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comparison gcc/lower-subreg.c @ 131:84e7813d76e9

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gcc-8.2
author mir3636
date Thu, 25 Oct 2018 07:37:49 +0900
parents 04ced10e8804
children 1830386684a0
comparison
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111:04ced10e8804 131:84e7813d76e9
1 /* Decompose multiword subregs. 1 /* Decompose multiword subregs.
2 Copyright (C) 2007-2017 Free Software Foundation, Inc. 2 Copyright (C) 2007-2018 Free Software Foundation, Inc.
3 Contributed by Richard Henderson <rth@redhat.com> 3 Contributed by Richard Henderson <rth@redhat.com>
4 Ian Lance Taylor <iant@google.com> 4 Ian Lance Taylor <iant@google.com>
5 5
6 This file is part of GCC. 6 This file is part of GCC.
7 7
101 #define twice_word_mode \ 101 #define twice_word_mode \
102 this_target_lower_subreg->x_twice_word_mode 102 this_target_lower_subreg->x_twice_word_mode
103 #define choices \ 103 #define choices \
104 this_target_lower_subreg->x_choices 104 this_target_lower_subreg->x_choices
105 105
106 /* Return true if MODE is a mode we know how to lower. When returning true,
107 store its byte size in *BYTES and its word size in *WORDS. */
108
109 static inline bool
110 interesting_mode_p (machine_mode mode, unsigned int *bytes,
111 unsigned int *words)
112 {
113 if (!GET_MODE_SIZE (mode).is_constant (bytes))
114 return false;
115 *words = CEIL (*bytes, UNITS_PER_WORD);
116 return true;
117 }
118
106 /* RTXes used while computing costs. */ 119 /* RTXes used while computing costs. */
107 struct cost_rtxes { 120 struct cost_rtxes {
108 /* Source and target registers. */ 121 /* Source and target registers. */
109 rtx source; 122 rtx source;
110 rtx target; 123 rtx target;
127 machine_mode mode, int op1) 140 machine_mode mode, int op1)
128 { 141 {
129 PUT_CODE (rtxes->shift, code); 142 PUT_CODE (rtxes->shift, code);
130 PUT_MODE (rtxes->shift, mode); 143 PUT_MODE (rtxes->shift, mode);
131 PUT_MODE (rtxes->source, mode); 144 PUT_MODE (rtxes->source, mode);
132 XEXP (rtxes->shift, 1) = GEN_INT (op1); 145 XEXP (rtxes->shift, 1) = gen_int_shift_amount (mode, op1);
133 return set_src_cost (rtxes->shift, mode, speed_p); 146 return set_src_cost (rtxes->shift, mode, speed_p);
134 } 147 }
135 148
136 /* For each X in the range [0, BITS_PER_WORD), set SPLITTING[X] 149 /* For each X in the range [0, BITS_PER_WORD), set SPLITTING[X]
137 to true if it is profitable to split a double-word CODE shift 150 to true if it is profitable to split a double-word CODE shift
197 GET_MODE_NAME (word_mode), word_move_zero_cost, word_move_cost); 210 GET_MODE_NAME (word_mode), word_move_zero_cost, word_move_cost);
198 211
199 for (i = 0; i < MAX_MACHINE_MODE; i++) 212 for (i = 0; i < MAX_MACHINE_MODE; i++)
200 { 213 {
201 machine_mode mode = (machine_mode) i; 214 machine_mode mode = (machine_mode) i;
202 int factor = GET_MODE_SIZE (mode) / UNITS_PER_WORD; 215 unsigned int size, factor;
203 if (factor > 1) 216 if (interesting_mode_p (mode, &size, &factor) && factor > 1)
204 { 217 {
205 int mode_move_cost; 218 unsigned int mode_move_cost;
206 219
207 PUT_MODE (rtxes->target, mode); 220 PUT_MODE (rtxes->target, mode);
208 PUT_MODE (rtxes->source, mode); 221 PUT_MODE (rtxes->source, mode);
209 mode_move_cost = set_rtx_cost (rtxes->set, speed_p); 222 mode_move_cost = set_rtx_cost (rtxes->set, speed_p);
210 223
467 { 480 {
468 iter.skip_subrtxes (); 481 iter.skip_subrtxes ();
469 continue; 482 continue;
470 } 483 }
471 484
472 outer_size = GET_MODE_SIZE (GET_MODE (x)); 485 if (!interesting_mode_p (GET_MODE (x), &outer_size, &outer_words)
473 inner_size = GET_MODE_SIZE (GET_MODE (inner)); 486 || !interesting_mode_p (GET_MODE (inner), &inner_size,
474 outer_words = (outer_size + UNITS_PER_WORD - 1) / UNITS_PER_WORD; 487 &inner_words))
475 inner_words = (inner_size + UNITS_PER_WORD - 1) / UNITS_PER_WORD; 488 continue;
476 489
477 /* We only try to decompose single word subregs of multi-word 490 /* We only try to decompose single word subregs of multi-word
478 registers. When we find one, we return -1 to avoid iterating 491 registers. When we find one, we return -1 to avoid iterating
479 over the inner register. 492 over the inner register.
