1 /* Convert tree expression to rtl instructions, for GNU compiler.
2 Copyright (C) 1988-2020 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
22 #include "coretypes.h"
32 #include "fold-const.h"
33 #include "stor-layout.h"
34 /* Include expr.h after insn-config.h so we get HAVE_conditional_move. */
38 #include "langhooks.h"
40 static bool prefer_and_bit_test (scalar_int_mode
, int);
41 static void do_jump (tree
, rtx_code_label
*, rtx_code_label
*,
43 static void do_jump_by_parts_greater (scalar_int_mode
, tree
, tree
, int,
44 rtx_code_label
*, rtx_code_label
*,
46 static void do_jump_by_parts_equality (scalar_int_mode
, tree
, tree
,
47 rtx_code_label
*, rtx_code_label
*,
49 static void do_compare_and_jump (tree
, tree
, enum rtx_code
, enum rtx_code
,
50 rtx_code_label
*, rtx_code_label
*,
53 /* At the start of a function, record that we have no previously-pushed
54 arguments waiting to be popped. */
57 init_pending_stack_adjust (void)
59 pending_stack_adjust
= 0;
62 /* Discard any pending stack adjustment. This avoid relying on the
63 RTL optimizers to remove useless adjustments when we know the
64 stack pointer value is dead. */
66 discard_pending_stack_adjust (void)
68 stack_pointer_delta
-= pending_stack_adjust
;
69 pending_stack_adjust
= 0;
72 /* When exiting from function, if safe, clear out any pending stack adjust
73 so the adjustment won't get done.
75 Note, if the current function calls alloca, then it must have a
76 frame pointer regardless of the value of flag_omit_frame_pointer. */
79 clear_pending_stack_adjust (void)
82 && (! flag_omit_frame_pointer
|| cfun
->calls_alloca
)
84 discard_pending_stack_adjust ();
87 /* Pop any previously-pushed arguments that have not been popped yet. */
90 do_pending_stack_adjust (void)
92 if (inhibit_defer_pop
== 0)
94 if (maybe_ne (pending_stack_adjust
, 0))
95 adjust_stack (gen_int_mode (pending_stack_adjust
, Pmode
));
96 pending_stack_adjust
= 0;
100 /* Remember pending_stack_adjust/stack_pointer_delta.
101 To be used around code that may call do_pending_stack_adjust (),
102 but the generated code could be discarded e.g. using delete_insns_since. */
105 save_pending_stack_adjust (saved_pending_stack_adjust
*save
)
107 save
->x_pending_stack_adjust
= pending_stack_adjust
;
108 save
->x_stack_pointer_delta
= stack_pointer_delta
;
111 /* Restore the saved pending_stack_adjust/stack_pointer_delta. */
114 restore_pending_stack_adjust (saved_pending_stack_adjust
*save
)
116 if (inhibit_defer_pop
== 0)
118 pending_stack_adjust
= save
->x_pending_stack_adjust
;
119 stack_pointer_delta
= save
->x_stack_pointer_delta
;
123 /* Used internally by prefer_and_bit_test. */
125 static GTY(()) rtx and_reg
;
126 static GTY(()) rtx and_test
;
127 static GTY(()) rtx shift_test
;
129 /* Compare the relative costs of "(X & (1 << BITNUM))" and "(X >> BITNUM) & 1",
130 where X is an arbitrary register of mode MODE. Return true if the former
134 prefer_and_bit_test (scalar_int_mode mode
, int bitnum
)
137 wide_int mask
= wi::set_bit_in_zero (bitnum
, GET_MODE_PRECISION (mode
));
141 /* Set up rtxes for the two variations. Use NULL as a placeholder
142 for the BITNUM-based constants. */
143 and_reg
= gen_rtx_REG (mode
, LAST_VIRTUAL_REGISTER
+ 1);
144 and_test
= gen_rtx_AND (mode
, and_reg
, NULL
);
145 shift_test
= gen_rtx_AND (mode
, gen_rtx_ASHIFTRT (mode
, and_reg
, NULL
),
150 /* Change the mode of the previously-created rtxes. */
151 PUT_MODE (and_reg
, mode
);
152 PUT_MODE (and_test
, mode
);
153 PUT_MODE (shift_test
, mode
);
154 PUT_MODE (XEXP (shift_test
, 0), mode
);
157 /* Fill in the integers. */
158 XEXP (and_test
, 1) = immed_wide_int_const (mask
, mode
);
159 XEXP (XEXP (shift_test
, 0), 1) = GEN_INT (bitnum
);
161 speed_p
= optimize_insn_for_speed_p ();
162 return (rtx_cost (and_test
, mode
, IF_THEN_ELSE
, 0, speed_p
)
163 <= rtx_cost (shift_test
, mode
, IF_THEN_ELSE
, 0, speed_p
));
