE. */
92 typedef struct value_range_d value_range_t
;
94 #define VR_INITIALIZER { VR_UNDEFINED, NULL_TREE, NULL_TREE, NULL }
96 /* Set of SSA names found live during the RPO traversal of the function
97 for still active basic-blocks. */
100 /* Return true if the SSA name NAME is live on the edge E. */
103 live_on_edge (edge e
, tree name
)
105 return (live
[e
->dest
->index
]
106 && bitmap_bit_p (live
[e
->dest
->index
], SSA_NAME_VERSION (name
)));
109 /* Local functions. */
110 static int compare_values (tree val1
, tree val2
);
111 static int compare_values_warnv (tree val1
, tree val2
, bool *);
112 static void vrp_meet (value_range_t
*, value_range_t
*);
113 static void vrp_intersect_ranges (value_range_t
*, value_range_t
*);
114 static tree
vrp_evaluate_conditional_warnv_with_ops (enum tree_code
,
115 tree
, tree
, bool, bool *,
118 /* Location information for ASSERT_EXPRs. Each instance of this
119 structure describes an ASSERT_EXPR for an SSA name. Since a single
120 SSA name may have more than one assertion associated with it, these
121 locations are kept in a linked list attached to the corresponding
123 struct assert_locus_d
125 /* Basic block where the assertion would be inserted. */
128 /* Some assertions need to be inserted on an edge (e.g., assertions
129 generated by COND_EXPRs). In those cases, BB will be NULL. */
132 /* Pointer to the statement that generated this assertion. */
133 gimple_stmt_iterator si
;
135 /* Predicate code for the ASSERT_EXPR. Must be COMPARISON_CLASS_P. */
136 enum tree_code comp_code
;
138 /* Value being compared against. */
141 /* Expression to compare. */
144 /* Next node in the linked list. */
145 struct assert_locus_d
*next
;
148 typedef struct assert_locus_d
*assert_locus_t
;
150 /* If bit I is present, it means that SSA name N_i has a list of
151 assertions that should be inserted in the IL. */
152 static bitmap need_assert_for
;
154 /* Array of locations lists where to insert assertions. ASSERTS_FOR[I]
155 holds a list of ASSERT_LOCUS_T nodes that describe where
156 ASSERT_EXPRs for SSA name N_I should be inserted. */
157 static assert_locus_t
*asserts_for
;
159 /* Value range array. After propagation, VR_VALUE[I] holds the range
160 of values that SSA name N_I may take. */
161 static unsigned num_vr_values
;
162 static value_range_t
**vr_value
;
163 static bool values_propagated
;
165 /* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the
166 number of executable edges we saw the last time we visited the
168 static int *vr_phi_edge_counts
;
175 static vec
<edge
> to_remove_edges
;
176 static vec
<switch_update
> to_update_switch_stmts
;
179 /* Return the maximum value for TYPE. */
182 vrp_val_max (const_tree type
)
184 if (!INTEGRAL_TYPE_P (type
))
187 return TYPE_MAX_VALUE (type
);
190 /* Return the minimum value for TYPE. */
193 vrp_val_min (const_tree type
)
195 if (!INTEGRAL_TYPE_P (type
))
198 return TYPE_MIN_VALUE (type
);
201 /* Return whether VAL is equal to the maximum value of its type. This
202 will be true for a positive overflow infinity. We can't do a
203 simple equality comparison with TYPE_MAX_VALUE because C typedefs
204 and Ada subtypes can produce types whose TYPE_MAX_VALUE is not ==
205 to the integer constant with the same value in the type. */
208 vrp_val_is_max (const_tree val
)
210 tree type_max
= vrp_val_max (TREE_TYPE (val
));
211 return (val
== type_max
212 || (type_max
!= NULL_TREE
213 && operand_equal_p (val
, type_max
, 0)));
216 /* Return whether VAL is equal to the minimum value of its type. This
217 will be true for a negative overflow infinity. */
220 vrp_val_is_min (const_tree val
)
222 tree type_min
= vrp_val_min (TREE_TYPE (val
));
223 return (val
== type_min
224 || (type_min
!= NULL_TREE
225 && operand_equal_p (val
, type_min
, 0)));
229 /* Return whether TYPE should use an overflow infinity distinct from
230 TYPE_{MIN,MAX}_VALUE. We use an overflow infinity value to
231 represent a signed overflow during VRP computations. An infinity
232 is distinct from a half-range, which will go from some number to
233 TYPE_{MIN,MAX}_VALUE. */
236 needs_overflow_infinity (const_tree type
)
238 return INTEGRAL_TYPE_P (type
) && !TYPE_OVERFLOW_WRAPS (type
);
241 /* Return whether TYPE can support our overflow infinity
242 representation: we use the TREE_OVERFLOW flag, which only exists
243 for constants. If TYPE doesn't support this, we don't optimize
244 cases which would require signed overflow--we drop them to
248 supports_overflow_infinity (const_tree type
)
250 tree min
= vrp_val_min (type
), max
= vrp_val_max (type
);
251 #ifdef ENABLE_CHECKING
252 gcc_assert (needs_overflow_infinity (type
));
254 return (min
!= NULL_TREE
255 && CONSTANT_CLASS_P (min
)
257 && CONSTANT_CLASS_P (max
));
260 /* VAL is the maximum or minimum value of a type. Return a
261 corresponding overflow infinity. */
264 make_overflow_infinity (tree val
)
266 gcc_checking_assert (val
!= NULL_TREE
&& CONSTANT_CLASS_P (val
));
267 val
= copy_node (val
);
268 TREE_OVERFLOW (val
) = 1;
272 /* Return a negative overflow infinity for TYPE. */
275 negative_overflow_infinity (tree type
)
277 gcc_checking_assert (supports_overflow_infinity (type
));
278 return make_overflow_infinity (vrp_val_min (type
));
281 /* Return a positive overflow infinity for TYPE. */
284 positive_overflow_infinity (tree type
)
286 gcc_checking_assert (supports_overflow_infinity (type
));
287 return make_overflow_infinity (vrp_val_max (type
));
290 /* Return whether VAL is a negative overflow infinity. */
293 is_negative_overflow_infinity (const_tree val
)
295 return (needs_overflow_infinity (TREE_TYPE (val
))
296 && CONSTANT_CLASS_P (val
)
297 && TREE_OVERFLOW (val
)
298 && vrp_val_is_min (val
));
301 /* Return whether VAL is a positive overflow infinity. */
304 is_positive_overflow_infinity (const_tree val
)
306 return (needs_overflow_infinity (TREE_TYPE (val
))
307 && CONSTANT_CLASS_P (val
)
308 && TREE_OVERFLOW (val
)
309 && vrp_val_is_max (val
));
312 /* Return whether VAL is a positive or negative overflow infinity. */
315 is_overflow_infinity (const_tree val
)
317 return (needs_overflow_infinity (TREE_TYPE (val
))
318 && CONSTANT_CLASS_P (val
)
319 && TREE_OVERFLOW (val
)
320 && (vrp_val_is_min (val
) || vrp_val_is_max (val
)));
323 /* Return whether STMT has a constant rhs that is_overflow_infinity. */
326 stmt_overflow_infinity (gimple stmt
)
328 if (is_gimple_assign (stmt
)
329 && get_gimple_rhs_class (gimple_assign_rhs_code (stmt
)) ==
331 return is_overflow_infinity (gimple_assign_rhs1 (stmt
));
335 /* If VAL is now an overflow infinity, return VAL. Otherwise, return
336 the same value with TREE_OVERFLOW clear. This can be used to avoid
337 confusing a regular value with an overflow value. */
340 avoid_overflow_infinity (tree val
)
342 if (!is_overflow_infinity (val
))
345 if (vrp_val_is_max (val
))
346 return vrp_val_max (TREE_TYPE (val
));
349 gcc_checking_assert (vrp_val_is_min (val
));
350 return vrp_val_min (TREE_TYPE (val
));
355 /* Return true if ARG is marked with the nonnull attribute in the
356 current function signature. */
359 nonnull_arg_p (const_tree arg
)
361 tree t
, attrs
, fntype
;
362 unsigned HOST_WIDE_INT arg_num
;
364 gcc_assert (TREE_CODE (arg
) == PARM_DECL
&& POINTER_TYPE_P (TREE_TYPE (arg
)));
366 /* The static chain decl is always non null. */
367 if (arg
== cfun
->static_chain_decl
)
370 fntype
= TREE_TYPE (current_function_decl
);
371 for (attrs
= TYPE_ATTRIBUTES (fntype
); attrs
; attrs
= TREE_CHAIN (attrs
))
373 attrs
= lookup_attribute ("nonnull", attrs
);
375 /* If "nonnull" wasn't specified, we know nothing about the argument. */
376 if (attrs
== NULL_TREE
)
379 /* If "nonnull" applies to all the arguments, then ARG is non-null. */
380 if (TREE_VALUE (attrs
) == NULL_TREE
)
383 /* Get the position number for ARG in the function signature. */
384 for (arg_num
= 1, t
= DECL_ARGUMENTS (current_function_decl
);
386 t
= DECL_CHAIN (t
), arg_num
++)
392 gcc_assert (t
== arg
);
394 /* Now see if ARG_NUM is mentioned in the nonnull list. */
395 for (t
= TREE_VALUE (attrs
); t
; t
= TREE_CHAIN (t
))
397 if (compare_tree_int (TREE_VALUE (t
), arg_num
) == 0)
406 /* Set value range VR to VR_UNDEFINED. */
409 set_value_range_to_undefined (value_range_t
*vr
)
411 vr
->type
= VR_UNDEFINED
;
412 vr
->min
= vr
->max
= NULL_TREE
;
414 bitmap_clear (vr
->equiv
);
418 /* Set value range VR to VR_VARYING. */
421 set_value_range_to_varying (value_range_t
*vr
)
423 vr
->type
= VR_VARYING
;
424 vr
->min
= vr
->max
= NULL_TREE
;
426 bitmap_clear (vr
->equiv
);
430 /* Set value range VR to {T, MIN, MAX, EQUIV}. */
433 set_value_range (value_range_t
*vr
, enum value_range_type t
, tree min
,
434 tree max
, bitmap equiv
)
436 #if defined ENABLE_CHECKING
437 /* Check the validity of the range. */
438 if (t
== VR_RANGE
|| t
== VR_ANTI_RANGE
)
442 gcc_assert (min
&& max
);
444 gcc_assert ((!TREE_OVERFLOW_P (min
) || is_overflow_infinity (min
))
445 && (!TREE_OVERFLOW_P (max
) || is_overflow_infinity (max
)));
447 if (INTEGRAL_TYPE_P (TREE_TYPE (min
)) && t
== VR_ANTI_RANGE
)
448 gcc_assert (!vrp_val_is_min (min
) || !vrp_val_is_max (max
));
450 cmp
= compare_values (min
, max
);
451 gcc_assert (cmp
== 0 || cmp
== -1 || cmp
== -2);
453 if (needs_overflow_infinity (TREE_TYPE (min
)))
454 gcc_assert (!is_overflow_infinity (min
)
455 || !is_overflow_infinity (max
));
458 if (t
== VR_UNDEFINED
|| t
== VR_VARYING
)
459 gcc_assert (min
== NULL_TREE
&& max
== NULL_TREE
);
461 if (t
== VR_UNDEFINED
|| t
== VR_VARYING
)
462 gcc_assert (equiv
== NULL
|| bitmap_empty_p (equiv
));
469 /* Since updating the equivalence set involves deep copying the
470 bitmaps, only do it if absolutely necessary. */
471 if (vr
->equiv
== NULL
473 vr
->equiv
= BITMAP_ALLOC (NULL
);
475 if (equiv
!= vr
->equiv
)
477 if (equiv
&& !bitmap_empty_p (equiv
))
478 bitmap_copy (vr
->equiv
, equiv
);
480 bitmap_clear (vr
->equiv
);
485 /* Set value range VR to the canonical form of {T, MIN, MAX, EQUIV}.
486 This means adjusting T, MIN and MAX representing the case of a
487 wrapping range with MAX < MIN covering [MIN, type_max] U [type_min, MAX]
488 as anti-rage ~[MAX+1, MIN-1]. Likewise for wrapping anti-ranges.
489 In corner cases where MAX+1 or MIN-1 wraps this will fall back
491 This routine exists to ease canonicalization in the case where we
492 extract ranges from var + CST op limit. */
495 set_and_canonicalize_value_range (value_range_t
*vr
, enum value_range_type t
,
496 tree min
, tree max
, bitmap equiv
)
498 /* Use the canonical setters for VR_UNDEFINED and VR_VARYING. */
499 if (t
== VR_UNDEFINED
)
501 set_value_range_to_undefined (vr
);
504 else if (t
== VR_VARYING
)
506 set_value_range_to_varying (vr
);
510 /* Nothing to canonicalize for symbolic ranges. */
511 if (TREE_CODE (min
) != INTEGER_CST
512 || TREE_CODE (max
) != INTEGER_CST
)
514 set_value_range (vr
, t
, min
, max
, equiv
);
518 /* Wrong order for min and max, to swap them and the VR type we need
520 if (tree_int_cst_lt (max
, min
))
524 /* For one bit precision if max < min, then the swapped
525 range covers all values, so for VR_RANGE it is varying and
526 for VR_ANTI_RANGE empty range, so drop to varying as well. */
527 if (TYPE_PRECISION (TREE_TYPE (min
)) == 1)
529 set_value_range_to_varying (vr
);
533 one
= build_int_cst (TREE_TYPE (min
), 1);
534 tmp
= int_const_binop (PLUS_EXPR
, max
, one
);
535 max
= int_const_binop (MINUS_EXPR
, min
, one
);
538 /* There's one corner case, if we had [C+1, C] before we now have
539 that again. But this represents an empty value range, so drop
540 to varying in this case. */
541 if (tree_int_cst_lt (max
, min
))
543 set_value_range_to_varying (vr
);
547 t
= t
== VR_RANGE
? VR_ANTI_RANGE
: VR_RANGE
;
550 /* Anti-ranges that can be represented as ranges should be so. */
551 if (t
== VR_ANTI_RANGE
)
553 bool is_min
= vrp_val_is_min (min
);
554 bool is_max
= vrp_val_is_max (max
);
556 if (is_min
&& is_max
)
558 /* We cannot deal with empty ranges, drop to varying.
559 ??? This could be VR_UNDEFINED instead. */
560 set_value_range_to_varying (vr
);
563 else if (TYPE_PRECISION (TREE_TYPE (min
)) == 1
564 && (is_min
|| is_max
))
566 /* Non-empty boolean ranges can always be represented
567 as a singleton range. */
569 min
= max
= vrp_val_max (TREE_TYPE (min
));
571 min
= max
= vrp_val_min (TREE_TYPE (min
));
575 /* As a special exception preserve non-null ranges. */
576 && !(TYPE_UNSIGNED (TREE_TYPE (min
))
577 && integer_zerop (max
)))
579 tree one
= build_int_cst (TREE_TYPE (max
), 1);
580 min
= int_const_binop (PLUS_EXPR
, max
, one
);
581 max
= vrp_val_max (TREE_TYPE (max
));
586 tree one
= build_int_cst (TREE_TYPE (min
), 1);
587 max
= int_const_binop (MINUS_EXPR
, min
, one
);
588 min
= vrp_val_min (TREE_TYPE (min
));
593 /* Drop [-INF(OVF), +INF(OVF)] to varying. */
594 if (needs_overflow_infinity (TREE_TYPE (min
))
595 && is_overflow_infinity (min
)
596 && is_overflow_infinity (max
))
598 set_value_range_to_varying (vr
);
602 set_value_range (vr
, t
, min
, max
, equiv
);
605 /* Copy value range FROM into value range TO. */
608 copy_value_range (value_range_t
*to
, value_range_t
*from
)
610 set_value_range (to
, from
->type
, from
->min
, from
->max
, from
->equiv
);
613 /* Set value range VR to a single value. This function is only called
614 with values we get from statements, and exists to clear the
615 TREE_OVERFLOW flag so that we don't think we have an overflow
616 infinity when we shouldn't. */
619 set_value_range_to_value (value_range_t
*vr
, tree val
, bitmap equiv
)
621 gcc_assert (is_gimple_min_invariant (val
));
622 if (TREE_OVERFLOW_P (val
))
623 val
= drop_tree_overflow (val
);
624 set_value_range (vr
, VR_RANGE
, val
, val
, equiv
);
627 /* Set value range VR to a non-negative range of type TYPE.
628 OVERFLOW_INFINITY indicates whether to use an overflow infinity
629 rather than TYPE_MAX_VALUE; this should be true if we determine
630 that the range is nonnegative based on the assumption that signed
631 overflow does not occur. */
634 set_value_range_to_nonnegative (value_range_t
*vr
, tree type
,
635 bool overflow_infinity
)
639 if (overflow_infinity
&& !supports_overflow_infinity (type
))
641 set_value_range_to_varying (vr
);
645 zero
= build_int_cst (type
, 0);
646 set_value_range (vr
, VR_RANGE
, zero
,
648 ? positive_overflow_infinity (type
)
649 : TYPE_MAX_VALUE (type
)),
653 /* Set value range VR to a non-NULL range of type TYPE. */
656 set_value_range_to_nonnull (value_range_t
*vr
, tree type
)
658 tree zero
= build_int_cst (type
, 0);
659 set_value_range (vr
, VR_ANTI_RANGE
, zero
, zero
, vr
->equiv
);
663 /* Set value range VR to a NULL range of type TYPE. */
666 set_value_range_to_null (value_range_t
*vr
, tree type
)
668 set_value_range_to_value (vr
, build_int_cst (type
, 0), vr
->equiv
);
672 /* Set value range VR to a range of a truthvalue of type TYPE. */
675 set_value_range_to_truthvalue (value_range_t
*vr
, tree type
)
677 if (TYPE_PRECISION (type
) == 1)
678 set_value_range_to_varying (vr
);
680 set_value_range (vr
, VR_RANGE
,
681 build_int_cst (type
, 0), build_int_cst (type
, 1),
686 /* If abs (min) < abs (max), set VR to [-max, max], if
687 abs (min) >= abs (max), set VR to [-min, min]. */
690 abs_extent_range (value_range_t
*vr
, tree min
, tree max
)
694 gcc_assert (TREE_CODE (min
) == INTEGER_CST
);
695 gcc_assert (TREE_CODE (max
) == INTEGER_CST
);
696 gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (min
)));
697 gcc_assert (!TYPE_UNSIGNED (TREE_TYPE (min
)));
698 min
= fold_unary (ABS_EXPR
, TREE_TYPE (min
), min
);
699 max
= fold_unary (ABS_EXPR
, TREE_TYPE (max
), max
);
700 if (TREE_OVERFLOW (min
) || TREE_OVERFLOW (max
))
702 set_value_range_to_varying (vr
);
705 cmp
= compare_values (min
, max
);
707 min
= fold_unary (NEGATE_EXPR
, TREE_TYPE (min
), max
);
708 else if (cmp
== 0 || cmp
== 1)
711 min
= fold_unary (NEGATE_EXPR
, TREE_TYPE (min
), min
);
715 set_value_range_to_varying (vr
);
718 set_and_canonicalize_value_range (vr
, VR_RANGE
, min
, max
, NULL
);
722 /* Return value range information for VAR.
724 If we have no values ranges recorded (ie, VRP is not running), then
725 return NULL. Otherwise create an empty range if none existed for VAR. */
727 static value_range_t
*
728 get_value_range (const_tree var
)
730 static const struct value_range_d vr_const_varying
731 = { VR_VARYING
, NULL_TREE
, NULL_TREE
, NULL
};
734 unsigned ver
= SSA_NAME_VERSION (var
);
736 /* If we have no recorded ranges, then return NULL. */
740 /* If we query the range for a new SSA name return an unmodifiable VARYING.
741 We should get here at most from the substitute-and-fold stage which
742 will never try to change values. */
743 if (ver
>= num_vr_values
)
744 return CONST_CAST (value_range_t
*, &vr_const_varying
);
750 /* After propagation finished do not allocate new value-ranges. */
751 if (values_propagated
)
752 return CONST_CAST (value_range_t
*, &vr_const_varying
);
754 /* Create a default value range. */
755 vr_value
[ver
] = vr
= XCNEW (value_range_t
);
757 /* Defer allocating the equivalence set. */
760 /* If VAR is a default definition of a parameter, the variable can
761 take any value in VAR's type. */
762 if (SSA_NAME_IS_DEFAULT_DEF (var
))
764 sym
= SSA_NAME_VAR (var
);
765 if (TREE_CODE (sym
) == PARM_DECL
)
767 /* Try to use the "nonnull" attribute to create ~[0, 0]
768 anti-ranges for pointers. Note that this is only valid with
769 default definitions of PARM_DECLs. */
770 if (POINTER_TYPE_P (TREE_TYPE (sym
))
771 && nonnull_arg_p (sym
))
772 set_value_range_to_nonnull (vr
, TREE_TYPE (sym
));
774 set_value_range_to_varying (vr
);
776 else if (TREE_CODE (sym
) == RESULT_DECL
777 && DECL_BY_REFERENCE (sym
))
778 set_value_range_to_nonnull (vr
, TREE_TYPE (sym
));
784 /* Return true, if VAL1 and VAL2 are equal values for VRP purposes. */
787 vrp_operand_equal_p (const_tree val1
, const_tree val2
)
791 if (!val1
|| !val2
|| !operand_equal_p (val1
, val2
, 0))
793 if (is_overflow_infinity (val1
))
794 return is_overflow_infinity (val2
);
798 /* Return true, if the bitmaps B1 and B2 are equal. */
801 vrp_bitmap_equal_p (const_bitmap b1
, const_bitmap b2
)
804 || ((!b1
|| bitmap_empty_p (b1
))
805 && (!b2
|| bitmap_empty_p (b2
)))
807 && bitmap_equal_p (b1
, b2
)));
810 /* Update the value range and equivalence set for variable VAR to
811 NEW_VR. Return true if NEW_VR is different from VAR's previous
814 NOTE: This function assumes that NEW_VR is a temporary value range
815 object created for the sole purpose of updating VAR's range. The
816 storage used by the equivalence set from NEW_VR will be freed by
817 this function. Do not call update_value_range when NEW_VR
818 is the range object associated with another SSA name. */
821 update_value_range (const_tree var
, value_range_t
*new_vr
)
823 value_range_t
*old_vr
;
826 /* Update the value range, if necessary. */
827 old_vr
= get_value_range (var
);
828 is_new
= old_vr
->type
!= new_vr
->type
829 || !vrp_operand_equal_p (old_vr
->min
, new_vr
->min
)
830 || !vrp_operand_equal_p (old_vr
->max
, new_vr
->max
)
831 || !vrp_bitmap_equal_p (old_vr
->equiv
, new_vr
->equiv
);
835 /* Do not allow transitions up the lattice. The following
836 is slightly more awkward than just new_vr->type < old_vr->type
837 because VR_RANGE and VR_ANTI_RANGE need to be considered
838 the same. We may not have is_new when transitioning to
839 UNDEFINED or from VARYING. */
840 if (new_vr
->type
== VR_UNDEFINED
841 || old_vr
->type
== VR_VARYING
)
842 set_value_range_to_varying (old_vr
);
844 set_value_range (old_vr
, new_vr
->type
, new_vr
->min
, new_vr
->max
,
848 BITMAP_FREE (new_vr
->equiv
);
854 /* Add VAR and VAR's equivalence set to EQUIV. This is the central
855 point where equivalence processing can be turned on/off. */
858 add_equivalence (bitmap
*equiv
, const_tree var
)
860 unsigned ver
= SSA_NAME_VERSION (var
);
861 value_range_t
*vr
= vr_value
[ver
];
864 *equiv
= BITMAP_ALLOC (NULL
);
865 bitmap_set_bit (*equiv
, ver
);
867 bitmap_ior_into (*equiv
, vr
->equiv
);
871 /* Return true if VR is ~[0, 0]. */
874 range_is_nonnull (value_range_t
*vr
)
876 return vr
->type
== VR_ANTI_RANGE
877 && integer_zerop (vr
->min
)
878 && integer_zerop (vr
->max
);
882 /* Return true if VR is [0, 0]. */
885 range_is_null (value_range_t
*vr
)
887 return vr
->type
== VR_RANGE
888 && integer_zerop (vr
->min
)
889 && integer_zerop (vr
->max
);
892 /* Return true if max and min of VR are INTEGER_CST. It's not necessary
896 range_int_cst_p (value_range_t
*vr
)
898 return (vr
->type
== VR_RANGE
899 && TREE_CODE (vr
->max
) == INTEGER_CST
900 && TREE_CODE (vr
->min
) == INTEGER_CST
);
903 /* Return true if VR is a INTEGER_CST singleton. */
906 range_int_cst_singleton_p (value_range_t
*vr
)
908 return (range_int_cst_p (vr
)
909 && !is_overflow_infinity (vr
->min
)
910 && !is_overflow_infinity (vr
->max
)
911 && tree_int_cst_equal (vr
->min
, vr
->max
));
914 /* Return true if value range VR involves at least one symbol. */
917 symbolic_range_p (value_range_t
*vr
)
919 return (!is_gimple_min_invariant (vr
->min
)
920 || !is_gimple_min_invariant (vr
->max
));
923 /* Return true if value range VR uses an overflow infinity. */
926 overflow_infinity_range_p (value_range_t
*vr
)
928 return (vr
->type
== VR_RANGE
929 && (is_overflow_infinity (vr
->min
)
930 || is_overflow_infinity (vr
->max
)));
933 /* Return false if we can not make a valid comparison based on VR;
934 this will be the case if it uses an overflow infinity and overflow
935 is not undefined (i.e., -fno-strict-overflow is in effect).
936 Otherwise return true, and set *STRICT_OVERFLOW_P to true if VR
937 uses an overflow infinity. */
940 usable_range_p (value_range_t
*vr
, bool *strict_overflow_p
)
942 gcc_assert (vr
->type
== VR_RANGE
);
943 if (is_overflow_infinity (vr
->min
))
945 *strict_overflow_p
= true;
946 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr
->min
)))
949 if (is_overflow_infinity (vr
->max
))
951 *strict_overflow_p
= true;
952 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr
->max
)))
959 /* Return true if the result of assignment STMT is know to be non-negative.
960 If the return value is based on the assumption that signed overflow is
961 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
962 *STRICT_OVERFLOW_P.*/
965 gimple_assign_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
967 enum tree_code code
= gimple_assign_rhs_code (stmt
);
968 switch (get_gimple_rhs_class (code
))
970 case GIMPLE_UNARY_RHS
:
971 return tree_unary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt
),
972 gimple_expr_type (stmt
),
973 gimple_assign_rhs1 (stmt
),
975 case GIMPLE_BINARY_RHS
:
976 return tree_binary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt
),
977 gimple_expr_type (stmt
),
978 gimple_assign_rhs1 (stmt
),
979 gimple_assign_rhs2 (stmt
),
981 case GIMPLE_TERNARY_RHS
:
983 case GIMPLE_SINGLE_RHS
:
984 return tree_single_nonnegative_warnv_p (gimple_assign_rhs1 (stmt
),
986 case GIMPLE_INVALID_RHS
:
993 /* Return true if return value of call STMT is know to be non-negative.
994 If the return value is based on the assumption that signed overflow is
995 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
996 *STRICT_OVERFLOW_P.*/
999 gimple_call_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
1001 tree arg0
= gimple_call_num_args (stmt
) > 0 ?
1002 gimple_call_arg (stmt
, 0) : NULL_TREE
;
1003 tree arg1
= gimple_call_num_args (stmt
) > 1 ?
1004 gimple_call_arg (stmt
, 1) : NULL_TREE
;
1006 return tree_call_nonnegative_warnv_p (gimple_expr_type (stmt
),
1007 gimple_call_fndecl (stmt
),
1013 /* Return true if STMT is know to to compute a non-negative value.
1014 If the return value is based on the assumption that signed overflow is
1015 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
1016 *STRICT_OVERFLOW_P.*/
1019 gimple_stmt_nonnegative_warnv_p (gimple stmt
, bool *strict_overflow_p
)
1021 switch (gimple_code (stmt
))
1024 return gimple_assign_nonnegative_warnv_p (stmt
, strict_overflow_p
);
1026 return gimple_call_nonnegative_warnv_p (stmt
, strict_overflow_p
);
1032 /* Return true if the result of assignment STMT is know to be non-zero.
1033 If the return value is based on the assumption that signed overflow is
1034 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
1035 *STRICT_OVERFLOW_P.*/
1038 gimple_assign_nonzero_warnv_p (gimple stmt
, bool *strict_overflow_p
)
1040 enum tree_code code
= gimple_assign_rhs_code (stmt
);
1041 switch (get_gimple_rhs_class (code
))
1043 case GIMPLE_UNARY_RHS
:
1044 return tree_unary_nonzero_warnv_p (gimple_assign_rhs_code (stmt
),
1045 gimple_expr_type (stmt
),
1046 gimple_assign_rhs1 (stmt
),
1048 case GIMPLE_BINARY_RHS
:
1049 return tree_binary_nonzero_warnv_p (gimple_assign_rhs_code (stmt
),
1050 gimple_expr_type (stmt
),
1051 gimple_assign_rhs1 (stmt
),
1052 gimple_assign_rhs2 (stmt
),
1054 case GIMPLE_TERNARY_RHS
:
1056 case GIMPLE_SINGLE_RHS
:
1057 return tree_single_nonzero_warnv_p (gimple_assign_rhs1 (stmt
),
1059 case GIMPLE_INVALID_RHS
:
1066 /* Return true if STMT is known to compute a non-zero value.
1067 If the return value is based on the assumption that signed overflow is
1068 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
1069 *STRICT_OVERFLOW_P.*/
1072 gimple_stmt_nonzero_warnv_p (gimple stmt
, bool *strict_overflow_p
)
1074 switch (gimple_code (stmt
))
1077 return gimple_assign_nonzero_warnv_p (stmt
, strict_overflow_p
);
1080 tree fndecl
= gimple_call_fndecl (stmt
);
1081 if (!fndecl
) return false;
1082 if (flag_delete_null_pointer_checks
&& !flag_check_new
1083 && DECL_IS_OPERATOR_NEW (fndecl
)
1084 && !TREE_NOTHROW (fndecl
))
1086 if (flag_delete_null_pointer_checks
&&
1087 lookup_attribute ("returns_nonnull",
1088 TYPE_ATTRIBUTES (gimple_call_fntype (stmt
))))
1090 return gimple_alloca_call_p (stmt
);
1097 /* Like tree_expr_nonzero_warnv_p, but this function uses value ranges
1101 vrp_stmt_computes_nonzero (gimple stmt
, bool *strict_overflow_p
)
1103 if (gimple_stmt_nonzero_warnv_p (stmt
, strict_overflow_p
))
1106 /* If we have an expression of the form &X->a, then the expression
1107 is nonnull if X is nonnull. */
1108 if (is_gimple_assign (stmt
)
1109 && gimple_assign_rhs_code (stmt
) == ADDR_EXPR
)
1111 tree expr
= gimple_assign_rhs1 (stmt
);
1112 tree base
= get_base_address (TREE_OPERAND (expr
, 0));
1114 if (base
!= NULL_TREE
1115 && TREE_CODE (base
) == MEM_REF
1116 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1118 value_range_t
*vr
= get_value_range (TREE_OPERAND (base
, 0));
1119 if (range_is_nonnull (vr
))
1127 /* Returns true if EXPR is a valid value (as expected by compare_values) --
1128 a gimple invariant, or SSA_NAME +- CST. */
1131 valid_value_p (tree expr
)
1133 if (TREE_CODE (expr
) == SSA_NAME
)
1136 if (TREE_CODE (expr
) == PLUS_EXPR
1137 || TREE_CODE (expr
) == MINUS_EXPR
)
1138 return (TREE_CODE (TREE_OPERAND (expr
, 0)) == SSA_NAME
1139 && TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
);
1141 return is_gimple_min_invariant (expr
);
1147 -2 if those are incomparable. */
1149 operand_less_p (tree val
, tree val2
)
1151 /* LT is folded faster than GE and others. Inline the common case. */
1152 if (TREE_CODE (val
) == INTEGER_CST
&& TREE_CODE (val2
) == INTEGER_CST
)
1154 if (TYPE_UNSIGNED (TREE_TYPE (val
)))
1155 return INT_CST_LT_UNSIGNED (val
, val2
);
1158 if (INT_CST_LT (val
, val2
))
1166 fold_defer_overflow_warnings ();
1168 tcmp
= fold_binary_to_constant (LT_EXPR
, boolean_type_node
, val
, val2
);
1170 fold_undefer_and_ignore_overflow_warnings ();
1173 || TREE_CODE (tcmp
) != INTEGER_CST
)
1176 if (!integer_zerop (tcmp
))
1180 /* val >= val2, not considering overflow infinity. */
1181 if (is_negative_overflow_infinity (val
))
1182 return is_negative_overflow_infinity (val2
) ? 0 : 1;
1183 else if (is_positive_overflow_infinity (val2
))
1184 return is_positive_overflow_infinity (val
) ? 0 : 1;
1189 /* Compare two values VAL1 and VAL2. Return
1191 -2 if VAL1 and VAL2 cannot be compared at compile-time,
1194 +1 if VAL1 > VAL2, and
1197 This is similar to tree_int_cst_compare but supports pointer values
1198 and values that cannot be compared at compile time.
1200 If STRICT_OVERFLOW_P is not NULL, then set *STRICT_OVERFLOW_P to
1201 true if the return value is only valid if we assume that signed
1202 overflow is undefined. */
1205 compare_values_warnv (tree val1
, tree val2
, bool *strict_overflow_p
)
1210 /* Below we rely on the fact that VAL1 and VAL2 are both pointers or
1212 gcc_assert (POINTER_TYPE_P (TREE_TYPE (val1
))
1213 == POINTER_TYPE_P (TREE_TYPE (val2
)));
1214 /* Convert the two values into the same type. This is needed because
1215 sizetype causes sign extension even for unsigned types. */
1216 val2
= fold_convert (TREE_TYPE (val1
), val2
);
1217 STRIP_USELESS_TYPE_CONVERSION (val2
);
1219 if ((TREE_CODE (val1
) == SSA_NAME
1220 || TREE_CODE (val1
) == PLUS_EXPR
1221 || TREE_CODE (val1
) == MINUS_EXPR
)
1222 && (TREE_CODE (val2
) == SSA_NAME
1223 || TREE_CODE (val2
) == PLUS_EXPR
1224 || TREE_CODE (val2
) == MINUS_EXPR
))
1226 tree n1
, c1
, n2
, c2
;
1227 enum tree_code code1
, code2
;
1229 /* If VAL1 and VAL2 are of the form 'NAME [+-] CST' or 'NAME',
1230 return -1 or +1 accordingly. If VAL1 and VAL2 don't use the
1231 same name, return -2. */
1232 if (TREE_CODE (val1
) == SSA_NAME
)
1240 code1
= TREE_CODE (val1
);
1241 n1
= TREE_OPERAND (val1
, 0);
1242 c1
= TREE_OPERAND (val1
, 1);
1243 if (tree_int_cst_sgn (c1
) == -1)
1245 if (is_negative_overflow_infinity (c1
))
1247 c1
= fold_unary_to_constant (NEGATE_EXPR
, TREE_TYPE (c1
), c1
);
1250 code1
= code1
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
;
1254 if (TREE_CODE (val2
) == SSA_NAME
)
1262 code2
= TREE_CODE (val2
);
1263 n2
= TREE_OPERAND (val2
, 0);
1264 c2
= TREE_OPERAND (val2
, 1);
1265 if (tree_int_cst_sgn (c2
) == -1)
1267 if (is_negative_overflow_infinity (c2
))
1269 c2
= fold_unary_to_constant (NEGATE_EXPR
, TREE_TYPE (c2
), c2
);
1272 code2
= code2
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
;
1276 /* Both values must use the same name. */
1280 if (code1
== SSA_NAME
1281 && code2
== SSA_NAME
)
1285 /* If overflow is defined we cannot simplify more. */
1286 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1
)))
1289 if (strict_overflow_p
!= NULL
1290 && (code1
== SSA_NAME
|| !TREE_NO_WARNING (val1
))
1291 && (code2
== SSA_NAME
|| !TREE_NO_WARNING (val2
)))
1292 *strict_overflow_p
= true;
1294 if (code1
== SSA_NAME
)
1296 if (code2
== PLUS_EXPR
)
1297 /* NAME < NAME + CST */
1299 else if (code2
== MINUS_EXPR
)
1300 /* NAME > NAME - CST */
1303 else if (code1
== PLUS_EXPR
)
1305 if (code2
== SSA_NAME
)
1306 /* NAME + CST > NAME */
1308 else if (code2
== PLUS_EXPR
)
1309 /* NAME + CST1 > NAME + CST2, if CST1 > CST2 */
1310 return compare_values_warnv (c1
, c2
, strict_overflow_p
);
1311 else if (code2
== MINUS_EXPR
)
1312 /* NAME + CST1 > NAME - CST2 */
1315 else if (code1
== MINUS_EXPR
)
1317 if (code2
== SSA_NAME
)
1318 /* NAME - CST < NAME */
1320 else if (code2
== PLUS_EXPR
)
1321 /* NAME - CST1 < NAME + CST2 */
1323 else if (code2
== MINUS_EXPR
)
1324 /* NAME - CST1 > NAME - CST2, if CST1 < CST2. Notice that
1325 C1 and C2 are swapped in the call to compare_values. */
1326 return compare_values_warnv (c2
, c1
, strict_overflow_p
);
1332 /* We cannot compare non-constants. */
1333 if (!is_gimple_min_invariant (val1
) || !is_gimple_min_invariant (val2
))
1336 if (!POINTER_TYPE_P (TREE_TYPE (val1
)))
1338 /* We cannot compare overflowed values, except for overflow
1340 if (TREE_OVERFLOW (val1
) || TREE_OVERFLOW (val2
))
1342 if (strict_overflow_p
!= NULL
)
1343 *strict_overflow_p
= true;
1344 if (is_negative_overflow_infinity (val1
))
1345 return is_negative_overflow_infinity (val2
) ? 0 : -1;
1346 else if (is_negative_overflow_infinity (val2
))
1348 else if (is_positive_overflow_infinity (val1
))
1349 return is_positive_overflow_infinity (val2
) ? 0 : 1;
1350 else if (is_positive_overflow_infinity (val2
))
1355 return tree_int_cst_compare (val1
, val2
);
1361 /* First see if VAL1 and VAL2 are not the same. */
1362 if (val1
== val2
|| operand_equal_p (val1
, val2
, 0))
1365 /* If VAL1 is a lower address than VAL2, return -1. */
1366 if (operand_less_p (val1
, val2
) == 1)
1369 /* If VAL1 is a higher address than VAL2, return +1. */
1370 if (operand_less_p (val2
, val1
) == 1)
1373 /* If VAL1 is different than VAL2, return +2.
1374 For integer constants we either have already returned -1 or 1
1375 or they are equivalent. We still might succeed in proving
1376 something about non-trivial operands. */
1377 if (TREE_CODE (val1
) != INTEGER_CST
1378 || TREE_CODE (val2
) != INTEGER_CST
)
1380 t
= fold_binary_to_constant (NE_EXPR
, boolean_type_node
, val1
, val2
);
1381 if (t
&& integer_onep (t
))
1389 /* Compare values like compare_values_warnv, but treat comparisons of
1390 nonconstants which rely on undefined overflow as incomparable. */
1393 compare_values (tree val1
, tree val2
)
1399 ret
= compare_values_warnv (val1
, val2
, &sop
);
1401 && (!is_gimple_min_invariant (val1
) || !is_gimple_min_invariant (val2
)))
1407 /* Return 1 if VAL is inside value range MIN <= VAL <= MAX,
1408 0 if VAL is not inside [MIN, MAX],
1409 -2 if we cannot tell either way.
