mirrored from git://gcc.gnu.org/git/gcc.git
/
explow.c
1933 lines (1599 loc) · 55.9 KB
/
explow.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* Subroutines for manipulating rtx's in semantically interesting ways.
Copyright (C) 1987, 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "diagnostic-core.h"
#include "rtl.h"
#include "tree.h"
#include "tm_p.h"
#include "flags.h"
#include "except.h"
#include "function.h"
#include "expr.h"
#include "optabs.h"
#include "libfuncs.h"
#include "hard-reg-set.h"
#include "insn-config.h"
#include "ggc.h"
#include "recog.h"
#include "langhooks.h"
#include "target.h"
#include "common/common-target.h"
#include "output.h"
static rtx break_out_memory_refs (rtx);
/* Truncate and perhaps sign-extend C as appropriate for MODE. */
HOST_WIDE_INT
trunc_int_for_mode (HOST_WIDE_INT c, enum machine_mode mode)
{
int width = GET_MODE_PRECISION (mode);
/* You want to truncate to a _what_? */
gcc_assert (SCALAR_INT_MODE_P (mode));
/* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
if (mode == BImode)
return c & 1 ? STORE_FLAG_VALUE : 0;
/* Sign-extend for the requested mode. */
if (width < HOST_BITS_PER_WIDE_INT)
{
HOST_WIDE_INT sign = 1;
sign <<= width - 1;
c &= (sign << 1) - 1;
c ^= sign;
c -= sign;
}
return c;
}
/* Return an rtx for the sum of X and the integer C, given that X has
mode MODE. */
rtx
plus_constant (enum machine_mode mode, rtx x, HOST_WIDE_INT c)
{
RTX_CODE code;
rtx y;
rtx tem;
int all_constant = 0;
gcc_assert (GET_MODE (x) == VOIDmode || GET_MODE (x) == mode);
if (c == 0)
return x;
restart:
code = GET_CODE (x);
y = x;
switch (code)
{
case CONST_INT:
if (GET_MODE_BITSIZE (mode) > HOST_BITS_PER_WIDE_INT)
{
double_int di_x = double_int::from_shwi (INTVAL (x));
double_int di_c = double_int::from_shwi (c);
bool overflow;
double_int v = di_x.add_with_sign (di_c, false, &overflow);
if (overflow)
gcc_unreachable ();
return immed_double_int_const (v, VOIDmode);
}
return GEN_INT (INTVAL (x) + c);
case CONST_DOUBLE:
{
double_int di_x = double_int::from_pair (CONST_DOUBLE_HIGH (x),
CONST_DOUBLE_LOW (x));
double_int di_c = double_int::from_shwi (c);
bool overflow;
double_int v = di_x.add_with_sign (di_c, false, &overflow);
if (overflow)
/* Sorry, we have no way to represent overflows this wide.
To fix, add constant support wider than CONST_DOUBLE. */
gcc_assert (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_DOUBLE_INT);
return immed_double_int_const (v, VOIDmode);
}
case MEM:
/* If this is a reference to the constant pool, try replacing it with
a reference to a new constant. If the resulting address isn't
valid, don't return it because we have no way to validize it. */
if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
&& CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
{
tem = plus_constant (mode, get_pool_constant (XEXP (x, 0)), c);
tem = force_const_mem (GET_MODE (x), tem);
if (memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
return tem;
}
break;
case CONST:
/* If adding to something entirely constant, set a flag
so that we can add a CONST around the result. */
x = XEXP (x, 0);
all_constant = 1;
goto restart;
case SYMBOL_REF:
case LABEL_REF:
all_constant = 1;
break;
case PLUS:
/* The interesting case is adding the integer to a sum. Look
for constant term in the sum and combine with C. For an
integer constant term or a constant term that is not an
explicit integer, we combine or group them together anyway.
