src/gallium/drivers/r300/r300_fs.c

   1 /*
   2  * Copyright 2008 Corbin Simpson <MostAwesomeDude@gmail.com>
   3  *                Joakim Sindholt <opensource@zhasha.com>
   4  * Copyright 2009 Marek Olšák <maraeo@gmail.com>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * on the rights to use, copy, modify, merge, publish, distribute, sub
  10  * license, and/or sell copies of the Software, and to permit persons to whom
  11  * the Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * 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 NON-INFRINGEMENT. IN NO EVENT SHALL
  20  * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
  21  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  22  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  23  * USE OR OTHER DEALINGS IN THE SOFTWARE. */
  24
  25 #include "util/u_math.h"
  26 #include "util/u_memory.h"
  27
  28 #include "tgsi/tgsi_dump.h"
  29 #include "tgsi/tgsi_ureg.h"
  30
  31 #include "r300_cb.h"
  32 #include "r300_context.h"
  33 #include "r300_emit.h"
  34 #include "r300_screen.h"
  35 #include "r300_fs.h"
  36 #include "r300_reg.h"
  37 #include "r300_tgsi_to_rc.h"
  38
  39 #include "radeon_code.h"
  40 #include "radeon_compiler.h"
  41
  42 /* Convert info about FS input semantics to r300_shader_semantics. */
  43 void r300_shader_read_fs_inputs(struct tgsi_shader_info* info,
  44                                 struct r300_shader_semantics* fs_inputs)
  45 {
  46     int i;
  47     unsigned index;
  48
  49     r300_shader_semantics_reset(fs_inputs);
  50
  51     for (i = 0; i < info->num_inputs; i++) {
  52         index = info->input_semantic_index[i];
  53
  54         switch (info->input_semantic_name[i]) {
  55             case TGSI_SEMANTIC_COLOR:
  56                 assert(index < ATTR_COLOR_COUNT);
  57                 fs_inputs->color[index] = i;
  58                 break;
  59
  60             case TGSI_SEMANTIC_GENERIC:
  61                 assert(index < ATTR_GENERIC_COUNT);
  62                 fs_inputs->generic[index] = i;
  63                 break;
  64
  65             case TGSI_SEMANTIC_FOG:
  66                 assert(index == 0);
  67                 fs_inputs->fog = i;
  68                 break;
  69
  70             case TGSI_SEMANTIC_POSITION:
  71                 assert(index == 0);
  72                 fs_inputs->wpos = i;
  73                 break;
  74
  75             case TGSI_SEMANTIC_FACE:
  76                 assert(index == 0);
  77                 fs_inputs->face = i;
  78                 break;
  79
  80             default:
  81                 fprintf(stderr, "r300: FP: Unknown input semantic: %i\n",
  82                         info->input_semantic_name[i]);
  83         }
  84     }
  85 }
  86
  87 static void find_output_registers(struct r300_fragment_program_compiler * compiler,
  88                                   struct r300_fragment_shader_code *shader)
  89 {
  90     unsigned i, colorbuf_count = 0;
  91
  92     /* Mark the outputs as not present initially */
  93     compiler->OutputColor[0] = shader->info.num_outputs;
  94     compiler->OutputColor[1] = shader->info.num_outputs;
  95     compiler->OutputColor[2] = shader->info.num_outputs;
  96     compiler->OutputColor[3] = shader->info.num_outputs;
  97     compiler->OutputDepth = shader->info.num_outputs;
  98
  99     /* Now see where they really are. */
 100     for(i = 0; i < shader->info.num_outputs; ++i) {
