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"
145 #include "tree-ssa-ccp.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, based on sgn. */
237 extend_mask (const wide_int
&nonzero_bits
, signop sgn
)
239 return widest_int::from (nonzero_bits
, sgn
);
242 /* Compute a default value for variable VAR and store it in the
243 CONST_VAL array. The following rules are used to get default
246 1- Global and static variables that are declared constant are
249 2- Any other value is considered UNDEFINED. This is useful when
250 considering PHI nodes. PHI arguments that are undefined do not
251 change the constant value of the PHI node, which allows for more
252 constants to be propagated.
254 3- Variables defined by statements other than assignments and PHI
255 nodes are considered VARYING.
257 4- Initial values of variables that are not GIMPLE registers are
258 considered VARYING. */
260 static ccp_prop_value_t
261 get_default_value (tree var
)
263 ccp_prop_value_t val
= { UNINITIALIZED
, NULL_TREE
, 0 };
266 stmt
= SSA_NAME_DEF_STMT (var
);
268 if (gimple_nop_p (stmt
))
270 /* Variables defined by an empty statement are those used
271 before being initialized. If VAR is a local variable, we
272 can assume initially that it is UNDEFINED, otherwise we must
273 consider it VARYING. */
274 if (!virtual_operand_p (var
)
275 && SSA_NAME_VAR (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
, TYPE_SIGN (TREE_TYPE (var
)));
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 void bit_value_binop (enum tree_code
, signop
, int, widest_int
*, widest_int
*,
540 signop
, int, const widest_int
&, const widest_int
&,
541 signop
, int, 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
;
905 /* Derive alignment and misalignment information from partially
906 constant pointers in the lattice or nonzero bits from partially
907 constant integers. */
908 FOR_EACH_SSA_NAME (i
, name
, cfun
)
910 ccp_prop_value_t
*val
;
911 unsigned int tem
, align
;
913 if (!POINTER_TYPE_P (TREE_TYPE (name
))
914 && (!INTEGRAL_TYPE_P (TREE_TYPE (name
))
915 /* Don't record nonzero bits before IPA to avoid
916 using too much memory. */
920 val
= get_value (name
);
921 if (val
->lattice_val
!= CONSTANT
922 || 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
= least_bit_hwi (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 (enum tree_code code
, signop type_sgn
, int type_precision
,
1229 widest_int
*val
, widest_int
*mask
,
1230 signop rtype_sgn
, int rtype_precision
,
1231 const widest_int
&rval
, const widest_int
&rmask
)
1242 widest_int temv
, temm
;
1243 /* Return ~rval + 1. */
1244 bit_value_unop (BIT_NOT_EXPR
, type_sgn
, type_precision
, &temv
, &temm
,
1245 type_sgn
, type_precision
, rval
, rmask
);
1246 bit_value_binop (PLUS_EXPR
, type_sgn
, type_precision
, val
, mask
,
1247 type_sgn
, type_precision
, temv
, temm
,
1248 type_sgn
, type_precision
, 1, 0);
1254 /* First extend mask and value according to the original type. */
1255 *mask
= wi::ext (rmask
, rtype_precision
, rtype_sgn
);
1256 *val
= wi::ext (rval
, rtype_precision
, rtype_sgn
);
1258 /* Then extend mask and value according to the target type. */
1259 *mask
= wi::ext (*mask
, type_precision
, type_sgn
);
1260 *val
= wi::ext (*val
, type_precision
, type_sgn
);
1270 /* Apply the operation CODE in type TYPE to the value, mask pairs
1271 R1VAL, R1MASK and R2VAL, R2MASK representing a values of type R1TYPE
1272 and R2TYPE and set the value, mask pair *VAL and *MASK to the result. */
1275 bit_value_binop (enum tree_code code
, signop sgn
, int width
,
1276 widest_int
*val
, widest_int
*mask
,
1277 signop r1type_sgn
, int r1type_precision
,
1278 const widest_int
&r1val
, const widest_int
&r1mask
,
1279 signop r2type_sgn
, int r2type_precision
,
1280 const widest_int
&r2val
, const widest_int
&r2mask
)
1282 bool swap_p
= false;
1284 /* Assume we'll get a constant result. Use an initial non varying
1285 value, we fall back to varying in the end if necessary. */
1291 /* The mask is constant where there is a known not
1292 set bit, (m1 | m2) & ((v1 | m1) & (v2 | m2)) */
1293 *mask
= (r1mask
| r2mask
) & (r1val
| r1mask
) & (r2val
| r2mask
);
1294 *val
= r1val
& r2val
;
1298 /* The mask is constant where there is a known
1299 set bit, (m1 | m2) & ~((v1 & ~m1) | (v2 & ~m2)). */
1300 *mask
= (r1mask
| r2mask
)
1301 .and_not (r1val
.and_not (r1mask
) | r2val
.and_not (r2mask
));
1302 *val
= r1val
| r2val
;
1307 *mask
= r1mask
| r2mask
;
1308 *val
= r1val
^ r2val
;
1315 widest_int shift
= r2val
;
1323 if (wi::neg_p (shift
))
1326 if (code
== RROTATE_EXPR
)
1327 code
= LROTATE_EXPR
;
1329 code
= RROTATE_EXPR
;
1331 if (code
== RROTATE_EXPR
)
1333 *mask
= wi::rrotate (r1mask
, shift
, width
);
1334 *val
= wi::rrotate (r1val
, shift
, width
);
1338 *mask
= wi::lrotate (r1mask
, shift
, width
);
1339 *val
= wi::lrotate (r1val
, shift
, width
);
1347 /* ??? We can handle partially known shift counts if we know
1348 its sign. That way we can tell that (x << (y | 8)) & 255
1352 widest_int shift
= r2val
;
1360 if (wi::neg_p (shift
))
1363 if (code
== RSHIFT_EXPR
)
1368 if (code
== RSHIFT_EXPR
)
1370 *mask
= wi::rshift (wi::ext (r1mask
, width
, sgn
), shift
, sgn
);
1371 *val
= wi::rshift (wi::ext (r1val
, width
, sgn
), shift
, sgn
);
1375 *mask
= wi::ext (r1mask
<< shift
, width
, sgn
);
1376 *val
= wi::ext (r1val
<< shift
, width
, sgn
);
1383 case POINTER_PLUS_EXPR
:
1385 /* Do the addition with unknown bits set to zero, to give carry-ins of
1386 zero wherever possible. */
1387 widest_int lo
= r1val
.and_not (r1mask
) + r2val
.and_not (r2mask
);
1388 lo
= wi::ext (lo
, width
, sgn
);
1389 /* Do the addition with unknown bits set to one, to give carry-ins of
1390 one wherever possible. */
1391 widest_int hi
= (r1val
| r1mask
) + (r2val
| r2mask
);
1392 hi
= wi::ext (hi
, width
, sgn
);
1393 /* Each bit in the result is known if (a) the corresponding bits in
1394 both inputs are known, and (b) the carry-in to that bit position
1395 is known. We can check condition (b) by seeing if we got the same
1396 result with minimised carries as with maximised carries. */
1397 *mask
= r1mask
| r2mask
| (lo
^ hi
);
1398 *mask
= wi::ext (*mask
, width
, sgn
);
1399 /* It shouldn't matter whether we choose lo or hi here. */
1406 widest_int temv
, temm
;
1407 bit_value_unop (NEGATE_EXPR
, r2type_sgn
, r2type_precision
, &temv
, &temm
,
1408 r2type_sgn
, r2type_precision
, r2val
, r2mask
);
1409 bit_value_binop (PLUS_EXPR
, sgn
, width
, val
, mask
,
1410 r1type_sgn
, r1type_precision
, r1val
, r1mask
,
1411 r2type_sgn
, r2type_precision
, temv
, temm
);
1417 /* Just track trailing zeros in both operands and transfer
1418 them to the other. */
1419 int r1tz
= wi::ctz (r1val
| r1mask
);
1420 int r2tz
= wi::ctz (r2val
| r2mask
);
1421 if (r1tz
+ r2tz
>= width
)
1426 else if (r1tz
+ r2tz
> 0)
1428 *mask
= wi::ext (wi::mask
<widest_int
> (r1tz
+ r2tz