We may not immediately return from the recursive call here, lest
all_constant gets lost. */
if (CONSTANT_P (XEXP (x, 1)))
{
x = gen_rtx_PLUS (mode, XEXP (x, 0),
plus_constant (mode, XEXP (x, 1), c));
c = 0;
}
else if (find_constant_term_loc (&y))
{
/* We need to be careful since X may be shared and we can't
modify it in place. */
rtx copy = copy_rtx (x);
rtx *const_loc = find_constant_term_loc (©);
*const_loc = plus_constant (mode, *const_loc, c);
x = copy;
c = 0;
}
break;
default:
break;
}
if (c != 0)
x = gen_rtx_PLUS (mode, x, GEN_INT (c));
if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
return x;
else if (all_constant)
return gen_rtx_CONST (mode, x);
else
return x;
}
/* If X is a sum, return a new sum like X but lacking any constant terms.
Add all the removed constant terms into *CONSTPTR.
X itself is not altered. The result != X if and only if
it is not isomorphic to X. */
rtx
eliminate_constant_term (rtx x, rtx *constptr)
{
rtx x0, x1;
rtx tem;
if (GET_CODE (x) != PLUS)
return x;
/* First handle constants appearing at this level explicitly. */
if (CONST_INT_P (XEXP (x, 1))
&& 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
XEXP (x, 1)))
&& CONST_INT_P (tem))
{
*constptr = tem;
return eliminate_constant_term (XEXP (x, 0), constptr);
}
tem = const0_rtx;
x0 = eliminate_constant_term (XEXP (x, 0), &tem);
x1 = eliminate_constant_term (XEXP (x, 1), &tem);
if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0))
&& 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x),
*constptr, tem))
&& CONST_INT_P (tem))
{
*constptr = tem;
return gen_rtx_PLUS (GET_MODE (x), x0, x1);
}
return x;
}
/* Return an rtx for the size in bytes of the value of EXP. */
rtx
expr_size (tree exp)
{
tree size;
if (TREE_CODE (exp) == WITH_SIZE_EXPR)
size = TREE_OPERAND (exp, 1);
else
{
size = tree_expr_size (exp);
gcc_assert (size);
gcc_assert (size == SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, exp));
}
return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype), EXPAND_NORMAL);
}
/* Return a wide integer for the size in bytes of the value of EXP, or -1
if the size can vary or is larger than an integer. */
HOST_WIDE_INT
int_expr_size (tree exp)
{
tree size;
if (TREE_CODE (exp) == WITH_SIZE_EXPR)
size = TREE_OPERAND (exp, 1);
else
{
size = tree_expr_size (exp);
gcc_assert (size);
}
if (size == 0 || !host_integerp (size, 0))
return -1;
return tree_low_cst (size, 0);
}
/* Return a copy of X in which all memory references
and all constants that involve symbol refs
have been replaced with new temporary registers.
Also emit code to load the memory locations and constants
into those registers.
If X contains no such constants or memory references,
X itself (not a copy) is returned.
If a constant is found in the address that is not a legitimate constant
in an insn, it is left alone in the hope that it might be valid in the
address.
X may contain no arithmetic except addition, subtraction and multiplication.
