Backup: don't do copy-on-read in before_write_notifier
[qemu.git] / tcg / optimize.c
blob10795ec9d517a1b137160405ebc856219c648b52
1 /*
2 * Optimizations for Tiny Code Generator for QEMU
4 * Copyright (c) 2010 Samsung Electronics.
5 * Contributed by Kirill Batuzov <batuzovk@ispras.ru>
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
26 #include "config.h"
28 #include <stdlib.h>
29 #include <stdio.h>
31 #include "qemu-common.h"
32 #include "tcg-op.h"
34 #define CASE_OP_32_64(x) \
35 glue(glue(case INDEX_op_, x), _i32): \
36 glue(glue(case INDEX_op_, x), _i64)
38 struct tcg_temp_info {
39 bool is_const;
40 uint16_t prev_copy;
41 uint16_t next_copy;
42 tcg_target_ulong val;
43 tcg_target_ulong mask;
46 static struct tcg_temp_info temps[TCG_MAX_TEMPS];
47 static TCGTempSet temps_used;
49 static inline bool temp_is_const(TCGArg arg)
51 return temps[arg].is_const;
54 static inline bool temp_is_copy(TCGArg arg)
56 return temps[arg].next_copy != arg;
59 /* Reset TEMP's state, possibly removing the temp for the list of copies. */
60 static void reset_temp(TCGArg temp)
62 temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy;
63 temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy;
64 temps[temp].next_copy = temp;
65 temps[temp].prev_copy = temp;
66 temps[temp].is_const = false;
67 temps[temp].mask = -1;
70 /* Reset all temporaries, given that there are NB_TEMPS of them. */
71 static void reset_all_temps(int nb_temps)
73 bitmap_zero(temps_used.l, nb_temps);
76 /* Initialize and activate a temporary. */
77 static void init_temp_info(TCGArg temp)
79 if (!test_bit(temp, temps_used.l)) {
80 temps[temp].next_copy = temp;
81 temps[temp].prev_copy = temp;
82 temps[temp].is_const = false;
83 temps[temp].mask = -1;
84 set_bit(temp, temps_used.l);
88 static TCGOp *insert_op_before(TCGContext *s, TCGOp *old_op,
89 TCGOpcode opc, int nargs)
91 int oi = s->gen_next_op_idx;
92 int pi = s->gen_next_parm_idx;
93 int prev = old_op->prev;
94 int next = old_op - s->gen_op_buf;
95 TCGOp *new_op;
97 tcg_debug_assert(oi < OPC_BUF_SIZE);
98 tcg_debug_assert(pi + nargs <= OPPARAM_BUF_SIZE);
99 s->gen_next_op_idx = oi + 1;
100 s->gen_next_parm_idx = pi + nargs;
102 new_op = &s->gen_op_buf[oi];
103 *new_op = (TCGOp){
104 .opc = opc,
105 .args = pi,
106 .prev = prev,
107 .next = next
109 if (prev >= 0) {
110 s->gen_op_buf[prev].next = oi;
111 } else {
112 s->gen_first_op_idx = oi;
114 old_op->prev = oi;
116 return new_op;
119 static int op_bits(TCGOpcode op)
121 const TCGOpDef *def = &tcg_op_defs[op];
122 return def->flags & TCG_OPF_64BIT ? 64 : 32;
125 static TCGOpcode op_to_mov(TCGOpcode op)
127 switch (op_bits(op)) {
128 case 32:
129 return INDEX_op_mov_i32;
130 case 64:
131 return INDEX_op_mov_i64;
132 default:
133 fprintf(stderr, "op_to_mov: unexpected return value of "
134 "function op_bits.\n");
135 tcg_abort();
139 static TCGOpcode op_to_movi(TCGOpcode op)
141 switch (op_bits(op)) {
142 case 32:
143 return INDEX_op_movi_i32;
144 case 64:
145 return INDEX_op_movi_i64;
146 default:
147 fprintf(stderr, "op_to_movi: unexpected return value of "
148 "function op_bits.\n");
149 tcg_abort();
153 static TCGArg find_better_copy(TCGContext *s, TCGArg temp)
155 TCGArg i;
157 /* If this is already a global, we can't do better. */
158 if (temp < s->nb_globals) {
159 return temp;
162 /* Search for a global first. */
163 for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy) {
164 if (i < s->nb_globals) {
165 return i;
169 /* If it is a temp, search for a temp local. */
170 if (!s->temps[temp].temp_local) {
171 for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy) {
172 if (s->temps[i].temp_local) {
173 return i;
178 /* Failure to find a better representation, return the same temp. */
179 return temp;
182 static bool temps_are_copies(TCGArg arg1, TCGArg arg2)
184 TCGArg i;
186 if (arg1 == arg2) {
187 return true;
190 if (!temp_is_copy(arg1) || !temp_is_copy(arg2)) {
191 return false;
194 for (i = temps[arg1].next_copy ; i != arg1 ; i = temps[i].next_copy) {
195 if (i == arg2) {
196 return true;
200 return false;
203 static void tcg_opt_gen_movi(TCGContext *s, TCGOp *op, TCGArg *args,
204 TCGArg dst, TCGArg val)