 101         switch(shader->info.output_semantic_name[i]) {
 102             case TGSI_SEMANTIC_COLOR:
 103                 compiler->OutputColor[colorbuf_count] = i;
 104                 colorbuf_count++;
 105                 break;
 106             case TGSI_SEMANTIC_POSITION:
 107                 compiler->OutputDepth = i;
 108                 break;
 109         }
 110     }
 111 }
 112
 113 static void allocate_hardware_inputs(
 114     struct r300_fragment_program_compiler * c,
 115     void (*allocate)(void * data, unsigned input, unsigned hwreg),
 116     void * mydata)
 117 {
 118     struct r300_shader_semantics* inputs =
 119         (struct r300_shader_semantics*)c->UserData;
 120     int i, reg = 0;
 121
 122     /* Allocate input registers. */
 123     for (i = 0; i < ATTR_COLOR_COUNT; i++) {
 124         if (inputs->color[i] != ATTR_UNUSED) {
 125             allocate(mydata, inputs->color[i], reg++);
 126         }
 127     }
 128     if (inputs->face != ATTR_UNUSED) {
 129         allocate(mydata, inputs->face, reg++);
 130     }
 131     for (i = 0; i < ATTR_GENERIC_COUNT; i++) {
 132         if (inputs->generic[i] != ATTR_UNUSED) {
 133             allocate(mydata, inputs->generic[i], reg++);
 134         }
 135     }
 136     if (inputs->fog != ATTR_UNUSED) {
 137         allocate(mydata, inputs->fog, reg++);
 138     }
 139     if (inputs->wpos != ATTR_UNUSED) {
 140         allocate(mydata, inputs->wpos, reg++);
 141     }
 142 }
 143
 144 static void get_external_state(
 145     struct r300_context* r300,
 146     struct r300_fragment_program_external_state* state)
 147 {
 148     struct r300_textures_state *texstate = r300->textures_state.state;
 149     struct r300_rs_state *rs = r300->rs_state.state;
 150     unsigned i;
 151     unsigned char *swizzle;
 152
 153     state->frag_clamp = rs ? rs->rs.clamp_fragment_color : 0;
 154
 155     for (i = 0; i < texstate->sampler_state_count; i++) {
 156         struct r300_sampler_state *s = texstate->sampler_states[i];
 157         struct r300_sampler_view *v = texstate->sampler_views[i];
 158         struct r300_resource *t;
 159
 160         if (!s || !v) {
 161             continue;
 162         }
 163
 164         t = r300_resource(texstate->sampler_views[i]->base.texture);
 165
 166         if (s->state.compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE) {
 167             state->unit[i].compare_mode_enabled = 1;
 168
 169             /* Pass depth texture swizzling to the compiler. */
 170             if (texstate->sampler_views[i]) {
 171                 swizzle = texstate->sampler_views[i]->swizzle;
 172
 173                 state->unit[i].depth_texture_swizzle =
 174                     RC_MAKE_SWIZZLE(swizzle[0], swizzle[1],
 175                                     swizzle[2], swizzle[3]);
 176             } else {
 177                 state->unit[i].depth_texture_swizzle = RC_SWIZZLE_XYZW;
 178             }
 179
 180             /* Fortunately, no need to translate this. */
 181             state->unit[i].texture_compare_func = s->state.compare_func;
 182         }
 183
 184         state->unit[i].non_normalized_coords = !s->state.normalized_coords;
 185
 186         /* XXX this should probably take into account STR, not just S. */
 187         if (t->tex.is_npot) {
 188             switch (s->state.wrap_s) {
 189             case PIPE_TEX_WRAP_REPEAT:
 190                 state->unit[i].wrap_mode = RC_WRAP_REPEAT;
 191                 break;
 192