Values returned by expand_expr with 1 for sum_ok fit this constraint. */
static rtx
break_out_memory_refs (rtx x)
{
if (MEM_P (x)
|| (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)
&& GET_MODE (x) != VOIDmode))
x = force_reg (GET_MODE (x), x);
else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
|| GET_CODE (x) == MULT)
{
rtx op0 = break_out_memory_refs (XEXP (x, 0));
rtx op1 = break_out_memory_refs (XEXP (x, 1));
if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
x = simplify_gen_binary (GET_CODE (x), GET_MODE (x), op0, op1);
}
return x;
}
/* Given X, a memory address in address space AS' pointer mode, convert it to
an address in the address space's address mode, or vice versa (TO_MODE says
which way). We take advantage of the fact that pointers are not allowed to
overflow by commuting arithmetic operations over conversions so that address
arithmetic insns can be used. */
rtx
convert_memory_address_addr_space (enum machine_mode to_mode ATTRIBUTE_UNUSED,
rtx x, addr_space_t as ATTRIBUTE_UNUSED)
{
#ifndef POINTERS_EXTEND_UNSIGNED
gcc_assert (GET_MODE (x) == to_mode || GET_MODE (x) == VOIDmode);
return x;
#else /* defined(POINTERS_EXTEND_UNSIGNED) */
enum machine_mode pointer_mode, address_mode, from_mode;
rtx temp;
enum rtx_code code;
/* If X already has the right mode, just return it. */
if (GET_MODE (x) == to_mode)
return x;
pointer_mode = targetm.addr_space.pointer_mode (as);
address_mode = targetm.addr_space.address_mode (as);
from_mode = to_mode == pointer_mode ? address_mode : pointer_mode;
/* Here we handle some special cases. If none of them apply, fall through
to the default case. */
switch (GET_CODE (x))
{
CASE_CONST_SCALAR_INT:
if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode))
code = TRUNCATE;
else if (POINTERS_EXTEND_UNSIGNED < 0)
break;
else if (POINTERS_EXTEND_UNSIGNED > 0)
code = ZERO_EXTEND;
else
code = SIGN_EXTEND;
temp = simplify_unary_operation (code, to_mode, x, from_mode);
if (temp)
return temp;
break;
case SUBREG:
if ((SUBREG_PROMOTED_VAR_P (x) || REG_POINTER (SUBREG_REG (x)))
&& GET_MODE (SUBREG_REG (x)) == to_mode)
return SUBREG_REG (x);
break;
case LABEL_REF:
temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0));
LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x);
return temp;
break;
case SYMBOL_REF:
temp = shallow_copy_rtx (x);
PUT_MODE (temp, to_mode);
return temp;
break;
case CONST:
return gen_rtx_CONST (to_mode,
convert_memory_address_addr_space
(to_mode, XEXP (x, 0), as));
break;
case PLUS:
case MULT:
/* FIXME: For addition, we used to permute the conversion and
addition operation only if one operand is a constant and
converting the constant does not change it or if one operand
is a constant and we are using a ptr_extend instruction
(POINTERS_EXTEND_UNSIGNED < 0) even if the resulting address
may overflow/underflow. We relax the condition to include
zero-extend (POINTERS_EXTEND_UNSIGNED > 0) since the other
parts of the compiler depend on it. See PR 49721.
We can always safely permute them if we are making the address
narrower. */
if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
|| (GET_CODE (x) == PLUS
&& CONST_INT_P (XEXP (x, 1))
&& (POINTERS_EXTEND_UNSIGNED != 0
|| XEXP (x, 1) == convert_memory_address_addr_space
(to_mode, XEXP (x, 1), as))))
return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
convert_memory_address_addr_space
(to_mode, XEXP (x, 0), as),
XEXP (x, 1));
break;
default:
break;
}
return convert_modes (to_mode, from_mode,
x, POINTERS_EXTEND_UNSIGNED);
#endif /* defined(POINTERS_EXTEND_UNSIGNED) */
}
/* Return something equivalent to X but valid as a memory address for something
of mode MODE in the named address space AS. When X is not itself valid,
this works by copying X or subexpressions of it into registers. */
rtx
memory_address_addr_space (enum machine_mode mode, rtx x, addr_space_t as)
{
rtx oldx = x;
enum machine_mode address_mode = targetm.addr_space.address_mode (as);
x = convert_memory_address_addr_space (address_mode, x, as);
/* By passing constant addresses through registers
we get a chance to cse them. */
if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x))
x = force_reg (address_mode, x);
/* We get better cse by rejecting indirect addressing at this stage.
Let the combiner create indirect addresses where appropriate.
