tcg/optimize.c

   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 };
  50
  51 static struct tcg_temp_info temps[TCG_MAX_TEMPS];
  52
  53 /* Reset TEMP's state to TCG_TEMP_UNDEF.  If TEMP only had one copy, remove
  54    the copy flag from the left temp.  */
  55 static void reset_temp(TCGArg temp)
  56 {
  57     if (temps[temp].state == TCG_TEMP_COPY) {
  58         if (temps[temp].prev_copy == temps[temp].next_copy) {
  59             temps[temps[temp].next_copy].state = TCG_TEMP_UNDEF;
  60         } else {
  61             temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy;
  62             temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy;
  63         }
  64     }
  65     temps[temp].state = TCG_TEMP_UNDEF;
  66 }
  67
  68 static int op_bits(TCGOpcode op)
  69 {
  70     const TCGOpDef *def = &tcg_op_defs[op];
  71     return def->flags & TCG_OPF_64BIT ? 64 : 32;
  72 }
  73
  74 static TCGOpcode op_to_movi(TCGOpcode op)
  75 {
  76     switch (op_bits(op)) {
  77     case 32:
  78         return INDEX_op_movi_i32;
  79     case 64:
  80         return INDEX_op_movi_i64;
  81     default:
  82         fprintf(stderr, "op_to_movi: unexpected return value of "
  83                 "function op_bits.\n");
  84         tcg_abort();
  85     }
  86 }
  87
  88 static TCGArg find_better_copy(TCGContext *s, TCGArg temp)
  89 {
  90     TCGArg i;
  91
  92     /* If this is already a global, we can't do better. */
  93     if (temp < s->nb_globals) {
  94         return temp;
  95     }
  96
  97     /* Search for a global first. */
  98     for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy) {
  99         if (i < s->nb_globals) {
 100             return i;
 101         }
 102     }
 103
 104     /* If it is a temp, search for a temp local. */
 105     if (!s->temps[temp].temp_local) {
 106         for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy) {
 107             if (s->temps[i].temp_local) {
 108                 return i;
 109             }
 110         }
 111     }
 112
 113     /* Failure to find a better representation, return the same temp. */
 114     return temp;
 115 }
 116
 117 static bool temps_are_copies(TCGArg arg1, TCGArg arg2)
 118 {
 119     TCGArg i;
 120
 121     if (arg1 == arg2) {
 122         return true;
 123     }
 124
 125     if (temps[arg1].state != TCG_TEMP_COPY
 126         || temps[arg2].state != TCG_TEMP_COPY) {
 127         return false;
 128     }
 129
 130     for (i = temps[arg1].next_copy ; i != arg1 ; i = temps[i].next_copy) {
 131         if (i == arg2) {
 132             return true;
 133         }
 134     }
 135
 136     return false;
 137 }
 138
 139 static void tcg_opt_gen_mov(TCGContext *s, TCGArg *gen_args,
 140                             TCGArg dst, TCGArg src)
 141 {
 142         reset_temp(dst);
 143         assert(temps[src].state != TCG_TEMP_CONST);
 144
 145         if (s->temps[src].type == s->temps[dst].type) {
 146             if (temps[src].state != TCG_TEMP_COPY) {
 147                 temps[src].state = TCG_TEMP_COPY;
 148                 temps[src].next_copy = src;
 149                 temps[src].prev_copy = src;
 150             }
 151             temps[dst].state = TCG_TEMP_COPY;
 152             temps[dst].next_copy = temps[src].next_copy;
 153             temps[dst].prev_copy = src;
 154             temps[temps[dst].next_copy].prev_copy = dst;
 155             temps[src].next_copy = dst;
 156         }
 157
 158         gen_args[0] = dst;
 159         gen_args[1] = src;
 160 }
 161
 162 static void tcg_opt_gen_movi(TCGArg *gen_args, TCGArg dst, TCGArg val)
 163 {
 164         reset_temp(dst);
 165         temps[dst].state = TCG_TEMP_CONST;
 166         temps[dst].val = val;
