1 /* Conditional constant propagation pass for the GNU compiler.
2 Copyright (C) 2000-2016 Free Software Foundation, Inc.
3 Adapted from original RTL SSA-CCP by Daniel Berlin <dberlin@dberlin.org>
4 Adapted to GIMPLE trees by Diego Novillo <dnovillo@redhat.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by the
10 Free Software Foundation; either version 3, or (at your option) any
13 GCC is distributed in the hope that it will be useful, but WITHOUT
14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Conditional constant propagation (CCP) is based on the SSA
23 propagation engine (tree-ssa-propagate.c). Constant assignments of
24 the form VAR = CST are propagated from the assignments into uses of
25 VAR, which in turn may generate new constants. The simulation uses
26 a four level lattice to keep track of constant values associated
27 with SSA names. Given an SSA name V_i, it may take one of the
30 UNINITIALIZED -> the initial state of the value. This value
31 is replaced with a correct initial value
32 the first time the value is used, so the
33 rest of the pass does not need to care about
34 it. Using this value simplifies initialization
35 of the pass, and prevents us from needlessly
36 scanning statements that are never reached.
38 UNDEFINED -> V_i is a local variable whose definition
39 has not been processed yet. Therefore we
40 don't yet know if its value is a constant
43 CONSTANT -> V_i has been found to hold a constant
46 VARYING -> V_i cannot take a constant value, or if it
47 does, it is not possible to determine it
50 The core of SSA-CCP is in ccp_visit_stmt and ccp_visit_phi_node:
52 1- In ccp_visit_stmt, we are interested in assignments whose RHS
53 evaluates into a constant and conditional jumps whose predicate
54 evaluates into a boolean true or false. When an assignment of
55 the form V_i = CONST is found, V_i's lattice value is set to
56 CONSTANT and CONST is associated with it. This causes the
57 propagation engine to add all the SSA edges coming out the
58 assignment into the worklists, so that statements that use V_i
61 If the statement is a conditional with a constant predicate, we
62 mark the outgoing edges as executable or not executable
63 depending on the predicate's value. This is then used when
64 visiting PHI nodes to know when a PHI argument can be ignored.
67 2- In ccp_visit_phi_node, if all the PHI arguments evaluate to the
68 same constant C, then the LHS of the PHI is set to C. This
69 evaluation is known as the "meet operation". Since one of the
70 goals of this evaluation is to optimistically return constant
71 values as often as possible, it uses two main short cuts:
73 - If an argument is flowing in through a non-executable edge, it
74 is ignored. This is useful in cases like this:
80 a_11 = PHI (a_9, a_10)
82 If PRED is known to always evaluate to false, then we can
83 assume that a_11 will always take its value from a_10, meaning
84 that instead of consider it VARYING (a_9 and a_10 have
85 different values), we can consider it CONSTANT 100.
87 - If an argument has an UNDEFINED value, then it does not affect
88 the outcome of the meet operation. If a variable V_i has an
89 UNDEFINED value, it means that either its defining statement
90 hasn't been visited yet or V_i has no defining statement, in
91 which case the original symbol 'V' is being used
92 uninitialized. Since 'V' is a local variable, the compiler
93 may assume any initial value for it.
96 After propagation, every variable V_i that ends up with a lattice
97 value of CONSTANT will have the associated constant value in the
98 array CONST_VAL[i].VALUE. That is fed into substitute_and_fold for
99 final substitution and folding.
101 This algorithm uses wide-ints at the max precision of the target.
102 This means that, with one uninteresting exception, variables with
103 UNSIGNED types never go to VARYING because the bits above the
104 precision of the type of the variable are always zero. The
105 uninteresting case is a variable of UNSIGNED type that has the
106 maximum precision of the target. Such variables can go to VARYING,
107 but this causes no loss of infomation since these variables will
112 Constant propagation with conditional branches,
113 Wegman and Zadeck, ACM TOPLAS 13(2):181-210.
115 Building an Optimizing Compiler,
116 Robert Morgan, Butterworth-Heinemann, 1998, Section 8.9.
118 Advanced Compiler Design and Implementation,
119 Steven Muchnick, Morgan Kaufmann, 1997, Section 12.6 */
123 #include "coretypes.h"
128 #include "tree-pass.h"
130 #include "gimple-pretty-print.h"
131 #include "fold-const.h"
132 #include "gimple-fold.h"
134 #include "gimplify.h"
135 #include "gimple-iterator.h"
136 #include "tree-cfg.h"
137 #include "tree-ssa-propagate.h"
140 #include "builtins.h"
141 #include "tree-chkp.h"
143 #include "stor-layout.h"
144 #include "optabs-query.h"
147 /* Possible lattice values. */
156 struct ccp_prop_value_t
{
158 ccp_lattice_t lattice_val
;
160 /* Propagated value. */
163 /* Mask that applies to the propagated value during CCP. For X
164 with a CONSTANT lattice value X & ~mask == value & ~mask. The
165 zero bits in the mask cover constant values. The ones mean no
170 /* Array of propagated constant values. After propagation,
171 CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If
172 the constant is held in an SSA name representing a memory store
173 (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual
174 memory reference used to store (i.e., the LHS of the assignment
176 static ccp_prop_value_t
*const_val
;
177 static unsigned n_const_val
;
179 static void canonicalize_value (ccp_prop_value_t
*);
180 static bool ccp_fold_stmt (gimple_stmt_iterator
*);
181 static void ccp_lattice_meet (ccp_prop_value_t
*, ccp_prop_value_t
*);
183 /* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */
186 dump_lattice_value (FILE *outf
, const char *prefix
, ccp_prop_value_t val
)
188 switch (val
.lattice_val
)
191 fprintf (outf
, "%sUNINITIALIZED", prefix
);
194 fprintf (outf
, "%sUNDEFINED", prefix
);
197 fprintf (outf
, "%sVARYING", prefix
);
200 if (TREE_CODE (val
.value
) != INTEGER_CST
203 fprintf (outf
, "%sCONSTANT ", prefix
);
204 print_generic_expr (outf
, val
.value
, dump_flags
);
208 widest_int cval
= wi::bit_and_not (wi::to_widest (val
.value
),
210 fprintf (outf
, "%sCONSTANT ", prefix
);
211 print_hex (cval
, outf
);
212 fprintf (outf
, " (");
213 print_hex (val
.mask
, outf
);
223 /* Print lattice value VAL to stderr. */
225 void debug_lattice_value (ccp_prop_value_t val
);
228 debug_lattice_value (ccp_prop_value_t val
)
230 dump_lattice_value (stderr
, "", val
);
231 fprintf (stderr
, "\n");
234 /* Extend NONZERO_BITS to a full mask, with the upper bits being set. */
237 extend_mask (const wide_int
&nonzero_bits
)
239 return (wi::mask
<widest_int
> (wi::get_precision (nonzero_bits
), true)
240 | widest_int::from (nonzero_bits
, UNSIGNED
));
243 /* Compute a default value for variable VAR and store it in the
244 CONST_VAL array. The following rules are used to get default
247 1- Global and static variables that are declared constant are
250 2- Any other value is considered UNDEFINED. This is useful when
251 considering PHI nodes. PHI arguments that are undefined do not
252 change the constant value of the PHI node, which allows for more
253 constants to be propagated.
255 3- Variables defined by statements other than assignments and PHI
256 nodes are considered VARYING.
258 4- Initial values of variables that are not GIMPLE registers are
259 considered VARYING. */
261 static ccp_prop_value_t
262 get_default_value (tree var
)
264 ccp_prop_value_t val
= { UNINITIALIZED
, NULL_TREE
, 0 };
267 stmt
= SSA_NAME_DEF_STMT (var
);
269 if (gimple_nop_p (stmt
))
271 /* Variables defined by an empty statement are those used
272 before being initialized. If VAR is a local variable, we
273 can assume initially that it is UNDEFINED, otherwise we must
274 consider it VARYING. */
275 if (!virtual_operand_p (var
)
276 && TREE_CODE (SSA_NAME_VAR (var
)) == VAR_DECL
)
277 val
.lattice_val
= UNDEFINED
;
280 val
.lattice_val
= VARYING
;
282 if (flag_tree_bit_ccp
)
284 wide_int nonzero_bits
= get_nonzero_bits (var
);
285 if (nonzero_bits
!= -1)
287 val
.lattice_val
= CONSTANT
;
288 val
.value
= build_zero_cst (TREE_TYPE (var
));
289 val
.mask
= extend_mask (nonzero_bits
);
294 else if (is_gimple_assign (stmt
))
297 if (gimple_assign_single_p (stmt
)
298 && DECL_P (gimple_assign_rhs1 (stmt
))
299 && (cst
= get_symbol_constant_value (gimple_assign_rhs1 (stmt
))))
301 val
.lattice_val
= CONSTANT
;
306 /* Any other variable defined by an assignment is considered
308 val
.lattice_val
= UNDEFINED
;
311 else if ((is_gimple_call (stmt
)
312 && gimple_call_lhs (stmt
) != NULL_TREE
)
313 || gimple_code (stmt
) == GIMPLE_PHI
)
315 /* A variable defined by a call or a PHI node is considered
317 val
.lattice_val
= UNDEFINED
;
321 /* Otherwise, VAR will never take on a constant value. */
322 val
.lattice_val
= VARYING
;
330 /* Get the constant value associated with variable VAR. */
332 static inline ccp_prop_value_t
*
335 ccp_prop_value_t
*val
;
337 if (const_val
== NULL
338 || SSA_NAME_VERSION (var
) >= n_const_val
)
341 val
= &const_val
[SSA_NAME_VERSION (var
)];
342 if (val
->lattice_val
== UNINITIALIZED
)
343 *val
= get_default_value (var
);
345 canonicalize_value (val
);
350 /* Return the constant tree value associated with VAR. */
353 get_constant_value (tree var
)
355 ccp_prop_value_t
*val
;
356 if (TREE_CODE (var
) != SSA_NAME
)
358 if (is_gimple_min_invariant (var
))
362 val
= get_value (var
);
364 && val
->lattice_val
== CONSTANT
365 && (TREE_CODE (val
->value
) != INTEGER_CST
371 /* Sets the value associated with VAR to VARYING. */
374 set_value_varying (tree var
)
376 ccp_prop_value_t
*val
= &const_val
[SSA_NAME_VERSION (var
)];
378 val
->lattice_val
= VARYING
;
379 val
->value
= NULL_TREE
;
383 /* For integer constants, make sure to drop TREE_OVERFLOW. */
386 canonicalize_value (ccp_prop_value_t
*val
)
388 if (val
->lattice_val
!= CONSTANT
)
391 if (TREE_OVERFLOW_P (val
->value
))
392 val
->value
= drop_tree_overflow (val
->value
);
395 /* Return whether the lattice transition is valid. */
398 valid_lattice_transition (ccp_prop_value_t old_val
, ccp_prop_value_t new_val
)
400 /* Lattice transitions must always be monotonically increasing in
402 if (old_val
.lattice_val
< new_val
.lattice_val
)
405 if (old_val
.lattice_val
!= new_val
.lattice_val
)
408 if (!old_val
.value
&& !new_val
.value
)
411 /* Now both lattice values are CONSTANT. */
413 /* Allow arbitrary copy changes as we might look through PHI <a_1, ...>
414 when only a single copy edge is executable. */
415 if (TREE_CODE (old_val
.value
) == SSA_NAME
416 && TREE_CODE (new_val
.value
) == SSA_NAME
)
419 /* Allow transitioning from a constant to a copy. */
420 if (is_gimple_min_invariant (old_val
.value
)
421 && TREE_CODE (new_val
.value
) == SSA_NAME
)
424 /* Allow transitioning from PHI <&x, not executable> == &x
425 to PHI <&x, &y> == common alignment. */
426 if (TREE_CODE (old_val
.value
) != INTEGER_CST
427 && TREE_CODE (new_val
.value
) == INTEGER_CST
)
430 /* Bit-lattices have to agree in the still valid bits. */
431 if (TREE_CODE (old_val
.value
) == INTEGER_CST
432 && TREE_CODE (new_val
.value
) == INTEGER_CST
)
433 return (wi::bit_and_not (wi::to_widest (old_val
.value
), new_val
.mask
)
434 == wi::bit_and_not (wi::to_widest (new_val
.value
), new_val
.mask
));
436 /* Otherwise constant values have to agree. */
437 if (operand_equal_p (old_val
.value
, new_val
.value
, 0))
440 /* At least the kinds and types should agree now. */
441 if (TREE_CODE (old_val
.value
) != TREE_CODE (new_val
.value
)
442 || !types_compatible_p (TREE_TYPE (old_val
.value
),
443 TREE_TYPE (new_val
.value
)))
446 /* For floats and !HONOR_NANS allow transitions from (partial) NaN
448 tree type
= TREE_TYPE (new_val
.value
);
449 if (SCALAR_FLOAT_TYPE_P (type
)
450 && !HONOR_NANS (type
))
452 if (REAL_VALUE_ISNAN (TREE_REAL_CST (old_val
.value
)))
455 else if (VECTOR_FLOAT_TYPE_P (type
)
456 && !HONOR_NANS (type
))
458 for (unsigned i
= 0; i
< VECTOR_CST_NELTS (old_val
.value
); ++i
)
459 if (!REAL_VALUE_ISNAN
460 (TREE_REAL_CST (VECTOR_CST_ELT (old_val
.value
, i
)))
461 && !operand_equal_p (VECTOR_CST_ELT (old_val
.value
, i
),
462 VECTOR_CST_ELT (new_val
.value
, i
), 0))
466 else if (COMPLEX_FLOAT_TYPE_P (type
)
467 && !HONOR_NANS (type
))
469 if (!REAL_VALUE_ISNAN (TREE_REAL_CST (TREE_REALPART (old_val
.value
)))
470 && !operand_equal_p (TREE_REALPART (old_val
.value
),
471 TREE_REALPART (new_val
.value
), 0))
473 if (!REAL_VALUE_ISNAN (TREE_REAL_CST (TREE_IMAGPART (old_val
.value
)))
474 && !operand_equal_p (TREE_IMAGPART (old_val
.value
),
475 TREE_IMAGPART (new_val
.value
), 0))
482 /* Set the value for variable VAR to NEW_VAL. Return true if the new
483 value is different from VAR's previous value. */
486 set_lattice_value (tree var
, ccp_prop_value_t
*new_val
)
488 /* We can deal with old UNINITIALIZED values just fine here. */
489 ccp_prop_value_t
*old_val
= &const_val
[SSA_NAME_VERSION (var
)];
491 canonicalize_value (new_val
);
493 /* We have to be careful to not go up the bitwise lattice
494 represented by the mask. Instead of dropping to VARYING
495 use the meet operator to retain a conservative value.