1411 Benchmark compile/20001226-1.c compilation time after changing this
1415 value_inside_range (tree val
, tree min
, tree max
)
1419 cmp1
= operand_less_p (val
, min
);
1425 cmp2
= operand_less_p (max
, val
);
1433 /* Return true if value ranges VR0 and VR1 have a non-empty
1436 Benchmark compile/20001226-1.c compilation time after changing this
1441 value_ranges_intersect_p (value_range_t
*vr0
, value_range_t
*vr1
)
1443 /* The value ranges do not intersect if the maximum of the first range is
1444 less than the minimum of the second range or vice versa.
1445 When those relations are unknown, we can't do any better. */
1446 if (operand_less_p (vr0
->max
, vr1
->min
) != 0)
1448 if (operand_less_p (vr1
->max
, vr0
->min
) != 0)
1454 /* Return 1 if [MIN, MAX] includes the value zero, 0 if it does not
1455 include the value zero, -2 if we cannot tell. */
1458 range_includes_zero_p (tree min
, tree max
)
1460 tree zero
= build_int_cst (TREE_TYPE (min
), 0);
1461 return value_inside_range (zero
, min
, max
);
1464 /* Return true if *VR is know to only contain nonnegative values. */
1467 value_range_nonnegative_p (value_range_t
*vr
)
1469 /* Testing for VR_ANTI_RANGE is not useful here as any anti-range
1470 which would return a useful value should be encoded as a
1472 if (vr
->type
== VR_RANGE
)
1474 int result
= compare_values (vr
->min
, integer_zero_node
);
1475 return (result
== 0 || result
== 1);
1481 /* If *VR has a value rante that is a single constant value return that,
1482 otherwise return NULL_TREE. */
1485 value_range_constant_singleton (value_range_t
*vr
)
1487 if (vr
->type
== VR_RANGE
1488 && operand_equal_p (vr
->min
, vr
->max
, 0)
1489 && is_gimple_min_invariant (vr
->min
))
1495 /* If OP has a value range with a single constant value return that,
1496 otherwise return NULL_TREE. This returns OP itself if OP is a
1500 op_with_constant_singleton_value_range (tree op
)
1502 if (is_gimple_min_invariant (op
))
1505 if (TREE_CODE (op
) != SSA_NAME
)
1508 return value_range_constant_singleton (get_value_range (op
));
1511 /* Return true if op is in a boolean [0, 1] value-range. */
1514 op_with_boolean_value_range_p (tree op
)
1518 if (TYPE_PRECISION (TREE_TYPE (op
)) == 1)
1521 if (integer_zerop (op
)
1522 || integer_onep (op
))
1525 if (TREE_CODE (op
) != SSA_NAME
)
1528 vr
= get_value_range (op
);
1529 return (vr
->type
== VR_RANGE
1530 && integer_zerop (vr
->min
)
1531 && integer_onep (vr
->max
));
1534 /* Extract value range information from an ASSERT_EXPR EXPR and store
1538 extract_range_from_assert (value_range_t
*vr_p
, tree expr
)
1540 tree var
, cond
, limit
, min
, max
, type
;
1541 value_range_t
*limit_vr
;
1542 enum tree_code cond_code
;
1544 var
= ASSERT_EXPR_VAR (expr
);
1545 cond
= ASSERT_EXPR_COND (expr
);
1547 gcc_assert (COMPARISON_CLASS_P (cond
));
1549 /* Find VAR in the ASSERT_EXPR conditional. */
1550 if (var
== TREE_OPERAND (cond
, 0)
1551 || TREE_CODE (TREE_OPERAND (cond
, 0)) == PLUS_EXPR
1552 || TREE_CODE (TREE_OPERAND (cond
, 0)) == NOP_EXPR
)
1554 /* If the predicate is of the form VAR COMP LIMIT, then we just
1555 take LIMIT from the RHS and use the same comparison code. */
1556 cond_code
= TREE_CODE (cond
);
1557 limit
= TREE_OPERAND (cond
, 1);
1558 cond
= TREE_OPERAND (cond
, 0);
1562 /* If the predicate is of the form LIMIT COMP VAR, then we need
1563 to flip around the comparison code to create the proper range
1565 cond_code
= swap_tree_comparison (TREE_CODE (cond
));
1566 limit
= TREE_OPERAND (cond
, 0);
1567 cond
= TREE_OPERAND (cond
, 1);
1570 limit
= avoid_overflow_infinity (limit
);
1572 type
= TREE_TYPE (var
);
1573 gcc_assert (limit
!= var
);
1575 /* For pointer arithmetic, we only keep track of pointer equality
1577 if (POINTER_TYPE_P (type
) && cond_code
!= NE_EXPR
&& cond_code
!= EQ_EXPR
)
1579 set_value_range_to_varying (vr_p
);
1583 /* If LIMIT is another SSA name and LIMIT has a range of its own,
1584 try to use LIMIT's range to avoid creating symbolic ranges
1586 limit_vr
= (TREE_CODE (limit
) == SSA_NAME
) ? get_value_range (limit
) : NULL
;
1588 /* LIMIT's range is only interesting if it has any useful information. */
1590 && (limit_vr
->type
== VR_UNDEFINED
1591 || limit_vr
->type
== VR_VARYING
1592 || symbolic_range_p (limit_vr
)))
1595 /* Initially, the new range has the same set of equivalences of
1596 VAR's range. This will be revised before returning the final
1597 value. Since assertions may be chained via mutually exclusive
1598 predicates, we will need to trim the set of equivalences before
1600 gcc_assert (vr_p
->equiv
== NULL
);
1601 add_equivalence (&vr_p
->equiv
, var
);
1603 /* Extract a new range based on the asserted comparison for VAR and
1604 LIMIT's value range. Notice that if LIMIT has an anti-range, we
1605 will only use it for equality comparisons (EQ_EXPR). For any
1606 other kind of assertion, we cannot derive a range from LIMIT's
1607 anti-range that can be used to describe the new range. For
1608 instance, ASSERT_EXPR <x_2, x_2 <= b_4>. If b_4 is ~[2, 10],
1609 then b_4 takes on the ranges [-INF, 1] and [11, +INF]. There is
1610 no single range for x_2 that could describe LE_EXPR, so we might
1611 as well build the range [b_4, +INF] for it.
1612 One special case we handle is extracting a range from a
1613 range test encoded as (unsigned)var + CST <= limit. */
1614 if (TREE_CODE (cond
) == NOP_EXPR
1615 || TREE_CODE (cond
) == PLUS_EXPR
)
1617 if (TREE_CODE (cond
) == PLUS_EXPR
)
1619 min
= fold_build1 (NEGATE_EXPR
, TREE_TYPE (TREE_OPERAND (cond
, 1)),
1620 TREE_OPERAND (cond
, 1));
1621 max
= int_const_binop (PLUS_EXPR
, limit
, min
);
1622 cond
= TREE_OPERAND (cond
, 0);
1626 min
= build_int_cst (TREE_TYPE (var
), 0);
1630 /* Make sure to not set TREE_OVERFLOW on the final type
1631 conversion. We are willingly interpreting large positive
1632 unsigned values as negative singed values here. */
1633 min
= force_fit_type_double (TREE_TYPE (var
), tree_to_double_int (min
),
1635 max
= force_fit_type_double (TREE_TYPE (var
), tree_to_double_int (max
),
1638 /* We can transform a max, min range to an anti-range or
1639 vice-versa. Use set_and_canonicalize_value_range which does
1641 if (cond_code
== LE_EXPR
)
1642 set_and_canonicalize_value_range (vr_p
, VR_RANGE
,
1643 min
, max
, vr_p
->equiv
);
1644 else if (cond_code
== GT_EXPR
)
1645 set_and_canonicalize_value_range (vr_p
, VR_ANTI_RANGE
,
1646 min
, max
, vr_p
->equiv
);
1650 else if (cond_code
== EQ_EXPR
)
1652 enum value_range_type range_type
;
1656 range_type
= limit_vr
->type
;
1657 min
= limit_vr
->min
;
1658 max
= limit_vr
->max
;
1662 range_type
= VR_RANGE
;
1667 set_value_range (vr_p
, range_type
, min
, max
, vr_p
->equiv
);
1669 /* When asserting the equality VAR == LIMIT and LIMIT is another
1670 SSA name, the new range will also inherit the equivalence set
1672 if (TREE_CODE (limit
) == SSA_NAME
)
1673 add_equivalence (&vr_p
->equiv
, limit
);
1675 else if (cond_code
== NE_EXPR
)
1677 /* As described above, when LIMIT's range is an anti-range and
1678 this assertion is an inequality (NE_EXPR), then we cannot
1679 derive anything from the anti-range. For instance, if
1680 LIMIT's range was ~[0, 0], the assertion 'VAR != LIMIT' does
1681 not imply that VAR's range is [0, 0]. So, in the case of
1682 anti-ranges, we just assert the inequality using LIMIT and
1685 If LIMIT_VR is a range, we can only use it to build a new
1686 anti-range if LIMIT_VR is a single-valued range. For
1687 instance, if LIMIT_VR is [0, 1], the predicate
1688 VAR != [0, 1] does not mean that VAR's range is ~[0, 1].
1689 Rather, it means that for value 0 VAR should be ~[0, 0]
1690 and for value 1, VAR should be ~[1, 1]. We cannot
1691 represent these ranges.
1693 The only situation in which we can build a valid
1694 anti-range is when LIMIT_VR is a single-valued range
1695 (i.e., LIMIT_VR->MIN == LIMIT_VR->MAX). In that case,
1696 build the anti-range ~[LIMIT_VR->MIN, LIMIT_VR->MAX]. */
1698 && limit_vr
->type
== VR_RANGE
1699 && compare_values (limit_vr
->min
, limit_vr
->max
) == 0)
1701 min
= limit_vr
->min
;
1702 max
= limit_vr
->max
;
1706 /* In any other case, we cannot use LIMIT's range to build a
1707 valid anti-range. */
1711 /* If MIN and MAX cover the whole range for their type, then
1712 just use the original LIMIT. */
1713 if (INTEGRAL_TYPE_P (type
)
1714 && vrp_val_is_min (min
)
1715 && vrp_val_is_max (max
))
1718 set_and_canonicalize_value_range (vr_p
, VR_ANTI_RANGE
,
1719 min
, max
, vr_p
->equiv
);
1721 else if (cond_code
== LE_EXPR
|| cond_code
== LT_EXPR
)
1723 min
= TYPE_MIN_VALUE (type
);
1725 if (limit_vr
== NULL
|| limit_vr
->type
== VR_ANTI_RANGE
)
1729 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1730 range [MIN, N2] for LE_EXPR and [MIN, N2 - 1] for
1732 max
= limit_vr
->max
;
1735 /* If the maximum value forces us to be out of bounds, simply punt.
1736 It would be pointless to try and do anything more since this
1737 all should be optimized away above us. */
1738 if ((cond_code
== LT_EXPR
1739 && compare_values (max
, min
) == 0)
1740 || is_overflow_infinity (max
))
1741 set_value_range_to_varying (vr_p
);
1744 /* For LT_EXPR, we create the range [MIN, MAX - 1]. */
1745 if (cond_code
== LT_EXPR
)
1747 if (TYPE_PRECISION (TREE_TYPE (max
)) == 1
1748 && !TYPE_UNSIGNED (TREE_TYPE (max
)))
1749 max
= fold_build2 (PLUS_EXPR
, TREE_TYPE (max
), max
,
1750 build_int_cst (TREE_TYPE (max
), -1));
1752 max
= fold_build2 (MINUS_EXPR
, TREE_TYPE (max
), max
,
1753 build_int_cst (TREE_TYPE (max
), 1));
1755 TREE_NO_WARNING (max
) = 1;
1758 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1761 else if (cond_code
== GE_EXPR
|| cond_code
== GT_EXPR
)
1763 max
= TYPE_MAX_VALUE (type
);
1765 if (limit_vr
== NULL
|| limit_vr
->type
== VR_ANTI_RANGE
)
1769 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1770 range [N1, MAX] for GE_EXPR and [N1 + 1, MAX] for
1772 min
= limit_vr
->min
;
1775 /* If the minimum value forces us to be out of bounds, simply punt.
1776 It would be pointless to try and do anything more since this
1777 all should be optimized away above us. */
1778 if ((cond_code
== GT_EXPR
1779 && compare_values (min
, max
) == 0)
1780 || is_overflow_infinity (min
))
1781 set_value_range_to_varying (vr_p
);
1784 /* For GT_EXPR, we create the range [MIN + 1, MAX]. */
1785 if (cond_code
== GT_EXPR
)
1787 if (TYPE_PRECISION (TREE_TYPE (min
)) == 1
1788 && !TYPE_UNSIGNED (TREE_TYPE (min
)))
1789 min
= fold_build2 (MINUS_EXPR
, TREE_TYPE (min
), min
,
1790 build_int_cst (TREE_TYPE (min
), -1));
1792 min
= fold_build2 (PLUS_EXPR
, TREE_TYPE (min
), min
,
1793 build_int_cst (TREE_TYPE (min
), 1));
1795 TREE_NO_WARNING (min
) = 1;
1798 set_value_range (vr_p
, VR_RANGE
, min
, max
, vr_p
->equiv
);
1804 /* Finally intersect the new range with what we already know about var. */
1805 vrp_intersect_ranges (vr_p
, get_value_range (var
));
1809 /* Extract range information from SSA name VAR and store it in VR. If
1810 VAR has an interesting range, use it. Otherwise, create the
1811 range [VAR, VAR] and return it. This is useful in situations where
1812 we may have conditionals testing values of VARYING names. For
1819 Even if y_5 is deemed VARYING, we can determine that x_3 > y_5 is
1823 extract_range_from_ssa_name (value_range_t
*vr
, tree var
)
1825 value_range_t
*var_vr
= get_value_range (var
);
1827 if (var_vr
->type
!= VR_UNDEFINED
&& var_vr
->type
!= VR_VARYING
)
1828 copy_value_range (vr
, var_vr
);
1830 set_value_range (vr
, VR_RANGE
, var
, var
, NULL
);
1832 add_equivalence (&vr
->equiv
, var
);
1836 /* Wrapper around int_const_binop. If the operation overflows and we
1837 are not using wrapping arithmetic, then adjust the result to be
1838 -INF or +INF depending on CODE, VAL1 and VAL2. This can return
1839 NULL_TREE if we need to use an overflow infinity representation but
1840 the type does not support it. */
1843 vrp_int_const_binop (enum tree_code code
, tree val1
, tree val2
)
1847 res
= int_const_binop (code
, val1
, val2
);
1849 /* If we are using unsigned arithmetic, operate symbolically
1850 on -INF and +INF as int_const_binop only handles signed overflow. */
1851 if (TYPE_UNSIGNED (TREE_TYPE (val1
)))
1853 int checkz
= compare_values (res
, val1
);
1854 bool overflow
= false;
1856 /* Ensure that res = val1 [+*] val2 >= val1
1857 or that res = val1 - val2 <= val1. */
1858 if ((code
== PLUS_EXPR
1859 && !(checkz
== 1 || checkz
== 0))
1860 || (code
== MINUS_EXPR
1861 && !(checkz
== 0 || checkz
== -1)))
1865 /* Checking for multiplication overflow is done by dividing the
1866 output of the multiplication by the first input of the
1867 multiplication. If the result of that division operation is
1868 not equal to the second input of the multiplication, then the
1869 multiplication overflowed. */
1870 else if (code
== MULT_EXPR
&& !integer_zerop (val1
))
1872 tree tmp
= int_const_binop (TRUNC_DIV_EXPR
,
1875 int check
= compare_values (tmp
, val2
);
1883 res
= copy_node (res
);
1884 TREE_OVERFLOW (res
) = 1;
1888 else if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (val1
)))
1889 /* If the singed operation wraps then int_const_binop has done
1890 everything we want. */
1892 else if ((TREE_OVERFLOW (res
)
1893 && !TREE_OVERFLOW (val1
)
1894 && !TREE_OVERFLOW (val2
))
1895 || is_overflow_infinity (val1
)
1896 || is_overflow_infinity (val2
))
1898 /* If the operation overflowed but neither VAL1 nor VAL2 are
1899 overflown, return -INF or +INF depending on the operation
1900 and the combination of signs of the operands. */
1901 int sgn1
= tree_int_cst_sgn (val1
);
1902 int sgn2
= tree_int_cst_sgn (val2
);
1904 if (needs_overflow_infinity (TREE_TYPE (res
))
1905 && !supports_overflow_infinity (TREE_TYPE (res
)))
1908 /* We have to punt on adding infinities of different signs,
1909 since we can't tell what the sign of the result should be.
1910 Likewise for subtracting infinities of the same sign. */
1911 if (((code
== PLUS_EXPR
&& sgn1
!= sgn2
)
1912 || (code
== MINUS_EXPR
&& sgn1
== sgn2
))
1913 && is_overflow_infinity (val1
)
1914 && is_overflow_infinity (val2
))
1917 /* Don't try to handle division or shifting of infinities. */
1918 if ((code
== TRUNC_DIV_EXPR
1919 || code
== FLOOR_DIV_EXPR
1920 || code
== CEIL_DIV_EXPR
1921 || code
== EXACT_DIV_EXPR
1922 || code
== ROUND_DIV_EXPR
1923 || code
== RSHIFT_EXPR
)
1924 && (is_overflow_infinity (val1
)
1925 || is_overflow_infinity (val2
)))
1928 /* Notice that we only need to handle the restricted set of
1929 operations handled by extract_range_from_binary_expr.
1930 Among them, only multiplication, addition and subtraction
1931 can yield overflow without overflown operands because we
1932 are working with integral types only... except in the
1933 case VAL1 = -INF and VAL2 = -1 which overflows to +INF
1934 for division too. */
1936 /* For multiplication, the sign of the overflow is given
1937 by the comparison of the signs of the operands. */
1938 if ((code
== MULT_EXPR
&& sgn1
== sgn2
)
1939 /* For addition, the operands must be of the same sign
1940 to yield an overflow. Its sign is therefore that
1941 of one of the operands, for example the first. For
1942 infinite operands X + -INF is negative, not positive. */
1943 || (code
== PLUS_EXPR
1945 ? !is_negative_overflow_infinity (val2
)
1946 : is_positive_overflow_infinity (val2
)))
1947 /* For subtraction, non-infinite operands must be of
1948 different signs to yield an overflow. Its sign is
1949 therefore that of the first operand or the opposite of
1950 that of the second operand. A first operand of 0 counts
1951 as positive here, for the corner case 0 - (-INF), which
1952 overflows, but must yield +INF. For infinite operands 0
1953 - INF is negative, not positive. */
1954 || (code
== MINUS_EXPR
1956 ? !is_positive_overflow_infinity (val2
)
1957 : is_negative_overflow_infinity (val2
)))
1958 /* We only get in here with positive shift count, so the
1959 overflow direction is the same as the sign of val1.
1960 Actually rshift does not overflow at all, but we only
1961 handle the case of shifting overflowed -INF and +INF. */
1962 || (code
== RSHIFT_EXPR
1964 /* For division, the only case is -INF / -1 = +INF. */
1965 || code
== TRUNC_DIV_EXPR
1966 || code
== FLOOR_DIV_EXPR
1967 || code
== CEIL_DIV_EXPR
1968 || code
== EXACT_DIV_EXPR
1969 || code
== ROUND_DIV_EXPR
)
1970 return (needs_overflow_infinity (TREE_TYPE (res
))
1971 ? positive_overflow_infinity (TREE_TYPE (res
))
1972 : TYPE_MAX_VALUE (TREE_TYPE (res
)));
1974 return (needs_overflow_infinity (TREE_TYPE (res
))
1975 ? negative_overflow_infinity (TREE_TYPE (res
))
1976 : TYPE_MIN_VALUE (TREE_TYPE (res
)));
1983 /* For range VR compute two double_int bitmasks. In *MAY_BE_NONZERO
1984 bitmask if some bit is unset, it means for all numbers in the range
1985 the bit is 0, otherwise it might be 0 or 1. In *MUST_BE_NONZERO
1986 bitmask if some bit is set, it means for all numbers in the range
1987 the bit is 1, otherwise it might be 0 or 1. */
1990 zero_nonzero_bits_from_vr (value_range_t
*vr
,
1991 double_int
*may_be_nonzero
,
1992 double_int
*must_be_nonzero
)
1994 *may_be_nonzero
= double_int_minus_one
;
1995 *must_be_nonzero
= double_int_zero
;
1996 if (!range_int_cst_p (vr
)
1997 || is_overflow_infinity (vr
->min
)
1998 || is_overflow_infinity (vr
->max
))
2001 if (range_int_cst_singleton_p (vr
))
2003 *may_be_nonzero
= tree_to_double_int (vr
->min
);
2004 *must_be_nonzero
= *may_be_nonzero
;
2006 else if (tree_int_cst_sgn (vr
->min
) >= 0
2007 || tree_int_cst_sgn (vr
->max
) < 0)
2009 double_int dmin
= tree_to_double_int (vr
->min
);
2010 double_int dmax
= tree_to_double_int (vr
->max
);
2011 double_int xor_mask
= dmin
^ dmax
;
2012 *may_be_nonzero
= dmin
| dmax
;
2013 *must_be_nonzero
= dmin
& dmax
;
2014 if (xor_mask
.high
!= 0)
2016 unsigned HOST_WIDE_INT mask
2017 = ((unsigned HOST_WIDE_INT
) 1
2018 << floor_log2 (xor_mask
.high
)) - 1;
2019 may_be_nonzero
->low
= ALL_ONES
;
2020 may_be_nonzero
->high
|= mask
;
2021 must_be_nonzero
->low
= 0;
2022 must_be_nonzero
->high
&= ~mask
;
2024 else if (xor_mask
.low
!= 0)
2026 unsigned HOST_WIDE_INT mask
2027 = ((unsigned HOST_WIDE_INT
) 1
2028 << floor_log2 (xor_mask
.low
)) - 1;
2029 may_be_nonzero
->low
|= mask
;
2030 must_be_nonzero
->low
&= ~mask
;
2037 /* Create two value-ranges in *VR0 and *VR1 from the anti-range *AR
2038 so that *VR0 U *VR1 == *AR. Returns true if that is possible,
2039 false otherwise. If *AR can be represented with a single range
2040 *VR1 will be VR_UNDEFINED. */
2043 ranges_from_anti_range (value_range_t
*ar
,
2044 value_range_t
*vr0
, value_range_t
*vr1
)
2046 tree type
= TREE_TYPE (ar
->min
);
2048 vr0
->type
= VR_UNDEFINED
;
2049 vr1
->type
= VR_UNDEFINED
;
2051 if (ar
->type
!= VR_ANTI_RANGE
2052 || TREE_CODE (ar
->min
) != INTEGER_CST
2053 || TREE_CODE (ar
->max
) != INTEGER_CST
2054 || !vrp_val_min (type
)
2055 || !vrp_val_max (type
))
2058 if (!vrp_val_is_min (ar
->min
))
2060 vr0
->type
= VR_RANGE
;
2061 vr0
->min
= vrp_val_min (type
);
2063 = double_int_to_tree (type
,
2064 tree_to_double_int (ar
->min
) - double_int_one
);
2066 if (!vrp_val_is_max (ar
->max
))
2068 vr1
->type
= VR_RANGE
;
2070 = double_int_to_tree (type
,
2071 tree_to_double_int (ar
->max
) + double_int_one
);
2072 vr1
->max
= vrp_val_max (type
);
2074 if (vr0
->type
== VR_UNDEFINED
)
2077 vr1
->type
= VR_UNDEFINED
;
2080 return vr0
->type
!= VR_UNDEFINED
;
2083 /* Helper to extract a value-range *VR for a multiplicative operation
2087 extract_range_from_multiplicative_op_1 (value_range_t
*vr
,
2088 enum tree_code code
,
2089 value_range_t
*vr0
, value_range_t
*vr1
)
2091 enum value_range_type type
;
2098 /* Multiplications, divisions and shifts are a bit tricky to handle,
2099 depending on the mix of signs we have in the two ranges, we
2100 need to operate on different values to get the minimum and
2101 maximum values for the new range. One approach is to figure
2102 out all the variations of range combinations and do the
2105 However, this involves several calls to compare_values and it
2106 is pretty convoluted. It's simpler to do the 4 operations
2107 (MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
2108 MAX1) and then figure the smallest and largest values to form
2110 gcc_assert (code
== MULT_EXPR
2111 || code
== TRUNC_DIV_EXPR
2112 || code
== FLOOR_DIV_EXPR
2113 || code
== CEIL_DIV_EXPR
2114 || code
== EXACT_DIV_EXPR
2115 || code
== ROUND_DIV_EXPR
2116 || code
== RSHIFT_EXPR
2117 || code
== LSHIFT_EXPR
);
2118 gcc_assert ((vr0
->type
== VR_RANGE
2119 || (code
== MULT_EXPR
&& vr0
->type
== VR_ANTI_RANGE
))
2120 && vr0
->type
== vr1
->type
);
2124 /* Compute the 4 cross operations. */
2126 val
[0] = vrp_int_const_binop (code
, vr0
->min
, vr1
->min
);
2127 if (val
[0] == NULL_TREE
)
2130 if (vr1
->max
== vr1
->min
)
2134 val
[1] = vrp_int_const_binop (code
, vr0
->min
, vr1
->max
);
2135 if (val
[1] == NULL_TREE
)
2139 if (vr0
->max
== vr0
->min
)
2143 val
[2] = vrp_int_const_binop (code
, vr0
->max
, vr1
->min
);
2144 if (val
[2] == NULL_TREE
)
2148 if (vr0
->min
== vr0
->max
|| vr1
->min
== vr1
->max
)
2152 val
[3] = vrp_int_const_binop (code
, vr0
->max
, vr1
->max
);
2153 if (val
[3] == NULL_TREE
)
2159 set_value_range_to_varying (vr
);
2163 /* Set MIN to the minimum of VAL[i] and MAX to the maximum
2167 for (i
= 1; i
< 4; i
++)
2169 if (!is_gimple_min_invariant (min
)
2170 || (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2171 || !is_gimple_min_invariant (max
)
2172 || (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2177 if (!is_gimple_min_invariant (val
[i
])
2178 || (TREE_OVERFLOW (val
[i
])
2179 && !is_overflow_infinity (val
[i
])))
2181 /* If we found an overflowed value, set MIN and MAX
2182 to it so that we set the resulting range to
2188 if (compare_values (val
[i
], min
) == -1)
2191 if (compare_values (val
[i
], max
) == 1)
2196 /* If either MIN or MAX overflowed, then set the resulting range to
2197 VARYING. But we do accept an overflow infinity
2199 if (min
== NULL_TREE
2200 || !is_gimple_min_invariant (min
)
2201 || (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
2203 || !is_gimple_min_invariant (max
)
2204 || (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
2206 set_value_range_to_varying (vr
);
2212 2) [-INF, +-INF(OVF)]
2213 3) [+-INF(OVF), +INF]
2214 4) [+-INF(OVF), +-INF(OVF)]
2215 We learn nothing when we have INF and INF(OVF) on both sides.
2216 Note that we do accept [-INF, -INF] and [+INF, +INF] without
2218 if ((vrp_val_is_min (min
) || is_overflow_infinity (min
))
2219 && (vrp_val_is_max (max
) || is_overflow_infinity (max
)))
2221 set_value_range_to_varying (vr
);
2225 cmp
= compare_values (min
, max
);
2226 if (cmp
== -2 || cmp
== 1)
2228 /* If the new range has its limits swapped around (MIN > MAX),
2229 then the operation caused one of them to wrap around, mark
2230 the new range VARYING. */
2231 set_value_range_to_varying (vr
);
2234 set_value_range (vr
, type
, min
, max
, NULL
);
2237 /* Some quadruple precision helpers. */
2239 quad_int_cmp (double_int l0
, double_int h0
,
2240 double_int l1
, double_int h1
, bool uns
)
2242 int c
= h0
.cmp (h1
, uns
);
2243 if (c
!= 0) return c
;
2244 return l0
.ucmp (l1
);
2248 quad_int_pair_sort (double_int
*l0
, double_int
*h0
,
2249 double_int
*l1
, double_int
*h1
, bool uns
)
2251 if (quad_int_cmp (*l0
, *h0
, *l1
, *h1
, uns
) > 0)
2254 tmp
= *l0
; *l0
= *l1
; *l1
= tmp
;
2255 tmp
= *h0
; *h0
= *h1
; *h1
= tmp
;
2259 /* Extract range information from a binary operation CODE based on
2260 the ranges of each of its operands, *VR0 and *VR1 with resulting
2261 type EXPR_TYPE. The resulting range is stored in *VR. */
2264 extract_range_from_binary_expr_1 (value_range_t
*vr
,
2265 enum tree_code code
, tree expr_type
,
2266 value_range_t
*vr0_
, value_range_t
*vr1_
)
2268 value_range_t vr0
= *vr0_
, vr1
= *vr1_
;
2269 value_range_t vrtem0
= VR_INITIALIZER
, vrtem1
= VR_INITIALIZER
;
2270 enum value_range_type type
;
2271 tree min
= NULL_TREE
, max
= NULL_TREE
;
2274 if (!INTEGRAL_TYPE_P (expr_type
)
2275 && !POINTER_TYPE_P (expr_type
))
2277 set_value_range_to_varying (vr
);
2281 /* Not all binary expressions can be applied to ranges in a
2282 meaningful way. Handle only arithmetic operations. */
2283 if (code
!= PLUS_EXPR
2284 && code
!= MINUS_EXPR
2285 && code
!= POINTER_PLUS_EXPR
2286 && code
!= MULT_EXPR
2287 && code
!= TRUNC_DIV_EXPR
2288 && code
!= FLOOR_DIV_EXPR
2289 && code
!= CEIL_DIV_EXPR
2290 && code
!= EXACT_DIV_EXPR
2291 && code
!= ROUND_DIV_EXPR
2292 && code
!= TRUNC_MOD_EXPR
2293 && code
!= RSHIFT_EXPR
2294 && code
!= LSHIFT_EXPR
2297 && code
!= BIT_AND_EXPR
2298 && code
!= BIT_IOR_EXPR
2299 && code
!= BIT_XOR_EXPR
)
2301 set_value_range_to_varying (vr
);
2305 /* If both ranges are UNDEFINED, so is the result. */
2306 if (vr0
.type
== VR_UNDEFINED
&& vr1
.type
== VR_UNDEFINED
)
2308 set_value_range_to_undefined (vr
);
2311 /* If one of the ranges is UNDEFINED drop it to VARYING for the following
2312 code. At some point we may want to special-case operations that
2313 have UNDEFINED result for all or some value-ranges of the not UNDEFINED
2315 else if (vr0
.type
== VR_UNDEFINED
)
2316 set_value_range_to_varying (&vr0
);
2317 else if (vr1
.type
== VR_UNDEFINED
)
2318 set_value_range_to_varying (&vr1
);
2320 /* Now canonicalize anti-ranges to ranges when they are not symbolic
2321 and express ~[] op X as ([]' op X) U ([]'' op X). */
2322 if (vr0
.type
== VR_ANTI_RANGE
2323 && ranges_from_anti_range (&vr0
, &vrtem0
, &vrtem1
))
2325 extract_range_from_binary_expr_1 (vr
, code
, expr_type
, &vrtem0
, vr1_
);
2326 if (vrtem1
.type
!= VR_UNDEFINED
)
2328 value_range_t vrres
= VR_INITIALIZER
;
2329 extract_range_from_binary_expr_1 (&vrres
, code
, expr_type
,
2331 vrp_meet (vr
, &vrres
);
2335 /* Likewise for X op ~[]. */
2336 if (vr1
.type
== VR_ANTI_RANGE
2337 && ranges_from_anti_range (&vr1
, &vrtem0
, &vrtem1
))
2339 extract_range_from_binary_expr_1 (vr
, code
, expr_type
, vr0_
, &vrtem0
);
2340 if (vrtem1
.type
!= VR_UNDEFINED
)
2342 value_range_t vrres
= VR_INITIALIZER
;
2343 extract_range_from_binary_expr_1 (&vrres
, code
, expr_type
,
2345 vrp_meet (vr
, &vrres
);
2350 /* The type of the resulting value range defaults to VR0.TYPE. */
2353 /* Refuse to operate on VARYING ranges, ranges of different kinds
2354 and symbolic ranges. As an exception, we allow BIT_AND_EXPR
2355 because we may be able to derive a useful range even if one of
2356 the operands is VR_VARYING or symbolic range. Similarly for
2357 divisions. TODO, we may be able to derive anti-ranges in
2359 if (code
!= BIT_AND_EXPR
2360 && code
!= BIT_IOR_EXPR
2361 && code
!= TRUNC_DIV_EXPR
2362 && code
!= FLOOR_DIV_EXPR
2363 && code
!= CEIL_DIV_EXPR
2364 && code
!= EXACT_DIV_EXPR
2365 && code
!= ROUND_DIV_EXPR
2366 && code
!= TRUNC_MOD_EXPR
2369 && (vr0
.type
== VR_VARYING
2370 || vr1
.type
== VR_VARYING
2371 || vr0
.type
!= vr1
.type
2372 || symbolic_range_p (&vr0
)
2373 || symbolic_range_p (&vr1
)))
2375 set_value_range_to_varying (vr
);
2379 /* Now evaluate the expression to determine the new range. */
2380 if (POINTER_TYPE_P (expr_type
))
2382 if (code
== MIN_EXPR
|| code
== MAX_EXPR
)
2384 /* For MIN/MAX expressions with pointers, we only care about
2385 nullness, if both are non null, then the result is nonnull.
2386 If both are null, then the result is null. Otherwise they
2388 if (range_is_nonnull (&vr0
) && range_is_nonnull (&vr1
))
2389 set_value_range_to_nonnull (vr
, expr_type
);
2390 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
2391 set_value_range_to_null (vr
, expr_type
);
2393 set_value_range_to_varying (vr
);
2395 else if (code
== POINTER_PLUS_EXPR
)
2397 /* For pointer types, we are really only interested in asserting
2398 whether the expression evaluates to non-NULL. */
2399 if (range_is_nonnull (&vr0
) || range_is_nonnull (&vr1
))
2400 set_value_range_to_nonnull (vr
, expr_type
);
2401 else if (range_is_null (&vr0
) && range_is_null (&vr1
))
2402 set_value_range_to_null (vr
, expr_type
);
2404 set_value_range_to_varying (vr
);
2406 else if (code
== BIT_AND_EXPR
)
2408 /* For pointer types, we are really only interested in asserting
2409 whether the expression evaluates to non-NULL. */
2410 if (range_is_nonnull (&vr0
) && range_is_nonnull (&vr1
))
2411 set_value_range_to_nonnull (vr
, expr_type
);
2412 else if (range_is_null (&vr0
) || range_is_null (&vr1
))
2413 set_value_range_to_null (vr
, expr_type
);
2415 set_value_range_to_varying (vr
);
2418 set_value_range_to_varying (vr
);
2423 /* For integer ranges, apply the operation to each end of the
2424 range and see what we end up with. */
2425 if (code
== PLUS_EXPR
|| code
== MINUS_EXPR
)
2427 /* If we have a PLUS_EXPR with two VR_RANGE integer constant
2428 ranges compute the precise range for such case if possible. */
2429 if (range_int_cst_p (&vr0
)
2430 && range_int_cst_p (&vr1
)
2431 /* We need as many bits as the possibly unsigned inputs. */
2432 && TYPE_PRECISION (expr_type
) <= HOST_BITS_PER_DOUBLE_INT
)
2434 double_int min0
= tree_to_double_int (vr0
.min
);
2435 double_int max0
= tree_to_double_int (vr0
.max
);
2436 double_int min1
= tree_to_double_int (vr1
.min
);
2437 double_int max1
= tree_to_double_int (vr1
.max
);
2438 bool uns
= TYPE_UNSIGNED (expr_type
);
2440 = double_int::min_value (TYPE_PRECISION (expr_type
), uns
);
2442 = double_int::max_value (TYPE_PRECISION (expr_type
), uns
);
2443 double_int dmin
, dmax
;
2447 if (code
== PLUS_EXPR
)
2452 /* Check for overflow in double_int. */
2453 if (min1
.cmp (double_int_zero
, uns
) != dmin
.cmp (min0
, uns
))
2454 min_ovf
= min0
.cmp (dmin
, uns
);
2455 if (max1
.cmp (double_int_zero
, uns
) != dmax
.cmp (max0
, uns
))
2456 max_ovf
= max0
.cmp (dmax
, uns
);
2458 else /* if (code == MINUS_EXPR) */
2463 if (double_int_zero
.cmp (max1
, uns
) != dmin
.cmp (min0
, uns
))
2464 min_ovf
= min0
.cmp (max1
, uns
);
2465 if (double_int_zero
.cmp (min1
, uns
) != dmax
.cmp (max0
, uns
))
2466 max_ovf
= max0
.cmp (min1
, uns
);
2469 /* For non-wrapping arithmetic look at possibly smaller
2470 value-ranges of the type. */
2471 if (!TYPE_OVERFLOW_WRAPS (expr_type
))
2473 if (vrp_val_min (expr_type
))
2474 type_min
= tree_to_double_int (vrp_val_min (expr_type
));
2475 if (vrp_val_max (expr_type
))
2476 type_max
= tree_to_double_int (vrp_val_max (expr_type
));
2479 /* Check for type overflow. */
2482 if (dmin
.cmp (type_min
, uns
) == -1)
2484 else if (dmin
.cmp (type_max
, uns
) == 1)
2489 if (dmax
.cmp (type_min
, uns
) == -1)
2491 else if (dmax
.cmp (type_max
, uns
) == 1)
2495 if (TYPE_OVERFLOW_WRAPS (expr_type
))
2497 /* If overflow wraps, truncate the values and adjust the
2498 range kind and bounds appropriately. */
2500 = dmin
.ext (TYPE_PRECISION (expr_type
), uns
);
2502 = dmax
.ext (TYPE_PRECISION (expr_type
), uns
);
2503 if (min_ovf
== max_ovf
)
2505 /* No overflow or both overflow or underflow. The
2506 range kind stays VR_RANGE. */
2507 min
= double_int_to_tree (expr_type
, tmin
);
2508 max
= double_int_to_tree (expr_type
, tmax
);
2510 else if (min_ovf
== -1
2513 /* Underflow and overflow, drop to VR_VARYING. */
2514 set_value_range_to_varying (vr
);
2519 /* Min underflow or max overflow. The range kind
2520 changes to VR_ANTI_RANGE. */
2521 bool covers
= false;
2522 double_int tem
= tmin
;
2523 gcc_assert ((min_ovf
== -1 && max_ovf
== 0)
2524 || (max_ovf
== 1 && min_ovf
== 0));
2525 type
= VR_ANTI_RANGE
;
2526 tmin
= tmax
+ double_int_one
;
2527 if (tmin
.cmp (tmax
, uns
) < 0)
2529 tmax
= tem
+ double_int_minus_one
;
2530 if (tmax
.cmp (tem
, uns
) > 0)
2532 /* If the anti-range would cover nothing, drop to varying.