206 TCGOpcode new_op = op_to_movi(op->opc);
207 tcg_target_ulong mask;
209 op->opc = new_op;
211 reset_temp(dst);
212 temps[dst].is_const = true;
213 temps[dst].val = val;
214 mask = val;
215 if (TCG_TARGET_REG_BITS > 32 && new_op == INDEX_op_movi_i32) {
216 /* High bits of the destination are now garbage. */
217 mask |= ~0xffffffffull;
219 temps[dst].mask = mask;
221 args[0] = dst;
222 args[1] = val;
225 static void tcg_opt_gen_mov(TCGContext *s, TCGOp *op, TCGArg *args,
226 TCGArg dst, TCGArg src)
228 if (temps_are_copies(dst, src)) {
229 tcg_op_remove(s, op);
230 return;
233 TCGOpcode new_op = op_to_mov(op->opc);
234 tcg_target_ulong mask;
236 op->opc = new_op;
238 reset_temp(dst);
239 mask = temps[src].mask;
240 if (TCG_TARGET_REG_BITS > 32 && new_op == INDEX_op_mov_i32) {
241 /* High bits of the destination are now garbage. */
242 mask |= ~0xffffffffull;
244 temps[dst].mask = mask;
246 if (s->temps[src].type == s->temps[dst].type) {
247 temps[dst].next_copy = temps[src].next_copy;
248 temps[dst].prev_copy = src;
249 temps[temps[dst].next_copy].prev_copy = dst;
250 temps[src].next_copy = dst;
251 temps[dst].is_const = temps[src].is_const;
252 temps[dst].val = temps[src].val;
255 args[0] = dst;
256 args[1] = src;
259 static TCGArg do_constant_folding_2(TCGOpcode op, TCGArg x, TCGArg y)
261 uint64_t l64, h64;
263 switch (op) {
264 CASE_OP_32_64(add):
265 return x + y;
267 CASE_OP_32_64(sub):
268 return x - y;
270 CASE_OP_32_64(mul):
271 return x * y;
273 CASE_OP_32_64(and):
274 return x & y;
276 CASE_OP_32_64(or):
277 return x | y;
279 CASE_OP_32_64(xor):
280 return x ^ y;
282 case INDEX_op_shl_i32:
283 return (uint32_t)x << (y & 31);
285 case INDEX_op_shl_i64:
286 return (uint64_t)x << (y & 63);
288 case INDEX_op_shr_i32:
289 return (uint32_t)x >> (y & 31);
291 case INDEX_op_shr_i64:
292 return (uint64_t)x >> (y & 63);
294 case INDEX_op_sar_i32:
295 return (int32_t)x >> (y & 31);
297 case INDEX_op_sar_i64:
298 return (int64_t)x >> (y & 63);
300 case INDEX_op_rotr_i32:
301 return ror32(x, y & 31);
303 case INDEX_op_rotr_i64:
304 return ror64(x, y & 63);
306 case INDEX_op_rotl_i32:
307 return rol32(x, y & 31);
309 case INDEX_op_rotl_i64:
310 return rol64(x, y & 63);
312 CASE_OP_32_64(not):
313 return ~x;
315 CASE_OP_32_64(neg):
316 return -x;
318 CASE_OP_32_64(andc):
319 return x & ~y;
321 CASE_OP_32_64(orc):
322 return x | ~y;
324 CASE_OP_32_64(eqv):
325 return ~(x ^ y);
327 CASE_OP_32_64(nand):
328 return ~(x & y);
330 CASE_OP_32_64(nor):
331 return ~(x | y);
333 CASE_OP_32_64(ext8s):
334 return (int8_t)x;
336 CASE_OP_32_64(ext16s):
337 return (int16_t)x;
339 CASE_OP_32_64(ext8u):
340 return (uint8_t)x;
342 CASE_OP_32_64(ext16u):
343 return (uint16_t)x;
345 case INDEX_op_ext_i32_i64:
346 case INDEX_op_ext32s_i64:
347 return (int32_t)x;
349 case INDEX_op_extu_i32_i64:
350 case INDEX_op_extrl_i64_i32:
351 case INDEX_op_ext32u_i64:
352 return (uint32_t)x;
354 case INDEX_op_extrh_i64_i32:
355 return (uint64_t)x >> 32;
357 case INDEX_op_muluh_i32:
358 return ((uint64_t)(uint32_t)x * (uint32_t)y) >> 32;
359 case INDEX_op_mulsh_i32:
360 return ((int64_t)(int32_t)x * (int32_t)y) >> 32;
362 case INDEX_op_muluh_i64:
363 mulu64(&l64, &h64, x, y);
364 return h64;
365 case INDEX_op_mulsh_i64:
366 muls64(&l64, &h64, x, y);
367 return h64;
369 case INDEX_op_div_i32:
370 /* Avoid crashing on divide by zero, otherwise undefined. */
371 return (int32_t)x / ((int32_t)y ? : 1);
372 case INDEX_op_divu_i32:
373 return (uint32_t)x / ((uint32_t)y ? : 1);
374 case INDEX_op_div_i64:
375 return (int64_t)x / ((int64_t)y ? : 1);
376 case INDEX_op_divu_i64:
377 return (uint64_t)x / ((uint64_t)y ? : 1);
379 case INDEX_op_rem_i32:
380 return (int32_t)x % ((int32_t)y ? : 1);
381 case INDEX_op_remu_i32:
382 return (uint32_t)x % ((uint32_t)y ? : 1);
383 case INDEX_op_rem_i64:
384 return (int64_t)x % ((int64_t)y ? : 1);
385 case INDEX_op_remu_i64:
386 return (uint64_t)x % ((uint64_t)y ? : 1);
388 default:
389 fprintf(stderr,
390 "Unrecognized operation %d in do_constant_folding.\n", op);
391 tcg_abort();
395 static TCGArg do_constant_folding(TCGOpcode op, TCGArg x, TCGArg y)
397 TCGArg res = do_constant_folding_2(op, x, y);
398 if (op_bits(op) == 32) {