496 Missed optimizations like PR65851 makes this necessary.
497 It also ensures we converge to a stable lattice solution. */
498 if (new_val
->lattice_val
== CONSTANT
499 && old_val
->lattice_val
== CONSTANT
500 && TREE_CODE (new_val
->value
) != SSA_NAME
)
501 ccp_lattice_meet (new_val
, old_val
);
503 gcc_checking_assert (valid_lattice_transition (*old_val
, *new_val
));
505 /* If *OLD_VAL and NEW_VAL are the same, return false to inform the
506 caller that this was a non-transition. */
507 if (old_val
->lattice_val
!= new_val
->lattice_val
508 || (new_val
->lattice_val
== CONSTANT
509 && (TREE_CODE (new_val
->value
) != TREE_CODE (old_val
->value
)
510 || (TREE_CODE (new_val
->value
) == INTEGER_CST
511 && (new_val
->mask
!= old_val
->mask
512 || (wi::bit_and_not (wi::to_widest (old_val
->value
),
514 != wi::bit_and_not (wi::to_widest (new_val
->value
),
516 || (TREE_CODE (new_val
->value
) != INTEGER_CST
517 && !operand_equal_p (new_val
->value
, old_val
->value
, 0)))))
519 /* ??? We would like to delay creation of INTEGER_CSTs from
520 partially constants here. */
522 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
524 dump_lattice_value (dump_file
, "Lattice value changed to ", *new_val
);
525 fprintf (dump_file
, ". Adding SSA edges to worklist.\n");
530 gcc_assert (new_val
->lattice_val
!= UNINITIALIZED
);
537 static ccp_prop_value_t
get_value_for_expr (tree
, bool);
538 static ccp_prop_value_t
bit_value_binop (enum tree_code
, tree
, tree
, tree
);
539 static void bit_value_binop_1 (enum tree_code
, tree
, widest_int
*, widest_int
*,
540 tree
, const widest_int
&, const widest_int
&,
541 tree
, const widest_int
&, const widest_int
&);
543 /* Return a widest_int that can be used for bitwise simplifications
547 value_to_wide_int (ccp_prop_value_t val
)
550 && TREE_CODE (val
.value
) == INTEGER_CST
)
551 return wi::to_widest (val
.value
);
556 /* Return the value for the address expression EXPR based on alignment
559 static ccp_prop_value_t
560 get_value_from_alignment (tree expr
)
562 tree type
= TREE_TYPE (expr
);
563 ccp_prop_value_t val
;
564 unsigned HOST_WIDE_INT bitpos
;
567 gcc_assert (TREE_CODE (expr
) == ADDR_EXPR
);
569 get_pointer_alignment_1 (expr
, &align
, &bitpos
);
570 val
.mask
= (POINTER_TYPE_P (type
) || TYPE_UNSIGNED (type
)
571 ? wi::mask
<widest_int
> (TYPE_PRECISION (type
), false)
572 : -1).and_not (align
/ BITS_PER_UNIT
- 1);
574 = wi::sext (val
.mask
, TYPE_PRECISION (type
)) == -1 ? VARYING
: CONSTANT
;
575 if (val
.lattice_val
== CONSTANT
)
576 val
.value
= build_int_cstu (type
, bitpos
/ BITS_PER_UNIT
);
578 val
.value
= NULL_TREE
;
583 /* Return the value for the tree operand EXPR. If FOR_BITS_P is true
584 return constant bits extracted from alignment information for
585 invariant addresses. */
587 static ccp_prop_value_t
588 get_value_for_expr (tree expr
, bool for_bits_p
)
590 ccp_prop_value_t val
;
592 if (TREE_CODE (expr
) == SSA_NAME
)
594 val
= *get_value (expr
);
596 && val
.lattice_val
== CONSTANT
597 && TREE_CODE (val
.value
) == ADDR_EXPR
)
598 val
= get_value_from_alignment (val
.value
);
599 /* Fall back to a copy value. */
601 && val
.lattice_val
== VARYING
602 && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (expr
))
604 val
.lattice_val
= CONSTANT
;
609 else if (is_gimple_min_invariant (expr
)
610 && (!for_bits_p
|| TREE_CODE (expr
) != ADDR_EXPR
))
612 val
.lattice_val
= CONSTANT
;
615 canonicalize_value (&val
);
617 else if (TREE_CODE (expr
) == ADDR_EXPR
)
618 val
= get_value_from_alignment (expr
);
621 val
.lattice_val
= VARYING
;
623 val
.value
= NULL_TREE
;
626 if (val
.lattice_val
== VARYING
627 && TYPE_UNSIGNED (TREE_TYPE (expr
)))
628 val
.mask
= wi::zext (val
.mask
, TYPE_PRECISION (TREE_TYPE (expr
)));
633 /* Return the likely CCP lattice value for STMT.
635 If STMT has no operands, then return CONSTANT.
637 Else if undefinedness of operands of STMT cause its value to be
638 undefined, then return UNDEFINED.
640 Else if any operands of STMT are constants, then return CONSTANT.
642 Else return VARYING. */
645 likely_value (gimple
*stmt
)
647 bool has_constant_operand
, has_undefined_operand
, all_undefined_operands
;
648 bool has_nsa_operand
;
653 enum gimple_code code
= gimple_code (stmt
);
655 /* This function appears to be called only for assignments, calls,
656 conditionals, and switches, due to the logic in visit_stmt. */
657 gcc_assert (code
== GIMPLE_ASSIGN
658 || code
== GIMPLE_CALL
659 || code
== GIMPLE_COND
660 || code
== GIMPLE_SWITCH
);
662 /* If the statement has volatile operands, it won't fold to a
664 if (gimple_has_volatile_ops (stmt
))
667 /* Arrive here for more complex cases. */
668 has_constant_operand
= false;
669 has_undefined_operand
= false;
670 all_undefined_operands
= true;
671 has_nsa_operand
= false;
672 FOR_EACH_SSA_TREE_OPERAND (use
, stmt
, iter
, SSA_OP_USE
)
674 ccp_prop_value_t
*val
= get_value (use
);
676 if (val
->lattice_val
== UNDEFINED
)
677 has_undefined_operand
= true;
679 all_undefined_operands
= false;
681 if (val
->lattice_val
== CONSTANT
)
682 has_constant_operand
= true;
684 if (SSA_NAME_IS_DEFAULT_DEF (use
)
685 || !prop_simulate_again_p (SSA_NAME_DEF_STMT (use
)))
686 has_nsa_operand
= true;
689 /* There may be constants in regular rhs operands. For calls we
690 have to ignore lhs, fndecl and static chain, otherwise only
692 for (i
= (is_gimple_call (stmt
) ? 2 : 0) + gimple_has_lhs (stmt
);
693 i
< gimple_num_ops (stmt
); ++i
)
695 tree op
= gimple_op (stmt
, i
);
696 if (!op
|| TREE_CODE (op
) == SSA_NAME
)
698 if (is_gimple_min_invariant (op
))
699 has_constant_operand
= true;
702 if (has_constant_operand
)
703 all_undefined_operands
= false;
705 if (has_undefined_operand
706 && code
== GIMPLE_CALL
707 && gimple_call_internal_p (stmt
))
708 switch (gimple_call_internal_fn (stmt
))
710 /* These 3 builtins use the first argument just as a magic
711 way how to find out a decl uid. */
712 case IFN_GOMP_SIMD_LANE
:
713 case IFN_GOMP_SIMD_VF
:
714 case IFN_GOMP_SIMD_LAST_LANE
:
715 has_undefined_operand
= false;
721 /* If the operation combines operands like COMPLEX_EXPR make sure to
722 not mark the result UNDEFINED if only one part of the result is
724 if (has_undefined_operand
&& all_undefined_operands
)
726 else if (code
== GIMPLE_ASSIGN
&& has_undefined_operand
)
728 switch (gimple_assign_rhs_code (stmt
))
730 /* Unary operators are handled with all_undefined_operands. */
733 case POINTER_PLUS_EXPR
:
734 /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected.
735 Not bitwise operators, one VARYING operand may specify the
736 result completely. Not logical operators for the same reason.
737 Not COMPLEX_EXPR as one VARYING operand makes the result partly
738 not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because
739 the undefined operand may be promoted. */
743 /* If any part of an address is UNDEFINED, like the index
744 of an ARRAY_EXPR, then treat the result as UNDEFINED. */
751 /* If there was an UNDEFINED operand but the result may be not UNDEFINED
752 fall back to CONSTANT. During iteration UNDEFINED may still drop
754 if (has_undefined_operand
)
757 /* We do not consider virtual operands here -- load from read-only
758 memory may have only VARYING virtual operands, but still be
759 constant. Also we can combine the stmt with definitions from
760 operands whose definitions are not simulated again. */
761 if (has_constant_operand
763 || gimple_references_memory_p (stmt
))
769 /* Returns true if STMT cannot be constant. */
772 surely_varying_stmt_p (gimple
*stmt
)
774 /* If the statement has operands that we cannot handle, it cannot be
776 if (gimple_has_volatile_ops (stmt
))
779 /* If it is a call and does not return a value or is not a
780 builtin and not an indirect call or a call to function with
781 assume_aligned/alloc_align attribute, it is varying. */
782 if (is_gimple_call (stmt
))
784 tree fndecl
, fntype
= gimple_call_fntype (stmt
);
785 if (!gimple_call_lhs (stmt
)
786 || ((fndecl
= gimple_call_fndecl (stmt
)) != NULL_TREE
787 && !DECL_BUILT_IN (fndecl
)
788 && !lookup_attribute ("assume_aligned",
789 TYPE_ATTRIBUTES (fntype
))
790 && !lookup_attribute ("alloc_align",
791 TYPE_ATTRIBUTES (fntype
))))
795 /* Any other store operation is not interesting. */
796 else if (gimple_vdef (stmt
))
799 /* Anything other than assignments and conditional jumps are not
800 interesting for CCP. */
801 if (gimple_code (stmt
) != GIMPLE_ASSIGN
802 && gimple_code (stmt
) != GIMPLE_COND
803 && gimple_code (stmt
) != GIMPLE_SWITCH
804 && gimple_code (stmt
) != GIMPLE_CALL
)
810 /* Initialize local data structures for CCP. */
813 ccp_initialize (void)
817 n_const_val
= num_ssa_names
;
818 const_val
= XCNEWVEC (ccp_prop_value_t
, n_const_val
);
820 /* Initialize simulation flags for PHI nodes and statements. */
821 FOR_EACH_BB_FN (bb
, cfun
)
823 gimple_stmt_iterator i
;
825 for (i
= gsi_start_bb (bb
); !gsi_end_p (i
); gsi_next (&i
))
827 gimple
*stmt
= gsi_stmt (i
);
830 /* If the statement is a control insn, then we do not
831 want to avoid simulating the statement once. Failure
832 to do so means that those edges will never get added. */
833 if (stmt_ends_bb_p (stmt
))
836 is_varying
= surely_varying_stmt_p (stmt
);
843 /* If the statement will not produce a constant, mark
844 all its outputs VARYING. */
845 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_ALL_DEFS
)
846 set_value_varying (def
);
848 prop_set_simulate_again (stmt
, !is_varying
);
852 /* Now process PHI nodes. We never clear the simulate_again flag on
853 phi nodes, since we do not know which edges are executable yet,
854 except for phi nodes for virtual operands when we do not do store ccp. */
855 FOR_EACH_BB_FN (bb
, cfun
)
859 for (i
= gsi_start_phis (bb
); !gsi_end_p (i
); gsi_next (&i
))
861 gphi
*phi
= i
.phi ();
863 if (virtual_operand_p (gimple_phi_result (phi
)))
864 prop_set_simulate_again (phi
, false);
866 prop_set_simulate_again (phi
, true);
871 /* Debug count support. Reset the values of ssa names
872 VARYING when the total number ssa names analyzed is
873 beyond the debug count specified. */
879 for (i
= 0; i
< num_ssa_names
; i
++)
883 const_val
[i
].lattice_val
= VARYING
;
884 const_val
[i
].mask
= -1;
885 const_val
[i
].value
= NULL_TREE
;
891 /* Do final substitution of propagated values, cleanup the flowgraph and
892 free allocated storage. If NONZERO_P, record nonzero bits.