2533 Likewise if the anti-range bounds are outside of the
2535 if (covers
|| tmin
.cmp (tmax
, uns
) > 0)
2537 set_value_range_to_varying (vr
);
2540 min
= double_int_to_tree (expr_type
, tmin
);
2541 max
= double_int_to_tree (expr_type
, tmax
);
2546 /* If overflow does not wrap, saturate to the types min/max
2550 if (needs_overflow_infinity (expr_type
)
2551 && supports_overflow_infinity (expr_type
))
2552 min
= negative_overflow_infinity (expr_type
);
2554 min
= double_int_to_tree (expr_type
, type_min
);
2556 else if (min_ovf
== 1)
2558 if (needs_overflow_infinity (expr_type
)
2559 && supports_overflow_infinity (expr_type
))
2560 min
= positive_overflow_infinity (expr_type
);
2562 min
= double_int_to_tree (expr_type
, type_max
);
2565 min
= double_int_to_tree (expr_type
, dmin
);
2569 if (needs_overflow_infinity (expr_type
)
2570 && supports_overflow_infinity (expr_type
))
2571 max
= negative_overflow_infinity (expr_type
);
2573 max
= double_int_to_tree (expr_type
, type_min
);
2575 else if (max_ovf
== 1)
2577 if (needs_overflow_infinity (expr_type
)
2578 && supports_overflow_infinity (expr_type
))
2579 max
= positive_overflow_infinity (expr_type
);
2581 max
= double_int_to_tree (expr_type
, type_max
);
2584 max
= double_int_to_tree (expr_type
, dmax
);
2586 if (needs_overflow_infinity (expr_type
)
2587 && supports_overflow_infinity (expr_type
))
2589 if (is_negative_overflow_infinity (vr0
.min
)
2590 || (code
== PLUS_EXPR
2591 ? is_negative_overflow_infinity (vr1
.min
)
2592 : is_positive_overflow_infinity (vr1
.max
)))
2593 min
= negative_overflow_infinity (expr_type
);
2594 if (is_positive_overflow_infinity (vr0
.max
)
2595 || (code
== PLUS_EXPR
2596 ? is_positive_overflow_infinity (vr1
.max
)
2597 : is_negative_overflow_infinity (vr1
.min
)))
2598 max
= positive_overflow_infinity (expr_type
);
2603 /* For other cases, for example if we have a PLUS_EXPR with two
2604 VR_ANTI_RANGEs, drop to VR_VARYING. It would take more effort
2605 to compute a precise range for such a case.
2606 ??? General even mixed range kind operations can be expressed
2607 by for example transforming ~[3, 5] + [1, 2] to range-only
2608 operations and a union primitive:
2609 [-INF, 2] + [1, 2] U [5, +INF] + [1, 2]
2610 [-INF+1, 4] U [6, +INF(OVF)]
2611 though usually the union is not exactly representable with
2612 a single range or anti-range as the above is
2613 [-INF+1, +INF(OVF)] intersected with ~[5, 5]
2614 but one could use a scheme similar to equivalences for this. */
2615 set_value_range_to_varying (vr
);
2619 else if (code
== MIN_EXPR
2620 || code
== MAX_EXPR
)
2622 if (vr0
.type
== VR_RANGE
2623 && !symbolic_range_p (&vr0
))
2626 if (vr1
.type
== VR_RANGE
2627 && !symbolic_range_p (&vr1
))
2629 /* For operations that make the resulting range directly
2630 proportional to the original ranges, apply the operation to
2631 the same end of each range. */
2632 min
= vrp_int_const_binop (code
, vr0
.min
, vr1
.min
);
2633 max
= vrp_int_const_binop (code
, vr0
.max
, vr1
.max
);
2635 else if (code
== MIN_EXPR
)
2637 min
= vrp_val_min (expr_type
);
2640 else if (code
== MAX_EXPR
)
2643 max
= vrp_val_max (expr_type
);
2646 else if (vr1
.type
== VR_RANGE
2647 && !symbolic_range_p (&vr1
))
2650 if (code
== MIN_EXPR
)
2652 min
= vrp_val_min (expr_type
);
2655 else if (code
== MAX_EXPR
)
2658 max
= vrp_val_max (expr_type
);
2663 set_value_range_to_varying (vr
);
2667 else if (code
== MULT_EXPR
)
2669 /* Fancy code so that with unsigned, [-3,-1]*[-3,-1] does not
2671 if (range_int_cst_p (&vr0
)
2672 && range_int_cst_p (&vr1
)
2673 && TYPE_OVERFLOW_WRAPS (expr_type
))
2675 double_int min0
, max0
, min1
, max1
, sizem1
, size
;
2676 double_int prod0l
, prod0h
, prod1l
, prod1h
,
2677 prod2l
, prod2h
, prod3l
, prod3h
;
2678 bool uns0
, uns1
, uns
;
2680 sizem1
= double_int::max_value (TYPE_PRECISION (expr_type
), true);
2681 size
= sizem1
+ double_int_one
;
2683 min0
= tree_to_double_int (vr0
.min
);
2684 max0
= tree_to_double_int (vr0
.max
);
2685 min1
= tree_to_double_int (vr1
.min
);
2686 max1
= tree_to_double_int (vr1
.max
);
2688 uns0
= TYPE_UNSIGNED (expr_type
);
2691 /* Canonicalize the intervals. */
2692 if (TYPE_UNSIGNED (expr_type
))
2694 double_int min2
= size
- min0
;
2695 if (!min2
.is_zero () && min2
.cmp (max0
, true) < 0)
2703 if (!min2
.is_zero () && min2
.cmp (max1
, true) < 0)
2713 prod0l
= min0
.wide_mul_with_sign (min1
, true, &prod0h
, &overflow
);
2714 if (!uns0
&& min0
.is_negative ())
2716 if (!uns1
&& min1
.is_negative ())
2719 prod1l
= min0
.wide_mul_with_sign (max1
, true, &prod1h
, &overflow
);
2720 if (!uns0
&& min0
.is_negative ())
2722 if (!uns1
&& max1
.is_negative ())
2725 prod2l
= max0
.wide_mul_with_sign (min1
, true, &prod2h
, &overflow
);
2726 if (!uns0
&& max0
.is_negative ())
2728 if (!uns1
&& min1
.is_negative ())
2731 prod3l
= max0
.wide_mul_with_sign (max1
, true, &prod3h
, &overflow
);
2732 if (!uns0
&& max0
.is_negative ())
2734 if (!uns1
&& max1
.is_negative ())
2737 /* Sort the 4 products. */
2738 quad_int_pair_sort (&prod0l
, &prod0h
, &prod3l
, &prod3h
, uns
);
2739 quad_int_pair_sort (&prod1l
, &prod1h
, &prod2l
, &prod2h
, uns
);
2740 quad_int_pair_sort (&prod0l
, &prod0h
, &prod1l
, &prod1h
, uns
);
2741 quad_int_pair_sort (&prod2l
, &prod2h
, &prod3l
, &prod3h
, uns
);
2744 if (prod0l
.is_zero ())
2746 prod1l
= double_int_zero
;
2754 prod2l
= prod3l
+ prod1l
;
2755 prod2h
= prod3h
+ prod1h
;
2756 if (prod2l
.ult (prod3l
))
2757 prod2h
+= double_int_one
; /* carry */
2759 if (!prod2h
.is_zero ()
2760 || prod2l
.cmp (sizem1
, true) >= 0)
2762 /* the range covers all values. */
2763 set_value_range_to_varying (vr
);
2767 /* The following should handle the wrapping and selecting
2768 VR_ANTI_RANGE for us. */
2769 min
= double_int_to_tree (expr_type
, prod0l
);
2770 max
= double_int_to_tree (expr_type
, prod3l
);
2771 set_and_canonicalize_value_range (vr
, VR_RANGE
, min
, max
, NULL
);
2775 /* If we have an unsigned MULT_EXPR with two VR_ANTI_RANGEs,
2776 drop to VR_VARYING. It would take more effort to compute a
2777 precise range for such a case. For example, if we have
2778 op0 == 65536 and op1 == 65536 with their ranges both being
2779 ~[0,0] on a 32-bit machine, we would have op0 * op1 == 0, so
2780 we cannot claim that the product is in ~[0,0]. Note that we
2781 are guaranteed to have vr0.type == vr1.type at this
2783 if (vr0
.type
== VR_ANTI_RANGE
2784 && !TYPE_OVERFLOW_UNDEFINED (expr_type
))
2786 set_value_range_to_varying (vr
);
2790 extract_range_from_multiplicative_op_1 (vr
, code
, &vr0
, &vr1
);
2793 else if (code
== RSHIFT_EXPR
2794 || code
== LSHIFT_EXPR
)
2796 /* If we have a RSHIFT_EXPR with any shift values outside [0..prec-1],
2797 then drop to VR_VARYING. Outside of this range we get undefined
2798 behavior from the shift operation. We cannot even trust
2799 SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl
2800 shifts, and the operation at the tree level may be widened. */
2801 if (range_int_cst_p (&vr1
)
2802 && compare_tree_int (vr1
.min
, 0) >= 0
2803 && compare_tree_int (vr1
.max
, TYPE_PRECISION (expr_type
)) == -1)
2805 if (code
== RSHIFT_EXPR
)
2807 extract_range_from_multiplicative_op_1 (vr
, code
, &vr0
, &vr1
);
2810 /* We can map lshifts by constants to MULT_EXPR handling. */
2811 else if (code
== LSHIFT_EXPR
2812 && range_int_cst_singleton_p (&vr1
))
2814 bool saved_flag_wrapv
;
2815 value_range_t vr1p
= VR_INITIALIZER
;
2816 vr1p
.type
= VR_RANGE
;
2818 = double_int_to_tree (expr_type
,
2820 .llshift (TREE_INT_CST_LOW (vr1
.min
),
2821 TYPE_PRECISION (expr_type
)));
2822 vr1p
.max
= vr1p
.min
;
2823 /* We have to use a wrapping multiply though as signed overflow
2824 on lshifts is implementation defined in C89. */
2825 saved_flag_wrapv
= flag_wrapv
;
2827 extract_range_from_binary_expr_1 (vr
, MULT_EXPR
, expr_type
,
2829 flag_wrapv
= saved_flag_wrapv
;
2832 else if (code
== LSHIFT_EXPR
2833 && range_int_cst_p (&vr0
))
2835 int prec
= TYPE_PRECISION (expr_type
);
2836 int overflow_pos
= prec
;
2838 double_int bound
, complement
, low_bound
, high_bound
;
2839 bool uns
= TYPE_UNSIGNED (expr_type
);
2840 bool in_bounds
= false;
2845 bound_shift
= overflow_pos
- TREE_INT_CST_LOW (vr1
.max
);
2846 /* If bound_shift == HOST_BITS_PER_DOUBLE_INT, the llshift can
2847 overflow. However, for that to happen, vr1.max needs to be
2848 zero, which means vr1 is a singleton range of zero, which
2849 means it should be handled by the previous LSHIFT_EXPR
2851 bound
= double_int_one
.llshift (bound_shift
, prec
);
2852 complement
= ~(bound
- double_int_one
);
2856 low_bound
= bound
.zext (prec
);
2857 high_bound
= complement
.zext (prec
);
2858 if (tree_to_double_int (vr0
.max
).ult (low_bound
))
2860 /* [5, 6] << [1, 2] == [10, 24]. */
2861 /* We're shifting out only zeroes, the value increases
2865 else if (high_bound
.ult (tree_to_double_int (vr0
.min
)))
2867 /* [0xffffff00, 0xffffffff] << [1, 2]
2868 == [0xfffffc00, 0xfffffffe]. */
2869 /* We're shifting out only ones, the value decreases
2876 /* [-1, 1] << [1, 2] == [-4, 4]. */
2877 low_bound
= complement
.sext (prec
);
2879 if (tree_to_double_int (vr0
.max
).slt (high_bound
)
2880 && low_bound
.slt (tree_to_double_int (vr0
.min
)))
2882 /* For non-negative numbers, we're shifting out only
2883 zeroes, the value increases monotonically.
2884 For negative numbers, we're shifting out only ones, the
2885 value decreases monotomically. */
2892 extract_range_from_multiplicative_op_1 (vr
, code
, &vr0
, &vr1
);
2897 set_value_range_to_varying (vr
);
2900 else if (code
== TRUNC_DIV_EXPR
2901 || code
== FLOOR_DIV_EXPR
2902 || code
== CEIL_DIV_EXPR
2903 || code
== EXACT_DIV_EXPR
2904 || code
== ROUND_DIV_EXPR
)
2906 if (vr0
.type
!= VR_RANGE
|| symbolic_range_p (&vr0
))
2908 /* For division, if op1 has VR_RANGE but op0 does not, something
2909 can be deduced just from that range. Say [min, max] / [4, max]
2910 gives [min / 4, max / 4] range. */
2911 if (vr1
.type
== VR_RANGE
2912 && !symbolic_range_p (&vr1
)
2913 && range_includes_zero_p (vr1
.min
, vr1
.max
) == 0)
2915 vr0
.type
= type
= VR_RANGE
;
2916 vr0
.min
= vrp_val_min (expr_type
);
2917 vr0
.max
= vrp_val_max (expr_type
);
2921 set_value_range_to_varying (vr
);
2926 /* For divisions, if flag_non_call_exceptions is true, we must
2927 not eliminate a division by zero. */
2928 if (cfun
->can_throw_non_call_exceptions
2929 && (vr1
.type
!= VR_RANGE
2930 || range_includes_zero_p (vr1
.min
, vr1
.max
) != 0))
2932 set_value_range_to_varying (vr
);
2936 /* For divisions, if op0 is VR_RANGE, we can deduce a range
2937 even if op1 is VR_VARYING, VR_ANTI_RANGE, symbolic or can
2939 if (vr0
.type
== VR_RANGE
2940 && (vr1
.type
!= VR_RANGE
2941 || range_includes_zero_p (vr1
.min
, vr1
.max
) != 0))
2943 tree zero
= build_int_cst (TREE_TYPE (vr0
.min
), 0);
2948 if (TYPE_UNSIGNED (expr_type
)
2949 || value_range_nonnegative_p (&vr1
))
2951 /* For unsigned division or when divisor is known
2952 to be non-negative, the range has to cover
2953 all numbers from 0 to max for positive max
2954 and all numbers from min to 0 for negative min. */
2955 cmp
= compare_values (vr0
.max
, zero
);
2958 else if (cmp
== 0 || cmp
== 1)
2962 cmp
= compare_values (vr0
.min
, zero
);
2965 else if (cmp
== 0 || cmp
== -1)
2972 /* Otherwise the range is -max .. max or min .. -min
2973 depending on which bound is bigger in absolute value,
2974 as the division can change the sign. */
2975 abs_extent_range (vr
, vr0
.min
, vr0
.max
);
2978 if (type
== VR_VARYING
)
2980 set_value_range_to_varying (vr
);
2986 extract_range_from_multiplicative_op_1 (vr
, code
, &vr0
, &vr1
);
2990 else if (code
== TRUNC_MOD_EXPR
)
2992 if (vr1
.type
!= VR_RANGE
2993 || range_includes_zero_p (vr1
.min
, vr1
.max
) != 0
2994 || vrp_val_is_min (vr1
.min
))
2996 set_value_range_to_varying (vr
);
3000 /* Compute MAX <|vr1.min|, |vr1.max|> - 1. */
3001 max
= fold_unary_to_constant (ABS_EXPR
, expr_type
, vr1
.min
);
3002 if (tree_int_cst_lt (max
, vr1
.max
))
3004 max
= int_const_binop (MINUS_EXPR
, max
, integer_one_node
);
3005 /* If the dividend is non-negative the modulus will be
3006 non-negative as well. */
3007 if (TYPE_UNSIGNED (expr_type
)
3008 || value_range_nonnegative_p (&vr0
))
3009 min
= build_int_cst (TREE_TYPE (max
), 0);
3011 min
= fold_unary_to_constant (NEGATE_EXPR
, expr_type
, max
);
3013 else if (code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
)
3015 bool int_cst_range0
, int_cst_range1
;
3016 double_int may_be_nonzero0
, may_be_nonzero1
;
3017 double_int must_be_nonzero0
, must_be_nonzero1
;
3019 int_cst_range0
= zero_nonzero_bits_from_vr (&vr0
, &may_be_nonzero0
,
3021 int_cst_range1
= zero_nonzero_bits_from_vr (&vr1
, &may_be_nonzero1
,
3025 if (code
== BIT_AND_EXPR
)
3028 min
= double_int_to_tree (expr_type
,
3029 must_be_nonzero0
& must_be_nonzero1
);
3030 dmax
= may_be_nonzero0
& may_be_nonzero1
;
3031 /* If both input ranges contain only negative values we can
3032 truncate the result range maximum to the minimum of the
3033 input range maxima. */
3034 if (int_cst_range0
&& int_cst_range1
3035 && tree_int_cst_sgn (vr0
.max
) < 0
3036 && tree_int_cst_sgn (vr1
.max
) < 0)
3038 dmax
= dmax
.min (tree_to_double_int (vr0
.max
),
3039 TYPE_UNSIGNED (expr_type
));
3040 dmax
= dmax
.min (tree_to_double_int (vr1
.max
),
3041 TYPE_UNSIGNED (expr_type
));
3043 /* If either input range contains only non-negative values
3044 we can truncate the result range maximum to the respective
3045 maximum of the input range. */
3046 if (int_cst_range0
&& tree_int_cst_sgn (vr0
.min
) >= 0)
3047 dmax
= dmax
.min (tree_to_double_int (vr0
.max
),
3048 TYPE_UNSIGNED (expr_type
));
3049 if (int_cst_range1
&& tree_int_cst_sgn (vr1
.min
) >= 0)
3050 dmax
= dmax
.min (tree_to_double_int (vr1
.max
),
3051 TYPE_UNSIGNED (expr_type
));
3052 max
= double_int_to_tree (expr_type
, dmax
);
3054 else if (code
== BIT_IOR_EXPR
)
3057 max
= double_int_to_tree (expr_type
,
3058 may_be_nonzero0
| may_be_nonzero1
);
3059 dmin
= must_be_nonzero0
| must_be_nonzero1
;
3060 /* If the input ranges contain only positive values we can
3061 truncate the minimum of the result range to the maximum
3062 of the input range minima. */
3063 if (int_cst_range0
&& int_cst_range1
3064 && tree_int_cst_sgn (vr0
.min
) >= 0
3065 && tree_int_cst_sgn (vr1
.min
) >= 0)
3067 dmin
= dmin
.max (tree_to_double_int (vr0
.min
),
3068 TYPE_UNSIGNED (expr_type
));
3069 dmin
= dmin
.max (tree_to_double_int (vr1
.min
),
3070 TYPE_UNSIGNED (expr_type
));
3072 /* If either input range contains only negative values
3073 we can truncate the minimum of the result range to the
3074 respective minimum range. */
3075 if (int_cst_range0
&& tree_int_cst_sgn (vr0
.max
) < 0)
3076 dmin
= dmin
.max (tree_to_double_int (vr0
.min
),
3077 TYPE_UNSIGNED (expr_type
));
3078 if (int_cst_range1
&& tree_int_cst_sgn (vr1
.max
) < 0)
3079 dmin
= dmin
.max (tree_to_double_int (vr1
.min
),
3080 TYPE_UNSIGNED (expr_type
));
3081 min
= double_int_to_tree (expr_type
, dmin
);
3083 else if (code
== BIT_XOR_EXPR
)
3085 double_int result_zero_bits
, result_one_bits
;
3086 result_zero_bits
= (must_be_nonzero0
& must_be_nonzero1
)
3087 | ~(may_be_nonzero0
| may_be_nonzero1
);
3088 result_one_bits
= must_be_nonzero0
.and_not (may_be_nonzero1
)
3089 | must_be_nonzero1
.and_not (may_be_nonzero0
);
3090 max
= double_int_to_tree (expr_type
, ~result_zero_bits
);
3091 min
= double_int_to_tree (expr_type
, result_one_bits
);
3092 /* If the range has all positive or all negative values the
3093 result is better than VARYING. */
3094 if (tree_int_cst_sgn (min
) < 0
3095 || tree_int_cst_sgn (max
) >= 0)
3098 max
= min
= NULL_TREE
;
3104 /* If either MIN or MAX overflowed, then set the resulting range to
3105 VARYING. But we do accept an overflow infinity
3107 if (min
== NULL_TREE
3108 || !is_gimple_min_invariant (min
)
3109 || (TREE_OVERFLOW (min
) && !is_overflow_infinity (min
))
3111 || !is_gimple_min_invariant (max
)
3112 || (TREE_OVERFLOW (max
) && !is_overflow_infinity (max
)))
3114 set_value_range_to_varying (vr
);
3120 2) [-INF, +-INF(OVF)]
3121 3) [+-INF(OVF), +INF]
3122 4) [+-INF(OVF), +-INF(OVF)]
3123 We learn nothing when we have INF and INF(OVF) on both sides.
3124 Note that we do accept [-INF, -INF] and [+INF, +INF] without
3126 if ((vrp_val_is_min (min
) || is_overflow_infinity (min
))
3127 && (vrp_val_is_max (max
) || is_overflow_infinity (max
)))
3129 set_value_range_to_varying (vr
);
3133 cmp
= compare_values (min
, max
);
3134 if (cmp
== -2 || cmp
== 1)
3136 /* If the new range has its limits swapped around (MIN > MAX),
3137 then the operation caused one of them to wrap around, mark
3138 the new range VARYING. */
3139 set_value_range_to_varying (vr
);
3142 set_value_range (vr
, type
, min
, max
, NULL
);
3145 /* Extract range information from a binary expression OP0 CODE OP1 based on
3146 the ranges of each of its operands with resulting type EXPR_TYPE.
3147 The resulting range is stored in *VR. */
3150 extract_range_from_binary_expr (value_range_t
*vr
,
3151 enum tree_code code
,
3152 tree expr_type
, tree op0
, tree op1
)
3154 value_range_t vr0
= VR_INITIALIZER
;
3155 value_range_t vr1
= VR_INITIALIZER
;
3157 /* Get value ranges for each operand. For constant operands, create
3158 a new value range with the operand to simplify processing. */
3159 if (TREE_CODE (op0
) == SSA_NAME
)
3160 vr0
= *(get_value_range (op0
));
3161 else if (is_gimple_min_invariant (op0
))
3162 set_value_range_to_value (&vr0
, op0
, NULL
);
3164 set_value_range_to_varying (&vr0
);
3166 if (TREE_CODE (op1
) == SSA_NAME
)
3167 vr1
= *(get_value_range (op1
));
3168 else if (is_gimple_min_invariant (op1
))
3169 set_value_range_to_value (&vr1
, op1
, NULL
);
3171 set_value_range_to_varying (&vr1
);
3173 extract_range_from_binary_expr_1 (vr
, code
, expr_type
, &vr0
, &vr1
);
3176 /* Extract range information from a unary operation CODE based on
3177 the range of its operand *VR0 with type OP0_TYPE with resulting type TYPE.
3178 The The resulting range is stored in *VR. */
3181 extract_range_from_unary_expr_1 (value_range_t
*vr
,
3182 enum tree_code code
, tree type
,
3183 value_range_t
*vr0_
, tree op0_type
)
3185 value_range_t vr0
= *vr0_
, vrtem0
= VR_INITIALIZER
, vrtem1
= VR_INITIALIZER
;
3187 /* VRP only operates on integral and pointer types. */
3188 if (!(INTEGRAL_TYPE_P (op0_type
)
3189 || POINTER_TYPE_P (op0_type
))
3190 || !(INTEGRAL_TYPE_P (type
)
3191 || POINTER_TYPE_P (type
)))
3193 set_value_range_to_varying (vr
);
3197 /* If VR0 is UNDEFINED, so is the result. */
3198 if (vr0
.type
== VR_UNDEFINED
)
3200 set_value_range_to_undefined (vr
);
3204 /* Handle operations that we express in terms of others. */
3205 if (code
== PAREN_EXPR
)
3207 /* PAREN_EXPR is a simple copy. */
3208 copy_value_range (vr
, &vr0
);
3211 else if (code
== NEGATE_EXPR
)
3213 /* -X is simply 0 - X, so re-use existing code that also handles
3214 anti-ranges fine. */
3215 value_range_t zero
= VR_INITIALIZER
;
3216 set_value_range_to_value (&zero
, build_int_cst (type
, 0), NULL
);
3217 extract_range_from_binary_expr_1 (vr
, MINUS_EXPR
, type
, &zero
, &vr0
);
3220 else if (code
== BIT_NOT_EXPR
)
3222 /* ~X is simply -1 - X, so re-use existing code that also handles
3223 anti-ranges fine. */
3224 value_range_t minusone
= VR_INITIALIZER
;
3225 set_value_range_to_value (&minusone
, build_int_cst (type
, -1), NULL
);
3226 extract_range_from_binary_expr_1 (vr
, MINUS_EXPR
,
3227 type
, &minusone
, &vr0
);
3231 /* Now canonicalize anti-ranges to ranges when they are not symbolic
3232 and express op ~[] as (op []') U (op []''). */
3233 if (vr0
.type
== VR_ANTI_RANGE
3234 && ranges_from_anti_range (&vr0
, &vrtem0
, &vrtem1
))
3236 extract_range_from_unary_expr_1 (vr
, code
, type
, &vrtem0
, op0_type
);
3237 if (vrtem1
.type
!= VR_UNDEFINED
)
3239 value_range_t vrres
= VR_INITIALIZER
;
3240 extract_range_from_unary_expr_1 (&vrres
, code
, type
,
3242 vrp_meet (vr
, &vrres
);
3247 if (CONVERT_EXPR_CODE_P (code
))
3249 tree inner_type
= op0_type
;
3250 tree outer_type
= type
;
3252 /* If the expression evaluates to a pointer, we are only interested in
3253 determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */
3254 if (POINTER_TYPE_P (type
))
3256 if (range_is_nonnull (&vr0
))
3257 set_value_range_to_nonnull (vr
, type
);
3258 else if (range_is_null (&vr0
))
3259 set_value_range_to_null (vr
, type
);
3261 set_value_range_to_varying (vr
);
3265 /* If VR0 is varying and we increase the type precision, assume
3266 a full range for the following transformation. */
3267 if (vr0
.type
== VR_VARYING
3268 && INTEGRAL_TYPE_P (inner_type
)
3269 && TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
))
3271 vr0
.type
= VR_RANGE
;
3272 vr0
.min
= TYPE_MIN_VALUE (inner_type
);
3273 vr0
.max
= TYPE_MAX_VALUE (inner_type
);
3276 /* If VR0 is a constant range or anti-range and the conversion is
3277 not truncating we can convert the min and max values and
3278 canonicalize the resulting range. Otherwise we can do the
3279 conversion if the size of the range is less than what the
3280 precision of the target type can represent and the range is
3281 not an anti-range. */
3282 if ((vr0
.type
== VR_RANGE
3283 || vr0
.type
== VR_ANTI_RANGE
)
3284 && TREE_CODE (vr0
.min
) == INTEGER_CST
3285 && TREE_CODE (vr0
.max
) == INTEGER_CST
3286 && (!is_overflow_infinity (vr0
.min
)
3287 || (vr0
.type
== VR_RANGE
3288 && TYPE_PRECISION (outer_type
) > TYPE_PRECISION (inner_type
)
3289 && needs_overflow_infinity (outer_type
)
3290 && supports_overflow_infinity (outer_type
)))
3291 && (!is_overflow_infinity (vr0
.max
)
3292 || (vr0
.type
== VR_RANGE
3293 && TYPE_PRECISION (outer_type
) > TYPE_PRECISION (inner_type
)
3294 && needs_overflow_infinity (outer_type
)
3295 && supports_overflow_infinity (outer_type
)))
3296 && (TYPE_PRECISION (outer_type
) >= TYPE_PRECISION (inner_type
)
3297 || (vr0
.type
== VR_RANGE
3298 && integer_zerop (int_const_binop (RSHIFT_EXPR
,
3299 int_const_binop (MINUS_EXPR
, vr0
.max
, vr0
.min
),
3300 size_int (TYPE_PRECISION (outer_type
)))))))
3302 tree new_min
, new_max
;
3303 if (is_overflow_infinity (vr0
.min
))
3304 new_min
= negative_overflow_infinity (outer_type
);
3306 new_min
= force_fit_type_double (outer_type
,
3307 tree_to_double_int (vr0
.min
),
3309 if (is_overflow_infinity (vr0
.max
))
3310 new_max
= positive_overflow_infinity (outer_type
);
3312 new_max
= force_fit_type_double (outer_type
,
3313 tree_to_double_int (vr0
.max
),
3315 set_and_canonicalize_value_range (vr
, vr0
.type
,
3316 new_min
, new_max
, NULL
);
3320 set_value_range_to_varying (vr
);
3323 else if (code
== ABS_EXPR
)
3328 /* Pass through vr0 in the easy cases. */
3329 if (TYPE_UNSIGNED (type
)
3330 || value_range_nonnegative_p (&vr0
))
3332 copy_value_range (vr
, &vr0
);
3336 /* For the remaining varying or symbolic ranges we can't do anything
3338 if (vr0
.type
== VR_VARYING
3339 || symbolic_range_p (&vr0
))
3341 set_value_range_to_varying (vr
);
3345 /* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a
3347 if (!TYPE_OVERFLOW_UNDEFINED (type
)
3348 && ((vr0
.type
== VR_RANGE
3349 && vrp_val_is_min (vr0
.min
))
3350 || (vr0
.type
== VR_ANTI_RANGE
3351 && !vrp_val_is_min (vr0
.min
))))
3353 set_value_range_to_varying (vr
);
3357 /* ABS_EXPR may flip the range around, if the original range
3358 included negative values. */
3359 if (is_overflow_infinity (vr0
.min
))
3360 min
= positive_overflow_infinity (type
);
3361 else if (!vrp_val_is_min (vr0
.min
))
3362 min
= fold_unary_to_constant (code
, type
, vr0
.min
);
3363 else if (!needs_overflow_infinity (type
))
3364 min
= TYPE_MAX_VALUE (type
);
3365 else if (supports_overflow_infinity (type
))
3366 min
= positive_overflow_infinity (type
);
3369 set_value_range_to_varying (vr
);
3373 if (is_overflow_infinity (vr0
.max
))
3374 max
= positive_overflow_infinity (type
);
3375 else if (!vrp_val_is_min (vr0
.max
))
3376 max
= fold_unary_to_constant (code
, type
, vr0
.max
);
3377 else if (!needs_overflow_infinity (type
))
3378 max
= TYPE_MAX_VALUE (type
);
3379 else if (supports_overflow_infinity (type
)
3380 /* We shouldn't generate [+INF, +INF] as set_value_range
3381 doesn't like this and ICEs. */
3382 && !is_positive_overflow_infinity (min
))
3383 max
= positive_overflow_infinity (type
);
3386 set_value_range_to_varying (vr
);
3390 cmp
= compare_values (min
, max
);
3392 /* If a VR_ANTI_RANGEs contains zero, then we have
3393 ~[-INF, min(MIN, MAX)]. */
3394 if (vr0
.type
== VR_ANTI_RANGE
)
3396 if (range_includes_zero_p (vr0
.min
, vr0
.max
) == 1)
3398 /* Take the lower of the two values. */
3402 /* Create ~[-INF, min (abs(MIN), abs(MAX))]
3403 or ~[-INF + 1, min (abs(MIN), abs(MAX))] when
3404 flag_wrapv is set and the original anti-range doesn't include
3405 TYPE_MIN_VALUE, remember -TYPE_MIN_VALUE = TYPE_MIN_VALUE. */
3406 if (TYPE_OVERFLOW_WRAPS (type
))
3408 tree type_min_value
= TYPE_MIN_VALUE (type
);
3410 min
= (vr0
.min
!= type_min_value
3411 ? int_const_binop (PLUS_EXPR
, type_min_value
,
3417 if (overflow_infinity_range_p (&vr0
))
3418 min
= negative_overflow_infinity (type
);
3420 min
= TYPE_MIN_VALUE (type
);
3425 /* All else has failed, so create the range [0, INF], even for
3426 flag_wrapv since TYPE_MIN_VALUE is in the original
3428 vr0
.type
= VR_RANGE
;
3429 min
= build_int_cst (type
, 0);
3430 if (needs_overflow_infinity (type
))
3432 if (supports_overflow_infinity (type
))
3433 max
= positive_overflow_infinity (type
);
3436 set_value_range_to_varying (vr
);
3441 max
= TYPE_MAX_VALUE (type
);
3445 /* If the range contains zero then we know that the minimum value in the
3446 range will be zero. */
3447 else if (range_includes_zero_p (vr0
.min
, vr0
.max
) == 1)
3451 min
= build_int_cst (type
, 0);
3455 /* If the range was reversed, swap MIN and MAX. */
3464 cmp
= compare_values (min
, max
);
3465 if (cmp
== -2 || cmp
== 1)
3467 /* If the new range has its limits swapped around (MIN > MAX),
3468 then the operation caused one of them to wrap around, mark
3469 the new range VARYING. */
3470 set_value_range_to_varying (vr
);
3473 set_value_range (vr
, vr0
.type
, min
, max
, NULL
);
3477 /* For unhandled operations fall back to varying. */
3478 set_value_range_to_varying (vr
);
3483 /* Extract range information from a unary expression CODE OP0 based on
3484 the range of its operand with resulting type TYPE.
3485 The resulting range is stored in *VR. */
3488 extract_range_from_unary_expr (value_range_t
*vr
, enum tree_code code
,
3489 tree type
, tree op0
)
3491 value_range_t vr0
= VR_INITIALIZER
;
3493 /* Get value ranges for the operand. For constant operands, create
3494 a new value range with the operand to simplify processing. */
3495 if (TREE_CODE (op0
) == SSA_NAME
)
3496 vr0
= *(get_value_range (op0
));
3497 else if (is_gimple_min_invariant (op0
))
3498 set_value_range_to_value (&vr0
, op0
, NULL
);
3500 set_value_range_to_varying (&vr0
);
3502 extract_range_from_unary_expr_1 (vr
, code
, type
, &vr0
, TREE_TYPE (op0
));
3506 /* Extract range information from a conditional expression STMT based on
3507 the ranges of each of its operands and the expression code. */
3510 extract_range_from_cond_expr (value_range_t
*vr
, gimple stmt
)
3513 value_range_t vr0
= VR_INITIALIZER
;
3514 value_range_t vr1
= VR_INITIALIZER
;
3516 /* Get value ranges for each operand. For constant operands, create
3517 a new value range with the operand to simplify processing. */
3518 op0
= gimple_assign_rhs2 (stmt
);
3519 if (TREE_CODE (op0
) == SSA_NAME
)
3520 vr0
= *(get_value_range (op0
));
3521 else if (is_gimple_min_invariant (op0
))
3522 set_value_range_to_value (&vr0
, op0
, NULL
);
3524 set_value_range_to_varying (&vr0
);
3526 op1
= gimple_assign_rhs3 (stmt
);
3527 if (TREE_CODE (op1
) == SSA_NAME
)
3528 vr1
= *(get_value_range (op1
));
3529 else if (is_gimple_min_invariant (op1
))
3530 set_value_range_to_value (&vr1
, op1
, NULL
);
3532 set_value_range_to_varying (&vr1
);
3534 /* The resulting value range is the union of the operand ranges */
3535 copy_value_range (vr
, &vr0
);
3536 vrp_meet (vr
, &vr1
);
3540 /* Extract range information from a comparison expression EXPR based
3541 on the range of its operand and the expression code. */
3544 extract_range_from_comparison (value_range_t
*vr
, enum tree_code code
,
3545 tree type
, tree op0
, tree op1
)
3550 val
= vrp_evaluate_conditional_warnv_with_ops (code
, op0
, op1
, false, &sop
,
3553 /* A disadvantage of using a special infinity as an overflow
3554 representation is that we lose the ability to record overflow
3555 when we don't have an infinity. So we have to ignore a result
3556 which relies on overflow. */
3558 if (val
&& !is_overflow_infinity (val
) && !sop
)
3560 /* Since this expression was found on the RHS of an assignment,
3561 its type may be different from _Bool. Convert VAL to EXPR's
3563 val
= fold_convert (type
, val
);
3564 if (is_gimple_min_invariant (val
))
3565 set_value_range_to_value (vr
, val
, vr
->equiv
);
3567 set_value_range (vr
, VR_RANGE
, val
, val
, vr
->equiv
);
3570 /* The result of a comparison is always true or false. */
3571 set_value_range_to_truthvalue (vr
, type
);
3574 /* Try to derive a nonnegative or nonzero range out of STMT relying
3575 primarily on generic routines in fold in conjunction with range data.
3576 Store the result in *VR */
3579 extract_range_basic (value_range_t
*vr
, gimple stmt
)
3582 tree type
= gimple_expr_type (stmt
);
3584 if (gimple_call_builtin_p (stmt
, BUILT_IN_NORMAL
))
3586 tree fndecl
= gimple_call_fndecl (stmt
), arg
;
3587 int mini
, maxi
, zerov
= 0, prec
;
3589 switch (DECL_FUNCTION_CODE (fndecl
))
3591 case BUILT_IN_CONSTANT_P
:
3592 /* If the call is __builtin_constant_p and the argument is a
3593 function parameter resolve it to false. This avoids bogus
3594 array bound warnings.
3595 ??? We could do this as early as inlining is finished. */
3596 arg
= gimple_call_arg (stmt
, 0);
3597 if (TREE_CODE (arg
) == SSA_NAME
3598 && SSA_NAME_IS_DEFAULT_DEF (arg
)
3599 && TREE_CODE (SSA_NAME_VAR (arg
)) == PARM_DECL
)
3601 set_value_range_to_null (vr
, type
);
3605 /* Both __builtin_ffs* and __builtin_popcount return
3607 CASE_INT_FN (BUILT_IN_FFS
):
3608 CASE_INT_FN (BUILT_IN_POPCOUNT
):
3609 arg
= gimple_call_arg (stmt
, 0);
3610 prec
= TYPE_PRECISION (TREE_TYPE (arg
));
3613 if (TREE_CODE (arg
) == SSA_NAME
)
3615 value_range_t
*vr0
= get_value_range (arg
);
3616 /* If arg is non-zero, then ffs or popcount
3618 if (((vr0
->type
== VR_RANGE
3619 && integer_nonzerop (vr0
->min
))
3620 || (vr0
->type
== VR_ANTI_RANGE
3621 && integer_zerop (vr0
->min
)))
3622 && !is_overflow_infinity (vr0
->min
))
3624 /* If some high bits are known to be zero,
3625 we can decrease the maximum. */
3626 if (vr0
->type
== VR_RANGE
3627 && TREE_CODE (vr0
->max
) == INTEGER_CST
3628 && !is_overflow_infinity (vr0
->max
))
3629 maxi
= tree_floor_log2 (vr0
->max
) + 1;
3632 /* __builtin_parity* returns [0, 1]. */
3633 CASE_INT_FN (BUILT_IN_PARITY
):
3637 /* __builtin_c[lt]z* return [0, prec-1], except for
3638 when the argument is 0, but that is undefined behavior.
