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virtio-scsi: replace AioContext lock with tmf_bh_lock
[qemu/kevin.git] / tcg / optimize.c
blobf2d01654c59ed1866d912eeed98678af73beee7e
1 /*
2 * Optimizations for Tiny Code Generator for QEMU
3 *
4 * Copyright (c) 2010 Samsung Electronics.
5 * Contributed by Kirill Batuzov <batuzovk@ispras.ru>
6 *
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:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
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.
24 */
25
26 #include "qemu/osdep.h"
27 #include "qemu/int128.h"
28 #include "qemu/interval-tree.h"
29 #include "tcg/tcg-op-common.h"
30 #include "tcg-internal.h"
31
32 #define CASE_OP_32_64(x) \
33 glue(glue(case INDEX_op_, x), _i32): \
34 glue(glue(case INDEX_op_, x), _i64)
35
36 #define CASE_OP_32_64_VEC(x) \
37 glue(glue(case INDEX_op_, x), _i32): \
38 glue(glue(case INDEX_op_, x), _i64): \
39 glue(glue(case INDEX_op_, x), _vec)
40
41 typedef struct MemCopyInfo {
42 IntervalTreeNode itree;
43 QSIMPLEQ_ENTRY (MemCopyInfo) next;
44 TCGTemp *ts;
45 TCGType type;
46 } MemCopyInfo;
47
48 typedef struct TempOptInfo {
49 bool is_const;
50 TCGTemp *prev_copy;
51 TCGTemp *next_copy;
52 QSIMPLEQ_HEAD(, MemCopyInfo) mem_copy;
53 uint64_t val;
54 uint64_t z_mask; /* mask bit is 0 if and only if value bit is 0 */
55 uint64_t s_mask; /* a left-aligned mask of clrsb(value) bits. */
56 } TempOptInfo;
57
58 typedef struct OptContext {
59 TCGContext *tcg;
60 TCGOp *prev_mb;
61 TCGTempSet temps_used;
62
63 IntervalTreeRoot mem_copy;
64 QSIMPLEQ_HEAD(, MemCopyInfo) mem_free;
65
66 /* In flight values from optimization. */
67 uint64_t a_mask; /* mask bit is 0 iff value identical to first input */
68 uint64_t z_mask; /* mask bit is 0 iff value bit is 0 */
69 uint64_t s_mask; /* mask of clrsb(value) bits */
70 TCGType type;
71 } OptContext;
72
73 /* Calculate the smask for a specific value. */
74 static uint64_t smask_from_value(uint64_t value)
75 {
76 int rep = clrsb64(value);
77 return ~(~0ull >> rep);
78 }
79
80 /*
81 * Calculate the smask for a given set of known-zeros.
82 * If there are lots of zeros on the left, we can consider the remainder
83 * an unsigned field, and thus the corresponding signed field is one bit
84 * larger.
85 */
86 static uint64_t smask_from_zmask(uint64_t zmask)
87 {
88 /*
89 * Only the 0 bits are significant for zmask, thus the msb itself
90 * must be zero, else we have no sign information.
91 */
92 int rep = clz64(zmask);
93 if (rep == 0) {
94 return 0;
95 }
96 rep -= 1;
97 return ~(~0ull >> rep);
98 }
99
100 /*
101 * Recreate a properly left-aligned smask after manipulation.
102 * Some bit-shuffling, particularly shifts and rotates, may
103 * retain sign bits on the left, but may scatter disconnected
104 * sign bits on the right. Retain only what remains to the left.
105 */
106 static uint64_t smask_from_smask(int64_t smask)
107 {
108 /* Only the 1 bits are significant for smask */
109 return smask_from_zmask(~smask);
110 }
111
112 static inline TempOptInfo *ts_info(TCGTemp *ts)
113 {
114 return ts->state_ptr;
115 }
116
117 static inline TempOptInfo *arg_info(TCGArg arg)
118 {
119 return ts_info(arg_temp(arg));
120 }
121
122 static inline bool ts_is_const(TCGTemp *ts)
123 {
124 return ts_info(ts)->is_const;
125 }
126
127 static inline bool arg_is_const(TCGArg arg)
128 {
129 return ts_is_const(arg_temp(arg));
130 }
131
132 static inline bool ts_is_copy(TCGTemp *ts)
133 {
134 return ts_info(ts)->next_copy != ts;
135 }
136
137 static TCGTemp *cmp_better_copy(TCGTemp *a, TCGTemp *b)
138 {
139 return a->kind < b->kind ? b : a;
140 }
141
142 /* Initialize and activate a temporary. */
143 static void init_ts_info(OptContext *ctx, TCGTemp *ts)
144 {
145 size_t idx = temp_idx(ts);
146 TempOptInfo *ti;
147
148 if (test_bit(idx, ctx->temps_used.l)) {
149 return;
150 }
151 set_bit(idx, ctx->temps_used.l);
152
153 ti = ts->state_ptr;
154 if (ti == NULL) {
155 ti = tcg_malloc(sizeof(TempOptInfo));
156 ts->state_ptr = ti;
157 }
158
159 ti->next_copy = ts;
160 ti->prev_copy = ts;
161 QSIMPLEQ_INIT(&ti->mem_copy);
162 if (ts->kind == TEMP_CONST) {
163 ti->is_const = true;
164 ti->val = ts->val;
165 ti->z_mask = ts->val;
166 ti->s_mask = smask_from_value(ts->val);
167 } else {
168 ti->is_const = false;
169 ti->z_mask = -1;
170 ti->s_mask = 0;
171 }
172 }
173
174 static MemCopyInfo *mem_copy_first(OptContext *ctx, intptr_t s, intptr_t l)
175 {
176 IntervalTreeNode *r = interval_tree_iter_first(&ctx->mem_copy, s, l);
177 return r ? container_of(r, MemCopyInfo, itree) : NULL;
178 }
179
180 static MemCopyInfo *mem_copy_next(MemCopyInfo *mem, intptr_t s, intptr_t l)
181 {
182 IntervalTreeNode *r = interval_tree_iter_next(&mem->itree, s, l);
183 return r ? container_of(r, MemCopyInfo, itree) : NULL;
184 }
185
186 static void remove_mem_copy(OptContext *ctx, MemCopyInfo *mc)
187 {
188 TCGTemp *ts = mc->ts;
189 TempOptInfo *ti = ts_info(ts);
190
191 interval_tree_remove(&mc->itree, &ctx->mem_copy);
192 QSIMPLEQ_REMOVE(&ti->mem_copy, mc, MemCopyInfo, next);
193 QSIMPLEQ_INSERT_TAIL(&ctx->mem_free, mc, next);
194 }
195
196 static void remove_mem_copy_in(OptContext *ctx, intptr_t s, intptr_t l)
197 {
198 while (true) {
199 MemCopyInfo *mc = mem_copy_first(ctx, s, l);
200 if (!mc) {
201 break;
202 }
203 remove_mem_copy(ctx, mc);
204 }
205 }
206
207 static void remove_mem_copy_all(OptContext *ctx)
208 {
209 remove_mem_copy_in(ctx, 0, -1);
210 tcg_debug_assert(interval_tree_is_empty(&ctx->mem_copy));
211 }
212
213 static TCGTemp *find_better_copy(TCGTemp *ts)
214 {
215 TCGTemp *i, *ret;
216
217 /* If this is already readonly, we can't do better. */
218 if (temp_readonly(ts)) {
219 return ts;
220 }
221
222 ret = ts;
223 for (i = ts_info(ts)->next_copy; i != ts; i = ts_info(i)->next_copy) {
224 ret = cmp_better_copy(ret, i);
225 }
226 return ret;
227 }
228
229 static void move_mem_copies(TCGTemp *dst_ts, TCGTemp *src_ts)
230 {
231 TempOptInfo *si = ts_info(src_ts);
232 TempOptInfo *di = ts_info(dst_ts);
233 MemCopyInfo *mc;
234
235 QSIMPLEQ_FOREACH(mc, &si->mem_copy, next) {
236 tcg_debug_assert(mc->ts == src_ts);
237 mc->ts = dst_ts;
238 }
239 QSIMPLEQ_CONCAT(&di->mem_copy, &si->mem_copy);
240 }
241
242 /* Reset TEMP's state, possibly removing the temp for the list of copies. */
243 static void reset_ts(OptContext *ctx, TCGTemp *ts)
244 {
245 TempOptInfo *ti = ts_info(ts);
246 TCGTemp *pts = ti->prev_copy;
247 TCGTemp *nts = ti->next_copy;
248 TempOptInfo *pi = ts_info(pts);
249 TempOptInfo *ni = ts_info(nts);
250
251 ni->prev_copy = ti->prev_copy;
252 pi->next_copy = ti->next_copy;
253 ti->next_copy = ts;
254 ti->prev_copy = ts;
255 ti->is_const = false;
256 ti->z_mask = -1;
257 ti->s_mask = 0;
258
259 if (!QSIMPLEQ_EMPTY(&ti->mem_copy)) {
260 if (ts == nts) {
261 /* Last temp copy being removed, the mem copies die. */
262 MemCopyInfo *mc;
263 QSIMPLEQ_FOREACH(mc, &ti->mem_copy, next) {
264 interval_tree_remove(&mc->itree, &ctx->mem_copy);
265 }
266 QSIMPLEQ_CONCAT(&ctx->mem_free, &ti->mem_copy);
267 } else {
268 move_mem_copies(find_better_copy(nts), ts);
269 }
270 }
271 }
272
273 static void reset_temp(OptContext *ctx, TCGArg arg)
274 {
275 reset_ts(ctx, arg_temp(arg));
276 }
277
278 static void record_mem_copy(OptContext *ctx, TCGType type,
279 TCGTemp *ts, intptr_t start, intptr_t last)
280 {
281 MemCopyInfo *mc;
282 TempOptInfo *ti;
283
284 mc = QSIMPLEQ_FIRST(&ctx->mem_free);
285 if (mc) {
286 QSIMPLEQ_REMOVE_HEAD(&ctx->mem_free, next);
287 } else {
288 mc = tcg_malloc(sizeof(*mc));
289 }
290
291 memset(mc, 0, sizeof(*mc));
292 mc->itree.start = start;
293 mc->itree.last = last;
294 mc->type = type;
295 interval_tree_insert(&mc->itree, &ctx->mem_copy);
296
297 ts = find_better_copy(ts);
298 ti = ts_info(ts);
299 mc->ts = ts;
300 QSIMPLEQ_INSERT_TAIL(&ti->mem_copy, mc, next);
301 }
302
303 static bool ts_are_copies(TCGTemp *ts1, TCGTemp *ts2)
304 {
305 TCGTemp *i;
306
307 if (ts1 == ts2) {
308 return true;
309 }
310
311 if (!ts_is_copy(ts1) || !ts_is_copy(ts2)) {
312 return false;
313 }
314