 167         gen_args[0] = dst;
 168         gen_args[1] = val;
 169 }
 170
 171 static TCGOpcode op_to_mov(TCGOpcode op)
 172 {
 173     switch (op_bits(op)) {
 174     case 32:
 175         return INDEX_op_mov_i32;
 176     case 64:
 177         return INDEX_op_mov_i64;
 178     default:
 179         fprintf(stderr, "op_to_mov: unexpected return value of "
 180                 "function op_bits.\n");
 181         tcg_abort();
 182     }
 183 }
 184
 185 static TCGArg do_constant_folding_2(TCGOpcode op, TCGArg x, TCGArg y)
 186 {
 187     switch (op) {
 188     CASE_OP_32_64(add):
 189         return x + y;
 190
 191     CASE_OP_32_64(sub):
 192         return x - y;
 193
 194     CASE_OP_32_64(mul):
 195         return x * y;
 196
 197     CASE_OP_32_64(and):
 198         return x & y;
 199
 200     CASE_OP_32_64(or):
 201         return x | y;
 202
 203     CASE_OP_32_64(xor):
 204         return x ^ y;
 205
 206     case INDEX_op_shl_i32:
 207         return (uint32_t)x << (uint32_t)y;
 208
 209     case INDEX_op_shl_i64:
 210         return (uint64_t)x << (uint64_t)y;
 211
 212     case INDEX_op_shr_i32:
 213         return (uint32_t)x >> (uint32_t)y;
 214
 215     case INDEX_op_shr_i64:
 216         return (uint64_t)x >> (uint64_t)y;
 217
 218     case INDEX_op_sar_i32:
 219         return (int32_t)x >> (int32_t)y;
 220
 221     case INDEX_op_sar_i64:
 222         return (int64_t)x >> (int64_t)y;
 223
 224     case INDEX_op_rotr_i32:
 225         x = ((uint32_t)x << (32 - y)) | ((uint32_t)x >> y);
 226         return x;
 227
 228     case INDEX_op_rotr_i64:
 229         x = ((uint64_t)x << (64 - y)) | ((uint64_t)x >> y);
 230         return x;
 231
 232     case INDEX_op_rotl_i32:
 233         x = ((uint32_t)x << y) | ((uint32_t)x >> (32 - y));
 234         return x;
 235
 236     case INDEX_op_rotl_i64:
 237         x = ((uint64_t)x << y) | ((uint64_t)x >> (64 - y));
 238         return x;
 239
 240     CASE_OP_32_64(not):
 241         return ~x;
 242
 243     CASE_OP_32_64(neg):
 244         return -x;
 245
 246     CASE_OP_32_64(andc):
 247         return x & ~y;
 248
 249     CASE_OP_32_64(orc):
 250         return x | ~y;
 251
 252     CASE_OP_32_64(eqv):
 253         return ~(x ^ y);
 254
 255     CASE_OP_32_64(nand):
 256         return ~(x & y);
 257
 258     CASE_OP_32_64(nor):
 259         return ~(x | y);
 260
 261     CASE_OP_32_64(ext8s):
 262         return (int8_t)x;
 263
 264     CASE_OP_32_64(ext16s):
 265         return (int16_t)x;
 266
 267     CASE_OP_32_64(ext8u):
 268         return (uint8_t)x;
 269
 270     CASE_OP_32_64(ext16u):
 271         return (uint16_t)x;
 272
 273     case INDEX_op_ext32s_i64:
 274         return (int32_t)x;
 275
 276     case INDEX_op_ext32u_i64:
 277         return (uint32_t)x;
 278
 279     default:
 280         fprintf(stderr,
 281                 "Unrecognized operation %d in do_constant_folding.\n", op);
 282         tcg_abort();
 283     }
 284 }
 285
 286 static TCGArg do_constant_folding(TCGOpcode op, TCGArg x, TCGArg y)
 287 {
 288     TCGArg res = do_constant_folding_2(op, x, y);
 289     if (op_bits(op) == 32) {
 290         res &= 0xffffffff;
 291     }
 292     return res;
 293 }
 294
 295 /* Return 2 if the condition can't be simplified, and the result
 296    of the condition (0 or 1) if it can */
 297 static TCGArg do_constant_folding_cond(TCGOpcode op, TCGArg x,
 298                                        TCGArg y, TCGCond c)
 299 {
 300     if (temps[x].state == TCG_TEMP_CONST && temps[y].state == TCG_TEMP_CONST) {
 301         switch (op_bits(op)) {
 302         case 32:
 303             switch (c) {
 304             case TCG_COND_EQ:
 305                 return (uint32_t)temps[x].val == (uint32_t)temps[y].val;