, true),
1438 widest_int m
= r1mask
| r2mask
;
1439 if (r1val
.and_not (m
) != r2val
.and_not (m
))
1442 *val
= ((code
== EQ_EXPR
) ? 0 : 1);
1446 /* We know the result of a comparison is always one or zero. */
1456 code
= swap_tree_comparison (code
);
1463 const widest_int
&o1val
= swap_p
? r2val
: r1val
;
1464 const widest_int
&o1mask
= swap_p
? r2mask
: r1mask
;
1465 const widest_int
&o2val
= swap_p
? r1val
: r2val
;
1466 const widest_int
&o2mask
= swap_p
? r1mask
: r2mask
;
1468 /* If the most significant bits are not known we know nothing. */
1469 if (wi::neg_p (o1mask
) || wi::neg_p (o2mask
))
1472 /* For comparisons the signedness is in the comparison operands. */
1475 /* If we know the most significant bits we know the values
1476 value ranges by means of treating varying bits as zero
1477 or one. Do a cross comparison of the max/min pairs. */
1478 maxmin
= wi::cmp (o1val
| o1mask
, o2val
.and_not (o2mask
), sgn
);
1479 minmax
= wi::cmp (o1val
.and_not (o1mask
), o2val
| o2mask
, sgn
);
1480 if (maxmin
< 0) /* o1 is less than o2. */
1485 else if (minmax
> 0) /* o1 is not less or equal to o2. */
1490 else if (maxmin
== minmax
) /* o1 and o2 are equal. */
1492 /* This probably should never happen as we'd have
1493 folded the thing during fully constant value folding. */
1495 *val
= (code
== LE_EXPR
? 1 : 0);
1499 /* We know the result of a comparison is always one or zero. */
1510 /* Return the propagation value when applying the operation CODE to
1511 the value RHS yielding type TYPE. */
1513 static ccp_prop_value_t
1514 bit_value_unop (enum tree_code code
, tree type
, tree rhs
)
1516 ccp_prop_value_t rval
= get_value_for_expr (rhs
, true);
1517 widest_int value
, mask
;
1518 ccp_prop_value_t val
;
1520 if (rval
.lattice_val
== UNDEFINED
)
1523 gcc_assert ((rval
.lattice_val
== CONSTANT
1524 && TREE_CODE (rval
.value
) == INTEGER_CST
)
1525 || wi::sext (rval
.mask
, TYPE_PRECISION (TREE_TYPE (rhs
))) == -1);
1526 bit_value_unop (code
, TYPE_SIGN (type
), TYPE_PRECISION (type
), &value
, &mask
,
1527 TYPE_SIGN (TREE_TYPE (rhs
)), TYPE_PRECISION (TREE_TYPE (rhs
)),
1528 value_to_wide_int (rval
), rval
.mask
);
1529 if (wi::sext (mask
, TYPE_PRECISION (type
)) != -1)
1531 val
.lattice_val
= CONSTANT
;
1533 /* ??? Delay building trees here. */
1534 val
.value
= wide_int_to_tree (type
, value
);
1538 val
.lattice_val
= VARYING
;
1539 val
.value
= NULL_TREE
;
1545 /* Return the propagation value when applying the operation CODE to
1546 the values RHS1 and RHS2 yielding type TYPE. */
1548 static ccp_prop_value_t
1549 bit_value_binop (enum tree_code code
, tree type
, tree rhs1
, tree rhs2
)
1551 ccp_prop_value_t r1val
= get_value_for_expr (rhs1
, true);
1552 ccp_prop_value_t r2val
= get_value_for_expr (rhs2
, true);
1553 widest_int value
, mask
;
1554 ccp_prop_value_t val
;
1556 if (r1val
.lattice_val
== UNDEFINED
1557 || r2val
.lattice_val
== UNDEFINED
)
1559 val
.lattice_val
= VARYING
;
1560 val
.value
= NULL_TREE
;
1565 gcc_assert ((r1val
.lattice_val
== CONSTANT
1566 && TREE_CODE (r1val
.value
) == INTEGER_CST
)
1567 || wi::sext (r1val
.mask
,
1568 TYPE_PRECISION (TREE_TYPE (rhs1
))) == -1);
1569 gcc_assert ((r2val
.lattice_val
== CONSTANT
1570 && TREE_CODE (r2val
.value
) == INTEGER_CST
)
1571 || wi::sext (r2val
.mask
,
1572 TYPE_PRECISION (TREE_TYPE (rhs2
))) == -1);
1573 bit_value_binop (code
, TYPE_SIGN (type
), TYPE_PRECISION (type
), &value
, &mask
,
1574 TYPE_SIGN (TREE_TYPE (rhs1
)), TYPE_PRECISION (TREE_TYPE (rhs1
)),
1575 value_to_wide_int (r1val
), r1val
.mask
,
1576 TYPE_SIGN (TREE_TYPE (rhs2
)), TYPE_PRECISION (TREE_TYPE (rhs2
)),
1577 value_to_wide_int (r2val
), r2val
.mask
);
1579 if (wi::sext (mask
, TYPE_PRECISION (type
)) != -1)
1581 val
.lattice_val
= CONSTANT
;
1583 /* ??? Delay building trees here. */
1584 val
.value
= wide_int_to_tree (type
, value
);
1588 val
.lattice_val
= VARYING
;
1589 val
.value
= NULL_TREE
;
1595 /* Return the propagation value for __builtin_assume_aligned
1596 and functions with assume_aligned or alloc_aligned attribute.
1597 For __builtin_assume_aligned, ATTR is NULL_TREE,
1598 for assume_aligned attribute ATTR is non-NULL and ALLOC_ALIGNED
1599 is false, for alloc_aligned attribute ATTR is non-NULL and
1600 ALLOC_ALIGNED is true. */
1602 static ccp_prop_value_t
1603 bit_value_assume_aligned (gimple
*stmt
, tree attr
, ccp_prop_value_t ptrval
,
1606 tree align
, misalign
= NULL_TREE
, type
;
1607 unsigned HOST_WIDE_INT aligni
, misaligni
= 0;
1608 ccp_prop_value_t alignval
;
1609 widest_int value
, mask
;
1610 ccp_prop_value_t val
;
1612 if (attr
== NULL_TREE
)
1614 tree ptr
= gimple_call_arg (stmt
, 0);
1615 type
= TREE_TYPE (ptr
);
1616 ptrval
= get_value_for_expr (ptr
, true);
1620 tree lhs
= gimple_call_lhs (stmt
);
1621 type
= TREE_TYPE (lhs
);
1624 if (ptrval
.lattice_val
== UNDEFINED
)
1626 gcc_assert ((ptrval
.lattice_val
== CONSTANT
1627 && TREE_CODE (ptrval
.value
) == INTEGER_CST
)
1628 || wi::sext (ptrval
.mask
, TYPE_PRECISION (type
)) == -1);
1629 if (attr
== NULL_TREE
)
1631 /* Get aligni and misaligni from __builtin_assume_aligned. */
1632 align
= gimple_call_arg (stmt
, 1);
1633 if (!tree_fits_uhwi_p (align
))
1635 aligni
= tree_to_uhwi (align
);
1636 if (gimple_call_num_args (stmt
) > 2)
1638 misalign
= gimple_call_arg (stmt
, 2);
1639 if (!tree_fits_uhwi_p (misalign
))
1641 misaligni
= tree_to_uhwi (misalign
);
1646 /* Get aligni and misaligni from assume_aligned or
1647 alloc_align attributes. */
1648 if (TREE_VALUE (attr
) == NULL_TREE
)
1650 attr
= TREE_VALUE (attr
);
1651 align
= TREE_VALUE (attr
);
1652 if (!tree_fits_uhwi_p (align
))
1654 aligni
= tree_to_uhwi (align
);
1657 if (aligni
== 0 || aligni
> gimple_call_num_args (stmt
))
1659 align
= gimple_call_arg (stmt
, aligni
- 1);
1660 if (!tree_fits_uhwi_p (align
))
1662 aligni
= tree_to_uhwi (align
);
1664 else if (TREE_CHAIN (attr
) && TREE_VALUE (TREE_CHAIN (attr
)))
1666 misalign
= TREE_VALUE (TREE_CHAIN (attr
));
1667 if (!tree_fits_uhwi_p (misalign
))
1669 misaligni
= tree_to_uhwi (misalign
);
1672 if (aligni
<= 1 || (aligni
& (aligni
- 1)) != 0 || misaligni
>= aligni
)
1675 align
= build_int_cst_type (type
, -aligni
);
1676 alignval
= get_value_for_expr (align
, true);
1677 bit_value_binop (BIT_AND_EXPR
, TYPE_SIGN (type
), TYPE_PRECISION (type
), &value
, &mask
,
1678 TYPE_SIGN (type
), TYPE_PRECISION (type
), value_to_wide_int (ptrval
), ptrval
.mask
,
1679 TYPE_SIGN (type
), TYPE_PRECISION (type
), value_to_wide_int (alignval
), alignval
.mask
);
1681 if (wi::sext (mask
, TYPE_PRECISION (type
)) != -1)
1683 val
.lattice_val
= CONSTANT
;
1685 gcc_assert ((mask
.to_uhwi () & (aligni
- 1)) == 0);
1686 gcc_assert ((value
.to_uhwi () & (aligni
- 1)) == 0);
1688 /* ??? Delay building trees here. */
1689 val
.value
= wide_int_to_tree (type
, value
);
1693 val
.lattice_val
= VARYING
;
1694 val
.value
= NULL_TREE
;
1700 /* Evaluate statement STMT.