315 for (i = ts_info(ts1)->next_copy; i != ts1; i = ts_info(i)->next_copy) {
316 if (i == ts2) {
317 return true;
318 }
319 }
320
321 return false;
322 }
323
324 static bool args_are_copies(TCGArg arg1, TCGArg arg2)
325 {
326 return ts_are_copies(arg_temp(arg1), arg_temp(arg2));
327 }
328
329 static TCGTemp *find_mem_copy_for(OptContext *ctx, TCGType type, intptr_t s)
330 {
331 MemCopyInfo *mc;
332
333 for (mc = mem_copy_first(ctx, s, s); mc; mc = mem_copy_next(mc, s, s)) {
334 if (mc->itree.start == s && mc->type == type) {
335 return find_better_copy(mc->ts);
336 }
337 }
338 return NULL;
339 }
340
341 static TCGArg arg_new_constant(OptContext *ctx, uint64_t val)
342 {
343 TCGType type = ctx->type;
344 TCGTemp *ts;
345
346 if (type == TCG_TYPE_I32) {
347 val = (int32_t)val;
348 }
349
350 ts = tcg_constant_internal(type, val);
351 init_ts_info(ctx, ts);
352
353 return temp_arg(ts);
354 }
355
356 static bool tcg_opt_gen_mov(OptContext *ctx, TCGOp *op, TCGArg dst, TCGArg src)
357 {
358 TCGTemp *dst_ts = arg_temp(dst);
359 TCGTemp *src_ts = arg_temp(src);
360 TempOptInfo *di;
361 TempOptInfo *si;
362 TCGOpcode new_op;
363
364 if (ts_are_copies(dst_ts, src_ts)) {
365 tcg_op_remove(ctx->tcg, op);
366 return true;
367 }
368
369 reset_ts(ctx, dst_ts);
370 di = ts_info(dst_ts);
371 si = ts_info(src_ts);
372
373 switch (ctx->type) {
374 case TCG_TYPE_I32:
375 new_op = INDEX_op_mov_i32;
376 break;
377 case TCG_TYPE_I64:
378 new_op = INDEX_op_mov_i64;
379 break;
380 case TCG_TYPE_V64:
381 case TCG_TYPE_V128:
382 case TCG_TYPE_V256:
383 /* TCGOP_VECL and TCGOP_VECE remain unchanged. */
384 new_op = INDEX_op_mov_vec;
385 break;
386 default:
387 g_assert_not_reached();
388 }
389 op->opc = new_op;
390 op->args[0] = dst;
391 op->args[1] = src;
392
393 di->z_mask = si->z_mask;
394 di->s_mask = si->s_mask;
395
396 if (src_ts->type == dst_ts->type) {
397 TempOptInfo *ni = ts_info(si->next_copy);
398
399 di->next_copy = si->next_copy;
400 di->prev_copy = src_ts;
401 ni->prev_copy = dst_ts;
402 si->next_copy = dst_ts;
403 di->is_const = si->is_const;
404 di->val = si->val;
405
406 if (!QSIMPLEQ_EMPTY(&si->mem_copy)
407 && cmp_better_copy(src_ts, dst_ts) == dst_ts) {
408 move_mem_copies(dst_ts, src_ts);
409 }
410 }
411 return true;
412 }
413
414 static bool tcg_opt_gen_movi(OptContext *ctx, TCGOp *op,
415 TCGArg dst, uint64_t val)
416 {
417 /* Convert movi to mov with constant temp. */
418 return tcg_opt_gen_mov(ctx, op, dst, arg_new_constant(ctx, val));
419 }
420
421 static uint64_t do_constant_folding_2(TCGOpcode op, uint64_t x, uint64_t y)
422 {
423 uint64_t l64, h64;
424
425 switch (op) {
426 CASE_OP_32_64(add):
427 return x + y;
428
429 CASE_OP_32_64(sub):
430 return x - y;
431
432 CASE_OP_32_64(mul):
433 return x * y;
434
435 CASE_OP_32_64_VEC(and):
436 return x & y;
437
438 CASE_OP_32_64_VEC(or):
439 return x | y;
440
441 CASE_OP_32_64_VEC(xor):
442 return x ^ y;
443
444 case INDEX_op_shl_i32:
445 return (uint32_t)x << (y & 31);
446
447 case INDEX_op_shl_i64:
448 return (uint64_t)x << (y & 63);
449
450 case INDEX_op_shr_i32:
451 return (uint32_t)x >> (y & 31);
452
453 case INDEX_op_shr_i64:
454 return (uint64_t)x >> (y & 63);
455
456 case INDEX_op_sar_i32:
457 return (int32_t)x >> (y & 31);
458
459 case INDEX_op_sar_i64:
460 return (int64_t)x >> (y & 63);
461
462 case INDEX_op_rotr_i32:
463 return ror32(x, y & 31);
464
465 case INDEX_op_rotr_i64:
466 return ror64(x, y & 63);
467
468 case INDEX_op_rotl_i32:
469 return rol32(x, y & 31);
470
471 case INDEX_op_rotl_i64:
472 return rol64(x, y & 63);
473
474 CASE_OP_32_64_VEC(not):
475 return ~x;
476
477 CASE_OP_32_64(neg):
478 return -x;
479
480 CASE_OP_32_64_VEC(andc):
481 return x & ~y;
482
483 CASE_OP_32_64_VEC(orc):
484 return x | ~y;
485
486 CASE_OP_32_64_VEC(eqv):
487 return ~(x ^ y);
488
489 CASE_OP_32_64_VEC(nand):
490 return ~(x & y);
491
492 CASE_OP_32_64_VEC(nor):
493 return ~(x | y);
494
495 case INDEX_op_clz_i32:
496 return (uint32_t)x ? clz32(x) : y;
497
498 case INDEX_op_clz_i64:
499 return x ? clz64(x) : y;
500
501 case INDEX_op_ctz_i32:
502 return (uint32_t)x ? ctz32(x) : y;
503
504 case INDEX_op_ctz_i64:
505 return x ? ctz64(x) : y;
506
507 case INDEX_op_ctpop_i32:
508 return ctpop32(x);
509
510 case INDEX_op_ctpop_i64:
511 return ctpop64(x);
512
513 CASE_OP_32_64(ext8s):
514 return (int8_t)x;
515
516 CASE_OP_32_64(ext16s):
517 return (int16_t)x;
518
519 CASE_OP_32_64(ext8u):
520 return (uint8_t)x;
521
522 CASE_OP_32_64(ext16u):
523 return (uint16_t)x;
524
525 CASE_OP_32_64(bswap16):
526 x = bswap16(x);
527 return y & TCG_BSWAP_OS ? (int16_t)x : x;
528
529 CASE_OP_32_64(bswap32):
530 x = bswap32(x);
531 return y & TCG_BSWAP_OS ? (int32_t)x : x;
532
533 case INDEX_op_bswap64_i64:
534 return bswap64(x);
535
536 case INDEX_op_ext_i32_i64:
537 case INDEX_op_ext32s_i64:
538 return (int32_t)x;
539
540 case INDEX_op_extu_i32_i64:
541 case INDEX_op_extrl_i64_i32:
542 case INDEX_op_ext32u_i64:
543 return (uint32_t)x;
544
545 case INDEX_op_extrh_i64_i32:
546 return (uint64_t)x >> 32;
547
548 case INDEX_op_muluh_i32:
549 return ((uint64_t)(uint32_t)x * (uint32_t)y) >> 32;
550 case INDEX_op_mulsh_i32:
551 return ((int64_t)(int32_t)x * (int32_t)y) >> 32;
552
553 case INDEX_op_muluh_i64:
554 mulu64(&l64, &h64, x, y);
555 return h64;
556 case INDEX_op_mulsh_i64:
557 muls64(&l64, &h64, x, y);
558 return h64;
559
560 case INDEX_op_div_i32:
561 /* Avoid crashing on divide by zero, otherwise undefined. */
562 return (int32_t)x / ((int32_t)y ? : 1);
563 case INDEX_op_divu_i32:
564 return (uint32_t)x / ((uint32_t)y ? : 1);
565 case INDEX_op_div_i64:
566 return (int64_t)x / ((int64_t)y ? : 1);
567 case INDEX_op_divu_i64:
568 return (uint64_t)x / ((uint64_t)y ? : 1);
569
570 case INDEX_op_rem_i32:
571 return (int32_t)x % ((int32_t)y ? : 1);
572 case INDEX_op_remu_i32:
573 return (uint32_t)x % ((uint32_t)y ? : 1);
574 case INDEX_op_rem_i64:
575 return (int64_t)x % ((int64_t)y ? : 1);
576 case INDEX_op_remu_i64:
577 return (uint64_t)x % ((uint64_t)y ? : 1);
578
579 default:
580 g_assert_not_reached();
581 }
582 }
583
584 static uint64_t do_constant_folding(TCGOpcode op, TCGType type,
585 uint64_t x, uint64_t y)
586 {
587 uint64_t res = do_constant_folding_2(op, x, y);
588 if (type == TCG_TYPE_I32) {
589 res = (int32_t)res;
590 }
591 return res;
592 }
593
594 static bool do_constant_folding_cond_32(uint32_t x, uint32_t y, TCGCond c)
595 {
596 switch (c) {
597 case TCG_COND_EQ:
598 return x == y;
599 case TCG_COND_NE:
600 return x != y;
601 case TCG_COND_LT:
602 return (int32_t)x < (int32_t)y;
603 case TCG_COND_GE:
604 return (int32_t)x >= (int32_t)y;
605 case TCG_COND_LE:
606 return (int32_t)x <= (int32_t)y;
607 case TCG_COND_GT:
608 return (int32_t)x > (int32_t)y;
609 case TCG_COND_LTU:
610 return x < y;
611 case TCG_COND_GEU:
612 return x >= y;
613 case TCG_COND_LEU:
614 return x <= y;
615 case TCG_COND_GTU:
616 return x > y;
617 default:
618 g_assert_not_reached();
619 }
620 }
621
622 static bool do_constant_folding_cond_64(uint64_t x, uint64_t y, TCGCond c)
623 {
624 switch (c) {
625 case TCG_COND_EQ:
626 return x == y;
627 case TCG_COND_NE:
628 return x != y;
629 case TCG_COND_LT:
630 return (int64_t)x < (int64_t)y;
631 case TCG_COND_GE:
632 return (int64_t)x >= (int64_t)y;
633 case TCG_COND_LE:
634 return (int64_t)x <= (int64_t)y;
635 case TCG_COND_GT:
636 return (int64_t)x > (int64_t)y;
637 case TCG_COND_LTU:
638 return x < y;
639 case TCG_COND_GEU:
640 return x >= y;
641 case TCG_COND_LEU:
642 return x <= y;
643 case TCG_COND_GTU:
644 return x > y;
645 default:
646 g_assert_not_reached();
647 }
648 }
649
650 static bool do_constant_folding_cond_eq(TCGCond c)
651 {
652 switch (c) {
653 case TCG_COND_GT:
654 case TCG_COND_LTU:
655 case TCG_COND_LT:
656 case TCG_COND_GTU:
657 case TCG_COND_NE:
658 return 0;
659 case TCG_COND_GE:
660 case TCG_COND_GEU:
661 case TCG_COND_LE:
662 case TCG_COND_LEU:
663 case TCG_COND_EQ:
664 return 1;
665 default:
666 g_assert_not_reached();
667 }
668 }
669
670 /*
671 * Return -1 if the condition can't be simplified,
672 * and the result of the condition (0 or 1) if it can.