 306             case TCG_COND_NE:
 307                 return (uint32_t)temps[x].val != (uint32_t)temps[y].val;
 308             case TCG_COND_LT:
 309                 return (int32_t)temps[x].val < (int32_t)temps[y].val;
 310             case TCG_COND_GE:
 311                 return (int32_t)temps[x].val >= (int32_t)temps[y].val;
 312             case TCG_COND_LE:
 313                 return (int32_t)temps[x].val <= (int32_t)temps[y].val;
 314             case TCG_COND_GT:
 315                 return (int32_t)temps[x].val > (int32_t)temps[y].val;
 316             case TCG_COND_LTU:
 317                 return (uint32_t)temps[x].val < (uint32_t)temps[y].val;
 318             case TCG_COND_GEU:
 319                 return (uint32_t)temps[x].val >= (uint32_t)temps[y].val;
 320             case TCG_COND_LEU:
 321                 return (uint32_t)temps[x].val <= (uint32_t)temps[y].val;
 322             case TCG_COND_GTU:
 323                 return (uint32_t)temps[x].val > (uint32_t)temps[y].val;
 324             }
 325             break;
 326         case 64:
 327             switch (c) {
 328             case TCG_COND_EQ:
 329                 return (uint64_t)temps[x].val == (uint64_t)temps[y].val;
 330             case TCG_COND_NE:
 331                 return (uint64_t)temps[x].val != (uint64_t)temps[y].val;
 332             case TCG_COND_LT:
 333                 return (int64_t)temps[x].val < (int64_t)temps[y].val;
 334             case TCG_COND_GE:
 335                 return (int64_t)temps[x].val >= (int64_t)temps[y].val;
 336             case TCG_COND_LE:
 337                 return (int64_t)temps[x].val <= (int64_t)temps[y].val;
 338             case TCG_COND_GT:
 339                 return (int64_t)temps[x].val > (int64_t)temps[y].val;
 340             case TCG_COND_LTU:
 341                 return (uint64_t)temps[x].val < (uint64_t)temps[y].val;
 342             case TCG_COND_GEU:
 343                 return (uint64_t)temps[x].val >= (uint64_t)temps[y].val;
 344             case TCG_COND_LEU:
 345                 return (uint64_t)temps[x].val <= (uint64_t)temps[y].val;
 346             case TCG_COND_GTU:
 347                 return (uint64_t)temps[x].val > (uint64_t)temps[y].val;
 348             }
 349             break;
 350         }
 351     } else if (temps_are_copies(x, y)) {
 352         switch (c) {
 353         case TCG_COND_GT:
 354         case TCG_COND_LTU:
 355         case TCG_COND_LT:
 356         case TCG_COND_GTU:
 357         case TCG_COND_NE:
 358             return 0;
 359         case TCG_COND_GE:
 360         case TCG_COND_GEU:
 361         case TCG_COND_LE:
 362         case TCG_COND_LEU:
 363         case TCG_COND_EQ:
 364             return 1;
 365         }
 366     } else if (temps[y].state == TCG_TEMP_CONST && temps[y].val == 0) {
 367         switch (c) {
 368         case TCG_COND_LTU:
 369             return 0;
 370         case TCG_COND_GEU:
 371             return 1;
 372         default:
 373             return 2;
 374         }
 375     } else {
 376         return 2;
 377     }
 378
 379     fprintf(stderr,
 380             "Unrecognized bitness %d or condition %d in "
 381             "do_constant_folding_cond.\n", op_bits(op), c);
 382     tcg_abort();
 383 }
 384
 385 /* Propagate constants and copies, fold constant expressions. */
 386 static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
 387                                     TCGArg *args, TCGOpDef *tcg_op_defs)
 388 {
 389     int i, nb_ops, op_index, nb_temps, nb_globals, nb_call_args;
 390     TCGOpcode op;
 391     const TCGOpDef *def;
 392     TCGArg *gen_args;
 393     TCGArg tmp;
 394     TCGCond cond;
 395
 396     /* Array VALS has an element for each temp.