3639 On many targets where the CLZ RTL or optab value is defined
3640 for 0 the value is prec, so include that in the range
3642 CASE_INT_FN (BUILT_IN_CLZ
):
3643 arg
= gimple_call_arg (stmt
, 0);
3644 prec
= TYPE_PRECISION (TREE_TYPE (arg
));
3647 if (optab_handler (clz_optab
, TYPE_MODE (TREE_TYPE (arg
)))
3649 && CLZ_DEFINED_VALUE_AT_ZERO (TYPE_MODE (TREE_TYPE (arg
)),
3651 /* Handle only the single common value. */
3653 /* Magic value to give up, unless vr0 proves
3656 if (TREE_CODE (arg
) == SSA_NAME
)
3658 value_range_t
*vr0
= get_value_range (arg
);
3659 /* From clz of VR_RANGE minimum we can compute
3661 if (vr0
->type
== VR_RANGE
3662 && TREE_CODE (vr0
->min
) == INTEGER_CST
3663 && !is_overflow_infinity (vr0
->min
))
3665 maxi
= prec
- 1 - tree_floor_log2 (vr0
->min
);
3669 else if (vr0
->type
== VR_ANTI_RANGE
3670 && integer_zerop (vr0
->min
)
3671 && !is_overflow_infinity (vr0
->min
))
3678 /* From clz of VR_RANGE maximum we can compute
3680 if (vr0
->type
== VR_RANGE
3681 && TREE_CODE (vr0
->max
) == INTEGER_CST
3682 && !is_overflow_infinity (vr0
->max
))
3684 mini
= prec
- 1 - tree_floor_log2 (vr0
->max
);
3692 /* __builtin_ctz* return [0, prec-1], except for
3693 when the argument is 0, but that is undefined behavior.
3694 If there is a ctz optab for this mode and
3695 CTZ_DEFINED_VALUE_AT_ZERO, include that in the range,
3696 otherwise just assume 0 won't be seen. */
3697 CASE_INT_FN (BUILT_IN_CTZ
):
3698 arg
= gimple_call_arg (stmt
, 0);
3699 prec
= TYPE_PRECISION (TREE_TYPE (arg
));
3702 if (optab_handler (ctz_optab
, TYPE_MODE (TREE_TYPE (arg
)))
3704 && CTZ_DEFINED_VALUE_AT_ZERO (TYPE_MODE (TREE_TYPE (arg
)),
3707 /* Handle only the two common values. */
3710 else if (zerov
== prec
)
3713 /* Magic value to give up, unless vr0 proves
3717 if (TREE_CODE (arg
) == SSA_NAME
)
3719 value_range_t
*vr0
= get_value_range (arg
);
3720 /* If arg is non-zero, then use [0, prec - 1]. */
3721 if (((vr0
->type
== VR_RANGE
3722 && integer_nonzerop (vr0
->min
))
3723 || (vr0
->type
== VR_ANTI_RANGE
3724 && integer_zerop (vr0
->min
)))
3725 && !is_overflow_infinity (vr0
->min
))
3730 /* If some high bits are known to be zero,
3731 we can decrease the result maximum. */
3732 if (vr0
->type
== VR_RANGE
3733 && TREE_CODE (vr0
->max
) == INTEGER_CST
3734 && !is_overflow_infinity (vr0
->max
))
3736 maxi
= tree_floor_log2 (vr0
->max
);
3737 /* For vr0 [0, 0] give up. */
3745 /* __builtin_clrsb* returns [0, prec-1]. */
3746 CASE_INT_FN (BUILT_IN_CLRSB
):
3747 arg
= gimple_call_arg (stmt
, 0);
3748 prec
= TYPE_PRECISION (TREE_TYPE (arg
));
3753 set_value_range (vr
, VR_RANGE
, build_int_cst (type
, mini
),
3754 build_int_cst (type
, maxi
), NULL
);
3760 if (INTEGRAL_TYPE_P (type
)
3761 && gimple_stmt_nonnegative_warnv_p (stmt
, &sop
))
3762 set_value_range_to_nonnegative (vr
, type
,
3763 sop
|| stmt_overflow_infinity (stmt
));
3764 else if (vrp_stmt_computes_nonzero (stmt
, &sop
)
3766 set_value_range_to_nonnull (vr
, type
);
3768 set_value_range_to_varying (vr
);
3772 /* Try to compute a useful range out of assignment STMT and store it
3776 extract_range_from_assignment (value_range_t
*vr
, gimple stmt
)
3778 enum tree_code code
= gimple_assign_rhs_code (stmt
);
3780 if (code
== ASSERT_EXPR
)
3781 extract_range_from_assert (vr
, gimple_assign_rhs1 (stmt
));
3782 else if (code
== SSA_NAME
)
3783 extract_range_from_ssa_name (vr
, gimple_assign_rhs1 (stmt
));
3784 else if (TREE_CODE_CLASS (code
) == tcc_binary
)
3785 extract_range_from_binary_expr (vr
, gimple_assign_rhs_code (stmt
),
3786 gimple_expr_type (stmt
),
3787 gimple_assign_rhs1 (stmt
),
3788 gimple_assign_rhs2 (stmt
));
3789 else if (TREE_CODE_CLASS (code
) == tcc_unary
)
3790 extract_range_from_unary_expr (vr
, gimple_assign_rhs_code (stmt
),
3791 gimple_expr_type (stmt
),
3792 gimple_assign_rhs1 (stmt
));
3793 else if (code
== COND_EXPR
)
3794 extract_range_from_cond_expr (vr
, stmt
);
3795 else if (TREE_CODE_CLASS (code
) == tcc_comparison
)
3796 extract_range_from_comparison (vr
, gimple_assign_rhs_code (stmt
),
3797 gimple_expr_type (stmt
),
3798 gimple_assign_rhs1 (stmt
),
3799 gimple_assign_rhs2 (stmt
));
3800 else if (get_gimple_rhs_class (code
) == GIMPLE_SINGLE_RHS
3801 && is_gimple_min_invariant (gimple_assign_rhs1 (stmt
)))
3802 set_value_range_to_value (vr
, gimple_assign_rhs1 (stmt
), NULL
);
3804 set_value_range_to_varying (vr
);
3806 if (vr
->type
== VR_VARYING
)
3807 extract_range_basic (vr
, stmt
);
3810 /* Given a range VR, a LOOP and a variable VAR, determine whether it
3811 would be profitable to adjust VR using scalar evolution information
3812 for VAR. If so, update VR with the new limits. */
3815 adjust_range_with_scev (value_range_t
*vr
, struct loop
*loop
,
3816 gimple stmt
, tree var
)
3818 tree init
, step
, chrec
, tmin
, tmax
, min
, max
, type
, tem
;
3819 enum ev_direction dir
;
3821 /* TODO. Don't adjust anti-ranges. An anti-range may provide
3822 better opportunities than a regular range, but I'm not sure. */
3823 if (vr
->type
== VR_ANTI_RANGE
)
3826 chrec
= instantiate_parameters (loop
, analyze_scalar_evolution (loop
, var
));
3828 /* Like in PR19590, scev can return a constant function. */
3829 if (is_gimple_min_invariant (chrec
))
3831 set_value_range_to_value (vr
, chrec
, vr
->equiv
);
3835 if (TREE_CODE (chrec
) != POLYNOMIAL_CHREC
)
3838 init
= initial_condition_in_loop_num (chrec
, loop
->num
);
3839 tem
= op_with_constant_singleton_value_range (init
);
3842 step
= evolution_part_in_loop_num (chrec
, loop
->num
);
3843 tem
= op_with_constant_singleton_value_range (step
);
3847 /* If STEP is symbolic, we can't know whether INIT will be the
3848 minimum or maximum value in the range. Also, unless INIT is
3849 a simple expression, compare_values and possibly other functions
3850 in tree-vrp won't be able to handle it. */
3851 if (step
== NULL_TREE
3852 || !is_gimple_min_invariant (step
)
3853 || !valid_value_p (init
))
3856 dir
= scev_direction (chrec
);
3857 if (/* Do not adjust ranges if we do not know whether the iv increases
3858 or decreases, ... */
3859 dir
== EV_DIR_UNKNOWN
3860 /* ... or if it may wrap. */
3861 || scev_probably_wraps_p (init
, step
, stmt
, get_chrec_loop (chrec
),
3865 /* We use TYPE_MIN_VALUE and TYPE_MAX_VALUE here instead of
3866 negative_overflow_infinity and positive_overflow_infinity,
3867 because we have concluded that the loop probably does not
3870 type
= TREE_TYPE (var
);
3871 if (POINTER_TYPE_P (type
) || !TYPE_MIN_VALUE (type
))
3872 tmin
= lower_bound_in_type (type
, type
);
3874 tmin
= TYPE_MIN_VALUE (type
);
3875 if (POINTER_TYPE_P (type
) || !TYPE_MAX_VALUE (type
))
3876 tmax
= upper_bound_in_type (type
, type
);
3878 tmax
= TYPE_MAX_VALUE (type
);
3880 /* Try to use estimated number of iterations for the loop to constrain the
3881 final value in the evolution. */
3882 if (TREE_CODE (step
) == INTEGER_CST
3883 && is_gimple_val (init
)
3884 && (TREE_CODE (init
) != SSA_NAME
3885 || get_value_range (init
)->type
== VR_RANGE
))
3889 /* We are only entering here for loop header PHI nodes, so using
3890 the number of latch executions is the correct thing to use. */
3891 if (max_loop_iterations (loop
, &nit
))
3893 value_range_t maxvr
= VR_INITIALIZER
;
3895 bool unsigned_p
= TYPE_UNSIGNED (TREE_TYPE (step
));
3896 bool overflow
= false;
3898 dtmp
= tree_to_double_int (step
)
3899 .mul_with_sign (nit
, unsigned_p
, &overflow
);
3900 /* If the multiplication overflowed we can't do a meaningful
3901 adjustment. Likewise if the result doesn't fit in the type
3902 of the induction variable. For a signed type we have to
3903 check whether the result has the expected signedness which
3904 is that of the step as number of iterations is unsigned. */
3906 && double_int_fits_to_tree_p (TREE_TYPE (init
), dtmp
)
3908 || ((dtmp
.high
^ TREE_INT_CST_HIGH (step
)) >= 0)))
3910 tem
= double_int_to_tree (TREE_TYPE (init
), dtmp
);
3911 extract_range_from_binary_expr (&maxvr
, PLUS_EXPR
,
3912 TREE_TYPE (init
), init
, tem
);
3913 /* Likewise if the addition did. */
3914 if (maxvr
.type
== VR_RANGE
)
3923 if (vr
->type
== VR_VARYING
|| vr
->type
== VR_UNDEFINED
)
3928 /* For VARYING or UNDEFINED ranges, just about anything we get
3929 from scalar evolutions should be better. */
3931 if (dir
== EV_DIR_DECREASES
)
3936 /* If we would create an invalid range, then just assume we
3937 know absolutely nothing. This may be over-conservative,
3938 but it's clearly safe, and should happen only in unreachable
3939 parts of code, or for invalid programs. */
3940 if (compare_values (min
, max
) == 1)
3943 set_value_range (vr
, VR_RANGE
, min
, max
, vr
->equiv
);
3945 else if (vr
->type
== VR_RANGE
)
3950 if (dir
== EV_DIR_DECREASES
)
3952 /* INIT is the maximum value. If INIT is lower than VR->MAX
3953 but no smaller than VR->MIN, set VR->MAX to INIT. */
3954 if (compare_values (init
, max
) == -1)
3957 /* According to the loop information, the variable does not
3958 overflow. If we think it does, probably because of an
3959 overflow due to arithmetic on a different INF value,
3961 if (is_negative_overflow_infinity (min
)
3962 || compare_values (min
, tmin
) == -1)
3968 /* If INIT is bigger than VR->MIN, set VR->MIN to INIT. */
3969 if (compare_values (init
, min
) == 1)
3972 if (is_positive_overflow_infinity (max
)
3973 || compare_values (tmax
, max
) == -1)
3977 /* If we just created an invalid range with the minimum
3978 greater than the maximum, we fail conservatively.
3979 This should happen only in unreachable
3980 parts of code, or for invalid programs. */
3981 if (compare_values (min
, max
) == 1)
3984 set_value_range (vr
, VR_RANGE
, min
, max
, vr
->equiv
);
3988 /* Return true if VAR may overflow at STMT. This checks any available
3989 loop information to see if we can determine that VAR does not
3993 vrp_var_may_overflow (tree var
, gimple stmt
)
3996 tree chrec
, init
, step
;
3998 if (current_loops
== NULL
)
4001 l
= loop_containing_stmt (stmt
);
4006 chrec
= instantiate_parameters (l
, analyze_scalar_evolution (l
, var
));
4007 if (TREE_CODE (chrec
) != POLYNOMIAL_CHREC
)
4010 init
= initial_condition_in_loop_num (chrec
, l
->num
);
4011 step
= evolution_part_in_loop_num (chrec
, l
->num
);
4013 if (step
== NULL_TREE
4014 || !is_gimple_min_invariant (step
)
4015 || !valid_value_p (init
))
4018 /* If we get here, we know something useful about VAR based on the
4019 loop information. If it wraps, it may overflow. */
4021 if (scev_probably_wraps_p (init
, step
, stmt
, get_chrec_loop (chrec
),
4025 if (dump_file
&& (dump_flags
& TDF_DETAILS
) != 0)
4027 print_generic_expr (dump_file
, var
, 0);
4028 fprintf (dump_file
, ": loop information indicates does not overflow\n");
4035 /* Given two numeric value ranges VR0, VR1 and a comparison code COMP:
4037 - Return BOOLEAN_TRUE_NODE if VR0 COMP VR1 always returns true for
4038 all the values in the ranges.
4040 - Return BOOLEAN_FALSE_NODE if the comparison always returns false.
4042 - Return NULL_TREE if it is not always possible to determine the
4043 value of the comparison.
4045 Also set *STRICT_OVERFLOW_P to indicate whether a range with an
4046 overflow infinity was used in the test. */
4050 compare_ranges (enum tree_code comp
, value_range_t
*vr0
, value_range_t
*vr1
,
4051 bool *strict_overflow_p
)
4053 /* VARYING or UNDEFINED ranges cannot be compared. */
4054 if (vr0
->type
== VR_VARYING
4055 || vr0
->type
== VR_UNDEFINED
4056 || vr1
->type
== VR_VARYING
4057 || vr1
->type
== VR_UNDEFINED
)
4060 /* Anti-ranges need to be handled separately. */
4061 if (vr0
->type
== VR_ANTI_RANGE
|| vr1
->type
== VR_ANTI_RANGE
)
4063 /* If both are anti-ranges, then we cannot compute any
4065 if (vr0
->type
== VR_ANTI_RANGE
&& vr1
->type
== VR_ANTI_RANGE
)
4068 /* These comparisons are never statically computable. */
4075 /* Equality can be computed only between a range and an
4076 anti-range. ~[VAL1, VAL2] == [VAL1, VAL2] is always false. */
4077 if (vr0
->type
== VR_RANGE
)
4079 /* To simplify processing, make VR0 the anti-range. */
4080 value_range_t
*tmp
= vr0
;
4085 gcc_assert (comp
== NE_EXPR
|| comp
== EQ_EXPR
);
4087 if (compare_values_warnv (vr0
->min
, vr1
->min
, strict_overflow_p
) == 0
4088 && compare_values_warnv (vr0
->max
, vr1
->max
, strict_overflow_p
) == 0)
4089 return (comp
== NE_EXPR
) ? boolean_true_node
: boolean_false_node
;
4094 if (!usable_range_p (vr0
, strict_overflow_p
)
4095 || !usable_range_p (vr1
, strict_overflow_p
))
4098 /* Simplify processing. If COMP is GT_EXPR or GE_EXPR, switch the
4099 operands around and change the comparison code. */
4100 if (comp
== GT_EXPR
|| comp
== GE_EXPR
)
4103 comp
= (comp
== GT_EXPR
) ? LT_EXPR
: LE_EXPR
;
4109 if (comp
== EQ_EXPR
)
4111 /* Equality may only be computed if both ranges represent
4112 exactly one value. */
4113 if (compare_values_warnv (vr0
->min
, vr0
->max
, strict_overflow_p
) == 0
4114 && compare_values_warnv (vr1
->min
, vr1
->max
, strict_overflow_p
) == 0)
4116 int cmp_min
= compare_values_warnv (vr0
->min
, vr1
->min
,
4118 int cmp_max
= compare_values_warnv (vr0
->max
, vr1
->max
,
4120 if (cmp_min
== 0 && cmp_max
== 0)
4121 return boolean_true_node
;
4122 else if (cmp_min
!= -2 && cmp_max
!= -2)
4123 return boolean_false_node
;
4125 /* If [V0_MIN, V1_MAX] < [V1_MIN, V1_MAX] then V0 != V1. */
4126 else if (compare_values_warnv (vr0
->min
, vr1
->max
,
4127 strict_overflow_p
) == 1
4128 || compare_values_warnv (vr1
->min
, vr0
->max
,
4129 strict_overflow_p
) == 1)
4130 return boolean_false_node
;
4134 else if (comp
== NE_EXPR
)
4138 /* If VR0 is completely to the left or completely to the right
4139 of VR1, they are always different. Notice that we need to
4140 make sure that both comparisons yield similar results to
4141 avoid comparing values that cannot be compared at
4143 cmp1
= compare_values_warnv (vr0
->max
, vr1
->min
, strict_overflow_p
);
4144 cmp2
= compare_values_warnv (vr0
->min
, vr1
->max
, strict_overflow_p
);
4145 if ((cmp1
== -1 && cmp2
== -1) || (cmp1
== 1 && cmp2
== 1))
4146 return boolean_true_node
;
4148 /* If VR0 and VR1 represent a single value and are identical,
4150 else if (compare_values_warnv (vr0
->min
, vr0
->max
,
4151 strict_overflow_p
) == 0
4152 && compare_values_warnv (vr1
->min
, vr1
->max
,
4153 strict_overflow_p
) == 0
4154 && compare_values_warnv (vr0
->min
, vr1
->min
,
4155 strict_overflow_p
) == 0
4156 && compare_values_warnv (vr0
->max
, vr1
->max
,
4157 strict_overflow_p
) == 0)
4158 return boolean_false_node
;
4160 /* Otherwise, they may or may not be different. */
4164 else if (comp
== LT_EXPR
|| comp
== LE_EXPR
)
4168 /* If VR0 is to the left of VR1, return true. */
4169 tst
= compare_values_warnv (vr0
->max
, vr1
->min
, strict_overflow_p
);
4170 if ((comp
== LT_EXPR
&& tst
== -1)
4171 || (comp
== LE_EXPR
&& (tst
== -1 || tst
== 0)))
4173 if (overflow_infinity_range_p (vr0
)
4174 || overflow_infinity_range_p (vr1
))
4175 *strict_overflow_p
= true;
4176 return boolean_true_node
;
4179 /* If VR0 is to the right of VR1, return false. */
4180 tst
= compare_values_warnv (vr0
->min
, vr1
->max
, strict_overflow_p
);
4181 if ((comp
== LT_EXPR
&& (tst
== 0 || tst
== 1))
4182 || (comp
== LE_EXPR
&& tst
== 1))
4184 if (overflow_infinity_range_p (vr0
)
4185 || overflow_infinity_range_p (vr1
))
4186 *strict_overflow_p
= true;
4187 return boolean_false_node
;
4190 /* Otherwise, we don't know. */
4198 /* Given a value range VR, a value VAL and a comparison code COMP, return
4199 BOOLEAN_TRUE_NODE if VR COMP VAL always returns true for all the
4200 values in VR. Return BOOLEAN_FALSE_NODE if the comparison
4201 always returns false. Return NULL_TREE if it is not always
4202 possible to determine the value of the comparison. Also set
4203 *STRICT_OVERFLOW_P to indicate whether a range with an overflow
4204 infinity was used in the test. */
4207 compare_range_with_value (enum tree_code comp
, value_range_t
*vr
, tree val
,
4208 bool *strict_overflow_p
)
4210 if (vr
->type
== VR_VARYING
|| vr
->type
== VR_UNDEFINED
)
4213 /* Anti-ranges need to be handled separately. */
4214 if (vr
->type
== VR_ANTI_RANGE
)
4216 /* For anti-ranges, the only predicates that we can compute at
4217 compile time are equality and inequality. */
4224 /* ~[VAL_1, VAL_2] OP VAL is known if VAL_1 <= VAL <= VAL_2. */
4225 if (value_inside_range (val
, vr
->min
, vr
->max
) == 1)
4226 return (comp
== NE_EXPR
) ? boolean_true_node
: boolean_false_node
;
4231 if (!usable_range_p (vr
, strict_overflow_p
))
4234 if (comp
== EQ_EXPR
)
4236 /* EQ_EXPR may only be computed if VR represents exactly
4238 if (compare_values_warnv (vr
->min
, vr
->max
, strict_overflow_p
) == 0)
4240 int cmp
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
4242 return boolean_true_node
;
4243 else if (cmp
== -1 || cmp
== 1 || cmp
== 2)
4244 return boolean_false_node
;
4246 else if (compare_values_warnv (val
, vr
->min
, strict_overflow_p
) == -1
4247 || compare_values_warnv (vr
->max
, val
, strict_overflow_p
) == -1)
4248 return boolean_false_node
;
4252 else if (comp
== NE_EXPR
)
4254 /* If VAL is not inside VR, then they are always different. */
4255 if (compare_values_warnv (vr
->max
, val
, strict_overflow_p
) == -1
4256 || compare_values_warnv (vr
->min
, val
, strict_overflow_p
) == 1)
4257 return boolean_true_node
;
4259 /* If VR represents exactly one value equal to VAL, then return
4261 if (compare_values_warnv (vr
->min
, vr
->max
, strict_overflow_p
) == 0
4262 && compare_values_warnv (vr
->min
, val
, strict_overflow_p
) == 0)
4263 return boolean_false_node
;
4265 /* Otherwise, they may or may not be different. */
4268 else if (comp
== LT_EXPR
|| comp
== LE_EXPR
)
4272 /* If VR is to the left of VAL, return true. */
4273 tst
= compare_values_warnv (vr
->max
, val
, strict_overflow_p
);
4274 if ((comp
== LT_EXPR
&& tst
== -1)
4275 || (comp
== LE_EXPR
&& (tst
== -1 || tst
== 0)))
4277 if (overflow_infinity_range_p (vr
))
4278 *strict_overflow_p
= true;
4279 return boolean_true_node
;
4282 /* If VR is to the right of VAL, return false. */
4283 tst
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
4284 if ((comp
== LT_EXPR
&& (tst
== 0 || tst
== 1))
4285 || (comp
== LE_EXPR
&& tst
== 1))
4287 if (overflow_infinity_range_p (vr
))
4288 *strict_overflow_p
= true;
4289 return boolean_false_node
;
4292 /* Otherwise, we don't know. */
4295 else if (comp
== GT_EXPR
|| comp
== GE_EXPR
)
4299 /* If VR is to the right of VAL, return true. */
4300 tst
= compare_values_warnv (vr
->min
, val
, strict_overflow_p
);
4301 if ((comp
== GT_EXPR
&& tst
== 1)
4302 || (comp
== GE_EXPR
&& (tst
== 0 || tst
== 1)))
4304 if (overflow_infinity_range_p (vr
))
4305 *strict_overflow_p
= true;
4306 return boolean_true_node
;
4309 /* If VR is to the left of VAL, return false. */
4310 tst
= compare_values_warnv (vr
->max
, val
, strict_overflow_p
);
4311 if ((comp
== GT_EXPR
&& (tst
== -1 || tst
== 0))
4312 || (comp
== GE_EXPR
&& tst
== -1))
4314 if (overflow_infinity_range_p (vr
))
4315 *strict_overflow_p
= true;
4316 return boolean_false_node
;
4319 /* Otherwise, we don't know. */
4327 /* Debugging dumps. */
4329 void dump_value_range (FILE *, value_range_t
*);
4330 void debug_value_range (value_range_t
*);
4331 void dump_all_value_ranges (FILE *);
4332 void debug_all_value_ranges (void);
4333 void dump_vr_equiv (FILE *, bitmap
);
4334 void debug_vr_equiv (bitmap
);
4337 /* Dump value range VR to FILE. */
4340 dump_value_range (FILE *file
, value_range_t
*vr
)
4343 fprintf (file
, "[]");
4344 else if (vr
->type
== VR_UNDEFINED
)
4345 fprintf (file
, "UNDEFINED");
4346 else if (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
)
4348 tree type
= TREE_TYPE (vr
->min
);
4350 fprintf (file
, "%s[", (vr
->type
== VR_ANTI_RANGE
) ? "~" : "");
4352 if (is_negative_overflow_infinity (vr
->min
))
4353 fprintf (file
, "-INF(OVF)");
4354 else if (INTEGRAL_TYPE_P (type
)
4355 && !TYPE_UNSIGNED (type
)
4356 && vrp_val_is_min (vr
->min
))
4357 fprintf (file
, "-INF");
4359 print_generic_expr (file
, vr
->min
, 0);
4361 fprintf (file
, ", ");
4363 if (is_positive_overflow_infinity (vr
->max
))
4364 fprintf (file
, "+INF(OVF)");
4365 else if (INTEGRAL_TYPE_P (type
)
4366 && vrp_val_is_max (vr
->max
))
4367 fprintf (file
, "+INF");
4369 print_generic_expr (file
, vr
->max
, 0);
4371 fprintf (file
, "]");
4378 fprintf (file
, " EQUIVALENCES: { ");
4380 EXECUTE_IF_SET_IN_BITMAP (vr
->equiv
, 0, i
, bi
)
4382 print_generic_expr (file
, ssa_name (i
), 0);
4383 fprintf (file
, " ");
4387 fprintf (file
, "} (%u elements)", c
);
4390 else if (vr
->type
== VR_VARYING
)
4391 fprintf (file
, "VARYING");
4393 fprintf (file
, "INVALID RANGE");
4397 /* Dump value range VR to stderr. */
4400 debug_value_range (value_range_t
*vr
)
4402 dump_value_range (stderr
, vr
);
4403 fprintf (stderr
, "\n");
4407 /* Dump value ranges of all SSA_NAMEs to FILE. */
4410 dump_all_value_ranges (FILE *file
)
4414 for (i
= 0; i
< num_vr_values
; i
++)
4418 print_generic_expr (file
, ssa_name (i
), 0);
4419 fprintf (file
, ": ");
4420 dump_value_range (file
, vr_value
[i
]);
4421 fprintf (file
, "\n");
4425 fprintf (file
, "\n");
4429 /* Dump all value ranges to stderr. */
4432 debug_all_value_ranges (void)
4434 dump_all_value_ranges (stderr
);
4438 /* Given a COND_EXPR COND of the form 'V OP W', and an SSA name V,
4439 create a new SSA name N and return the assertion assignment
4440 'V = ASSERT_EXPR <V, V OP W>'. */
4443 build_assert_expr_for (tree cond
, tree v
)
4448 gcc_assert (TREE_CODE (v
) == SSA_NAME
4449 && COMPARISON_CLASS_P (cond
));
4451 a
= build2 (ASSERT_EXPR
, TREE_TYPE (v
), v
, cond
);
4452 assertion
= gimple_build_assign (NULL_TREE
, a
);
4454 /* The new ASSERT_EXPR, creates a new SSA name that replaces the
4455 operand of the ASSERT_EXPR. Create it so the new name and the old one
4456 are registered in the replacement table so that we can fix the SSA web
4457 after adding all the ASSERT_EXPRs. */
4458 create_new_def_for (v
, assertion
, NULL
);
4464 /* Return false if EXPR is a predicate expression involving floating
4468 fp_predicate (gimple stmt
)
4470 GIMPLE_CHECK (stmt
, GIMPLE_COND
);
4472 return FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (stmt
)));
4475 /* If the range of values taken by OP can be inferred after STMT executes,
4476 return the comparison code (COMP_CODE_P) and value (VAL_P) that
4477 describes the inferred range. Return true if a range could be
4481 infer_value_range (gimple stmt
, tree op
, enum tree_code
*comp_code_p
, tree
*val_p
)
4484 *comp_code_p
= ERROR_MARK
;
4486 /* Do not attempt to infer anything in names that flow through
4488 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op
))
4491 /* Similarly, don't infer anything from statements that may throw
4492 exceptions. ??? Relax this requirement? */
4493 if (stmt_could_throw_p (stmt
))
4496 /* If STMT is the last statement of a basic block with no
4497 successors, there is no point inferring anything about any of its
4498 operands. We would not be able to find a proper insertion point
4499 for the assertion, anyway. */
4500 if (stmt_ends_bb_p (stmt
) && EDGE_COUNT (gimple_bb (stmt
)->succs
) == 0)
4503 if (infer_nonnull_range (stmt
, op
))
4505 *val_p
= build_int_cst (TREE_TYPE (op
), 0);
4506 *comp_code_p
= NE_EXPR
;
4514 void dump_asserts_for (FILE *, tree
);
4515 void debug_asserts_for (tree
);
4516 void dump_all_asserts (FILE *);
4517 void debug_all_asserts (void);
4519 /* Dump all the registered assertions for NAME to FILE. */
4522 dump_asserts_for (FILE *file
, tree name
)
4526 fprintf (file
, "Assertions to be inserted for ");
4527 print_generic_expr (file
, name
, 0);
4528 fprintf (file
, "\n");
4530 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
4533 fprintf (file
, "\t");
4534 print_gimple_stmt (file
, gsi_stmt (loc
->si
), 0, 0);
4535 fprintf (file
, "\n\tBB #%d", loc
->bb
->index
);
4538 fprintf (file
, "\n\tEDGE %d->%d", loc
->e
->src
->index
,
4539 loc
->e
->dest
->index
);
4540 dump_edge_info (file
, loc
->e
, dump_flags
, 0);
4542 fprintf (file
, "\n\tPREDICATE: ");
4543 print_generic_expr (file
, name
, 0);
4544 fprintf (file
, " %s ", get_tree_code_name (loc
->comp_code
));
4545 print_generic_expr (file
, loc
->val
, 0);
4546 fprintf (file
, "\n\n");
4550 fprintf (file
, "\n");
4554 /* Dump all the registered assertions for NAME to stderr. */
4557 debug_asserts_for (tree name
)
4559 dump_asserts_for (stderr
, name
);
4563 /* Dump all the registered assertions for all the names to FILE. */
4566 dump_all_asserts (FILE *file
)
4571 fprintf (file
, "\nASSERT_EXPRs to be inserted\n\n");
4572 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
4573 dump_asserts_for (file
, ssa_name (i
));
4574 fprintf (file
, "\n");
4578 /* Dump all the registered assertions for all the names to stderr. */
4581 debug_all_asserts (void)
4583 dump_all_asserts (stderr
);
4587 /* If NAME doesn't have an ASSERT_EXPR registered for asserting
4588 'EXPR COMP_CODE VAL' at a location that dominates block BB or
4589 E->DEST, then register this location as a possible insertion point
4590 for ASSERT_EXPR <NAME, EXPR COMP_CODE VAL>.
4592 BB, E and SI provide the exact insertion point for the new
4593 ASSERT_EXPR. If BB is NULL, then the ASSERT_EXPR is to be inserted
4594 on edge E. Otherwise, if E is NULL, the ASSERT_EXPR is inserted on
4595 BB. If SI points to a COND_EXPR or a SWITCH_EXPR statement, then E
4596 must not be NULL. */
4599 register_new_assert_for (tree name
, tree expr
,
4600 enum tree_code comp_code
,
4604 gimple_stmt_iterator si
)
4606 assert_locus_t n
, loc
, last_loc
;
4607 basic_block dest_bb
;
4609 gcc_checking_assert (bb
== NULL
|| e
== NULL
);
4612 gcc_checking_assert (gimple_code (gsi_stmt (si
)) != GIMPLE_COND
4613 && gimple_code (gsi_stmt (si
)) != GIMPLE_SWITCH
);
4615 /* Never build an assert comparing against an integer constant with
4616 TREE_OVERFLOW set. This confuses our undefined overflow warning
4618 if (TREE_OVERFLOW_P (val
))
4619 val
= drop_tree_overflow (val
);
4621 /* The new assertion A will be inserted at BB or E. We need to
4622 determine if the new location is dominated by a previously
4623 registered location for A. If we are doing an edge insertion,
4624 assume that A will be inserted at E->DEST. Note that this is not
4627 If E is a critical edge, it will be split. But even if E is
4628 split, the new block will dominate the same set of blocks that
4631 The reverse, however, is not true, blocks dominated by E->DEST
4632 will not be dominated by the new block created to split E. So,
4633 if the insertion location is on a critical edge, we will not use
4634 the new location to move another assertion previously registered
4635 at a block dominated by E->DEST. */
4636 dest_bb
= (bb
) ? bb
: e
->dest
;
4638 /* If NAME already has an ASSERT_EXPR registered for COMP_CODE and
4639 VAL at a block dominating DEST_BB, then we don't need to insert a new
4640 one. Similarly, if the same assertion already exists at a block
4641 dominated by DEST_BB and the new location is not on a critical
4642 edge, then update the existing location for the assertion (i.e.,
4643 move the assertion up in the dominance tree).
4645 Note, this is implemented as a simple linked list because there
4646 should not be more than a handful of assertions registered per
4647 name. If this becomes a performance problem, a table hashed by
4648 COMP_CODE and VAL could be implemented. */
4649 loc
= asserts_for
[SSA_NAME_VERSION (name
)];
4653 if (loc
->comp_code
== comp_code
4655 || operand_equal_p (loc
->val
, val
, 0))
4656 && (loc
->expr
== expr
4657 || operand_equal_p (loc
->expr
, expr
, 0)))
4659 /* If E is not a critical edge and DEST_BB
4660 dominates the existing location for the assertion, move
4661 the assertion up in the dominance tree by updating its
4662 location information. */
4663 if ((e
== NULL
|| !EDGE_CRITICAL_P (e
))
4664 && dominated_by_p (CDI_DOMINATORS
, loc
->bb
, dest_bb
))
4673 /* Update the last node of the list and move to the next one. */
4678 /* If we didn't find an assertion already registered for
4679 NAME COMP_CODE VAL, add a new one at the end of the list of
4680 assertions associated with NAME. */
4681 n
= XNEW (struct assert_locus_d
);
4685 n
->comp_code
= comp_code
;
4693 asserts_for
[SSA_NAME_VERSION (name
)] = n
;
4695 bitmap_set_bit (need_assert_for
, SSA_NAME_VERSION (name
));
4698 /* (COND_OP0 COND_CODE COND_OP1) is a predicate which uses NAME.
4699 Extract a suitable test code and value and store them into *CODE_P and
4700 *VAL_P so the predicate is normalized to NAME *CODE_P *VAL_P.
4702 If no extraction was possible, return FALSE, otherwise return TRUE.
4704 If INVERT is true, then we invert the result stored into *CODE_P. */
4707 extract_code_and_val_from_cond_with_ops (tree name
, enum tree_code cond_code
,
4708 tree cond_op0
, tree cond_op1
,
4709 bool invert
, enum tree_code
*code_p
,
4712 enum tree_code comp_code
;
4715 /* Otherwise, we have a comparison of the form NAME COMP VAL
4716 or VAL COMP NAME. */
4717 if (name
== cond_op1
)
4719 /* If the predicate is of the form VAL COMP NAME, flip
4720 COMP around because we need to register NAME as the
4721 first operand in the predicate. */
4722 comp_code
= swap_tree_comparison (cond_code
);
4727 /* The comparison is of the form NAME COMP VAL, so the
4728 comparison code remains unchanged. */
4729 comp_code
= cond_code
;
4733 /* Invert the comparison code as necessary. */
4735 comp_code
= invert_tree_comparison (comp_code
, 0);
4737 /* VRP does not handle float types. */
4738 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (val
)))
4741 /* Do not register always-false predicates.
4742 FIXME: this works around a limitation in fold() when dealing with
4743 enumerations. Given 'enum { N1, N2 } x;', fold will not
4744 fold 'if (x > N2)' to 'if (0)'. */
4745 if ((comp_code
== GT_EXPR
|| comp_code
== LT_EXPR
)
4746 && INTEGRAL_TYPE_P (TREE_TYPE (val
)))
4748 tree min
= TYPE_MIN_VALUE (TREE_TYPE (val
));
4749 tree max
= TYPE_MAX_VALUE (TREE_TYPE (val
));
4751 if (comp_code
== GT_EXPR
4753 || compare_values (val
, max
) == 0))
4756 if (comp_code
== LT_EXPR
4758 || compare_values (val
, min
) == 0))
4761 *code_p
= comp_code
;
4766 /* Find out smallest RES where RES > VAL && (RES & MASK) == RES, if any
4767 (otherwise return VAL). VAL and MASK must be zero-extended for
4768 precision PREC. If SGNBIT is non-zero, first xor VAL with SGNBIT
4769 (to transform signed values into unsigned) and at the end xor
4773 masked_increment (double_int val
, double_int mask
, double_int sgnbit
,
4776 double_int bit
= double_int_one
, res
;
4780 for (i
= 0; i
< prec
; i
++, bit
+= bit
)
4783 if ((res
& bit
).is_zero ())
4785 res
= bit
- double_int_one
;
4786 res
= (val
+ bit
).and_not (res
);
4789 return res
^ sgnbit
;
4791 return val
^ sgnbit
;
4794 /* Try to register an edge assertion for SSA name NAME on edge E for
4795 the condition COND contributing to the conditional jump pointed to by BSI.
4796 Invert the condition COND if INVERT is true.
4797 Return true if an assertion for NAME could be registered. */
4800 register_edge_assert_for_2 (tree name
, edge e
, gimple_stmt_iterator bsi
,
4801 enum tree_code cond_code
,
4802 tree cond_op0
, tree cond_op1
, bool invert
)
4805 enum tree_code comp_code
;
4806 bool retval
= false;
4808 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
4811 invert
, &comp_code
, &val
))
4814 /* Only register an ASSERT_EXPR if NAME was found in the sub-graph
4815 reachable from E. */
4816 if (live_on_edge (e
, name
)
4817 && !has_single_use (name
))
4819 register_new_assert_for (name
, name
, comp_code
, val
, NULL
, e
, bsi
);
4823 /* In the case of NAME <= CST and NAME being defined as
4824 NAME = (unsigned) NAME2 + CST2 we can assert NAME2 >= -CST2
4825 and NAME2 <= CST - CST2. We can do the same for NAME > CST.