399 res = (int32_t)res;
401 return res;
404 static bool do_constant_folding_cond_32(uint32_t x, uint32_t y, TCGCond c)
406 switch (c) {
407 case TCG_COND_EQ:
408 return x == y;
409 case TCG_COND_NE:
410 return x != y;
411 case TCG_COND_LT:
412 return (int32_t)x < (int32_t)y;
413 case TCG_COND_GE:
414 return (int32_t)x >= (int32_t)y;
415 case TCG_COND_LE:
416 return (int32_t)x <= (int32_t)y;
417 case TCG_COND_GT:
418 return (int32_t)x > (int32_t)y;
419 case TCG_COND_LTU:
420 return x < y;
421 case TCG_COND_GEU:
422 return x >= y;
423 case TCG_COND_LEU:
424 return x <= y;
425 case TCG_COND_GTU:
426 return x > y;
427 default:
428 tcg_abort();
432 static bool do_constant_folding_cond_64(uint64_t x, uint64_t y, TCGCond c)
434 switch (c) {
435 case TCG_COND_EQ:
436 return x == y;
437 case TCG_COND_NE:
438 return x != y;
439 case TCG_COND_LT:
440 return (int64_t)x < (int64_t)y;
441 case TCG_COND_GE:
442 return (int64_t)x >= (int64_t)y;
443 case TCG_COND_LE:
444 return (int64_t)x <= (int64_t)y;
445 case TCG_COND_GT:
446 return (int64_t)x > (int64_t)y;
447 case TCG_COND_LTU:
448 return x < y;
449 case TCG_COND_GEU:
450 return x >= y;
451 case TCG_COND_LEU:
452 return x <= y;
453 case TCG_COND_GTU:
454 return x > y;
455 default:
456 tcg_abort();
460 static bool do_constant_folding_cond_eq(TCGCond c)
462 switch (c) {
463 case TCG_COND_GT:
464 case TCG_COND_LTU:
465 case TCG_COND_LT:
466 case TCG_COND_GTU:
467 case TCG_COND_NE:
468 return 0;
469 case TCG_COND_GE:
470 case TCG_COND_GEU:
471 case TCG_COND_LE:
472 case TCG_COND_LEU:
473 case TCG_COND_EQ:
474 return 1;
475 default:
476 tcg_abort();
480 /* Return 2 if the condition can't be simplified, and the result
481 of the condition (0 or 1) if it can */
482 static TCGArg do_constant_folding_cond(TCGOpcode op, TCGArg x,
483 TCGArg y, TCGCond c)
485 if (temp_is_const(x) && temp_is_const(y)) {
486 switch (op_bits(op)) {
487 case 32:
488 return do_constant_folding_cond_32(temps[x].val, temps[y].val, c);
489 case 64:
490 return do_constant_folding_cond_64(temps[x].val, temps[y].val, c);
491 default:
492 tcg_abort();
494 } else if (temps_are_copies(x, y)) {
495 return do_constant_folding_cond_eq(c);
496 } else if (temp_is_const(y) && temps[y].val == 0) {
497 switch (c) {
498 case TCG_COND_LTU:
499 return 0;
500 case TCG_COND_GEU:
501 return 1;
502 default:
503 return 2;
505 } else {
506 return 2;
510 /* Return 2 if the condition can't be simplified, and the result
511 of the condition (0 or 1) if it can */
512 static TCGArg do_constant_folding_cond2(TCGArg *p1, TCGArg *p2, TCGCond c)
514 TCGArg al = p1[0], ah = p1[1];
515 TCGArg bl = p2[0], bh = p2[1];
517 if (temp_is_const(bl) && temp_is_const(bh)) {
518 uint64_t b = ((uint64_t)temps[bh].val << 32) | (uint32_t)temps[bl].val;
520 if (temp_is_const(al) && temp_is_const(ah)) {
521 uint64_t a;
522 a = ((uint64_t)temps[ah].val << 32) | (uint32_t)temps[al].val;
523 return do_constant_folding_cond_64(a, b, c);
525 if (b == 0) {
526 switch (c) {
527 case TCG_COND_LTU:
528 return 0;
529 case TCG_COND_GEU:
530 return 1;
531 default:
532 break;
536 if (temps_are_copies(al, bl) && temps_are_copies(ah, bh)) {
537 return do_constant_folding_cond_eq(c);
539 return 2;
542 static bool swap_commutative(TCGArg dest, TCGArg *p1, TCGArg *p2)
544 TCGArg a1 = *p1, a2 = *p2;
545 int sum = 0;
546 sum += temp_is_const(a1);
547 sum -= temp_is_const(a2);
549 /* Prefer the constant in second argument, and then the form
550 op a, a, b, which is better handled on non-RISC hosts. */
551 if (sum > 0 || (sum == 0 && dest == a2)) {
552 *p1 = a2;
553 *p2 = a1;
554 return true;
556 return false;
559 static bool swap_commutative2(TCGArg *p1, TCGArg *p2)
561 int sum = 0;
562 sum += temp_is_const(p1[0]);
563 sum += temp_is_const(p1[1]);
564 sum -= temp_is_const(p2[0]);
565 sum -= temp_is_const(p2[1]);
566 if (sum > 0) {
567 TCGArg t;
568 t = p1[0], p1[0] = p2[0], p2[0] = t;
569 t = p1[1], p1[1] = p2[1], p2[1] = t;
570 return true;
572 return false;
575 /* Propagate constants and copies, fold constant expressions. */
576 void tcg_optimize(TCGContext *s)
578 int oi, oi_next, nb_temps, nb_globals;
580 /* Array VALS has an element for each temp.
