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 "config.h" 27 28 #include <stdlib.h> 29 #include <stdio.h> 30 31 #include "qemu-common.h" 32 #include "tcg-op.h" 33 34 #define CASE_OP_32_64(x) \ 35 glue(glue(case INDEX_op_, x), _i32): \ 36 glue(glue(case INDEX_op_, x), _i64) 37 38 typedef enum { 39 TCG_TEMP_UNDEF = 0, 40 TCG_TEMP_CONST, 41 TCG_TEMP_COPY, 42 } tcg_temp_state; 43 44 struct tcg_temp_info { 45 tcg_temp_state state; 46 uint16_t prev_copy; 47 uint16_t next_copy; 48 tcg_target_ulong val; 49 tcg_target_ulong mask; 50 }; 51 52 static struct tcg_temp_info temps[TCG_MAX_TEMPS]; 53 54 /* Reset TEMP's state to TCG_TEMP_UNDEF. If TEMP only had one copy, remove 55 the copy flag from the left temp. */ 56 static void reset_temp(TCGArg temp) 57 { 58 if (temps[temp].state == TCG_TEMP_COPY) { 59 if (temps[temp].prev_copy == temps[temp].next_copy) { 60 temps[temps[temp].next_copy].state = TCG_TEMP_UNDEF; 61 } else { 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 } 65 } 66 temps[temp].state = TCG_TEMP_UNDEF; 67 temps[temp].mask = -1; 68 } 69 70 /* Reset all temporaries, given that there are NB_TEMPS of them. */ 71 static void reset_all_temps(int nb_temps) 72 { 73 int i; 74 for (i = 0; i < nb_temps; i++) { 75 temps[i].state = TCG_TEMP_UNDEF; 76 temps[i].mask = -1; 77 } 78 } 79 80 static int op_bits(TCGOpcode op) 81 { 82 const TCGOpDef *def = &tcg_op_defs[op]; 83 return def->flags & TCG_OPF_64BIT ? 64 : 32; 84 } 85 86 static TCGOpcode op_to_movi(TCGOpcode op) 87 { 88 switch (op_bits(op)) { 89 case 32: 90 return INDEX_op_movi_i32; 91 case 64: 92 return INDEX_op_movi_i64; 93 default: 94 fprintf(stderr, "op_to_movi: unexpected return value of " 95 "function op_bits.\n"); 96 tcg_abort(); 97 } 98 } 99 100 static TCGArg find_better_copy(TCGContext *s, TCGArg temp) 101 { 102 TCGArg i; 103 104 /* If this is already a global, we can't do better. */ 105 if (temp < s->nb_globals) { 106 return temp; 107 } 108 109 /* Search for a global first. */ 110 for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy) { 111 if (i < s->nb_globals) { 112 return i; 113 } 114 } 115 116 /* If it is a temp, search for a temp local. */ 117 if (!s->temps[temp].temp_local) { 118 for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy) { 119 if (s->temps[i].temp_local) { 120 return i; 121 } 122 } 123 } 124 125 /* Failure to find a better representation, return the same temp. */ 126 return temp; 127 } 128 129 static bool temps_are_copies(TCGArg arg1, TCGArg arg2) 130 { 131 TCGArg i; 132 133 if (arg1 == arg2) { 134 return true; 135 } 136 137 if (temps[arg1].state != TCG_TEMP_COPY 138 || temps[arg2].state != TCG_TEMP_COPY) { 139 return false; 140 } 141 142 for (i = temps[arg1].next_copy ; i != arg1 ; i = temps[i].next_copy) { 143 if (i == arg2) { 144 return true; 145 } 146 } 147 148 return false; 149 } 150 151 static void tcg_opt_gen_mov(TCGContext *s, TCGArg *gen_args, 152 TCGArg dst, TCGArg src) 153 { 154 reset_temp(dst); 155 temps[dst].mask = temps[src].mask; 156 assert(temps[src].state != TCG_TEMP_CONST); 157 158 if (s->temps[src].type == s->temps[dst].type) { 159 if (temps[src].state != TCG_TEMP_COPY) { 160 temps[src].state = TCG_TEMP_COPY; 161 temps[src].next_copy = src; 162 temps[src].prev_copy = src; 163 } 164 temps[dst].state = TCG_TEMP_COPY; 165 temps[dst].next_copy = temps[src].next_copy; 166 temps[dst].prev_copy = src; 167 temps[temps[dst].next_copy].prev_copy = dst; 168 temps[src].next_copy = dst; 169 } 170 171 gen_args[0] = dst; 172 gen_args[1] = src; 173 } 174 175 static void tcg_opt_gen_movi(TCGArg *gen_args, TCGArg dst, TCGArg val) 176 { 177 reset_temp(dst); 178 temps[dst].state = TCG_TEMP_CONST; 179 temps[dst].val = val; 180 temps[dst].mask = val; 181 gen_args[0] = dst; 182 gen_args[1] = val; 183 } 184 185 static TCGOpcode op_to_mov(TCGOpcode op) 186 { 187 switch (op_bits(op)) { 188 case 32: 189 return INDEX_op_mov_i32; 190 case 64: 191 return INDEX_op_mov_i64; 192 default: 193 fprintf(stderr, "op_to_mov: unexpected return value of " 194 "function op_bits.\n"); 195 tcg_abort(); 196 } 197 } 198 199 static TCGArg do_constant_folding_2(TCGOpcode op, TCGArg x, TCGArg y) 200 { 201 switch (op) { 202 CASE_OP_32_64(add): 203 return x + y; 204 205 CASE_OP_32_64(sub): 206 return x - y; 207 208 CASE_OP_32_64(mul): 209 return x * y; 210 211 CASE_OP_32_64(and): 212 return x & y; 213 214 CASE_OP_32_64(or): 215 return x | y; 216 217 CASE_OP_32_64(xor): 218 return x ^ y; 219 220 case INDEX_op_shl_i32: 221 return (uint32_t)x << (uint32_t)y; 222 223 case INDEX_op_shl_i64: 224 return (uint64_t)x << (uint64_t)y; 225 226 case INDEX_op_shr_i32: 227 return (uint32_t)x >> (uint32_t)y; 228 229 case INDEX_op_shr_i64: 230 return (uint64_t)x >> (uint64_t)y; 231 232 case INDEX_op_sar_i32: 233 return (int32_t)x >> (int32_t)y; 234 235 case INDEX_op_sar_i64: 236 return (int64_t)x >> (int64_t)y; 237 238 case INDEX_op_rotr_i32: 239 x = ((uint32_t)x << (32 - y)) | ((uint32_t)x >> y); 240 return x; 241 242 case INDEX_op_rotr_i64: 243 x = ((uint64_t)x << (64 - y)) | ((uint64_t)x >> y); 244 return x; 245 246 case INDEX_op_rotl_i32: 247 x = ((uint32_t)x << y) | ((uint32_t)x >> (32 - y)); 248 return x; 249 250 case INDEX_op_rotl_i64: 251 x = ((uint64_t)x << y) | ((uint64_t)x >> (64 - y)); 252 return x; 253 254 CASE_OP_32_64(not): 255 return ~x; 256 257 CASE_OP_32_64(neg): 258 return -x; 259 260 CASE_OP_32_64(andc): 261 return x & ~y; 262 263 CASE_OP_32_64(orc): 264 return x | ~y; 265 266 CASE_OP_32_64(eqv): 267 return ~(x ^ y); 268 269 CASE_OP_32_64(nand): 270 return ~(x & y); 271 272 CASE_OP_32_64(nor): 273 return ~(x | y); 274 275 CASE_OP_32_64(ext8s): 276 return (int8_t)x; 277 278 CASE_OP_32_64(ext16s): 279 return (int16_t)x; 280 281 CASE_OP_32_64(ext8u): 282 return (uint8_t)x; 283 284 CASE_OP_32_64(ext16u): 285 return (uint16_t)x; 286 287 case INDEX_op_ext32s_i64: 288 return (int32_t)x; 289 290 case INDEX_op_ext32u_i64: 291 return (uint32_t)x; 292 293 default: 294 fprintf(stderr, 295 "Unrecognized operation %d in do_constant_folding.\n", op); 296 tcg_abort(); 297 } 298 } 299 300 static TCGArg do_constant_folding(TCGOpcode op, TCGArg x, TCGArg y) 301 { 302 TCGArg res = do_constant_folding_2(op, x, y); 303 if (op_bits(op) == 32) { 304 res &= 0xffffffff; 305 } 306 return res; 307 } 308 309 static bool do_constant_folding_cond_32(uint32_t x, uint32_t y, TCGCond c) 310 { 311 switch (c) { 312 case TCG_COND_EQ: 313 return x == y; 314 case TCG_COND_NE: 315 return x != y; 316 case TCG_COND_LT: 317 return (int32_t)x < (int32_t)y; 318 case TCG_COND_GE: 319 return (int32_t)x >= (int32_t)y; 320 case TCG_COND_LE: 321 return (int32_t)x <= (int32_t)y; 322 case TCG_COND_GT: 323 return (int32_t)x > (int32_t)y; 324 case TCG_COND_LTU: 325 return x < y; 326 case TCG_COND_GEU: 327 return x >= y; 328 case TCG_COND_LEU: 329 return x <= y; 330 case TCG_COND_GTU: 331 return x > y; 332 default: 333 tcg_abort(); 