4826 This catches range and anti-range tests. */
4827 if ((comp_code
== LE_EXPR
4828 || comp_code
== GT_EXPR
)
4829 && TREE_CODE (val
) == INTEGER_CST
4830 && TYPE_UNSIGNED (TREE_TYPE (val
)))
4832 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
4833 tree cst2
= NULL_TREE
, name2
= NULL_TREE
, name3
= NULL_TREE
;
4835 /* Extract CST2 from the (optional) addition. */
4836 if (is_gimple_assign (def_stmt
)
4837 && gimple_assign_rhs_code (def_stmt
) == PLUS_EXPR
)
4839 name2
= gimple_assign_rhs1 (def_stmt
);
4840 cst2
= gimple_assign_rhs2 (def_stmt
);
4841 if (TREE_CODE (name2
) == SSA_NAME
4842 && TREE_CODE (cst2
) == INTEGER_CST
)
4843 def_stmt
= SSA_NAME_DEF_STMT (name2
);
4846 /* Extract NAME2 from the (optional) sign-changing cast. */
4847 if (gimple_assign_cast_p (def_stmt
))
4849 if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
))
4850 && ! TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))
4851 && (TYPE_PRECISION (gimple_expr_type (def_stmt
))
4852 == TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))))
4853 name3
= gimple_assign_rhs1 (def_stmt
);
4856 /* If name3 is used later, create an ASSERT_EXPR for it. */
4857 if (name3
!= NULL_TREE
4858 && TREE_CODE (name3
) == SSA_NAME
4859 && (cst2
== NULL_TREE
4860 || TREE_CODE (cst2
) == INTEGER_CST
)
4861 && INTEGRAL_TYPE_P (TREE_TYPE (name3
))
4862 && live_on_edge (e
, name3
)
4863 && !has_single_use (name3
))
4867 /* Build an expression for the range test. */
4868 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), name3
);
4869 if (cst2
!= NULL_TREE
)
4870 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
4874 fprintf (dump_file
, "Adding assert for ");
4875 print_generic_expr (dump_file
, name3
, 0);
4876 fprintf (dump_file
, " from ");
4877 print_generic_expr (dump_file
, tmp
, 0);
4878 fprintf (dump_file
, "\n");
4881 register_new_assert_for (name3
, tmp
, comp_code
, val
, NULL
, e
, bsi
);
4886 /* If name2 is used later, create an ASSERT_EXPR for it. */
4887 if (name2
!= NULL_TREE
4888 && TREE_CODE (name2
) == SSA_NAME
4889 && TREE_CODE (cst2
) == INTEGER_CST
4890 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
4891 && live_on_edge (e
, name2
)
4892 && !has_single_use (name2
))
4896 /* Build an expression for the range test. */
4898 if (TREE_TYPE (name
) != TREE_TYPE (name2
))
4899 tmp
= build1 (NOP_EXPR
, TREE_TYPE (name
), tmp
);
4900 if (cst2
!= NULL_TREE
)
4901 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name
), tmp
, cst2
);
4905 fprintf (dump_file
, "Adding assert for ");
4906 print_generic_expr (dump_file
, name2
, 0);
4907 fprintf (dump_file
, " from ");
4908 print_generic_expr (dump_file
, tmp
, 0);
4909 fprintf (dump_file
, "\n");
4912 register_new_assert_for (name2
, tmp
, comp_code
, val
, NULL
, e
, bsi
);
4918 /* In the case of post-in/decrement tests like if (i++) ... and uses
4919 of the in/decremented value on the edge the extra name we want to
4920 assert for is not on the def chain of the name compared. Instead
4921 it is in the set of use stmts. */
4922 if ((comp_code
== NE_EXPR
4923 || comp_code
== EQ_EXPR
)
4924 && TREE_CODE (val
) == INTEGER_CST
)
4926 imm_use_iterator ui
;
4928 FOR_EACH_IMM_USE_STMT (use_stmt
, ui
, name
)
4930 /* Cut off to use-stmts that are in the predecessor. */
4931 if (gimple_bb (use_stmt
) != e
->src
)
4934 if (!is_gimple_assign (use_stmt
))
4937 enum tree_code code
= gimple_assign_rhs_code (use_stmt
);
4938 if (code
!= PLUS_EXPR
4939 && code
!= MINUS_EXPR
)
4942 tree cst
= gimple_assign_rhs2 (use_stmt
);
4943 if (TREE_CODE (cst
) != INTEGER_CST
)
4946 tree name2
= gimple_assign_lhs (use_stmt
);
4947 if (live_on_edge (e
, name2
))
4949 cst
= int_const_binop (code
, val
, cst
);
4950 register_new_assert_for (name2
, name2
, comp_code
, cst
,
4957 if (TREE_CODE_CLASS (comp_code
) == tcc_comparison
4958 && TREE_CODE (val
) == INTEGER_CST
)
4960 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
4961 tree name2
= NULL_TREE
, names
[2], cst2
= NULL_TREE
;
4962 tree val2
= NULL_TREE
;
4963 double_int mask
= double_int_zero
;
4964 unsigned int prec
= TYPE_PRECISION (TREE_TYPE (val
));
4965 unsigned int nprec
= prec
;
4966 enum tree_code rhs_code
= ERROR_MARK
;
4968 if (is_gimple_assign (def_stmt
))
4969 rhs_code
= gimple_assign_rhs_code (def_stmt
);
4971 /* Add asserts for NAME cmp CST and NAME being defined
4972 as NAME = (int) NAME2. */
4973 if (!TYPE_UNSIGNED (TREE_TYPE (val
))
4974 && (comp_code
== LE_EXPR
|| comp_code
== LT_EXPR
4975 || comp_code
== GT_EXPR
|| comp_code
== GE_EXPR
)
4976 && gimple_assign_cast_p (def_stmt
))
4978 name2
= gimple_assign_rhs1 (def_stmt
);
4979 if (CONVERT_EXPR_CODE_P (rhs_code
)
4980 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
4981 && TYPE_UNSIGNED (TREE_TYPE (name2
))
4982 && prec
== TYPE_PRECISION (TREE_TYPE (name2
))
4983 && (comp_code
== LE_EXPR
|| comp_code
== GT_EXPR
4984 || !tree_int_cst_equal (val
,
4985 TYPE_MIN_VALUE (TREE_TYPE (val
))))
4986 && live_on_edge (e
, name2
)
4987 && !has_single_use (name2
))
4990 enum tree_code new_comp_code
= comp_code
;
4992 cst
= fold_convert (TREE_TYPE (name2
),
4993 TYPE_MIN_VALUE (TREE_TYPE (val
)));
4994 /* Build an expression for the range test. */
4995 tmp
= build2 (PLUS_EXPR
, TREE_TYPE (name2
), name2
, cst
);
4996 cst
= fold_build2 (PLUS_EXPR
, TREE_TYPE (name2
), cst
,
4997 fold_convert (TREE_TYPE (name2
), val
));
4998 if (comp_code
== LT_EXPR
|| comp_code
== GE_EXPR
)
5000 new_comp_code
= comp_code
== LT_EXPR
? LE_EXPR
: GT_EXPR
;
5001 cst
= fold_build2 (MINUS_EXPR
, TREE_TYPE (name2
), cst
,
5002 build_int_cst (TREE_TYPE (name2
), 1));
5007 fprintf (dump_file
, "Adding assert for ");
5008 print_generic_expr (dump_file
, name2
, 0);
5009 fprintf (dump_file
, " from ");
5010 print_generic_expr (dump_file
, tmp
, 0);
5011 fprintf (dump_file
, "\n");
5014 register_new_assert_for (name2
, tmp
, new_comp_code
, cst
, NULL
,
5021 /* Add asserts for NAME cmp CST and NAME being defined as
5022 NAME = NAME2 >> CST2.
5024 Extract CST2 from the right shift. */
5025 if (rhs_code
== RSHIFT_EXPR
)
5027 name2
= gimple_assign_rhs1 (def_stmt
);
5028 cst2
= gimple_assign_rhs2 (def_stmt
);
5029 if (TREE_CODE (name2
) == SSA_NAME
5030 && tree_fits_uhwi_p (cst2
)
5031 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
5032 && IN_RANGE (tree_to_uhwi (cst2
), 1, prec
- 1)
5033 && prec
<= HOST_BITS_PER_DOUBLE_INT
5034 && prec
== GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (val
)))
5035 && live_on_edge (e
, name2
)
5036 && !has_single_use (name2
))
5038 mask
= double_int::mask (tree_to_uhwi (cst2
));
5039 val2
= fold_binary (LSHIFT_EXPR
, TREE_TYPE (val
), val
, cst2
);
5042 if (val2
!= NULL_TREE
5043 && TREE_CODE (val2
) == INTEGER_CST
5044 && simple_cst_equal (fold_build2 (RSHIFT_EXPR
,
5048 enum tree_code new_comp_code
= comp_code
;
5052 if (comp_code
== EQ_EXPR
|| comp_code
== NE_EXPR
)
5054 if (!TYPE_UNSIGNED (TREE_TYPE (val
)))
5056 tree type
= build_nonstandard_integer_type (prec
, 1);
5057 tmp
= build1 (NOP_EXPR
, type
, name2
);
5058 val2
= fold_convert (type
, val2
);
5060 tmp
= fold_build2 (MINUS_EXPR
, TREE_TYPE (tmp
), tmp
, val2
);
5061 new_val
= double_int_to_tree (TREE_TYPE (tmp
), mask
);
5062 new_comp_code
= comp_code
== EQ_EXPR
? LE_EXPR
: GT_EXPR
;
5064 else if (comp_code
== LT_EXPR
|| comp_code
== GE_EXPR
)
5067 = double_int::min_value (prec
, TYPE_UNSIGNED (TREE_TYPE (val
)));
5069 if (minval
== tree_to_double_int (new_val
))
5070 new_val
= NULL_TREE
;
5075 = double_int::max_value (prec
, TYPE_UNSIGNED (TREE_TYPE (val
)));
5076 mask
|= tree_to_double_int (val2
);
5078 new_val
= NULL_TREE
;
5080 new_val
= double_int_to_tree (TREE_TYPE (val2
), mask
);
5087 fprintf (dump_file
, "Adding assert for ");
5088 print_generic_expr (dump_file
, name2
, 0);
5089 fprintf (dump_file
, " from ");
5090 print_generic_expr (dump_file
, tmp
, 0);
5091 fprintf (dump_file
, "\n");
5094 register_new_assert_for (name2
, tmp
, new_comp_code
, new_val
,
5100 /* Add asserts for NAME cmp CST and NAME being defined as
5101 NAME = NAME2 & CST2.
5103 Extract CST2 from the and.
5106 NAME = (unsigned) NAME2;
5107 casts where NAME's type is unsigned and has smaller precision
5108 than NAME2's type as if it was NAME = NAME2 & MASK. */
5109 names
[0] = NULL_TREE
;
5110 names
[1] = NULL_TREE
;
5112 if (rhs_code
== BIT_AND_EXPR
5113 || (CONVERT_EXPR_CODE_P (rhs_code
)
5114 && TREE_CODE (TREE_TYPE (val
)) == INTEGER_TYPE
5115 && TYPE_UNSIGNED (TREE_TYPE (val
))
5116 && TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt
)))
5120 name2
= gimple_assign_rhs1 (def_stmt
);
5121 if (rhs_code
== BIT_AND_EXPR
)
5122 cst2
= gimple_assign_rhs2 (def_stmt
);
5125 cst2
= TYPE_MAX_VALUE (TREE_TYPE (val
));
5126 nprec
= TYPE_PRECISION (TREE_TYPE (name2
));
5128 if (TREE_CODE (name2
) == SSA_NAME
5129 && INTEGRAL_TYPE_P (TREE_TYPE (name2
))
5130 && TREE_CODE (cst2
) == INTEGER_CST
5131 && !integer_zerop (cst2
)
5132 && nprec
<= HOST_BITS_PER_DOUBLE_INT
5134 || TYPE_UNSIGNED (TREE_TYPE (val
))))
5136 gimple def_stmt2
= SSA_NAME_DEF_STMT (name2
);
5137 if (gimple_assign_cast_p (def_stmt2
))
5139 names
[1] = gimple_assign_rhs1 (def_stmt2
);
5140 if (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt2
))
5141 || !INTEGRAL_TYPE_P (TREE_TYPE (names
[1]))
5142 || (TYPE_PRECISION (TREE_TYPE (name2
))
5143 != TYPE_PRECISION (TREE_TYPE (names
[1])))
5144 || !live_on_edge (e
, names
[1])
5145 || has_single_use (names
[1]))
5146 names
[1] = NULL_TREE
;
5148 if (live_on_edge (e
, name2
)
5149 && !has_single_use (name2
))
5153 if (names
[0] || names
[1])
5155 double_int minv
, maxv
= double_int_zero
, valv
, cst2v
;
5156 double_int tem
, sgnbit
;
5157 bool valid_p
= false, valn
= false, cst2n
= false;
5158 enum tree_code ccode
= comp_code
;
5160 valv
= tree_to_double_int (val
).zext (nprec
);
5161 cst2v
= tree_to_double_int (cst2
).zext (nprec
);
5162 if (!TYPE_UNSIGNED (TREE_TYPE (val
)))
5164 valn
= valv
.sext (nprec
).is_negative ();
5165 cst2n
= cst2v
.sext (nprec
).is_negative ();
5167 /* If CST2 doesn't have most significant bit set,
5168 but VAL is negative, we have comparison like
5169 if ((x & 0x123) > -4) (always true). Just give up. */
5173 sgnbit
= double_int_one
.llshift (nprec
- 1, nprec
).zext (nprec
);
5175 sgnbit
= double_int_zero
;
5176 minv
= valv
& cst2v
;
5180 /* Minimum unsigned value for equality is VAL & CST2
5181 (should be equal to VAL, otherwise we probably should
5182 have folded the comparison into false) and
5183 maximum unsigned value is VAL | ~CST2. */
5184 maxv
= valv
| ~cst2v
;
5185 maxv
= maxv
.zext (nprec
);
5189 tem
= valv
| ~cst2v
;
5190 tem
= tem
.zext (nprec
);
5191 /* If VAL is 0, handle (X & CST2) != 0 as (X & CST2) > 0U. */
5192 if (valv
.is_zero ())
5195 sgnbit
= double_int_zero
;
5198 /* If (VAL | ~CST2) is all ones, handle it as
5199 (X & CST2) < VAL. */
5200 if (tem
== double_int::mask (nprec
))
5204 sgnbit
= double_int_zero
;
5208 && cst2v
.sext (nprec
).is_negative ())
5210 = double_int_one
.llshift (nprec
- 1, nprec
).zext (nprec
);
5211 if (!sgnbit
.is_zero ())
5219 if (tem
== double_int::mask (nprec
- 1))
5225 sgnbit
= double_int_zero
;
5229 /* Minimum unsigned value for >= if (VAL & CST2) == VAL
5230 is VAL and maximum unsigned value is ~0. For signed
5231 comparison, if CST2 doesn't have most significant bit
5232 set, handle it similarly. If CST2 has MSB set,
5233 the minimum is the same, and maximum is ~0U/2. */
5236 /* If (VAL & CST2) != VAL, X & CST2 can't be equal to
5238 minv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
5242 maxv
= double_int::mask (nprec
- (cst2n
? 1 : 0));
5247 /* Find out smallest MINV where MINV > VAL
5248 && (MINV & CST2) == MINV, if any. If VAL is signed and
5249 CST2 has MSB set, compute it biased by 1 << (nprec - 1). */
5250 minv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
5253 maxv
= double_int::mask (nprec
- (cst2n
? 1 : 0));
5257 /* Minimum unsigned value for <= is 0 and maximum
5258 unsigned value is VAL | ~CST2 if (VAL & CST2) == VAL.
5259 Otherwise, find smallest VAL2 where VAL2 > VAL
5260 && (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2
5262 For signed comparison, if CST2 doesn't have most
5263 significant bit set, handle it similarly. If CST2 has
5264 MSB set, the maximum is the same and minimum is INT_MIN. */
5269 maxv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
5272 maxv
-= double_int_one
;
5275 maxv
= maxv
.zext (nprec
);
5281 /* Minimum unsigned value for < is 0 and maximum
5282 unsigned value is (VAL-1) | ~CST2 if (VAL & CST2) == VAL.
5283 Otherwise, find smallest VAL2 where VAL2 > VAL
5284 && (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2
5286 For signed comparison, if CST2 doesn't have most
5287 significant bit set, handle it similarly. If CST2 has
5288 MSB set, the maximum is the same and minimum is INT_MIN. */
5297 maxv
= masked_increment (valv
, cst2v
, sgnbit
, nprec
);
5301 maxv
-= double_int_one
;
5303 maxv
= maxv
.zext (nprec
);
5311 && (maxv
- minv
).zext (nprec
) != double_int::mask (nprec
))
5313 tree tmp
, new_val
, type
;
5316 for (i
= 0; i
< 2; i
++)
5319 double_int maxv2
= maxv
;
5321 type
= TREE_TYPE (names
[i
]);
5322 if (!TYPE_UNSIGNED (type
))
5324 type
= build_nonstandard_integer_type (nprec
, 1);
5325 tmp
= build1 (NOP_EXPR
, type
, names
[i
]);
5327 if (!minv
.is_zero ())
5329 tmp
= build2 (PLUS_EXPR
, type
, tmp
,
5330 double_int_to_tree (type
, -minv
));
5331 maxv2
= maxv
- minv
;
5333 new_val
= double_int_to_tree (type
, maxv2
);
5337 fprintf (dump_file
, "Adding assert for ");
5338 print_generic_expr (dump_file
, names
[i
], 0);
5339 fprintf (dump_file
, " from ");
5340 print_generic_expr (dump_file
, tmp
, 0);
5341 fprintf (dump_file
, "\n");
5344 register_new_assert_for (names
[i
], tmp
, LE_EXPR
,
5345 new_val
, NULL
, e
, bsi
);
5355 /* OP is an operand of a truth value expression which is known to have
5356 a particular value. Register any asserts for OP and for any
5357 operands in OP's defining statement.
5359 If CODE is EQ_EXPR, then we want to register OP is zero (false),
5360 if CODE is NE_EXPR, then we want to register OP is nonzero (true). */
5363 register_edge_assert_for_1 (tree op
, enum tree_code code
,
5364 edge e
, gimple_stmt_iterator bsi
)
5366 bool retval
= false;
5369 enum tree_code rhs_code
;
5371 /* We only care about SSA_NAMEs. */
5372 if (TREE_CODE (op
) != SSA_NAME
)
5375 /* We know that OP will have a zero or nonzero value. If OP is used
5376 more than once go ahead and register an assert for OP.
5378 The FOUND_IN_SUBGRAPH support is not helpful in this situation as
5379 it will always be set for OP (because OP is used in a COND_EXPR in
5381 if (!has_single_use (op
))
5383 val
= build_int_cst (TREE_TYPE (op
), 0);
5384 register_new_assert_for (op
, op
, code
, val
, NULL
, e
, bsi
);
5388 /* Now look at how OP is set. If it's set from a comparison,
5389 a truth operation or some bit operations, then we may be able
5390 to register information about the operands of that assignment. */
5391 op_def
= SSA_NAME_DEF_STMT (op
);
5392 if (gimple_code (op_def
) != GIMPLE_ASSIGN
)
5395 rhs_code
= gimple_assign_rhs_code (op_def
);
5397 if (TREE_CODE_CLASS (rhs_code
) == tcc_comparison
)
5399 bool invert
= (code
== EQ_EXPR
? true : false);
5400 tree op0
= gimple_assign_rhs1 (op_def
);
5401 tree op1
= gimple_assign_rhs2 (op_def
);
5403 if (TREE_CODE (op0
) == SSA_NAME
)
5404 retval
|= register_edge_assert_for_2 (op0
, e
, bsi
, rhs_code
, op0
, op1
,
5406 if (TREE_CODE (op1
) == SSA_NAME
)
5407 retval
|= register_edge_assert_for_2 (op1
, e
, bsi
, rhs_code
, op0
, op1
,
5410 else if ((code
== NE_EXPR
5411 && gimple_assign_rhs_code (op_def
) == BIT_AND_EXPR
)
5413 && gimple_assign_rhs_code (op_def
) == BIT_IOR_EXPR
))
5415 /* Recurse on each operand. */
5416 tree op0
= gimple_assign_rhs1 (op_def
);
5417 tree op1
= gimple_assign_rhs2 (op_def
);
5418 if (TREE_CODE (op0
) == SSA_NAME
5419 && has_single_use (op0
))
5420 retval
|= register_edge_assert_for_1 (op0
, code
, e
, bsi
);
5421 if (TREE_CODE (op1
) == SSA_NAME
5422 && has_single_use (op1
))
5423 retval
|= register_edge_assert_for_1 (op1
, code
, e
, bsi
);
5425 else if (gimple_assign_rhs_code (op_def
) == BIT_NOT_EXPR
5426 && TYPE_PRECISION (TREE_TYPE (gimple_assign_lhs (op_def
))) == 1)
5428 /* Recurse, flipping CODE. */
5429 code
= invert_tree_comparison (code
, false);
5430 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
5433 else if (gimple_assign_rhs_code (op_def
) == SSA_NAME
)
5435 /* Recurse through the copy. */
5436 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
5439 else if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (op_def
)))
5441 /* Recurse through the type conversion. */
5442 retval
|= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def
),
5449 /* Try to register an edge assertion for SSA name NAME on edge E for
5450 the condition COND contributing to the conditional jump pointed to by SI.
5451 Return true if an assertion for NAME could be registered. */
5454 register_edge_assert_for (tree name
, edge e
, gimple_stmt_iterator si
,
5455 enum tree_code cond_code
, tree cond_op0
,
5459 enum tree_code comp_code
;
5460 bool retval
= false;
5461 bool is_else_edge
= (e
->flags
& EDGE_FALSE_VALUE
) != 0;
5463 /* Do not attempt to infer anything in names that flow through
5465 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name
))
5468 if (!extract_code_and_val_from_cond_with_ops (name
, cond_code
,
5474 /* Register ASSERT_EXPRs for name. */
5475 retval
|= register_edge_assert_for_2 (name
, e
, si
, cond_code
, cond_op0
,
5476 cond_op1
, is_else_edge
);
5479 /* If COND is effectively an equality test of an SSA_NAME against
5480 the value zero or one, then we may be able to assert values
5481 for SSA_NAMEs which flow into COND. */
5483 /* In the case of NAME == 1 or NAME != 0, for BIT_AND_EXPR defining
5484 statement of NAME we can assert both operands of the BIT_AND_EXPR
5485 have nonzero value. */
5486 if (((comp_code
== EQ_EXPR
&& integer_onep (val
))
5487 || (comp_code
== NE_EXPR
&& integer_zerop (val
))))
5489 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
5491 if (is_gimple_assign (def_stmt
)
5492 && gimple_assign_rhs_code (def_stmt
) == BIT_AND_EXPR
)
5494 tree op0
= gimple_assign_rhs1 (def_stmt
);
5495 tree op1
= gimple_assign_rhs2 (def_stmt
);
5496 retval
|= register_edge_assert_for_1 (op0
, NE_EXPR
, e
, si
);
5497 retval
|= register_edge_assert_for_1 (op1
, NE_EXPR
, e
, si
);
5501 /* In the case of NAME == 0 or NAME != 1, for BIT_IOR_EXPR defining
5502 statement of NAME we can assert both operands of the BIT_IOR_EXPR
5504 if (((comp_code
== EQ_EXPR
&& integer_zerop (val
))
5505 || (comp_code
== NE_EXPR
&& integer_onep (val
))))
5507 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
5509 /* For BIT_IOR_EXPR only if NAME == 0 both operands have
5510 necessarily zero value, or if type-precision is one. */
5511 if (is_gimple_assign (def_stmt
)
5512 && (gimple_assign_rhs_code (def_stmt
) == BIT_IOR_EXPR
5513 && (TYPE_PRECISION (TREE_TYPE (name
)) == 1
5514 || comp_code
== EQ_EXPR
)))
5516 tree op0
= gimple_assign_rhs1 (def_stmt
);
5517 tree op1
= gimple_assign_rhs2 (def_stmt
);
5518 retval
|= register_edge_assert_for_1 (op0
, EQ_EXPR
, e
, si
);
5519 retval
|= register_edge_assert_for_1 (op1
, EQ_EXPR
, e
, si
);
5527 /* Determine whether the outgoing edges of BB should receive an
5528 ASSERT_EXPR for each of the operands of BB's LAST statement.
5529 The last statement of BB must be a COND_EXPR.
5531 If any of the sub-graphs rooted at BB have an interesting use of
5532 the predicate operands, an assert location node is added to the
5533 list of assertions for the corresponding operands. */
5536 find_conditional_asserts (basic_block bb
, gimple last
)
5539 gimple_stmt_iterator bsi
;
5545 need_assert
= false;
5546 bsi
= gsi_for_stmt (last
);
5548 /* Look for uses of the operands in each of the sub-graphs
5549 rooted at BB. We need to check each of the outgoing edges
5550 separately, so that we know what kind of ASSERT_EXPR to
5552 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5557 /* Register the necessary assertions for each operand in the
5558 conditional predicate. */
5559 FOR_EACH_SSA_TREE_OPERAND (op
, last
, iter
, SSA_OP_USE
)
5561 need_assert
|= register_edge_assert_for (op
, e
, bsi
,
5562 gimple_cond_code (last
),
5563 gimple_cond_lhs (last
),
5564 gimple_cond_rhs (last
));
5577 /* Compare two case labels sorting first by the destination bb index
5578 and then by the case value. */
5581 compare_case_labels (const void *p1
, const void *p2
)
5583 const struct case_info
*ci1
= (const struct case_info
*) p1
;
5584 const struct case_info
*ci2
= (const struct case_info
*) p2
;
5585 int idx1
= ci1
->bb
->index
;
5586 int idx2
= ci2
->bb
->index
;
5590 else if (idx1
== idx2
)
5592 /* Make sure the default label is first in a group. */
5593 if (!CASE_LOW (ci1
->expr
))
5595 else if (!CASE_LOW (ci2
->expr
))
5598 return tree_int_cst_compare (CASE_LOW (ci1
->expr
),
5599 CASE_LOW (ci2
->expr
));
5605 /* Determine whether the outgoing edges of BB should receive an
5606 ASSERT_EXPR for each of the operands of BB's LAST statement.
5607 The last statement of BB must be a SWITCH_EXPR.
5609 If any of the sub-graphs rooted at BB have an interesting use of
5610 the predicate operands, an assert location node is added to the
5611 list of assertions for the corresponding operands. */
5614 find_switch_asserts (basic_block bb
, gimple last
)
5617 gimple_stmt_iterator bsi
;
5620 struct case_info
*ci
;
5621 size_t n
= gimple_switch_num_labels (last
);
5622 #if GCC_VERSION >= 4000
5625 /* Work around GCC 3.4 bug (PR 37086). */
5626 volatile unsigned int idx
;
5629 need_assert
= false;
5630 bsi
= gsi_for_stmt (last
);
5631 op
= gimple_switch_index (last
);
5632 if (TREE_CODE (op
) != SSA_NAME
)
5635 /* Build a vector of case labels sorted by destination label. */
5636 ci
= XNEWVEC (struct case_info
, n
);
5637 for (idx
= 0; idx
< n
; ++idx
)
5639 ci
[idx
].expr
= gimple_switch_label (last
, idx
);
5640 ci
[idx
].bb
= label_to_block (CASE_LABEL (ci
[idx
].expr
));
5642 qsort (ci
, n
, sizeof (struct case_info
), compare_case_labels
);
5644 for (idx
= 0; idx
< n
; ++idx
)
5647 tree cl
= ci
[idx
].expr
;
5648 basic_block cbb
= ci
[idx
].bb
;
5650 min
= CASE_LOW (cl
);
5651 max
= CASE_HIGH (cl
);
5653 /* If there are multiple case labels with the same destination
5654 we need to combine them to a single value range for the edge. */
5655 if (idx
+ 1 < n
&& cbb
== ci
[idx
+ 1].bb
)
5657 /* Skip labels until the last of the group. */
5660 } while (idx
< n
&& cbb
== ci
[idx
].bb
);
5663 /* Pick up the maximum of the case label range. */
5664 if (CASE_HIGH (ci
[idx
].expr
))
5665 max
= CASE_HIGH (ci
[idx
].expr
);
5667 max
= CASE_LOW (ci
[idx
].expr
);
5670 /* Nothing to do if the range includes the default label until we
5671 can register anti-ranges. */
5672 if (min
== NULL_TREE
)
5675 /* Find the edge to register the assert expr on. */
5676 e
= find_edge (bb
, cbb
);
5678 /* Register the necessary assertions for the operand in the
5680 need_assert
|= register_edge_assert_for (op
, e
, bsi
,
5681 max
? GE_EXPR
: EQ_EXPR
,
5683 fold_convert (TREE_TYPE (op
),
5687 need_assert
|= register_edge_assert_for (op
, e
, bsi
, LE_EXPR
,
5689 fold_convert (TREE_TYPE (op
),
5699 /* Traverse all the statements in block BB looking for statements that
5700 may generate useful assertions for the SSA names in their operand.
5701 If a statement produces a useful assertion A for name N_i, then the
5702 list of assertions already generated for N_i is scanned to
5703 determine if A is actually needed.
5705 If N_i already had the assertion A at a location dominating the
5706 current location, then nothing needs to be done. Otherwise, the
5707 new location for A is recorded instead.
5709 1- For every statement S in BB, all the variables used by S are
5710 added to bitmap FOUND_IN_SUBGRAPH.
5712 2- If statement S uses an operand N in a way that exposes a known
5713 value range for N, then if N was not already generated by an
5714 ASSERT_EXPR, create a new assert location for N. For instance,
5715 if N is a pointer and the statement dereferences it, we can
5716 assume that N is not NULL.
5718 3- COND_EXPRs are a special case of #2. We can derive range
5719 information from the predicate but need to insert different
5720 ASSERT_EXPRs for each of the sub-graphs rooted at the
5721 conditional block. If the last statement of BB is a conditional
5722 expression of the form 'X op Y', then
5724 a) Remove X and Y from the set FOUND_IN_SUBGRAPH.
5726 b) If the conditional is the only entry point to the sub-graph
5727 corresponding to the THEN_CLAUSE, recurse into it. On
5728 return, if X and/or Y are marked in FOUND_IN_SUBGRAPH, then
5729 an ASSERT_EXPR is added for the corresponding variable.
5731 c) Repeat step (b) on the ELSE_CLAUSE.
5733 d) Mark X and Y in FOUND_IN_SUBGRAPH.
5742 In this case, an assertion on the THEN clause is useful to
5743 determine that 'a' is always 9 on that edge. However, an assertion
5744 on the ELSE clause would be unnecessary.
5746 4- If BB does not end in a conditional expression, then we recurse
5747 into BB's dominator children.
5749 At the end of the recursive traversal, every SSA name will have a
5750 list of locations where ASSERT_EXPRs should be added. When a new
5751 location for name N is found, it is registered by calling
5752 register_new_assert_for. That function keeps track of all the
5753 registered assertions to prevent adding unnecessary assertions.
5754 For instance, if a pointer P_4 is dereferenced more than once in a
5755 dominator tree, only the location dominating all the dereference of
5756 P_4 will receive an ASSERT_EXPR.
5758 If this function returns true, then it means that there are names
5759 for which we need to generate ASSERT_EXPRs. Those assertions are
5760 inserted by process_assert_insertions. */
5763 find_assert_locations_1 (basic_block bb
, sbitmap live
)
5765 gimple_stmt_iterator si
;
5769 need_assert
= false;
5770 last
= last_stmt (bb
);
5772 /* If BB's last statement is a conditional statement involving integer
5773 operands, determine if we need to add ASSERT_EXPRs. */
5775 && gimple_code (last
) == GIMPLE_COND
5776 && !fp_predicate (last
)
5777 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
5778 need_assert
|= find_conditional_asserts (bb
, last
);
5780 /* If BB's last statement is a switch statement involving integer
5781 operands, determine if we need to add ASSERT_EXPRs. */
5783 && gimple_code (last
) == GIMPLE_SWITCH
5784 && !ZERO_SSA_OPERANDS (last
, SSA_OP_USE
))
5785 need_assert
|= find_switch_asserts (bb
, last
);
5787 /* Traverse all the statements in BB marking used names and looking
5788 for statements that may infer assertions for their used operands. */
5789 for (si
= gsi_last_bb (bb
); !gsi_end_p (si
); gsi_prev (&si
))
5795 stmt
= gsi_stmt (si
);
5797 if (is_gimple_debug (stmt
))
5800 /* See if we can derive an assertion for any of STMT's operands. */
5801 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_USE
)
5804 enum tree_code comp_code
;
5806 /* If op is not live beyond this stmt, do not bother to insert
5808 if (!bitmap_bit_p (live
, SSA_NAME_VERSION (op
)))
5811 /* If OP is used in such a way that we can infer a value
5812 range for it, and we don't find a previous assertion for
5813 it, create a new assertion location node for OP. */
5814 if (infer_value_range (stmt
, op
, &comp_code
, &value
))
5816 /* If we are able to infer a nonzero value range for OP,
5817 then walk backwards through the use-def chain to see if OP
5818 was set via a typecast.
5820 If so, then we can also infer a nonzero value range
5821 for the operand of the NOP_EXPR. */
5822 if (comp_code
== NE_EXPR
&& integer_zerop (value
))
5825 gimple def_stmt
= SSA_NAME_DEF_STMT (t
);
5827 while (is_gimple_assign (def_stmt
)
5828 && gimple_assign_rhs_code (def_stmt
) == NOP_EXPR
5830 (gimple_assign_rhs1 (def_stmt
)) == SSA_NAME
5832 (TREE_TYPE (gimple_assign_rhs1 (def_stmt
))))
5834 t
= gimple_assign_rhs1 (def_stmt
);
5835 def_stmt
= SSA_NAME_DEF_STMT (t
);
5837 /* Note we want to register the assert for the
5838 operand of the NOP_EXPR after SI, not after the
5840 if (! has_single_use (t
))
5842 register_new_assert_for (t
, t
, comp_code
, value
,
5849 register_new_assert_for (op
, op
, comp_code
, value
, bb
, NULL
, si
);
5855 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_USE
)
5856 bitmap_set_bit (live
, SSA_NAME_VERSION (op
));
5857 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_DEF
)
5858 bitmap_clear_bit (live
, SSA_NAME_VERSION (op
));
5861 /* Traverse all PHI nodes in BB, updating live. */
5862 for (si
= gsi_start_phis (bb
); !gsi_end_p (si
); gsi_next (&si
))
5864 use_operand_p arg_p
;
5866 gimple phi
= gsi_stmt (si
);
5867 tree res
= gimple_phi_result (phi
);
5869 if (virtual_operand_p (res
))
5872 FOR_EACH_PHI_ARG (arg_p
, phi
, i
, SSA_OP_USE
)
5874 tree arg
= USE_FROM_PTR (arg_p
);
5875 if (TREE_CODE (arg
) == SSA_NAME
)
5876 bitmap_set_bit (live
, SSA_NAME_VERSION (arg
));
5879 bitmap_clear_bit (live
, SSA_NAME_VERSION (res
));
5885 /* Do an RPO walk over the function computing SSA name liveness
5886 on-the-fly and deciding on assert expressions to insert.
5887 Returns true if there are assert expressions to be inserted. */
5890 find_assert_locations (void)
5892 int *rpo
= XNEWVEC (int, last_basic_block
);
5893 int *bb_rpo
= XNEWVEC (int, last_basic_block
);
5894 int *last_rpo
= XCNEWVEC (int, last_basic_block
);
5898 live
= XCNEWVEC (sbitmap
, last_basic_block
);
5899 rpo_cnt
= pre_and_rev_post_order_compute (NULL
, rpo
, false);
5900 for (i
= 0; i
< rpo_cnt
; ++i
)
5903 /* Pre-seed loop latch liveness from loop header PHI nodes. Due to
5904 the order we compute liveness and insert asserts we otherwise
5905 fail to insert asserts into the loop latch. */
5907 FOR_EACH_LOOP (loop
, 0)
5909 i
= loop
->latch
->index
;
5910 unsigned int j
= single_succ_edge (loop
->latch
)->dest_idx
;
5911 for (gimple_stmt_iterator gsi
= gsi_start_phis (loop
->header
);
5912 !gsi_end_p (gsi
); gsi_next (&gsi
))
5914 gimple phi
= gsi_stmt (gsi
);
5915 if (virtual_operand_p (gimple_phi_result (phi
)))
5917 tree arg
= gimple_phi_arg_def (phi
, j
);
5918 if (TREE_CODE (arg
) == SSA_NAME
)
5920 if (live
[i
] == NULL
)
5922 live
[i
] = sbitmap_alloc (num_ssa_names
);
5923 bitmap_clear (live
[i
]);
5925 bitmap_set_bit (live
[i
], SSA_NAME_VERSION (arg
));
5930 need_asserts
= false;
5931 for (i
= rpo_cnt
- 1; i
>= 0; --i
)
5933 basic_block bb
= BASIC_BLOCK (rpo
[i
]);
5939 live
[rpo
[i
]] = sbitmap_alloc (num_ssa_names
);
5940 bitmap_clear (live
[rpo
[i
]]);
5943 /* Process BB and update the live information with uses in
5945 need_asserts
|= find_assert_locations_1 (bb
, live
[rpo
[i
]]);
5947 /* Merge liveness into the predecessor blocks and free it. */
5948 if (!bitmap_empty_p (live
[rpo
[i
]]))
5951 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
5953 int pred
= e
->src
->index
;
5954 if ((e
->flags
& EDGE_DFS_BACK
) || pred
== ENTRY_BLOCK
)
5959 live
[pred
] = sbitmap_alloc (num_ssa_names
);
5960 bitmap_clear (live
[pred
]);
5962 bitmap_ior (live
[pred
], live
[pred
], live
[rpo
[i
]]);
5964 if (bb_rpo
[pred
] < pred_rpo
)
5965 pred_rpo
= bb_rpo
[pred
];
5968 /* Record the RPO number of the last visited block that needs
5969 live information from this block. */
5970 last_rpo
[rpo
[i
]] = pred_rpo
;
5974 sbitmap_free (live
[rpo
[i
]]);
5975 live
[rpo
[i
]] = NULL
;
5978 /* We can free all successors live bitmaps if all their
5979 predecessors have been visited already. */
5980 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5981 if (last_rpo
[e
->dest
->index
] == i
5982 && live
[e
->dest
->index
])
5984 sbitmap_free (live
[e
->dest
->index
]);
5985 live
[e
->dest
->index
] = NULL
;
5990 XDELETEVEC (bb_rpo
);
5991 XDELETEVEC (last_rpo
);
5992 for (i
= 0; i
< last_basic_block
; ++i
)
5994 sbitmap_free (live
[i
]);
5997 return need_asserts
;
6000 /* Create an ASSERT_EXPR for NAME and insert it in the location
6001 indicated by LOC. Return true if we made any edge insertions. */
6004 process_assert_insertions_for (tree name
, assert_locus_t loc
)
6006 /* Build the comparison expression NAME_i COMP_CODE VAL. */
6013 /* If we have X <=> X do not insert an assert expr for that. */
6014 if (loc
->expr
== loc
->val
)
6017 cond
= build2 (loc
->comp_code
, boolean_type_node
, loc
->expr
, loc
->val
);
6018 assert_stmt
= build_assert_expr_for (cond
, name
);
6021 /* We have been asked to insert the assertion on an edge. This
6022 is used only by COND_EXPR and SWITCH_EXPR assertions. */
6023 gcc_checking_assert (gimple_code (gsi_stmt (loc
->si
)) == GIMPLE_COND
6024 || (gimple_code (gsi_stmt (loc
->si
))
6027 gsi_insert_on_edge (loc
->e
, assert_stmt
);
6031 /* Otherwise, we can insert right after LOC->SI iff the
6032 statement must not be the last statement in the block. */
6033 stmt
= gsi_stmt (loc
->si
);
6034 if (!stmt_ends_bb_p (stmt
))
6036 gsi_insert_after (&loc
->si
, assert_stmt
, GSI_SAME_STMT
);
6040 /* If STMT must be the last statement in BB, we can only insert new
6041 assertions on the non-abnormal edge out of BB. Note that since
6042 STMT is not control flow, there may only be one non-abnormal edge
6044 FOR_EACH_EDGE (e
, ei
, loc
->bb
->succs
)
6045 if (!(e
->flags
& EDGE_ABNORMAL
))
6047 gsi_insert_on_edge (e
, assert_stmt
);
6055 /* Process all the insertions registered for every name N_i registered
6056 in NEED_ASSERT_FOR. The list of assertions to be inserted are
6057 found in ASSERTS_FOR[i]. */
6060 process_assert_insertions (void)
6064 bool update_edges_p
= false;
6065 int num_asserts
= 0;
6067 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6068 dump_all_asserts (dump_file
);
6070 EXECUTE_IF_SET_IN_BITMAP (need_assert_for
, 0, i
, bi
)
6072 assert_locus_t loc
= asserts_for
[i
];
6077 assert_locus_t next
= loc
->next
;
6078 update_edges_p
|= process_assert_insertions_for (ssa_name (i
), loc
);
6086 gsi_commit_edge_inserts ();
6088 statistics_counter_event (cfun
, "Number of ASSERT_EXPR expressions inserted",
6093 /* Traverse the flowgraph looking for conditional jumps to insert range
6094 expressions. These range expressions are meant to provide information
6095 to optimizations that need to reason in terms of value ranges. They
6096 will not be expanded into RTL. For instance, given:
6105 this pass will transform the code into:
6111 x = ASSERT_EXPR <x, x < y>
6116 y = ASSERT_EXPR <y, x <= y>
6120 The idea is that once copy and constant propagation have run, other
6121 optimizations will be able to determine what ranges of values can 'x'
6122 take in different paths of the code, simply by checking the reaching
6123 definition of 'x'. */
6126 insert_range_assertions (void)
6128 need_assert_for
= BITMAP_ALLOC (NULL
);
6129 asserts_for
= XCNEWVEC (assert_locus_t
, num_ssa_names
);
6131 calculate_dominance_info (CDI_DOMINATORS
);
6133 if (find_assert_locations ())
6135 process_assert_insertions ();
6136 update_ssa (TODO_update_ssa_no_phi
);
6139 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6141 fprintf (dump_file
, "\nSSA form after inserting ASSERT_EXPRs\n");
6142 dump_function_to_file (current_function_decl
, dump_file
, dump_flags
);
6146 BITMAP_FREE (need_assert_for
);
6149 /* Checks one ARRAY_REF in REF, located at LOCUS. Ignores flexible arrays
6150 and "struct" hacks. If VRP can determine that the
6151 array subscript is a constant, check if it is outside valid
6152 range. If the array subscript is a RANGE, warn if it is
6153 non-overlapping with valid range.
