src/gallium/auxiliary/gallivm/lp_bld_tgsi_info.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2010 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  18  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  19  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  20  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * The above copyright notice and this permission notice (including the
  23  * next paragraph) shall be included in all copies or substantial portions
  24  * of the Software.
  25  *
  26  **************************************************************************/
  27
  28
  29 #include "util/u_memory.h"
  30 #include "util/u_math.h"
  31 #include "tgsi/tgsi_parse.h"
  32 #include "tgsi/tgsi_util.h"
  33 #include "tgsi/tgsi_dump.h"
  34 #include "tgsi/tgsi_strings.h"
  35 #include "lp_bld_debug.h"
  36 #include "lp_bld_tgsi.h"
  37
  38
  39 /**
  40  * Analysis context.
  41  *
  42  * This is where we keep store the value of each channel of the IMM/TEMP/OUT
  43  * register values, as we walk the shader.
  44  */
  45 struct analysis_context
  46 {
  47    struct lp_tgsi_info *info;
  48
  49    unsigned num_imms;
  50    float imm[LP_MAX_TGSI_IMMEDIATES][4];
  51    unsigned sample_target[PIPE_MAX_SHADER_SAMPLER_VIEWS];
  52
  53    struct lp_tgsi_channel_info temp[32][4];
  54 };
  55
  56
  57 /**
  58  * Describe the specified channel of the src register.
  59  */
  60 static void
  61 analyse_src(struct analysis_context *ctx,
  62             struct lp_tgsi_channel_info *chan_info,
  63             const struct tgsi_src_register *src,
  64             unsigned chan)
  65 {
  66    chan_info->file = TGSI_FILE_NULL;
  67    if (!src->Indirect && !src->Absolute && !src->Negate) {
  68       unsigned swizzle = tgsi_util_get_src_register_swizzle(src, chan);
  69       if (src->File == TGSI_FILE_TEMPORARY) {
  70          if (src->Index < ARRAY_SIZE(ctx->temp)) {
  71             *chan_info = ctx->temp[src->Index][swizzle];
  72          }
  73       } else {
  74          chan_info->file = src->File;
  75          if (src->File == TGSI_FILE_IMMEDIATE) {
  76             assert(src->Index < ARRAY_SIZE(ctx->imm));
  77             if (src->Index < ARRAY_SIZE(ctx->imm)) {
  78                chan_info->u.value = ctx->imm[src->Index][swizzle];
  79             }
  80          } else {
  81             chan_info->u.index = src->Index;
  82             chan_info->swizzle = swizzle;
  83          }
  84       }
  85    }
  86 }
  87
  88
  89 /**
  90  * Whether this register channel refers to a specific immediate value.
  91  */
  92 static boolean
  93 is_immediate(const struct lp_tgsi_channel_info *chan_info, float value)
  94 {
  95    return chan_info->file == TGSI_FILE_IMMEDIATE &&
  96           chan_info->u.value == value;
  97 }
  98
  99
 100 /**
 101  * Analyse properties of tex instructions, in particular used
 102  * to figure out if a texture is considered indirect.
 103  * Not actually used by much except the tgsi dumping code.