166 /* Subroutine of do_jump, dealing with exploded comparisons of the type
167 OP0 CODE OP1 . IF_FALSE_LABEL and IF_TRUE_LABEL like in do_jump.
168 PROB is probability of jump to if_true_label. */
171 do_jump_1 (enum tree_code code
, tree op0
, tree op1
,
172 rtx_code_label
*if_false_label
, rtx_code_label
*if_true_label
,
173 profile_probability prob
)
176 rtx_code_label
*drop_through_label
= 0;
177 scalar_int_mode int_mode
;
183 tree inner_type
= TREE_TYPE (op0
);
185 gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type
))
186 != MODE_COMPLEX_FLOAT
);
187 gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type
))
188 != MODE_COMPLEX_INT
);
190 if (integer_zerop (op1
))
191 do_jump (op0
, if_true_label
, if_false_label
,
193 else if (is_int_mode (TYPE_MODE (inner_type
), &int_mode
)
194 && !can_compare_p (EQ
, int_mode
, ccp_jump
))
195 do_jump_by_parts_equality (int_mode
, op0
, op1
, if_false_label
,
196 if_true_label
, prob
);
198 do_compare_and_jump (op0
, op1
, EQ
, EQ
, if_false_label
, if_true_label
,
205 tree inner_type
= TREE_TYPE (op0
);
207 gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type
))
208 != MODE_COMPLEX_FLOAT
);
209 gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type
))
210 != MODE_COMPLEX_INT
);
212 if (integer_zerop (op1
))
213 do_jump (op0
, if_false_label
, if_true_label
, prob
);
214 else if (is_int_mode (TYPE_MODE (inner_type
), &int_mode
)
215 && !can_compare_p (NE
, int_mode
, ccp_jump
))
216 do_jump_by_parts_equality (int_mode
, op0
, op1
, if_true_label
,
217 if_false_label
, prob
.invert ());
219 do_compare_and_jump (op0
, op1
, NE
, NE
, if_false_label
, if_true_label
,
225 mode
= TYPE_MODE (TREE_TYPE (op0
));
226 if (is_int_mode (mode
, &int_mode
)
227 && ! can_compare_p (LT
, int_mode
, ccp_jump
))
228 do_jump_by_parts_greater (int_mode
, op0
, op1
, 1, if_false_label
,
229 if_true_label
, prob
);
231 do_compare_and_jump (op0
, op1
, LT
, LTU
, if_false_label
, if_true_label
,
236 mode
= TYPE_MODE (TREE_TYPE (op0
));
237 if (is_int_mode (mode
, &int_mode
)
238 && ! can_compare_p (LE
, int_mode
, ccp_jump
))
239 do_jump_by_parts_greater (int_mode
, op0
, op1
, 0, if_true_label
,
240 if_false_label
, prob
.invert ());
242 do_compare_and_jump (op0
, op1
, LE
, LEU
, if_false_label
, if_true_label
,
247 mode
= TYPE_MODE (TREE_TYPE (op0
));
248 if (is_int_mode (mode
, &int_mode
)
249 && ! can_compare_p (GT
, int_mode
, ccp_jump
))
250 do_jump_by_parts_greater (int_mode
, op0
, op1
, 0, if_false_label
,
251 if_true_label
, prob
);
253 do_compare_and_jump (op0
, op1
, GT
, GTU
, if_false_label
, if_true_label
,
258 mode
= TYPE_MODE (TREE_TYPE (op0
));
259 if (is_int_mode (mode
, &int_mode
)
260 && ! can_compare_p (GE
, int_mode
, ccp_jump
))
261 do_jump_by_parts_greater (int_mode
, op0
, op1
, 1, if_true_label
,
262 if_false_label
, prob
.invert ());
264 do_compare_and_jump (op0
, op1
, GE
, GEU
, if_false_label
, if_true_label
,
269 do_compare_and_jump (op0
, op1
, ORDERED
, ORDERED
,
270 if_false_label
, if_true_label
, prob
);
274 do_compare_and_jump (op0
, op1
, UNORDERED
, UNORDERED
,
275 if_false_label
, if_true_label
, prob
);
279 do_compare_and_jump (op0
, op1
, UNLT
, UNLT
, if_false_label
, if_true_label
,
284 do_compare_and_jump (op0
, op1
, UNLE
, UNLE
, if_false_label
, if_true_label
,
289 do_compare_and_jump (op0
, op1
, UNGT
, UNGT
, if_false_label
, if_true_label
,
294 do_compare_and_jump (op0
, op1
, UNGE
, UNGE
, if_false_label
, if_true_label
,
299 do_compare_and_jump (op0
, op1
, UNEQ
, UNEQ
, if_false_label
, if_true_label
,
304 do_compare_and_jump (op0
, op1
, LTGT
, LTGT
, if_false_label
, if_true_label
,
308 case TRUTH_ANDIF_EXPR
:
310 /* Spread the probability that the expression is false evenly between
311 the two conditions. So the first condition is false half the total
312 probability of being false. The second condition is false the other
313 half of the total probability of being false, so its jump has a false
314 probability of half the total, relative to the probability we
315 reached it (i.e. the first condition was true). */
316 profile_probability op0_prob
= profile_probability::uninitialized ();
317 profile_probability op1_prob
= profile_probability::uninitialized ();
318 if (prob
.initialized_p ())
320 op1_prob
= prob
.invert ();
321 op0_prob
= op1_prob
.split (profile_probability::even ());
322 /* Get the probability that each jump below is true. */
323 op0_prob
= op0_prob
.invert ();
324 op1_prob
= op1_prob
.invert ();
326 if (if_false_label
== NULL
)
328 drop_through_label
= gen_label_rtx ();
329 do_jump (op0
, drop_through_label
, NULL
, op0_prob
);
330 do_jump (op1
, NULL
, if_true_label
, op1_prob
);
334 do_jump (op0
, if_false_label
, NULL
, op0_prob
);
335 do_jump (op1
, if_false_label
, if_true_label
, op1_prob
);
340 case TRUTH_ORIF_EXPR
:
342 /* Spread the probability evenly between the two conditions. So
343 the first condition has half the total probability of being true.