334 } 335 } 336 337 static bool do_constant_folding_cond_64(uint64_t x, uint64_t y, TCGCond c) 338 { 339 switch (c) { 340 case TCG_COND_EQ: 341 return x == y; 342 case TCG_COND_NE: 343 return x != y; 344 case TCG_COND_LT: 345 return (int64_t)x < (int64_t)y; 346 case TCG_COND_GE: 347 return (int64_t)x >= (int64_t)y; 348 case TCG_COND_LE: 349 return (int64_t)x <= (int64_t)y; 350 case TCG_COND_GT: 351 return (int64_t)x > (int64_t)y; 352 case TCG_COND_LTU: 353 return x < y; 354 case TCG_COND_GEU: 355 return x >= y; 356 case TCG_COND_LEU: 357 return x <= y; 358 case TCG_COND_GTU: 359 return x > y; 360 default: 361 tcg_abort(); 362 } 363 } 364 365 static bool do_constant_folding_cond_eq(TCGCond c) 366 { 367 switch (c) { 368 case TCG_COND_GT: 369 case TCG_COND_LTU: 370 case TCG_COND_LT: 371 case TCG_COND_GTU: 372 case TCG_COND_NE: 373 return 0; 374 case TCG_COND_GE: 375 case TCG_COND_GEU: 376 case TCG_COND_LE: 377 case TCG_COND_LEU: 378 case TCG_COND_EQ: 379 return 1; 380 default: 381 tcg_abort(); 382 } 383 } 384 385 /* Return 2 if the condition can't be simplified, and the result 386 of the condition (0 or 1) if it can */ 387 static TCGArg do_constant_folding_cond(TCGOpcode op, TCGArg x, 388 TCGArg y, TCGCond c) 389 { 390 if (temps[x].state == TCG_TEMP_CONST && temps[y].state == TCG_TEMP_CONST) { 391 switch (op_bits(op)) { 392 case 32: 393 return do_constant_folding_cond_32(temps[x].val, temps[y].val, c); 394 case 64: 395 return do_constant_folding_cond_64(temps[x].val, temps[y].val, c); 396 default: 397 tcg_abort(); 398 } 399 } else if (temps_are_copies(x, y)) { 400 return do_constant_folding_cond_eq(c); 401 } else if (temps[y].state == TCG_TEMP_CONST && temps[y].val == 0) { 402 switch (c) { 403 case TCG_COND_LTU: 404 return 0; 405 case TCG_COND_GEU: 406 return 1; 407 default: 408 return 2; 409 } 410 } else { 411 return 2; 412 } 413 } 414 415 /* Return 2 if the condition can't be simplified, and the result 416 of the condition (0 or 1) if it can */ 417 static TCGArg do_constant_folding_cond2(TCGArg *p1, TCGArg *p2, TCGCond c) 418 { 419 TCGArg al = p1[0], ah = p1[1]; 420 TCGArg bl = p2[0], bh = p2[1]; 421 422 if (temps[bl].state == TCG_TEMP_CONST 423 && temps[bh].state == TCG_TEMP_CONST) { 424 uint64_t b = ((uint64_t)temps[bh].val << 32) | (uint32_t)temps[bl].val; 425 426 if (temps[al].state == TCG_TEMP_CONST 427 && temps[ah].state == TCG_TEMP_CONST) { 428 uint64_t a; 429 a = ((uint64_t)temps[ah].val << 32) | (uint32_t)temps[al].val; 430 return do_constant_folding_cond_64(a, b, c); 431 } 432 if (b == 0) { 433 switch (c) { 434 case TCG_COND_LTU: 435 return 0; 436 case TCG_COND_GEU: 437 return 1; 438 default: 439 break; 440 } 441 } 442 } 443 if (temps_are_copies(al, bl) && temps_are_copies(ah, bh)) { 444 return do_constant_folding_cond_eq(c); 445 } 446 return 2; 447 } 448 449 static bool swap_commutative(TCGArg dest, TCGArg *p1, TCGArg *p2) 450 { 451 TCGArg a1 = *p1, a2 = *p2; 452 int sum = 0; 453 sum += temps[a1].state == TCG_TEMP_CONST; 454 sum -= temps[a2].state == TCG_TEMP_CONST; 455 456 /* Prefer the constant in second argument, and then the form 457 op a, a, b, which is better handled on non-RISC hosts. */ 458 if (sum > 0 || (sum == 0 && dest == a2)) { 459 *p1 = a2; 460 *p2 = a1; 461 return true; 462 } 463 return false; 464 } 465 466 static bool swap_commutative2(TCGArg *p1, TCGArg *p2) 467 { 468 int sum = 0; 469 sum += temps[p1[0]].state == TCG_TEMP_CONST; 470 sum += temps[p1[1]].state == TCG_TEMP_CONST; 471 sum -= temps[p2[0]].state == TCG_TEMP_CONST; 472 sum -= temps[p2[1]].state == TCG_TEMP_CONST; 473 if (sum > 0) { 474 TCGArg t; 475 t = p1[0], p1[0] = p2[0], p2[0] = t; 476 t = p1[1], p1[1] = p2[1], p2[1] = t; 477 return true; 478 } 479 return false; 480 } 481 482 /* Propagate constants and copies, fold constant expressions. */ 483 static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, 484 TCGArg *args, TCGOpDef *tcg_op_defs) 485 { 486 int i, nb_ops, op_index, nb_temps, nb_globals, nb_call_args; 487 tcg_target_ulong mask, affected; 488 TCGOpcode op; 489 const TCGOpDef *def; 490 TCGArg *gen_args; 491 TCGArg tmp; 492 493 /* Array VALS has an element for each temp. 494 If this temp holds a constant then its value is kept in VALS' element. 495 If this temp is a copy of other ones then the other copies are 496 available through the doubly linked circular list. */ 497 498 nb_temps = s->nb_temps; 499 nb_globals = s->nb_globals; 500 reset_all_temps(nb_temps); 501 502 nb_ops = tcg_opc_ptr - s->gen_opc_buf; 503 gen_args = args; 504 for (op_index = 0; op_index < nb_ops; op_index++) { 505 op = s->gen_opc_buf[op_index]; 506 def = &tcg_op_defs[op]; 507 /* Do copy propagation */ 508 if (op == INDEX_op_call) { 509 int nb_oargs = args[0] >> 16; 510 int nb_iargs = args[0] & 0xffff; 511 for (i = nb_oargs + 1; i < nb_oargs + nb_iargs + 1; i++) { 512 if (temps[args[i]].state == TCG_TEMP_COPY) { 513 args[i] = find_better_copy(s, args[i]); 514 } 515 } 516 } else { 517 for (i = def->nb_oargs; i < def->nb_oargs + def->nb_iargs; i++) { 518 if (temps[args[i]].state == TCG_TEMP_COPY) { 519 args[i] = find_better_copy(s, args[i]); 520 } 521 } 522 } 523 524 /* For commutative operations make constant second argument */ 525 switch (op) { 526 CASE_OP_32_64(add): 527 CASE_OP_32_64(mul): 528 CASE_OP_32_64(and): 529 CASE_OP_32_64(or): 530 CASE_OP_32_64(xor): 531 CASE_OP_32_64(eqv): 532 CASE_OP_32_64(nand): 533 CASE_OP_32_64(nor): 534 swap_commutative(args[0], &args[1], &args[2]); 535 break; 536 CASE_OP_32_64(brcond): 537 if (swap_commutative(-1, &args[0], &args[1])) { 538 args[2] = tcg_swap_cond(args[2]); 539 } 540 break; 541 CASE_OP_32_64(setcond): 542 if (swap_commutative(args[0], &args[1], &args[2])) { 543 args[3] = tcg_swap_cond(args[3]); 544 } 545 break; 546 CASE_OP_32_64(movcond): 547 if (swap_commutative(-1, &args[1], &args[2])) { 548 args[5] = tcg_swap_cond(args[5]); 549 } 550 /* For movcond, we canonicalize the "false" input reg to match 551 the destination reg so that the tcg backend can implement 552 a "move if true" operation. */ 553 if (swap_commutative(args[0], &args[4], &args[3])) { 554 args[5] = tcg_invert_cond(args[5]); 555 } 556 break; 557 CASE_OP_32_64(add2): 558 swap_commutative(args[0], &args[2], &args[4]); 559 swap_commutative(args[1], &args[3], &args[5]); 560 break; 561 CASE_OP_32_64(mulu2): 562 CASE_OP_32_64(muls2): 563 swap_commutative(args[0], &args[2], &args[3]); 564 break; 565 case INDEX_op_brcond2_i32: 566 if (swap_commutative2(&args[0], &args[2])) { 567 args[4] = tcg_swap_cond(args[4]); 568 } 569 break; 570 case INDEX_op_setcond2_i32: 571 if (swap_commutative2(&args[1], &args[3])) { 572 args[5] = tcg_swap_cond(args[5]); 573 } 574 break; 575 default: 576 break; 577 } 578 579 /* Simplify expressions for "shift/rot r, 0, a => movi r, 0" */ 580 switch (op) { 581 CASE_OP_32_64(shl): 582 CASE_OP_32_64(shr): 583 CASE_OP_32_64(sar): 584 