480 493
482 on 32-bit targets. We would need to record the way the 495 on 32-bit targets. We would need to record the way the
483 pseudo-register was used, and only decompose if all the uses 496 pseudo-register was used, and only decompose if all the uses
484 were the same number and size of pieces. Hopefully this 497 were the same number and size of pieces. Hopefully this
485 doesn't happen much. */ 498 doesn't happen much. */
486 499
487 if (outer_words == 1 && inner_words > 1) 500 if (outer_words == 1
501 && inner_words > 1
502 /* Don't allow to decompose floating point subregs of
503 multi-word pseudos if the floating point mode does
504 not have word size, because otherwise we'd generate
505 a subreg with that floating mode from a different
506 sized integral pseudo which is not allowed by
507 validate_subreg. */
508 && (!FLOAT_MODE_P (GET_MODE (x))
509 || outer_size == UNITS_PER_WORD))
488 { 510 {
489 bitmap_set_bit (decomposable_context, regno); 511 bitmap_set_bit (decomposable_context, regno);
490 iter.skip_subrtxes (); 512 iter.skip_subrtxes ();
491 continue; 513 continue;
492 } 514 }
505 continue; 527 continue;
506 } 528 }
507 } 529 }
508 else if (REG_P (x)) 530 else if (REG_P (x))
509 { 531 {
510 unsigned int regno; 532 unsigned int regno, size, words;
511 533
512 /* We will see an outer SUBREG before we see the inner REG, so 534 /* We will see an outer SUBREG before we see the inner REG, so
513 when we see a plain REG here it means a direct reference to 535 when we see a plain REG here it means a direct reference to
514 the register. 536 the register.
515 537
525 pseudo-registers, since those are the only ones we care about 547 pseudo-registers, since those are the only ones we care about
526 and it keeps the size of the bitmaps down. */ 548 and it keeps the size of the bitmaps down. */
527 549
528 regno = REGNO (x); 550 regno = REGNO (x);
529 if (!HARD_REGISTER_NUM_P (regno) 551 if (!HARD_REGISTER_NUM_P (regno)
530 && GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD) 552 && interesting_mode_p (GET_MODE (x), &size, &words)
553 && words > 1)
531 { 554 {
532 switch (*pcmi) 555 switch (*pcmi)
533 { 556 {
534 case NOT_SIMPLE_MOVE: 557 case NOT_SIMPLE_MOVE:
535 bitmap_set_bit (non_decomposable_context, regno); 558 bitmap_set_bit (non_decomposable_context, regno);
565 588
566 static void 589 static void
567 decompose_register (unsigned int regno) 590 decompose_register (unsigned int regno)
568 { 591 {
569 rtx reg; 592 rtx reg;
570 unsigned int words, i; 593 unsigned int size, words, i;
571 rtvec v; 594 rtvec v;
572 595
573 reg = regno_reg_rtx[regno]; 596 reg = regno_reg_rtx[regno];
574 597
575 regno_reg_rtx[regno] = NULL_RTX; 598 regno_reg_rtx[regno] = NULL_RTX;
576 599
577 words = GET_MODE_SIZE (GET_MODE (reg)); 600 if (!interesting_mode_p (GET_MODE (reg), &size, &words))
578 words = (words + UNITS_PER_WORD - 1) / UNITS_PER_WORD; 601 gcc_unreachable ();
579 602
580 v = rtvec_alloc (words); 603 v = rtvec_alloc (words);
581 for (i = 0; i < words; ++i) 604 for (i = 0; i < words; ++i)