673 */
674 static int do_constant_folding_cond(TCGType type, TCGArg x,
675 TCGArg y, TCGCond c)
676 {
677 if (arg_is_const(x) && arg_is_const(y)) {
678 uint64_t xv = arg_info(x)->val;
679 uint64_t yv = arg_info(y)->val;
680
681 switch (type) {
682 case TCG_TYPE_I32:
683 return do_constant_folding_cond_32(xv, yv, c);
684 case TCG_TYPE_I64:
685 return do_constant_folding_cond_64(xv, yv, c);
686 default:
687 /* Only scalar comparisons are optimizable */
688 return -1;
689 }
690 } else if (args_are_copies(x, y)) {
691 return do_constant_folding_cond_eq(c);
692 } else if (arg_is_const(y) && arg_info(y)->val == 0) {
693 switch (c) {
694 case TCG_COND_LTU:
695 return 0;
696 case TCG_COND_GEU:
697 return 1;
698 default:
699 return -1;
700 }
701 }
702 return -1;
703 }
704
705 /*
706 * Return -1 if the condition can't be simplified,
707 * and the result of the condition (0 or 1) if it can.
708 */
709 static int do_constant_folding_cond2(TCGArg *p1, TCGArg *p2, TCGCond c)
710 {
711 TCGArg al = p1[0], ah = p1[1];
712 TCGArg bl = p2[0], bh = p2[1];
713
714 if (arg_is_const(bl) && arg_is_const(bh)) {
715 tcg_target_ulong blv = arg_info(bl)->val;
716 tcg_target_ulong bhv = arg_info(bh)->val;
717 uint64_t b = deposit64(blv, 32, 32, bhv);
718
719 if (arg_is_const(al) && arg_is_const(ah)) {
720 tcg_target_ulong alv = arg_info(al)->val;
721 tcg_target_ulong ahv = arg_info(ah)->val;
722 uint64_t a = deposit64(alv, 32, 32, ahv);
723 return do_constant_folding_cond_64(a, b, c);
724 }
725 if (b == 0) {
726 switch (c) {
727 case TCG_COND_LTU:
728 return 0;
729 case TCG_COND_GEU:
730 return 1;
731 default:
732 break;
733 }
734 }
735 }
736 if (args_are_copies(al, bl) && args_are_copies(ah, bh)) {
737 return do_constant_folding_cond_eq(c);
738 }
739 return -1;
740 }
741
742 /**
743 * swap_commutative:
744 * @dest: TCGArg of the destination argument, or NO_DEST.
745 * @p1: first paired argument
746 * @p2: second paired argument
747 *
748 * If *@p1 is a constant and *@p2 is not, swap.
749 * If *@p2 matches @dest, swap.
750 * Return true if a swap was performed.
751 */
752
753 #define NO_DEST temp_arg(NULL)
754
755 static bool swap_commutative(TCGArg dest, TCGArg *p1, TCGArg *p2)
756 {
757 TCGArg a1 = *p1, a2 = *p2;
758 int sum = 0;
759 sum += arg_is_const(a1);
760 sum -= arg_is_const(a2);
761
762 /* Prefer the constant in second argument, and then the form
763 op a, a, b, which is better handled on non-RISC hosts. */
764 if (sum > 0 || (sum == 0 && dest == a2)) {
765 *p1 = a2;
766 *p2 = a1;
767 return true;
768 }
769 return false;
770 }
771
772 static bool swap_commutative2(TCGArg *p1, TCGArg *p2)
773 {
774 int sum = 0;
775 sum += arg_is_const(p1[0]);
776 sum += arg_is_const(p1[1]);
777 sum -= arg_is_const(p2[0]);
778 sum -= arg_is_const(p2[1]);
779 if (sum > 0) {
780 TCGArg t;
781 t = p1[0], p1[0] = p2[0], p2[0] = t;
782 t = p1[1], p1[1] = p2[1], p2[1] = t;
783 return true;
784 }
785 return false;
786 }
787
788 static void init_arguments(OptContext *ctx, TCGOp *op, int nb_args)
789 {
790 for (int i = 0; i < nb_args; i++) {
791 TCGTemp *ts = arg_temp(op->args[i]);
792 init_ts_info(ctx, ts);
793 }
794 }
795
796 static void copy_propagate(OptContext *ctx, TCGOp *op,
797 int nb_oargs, int nb_iargs)
798 {
799 for (int i = nb_oargs; i < nb_oargs + nb_iargs; i++) {
800 TCGTemp *ts = arg_temp(op->args[i]);
801 if (ts_is_copy(ts)) {
802 op->args[i] = temp_arg(find_better_copy(ts));
803 }
804 }
805 }
806
807 static void finish_folding(OptContext *ctx, TCGOp *op)
808 {
809 const TCGOpDef *def = &tcg_op_defs[op->opc];
810 int i, nb_oargs;
811
812 /*
813 * We only optimize extended basic blocks. If the opcode ends a BB
814 * and is not a conditional branch, reset all temp data.
815 */
816 if (def->flags & TCG_OPF_BB_END) {
817 ctx->prev_mb = NULL;
818 if (!(def->flags & TCG_OPF_COND_BRANCH)) {
819 memset(&ctx->temps_used, 0, sizeof(ctx->temps_used));
820 remove_mem_copy_all(ctx);
821 }
822 return;
823 }
824
825 nb_oargs = def->nb_oargs;
826 for (i = 0; i < nb_oargs; i++) {
827 TCGTemp *ts = arg_temp(op->args[i]);
828 reset_ts(ctx, ts);
829 /*
830 * Save the corresponding known-zero/sign bits mask for the
831 * first output argument (only one supported so far).
832 */
833 if (i == 0) {
834 ts_info(ts)->z_mask = ctx->z_mask;
835 ts_info(ts)->s_mask = ctx->s_mask;
836 }
837 }
838 }
839
840 /*
841 * The fold_* functions return true when processing is complete,
842 * usually by folding the operation to a constant or to a copy,
843 * and calling tcg_opt_gen_{mov,movi}. They may do other things,
844 * like collect information about the value produced, for use in
845 * optimizing a subsequent operation.
846 *
847 * These first fold_* functions are all helpers, used by other
848 * folders for more specific operations.
849 */
850
851 static bool fold_const1(OptContext *ctx, TCGOp *op)
852 {
853 if (arg_is_const(op->args[1])) {
854 uint64_t t;
855
856 t = arg_info(op->args[1])->val;
857 t = do_constant_folding(op->opc, ctx->type, t, 0);
858 return tcg_opt_gen_movi(ctx, op, op->args[0], t);
859 }
860 return false;
861 }
862
863 static bool fold_const2(OptContext *ctx, TCGOp *op)
864 {
865 if (arg_is_const(op->args[1]) && arg_is_const(op->args[2])) {
866 uint64_t t1 = arg_info(op->args[1])->val;
867 uint64_t t2 = arg_info(op->args[2])->val;
868
869 t1 = do_constant_folding(op->opc, ctx->type, t1, t2);
870 return tcg_opt_gen_movi(ctx, op, op->args[0], t1);
871 }
872 return false;
873 }
874
875 static bool fold_commutative(OptContext *ctx, TCGOp *op)
876 {
877 swap_commutative(op->args[0], &op->args[1], &op->args[2]);
878 return false;
879 }
880
881 static bool fold_const2_commutative(OptContext *ctx, TCGOp *op)
882 {
883 swap_commutative(op->args[0], &op->args[1], &op->args[2]);
884 return fold_const2(ctx, op);
885 }
886
887 static bool fold_masks(OptContext *ctx, TCGOp *op)
888 {
889 uint64_t a_mask = ctx->a_mask;
890 uint64_t z_mask = ctx->z_mask;
891 uint64_t s_mask = ctx->s_mask;
892
893 /*
894 * 32-bit ops generate 32-bit results, which for the purpose of
895 * simplifying tcg are sign-extended. Certainly that's how we
896 * represent our constants elsewhere. Note that the bits will
897 * be reset properly for a 64-bit value when encountering the
898 * type changing opcodes.
899 */
900 if (ctx->type == TCG_TYPE_I32) {
901 a_mask = (int32_t)a_mask;
902 z_mask = (int32_t)z_mask;
903 s_mask |= MAKE_64BIT_MASK(32, 32);
904 ctx->z_mask = z_mask;
905 ctx->s_mask = s_mask;
906 }
907
908 if (z_mask == 0) {
909 return tcg_opt_gen_movi(ctx, op, op->args[0], 0);
910 }
911 if (a_mask == 0) {
912 return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
913 }
914 return false;
915 }
916
917 /*
918 * Convert @op to NOT, if NOT is supported by the host.
919 * Return true f the conversion is successful, which will still
920 * indicate that the processing is complete.
921 */
922 static bool fold_not(OptContext *ctx, TCGOp *op);
923 static bool fold_to_not(OptContext *ctx, TCGOp *op, int idx)
924 {
925 TCGOpcode not_op;
926 bool have_not;
927
928 switch (ctx->type) {
929 case TCG_TYPE_I32:
930 not_op = INDEX_op_not_i32;
931 have_not = TCG_TARGET_HAS_not_i32;
932 break;
933 case TCG_TYPE_I64:
934 not_op = INDEX_op_not_i64;
935 have_not = TCG_TARGET_HAS_not_i64;
936 break;
937 case TCG_TYPE_V64:
938 case TCG_TYPE_V128:
939 case TCG_TYPE_V256:
940 not_op = INDEX_op_not_vec;
941 have_not = TCG_TARGET_HAS_not_vec;
942 break;
943 default:
944 g_assert_not_reached();
945 }
946 if (have_not) {
947 op->opc = not_op;
948 op->args[1] = op->args[idx];
949 return fold_not(ctx, op);
950 }
951 return false;
952 }
953
954 /* If the binary operation has first argument @i, fold to @i. */
955 static bool fold_ix_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
956 {
957 if (arg_is_const(op->args[1]) && arg_info(op->args[1])->val == i) {
958 return tcg_opt_gen_movi(ctx, op, op->args[0], i);
959 }
960 return false;
961 }
962
963 /* If the binary operation has first argument @i, fold to NOT. */
964 static bool fold_ix_to_not(OptContext *ctx, TCGOp *op, uint64_t i)
965 {
966 if (arg_is_const(op->args[1]) && arg_info(op->args[1])->val == i) {
967 return fold_to_not(ctx, op, 2);
968 }
969 return false;
970 }
971
972 /* If the binary operation has second argument @i, fold to @i. */
973 static bool fold_xi_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
974 {
975 if (arg_is_const(op->args[2]) && arg_info(op->args[2])->val == i) {
976 return tcg_opt_gen_movi(ctx, op, op->args[0], i);
977 }
978 return false;
979 }
980
981 /* If the binary operation has second argument @i, fold to identity. */
982 static bool fold_xi_to_x(OptContext *ctx, TCGOp *op, uint64_t i)
983 {
984 if (arg_is_const(op->args[2]) && arg_info(op->args[2])->val == i) {
985 return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
986 }
987 return false;
988 }
989
990 /* If the binary operation has second argument @i, fold to NOT. */
991 static bool fold_xi_to_not(OptContext *ctx, TCGOp *op, uint64_t i)
992 {
993 if (arg_is_const(op->args[2]) && arg_info(op->args[2])->val == i) {
994 return fold_to_not(ctx, op, 1);
995 }
996 return false;
997 }
998
999 /* If the binary operation has both arguments equal, fold to @i. */
1000 static bool fold_xx_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
1001 {
1002 if (args_are_copies(op->args[1], op->args[2])) {
1003 return tcg_opt_gen_movi(ctx, op, op->args[0], i);
1004 }
1005 return false;
1006 }
1007
1008 /* If the binary operation has both arguments equal, fold to identity. */
1009 static bool fold_xx_to_x(OptContext *ctx, TCGOp *op)
1010 {
1011 if (args_are_copies(op->args[1], op->args[2])) {
1012 return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
1013 }
1014 return false;
1015 }
1016
1017 /*
1018 * These outermost fold_<op> functions are sorted alphabetically.