344 The second condition has the other half of the total probability,
345 so its jump has a probability of half the total, relative to
346 the probability we reached it (i.e. the first condition was false). */
347 profile_probability op0_prob
= profile_probability::uninitialized ();
348 profile_probability op1_prob
= profile_probability::uninitialized ();
349 if (prob
.initialized_p ())
352 op0_prob
= op1_prob
.split (profile_probability::even ());
354 if (if_true_label
== NULL
)
356 drop_through_label
= gen_label_rtx ();
357 do_jump (op0
, NULL
, drop_through_label
, op0_prob
);
358 do_jump (op1
, if_false_label
, NULL
, op1_prob
);
362 do_jump (op0
, NULL
, if_true_label
, op0_prob
);
363 do_jump (op1
, if_false_label
, if_true_label
, op1_prob
);
372 if (drop_through_label
)
374 do_pending_stack_adjust ();
375 emit_label (drop_through_label
);
379 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
380 the result is zero, or IF_TRUE_LABEL if the result is one.
381 Either of IF_FALSE_LABEL and IF_TRUE_LABEL may be zero,
382 meaning fall through in that case.
384 do_jump always does any pending stack adjust except when it does not
385 actually perform a jump. An example where there is no jump
386 is when EXP is `(foo (), 0)' and IF_FALSE_LABEL is null.
388 PROB is probability of jump to if_true_label. */
391 do_jump (tree exp
, rtx_code_label
*if_false_label
,
392 rtx_code_label
*if_true_label
, profile_probability prob
)
394 enum tree_code code
= TREE_CODE (exp
);
398 scalar_int_mode mode
;
399 rtx_code_label
*drop_through_label
= NULL
;
408 rtx_code_label
*lab
= integer_zerop (exp
) ? if_false_label
416 /* This is not true with #pragma weak */
418 /* The address of something can never be zero. */
420 emit_jump (if_true_label
);
425 if (TREE_CODE (TREE_OPERAND (exp
, 0)) == COMPONENT_REF
426 || TREE_CODE (TREE_OPERAND (exp
, 0)) == BIT_FIELD_REF
427 || TREE_CODE (TREE_OPERAND (exp
, 0)) == ARRAY_REF
428 || TREE_CODE (TREE_OPERAND (exp
, 0)) == ARRAY_RANGE_REF
)
432 /* If we are narrowing the operand, we have to do the compare in the
434 if ((TYPE_PRECISION (TREE_TYPE (exp
))
435 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp
, 0)))))
438 case NON_LVALUE_EXPR
:
444 /* These cannot change zero->nonzero or vice versa. */
445 do_jump (TREE_OPERAND (exp
, 0), if_false_label
, if_true_label
, prob
);
449 do_jump (TREE_OPERAND (exp
, 0), if_true_label
, if_false_label
,
455 rtx_code_label
*label1
= gen_label_rtx ();
456 if (!if_true_label
|| !if_false_label
)
458 drop_through_label
= gen_label_rtx ();
460 if_true_label
= drop_through_label
;
462 if_false_label
= drop_through_label
;
465 do_pending_stack_adjust ();
466 do_jump (TREE_OPERAND (exp
, 0), label1
, NULL
,
467 profile_probability::uninitialized ());
468 do_jump (TREE_OPERAND (exp
, 1), if_false_label
, if_true_label
, prob
);
470 do_jump (TREE_OPERAND (exp
, 2), if_false_label
, if_true_label
, prob
);
475 /* Lowered by gimplify.c. */
479 /* Nonzero iff operands of minus differ. */
497 case TRUTH_ANDIF_EXPR
:
498 case TRUTH_ORIF_EXPR
:
500 do_jump_1 (code
, TREE_OPERAND (exp
, 0), TREE_OPERAND (exp
, 1),
501 if_false_label
, if_true_label
, prob
);
505 /* fold_single_bit_test() converts (X & (1 << C)) into (X >> C) & 1.