6154 IGNORE_OFF_BY_ONE is true if the ARRAY_REF is inside a ADDR_EXPR. */
6157 check_array_ref (location_t location
, tree ref
, bool ignore_off_by_one
)
6159 value_range_t
* vr
= NULL
;
6160 tree low_sub
, up_sub
;
6161 tree low_bound
, up_bound
, up_bound_p1
;
6164 if (TREE_NO_WARNING (ref
))
6167 low_sub
= up_sub
= TREE_OPERAND (ref
, 1);
6168 up_bound
= array_ref_up_bound (ref
);
6170 /* Can not check flexible arrays. */
6172 || TREE_CODE (up_bound
) != INTEGER_CST
)
6175 /* Accesses to trailing arrays via pointers may access storage
6176 beyond the types array bounds. */
6177 base
= get_base_address (ref
);
6178 if (base
&& TREE_CODE (base
) == MEM_REF
)
6180 tree cref
, next
= NULL_TREE
;
6182 if (TREE_CODE (TREE_OPERAND (ref
, 0)) != COMPONENT_REF
)
6185 cref
= TREE_OPERAND (ref
, 0);
6186 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (cref
, 0))) == RECORD_TYPE
)
6187 for (next
= DECL_CHAIN (TREE_OPERAND (cref
, 1));
6188 next
&& TREE_CODE (next
) != FIELD_DECL
;
6189 next
= DECL_CHAIN (next
))
6192 /* If this is the last field in a struct type or a field in a
6193 union type do not warn. */
6198 low_bound
= array_ref_low_bound (ref
);
6199 up_bound_p1
= int_const_binop (PLUS_EXPR
, up_bound
, integer_one_node
);
6201 if (TREE_CODE (low_sub
) == SSA_NAME
)
6203 vr
= get_value_range (low_sub
);
6204 if (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
)
6206 low_sub
= vr
->type
== VR_RANGE
? vr
->max
: vr
->min
;
6207 up_sub
= vr
->type
== VR_RANGE
? vr
->min
: vr
->max
;
6211 if (vr
&& vr
->type
== VR_ANTI_RANGE
)
6213 if (TREE_CODE (up_sub
) == INTEGER_CST
6214 && tree_int_cst_lt (up_bound
, up_sub
)
6215 && TREE_CODE (low_sub
) == INTEGER_CST
6216 && tree_int_cst_lt (low_sub
, low_bound
))
6218 warning_at (location
, OPT_Warray_bounds
,
6219 "array subscript is outside array bounds");
6220 TREE_NO_WARNING (ref
) = 1;
6223 else if (TREE_CODE (up_sub
) == INTEGER_CST
6224 && (ignore_off_by_one
6225 ? (tree_int_cst_lt (up_bound
, up_sub
)
6226 && !tree_int_cst_equal (up_bound_p1
, up_sub
))
6227 : (tree_int_cst_lt (up_bound
, up_sub
)
6228 || tree_int_cst_equal (up_bound_p1
, up_sub
))))
6230 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6232 fprintf (dump_file
, "Array bound warning for ");
6233 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, ref
);
6234 fprintf (dump_file
, "\n");
6236 warning_at (location
, OPT_Warray_bounds
,
6237 "array subscript is above array bounds");
6238 TREE_NO_WARNING (ref
) = 1;
6240 else if (TREE_CODE (low_sub
) == INTEGER_CST
6241 && tree_int_cst_lt (low_sub
, low_bound
))
6243 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6245 fprintf (dump_file
, "Array bound warning for ");
6246 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, ref
);
6247 fprintf (dump_file
, "\n");
6249 warning_at (location
, OPT_Warray_bounds
,
6250 "array subscript is below array bounds");
6251 TREE_NO_WARNING (ref
) = 1;
6255 /* Searches if the expr T, located at LOCATION computes
6256 address of an ARRAY_REF, and call check_array_ref on it. */
6259 search_for_addr_array (tree t
, location_t location
)
6261 while (TREE_CODE (t
) == SSA_NAME
)
6263 gimple g
= SSA_NAME_DEF_STMT (t
);
6265 if (gimple_code (g
) != GIMPLE_ASSIGN
)
6268 if (get_gimple_rhs_class (gimple_assign_rhs_code (g
))
6269 != GIMPLE_SINGLE_RHS
)
6272 t
= gimple_assign_rhs1 (g
);
6276 /* We are only interested in addresses of ARRAY_REF's. */
6277 if (TREE_CODE (t
) != ADDR_EXPR
)
6280 /* Check each ARRAY_REFs in the reference chain. */
6283 if (TREE_CODE (t
) == ARRAY_REF
)
6284 check_array_ref (location
, t
, true /*ignore_off_by_one*/);
6286 t
= TREE_OPERAND (t
, 0);
6288 while (handled_component_p (t
));
6290 if (TREE_CODE (t
) == MEM_REF
6291 && TREE_CODE (TREE_OPERAND (t
, 0)) == ADDR_EXPR
6292 && !TREE_NO_WARNING (t
))
6294 tree tem
= TREE_OPERAND (TREE_OPERAND (t
, 0), 0);
6295 tree low_bound
, up_bound
, el_sz
;
6297 if (TREE_CODE (TREE_TYPE (tem
)) != ARRAY_TYPE
6298 || TREE_CODE (TREE_TYPE (TREE_TYPE (tem
))) == ARRAY_TYPE
6299 || !TYPE_DOMAIN (TREE_TYPE (tem
)))
6302 low_bound
= TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (tem
)));
6303 up_bound
= TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (tem
)));
6304 el_sz
= TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (tem
)));
6306 || TREE_CODE (low_bound
) != INTEGER_CST
6308 || TREE_CODE (up_bound
) != INTEGER_CST
6310 || TREE_CODE (el_sz
) != INTEGER_CST
)
6313 idx
= mem_ref_offset (t
);
6314 idx
= idx
.sdiv (tree_to_double_int (el_sz
), TRUNC_DIV_EXPR
);
6315 if (idx
.slt (double_int_zero
))
6317 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6319 fprintf (dump_file
, "Array bound warning for ");
6320 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, t
);
6321 fprintf (dump_file
, "\n");
6323 warning_at (location
, OPT_Warray_bounds
,
6324 "array subscript is below array bounds");
6325 TREE_NO_WARNING (t
) = 1;
6327 else if (idx
.sgt (tree_to_double_int (up_bound
)
6328 - tree_to_double_int (low_bound
)
6331 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6333 fprintf (dump_file
, "Array bound warning for ");
6334 dump_generic_expr (MSG_NOTE
, TDF_SLIM
, t
);
6335 fprintf (dump_file
, "\n");
6337 warning_at (location
, OPT_Warray_bounds
,
6338 "array subscript is above array bounds");
6339 TREE_NO_WARNING (t
) = 1;
6344 /* walk_tree() callback that checks if *TP is
6345 an ARRAY_REF inside an ADDR_EXPR (in which an array
6346 subscript one outside the valid range is allowed). Call
6347 check_array_ref for each ARRAY_REF found. The location is
6351 check_array_bounds (tree
*tp
, int *walk_subtree
, void *data
)
6354 struct walk_stmt_info
*wi
= (struct walk_stmt_info
*) data
;
6355 location_t location
;
6357 if (EXPR_HAS_LOCATION (t
))
6358 location
= EXPR_LOCATION (t
);
6361 location_t
*locp
= (location_t
*) wi
->info
;
6365 *walk_subtree
= TRUE
;
6367 if (TREE_CODE (t
) == ARRAY_REF
)
6368 check_array_ref (location
, t
, false /*ignore_off_by_one*/);
6370 if (TREE_CODE (t
) == MEM_REF
6371 || (TREE_CODE (t
) == RETURN_EXPR
&& TREE_OPERAND (t
, 0)))
6372 search_for_addr_array (TREE_OPERAND (t
, 0), location
);
6374 if (TREE_CODE (t
) == ADDR_EXPR
)
6375 *walk_subtree
= FALSE
;
6380 /* Walk over all statements of all reachable BBs and call check_array_bounds
6384 check_all_array_refs (void)
6387 gimple_stmt_iterator si
;
6393 bool executable
= false;
6395 /* Skip blocks that were found to be unreachable. */
6396 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
6397 executable
|= !!(e
->flags
& EDGE_EXECUTABLE
);
6401 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
6403 gimple stmt
= gsi_stmt (si
);
6404 struct walk_stmt_info wi
;
6405 if (!gimple_has_location (stmt
))
6408 if (is_gimple_call (stmt
))
6411 size_t n
= gimple_call_num_args (stmt
);
6412 for (i
= 0; i
< n
; i
++)
6414 tree arg
= gimple_call_arg (stmt
, i
);
6415 search_for_addr_array (arg
, gimple_location (stmt
));
6420 memset (&wi
, 0, sizeof (wi
));
6421 wi
.info
= CONST_CAST (void *, (const void *)
6422 gimple_location_ptr (stmt
));
6424 walk_gimple_op (gsi_stmt (si
),
6432 /* Return true if all imm uses of VAR are either in STMT, or
6433 feed (optionally through a chain of single imm uses) GIMPLE_COND
6434 in basic block COND_BB. */
6437 all_imm_uses_in_stmt_or_feed_cond (tree var
, gimple stmt
, basic_block cond_bb
)
6439 use_operand_p use_p
, use2_p
;
6440 imm_use_iterator iter
;
6442 FOR_EACH_IMM_USE_FAST (use_p
, iter
, var
)
6443 if (USE_STMT (use_p
) != stmt
)
6445 gimple use_stmt
= USE_STMT (use_p
), use_stmt2
;
6446 if (is_gimple_debug (use_stmt
))
6448 while (is_gimple_assign (use_stmt
)
6449 && TREE_CODE (gimple_assign_lhs (use_stmt
)) == SSA_NAME
6450 && single_imm_use (gimple_assign_lhs (use_stmt
),
6451 &use2_p
, &use_stmt2
))
6452 use_stmt
= use_stmt2
;
6453 if (gimple_code (use_stmt
) != GIMPLE_COND
6454 || gimple_bb (use_stmt
) != cond_bb
)
6467 __builtin_unreachable ();
6469 x_5 = ASSERT_EXPR <x_3, ...>;
6470 If x_3 has no other immediate uses (checked by caller),
6471 var is the x_3 var from ASSERT_EXPR, we can clear low 5 bits
6472 from the non-zero bitmask. */
6475 maybe_set_nonzero_bits (basic_block bb
, tree var
)
6477 edge e
= single_pred_edge (bb
);
6478 basic_block cond_bb
= e
->src
;
6479 gimple stmt
= last_stmt (cond_bb
);
6483 || gimple_code (stmt
) != GIMPLE_COND
6484 || gimple_cond_code (stmt
) != ((e
->flags
& EDGE_TRUE_VALUE
)
6485 ? EQ_EXPR
: NE_EXPR
)
6486 || TREE_CODE (gimple_cond_lhs (stmt
)) != SSA_NAME
6487 || !integer_zerop (gimple_cond_rhs (stmt
)))
6490 stmt
= SSA_NAME_DEF_STMT (gimple_cond_lhs (stmt
));
6491 if (!is_gimple_assign (stmt
)
6492 || gimple_assign_rhs_code (stmt
) != BIT_AND_EXPR
6493 || TREE_CODE (gimple_assign_rhs2 (stmt
)) != INTEGER_CST
)
6495 if (gimple_assign_rhs1 (stmt
) != var
)
6499 if (TREE_CODE (gimple_assign_rhs1 (stmt
)) != SSA_NAME
)
6501 stmt2
= SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt
));
6502 if (!gimple_assign_cast_p (stmt2
)
6503 || gimple_assign_rhs1 (stmt2
) != var
6504 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt2
))
6505 || (TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (stmt
)))
6506 != TYPE_PRECISION (TREE_TYPE (var
))))
6509 cst
= gimple_assign_rhs2 (stmt
);
6510 set_nonzero_bits (var
, (get_nonzero_bits (var
)
6511 & ~tree_to_double_int (cst
)));
6514 /* Convert range assertion expressions into the implied copies and
6515 copy propagate away the copies. Doing the trivial copy propagation
6516 here avoids the need to run the full copy propagation pass after
6519 FIXME, this will eventually lead to copy propagation removing the
6520 names that had useful range information attached to them. For
6521 instance, if we had the assertion N_i = ASSERT_EXPR <N_j, N_j > 3>,
6522 then N_i will have the range [3, +INF].
6524 However, by converting the assertion into the implied copy
6525 operation N_i = N_j, we will then copy-propagate N_j into the uses
6526 of N_i and lose the range information. We may want to hold on to
6527 ASSERT_EXPRs a little while longer as the ranges could be used in
6528 things like jump threading.
6530 The problem with keeping ASSERT_EXPRs around is that passes after
6531 VRP need to handle them appropriately.
6533 Another approach would be to make the range information a first
6534 class property of the SSA_NAME so that it can be queried from
6535 any pass. This is made somewhat more complex by the need for
6536 multiple ranges to be associated with one SSA_NAME. */
6539 remove_range_assertions (void)
6542 gimple_stmt_iterator si
;
6543 /* 1 if looking at ASSERT_EXPRs immediately at the beginning of
6544 a basic block preceeded by GIMPLE_COND branching to it and
6545 __builtin_trap, -1 if not yet checked, 0 otherwise. */
6548 /* Note that the BSI iterator bump happens at the bottom of the
6549 loop and no bump is necessary if we're removing the statement
6550 referenced by the current BSI. */
6552 for (si
= gsi_after_labels (bb
), is_unreachable
= -1; !gsi_end_p (si
);)
6554 gimple stmt
= gsi_stmt (si
);
6557 if (is_gimple_assign (stmt
)
6558 && gimple_assign_rhs_code (stmt
) == ASSERT_EXPR
)
6560 tree lhs
= gimple_assign_lhs (stmt
);
6561 tree rhs
= gimple_assign_rhs1 (stmt
);
6563 tree cond
= fold (ASSERT_EXPR_COND (rhs
));
6564 use_operand_p use_p
;
6565 imm_use_iterator iter
;
6567 gcc_assert (cond
!= boolean_false_node
);
6569 var
= ASSERT_EXPR_VAR (rhs
);
6570 gcc_assert (TREE_CODE (var
) == SSA_NAME
);
6572 if (!POINTER_TYPE_P (TREE_TYPE (lhs
))
6573 && SSA_NAME_RANGE_INFO (lhs
))
6575 if (is_unreachable
== -1)
6578 if (single_pred_p (bb
)
6579 && assert_unreachable_fallthru_edge_p
6580 (single_pred_edge (bb
)))
6584 if (x_7 >= 10 && x_7 < 20)
6585 __builtin_unreachable ();
6586 x_8 = ASSERT_EXPR <x_7, ...>;
6587 if the only uses of x_7 are in the ASSERT_EXPR and
6588 in the condition. In that case, we can copy the
6589 range info from x_8 computed in this pass also
6592 && all_imm_uses_in_stmt_or_feed_cond (var
, stmt
,
6595 set_range_info (var
, SSA_NAME_RANGE_INFO (lhs
)->min
,
6596 SSA_NAME_RANGE_INFO (lhs
)->max
);
6597 maybe_set_nonzero_bits (bb
, var
);
6601 /* Propagate the RHS into every use of the LHS. */
6602 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, lhs
)
6603 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
6604 SET_USE (use_p
, var
);
6606 /* And finally, remove the copy, it is not needed. */
6607 gsi_remove (&si
, true);
6608 release_defs (stmt
);
6619 /* Return true if STMT is interesting for VRP. */
6622 stmt_interesting_for_vrp (gimple stmt
)
6624 if (gimple_code (stmt
) == GIMPLE_PHI
)
6626 tree res
= gimple_phi_result (stmt
);
6627 return (!virtual_operand_p (res
)
6628 && (INTEGRAL_TYPE_P (TREE_TYPE (res
))
6629 || POINTER_TYPE_P (TREE_TYPE (res
))));
6631 else if (is_gimple_assign (stmt
) || is_gimple_call (stmt
))
6633 tree lhs
= gimple_get_lhs (stmt
);
6635 /* In general, assignments with virtual operands are not useful
6636 for deriving ranges, with the obvious exception of calls to
6637 builtin functions. */
6638 if (lhs
&& TREE_CODE (lhs
) == SSA_NAME
6639 && (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
6640 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
6641 && (is_gimple_call (stmt
)
6642 || !gimple_vuse (stmt
)))
6645 else if (gimple_code (stmt
) == GIMPLE_COND
6646 || gimple_code (stmt
) == GIMPLE_SWITCH
)
6653 /* Initialize local data structures for VRP. */
6656 vrp_initialize (void)
6660 values_propagated
= false;
6661 num_vr_values
= num_ssa_names
;
6662 vr_value
= XCNEWVEC (value_range_t
*, num_vr_values
);
6663 vr_phi_edge_counts
= XCNEWVEC (int, num_ssa_names
);
6667 gimple_stmt_iterator si
;
6669 for (si
= gsi_start_phis (bb
); !gsi_end_p (si
); gsi_next (&si
))
6671 gimple phi
= gsi_stmt (si
);
6672 if (!stmt_interesting_for_vrp (phi
))
6674 tree lhs
= PHI_RESULT (phi
);
6675 set_value_range_to_varying (get_value_range (lhs
));
6676 prop_set_simulate_again (phi
, false);
6679 prop_set_simulate_again (phi
, true);
6682 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
6684 gimple stmt
= gsi_stmt (si
);
6686 /* If the statement is a control insn, then we do not
6687 want to avoid simulating the statement once. Failure
6688 to do so means that those edges will never get added. */
6689 if (stmt_ends_bb_p (stmt
))
6690 prop_set_simulate_again (stmt
, true);
6691 else if (!stmt_interesting_for_vrp (stmt
))
6695 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, i
, SSA_OP_DEF
)
6696 set_value_range_to_varying (get_value_range (def
));
6697 prop_set_simulate_again (stmt
, false);
6700 prop_set_simulate_again (stmt
, true);
6705 /* Return the singleton value-range for NAME or NAME. */
6708 vrp_valueize (tree name
)
6710 if (TREE_CODE (name
) == SSA_NAME
)
6712 value_range_t
*vr
= get_value_range (name
);
6713 if (vr
->type
== VR_RANGE
6714 && (vr
->min
== vr
->max
6715 || operand_equal_p (vr
->min
, vr
->max
, 0)))
6721 /* Visit assignment STMT. If it produces an interesting range, record
6722 the SSA name in *OUTPUT_P. */
6724 static enum ssa_prop_result
6725 vrp_visit_assignment_or_call (gimple stmt
, tree
*output_p
)
6729 enum gimple_code code
= gimple_code (stmt
);
6730 lhs
= gimple_get_lhs (stmt
);
6732 /* We only keep track of ranges in integral and pointer types. */
6733 if (TREE_CODE (lhs
) == SSA_NAME
6734 && ((INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
6735 /* It is valid to have NULL MIN/MAX values on a type. See
6736 build_range_type. */
6737 && TYPE_MIN_VALUE (TREE_TYPE (lhs
))
6738 && TYPE_MAX_VALUE (TREE_TYPE (lhs
)))
6739 || POINTER_TYPE_P (TREE_TYPE (lhs
))))
6741 value_range_t new_vr
= VR_INITIALIZER
;
6743 /* Try folding the statement to a constant first. */
6744 tree tem
= gimple_fold_stmt_to_constant (stmt
, vrp_valueize
);
6746 set_value_range_to_value (&new_vr
, tem
, NULL
);
6747 /* Then dispatch to value-range extracting functions. */
6748 else if (code
== GIMPLE_CALL
)
6749 extract_range_basic (&new_vr
, stmt
);
6751 extract_range_from_assignment (&new_vr
, stmt
);
6753 if (update_value_range (lhs
, &new_vr
))
6757 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6759 fprintf (dump_file
, "Found new range for ");
6760 print_generic_expr (dump_file
, lhs
, 0);
6761 fprintf (dump_file
, ": ");
6762 dump_value_range (dump_file
, &new_vr
);
6763 fprintf (dump_file
, "\n\n");
6766 if (new_vr
.type
== VR_VARYING
)
6767 return SSA_PROP_VARYING
;
6769 return SSA_PROP_INTERESTING
;
6772 return SSA_PROP_NOT_INTERESTING
;
6775 /* Every other statement produces no useful ranges. */
6776 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_DEF
)
6777 set_value_range_to_varying (get_value_range (def
));
6779 return SSA_PROP_VARYING
;
6782 /* Helper that gets the value range of the SSA_NAME with version I
6783 or a symbolic range containing the SSA_NAME only if the value range
6784 is varying or undefined. */
6786 static inline value_range_t
6787 get_vr_for_comparison (int i
)
6789 value_range_t vr
= *get_value_range (ssa_name (i
));
6791 /* If name N_i does not have a valid range, use N_i as its own
6792 range. This allows us to compare against names that may
6793 have N_i in their ranges. */
6794 if (vr
.type
== VR_VARYING
|| vr
.type
== VR_UNDEFINED
)
6797 vr
.min
= ssa_name (i
);
6798 vr
.max
= ssa_name (i
);
6804 /* Compare all the value ranges for names equivalent to VAR with VAL
6805 using comparison code COMP. Return the same value returned by
6806 compare_range_with_value, including the setting of
6807 *STRICT_OVERFLOW_P. */
6810 compare_name_with_value (enum tree_code comp
, tree var
, tree val
,
6811 bool *strict_overflow_p
)
6817 int used_strict_overflow
;
6819 value_range_t equiv_vr
;
6821 /* Get the set of equivalences for VAR. */
6822 e
= get_value_range (var
)->equiv
;
6824 /* Start at -1. Set it to 0 if we do a comparison without relying
6825 on overflow, or 1 if all comparisons rely on overflow. */
6826 used_strict_overflow
= -1;
6828 /* Compare vars' value range with val. */
6829 equiv_vr
= get_vr_for_comparison (SSA_NAME_VERSION (var
));
6831 retval
= compare_range_with_value (comp
, &equiv_vr
, val
, &sop
);
6833 used_strict_overflow
= sop
? 1 : 0;
6835 /* If the equiv set is empty we have done all work we need to do. */
6839 && used_strict_overflow
> 0)
6840 *strict_overflow_p
= true;
6844 EXECUTE_IF_SET_IN_BITMAP (e
, 0, i
, bi
)
6846 equiv_vr
= get_vr_for_comparison (i
);
6848 t
= compare_range_with_value (comp
, &equiv_vr
, val
, &sop
);
6851 /* If we get different answers from different members
6852 of the equivalence set this check must be in a dead
6853 code region. Folding it to a trap representation
6854 would be correct here. For now just return don't-know. */
6864 used_strict_overflow
= 0;
6865 else if (used_strict_overflow
< 0)
6866 used_strict_overflow
= 1;
6871 && used_strict_overflow
> 0)
6872 *strict_overflow_p
= true;
6878 /* Given a comparison code COMP and names N1 and N2, compare all the
6879 ranges equivalent to N1 against all the ranges equivalent to N2
6880 to determine the value of N1 COMP N2. Return the same value
6881 returned by compare_ranges. Set *STRICT_OVERFLOW_P to indicate
6882 whether we relied on an overflow infinity in the comparison. */
6886 compare_names (enum tree_code comp
, tree n1
, tree n2
,
6887 bool *strict_overflow_p
)
6891 bitmap_iterator bi1
, bi2
;
6893 int used_strict_overflow
;
6894 static bitmap_obstack
*s_obstack
= NULL
;
6895 static bitmap s_e1
= NULL
, s_e2
= NULL
;
6897 /* Compare the ranges of every name equivalent to N1 against the
6898 ranges of every name equivalent to N2. */
6899 e1
= get_value_range (n1
)->equiv
;
6900 e2
= get_value_range (n2
)->equiv
;
6902 /* Use the fake bitmaps if e1 or e2 are not available. */
6903 if (s_obstack
== NULL
)
6905 s_obstack
= XNEW (bitmap_obstack
);
6906 bitmap_obstack_initialize (s_obstack
);
6907 s_e1
= BITMAP_ALLOC (s_obstack
);
6908 s_e2
= BITMAP_ALLOC (s_obstack
);
6915 /* Add N1 and N2 to their own set of equivalences to avoid
6916 duplicating the body of the loop just to check N1 and N2
6918 bitmap_set_bit (e1
, SSA_NAME_VERSION (n1
));
6919 bitmap_set_bit (e2
, SSA_NAME_VERSION (n2
));
6921 /* If the equivalence sets have a common intersection, then the two
6922 names can be compared without checking their ranges. */
6923 if (bitmap_intersect_p (e1
, e2
))
6925 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
6926 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
6928 return (comp
== EQ_EXPR
|| comp
== GE_EXPR
|| comp
== LE_EXPR
)
6930 : boolean_false_node
;
6933 /* Start at -1. Set it to 0 if we do a comparison without relying
6934 on overflow, or 1 if all comparisons rely on overflow. */
6935 used_strict_overflow
= -1;
6937 /* Otherwise, compare all the equivalent ranges. First, add N1 and
6938 N2 to their own set of equivalences to avoid duplicating the body
6939 of the loop just to check N1 and N2 ranges. */
6940 EXECUTE_IF_SET_IN_BITMAP (e1
, 0, i1
, bi1
)
6942 value_range_t vr1
= get_vr_for_comparison (i1
);
6944 t
= retval
= NULL_TREE
;
6945 EXECUTE_IF_SET_IN_BITMAP (e2
, 0, i2
, bi2
)
6949 value_range_t vr2
= get_vr_for_comparison (i2
);
6951 t
= compare_ranges (comp
, &vr1
, &vr2
, &sop
);
6954 /* If we get different answers from different members
6955 of the equivalence set this check must be in a dead
6956 code region. Folding it to a trap representation
6957 would be correct here. For now just return don't-know. */
6961 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
6962 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
6968 used_strict_overflow
= 0;
6969 else if (used_strict_overflow
< 0)
6970 used_strict_overflow
= 1;
6976 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
6977 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
6978 if (used_strict_overflow
> 0)
6979 *strict_overflow_p
= true;
6984 /* None of the equivalent ranges are useful in computing this
6986 bitmap_clear_bit (e1
, SSA_NAME_VERSION (n1
));
6987 bitmap_clear_bit (e2
, SSA_NAME_VERSION (n2
));
6991 /* Helper function for vrp_evaluate_conditional_warnv. */
6994 vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code code
,
6996 bool * strict_overflow_p
)
6998 value_range_t
*vr0
, *vr1
;
7000 vr0
= (TREE_CODE (op0
) == SSA_NAME
) ? get_value_range (op0
) : NULL
;
7001 vr1
= (TREE_CODE (op1
) == SSA_NAME
) ? get_value_range (op1
) : NULL
;
7004 return compare_ranges (code
, vr0
, vr1
, strict_overflow_p
);
7005 else if (vr0
&& vr1
== NULL
)
7006 return compare_range_with_value (code
, vr0
, op1
, strict_overflow_p
);
7007 else if (vr0
== NULL
&& vr1
)
7008 return (compare_range_with_value
7009 (swap_tree_comparison (code
), vr1
, op0
, strict_overflow_p
));
7013 /* Helper function for vrp_evaluate_conditional_warnv. */
7016 vrp_evaluate_conditional_warnv_with_ops (enum tree_code code
, tree op0
,
7017 tree op1
, bool use_equiv_p
,
7018 bool *strict_overflow_p
, bool *only_ranges
)
7022 *only_ranges
= true;
7024 /* We only deal with integral and pointer types. */
7025 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0
))
7026 && !POINTER_TYPE_P (TREE_TYPE (op0
)))
7032 && (ret
= vrp_evaluate_conditional_warnv_with_ops_using_ranges
7033 (code
, op0
, op1
, strict_overflow_p
)))
7035 *only_ranges
= false;
7036 if (TREE_CODE (op0
) == SSA_NAME
&& TREE_CODE (op1
) == SSA_NAME
)
7037 return compare_names (code
, op0
, op1
, strict_overflow_p
);
7038 else if (TREE_CODE (op0
) == SSA_NAME
)
7039 return compare_name_with_value (code
, op0
, op1
, strict_overflow_p
);
7040 else if (TREE_CODE (op1
) == SSA_NAME
)
7041 return (compare_name_with_value
7042 (swap_tree_comparison (code
), op1
, op0
, strict_overflow_p
));
7045 return vrp_evaluate_conditional_warnv_with_ops_using_ranges (code
, op0
, op1
,
7050 /* Given (CODE OP0 OP1) within STMT, try to simplify it based on value range
7051 information. Return NULL if the conditional can not be evaluated.
7052 The ranges of all the names equivalent with the operands in COND
7053 will be used when trying to compute the value. If the result is
7054 based on undefined signed overflow, issue a warning if
7058 vrp_evaluate_conditional (enum tree_code code
, tree op0
, tree op1
, gimple stmt
)
7064 /* Some passes and foldings leak constants with overflow flag set
7065 into the IL. Avoid doing wrong things with these and bail out. */
7066 if ((TREE_CODE (op0
) == INTEGER_CST
7067 && TREE_OVERFLOW (op0
))
7068 || (TREE_CODE (op1
) == INTEGER_CST
7069 && TREE_OVERFLOW (op1
)))
7073 ret
= vrp_evaluate_conditional_warnv_with_ops (code
, op0
, op1
, true, &sop
,
7078 enum warn_strict_overflow_code wc
;
7079 const char* warnmsg
;
7081 if (is_gimple_min_invariant (ret
))
7083 wc
= WARN_STRICT_OVERFLOW_CONDITIONAL
;
7084 warnmsg
= G_("assuming signed overflow does not occur when "
7085 "simplifying conditional to constant");
7089 wc
= WARN_STRICT_OVERFLOW_COMPARISON
;
7090 warnmsg
= G_("assuming signed overflow does not occur when "
7091 "simplifying conditional");
7094 if (issue_strict_overflow_warning (wc
))
7096 location_t location
;
7098 if (!gimple_has_location (stmt
))
7099 location
= input_location
;
7101 location
= gimple_location (stmt
);
7102 warning_at (location
, OPT_Wstrict_overflow
, "%s", warnmsg
);
7106 if (warn_type_limits
7107 && ret
&& only_ranges
7108 && TREE_CODE_CLASS (code
) == tcc_comparison
7109 && TREE_CODE (op0
) == SSA_NAME
)
7111 /* If the comparison is being folded and the operand on the LHS
7112 is being compared against a constant value that is outside of
7113 the natural range of OP0's type, then the predicate will
7114 always fold regardless of the value of OP0. If -Wtype-limits
7115 was specified, emit a warning. */
7116 tree type
= TREE_TYPE (op0
);
7117 value_range_t
*vr0
= get_value_range (op0
);
7119 if (vr0
->type
!= VR_VARYING
7120 && INTEGRAL_TYPE_P (type
)
7121 && vrp_val_is_min (vr0
->min
)
7122 && vrp_val_is_max (vr0
->max
)
7123 && is_gimple_min_invariant (op1
))
7125 location_t location
;
7127 if (!gimple_has_location (stmt
))
7128 location
= input_location
;
7130 location
= gimple_location (stmt
);
7132 warning_at (location
, OPT_Wtype_limits
,
7134 ? G_("comparison always false "
7135 "due to limited range of data type")
7136 : G_("comparison always true "
7137 "due to limited range of data type"));
7145 /* Visit conditional statement STMT. If we can determine which edge
7146 will be taken out of STMT's basic block, record it in
7147 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
7148 SSA_PROP_VARYING. */
7150 static enum ssa_prop_result
7151 vrp_visit_cond_stmt (gimple stmt
, edge
*taken_edge_p
)
7156 *taken_edge_p
= NULL
;
7158 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7163 fprintf (dump_file
, "\nVisiting conditional with predicate: ");
7164 print_gimple_stmt (dump_file
, stmt
, 0, 0);
7165 fprintf (dump_file
, "\nWith known ranges\n");
7167 FOR_EACH_SSA_TREE_OPERAND (use
, stmt
, i
, SSA_OP_USE
)
7169 fprintf (dump_file
, "\t");
7170 print_generic_expr (dump_file
, use
, 0);
7171 fprintf (dump_file
, ": ");
7172 dump_value_range (dump_file
, vr_value
[SSA_NAME_VERSION (use
)]);
7175 fprintf (dump_file
, "\n");
7178 /* Compute the value of the predicate COND by checking the known
7179 ranges of each of its operands.
7181 Note that we cannot evaluate all the equivalent ranges here
7182 because those ranges may not yet be final and with the current
7183 propagation strategy, we cannot determine when the value ranges
7184 of the names in the equivalence set have changed.
7186 For instance, given the following code fragment
7190 i_14 = ASSERT_EXPR <i_5, i_5 != 0>
7194 Assume that on the first visit to i_14, i_5 has the temporary
7195 range [8, 8] because the second argument to the PHI function is
7196 not yet executable. We derive the range ~[0, 0] for i_14 and the
7197 equivalence set { i_5 }. So, when we visit 'if (i_14 == 1)' for
7198 the first time, since i_14 is equivalent to the range [8, 8], we
7199 determine that the predicate is always false.
7201 On the next round of propagation, i_13 is determined to be
7202 VARYING, which causes i_5 to drop down to VARYING. So, another
7203 visit to i_14 is scheduled. In this second visit, we compute the
7204 exact same range and equivalence set for i_14, namely ~[0, 0] and
7205 { i_5 }. But we did not have the previous range for i_5
7206 registered, so vrp_visit_assignment thinks that the range for
7207 i_14 has not changed. Therefore, the predicate 'if (i_14 == 1)'
7208 is not visited again, which stops propagation from visiting
7209 statements in the THEN clause of that if().
7211 To properly fix this we would need to keep the previous range
7212 value for the names in the equivalence set. This way we would've
7213 discovered that from one visit to the other i_5 changed from
7214 range [8, 8] to VR_VARYING.
7216 However, fixing this apparent limitation may not be worth the
7217 additional checking. Testing on several code bases (GCC, DLV,
7218 MICO, TRAMP3D and SPEC2000) showed that doing this results in
7219 4 more predicates folded in SPEC. */
7222 val
= vrp_evaluate_conditional_warnv_with_ops (gimple_cond_code (stmt
),
7223 gimple_cond_lhs (stmt
),
7224 gimple_cond_rhs (stmt
),
7229 *taken_edge_p
= find_taken_edge (gimple_bb (stmt
), val
);
7232 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7234 "\nIgnoring predicate evaluation because "
7235 "it assumes that signed overflow is undefined");
7240 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7242 fprintf (dump_file
, "\nPredicate evaluates to: ");
7243 if (val
== NULL_TREE
)
7244 fprintf (dump_file
, "DON'T KNOW\n");
7246 print_generic_stmt (dump_file
, val
, 0);
7249 return (*taken_edge_p
) ? SSA_PROP_INTERESTING
: SSA_PROP_VARYING
;
7252 /* Searches the case label vector VEC for the index *IDX of the CASE_LABEL
7253 that includes the value VAL. The search is restricted to the range
7254 [START_IDX, n - 1] where n is the size of VEC.
7256 If there is a CASE_LABEL for VAL, its index is placed in IDX and true is
7259 If there is no CASE_LABEL for VAL and there is one that is larger than VAL,
7260 it is placed in IDX and false is returned.
7262 If VAL is larger than any CASE_LABEL, n is placed on IDX and false is
7266 find_case_label_index (gimple stmt
, size_t start_idx
, tree val
, size_t *idx
)
7268 size_t n
= gimple_switch_num_labels (stmt
);
7271 /* Find case label for minimum of the value range or the next one.
7272 At each iteration we are searching in [low, high - 1]. */
7274 for (low
= start_idx
, high
= n
; high
!= low
; )
7278 /* Note that i != high, so we never ask for n. */
7279 size_t i
= (high
+ low
) / 2;
7280 t
= gimple_switch_label (stmt
, i
);
7282 /* Cache the result of comparing CASE_LOW and val. */
7283 cmp
= tree_int_cst_compare (CASE_LOW (t
), val
);
7287 /* Ranges cannot be empty. */
7296 if (CASE_HIGH (t
) != NULL
7297 && tree_int_cst_compare (CASE_HIGH (t
), val
) >= 0)
7309 /* Searches the case label vector VEC for the range of CASE_LABELs that is used
7310 for values between MIN and MAX. The first index is placed in MIN_IDX. The
7311 last index is placed in MAX_IDX. If the range of CASE_LABELs is empty
7312 then MAX_IDX < MIN_IDX.
7313 Returns true if the default label is not needed. */
7316 find_case_label_range (gimple stmt
, tree min
, tree max
, size_t *min_idx
,
7320 bool min_take_default
= !find_case_label_index (stmt
, 1, min
, &i
);
7321 bool max_take_default
= !find_case_label_index (stmt
, i
, max
, &j
);
7325 && max_take_default
)
7327 /* Only the default case label reached.