1019 *
1020 * The ordering of the transformations should be:
1021 * 1) those that produce a constant
1022 * 2) those that produce a copy
1023 * 3) those that produce information about the result value.
1024 */
1025
1026 static bool fold_add(OptContext *ctx, TCGOp *op)
1027 {
1028 if (fold_const2_commutative(ctx, op) ||
1029 fold_xi_to_x(ctx, op, 0)) {
1030 return true;
1031 }
1032 return false;
1033 }
1034
1035 /* We cannot as yet do_constant_folding with vectors. */
1036 static bool fold_add_vec(OptContext *ctx, TCGOp *op)
1037 {
1038 if (fold_commutative(ctx, op) ||
1039 fold_xi_to_x(ctx, op, 0)) {
1040 return true;
1041 }
1042 return false;
1043 }
1044
1045 static bool fold_addsub2(OptContext *ctx, TCGOp *op, bool add)
1046 {
1047 bool a_const = arg_is_const(op->args[2]) && arg_is_const(op->args[3]);
1048 bool b_const = arg_is_const(op->args[4]) && arg_is_const(op->args[5]);
1049
1050 if (a_const && b_const) {
1051 uint64_t al = arg_info(op->args[2])->val;
1052 uint64_t ah = arg_info(op->args[3])->val;
1053 uint64_t bl = arg_info(op->args[4])->val;
1054 uint64_t bh = arg_info(op->args[5])->val;
1055 TCGArg rl, rh;
1056 TCGOp *op2;
1057
1058 if (ctx->type == TCG_TYPE_I32) {
1059 uint64_t a = deposit64(al, 32, 32, ah);
1060 uint64_t b = deposit64(bl, 32, 32, bh);
1061
1062 if (add) {
1063 a += b;
1064 } else {
1065 a -= b;
1066 }
1067
1068 al = sextract64(a, 0, 32);
1069 ah = sextract64(a, 32, 32);
1070 } else {
1071 Int128 a = int128_make128(al, ah);
1072 Int128 b = int128_make128(bl, bh);
1073
1074 if (add) {
1075 a = int128_add(a, b);
1076 } else {
1077 a = int128_sub(a, b);
1078 }
1079
1080 al = int128_getlo(a);
1081 ah = int128_gethi(a);
1082 }
1083
1084 rl = op->args[0];
1085 rh = op->args[1];
1086
1087 /* The proper opcode is supplied by tcg_opt_gen_mov. */
1088 op2 = tcg_op_insert_before(ctx->tcg, op, 0, 2);
1089
1090 tcg_opt_gen_movi(ctx, op, rl, al);
1091 tcg_opt_gen_movi(ctx, op2, rh, ah);
1092 return true;
1093 }
1094
1095 /* Fold sub2 r,x,i to add2 r,x,-i */
1096 if (!add && b_const) {
1097 uint64_t bl = arg_info(op->args[4])->val;
1098 uint64_t bh = arg_info(op->args[5])->val;
1099
1100 /* Negate the two parts without assembling and disassembling. */
1101 bl = -bl;
1102 bh = ~bh + !bl;
1103
1104 op->opc = (ctx->type == TCG_TYPE_I32
1105 ? INDEX_op_add2_i32 : INDEX_op_add2_i64);
1106 op->args[4] = arg_new_constant(ctx, bl);
1107 op->args[5] = arg_new_constant(ctx, bh);
1108 }
1109 return false;
1110 }
1111
1112 static bool fold_add2(OptContext *ctx, TCGOp *op)
1113 {
1114 /* Note that the high and low parts may be independently swapped. */
1115 swap_commutative(op->args[0], &op->args[2], &op->args[4]);
1116 swap_commutative(op->args[1], &op->args[3], &op->args[5]);
1117
1118 return fold_addsub2(ctx, op, true);
1119 }
1120
1121 static bool fold_and(OptContext *ctx, TCGOp *op)
1122 {
1123 uint64_t z1, z2;
1124
1125 if (fold_const2_commutative(ctx, op) ||
1126 fold_xi_to_i(ctx, op, 0) ||
1127 fold_xi_to_x(ctx, op, -1) ||
1128 fold_xx_to_x(ctx, op)) {
1129 return true;
1130 }
1131
1132 z1 = arg_info(op->args[1])->z_mask;
1133 z2 = arg_info(op->args[2])->z_mask;
1134 ctx->z_mask = z1 & z2;
1135
1136 /*
1137 * Sign repetitions are perforce all identical, whether they are 1 or 0.
1138 * Bitwise operations preserve the relative quantity of the repetitions.
1139 */
1140 ctx->s_mask = arg_info(op->args[1])->s_mask
1141 & arg_info(op->args[2])->s_mask;
1142
1143 /*
1144 * Known-zeros does not imply known-ones. Therefore unless
1145 * arg2 is constant, we can't infer affected bits from it.
1146 */
1147 if (arg_is_const(op->args[2])) {
1148 ctx->a_mask = z1 & ~z2;
1149 }
1150
1151 return fold_masks(ctx, op);
1152 }
1153
1154 static bool fold_andc(OptContext *ctx, TCGOp *op)
1155 {
1156 uint64_t z1;
1157
1158 if (fold_const2(ctx, op) ||
1159 fold_xx_to_i(ctx, op, 0) ||
1160 fold_xi_to_x(ctx, op, 0) ||
1161 fold_ix_to_not(ctx, op, -1)) {
1162 return true;
1163 }
1164
1165 z1 = arg_info(op->args[1])->z_mask;
1166
1167 /*
1168 * Known-zeros does not imply known-ones. Therefore unless
1169 * arg2 is constant, we can't infer anything from it.
1170 */
1171 if (arg_is_const(op->args[2])) {
1172 uint64_t z2 = ~arg_info(op->args[2])->z_mask;
1173 ctx->a_mask = z1 & ~z2;
1174 z1 &= z2;
1175 }
1176 ctx->z_mask = z1;
1177
1178 ctx->s_mask = arg_info(op->args[1])->s_mask
1179 & arg_info(op->args[2])->s_mask;
1180 return fold_masks(ctx, op);
1181 }
1182
1183 static bool fold_brcond(OptContext *ctx, TCGOp *op)
1184 {
1185 TCGCond cond = op->args[2];
1186 int i;
1187
1188 if (swap_commutative(NO_DEST, &op->args[0], &op->args[1])) {
1189 op->args[2] = cond = tcg_swap_cond(cond);
1190 }
1191
1192 i = do_constant_folding_cond(ctx->type, op->args[0], op->args[1], cond);
1193 if (i == 0) {
1194 tcg_op_remove(ctx->tcg, op);
1195 return true;
1196 }
1197 if (i > 0) {
1198 op->opc = INDEX_op_br;
1199 op->args[0] = op->args[3];
1200 }
1201 return false;
1202 }
1203
1204 static bool fold_brcond2(OptContext *ctx, TCGOp *op)
1205 {
1206 TCGCond cond = op->args[4];
1207 TCGArg label = op->args[5];
1208 int i, inv = 0;
1209
1210 if (swap_commutative2(&op->args[0], &op->args[2])) {
1211 op->args[4] = cond = tcg_swap_cond(cond);
1212 }
1213
1214 i = do_constant_folding_cond2(&op->args[0], &op->args[2], cond);
1215 if (i >= 0) {
1216 goto do_brcond_const;
1217 }
1218
1219 switch (cond) {
1220 case TCG_COND_LT:
1221 case TCG_COND_GE:
1222 /*
1223 * Simplify LT/GE comparisons vs zero to a single compare
1224 * vs the high word of the input.
1225 */
1226 if (arg_is_const(op->args[2]) && arg_info(op->args[2])->val == 0 &&
1227 arg_is_const(op->args[3]) && arg_info(op->args[3])->val == 0) {
1228 goto do_brcond_high;
1229 }
1230 break;
1231
1232 case TCG_COND_NE:
1233 inv = 1;
1234 QEMU_FALLTHROUGH;
1235 case TCG_COND_EQ:
1236 /*
1237 * Simplify EQ/NE comparisons where one of the pairs
1238 * can be simplified.