506 See if the former is preferred for jump tests and restore it
508 if (integer_onep (TREE_OPERAND (exp
, 1)))
510 tree exp0
= TREE_OPERAND (exp
, 0);
511 rtx_code_label
*set_label
, *clr_label
;
512 profile_probability setclr_prob
= prob
;
514 /* Strip narrowing integral type conversions. */
515 while (CONVERT_EXPR_P (exp0
)
516 && TREE_OPERAND (exp0
, 0) != error_mark_node
517 && TYPE_PRECISION (TREE_TYPE (exp0
))
518 <= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp0
, 0))))
519 exp0
= TREE_OPERAND (exp0
, 0);
521 /* "exp0 ^ 1" inverts the sense of the single bit test. */
522 if (TREE_CODE (exp0
) == BIT_XOR_EXPR
523 && integer_onep (TREE_OPERAND (exp0
, 1)))
525 exp0
= TREE_OPERAND (exp0
, 0);
526 clr_label
= if_true_label
;
527 set_label
= if_false_label
;
528 setclr_prob
= prob
.invert ();
532 clr_label
= if_false_label
;
533 set_label
= if_true_label
;
536 if (TREE_CODE (exp0
) == RSHIFT_EXPR
)
538 tree arg
= TREE_OPERAND (exp0
, 0);
539 tree shift
= TREE_OPERAND (exp0
, 1);
540 tree argtype
= TREE_TYPE (arg
);
541 if (TREE_CODE (shift
) == INTEGER_CST
542 && compare_tree_int (shift
, 0) >= 0
543 && compare_tree_int (shift
, HOST_BITS_PER_WIDE_INT
) < 0
544 && prefer_and_bit_test (SCALAR_INT_TYPE_MODE (argtype
),
545 TREE_INT_CST_LOW (shift
)))
547 unsigned HOST_WIDE_INT mask
548 = HOST_WIDE_INT_1U
<< TREE_INT_CST_LOW (shift
);
549 do_jump (build2 (BIT_AND_EXPR
, argtype
, arg
,
550 build_int_cstu (argtype
, mask
)),
551 clr_label
, set_label
, setclr_prob
);
557 /* If we are AND'ing with a small constant, do this comparison in the
558 smallest type that fits. If the machine doesn't have comparisons
559 that small, it will be converted back to the wider comparison.
560 This helps if we are testing the sign bit of a narrower object.
561 combine can't do this for us because it can't know whether a
562 ZERO_EXTRACT or a compare in a smaller mode exists, but we do. */
564 if (! SLOW_BYTE_ACCESS
565 && TREE_CODE (TREE_OPERAND (exp
, 1)) == INTEGER_CST
566 && TYPE_PRECISION (TREE_TYPE (exp
)) <= HOST_BITS_PER_WIDE_INT
567 && (i
= tree_floor_log2 (TREE_OPERAND (exp
, 1))) >= 0
568 && int_mode_for_size (i
+ 1, 0).exists (&mode
)
569 && (type
= lang_hooks
.types
.type_for_mode (mode
, 1)) != 0
570 && TYPE_PRECISION (type
) < TYPE_PRECISION (TREE_TYPE (exp
))
571 && have_insn_for (COMPARE
, TYPE_MODE (type
)))
573 do_jump (fold_convert (type
, exp
), if_false_label
, if_true_label
,
578 if (TYPE_PRECISION (TREE_TYPE (exp
)) > 1
579 || TREE_CODE (TREE_OPERAND (exp
, 1)) == INTEGER_CST
)
582 /* Boolean comparisons can be compiled as TRUTH_AND_EXPR. */
586 /* High branch cost, expand as the bitwise AND of the conditions.
587 Do the same if the RHS has side effects, because we're effectively
588 turning a TRUTH_AND_EXPR into a TRUTH_ANDIF_EXPR. */
589 if (BRANCH_COST (optimize_insn_for_speed_p (),
591 || TREE_SIDE_EFFECTS (TREE_OPERAND (exp
, 1)))
593 code
= TRUTH_ANDIF_EXPR
;
598 /* High branch cost, expand as the bitwise OR of the conditions.
599 Do the same if the RHS has side effects, because we're effectively
600 turning a TRUTH_OR_EXPR into a TRUTH_ORIF_EXPR. */
601 if (BRANCH_COST (optimize_insn_for_speed_p (), false) >= 4
602 || TREE_SIDE_EFFECTS (TREE_OPERAND (exp
, 1)))
604 code
= TRUTH_ORIF_EXPR
;
607 /* Fall through and generate the normal code. */
610 temp
= expand_normal (exp
);
611 do_pending_stack_adjust ();
612 /* The RTL optimizers prefer comparisons against pseudos. */
613 if (GET_CODE (temp
) == SUBREG
)
615 /* Compare promoted variables in their promoted mode. */
616 if (SUBREG_PROMOTED_VAR_P (temp
)
617 && REG_P (XEXP (temp
, 0)))
618 temp
= XEXP (temp
, 0);
620 temp
= copy_to_reg (temp
);
622 do_compare_rtx_and_jump (temp
, CONST0_RTX (GET_MODE (temp
)),
623 NE
, TYPE_UNSIGNED (TREE_TYPE (exp
)),
624 GET_MODE (temp
), NULL_RTX
,
625 if_false_label
, if_true_label
, prob
);
628 if (drop_through_label
)
630 do_pending_stack_adjust ();
631 emit_label (drop_through_label
);
635 /* Compare OP0 with OP1, word at a time, in mode MODE.