1701 Valid only for assignments, calls, conditionals, and switches. */
1703 static ccp_prop_value_t
1704 evaluate_stmt (gimple
*stmt
)
1706 ccp_prop_value_t val
;
1707 tree simplified
= NULL_TREE
;
1708 ccp_lattice_t likelyvalue
= likely_value (stmt
);
1709 bool is_constant
= false;
1712 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1714 fprintf (dump_file
, "which is likely ");
1715 switch (likelyvalue
)
1718 fprintf (dump_file
, "CONSTANT");
1721 fprintf (dump_file
, "UNDEFINED");
1724 fprintf (dump_file
, "VARYING");
1728 fprintf (dump_file
, "\n");
1731 /* If the statement is likely to have a CONSTANT result, then try
1732 to fold the statement to determine the constant value. */
1733 /* FIXME. This is the only place that we call ccp_fold.
1734 Since likely_value never returns CONSTANT for calls, we will
1735 not attempt to fold them, including builtins that may profit. */
1736 if (likelyvalue
== CONSTANT
)
1738 fold_defer_overflow_warnings ();
1739 simplified
= ccp_fold (stmt
);
1740 if (simplified
&& TREE_CODE (simplified
) == SSA_NAME
)
1742 val
= *get_value (simplified
);
1743 if (val
.lattice_val
!= VARYING
)
1745 fold_undefer_overflow_warnings (true, stmt
, 0);
1749 is_constant
= simplified
&& is_gimple_min_invariant (simplified
);
1750 fold_undefer_overflow_warnings (is_constant
, stmt
, 0);
1753 /* The statement produced a constant value. */
1754 val
.lattice_val
= CONSTANT
;
1755 val
.value
= simplified
;
1760 /* If the statement is likely to have a VARYING result, then do not
1761 bother folding the statement. */
1762 else if (likelyvalue
== VARYING
)
1764 enum gimple_code code
= gimple_code (stmt
);
1765 if (code
== GIMPLE_ASSIGN
)
1767 enum tree_code subcode
= gimple_assign_rhs_code (stmt
);
1769 /* Other cases cannot satisfy is_gimple_min_invariant
1771 if (get_gimple_rhs_class (subcode
) == GIMPLE_SINGLE_RHS
)
1772 simplified
= gimple_assign_rhs1 (stmt
);
1774 else if (code
== GIMPLE_SWITCH
)
1775 simplified
= gimple_switch_index (as_a
<gswitch
*> (stmt
));
1777 /* These cannot satisfy is_gimple_min_invariant without folding. */
1778 gcc_assert (code
== GIMPLE_CALL
|| code
== GIMPLE_COND
);
1779 is_constant
= simplified
&& is_gimple_min_invariant (simplified
);
1782 /* The statement produced a constant value. */
1783 val
.lattice_val
= CONSTANT
;
1784 val
.value
= simplified
;
1788 /* If the statement result is likely UNDEFINED, make it so. */
1789 else if (likelyvalue
== UNDEFINED
)
1791 val
.lattice_val
= UNDEFINED
;
1792 val
.value
= NULL_TREE
;
1797 /* Resort to simplification for bitwise tracking. */
1798 if (flag_tree_bit_ccp
1799 && (likelyvalue
== CONSTANT
|| is_gimple_call (stmt
)
1800 || (gimple_assign_single_p (stmt
)
1801 && gimple_assign_rhs_code (stmt
) == ADDR_EXPR
))
1804 enum gimple_code code
= gimple_code (stmt
);
1805 val
.lattice_val
= VARYING
;
1806 val
.value
= NULL_TREE
;
1808 if (code
== GIMPLE_ASSIGN
)
1810 enum tree_code subcode
= gimple_assign_rhs_code (stmt
);
1811 tree rhs1
= gimple_assign_rhs1 (stmt
);
1812 tree lhs
= gimple_assign_lhs (stmt
);
1813 if ((INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
1814 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
1815 && (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
1816 || POINTER_TYPE_P (TREE_TYPE (rhs1
))))
1817 switch (get_gimple_rhs_class (subcode
))
1819 case GIMPLE_SINGLE_RHS
:
1820 val
= get_value_for_expr (rhs1
, true);
1823 case GIMPLE_UNARY_RHS
:
1824 val
= bit_value_unop (subcode
, TREE_TYPE (lhs
), rhs1
);
1827 case GIMPLE_BINARY_RHS
:
1828 val
= bit_value_binop (subcode
, TREE_TYPE (lhs
), rhs1
,
1829 gimple_assign_rhs2 (stmt
));
1835 else if (code
== GIMPLE_COND
)
1837 enum tree_code code
= gimple_cond_code (stmt
);
1838 tree rhs1
= gimple_cond_lhs (stmt
);
1839 tree rhs2
= gimple_cond_rhs (stmt
);
1840 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
1841 || POINTER_TYPE_P (TREE_TYPE (rhs1
)))
1842 val
= bit_value_binop (code
, TREE_TYPE (rhs1
), rhs1
, rhs2
);
1844 else if (gimple_call_builtin_p (stmt
, BUILT_IN_NORMAL
))
1846 tree fndecl
= gimple_call_fndecl (stmt
);
1847 switch (DECL_FUNCTION_CODE (fndecl
))
1849 case BUILT_IN_MALLOC
:
1850 case BUILT_IN_REALLOC
:
1851 case BUILT_IN_CALLOC
:
1852 case BUILT_IN_STRDUP
:
1853 case BUILT_IN_STRNDUP
:
1854 val
.lattice_val
= CONSTANT
;
1855 val
.value
= build_int_cst (TREE_TYPE (gimple_get_lhs (stmt
)), 0);
1856 val
.mask
= ~((HOST_WIDE_INT
) MALLOC_ABI_ALIGNMENT
1857 / BITS_PER_UNIT
- 1);
1860 case BUILT_IN_ALLOCA
:
1861 case BUILT_IN_ALLOCA_WITH_ALIGN
:
1862 align
= (DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_ALLOCA_WITH_ALIGN
1863 ? TREE_INT_CST_LOW (gimple_call_arg (stmt
, 1))
1864 : BIGGEST_ALIGNMENT
);
1865 val
.lattice_val
= CONSTANT
;
1866 val
.value
= build_int_cst (TREE_TYPE (gimple_get_lhs (stmt
)), 0);
1867 val
.mask
= ~((HOST_WIDE_INT
) align
/ BITS_PER_UNIT
- 1);
1870 /* These builtins return their first argument, unmodified. */
1871 case BUILT_IN_MEMCPY
:
1872 case BUILT_IN_MEMMOVE
:
1873 case BUILT_IN_MEMSET
:
1874 case BUILT_IN_STRCPY
:
1875 case BUILT_IN_STRNCPY
:
1876 case BUILT_IN_MEMCPY_CHK
:
1877 case BUILT_IN_MEMMOVE_CHK
:
1878 case BUILT_IN_MEMSET_CHK
:
1879 case BUILT_IN_STRCPY_CHK
:
1880 case BUILT_IN_STRNCPY_CHK
:
1881 val
= get_value_for_expr (gimple_call_arg (stmt
, 0), true);
1884 case BUILT_IN_ASSUME_ALIGNED
:
1885 val
= bit_value_assume_aligned (stmt
, NULL_TREE
, val
, false);
1888 case BUILT_IN_ALIGNED_ALLOC
:
1890 tree align
= get_constant_value (gimple_call_arg (stmt
, 0));
1892 && tree_fits_uhwi_p (align
))
1894 unsigned HOST_WIDE_INT aligni
= tree_to_uhwi (align
);
1896 /* align must be power-of-two */
1897 && (aligni
& (aligni
- 1)) == 0)
1899 val
.lattice_val
= CONSTANT
;
1900 val
.value
= build_int_cst (ptr_type_node
, 0);
1910 if (is_gimple_call (stmt
) && gimple_call_lhs (stmt
))
1912 tree fntype
= gimple_call_fntype (stmt
);
1915 tree attrs
= lookup_attribute ("assume_aligned",
1916 TYPE_ATTRIBUTES (fntype
));
1918 val
= bit_value_assume_aligned (stmt
, attrs
, val
, false);
1919 attrs
= lookup_attribute ("alloc_align",
1920 TYPE_ATTRIBUTES (fntype
));
1922 val