1239 */
1240 i = do_constant_folding_cond(TCG_TYPE_I32, op->args[0],
1241 op->args[2], cond);
1242 switch (i ^ inv) {
1243 case 0:
1244 goto do_brcond_const;
1245 case 1:
1246 goto do_brcond_high;
1247 }
1248
1249 i = do_constant_folding_cond(TCG_TYPE_I32, op->args[1],
1250 op->args[3], cond);
1251 switch (i ^ inv) {
1252 case 0:
1253 goto do_brcond_const;
1254 case 1:
1255 op->opc = INDEX_op_brcond_i32;
1256 op->args[1] = op->args[2];
1257 op->args[2] = cond;
1258 op->args[3] = label;
1259 break;
1260 }
1261 break;
1262
1263 default:
1264 break;
1265
1266 do_brcond_high:
1267 op->opc = INDEX_op_brcond_i32;
1268 op->args[0] = op->args[1];
1269 op->args[1] = op->args[3];
1270 op->args[2] = cond;
1271 op->args[3] = label;
1272 break;
1273
1274 do_brcond_const:
1275 if (i == 0) {
1276 tcg_op_remove(ctx->tcg, op);
1277 return true;
1278 }
1279 op->opc = INDEX_op_br;
1280 op->args[0] = label;
1281 break;
1282 }
1283 return false;
1284 }
1285
1286 static bool fold_bswap(OptContext *ctx, TCGOp *op)
1287 {
1288 uint64_t z_mask, s_mask, sign;
1289
1290 if (arg_is_const(op->args[1])) {
1291 uint64_t t = arg_info(op->args[1])->val;
1292
1293 t = do_constant_folding(op->opc, ctx->type, t, op->args[2]);
1294 return tcg_opt_gen_movi(ctx, op, op->args[0], t);
1295 }
1296
1297 z_mask = arg_info(op->args[1])->z_mask;
1298
1299 switch (op->opc) {
1300 case INDEX_op_bswap16_i32:
1301 case INDEX_op_bswap16_i64:
1302 z_mask = bswap16(z_mask);
1303 sign = INT16_MIN;
1304 break;
1305 case INDEX_op_bswap32_i32:
1306 case INDEX_op_bswap32_i64:
1307 z_mask = bswap32(z_mask);
1308 sign = INT32_MIN;
1309 break;
1310 case INDEX_op_bswap64_i64:
1311 z_mask = bswap64(z_mask);
1312 sign = INT64_MIN;
1313 break;
1314 default:
1315 g_assert_not_reached();
1316 }
1317 s_mask = smask_from_zmask(z_mask);
1318
1319 switch (op->args[2] & (TCG_BSWAP_OZ | TCG_BSWAP_OS)) {
1320 case TCG_BSWAP_OZ:
1321 break;
1322 case TCG_BSWAP_OS:
1323 /* If the sign bit may be 1, force all the bits above to 1. */
1324 if (z_mask & sign) {
1325 z_mask |= sign;
1326 s_mask = sign << 1;
1327 }
1328 break;
1329 default:
1330 /* The high bits are undefined: force all bits above the sign to 1. */
1331 z_mask |= sign << 1;
1332 s_mask = 0;
1333 break;
1334 }
1335 ctx->z_mask = z_mask;
1336 ctx->s_mask = s_mask;
1337
1338 return fold_masks(ctx, op);
1339 }
1340
1341 static bool fold_call(OptContext *ctx, TCGOp *op)
1342 {
1343 TCGContext *s = ctx->tcg;
1344 int nb_oargs = TCGOP_CALLO(op);
1345 int nb_iargs = TCGOP_CALLI(op);
1346 int flags, i;
1347
1348 init_arguments(ctx, op, nb_oargs + nb_iargs);
1349 copy_propagate(ctx, op, nb_oargs, nb_iargs);
1350
1351 /* If the function reads or writes globals, reset temp data. */
1352 flags = tcg_call_flags(op);
1353 if (!(flags & (TCG_CALL_NO_READ_GLOBALS | TCG_CALL_NO_WRITE_GLOBALS))) {
1354 int nb_globals = s->nb_globals;
1355
1356 for (i = 0; i < nb_globals; i++) {
1357 if (test_bit(i, ctx->temps_used.l)) {
1358 reset_ts(ctx, &ctx->tcg->temps[i]);
1359 }
1360 }
1361 }
1362
1363 /* If the function has side effects, reset mem data. */
1364 if (!(flags & TCG_CALL_NO_SIDE_EFFECTS)) {
1365 remove_mem_copy_all(ctx);
1366 }
1367
1368 /* Reset temp data for outputs. */
1369 for (i = 0; i < nb_oargs; i++) {
1370 reset_temp(ctx, op->args[i]);
1371 }
1372
1373 /* Stop optimizing MB across calls. */
1374 ctx->prev_mb = NULL;
1375 return true;
1376 }
1377
1378 static bool fold_count_zeros(OptContext *ctx, TCGOp *op)
1379 {
1380 uint64_t z_mask;
1381
1382 if (arg_is_const(op->args[1])) {
1383 uint64_t t = arg_info(op->args[1])->val;
1384
1385 if (t != 0) {
1386 t = do_constant_folding(op->opc, ctx->type, t, 0);
1387 return tcg_opt_gen_movi(ctx, op, op->args[0], t);
1388 }
1389 return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[2]);
1390 }
1391
1392 switch (ctx->type) {
1393 case TCG_TYPE_I32:
1394 z_mask = 31;
1395 break;
1396 case TCG_TYPE_I64:
1397 z_mask = 63;
1398 break;
1399 default:
1400 g_assert_not_reached();
1401 }
1402 ctx->z_mask = arg_info(op->args[2])->z_mask | z_mask;
1403 ctx->s_mask = smask_from_zmask(ctx->z_mask);
1404 return false;
1405 }
1406
1407 static bool fold_ctpop(OptContext *ctx, TCGOp *op)
1408 {
1409 if (fold_const1(ctx, op)) {
1410 return true;
1411 }
1412
1413 switch (ctx->type) {
1414 case TCG_TYPE_I32:
1415 ctx->z_mask = 32 | 31;
1416 break;
1417 case TCG_TYPE_I64:
1418 ctx->z_mask = 64 | 63;
1419 break;
1420 default:
1421 g_assert_not_reached();
1422 }
1423 ctx->s_mask = smask_from_zmask(ctx->z_mask);
1424 return false;
1425 }
1426
1427 static bool fold_deposit(OptContext *ctx, TCGOp *op)
1428 {
1429 TCGOpcode and_opc;
1430
1431 if (arg_is_const(op->args[1]) && arg_is_const(op->args[2])) {
1432 uint64_t t1 = arg_info(op->args[1])->val;
1433 uint64_t t2 = arg_info(op->args[2])->val;
1434
1435 t1 = deposit64(t1, op->args[3], op->args[4], t2);
1436 return tcg_opt_gen_movi(ctx, op, op->args[0], t1);
1437 }
1438
1439 switch (ctx->type) {
1440 case TCG_TYPE_I32:
1441 and_opc = INDEX_op_and_i32;
1442 break;
1443 case TCG_TYPE_I64:
1444 and_opc = INDEX_op_and_i64;
1445 break;
1446 default:
1447 g_assert_not_reached();
1448 }
1449
1450 /* Inserting a value into zero at offset 0. */
1451 if (arg_is_const(op->args[1])
1452 && arg_info(op->args[1])->val == 0
1453 && op->args[3] == 0) {
1454 uint64_t mask = MAKE_64BIT_MASK(0, op->args[4]);
1455
1456 op->opc = and_opc;
1457 op->args[1] = op->args[2];
1458 op->args[2] = arg_new_constant(ctx, mask);
1459 ctx->z_mask = mask & arg_info(op->args[1])->z_mask;
1460 return false;
1461 }
1462
1463 /* Inserting zero into a value. */
1464 if (arg_is_const(op->args[2])
1465 && arg_info(op->args[2])->val == 0) {
1466 uint64_t mask = deposit64(-1, op->args[3], op->args[4], 0);
1467
1468 op->opc = and_opc;
1469 op->args[2] = arg_new_constant(ctx, mask);
1470 ctx->z_mask = mask & arg_info(op->args[1])->z_mask;
1471 return false;
1472 }
1473
1474 ctx->z_mask = deposit64(arg_info(op->args[1])->z_mask,
1475 op->args[3], op->args[4],
1476 arg_info(op->args[2])->z_mask);
1477 return false;
1478 }
1479
1480 static bool fold_divide(OptContext *ctx, TCGOp *op)
1481 {
1482 if (fold_const2(ctx, op) ||
1483 fold_xi_to_x(ctx, op, 1)) {
1484 return true;
1485 }
1486 return false;
1487 }
1488
1489 static bool fold_dup(OptContext *ctx, TCGOp *op)
1490 {
1491 if (arg_is_const(op->args[1])) {
1492 uint64_t t = arg_info(op->args[1])->val;
1493 t = dup_const(TCGOP_VECE(op), t);
1494 return tcg_opt_gen_movi(ctx, op, op->args[0], t);
1495 }
1496 return false;
1497 }
1498
1499 static bool fold_dup2(OptContext *ctx, TCGOp *op)
1500 {
1501 if (arg_is_const(op->args[1]) && arg_is_const(op->args[2])) {
1502 uint64_t t = deposit64(arg_info(op->args[1])->val, 32, 32,
1503 arg_info(op->args[2])->val);
1504 return tcg_opt_gen_movi(ctx, op, op->args[0], t);
1505 }
1506
1507 if (args_are_copies(op->args[1], op->args[2])) {
1508 op->opc = INDEX_op_dup_vec;
1509 TCGOP_VECE(op) = MO_32;
1510 }
1511 return false;
1512 }
1513
1514 static bool fold_eqv(OptContext *ctx, TCGOp *op)
1515 {
1516 if (fold_const2_commutative(ctx, op) ||
1517 fold_xi_to_x(ctx, op, -1) ||
1518 fold_xi_to_not(ctx, op, 0)) {
1519 return true;
1520 }
1521
1522 ctx->s_mask = arg_info(op->args[1])->s_mask
1523 & arg_info(op->args[2])->s_mask;
1524 return false;
1525 }
1526
1527 static bool fold_extract(OptContext *ctx, TCGOp *op)
1528 {
1529 uint64_t z_mask_old, z_mask;
1530 int pos = op->args[2];
1531 int len = op->args[3];
1532
1533 if (arg_is_const(op->args[1])) {
1534 uint64_t t;
1535
1536 t = arg_info(op->args[1])->val;
1537 t = extract64(t, pos, len);
1538 return tcg_opt_gen_movi(ctx, op, op->args[0], t);
1539 }
1540
1541 z_mask_old = arg_info(op->args[1])->z_mask;
1542 z_mask = extract64(z_mask_old, pos, len);
1543 if (pos == 0) {
1544 ctx->a_mask = z_mask_old ^ z_mask;
1545 }
1546 ctx->z_mask = z_mask;
1547 ctx->s_mask = smask_from_zmask(z_mask);
1548
1549 return fold_masks(ctx, op);
1550 }
1551
1552 static bool fold_extract2(OptContext *ctx, TCGOp *op)
1553 {
1554 if (arg_is_const(op->args[1]) && arg_is_const(op->args[2])) {
1555 uint64_t v1 = arg_info(op->args[1])->val;
1556 uint64_t v2 = arg_info(op->args[2])->val;
1557 int shr = op->args[3];
1558
1559 if (op->opc == INDEX_op_extract2_i64) {
1560 v1 >>= shr;
1561 v2 <<= 64 - shr;
1562 } else {
1563 v1 = (uint32_t)v1 >> shr;
1564 v2 = (uint64_t)((int32_t)v2 << (32 - shr));
1565 }
1566 return tcg_opt_gen_movi(ctx, op, op->args[0], v1 | v2);
1567 }
1568 return false;
1569 }
1570
1571 static bool fold_exts(OptContext *ctx, TCGOp *op)
1572 {
1573 uint64_t s_mask_old, s_mask, z_mask, sign;
1574 bool type_change = false;
1575
1576 if (fold_const1(ctx, op)) {
1577 return true;
1578 }
1579
1580 z_mask = arg_info(op->args[1])->z_mask;
1581 s_mask = arg_info(op->args[1])->s_mask;
1582 s_mask_old = s_mask;
1583
1584 switch (op->opc) {
1585 CASE_OP_32_64(ext8s):
1586 sign = INT8_MIN;
1587 z_mask = (uint8_t)z_mask;
1588 break;
1589 CASE_OP_32_64(ext16s):
1590 sign = INT16_MIN;
1591 z_mask = (uint16_t)z_mask;
1592 break;
1593 case INDEX_op_ext_i32_i64:
1594 type_change = true;
1595 QEMU_FALLTHROUGH;
1596 case INDEX_op_ext32s_i64:
1597 sign = INT32_MIN;
1598 z_mask = (uint32_t)z_mask;
1599 break;
1600 default:
1601 g_assert_not_reached();
1602 }
1603
1604 if (z_mask & sign) {
1605 z_mask |= sign;
1606 }
1607 s_mask |= sign << 1;
1608
1609 ctx->z_mask = z_mask;
1610 ctx->s_mask = s_mask;
1611 if (!type_change) {
1612 ctx->a_mask = s_mask & ~s_mask_old;
1613 }
1614
1615 return fold_masks(ctx, op);
1616 }
1617
1618 static bool fold_extu(OptContext *ctx, TCGOp *op)
1619 {
1620 uint64_t z_mask_old, z_mask;
1621 bool type_change = false;
1622
1623 if (fold_const1(ctx, op)) {
1624 return true;
1625 }
1626
1627 z_mask_old = z_mask = arg_info(op->args[1])->z_mask;
1628
1629 switch (op->opc) {
1630 CASE_OP_32_64(ext8u):
1631 z_mask = (uint8_t)z_mask;
1632 break;
1633 CASE_OP_32_64(ext16u):
1634 z_mask = (uint16_t)z_mask;
1635 break;
1636 case INDEX_op_extrl_i64_i32:
1637 case INDEX_op_extu_i32_i64:
1638 type_change = true;
1639 QEMU_FALLTHROUGH;
1640 case INDEX_op_ext32u_i64:
1641 z_mask = (uint32_t)z_mask;
1642 break;
1643 case INDEX_op_extrh_i64_i32:
1644 type_change = true;
1645 z_mask >>= 32;
1646 break;
1647 default:
1648 g_assert_not_reached();
1649 }
1650
1651 ctx->z_mask = z_mask;
1652 ctx->s_mask = smask_from_zmask(z_mask);
1653 if (!type_change) {
1654 ctx->a_mask = z_mask_old ^ z_mask;
1655 }
1656 return fold_masks(ctx, op);
1657 }
1658
1659 static bool fold_mb(OptContext *ctx, TCGOp *op)
1660 {
1661 /* Eliminate duplicate and redundant fence instructions. */
1662 if (ctx->prev_mb) {
1663 /*
1664 * Merge two barriers of the same type into one,
1665 * or a weaker barrier into a stronger one,
1666 * or two weaker barriers into a stronger one.