581 If this temp holds a constant then its value is kept in VALS' element.
582 If this temp is a copy of other ones then the other copies are
583 available through the doubly linked circular list. */
585 nb_temps = s->nb_temps;
586 nb_globals = s->nb_globals;
587 reset_all_temps(nb_temps);
589 for (oi = s->gen_first_op_idx; oi >= 0; oi = oi_next) {
590 tcg_target_ulong mask, partmask, affected;
591 int nb_oargs, nb_iargs, i;
592 TCGArg tmp;
594 TCGOp * const op = &s->gen_op_buf[oi];
595 TCGArg * const args = &s->gen_opparam_buf[op->args];
596 TCGOpcode opc = op->opc;
597 const TCGOpDef *def = &tcg_op_defs[opc];
599 oi_next = op->next;
601 /* Count the arguments, and initialize the temps that are
602 going to be used */
603 if (opc == INDEX_op_call) {
604 nb_oargs = op->callo;
605 nb_iargs = op->calli;
606 for (i = 0; i < nb_oargs + nb_iargs; i++) {
607 tmp = args[i];
608 if (tmp != TCG_CALL_DUMMY_ARG) {
609 init_temp_info(tmp);
612 } else {
613 nb_oargs = def->nb_oargs;
614 nb_iargs = def->nb_iargs;
615 for (i = 0; i < nb_oargs + nb_iargs; i++) {
616 init_temp_info(args[i]);
620 /* Do copy propagation */
621 for (i = nb_oargs; i < nb_oargs + nb_iargs; i++) {
622 if (temp_is_copy(args[i])) {
623 args[i] = find_better_copy(s, args[i]);
627 /* For commutative operations make constant second argument */
628 switch (opc) {
629 CASE_OP_32_64(add):
630 CASE_OP_32_64(mul):
631 CASE_OP_32_64(and):
632 CASE_OP_32_64(or):
633 CASE_OP_32_64(xor):
634 CASE_OP_32_64(eqv):
635 CASE_OP_32_64(nand):
636 CASE_OP_32_64(nor):
637 CASE_OP_32_64(muluh):
638 CASE_OP_32_64(mulsh):
639 swap_commutative(args[0], &args[1], &args[2]);
640 break;
641 CASE_OP_32_64(brcond):
642 if (swap_commutative(-1, &args[0], &args[1])) {
643 args[2] = tcg_swap_cond(args[2]);
645 break;
646 CASE_OP_32_64(setcond):
647 if (swap_commutative(args[0], &args[1], &args[2])) {
648 args[3] = tcg_swap_cond(args[3]);
650 break;
651 CASE_OP_32_64(movcond):
652 if (swap_commutative(-1, &args[1], &args[2])) {
653 args[5] = tcg_swap_cond(args[5]);
655 /* For movcond, we canonicalize the "false" input reg to match
656 the destination reg so that the tcg backend can implement
657 a "move if true" operation. */
658 if (swap_commutative(args[0], &args[4], &args[3])) {
659 args[5] = tcg_invert_cond(args[5]);
661 break;
662 CASE_OP_32_64(add2):
663 swap_commutative(args[0], &args[2], &args[4]);
664 swap_commutative(args[1], &args[3], &args[5]);
665 break;
666 CASE_OP_32_64(mulu2):
667 CASE_OP_32_64(muls2):
668 swap_commutative(args[0], &args[2], &args[3]);
669 break;
670 case INDEX_op_brcond2_i32:
671 if (swap_commutative2(&args[0], &args[2])) {
672 args[4] = tcg_swap_cond(args[4]);
674 break;
675 case INDEX_op_setcond2_i32:
676 if (swap_commutative2(&args[1], &args[3])) {
677 args[5] = tcg_swap_cond(args[5]);
679 break;
680 default:
681 break;
684 /* Simplify expressions for "shift/rot r, 0, a => movi r, 0",
685 and "sub r, 0, a => neg r, a" case. */
686 switch (opc) {
687 CASE_OP_32_64(shl):
688 CASE_OP_32_64(shr):
689 CASE_OP_32_64(sar):
690 CASE_OP_32_64(rotl):
691 CASE_OP_32_64(rotr):
692 if (temp_is_const(args[1]) && temps[args[1]].val == 0) {
693 tcg_opt_gen_movi(s, op, args, args[0], 0);
694 continue;
696 break;
697 CASE_OP_32_64(sub):
699 TCGOpcode neg_op;
700 bool have_neg;
702 if (temp_is_const(args[2])) {
703 /* Proceed with possible constant folding. */
704 break;
706 if (opc == INDEX_op_sub_i32) {
707 neg_op = INDEX_op_neg_i32;
708 have_neg = TCG_TARGET_HAS_neg_i32;
709 } else {
710 neg_op = INDEX_op_neg_i64;
711 have_neg = TCG_TARGET_HAS_neg_i64;
713 if (!have_neg) {
714 break;
716 if (temp_is_const(args[1]) && temps[args[1]].val == 0) {
717 op->opc = neg_op;
718 reset_temp(args[0]);
719 args[1] = args[2];
720 continue;
723 break;
724 CASE_OP_32_64(xor):
725 CASE_OP_32_64(nand):
726 if (!temp_is_const(args[1])
727 && temp_is_const(args[2]) && temps[args[2]].val == -1) {
728 i = 1;
729 goto try_not;