894 Return TRUE when something was optimized. */
897 ccp_finalize (bool nonzero_p
)
899 bool something_changed
;
904 /* Derive alignment and misalignment information from partially
905 constant pointers in the lattice or nonzero bits from partially
906 constant integers. */
907 for (i
= 1; i
< num_ssa_names
; ++i
)
909 tree name
= ssa_name (i
);
910 ccp_prop_value_t
*val
;
911 unsigned int tem
, align
;
914 || (!POINTER_TYPE_P (TREE_TYPE (name
))
915 && (!INTEGRAL_TYPE_P (TREE_TYPE (name
))
916 /* Don't record nonzero bits before IPA to avoid
917 using too much memory. */
921 val
= get_value (name
);
922 if (val
->lattice_val
!= CONSTANT
923 || TREE_CODE (val
->value
) != INTEGER_CST
)
926 if (POINTER_TYPE_P (TREE_TYPE (name
)))
928 /* Trailing mask bits specify the alignment, trailing value
929 bits the misalignment. */
930 tem
= val
->mask
.to_uhwi ();
931 align
= (tem
& -tem
);
933 set_ptr_info_alignment (get_ptr_info (name
), align
,
934 (TREE_INT_CST_LOW (val
->value
)
939 unsigned int precision
= TYPE_PRECISION (TREE_TYPE (val
->value
));
940 wide_int nonzero_bits
= wide_int::from (val
->mask
, precision
,
941 UNSIGNED
) | val
->value
;
942 nonzero_bits
&= get_nonzero_bits (name
);
943 set_nonzero_bits (name
, nonzero_bits
);
947 /* Perform substitutions based on the known constant values. */
948 something_changed
= substitute_and_fold (get_constant_value
,
949 ccp_fold_stmt
, true);
953 return something_changed
;;
957 /* Compute the meet operator between *VAL1 and *VAL2. Store the result
960 any M UNDEFINED = any
961 any M VARYING = VARYING
962 Ci M Cj = Ci if (i == j)
963 Ci M Cj = VARYING if (i != j)
967 ccp_lattice_meet (ccp_prop_value_t
*val1
, ccp_prop_value_t
*val2
)
969 if (val1
->lattice_val
== UNDEFINED
970 /* For UNDEFINED M SSA we can't always SSA because its definition
971 may not dominate the PHI node. Doing optimistic copy propagation
972 also causes a lot of gcc.dg/uninit-pred*.c FAILs. */
973 && (val2
->lattice_val
!= CONSTANT
974 || TREE_CODE (val2
->value
) != SSA_NAME
))
976 /* UNDEFINED M any = any */
979 else if (val2
->lattice_val
== UNDEFINED
981 && (val1
->lattice_val
!= CONSTANT
982 || TREE_CODE (val1
->value
) != SSA_NAME
))
984 /* any M UNDEFINED = any
985 Nothing to do. VAL1 already contains the value we want. */
988 else if (val1
->lattice_val
== VARYING
989 || val2
->lattice_val
== VARYING
)
991 /* any M VARYING = VARYING. */
992 val1
->lattice_val
= VARYING
;
994 val1
->value
= NULL_TREE
;
996 else if (val1
->lattice_val
== CONSTANT
997 && val2
->lattice_val
== CONSTANT
998 && TREE_CODE (val1
->value
) == INTEGER_CST
999 && TREE_CODE (val2
->value
) == INTEGER_CST
)
1001 /* Ci M Cj = Ci if (i == j)
1002 Ci M Cj = VARYING if (i != j)
1004 For INTEGER_CSTs mask unequal bits. If no equal bits remain,
1006 val1
->mask
= (val1
->mask
| val2
->mask
1007 | (wi::to_widest (val1
->value
)
1008 ^ wi::to_widest (val2
->value
)));
1009 if (wi::sext (val1
->mask
, TYPE_PRECISION (TREE_TYPE (val1
->value
))) == -1)
1011 val1
->lattice_val
= VARYING
;
1012 val1
->value
= NULL_TREE
;
1015 else if (val1
->lattice_val
== CONSTANT
1016 && val2
->lattice_val
== CONSTANT
1017 && operand_equal_p (val1
->value
, val2
->value
, 0))
1019 /* Ci M Cj = Ci if (i == j)
1020 Ci M Cj = VARYING if (i != j)
1022 VAL1 already contains the value we want for equivalent values. */
1024 else if (val1
->lattice_val
== CONSTANT
1025 && val2
->lattice_val
== CONSTANT
1026 && (TREE_CODE (val1
->value
) == ADDR_EXPR
1027 || TREE_CODE (val2
->value
) == ADDR_EXPR
))
1029 /* When not equal addresses are involved try meeting for
1031 ccp_prop_value_t tem
= *val2
;
1032 if (TREE_CODE (val1
->value
) == ADDR_EXPR
)
1033 *val1
= get_value_for_expr (val1
->value
, true);
1034 if (TREE_CODE (val2
->value
) == ADDR_EXPR
)
1035 tem
= get_value_for_expr (val2
->value
, true);
1036 ccp_lattice_meet (val1
, &tem
);
1040 /* Any other combination is VARYING. */
1041 val1
->lattice_val
= VARYING
;
1043 val1
->value
= NULL_TREE
;
1048 /* Loop through the PHI_NODE's parameters for BLOCK and compare their
1049 lattice values to determine PHI_NODE's lattice value. The value of a
1050 PHI node is determined calling ccp_lattice_meet with all the arguments
1051 of the PHI node that are incoming via executable edges. */
1053 static enum ssa_prop_result
1054 ccp_visit_phi_node (gphi
*phi
)
1057 ccp_prop_value_t new_val
;
1059 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1061 fprintf (dump_file
, "\nVisiting PHI node: ");
1062 print_gimple_stmt (dump_file
, phi
, 0, dump_flags
);
1065 new_val
.lattice_val
= UNDEFINED
;
1066 new_val
.value
= NULL_TREE
;
1070 bool non_exec_edge
= false;
1071 for (i
= 0; i
< gimple_phi_num_args (phi
); i
++)
1073 /* Compute the meet operator over all the PHI arguments flowing
1074 through executable edges. */
1075 edge e
= gimple_phi_arg_edge (phi
, i
);
1077 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1080 "\n Argument #%d (%d -> %d %sexecutable)\n",
1081 i
, e
->src
->index
, e
->dest
->index
,
1082 (e
->flags
& EDGE_EXECUTABLE
) ? "" : "not ");
1085 /* If the incoming edge is executable, Compute the meet operator for
1086 the existing value of the PHI node and the current PHI argument. */
1087 if (e
->flags
& EDGE_EXECUTABLE
)
1089 tree arg
= gimple_phi_arg (phi
, i
)->def
;
1090 ccp_prop_value_t arg_val
= get_value_for_expr (arg
, false);
1098 ccp_lattice_meet (&new_val
, &arg_val
);
1100 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1102 fprintf (dump_file
, "\t");
1103 print_generic_expr (dump_file
, arg
, dump_flags
);
1104 dump_lattice_value (dump_file
, "\tValue: ", arg_val
);
1105 fprintf (dump_file
, "\n");
1108 if (new_val
.lattice_val
== VARYING
)
1112 non_exec_edge
= true;
1115 /* In case there were non-executable edges and the value is a copy
1116 make sure its definition dominates the PHI node. */
1118 && new_val
.lattice_val
== CONSTANT
1119 && TREE_CODE (new_val
.value
) == SSA_NAME
1120 && ! SSA_NAME_IS_DEFAULT_DEF (new_val
.value
)
1121 && ! dominated_by_p (CDI_DOMINATORS
, gimple_bb (phi
),
1122 gimple_bb (SSA_NAME_DEF_STMT (new_val
.value
))))
1124 new_val
.lattice_val
= VARYING
;
1125 new_val
.value
= NULL_TREE
;
1129 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1131 dump_lattice_value (dump_file
, "\n PHI node value: ", new_val
);
1132 fprintf (dump_file
, "\n\n");
1135 /* Make the transition to the new value. */
1136 if (set_lattice_value (gimple_phi_result (phi
), &new_val
))
1138 if (new_val
.lattice_val
== VARYING
)
1139 return SSA_PROP_VARYING
;
1141 return SSA_PROP_INTERESTING
;
1144 return SSA_PROP_NOT_INTERESTING
;
1147 /* Return the constant value for OP or OP otherwise. */
1150 valueize_op (tree op
)
1152 if (TREE_CODE (op
) == SSA_NAME
)
1154 tree tem
= get_constant_value (op
);
1161 /* Return the constant value for OP, but signal to not follow SSA
1162 edges if the definition may be simulated again. */
1165 valueize_op_1 (tree op
)
1167 if (TREE_CODE (op
) == SSA_NAME
)
1169 /* If the definition may be simulated again we cannot follow
1170 this SSA edge as the SSA propagator does not necessarily
1171 re-visit the use. */
1172 gimple
*def_stmt
= SSA_NAME_DEF_STMT (op
);
1173 if (!gimple_nop_p (def_stmt
)
1174 && prop_simulate_again_p (def_stmt
))
1176 tree tem
= get_constant_value (op
);
1183 /* CCP specific front-end to the non-destructive constant folding
1186 Attempt to simplify the RHS of STMT knowing that one or more
1187 operands are constants.