1667 * mb X; mb Y => mb X|Y
1668 * mb; strl => mb; st
1669 * ldaq; mb => ld; mb
1670 * ldaq; strl => ld; mb; st
1671 * Other combinations are also merged into a strong
1672 * barrier. This is stricter than specified but for
1673 * the purposes of TCG is better than not optimizing.
1674 */
1675 ctx->prev_mb->args[0] |= op->args[0];
1676 tcg_op_remove(ctx->tcg, op);
1677 } else {
1678 ctx->prev_mb = op;
1679 }
1680 return true;
1681 }
1682
1683 static bool fold_mov(OptContext *ctx, TCGOp *op)
1684 {
1685 return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
1686 }
1687
1688 static bool fold_movcond(OptContext *ctx, TCGOp *op)
1689 {
1690 TCGCond cond = op->args[5];
1691 int i;
1692
1693 if (swap_commutative(NO_DEST, &op->args[1], &op->args[2])) {
1694 op->args[5] = cond = tcg_swap_cond(cond);
1695 }
1696 /*
1697 * Canonicalize the "false" input reg to match the destination reg so
1698 * that the tcg backend can implement a "move if true" operation.
1699 */
1700 if (swap_commutative(op->args[0], &op->args[4], &op->args[3])) {
1701 op->args[5] = cond = tcg_invert_cond(cond);
1702 }
1703
1704 i = do_constant_folding_cond(ctx->type, op->args[1], op->args[2], cond);
1705 if (i >= 0) {
1706 return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[4 - i]);
1707 }
1708
1709 ctx->z_mask = arg_info(op->args[3])->z_mask
1710 | arg_info(op->args[4])->z_mask;
1711 ctx->s_mask = arg_info(op->args[3])->s_mask
1712 & arg_info(op->args[4])->s_mask;
1713
1714 if (arg_is_const(op->args[3]) && arg_is_const(op->args[4])) {
1715 uint64_t tv = arg_info(op->args[3])->val;
1716 uint64_t fv = arg_info(op->args[4])->val;
1717 TCGOpcode opc, negopc = 0;
1718
1719 switch (ctx->type) {
1720 case TCG_TYPE_I32:
1721 opc = INDEX_op_setcond_i32;
1722 if (TCG_TARGET_HAS_negsetcond_i32) {
1723 negopc = INDEX_op_negsetcond_i32;
1724 }
1725 tv = (int32_t)tv;
1726 fv = (int32_t)fv;
1727 break;
1728 case TCG_TYPE_I64:
1729 opc = INDEX_op_setcond_i64;
1730 if (TCG_TARGET_HAS_negsetcond_i64) {
1731 negopc = INDEX_op_negsetcond_i64;
1732 }
1733 break;
1734 default:
1735 g_assert_not_reached();
1736 }
1737
1738 if (tv == 1 && fv == 0) {
1739 op->opc = opc;
1740 op->args[3] = cond;
1741 } else if (fv == 1 && tv == 0) {
1742 op->opc = opc;
1743 op->args[3] = tcg_invert_cond(cond);
1744 } else if (negopc) {
1745 if (tv == -1 && fv == 0) {
1746 op->opc = negopc;
1747 op->args[3] = cond;
1748 } else if (fv == -1 && tv == 0) {
1749 op->opc = negopc;
1750 op->args[3] = tcg_invert_cond(cond);
1751 }
1752 }
1753 }
1754 return false;
1755 }
1756
1757 static bool fold_mul(OptContext *ctx, TCGOp *op)
1758 {
1759 if (fold_const2(ctx, op) ||
1760 fold_xi_to_i(ctx, op, 0) ||
1761 fold_xi_to_x(ctx, op, 1)) {
1762 return true;
1763 }
1764 return false;
1765 }
1766
1767 static bool fold_mul_highpart(OptContext *ctx, TCGOp *op)
1768 {
1769 if (fold_const2_commutative(ctx, op) ||
1770 fold_xi_to_i(ctx, op, 0)) {
1771 return true;
1772 }
1773 return false;
1774 }
1775
1776 static bool fold_multiply2(OptContext *ctx, TCGOp *op)
1777 {
1778 swap_commutative(op->args[0], &op->args[2], &op->args[3]);
1779
1780 if (arg_is_const(op->args[2]) && arg_is_const(op->args[3])) {
1781 uint64_t a = arg_info(op->args[2])->val;
1782 uint64_t b = arg_info(op->args[3])->val;
1783 uint64_t h, l;
1784 TCGArg rl, rh;
1785 TCGOp *op2;
1786
1787 switch (op->opc) {
1788 case INDEX_op_mulu2_i32:
1789 l = (uint64_t)(uint32_t)a * (uint32_t)b;
1790 h = (int32_t)(l >> 32);
1791 l = (int32_t)l;
1792 break;
1793 case INDEX_op_muls2_i32:
1794 l = (int64_t)(int32_t)a * (int32_t)b;
1795 h = l >> 32;
1796 l = (int32_t)l;
1797 break;
1798 case INDEX_op_mulu2_i64:
1799 mulu64(&l, &h, a, b);
1800 break;
1801 case INDEX_op_muls2_i64:
1802 muls64(&l, &h, a, b);
1803 break;
1804 default:
1805 g_assert_not_reached();
1806 }
1807
1808 rl = op->args[0];
1809 rh = op->args[1];
1810
1811 /* The proper opcode is supplied by tcg_opt_gen_mov. */
1812 op2 = tcg_op_insert_before(ctx->tcg, op, 0, 2);
1813
1814 tcg_opt_gen_movi(ctx, op, rl, l);
1815 tcg_opt_gen_movi(ctx, op2, rh, h);
1816 return true;
1817 }
1818 return false;
1819 }
1820
1821 static bool fold_nand(OptContext *ctx, TCGOp *op)
1822 {
1823 if (fold_const2_commutative(ctx, op) ||
1824 fold_xi_to_not(ctx, op, -1)) {
1825 return true;
1826 }
1827
1828 ctx->s_mask = arg_info(op->args[1])->s_mask
1829 & arg_info(op->args[2])->s_mask;
1830 return false;
1831 }
1832
1833 static bool fold_neg(OptContext *ctx, TCGOp *op)
1834 {
1835 uint64_t z_mask;
1836
1837 if (fold_const1(ctx, op)) {
1838 return true;
1839 }
1840
1841 /* Set to 1 all bits to the left of the rightmost. */
1842 z_mask = arg_info(op->args[1])->z_mask;
1843 ctx->z_mask = -(z_mask & -z_mask);
1844
1845 /*
1846 * Because of fold_sub_to_neg, we want to always return true,
1847 * via finish_folding.
1848 */
1849 finish_folding(ctx, op);
1850 return true;
1851 }
1852
1853 static bool fold_nor(OptContext *ctx, TCGOp *op)
1854 {
1855 if (fold_const2_commutative(ctx, op) ||
1856 fold_xi_to_not(ctx, op, 0)) {
1857 return true;
1858 }
1859
1860 ctx->s_mask = arg_info(op->args[1])->s_mask
1861 & arg_info(op->args[2])->s_mask;
1862 return false;
1863 }
1864
1865 static bool fold_not(OptContext *ctx, TCGOp *op)
1866 {
1867 if (fold_const1(ctx, op)) {
1868 return true;
1869 }
1870
1871 ctx->s_mask = arg_info(op->args[1])->s_mask;
1872
1873 /* Because of fold_to_not, we want to always return true, via finish. */
1874 finish_folding(ctx, op);
1875 return true;
1876 }
1877
1878 static bool fold_or(OptContext *ctx, TCGOp *op)
1879 {
1880 if (fold_const2_commutative(ctx, op) ||
1881 fold_xi_to_x(ctx, op, 0) ||
1882 fold_xx_to_x(ctx, op)) {
1883 return true;
1884 }
1885
1886 ctx->z_mask = arg_info(op->args[1])->z_mask
1887 | arg_info(op->args[2])->z_mask;
1888 ctx->s_mask = arg_info(op->args[1])->s_mask
1889 & arg_info(op->args[2])->s_mask;
1890 return fold_masks(ctx, op);
1891 }
1892
1893 static bool fold_orc(OptContext *ctx, TCGOp *op)
1894 {
1895 if (fold_const2(ctx, op) ||
1896 fold_xx_to_i(ctx, op, -1) ||
1897 fold_xi_to_x(ctx, op, -1) ||
1898 fold_ix_to_not(ctx, op, 0)) {
1899 return true;
1900 }
1901
1902 ctx->s_mask = arg_info(op->args[1])->s_mask
1903 & arg_info(op->args[2])->s_mask;
1904 return false;
1905 }
1906
1907 static bool fold_qemu_ld(OptContext *ctx, TCGOp *op)
1908 {
1909 const TCGOpDef *def = &tcg_op_defs[op->opc];
1910 MemOpIdx oi = op->args[def->nb_oargs + def->nb_iargs];
1911 MemOp mop = get_memop(oi);
1912 int width = 8 * memop_size(mop);
1913
1914 if (width < 64) {
1915 ctx->s_mask = MAKE_64BIT_MASK(width, 64 - width);
1916 if (!(mop & MO_SIGN)) {
1917 ctx->z_mask = MAKE_64BIT_MASK(0, width);
1918 ctx->s_mask <<= 1;
1919 }
1920 }
1921
1922 /* Opcodes that touch guest memory stop the mb optimization. */
1923 ctx->prev_mb = NULL;
1924 return false;
1925 }
1926
1927 static bool fold_qemu_st(OptContext *ctx, TCGOp *op)
1928 {
1929 /* Opcodes that touch guest memory stop the mb optimization. */
1930 ctx->prev_mb = NULL;
1931 return false;
1932 }
1933
1934 static bool fold_remainder(OptContext *ctx, TCGOp *op)
1935 {
1936 if (fold_const2(ctx, op) ||
1937 fold_xx_to_i(ctx, op, 0)) {
1938 return true;
1939 }
1940 return false;
1941 }
1942
1943 static bool fold_setcond(OptContext *ctx, TCGOp *op)
1944 {
1945 TCGCond cond = op->args[3];
1946 int i;
1947
1948 if (swap_commutative(op->args[0], &op->args[1], &op->args[2])) {
1949 op->args[3] = cond = tcg_swap_cond(cond);
1950 }
1951
1952 i = do_constant_folding_cond(ctx->type, op->args[1], op->args[2], cond);
1953 if (i >= 0) {
1954 return tcg_opt_gen_movi(ctx, op, op->args[0], i);
1955 }
1956
1957 ctx->z_mask = 1;
1958 ctx->s_mask = smask_from_zmask(1);
1959 return false;
1960 }
1961
1962 static bool fold_negsetcond(OptContext *ctx, TCGOp *op)
1963 {
1964 TCGCond cond = op->args[3];
1965 int i;
1966
1967 if (swap_commutative(op->args[0], &op->args[1], &op->args[2])) {
1968 op->args[3] = cond = tcg_swap_cond(cond);
1969 }
1970
1971 i = do_constant_folding_cond(ctx->type, op->args[1], op->args[2], cond);
1972 if (i >= 0) {
1973 return tcg_opt_gen_movi(ctx, op, op->args[0], -i);
1974 }
1975
1976 /* Value is {0,-1} so all bits are repetitions of the sign. */
1977 ctx->s_mask = -1;
1978 return false;
1979 }
1980
1981
1982 static bool fold_setcond2(OptContext *ctx, TCGOp *op)
1983 {
1984 TCGCond cond = op->args[5];
1985 int i, inv = 0;
1986
1987 if (swap_commutative2(&op->args[1], &op->args[3])) {
1988 op->args[5] = cond = tcg_swap_cond(cond);
1989 }
1990
1991 i = do_constant_folding_cond2(&op->args[1], &op->args[3], cond);
1992 if (i >= 0) {
1993 goto do_setcond_const;
1994 }
1995
1996 switch (cond) {
1997 case TCG_COND_LT:
1998 case TCG_COND_GE:
1999 /*
2000 * Simplify LT/GE comparisons vs zero to a single compare
2001 * vs the high word of the input.