 397        If this temp holds a constant then its value is kept in VALS' element.
 398        If this temp is a copy of other ones then the other copies are
 399        available through the doubly linked circular list. */
 400
 401     nb_temps = s->nb_temps;
 402     nb_globals = s->nb_globals;
 403     memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
 404
 405     nb_ops = tcg_opc_ptr - gen_opc_buf;
 406     gen_args = args;
 407     for (op_index = 0; op_index < nb_ops; op_index++) {
 408         op = gen_opc_buf[op_index];
 409         def = &tcg_op_defs[op];
 410         /* Do copy propagation */
 411         if (op == INDEX_op_call) {
 412             int nb_oargs = args[0] >> 16;
 413             int nb_iargs = args[0] & 0xffff;
 414             for (i = nb_oargs + 1; i < nb_oargs + nb_iargs + 1; i++) {
 415                 if (temps[args[i]].state == TCG_TEMP_COPY) {
 416                     args[i] = find_better_copy(s, args[i]);
 417                 }
 418             }
 419         } else {
 420             for (i = def->nb_oargs; i < def->nb_oargs + def->nb_iargs; i++) {
 421                 if (temps[args[i]].state == TCG_TEMP_COPY) {
 422                     args[i] = find_better_copy(s, args[i]);
 423                 }
 424             }
 425         }
 426
 427         /* For commutative operations make constant second argument */
 428         switch (op) {
 429         CASE_OP_32_64(add):
 430         CASE_OP_32_64(mul):
 431         CASE_OP_32_64(and):
 432         CASE_OP_32_64(or):
 433         CASE_OP_32_64(xor):
 434         CASE_OP_32_64(eqv):
 435         CASE_OP_32_64(nand):
 436         CASE_OP_32_64(nor):
 437             /* Prefer the constant in second argument, and then the form
 438                op a, a, b, which is better handled on non-RISC hosts. */
 439             if (temps[args[1]].state == TCG_TEMP_CONST || (args[0] == args[2]
 440                 && temps[args[2]].state != TCG_TEMP_CONST)) {
 441                 tmp = args[1];
 442                 args[1] = args[2];
 443                 args[2] = tmp;
 444             }
 445             break;
 446         CASE_OP_32_64(brcond):
 447             if (temps[args[0]].state == TCG_TEMP_CONST
 448                 && temps[args[1]].state != TCG_TEMP_CONST) {
 449                 tmp = args[0];
 450                 args[0] = args[1];
 451                 args[1] = tmp;
 452                 args[2] = tcg_swap_cond(args[2]);
 453             }
 454             break;
 455         CASE_OP_32_64(setcond):
 456             if (temps[args[1]].state == TCG_TEMP_CONST
 457                 && temps[args[2]].state != TCG_TEMP_CONST) {
 458                 tmp = args[1];
 459                 args[1] = args[2];
 460                 args[2] = tmp;
 461                 args[3] = tcg_swap_cond(args[3]);
 462             }
 463             break;
 464         CASE_OP_32_64(movcond):
 465             cond = args[5];
 466             if (temps[args[1]].state == TCG_TEMP_CONST
 467                 && temps[args[2]].state != TCG_TEMP_CONST) {
 468                 tmp = args[1];
 469                 args[1] = args[2];
 470                 args[2] = tmp;
 471                 cond = tcg_swap_cond(cond);
 472             }
 473             /* For movcond, we canonicalize the "false" input reg to match
 474                the destination reg so that the tcg backend can implement
 475                a "move if true" operation.  */
 476             if (args[0] == args[3]) {
 477                 tmp = args[3];
 478                 args[3] = args[4];
 479                 args[4] = tmp;
 480                 cond = tcg_invert_cond(cond);
 481             }
 482             args[5] = cond;
 483         default:
 484             break;
 485         }
 486
 487         /* Simplify expressions for "shift/rot r, 0, a => movi r, 0" */
 488         switch (op) {