For now, generate the code so that the subexpressions useful to share
are visible. But not if cse won't be done! */
else
{
if (! cse_not_expected && !REG_P (x))
x = break_out_memory_refs (x);
/* At this point, any valid address is accepted. */
if (memory_address_addr_space_p (mode, x, as))
goto done;
/* If it was valid before but breaking out memory refs invalidated it,
use it the old way. */
if (memory_address_addr_space_p (mode, oldx, as))
{
x = oldx;
goto done;
}
/* Perform machine-dependent transformations on X
in certain cases. This is not necessary since the code
below can handle all possible cases, but machine-dependent
transformations can make better code. */
{
rtx orig_x = x;
x = targetm.addr_space.legitimize_address (x, oldx, mode, as);
if (orig_x != x && memory_address_addr_space_p (mode, x, as))
goto done;
}
/* PLUS and MULT can appear in special ways
as the result of attempts to make an address usable for indexing.
Usually they are dealt with by calling force_operand, below.
But a sum containing constant terms is special
if removing them makes the sum a valid address:
then we generate that address in a register
and index off of it. We do this because it often makes
shorter code, and because the addresses thus generated
in registers often become common subexpressions. */
if (GET_CODE (x) == PLUS)
{
rtx constant_term = const0_rtx;
rtx y = eliminate_constant_term (x, &constant_term);
if (constant_term == const0_rtx
|| ! memory_address_addr_space_p (mode, y, as))
x = force_operand (x, NULL_RTX);
else
{
y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term);
if (! memory_address_addr_space_p (mode, y, as))
x = force_operand (x, NULL_RTX);
else
x = y;
}
}
else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS)
x = force_operand (x, NULL_RTX);
/* If we have a register that's an invalid address,
it must be a hard reg of the wrong class. Copy it to a pseudo. */
else if (REG_P (x))
x = copy_to_reg (x);
/* Last resort: copy the value to a register, since
the register is a valid address. */
else
x = force_reg (address_mode, x);
}
done:
gcc_assert (memory_address_addr_space_p (mode, x, as));
/* If we didn't change the address, we are done. Otherwise, mark
a reg as a pointer if we have REG or REG + CONST_INT. */
if (oldx == x)
return x;
else if (REG_P (x))
mark_reg_pointer (x, BITS_PER_UNIT);
else if (GET_CODE (x) == PLUS
&& REG_P (XEXP (x, 0))
&& CONST_INT_P (XEXP (x, 1)))
mark_reg_pointer (XEXP (x, 0), BITS_PER_UNIT);
/* OLDX may have been the address on a temporary. Update the address
to indicate that X is now used. */
update_temp_slot_address (oldx, x);
return x;
}
/* Convert a mem ref into one with a valid memory address.
Pass through anything else unchanged. */
rtx
validize_mem (rtx ref)
{
if (!MEM_P (ref))
return ref;
ref = use_anchored_address (ref);
if (memory_address_addr_space_p (GET_MODE (ref), XEXP (ref, 0),
MEM_ADDR_SPACE (ref)))
return ref;
/* Don't alter REF itself, since that is probably a stack slot. */
return replace_equiv_address (ref, XEXP (ref, 0));
}
/* If X is a memory reference to a member of an object block, try rewriting
it to use an anchor instead. Return the new memory reference on success
and the old one on failure. */
rtx
use_anchored_address (rtx x)
{
rtx base;
HOST_WIDE_INT offset;
enum machine_mode mode;
if (!flag_section_anchors)
return x;
if (!MEM_P (x))
return x;
/* Split the address into a base and offset. */
base = XEXP (x, 0);
offset = 0;
if (GET_CODE (base) == CONST
&& GET_CODE (XEXP (base, 0)) == PLUS
&& CONST_INT_P (XEXP (XEXP (base, 0), 1)))
{
offset += INTVAL (XEXP (XEXP (base, 0), 1));
base = XEXP (XEXP (base, 0), 0);
}
/* Check whether BASE is suitable for anchors. */
if (GET_CODE (base) != SYMBOL_REF
|| !SYMBOL_REF_HAS_BLOCK_INFO_P (base)
|| SYMBOL_REF_ANCHOR_P (base)
|| SYMBOL_REF_BLOCK (base) == NULL
|| !targetm.use_anchors_for_symbol_p (base))
return x;
/* Decide where BASE is going to be. */
place_block_symbol (base);
/* Get the anchor we need to use. */
offset += SYMBOL_REF_BLOCK_OFFSET (base);
base = get_section_anchor (SYMBOL_REF_BLOCK (base), offset,
SYMBOL_REF_TLS_MODEL (base));
/* Work out the offset from the anchor. */
offset -= SYMBOL_REF_BLOCK_OFFSET (base);
/* If we're going to run a CSE pass, force the anchor into a register.