7328 Return an empty range. */
7335 bool take_default
= min_take_default
|| max_take_default
;
7339 if (max_take_default
)
7342 /* If the case label range is continuous, we do not need
7343 the default case label. Verify that. */
7344 high
= CASE_LOW (gimple_switch_label (stmt
, i
));
7345 if (CASE_HIGH (gimple_switch_label (stmt
, i
)))
7346 high
= CASE_HIGH (gimple_switch_label (stmt
, i
));
7347 for (k
= i
+ 1; k
<= j
; ++k
)
7349 low
= CASE_LOW (gimple_switch_label (stmt
, k
));
7350 if (!integer_onep (int_const_binop (MINUS_EXPR
, low
, high
)))
7352 take_default
= true;
7356 if (CASE_HIGH (gimple_switch_label (stmt
, k
)))
7357 high
= CASE_HIGH (gimple_switch_label (stmt
, k
));
7362 return !take_default
;
7366 /* Searches the case label vector VEC for the ranges of CASE_LABELs that are
7367 used in range VR. The indices are placed in MIN_IDX1, MAX_IDX, MIN_IDX2 and
7368 MAX_IDX2. If the ranges of CASE_LABELs are empty then MAX_IDX1 < MIN_IDX1.
7369 Returns true if the default label is not needed. */
7372 find_case_label_ranges (gimple stmt
, value_range_t
*vr
, size_t *min_idx1
,
7373 size_t *max_idx1
, size_t *min_idx2
,
7377 unsigned int n
= gimple_switch_num_labels (stmt
);
7379 tree case_low
, case_high
;
7380 tree min
= vr
->min
, max
= vr
->max
;
7382 gcc_checking_assert (vr
->type
== VR_RANGE
|| vr
->type
== VR_ANTI_RANGE
);
7384 take_default
= !find_case_label_range (stmt
, min
, max
, &i
, &j
);
7386 /* Set second range to emtpy. */
7390 if (vr
->type
== VR_RANGE
)
7394 return !take_default
;
7397 /* Set first range to all case labels. */
7404 /* Make sure all the values of case labels [i , j] are contained in
7405 range [MIN, MAX]. */
7406 case_low
= CASE_LOW (gimple_switch_label (stmt
, i
));
7407 case_high
= CASE_HIGH (gimple_switch_label (stmt
, j
));
7408 if (tree_int_cst_compare (case_low
, min
) < 0)
7410 if (case_high
!= NULL_TREE
7411 && tree_int_cst_compare (max
, case_high
) < 0)
7417 /* If the range spans case labels [i, j], the corresponding anti-range spans
7418 the labels [1, i - 1] and [j + 1, n - 1]. */
7444 /* Visit switch statement STMT. If we can determine which edge
7445 will be taken out of STMT's basic block, record it in
7446 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
7447 SSA_PROP_VARYING. */
7449 static enum ssa_prop_result
7450 vrp_visit_switch_stmt (gimple stmt
, edge
*taken_edge_p
)
7454 size_t i
= 0, j
= 0, k
, l
;
7457 *taken_edge_p
= NULL
;
7458 op
= gimple_switch_index (stmt
);
7459 if (TREE_CODE (op
) != SSA_NAME
)
7460 return SSA_PROP_VARYING
;
7462 vr
= get_value_range (op
);
7463 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7465 fprintf (dump_file
, "\nVisiting switch expression with operand ");
7466 print_generic_expr (dump_file
, op
, 0);
7467 fprintf (dump_file
, " with known range ");
7468 dump_value_range (dump_file
, vr
);
7469 fprintf (dump_file
, "\n");
7472 if ((vr
->type
!= VR_RANGE
7473 && vr
->type
!= VR_ANTI_RANGE
)
7474 || symbolic_range_p (vr
))
7475 return SSA_PROP_VARYING
;
7477 /* Find the single edge that is taken from the switch expression. */
7478 take_default
= !find_case_label_ranges (stmt
, vr
, &i
, &j
, &k
, &l
);
7480 /* Check if the range spans no CASE_LABEL. If so, we only reach the default
7484 gcc_assert (take_default
);
7485 val
= gimple_switch_default_label (stmt
);
7489 /* Check if labels with index i to j and maybe the default label
7490 are all reaching the same label. */
7492 val
= gimple_switch_label (stmt
, i
);
7494 && CASE_LABEL (gimple_switch_default_label (stmt
))
7495 != CASE_LABEL (val
))
7497 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7498 fprintf (dump_file
, " not a single destination for this "
7500 return SSA_PROP_VARYING
;
7502 for (++i
; i
<= j
; ++i
)
7504 if (CASE_LABEL (gimple_switch_label (stmt
, i
)) != CASE_LABEL (val
))
7506 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7507 fprintf (dump_file
, " not a single destination for this "
7509 return SSA_PROP_VARYING
;
7514 if (CASE_LABEL (gimple_switch_label (stmt
, k
)) != CASE_LABEL (val
))
7516 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7517 fprintf (dump_file
, " not a single destination for this "
7519 return SSA_PROP_VARYING
;
7524 *taken_edge_p
= find_edge (gimple_bb (stmt
),
7525 label_to_block (CASE_LABEL (val
)));
7527 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7529 fprintf (dump_file
, " will take edge to ");
7530 print_generic_stmt (dump_file
, CASE_LABEL (val
), 0);
7533 return SSA_PROP_INTERESTING
;
7537 /* Evaluate statement STMT. If the statement produces a useful range,
7538 return SSA_PROP_INTERESTING and record the SSA name with the
7539 interesting range into *OUTPUT_P.
7541 If STMT is a conditional branch and we can determine its truth
7542 value, the taken edge is recorded in *TAKEN_EDGE_P.
7544 If STMT produces a varying value, return SSA_PROP_VARYING. */
7546 static enum ssa_prop_result
7547 vrp_visit_stmt (gimple stmt
, edge
*taken_edge_p
, tree
*output_p
)
7552 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7554 fprintf (dump_file
, "\nVisiting statement:\n");
7555 print_gimple_stmt (dump_file
, stmt
, 0, dump_flags
);
7556 fprintf (dump_file
, "\n");
7559 if (!stmt_interesting_for_vrp (stmt
))
7560 gcc_assert (stmt_ends_bb_p (stmt
));
7561 else if (is_gimple_assign (stmt
) || is_gimple_call (stmt
))
7562 return vrp_visit_assignment_or_call (stmt
, output_p
);
7563 else if (gimple_code (stmt
) == GIMPLE_COND
)
7564 return vrp_visit_cond_stmt (stmt
, taken_edge_p
);
7565 else if (gimple_code (stmt
) == GIMPLE_SWITCH
)
7566 return vrp_visit_switch_stmt (stmt
, taken_edge_p
);
7568 /* All other statements produce nothing of interest for VRP, so mark
7569 their outputs varying and prevent further simulation. */
7570 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_DEF
)
7571 set_value_range_to_varying (get_value_range (def
));
7573 return SSA_PROP_VARYING
;
7576 /* Union the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and
7577 { VR1TYPE, VR0MIN, VR0MAX } and store the result
7578 in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest
7579 possible such range. The resulting range is not canonicalized. */
7582 union_ranges (enum value_range_type
*vr0type
,
7583 tree
*vr0min
, tree
*vr0max
,
7584 enum value_range_type vr1type
,
7585 tree vr1min
, tree vr1max
)
7587 bool mineq
= operand_equal_p (*vr0min
, vr1min
, 0);
7588 bool maxeq
= operand_equal_p (*vr0max
, vr1max
, 0);
7590 /* [] is vr0, () is vr1 in the following classification comments. */
7594 if (*vr0type
== vr1type
)
7595 /* Nothing to do for equal ranges. */
7597 else if ((*vr0type
== VR_RANGE
7598 && vr1type
== VR_ANTI_RANGE
)
7599 || (*vr0type
== VR_ANTI_RANGE
7600 && vr1type
== VR_RANGE
))
7602 /* For anti-range with range union the result is varying. */
7608 else if (operand_less_p (*vr0max
, vr1min
) == 1
7609 || operand_less_p (vr1max
, *vr0min
) == 1)
7611 /* [ ] ( ) or ( ) [ ]
7612 If the ranges have an empty intersection, result of the union
7613 operation is the anti-range or if both are anti-ranges
7615 if (*vr0type
== VR_ANTI_RANGE
7616 && vr1type
== VR_ANTI_RANGE
)
7618 else if (*vr0type
== VR_ANTI_RANGE
7619 && vr1type
== VR_RANGE
)
7621 else if (*vr0type
== VR_RANGE
7622 && vr1type
== VR_ANTI_RANGE
)
7628 else if (*vr0type
== VR_RANGE
7629 && vr1type
== VR_RANGE
)
7631 /* The result is the convex hull of both ranges. */
7632 if (operand_less_p (*vr0max
, vr1min
) == 1)
7634 /* If the result can be an anti-range, create one. */
7635 if (TREE_CODE (*vr0max
) == INTEGER_CST
7636 && TREE_CODE (vr1min
) == INTEGER_CST
7637 && vrp_val_is_min (*vr0min
)
7638 && vrp_val_is_max (vr1max
))
7640 tree min
= int_const_binop (PLUS_EXPR
,
7641 *vr0max
, integer_one_node
);
7642 tree max
= int_const_binop (MINUS_EXPR
,
7643 vr1min
, integer_one_node
);
7644 if (!operand_less_p (max
, min
))
7646 *vr0type
= VR_ANTI_RANGE
;
7658 /* If the result can be an anti-range, create one. */
7659 if (TREE_CODE (vr1max
) == INTEGER_CST
7660 && TREE_CODE (*vr0min
) == INTEGER_CST
7661 && vrp_val_is_min (vr1min
)
7662 && vrp_val_is_max (*vr0max
))
7664 tree min
= int_const_binop (PLUS_EXPR
,
7665 vr1max
, integer_one_node
);
7666 tree max
= int_const_binop (MINUS_EXPR
,
7667 *vr0min
, integer_one_node
);
7668 if (!operand_less_p (max
, min
))
7670 *vr0type
= VR_ANTI_RANGE
;
7684 else if ((maxeq
|| operand_less_p (vr1max
, *vr0max
) == 1)
7685 && (mineq
|| operand_less_p (*vr0min
, vr1min
) == 1))
7687 /* [ ( ) ] or [( ) ] or [ ( )] */
7688 if (*vr0type
== VR_RANGE
7689 && vr1type
== VR_RANGE
)
7691 else if (*vr0type
== VR_ANTI_RANGE
7692 && vr1type
== VR_ANTI_RANGE
)
7698 else if (*vr0type
== VR_ANTI_RANGE
7699 && vr1type
== VR_RANGE
)
7701 /* Arbitrarily choose the right or left gap. */
7702 if (!mineq
&& TREE_CODE (vr1min
) == INTEGER_CST
)
7703 *vr0max
= int_const_binop (MINUS_EXPR
, vr1min
, integer_one_node
);
7704 else if (!maxeq
&& TREE_CODE (vr1max
) == INTEGER_CST
)
7705 *vr0min
= int_const_binop (PLUS_EXPR
, vr1max
, integer_one_node
);
7709 else if (*vr0type
== VR_RANGE
7710 && vr1type
== VR_ANTI_RANGE
)
7711 /* The result covers everything. */
7716 else if ((maxeq
|| operand_less_p (*vr0max
, vr1max
) == 1)
7717 && (mineq
|| operand_less_p (vr1min
, *vr0min
) == 1))
7719 /* ( [ ] ) or ([ ] ) or ( [ ]) */
7720 if (*vr0type
== VR_RANGE
7721 && vr1type
== VR_RANGE
)
7727 else if (*vr0type
== VR_ANTI_RANGE
7728 && vr1type
== VR_ANTI_RANGE
)
7730 else if (*vr0type
== VR_RANGE
7731 && vr1type
== VR_ANTI_RANGE
)
7733 *vr0type
= VR_ANTI_RANGE
;
7734 if (!mineq
&& TREE_CODE (*vr0min
) == INTEGER_CST
)
7736 *vr0max
= int_const_binop (MINUS_EXPR
, *vr0min
, integer_one_node
);
7739 else if (!maxeq
&& TREE_CODE (*vr0max
) == INTEGER_CST
)
7741 *vr0min
= int_const_binop (PLUS_EXPR
, *vr0max
, integer_one_node
);
7747 else if (*vr0type
== VR_ANTI_RANGE
7748 && vr1type
== VR_RANGE
)
7749 /* The result covers everything. */
7754 else if ((operand_less_p (vr1min
, *vr0max
) == 1
7755 || operand_equal_p (vr1min
, *vr0max
, 0))
7756 && operand_less_p (*vr0min
, vr1min
) == 1)
7758 /* [ ( ] ) or [ ]( ) */
7759 if (*vr0type
== VR_RANGE
7760 && vr1type
== VR_RANGE
)
7762 else if (*vr0type
== VR_ANTI_RANGE
7763 && vr1type
== VR_ANTI_RANGE
)
7765 else if (*vr0type
== VR_ANTI_RANGE
7766 && vr1type
== VR_RANGE
)
7768 if (TREE_CODE (vr1min
) == INTEGER_CST
)
7769 *vr0max
= int_const_binop (MINUS_EXPR
, vr1min
, integer_one_node
);
7773 else if (*vr0type
== VR_RANGE
7774 && vr1type
== VR_ANTI_RANGE
)
7776 if (TREE_CODE (*vr0max
) == INTEGER_CST
)
7779 *vr0min
= int_const_binop (PLUS_EXPR
, *vr0max
, integer_one_node
);
7788 else if ((operand_less_p (*vr0min
, vr1max
) == 1
7789 || operand_equal_p (*vr0min
, vr1max
, 0))
7790 && operand_less_p (vr1min
, *vr0min
) == 1)
7792 /* ( [ ) ] or ( )[ ] */
7793 if (*vr0type
== VR_RANGE
7794 && vr1type
== VR_RANGE
)
7796 else if (*vr0type
== VR_ANTI_RANGE
7797 && vr1type
== VR_ANTI_RANGE
)
7799 else if (*vr0type
== VR_ANTI_RANGE
7800 && vr1type
== VR_RANGE
)
7802 if (TREE_CODE (vr1max
) == INTEGER_CST
)
7803 *vr0min
= int_const_binop (PLUS_EXPR
, vr1max
, integer_one_node
);
7807 else if (*vr0type
== VR_RANGE
7808 && vr1type
== VR_ANTI_RANGE
)
7810 if (TREE_CODE (*vr0min
) == INTEGER_CST
)
7814 *vr0max
= int_const_binop (MINUS_EXPR
, *vr0min
, integer_one_node
);
7828 *vr0type
= VR_VARYING
;
7829 *vr0min
= NULL_TREE
;
7830 *vr0max
= NULL_TREE
;
7833 /* Intersect the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and
7834 { VR1TYPE, VR0MIN, VR0MAX } and store the result
7835 in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest
7836 possible such range. The resulting range is not canonicalized. */
7839 intersect_ranges (enum value_range_type
*vr0type
,
7840 tree
*vr0min
, tree
*vr0max
,
7841 enum value_range_type vr1type
,
7842 tree vr1min
, tree vr1max
)
7844 bool mineq
= operand_equal_p (*vr0min
, vr1min
, 0);
7845 bool maxeq
= operand_equal_p (*vr0max
, vr1max
, 0);
7847 /* [] is vr0, () is vr1 in the following classification comments. */
7851 if (*vr0type
== vr1type
)
7852 /* Nothing to do for equal ranges. */
7854 else if ((*vr0type
== VR_RANGE
7855 && vr1type
== VR_ANTI_RANGE
)
7856 || (*vr0type
== VR_ANTI_RANGE
7857 && vr1type
== VR_RANGE
))
7859 /* For anti-range with range intersection the result is empty. */
7860 *vr0type
= VR_UNDEFINED
;
7861 *vr0min
= NULL_TREE
;
7862 *vr0max
= NULL_TREE
;
7867 else if (operand_less_p (*vr0max
, vr1min
) == 1
7868 || operand_less_p (vr1max
, *vr0min
) == 1)
7870 /* [ ] ( ) or ( ) [ ]
7871 If the ranges have an empty intersection, the result of the
7872 intersect operation is the range for intersecting an
7873 anti-range with a range or empty when intersecting two ranges. */
7874 if (*vr0type
== VR_RANGE
7875 && vr1type
== VR_ANTI_RANGE
)
7877 else if (*vr0type
== VR_ANTI_RANGE
7878 && vr1type
== VR_RANGE
)
7884 else if (*vr0type
== VR_RANGE
7885 && vr1type
== VR_RANGE
)
7887 *vr0type
= VR_UNDEFINED
;
7888 *vr0min
= NULL_TREE
;
7889 *vr0max
= NULL_TREE
;
7891 else if (*vr0type
== VR_ANTI_RANGE
7892 && vr1type
== VR_ANTI_RANGE
)
7894 /* If the anti-ranges are adjacent to each other merge them. */
7895 if (TREE_CODE (*vr0max
) == INTEGER_CST
7896 && TREE_CODE (vr1min
) == INTEGER_CST
7897 && operand_less_p (*vr0max
, vr1min
) == 1
7898 && integer_onep (int_const_binop (MINUS_EXPR
,
7901 else if (TREE_CODE (vr1max
) == INTEGER_CST
7902 && TREE_CODE (*vr0min
) == INTEGER_CST
7903 && operand_less_p (vr1max
, *vr0min
) == 1
7904 && integer_onep (int_const_binop (MINUS_EXPR
,
7907 /* Else arbitrarily take VR0. */
7910 else if ((maxeq
|| operand_less_p (vr1max
, *vr0max
) == 1)
7911 && (mineq
|| operand_less_p (*vr0min
, vr1min
) == 1))
7913 /* [ ( ) ] or [( ) ] or [ ( )] */
7914 if (*vr0type
== VR_RANGE
7915 && vr1type
== VR_RANGE
)
7917 /* If both are ranges the result is the inner one. */
7922 else if (*vr0type
== VR_RANGE
7923 && vr1type
== VR_ANTI_RANGE
)
7925 /* Choose the right gap if the left one is empty. */
7928 if (TREE_CODE (vr1max
) == INTEGER_CST
)
7929 *vr0min
= int_const_binop (PLUS_EXPR
, vr1max
, integer_one_node
);
7933 /* Choose the left gap if the right one is empty. */
7936 if (TREE_CODE (vr1min
) == INTEGER_CST
)
7937 *vr0max
= int_const_binop (MINUS_EXPR
, vr1min
,
7942 /* Choose the anti-range if the range is effectively varying. */
7943 else if (vrp_val_is_min (*vr0min
)
7944 && vrp_val_is_max (*vr0max
))
7950 /* Else choose the range. */
7952 else if (*vr0type
== VR_ANTI_RANGE
7953 && vr1type
== VR_ANTI_RANGE
)
7954 /* If both are anti-ranges the result is the outer one. */
7956 else if (*vr0type
== VR_ANTI_RANGE
7957 && vr1type
== VR_RANGE
)
7959 /* The intersection is empty. */
7960 *vr0type
= VR_UNDEFINED
;
7961 *vr0min
= NULL_TREE
;
7962 *vr0max
= NULL_TREE
;
7967 else if ((maxeq
|| operand_less_p (*vr0max
, vr1max
) == 1)
7968 && (mineq
|| operand_less_p (vr1min
, *vr0min
) == 1))
7970 /* ( [ ] ) or ([ ] ) or ( [ ]) */
7971 if (*vr0type
== VR_RANGE
7972 && vr1type
== VR_RANGE
)
7973 /* Choose the inner range. */
7975 else if (*vr0type
== VR_ANTI_RANGE
7976 && vr1type
== VR_RANGE
)
7978 /* Choose the right gap if the left is empty. */
7981 *vr0type
= VR_RANGE
;
7982 if (TREE_CODE (*vr0max
) == INTEGER_CST
)
7983 *vr0min
= int_const_binop (PLUS_EXPR
, *vr0max
,
7989 /* Choose the left gap if the right is empty. */
7992 *vr0type
= VR_RANGE
;
7993 if (TREE_CODE (*vr0min
) == INTEGER_CST
)
7994 *vr0max
= int_const_binop (MINUS_EXPR
, *vr0min
,
8000 /* Choose the anti-range if the range is effectively varying. */
8001 else if (vrp_val_is_min (vr1min
)
8002 && vrp_val_is_max (vr1max
))
8004 /* Else choose the range. */
8012 else if (*vr0type
== VR_ANTI_RANGE
8013 && vr1type
== VR_ANTI_RANGE
)
8015 /* If both are anti-ranges the result is the outer one. */
8020 else if (vr1type
== VR_ANTI_RANGE
8021 && *vr0type
== VR_RANGE
)
8023 /* The intersection is empty. */
8024 *vr0type
= VR_UNDEFINED
;
8025 *vr0min
= NULL_TREE
;
8026 *vr0max
= NULL_TREE
;
8031 else if ((operand_less_p (vr1min
, *vr0max
) == 1
8032 || operand_equal_p (vr1min
, *vr0max
, 0))
8033 && operand_less_p (*vr0min
, vr1min
) == 1)
8035 /* [ ( ] ) or [ ]( ) */
8036 if (*vr0type
== VR_ANTI_RANGE
8037 && vr1type
== VR_ANTI_RANGE
)
8039 else if (*vr0type
== VR_RANGE
8040 && vr1type
== VR_RANGE
)
8042 else if (*vr0type
== VR_RANGE
8043 && vr1type
== VR_ANTI_RANGE
)
8045 if (TREE_CODE (vr1min
) == INTEGER_CST
)
8046 *vr0max
= int_const_binop (MINUS_EXPR
, vr1min
,
8051 else if (*vr0type
== VR_ANTI_RANGE
8052 && vr1type
== VR_RANGE
)
8054 *vr0type
= VR_RANGE
;
8055 if (TREE_CODE (*vr0max
) == INTEGER_CST
)
8056 *vr0min
= int_const_binop (PLUS_EXPR
, *vr0max
,
8065 else if ((operand_less_p (*vr0min
, vr1max
) == 1
8066 || operand_equal_p (*vr0min
, vr1max
, 0))
8067 && operand_less_p (vr1min
, *vr0min
) == 1)
8069 /* ( [ ) ] or ( )[ ] */
8070 if (*vr0type
== VR_ANTI_RANGE
8071 && vr1type
== VR_ANTI_RANGE
)
8073 else if (*vr0type
== VR_RANGE
8074 && vr1type
== VR_RANGE
)
8076 else if (*vr0type
== VR_RANGE
8077 && vr1type
== VR_ANTI_RANGE
)
8079 if (TREE_CODE (vr1max
) == INTEGER_CST
)
8080 *vr0min
= int_const_binop (PLUS_EXPR
, vr1max
,
8085 else if (*vr0type
== VR_ANTI_RANGE
8086 && vr1type
== VR_RANGE
)
8088 *vr0type
= VR_RANGE
;
8089 if (TREE_CODE (*vr0min
) == INTEGER_CST
)
8090 *vr0max
= int_const_binop (MINUS_EXPR
, *vr0min
,
8100 /* As a fallback simply use { *VRTYPE, *VR0MIN, *VR0MAX } as
8101 result for the intersection. That's always a conservative
8102 correct estimate. */
8108 /* Intersect the two value-ranges *VR0 and *VR1 and store the result
8109 in *VR0. This may not be the smallest possible such range. */
8112 vrp_intersect_ranges_1 (value_range_t
*vr0
, value_range_t
*vr1
)
8114 value_range_t saved
;
8116 /* If either range is VR_VARYING the other one wins. */
8117 if (vr1
->type
== VR_VARYING
)
8119 if (vr0
->type
== VR_VARYING
)
8121 copy_value_range (vr0
, vr1
);
8125 /* When either range is VR_UNDEFINED the resulting range is
8126 VR_UNDEFINED, too. */
8127 if (vr0
->type
== VR_UNDEFINED
)
8129 if (vr1
->type
== VR_UNDEFINED
)
8131 set_value_range_to_undefined (vr0
);
8135 /* Save the original vr0 so we can return it as conservative intersection
8136 result when our worker turns things to varying. */
8138 intersect_ranges (&vr0
->type
, &vr0
->min
, &vr0
->max
,
8139 vr1
->type
, vr1
->min
, vr1
->max
);
8140 /* Make sure to canonicalize the result though as the inversion of a
8141 VR_RANGE can still be a VR_RANGE. */
8142 set_and_canonicalize_value_range (vr0
, vr0
->type
,
8143 vr0
->min
, vr0
->max
, vr0
->equiv
);
8144 /* If that failed, use the saved original VR0. */
8145 if (vr0
->type
== VR_VARYING
)
8150 /* If the result is VR_UNDEFINED there is no need to mess with
8151 the equivalencies. */
8152 if (vr0
->type
== VR_UNDEFINED
)
8155 /* The resulting set of equivalences for range intersection is the union of
8157 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
8158 bitmap_ior_into (vr0
->equiv
, vr1
->equiv
);
8159 else if (vr1
->equiv
&& !vr0
->equiv
)
8160 bitmap_copy (vr0
->equiv
, vr1
->equiv
);
8164 vrp_intersect_ranges (value_range_t
*vr0
, value_range_t
*vr1
)
8166 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8168 fprintf (dump_file
, "Intersecting\n ");
8169 dump_value_range (dump_file
, vr0
);
8170 fprintf (dump_file
, "\nand\n ");
8171 dump_value_range (dump_file
, vr1
);
8172 fprintf (dump_file
, "\n");
8174 vrp_intersect_ranges_1 (vr0
, vr1
);
8175 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8177 fprintf (dump_file
, "to\n ");
8178 dump_value_range (dump_file
, vr0
);
8179 fprintf (dump_file
, "\n");
8183 /* Meet operation for value ranges. Given two value ranges VR0 and
8184 VR1, store in VR0 a range that contains both VR0 and VR1. This
8185 may not be the smallest possible such range. */
8188 vrp_meet_1 (value_range_t
*vr0
, value_range_t
*vr1
)
8190 value_range_t saved
;
8192 if (vr0
->type
== VR_UNDEFINED
)
8194 set_value_range (vr0
, vr1
->type
, vr1
->min
, vr1
->max
, vr1
->equiv
);
8198 if (vr1
->type
== VR_UNDEFINED
)
8200 /* VR0 already has the resulting range. */
8204 if (vr0
->type
== VR_VARYING
)
8206 /* Nothing to do. VR0 already has the resulting range. */
8210 if (vr1
->type
== VR_VARYING
)
8212 set_value_range_to_varying (vr0
);
8217 union_ranges (&vr0
->type
, &vr0
->min
, &vr0
->max
,
8218 vr1
->type
, vr1
->min
, vr1
->max
);
8219 if (vr0
->type
== VR_VARYING
)
8221 /* Failed to find an efficient meet. Before giving up and setting
8222 the result to VARYING, see if we can at least derive a useful
8223 anti-range. FIXME, all this nonsense about distinguishing
8224 anti-ranges from ranges is necessary because of the odd
8225 semantics of range_includes_zero_p and friends. */
8226 if (((saved
.type
== VR_RANGE
8227 && range_includes_zero_p (saved
.min
, saved
.max
) == 0)
8228 || (saved
.type
== VR_ANTI_RANGE
8229 && range_includes_zero_p (saved
.min
, saved
.max
) == 1))
8230 && ((vr1
->type
== VR_RANGE
8231 && range_includes_zero_p (vr1
->min
, vr1
->max
) == 0)
8232 || (vr1
->type
== VR_ANTI_RANGE
8233 && range_includes_zero_p (vr1
->min
, vr1
->max
) == 1)))
8235 set_value_range_to_nonnull (vr0
, TREE_TYPE (saved
.min
));
8237 /* Since this meet operation did not result from the meeting of
8238 two equivalent names, VR0 cannot have any equivalences. */
8240 bitmap_clear (vr0
->equiv
);
8244 set_value_range_to_varying (vr0
);
8247 set_and_canonicalize_value_range (vr0
, vr0
->type
, vr0
->min
, vr0
->max
,
8249 if (vr0
->type
== VR_VARYING
)
8252 /* The resulting set of equivalences is always the intersection of
8254 if (vr0
->equiv
&& vr1
->equiv
&& vr0
->equiv
!= vr1
->equiv
)
8255 bitmap_and_into (vr0
->equiv
, vr1
->equiv
);
8256 else if (vr0
->equiv
&& !vr1
->equiv
)
8257 bitmap_clear (vr0
->equiv
);
8261 vrp_meet (value_range_t
*vr0
, value_range_t
*vr1
)
8263 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8265 fprintf (dump_file
, "Meeting\n ");
8266 dump_value_range (dump_file
, vr0
);
8267 fprintf (dump_file
, "\nand\n ");
8268 dump_value_range (dump_file
, vr1
);
8269 fprintf (dump_file
, "\n");
8271 vrp_meet_1 (vr0
, vr1
);
8272 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8274 fprintf (dump_file
, "to\n ");
8275 dump_value_range (dump_file
, vr0
);
8276 fprintf (dump_file
, "\n");
8281 /* Visit all arguments for PHI node PHI that flow through executable
8282 edges. If a valid value range can be derived from all the incoming
8283 value ranges, set a new range for the LHS of PHI. */
8285 static enum ssa_prop_result
8286 vrp_visit_phi_node (gimple phi
)
8289 tree lhs
= PHI_RESULT (phi
);
8290 value_range_t
*lhs_vr
= get_value_range (lhs
);
8291 value_range_t vr_result
= VR_INITIALIZER
;
8293 int edges
, old_edges
;
8296 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8298 fprintf (dump_file
, "\nVisiting PHI node: ");
8299 print_gimple_stmt (dump_file
, phi
, 0, dump_flags
);
8303 for (i
= 0; i
< gimple_phi_num_args (phi
); i
++)
8305 edge e
= gimple_phi_arg_edge (phi
, i
);
8307 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8310 "\n Argument #%d (%d -> %d %sexecutable)\n",
8311 (int) i
, e
->src
->index
, e
->dest
->index
,
8312 (e
->flags
& EDGE_EXECUTABLE
) ? "" : "not ");
8315 if (e
->flags
& EDGE_EXECUTABLE
)
8317 tree arg
= PHI_ARG_DEF (phi
, i
);
8318 value_range_t vr_arg
;
8322 if (TREE_CODE (arg
) == SSA_NAME
)
8324 vr_arg
= *(get_value_range (arg
));
8325 /* Do not allow equivalences or symbolic ranges to leak in from
8326 backedges. That creates invalid equivalencies.
8327 See PR53465 and PR54767. */
8328 if (e
->flags
& EDGE_DFS_BACK
8329 && (vr_arg
.type
== VR_RANGE
8330 || vr_arg
.type
== VR_ANTI_RANGE
))
8332 vr_arg
.equiv
= NULL
;
8333 if (symbolic_range_p (&vr_arg
))
8335 vr_arg
.type
= VR_VARYING
;
8336 vr_arg
.min
= NULL_TREE
;
8337 vr_arg
.max
= NULL_TREE
;
8343 if (TREE_OVERFLOW_P (arg
))
8344 arg
= drop_tree_overflow (arg
);
8346 vr_arg
.type
= VR_RANGE
;
8349 vr_arg
.equiv
= NULL
;
8352 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8354 fprintf (dump_file
, "\t");
8355 print_generic_expr (dump_file
, arg
, dump_flags
);
8356 fprintf (dump_file
, "\n\tValue: ");
8357 dump_value_range (dump_file
, &vr_arg
);
8358 fprintf (dump_file
, "\n");
8362 copy_value_range (&vr_result
, &vr_arg
);
8364 vrp_meet (&vr_result
, &vr_arg
);
8367 if (vr_result
.type
== VR_VARYING
)
8372 if (vr_result
.type
== VR_VARYING
)
8374 else if (vr_result
.type
== VR_UNDEFINED
)
8377 old_edges
= vr_phi_edge_counts
[SSA_NAME_VERSION (lhs
)];
8378 vr_phi_edge_counts
[SSA_NAME_VERSION (lhs
)] = edges
;
8380 /* To prevent infinite iterations in the algorithm, derive ranges
8381 when the new value is slightly bigger or smaller than the
8382 previous one. We don't do this if we have seen a new executable
8383 edge; this helps us avoid an overflow infinity for conditionals
8384 which are not in a loop. If the old value-range was VR_UNDEFINED
8385 use the updated range and iterate one more time. */
8387 && gimple_phi_num_args (phi
) > 1
8388 && edges
== old_edges
8389 && lhs_vr
->type
!= VR_UNDEFINED
)
8391 int cmp_min
= compare_values (lhs_vr
->min
, vr_result
.min
);
8392 int cmp_max
= compare_values (lhs_vr
->max
, vr_result
.max
);
8394 /* For non VR_RANGE or for pointers fall back to varying if
8395 the range changed. */
8396 if ((lhs_vr
->type
!= VR_RANGE
|| vr_result
.type
!= VR_RANGE
8397 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
8398 && (cmp_min
!= 0 || cmp_max
!= 0))
8401 /* If the new minimum is smaller or larger than the previous
8402 one, go all the way to -INF. In the first case, to avoid
8403 iterating millions of times to reach -INF, and in the
8404 other case to avoid infinite bouncing between different
8406 if (cmp_min
> 0 || cmp_min
< 0)
8408 if (!needs_overflow_infinity (TREE_TYPE (vr_result
.min
))
8409 || !vrp_var_may_overflow (lhs
, phi
))
8410 vr_result
.min
= TYPE_MIN_VALUE (TREE_TYPE (vr_result
.min
));
8411 else if (supports_overflow_infinity (TREE_TYPE (vr_result
.min
)))
8413 negative_overflow_infinity (TREE_TYPE (vr_result
.min
));
8416 /* Similarly, if the new maximum is smaller or larger than
8417 the previous one, go all the way to +INF. */
8418 if (cmp_max
< 0 || cmp_max
> 0)
8420 if (!needs_overflow_infinity (TREE_TYPE (vr_result
.max
))
8421 || !vrp_var_may_overflow (lhs
, phi
))
8422 vr_result
.max
= TYPE_MAX_VALUE (TREE_TYPE (vr_result
.max
));
8423 else if (supports_overflow_infinity (TREE_TYPE (vr_result
.max
)))
8425 positive_overflow_infinity (TREE_TYPE (vr_result
.max
));
8428 /* If we dropped either bound to +-INF then if this is a loop
8429 PHI node SCEV may known more about its value-range. */
8430 if ((cmp_min
> 0 || cmp_min
< 0
8431 || cmp_max
< 0 || cmp_max
> 0)
8433 && (l
= loop_containing_stmt (phi
))
8434 && l
->header
== gimple_bb (phi
))
8435 adjust_range_with_scev (&vr_result
, l
, phi
, lhs
);
8437 /* If we will end up with a (-INF, +INF) range, set it to
8438 VARYING. Same if the previous max value was invalid for
8439 the type and we end up with vr_result.min > vr_result.max. */
8440 if ((vrp_val_is_max (vr_result
.max
)
8441 && vrp_val_is_min (vr_result
.min
))
8442 || compare_values (vr_result
.min
,
8447 /* If the new range is different than the previous value, keep
8450 if (update_value_range (lhs
, &vr_result
))
8452 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
8454 fprintf (dump_file
, "Found new range for ");
8455 print_generic_expr (dump_file
, lhs
, 0);
8456 fprintf (dump_file
, ": ");
8457 dump_value_range (dump_file
, &vr_result
);
8458 fprintf (dump_file
, "\n\n");
8461 return SSA_PROP_INTERESTING
;
8464 /* Nothing changed, don't add outgoing edges. */
8465 return SSA_PROP_NOT_INTERESTING
;
8467 /* No match found. Set the LHS to VARYING. */
8469 set_value_range_to_varying (lhs_vr
);
8470 return SSA_PROP_VARYING
;
8473 /* Simplify boolean operations if the source is known
8474 to be already a boolean. */
8476 simplify_truth_ops_using_ranges (gimple_stmt_iterator
*gsi
, gimple stmt
)
8478 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
8480 bool need_conversion
;
8482 /* We handle only !=/== case here. */
8483 gcc_assert (rhs_code
== EQ_EXPR
|| rhs_code
== NE_EXPR
);
8485 op0
= gimple_assign_rhs1 (stmt
);
8486 if (!op_with_boolean_value_range_p (op0
))
8489 op1
= gimple_assign_rhs2 (stmt
);
8490 if (!op_with_boolean_value_range_p (op1
))
8493 /* Reduce number of cases to handle to NE_EXPR. As there is no
8494 BIT_XNOR_EXPR we cannot replace A == B with a single statement. */
8495 if (rhs_code
== EQ_EXPR
)
8497 if (TREE_CODE (op1
) == INTEGER_CST
)
8498 op1
= int_const_binop (BIT_XOR_EXPR
, op1
, integer_one_node
);
8503 lhs
= gimple_assign_lhs (stmt
);
8505 = !useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (op0
));
8507 /* Make sure to not sign-extend a 1-bit 1 when converting the result. */
8509 && !TYPE_UNSIGNED (TREE_TYPE (op0
))
8510 && TYPE_PRECISION (TREE_TYPE (op0
)) == 1
8511 && TYPE_PRECISION (TREE_TYPE (lhs
)) > 1)
8514 /* For A != 0 we can substitute A itself. */
8515 if (integer_zerop (op1
))
8516 gimple_assign_set_rhs_with_ops (gsi
,
8518 ? NOP_EXPR
: TREE_CODE (op0
),
8520 /* For A != B we substitute A ^ B. Either with conversion. */
8521 else if (need_conversion
)
8523 tree tem
= make_ssa_name (TREE_TYPE (op0
), NULL
);
8524 gimple newop
= gimple_build_assign_with_ops (BIT_XOR_EXPR
, tem
, op0
, op1
);
8525 gsi_insert_before (gsi
, newop
, GSI_SAME_STMT
);
8526 gimple_assign_set_rhs_with_ops (gsi
, NOP_EXPR
, tem
, NULL_TREE
);
8530 gimple_assign_set_rhs_with_ops (gsi
, BIT_XOR_EXPR
, op0
, op1
);
8531 update_stmt (gsi_stmt (*gsi
));
8536 /* Simplify a division or modulo operator to a right shift or
8537 bitwise and if the first operand is unsigned or is greater
8538 than zero and the second operand is an exact power of two. */
8541 simplify_div_or_mod_using_ranges (gimple stmt
)
8543 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
8545 tree op0
= gimple_assign_rhs1 (stmt
);
8546 tree op1
= gimple_assign_rhs2 (stmt
);
8547 value_range_t
*vr
= get_value_range (gimple_assign_rhs1 (stmt
));
8549 if (TYPE_UNSIGNED (TREE_TYPE (op0
)))
8551 val
= integer_one_node
;
8557 val
= compare_range_with_value (GE_EXPR
, vr
, integer_zero_node
, &sop
);
8561 && integer_onep (val
)
8562 && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
8564 location_t location
;
8566 if (!gimple_has_location (stmt
))
8567 location
= input_location
;
8569 location
= gimple_location (stmt
);
8570 warning_at (location
, OPT_Wstrict_overflow
,
8571 "assuming signed overflow does not occur when "
8572 "simplifying %</%> or %<%%%> to %<>>%> or %<&%>");
8576 if (val
&& integer_onep (val
))
8580 if (rhs_code
== TRUNC_DIV_EXPR
)
8582 t
= build_int_cst (integer_type_node
, tree_log2 (op1
));
8583 gimple_assign_set_rhs_code (stmt
, RSHIFT_EXPR
);
8584 gimple_assign_set_rhs1 (stmt
, op0
);
8585 gimple_assign_set_rhs2 (stmt
, t
);
8589 t
= build_int_cst (TREE_TYPE (op1
), 1);
8590 t
= int_const_binop (MINUS_EXPR
, op1
, t
);
8591 t
= fold_convert (TREE_TYPE (op0
), t
);
8593 gimple_assign_set_rhs_code (stmt
, BIT_AND_EXPR
);
8594 gimple_assign_set_rhs1 (stmt
, op0
);
8595 gimple_assign_set_rhs2 (stmt
, t
);
8605 /* If the operand to an ABS_EXPR is >= 0, then eliminate the
8606 ABS_EXPR. If the operand is <= 0, then simplify the
8607 ABS_EXPR into a NEGATE_EXPR. */
8610 simplify_abs_using_ranges (gimple stmt
)
8613 tree op
= gimple_assign_rhs1 (stmt
);
8614 tree type
= TREE_TYPE (op
);
8615 value_range_t
*vr
= get_value_range (op
);
8617 if (TYPE_UNSIGNED (type
))
8619 val
= integer_zero_node
;
8625 val
= compare_range_with_value (LE_EXPR
, vr
, integer_zero_node
, &sop
);
8629 val
= compare_range_with_value (GE_EXPR
, vr
, integer_zero_node
,
8634 if (integer_zerop (val
))
8635 val
= integer_one_node
;
8636 else if (integer_onep (val
))
8637 val
= integer_zero_node
;
8642 && (integer_onep (val
) || integer_zerop (val
)))
8644 if (sop
&& issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC
))
8646 location_t location
;
8648 if (!gimple_has_location (stmt
))
8649 location
= input_location
;
8651 location
= gimple_location (stmt
);
8652 warning_at (location
, OPT_Wstrict_overflow
,
8653 "assuming signed overflow does not occur when "
8654 "simplifying %<abs (X)%> to %<X%> or %<-X%>");
8657 gimple_assign_set_rhs1 (stmt
, op
);
8658 if (integer_onep (val
))
8659 gimple_assign_set_rhs_code (stmt
, NEGATE_EXPR
);
8661 gimple_assign_set_rhs_code (stmt
, SSA_NAME
);
8670 /* Optimize away redundant BIT_AND_EXPR and BIT_IOR_EXPR.