1189 If simplification is possible, return the simplified RHS,
1190 otherwise return the original RHS or NULL_TREE. */
1193 ccp_fold (gimple
*stmt
)
1195 location_t loc
= gimple_location (stmt
);
1196 switch (gimple_code (stmt
))
1200 /* Handle comparison operators that can appear in GIMPLE form. */
1201 tree op0
= valueize_op (gimple_cond_lhs (stmt
));
1202 tree op1
= valueize_op (gimple_cond_rhs (stmt
));
1203 enum tree_code code
= gimple_cond_code (stmt
);
1204 return fold_binary_loc (loc
, code
, boolean_type_node
, op0
, op1
);
1209 /* Return the constant switch index. */
1210 return valueize_op (gimple_switch_index (as_a
<gswitch
*> (stmt
)));
1215 return gimple_fold_stmt_to_constant_1 (stmt
,
1216 valueize_op
, valueize_op_1
);
1223 /* Apply the operation CODE in type TYPE to the value, mask pair
1224 RVAL and RMASK representing a value of type RTYPE and set
1225 the value, mask pair *VAL and *MASK to the result. */
1228 bit_value_unop_1 (enum tree_code code
, tree type
,
1229 widest_int
*val
, widest_int
*mask
,
1230 tree rtype
, const widest_int
&rval
, const widest_int
&rmask
)
1241 widest_int temv
, temm
;
1242 /* Return ~rval + 1. */
1243 bit_value_unop_1 (BIT_NOT_EXPR
, type
, &temv
, &temm
, type
, rval
, rmask
);
1244 bit_value_binop_1 (PLUS_EXPR
, type
, val
, mask
,
1245 type
, temv
, temm
, type
, 1, 0);
1253 /* First extend mask and value according to the original type. */
1254 sgn
= TYPE_SIGN (rtype
);
1255 *mask
= wi::ext (rmask
, TYPE_PRECISION (rtype
), sgn
);
1256 *val
= wi::ext (rval
, TYPE_PRECISION (rtype
), sgn
);
1258 /* Then extend mask and value according to the target type. */
1259 sgn
= TYPE_SIGN (type
);
1260 *mask
= wi::ext (*mask
, TYPE_PRECISION (type
), sgn
);
1261 *val
= wi::ext (*val
, TYPE_PRECISION (type
), sgn
);
1271 /* Apply the operation CODE in type TYPE to the value, mask pairs
1272 R1VAL, R1MASK and R2VAL, R2MASK representing a values of type R1TYPE
1273 and R2TYPE and set the value, mask pair *VAL and *MASK to the result. */
1276 bit_value_binop_1 (enum tree_code code
, tree type
,
1277 widest_int
*val
, widest_int
*mask
,
1278 tree r1type
, const widest_int
&r1val
,
1279 const widest_int
&r1mask
, tree r2type
,
1280 const widest_int
&r2val
, const widest_int
&r2mask
)
1282 signop sgn
= TYPE_SIGN (type
);
1283 int width
= TYPE_PRECISION (type
);
1284 bool swap_p
= false;
1286 /* Assume we'll get a constant result. Use an initial non varying
1287 value, we fall back to varying in the end if necessary. */
1293 /* The mask is constant where there is a known not
1294 set bit, (m1 | m2) & ((v1 | m1) & (v2 | m2)) */
1295 *mask
= (r1mask
| r2mask
) & (r1val
| r1mask
) & (r2val
| r2mask
);
1296 *val
= r1val
& r2val
;
1300 /* The mask is constant where there is a known
1301 set bit, (m1 | m2) & ~((v1 & ~m1) | (v2 & ~m2)). */
1302 *mask
= (r1mask
| r2mask
)
1303 .and_not (r1val
.and_not (r1mask
) | r2val
.and_not (r2mask
));
1304 *val
= r1val
| r2val
;
1309 *mask
= r1mask
| r2mask
;
1310 *val
= r1val
^ r2val
;
1317 widest_int shift
= r2val
;
1325 if (wi::neg_p (shift
))
1328 if (code
== RROTATE_EXPR
)
1329 code
= LROTATE_EXPR
;
1331 code
= RROTATE_EXPR
;
1333 if (code
== RROTATE_EXPR
)
1335 *mask
= wi::rrotate (r1mask
, shift
, width
);
1336 *val
= wi::rrotate (r1val
, shift
, width
);
1340 *mask
= wi::lrotate (r1mask
, shift
, width
);
1341 *val
= wi::lrotate (r1val
, shift
, width
);
1349 /* ??? We can handle partially known shift counts if we know
1350 its sign. That way we can tell that (x << (y | 8)) & 255
1354 widest_int shift
= r2val
;
1362 if (wi::neg_p (shift
))
1365 if (code
== RSHIFT_EXPR
)
1370 if (code
== RSHIFT_EXPR
)
1372 *mask
= wi::rshift (wi::ext (r1mask
, width
, sgn
), shift
, sgn
);
1373 *val
= wi::rshift (wi::ext (r1val
, width
, sgn
), shift
, sgn
);
1377 *mask
= wi::ext (r1mask
<< shift
, width
, sgn
);
1378 *val
= wi::ext (r1val
<< shift
, width
, sgn
);
1385 case POINTER_PLUS_EXPR
:
1387 /* Do the addition with unknown bits set to zero, to give carry-ins of
1388 zero wherever possible. */
1389 widest_int lo
= r1val
.and_not (r1mask
) + r2val
.and_not (r2mask
);
1390 lo
= wi::ext (lo
, width
, sgn
);
1391 /* Do the addition with unknown bits set to one, to give carry-ins of
1392 one wherever possible. */
1393 widest_int hi
= (r1val
| r1mask
) + (r2val
| r2mask
);
1394 hi
= wi::ext (hi
, width
, sgn
);
1395 /* Each bit in the result is known if (a) the corresponding bits in
1396 both inputs are known, and (b) the carry-in to that bit position
1397 is known. We can check condition (b) by seeing if we got the same
1398 result with minimised carries as with maximised carries. */
1399 *mask
= r1mask
| r2mask
| (lo
^ hi
);
1400 *mask
= wi::ext (*mask
, width
, sgn
);
1401 /* It shouldn't matter whether we choose lo or hi here. */
1408 widest_int temv
, temm
;
1409 bit_value_unop_1 (NEGATE_EXPR
, r2type
, &temv
, &temm
,
1410 r2type
, r2val
, r2mask
);
1411 bit_value_binop_1 (PLUS_EXPR
, type
, val
, mask
,
1412 r1type
, r1val
, r1mask
,
1413 r2type
, temv
, temm
);
1419 /* Just track trailing zeros in both operands and transfer
1420 them to the other. */
1421 int r1tz
= wi::ctz (r1val
| r1mask
);
1422 int r2tz
= wi::ctz (r2val
| r2mask
);
1423 if (r1tz
+ r2tz
>= width
)
1428 else if (r1tz
+ r2tz
> 0)
1430 *mask
= wi::ext (wi::mask
<widest_int
> (r1tz
+ r2tz
, true),
1440 widest_int m
= r1mask
| r2mask
;
1441 if (r1val
.and_not (m
) != r2val
.and_not (m
))
1444 *val
= ((code
== EQ_EXPR
) ? 0 : 1);
1448 /* We know the result of a comparison is always one or zero. */
1458 code
= swap_tree_comparison (code
);
1465 const widest_int
&o1val
= swap_p
? r2val
: r1val
;
1466 const widest_int
&o1mask
= swap_p
? r2mask
: r1mask
;
1467 const widest_int
&o2val
= swap_p
? r1val
: r2val
;
1468 const widest_int
&o2mask
= swap_p
? r1mask
: r2mask
;
1470 /* If the most significant bits are not known we know nothing. */
1471 if (wi::neg_p (o1mask
) || wi::neg_p (o2mask
))
1474 /* For comparisons the signedness is in the comparison operands. */
1475 sgn
= TYPE_SIGN (r1type
);
1477 /* If we know the most significant bits we know the values
1478 value ranges by means of treating varying bits as zero
1479 or one. Do a cross comparison of the max/min pairs. */
1480 maxmin
= wi::cmp (o1val
| o1mask
, o2val
.and_not (o2mask
), sgn
);
1481 minmax
= wi::cmp (o1val
.and_not (o1mask
), o2val
| o2mask
, sgn
);
1482 if (maxmin
< 0) /* o1 is less than o2. */
1487 else if (minmax
> 0) /* o1 is not less or equal to o2. */
1492 else if (maxmin
== minmax
) /* o1 and o2 are equal. */
1494 /* This probably should never happen as we'd have
1495 folded the thing during fully constant value folding. */
1497 *val
= (code
== LE_EXPR
? 1 : 0);
1501 /* We know the result of a comparison is always one or zero. */
1512 /* Return the propagation value when applying the operation CODE to
1513 the value RHS yielding type TYPE. */
1515 static ccp_prop_value_t
1516 bit_value_unop (enum tree_code code
, tree type
, tree rhs
)
1518 ccp_prop_value_t rval
= get_value_for_expr (rhs
, true);
1519 widest_int value
, mask
;
1520 ccp_prop_value_t val
;
1522 if (rval
.lattice_val
== UNDEFINED
)
1525 gcc_assert ((rval
.lattice_val
== CONSTANT
1526 && TREE_CODE (rval
.value
) == INTEGER_CST
)
1527 || wi::sext (rval
.mask
, TYPE_PRECISION (TREE_TYPE (rhs
))) == -1);
1528 bit_value_unop_1 (code
, type
, &value
, &mask
,
1529 TREE_TYPE (rhs
), value_to_wide_int (rval
), rval
.mask
);
1530 if (wi::sext (mask
, TYPE_PRECISION (type
)) != -1)
1532 val
.lattice_val
= CONSTANT
;
1534 /* ??? Delay building trees here. */
1535 val
.value
= wide_int_to_tree (type
, value
);
1539 val
.lattice_val
= VARYING
;
1540 val
.value
= NULL_TREE
;
1546 /* Return the propagation value when applying the operation CODE to
1547 the values RHS1 and RHS2 yielding type TYPE. */
1549 static ccp_prop_value_t
1550 bit_value_binop (enum tree_code code
, tree type
, tree rhs1
, tree rhs2
)
1552 ccp_prop_value_t r1val
= get_value_for_expr (rhs1
, true);
1553 ccp_prop_value_t r2val
= get_value_for_expr (rhs2
, true);
1554 widest_int value
, mask
;
1555 ccp_prop_value_t val
;
1557 if (r1val
.lattice_val
== UNDEFINED
1558 || r2val
.lattice_val
== UNDEFINED
)
1560 val
.lattice_val
= VARYING
;
1561 val
.value
= NULL_TREE
;
1566 gcc_assert ((r1val
.lattice_val
== CONSTANT
1567 && TREE_CODE (r1val
.value
) == INTEGER_CST
)
1568 || wi::sext (r1val
.mask
,
1569 TYPE_PRECISION (TREE_TYPE (rhs1
))) == -1);
1570 gcc_assert ((r2val
.lattice_val
== CONSTANT
1571 && TREE_CODE (r2val
.value
) == INTEGER_CST
)
1572 || wi::sext (r2val
.mask
,
1573 TYPE_PRECISION (TREE_TYPE (rhs2
))) == -1);
1574 bit_value_binop_1 (code
, type
, &value
, &mask
,
1575 TREE_TYPE (rhs1
), value_to_wide_int (r1val
), r1val
.mask
,
1576 TREE_TYPE (rhs2
), value_to_wide_int (r2val
), r2val
.mask
);
1577 if (wi::sext (mask
, TYPE_PRECISION (type
)) != -1)
1579 val
.lattice_val
= CONSTANT
;
1581 /* ??? Delay building trees here. */
1582 val
.value
= wide_int_to_tree (type
, value
);
1586 val
.lattice_val
= VARYING
;
1587 val
.value
= NULL_TREE
;
1593 /* Return the propagation value for __builtin_assume_aligned
1594 and functions with assume_aligned or alloc_aligned attribute.
1595 For __builtin_assume_aligned, ATTR is NULL_TREE,
1596 for assume_aligned attribute ATTR is non-NULL and ALLOC_ALIGNED
1597 is false, for alloc_aligned attribute ATTR is non-NULL and
1598 ALLOC_ALIGNED is true. */
1600 static ccp_prop_value_t
1601 bit_value_assume_aligned (gimple
*stmt
, tree attr
, ccp_prop_value_t ptrval
,
1604 tree align
, misalign
= NULL_TREE
, type
;
1605 unsigned HOST_WIDE_INT aligni
, misaligni
= 0;
1606 ccp_prop_value_t alignval
;
1607 widest_int value
, mask
;
1608 ccp_prop_value_t val
;
1610 if (attr
== NULL_TREE
)
1612 tree ptr
= gimple_call_arg (stmt
, 0);
1613 type
= TREE_TYPE (ptr
);
1614 ptrval
= get_value_for_expr (ptr
, true);
1618 tree lhs
= gimple_call_lhs (stmt
);
1619 type
= TREE_TYPE (lhs
);
1622 if (ptrval
.lattice_val
== UNDEFINED
)
1624 gcc_assert ((ptrval
.lattice_val
== CONSTANT
1625 && TREE_CODE (ptrval
.value
) == INTEGER_CST
)
1626 || wi::sext (ptrval
.mask
, TYPE_PRECISION (type
)) == -1);
1627 if (attr
== NULL_TREE
)
1629 /* Get aligni and misaligni from __builtin_assume_aligned. */
1630 align
= gimple_call_arg (stmt
, 1);
1631 if (!tree_fits_uhwi_p (align
))
1633 aligni
= tree_to_uhwi (align
);
1634 if (gimple_call_num_args (stmt
) > 2)
1636 misalign
= gimple_call_arg (stmt
, 2);
1637 if (!tree_fits_uhwi_p (misalign
))
1639 misaligni
= tree_to_uhwi (misalign
);
1644 /* Get aligni and misaligni from assume_aligned or
1645 alloc_align attributes. */
1646 if (TREE_VALUE (attr
) == NULL_TREE
)
1648 attr
= TREE_VALUE (attr
);
1649 align
= TREE_VALUE (attr
);
1650 if (!tree_fits_uhwi_p (align
))
1652 aligni
= tree_to_uhwi (align
);
1655 if (aligni
== 0 || aligni
> gimple_call_num_args (stmt
))
1657 align
= gimple_call_arg (stmt
, aligni
- 1);
1658 if (!tree_fits_uhwi_p (align
))
1660 aligni
= tree_to_uhwi (align
);
1662 else if (TREE_CHAIN (attr
) && TREE_VALUE (TREE_CHAIN (attr
)))
1664 misalign
= TREE_VALUE (TREE_CHAIN (attr
));
1665 if (!tree_fits_uhwi_p (misalign
))
1667 misaligni
= tree_to_uhwi (misalign
);
1670 if (aligni
<= 1 || (aligni
& (aligni
- 1)) != 0 || misaligni
>= aligni
)
1673 align
= build_int_cst_type (type
, -aligni
);
1674 alignval
= get_value_for_expr (align
, true);
1675 bit_value_binop_1 (BIT_AND_EXPR
, type
, &value
, &mask
,
1676 type
, value_to_wide_int (ptrval
), ptrval
.mask
,
1677 type
, value_to_wide_int (alignval
), alignval
.mask
);
1678 if (wi::sext (mask
, TYPE_PRECISION (type
)) != -1)
1680 val
.lattice_val
= CONSTANT
;
1682 gcc_assert ((mask
.to_uhwi () & (aligni
- 1)) == 0);
1683 gcc_assert ((value
.to_uhwi () & (aligni
- 1)) == 0);
1685 /* ??? Delay building trees here. */
1686 val
.value
= wide_int_to_tree (type
, value
);
1690 val
.lattice_val
= VARYING
;
1691 val
.value
= NULL_TREE
;
1697 /* Evaluate statement STMT.