582 RTVEC_ELT (v, i) = gen_reg_rtx_offset (reg, word_mode, i * UNITS_PER_WORD); 605 RTVEC_ELT (v, i) = gen_reg_rtx_offset (reg, word_mode, i * UNITS_PER_WORD);
583 606
594 } 617 }
595 618
596 /* Get a SUBREG of a CONCATN. */ 619 /* Get a SUBREG of a CONCATN. */
597 620
598 static rtx 621 static rtx
599 simplify_subreg_concatn (machine_mode outermode, rtx op, 622 simplify_subreg_concatn (machine_mode outermode, rtx op, poly_uint64 orig_byte)
600 unsigned int byte) 623 {
601 { 624 unsigned int outer_size, outer_words, inner_size, inner_words;
602 unsigned int inner_size;
603 machine_mode innermode, partmode; 625 machine_mode innermode, partmode;
604 rtx part; 626 rtx part;
605 unsigned int final_offset; 627 unsigned int final_offset;
606 628 unsigned int byte;
629
630 innermode = GET_MODE (op);
631 if (!interesting_mode_p (outermode, &outer_size, &outer_words)
632 || !interesting_mode_p (innermode, &inner_size, &inner_words))
633 gcc_unreachable ();
634
635 /* Must be constant if interesting_mode_p passes. */
636 byte = orig_byte.to_constant ();
607 gcc_assert (GET_CODE (op) == CONCATN); 637 gcc_assert (GET_CODE (op) == CONCATN);
608 gcc_assert (byte % GET_MODE_SIZE (outermode) == 0); 638 gcc_assert (byte % outer_size == 0);
609 639
610 innermode = GET_MODE (op); 640 gcc_assert (byte < inner_size);
611 gcc_assert (byte < GET_MODE_SIZE (innermode)); 641 if (outer_size > inner_size)
612 if (GET_MODE_SIZE (outermode) > GET_MODE_SIZE (innermode))
613 return NULL_RTX; 642 return NULL_RTX;
614 643
615 inner_size = GET_MODE_SIZE (innermode) / XVECLEN (op, 0); 644 inner_size /= XVECLEN (op, 0);
616 part = XVECEXP (op, 0, byte / inner_size); 645 part = XVECEXP (op, 0, byte / inner_size);
617 partmode = GET_MODE (part); 646 partmode = GET_MODE (part);
618 647
619 final_offset = byte % inner_size; 648 final_offset = byte % inner_size;
620 if (final_offset + GET_MODE_SIZE (outermode) > inner_size) 649 if (final_offset + outer_size > inner_size)
621 return NULL_RTX; 650 return NULL_RTX;
622 651
623 /* VECTOR_CSTs in debug expressions are expanded into CONCATN instead of 652 /* VECTOR_CSTs in debug expressions are expanded into CONCATN instead of
624 regular CONST_VECTORs. They have vector or integer modes, depending 653 regular CONST_VECTORs. They have vector or integer modes, depending
625 on the capabilities of the target. Cope with them. */ 654 on the capabilities of the target. Cope with them. */
646 part. We shouldn't see anything else here. */ 675 part. We shouldn't see anything else here. */
647 if (GET_CODE (op) == SUBREG && GET_CODE (SUBREG_REG (op)) == CONCATN) 676 if (GET_CODE (op) == SUBREG && GET_CODE (SUBREG_REG (op)) == CONCATN)
648 { 677 {
649 rtx op2; 678 rtx op2;
650 679
651 if ((GET_MODE_SIZE (GET_MODE (op)) 680 if (known_eq (GET_MODE_SIZE (GET_MODE (op)),
652 == GET_MODE_SIZE (GET_MODE (SUBREG_REG (op)))) 681 GET_MODE_SIZE (GET_MODE (SUBREG_REG (op))))
653 && SUBREG_BYTE (op) == 0) 682 && known_eq (SUBREG_BYTE (op), 0))
654 return simplify_gen_subreg_concatn (outermode, SUBREG_REG (op), 683 return simplify_gen_subreg_concatn (outermode, SUBREG_REG (op),
655 GET_MODE (SUBREG_REG (op)), byte); 684 GET_MODE (SUBREG_REG (op)), byte);
656 685