 193             case PIPE_TEX_WRAP_MIRROR_REPEAT:
 194                 state->unit[i].wrap_mode = RC_WRAP_MIRRORED_REPEAT;
 195                 break;
 196
 197             case PIPE_TEX_WRAP_MIRROR_CLAMP:
 198             case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
 199             case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
 200                 state->unit[i].wrap_mode = RC_WRAP_MIRRORED_CLAMP;
 201                 break;
 202
 203             default:
 204                 state->unit[i].wrap_mode = RC_WRAP_NONE;
 205             }
 206
 207             if (t->b.b.b.target == PIPE_TEXTURE_3D)
 208                 state->unit[i].clamp_and_scale_before_fetch = TRUE;
 209         }
 210     }
 211 }
 212
 213 static void r300_translate_fragment_shader(
 214     struct r300_context* r300,
 215     struct r300_fragment_shader_code* shader,
 216     const struct tgsi_token *tokens);
 217
 218 static void r300_dummy_fragment_shader(
 219     struct r300_context* r300,
 220     struct r300_fragment_shader_code* shader)
 221 {
 222     struct pipe_shader_state state;
 223     struct ureg_program *ureg;
 224     struct ureg_dst out;
 225     struct ureg_src imm;
 226
 227     /* Make a simple fragment shader which outputs (0, 0, 0, 1) */
 228     ureg = ureg_create(TGSI_PROCESSOR_FRAGMENT);
 229     out = ureg_DECL_output(ureg, TGSI_SEMANTIC_COLOR, 0);
 230     imm = ureg_imm4f(ureg, 0, 0, 0, 1);
 231
 232     ureg_MOV(ureg, out, imm);
 233     ureg_END(ureg);
 234
 235     state.tokens = ureg_finalize(ureg);
 236
 237     shader->dummy = TRUE;
 238     r300_translate_fragment_shader(r300, shader, state.tokens);
 239
 240     ureg_destroy(ureg);
 241 }
 242
 243 static void r300_emit_fs_code_to_buffer(
 244     struct r300_context *r300,
 245     struct r300_fragment_shader_code *shader)
 246 {
 247     struct rX00_fragment_program_code *generic_code = &shader->code;
 248     unsigned imm_count = shader->immediates_count;
 249     unsigned imm_first = shader->externals_count;
 250     unsigned imm_end = generic_code->constants.Count;
 251     struct rc_constant *constants = generic_code->constants.Constants;
 252     unsigned i;
 253     CB_LOCALS;
 254
 255     if (r300->screen->caps.is_r500) {
 256         struct r500_fragment_program_code *code = &generic_code->code.r500;
 257
 258         shader->cb_code_size = 19 +
 259                                ((code->inst_end + 1) * 6) +
 260                                imm_count * 7 +
 261                                code->int_constant_count * 2;
 262
 263         NEW_CB(shader->cb_code, shader->cb_code_size);
 264         OUT_CB_REG(R500_US_CONFIG, R500_ZERO_TIMES_ANYTHING_EQUALS_ZERO);
 265         OUT_CB_REG(R500_US_PIXSIZE, code->max_temp_idx);
 266         OUT_CB_REG(R500_US_FC_CTRL, code->us_fc_ctrl);
 267         for(i = 0; i < code->int_constant_count; i++){
 268                 OUT_CB_REG(R500_US_FC_INT_CONST_0 + (i * 4),
 269                                                 code->int_constants[i]);
 270         }
 271         OUT_CB_REG(R500_US_CODE_RANGE,
 272                    R500_US_CODE_RANGE_ADDR(0) | R500_US_CODE_RANGE_SIZE(code->inst_end));
 273         OUT_CB_REG(R500_US_CODE_OFFSET, 0);
 274         OUT_CB_REG(R500_US_CODE_ADDR,
 275                    R500_US_CODE_START_ADDR(0) | R500_US_CODE_END_ADDR(code->inst_end));
 276
 277         OUT_CB_REG(R500_GA_US_VECTOR_INDEX, R500_GA_US_VECTOR_INDEX_TYPE_INSTR);
 278         OUT_CB_ONE_REG(R500_GA_US_VECTOR_DATA, (code->inst_end + 1) * 6);