 104  */
 105 static void
 106 analyse_tex(struct analysis_context *ctx,
 107             const struct tgsi_full_instruction *inst,
 108             enum lp_build_tex_modifier modifier)
 109 {
 110    struct lp_tgsi_info *info = ctx->info;
 111    unsigned chan;
 112
 113    if (info->num_texs < ARRAY_SIZE(info->tex)) {
 114       struct lp_tgsi_texture_info *tex_info = &info->tex[info->num_texs];
 115       boolean indirect = FALSE;
 116       unsigned readmask = 0;
 117
 118       tex_info->target = inst->Texture.Texture;
 119       switch (inst->Texture.Texture) {
 120       case TGSI_TEXTURE_1D:
 121          readmask = TGSI_WRITEMASK_X;
 122          break;
 123       case TGSI_TEXTURE_1D_ARRAY:
 124       case TGSI_TEXTURE_2D:
 125       case TGSI_TEXTURE_RECT:
 126          readmask = TGSI_WRITEMASK_XY;
 127          break;
 128       case TGSI_TEXTURE_SHADOW1D:
 129       case TGSI_TEXTURE_SHADOW1D_ARRAY:
 130       case TGSI_TEXTURE_SHADOW2D:
 131       case TGSI_TEXTURE_SHADOWRECT:
 132       case TGSI_TEXTURE_2D_ARRAY:
 133       case TGSI_TEXTURE_2D_MSAA:
 134       case TGSI_TEXTURE_3D:
 135       case TGSI_TEXTURE_CUBE:
 136          readmask = TGSI_WRITEMASK_XYZ;
 137          break;
 138       case TGSI_TEXTURE_SHADOW2D_ARRAY:
 139       case TGSI_TEXTURE_SHADOWCUBE:
 140       case TGSI_TEXTURE_2D_ARRAY_MSAA:
 141       case TGSI_TEXTURE_CUBE_ARRAY:
 142          readmask = TGSI_WRITEMASK_XYZW;
 143          /* modifier would be in another not analyzed reg so just say indirect */
 144          if (modifier != LP_BLD_TEX_MODIFIER_NONE) {
 145             indirect = TRUE;
 146          }
 147          break;
 148       case TGSI_TEXTURE_SHADOWCUBE_ARRAY:
 149          readmask = TGSI_WRITEMASK_XYZW;
 150          indirect = TRUE;
 151          break;
 152       default:
 153          assert(0);
 154          return;
 155       }
 156
 157       if (modifier == LP_BLD_TEX_MODIFIER_EXPLICIT_DERIV) {
 158          /* We don't track explicit derivatives, although we could */
 159          indirect = TRUE;
 160          tex_info->sampler_unit = inst->Src[3].Register.Index;
 161          tex_info->texture_unit = inst->Src[3].Register.Index;
 162       }  else {
 163          if (modifier == LP_BLD_TEX_MODIFIER_PROJECTED ||
 164              modifier == LP_BLD_TEX_MODIFIER_LOD_BIAS ||
 165              modifier == LP_BLD_TEX_MODIFIER_EXPLICIT_LOD) {
 166             readmask |= TGSI_WRITEMASK_W;
 167          }
 168          tex_info->sampler_unit = inst->Src[1].Register.Index;
 169          tex_info->texture_unit = inst->Src[1].Register.Index;
 170       }
 171
 172       for (chan = 0; chan < 4; ++chan) {
 173          struct lp_tgsi_channel_info *chan_info = &tex_info->coord[chan];
 174          if (readmask & (1 << chan)) {
 175             analyse_src(ctx, chan_info, &inst->Src[0].Register, chan);
 176             if (chan_info->file != TGSI_FILE_INPUT) {
 177                indirect = TRUE;
 178             }
 179          } else {
 180             memset(chan_info, 0, sizeof *chan_info);
 181          }
 182       }
 183
 184       if (indirect) {
 185          info->indirect_textures = TRUE;
 186       }
 187
 188       ++info->num_texs;
 189    } else {
 190       info->indirect_textures = TRUE;
 191    }
 192 }
 193
 194
 195 /**
 196  * Analyse properties of sample instructions, in particular used
 197  * to figure out if a texture is considered indirect.
 198  * Not actually used by much except the tgsi dumping code.