We will then be able to reuse registers for several accesses, if the
target costs say that that's worthwhile. */
mode = GET_MODE (base);
if (!cse_not_expected)
base = force_reg (mode, base);
return replace_equiv_address (x, plus_constant (mode, base, offset));
}
/* Copy the value or contents of X to a new temp reg and return that reg. */
rtx
copy_to_reg (rtx x)
{
rtx temp = gen_reg_rtx (GET_MODE (x));
/* If not an operand, must be an address with PLUS and MULT so
do the computation. */
if (! general_operand (x, VOIDmode))
x = force_operand (x, temp);
if (x != temp)
emit_move_insn (temp, x);
return temp;
}
/* Like copy_to_reg but always give the new register mode Pmode
in case X is a constant. */
rtx
copy_addr_to_reg (rtx x)
{
return copy_to_mode_reg (Pmode, x);
}
/* Like copy_to_reg but always give the new register mode MODE
in case X is a constant. */
rtx
copy_to_mode_reg (enum machine_mode mode, rtx x)
{
rtx temp = gen_reg_rtx (mode);
/* If not an operand, must be an address with PLUS and MULT so
do the computation. */
if (! general_operand (x, VOIDmode))
x = force_operand (x, temp);
gcc_assert (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode);
if (x != temp)
emit_move_insn (temp, x);
return temp;
}
/* Load X into a register if it is not already one.
Use mode MODE for the register.
X should be valid for mode MODE, but it may be a constant which
is valid for all integer modes; that's why caller must specify MODE.
The caller must not alter the value in the register we return,
since we mark it as a "constant" register. */
rtx
force_reg (enum machine_mode mode, rtx x)
{
rtx temp, insn, set;
if (REG_P (x))
return x;
if (general_operand (x, mode))
{
temp = gen_reg_rtx (mode);
insn = emit_move_insn (temp, x);
}
else
{
temp = force_operand (x, NULL_RTX);
if (REG_P (temp))
insn = get_last_insn ();
else
{
rtx temp2 = gen_reg_rtx (mode);
insn = emit_move_insn (temp2, temp);
temp = temp2;
}
}
/* Let optimizers know that TEMP's value never changes
and that X can be substituted for it. Don't get confused
if INSN set something else (such as a SUBREG of TEMP). */
if (CONSTANT_P (x)
&& (set = single_set (insn)) != 0
&& SET_DEST (set) == temp
&& ! rtx_equal_p (x, SET_SRC (set)))
set_unique_reg_note (insn, REG_EQUAL, x);
/* Let optimizers know that TEMP is a pointer, and if so, the
known alignment of that pointer. */
{
unsigned align = 0;
if (GET_CODE (x) == SYMBOL_REF)
{
align = BITS_PER_UNIT;
if (SYMBOL_REF_DECL (x) && DECL_P (SYMBOL_REF_DECL (x)))
align = DECL_ALIGN (SYMBOL_REF_DECL (x));
}
else if (GET_CODE (x) == LABEL_REF)
align = BITS_PER_UNIT;
else if (GET_CODE (x) == CONST
&& GET_CODE (XEXP (x, 0)) == PLUS
&& GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF
&& CONST_INT_P (XEXP (XEXP (x, 0), 1)))
{
rtx s = XEXP (XEXP (x, 0), 0);
rtx c = XEXP (XEXP (x, 0), 1);
unsigned sa, ca;
sa = BITS_PER_UNIT;
if (SYMBOL_REF_DECL (s) && DECL_P (SYMBOL_REF_DECL (s)))
sa = DECL_ALIGN (SYMBOL_REF_DECL (s));
if (INTVAL (c) == 0)
align = sa;
else
{
ca = ctz_hwi (INTVAL (c)) * BITS_PER_UNIT;
align = MIN (sa, ca);
}
}
if (align || (MEM_P (x) && MEM_POINTER (x)))
mark_reg_pointer (temp, align);
}
return temp;
}
/* If X is a memory ref, copy its contents to a new temp reg and return
that reg. Otherwise, return X. */
rtx
force_not_mem (rtx x)
{
rtx temp;
if (!MEM_P (x) || GET_MODE (x) == BLKmode)
return x;
temp = gen_reg_rtx (GET_MODE (x));
if (MEM_POINTER (x))
REG_POINTER (temp) = 1;
emit_move_insn (temp, x);
return temp;
}
/* Copy X to TARGET (if it's nonzero and a reg)
or to a new temp reg and return that reg.