 279         for (i = 0; i <= code->inst_end; i++) {
 280             OUT_CB(code->inst[i].inst0);
 281             OUT_CB(code->inst[i].inst1);
 282             OUT_CB(code->inst[i].inst2);
 283             OUT_CB(code->inst[i].inst3);
 284             OUT_CB(code->inst[i].inst4);
 285             OUT_CB(code->inst[i].inst5);
 286         }
 287
 288         /* Emit immediates. */
 289         if (imm_count) {
 290             for(i = imm_first; i < imm_end; ++i) {
 291                 if (constants[i].Type == RC_CONSTANT_IMMEDIATE) {
 292                     const float *data = constants[i].u.Immediate;
 293
 294                     OUT_CB_REG(R500_GA_US_VECTOR_INDEX,
 295                                R500_GA_US_VECTOR_INDEX_TYPE_CONST |
 296                                (i & R500_GA_US_VECTOR_INDEX_MASK));
 297                     OUT_CB_ONE_REG(R500_GA_US_VECTOR_DATA, 4);
 298                     OUT_CB_TABLE(data, 4);
 299                 }
 300             }
 301         }
 302     } else { /* r300 */
 303         struct r300_fragment_program_code *code = &generic_code->code.r300;
 304         unsigned int alu_length = code->alu.length;
 305         unsigned int alu_iterations = ((alu_length - 1) / 64) + 1;
 306         unsigned int tex_length = code->tex.length;
 307         unsigned int tex_iterations =
 308             tex_length > 0 ? ((tex_length - 1) / 32) + 1 : 0;
 309         unsigned int iterations =
 310             alu_iterations > tex_iterations ? alu_iterations : tex_iterations;
 311         unsigned int bank = 0;
 312
 313         shader->cb_code_size = 15 +
 314             /* R400_US_CODE_BANK */
 315             (r300->screen->caps.is_r400 ? 2 * (iterations + 1): 0) +
 316             /* R400_US_CODE_EXT */
 317             (r300->screen->caps.is_r400 ? 2 : 0) +
 318             /* R300_US_ALU_{RGB,ALPHA}_{INST,ADDR}_0, R400_US_ALU_EXT_ADDR_0 */
 319             (code->r390_mode ? (5 * alu_iterations) : 4) +
 320             /* R400_US_ALU_EXT_ADDR_[0-63] */
 321             (code->r390_mode ? (code->alu.length) : 0) +
 322             /* R300_US_ALU_{RGB,ALPHA}_{INST,ADDR}_0 */
 323             code->alu.length * 4 +
 324             /* R300_US_TEX_INST_0, R300_US_TEX_INST_[0-31] */
 325             (code->tex.length > 0 ? code->tex.length + tex_iterations : 0) +
 326             imm_count * 5;
 327
 328         NEW_CB(shader->cb_code, shader->cb_code_size);
 329
 330         OUT_CB_REG(R300_US_CONFIG, code->config);
 331         OUT_CB_REG(R300_US_PIXSIZE, code->pixsize);
 332         OUT_CB_REG(R300_US_CODE_OFFSET, code->code_offset);
 333
 334         if (code->r390_mode) {
 335             OUT_CB_REG(R400_US_CODE_EXT, code->r400_code_offset_ext);
 336         } else if (r300->screen->caps.is_r400) {
 337             /* This register appears to affect shaders even if r390_mode is
 338              * disabled, so it needs to be set to 0 for shaders that
 339              * don't use r390_mode. */
 340             OUT_CB_REG(R400_US_CODE_EXT, 0);
 341         }
 342
 343         OUT_CB_REG_SEQ(R300_US_CODE_ADDR_0, 4);
 344         OUT_CB_TABLE(code->code_addr, 4);
 345
 346         do {
 347             unsigned int bank_alu_length = (alu_length < 64 ? alu_length : 64);
 348             unsigned int bank_alu_offset = bank * 64;
 349             unsigned int bank_tex_length = (tex_length < 32 ? tex_length : 32);
 350             unsigned int bank_tex_offset = bank * 32;