731 break;
732 CASE_OP_32_64(nor):
733 if (!temp_is_const(args[1])
734 && temp_is_const(args[2]) && temps[args[2]].val == 0) {
735 i = 1;
736 goto try_not;
738 break;
739 CASE_OP_32_64(andc):
740 if (!temp_is_const(args[2])
741 && temp_is_const(args[1]) && temps[args[1]].val == -1) {
742 i = 2;
743 goto try_not;
745 break;
746 CASE_OP_32_64(orc):
747 CASE_OP_32_64(eqv):
748 if (!temp_is_const(args[2])
749 && temp_is_const(args[1]) && temps[args[1]].val == 0) {
750 i = 2;
751 goto try_not;
753 break;
754 try_not:
756 TCGOpcode not_op;
757 bool have_not;
759 if (def->flags & TCG_OPF_64BIT) {
760 not_op = INDEX_op_not_i64;
761 have_not = TCG_TARGET_HAS_not_i64;
762 } else {
763 not_op = INDEX_op_not_i32;
764 have_not = TCG_TARGET_HAS_not_i32;
766 if (!have_not) {
767 break;
769 op->opc = not_op;
770 reset_temp(args[0]);
771 args[1] = args[i];
772 continue;
774 default:
775 break;
778 /* Simplify expression for "op r, a, const => mov r, a" cases */
779 switch (opc) {
780 CASE_OP_32_64(add):
781 CASE_OP_32_64(sub):
782 CASE_OP_32_64(shl):
783 CASE_OP_32_64(shr):
784 CASE_OP_32_64(sar):
785 CASE_OP_32_64(rotl):
786 CASE_OP_32_64(rotr):
787 CASE_OP_32_64(or):
788 CASE_OP_32_64(xor):
789 CASE_OP_32_64(andc):
790 if (!temp_is_const(args[1])
791 && temp_is_const(args[2]) && temps[args[2]].val == 0) {
792 tcg_opt_gen_mov(s, op, args, args[0], args[1]);
793 continue;
795 break;
796 CASE_OP_32_64(and):
797 CASE_OP_32_64(orc):
798 CASE_OP_32_64(eqv):
799 if (!temp_is_const(args[1])
800 && temp_is_const(args[2]) && temps[args[2]].val == -1) {
801 tcg_opt_gen_mov(s, op, args, args[0], args[1]);
802 continue;
804 break;
805 default:
806 break;
809 /* Simplify using known-zero bits. Currently only ops with a single
810 output argument is supported. */
811 mask = -1;
812 affected = -1;
813 switch (opc) {
814 CASE_OP_32_64(ext8s):
815 if ((temps[args[1]].mask & 0x80) != 0) {
816 break;
818 CASE_OP_32_64(ext8u):
819 mask = 0xff;
820 goto and_const;
821 CASE_OP_32_64(ext16s):
822 if ((temps[args[1]].mask & 0x8000) != 0) {
823 break;
825 CASE_OP_32_64(ext16u):
826 mask = 0xffff;
827 goto and_const;
828 case INDEX_op_ext32s_i64:
829 if ((temps[args[1]].mask & 0x80000000) != 0) {
830 break;
832 case INDEX_op_ext32u_i64:
833 mask = 0xffffffffU;
834 goto and_const;
836 CASE_OP_32_64(and):
837 mask = temps[args[2]].mask;
838 if (temp_is_const(args[2])) {
839 and_const:
840 affected = temps[args[1]].mask & ~mask;
842 mask = temps[args[1]].mask & mask;
843 break;
845 case INDEX_op_ext_i32_i64:
846 if ((temps[args[1]].mask & 0x80000000) != 0) {
847 break;
849 case INDEX_op_extu_i32_i64:
850 /* We do not compute affected as it is a size changing op. */
851 mask = (uint32_t)temps[args[1]].mask;
852 break;
854 CASE_OP_32_64(andc):
855 /* Known-zeros does not imply known-ones. Therefore unless
856 args[2] is constant, we can't infer anything from it. */
857 if (temp_is_const(args[2])) {
858 mask = ~temps[args[2]].mask;
859 goto and_const;
861 /* But we certainly know nothing outside args[1] may be set. */
862 mask = temps[args[1]].mask;
863 break;
865 case INDEX_op_sar_i32:
866 if (temp_is_const(args[2])) {
867 tmp = temps[args[2]].val & 31;
868 mask = (int32_t)temps[args[1]].mask >> tmp;
870 break;
871 case INDEX_op_sar_i64:
872 if (temp_is_const(args[2])) {
873 tmp = temps[args[2]].val & 63;
874 mask = (int64_t)temps[args[1]].mask >> tmp;
876 break;
878 case INDEX_op_shr_i32:
879 if (temp_is_const(args[2])) {
880 tmp = temps[args[2]].val & 31;
881 mask = (uint32_t)temps[args[1]].mask >> tmp;
883 break;
884 case INDEX_op_shr_i64:
885 if (temp_is_const(args[2])) {
886 tmp = temps[args[2]].val & 63;
887 mask = (uint64_t)temps[args[1]].mask >> tmp;
889 break;
891 case INDEX_op_extrl_i64_i32:
892 mask = (uint32_t)temps[args[1]].mask;
893 break;
894 case INDEX_op_extrh_i64_i32:
895 mask = (uint64_t)temps[args[1]].mask >> 32;
896 break;
898 CASE_OP_32_64(shl):
899 if (temp_is_const(args[2])) {