2002 */
2003 if (arg_is_const(op->args[3]) && arg_info(op->args[3])->val == 0 &&
2004 arg_is_const(op->args[4]) && arg_info(op->args[4])->val == 0) {
2005 goto do_setcond_high;
2006 }
2007 break;
2008
2009 case TCG_COND_NE:
2010 inv = 1;
2011 QEMU_FALLTHROUGH;
2012 case TCG_COND_EQ:
2013 /*
2014 * Simplify EQ/NE comparisons where one of the pairs
2015 * can be simplified.
2016 */
2017 i = do_constant_folding_cond(TCG_TYPE_I32, op->args[1],
2018 op->args[3], cond);
2019 switch (i ^ inv) {
2020 case 0:
2021 goto do_setcond_const;
2022 case 1:
2023 goto do_setcond_high;
2024 }
2025
2026 i = do_constant_folding_cond(TCG_TYPE_I32, op->args[2],
2027 op->args[4], cond);
2028 switch (i ^ inv) {
2029 case 0:
2030 goto do_setcond_const;
2031 case 1:
2032 op->args[2] = op->args[3];
2033 op->args[3] = cond;
2034 op->opc = INDEX_op_setcond_i32;
2035 break;
2036 }
2037 break;
2038
2039 default:
2040 break;
2041
2042 do_setcond_high:
2043 op->args[1] = op->args[2];
2044 op->args[2] = op->args[4];
2045 op->args[3] = cond;
2046 op->opc = INDEX_op_setcond_i32;
2047 break;
2048 }
2049
2050 ctx->z_mask = 1;
2051 ctx->s_mask = smask_from_zmask(1);
2052 return false;
2053
2054 do_setcond_const:
2055 return tcg_opt_gen_movi(ctx, op, op->args[0], i);
2056 }
2057
2058 static bool fold_sextract(OptContext *ctx, TCGOp *op)
2059 {
2060 uint64_t z_mask, s_mask, s_mask_old;
2061 int pos = op->args[2];
2062 int len = op->args[3];
2063
2064 if (arg_is_const(op->args[1])) {
2065 uint64_t t;
2066
2067 t = arg_info(op->args[1])->val;
2068 t = sextract64(t, pos, len);
2069 return tcg_opt_gen_movi(ctx, op, op->args[0], t);
2070 }
2071
2072 z_mask = arg_info(op->args[1])->z_mask;
2073 z_mask = sextract64(z_mask, pos, len);
2074 ctx->z_mask = z_mask;
2075
2076 s_mask_old = arg_info(op->args[1])->s_mask;
2077 s_mask = sextract64(s_mask_old, pos, len);
2078 s_mask |= MAKE_64BIT_MASK(len, 64 - len);
2079 ctx->s_mask = s_mask;
2080
2081 if (pos == 0) {
2082 ctx->a_mask = s_mask & ~s_mask_old;
2083 }
2084
2085 return fold_masks(ctx, op);
2086 }
2087
2088 static bool fold_shift(OptContext *ctx, TCGOp *op)
2089 {
2090 uint64_t s_mask, z_mask, sign;
2091
2092 if (fold_const2(ctx, op) ||
2093 fold_ix_to_i(ctx, op, 0) ||
2094 fold_xi_to_x(ctx, op, 0)) {
2095 return true;
2096 }
2097
2098 s_mask = arg_info(op->args[1])->s_mask;
2099 z_mask = arg_info(op->args[1])->z_mask;
2100
2101 if (arg_is_const(op->args[2])) {
2102 int sh = arg_info(op->args[2])->val;
2103
2104 ctx->z_mask = do_constant_folding(op->opc, ctx->type, z_mask, sh);
2105
2106 s_mask = do_constant_folding(op->opc, ctx->type, s_mask, sh);
2107 ctx->s_mask = smask_from_smask(s_mask);
2108
2109 return fold_masks(ctx, op);
2110 }
2111
2112 switch (op->opc) {
2113 CASE_OP_32_64(sar):
2114 /*
2115 * Arithmetic right shift will not reduce the number of
2116 * input sign repetitions.
2117 */
2118 ctx->s_mask = s_mask;
2119 break;
2120 CASE_OP_32_64(shr):
2121 /*
2122 * If the sign bit is known zero, then logical right shift
2123 * will not reduced the number of input sign repetitions.
2124 */
2125 sign = (s_mask & -s_mask) >> 1;
2126 if (!(z_mask & sign)) {
2127 ctx->s_mask = s_mask;
2128 }
2129 break;
2130 default:
2131 break;
2132 }
2133
2134 return false;
2135 }
2136
2137 static bool fold_sub_to_neg(OptContext *ctx, TCGOp *op)
2138 {
2139 TCGOpcode neg_op;
2140 bool have_neg;
2141
2142 if (!arg_is_const(op->args[1]) || arg_info(op->args[1])->val != 0) {
2143 return false;
2144 }
2145
2146 switch (ctx->type) {
2147 case TCG_TYPE_I32:
2148 neg_op = INDEX_op_neg_i32;
2149 have_neg = true;
2150 break;
2151 case TCG_TYPE_I64:
2152 neg_op = INDEX_op_neg_i64;
2153 have_neg = true;
2154 break;
2155 case TCG_TYPE_V64:
2156 case TCG_TYPE_V128:
2157 case TCG_TYPE_V256:
2158 neg_op = INDEX_op_neg_vec;
2159 have_neg = (TCG_TARGET_HAS_neg_vec &&
2160 tcg_can_emit_vec_op(neg_op, ctx->type, TCGOP_VECE(op)) > 0);
2161 break;
2162 default:
2163 g_assert_not_reached();
2164 }
2165 if (have_neg) {
2166 op->opc = neg_op;
2167 op->args[1] = op->args[2];
2168 return fold_neg(ctx, op);
2169 }
2170 return false;
2171 }
2172
2173 /* We cannot as yet do_constant_folding with vectors. */
2174 static bool fold_sub_vec(OptContext *ctx, TCGOp *op)
2175 {
2176 if (fold_xx_to_i(ctx, op, 0) ||
2177 fold_xi_to_x(ctx, op, 0) ||
2178 fold_sub_to_neg(ctx, op)) {
2179 return true;
2180 }
2181 return false;
2182 }
2183
2184 static bool fold_sub(OptContext *ctx, TCGOp *op)
2185 {
2186 if (fold_const2(ctx, op) || fold_sub_vec(ctx, op)) {
2187 return true;
2188 }
2189
2190 /* Fold sub r,x,i to add r,x,-i */
2191 if (arg_is_const(op->args[2])) {
2192 uint64_t val = arg_info(op->args[2])->val;
2193
2194 op->opc = (ctx->type == TCG_TYPE_I32
2195 ? INDEX_op_add_i32 : INDEX_op_add_i64);
2196 op->args[2] = arg_new_constant(ctx, -val);
2197 }
2198 return false;
2199 }
2200
2201 static bool fold_sub2(OptContext *ctx, TCGOp *op)
2202 {
2203 return fold_addsub2(ctx, op, false);
2204 }
2205
2206 static bool fold_tcg_ld(OptContext *ctx, TCGOp *op)
2207 {
2208 /* We can't do any folding with a load, but we can record bits. */
2209 switch (op->opc) {
2210 CASE_OP_32_64(ld8s):
2211 ctx->s_mask = MAKE_64BIT_MASK(8, 56);
2212 break;
2213 CASE_OP_32_64(ld8u):
2214 ctx->z_mask = MAKE_64BIT_MASK(0, 8);
2215 ctx->s_mask = MAKE_64BIT_MASK(9, 55);
2216 break;
2217 CASE_OP_32_64(ld16s):
2218 ctx->s_mask = MAKE_64BIT_MASK(16, 48);
2219 break;
2220 CASE_OP_32_64(ld16u):
2221 ctx->z_mask = MAKE_64BIT_MASK(0, 16);
2222 ctx->s_mask = MAKE_64BIT_MASK(17, 47);
2223 break;
2224 case INDEX_op_ld32s_i64:
2225 ctx->s_mask = MAKE_64BIT_MASK(32, 32);
2226 break;
2227 case INDEX_op_ld32u_i64:
2228 ctx->z_mask = MAKE_64BIT_MASK(0, 32);
2229 ctx->s_mask = MAKE_64BIT_MASK(33, 31);
2230 break;
2231 default:
2232 g_assert_not_reached();
2233 }
2234 return false;
2235 }
2236
2237 static bool fold_tcg_ld_memcopy(OptContext *ctx, TCGOp *op)
2238 {
2239 TCGTemp *dst, *src;
2240 intptr_t ofs;
2241 TCGType type;
2242
2243 if (op->args[1] != tcgv_ptr_arg(tcg_env)) {
2244 return false;
2245 }
2246
2247 type = ctx->type;
2248 ofs = op->args[2];
2249 dst = arg_temp(op->args[0]);
2250 src = find_mem_copy_for(ctx, type, ofs);
2251 if (src && src->base_type == type) {
2252 return tcg_opt_gen_mov(ctx, op, temp_arg(dst), temp_arg(src));
2253 }
2254
2255 reset_ts(ctx, dst);
2256 record_mem_copy(ctx, type, dst, ofs, ofs + tcg_type_size(type) - 1);
2257 return true;
2258 }
2259
2260 static bool fold_tcg_st(OptContext *ctx, TCGOp *op)
2261 {
2262 intptr_t ofs = op->args[2];
2263 intptr_t lm1;
2264
2265 if (op->args[1] != tcgv_ptr_arg(tcg_env)) {
2266 remove_mem_copy_all(ctx);
2267 return false;
2268 }
2269
2270 switch (op->opc) {
2271 CASE_OP_32_64(st8):
2272 lm1 = 0;
2273 break;
2274 CASE_OP_32_64(st16):
2275 lm1 = 1;
2276 break;
2277 case INDEX_op_st32_i64:
2278 case INDEX_op_st_i32:
2279 lm1 = 3;
2280 break;
2281 case INDEX_op_st_i64:
2282 lm1 = 7;
2283 break;
2284 case INDEX_op_st_vec:
2285 lm1 = tcg_type_size(ctx->type) - 1;
2286 break;
2287 default:
2288 g_assert_not_reached();
2289 }
2290 remove_mem_copy_in(ctx, ofs, ofs + lm1);
2291 return false;
2292 }
2293
2294 static bool fold_tcg_st_memcopy(OptContext *ctx, TCGOp *op)
2295 {
2296 TCGTemp *src;
2297 intptr_t ofs, last;
2298 TCGType type;
2299
2300 if (op->args[1] != tcgv_ptr_arg(tcg_env)) {
2301 fold_tcg_st(ctx, op);
2302 return false;
2303 }
2304
2305 src = arg_temp(op->args[0]);
2306 ofs = op->args[2];
2307 type = ctx->type;
2308
2309 /*
2310 * Eliminate duplicate stores of a constant.