657 op2 = simplify_subreg_concatn (GET_MODE (op), SUBREG_REG (op), 686 op2 = simplify_subreg_concatn (GET_MODE (op), SUBREG_REG (op),
658 SUBREG_BYTE (op)); 687 SUBREG_BYTE (op));
799 { 828 {
800 unsigned int regno = REGNO (x); 829 unsigned int regno = REGNO (x);
801 830
802 if (HARD_REGISTER_NUM_P (regno)) 831 if (HARD_REGISTER_NUM_P (regno))
803 { 832 {
804 unsigned int byte, num_bytes; 833 unsigned int byte, num_bytes, num_words;
805 834
806 num_bytes = GET_MODE_SIZE (GET_MODE (x)); 835 if (!interesting_mode_p (GET_MODE (x), &num_bytes, &num_words))
836 return false;
807 for (byte = 0; byte < num_bytes; byte += UNITS_PER_WORD) 837 for (byte = 0; byte < num_bytes; byte += UNITS_PER_WORD)
808 if (simplify_subreg_regno (regno, GET_MODE (x), byte, word_mode) < 0) 838 if (simplify_subreg_regno (regno, GET_MODE (x), byte, word_mode) < 0)
809 return false; 839 return false;
810 return true; 840 return true;
811 } 841 }
824 resolve_simple_move (rtx set, rtx_insn *insn) 854 resolve_simple_move (rtx set, rtx_insn *insn)
825 { 855 {
826 rtx src, dest, real_dest; 856 rtx src, dest, real_dest;
827 rtx_insn *insns; 857 rtx_insn *insns;
828 machine_mode orig_mode, dest_mode; 858 machine_mode orig_mode, dest_mode;
829 unsigned int words; 859 unsigned int orig_size, words;
830 bool pushing; 860 bool pushing;
831 861
832 src = SET_SRC (set); 862 src = SET_SRC (set);
833 dest = SET_DEST (set); 863 dest = SET_DEST (set);
834 orig_mode = GET_MODE (dest); 864 orig_mode = GET_MODE (dest);
835 865
836 words = (GET_MODE_SIZE (orig_mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD; 866 if (!interesting_mode_p (orig_mode, &orig_size, &words))
867 gcc_unreachable ();
837 gcc_assert (words > 1); 868 gcc_assert (words > 1);
838 869
839 start_sequence (); 870 start_sequence ();
840 871
841 /* We have to handle copying from a SUBREG of a decomposed reg where 872 /* We have to handle copying from a SUBREG of a decomposed reg where
845 876
846 real_dest = NULL_RTX; 877 real_dest = NULL_RTX;
847 878
848 if (GET_CODE (src) == SUBREG 879 if (GET_CODE (src) == SUBREG
849 && resolve_reg_p (SUBREG_REG (src)) 880 && resolve_reg_p (SUBREG_REG (src))
850 && (SUBREG_BYTE (src) != 0 881 && (maybe_ne (SUBREG_BYTE (src), 0)
851 || (GET_MODE_SIZE (orig_mode) 882 || maybe_ne (orig_size, GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))))))
852 != GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))))))
853 { 883 {
854 real_dest = dest; 884 real_dest = dest;
855 dest = gen_reg_rtx (orig_mode); 885 dest = gen_reg_rtx (orig_mode);
856 if (REG_P (real_dest)) 886 if (REG_P (real_dest))
857 REG_ATTRS (dest) = REG_ATTRS (real_dest); 887 REG_ATTRS (dest) = REG_ATTRS (real_dest);
860 /* Similarly if we are copying to a SUBREG of a decomposed reg where 890 /* Similarly if we are copying to a SUBREG of a decomposed reg where
861 the SUBREG is larger than word size. */ 891 the SUBREG is larger than word size. */
862 892
863 if (GET_CODE (dest) == SUBREG 893 if (GET_CODE (dest) == SUBREG
864 && resolve_reg_p (SUBREG_REG (dest)) 894 && resolve_reg_p (SUBREG_REG (dest))
865 && (SUBREG_BYTE (dest) != 0 895 && (maybe_ne (SUBREG_BYTE (dest), 0)