= bit_value_assume_aligned (stmt
, attrs
, val
, true);
1925 is_constant
= (val
.lattice_val
== CONSTANT
);
1928 if (flag_tree_bit_ccp
1929 && ((is_constant
&& TREE_CODE (val
.value
) == INTEGER_CST
)
1931 && gimple_get_lhs (stmt
)
1932 && TREE_CODE (gimple_get_lhs (stmt
)) == SSA_NAME
)
1934 tree lhs
= gimple_get_lhs (stmt
);
1935 wide_int nonzero_bits
= get_nonzero_bits (lhs
);
1936 if (nonzero_bits
!= -1)
1940 val
.lattice_val
= CONSTANT
;
1941 val
.value
= build_zero_cst (TREE_TYPE (lhs
));
1942 val
.mask
= extend_mask (nonzero_bits
, TYPE_SIGN (TREE_TYPE (lhs
)));
1947 if (wi::bit_and_not (val
.value
, nonzero_bits
) != 0)
1948 val
.value
= wide_int_to_tree (TREE_TYPE (lhs
),
1949 nonzero_bits
& val
.value
);
1950 if (nonzero_bits
== 0)
1953 val
.mask
= val
.mask
& extend_mask (nonzero_bits
,
1954 TYPE_SIGN (TREE_TYPE (lhs
)));
1959 /* The statement produced a nonconstant value. */
1962 /* The statement produced a copy. */
1963 if (simplified
&& TREE_CODE (simplified
) == SSA_NAME
1964 && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (simplified
))
1966 val
.lattice_val
= CONSTANT
;
1967 val
.value
= simplified
;
1970 /* The statement is VARYING. */
1973 val
.lattice_val
= VARYING
;
1974 val
.value
= NULL_TREE
;
1982 typedef hash_table
<nofree_ptr_hash
<gimple
> > gimple_htab
;
1984 /* Given a BUILT_IN_STACK_SAVE value SAVED_VAL, insert a clobber of VAR before
1985 each matching BUILT_IN_STACK_RESTORE. Mark visited phis in VISITED. */
1988 insert_clobber_before_stack_restore (tree saved_val
, tree var
,
1989 gimple_htab
**visited
)
1992 gassign
*clobber_stmt
;
1994 imm_use_iterator iter
;
1995 gimple_stmt_iterator i
;
1998 FOR_EACH_IMM_USE_STMT (stmt
, iter
, saved_val
)
1999 if (gimple_call_builtin_p (stmt
, BUILT_IN_STACK_RESTORE
))
2001 clobber
= build_constructor (TREE_TYPE (var
),
2003 TREE_THIS_VOLATILE (clobber
) = 1;
2004 clobber_stmt
= gimple_build_assign (var
, clobber
);
2006 i
= gsi_for_stmt (stmt
);
2007 gsi_insert_before (&i
, clobber_stmt
, GSI_SAME_STMT
);
2009 else if (gimple_code (stmt
) == GIMPLE_PHI
)
2012 *visited
= new gimple_htab (10);
2014 slot
= (*visited
)->find_slot (stmt
, INSERT
);
2019 insert_clobber_before_stack_restore (gimple_phi_result (stmt
), var
,
2022 else if (gimple_assign_ssa_name_copy_p (stmt
))
2023 insert_clobber_before_stack_restore (gimple_assign_lhs (stmt
), var
,
2025 else if (chkp_gimple_call_builtin_p (stmt
, BUILT_IN_CHKP_BNDRET
))
2028 gcc_assert (is_gimple_debug (stmt
));
2031 /* Advance the iterator to the previous non-debug gimple statement in the same
2032 or dominating basic block. */
2035 gsi_prev_dom_bb_nondebug (gimple_stmt_iterator
*i
)
2039 gsi_prev_nondebug (i
);
2040 while (gsi_end_p (*i
))
2042 dom
= get_immediate_dominator (CDI_DOMINATORS
, i
->bb
);
2043 if (dom
== NULL
|| dom
== ENTRY_BLOCK_PTR_FOR_FN (cfun
))
2046 *i
= gsi_last_bb (dom
);
2050 /* Find a BUILT_IN_STACK_SAVE dominating gsi_stmt (I), and insert
2051 a clobber of VAR before each matching BUILT_IN_STACK_RESTORE.
2053 It is possible that BUILT_IN_STACK_SAVE cannot be find in a dominator when a
2054 previous pass (such as DOM) duplicated it along multiple paths to a BB. In
2055 that case the function gives up without inserting the clobbers. */
2058 insert_clobbers_for_var (gimple_stmt_iterator i
, tree var
)
2062 gimple_htab
*visited
= NULL
;
2064 for (; !gsi_end_p (i
); gsi_prev_dom_bb_nondebug (&i
))
2066 stmt
= gsi_stmt (i
);
2068 if (!gimple_call_builtin_p (stmt
, BUILT_IN_STACK_SAVE
))
2071 saved_val
= gimple_call_lhs (stmt
);
2072 if (saved_val
== NULL_TREE
)
2075 insert_clobber_before_stack_restore (saved_val
, var
, &visited
);
2082 /* Detects a __builtin_alloca_with_align with constant size argument. Declares
2083 fixed-size array and returns the address, if found, otherwise returns
2087 fold_builtin_alloca_with_align (gimple
*stmt
)
2089 unsigned HOST_WIDE_INT size
, threshold
, n_elem
;
2090 tree lhs
, arg
, block
, var
, elem_type
, array_type
;
2093 lhs
= gimple_call_lhs (stmt
);
2094 if (lhs
== NULL_TREE
)
2097 /* Detect constant argument. */
2098 arg
= get_constant_value (gimple_call_arg (stmt
, 0));
2099 if (arg
== NULL_TREE
2100 || TREE_CODE (arg
) != INTEGER_CST
2101 || !tree_fits_uhwi_p (arg
))
2104 size
= tree_to_uhwi (arg
);
2106 /* Heuristic: don't fold large allocas. */
2107 threshold
= (unsigned HOST_WIDE_INT
)PARAM_VALUE (PARAM_LARGE_STACK_FRAME
);
2108 /* In case the alloca is located at function entry, it has the same lifetime
2109 as a declared array, so we allow a larger size. */
2110 block
= gimple_block (stmt
);
2111 if (!(cfun
->after_inlining
2113 && TREE_CODE (BLOCK_SUPERCONTEXT (block
)) == FUNCTION_DECL
))
2115 if (size
> threshold
)
2118 /* Declare array. */
2119 elem_type
= build_nonstandard_integer_type (BITS_PER_UNIT
, 1);
2120 n_elem
= size
* 8 / BITS_PER_UNIT
;
2121 array_type
= build_array_type_nelts (elem_type
, n_elem
);
2122 var
= create_tmp_var (array_type
);
2123 SET_DECL_ALIGN (var
, TREE_INT_CST_LOW (gimple_call_arg (stmt
, 1)));
2125 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (lhs
);
2126 if (pi
!= NULL
&& !pi
->pt
.anything
)
2130 singleton_p
= pt_solution_singleton_p (&pi
->pt
, &uid
);
2131 gcc_assert (singleton_p
);
2132 SET_DECL_PT_UID (var
, uid
);
2136 /* Fold alloca to the address of the array. */
2137 return fold_convert (TREE_TYPE (lhs
), build_fold_addr_expr (var
));
2140 /* Fold the stmt at *GSI with CCP specific information that propagating
2141 and regular folding does not catch. */
2144 ccp_fold_stmt (gimple_stmt_iterator
*gsi
)
2146 gimple
*stmt
= gsi_stmt (*gsi
);
2148 switch (gimple_code (stmt
))
2152 gcond
*cond_stmt
= as_a
<gcond
*> (stmt
);
2153 ccp_prop_value_t val
;
2154 /* Statement evaluation will handle type mismatches in constants
2155 more gracefully than the final propagation. This allows us to
2156 fold more conditionals here. */
2157 val
= evaluate_stmt (stmt
);
2158 if (val
.lattice_val
!= CONSTANT
2164 fprintf (dump_file
, "Folding predicate ");
2165 print_gimple_expr (dump_file
, stmt
, 0, 0);
2166 fprintf (dump_file
, " to ");
2167 print_generic_expr (dump_file
, val
.value