8671 If all the bits that are being cleared by & are already
8672 known to be zero from VR, or all the bits that are being
8673 set by | are already known to be one from VR, the bit
8674 operation is redundant. */
8677 simplify_bit_ops_using_ranges (gimple_stmt_iterator
*gsi
, gimple stmt
)
8679 tree op0
= gimple_assign_rhs1 (stmt
);
8680 tree op1
= gimple_assign_rhs2 (stmt
);
8681 tree op
= NULL_TREE
;
8682 value_range_t vr0
= VR_INITIALIZER
;
8683 value_range_t vr1
= VR_INITIALIZER
;
8684 double_int may_be_nonzero0
, may_be_nonzero1
;
8685 double_int must_be_nonzero0
, must_be_nonzero1
;
8688 if (TREE_CODE (op0
) == SSA_NAME
)
8689 vr0
= *(get_value_range (op0
));
8690 else if (is_gimple_min_invariant (op0
))
8691 set_value_range_to_value (&vr0
, op0
, NULL
);
8695 if (TREE_CODE (op1
) == SSA_NAME
)
8696 vr1
= *(get_value_range (op1
));
8697 else if (is_gimple_min_invariant (op1
))
8698 set_value_range_to_value (&vr1
, op1
, NULL
);
8702 if (!zero_nonzero_bits_from_vr (&vr0
, &may_be_nonzero0
, &must_be_nonzero0
))
8704 if (!zero_nonzero_bits_from_vr (&vr1
, &may_be_nonzero1
, &must_be_nonzero1
))
8707 switch (gimple_assign_rhs_code (stmt
))
8710 mask
= may_be_nonzero0
.and_not (must_be_nonzero1
);
8711 if (mask
.is_zero ())
8716 mask
= may_be_nonzero1
.and_not (must_be_nonzero0
);
8717 if (mask
.is_zero ())
8724 mask
= may_be_nonzero0
.and_not (must_be_nonzero1
);
8725 if (mask
.is_zero ())
8730 mask
= may_be_nonzero1
.and_not (must_be_nonzero0
);
8731 if (mask
.is_zero ())
8741 if (op
== NULL_TREE
)
8744 gimple_assign_set_rhs_with_ops (gsi
, TREE_CODE (op
), op
, NULL
);
8745 update_stmt (gsi_stmt (*gsi
));
8749 /* We are comparing trees OP0 and OP1 using COND_CODE. OP0 has
8750 a known value range VR.
8752 If there is one and only one value which will satisfy the
8753 conditional, then return that value. Else return NULL. */
8756 test_for_singularity (enum tree_code cond_code
, tree op0
,
8757 tree op1
, value_range_t
*vr
)
8762 /* Extract minimum/maximum values which satisfy the
8763 the conditional as it was written. */
8764 if (cond_code
== LE_EXPR
|| cond_code
== LT_EXPR
)
8766 /* This should not be negative infinity; there is no overflow
8768 min
= TYPE_MIN_VALUE (TREE_TYPE (op0
));
8771 if (cond_code
== LT_EXPR
&& !is_overflow_infinity (max
))
8773 tree one
= build_int_cst (TREE_TYPE (op0
), 1);
8774 max
= fold_build2 (MINUS_EXPR
, TREE_TYPE (op0
), max
, one
);
8776 TREE_NO_WARNING (max
) = 1;
8779 else if (cond_code
== GE_EXPR
|| cond_code
== GT_EXPR
)
8781 /* This should not be positive infinity; there is no overflow
8783 max
= TYPE_MAX_VALUE (TREE_TYPE (op0
));
8786 if (cond_code
== GT_EXPR
&& !is_overflow_infinity (min
))
8788 tree one
= build_int_cst (TREE_TYPE (op0
), 1);
8789 min
= fold_build2 (PLUS_EXPR
, TREE_TYPE (op0
), min
, one
);
8791 TREE_NO_WARNING (min
) = 1;
8795 /* Now refine the minimum and maximum values using any
8796 value range information we have for op0. */
8799 if (compare_values (vr
->min
, min
) == 1)
8801 if (compare_values (vr
->max
, max
) == -1)
8804 /* If the new min/max values have converged to a single value,
8805 then there is only one value which can satisfy the condition,
8806 return that value. */
8807 if (operand_equal_p (min
, max
, 0) && is_gimple_min_invariant (min
))
8813 /* Return whether the value range *VR fits in an integer type specified
8814 by PRECISION and UNSIGNED_P. */
8817 range_fits_type_p (value_range_t
*vr
, unsigned precision
, bool unsigned_p
)
8820 unsigned src_precision
;
8823 /* We can only handle integral and pointer types. */
8824 src_type
= TREE_TYPE (vr
->min
);
8825 if (!INTEGRAL_TYPE_P (src_type
)
8826 && !POINTER_TYPE_P (src_type
))
8829 /* An extension is fine unless VR is signed and unsigned_p,
8830 and so is an identity transform. */
8831 src_precision
= TYPE_PRECISION (TREE_TYPE (vr
->min
));
8832 if ((src_precision
< precision
8833 && !(unsigned_p
&& !TYPE_UNSIGNED (src_type
)))
8834 || (src_precision
== precision
8835 && TYPE_UNSIGNED (src_type
) == unsigned_p
))
8838 /* Now we can only handle ranges with constant bounds. */
8839 if (vr
->type
!= VR_RANGE
8840 || TREE_CODE (vr
->min
) != INTEGER_CST
8841 || TREE_CODE (vr
->max
) != INTEGER_CST
)
8844 /* For sign changes, the MSB of the double_int has to be clear.
8845 An unsigned value with its MSB set cannot be represented by
8846 a signed double_int, while a negative value cannot be represented
8847 by an unsigned double_int. */
8848 if (TYPE_UNSIGNED (src_type
) != unsigned_p
8849 && (TREE_INT_CST_HIGH (vr
->min
) | TREE_INT_CST_HIGH (vr
->max
)) < 0)
8852 /* Then we can perform the conversion on both ends and compare
8853 the result for equality. */
8854 tem
= tree_to_double_int (vr
->min
).ext (precision
, unsigned_p
);
8855 if (tree_to_double_int (vr
->min
) != tem
)
8857 tem
= tree_to_double_int (vr
->max
).ext (precision
, unsigned_p
);
8858 if (tree_to_double_int (vr
->max
) != tem
)
8864 /* Simplify a conditional using a relational operator to an equality
8865 test if the range information indicates only one value can satisfy
8866 the original conditional. */
8869 simplify_cond_using_ranges (gimple stmt
)
8871 tree op0
= gimple_cond_lhs (stmt
);
8872 tree op1
= gimple_cond_rhs (stmt
);
8873 enum tree_code cond_code
= gimple_cond_code (stmt
);
8875 if (cond_code
!= NE_EXPR
8876 && cond_code
!= EQ_EXPR
8877 && TREE_CODE (op0
) == SSA_NAME
8878 && INTEGRAL_TYPE_P (TREE_TYPE (op0
))
8879 && is_gimple_min_invariant (op1
))
8881 value_range_t
*vr
= get_value_range (op0
);
8883 /* If we have range information for OP0, then we might be
8884 able to simplify this conditional. */
8885 if (vr
->type
== VR_RANGE
)
8887 tree new_tree
= test_for_singularity (cond_code
, op0
, op1
, vr
);
8893 fprintf (dump_file
, "Simplified relational ");
8894 print_gimple_stmt (dump_file
, stmt
, 0, 0);
8895 fprintf (dump_file
, " into ");
8898 gimple_cond_set_code (stmt
, EQ_EXPR
);
8899 gimple_cond_set_lhs (stmt
, op0
);
8900 gimple_cond_set_rhs (stmt
, new_tree
);
8906 print_gimple_stmt (dump_file
, stmt
, 0, 0);
8907 fprintf (dump_file
, "\n");
8913 /* Try again after inverting the condition. We only deal
8914 with integral types here, so no need to worry about
8915 issues with inverting FP comparisons. */
8916 cond_code
= invert_tree_comparison (cond_code
, false);
8917 new_tree
= test_for_singularity (cond_code
, op0
, op1
, vr
);
8923 fprintf (dump_file
, "Simplified relational ");
8924 print_gimple_stmt (dump_file
, stmt
, 0, 0);
8925 fprintf (dump_file
, " into ");
8928 gimple_cond_set_code (stmt
, NE_EXPR
);
8929 gimple_cond_set_lhs (stmt
, op0
);
8930 gimple_cond_set_rhs (stmt
, new_tree
);
8936 print_gimple_stmt (dump_file
, stmt
, 0, 0);
8937 fprintf (dump_file
, "\n");
8945 /* If we have a comparison of an SSA_NAME (OP0) against a constant,
8946 see if OP0 was set by a type conversion where the source of
8947 the conversion is another SSA_NAME with a range that fits
8948 into the range of OP0's type.
8950 If so, the conversion is redundant as the earlier SSA_NAME can be
8951 used for the comparison directly if we just massage the constant in the
8953 if (TREE_CODE (op0
) == SSA_NAME
8954 && TREE_CODE (op1
) == INTEGER_CST
)
8956 gimple def_stmt
= SSA_NAME_DEF_STMT (op0
);
8959 if (!is_gimple_assign (def_stmt
)
8960 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
)))
8963 innerop
= gimple_assign_rhs1 (def_stmt
);
8965 if (TREE_CODE (innerop
) == SSA_NAME
8966 && !POINTER_TYPE_P (TREE_TYPE (innerop
)))
8968 value_range_t
*vr
= get_value_range (innerop
);
8970 if (range_int_cst_p (vr
)
8971 && range_fits_type_p (vr
,
8972 TYPE_PRECISION (TREE_TYPE (op0
)),
8973 TYPE_UNSIGNED (TREE_TYPE (op0
)))
8974 && int_fits_type_p (op1
, TREE_TYPE (innerop
))
8975 /* The range must not have overflowed, or if it did overflow
8976 we must not be wrapping/trapping overflow and optimizing
8977 with strict overflow semantics. */
8978 && ((!is_negative_overflow_infinity (vr
->min
)
8979 && !is_positive_overflow_infinity (vr
->max
))
8980 || TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (innerop
))))
8982 /* If the range overflowed and the user has asked for warnings
8983 when strict overflow semantics were used to optimize code,
8984 issue an appropriate warning. */
8985 if ((is_negative_overflow_infinity (vr
->min
)
8986 || is_positive_overflow_infinity (vr
->max
))
8987 && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_CONDITIONAL
))
8989 location_t location
;
8991 if (!gimple_has_location (stmt
))
8992 location
= input_location
;
8994 location
= gimple_location (stmt
);
8995 warning_at (location
, OPT_Wstrict_overflow
,
8996 "assuming signed overflow does not occur when "
8997 "simplifying conditional");
9000 tree newconst
= fold_convert (TREE_TYPE (innerop
), op1
);
9001 gimple_cond_set_lhs (stmt
, innerop
);
9002 gimple_cond_set_rhs (stmt
, newconst
);
9011 /* Simplify a switch statement using the value range of the switch
9015 simplify_switch_using_ranges (gimple stmt
)
9017 tree op
= gimple_switch_index (stmt
);
9022 size_t i
= 0, j
= 0, n
, n2
;
9025 size_t k
= 1, l
= 0;
9027 if (TREE_CODE (op
) == SSA_NAME
)
9029 vr
= get_value_range (op
);
9031 /* We can only handle integer ranges. */
9032 if ((vr
->type
!= VR_RANGE
9033 && vr
->type
!= VR_ANTI_RANGE
)
9034 || symbolic_range_p (vr
))
9037 /* Find case label for min/max of the value range. */
9038 take_default
= !find_case_label_ranges (stmt
, vr
, &i
, &j
, &k
, &l
);
9040 else if (TREE_CODE (op
) == INTEGER_CST
)
9042 take_default
= !find_case_label_index (stmt
, 1, op
, &i
);
9056 n
= gimple_switch_num_labels (stmt
);
9058 /* Bail out if this is just all edges taken. */
9064 /* Build a new vector of taken case labels. */
9065 vec2
= make_tree_vec (j
- i
+ 1 + l
- k
+ 1 + (int)take_default
);
9068 /* Add the default edge, if necessary. */
9070 TREE_VEC_ELT (vec2
, n2
++) = gimple_switch_default_label (stmt
);
9072 for (; i
<= j
; ++i
, ++n2
)
9073 TREE_VEC_ELT (vec2
, n2
) = gimple_switch_label (stmt
, i
);
9075 for (; k
<= l
; ++k
, ++n2
)
9076 TREE_VEC_ELT (vec2
, n2
) = gimple_switch_label (stmt
, k
);
9078 /* Mark needed edges. */
9079 for (i
= 0; i
< n2
; ++i
)
9081 e
= find_edge (gimple_bb (stmt
),
9082 label_to_block (CASE_LABEL (TREE_VEC_ELT (vec2
, i
))));
9083 e
->aux
= (void *)-1;
9086 /* Queue not needed edges for later removal. */
9087 FOR_EACH_EDGE (e
, ei
, gimple_bb (stmt
)->succs
)
9089 if (e
->aux
== (void *)-1)
9095 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
9097 fprintf (dump_file
, "removing unreachable case label\n");
9099 to_remove_edges
.safe_push (e
);
9100 e
->flags
&= ~EDGE_EXECUTABLE
;
9103 /* And queue an update for the stmt. */
9106 to_update_switch_stmts
.safe_push (su
);
9110 /* Simplify an integral conversion from an SSA name in STMT. */
9113 simplify_conversion_using_ranges (gimple stmt
)
9115 tree innerop
, middleop
, finaltype
;
9117 value_range_t
*innervr
;
9118 bool inner_unsigned_p
, middle_unsigned_p
, final_unsigned_p
;
9119 unsigned inner_prec
, middle_prec
, final_prec
;
9120 double_int innermin
, innermed
, innermax
, middlemin
, middlemed
, middlemax
;
9122 finaltype
= TREE_TYPE (gimple_assign_lhs (stmt
));
9123 if (!INTEGRAL_TYPE_P (finaltype
))
9125 middleop
= gimple_assign_rhs1 (stmt
);
9126 def_stmt
= SSA_NAME_DEF_STMT (middleop
);
9127 if (!is_gimple_assign (def_stmt
)
9128 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
)))
9130 innerop
= gimple_assign_rhs1 (def_stmt
);
9131 if (TREE_CODE (innerop
) != SSA_NAME
9132 || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (innerop
))
9135 /* Get the value-range of the inner operand. */
9136 innervr
= get_value_range (innerop
);
9137 if (innervr
->type
!= VR_RANGE
9138 || TREE_CODE (innervr
->min
) != INTEGER_CST
9139 || TREE_CODE (innervr
->max
) != INTEGER_CST
)
9142 /* Simulate the conversion chain to check if the result is equal if
9143 the middle conversion is removed. */
9144 innermin
= tree_to_double_int (innervr
->min
);
9145 innermax
= tree_to_double_int (innervr
->max
);
9147 inner_prec
= TYPE_PRECISION (TREE_TYPE (innerop
));
9148 middle_prec
= TYPE_PRECISION (TREE_TYPE (middleop
));
9149 final_prec
= TYPE_PRECISION (finaltype
);
9151 /* If the first conversion is not injective, the second must not
9153 if ((innermax
- innermin
).ugt (double_int::mask (middle_prec
))
9154 && middle_prec
< final_prec
)
9156 /* We also want a medium value so that we can track the effect that
9157 narrowing conversions with sign change have. */
9158 inner_unsigned_p
= TYPE_UNSIGNED (TREE_TYPE (innerop
));
9159 if (inner_unsigned_p
)
9160 innermed
= double_int::mask (inner_prec
).lrshift (1, inner_prec
);
9162 innermed
= double_int_zero
;
9163 if (innermin
.cmp (innermed
, inner_unsigned_p
) >= 0
9164 || innermed
.cmp (innermax
, inner_unsigned_p
) >= 0)
9165 innermed
= innermin
;
9167 middle_unsigned_p
= TYPE_UNSIGNED (TREE_TYPE (middleop
));
9168 middlemin
= innermin
.ext (middle_prec
, middle_unsigned_p
);
9169 middlemed
= innermed
.ext (middle_prec
, middle_unsigned_p
);
9170 middlemax
= innermax
.ext (middle_prec
, middle_unsigned_p
);
9172 /* Require that the final conversion applied to both the original
9173 and the intermediate range produces the same result. */
9174 final_unsigned_p
= TYPE_UNSIGNED (finaltype
);
9175 if (middlemin
.ext (final_prec
, final_unsigned_p
)
9176 != innermin
.ext (final_prec
, final_unsigned_p
)
9177 || middlemed
.ext (final_prec
, final_unsigned_p
)
9178 != innermed
.ext (final_prec
, final_unsigned_p
)
9179 || middlemax
.ext (final_prec
, final_unsigned_p
)
9180 != innermax
.ext (final_prec
, final_unsigned_p
))
9183 gimple_assign_set_rhs1 (stmt
, innerop
);
9188 /* Simplify a conversion from integral SSA name to float in STMT. */
9191 simplify_float_conversion_using_ranges (gimple_stmt_iterator
*gsi
, gimple stmt
)
9193 tree rhs1
= gimple_assign_rhs1 (stmt
);
9194 value_range_t
*vr
= get_value_range (rhs1
);
9195 enum machine_mode fltmode
= TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt
)));
9196 enum machine_mode mode
;
9200 /* We can only handle constant ranges. */
9201 if (vr
->type
!= VR_RANGE
9202 || TREE_CODE (vr
->min
) != INTEGER_CST
9203 || TREE_CODE (vr
->max
) != INTEGER_CST
)
9206 /* First check if we can use a signed type in place of an unsigned. */
9207 if (TYPE_UNSIGNED (TREE_TYPE (rhs1
))
9208 && (can_float_p (fltmode
, TYPE_MODE (TREE_TYPE (rhs1
)), 0)
9209 != CODE_FOR_nothing
)
9210 && range_fits_type_p (vr
, GET_MODE_PRECISION
9211 (TYPE_MODE (TREE_TYPE (rhs1
))), 0))
9212 mode
= TYPE_MODE (TREE_TYPE (rhs1
));
9213 /* If we can do the conversion in the current input mode do nothing. */
9214 else if (can_float_p (fltmode
, TYPE_MODE (TREE_TYPE (rhs1
)),
9215 TYPE_UNSIGNED (TREE_TYPE (rhs1
))) != CODE_FOR_nothing
)
9217 /* Otherwise search for a mode we can use, starting from the narrowest
9218 integer mode available. */
9221 mode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
9224 /* If we cannot do a signed conversion to float from mode
9225 or if the value-range does not fit in the signed type
9226 try with a wider mode. */
9227 if (can_float_p (fltmode
, mode
, 0) != CODE_FOR_nothing
9228 && range_fits_type_p (vr
, GET_MODE_PRECISION (mode
), 0))
9231 mode
= GET_MODE_WIDER_MODE (mode
);
9232 /* But do not widen the input. Instead leave that to the
9233 optabs expansion code. */
9234 if (GET_MODE_PRECISION (mode
) > TYPE_PRECISION (TREE_TYPE (rhs1
)))
9237 while (mode
!= VOIDmode
);
9238 if (mode
== VOIDmode
)
9242 /* It works, insert a truncation or sign-change before the
9243 float conversion. */
9244 tem
= make_ssa_name (build_nonstandard_integer_type
9245 (GET_MODE_PRECISION (mode
), 0), NULL
);
9246 conv
= gimple_build_assign_with_ops (NOP_EXPR
, tem
, rhs1
, NULL_TREE
);
9247 gsi_insert_before (gsi
, conv
, GSI_SAME_STMT
);
9248 gimple_assign_set_rhs1 (stmt
, tem
);
9254 /* Simplify STMT using ranges if possible. */
9257 simplify_stmt_using_ranges (gimple_stmt_iterator
*gsi
)
9259 gimple stmt
= gsi_stmt (*gsi
);
9260 if (is_gimple_assign (stmt
))
9262 enum tree_code rhs_code
= gimple_assign_rhs_code (stmt
);
9263 tree rhs1
= gimple_assign_rhs1 (stmt
);
9269 /* Transform EQ_EXPR, NE_EXPR into BIT_XOR_EXPR or identity
9270 if the RHS is zero or one, and the LHS are known to be boolean
9272 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
9273 return simplify_truth_ops_using_ranges (gsi
, stmt
);
9276 /* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
9277 and BIT_AND_EXPR respectively if the first operand is greater
9278 than zero and the second operand is an exact power of two. */
9279 case TRUNC_DIV_EXPR
:
9280 case TRUNC_MOD_EXPR
:
9281 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
9282 && integer_pow2p (gimple_assign_rhs2 (stmt
)))
9283 return simplify_div_or_mod_using_ranges (stmt
);
9286 /* Transform ABS (X) into X or -X as appropriate. */
9288 if (TREE_CODE (rhs1
) == SSA_NAME
9289 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
9290 return simplify_abs_using_ranges (stmt
);
9295 /* Optimize away BIT_AND_EXPR and BIT_IOR_EXPR
9296 if all the bits being cleared are already cleared or
9297 all the bits being set are already set. */
9298 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
9299 return simplify_bit_ops_using_ranges (gsi
, stmt
);
9303 if (TREE_CODE (rhs1
) == SSA_NAME
9304 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
9305 return simplify_conversion_using_ranges (stmt
);
9309 if (TREE_CODE (rhs1
) == SSA_NAME
9310 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1
)))
9311 return simplify_float_conversion_using_ranges (gsi
, stmt
);
9318 else if (gimple_code (stmt
) == GIMPLE_COND
)
9319 return simplify_cond_using_ranges (stmt
);
9320 else if (gimple_code (stmt
) == GIMPLE_SWITCH
)
9321 return simplify_switch_using_ranges (stmt
);
9326 /* If the statement pointed by SI has a predicate whose value can be
9327 computed using the value range information computed by VRP, compute
9328 its value and return true. Otherwise, return false. */
9331 fold_predicate_in (gimple_stmt_iterator
*si
)
9333 bool assignment_p
= false;
9335 gimple stmt
= gsi_stmt (*si
);
9337 if (is_gimple_assign (stmt
)
9338 && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt
)) == tcc_comparison
)
9340 assignment_p
= true;
9341 val
= vrp_evaluate_conditional (gimple_assign_rhs_code (stmt
),
9342 gimple_assign_rhs1 (stmt
),
9343 gimple_assign_rhs2 (stmt
),
9346 else if (gimple_code (stmt
) == GIMPLE_COND
)
9347 val
= vrp_evaluate_conditional (gimple_cond_code (stmt
),
9348 gimple_cond_lhs (stmt
),
9349 gimple_cond_rhs (stmt
),
9357 val
= fold_convert (gimple_expr_type (stmt
), val
);
9361 fprintf (dump_file
, "Folding predicate ");
9362 print_gimple_expr (dump_file
, stmt
, 0, 0);
9363 fprintf (dump_file
, " to ");
9364 print_generic_expr (dump_file
, val
, 0);
9365 fprintf (dump_file
, "\n");
9368 if (is_gimple_assign (stmt
))
9369 gimple_assign_set_rhs_from_tree (si
, val
);
9372 gcc_assert (gimple_code (stmt
) == GIMPLE_COND
);
9373 if (integer_zerop (val
))
9374 gimple_cond_make_false (stmt
);
9375 else if (integer_onep (val
))
9376 gimple_cond_make_true (stmt
);
9387 /* Callback for substitute_and_fold folding the stmt at *SI. */
9390 vrp_fold_stmt (gimple_stmt_iterator
*si
)
9392 if (fold_predicate_in (si
))
9395 return simplify_stmt_using_ranges (si
);
9398 /* Stack of dest,src equivalency pairs that need to be restored after
9399 each attempt to thread a block's incoming edge to an outgoing edge.
9401 A NULL entry is used to mark the end of pairs which need to be
9403 static vec
<tree
> equiv_stack
;
9405 /* A trivial wrapper so that we can present the generic jump threading
9406 code with a simple API for simplifying statements. STMT is the
9407 statement we want to simplify, WITHIN_STMT provides the location
9408 for any overflow warnings. */
9411 simplify_stmt_for_jump_threading (gimple stmt
, gimple within_stmt
)
9413 if (gimple_code (stmt
) == GIMPLE_COND
)
9414 return vrp_evaluate_conditional (gimple_cond_code (stmt
),
9415 gimple_cond_lhs (stmt
),
9416 gimple_cond_rhs (stmt
), within_stmt
);
9418 if (gimple_code (stmt
) == GIMPLE_ASSIGN
)
9420 value_range_t new_vr
= VR_INITIALIZER
;
9421 tree lhs
= gimple_assign_lhs (stmt
);
9423 if (TREE_CODE (lhs
) == SSA_NAME
9424 && (INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
9425 || POINTER_TYPE_P (TREE_TYPE (lhs
))))
9427 extract_range_from_assignment (&new_vr
, stmt
);
9428 if (range_int_cst_singleton_p (&new_vr
))
9436 /* Blocks which have more than one predecessor and more than
9437 one successor present jump threading opportunities, i.e.,
9438 when the block is reached from a specific predecessor, we
9439 may be able to determine which of the outgoing edges will
9440 be traversed. When this optimization applies, we are able
9441 to avoid conditionals at runtime and we may expose secondary
9442 optimization opportunities.
9444 This routine is effectively a driver for the generic jump
9445 threading code. It basically just presents the generic code
9446 with edges that may be suitable for jump threading.
9448 Unlike DOM, we do not iterate VRP if jump threading was successful.
9449 While iterating may expose new opportunities for VRP, it is expected
9450 those opportunities would be very limited and the compile time cost
9451 to expose those opportunities would be significant.
9453 As jump threading opportunities are discovered, they are registered
9454 for later realization. */
9457 identify_jump_threads (void)
9464 /* Ugh. When substituting values earlier in this pass we can
9465 wipe the dominance information. So rebuild the dominator
9466 information as we need it within the jump threading code. */
9467 calculate_dominance_info (CDI_DOMINATORS
);
9469 /* We do not allow VRP information to be used for jump threading
9470 across a back edge in the CFG. Otherwise it becomes too
9471 difficult to avoid eliminating loop exit tests. Of course
9472 EDGE_DFS_BACK is not accurate at this time so we have to
9474 mark_dfs_back_edges ();
9476 /* Do not thread across edges we are about to remove. Just marking
9477 them as EDGE_DFS_BACK will do. */
9478 FOR_EACH_VEC_ELT (to_remove_edges
, i
, e
)
9479 e
->flags
|= EDGE_DFS_BACK
;
9481 /* Allocate our unwinder stack to unwind any temporary equivalences
9482 that might be recorded. */
9483 equiv_stack
.create (20);
9485 /* To avoid lots of silly node creation, we create a single
9486 conditional and just modify it in-place when attempting to
9488 dummy
= gimple_build_cond (EQ_EXPR
,
9489 integer_zero_node
, integer_zero_node
,
9492 /* Walk through all the blocks finding those which present a
9493 potential jump threading opportunity. We could set this up
9494 as a dominator walker and record data during the walk, but
9495 I doubt it's worth the effort for the classes of jump
9496 threading opportunities we are trying to identify at this
9497 point in compilation. */
9502 /* If the generic jump threading code does not find this block
9503 interesting, then there is nothing to do. */
9504 if (! potentially_threadable_block (bb
))
9507 /* We only care about blocks ending in a COND_EXPR. While there
9508 may be some value in handling SWITCH_EXPR here, I doubt it's
9509 terribly important. */
9510 last
= gsi_stmt (gsi_last_bb (bb
));
9512 /* We're basically looking for a switch or any kind of conditional with
9513 integral or pointer type arguments. Note the type of the second
9514 argument will be the same as the first argument, so no need to
9515 check it explicitly. */
9516 if (gimple_code (last
) == GIMPLE_SWITCH
9517 || (gimple_code (last
) == GIMPLE_COND
9518 && TREE_CODE (gimple_cond_lhs (last
)) == SSA_NAME
9519 && (INTEGRAL_TYPE_P (TREE_TYPE (gimple_cond_lhs (last
)))
9520 || POINTER_TYPE_P (TREE_TYPE (gimple_cond_lhs (last
))))
9521 && (TREE_CODE (gimple_cond_rhs (last
)) == SSA_NAME
9522 || is_gimple_min_invariant (gimple_cond_rhs (last
)))))
9526 /* We've got a block with multiple predecessors and multiple
9527 successors which also ends in a suitable conditional or
9528 switch statement. For each predecessor, see if we can thread
9529 it to a specific successor. */
9530 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
9532 /* Do not thread across back edges or abnormal edges
9534 if (e
->flags
& (EDGE_DFS_BACK
| EDGE_COMPLEX
))
9537 thread_across_edge (dummy
, e
, true, &equiv_stack
,
9538 simplify_stmt_for_jump_threading
);
9543 /* We do not actually update the CFG or SSA graphs at this point as
9544 ASSERT_EXPRs are still in the IL and cfg cleanup code does not yet
9545 handle ASSERT_EXPRs gracefully. */
9548 /* We identified all the jump threading opportunities earlier, but could
9549 not transform the CFG at that time. This routine transforms the
9550 CFG and arranges for the dominator tree to be rebuilt if necessary.
9552 Note the SSA graph update will occur during the normal TODO
9553 processing by the pass manager. */
9555 finalize_jump_threads (void)
9557 thread_through_all_blocks (false);
9558 equiv_stack
.release ();
9562 /* Traverse all the blocks folding conditionals with known ranges. */
9569 values_propagated
= true;
9573 fprintf (dump_file
, "\nValue ranges after VRP:\n\n");
9574 dump_all_value_ranges (dump_file
);
9575 fprintf (dump_file
, "\n");
9578 substitute_and_fold (op_with_constant_singleton_value_range
,
9579 vrp_fold_stmt
, false);
9581 if (warn_array_bounds
)
9582 check_all_array_refs ();
9584 /* We must identify jump threading opportunities before we release
9585 the datastructures built by VRP. */
9586 identify_jump_threads ();
9588 /* Set value range to non pointer SSA_NAMEs. */
9589 for (i
= 0; i
< num_vr_values
; i
++)
9592 tree name
= ssa_name (i
);
9595 || POINTER_TYPE_P (TREE_TYPE (name
))
9596 || (vr_value
[i
]->type
== VR_VARYING
)
9597 || (vr_value
[i
]->type
== VR_UNDEFINED
))
9600 if ((TREE_CODE (vr_value
[i
]->min
) == INTEGER_CST
)
9601 && (TREE_CODE (vr_value
[i
]->max
) == INTEGER_CST
))
9603 if (vr_value
[i
]->type
== VR_RANGE
)
9604 set_range_info (name
,
9605 tree_to_double_int (vr_value
[i
]->min
),
9606 tree_to_double_int (vr_value
[i
]->max
));
9607 else if (vr_value
[i
]->type
== VR_ANTI_RANGE
)
9609 /* VR_ANTI_RANGE ~[min, max] is encoded compactly as
9610 [max + 1, min - 1] without additional attributes.
9611 When min value > max value, we know that it is
9612 VR_ANTI_RANGE; it is VR_RANGE otherwise. */
9614 /* ~[0,0] anti-range is represented as
9616 if (TYPE_UNSIGNED (TREE_TYPE (name
))
9617 && integer_zerop (vr_value
[i
]->min
)
9618 && integer_zerop (vr_value
[i
]->max
))
9619 set_range_info (name
,
9621 double_int::max_value
9622 (TYPE_PRECISION (TREE_TYPE (name
)), true));
9624 set_range_info (name
,
9625 tree_to_double_int (vr_value
[i
]->max
)
9627 tree_to_double_int (vr_value
[i
]->min
)
9633 /* Free allocated memory. */
9634 for (i
= 0; i
< num_vr_values
; i
++)
9637 BITMAP_FREE (vr_value
[i
]->equiv
);
9642 free (vr_phi_edge_counts
);
9644 /* So that we can distinguish between VRP data being available
9645 and not available. */
9647 vr_phi_edge_counts
= NULL
;
9651 /* Main entry point to VRP (Value Range Propagation). This pass is
9652 loosely based on J. R. C. Patterson, ``Accurate Static Branch
9653 Prediction by Value Range Propagation,'' in SIGPLAN Conference on
9654 Programming Language Design and Implementation, pp. 67-78, 1995.
9655 Also available at http://citeseer.ist.psu.edu/patterson95accurate.html
9657 This is essentially an SSA-CCP pass modified to deal with ranges
9658 instead of constants.
9660 While propagating ranges, we may find that two or more SSA name
9661 have equivalent, though distinct ranges. For instance,
9664 2 p_4 = ASSERT_EXPR <p_3, p_3 != 0>
9666 4 p_5 = ASSERT_EXPR <p_4, p_4 == q_2>;
9670 In the code above, pointer p_5 has range [q_2, q_2], but from the
9671 code we can also determine that p_5 cannot be NULL and, if q_2 had
9672 a non-varying range, p_5's range should also be compatible with it.
9674 These equivalences are created by two expressions: ASSERT_EXPR and
9675 copy operations. Since p_5 is an assertion on p_4, and p_4 was the
9676 result of another assertion, then we can use the fact that p_5 and
9677 p_4 are equivalent when evaluating p_5's range.
9679 Together with value ranges, we also propagate these equivalences
9680 between names so that we can take advantage of information from
9681 multiple ranges when doing final replacement. Note that this
9682 equivalency relation is transitive but not symmetric.
9684 In the example above, p_5 is equivalent to p_4, q_2 and p_3, but we
9685 cannot assert that q_2 is equivalent to p_5 because q_2 may be used
9686 in contexts where that assertion does not hold (e.g., in line 6).
9688 TODO, the main difference between this pass and Patterson's is that
9689 we do not propagate edge probabilities. We only compute whether
9690 edges can be taken or not. That is, instead of having a spectrum
9691 of jump probabilities between 0 and 1, we only deal with 0, 1 and
9692 DON'T KNOW. In the future, it may be worthwhile to propagate
9693 probabilities to aid branch prediction. */
9702 loop_optimizer_init (LOOPS_NORMAL
| LOOPS_HAVE_RECORDED_EXITS
);
9703 rewrite_into_loop_closed_ssa (NULL
, TODO_update_ssa
);
9706 /* ??? This ends up using stale EDGE_DFS_BACK for liveness computation.
9707 Inserting assertions may split edges which will invalidate
9709 insert_range_assertions ();
9711 to_remove_edges
.create (10);
9712 to_update_switch_stmts
.create (5);
9713 threadedge_initialize_values ();
9715 /* For visiting PHI nodes we need EDGE_DFS_BACK computed. */
9716 mark_dfs_back_edges ();
9719 ssa_propagate (vrp_visit_stmt
, vrp_visit_phi_node
);
9722 free_numbers_of_iterations_estimates ();
9724 /* ASSERT_EXPRs must be removed before finalizing jump threads
9725 as finalizing jump threads calls the CFG cleanup code which
9726 does not properly handle ASSERT_EXPRs. */
9727 remove_range_assertions ();
9729 /* If we exposed any new variables, go ahead and put them into
9730 SSA form now, before we handle jump threading. This simplifies
9731 interactions between rewriting of _DECL nodes into SSA form
9732 and rewriting SSA_NAME nodes into SSA form after block
9733 duplication and CFG manipulation. */
9734 update_ssa (TODO_update_ssa
);
9736 finalize_jump_threads ();
9738 /* Remove dead edges from SWITCH_EXPR optimization. This leaves the
9739 CFG in a broken state and requires a cfg_cleanup run. */
9740 FOR_EACH_VEC_ELT (to_remove_edges
, i
, e
)
9742 /* Update SWITCH_EXPR case label vector. */
9743 FOR_EACH_VEC_ELT (to_update_switch_stmts
, i
, su
)
9746 size_t n
= TREE_VEC_LENGTH (su
->vec
);
9748 gimple_switch_set_num_labels (su
->stmt
, n
);
9749 for (j
= 0; j
< n
; j
++)
9750 gimple_switch_set_label (su
->stmt
, j
, TREE_VEC_ELT (su
->vec
, j
));
9751 /* As we may have replaced the default label with a regular one
9752 make sure to make it a real default label again. This ensures
9753 optimal expansion. */
9754 label
= gimple_switch_label (su
->stmt
, 0);
9755 CASE_LOW (label
) = NULL_TREE
;
9756 CASE_HIGH (label
) = NULL_TREE
;
9759 if (to_remove_edges
.length () > 0)
9761 free_dominance_info (CDI_DOMINATORS
);
9763 loops_state_set (LOOPS_NEED_FIXUP
);
9766 to_remove_edges
.release ();
9767 to_update_switch_stmts
.release ();
9768 threadedge_finalize_values ();
9771 loop_optimizer_finalize ();
9778 return flag_tree_vrp
!= 0;
9783 const pass_data pass_data_vrp
=
9785 GIMPLE_PASS
, /* type */
9787 OPTGROUP_NONE
, /* optinfo_flags */
9788 true, /* has_gate */
9789 true, /* has_execute */
9790 TV_TREE_VRP
, /* tv_id */
9791 PROP_ssa
, /* properties_required */
9792 0, /* properties_provided */
9793 0, /* properties_destroyed */
9794 0, /* todo_flags_start */
9795 ( TODO_cleanup_cfg
| TODO_update_ssa
9797 | TODO_verify_flow
), /* todo_flags_finish */
9800 class pass_vrp
: public gimple_opt_pass
9803 pass_vrp (gcc::context
*ctxt
)
9804 : gimple_opt_pass (pass_data_vrp
, ctxt
)
9807 /* opt_pass methods: */
9808 opt_pass
* clone () { return new pass_vrp (m_ctxt
); }
9809 bool gate () { return gate_vrp (); }
9810 unsigned int execute () { return execute_vrp (); }
9812 }; // class pass_vrp
9817 make_pass_vrp (gcc::context
*ctxt
)
9819 return new pass_vrp (ctxt
);