636 UNSIGNEDP says to do unsigned comparison.
637 Jump to IF_TRUE_LABEL if OP0 is greater, IF_FALSE_LABEL otherwise. */
640 do_jump_by_parts_greater_rtx (scalar_int_mode mode
, int unsignedp
, rtx op0
,
641 rtx op1
, rtx_code_label
*if_false_label
,
642 rtx_code_label
*if_true_label
,
643 profile_probability prob
)
645 int nwords
= (GET_MODE_SIZE (mode
) / UNITS_PER_WORD
);
646 rtx_code_label
*drop_through_label
= 0;
647 bool drop_through_if_true
= false, drop_through_if_false
= false;
648 enum rtx_code code
= GT
;
651 if (! if_true_label
|| ! if_false_label
)
652 drop_through_label
= gen_label_rtx ();
655 if_true_label
= drop_through_label
;
656 drop_through_if_true
= true;
658 if (! if_false_label
)
660 if_false_label
= drop_through_label
;
661 drop_through_if_false
= true;
664 /* Deal with the special case 0 > x: only one comparison is necessary and
665 we reverse it to avoid jumping to the drop-through label. */
666 if (op0
== const0_rtx
&& drop_through_if_true
&& !drop_through_if_false
)
669 if_true_label
= if_false_label
;
670 if_false_label
= drop_through_label
;
671 prob
= prob
.invert ();
674 /* Compare a word at a time, high order first. */
675 for (i
= 0; i
< nwords
; i
++)
677 rtx op0_word
, op1_word
;
679 if (WORDS_BIG_ENDIAN
)
681 op0_word
= operand_subword_force (op0
, i
, mode
);
682 op1_word
= operand_subword_force (op1
, i
, mode
);
686 op0_word
= operand_subword_force (op0
, nwords
- 1 - i
, mode
);
687 op1_word
= operand_subword_force (op1
, nwords
- 1 - i
, mode
);
690 /* All but high-order word must be compared as unsigned. */
691 do_compare_rtx_and_jump (op0_word
, op1_word
, code
, (unsignedp
|| i
> 0),
692 word_mode
, NULL_RTX
, NULL
, if_true_label
,
695 /* Emit only one comparison for 0. Do not emit the last cond jump. */
696 if (op0
== const0_rtx
|| i
== nwords
- 1)
699 /* Consider lower words only if these are equal. */
700 do_compare_rtx_and_jump (op0_word
, op1_word
, NE
, unsignedp
, word_mode
,
701 NULL_RTX
, NULL
, if_false_label
,
705 if (!drop_through_if_false
)
706 emit_jump (if_false_label
);
707 if (drop_through_label
)
708 emit_label (drop_through_label
);
711 /* Given a comparison expression EXP for values too wide to be compared
712 with one insn, test the comparison and jump to the appropriate label.
713 The code of EXP is ignored; we always test GT if SWAP is 0,
714 and LT if SWAP is 1. MODE is the mode of the two operands. */
717 do_jump_by_parts_greater (scalar_int_mode mode
, tree treeop0
, tree treeop1
,
718 int swap
, rtx_code_label
*if_false_label
,
719 rtx_code_label
*if_true_label
,
720 profile_probability prob
)
722 rtx op0
= expand_normal (swap
? treeop1
: treeop0
);
723 rtx op1
= expand_normal (swap
? treeop0
: treeop1
);
724 int unsignedp
= TYPE_UNSIGNED (TREE_TYPE (treeop0
));
726 do_jump_by_parts_greater_rtx (mode
, unsignedp
, op0
, op1
, if_false_label
,
727 if_true_label
, prob
);
730 /* Jump according to whether OP0 is 0. We assume that OP0 has an integer
731 mode, MODE, that is too wide for the available compare insns. Either
732 Either (but not both) of IF_TRUE_LABEL and IF_FALSE_LABEL may be NULL
733 to indicate drop through. */
736 do_jump_by_parts_zero_rtx (scalar_int_mode mode
, rtx op0
,
737 rtx_code_label
*if_false_label
,
738 rtx_code_label
*if_true_label
,
739 profile_probability prob
)
741 int nwords
= GET_MODE_SIZE (mode
) / UNITS_PER_WORD
;
744 rtx_code_label
*drop_through_label
= NULL
;
746 /* The fastest way of doing this comparison on almost any machine is to
747 "or" all the words and compare the result. If all have to be loaded
748 from memory and this is a very wide item, it's possible this may
749 be slower, but that's highly unlikely. */
751 part
= gen_reg_rtx (word_mode
);
752 emit_move_insn (part
, operand_subword_force (op0
, 0, mode
));
753 for (i
= 1; i
< nwords
&& part
!= 0; i
++)
754 part
= expand_binop (word_mode
, ior_optab
, part
,
755 operand_subword_force (op0
, i
, mode
),
756 part
, 1, OPTAB_WIDEN
);
760 do_compare_rtx_and_jump (part
, const0_rtx
, EQ
, 1, word_mode
,
761 NULL_RTX
, if_false_label
, if_true_label
, prob
);
765 /* If we couldn't do the "or" simply, do this with a series of compares. */
766 if (! if_false_label
)
767 if_false_label
= drop_through_label
= gen_label_rtx ();
769 for (i
= 0; i
< nwords
; i
++)
770 do_compare_rtx_and_jump (operand_subword_force (op0
, i
, mode
),
771 const0_rtx
, EQ
, 1, word_mode
, NULL_RTX
,
772 if_false_label
, NULL
, prob
);
775 emit_jump (if_true_label
);
777 if (drop_through_label
)
778 emit_label (drop_through_label
);
781 /* Test for the equality of two RTX expressions OP0 and OP1 in mode MODE,
782 where MODE is an integer mode too wide to be compared with one insn.