1698 Valid only for assignments, calls, conditionals, and switches. */
1700 static ccp_prop_value_t
1701 evaluate_stmt (gimple
*stmt
)
1703 ccp_prop_value_t val
;
1704 tree simplified
= NULL_TREE
;
1705 ccp_lattice_t likelyvalue
= likely_value (stmt
);
1706 bool is_constant
= false;
1709 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1711 fprintf (dump_file
, "which is likely ");
1712 switch (likelyvalue
)
1715 fprintf (dump_file
, "CONSTANT");
1718 fprintf (dump_file
, "UNDEFINED");
1721 fprintf (dump_file
, "VARYING");
1725 fprintf (dump_file
, "\n");
1728 /* If the statement is likely to have a CONSTANT result, then try
1729 to fold the statement to determine the constant value. */
1730 /* FIXME. This is the only place that we call ccp_fold.
1731 Since likely_value never returns CONSTANT for calls, we will
1732 not attempt to fold them, including builtins that may profit. */
1733 if (likelyvalue
== CONSTANT
)
1735 fold_defer_overflow_warnings ();
1736 simplified
= ccp_fold (stmt
);
1737 if (simplified
&& TREE_CODE (simplified
) == SSA_NAME
)
1739 val
= *get_value (simplified
);
1740 if (val
.lattice_val
!= VARYING
)
1742 fold_undefer_overflow_warnings (true, stmt
, 0);
1746 is_constant
= simplified
&& is_gimple_min_invariant (simplified
);
1747 fold_undefer_overflow_warnings (is_constant
, stmt
, 0);
1750 /* The statement produced a constant value. */
1751 val
.lattice_val
= CONSTANT
;
1752 val
.value
= simplified
;
1757 /* If the statement is likely to have a VARYING result, then do not
1758 bother folding the statement. */
1759 else if (likelyvalue
== VARYING
)
1761 enum gimple_code code
= gimple_code (stmt
);
1762 if (code
== GIMPLE_ASSIGN
)
1764 enum tree_code subcode
= gimple_assign_rhs_code (stmt
);
1766 /* Other cases cannot satisfy is_gimple_min_invariant
1768 if (get_gimple_rhs_class (subcode
) == GIMPLE_SINGLE_RHS
)
1769 simplified
= gimple_assign_rhs1 (stmt
);
1771 else if (code
== GIMPLE_SWITCH
)
1772 simplified
= gimple_switch_index (as_a
<gswitch
*> (stmt
));
1774 /* These cannot satisfy is_gimple_min_invariant without folding. */
1775 gcc_assert (code
== GIMPLE_CALL
|| code
== GIMPLE_COND
);
1776 is_constant
= simplified
&& is_gimple_min_invariant (simplified
);
1779 /* The statement produced a constant value. */
1780 val
.lattice_val
= CONSTANT
;
1781 val
.value
= simplified
;
1785 /* If the statement result is likely UNDEFINED, make it so. */
1786 else if (likelyvalue
== UNDEFINED
)
1788 val
.lattice_val
= UNDEFINED
;
1789 val
.value
= NULL_TREE
;
1794 /* Resort to simplification for bitwise tracking. */
1795 if (flag_tree_bit_ccp
1796 && (likelyvalue
== CONSTANT
|| is_gimple_call (stmt
)
1797 || (gimple_assign_single_p (stmt
)
1798 && gimple_assign_rhs_code (stmt
) == ADDR_EXPR
))
1801 enum gimple_code code
= gimple_code (stmt
);
1802 val
.lattice_val
= VARYING
;
1803 val
.value
= NULL_TREE
;
1805 if (code
== GIMPLE_ASSIGN
)
1807 enum tree_code subcode
= gimple_assign_rhs_code (stmt
);
1808 tree rhs1
= gimple_assign_rhs1 (stmt
);
1809 tree lhs
= gimple_assign_lhs (stmt
);
1810 if ((INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
1811 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
1812 && (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
1813 || POINTER_TYPE_P (TREE_TYPE (rhs1
))))
1814 switch (get_gimple_rhs_class (subcode
))
1816 case GIMPLE_SINGLE_RHS
:
1817 val
= get_value_for_expr (rhs1
, true);
1820 case GIMPLE_UNARY_RHS
:
1821 val
= bit_value_unop (subcode
, TREE_TYPE (lhs
), rhs1
);
1824 case GIMPLE_BINARY_RHS
:
1825 val
= bit_value_binop (subcode
, TREE_TYPE (lhs
), rhs1
,
1826 gimple_assign_rhs2 (stmt
));
1832 else if (code
== GIMPLE_COND
)
1834 enum tree_code code
= gimple_cond_code (stmt
);
1835 tree rhs1
= gimple_cond_lhs (stmt
);
1836 tree rhs2
= gimple_cond_rhs (stmt
);
1837 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
1838 || POINTER_TYPE_P (TREE_TYPE (rhs1
)))
1839 val
= bit_value_binop (code
, TREE_TYPE (rhs1
), rhs1
, rhs2
);
1841 else if (gimple_call_builtin_p (stmt
, BUILT_IN_NORMAL
))
1843 tree fndecl
= gimple_call_fndecl (stmt
);
1844 switch (DECL_FUNCTION_CODE (fndecl
))
1846 case BUILT_IN_MALLOC
:
1847 case BUILT_IN_REALLOC
:
1848 case BUILT_IN_CALLOC
:
1849 case BUILT_IN_STRDUP
:
1850 case BUILT_IN_STRNDUP
:
1851 val
.lattice_val
= CONSTANT
;
1852 val
.value
= build_int_cst (TREE_TYPE (gimple_get_lhs (stmt
)), 0);
1853 val
.mask
= ~((HOST_WIDE_INT
) MALLOC_ABI_ALIGNMENT
1854 / BITS_PER_UNIT
- 1);
1857 case BUILT_IN_ALLOCA
:
1858 case BUILT_IN_ALLOCA_WITH_ALIGN
:
1859 align
= (DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_ALLOCA_WITH_ALIGN
1860 ? TREE_INT_CST_LOW (gimple_call_arg (stmt
, 1))
1861 : BIGGEST_ALIGNMENT
);
1862 val
.lattice_val
= CONSTANT
;
1863 val
.value
= build_int_cst (TREE_TYPE (gimple_get_lhs (stmt
)), 0);
1864 val
.mask
= ~((HOST_WIDE_INT
) align
/ BITS_PER_UNIT
- 1);
1867 /* These builtins return their first argument, unmodified. */
1868 case BUILT_IN_MEMCPY
:
1869 case BUILT_IN_MEMMOVE
:
1870 case BUILT_IN_MEMSET
:
1871 case BUILT_IN_STRCPY
:
1872 case BUILT_IN_STRNCPY
:
1873 case BUILT_IN_MEMCPY_CHK
:
1874 case BUILT_IN_MEMMOVE_CHK
:
1875 case BUILT_IN_MEMSET_CHK
:
1876 case BUILT_IN_STRCPY_CHK
:
1877 case BUILT_IN_STRNCPY_CHK
:
1878 val
= get_value_for_expr (gimple_call_arg (stmt
, 0), true);
1881 case BUILT_IN_ASSUME_ALIGNED
:
1882 val
= bit_value_assume_aligned (stmt
, NULL_TREE
, val
, false);
1885 case BUILT_IN_ALIGNED_ALLOC
:
1887 tree align
= get_constant_value (gimple_call_arg (stmt
, 0));
1889 && tree_fits_uhwi_p (align
))
1891 unsigned HOST_WIDE_INT aligni
= tree_to_uhwi (align
);
1893 /* align must be power-of-two */
1894 && (aligni
& (aligni
- 1)) == 0)
1896 val
.lattice_val
= CONSTANT
;
1897 val
.value
= build_int_cst (ptr_type_node
, 0);
1907 if (is_gimple_call (stmt
) && gimple_call_lhs (stmt
))
1909 tree fntype
= gimple_call_fntype (stmt
);
1912 tree attrs
= lookup_attribute ("assume_aligned",
1913 TYPE_ATTRIBUTES (fntype
));
1915 val
= bit_value_assume_aligned (stmt
, attrs
, val
, false);
1916 attrs
= lookup_attribute ("alloc_align",
1917 TYPE_ATTRIBUTES (fntype
));
1919 val
= bit_value_assume_aligned (stmt
, attrs
, val
, true);
1922 is_constant
= (val
.lattice_val
== CONSTANT
);
1925 if (flag_tree_bit_ccp
1926 && ((is_constant
&& TREE_CODE (val
.value
) == INTEGER_CST
)
1928 && gimple_get_lhs (stmt
)
1929 && TREE_CODE (gimple_get_lhs (stmt
)) == SSA_NAME
)
1931 tree lhs
= gimple_get_lhs (stmt
);
1932 wide_int nonzero_bits
= get_nonzero_bits (lhs
);
1933 if (nonzero_bits
!= -1)
1937 val
.lattice_val
= CONSTANT
;
1938 val
.value
= build_zero_cst (TREE_TYPE (lhs
));
1939 val
.mask
= extend_mask (nonzero_bits
);
1944 if (wi::bit_and_not (val
.value
, nonzero_bits
) != 0)
1945 val
.value
= wide_int_to_tree (TREE_TYPE (lhs
),
1946 nonzero_bits
& val
.value
);
1947 if (nonzero_bits
== 0)
1950 val
.mask
= val
.mask
& extend_mask (nonzero_bits
);
1955 /* The statement produced a nonconstant value. */
1958 /* The statement produced a copy. */
1959 if (simplified
&& TREE_CODE (simplified
) == SSA_NAME
1960 && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (simplified
))
1962 val
.lattice_val
= CONSTANT
;
1963 val
.value
= simplified
;
1966 /* The statement is VARYING. */
1969 val
.lattice_val
= VARYING
;
1970 val
.value
= NULL_TREE
;
1978 typedef hash_table
<nofree_ptr_hash
<gimple
> > gimple_htab
;
1980 /* Given a BUILT_IN_STACK_SAVE value SAVED_VAL, insert a clobber of VAR before
1981 each matching BUILT_IN_STACK_RESTORE. Mark visited phis in VISITED. */
1984 insert_clobber_before_stack_restore (tree saved_val
, tree var
,
1985 gimple_htab
**visited
)
1988 gassign
*clobber_stmt
;
1990 imm_use_iterator iter
;
1991 gimple_stmt_iterator i
;
1994 FOR_EACH_IMM_USE_STMT (stmt
, iter
, saved_val
)
1995 if (gimple_call_builtin_p (stmt
, BUILT_IN_STACK_RESTORE
))
1997 clobber
= build_constructor (TREE_TYPE (var
),
1999 TREE_THIS_VOLATILE (clobber
) = 1;
2000 clobber_stmt
= gimple_build_assign (var
, clobber
);
2002 i
= gsi_for_stmt (stmt
);
2003 gsi_insert_before (&i
, clobber_stmt
, GSI_SAME_STMT
);
2005 else if (gimple_code (stmt
) == GIMPLE_PHI
)
2008 *visited
= new gimple_htab (10);
2010 slot
= (*visited
)->find_slot (stmt
, INSERT
);
2015 insert_clobber_before_stack_restore (gimple_phi_result (stmt
), var
,
2018 else if (gimple_assign_ssa_name_copy_p (stmt
))
2019 insert_clobber_before_stack_restore (gimple_assign_lhs (stmt
), var
,
2021 else if (chkp_gimple_call_builtin_p (stmt
, BUILT_IN_CHKP_BNDRET
))
2024 gcc_assert (is_gimple_debug (stmt
));
2027 /* Advance the iterator to the previous non-debug gimple statement in the same
2028 or dominating basic block. */
2031 gsi_prev_dom_bb_nondebug (gimple_stmt_iterator
*i
)
2035 gsi_prev_nondebug (i
);
2036 while (gsi_end_p (*i
))
2038 dom
= get_immediate_dominator (CDI_DOMINATORS
, i
->bb
);
2039 if (dom
== NULL
|| dom
== ENTRY_BLOCK_PTR_FOR_FN (cfun
))
2042 *i
= gsi_last_bb (dom
);
2046 /* Find a BUILT_IN_STACK_SAVE dominating gsi_stmt (I), and insert
2047 a clobber of VAR before each matching BUILT_IN_STACK_RESTORE.