866 || (GET_MODE_SIZE (orig_mode) 896 || maybe_ne (orig_size,
867 != GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))))) 897 GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))))))
868 { 898 {
869 rtx reg, smove; 899 rtx reg, smove;
870 rtx_insn *minsn; 900 rtx_insn *minsn;
871 901
872 reg = gen_reg_rtx (orig_mode); 902 reg = gen_reg_rtx (orig_mode);
962 992
963 if (pushing) 993 if (pushing)
964 { 994 {
965 unsigned int i, j, jinc; 995 unsigned int i, j, jinc;
966 996
967 gcc_assert (GET_MODE_SIZE (orig_mode) % UNITS_PER_WORD == 0); 997 gcc_assert (orig_size % UNITS_PER_WORD == 0);
968 gcc_assert (GET_CODE (XEXP (dest, 0)) != PRE_MODIFY); 998 gcc_assert (GET_CODE (XEXP (dest, 0)) != PRE_MODIFY);
969 gcc_assert (GET_CODE (XEXP (dest, 0)) != POST_MODIFY); 999 gcc_assert (GET_CODE (XEXP (dest, 0)) != POST_MODIFY);
970 1000
971 if (WORDS_BIG_ENDIAN == STACK_GROWS_DOWNWARD) 1001 if (WORDS_BIG_ENDIAN == STACK_GROWS_DOWNWARD)
972 { 1002 {
1057 static bool 1087 static bool
1058 resolve_clobber (rtx pat, rtx_insn *insn) 1088 resolve_clobber (rtx pat, rtx_insn *insn)
1059 { 1089 {
1060 rtx reg; 1090 rtx reg;
1061 machine_mode orig_mode; 1091 machine_mode orig_mode;
1062 unsigned int words, i; 1092 unsigned int orig_size, words, i;
1063 int ret; 1093 int ret;
1064 1094
1065 reg = XEXP (pat, 0); 1095 reg = XEXP (pat, 0);
1066 if (!resolve_reg_p (reg) && !resolve_subreg_p (reg)) 1096 if (!resolve_reg_p (reg) && !resolve_subreg_p (reg))
1067 return false; 1097 return false;
1068 1098
1069 orig_mode = GET_MODE (reg); 1099 orig_mode = GET_MODE (reg);
1070 words = GET_MODE_SIZE (orig_mode); 1100 if (!interesting_mode_p (orig_mode, &orig_size, &words))
1071 words = (words + UNITS_PER_WORD - 1) / UNITS_PER_WORD; 1101 gcc_unreachable ();
1072 1102
1073 ret = validate_change (NULL_RTX, &XEXP (pat, 0), 1103 ret = validate_change (NULL_RTX, &XEXP (pat, 0),
1074 simplify_gen_subreg_concatn (word_mode, reg, 1104 simplify_gen_subreg_concatn (word_mode, reg,
1075 orig_mode, 0), 1105 orig_mode, 0),
1076 0); 1106 0);
1330 of the SPEED_P choice. */ 1360 of the SPEED_P choice. */
1331 1361
1332 static void 1362 static void
1333 dump_choices (bool speed_p, const char *description) 1363 dump_choices (bool speed_p, const char *description)
1334 { 1364 {
1335 unsigned int i; 1365 unsigned int size, factor, i;
1336 1366
1337 fprintf (dump_file, "Choices when optimizing for %s:\n", description); 1367 fprintf (dump_file, "Choices when optimizing for %s:\n", description);
1338 1368
1339 for (i = 0; i < MAX_MACHINE_MODE; i++) 1369 for (i = 0; i < MAX_MACHINE_MODE; i++)
1340 if (GET_MODE_SIZE ((machine_mode) i) > UNITS_PER_WORD) 1370 if (interesting_mode_p ((machine_mode) i, &size, &factor)
1371 && factor > 1)
1341 fprintf (dump_file, " %s mode %s for copy lowering.\n", 1372 fprintf (dump_file, " %s mode %s for copy lowering.\n",
1342 choices[speed_p].move_modes_to_split[i] 1373 choices[speed_p].move_modes_to_split[i]
1343 ? "Splitting" 1374 ? "Splitting"
1344 : "Skipping", 1375 : "Skipping",
1345 GET_MODE_NAME ((machine_mode) i)); 1376 GET_MODE_NAME ((machine_mode) i));