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     unsigned i;
 150     unsigned char *swizzle;
 151
 152     for (i = 0; i < texstate->sampler_state_count; i++) {
 153         struct r300_sampler_state *s = texstate->sampler_states[i];
 154         struct r300_sampler_view *v = texstate->sampler_views[i];
 155         struct r300_resource *t;
 156
 157         if (!s || !v) {
 158             continue;
 159         }
 160
 161         t = r300_resource(texstate->sampler_views[i]->base.texture);
 162
 163         if (s->state.compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE) {
 164             state->unit[i].compare_mode_enabled = 1;
 165
 166             /* Pass depth texture swizzling to the compiler. */
 167             if (texstate->sampler_views[i]) {
 168                 swizzle = texstate->sampler_views[i]->swizzle;
 169
 170                 state->unit[i].depth_texture_swizzle =
 171                     RC_MAKE_SWIZZLE(swizzle[0], swizzle[1],
 172                                     swizzle[2], swizzle[3]);
 173             } else {
 174                 state->unit[i].depth_texture_swizzle = RC_SWIZZLE_XYZW;
 175             }
 176
 177             /* Fortunately, no need to translate this. */
 178             state->unit[i].texture_compare_func = s->state.compare_func;
 179         }
 180
 181         state->unit[i].non_normalized_coords = !s->state.normalized_coords;
 182
 183         /* XXX this should probably take into account STR, not just S. */
 184         if (t->tex.is_npot) {
 185             switch (s->state.wrap_s) {
 186             case PIPE_TEX_WRAP_REPEAT:
 187                 state->unit[i].wrap_mode = RC_WRAP_REPEAT;
 188                 break;
 189
 190             case PIPE_TEX_WRAP_MIRROR_REPEAT:
 191                 state->unit[i].wrap_mode = RC_WRAP_MIRRORED_REPEAT;
 192                 break;
 193
 194             case PIPE_TEX_WRAP_MIRROR_CLAMP:
 195             case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
 196             case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
 197                 state->unit[i].wrap_mode = RC_WRAP_MIRRORED_CLAMP;
 198                 break;
 199
 200             default:
 201                 state->unit[i].wrap_mode = RC_WRAP_NONE;
 202             }
 203
 204             if (t->b.b.b.target == PIPE_TEXTURE_3D)
 205                 state->unit[i].clamp_and_scale_before_fetch = TRUE;
 206         }
 207     }
 208 }
 209
 210 static void r300_translate_fragment_shader(
 211     struct r300_context* r300,
 212     struct r300_fragment_shader_code* shader,
 213     const struct tgsi_token *tokens);
 214
 215 static void r300_dummy_fragment_shader(
 216     struct r300_context* r300,
 217     struct r300_fragment_shader_code* shader)
 218 {
 219     struct pipe_shader_state state;
 220     struct ureg_program *ureg;
 221     struct ureg_dst out;
 222     struct ureg_src imm;
 223
 224     /* Make a simple fragment shader which outputs (0, 0, 0, 1) */
 225     ureg = ureg_create(TGSI_PROCESSOR_FRAGMENT);
 226     out = ureg_DECL_output(ureg, TGSI_SEMANTIC_COLOR, 0);
 227     imm = ureg_imm4f(ureg, 0, 0, 0, 1);
 228
 229     ureg_MOV(ureg, out, imm);
 230     ureg_END(ureg);
 231
 232     state.tokens = ureg_finalize(ureg);
 233
 234     shader->dummy = TRUE;
 235     r300_translate_fragment_shader(r300, shader, state.tokens);
 236
 237     ureg_destroy(ureg);
 238 }
 239
 240 static void r300_emit_fs_code_to_buffer(
 241     struct r300_context *r300,
 242     struct r300_fragment_shader_code *shader)
 243 {
 244     struct rX00_fragment_program_code *generic_code = &shader->code;