, 0);
2168 fprintf (dump_file
, "\n");
2171 if (integer_zerop (val
.value
))
2172 gimple_cond_make_false (cond_stmt
);
2174 gimple_cond_make_true (cond_stmt
);
2181 tree lhs
= gimple_call_lhs (stmt
);
2182 int flags
= gimple_call_flags (stmt
);
2185 bool changed
= false;
2188 /* If the call was folded into a constant make sure it goes
2189 away even if we cannot propagate into all uses because of
2192 && TREE_CODE (lhs
) == SSA_NAME
2193 && (val
= get_constant_value (lhs
))
2194 /* Don't optimize away calls that have side-effects. */
2195 && (flags
& (ECF_CONST
|ECF_PURE
)) != 0
2196 && (flags
& ECF_LOOPING_CONST_OR_PURE
) == 0)
2198 tree new_rhs
= unshare_expr (val
);
2200 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
2201 TREE_TYPE (new_rhs
)))
2202 new_rhs
= fold_convert (TREE_TYPE (lhs
), new_rhs
);
2203 res
= update_call_from_tree (gsi
, new_rhs
);
2208 /* Internal calls provide no argument types, so the extra laxity
2209 for normal calls does not apply. */
2210 if (gimple_call_internal_p (stmt
))
2213 /* The heuristic of fold_builtin_alloca_with_align differs before and
2214 after inlining, so we don't require the arg to be changed into a
2215 constant for folding, but just to be constant. */
2216 if (gimple_call_builtin_p (stmt
, BUILT_IN_ALLOCA_WITH_ALIGN
))
2218 tree new_rhs
= fold_builtin_alloca_with_align (stmt
);
2221 bool res
= update_call_from_tree (gsi
, new_rhs
);
2222 tree var
= TREE_OPERAND (TREE_OPERAND (new_rhs
, 0),0);
2224 insert_clobbers_for_var (*gsi
, var
);
2229 /* Propagate into the call arguments. Compared to replace_uses_in
2230 this can use the argument slot types for type verification
2231 instead of the current argument type. We also can safely
2232 drop qualifiers here as we are dealing with constants anyway. */
2233 argt
= TYPE_ARG_TYPES (gimple_call_fntype (stmt
));
2234 for (i
= 0; i
< gimple_call_num_args (stmt
) && argt
;
2235 ++i
, argt
= TREE_CHAIN (argt
))
2237 tree arg
= gimple_call_arg (stmt
, i
);
2238 if (TREE_CODE (arg
) == SSA_NAME
2239 && (val
= get_constant_value (arg
))
2240 && useless_type_conversion_p
2241 (TYPE_MAIN_VARIANT (TREE_VALUE (argt
)),
2242 TYPE_MAIN_VARIANT (TREE_TYPE (val
))))
2244 gimple_call_set_arg (stmt
, i
, unshare_expr (val
));
2254 tree lhs
= gimple_assign_lhs (stmt
);
2257 /* If we have a load that turned out to be constant replace it
2258 as we cannot propagate into all uses in all cases. */
2259 if (gimple_assign_single_p (stmt
)
2260 && TREE_CODE (lhs
) == SSA_NAME
2261 && (val
= get_constant_value (lhs
)))
2263 tree rhs
= unshare_expr (val
);
2264 if (!useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (rhs
)))
2265 rhs
= fold_build1 (VIEW_CONVERT_EXPR
, TREE_TYPE (lhs
), rhs
);
2266 gimple_assign_set_rhs_from_tree (gsi
, rhs
);
2278 /* Visit the assignment statement STMT. Set the value of its LHS to the
2279 value computed by the RHS and store LHS in *OUTPUT_P. If STMT
2280 creates virtual definitions, set the value of each new name to that
2281 of the RHS (if we can derive a constant out of the RHS).
2282 Value-returning call statements also perform an assignment, and
2283 are handled here. */
2285 static enum ssa_prop_result
2286 visit_assignment (gimple
*stmt
, tree
*output_p
)
2288 ccp_prop_value_t val
;
2289 enum ssa_prop_result retval
= SSA_PROP_NOT_INTERESTING
;
2291 tree lhs
= gimple_get_lhs (stmt
);
2292 if (TREE_CODE (lhs
) == SSA_NAME
)
2294 /* Evaluate the statement, which could be
2295 either a GIMPLE_ASSIGN or a GIMPLE_CALL. */
2296 val
= evaluate_stmt (stmt
);
2298 /* If STMT is an assignment to an SSA_NAME, we only have one
2300 if (set_lattice_value (lhs
, &val
))
2303 if (val
.lattice_val
== VARYING
)
2304 retval
= SSA_PROP_VARYING
;
2306 retval
= SSA_PROP_INTERESTING
;
2314 /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING
2315 if it can determine which edge will be taken. Otherwise, return
2316 SSA_PROP_VARYING. */
2318 static enum ssa_prop_result
2319 visit_cond_stmt (gimple
*stmt
, edge
*taken_edge_p
)
2321 ccp_prop_value_t val
;
2324 block
= gimple_bb (stmt
);
2325 val
= evaluate_stmt (stmt
);
2326 if (val
.lattice_val
!= CONSTANT
2328 return SSA_PROP_VARYING
;
2330 /* Find which edge out of the conditional block will be taken and add it
2331 to the worklist. If no single edge can be determined statically,
2332 return SSA_PROP_VARYING to feed all the outgoing edges to the
2333 propagation engine. */
2334 *taken_edge_p
= find_taken_edge (block
, val
.value
);
2336 return SSA_PROP_INTERESTING
;
2338 return SSA_PROP_VARYING
;
2342 /* Evaluate statement STMT. If the statement produces an output value and
2343 its evaluation changes the lattice value of its output, return
2344 SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the
2347 If STMT is a conditional branch and we can determine its truth
2348 value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying
2349 value, return SSA_PROP_VARYING. */
2351 static enum ssa_prop_result
2352 ccp_visit_stmt (gimple
*stmt
, edge
*taken_edge_p
, tree
*output_p
)
2357 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2359 fprintf (dump_file
, "\nVisiting statement:\n");
2360 print_gimple_stmt (dump_file
, stmt
, 0, dump_flags
);
2363 switch (gimple_code (stmt
))
2366 /* If the statement is an assignment that produces a single
2367 output value, evaluate its RHS to see if the lattice value of
2368 its output has changed. */
2369 return visit_assignment (stmt
, output_p
);
2372 /* A value-returning call also performs an assignment. */
2373 if (gimple_call_lhs (stmt
) != NULL_TREE
)
2374 return visit_assignment (stmt
, output_p
);
2379 /* If STMT is a conditional branch, see if we can determine
2380 which branch will be taken. */
2381 /* FIXME. It appears that we should be able to optimize
2382 computed GOTOs here as well. */
2383 return visit_cond_stmt (stmt
, taken_edge_p
);
2389 /* Any other kind of statement is not interesting for constant
2390 propagation and, therefore, not worth simulating. */
2391 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2392 fprintf (dump_file
, "No interesting values produced. Marked VARYING.\n");