2049 It is possible that BUILT_IN_STACK_SAVE cannot be find in a dominator when a
2050 previous pass (such as DOM) duplicated it along multiple paths to a BB. In
2051 that case the function gives up without inserting the clobbers. */
2054 insert_clobbers_for_var (gimple_stmt_iterator i
, tree var
)
2058 gimple_htab
*visited
= NULL
;
2060 for (; !gsi_end_p (i
); gsi_prev_dom_bb_nondebug (&i
))
2062 stmt
= gsi_stmt (i
);
2064 if (!gimple_call_builtin_p (stmt
, BUILT_IN_STACK_SAVE
))
2067 saved_val
= gimple_call_lhs (stmt
);
2068 if (saved_val
== NULL_TREE
)
2071 insert_clobber_before_stack_restore (saved_val
, var
, &visited
);
2078 /* Detects a __builtin_alloca_with_align with constant size argument. Declares
2079 fixed-size array and returns the address, if found, otherwise returns
2083 fold_builtin_alloca_with_align (gimple
*stmt
)
2085 unsigned HOST_WIDE_INT size
, threshold
, n_elem
;
2086 tree lhs
, arg
, block
, var
, elem_type
, array_type
;
2089 lhs
= gimple_call_lhs (stmt
);
2090 if (lhs
== NULL_TREE
)
2093 /* Detect constant argument. */
2094 arg
= get_constant_value (gimple_call_arg (stmt
, 0));
2095 if (arg
== NULL_TREE
2096 || TREE_CODE (arg
) != INTEGER_CST
2097 || !tree_fits_uhwi_p (arg
))
2100 size
= tree_to_uhwi (arg
);
2102 /* Heuristic: don't fold large allocas. */
2103 threshold
= (unsigned HOST_WIDE_INT
)PARAM_VALUE (PARAM_LARGE_STACK_FRAME
);
2104 /* In case the alloca is located at function entry, it has the same lifetime
2105 as a declared array, so we allow a larger size. */
2106 block
= gimple_block (stmt
);
2107 if (!(cfun
->after_inlining
2109 && TREE_CODE (BLOCK_SUPERCONTEXT (block
)) == FUNCTION_DECL
))
2111 if (size
> threshold
)
2114 /* Declare array. */
2115 elem_type
= build_nonstandard_integer_type (BITS_PER_UNIT
, 1);
2116 n_elem
= size
* 8 / BITS_PER_UNIT
;
2117 array_type
= build_array_type_nelts (elem_type
, n_elem
);
2118 var
= create_tmp_var (array_type
);
2119 SET_DECL_ALIGN (var
, TREE_INT_CST_LOW (gimple_call_arg (stmt
, 1)));
2121 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (lhs
);
2122 if (pi
!= NULL
&& !pi
->pt
.anything
)
2126 singleton_p
= pt_solution_singleton_p (&pi
->pt
, &uid
);
2127 gcc_assert (singleton_p
);
2128 SET_DECL_PT_UID (var
, uid
);
2132 /* Fold alloca to the address of the array. */
2133 return fold_convert (TREE_TYPE (lhs
), build_fold_addr_expr (var
));
2136 /* Fold the stmt at *GSI with CCP specific information that propagating
2137 and regular folding does not catch. */
2140 ccp_fold_stmt (gimple_stmt_iterator
*gsi
)
2142 gimple
*stmt
= gsi_stmt (*gsi
);
2144 switch (gimple_code (stmt
))
2148 gcond
*cond_stmt
= as_a
<gcond
*> (stmt
);
2149 ccp_prop_value_t val
;
2150 /* Statement evaluation will handle type mismatches in constants
2151 more gracefully than the final propagation. This allows us to
2152 fold more conditionals here. */
2153 val
= evaluate_stmt (stmt
);
2154 if (val
.lattice_val
!= CONSTANT
2160 fprintf (dump_file
, "Folding predicate ");
2161 print_gimple_expr (dump_file
, stmt
, 0, 0);
2162 fprintf (dump_file
, " to ");
2163 print_generic_expr (dump_file
, val
.value
, 0);
2164 fprintf (dump_file
, "\n");
2167 if (integer_zerop (val
.value
))
2168 gimple_cond_make_false (cond_stmt
);
2170 gimple_cond_make_true (cond_stmt
);
2177 tree lhs
= gimple_call_lhs (stmt
);
2178 int flags
= gimple_call_flags (stmt
);
2181 bool changed
= false;
2184 /* If the call was folded into a constant make sure it goes
2185 away even if we cannot propagate into all uses because of
2188 && TREE_CODE (lhs
) == SSA_NAME
2189 && (val
= get_constant_value (lhs
))
2190 /* Don't optimize away calls that have side-effects. */
2191 && (flags
& (ECF_CONST
|ECF_PURE
)) != 0
2192 && (flags
& ECF_LOOPING_CONST_OR_PURE
) == 0)
2194 tree new_rhs
= unshare_expr (val
);
2196 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
2197 TREE_TYPE (new_rhs
)))
2198 new_rhs
= fold_convert (TREE_TYPE (lhs
), new_rhs
);
2199 res
= update_call_from_tree (gsi
, new_rhs
);
2204 /* Internal calls provide no argument types, so the extra laxity
2205 for normal calls does not apply. */
2206 if (gimple_call_internal_p (stmt
))
2209 /* The heuristic of fold_builtin_alloca_with_align differs before and
2210 after inlining, so we don't require the arg to be changed into a
2211 constant for folding, but just to be constant. */
2212 if (gimple_call_builtin_p (stmt
, BUILT_IN_ALLOCA_WITH_ALIGN
))
2214 tree new_rhs
= fold_builtin_alloca_with_align (stmt
);
2217 bool res
= update_call_from_tree (gsi
, new_rhs
);
2218 tree var
= TREE_OPERAND (TREE_OPERAND (new_rhs
, 0),0);
2220 insert_clobbers_for_var (*gsi
, var
);
2225 /* Propagate into the call arguments. Compared to replace_uses_in
2226 this can use the argument slot types for type verification
2227 instead of the current argument type. We also can safely
2228 drop qualifiers here as we are dealing with constants anyway. */
2229 argt
= TYPE_ARG_TYPES (gimple_call_fntype (stmt
));
2230 for (i
= 0; i
< gimple_call_num_args (stmt
) && argt
;
2231 ++i
, argt
= TREE_CHAIN (argt
))
2233 tree arg
= gimple_call_arg (stmt
, i
);
2234 if (TREE_CODE (arg
) == SSA_NAME
2235 && (val
= get_constant_value (arg
))
2236 && useless_type_conversion_p
2237 (TYPE_MAIN_VARIANT (TREE_VALUE (argt
)),
2238 TYPE_MAIN_VARIANT (TREE_TYPE (val
))))
2240 gimple_call_set_arg (stmt
, i
, unshare_expr (val
));
2250 tree lhs
= gimple_assign_lhs (stmt
);
2253 /* If we have a load that turned out to be constant replace it
2254 as we cannot propagate into all uses in all cases. */
2255 if (gimple_assign_single_p (stmt
)
2256 && TREE_CODE (lhs
) == SSA_NAME
2257 && (val
= get_constant_value (lhs
)))
2259 tree rhs
= unshare_expr (val
);
2260 if (!useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (rhs
)))
2261 rhs
= fold_build1 (VIEW_CONVERT_EXPR
, TREE_TYPE (lhs
), rhs
);
2262 gimple_assign_set_rhs_from_tree (gsi
, rhs
);
2274 /* Visit the assignment statement STMT. Set the value of its LHS to the
2275 value computed by the RHS and store LHS in *OUTPUT_P. If STMT
2276 creates virtual definitions, set the value of each new name to that
2277 of the RHS (if we can derive a constant out of the RHS).
2278 Value-returning call statements also perform an assignment, and
2279 are handled here. */
2281 static enum ssa_prop_result
2282 visit_assignment (gimple
*stmt
, tree
*output_p
)
2284 ccp_prop_value_t val
;
2285 enum ssa_prop_result retval
= SSA_PROP_NOT_INTERESTING
;
2287 tree lhs
= gimple_get_lhs (stmt
);
2288 if (TREE_CODE (lhs
) == SSA_NAME
)
2290 /* Evaluate the statement, which could be
2291 either a GIMPLE_ASSIGN or a GIMPLE_CALL. */
2292 val
= evaluate_stmt (stmt
);
2294 /* If STMT is an assignment to an SSA_NAME, we only have one
2296 if (set_lattice_value (lhs
, &val
))
2299 if (val
.lattice_val
== VARYING
)
2300 retval
= SSA_PROP_VARYING
;
2302 retval
= SSA_PROP_INTERESTING
;
2310 /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING
2311 if it can determine which edge will be taken. Otherwise, return
2312 SSA_PROP_VARYING. */
2314 static enum ssa_prop_result
2315 visit_cond_stmt (gimple
*stmt
, edge
*taken_edge_p
)
2317 ccp_prop_value_t val
;
2320 block
= gimple_bb (stmt
);
2321 val
= evaluate_stmt (stmt
);
2322 if (val
.lattice_val
!= CONSTANT
2324 return SSA_PROP_VARYING
;
2326 /* Find which edge out of the conditional block will be taken and add it
2327 to the worklist. If no single edge can be determined statically,
2328 return SSA_PROP_VARYING to feed all the outgoing edges to the
2329 propagation engine. */
2330 *taken_edge_p
= find_taken_edge (block
, val
.value
);
2332 return SSA_PROP_INTERESTING
;
2334 return SSA_PROP_VARYING
;
2338 /* Evaluate statement STMT. If the statement produces an output value and
2339 its evaluation changes the lattice value of its output, return
2340 SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the
2343 If STMT is a conditional branch and we can determine its truth
2344 value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying
2345 value, return SSA_PROP_VARYING. */
2347 static enum ssa_prop_result
2348 ccp_visit_stmt (gimple
*stmt
, edge
*taken_edge_p
, tree
*output_p
)
2353 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2355 fprintf (dump_file
, "\nVisiting statement:\n");
2356 print_gimple_stmt (dump_file
, stmt
, 0, dump_flags
);
2359 switch (gimple_code (stmt
))
2362 /* If the statement is an assignment that produces a single
2363 output value, evaluate its RHS to see if the lattice value of
2364 its output has changed. */
2365 return visit_assignment (stmt
, output_p
);
2368 /* A value-returning call also performs an assignment. */
2369 if (gimple_call_lhs (stmt
) != NULL_TREE
)
2370 return visit_assignment (stmt
, output_p
);
2375 /* If STMT is a conditional branch, see if we can determine
2376 which branch will be taken. */
2377 /* FIXME. It appears that we should be able to optimize
2378 computed GOTOs here as well. */
2379 return visit_cond_stmt (stmt
, taken_edge_p
);
2385 /* Any other kind of statement is not interesting for constant
2386 propagation and, therefore, not worth simulating. */
2387 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2388 fprintf (dump_file
, "No interesting values produced. Marked VARYING.\n");