 199  */
 200 static void
 201 analyse_sample(struct analysis_context *ctx,
 202                const struct tgsi_full_instruction *inst,
 203                enum lp_build_tex_modifier modifier,
 204                boolean shadow)
 205 {
 206    struct lp_tgsi_info *info = ctx->info;
 207    unsigned chan;
 208
 209    if (info->num_texs < ARRAY_SIZE(info->tex)) {
 210       struct lp_tgsi_texture_info *tex_info = &info->tex[info->num_texs];
 211       unsigned target = ctx->sample_target[inst->Src[1].Register.Index];
 212       boolean indirect = FALSE;
 213       boolean shadow = FALSE;
 214       unsigned readmask;
 215
 216       switch (target) {
 217       /* note no shadow targets here */
 218       case TGSI_TEXTURE_BUFFER:
 219       case TGSI_TEXTURE_1D:
 220          readmask = TGSI_WRITEMASK_X;
 221          break;
 222       case TGSI_TEXTURE_1D_ARRAY:
 223       case TGSI_TEXTURE_2D:
 224       case TGSI_TEXTURE_RECT:
 225          readmask = TGSI_WRITEMASK_XY;
 226          break;
 227       case TGSI_TEXTURE_2D_ARRAY:
 228       case TGSI_TEXTURE_2D_MSAA:
 229       case TGSI_TEXTURE_3D:
 230       case TGSI_TEXTURE_CUBE:
 231          readmask = TGSI_WRITEMASK_XYZ;
 232          break;
 233       case TGSI_TEXTURE_CUBE_ARRAY:
 234       case TGSI_TEXTURE_2D_ARRAY_MSAA:
 235          readmask = TGSI_WRITEMASK_XYZW;
 236          break;
 237       default:
 238          assert(0);
 239          return;
 240       }
 241
 242       tex_info->target = target;
 243       tex_info->texture_unit = inst->Src[1].Register.Index;
 244       tex_info->sampler_unit = inst->Src[2].Register.Index;
 245
 246       if (tex_info->texture_unit != tex_info->sampler_unit) {
 247          info->sampler_texture_units_different = TRUE;
 248       }
 249
 250       if (modifier == LP_BLD_TEX_MODIFIER_EXPLICIT_DERIV ||
 251           modifier == LP_BLD_TEX_MODIFIER_EXPLICIT_LOD ||
 252           modifier == LP_BLD_TEX_MODIFIER_LOD_BIAS || shadow) {
 253          /* We don't track insts with additional regs, although we could */
 254          indirect = TRUE;
 255       }
 256
 257       for (chan = 0; chan < 4; ++chan) {
 258          struct lp_tgsi_channel_info *chan_info = &tex_info->coord[chan];
 259          if (readmask & (1 << chan)) {
 260             analyse_src(ctx, chan_info, &inst->Src[0].Register, chan);
 261             if (chan_info->file != TGSI_FILE_INPUT) {
 262                indirect = TRUE;
 263             }
 264          } else {
 265             memset(chan_info, 0, sizeof *chan_info);
 266          }
 267       }
 268
 269       if (indirect) {
 270          info->indirect_textures = TRUE;
 271       }
 272
 273       ++info->num_texs;
 274    } else {
 275       info->indirect_textures = TRUE;
 276    }
 277 }
 278
 279
 280 /**
 281  * Process an instruction, and update the register values accordingly.
 282  */
 283 static void
 284 analyse_instruction(struct analysis_context *ctx,
 285                     struct tgsi_full_instruction *inst)
 286 {
 287    struct lp_tgsi_info *info = ctx->info;
 288    struct lp_tgsi_channel_info (*regs)[4];
 289    unsigned max_regs;
 290    unsigned i;
 291    unsigned index;
 292    unsigned chan;
 293
 294    for (i = 0; i < inst->Instruction.NumDstRegs; ++i) {
 295       const struct tgsi_dst_register *dst = &inst->Dst[i].Register;
 296
 297       /*
 298        * Get the lp_tgsi_channel_info array corresponding to the destination
 299        * register file.