900 tmp = temps[args[2]].val & (TCG_TARGET_REG_BITS - 1);
901 mask = temps[args[1]].mask << tmp;
903 break;
905 CASE_OP_32_64(neg):
906 /* Set to 1 all bits to the left of the rightmost. */
907 mask = -(temps[args[1]].mask & -temps[args[1]].mask);
908 break;
910 CASE_OP_32_64(deposit):
911 mask = deposit64(temps[args[1]].mask, args[3], args[4],
912 temps[args[2]].mask);
913 break;
915 CASE_OP_32_64(or):
916 CASE_OP_32_64(xor):
917 mask = temps[args[1]].mask | temps[args[2]].mask;
918 break;
920 CASE_OP_32_64(setcond):
921 case INDEX_op_setcond2_i32:
922 mask = 1;
923 break;
925 CASE_OP_32_64(movcond):
926 mask = temps[args[3]].mask | temps[args[4]].mask;
927 break;
929 CASE_OP_32_64(ld8u):
930 mask = 0xff;
931 break;
932 CASE_OP_32_64(ld16u):
933 mask = 0xffff;
934 break;
935 case INDEX_op_ld32u_i64:
936 mask = 0xffffffffu;
937 break;
939 CASE_OP_32_64(qemu_ld):
941 TCGMemOpIdx oi = args[nb_oargs + nb_iargs];
942 TCGMemOp mop = get_memop(oi);
943 if (!(mop & MO_SIGN)) {
944 mask = (2ULL << ((8 << (mop & MO_SIZE)) - 1)) - 1;
947 break;
949 default:
950 break;
953 /* 32-bit ops generate 32-bit results. For the result is zero test
954 below, we can ignore high bits, but for further optimizations we
955 need to record that the high bits contain garbage. */
956 partmask = mask;
957 if (!(def->flags & TCG_OPF_64BIT)) {
958 mask |= ~(tcg_target_ulong)0xffffffffu;
959 partmask &= 0xffffffffu;
960 affected &= 0xffffffffu;
963 if (partmask == 0) {
964 assert(nb_oargs == 1);
965 tcg_opt_gen_movi(s, op, args, args[0], 0);
966 continue;
968 if (affected == 0) {
969 assert(nb_oargs == 1);
970 tcg_opt_gen_mov(s, op, args, args[0], args[1]);
971 continue;
974 /* Simplify expression for "op r, a, 0 => movi r, 0" cases */
975 switch (opc) {
976 CASE_OP_32_64(and):
977 CASE_OP_32_64(mul):
978 CASE_OP_32_64(muluh):
979 CASE_OP_32_64(mulsh):
980 if ((temp_is_const(args[2]) && temps[args[2]].val == 0)) {
981 tcg_opt_gen_movi(s, op, args, args[0], 0);
982 continue;
984 break;
985 default:
986 break;
989 /* Simplify expression for "op r, a, a => mov r, a" cases */
990 switch (opc) {
991 CASE_OP_32_64(or):
992 CASE_OP_32_64(and):
993 if (temps_are_copies(args[1], args[2])) {
994 tcg_opt_gen_mov(s, op, args, args[0], args[1]);
995 continue;
997 break;
998 default:
999 break;
1002 /* Simplify expression for "op r, a, a => movi r, 0" cases */
1003 switch (opc) {
1004 CASE_OP_32_64(andc):
1005 CASE_OP_32_64(sub):
1006 CASE_OP_32_64(xor):
1007 if (temps_are_copies(args[1], args[2])) {
1008 tcg_opt_gen_movi(s, op, args, args[0], 0);
1009 continue;
1011 break;
1012 default:
1013 break;
1016 /* Propagate constants through copy operations and do constant
1017 folding. Constants will be substituted to arguments by register
1018 allocator where needed and possible. Also detect copies. */
1019 switch (opc) {
1020 CASE_OP_32_64(mov):
1021 tcg_opt_gen_mov(s, op, args, args[0], args[1]);
1022 break;
1023 CASE_OP_32_64(movi):
1024 tcg_opt_gen_movi(s, op, args, args[0], args[1]);
1025 break;
1027 CASE_OP_32_64(not):
1028 CASE_OP_32_64(neg):
1029 CASE_OP_32_64(ext8s):
1030 CASE_OP_32_64(ext8u):
1031 CASE_OP_32_64(ext16s):
1032 CASE_OP_32_64(ext16u):
1033 case INDEX_op_ext32s_i64:
1034 case INDEX_op_ext32u_i64:
1035 case INDEX_op_ext_i32_i64:
1036 case INDEX_op_extu_i32_i64:
1037 case INDEX_op_extrl_i64_i32:
1038 case INDEX_op_extrh_i64_i32:
1039 if (temp_is_const(args[1])) {
1040 tmp = do_constant_folding(opc, temps[args[1]].val, 0);
1041 tcg_opt_gen_movi(s, op, args, args[0], tmp);
1042 break;
1044 goto do_default;
1046 CASE_OP_32_64(add):
1047 CASE_OP_32_64(sub):
1048 CASE_OP_32_64(mul):
1049 CASE_OP_32_64(or):
1050 CASE_OP_32_64(and):
1051 CASE_OP_32_64(xor):
1052 CASE_OP_32_64(shl):
1053 CASE_OP_32_64(shr):
1054 CASE_OP_32_64(sar):
1055 CASE_OP_32_64(rotl):
1056 CASE_OP_32_64(rotr):
1057 CASE_OP_32_64(andc):
1058 CASE_OP_32_64(orc):
1059 CASE_OP_32_64(eqv):
1060 CASE_OP_32_64(nand):