MODE is the mode to use for X in case it is a constant. */
rtx
copy_to_suggested_reg (rtx x, rtx target, enum machine_mode mode)
{
rtx temp;
if (target && REG_P (target))
temp = target;
else
temp = gen_reg_rtx (mode);
emit_move_insn (temp, x);
return temp;
}
/* Return the mode to use to pass or return a scalar of TYPE and MODE.
PUNSIGNEDP points to the signedness of the type and may be adjusted
to show what signedness to use on extension operations.
FOR_RETURN is nonzero if the caller is promoting the return value
of FNDECL, else it is for promoting args. */
enum machine_mode
promote_function_mode (const_tree type, enum machine_mode mode, int *punsignedp,
const_tree funtype, int for_return)
{
/* Called without a type node for a libcall. */
if (type == NULL_TREE)
{
if (INTEGRAL_MODE_P (mode))
return targetm.calls.promote_function_mode (NULL_TREE, mode,
punsignedp, funtype,
for_return);
else
return mode;
}
switch (TREE_CODE (type))
{
case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
case REAL_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE:
case POINTER_TYPE: case REFERENCE_TYPE:
return targetm.calls.promote_function_mode (type, mode, punsignedp, funtype,
for_return);
default:
return mode;
}
}
/* Return the mode to use to store a scalar of TYPE and MODE.
PUNSIGNEDP points to the signedness of the type and may be adjusted
to show what signedness to use on extension operations. */
enum machine_mode
promote_mode (const_tree type ATTRIBUTE_UNUSED, enum machine_mode mode,
int *punsignedp ATTRIBUTE_UNUSED)
{
#ifdef PROMOTE_MODE
enum tree_code code;
int unsignedp;
#endif
/* For libcalls this is invoked without TYPE from the backends
TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
case. */
if (type == NULL_TREE)
return mode;
/* FIXME: this is the same logic that was there until GCC 4.4, but we
probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
is not defined. The affected targets are M32C, S390, SPARC. */
#ifdef PROMOTE_MODE
code = TREE_CODE (type);
unsignedp = *punsignedp;
switch (code)
{
case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
case REAL_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE:
PROMOTE_MODE (mode, unsignedp, type);
*punsignedp = unsignedp;
return mode;
break;
#ifdef POINTERS_EXTEND_UNSIGNED
case REFERENCE_TYPE:
case POINTER_TYPE:
*punsignedp = POINTERS_EXTEND_UNSIGNED;
return targetm.addr_space.address_mode
(TYPE_ADDR_SPACE (TREE_TYPE (type)));
break;
#endif
default:
return mode;
}
#else
return mode;
#endif
}
/* Use one of promote_mode or promote_function_mode to find the promoted
mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
of DECL after promotion. */
enum machine_mode
promote_decl_mode (const_tree decl, int *punsignedp)
{
tree type = TREE_TYPE (decl);
int unsignedp = TYPE_UNSIGNED (type);
enum machine_mode mode = DECL_MODE (decl);
enum machine_mode pmode;
if (TREE_CODE (decl) == RESULT_DECL
|| TREE_CODE (decl) == PARM_DECL)
pmode = promote_function_mode (type, mode, &unsignedp,