2390 /* Definitions made by statements other than assignments to
2391 SSA_NAMEs represent unknown modifications to their outputs.
2392 Mark them VARYING. */
2393 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_ALL_DEFS
)
2394 set_value_varying (def
);
2396 return SSA_PROP_VARYING
;
2400 /* Main entry point for SSA Conditional Constant Propagation. If NONZERO_P,
2401 record nonzero bits. */
2404 do_ssa_ccp (bool nonzero_p
)
2406 unsigned int todo
= 0;
2407 calculate_dominance_info (CDI_DOMINATORS
);
2410 ssa_propagate (ccp_visit_stmt
, ccp_visit_phi_node
);
2411 if (ccp_finalize (nonzero_p
))
2413 todo
= (TODO_cleanup_cfg
| TODO_update_ssa
);
2415 /* ccp_finalize does not preserve loop-closed ssa. */
2416 loops_state_clear (LOOP_CLOSED_SSA
);
2419 free_dominance_info (CDI_DOMINATORS
);
2426 const pass_data pass_data_ccp
=
2428 GIMPLE_PASS
, /* type */
2430 OPTGROUP_NONE
, /* optinfo_flags */
2431 TV_TREE_CCP
, /* tv_id */
2432 ( PROP_cfg
| PROP_ssa
), /* properties_required */
2433 0, /* properties_provided */
2434 0, /* properties_destroyed */
2435 0, /* todo_flags_start */
2436 TODO_update_address_taken
, /* todo_flags_finish */
2439 class pass_ccp
: public gimple_opt_pass
2442 pass_ccp (gcc::context
*ctxt
)
2443 : gimple_opt_pass (pass_data_ccp
, ctxt
), nonzero_p (false)
2446 /* opt_pass methods: */
2447 opt_pass
* clone () { return new pass_ccp (m_ctxt
); }
2448 void set_pass_param (unsigned int n
, bool param
)
2450 gcc_assert (n
== 0);
2453 virtual bool gate (function
*) { return flag_tree_ccp
!= 0; }
2454 virtual unsigned int execute (function
*) { return do_ssa_ccp (nonzero_p
); }
2457 /* Determines whether the pass instance records nonzero bits. */
2459 }; // class pass_ccp
2464 make_pass_ccp (gcc::context
*ctxt
)
2466 return new pass_ccp (ctxt
);
2471 /* Try to optimize out __builtin_stack_restore. Optimize it out
2472 if there is another __builtin_stack_restore in the same basic
2473 block and no calls or ASM_EXPRs are in between, or if this block's
2474 only outgoing edge is to EXIT_BLOCK and there are no calls or
2475 ASM_EXPRs after this __builtin_stack_restore. */
2478 optimize_stack_restore (gimple_stmt_iterator i
)
2483 basic_block bb
= gsi_bb (i
);
2484 gimple
*call
= gsi_stmt (i
);
2486 if (gimple_code (call
) != GIMPLE_CALL
2487 || gimple_call_num_args (call
) != 1
2488 || TREE_CODE (gimple_call_arg (call
, 0)) != SSA_NAME
2489 || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call
, 0))))
2492 for (gsi_next (&i
); !gsi_end_p (i
); gsi_next (&i
))
2494 stmt
= gsi_stmt (i
);
2495 if (gimple_code (stmt
) == GIMPLE_ASM
)
2497 if (gimple_code (stmt
) != GIMPLE_CALL
)
2500 callee
= gimple_call_fndecl (stmt
);
2502 || DECL_BUILT_IN_CLASS (callee
) != BUILT_IN_NORMAL
2503 /* All regular builtins are ok, just obviously not alloca. */
2504 || DECL_FUNCTION_CODE (callee
) == BUILT_IN_ALLOCA
2505 || DECL_FUNCTION_CODE (callee
) == BUILT_IN_ALLOCA_WITH_ALIGN
)
2508 if (DECL_FUNCTION_CODE (callee
) == BUILT_IN_STACK_RESTORE
)
2509 goto second_stack_restore
;
2515 /* Allow one successor of the exit block, or zero successors. */
2516 switch (EDGE_COUNT (bb
->succs
))
2521 if (single_succ_edge (bb
)->dest
!= EXIT_BLOCK_PTR_FOR_FN (cfun
))
2527 second_stack_restore
:
2529 /* If there's exactly one use, then zap the call to __builtin_stack_save.
2530 If there are multiple uses, then the last one should remove the call.
2531 In any case, whether the call to __builtin_stack_save can be removed
2532 or not is irrelevant to removing the call to __builtin_stack_restore. */
2533 if (has_single_use (gimple_call_arg (call
, 0)))
2535 gimple
*stack_save
= SSA_NAME_DEF_STMT (gimple_call_arg (call
, 0));
2536 if (is_gimple_call (stack_save
))
2538 callee
= gimple_call_fndecl (stack_save
);
2540 && DECL_BUILT_IN_CLASS (callee
) == BUILT_IN_NORMAL
2541 && DECL_FUNCTION_CODE (callee
) == BUILT_IN_STACK_SAVE
)
2543 gimple_stmt_iterator stack_save_gsi
;
2546 stack_save_gsi
= gsi_for_stmt (stack_save
);
2547 rhs
= build_int_cst (TREE_TYPE (gimple_call_arg (call
, 0)), 0);
2548 update_call_from_tree (&stack_save_gsi
, rhs
);
2553 /* No effect, so the statement will be deleted. */
2554 return integer_zero_node
;
2557 /* If va_list type is a simple pointer and nothing special is needed,
2558 optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0),
2559 __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple
2560 pointer assignment. */
2563 optimize_stdarg_builtin (gimple
*call
)
2565 tree callee
, lhs
, rhs
, cfun_va_list
;
2566 bool va_list_simple_ptr
;
2567 location_t loc
= gimple_location (call
);
2569 if (gimple_code (call
) != GIMPLE_CALL
)
2572 callee
= gimple_call_fndecl (call
);
2574 cfun_va_list
= targetm
.fn_abi_va_list (callee
);
2575 va_list_simple_ptr
= POINTER_TYPE_P (cfun_va_list
)
2576 && (TREE_TYPE (cfun_va_list
) == void_type_node
2577 || TREE_TYPE (cfun_va_list
) == char_type_node
);
2579 switch (DECL_FUNCTION_CODE (callee
))
2581 case BUILT_IN_VA_START
:
2582 if (!va_list_simple_ptr
2583 || targetm
.expand_builtin_va_start
!= NULL
2584 || !builtin_decl_explicit_p (BUILT_IN_NEXT_ARG
))
2587 if (gimple_call_num_args (call
) != 2)
2590 lhs
= gimple_call_arg (call
, 0);
2591 if (!POINTER_TYPE_P (TREE_TYPE (lhs
))
2592 || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs
)))
2593 != TYPE_MAIN_VARIANT (cfun_va_list
))
2596 lhs
= build_fold_indirect_ref_loc (loc
, lhs
);
2597 rhs
= build_call_expr_loc (loc
, builtin_decl_explicit (BUILT_IN_NEXT_ARG
),
2598 1, integer_zero_node
);
2599 rhs
= fold_convert_loc (loc
, TREE_TYPE (lhs
), rhs
);
2600 return build2 (MODIFY_EXPR
, TREE_TYPE (lhs
), lhs
, rhs
);
2602 case BUILT_IN_VA_COPY
:
2603 if (!va_list_simple_ptr
)
2606 if (gimple_call_num_args (call
) != 2)
2609 lhs
= gimple_call_arg (call
, 0);
2610 if (!POINTER_TYPE_P (TREE_TYPE (lhs
))
2611 || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs
)))
2612 != TYPE_MAIN_VARIANT (cfun_va_list
))
2615 lhs
= build_fold_indirect_ref_loc (loc
, lhs
);
2616 rhs
= gimple_call_arg (call
, 1);
2617 if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs
))
2618 != TYPE_MAIN_VARIANT (cfun_va_list
))
2621 rhs
= fold_convert_loc (loc
, TREE_TYPE (lhs
), rhs
);
2622 return build2 (MODIFY_EXPR
, TREE_TYPE (lhs
), lhs
, rhs
);
2624 case BUILT_IN_VA_END
:
2625 /* No effect, so the statement will be deleted. */
2626 return integer_zero_node
;
2633 /* Attemp to make the block of __builtin_unreachable I unreachable by changing
2634 the incoming jumps. Return true if at least one jump was changed. */
2637 optimize_unreachable (gimple_stmt_iterator i
)
2639 basic_block bb
= gsi_bb (i
);
2640 gimple_stmt_iterator gsi
;
2646 if (flag_sanitize
& SANITIZE_UNREACHABLE
)
2649 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
2651 stmt
= gsi_stmt (gsi
);
2653 if (is_gimple_debug (stmt
))
2656 if (glabel
*label_stmt
= dyn_cast
<glabel
*> (stmt
))
2658 /* Verify we do not need to preserve the label. */
2659 if (FORCED_LABEL (gimple_label_label (label_stmt
)))
2665 /* Only handle the case that __builtin_unreachable is the first statement
2666 in the block. We rely on DCE to remove stmts without side-effects
2667 before __builtin_unreachable. */
2668 if (gsi_stmt (gsi
) != gsi_stmt (i
))
2673 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
2675 gsi
= gsi_last_bb (e
->src
);
2676 if (gsi_end_p (gsi
))
2679 stmt
= gsi_stmt (gsi
);
2680 if (gcond
*cond_stmt
= dyn_cast
<gcond
*> (stmt
))
2682 if (e
->flags
& EDGE_TRUE_VALUE
)
2683 gimple_cond_make_false (cond_stmt
);
2684 else if (e
->flags
& EDGE_FALSE_VALUE
)
2685 gimple_cond_make_true (cond_stmt
);
2688 update_stmt (cond_stmt
);
2692 /* Todo: handle other cases, f.i. switch statement. */
2703 mask_2 = 1 << cnt_1;
2704 _4 = __atomic_fetch_or_* (ptr_6, mask_2, _3);
2707 _4 = ATOMIC_BIT_TEST_AND_SET (ptr_6, cnt_1, 0, _3);
2709 If _5 is only used in _5 != 0 or _5 == 0 comparisons, 1
2710 is passed instead of 0, and the builtin just returns a zero
2711 or 1 value instead of the actual bit.
2712 Similarly for __sync_fetch_and_or_* (without the ", _3" part
2713 in there), and/or if mask_2 is a power of 2 constant.