 245     unsigned imm_count = shader->immediates_count;
 246     unsigned imm_first = shader->externals_count;
 247     unsigned imm_end = generic_code->constants.Count;
 248     struct rc_constant *constants = generic_code->constants.Constants;
 249     unsigned i;
 250     CB_LOCALS;
 251
 252     if (r300->screen->caps.is_r500) {
 253         struct r500_fragment_program_code *code = &generic_code->code.r500;
 254
 255         shader->cb_code_size = 19 +
 256                                ((code->inst_end + 1) * 6) +
 257                                imm_count * 7 +
 258                                code->int_constant_count * 2;
 259
 260         NEW_CB(shader->cb_code, shader->cb_code_size);
 261         OUT_CB_REG(R500_US_CONFIG, R500_ZERO_TIMES_ANYTHING_EQUALS_ZERO);
 262         OUT_CB_REG(R500_US_PIXSIZE, code->max_temp_idx);
 263         OUT_CB_REG(R500_US_FC_CTRL, code->us_fc_ctrl);
 264         for(i = 0; i < code->int_constant_count; i++){
 265                 OUT_CB_REG(R500_US_FC_INT_CONST_0 + (i * 4),
 266                                                 code->int_constants[i]);
 267         }
 268         OUT_CB_REG(R500_US_CODE_RANGE,
 269                    R500_US_CODE_RANGE_ADDR(0) | R500_US_CODE_RANGE_SIZE(code->inst_end));
 270         OUT_CB_REG(R500_US_CODE_OFFSET, 0);
 271         OUT_CB_REG(R500_US_CODE_ADDR,
 272                    R500_US_CODE_START_ADDR(0) | R500_US_CODE_END_ADDR(code->inst_end));
 273
 274         OUT_CB_REG(R500_GA_US_VECTOR_INDEX, R500_GA_US_VECTOR_INDEX_TYPE_INSTR);
 275         OUT_CB_ONE_REG(R500_GA_US_VECTOR_DATA, (code->inst_end + 1) * 6);
 276         for (i = 0; i <= code->inst_end; i++) {
 277             OUT_CB(code->inst[i].inst0);
 278             OUT_CB(code->inst[i].inst1);
 279             OUT_CB(code->inst[i].inst2);
 280             OUT_CB(code->inst[i].inst3);
 281             OUT_CB(code->inst[i].inst4);
 282             OUT_CB(code->inst[i].inst5);
 283         }
 284
 285         /* Emit immediates. */
 286         if (imm_count) {
 287             for(i = imm_first; i < imm_end; ++i) {
 288                 if (constants[i].Type == RC_CONSTANT_IMMEDIATE) {
 289                     const float *data = constants[i].u.Immediate;
 290
 291                     OUT_CB_REG(R500_GA_US_VECTOR_INDEX,
 292                                R500_GA_US_VECTOR_INDEX_TYPE_CONST |
 293                                (i & R500_GA_US_VECTOR_INDEX_MASK));
 294                     OUT_CB_ONE_REG(R500_GA_US_VECTOR_DATA, 4);
 295                     OUT_CB_TABLE(data, 4);
 296                 }
 297             }
 298         }
 299     } else { /* r300 */
 300         struct r300_fragment_program_code *code = &generic_code->code.r300;
 301         unsigned int alu_length = code->alu.length;
 302         unsigned int alu_iterations = ((alu_length - 1) / 64) + 1;
 303         unsigned int tex_length = code->tex.length;
 304         unsigned int tex_iterations =
 305             tex_length > 0 ? ((tex_length - 1) / 32) + 1 : 0;
 306         unsigned int iterations =
 307             alu_iterations > tex_iterations ? alu_iterations : tex_iterations;
 308         unsigned int bank = 0;
 309
 310         shader->cb_code_size = 15 +
 311             /* R400_US_CODE_BANK */
 312             (r300->screen->caps.is_r400 ? 2 * (iterations + 1): 0) +
 313             /* R400_US_CODE_EXT */
 314             (r300->screen->caps.is_r400 ? 2 : 0) +
 315             /* R300_US_ALU_{RGB,ALPHA}_{INST,ADDR}_0, R400_US_ALU_EXT_ADDR_0 */
 316             (code->r390_mode ? (5 * alu_iterations) : 4) +
 317             /* R400_US_ALU_EXT_ADDR_[0-63] */
 318             (code->r390_mode ? (code->alu.length) : 0) +