TREE_TYPE (current_function_decl), 2);
else
pmode = promote_mode (type, mode, &unsignedp);
if (punsignedp)
*punsignedp = unsignedp;
return pmode;
}
/* Controls the behaviour of {anti_,}adjust_stack. */
static bool suppress_reg_args_size;
/* A helper for adjust_stack and anti_adjust_stack. */
static void
adjust_stack_1 (rtx adjust, bool anti_p)
{
rtx temp, insn;
#ifndef STACK_GROWS_DOWNWARD
/* Hereafter anti_p means subtract_p. */
anti_p = !anti_p;
#endif
temp = expand_binop (Pmode,
anti_p ? sub_optab : add_optab,
stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
OPTAB_LIB_WIDEN);
if (temp != stack_pointer_rtx)
insn = emit_move_insn (stack_pointer_rtx, temp);
else
{
insn = get_last_insn ();
temp = single_set (insn);
gcc_assert (temp != NULL && SET_DEST (temp) == stack_pointer_rtx);
}
if (!suppress_reg_args_size)
add_reg_note (insn, REG_ARGS_SIZE, GEN_INT (stack_pointer_delta));
}
/* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
This pops when ADJUST is positive. ADJUST need not be constant. */
void
adjust_stack (rtx adjust)
{
if (adjust == const0_rtx)
return;
/* We expect all variable sized adjustments to be multiple of
PREFERRED_STACK_BOUNDARY. */
if (CONST_INT_P (adjust))
stack_pointer_delta -= INTVAL (adjust);
adjust_stack_1 (adjust, false);
}
/* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
This pushes when ADJUST is positive. ADJUST need not be constant. */
void
anti_adjust_stack (rtx adjust)
{
if (adjust == const0_rtx)
return;
/* We expect all variable sized adjustments to be multiple of
PREFERRED_STACK_BOUNDARY. */
if (CONST_INT_P (adjust))
stack_pointer_delta += INTVAL (adjust);
adjust_stack_1 (adjust, true);
}
/* Round the size of a block to be pushed up to the boundary required
by this machine. SIZE is the desired size, which need not be constant. */
static rtx
round_push (rtx size)
{
rtx align_rtx, alignm1_rtx;
if (!SUPPORTS_STACK_ALIGNMENT
|| crtl->preferred_stack_boundary == MAX_SUPPORTED_STACK_ALIGNMENT)
{
int align = crtl->preferred_stack_boundary / BITS_PER_UNIT;
if (align == 1)
return size;
if (CONST_INT_P (size))
{
HOST_WIDE_INT new_size = (INTVAL (size) + align - 1) / align * align;
if (INTVAL (size) != new_size)
size = GEN_INT (new_size);
return size;
}
align_rtx = GEN_INT (align);
alignm1_rtx = GEN_INT (align - 1);
}
else
{
/* If crtl->preferred_stack_boundary might still grow, use
virtual_preferred_stack_boundary_rtx instead. This will be
substituted by the right value in vregs pass and optimized
during combine. */
align_rtx = virtual_preferred_stack_boundary_rtx;
alignm1_rtx = force_operand (plus_constant (Pmode, align_rtx, -1),
NULL_RTX);
}
/* CEIL_DIV_EXPR needs to worry about the addition overflowing,
but we know it can't. So add ourselves and then do
TRUNC_DIV_EXPR. */
size = expand_binop (Pmode, add_optab, size, alignm1_rtx,
NULL_RTX, 1, OPTAB_LIB_WIDEN);
size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, align_rtx,
NULL_RTX, 1);
size = expand_mult (Pmode, size, align_rtx, NULL_RTX, 1);
return size;
}