783 Either (but not both) of IF_TRUE_LABEL and IF_FALSE_LABEL may be NULL_RTX
784 to indicate drop through. */
787 do_jump_by_parts_equality_rtx (scalar_int_mode mode
, rtx op0
, rtx op1
,
788 rtx_code_label
*if_false_label
,
789 rtx_code_label
*if_true_label
,
790 profile_probability prob
)
792 int nwords
= (GET_MODE_SIZE (mode
) / UNITS_PER_WORD
);
793 rtx_code_label
*drop_through_label
= NULL
;
796 if (op1
== const0_rtx
)
798 do_jump_by_parts_zero_rtx (mode
, op0
, if_false_label
, if_true_label
,
802 else if (op0
== const0_rtx
)
804 do_jump_by_parts_zero_rtx (mode
, op1
, if_false_label
, if_true_label
,
809 if (! if_false_label
)
810 drop_through_label
= if_false_label
= gen_label_rtx ();
812 for (i
= 0; i
< nwords
; i
++)
813 do_compare_rtx_and_jump (operand_subword_force (op0
, i
, mode
),
814 operand_subword_force (op1
, i
, mode
),
815 EQ
, 0, word_mode
, NULL_RTX
,
816 if_false_label
, NULL
, prob
);
819 emit_jump (if_true_label
);
820 if (drop_through_label
)
821 emit_label (drop_through_label
);
824 /* Given an EQ_EXPR expression EXP for values too wide to be compared
825 with one insn, test the comparison and jump to the appropriate label.
826 MODE is the mode of the two operands. */
829 do_jump_by_parts_equality (scalar_int_mode mode
, tree treeop0
, tree treeop1
,
830 rtx_code_label
*if_false_label
,
831 rtx_code_label
*if_true_label
,
832 profile_probability prob
)
834 rtx op0
= expand_normal (treeop0
);
835 rtx op1
= expand_normal (treeop1
);
836 do_jump_by_parts_equality_rtx (mode
, op0
, op1
, if_false_label
,
837 if_true_label
, prob
);
840 /* Split a comparison into two others, the second of which has the other
841 "orderedness". The first is always ORDERED or UNORDERED if MODE
842 does not honor NaNs (which means that it can be skipped in that case;
843 see do_compare_rtx_and_jump).
845 The two conditions are written in *CODE1 and *CODE2. Return true if
846 the conditions must be ANDed, false if they must be ORed. */
849 split_comparison (enum rtx_code code
, machine_mode mode
,
850 enum rtx_code
*code1
, enum rtx_code
*code2
)
899 /* Do not turn a trapping comparison into a non-trapping one. */
900 if (HONOR_NANS (mode
))
917 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.
918 PROB is probability of jump to LABEL. */
921 jumpif (tree exp
, rtx_code_label
*label
, profile_probability prob
)
923 do_jump (exp
, NULL
, label
, prob
);
926 /* Similar to jumpif but dealing with exploded comparisons of the type
927 OP0 CODE OP1 . LABEL and PROB are like in jumpif. */
930 jumpif_1 (enum tree_code code
, tree op0
, tree op1
, rtx_code_label
*label
,
931 profile_probability prob
)
933 do_jump_1 (code
, op0
, op1
, NULL
, label
, prob
);
936 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.
937 PROB is probability of jump to LABEL. */
940 jumpifnot (tree exp
, rtx_code_label
*label
, profile_probability prob
)
942 do_jump (exp
, label
, NULL
, prob
.invert ());
945 /* Similar to jumpifnot but dealing with exploded comparisons of the type
946 OP0 CODE OP1 . LABEL and PROB are like in jumpifnot. */
949 jumpifnot_1 (enum tree_code code
, tree op0
, tree op1
, rtx_code_label
*label
,
950 profile_probability prob
)
952 do_jump_1 (code
, op0
, op1
, label
, NULL
, prob
.invert ());
955 /* Like do_compare_and_jump but expects the values to compare as two rtx's.