 489         CASE_OP_32_64(shl):
 490         CASE_OP_32_64(shr):
 491         CASE_OP_32_64(sar):
 492         CASE_OP_32_64(rotl):
 493         CASE_OP_32_64(rotr):
 494             if (temps[args[1]].state == TCG_TEMP_CONST
 495                 && temps[args[1]].val == 0) {
 496                 gen_opc_buf[op_index] = op_to_movi(op);
 497                 tcg_opt_gen_movi(gen_args, args[0], 0);
 498                 args += 3;
 499                 gen_args += 2;
 500                 continue;
 501             }
 502             break;
 503         default:
 504             break;
 505         }
 506
 507         /* Simplify expression for "op r, a, 0 => mov r, a" cases */
 508         switch (op) {
 509         CASE_OP_32_64(add):
 510         CASE_OP_32_64(sub):
 511         CASE_OP_32_64(shl):
 512         CASE_OP_32_64(shr):
 513         CASE_OP_32_64(sar):
 514         CASE_OP_32_64(rotl):
 515         CASE_OP_32_64(rotr):
 516         CASE_OP_32_64(or):
 517         CASE_OP_32_64(xor):
 518             if (temps[args[1]].state == TCG_TEMP_CONST) {
 519                 /* Proceed with possible constant folding. */
 520                 break;
 521             }
 522             if (temps[args[2]].state == TCG_TEMP_CONST
 523                 && temps[args[2]].val == 0) {
 524                 if (temps_are_copies(args[0], args[1])) {
 525                     gen_opc_buf[op_index] = INDEX_op_nop;
 526                 } else {
 527                     gen_opc_buf[op_index] = op_to_mov(op);
 528                     tcg_opt_gen_mov(s, gen_args, args[0], args[1]);
 529                     gen_args += 2;
 530                 }
 531                 args += 3;
 532                 continue;
 533             }
 534             break;
 535         default:
 536             break;
 537         }
 538
 539         /* Simplify expression for "op r, a, 0 => movi r, 0" cases */
 540         switch (op) {
 541         CASE_OP_32_64(and):
 542         CASE_OP_32_64(mul):
 543             if ((temps[args[2]].state == TCG_TEMP_CONST
 544                 && temps[args[2]].val == 0)) {
 545                 gen_opc_buf[op_index] = op_to_movi(op);
 546                 tcg_opt_gen_movi(gen_args, args[0], 0);
 547                 args += 3;
 548                 gen_args += 2;
 549                 continue;
 550             }
 551             break;
 552         default:
 553             break;
 554         }
 555
 556         /* Simplify expression for "op r, a, a => mov r, a" cases */
 557         switch (op) {
 558         CASE_OP_32_64(or):
 559         CASE_OP_32_64(and):
 560             if (temps_are_copies(args[1], args[2])) {
 561                 if (temps_are_copies(args[0], args[1])) {
 562                     gen_opc_buf[op_index] = INDEX_op_nop;
 563                 } else {
 564                     gen_opc_buf[op_index] = op_to_mov(op);
 565                     tcg_opt_gen_mov(s, gen_args, args[0], args[1]);
 566                     gen_args += 2;
 567                 }
 568                 args += 3;
 569                 continue;
 570             }
 571             break;
 572         default:
 573             break;
 574         }
 575
 576         /* Simplify expression for "op r, a, a => movi r, 0" cases */
 577         switch (op) {
 578         CASE_OP_32_64(sub):
 579         CASE_OP_32_64(xor):
 580             if (temps_are_copies(args[1], args[2])) {
 581                 gen_opc_buf[op_index] = op_to_movi(op);
 582                 tcg_opt_gen_movi(gen_args, args[0], 0);
 583                 gen_args += 2;
 584                 args += 3;
 585                 continue;
 586             }
 587             break;
 588         default:
 589             break;
 590         }
 591
 592         /* Propagate constants through copy operations and do constant
 593            folding.  Constants will be substituted to arguments by register