2394 /* Definitions made by statements other than assignments to
2395 SSA_NAMEs represent unknown modifications to their outputs.
2396 Mark them VARYING. */
2397 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_ALL_DEFS
)
2398 set_value_varying (def
);
2400 return SSA_PROP_VARYING
;
2404 /* Main entry point for SSA Conditional Constant Propagation. If NONZERO_P,
2405 record nonzero bits. */
2408 do_ssa_ccp (bool nonzero_p
)
2410 unsigned int todo
= 0;
2411 calculate_dominance_info (CDI_DOMINATORS
);
2414 ssa_propagate (ccp_visit_stmt
, ccp_visit_phi_node
);
2415 if (ccp_finalize (nonzero_p
|| flag_ipa_bit_cp
))
2417 todo
= (TODO_cleanup_cfg
| TODO_update_ssa
);
2419 /* ccp_finalize does not preserve loop-closed ssa. */
2420 loops_state_clear (LOOP_CLOSED_SSA
);
2423 free_dominance_info (CDI_DOMINATORS
);
2430 const pass_data pass_data_ccp
=
2432 GIMPLE_PASS
, /* type */
2434 OPTGROUP_NONE
, /* optinfo_flags */
2435 TV_TREE_CCP
, /* tv_id */
2436 ( PROP_cfg
| PROP_ssa
), /* properties_required */
2437 0, /* properties_provided */
2438 0, /* properties_destroyed */
2439 0, /* todo_flags_start */
2440 TODO_update_address_taken
, /* todo_flags_finish */
2443 class pass_ccp
: public gimple_opt_pass
2446 pass_ccp (gcc::context
*ctxt
)
2447 : gimple_opt_pass (pass_data_ccp
, ctxt
), nonzero_p (false)
2450 /* opt_pass methods: */
2451 opt_pass
* clone () { return new pass_ccp (m_ctxt
); }
2452 void set_pass_param (unsigned int n
, bool param
)
2454 gcc_assert (n
== 0);
2457 virtual bool gate (function
*) { return flag_tree_ccp
!= 0; }
2458 virtual unsigned int execute (function
*) { return do_ssa_ccp (nonzero_p
); }
2461 /* Determines whether the pass instance records nonzero bits. */
2463 }; // class pass_ccp
2468 make_pass_ccp (gcc::context
*ctxt
)
2470 return new pass_ccp (ctxt
);
2475 /* Try to optimize out __builtin_stack_restore. Optimize it out
2476 if there is another __builtin_stack_restore in the same basic
2477 block and no calls or ASM_EXPRs are in between, or if this block's
2478 only outgoing edge is to EXIT_BLOCK and there are no calls or
2479 ASM_EXPRs after this __builtin_stack_restore. */
2482 optimize_stack_restore (gimple_stmt_iterator i
)
2487 basic_block bb
= gsi_bb (i
);
2488 gimple
*call
= gsi_stmt (i
);
2490 if (gimple_code (call
) != GIMPLE_CALL
2491 || gimple_call_num_args (call
) != 1
2492 || TREE_CODE (gimple_call_arg (call
, 0)) != SSA_NAME
2493 || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call
, 0))))
2496 for (gsi_next (&i
); !gsi_end_p (i
); gsi_next (&i
))
2498 stmt
= gsi_stmt (i
);
2499 if (gimple_code (stmt
) == GIMPLE_ASM
)
2501 if (gimple_code (stmt
) != GIMPLE_CALL
)
2504 callee
= gimple_call_fndecl (stmt
);
2506 || DECL_BUILT_IN_CLASS (callee
) != BUILT_IN_NORMAL
2507 /* All regular builtins are ok, just obviously not alloca. */
2508 || DECL_FUNCTION_CODE (callee
) == BUILT_IN_ALLOCA
2509 || DECL_FUNCTION_CODE (callee
) == BUILT_IN_ALLOCA_WITH_ALIGN
)
2512 if (DECL_FUNCTION_CODE (callee
) == BUILT_IN_STACK_RESTORE
)
2513 goto second_stack_restore
;
2519 /* Allow one successor of the exit block, or zero successors. */
2520 switch (EDGE_COUNT (bb
->succs
))
2525 if (single_succ_edge (bb
)->dest
!= EXIT_BLOCK_PTR_FOR_FN (cfun
))
2531 second_stack_restore
:
2533 /* If there's exactly one use, then zap the call to __builtin_stack_save.
2534 If there are multiple uses, then the last one should remove the call.
2535 In any case, whether the call to __builtin_stack_save can be removed
2536 or not is irrelevant to removing the call to __builtin_stack_restore. */
2537 if (has_single_use (gimple_call_arg (call
, 0)))
2539 gimple
*stack_save
= SSA_NAME_DEF_STMT (gimple_call_arg (call
, 0));
2540 if (is_gimple_call (stack_save
))
2542 callee
= gimple_call_fndecl (stack_save
);
2544 && DECL_BUILT_IN_CLASS (callee
) == BUILT_IN_NORMAL
2545 && DECL_FUNCTION_CODE (callee
) == BUILT_IN_STACK_SAVE
)
2547 gimple_stmt_iterator stack_save_gsi
;
2550 stack_save_gsi
= gsi_for_stmt (stack_save
);
2551 rhs
= build_int_cst (TREE_TYPE (gimple_call_arg (call
, 0)), 0);
2552 update_call_from_tree (&stack_save_gsi
, rhs
);
2557 /* No effect, so the statement will be deleted. */
2558 return integer_zero_node
;
2561 /* If va_list type is a simple pointer and nothing special is needed,
2562 optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0),
2563 __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple
2564 pointer assignment. */
2567 optimize_stdarg_builtin (gimple
*call
)
2569 tree callee
, lhs
, rhs
, cfun_va_list
;
2570 bool va_list_simple_ptr
;
2571 location_t loc
= gimple_location (call
);
2573 if (gimple_code (call
) != GIMPLE_CALL
)
2576 callee
= gimple_call_fndecl (call
);
2578 cfun_va_list
= targetm
.fn_abi_va_list (callee
);
2579 va_list_simple_ptr
= POINTER_TYPE_P (cfun_va_list
)
2580 && (TREE_TYPE (cfun_va_list
) == void_type_node
2581 || TREE_TYPE (cfun_va_list
) == char_type_node
);
2583 switch (DECL_FUNCTION_CODE (callee
))
2585 case BUILT_IN_VA_START
:
2586 if (!va_list_simple_ptr
2587 || targetm
.expand_builtin_va_start
!= NULL
2588 || !builtin_decl_explicit_p (BUILT_IN_NEXT_ARG
))
2591 if (gimple_call_num_args (call
) != 2)
2594 lhs
= gimple_call_arg (call
, 0);
2595 if (!POINTER_TYPE_P (TREE_TYPE (lhs
))
2596 || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs
)))
2597 != TYPE_MAIN_VARIANT (cfun_va_list
))
2600 lhs
= build_fold_indirect_ref_loc (loc
, lhs
);
2601 rhs
= build_call_expr_loc (loc
, builtin_decl_explicit (BUILT_IN_NEXT_ARG
),
2602 1, integer_zero_node
);
2603 rhs
= fold_convert_loc (loc
, TREE_TYPE (lhs
), rhs
);
2604 return build2 (MODIFY_EXPR
, TREE_TYPE (lhs
), lhs
, rhs
);
2606 case BUILT_IN_VA_COPY
:
2607 if (!va_list_simple_ptr
)
2610 if (gimple_call_num_args (call
) != 2)
2613 lhs
= gimple_call_arg (call
, 0);
2614 if (!POINTER_TYPE_P (TREE_TYPE (lhs
))
2615 || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs
)))
2616 != TYPE_MAIN_VARIANT (cfun_va_list
))
2619 lhs
= build_fold_indirect_ref_loc (loc
, lhs
);
2620 rhs
= gimple_call_arg (call
, 1);
2621 if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs
))
2622 != TYPE_MAIN_VARIANT (cfun_va_list
))
2625 rhs
= fold_convert_loc (loc
, TREE_TYPE (lhs
), rhs
);
2626 return build2 (MODIFY_EXPR
, TREE_TYPE (lhs
), lhs
, rhs
);
2628 case BUILT_IN_VA_END
:
2629 /* No effect, so the statement will be deleted. */
2630 return integer_zero_node
;
2637 /* Attemp to make the block of __builtin_unreachable I unreachable by changing
2638 the incoming jumps. Return true if at least one jump was changed. */
2641 optimize_unreachable (gimple_stmt_iterator i
)
2643 basic_block bb
= gsi_bb (i
);
2644 gimple_stmt_iterator gsi
;
2650 if (flag_sanitize
& SANITIZE_UNREACHABLE
)
2653 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
2655 stmt
= gsi_stmt (gsi
);
2657 if (is_gimple_debug (stmt
))
2660 if (glabel
*label_stmt
= dyn_cast
<glabel
*> (stmt
))
2662 /* Verify we do not need to preserve the label. */
2663 if (FORCED_LABEL (gimple_label_label (label_stmt
)))
2669 /* Only handle the case that __builtin_unreachable is the first statement
2670 in the block. We rely on DCE to remove stmts without side-effects
2671 before __builtin_unreachable. */
2672 if (gsi_stmt (gsi
) != gsi_stmt (i
))
2677 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
2679 gsi
= gsi_last_bb (e
->src
);
2680 if (gsi_end_p (gsi
))
2683 stmt
= gsi_stmt (gsi
);
2684 if (gcond
*cond_stmt
= dyn_cast
<gcond
*> (stmt
))
2686 if (e
->flags
& EDGE_TRUE_VALUE
)
2687 gimple_cond_make_false (cond_stmt
);
2688 else if (e
->flags
& EDGE_FALSE_VALUE
)
2689 gimple_cond_make_true (cond_stmt
);
2692 update_stmt (cond_stmt
);
2696 /* Todo: handle other cases, f.i. switch statement. */
2707 mask_2 = 1 << cnt_1;
2708 _4 = __atomic_fetch_or_* (ptr_6, mask_2, _3);
2711 _4 = ATOMIC_BIT_TEST_AND_SET (ptr_6, cnt_1, 0, _3);
2713 If _5 is only used in _5 != 0 or _5 == 0 comparisons, 1
2714 is passed instead of 0, and the builtin just returns a zero
2715 or 1 value instead of the actual bit.