1061 CASE_OP_32_64(nor):
1062 CASE_OP_32_64(muluh):
1063 CASE_OP_32_64(mulsh):
1064 CASE_OP_32_64(div):
1065 CASE_OP_32_64(divu):
1066 CASE_OP_32_64(rem):
1067 CASE_OP_32_64(remu):
1068 if (temp_is_const(args[1]) && temp_is_const(args[2])) {
1069 tmp = do_constant_folding(opc, temps[args[1]].val,
1070 temps[args[2]].val);
1071 tcg_opt_gen_movi(s, op, args, args[0], tmp);
1072 break;
1074 goto do_default;
1076 CASE_OP_32_64(deposit):
1077 if (temp_is_const(args[1]) && temp_is_const(args[2])) {
1078 tmp = deposit64(temps[args[1]].val, args[3], args[4],
1079 temps[args[2]].val);
1080 tcg_opt_gen_movi(s, op, args, args[0], tmp);
1081 break;
1083 goto do_default;
1085 CASE_OP_32_64(setcond):
1086 tmp = do_constant_folding_cond(opc, args[1], args[2], args[3]);
1087 if (tmp != 2) {
1088 tcg_opt_gen_movi(s, op, args, args[0], tmp);
1089 break;
1091 goto do_default;
1093 CASE_OP_32_64(brcond):
1094 tmp = do_constant_folding_cond(opc, args[0], args[1], args[2]);
1095 if (tmp != 2) {
1096 if (tmp) {
1097 reset_all_temps(nb_temps);
1098 op->opc = INDEX_op_br;
1099 args[0] = args[3];
1100 } else {
1101 tcg_op_remove(s, op);
1103 break;
1105 goto do_default;
1107 CASE_OP_32_64(movcond):
1108 tmp = do_constant_folding_cond(opc, args[1], args[2], args[5]);
1109 if (tmp != 2) {
1110 tcg_opt_gen_mov(s, op, args, args[0], args[4-tmp]);
1111 break;
1113 goto do_default;
1115 case INDEX_op_add2_i32:
1116 case INDEX_op_sub2_i32:
1117 if (temp_is_const(args[2]) && temp_is_const(args[3])
1118 && temp_is_const(args[4]) && temp_is_const(args[5])) {
1119 uint32_t al = temps[args[2]].val;
1120 uint32_t ah = temps[args[3]].val;
1121 uint32_t bl = temps[args[4]].val;
1122 uint32_t bh = temps[args[5]].val;
1123 uint64_t a = ((uint64_t)ah << 32) | al;
1124 uint64_t b = ((uint64_t)bh << 32) | bl;
1125 TCGArg rl, rh;
1126 TCGOp *op2 = insert_op_before(s, op, INDEX_op_movi_i32, 2);
1127 TCGArg *args2 = &s->gen_opparam_buf[op2->args];
1129 if (opc == INDEX_op_add2_i32) {
1130 a += b;
1131 } else {
1132 a -= b;
1135 rl = args[0];
1136 rh = args[1];
1137 tcg_opt_gen_movi(s, op, args, rl, (int32_t)a);
1138 tcg_opt_gen_movi(s, op2, args2, rh, (int32_t)(a >> 32));
1140 /* We've done all we need to do with the movi. Skip it. */
1141 oi_next = op2->next;
1142 break;
1144 goto do_default;
1146 case INDEX_op_mulu2_i32:
1147 if (temp_is_const(args[2]) && temp_is_const(args[3])) {
1148 uint32_t a = temps[args[2]].val;
1149 uint32_t b = temps[args[3]].val;
1150 uint64_t r = (uint64_t)a * b;
1151 TCGArg rl, rh;
1152 TCGOp *op2 = insert_op_before(s, op, INDEX_op_movi_i32, 2);
1153 TCGArg *args2 = &s->gen_opparam_buf[op2->args];
1155 rl = args[0];
1156 rh = args[1];
1157 tcg_opt_gen_movi(s, op, args, rl, (int32_t)r);
1158 tcg_opt_gen_movi(s, op2, args2, rh, (int32_t)(r >> 32));
1160 /* We've done all we need to do with the movi. Skip it. */
1161 oi_next = op2->next;
1162 break;
1164 goto do_default;
1166 case INDEX_op_brcond2_i32:
1167 tmp = do_constant_folding_cond2(&args[0], &args[2], args[4]);
1168 if (tmp != 2) {
1169 if (tmp) {
1170 do_brcond_true:
1171 reset_all_temps(nb_temps);
1172 op->opc = INDEX_op_br;
1173 args[0] = args[5];
1174 } else {
1175 do_brcond_false:
1176 tcg_op_remove(s, op);
1178 } else if ((args[4] == TCG_COND_LT || args[4] == TCG_COND_GE)
1179 && temp_is_const(args[2]) && temps[args[2]].val == 0
1180 && temp_is_const(args[3]) && temps[args[3]].val == 0) {
1181 /* Simplify LT/GE comparisons vs zero to a single compare
1182 vs the high word of the input. */
1183 do_brcond_high:
1184 reset_all_temps(nb_temps);
1185 op->opc = INDEX_op_brcond_i32;
1186 args[0] = args[1];
1187 args[1] = args[3];
1188 args[2] = args[4];
1189 args[3] = args[5];
1190 } else if (args[4] == TCG_COND_EQ) {
1191 /* Simplify EQ comparisons where one of the pairs
1192 can be simplified. */
1193 tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
1194 args[0], args[2], TCG_COND_EQ);
1195 if (tmp == 0) {