 351
 352             if (r300->screen->caps.is_r400) {
 353                 OUT_CB_REG(R400_US_CODE_BANK, code->r390_mode ?
 354                                 (bank << R400_BANK_SHIFT) | R400_R390_MODE_ENABLE : 0);//2
 355             }
 356
 357             if (bank_alu_length > 0) {
 358                 OUT_CB_REG_SEQ(R300_US_ALU_RGB_INST_0, bank_alu_length);
 359                 for (i = 0; i < bank_alu_length; i++)
 360                     OUT_CB(code->alu.inst[i + bank_alu_offset].rgb_inst);
 361
 362                 OUT_CB_REG_SEQ(R300_US_ALU_RGB_ADDR_0, bank_alu_length);
 363                 for (i = 0; i < bank_alu_length; i++)
 364                     OUT_CB(code->alu.inst[i + bank_alu_offset].rgb_addr);
 365
 366                 OUT_CB_REG_SEQ(R300_US_ALU_ALPHA_INST_0, bank_alu_length);
 367                 for (i = 0; i < bank_alu_length; i++)
 368                     OUT_CB(code->alu.inst[i + bank_alu_offset].alpha_inst);
 369
 370                 OUT_CB_REG_SEQ(R300_US_ALU_ALPHA_ADDR_0, bank_alu_length);
 371                 for (i = 0; i < bank_alu_length; i++)
 372                     OUT_CB(code->alu.inst[i + bank_alu_offset].alpha_addr);
 373
 374                 if (code->r390_mode) {
 375                     OUT_CB_REG_SEQ(R400_US_ALU_EXT_ADDR_0, bank_alu_length);
 376                     for (i = 0; i < bank_alu_length; i++)
 377                         OUT_CB(code->alu.inst[i + bank_alu_offset].r400_ext_addr);
 378                 }
 379             }
 380
 381             if (bank_tex_length > 0) {
 382                 OUT_CB_REG_SEQ(R300_US_TEX_INST_0, bank_tex_length);
 383                 OUT_CB_TABLE(code->tex.inst + bank_tex_offset, bank_tex_length);
 384             }
 385
 386             alu_length -= bank_alu_length;
 387             tex_length -= bank_tex_length;
 388             bank++;
 389         } while(code->r390_mode && (alu_length > 0 || tex_length > 0));
 390
 391         /* R400_US_CODE_BANK needs to be reset to 0, otherwise some shaders
 392          * will be rendered incorrectly. */
 393         if (r300->screen->caps.is_r400) {
 394             OUT_CB_REG(R400_US_CODE_BANK,
 395                 code->r390_mode ? R400_R390_MODE_ENABLE : 0);
 396         }
 397
 398         /* Emit immediates. */
 399         if (imm_count) {
 400             for(i = imm_first; i < imm_end; ++i) {
 401                 if (constants[i].Type == RC_CONSTANT_IMMEDIATE) {
 402                     const float *data = constants[i].u.Immediate;
 403
 404                     OUT_CB_REG_SEQ(R300_PFS_PARAM_0_X + i * 16, 4);
 405                     OUT_CB(pack_float24(data[0]));
 406                     OUT_CB(pack_float24(data[1]));
 407                     OUT_CB(pack_float24(data[2]));
 408                     OUT_CB(pack_float24(data[3]));
 409                 }
 410             }
 411         }
 412     }
 413
 414     OUT_CB_REG(R300_FG_DEPTH_SRC, shader->fg_depth_src);
 415     OUT_CB_REG(R300_US_W_FMT, shader->us_out_w);
 416     END_CB;
 417 }
 418