2716 Similarly for __sync_fetch_and_or_* (without the ", _3" part
2717 in there), and/or if mask_2 is a power of 2 constant.
2718 Similarly for xor instead of or, use ATOMIC_BIT_TEST_AND_COMPLEMENT
2719 in that case. And similarly for and instead of or, except that
2720 the second argument to the builtin needs to be one's complement
2721 of the mask instead of mask. */
2724 optimize_atomic_bit_test_and (gimple_stmt_iterator
*gsip
,
2725 enum internal_fn fn
, bool has_model_arg
,
2728 gimple
*call
= gsi_stmt (*gsip
);
2729 tree lhs
= gimple_call_lhs (call
);
2730 use_operand_p use_p
;
2735 if (!flag_inline_atomics
2737 || !gimple_call_builtin_p (call
, BUILT_IN_NORMAL
)
2739 || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs
)
2740 || !single_imm_use (lhs
, &use_p
, &use_stmt
)
2741 || !is_gimple_assign (use_stmt
)
2742 || gimple_assign_rhs_code (use_stmt
) != BIT_AND_EXPR
2743 || !gimple_vdef (call
))
2748 case IFN_ATOMIC_BIT_TEST_AND_SET
:
2749 optab
= atomic_bit_test_and_set_optab
;
2751 case IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT
:
2752 optab
= atomic_bit_test_and_complement_optab
;
2754 case IFN_ATOMIC_BIT_TEST_AND_RESET
:
2755 optab
= atomic_bit_test_and_reset_optab
;
2761 if (optab_handler (optab
, TYPE_MODE (TREE_TYPE (lhs
))) == CODE_FOR_nothing
)
2764 mask
= gimple_call_arg (call
, 1);
2765 tree use_lhs
= gimple_assign_lhs (use_stmt
);
2769 if (TREE_CODE (mask
) == INTEGER_CST
)
2771 if (fn
== IFN_ATOMIC_BIT_TEST_AND_RESET
)
2772 mask
= const_unop (BIT_NOT_EXPR
, TREE_TYPE (mask
), mask
);
2773 mask
= fold_convert (TREE_TYPE (lhs
), mask
);
2774 int ibit
= tree_log2 (mask
);
2777 bit
= build_int_cst (TREE_TYPE (lhs
), ibit
);
2779 else if (TREE_CODE (mask
) == SSA_NAME
)
2781 gimple
*g
= SSA_NAME_DEF_STMT (mask
);
2782 if (fn
== IFN_ATOMIC_BIT_TEST_AND_RESET
)
2784 if (!is_gimple_assign (g
)
2785 || gimple_assign_rhs_code (g
) != BIT_NOT_EXPR
)
2787 mask
= gimple_assign_rhs1 (g
);
2788 if (TREE_CODE (mask
) != SSA_NAME
)
2790 g
= SSA_NAME_DEF_STMT (mask
);
2792 if (!is_gimple_assign (g
)
2793 || gimple_assign_rhs_code (g
) != LSHIFT_EXPR
2794 || !integer_onep (gimple_assign_rhs1 (g
)))
2796 bit
= gimple_assign_rhs2 (g
);
2801 if (gimple_assign_rhs1 (use_stmt
) == lhs
)
2803 if (!operand_equal_p (gimple_assign_rhs2 (use_stmt
), mask
, 0))
2806 else if (gimple_assign_rhs2 (use_stmt
) != lhs
2807 || !operand_equal_p (gimple_assign_rhs1 (use_stmt
), mask
, 0))
2810 bool use_bool
= true;
2811 bool has_debug_uses
= false;
2812 imm_use_iterator iter
;
2815 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (use_lhs
))
2817 FOR_EACH_IMM_USE_STMT (g
, iter
, use_lhs
)
2819 enum tree_code code
= ERROR_MARK
;
2821 if (is_gimple_debug (g
))
2823 has_debug_uses
= true;
2826 else if (is_gimple_assign (g
))
2827 switch (gimple_assign_rhs_code (g
))
2830 op1
= gimple_assign_rhs1 (g
);
2831 code
= TREE_CODE (op1
);
2832 op0
= TREE_OPERAND (op1
, 0);
2833 op1
= TREE_OPERAND (op1
, 1);
2837 code
= gimple_assign_rhs_code (g
);
2838 op0
= gimple_assign_rhs1 (g
);
2839 op1
= gimple_assign_rhs2 (g
);
2844 else if (gimple_code (g
) == GIMPLE_COND
)
2846 code
= gimple_cond_code (g
);
2847 op0
= gimple_cond_lhs (g
);
2848 op1
= gimple_cond_rhs (g
);
2851 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
2853 && integer_zerop (op1
))
2855 use_operand_p use_p
;
2857 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
2864 BREAK_FROM_IMM_USE_STMT (iter
);
2867 tree new_lhs
= make_ssa_name (TREE_TYPE (lhs
));
2868 tree flag
= build_int_cst (TREE_TYPE (lhs
), use_bool
);
2870 g
= gimple_build_call_internal (fn
, 4, gimple_call_arg (call
, 0),
2871 bit
, flag
, gimple_call_arg (call
, 2));
2873 g
= gimple_build_call_internal (fn
, 3, gimple_call_arg (call
, 0),
2875 gimple_call_set_lhs (g
, new_lhs
);
2876 gimple_set_location (g
, gimple_location (call
));
2877 gimple_set_vuse (g
, gimple_vuse (call
));
2878 gimple_set_vdef (g
, gimple_vdef (call
));
2879 SSA_NAME_DEF_STMT (gimple_vdef (call
)) = g
;
2880 gimple_stmt_iterator gsi
= *gsip
;
2881 gsi_insert_after (&gsi
, g
, GSI_NEW_STMT
);
2884 /* The internal function returns the value of the specified bit
2885 before the atomic operation. If we are interested in the value
2886 of the specified bit after the atomic operation (makes only sense
2887 for xor, otherwise the bit content is compile time known),
2888 we need to invert the bit. */
2889 g
= gimple_build_assign (make_ssa_name (TREE_TYPE (lhs
)),
2890 BIT_XOR_EXPR
, new_lhs
,
2891 use_bool
? build_int_cst (TREE_TYPE (lhs
), 1)
2893 new_lhs
= gimple_assign_lhs (g
);
2894 gsi_insert_after (&gsi
, g
, GSI_NEW_STMT
);
2896 if (use_bool
&& has_debug_uses
)
2898 tree temp
= make_node (DEBUG_EXPR_DECL
);
2899 DECL_ARTIFICIAL (temp
) = 1;
2900 TREE_TYPE (temp
) = TREE_TYPE (lhs
);
2901 DECL_MODE (temp
) = TYPE_MODE (TREE_TYPE (lhs
));
2902 tree t
= build2 (LSHIFT_EXPR
, TREE_TYPE (lhs
), new_lhs
, bit
);
2903 g
= gimple_build_debug_bind (temp
, t
, g
);
2904 gsi_insert_after (&gsi
, g
, GSI_NEW_STMT
);
2905 FOR_EACH_IMM_USE_STMT (g
, iter
, use_lhs
)
2906 if (is_gimple_debug (g
))
2908 use_operand_p use_p
;
2909 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
2910 SET_USE (use_p
, temp
);
2914 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_lhs
)
2915 = SSA_NAME_OCCURS_IN_ABNORMAL_PHI (use_lhs
);
2916 replace_uses_by (use_lhs
, new_lhs
);
2917 gsi
= gsi_for_stmt (use_stmt
);
2918 gsi_remove (&gsi
, true);
2919 release_defs (use_stmt
);
2920 gsi_remove (gsip
, true);
2921 release_ssa_name (lhs
);
2924 /* A simple pass that attempts to fold all builtin functions. This pass
2925 is run after we've propagated as many constants as we can. */
2929 const pass_data pass_data_fold_builtins
=
2931 GIMPLE_PASS
, /* type */
2933 OPTGROUP_NONE
, /* optinfo_flags */