1196 goto do_brcond_false;
1197 } else if (tmp == 1) {
1198 goto do_brcond_high;
1200 tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
1201 args[1], args[3], TCG_COND_EQ);
1202 if (tmp == 0) {
1203 goto do_brcond_false;
1204 } else if (tmp != 1) {
1205 goto do_default;
1207 do_brcond_low:
1208 reset_all_temps(nb_temps);
1209 op->opc = INDEX_op_brcond_i32;
1210 args[1] = args[2];
1211 args[2] = args[4];
1212 args[3] = args[5];
1213 } else if (args[4] == TCG_COND_NE) {
1214 /* Simplify NE comparisons where one of the pairs
1215 can be simplified. */
1216 tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
1217 args[0], args[2], TCG_COND_NE);
1218 if (tmp == 0) {
1219 goto do_brcond_high;
1220 } else if (tmp == 1) {
1221 goto do_brcond_true;
1223 tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
1224 args[1], args[3], TCG_COND_NE);
1225 if (tmp == 0) {
1226 goto do_brcond_low;
1227 } else if (tmp == 1) {
1228 goto do_brcond_true;
1230 goto do_default;
1231 } else {
1232 goto do_default;
1234 break;
1236 case INDEX_op_setcond2_i32:
1237 tmp = do_constant_folding_cond2(&args[1], &args[3], args[5]);
1238 if (tmp != 2) {
1239 do_setcond_const:
1240 tcg_opt_gen_movi(s, op, args, args[0], tmp);
1241 } else if ((args[5] == TCG_COND_LT || args[5] == TCG_COND_GE)
1242 && temp_is_const(args[3]) && temps[args[3]].val == 0
1243 && temp_is_const(args[4]) && temps[args[4]].val == 0) {
1244 /* Simplify LT/GE comparisons vs zero to a single compare
1245 vs the high word of the input. */
1246 do_setcond_high:
1247 reset_temp(args[0]);
1248 temps[args[0]].mask = 1;
1249 op->opc = INDEX_op_setcond_i32;
1250 args[1] = args[2];
1251 args[2] = args[4];
1252 args[3] = args[5];
1253 } else if (args[5] == TCG_COND_EQ) {
1254 /* Simplify EQ comparisons where one of the pairs
1255 can be simplified. */
1256 tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
1257 args[1], args[3], TCG_COND_EQ);
1258 if (tmp == 0) {
1259 goto do_setcond_const;
1260 } else if (tmp == 1) {
1261 goto do_setcond_high;
1263 tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
1264 args[2], args[4], TCG_COND_EQ);
1265 if (tmp == 0) {
1266 goto do_setcond_high;
1267 } else if (tmp != 1) {
1268 goto do_default;
1270 do_setcond_low:
1271 reset_temp(args[0]);
1272 temps[args[0]].mask = 1;
1273 op->opc = INDEX_op_setcond_i32;
1274 args[2] = args[3];
1275 args[3] = args[5];
1276 } else if (args[5] == TCG_COND_NE) {
1277 /* Simplify NE comparisons where one of the pairs
1278 can be simplified. */
1279 tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
1280 args[1], args[3], TCG_COND_NE);
1281 if (tmp == 0) {
1282 goto do_setcond_high;
1283 } else if (tmp == 1) {
1284 goto do_setcond_const;
1286 tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
1287 args[2], args[4], TCG_COND_NE);
1288 if (tmp == 0) {
1289 goto do_setcond_low;
1290 } else if (tmp == 1) {
1291 goto do_setcond_const;
1293 goto do_default;
1294 } else {
1295 goto do_default;
1297 break;
1299 case INDEX_op_call:
1300 if (!(args[nb_oargs + nb_iargs + 1]
1301 & (TCG_CALL_NO_READ_GLOBALS | TCG_CALL_NO_WRITE_GLOBALS))) {
1302 for (i = 0; i < nb_globals; i++) {
1303 if (test_bit(i, temps_used.l)) {
1304 reset_temp(i);
1308 goto do_reset_output;
1310 default:
1311 do_default:
1312 /* Default case: we know nothing about operation (or were unable
1313 to compute the operation result) so no propagation is done.
1314 We trash everything if the operation is the end of a basic
1315 block, otherwise we only trash the output args. "mask" is
1316 the non-zero bits mask for the first output arg. */
1317 if (def->flags & TCG_OPF_BB_END) {
1318 reset_all_temps(nb_temps);
1319 } else {
1320 do_reset_output:
1321 for (i = 0; i < nb_oargs; i++) {
1322 reset_temp(args[i]);
1323 /* Save the corresponding known-zero bits mask for the
1324 first output argument (only one supported so far). */
1325 if (i == 0) {
1326 temps[args[i]].mask = mask;
1330 break;