CASE_OP_32_64(rotl): 585 CASE_OP_32_64(rotr): 586 if (temps[args[1]].state == TCG_TEMP_CONST 587 && temps[args[1]].val == 0) { 588 s->gen_opc_buf[op_index] = op_to_movi(op); 589 tcg_opt_gen_movi(gen_args, args[0], 0); 590 args += 3; 591 gen_args += 2; 592 continue; 593 } 594 break; 595 default: 596 break; 597 } 598 599 /* Simplify expression for "op r, a, 0 => mov r, a" cases */ 600 switch (op) { 601 CASE_OP_32_64(add): 602 CASE_OP_32_64(sub): 603 CASE_OP_32_64(shl): 604 CASE_OP_32_64(shr): 605 CASE_OP_32_64(sar): 606 CASE_OP_32_64(rotl): 607 CASE_OP_32_64(rotr): 608 CASE_OP_32_64(or): 609 CASE_OP_32_64(xor): 610 if (temps[args[1]].state == TCG_TEMP_CONST) { 611 /* Proceed with possible constant folding. */ 612 break; 613 } 614 if (temps[args[2]].state == TCG_TEMP_CONST 615 && temps[args[2]].val == 0) { 616 if (temps_are_copies(args[0], args[1])) { 617 s->gen_opc_buf[op_index] = INDEX_op_nop; 618 } else { 619 s->gen_opc_buf[op_index] = op_to_mov(op); 620 tcg_opt_gen_mov(s, gen_args, args[0], args[1]); 621 gen_args += 2; 622 } 623 args += 3; 624 continue; 625 } 626 break; 627 default: 628 break; 629 } 630 631 /* Simplify using known-zero bits */ 632 mask = -1; 633 affected = -1; 634 switch (op) { 635 CASE_OP_32_64(ext8s): 636 if ((temps[args[1]].mask & 0x80) != 0) { 637 break; 638 } 639 CASE_OP_32_64(ext8u): 640 mask = 0xff; 641 goto and_const; 642 CASE_OP_32_64(ext16s): 643 if ((temps[args[1]].mask & 0x8000) != 0) { 644 break; 645 } 646 CASE_OP_32_64(ext16u): 647 mask = 0xffff; 648 goto and_const; 649 case INDEX_op_ext32s_i64: 650 if ((temps[args[1]].mask & 0x80000000) != 0) { 651 break; 652 } 653 case INDEX_op_ext32u_i64: 654 mask = 0xffffffffU; 655 goto and_const; 656 657 CASE_OP_32_64(and): 658 mask = temps[args[2]].mask; 659 if (temps[args[2]].state == TCG_TEMP_CONST) { 660 and_const: 661 affected = temps[args[1]].mask & ~mask; 662 } 663 mask = temps[args[1]].mask & mask; 664 break; 665 666 CASE_OP_32_64(sar): 667 if (temps[args[2]].state == TCG_TEMP_CONST) { 668 mask = ((tcg_target_long)temps[args[1]].mask 669 >> temps[args[2]].val); 670 } 671 break; 672 673 CASE_OP_32_64(shr): 674 if (temps[args[2]].state == TCG_TEMP_CONST) { 675 mask = temps[args[1]].mask >> temps[args[2]].val; 676 } 677 break; 678 679 CASE_OP_32_64(shl): 680 if (temps[args[2]].state == TCG_TEMP_CONST) { 681 mask = temps[args[1]].mask << temps[args[2]].val; 682 } 683 break; 684 685 CASE_OP_32_64(neg): 686 /* Set to 1 all bits to the left of the rightmost. */ 687 mask = -(temps[args[1]].mask & -temps[args[1]].mask); 688 break; 689 690 CASE_OP_32_64(deposit): 691 tmp = ((1ull << args[4]) - 1); 692 mask = ((temps[args[1]].mask & ~(tmp << args[3])) 693 | ((temps[args[2]].mask & tmp) << args[3])); 694 break; 695 696 CASE_OP_32_64(or): 697 CASE_OP_32_64(xor): 698 mask = temps[args[1]].mask | temps[args[2]].mask; 699 break; 700 701 CASE_OP_32_64(setcond): 702 mask = 1; 703 break; 704 705 CASE_OP_32_64(movcond): 706 mask = temps[args[3]].mask | temps[args[4]].mask; 707 break; 708 709 default: 710 break; 711 } 712 713 if (mask == 0) { 714 assert(def->nb_oargs == 1); 715 s->gen_opc_buf[op_index] = op_to_movi(op); 716 tcg_opt_gen_movi(gen_args, args[0], 0); 717 args += def->nb_oargs + def->nb_iargs + def->nb_cargs; 718 gen_args += 2; 719 continue; 720 } 721 if (affected == 0) { 722 assert(def->nb_oargs == 1); 723 if (temps_are_copies(args[0], args[1])) { 724 s->gen_opc_buf[op_index] = INDEX_op_nop; 725 } else