2934 TV_NONE
, /* tv_id */
2935 ( PROP_cfg
| PROP_ssa
), /* properties_required */
2936 0, /* properties_provided */
2937 0, /* properties_destroyed */
2938 0, /* todo_flags_start */
2939 TODO_update_ssa
, /* todo_flags_finish */
2942 class pass_fold_builtins
: public gimple_opt_pass
2945 pass_fold_builtins (gcc::context
*ctxt
)
2946 : gimple_opt_pass (pass_data_fold_builtins
, ctxt
)
2949 /* opt_pass methods: */
2950 opt_pass
* clone () { return new pass_fold_builtins (m_ctxt
); }
2951 virtual unsigned int execute (function
*);
2953 }; // class pass_fold_builtins
2956 pass_fold_builtins::execute (function
*fun
)
2958 bool cfg_changed
= false;
2960 unsigned int todoflags
= 0;
2962 FOR_EACH_BB_FN (bb
, fun
)
2964 gimple_stmt_iterator i
;
2965 for (i
= gsi_start_bb (bb
); !gsi_end_p (i
); )
2967 gimple
*stmt
, *old_stmt
;
2969 enum built_in_function fcode
;
2971 stmt
= gsi_stmt (i
);
2973 if (gimple_code (stmt
) != GIMPLE_CALL
)
2975 /* Remove all *ssaname_N ={v} {CLOBBER}; stmts,
2976 after the last GIMPLE DSE they aren't needed and might
2977 unnecessarily keep the SSA_NAMEs live. */
2978 if (gimple_clobber_p (stmt
))
2980 tree lhs
= gimple_assign_lhs (stmt
);
2981 if (TREE_CODE (lhs
) == MEM_REF
2982 && TREE_CODE (TREE_OPERAND (lhs
, 0)) == SSA_NAME
)
2984 unlink_stmt_vdef (stmt
);
2985 gsi_remove (&i
, true);
2986 release_defs (stmt
);
2994 callee
= gimple_call_fndecl (stmt
);
2995 if (!callee
|| DECL_BUILT_IN_CLASS (callee
) != BUILT_IN_NORMAL
)
3001 fcode
= DECL_FUNCTION_CODE (callee
);
3006 tree result
= NULL_TREE
;
3007 switch (DECL_FUNCTION_CODE (callee
))
3009 case BUILT_IN_CONSTANT_P
:
3010 /* Resolve __builtin_constant_p. If it hasn't been
3011 folded to integer_one_node by now, it's fairly
3012 certain that the value simply isn't constant. */
3013 result
= integer_zero_node
;
3016 case BUILT_IN_ASSUME_ALIGNED
:
3017 /* Remove __builtin_assume_aligned. */
3018 result
= gimple_call_arg (stmt
, 0);
3021 case BUILT_IN_STACK_RESTORE
:
3022 result
= optimize_stack_restore (i
);
3028 case BUILT_IN_UNREACHABLE
:
3029 if (optimize_unreachable (i
))
3033 case BUILT_IN_ATOMIC_FETCH_OR_1
:
3034 case BUILT_IN_ATOMIC_FETCH_OR_2
:
3035 case BUILT_IN_ATOMIC_FETCH_OR_4
:
3036 case BUILT_IN_ATOMIC_FETCH_OR_8
:
3037 case BUILT_IN_ATOMIC_FETCH_OR_16
:
3038 optimize_atomic_bit_test_and (&i
,
3039 IFN_ATOMIC_BIT_TEST_AND_SET
,
3042 case BUILT_IN_SYNC_FETCH_AND_OR_1
:
3043 case BUILT_IN_SYNC_FETCH_AND_OR_2
:
3044 case BUILT_IN_SYNC_FETCH_AND_OR_4
:
3045 case BUILT_IN_SYNC_FETCH_AND_OR_8
:
3046 case BUILT_IN_SYNC_FETCH_AND_OR_16
:
3047 optimize_atomic_bit_test_and (&i
,
3048 IFN_ATOMIC_BIT_TEST_AND_SET
,
3052 case BUILT_IN_ATOMIC_FETCH_XOR_1
:
3053 case BUILT_IN_ATOMIC_FETCH_XOR_2
:
3054 case BUILT_IN_ATOMIC_FETCH_XOR_4
:
3055 case BUILT_IN_ATOMIC_FETCH_XOR_8
:
3056 case BUILT_IN_ATOMIC_FETCH_XOR_16
:
3057 optimize_atomic_bit_test_and
3058 (&i
, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT
, true, false);
3060 case BUILT_IN_SYNC_FETCH_AND_XOR_1
:
3061 case BUILT_IN_SYNC_FETCH_AND_XOR_2
:
3062 case BUILT_IN_SYNC_FETCH_AND_XOR_4
:
3063 case BUILT_IN_SYNC_FETCH_AND_XOR_8
:
3064 case BUILT_IN_SYNC_FETCH_AND_XOR_16
:
3065 optimize_atomic_bit_test_and
3066 (&i
, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT
, false, false);
3069 case BUILT_IN_ATOMIC_XOR_FETCH_1
:
3070 case BUILT_IN_ATOMIC_XOR_FETCH_2
:
3071 case BUILT_IN_ATOMIC_XOR_FETCH_4
:
3072 case BUILT_IN_ATOMIC_XOR_FETCH_8
:
3073 case BUILT_IN_ATOMIC_XOR_FETCH_16
:
3074 optimize_atomic_bit_test_and
3075 (&i
, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT
, true, true);
3077 case BUILT_IN_SYNC_XOR_AND_FETCH_1
:
3078 case BUILT_IN_SYNC_XOR_AND_FETCH_2
:
3079 case BUILT_IN_SYNC_XOR_AND_FETCH_4
:
3080 case BUILT_IN_SYNC_XOR_AND_FETCH_8
:
3081 case BUILT_IN_SYNC_XOR_AND_FETCH_16
:
3082 optimize_atomic_bit_test_and
3083 (&i
, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT
, false, true);
3086 case BUILT_IN_ATOMIC_FETCH_AND_1
:
3087 case BUILT_IN_ATOMIC_FETCH_AND_2
:
3088 case BUILT_IN_ATOMIC_FETCH_AND_4
:
3089 case BUILT_IN_ATOMIC_FETCH_AND_8
:
3090 case BUILT_IN_ATOMIC_FETCH_AND_16
:
3091 optimize_atomic_bit_test_and (&i
,
3092 IFN_ATOMIC_BIT_TEST_AND_RESET
,
3095 case BUILT_IN_SYNC_FETCH_AND_AND_1
:
3096 case BUILT_IN_SYNC_FETCH_AND_AND_2
:
3097 case BUILT_IN_SYNC_FETCH_AND_AND_4
:
3098 case BUILT_IN_SYNC_FETCH_AND_AND_8
:
3099 case BUILT_IN_SYNC_FETCH_AND_AND_16
:
3100 optimize_atomic_bit_test_and (&i
,
3101 IFN_ATOMIC_BIT_TEST_AND_RESET
,
3105 case BUILT_IN_VA_START
:
3106 case BUILT_IN_VA_END
:
3107 case BUILT_IN_VA_COPY
:
3108 /* These shouldn't be folded before pass_stdarg. */
3109 result
= optimize_stdarg_builtin (stmt
);
3123 if (!update_call_from_tree (&i
, result
))
3124 gimplify_and_update_call_from_tree (&i
, result
);
3127 todoflags
|= TODO_update_address_taken
;
3129 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3131 fprintf (dump_file
, "Simplified\n ");
3132 print_gimple_stmt (dump_file
, stmt
, 0, dump_flags
);
3136 stmt
= gsi_stmt (i
);
3139 if (maybe_clean_or_replace_eh_stmt (old_stmt
, stmt
)
3140 && gimple_purge_dead_eh_edges (bb
))
3143 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3145 fprintf (dump_file
, "to\n ");
3146 print_gimple_stmt (dump_file
, stmt
, 0, dump_flags
);
3147 fprintf (dump_file
, "\n");
3150 /* Retry the same statement if it changed into another
3151 builtin, there might be new opportunities now. */
3152 if (gimple_code (stmt
) != GIMPLE_CALL
)
3157 callee
= gimple_call_fndecl (stmt
);
3159 || DECL_BUILT_IN_CLASS (callee
) != BUILT_IN_NORMAL
3160 || DECL_FUNCTION_CODE (callee
) == fcode
)
3165 /* Delete unreachable blocks. */
3167 todoflags
|= TODO_cleanup_cfg
;
3175 make_pass_fold_builtins (gcc::context
*ctxt
)
3177 return new pass_fold_builtins (ctxt
);