 300        */
 301
 302       if (dst->File == TGSI_FILE_TEMPORARY) {
 303          regs = ctx->temp;
 304          max_regs = ARRAY_SIZE(ctx->temp);
 305       } else if (dst->File == TGSI_FILE_OUTPUT) {
 306          regs = info->output;
 307          max_regs = ARRAY_SIZE(info->output);
 308       } else if (dst->File == TGSI_FILE_ADDRESS) {
 309          continue;
 310       } else if (dst->File == TGSI_FILE_BUFFER) {
 311          continue;
 312       } else if (dst->File == TGSI_FILE_IMAGE) {
 313          continue;
 314       } else if (dst->File == TGSI_FILE_MEMORY) {
 315          continue;
 316       } else {
 317          assert(0);
 318          continue;
 319       }
 320
 321       /*
 322        * Detect direct TEX instructions
 323        */
 324
 325       switch (inst->Instruction.Opcode) {
 326       case TGSI_OPCODE_TEX:
 327          analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_NONE);
 328          break;
 329       case TGSI_OPCODE_TXD:
 330          analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_EXPLICIT_DERIV);
 331          break;
 332       case TGSI_OPCODE_TXB:
 333          analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_LOD_BIAS);
 334          break;
 335       case TGSI_OPCODE_TXL:
 336          analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_EXPLICIT_LOD);
 337          break;
 338       case TGSI_OPCODE_TXP:
 339          analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_PROJECTED);
 340          break;
 341       case TGSI_OPCODE_TEX2:
 342          analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_NONE);
 343          break;
 344       case TGSI_OPCODE_TXB2:
 345          analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_LOD_BIAS);
 346          break;
 347       case TGSI_OPCODE_TXL2:
 348          analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_EXPLICIT_LOD);
 349          break;
 350       case TGSI_OPCODE_SAMPLE:
 351          analyse_sample(ctx, inst, LP_BLD_TEX_MODIFIER_NONE, FALSE);
 352          break;
 353       case TGSI_OPCODE_SAMPLE_C:
 354          analyse_sample(ctx, inst, LP_BLD_TEX_MODIFIER_NONE, TRUE);
 355          break;
 356       case TGSI_OPCODE_SAMPLE_C_LZ:
 357          analyse_sample(ctx, inst, LP_BLD_TEX_MODIFIER_LOD_ZERO, TRUE);
 358          break;
 359       case TGSI_OPCODE_SAMPLE_D:
 360          analyse_sample(ctx, inst, LP_BLD_TEX_MODIFIER_EXPLICIT_DERIV, FALSE);
 361          break;
 362       case TGSI_OPCODE_SAMPLE_B:
 363          analyse_sample(ctx, inst, LP_BLD_TEX_MODIFIER_LOD_BIAS, FALSE);
 364          break;
 365       case TGSI_OPCODE_SAMPLE_L:
 366          analyse_sample(ctx, inst, LP_BLD_TEX_MODIFIER_EXPLICIT_LOD, FALSE);
 367          break;
 368       default:
 369          break;
 370       }
 371
 372       /*
 373        * Keep track of assignments and writes
 374        */
 375
 376       if (dst->Indirect) {
 377          /*
 378           * It could be any register index so clear all register indices.
 379           */
 380
 381          for (chan = 0; chan < 4; ++chan) {
 382             if (dst->WriteMask & (1 << chan)) {
 383                for (index = 0; index < max_regs; ++index) {
 384                   regs[index][chan].file = TGSI_FILE_NULL;
 385                }
 386             }
 387          }
 388       } else if (dst->Index < max_regs) {
 389          /*
 390           * Update this destination register value.
 391           */
 392
 393          struct lp_tgsi_channel_info res[4];
 394
 395          memset(res, 0, sizeof res);
 396
 397          if (!inst->Instruction.Saturate) {
 398             for (chan = 0; chan < 4; ++chan) {
 399                if (dst->WriteMask & (1 << chan)) {
 400                   if (inst->Instruction.Opcode == TGSI_OPCODE_MOV) {
 401                      analyse_src(ctx, &res[chan],
 402                                  &inst->Src[0].Register, chan);
 403                   } else if (inst->Instruction.Opcode == TGSI_OPCODE_MUL) {
 404                      /*
 405                       * Propagate values across 1.0 and 0.0 multiplications.