956 The decision as to signed or unsigned comparison must be made by the caller.
958 If MODE is BLKmode, SIZE is an RTX giving the size of the objects being
962 do_compare_rtx_and_jump (rtx op0
, rtx op1
, enum rtx_code code
, int unsignedp
,
963 machine_mode mode
, rtx size
,
964 rtx_code_label
*if_false_label
,
965 rtx_code_label
*if_true_label
,
966 profile_probability prob
)
969 rtx_code_label
*dummy_label
= NULL
;
971 /* Reverse the comparison if that is safe and we want to jump if it is
972 false. Also convert to the reverse comparison if the target can
975 || ! can_compare_p (code
, mode
, ccp_jump
))
976 && (! FLOAT_MODE_P (mode
)
977 || code
== ORDERED
|| code
== UNORDERED
978 || (! HONOR_NANS (mode
) && (code
== LTGT
|| code
== UNEQ
))
979 || (! HONOR_SNANS (mode
) && (code
== EQ
|| code
== NE
))))
982 if (FLOAT_MODE_P (mode
))
983 rcode
= reverse_condition_maybe_unordered (code
);
985 rcode
= reverse_condition (code
);
987 /* Canonicalize to UNORDERED for the libcall. */
988 if (can_compare_p (rcode
, mode
, ccp_jump
)
989 || (code
== ORDERED
&& ! can_compare_p (ORDERED
, mode
, ccp_jump
)))
991 std::swap (if_true_label
, if_false_label
);
993 prob
= prob
.invert ();
997 /* If one operand is constant, make it the second one. Only do this
998 if the other operand is not constant as well. */
1000 if (swap_commutative_operands_p (op0
, op1
))
1002 std::swap (op0
, op1
);
1003 code
= swap_condition (code
);
1006 do_pending_stack_adjust ();
1008 code
= unsignedp
? unsigned_condition (code
) : code
;
1009 if ((tem
= simplify_relational_operation (code
, mode
, VOIDmode
,
1012 if (CONSTANT_P (tem
))
1014 rtx_code_label
*label
= (tem
== const0_rtx
1015 || tem
== CONST0_RTX (mode
))
1016 ? if_false_label
: if_true_label
;
1022 code
= GET_CODE (tem
);
1023 mode
= GET_MODE (tem
);
1024 op0
= XEXP (tem
, 0);
1025 op1
= XEXP (tem
, 1);
1026 unsignedp
= (code
== GTU
|| code
== LTU
|| code
== GEU
|| code
== LEU
);
1029 if (! if_true_label
)
1030 dummy_label
= if_true_label
= gen_label_rtx ();
1032 scalar_int_mode int_mode
;
1033 if (is_int_mode (mode
, &int_mode
)
1034 && ! can_compare_p (code
, int_mode
, ccp_jump
))
1039 do_jump_by_parts_greater_rtx (int_mode
, 1, op1
, op0
,
1040 if_false_label
, if_true_label
, prob
);
1044 do_jump_by_parts_greater_rtx (int_mode
, 1, op0
, op1
,
1045 if_true_label
, if_false_label
,
1050 do_jump_by_parts_greater_rtx (int_mode
, 1, op0
, op1
,
1051 if_false_label
, if_true_label
, prob
);
1055 do_jump_by_parts_greater_rtx (int_mode
, 1, op1
, op0
,
1056 if_true_label
, if_false_label
,
1061 do_jump_by_parts_greater_rtx (int_mode
, 0, op1
, op0
,
1062 if_false_label
, if_true_label
, prob
);
1066 do_jump_by_parts_greater_rtx (int_mode
, 0, op0
, op1
,
1067 if_true_label
, if_false_label
,
1072 do_jump_by_parts_greater_rtx (int_mode
, 0, op0
, op1
,
1073 if_false_label
, if_true_label
, prob
);
1077 do_jump_by_parts_greater_rtx (int_mode
, 0, op1
, op0
,
1078 if_true_label
, if_false_label
,
1083 do_jump_by_parts_equality_rtx (int_mode
, op0
, op1
, if_false_label
,
1084 if_true_label
, prob
);
1088 do_jump_by_parts_equality_rtx (int_mode
, op0
, op1
, if_true_label
,
1099 if (SCALAR_FLOAT_MODE_P (mode
)
1100 && ! can_compare_p (code
, mode
, ccp_jump
)
1101 && can_compare_p (swap_condition (code
), mode
, ccp_jump
))
1103 code
= swap_condition (code
);
1104 std::swap (op0
, op1
);
1106 else if (SCALAR_FLOAT_MODE_P (mode
)
1107 && ! can_compare_p (code
, mode
, ccp_jump
)
1108 /* Never split ORDERED and UNORDERED.