 594            allocator where needed and possible.  Also detect copies. */
 595         switch (op) {
 596         CASE_OP_32_64(mov):
 597             if (temps_are_copies(args[0], args[1])) {
 598                 args += 2;
 599                 gen_opc_buf[op_index] = INDEX_op_nop;
 600                 break;
 601             }
 602             if (temps[args[1]].state != TCG_TEMP_CONST) {
 603                 tcg_opt_gen_mov(s, gen_args, args[0], args[1]);
 604                 gen_args += 2;
 605                 args += 2;
 606                 break;
 607             }
 608             /* Source argument is constant.  Rewrite the operation and
 609                let movi case handle it. */
 610             op = op_to_movi(op);
 611             gen_opc_buf[op_index] = op;
 612             args[1] = temps[args[1]].val;
 613             /* fallthrough */
 614         CASE_OP_32_64(movi):
 615             tcg_opt_gen_movi(gen_args, args[0], args[1]);
 616             gen_args += 2;
 617             args += 2;
 618             break;
 619         CASE_OP_32_64(not):
 620         CASE_OP_32_64(neg):
 621         CASE_OP_32_64(ext8s):
 622         CASE_OP_32_64(ext8u):
 623         CASE_OP_32_64(ext16s):
 624         CASE_OP_32_64(ext16u):
 625         case INDEX_op_ext32s_i64:
 626         case INDEX_op_ext32u_i64:
 627             if (temps[args[1]].state == TCG_TEMP_CONST) {
 628                 gen_opc_buf[op_index] = op_to_movi(op);
 629                 tmp = do_constant_folding(op, temps[args[1]].val, 0);
 630                 tcg_opt_gen_movi(gen_args, args[0], tmp);
 631             } else {
 632                 reset_temp(args[0]);
 633                 gen_args[0] = args[0];
 634                 gen_args[1] = args[1];
 635             }
 636             gen_args += 2;
 637             args += 2;
 638             break;
 639         CASE_OP_32_64(add):
 640         CASE_OP_32_64(sub):
 641         CASE_OP_32_64(mul):
 642         CASE_OP_32_64(or):
 643         CASE_OP_32_64(and):
 644         CASE_OP_32_64(xor):
 645         CASE_OP_32_64(shl):
 646         CASE_OP_32_64(shr):
 647         CASE_OP_32_64(sar):
 648         CASE_OP_32_64(rotl):
 649         CASE_OP_32_64(rotr):
 650         CASE_OP_32_64(andc):
 651         CASE_OP_32_64(orc):
 652         CASE_OP_32_64(eqv):
 653         CASE_OP_32_64(nand):
 654         CASE_OP_32_64(nor):
 655             if (temps[args[1]].state == TCG_TEMP_CONST
 656                 && temps[args[2]].state == TCG_TEMP_CONST) {
 657                 gen_opc_buf[op_index] = op_to_movi(op);
 658                 tmp = do_constant_folding(op, temps[args[1]].val,
 659                                           temps[args[2]].val);
 660                 tcg_opt_gen_movi(gen_args, args[0], tmp);
 661                 gen_args += 2;
 662             } else {
 663                 reset_temp(args[0]);
 664                 gen_args[0] = args[0];
 665                 gen_args[1] = args[1];
 666                 gen_args[2] = args[2];
 667                 gen_args += 3;
 668             }
 669             args += 3;
 670             break;
 671         CASE_OP_32_64(setcond):
 672             tmp = do_constant_folding_cond(op, args[1], args[2], args[3]);
 673             if (tmp != 2) {
 674                 gen_opc_buf[op_index] = op_to_movi(op);
 675                 tcg_opt_gen_movi(gen_args, args[0], tmp);
 676                 gen_args += 2;
 677             } else {
 678                 reset_temp(args[0]);
 679                 gen_args[0] = args[0];
 680                 gen_args[1] = args[1];
 681                 gen_args[2] = args[2];
 682                 gen_args[3] = args[3];
 683                 gen_args += 4;
 684             }
 685             args += 4;
 686             break;
 687         CASE_OP_32_64(brcond):
 688             tmp = do_constant_folding_cond(op, args[0], args[1], args[2]);