 406                       */
 407
 408                      struct lp_tgsi_channel_info src0;
 409                      struct lp_tgsi_channel_info src1;
 410
 411                      analyse_src(ctx, &src0, &inst->Src[0].Register, chan);
 412                      analyse_src(ctx, &src1, &inst->Src[1].Register, chan);
 413
 414                      if (is_immediate(&src0, 0.0f)) {
 415                         res[chan] = src0;
 416                      } else if (is_immediate(&src1, 0.0f)) {
 417                         res[chan] = src1;
 418                      } else if (is_immediate(&src0, 1.0f)) {
 419                         res[chan] = src1;
 420                      } else if (is_immediate(&src1, 1.0f)) {
 421                         res[chan] = src0;
 422                      }
 423                   }
 424                }
 425             }
 426          }
 427
 428          for (chan = 0; chan < 4; ++chan) {
 429             if (dst->WriteMask & (1 << chan)) {
 430                regs[dst->Index][chan] = res[chan];
 431             }
 432          }
 433       }
 434    }
 435
 436    /*
 437     * Clear all temporaries information in presence of a control flow opcode.
 438     */
 439
 440    switch (inst->Instruction.Opcode) {
 441    case TGSI_OPCODE_IF:
 442    case TGSI_OPCODE_UIF:
 443    case TGSI_OPCODE_ELSE:
 444    case TGSI_OPCODE_ENDIF:
 445    case TGSI_OPCODE_BGNLOOP:
 446    case TGSI_OPCODE_BRK:
 447    case TGSI_OPCODE_CONT:
 448    case TGSI_OPCODE_ENDLOOP:
 449    case TGSI_OPCODE_CAL:
 450    case TGSI_OPCODE_BGNSUB:
 451    case TGSI_OPCODE_ENDSUB:
 452    case TGSI_OPCODE_SWITCH:
 453    case TGSI_OPCODE_CASE:
 454    case TGSI_OPCODE_DEFAULT:
 455    case TGSI_OPCODE_ENDSWITCH:
 456    case TGSI_OPCODE_RET:
 457    case TGSI_OPCODE_END:
 458       /* XXX: Are there more cases? */
 459       memset(&ctx->temp, 0, sizeof ctx->temp);
 460       memset(&info->output, 0, sizeof info->output);
 461    default:
 462       break;
 463    }
 464 }
 465
 466
 467 static inline void
 468 dump_info(const struct tgsi_token *tokens,
 469           struct lp_tgsi_info *info)
 470 {
 471    unsigned index;
 472    unsigned chan;
 473
 474    tgsi_dump(tokens, 0);
 475
 476    for (index = 0; index < info->num_texs; ++index) {
 477       const struct lp_tgsi_texture_info *tex_info = &info->tex[index];
 478       debug_printf("TEX[%u] =", index);
 479       for (chan = 0; chan < 4; ++chan) {
 480          const struct lp_tgsi_channel_info *chan_info =
 481                &tex_info->coord[chan];
 482          if (chan_info->file != TGSI_FILE_NULL) {
 483             debug_printf(" %s[%u].%c",
 484                          tgsi_file_name(chan_info->file),
 485                          chan_info->u.index,
 486                          "xyzw01"[chan_info->swizzle]);
 487          } else {
 488             debug_printf(" _");
 489          }
 490       }
 491       debug_printf(", RES[%u], SAMP[%u], %s\n",
 492                    tex_info->texture_unit,
 493                    tex_info->sampler_unit,
 494                    tgsi_texture_names[tex_info->target]);
 495    }
 496
 497    for (index = 0; index < PIPE_MAX_SHADER_OUTPUTS; ++index) {
 498       for (chan = 0; chan < 4; ++chan) {
 499          const struct lp_tgsi_channel_info *chan_info =
 500                &info->output[index][chan];
 501          if (chan_info->file != TGSI_FILE_NULL) {
 502             debug_printf("OUT[%u].%c = ", index, "xyzw"[chan]);
 503             if (chan_info->file == TGSI_FILE_IMMEDIATE) {
 504                debug_printf("%f", chan_info->u.value);
 505             } else {
 506                const char *file_name;
 507                switch (chan_info->file) {
 508                case TGSI_FILE_CONSTANT:
 509                   file_name = "CONST";
 510                   break;
 511                case TGSI_FILE_INPUT:
 512                   file_name = "IN";