1109 These must be implemented. */
1110 && (code
!= ORDERED
&& code
!= UNORDERED
)
1111 /* Split a floating-point comparison if
1112 we can jump on other conditions... */
1113 && (have_insn_for (COMPARE
, mode
)
1114 /* ... or if there is no libcall for it. */
1115 || code_to_optab (code
) == unknown_optab
))
1117 enum rtx_code first_code
;
1118 bool and_them
= split_comparison (code
, mode
, &first_code
, &code
);
1120 /* If there are no NaNs, the first comparison should always fall
1122 if (!HONOR_NANS (mode
))
1123 gcc_assert (first_code
== (and_them
? ORDERED
: UNORDERED
));
1127 profile_probability cprob
1128 = profile_probability::guessed_always ();
1129 if (first_code
== UNORDERED
)
1130 cprob
= cprob
.apply_scale (1, 100);
1131 else if (first_code
== ORDERED
)
1132 cprob
= cprob
.apply_scale (99, 100);
1134 cprob
= profile_probability::even ();
1135 /* We want to split:
1136 if (x) goto t; // prob;
1138 if (a) goto t; // first_prob;
1139 if (b) goto t; // prob;
1140 such that the overall probability of jumping to t
1141 remains the same and first_prob is prob * cprob. */
1144 rtx_code_label
*dest_label
;
1145 prob
= prob
.invert ();
1146 profile_probability first_prob
= prob
.split (cprob
).invert ();
1147 prob
= prob
.invert ();
1148 /* If we only jump if true, just bypass the second jump. */
1149 if (! if_false_label
)
1152 dummy_label
= gen_label_rtx ();
1153 dest_label
= dummy_label
;
1156 dest_label
= if_false_label
;
1157 do_compare_rtx_and_jump (op0
, op1
, first_code
, unsignedp
, mode
,
1158 size
, dest_label
, NULL
, first_prob
);
1162 profile_probability first_prob
= prob
.split (cprob
);
1163 do_compare_rtx_and_jump (op0
, op1
, first_code
, unsignedp
, mode
,
1164 size
, NULL
, if_true_label
, first_prob
);
1169 emit_cmp_and_jump_insns (op0
, op1
, code
, size
, mode
, unsignedp
,
1170 if_true_label
, prob
);
1174 emit_jump (if_false_label
);
1176 emit_label (dummy_label
);
1179 /* Generate code for a comparison expression EXP (including code to compute
1180 the values to be compared) and a conditional jump to IF_FALSE_LABEL and/or
1181 IF_TRUE_LABEL. One of the labels can be NULL_RTX, in which case the
1182 generated code will drop through.
1183 SIGNED_CODE should be the rtx operation for this comparison for
1184 signed data; UNSIGNED_CODE, likewise for use if data is unsigned.
1186 We force a stack adjustment unless there are currently
1187 things pushed on the stack that aren't yet used. */
1190 do_compare_and_jump (tree treeop0
, tree treeop1
, enum rtx_code signed_code
,
1191 enum rtx_code unsigned_code
,
1192 rtx_code_label
*if_false_label
,
1193 rtx_code_label
*if_true_label
, profile_probability prob
)
1201 /* Don't crash if the comparison was erroneous. */
1202 op0
= expand_normal (treeop0
);
1203 if (TREE_CODE (treeop0
) == ERROR_MARK
)
1206 op1
= expand_normal (treeop1
);
1207 if (TREE_CODE (treeop1
) == ERROR_MARK
)
1210 type
= TREE_TYPE (treeop0
);
1211 if (TREE_CODE (treeop0
) == INTEGER_CST
1212 && (TREE_CODE (treeop1
) != INTEGER_CST
1213 || (GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE (type
))
1214 > GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE (TREE_TYPE (treeop1
))))))
1215 /* op0 might have been replaced by promoted constant, in which
1216 case the type of second argument should be used. */
1217 type
= TREE_TYPE (treeop1
);
1218 mode
= TYPE_MODE (type
);
1219 unsignedp
= TYPE_UNSIGNED (type
);
1220 code
= unsignedp
? unsigned_code
: signed_code
;
1222 /* If function pointers need to be "canonicalized" before they can
1223 be reliably compared, then canonicalize them. Canonicalize the
1224 expression when one of the operands is a function pointer. This
1225 handles the case where the other operand is a void pointer. See
1226 PR middle-end/17564. */
1227 if (targetm
.have_canonicalize_funcptr_for_compare ()
1228 && ((POINTER_TYPE_P (TREE_TYPE (treeop0
))
1229 && FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (treeop0
))))
1230 || (POINTER_TYPE_P (TREE_TYPE (treeop1
))
1231 && FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (treeop1
))))))
1233 rtx new_op0
= gen_reg_rtx (mode
);
1234 rtx new_op1
= gen_reg_rtx (mode
);
1236 emit_insn (targetm
.gen_canonicalize_funcptr_for_compare (new_op0
, op0
));
1239 emit_insn (targetm
.gen_canonicalize_funcptr_for_compare (new_op1
, op1
));
1243 do_compare_rtx_and_jump (op0
, op1
, code
, unsignedp
, mode
,
1245 ? expr_size (treeop0
) : NULL_RTX
),
1246 if_false_label
, if_true_label
, prob
);
1249 #include "gt-dojump.h"