 689             if (tmp != 2) {
 690                 if (tmp) {
 691                     memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
 692                     gen_opc_buf[op_index] = INDEX_op_br;
 693                     gen_args[0] = args[3];
 694                     gen_args += 1;
 695                 } else {
 696                     gen_opc_buf[op_index] = INDEX_op_nop;
 697                 }
 698             } else {
 699                 memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
 700                 reset_temp(args[0]);
 701                 gen_args[0] = args[0];
 702                 gen_args[1] = args[1];
 703                 gen_args[2] = args[2];
 704                 gen_args[3] = args[3];
 705                 gen_args += 4;
 706             }
 707             args += 4;
 708             break;
 709         CASE_OP_32_64(movcond):
 710             tmp = do_constant_folding_cond(op, args[1], args[2], args[5]);
 711             if (tmp != 2) {
 712                 if (temps_are_copies(args[0], args[4-tmp])) {
 713                     gen_opc_buf[op_index] = INDEX_op_nop;
 714                 } else if (temps[args[4-tmp]].state == TCG_TEMP_CONST) {
 715                     gen_opc_buf[op_index] = op_to_movi(op);
 716                     tcg_opt_gen_movi(gen_args, args[0], temps[args[4-tmp]].val);
 717                     gen_args += 2;
 718                 } else {
 719                     gen_opc_buf[op_index] = op_to_mov(op);
 720                     tcg_opt_gen_mov(s, gen_args, args[0], args[4-tmp]);
 721                     gen_args += 2;
 722                 }
 723             } else {
 724                 reset_temp(args[0]);
 725                 gen_args[0] = args[0];
 726                 gen_args[1] = args[1];
 727                 gen_args[2] = args[2];
 728                 gen_args[3] = args[3];
 729                 gen_args[4] = args[4];
 730                 gen_args[5] = args[5];
 731                 gen_args += 6;
 732             }
 733             args += 6;
 734             break;
 735         case INDEX_op_call:
 736             nb_call_args = (args[0] >> 16) + (args[0] & 0xffff);
 737             if (!(args[nb_call_args + 1] & (TCG_CALL_CONST | TCG_CALL_PURE))) {
 738                 for (i = 0; i < nb_globals; i++) {
 739                     reset_temp(i);
 740                 }
 741             }
 742             for (i = 0; i < (args[0] >> 16); i++) {
 743                 reset_temp(args[i + 1]);
 744             }
 745             i = nb_call_args + 3;
 746             while (i) {
 747                 *gen_args = *args;
 748                 args++;
 749                 gen_args++;
 750                 i--;
 751             }
 752             break;
 753         default:
 754             /* Default case: we do know nothing about operation so no
 755                propagation is done.  We trash everything if the operation
 756                is the end of a basic block, otherwise we only trash the
 757                output args.  */
 758             if (def->flags & TCG_OPF_BB_END) {
 759                 memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
 760             } else {
 761                 for (i = 0; i < def->nb_oargs; i++) {
 762                     reset_temp(args[i]);
 763                 }
 764             }
 765             for (i = 0; i < def->nb_args; i++) {
 766                 gen_args[i] = args[i];
 767             }
 768             args += def->nb_args;
 769             gen_args += def->nb_args;
 770             break;
 771         }
 772     }
 773
 774     return gen_args;
 775 }
 776
 777 TCGArg *tcg_optimize(TCGContext *s, uint16_t *tcg_opc_ptr,
 778         TCGArg *args, TCGOpDef *tcg_op_defs)
 779 {
 780     TCGArg *res;
 781     res = tcg_constant_folding(s, tcg_opc_ptr, args, tcg_op_defs);
 782     return res;
 783 }