2714 Similarly for xor instead of or, use ATOMIC_BIT_TEST_AND_COMPLEMENT
2715 in that case. And similarly for and instead of or, except that
2716 the second argument to the builtin needs to be one's complement
2717 of the mask instead of mask. */
2720 optimize_atomic_bit_test_and (gimple_stmt_iterator
*gsip
,
2721 enum internal_fn fn
, bool has_model_arg
,
2724 gimple
*call
= gsi_stmt (*gsip
);
2725 tree lhs
= gimple_call_lhs (call
);
2726 use_operand_p use_p
;
2731 if (!flag_inline_atomics
2733 || !gimple_call_builtin_p (call
, BUILT_IN_NORMAL
)
2735 || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs
)
2736 || !single_imm_use (lhs
, &use_p
, &use_stmt
)
2737 || !is_gimple_assign (use_stmt
)
2738 || gimple_assign_rhs_code (use_stmt
) != BIT_AND_EXPR
2739 || !gimple_vdef (call
))
2744 case IFN_ATOMIC_BIT_TEST_AND_SET
:
2745 optab
= atomic_bit_test_and_set_optab
;
2747 case IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT
:
2748 optab
= atomic_bit_test_and_complement_optab
;
2750 case IFN_ATOMIC_BIT_TEST_AND_RESET
:
2751 optab
= atomic_bit_test_and_reset_optab
;
2757 if (optab_handler (optab
, TYPE_MODE (TREE_TYPE (lhs
))) == CODE_FOR_nothing
)
2760 mask
= gimple_call_arg (call
, 1);
2761 tree use_lhs
= gimple_assign_lhs (use_stmt
);
2765 if (TREE_CODE (mask
) == INTEGER_CST
)
2767 if (fn
== IFN_ATOMIC_BIT_TEST_AND_RESET
)
2768 mask
= const_unop (BIT_NOT_EXPR
, TREE_TYPE (mask
), mask
);
2769 mask
= fold_convert (TREE_TYPE (lhs
), mask
);
2770 int ibit
= tree_log2 (mask
);
2773 bit
= build_int_cst (TREE_TYPE (lhs
), ibit
);
2775 else if (TREE_CODE (mask
) == SSA_NAME
)
2777 gimple
*g
= SSA_NAME_DEF_STMT (mask
);
2778 if (fn
== IFN_ATOMIC_BIT_TEST_AND_RESET
)
2780 if (!is_gimple_assign (g
)
2781 || gimple_assign_rhs_code (g
) != BIT_NOT_EXPR
)
2783 mask
= gimple_assign_rhs1 (g
);
2784 if (TREE_CODE (mask
) != SSA_NAME
)
2786 g
= SSA_NAME_DEF_STMT (mask
);
2788 if (!is_gimple_assign (g
)
2789 || gimple_assign_rhs_code (g
) != LSHIFT_EXPR
2790 || !integer_onep (gimple_assign_rhs1 (g
)))
2792 bit
= gimple_assign_rhs2 (g
);
2797 if (gimple_assign_rhs1 (use_stmt
) == lhs
)
2799 if (!operand_equal_p (gimple_assign_rhs2 (use_stmt
), mask
, 0))
2802 else if (gimple_assign_rhs2 (use_stmt
) != lhs
2803 || !operand_equal_p (gimple_assign_rhs1 (use_stmt
), mask
, 0))
2806 bool use_bool
= true;
2807 bool has_debug_uses
= false;
2808 imm_use_iterator iter
;
2811 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (use_lhs
))
2813 FOR_EACH_IMM_USE_STMT (g
, iter
, use_lhs
)
2815 enum tree_code code
= ERROR_MARK
;
2817 if (is_gimple_debug (g
))
2819 has_debug_uses
= true;
2822 else if (is_gimple_assign (g
))
2823 switch (gimple_assign_rhs_code (g
))
2826 op1
= gimple_assign_rhs1 (g
);
2827 code
= TREE_CODE (op1
);
2828 op0
= TREE_OPERAND (op1
, 0);
2829 op1
= TREE_OPERAND (op1
, 1);
2833 code
= gimple_assign_rhs_code (g
);
2834 op0
= gimple_assign_rhs1 (g
);
2835 op1
= gimple_assign_rhs2 (g
);
2840 else if (gimple_code (g
) == GIMPLE_COND
)
2842 code
= gimple_cond_code (g
);
2843 op0
= gimple_cond_lhs (g
);
2844 op1
= gimple_cond_rhs (g
);
2847 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
2849 && integer_zerop (op1
))
2851 use_operand_p use_p
;
2853 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
2860 BREAK_FROM_IMM_USE_STMT (iter
);
2863 tree new_lhs
= make_ssa_name (TREE_TYPE (lhs
));
2864 tree flag
= build_int_cst (TREE_TYPE (lhs
), use_bool
);
2866 g
= gimple_build_call_internal (fn
, 4, gimple_call_arg (call
, 0),
2867 bit
, flag
, gimple_call_arg (call
, 2));
2869 g
= gimple_build_call_internal (fn
, 3, gimple_call_arg (call
, 0),
2871 gimple_call_set_lhs (g
, new_lhs
);
2872 gimple_set_location (g
, gimple_location (call
));
2873 gimple_set_vuse (g
, gimple_vuse (call
));
2874 gimple_set_vdef (g
, gimple_vdef (call
));
2875 SSA_NAME_DEF_STMT (gimple_vdef (call
)) = g
;
2876 gimple_stmt_iterator gsi
= *gsip
;
2877 gsi_insert_after (&gsi
, g
, GSI_NEW_STMT
);
2880 /* The internal function returns the value of the specified bit
2881 before the atomic operation. If we are interested in the value
2882 of the specified bit after the atomic operation (makes only sense
2883 for xor, otherwise the bit content is compile time known),
2884 we need to invert the bit. */
2885 g
= gimple_build_assign (make_ssa_name (TREE_TYPE (lhs
)),
2886 BIT_XOR_EXPR
, new_lhs
,
2887 use_bool
? build_int_cst (TREE_TYPE (lhs
), 1)
2889 new_lhs
= gimple_assign_lhs (g
);
2890 gsi_insert_after (&gsi
, g
, GSI_NEW_STMT
);
2892 if (use_bool
&& has_debug_uses
)
2894 tree temp
= make_node (DEBUG_EXPR_DECL
);
2895 DECL_ARTIFICIAL (temp
) = 1;
2896 TREE_TYPE (temp
) = TREE_TYPE (lhs
);
2897 DECL_MODE (temp
) = TYPE_MODE (TREE_TYPE (lhs
));
2898 tree t
= build2 (LSHIFT_EXPR
, TREE_TYPE (lhs
), new_lhs
, bit
);
2899 g
= gimple_build_debug_bind (temp
, t
, g
);
2900 gsi_insert_after (&gsi
, g
, GSI_NEW_STMT
);
2901 FOR_EACH_IMM_USE_STMT (g
, iter
, use_lhs
)
2902 if (is_gimple_debug (g
))
2904 use_operand_p use_p
;
2905 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
2906 SET_USE (use_p
, temp
);
2910 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_lhs
)
2911 = SSA_NAME_OCCURS_IN_ABNORMAL_PHI (use_lhs
);
2912 replace_uses_by (use_lhs
, new_lhs
);
2913 gsi
= gsi_for_stmt (use_stmt
);
2914 gsi_remove (&gsi
, true);
2915 release_defs (use_stmt
);
2916 gsi_remove (gsip
, true);
2917 release_ssa_name (lhs
);
2920 /* A simple pass that attempts to fold all builtin functions. This pass
2921 is run after we've propagated as many constants as we can. */
2925 const pass_data pass_data_fold_builtins
=
2927 GIMPLE_PASS
, /* type */
2929 OPTGROUP_NONE
, /* optinfo_flags */
2930 TV_NONE
, /* tv_id */
2931 ( PROP_cfg
| PROP_ssa
), /* properties_required */
2932 0, /* properties_provided */
2933 0, /* properties_destroyed */
2934 0, /* todo_flags_start */
2935 TODO_update_ssa
, /* todo_flags_finish */
2938 class pass_fold_builtins
: public gimple_opt_pass
2941 pass_fold_builtins (gcc::context
*ctxt
)
2942 : gimple_opt_pass (pass_data_fold_builtins
, ctxt
)
2945 /* opt_pass methods: */
2946 opt_pass
* clone () { return new pass_fold_builtins (m_ctxt
); }
2947 virtual unsigned int execute (function
*);
2949 }; // class pass_fold_builtins
2952 pass_fold_builtins::execute (function
*fun
)
2954 bool cfg_changed
= false;
2956 unsigned int todoflags
= 0;
2958 FOR_EACH_BB_FN (bb
, fun
)
2960 gimple_stmt_iterator i
;
2961 for (i
= gsi_start_bb (bb
); !gsi_end_p (i
); )
2963 gimple
*stmt
, *old_stmt
;
2965 enum built_in_function fcode
;
2967 stmt
= gsi_stmt (i
);
2969 if (gimple_code (stmt
) != GIMPLE_CALL
)
2971 /* Remove all *ssaname_N ={v} {CLOBBER}; stmts,
2972 after the last GIMPLE DSE they aren't needed and might
2973 unnecessarily keep the SSA_NAMEs live. */
2974 if (gimple_clobber_p (stmt
))
2976 tree lhs
= gimple_assign_lhs (stmt
);
2977 if (TREE_CODE (lhs
) == MEM_REF
2978 && TREE_CODE (TREE_OPERAND (lhs
, 0)) == SSA_NAME
)
2980 unlink_stmt_vdef (stmt
);
2981 gsi_remove (&i
, true);
2982 release_defs (stmt
);
2990 callee
= gimple_call_fndecl (stmt
);
2991 if (!callee
|| DECL_BUILT_IN_CLASS (callee
) != BUILT_IN_NORMAL
)
2997 fcode
= DECL_FUNCTION_CODE (callee
);
3002 tree result
= NULL_TREE
;
3003 switch (DECL_FUNCTION_CODE (callee
))
3005 case BUILT_IN_CONSTANT_P
:
3006 /* Resolve __builtin_constant_p. If it hasn't been
3007 folded to integer_one_node by now, it's fairly
3008 certain that the value simply isn't constant. */
3009 result
= integer_zero_node
;
3012 case BUILT_IN_ASSUME_ALIGNED
:
3013 /* Remove __builtin_assume_aligned. */
3014 result
= gimple_call_arg (stmt
, 0);
3017 case BUILT_IN_STACK_RESTORE
:
3018 result
= optimize_stack_restore (i
);
3024 case BUILT_IN_UNREACHABLE
:
3025 if (optimize_unreachable (i
))
3029 case BUILT_IN_ATOMIC_FETCH_OR_1
:
3030 case BUILT_IN_ATOMIC_FETCH_OR_2
:
3031 case BUILT_IN_ATOMIC_FETCH_OR_4
:
3032 case BUILT_IN_ATOMIC_FETCH_OR_8
:
3033 case BUILT_IN_ATOMIC_FETCH_OR_16
:
3034 optimize_atomic_bit_test_and (&i
,
3035 IFN_ATOMIC_BIT_TEST_AND_SET
,
3038 case BUILT_IN_SYNC_FETCH_AND_OR_1
:
3039 case BUILT_IN_SYNC_FETCH_AND_OR_2
:
3040 case BUILT_IN_SYNC_FETCH_AND_OR_4
:
3041 case BUILT_IN_SYNC_FETCH_AND_OR_8
:
3042 case BUILT_IN_SYNC_FETCH_AND_OR_16
:
3043 optimize_atomic_bit_test_and (&i
,
3044 IFN_ATOMIC_BIT_TEST_AND_SET
,
3048 case BUILT_IN_ATOMIC_FETCH_XOR_1
:
3049 case BUILT_IN_ATOMIC_FETCH_XOR_2
:
3050 case BUILT_IN_ATOMIC_FETCH_XOR_4
:
3051 case BUILT_IN_ATOMIC_FETCH_XOR_8
:
3052 case BUILT_IN_ATOMIC_FETCH_XOR_16
:
3053 optimize_atomic_bit_test_and
3054 (&i
, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT
, true, false);
3056 case BUILT_IN_SYNC_FETCH_AND_XOR_1
:
3057 case BUILT_IN_SYNC_FETCH_AND_XOR_2
:
3058 case BUILT_IN_SYNC_FETCH_AND_XOR_4
:
3059 case BUILT_IN_SYNC_FETCH_AND_XOR_8
:
3060 case BUILT_IN_SYNC_FETCH_AND_XOR_16
:
3061 optimize_atomic_bit_test_and
3062 (&i
, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT
, false, false);
3065 case BUILT_IN_ATOMIC_XOR_FETCH_1
:
3066 case BUILT_IN_ATOMIC_XOR_FETCH_2
:
3067 case BUILT_IN_ATOMIC_XOR_FETCH_4
:
3068 case BUILT_IN_ATOMIC_XOR_FETCH_8
:
3069 case BUILT_IN_ATOMIC_XOR_FETCH_16
:
3070 optimize_atomic_bit_test_and
3071 (&i
, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT
, true, true);
3073 case BUILT_IN_SYNC_XOR_AND_FETCH_1
:
3074 case BUILT_IN_SYNC_XOR_AND_FETCH_2
:
3075 case BUILT_IN_SYNC_XOR_AND_FETCH_4
:
3076 case BUILT_IN_SYNC_XOR_AND_FETCH_8
:
3077 case BUILT_IN_SYNC_XOR_AND_FETCH_16
:
3078 optimize_atomic_bit_test_and
3079 (&i
, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT
, false, true);
3082 case BUILT_IN_ATOMIC_FETCH_AND_1
:
3083 case BUILT_IN_ATOMIC_FETCH_AND_2
:
3084 case BUILT_IN_ATOMIC_FETCH_AND_4
:
3085 case BUILT_IN_ATOMIC_FETCH_AND_8
:
3086 case BUILT_IN_ATOMIC_FETCH_AND_16
:
3087 optimize_atomic_bit_test_and (&i
,
3088 IFN_ATOMIC_BIT_TEST_AND_RESET
,
3091 case BUILT_IN_SYNC_FETCH_AND_AND_1
:
3092 case BUILT_IN_SYNC_FETCH_AND_AND_2
:
3093 case BUILT_IN_SYNC_FETCH_AND_AND_4
:
3094 case BUILT_IN_SYNC_FETCH_AND_AND_8
:
3095 case BUILT_IN_SYNC_FETCH_AND_AND_16
:
3096 optimize_atomic_bit_test_and (&i
,
3097 IFN_ATOMIC_BIT_TEST_AND_RESET
,
3101 case BUILT_IN_VA_START
:
3102 case BUILT_IN_VA_END
:
3103 case BUILT_IN_VA_COPY
:
3104 /* These shouldn't be folded before pass_stdarg. */
3105 result
= optimize_stdarg_builtin (stmt
);
3119 if (!update_call_from_tree (&i
, result
))
3120 gimplify_and_update_call_from_tree (&i
, result
);
3123 todoflags
|= TODO_update_address_taken
;
3125 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3127 fprintf (dump_file
, "Simplified\n ");
3128 print_gimple_stmt (dump_file
, stmt
, 0, dump_flags
);
3132 stmt
= gsi_stmt (i
);
3135 if (maybe_clean_or_replace_eh_stmt (old_stmt
, stmt
)
3136 && gimple_purge_dead_eh_edges (bb
))
3139 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3141 fprintf (dump_file
, "to\n ");
3142 print_gimple_stmt (dump_file
, stmt
, 0, dump_flags
);
3143 fprintf (dump_file
, "\n");
3146 /* Retry the same statement if it changed into another
3147 builtin, there might be new opportunities now. */
3148 if (gimple_code (stmt
) != GIMPLE_CALL
)
3153 callee
= gimple_call_fndecl (stmt
);
3155 || DECL_BUILT_IN_CLASS (callee
) != BUILT_IN_NORMAL
3156 || DECL_FUNCTION_CODE (callee
) == fcode
)
3161 /* Delete unreachable blocks. */
3163 todoflags
|= TODO_cleanup_cfg
;
3171 make_pass_fold_builtins (gcc::context
*ctxt
)
3173 return new pass_fold_builtins (ctxt
);