 319             /* R300_US_ALU_{RGB,ALPHA}_{INST,ADDR}_0 */
 320             code->alu.length * 4 +
 321             /* R300_US_TEX_INST_0, R300_US_TEX_INST_[0-31] */
 322             (code->tex.length > 0 ? code->tex.length + tex_iterations : 0) +
 323             imm_count * 5;
 324
 325         NEW_CB(shader->cb_code, shader->cb_code_size);
 326
 327         OUT_CB_REG(R300_US_CONFIG, code->config);
 328         OUT_CB_REG(R300_US_PIXSIZE, code->pixsize);
 329         OUT_CB_REG(R300_US_CODE_OFFSET, code->code_offset);
 330
 331         if (code->r390_mode) {
 332             OUT_CB_REG(R400_US_CODE_EXT, code->r400_code_offset_ext);
 333         } else if (r300->screen->caps.is_r400) {
 334             /* This register appears to affect shaders even if r390_mode is
 335              * disabled, so it needs to be set to 0 for shaders that
 336              * don't use r390_mode. */
 337             OUT_CB_REG(R400_US_CODE_EXT, 0);
 338         }
 339
 340         OUT_CB_REG_SEQ(R300_US_CODE_ADDR_0, 4);
 341         OUT_CB_TABLE(code->code_addr, 4);
 342
 343         do {
 344             unsigned int bank_alu_length = (alu_length < 64 ? alu_length : 64);
 345             unsigned int bank_alu_offset = bank * 64;
 346             unsigned int bank_tex_length = (tex_length < 32 ? tex_length : 32);
 347             unsigned int bank_tex_offset = bank * 32;
 348
 349             if (r300->screen->caps.is_r400) {
 350                 OUT_CB_REG(R400_US_CODE_BANK, code->r390_mode ?
 351                                 (bank << R400_BANK_SHIFT) | R400_R390_MODE_ENABLE : 0);//2
 352             }
 353
 354             if (bank_alu_length > 0) {
 355                 OUT_CB_REG_SEQ(R300_US_ALU_RGB_INST_0, bank_alu_length);
 356                 for (i = 0; i < bank_alu_length; i++)
 357                     OUT_CB(code->alu.inst[i + bank_alu_offset].rgb_inst);
 358
 359                 OUT_CB_REG_SEQ(R300_US_ALU_RGB_ADDR_0, bank_alu_length);
 360                 for (i = 0; i < bank_alu_length; i++)
 361                     OUT_CB(code->alu.inst[i + bank_alu_offset].rgb_addr);
 362
 363                 OUT_CB_REG_SEQ(R300_US_ALU_ALPHA_INST_0, bank_alu_length);
 364                 for (i = 0; i < bank_alu_length; i++)
 365                     OUT_CB(code->alu.inst[i + bank_alu_offset].alpha_inst);
 366
 367                 OUT_CB_REG_SEQ(R300_US_ALU_ALPHA_ADDR_0, bank_alu_length);
 368                 for (i = 0; i < bank_alu_length; i++)
 369                     OUT_CB(code->alu.inst[i + bank_alu_offset].alpha_addr);
 370
 371                 if (code->r390_mode) {
 372                     OUT_CB_REG_SEQ(R400_US_ALU_EXT_ADDR_0, bank_alu_length);
 373                     for (i = 0; i < bank_alu_length; i++)
 374                         OUT_CB(code->alu.inst[i + bank_alu_offset].r400_ext_addr);
 375                 }
 376             }
 377
 378             if (bank_tex_length > 0) {
 379                 OUT_CB_REG_SEQ(R300_US_TEX_INST_0, bank_tex_length);
 380                 OUT_CB_TABLE(code->tex.inst + bank_tex_offset, bank_tex_length);
 381             }
 382
 383             alu_length -= bank_alu_length;
 384             tex_length -= bank_tex_length;
 385             bank++;
 386         } while(code->r390_mode && (alu_length > 0 || tex_length > 0));
 387
 388         /* R400_US_CODE_BANK needs to be reset to 0, otherwise some shaders
 389          * will be rendered incorrectly. */
 390         if (r300->screen->caps.is_r400) {
 391             OUT_CB_REG(R400_US_CODE_BANK,
 392                 code->r390_mode ? R400_R390_MODE_ENABLE : 0);
 393         }
 394
 395         /* Emit immediates. */