 419 static void r300_translate_fragment_shader(
 420     struct r300_context* r300,
 421     struct r300_fragment_shader_code* shader,
 422     const struct tgsi_token *tokens)
 423 {
 424     struct r300_fragment_program_compiler compiler;
 425     struct tgsi_to_rc ttr;
 426     int wpos, face;
 427     unsigned i;
 428
 429     tgsi_scan_shader(tokens, &shader->info);
 430     r300_shader_read_fs_inputs(&shader->info, &shader->inputs);
 431
 432     wpos = shader->inputs.wpos;
 433     face = shader->inputs.face;
 434
 435     /* Setup the compiler. */
 436     memset(&compiler, 0, sizeof(compiler));
 437     rc_init(&compiler.Base);
 438     DBG_ON(r300, DBG_FP) ? compiler.Base.Debug |= RC_DBG_LOG : 0;
 439     DBG_ON(r300, DBG_P_STAT) ? compiler.Base.Debug |= RC_DBG_STATS : 0;
 440
 441     compiler.code = &shader->code;
 442     compiler.state = shader->compare_state;
 443     compiler.Base.is_r500 = r300->screen->caps.is_r500;
 444     compiler.Base.is_r400 = r300->screen->caps.is_r400;
 445     compiler.Base.disable_optimizations = DBG_ON(r300, DBG_NO_OPT);
 446     compiler.Base.has_half_swizzles = TRUE;
 447     compiler.Base.has_presub = TRUE;
 448     compiler.Base.max_temp_regs =
 449         compiler.Base.is_r500 ? 128 : (compiler.Base.is_r400 ? 64 : 32);
 450     compiler.Base.max_constants = compiler.Base.is_r500 ? 256 : 32;
 451     compiler.Base.max_alu_insts =
 452         (compiler.Base.is_r500 || compiler.Base.is_r400) ? 512 : 64;
 453     compiler.Base.max_tex_insts =
 454         (compiler.Base.is_r500 || compiler.Base.is_r400) ? 512 : 32;
 455     compiler.AllocateHwInputs = &allocate_hardware_inputs;
 456     compiler.UserData = &shader->inputs;
 457
 458     find_output_registers(&compiler, shader);
 459
 460     shader->write_all = FALSE;
 461     for (i = 0; i < shader->info.num_properties; i++) {
 462         if (shader->info.properties[i].name == TGSI_PROPERTY_FS_COLOR0_WRITES_ALL_CBUFS) {
 463             shader->write_all = TRUE;
 464         }
 465     }
 466
 467     if (compiler.Base.Debug & RC_DBG_LOG) {
 468         DBG(r300, DBG_FP, "r300: Initial fragment program\n");
 469         tgsi_dump(tokens, 0);
 470     }
 471
 472     /* Translate TGSI to our internal representation */
 473     ttr.compiler = &compiler.Base;
 474     ttr.info = &shader->info;
 475     ttr.use_half_swizzles = TRUE;
 476
 477     r300_tgsi_to_rc(&ttr, tokens);
 478
 479     if (ttr.error) {
 480         fprintf(stderr, "r300 FP: Cannot translate a shader. "
 481                 "Using a dummy shader instead.\n");
 482         r300_dummy_fragment_shader(r300, shader);
 483         return;
 484     }
 485
 486     if (!r300->screen->caps.is_r500 ||
 487         compiler.Base.Program.Constants.Count > 200) {
 488         compiler.Base.remove_unused_constants = TRUE;
 489     }
 490
 491     /**
 492      * Transform the program to support WPOS.
 493      *
 494      * Introduce a small fragment at the start of the program that will be
 495      * the only code that directly reads the WPOS input.