if (temps[args[1]].state != TCG_TEMP_CONST) { 726 s->gen_opc_buf[op_index] = op_to_mov(op); 727 tcg_opt_gen_mov(s, gen_args, args[0], args[1]); 728 gen_args += 2; 729 } else { 730 s->gen_opc_buf[op_index] = op_to_movi(op); 731 tcg_opt_gen_movi(gen_args, args[0], temps[args[1]].val); 732 gen_args += 2; 733 } 734 args += def->nb_iargs + 1; 735 continue; 736 } 737 738 /* Simplify expression for "op r, a, 0 => movi r, 0" cases */ 739 switch (op) { 740 CASE_OP_32_64(and): 741 CASE_OP_32_64(mul): 742 if ((temps[args[2]].state == TCG_TEMP_CONST 743 && temps[args[2]].val == 0)) { 744 s->gen_opc_buf[op_index] = op_to_movi(op); 745 tcg_opt_gen_movi(gen_args, args[0], 0); 746 args += 3; 747 gen_args += 2; 748 continue; 749 } 750 break; 751 default: 752 break; 753 } 754 755 /* Simplify expression for "op r, a, a => mov r, a" cases */ 756 switch (op) { 757 CASE_OP_32_64(or): 758 CASE_OP_32_64(and): 759 if (temps_are_copies(args[1], args[2])) { 760 if (temps_are_copies(args[0], args[1])) { 761 s->gen_opc_buf[op_index] = INDEX_op_nop; 762 } else { 763 s->gen_opc_buf[op_index] = op_to_mov(op); 764 tcg_opt_gen_mov(s, gen_args, args[0], args[1]); 765 gen_args += 2; 766 } 767 args += 3; 768 continue; 769 } 770 break; 771 default: 772 break; 773 } 774 775 /* Simplify expression for "op r, a, a => movi r, 0" cases */ 776 switch (op) { 777 CASE_OP_32_64(sub): 778 CASE_OP_32_64(xor): 779 if (temps_are_copies(args[1], args[2])) { 780 s->gen_opc_buf[op_index] = op_to_movi(op); 781 tcg_opt_gen_movi(gen_args, args[0], 0); 782 gen_args += 2; 783 args += 3; 784 continue; 785 } 786 break; 787 default: 788 break; 789 } 790 791 /* Propagate constants through copy operations and do constant 792 folding. Constants will be substituted to arguments by register 793 allocator where needed and possible. Also detect copies. */ 794 switch (op) { 795 CASE_OP_32_64(mov): 796 if (temps_are_copies(args[0], args[1])) { 797 args += 2; 798 s->gen_opc_buf[op_index] = INDEX_op_nop; 799 break; 800 } 801 if (temps[args[1]].state != TCG_TEMP_CONST) { 802 tcg_opt_gen_mov(s, gen_args, args[0], args[1]); 803 gen_args += 2; 804 args += 2; 805 break; 806 } 807 /* Source argument is constant. Rewrite the operation and 808 let movi case handle it. */ 809 op = op_to_movi(op); 810 s->gen_opc_buf[op_index] = op; 811 args[1] = temps[args[1]].val; 812 /* fallthrough */ 813 CASE_OP_32_64(movi): 814 tcg_opt_gen_movi(gen_args, args[0], args[1]); 815 gen_args += 2; 816 args += 2; 817 break; 818 819 CASE_OP_32_64(not): 820 CASE_OP_32_64(neg): 821 CASE_OP_32_64(ext8s): 822 CASE_OP_32_64(ext8u): 823 CASE_OP_32_64(ext16s): 824 CASE_OP_32_64(ext16u): 825 case INDEX_op_ext32s_i64: 826 case INDEX_op_ext32u_i64: 827 if (temps[args[1]].state == TCG_TEMP_CONST) { 828 s->gen_opc_buf[op_index] = op_to_movi(op); 829 tmp = do_constant_folding(op, temps[args[1]].val, 0); 830 tcg_opt_gen_movi(gen_args, args[0], tmp); 831 gen_args += 2; 832 args += 2; 833 break; 834 } 835 goto do_default; 836 837 CASE_OP_32_64(add): 838 CASE_OP_32_64(sub): 839 CASE_OP_32_64(mul): 840 CASE_OP_32_64(or): 841 CASE_OP_32_64(and): 842 CASE_OP_32_64(xor): 843 CASE_OP_32_64(shl): 844 CASE_OP_32_64(shr): 845 CASE_OP_32_64(sar): 846 CASE_OP_32_64(rotl): 847 CASE_OP_32_64(rotr): 848 CASE_OP_32_64(andc): 849 CASE_OP_32_64(orc): 850 CASE_OP_32_64(eqv): 851 CASE_OP_32_64(nand): 852 CASE_OP_32_64(nor): 853 if (temps[args[1]].state == TCG_TEMP_CONST 854 && temps[args[2]].state == TCG_TEMP_CONST) { 855 s->gen_opc_buf[op_index] = op_to_movi(op); 856 tmp = do_constant_folding(op, temps[args[1]].val, 857 temps[args[2]].val); 858 tcg_opt_gen_movi(gen_args, args[0], tmp); 859 gen_args += 2; 860 args += 3; 861 break; 862 } 863 goto do_default; 864 865 CASE_OP_32_64(deposit): 866 if (temps[args[1]].state == TCG_TEMP_CONST 867 && temps[args[2]].state == TCG_TEMP_CONST) { 868 s->gen_opc_buf[op_index] = op_to_movi(op); 869 tmp = ((1ull << args[4]) - 1); 870 tmp = (temps[args[1]].val & ~(tmp << args[3])) 871 | ((temps[args[2]].val & tmp) << args[3]); 872 tcg_opt_gen_movi(gen_args, args[0], tmp); 873 gen_args += 2; 874 args += 5; 875 break; 876 } 877 goto do_default; 878 879 CASE_OP_32_64(setcond): 880 tmp = do_constant_folding_cond(op, args[1], args[2], args[3]); 881 if (tmp != 2) { 882 s->gen_opc_buf[op_index] = op_to_movi(op); 883 tcg_opt_gen_movi(gen_args, args[0], tmp); 884 gen_args += 2; 885 args += 4; 886 break; 887 } 888 goto do_default; 889 890 CASE_OP_32_64(brcond): 891 tmp = do_constant_folding_cond(op, args[0], args[1], args[2]); 892 if (tmp != 2) { 893 if (tmp) { 894 reset_all_temps(nb_temps); 895 s->gen_opc_buf[op_index] = INDEX_op_br; 896 gen_args[0] = args[3]; 897 gen_args += 1; 898 } else { 899 s->gen_opc_buf[op_index] = INDEX_op_nop; 900 } 901 args += 4; 902 break; 903 } 904 goto do_default; 905 906 CASE_OP_32_64(movcond): 907 tmp = do_constant_folding_cond(op, args[1], args[2], args[5]); 908 if (tmp != 2) { 909 if (temps_are_copies(args[0], args[4-tmp])) { 910 s->gen_opc_buf[op_index] = INDEX_op_nop; 911 } else if (temps[args[4-tmp]].state == TCG_TEMP_CONST) { 912 s->gen_opc_buf[op_index] = op_to_movi(op); 913 tcg_opt_gen_movi(gen_args, args[0], temps[args[4-tmp]].val); 914 gen_args += 2; 915 } else { 916 s->gen_opc_buf[op_index] = op_to_mov(op); 917 tcg_opt_gen_mov(s, gen_args, args[0], args[4-tmp]); 918 gen_args += 2; 919 } 920 args += 6; 921 break; 922 } 923 goto do_default; 924 925 case INDEX_op_add2_i32: 926 case INDEX_op_sub2_i32: 927 if (temps[args[2]].state == TCG_TEMP_CONST 928 && temps[args[3]].state == TCG_TEMP_CONST 929 && temps[args[4]].state == TCG_TEMP_CONST 930 && temps[args[5]].state == TCG_TEMP_CONST) { 931 uint32_t al = temps[args[2]].val; 932 uint32_t ah = temps[args[3]].val; 933 uint32_t bl = temps[args[4]].val; 934 uint32_t bh = temps[args[5]].val; 935 uint64_t a = ((uint64_t)ah << 32) | al; 936 uint64_t b = ((uint64_t)bh << 32) | bl; 937 TCGArg rl, rh; 938 939 if (op == INDEX_op_add2_i32) { 940 a += b; 941 } else { 942 a -= b; 943 } 944 945 /* We emit the extra nop when we emit the add2/sub2. */ 946 assert(s->gen_opc_buf[op_index + 1] == INDEX_op_nop); 947 948 rl = args[0]; 949 rh = args[1]; 950 s->gen_opc_buf[op_index] = INDEX_op_movi_i32; 951 s->gen_opc_buf[++op_index] = INDEX_op_movi_i32; 952 tcg_opt_gen_movi(&gen_args[0], rl, (uint32_t)a); 953 tcg_opt_gen_movi(&gen_args[2], rh, (uint32_t)(a >> 32)); 954 gen_args += 4; 955 args += 6; 956 break; 957 } 958 goto do_default; 959 960 case INDEX_op_mulu2_i32: 961 if (temps[args[2]].state == TCG_TEMP_CONST 962 && temps[args[3]].state == TCG_TEMP_CONST) { 963 uint32_t a = temps[args[2]].val; 964 uint32_t b = temps[args[3]].val; 965 uint64_t r = (uint64_t)a * b; 966 TCGArg rl, rh; 967 968 /* We emit the extra nop when we emit the mulu2. */ 969 assert(s->gen_opc_buf[op_index + 1] == INDEX_op_nop); 970 971 rl = args[0]; 972 rh = args[1]; 973 s->gen_opc_buf[op_index] = INDEX_op_movi_i32; 