 513                   break;
 514                default:
 515                   file_name = "???";
 516                   break;
 517                }
 518                debug_printf("%s[%u].%c",
 519                             file_name,
 520                             chan_info->u.index,
 521                             "xyzw01"[chan_info->swizzle]);
 522             }
 523             debug_printf("\n");
 524          }
 525       }
 526    }
 527 }
 528
 529
 530 /**
 531  * Detect any direct relationship between the output color
 532  */
 533 void
 534 lp_build_tgsi_info(const struct tgsi_token *tokens,
 535                    struct lp_tgsi_info *info)
 536 {
 537    struct tgsi_parse_context parse;
 538    struct analysis_context *ctx;
 539    unsigned index;
 540    unsigned chan;
 541
 542    memset(info, 0, sizeof *info);
 543
 544    tgsi_scan_shader(tokens, &info->base);
 545
 546    ctx = CALLOC(1, sizeof(struct analysis_context));
 547    ctx->info = info;
 548
 549    tgsi_parse_init(&parse, tokens);
 550
 551    while (!tgsi_parse_end_of_tokens(&parse)) {
 552       tgsi_parse_token(&parse);
 553
 554       switch (parse.FullToken.Token.Type) {
 555       case TGSI_TOKEN_TYPE_DECLARATION: {
 556          struct tgsi_full_declaration *decl = &parse.FullToken.FullDeclaration;
 557          if (decl->Declaration.File == TGSI_FILE_SAMPLER_VIEW) {
 558             for (index = decl->Range.First; index <= decl->Range.Last; index++) {
 559                ctx->sample_target[index] = decl->SamplerView.Resource;
 560             }
 561          }
 562       }
 563          break;
 564
 565       case TGSI_TOKEN_TYPE_INSTRUCTION:
 566          {
 567             struct tgsi_full_instruction *inst =
 568                   &parse.FullToken.FullInstruction;
 569
 570             if (inst->Instruction.Opcode == TGSI_OPCODE_END ||
 571                 inst->Instruction.Opcode == TGSI_OPCODE_BGNSUB) {
 572                /* We reached the end of main function body. */
 573                goto finished;
 574             }
 575
 576             analyse_instruction(ctx, inst);
 577          }
 578          break;
 579
 580       case TGSI_TOKEN_TYPE_IMMEDIATE:
 581          {
 582             const unsigned size =
 583                   parse.FullToken.FullImmediate.Immediate.NrTokens - 1;
 584             assert(size <= 4);
 585             if (ctx->num_imms < ARRAY_SIZE(ctx->imm)) {
 586                for (chan = 0; chan < size; ++chan) {
 587                   float value = parse.FullToken.FullImmediate.u[chan].Float;
 588                   ctx->imm[ctx->num_imms][chan] = value;
 589
 590                   if (value < 0.0f || value > 1.0f) {
 591                      info->unclamped_immediates = TRUE;
 592                   }
 593                }
 594                ++ctx->num_imms;
 595             }
 596          }
 597          break;
 598
 599       case TGSI_TOKEN_TYPE_PROPERTY:
 600          break;
 601
 602       default:
 603          assert(0);
 604       }
 605    }
 606 finished:
 607
 608    tgsi_parse_free(&parse);
 609    FREE(ctx);
 610
 611
 612    /*
 613     * Link the output color values.
 614     */
 615
 616    for (index = 0; index < PIPE_MAX_COLOR_BUFS; ++index) {
 617       static const struct lp_tgsi_channel_info null_output[4];
 618       info->cbuf[index] = null_output;
 619    }
 620
 621    for (index = 0; index < info->base.num_outputs; ++index) {
 622       unsigned semantic_name = info->base.output_semantic_name[index];
 623       unsigned semantic_index = info->base.output_semantic_index[index];
 624       if (semantic_name == TGSI_SEMANTIC_COLOR &&
 625           semantic_index < PIPE_MAX_COLOR_BUFS) {
 626          info->cbuf[semantic_index] = info->output[index];
 627       }
 628    }
 629
 630    if (gallivm_debug & GALLIVM_DEBUG_TGSI) {
 631       dump_info(tokens, info);
 632    }
 633 }