 496      * All other code pieces that reference that input will be rewritten
 497      * to read from a newly allocated temporary. */
 498     if (wpos != ATTR_UNUSED) {
 499         /* Moving the input to some other reg is not really necessary. */
 500         rc_transform_fragment_wpos(&compiler.Base, wpos, wpos, TRUE);
 501     }
 502
 503     if (face != ATTR_UNUSED) {
 504         rc_transform_fragment_face(&compiler.Base, face);
 505     }
 506
 507     /* Invoke the compiler */
 508     r3xx_compile_fragment_program(&compiler);
 509
 510     if (compiler.Base.Error) {
 511         fprintf(stderr, "r300 FP: Compiler Error:\n%sUsing a dummy shader"
 512                 " instead.\n", compiler.Base.ErrorMsg);
 513
 514         if (shader->dummy) {
 515             fprintf(stderr, "r300 FP: Cannot compile the dummy shader! "
 516                     "Giving up...\n");
 517             abort();
 518         }
 519
 520         rc_destroy(&compiler.Base);
 521         r300_dummy_fragment_shader(r300, shader);
 522         return;
 523     }
 524
 525     /* Shaders with zero instructions are invalid,
 526      * use the dummy shader instead. */
 527     if (shader->code.code.r500.inst_end == -1) {
 528         rc_destroy(&compiler.Base);
 529         r300_dummy_fragment_shader(r300, shader);
 530         return;
 531     }
 532
 533     /* Initialize numbers of constants for each type. */
 534     shader->externals_count = 0;
 535     for (i = 0;
 536          i < shader->code.constants.Count &&
 537          shader->code.constants.Constants[i].Type == RC_CONSTANT_EXTERNAL; i++) {
 538         shader->externals_count = i+1;
 539     }
 540     shader->immediates_count = 0;
 541     shader->rc_state_count = 0;
 542
 543     for (i = shader->externals_count; i < shader->code.constants.Count; i++) {
 544         switch (shader->code.constants.Constants[i].Type) {
 545             case RC_CONSTANT_IMMEDIATE:
 546                 ++shader->immediates_count;
 547                 break;
 548             case RC_CONSTANT_STATE:
 549                 ++shader->rc_state_count;
 550                 break;
 551             default:
 552                 assert(0);
 553         }
 554     }
 555
 556     /* Setup shader depth output. */
 557     if (shader->code.writes_depth) {
 558         shader->fg_depth_src = R300_FG_DEPTH_SRC_SHADER;
 559         shader->us_out_w = R300_W_FMT_W24 | R300_W_SRC_US;
 560     } else {
 561         shader->fg_depth_src = R300_FG_DEPTH_SRC_SCAN;
 562         shader->us_out_w = R300_W_FMT_W0 | R300_W_SRC_US;
 563     }
 564
 565     /* And, finally... */
 566     rc_destroy(&compiler.Base);
 567
 568     /* Build the command buffer. */
 569     r300_emit_fs_code_to_buffer(r300, shader);
 570 }
 571
 572 boolean r300_pick_fragment_shader(struct r300_context* r300)
 573 {
 574     struct r300_fragment_shader* fs = r300_fs(r300);
 575     struct r300_fragment_program_external_state state = {{{ 0 }}};
 576     struct r300_fragment_shader_code* ptr;
 577
 578     get_external_state(r300, &state);
 579
 580     if (!fs->first) {
 581         /* Build the fragment shader for the first time. */
 582         fs->first = fs->shader = CALLOC_STRUCT(r300_fragment_shader_code);
 583
 584         memcpy(&fs->shader->compare_state, &state,
 585             sizeof(struct r300_fragment_program_external_state));
 586         r300_translate_fragment_shader(r300, fs->shader, fs->state.tokens);
 587         return TRUE;
 588
 589     } else {
 590         /* Check if the currently-bound shader has been compiled
 591          * with the texture-compare state we need. */
 592         if (memcmp(&fs->shader->compare_state, &state, sizeof(state)) != 0) {
 593             /* Search for the right shader. */
 594             ptr = fs->first;
 595             while (ptr) {
 596                 if (memcmp(&ptr->compare_state, &state, sizeof(state)) == 0) {
 597                     if (fs->shader != ptr) {
 598                         fs->shader = ptr;
 599                         return TRUE;
 600                     }
 601                     /* The currently-bound one is OK. */
 602                     return FALSE;
 603                 }
 604                 ptr = ptr->next;
 605             }
 606
 607             /* Not found, gotta compile a new one. */
 608             ptr = CALLOC_STRUCT(r300_fragment_shader_code);
 609             ptr->next = fs->first;
 610             fs->first = fs->shader = ptr;
 611
 612             ptr->compare_state = state;
 613             r300_translate_fragment_shader(r300, ptr, fs->state.tokens);
 614             return TRUE;
 615         }
 616     }
 617
 618     return FALSE;
 619 }