974 s->gen_opc_buf[++op_index] = INDEX_op_movi_i32; 975 tcg_opt_gen_movi(&gen_args[0], rl, (uint32_t)r); 976 tcg_opt_gen_movi(&gen_args[2], rh, (uint32_t)(r >> 32)); 977 gen_args += 4; 978 args += 4; 979 break; 980 } 981 goto do_default; 982 983 case INDEX_op_brcond2_i32: 984 tmp = do_constant_folding_cond2(&args[0], &args[2], args[4]); 985 if (tmp != 2) { 986 if (tmp) { 987 reset_all_temps(nb_temps); 988 s->gen_opc_buf[op_index] = INDEX_op_br; 989 gen_args[0] = args[5]; 990 gen_args += 1; 991 } else { 992 s->gen_opc_buf[op_index] = INDEX_op_nop; 993 } 994 } else if ((args[4] == TCG_COND_LT || args[4] == TCG_COND_GE) 995 && temps[args[2]].state == TCG_TEMP_CONST 996 && temps[args[3]].state == TCG_TEMP_CONST 997 && temps[args[2]].val == 0 998 && temps[args[3]].val == 0) { 999 /* Simplify LT/GE comparisons vs zero to a single compare 1000 vs the high word of the input. */ 1001 reset_all_temps(nb_temps); 1002 s->gen_opc_buf[op_index] = INDEX_op_brcond_i32; 1003 gen_args[0] = args[1]; 1004 gen_args[1] = args[3]; 1005 gen_args[2] = args[4]; 1006 gen_args[3] = args[5]; 1007 gen_args += 4; 1008 } else { 1009 goto do_default; 1010 } 1011 args += 6; 1012 break; 1013 1014 case INDEX_op_setcond2_i32: 1015 tmp = do_constant_folding_cond2(&args[1], &args[3], args[5]); 1016 if (tmp != 2) { 1017 s->gen_opc_buf[op_index] = INDEX_op_movi_i32; 1018 tcg_opt_gen_movi(gen_args, args[0], tmp); 1019 gen_args += 2; 1020 } else if ((args[5] == TCG_COND_LT || args[5] == TCG_COND_GE) 1021 && temps[args[3]].state == TCG_TEMP_CONST 1022 && temps[args[4]].state == TCG_TEMP_CONST 1023 && temps[args[3]].val == 0 1024 && temps[args[4]].val == 0) { 1025 /* Simplify LT/GE comparisons vs zero to a single compare 1026 vs the high word of the input. */ 1027 s->gen_opc_buf[op_index] = INDEX_op_setcond_i32; 1028 gen_args[0] = args[0]; 1029 gen_args[1] = args[2]; 1030 gen_args[2] = args[4]; 1031 gen_args[3] = args[5]; 1032 gen_args += 4; 1033 } else { 1034 goto do_default; 1035 } 1036 args += 6; 1037 break; 1038 1039 case INDEX_op_call: 1040 nb_call_args = (args[0] >> 16) + (args[0] & 0xffff); 1041 if (!(args[nb_call_args + 1] & (TCG_CALL_NO_READ_GLOBALS | 1042 TCG_CALL_NO_WRITE_GLOBALS))) { 1043 for (i = 0; i < nb_globals; i++) { 1044 reset_temp(i); 1045 } 1046 } 1047 for (i = 0; i < (args[0] >> 16); i++) { 1048 reset_temp(args[i + 1]); 1049 } 1050 i = nb_call_args + 3; 1051 while (i) { 1052 *gen_args = *args; 1053 args++; 1054 gen_args++; 1055 i--; 1056 } 1057 break; 1058 1059 default: 1060 do_default: 1061 /* Default case: we know nothing about operation (or were unable 1062 to compute the operation result) so no propagation is done. 1063 We trash everything if the operation is the end of a basic 1064 block, otherwise we only trash the output args. "mask" is 1065 the non-zero bits mask for the first output arg. */ 1066 if (def->flags & TCG_OPF_BB_END) { 1067 reset_all_temps(nb_temps); 1068 } else { 1069 for (i = 0; i < def->nb_oargs; i++) { 1070 reset_temp(args[i]); 1071 } 1072 } 1073 for (i = 0; i < def->nb_args; i++) { 1074 gen_args[i] = args[i]; 1075 } 1076 args += def->nb_args; 1077 gen_args += def->nb_args; 1078 break; 1079 } 1080 } 1081 1082 return gen_args; 1083 } 1084 1085 TCGArg *tcg_optimize(TCGContext *s, uint16_t *tcg_opc_ptr, 1086 TCGArg *args, TCGOpDef *tcg_op_defs) 1087 { 1088 TCGArg *res; 1089 res = tcg_constant_folding(s, tcg_opc_ptr, args, tcg_op_defs); 1090 return res; 1091 } 1092