2311 * This happens frequently when the target ISA zero-extends.
2312 */
2313 if (ts_is_const(src)) {
2314 TCGTemp *prev = find_mem_copy_for(ctx, type, ofs);
2315 if (src == prev) {
2316 tcg_op_remove(ctx->tcg, op);
2317 return true;
2318 }
2319 }
2320
2321 last = ofs + tcg_type_size(type) - 1;
2322 remove_mem_copy_in(ctx, ofs, last);
2323 record_mem_copy(ctx, type, src, ofs, last);
2324 return false;
2325 }
2326
2327 static bool fold_xor(OptContext *ctx, TCGOp *op)
2328 {
2329 if (fold_const2_commutative(ctx, op) ||
2330 fold_xx_to_i(ctx, op, 0) ||
2331 fold_xi_to_x(ctx, op, 0) ||
2332 fold_xi_to_not(ctx, op, -1)) {
2333 return true;
2334 }
2335
2336 ctx->z_mask = arg_info(op->args[1])->z_mask
2337 | arg_info(op->args[2])->z_mask;
2338 ctx->s_mask = arg_info(op->args[1])->s_mask
2339 & arg_info(op->args[2])->s_mask;
2340 return fold_masks(ctx, op);
2341 }
2342
2343 /* Propagate constants and copies, fold constant expressions. */
2344 void tcg_optimize(TCGContext *s)
2345 {
2346 int nb_temps, i;
2347 TCGOp *op, *op_next;
2348 OptContext ctx = { .tcg = s };
2349
2350 QSIMPLEQ_INIT(&ctx.mem_free);
2351
2352 /* Array VALS has an element for each temp.
2353 If this temp holds a constant then its value is kept in VALS' element.
2354 If this temp is a copy of other ones then the other copies are
2355 available through the doubly linked circular list. */
2356
2357 nb_temps = s->nb_temps;
2358 for (i = 0; i < nb_temps; ++i) {
2359 s->temps[i].state_ptr = NULL;
2360 }
2361
2362 QTAILQ_FOREACH_SAFE(op, &s->ops, link, op_next) {
2363 TCGOpcode opc = op->opc;
2364 const TCGOpDef *def;
2365 bool done = false;
2366
2367 /* Calls are special. */
2368 if (opc == INDEX_op_call) {
2369 fold_call(&ctx, op);
2370 continue;
2371 }
2372
2373 def = &tcg_op_defs[opc];
2374 init_arguments(&ctx, op, def->nb_oargs + def->nb_iargs);
2375 copy_propagate(&ctx, op, def->nb_oargs, def->nb_iargs);
2376
2377 /* Pre-compute the type of the operation. */
2378 if (def->flags & TCG_OPF_VECTOR) {
2379 ctx.type = TCG_TYPE_V64 + TCGOP_VECL(op);
2380 } else if (def->flags & TCG_OPF_64BIT) {
2381 ctx.type = TCG_TYPE_I64;
2382 } else {
2383 ctx.type = TCG_TYPE_I32;
2384 }
2385
2386 /* Assume all bits affected, no bits known zero, no sign reps. */
2387 ctx.a_mask = -1;
2388 ctx.z_mask = -1;
2389 ctx.s_mask = 0;
2390
2391 /*
2392 * Process each opcode.
2393 * Sorted alphabetically by opcode as much as possible.
2394 */
2395 switch (opc) {
2396 CASE_OP_32_64(add):
2397 done = fold_add(&ctx, op);
2398 break;
2399 case INDEX_op_add_vec:
2400 done = fold_add_vec(&ctx, op);
2401 break;
2402 CASE_OP_32_64(add2):
2403 done = fold_add2(&ctx, op);
2404 break;
2405 CASE_OP_32_64_VEC(and):
2406 done = fold_and(&ctx, op);
2407 break;
2408 CASE_OP_32_64_VEC(andc):
2409 done = fold_andc(&ctx, op);
2410 break;
2411 CASE_OP_32_64(brcond):
2412 done = fold_brcond(&ctx, op);
2413 break;
2414 case INDEX_op_brcond2_i32:
2415 done = fold_brcond2(&ctx, op);
2416 break;
2417 CASE_OP_32_64(bswap16):
2418 CASE_OP_32_64(bswap32):
2419 case INDEX_op_bswap64_i64:
2420 done = fold_bswap(&ctx, op);
2421 break;
2422 CASE_OP_32_64(clz):
2423 CASE_OP_32_64(ctz):
2424 done = fold_count_zeros(&ctx, op);
2425 break;
2426 CASE_OP_32_64(ctpop):
2427 done = fold_ctpop(&ctx, op);
2428 break;
2429 CASE_OP_32_64(deposit):
2430 done = fold_deposit(&ctx, op);
2431 break;
2432 CASE_OP_32_64(div):
2433 CASE_OP_32_64(divu):
2434 done = fold_divide(&ctx, op);
2435 break;
2436 case INDEX_op_dup_vec:
2437 done = fold_dup(&ctx, op);
2438 break;
2439 case INDEX_op_dup2_vec:
2440 done = fold_dup2(&ctx, op);
2441 break;
2442 CASE_OP_32_64_VEC(eqv):
2443 done = fold_eqv(&ctx, op);
2444 break;
2445 CASE_OP_32_64(extract):
2446 done = fold_extract(&ctx, op);
2447 break;
2448 CASE_OP_32_64(extract2):
2449 done = fold_extract2(&ctx, op);
2450 break;
2451 CASE_OP_32_64(ext8s):
2452 CASE_OP_32_64(ext16s):
2453 case INDEX_op_ext32s_i64:
2454 case INDEX_op_ext_i32_i64:
2455 done = fold_exts(&ctx, op);
2456 break;
2457 CASE_OP_32_64(ext8u):
2458 CASE_OP_32_64(ext16u):
2459 case INDEX_op_ext32u_i64:
2460 case INDEX_op_extu_i32_i64:
2461 case INDEX_op_extrl_i64_i32:
2462 case INDEX_op_extrh_i64_i32:
2463 done = fold_extu(&ctx, op);
2464 break;
2465 CASE_OP_32_64(ld8s):
2466 CASE_OP_32_64(ld8u):
2467 CASE_OP_32_64(ld16s):
2468 CASE_OP_32_64(ld16u):
2469 case INDEX_op_ld32s_i64:
2470 case INDEX_op_ld32u_i64:
2471 done = fold_tcg_ld(&ctx, op);
2472 break;
2473 case INDEX_op_ld_i32:
2474 case INDEX_op_ld_i64:
2475 case INDEX_op_ld_vec:
2476 done = fold_tcg_ld_memcopy(&ctx, op);
2477 break;
2478 CASE_OP_32_64(st8):
2479 CASE_OP_32_64(st16):
2480 case INDEX_op_st32_i64:
2481 done = fold_tcg_st(&ctx, op);
2482 break;
2483 case INDEX_op_st_i32:
2484 case INDEX_op_st_i64:
2485 case INDEX_op_st_vec:
2486 done = fold_tcg_st_memcopy(&ctx, op);
2487 break;
2488 case INDEX_op_mb:
2489 done = fold_mb(&ctx, op);
2490 break;
2491 CASE_OP_32_64_VEC(mov):
2492 done = fold_mov(&ctx, op);
2493 break;
2494 CASE_OP_32_64(movcond):
2495 done = fold_movcond(&ctx, op);
2496 break;
2497 CASE_OP_32_64(mul):
2498 done = fold_mul(&ctx, op);
2499 break;
2500 CASE_OP_32_64(mulsh):
2501 CASE_OP_32_64(muluh):
2502 done = fold_mul_highpart(&ctx, op);
2503 break;
2504 CASE_OP_32_64(muls2):
2505 CASE_OP_32_64(mulu2):
2506 done = fold_multiply2(&ctx, op);
2507 break;
2508 CASE_OP_32_64_VEC(nand):
2509 done = fold_nand(&ctx, op);
2510 break;
2511 CASE_OP_32_64(neg):
2512 done = fold_neg(&ctx, op);
2513 break;
2514 CASE_OP_32_64_VEC(nor):
2515 done = fold_nor(&ctx, op);
2516 break;
2517 CASE_OP_32_64_VEC(not):
2518 done = fold_not(&ctx, op);
2519 break;
2520 CASE_OP_32_64_VEC(or):
2521 done = fold_or(&ctx, op);
2522 break;
2523 CASE_OP_32_64_VEC(orc):
2524 done = fold_orc(&ctx, op);
2525 break;
2526 case INDEX_op_qemu_ld_a32_i32:
2527 case INDEX_op_qemu_ld_a64_i32:
2528 case INDEX_op_qemu_ld_a32_i64:
2529 case INDEX_op_qemu_ld_a64_i64:
2530 case INDEX_op_qemu_ld_a32_i128:
2531 case INDEX_op_qemu_ld_a64_i128:
2532 done = fold_qemu_ld(&ctx, op);
2533 break;
2534 case INDEX_op_qemu_st8_a32_i32:
2535 case INDEX_op_qemu_st8_a64_i32:
2536 case INDEX_op_qemu_st_a32_i32:
2537 case INDEX_op_qemu_st_a64_i32:
2538 case INDEX_op_qemu_st_a32_i64:
2539 case INDEX_op_qemu_st_a64_i64:
2540 case INDEX_op_qemu_st_a32_i128:
2541 case INDEX_op_qemu_st_a64_i128:
2542 done = fold_qemu_st(&ctx, op);
2543 break;
2544 CASE_OP_32_64(rem):
2545 CASE_OP_32_64(remu):
2546 done = fold_remainder(&ctx, op);
2547 break;
2548 CASE_OP_32_64(rotl):
2549 CASE_OP_32_64(rotr):
2550 CASE_OP_32_64(sar):
2551 CASE_OP_32_64(shl):
2552 CASE_OP_32_64(shr):
2553 done = fold_shift(&ctx, op);
2554 break;
2555 CASE_OP_32_64(setcond):
2556 done = fold_setcond(&ctx, op);
2557 break;
2558 CASE_OP_32_64(negsetcond):
2559 done = fold_negsetcond(&ctx, op);
2560 break;
2561 case INDEX_op_setcond2_i32:
2562 done = fold_setcond2(&ctx, op);
2563 break;
2564 CASE_OP_32_64(sextract):
2565 done = fold_sextract(&ctx, op);
2566 break;
2567 CASE_OP_32_64(sub):
2568 done = fold_sub(&ctx, op);
2569 break;
2570 case INDEX_op_sub_vec:
2571 done = fold_sub_vec(&ctx, op);
2572 break;
2573 CASE_OP_32_64(sub2):
2574 done = fold_sub2(&ctx, op);
2575 break;
2576 CASE_OP_32_64_VEC(xor):
2577 done = fold_xor(&ctx, op);
2578 break;
2579 default:
2580 break;
2581 }
2582
2583 if (!done) {
2584 finish_folding(&ctx, op);
2585 }
2586 }
2587 }
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