 396         if (imm_count) {
 397             for(i = imm_first; i < imm_end; ++i) {
 398                 if (constants[i].Type == RC_CONSTANT_IMMEDIATE) {
 399                     const float *data = constants[i].u.Immediate;
 400
 401                     OUT_CB_REG_SEQ(R300_PFS_PARAM_0_X + i * 16, 4);
 402                     OUT_CB(pack_float24(data[0]));
 403                     OUT_CB(pack_float24(data[1]));
 404                     OUT_CB(pack_float24(data[2]));
 405                     OUT_CB(pack_float24(data[3]));
 406                 }
 407             }
 408         }
 409     }
 410
 411     OUT_CB_REG(R300_FG_DEPTH_SRC, shader->fg_depth_src);
 412     OUT_CB_REG(R300_US_W_FMT, shader->us_out_w);
 413     END_CB;
 414 }
 415
 416 static void r300_translate_fragment_shader(
 417     struct r300_context* r300,
 418     struct r300_fragment_shader_code* shader,
 419     const struct tgsi_token *tokens)
 420 {
 421     struct r300_fragment_program_compiler compiler;
 422     struct tgsi_to_rc ttr;
 423     int wpos, face;
 424     unsigned i;
 425
 426     tgsi_scan_shader(tokens, &shader->info);
 427     r300_shader_read_fs_inputs(&shader->info, &shader->inputs);
 428
 429     wpos = shader->inputs.wpos;
 430     face = shader->inputs.face;
 431
 432     /* Setup the compiler. */
 433     memset(&compiler, 0, sizeof(compiler));
 434     rc_init(&compiler.Base);
 435     DBG_ON(r300, DBG_FP) ? compiler.Base.Debug |= RC_DBG_LOG : 0;
 436     DBG_ON(r300, DBG_P_STAT) ? compiler.Base.Debug |= RC_DBG_STATS : 0;
 437
 438     compiler.code = &shader->code;
 439     compiler.state = shader->compare_state;
 440     compiler.Base.is_r500 = r300->screen->caps.is_r500;
 441     compiler.Base.is_r400 = r300->screen->caps.is_r400;
 442     compiler.Base.disable_optimizations = DBG_ON(r300, DBG_NO_OPT);
 443     compiler.Base.has_half_swizzles = TRUE;
 444     compiler.Base.has_presub = TRUE;
 445     compiler.Base.max_temp_regs =
 446         compiler.Base.is_r500 ? 128 : (compiler.Base.is_r400 ? 64 : 32);
 447     compiler.Base.max_constants = compiler.Base.is_r500 ? 256 : 32;
 448     compiler.Base.max_alu_insts =
 449         (compiler.Base.is_r500 || compiler.Base.is_r400) ? 512 : 64;
 450     compiler.Base.max_tex_insts =
 451         (compiler.Base.is_r500 || compiler.Base.is_r400) ? 512 : 32;
 452     compiler.AllocateHwInputs = &allocate_hardware_inputs;
 453     compiler.UserData = &shader->inputs;
 454
 455     find_output_registers(&compiler, shader);
 456
 457     shader->write_all = FALSE;
 458     for (i = 0; i < shader->info.num_properties; i++) {
 459         if (shader->info.properties[i].name == TGSI_PROPERTY_FS_COLOR0_WRITES_ALL_CBUFS) {
 460             shader->write_all = TRUE;
 461         }
 462     }
 463
 464     if (compiler.Base.Debug & RC_DBG_LOG) {
 465         DBG(r300, DBG_FP, "r300: Initial fragment program\n");
 466         tgsi_dump(tokens, 0);
 467     }
 468
 469     /* Translate TGSI to our internal representation */
 470     ttr.compiler = &compiler.Base;
 471     ttr.info = &shader->info;
 472     ttr.use_half_swizzles = TRUE;
 473
 474     r300_tgsi_to_rc(&ttr, tokens);
 475
 476     if (ttr.error) {
 477         fprintf(stderr, "r300 FP: Cannot translate a shader. "
 478                 "Using a dummy shader instead.\n");
 479         r300_dummy_fragment_shader(r300, shader);
 480         return;
 481     }
 482
 483     if (!r300->screen->caps.is_r500 ||
 484         compiler.Base.Program.Constants.Count > 200) {
 485         compiler.Base.remove_unused_constants = TRUE;
 486     }
 487
 488     /**
 489      * Transform the program to support WPOS.
 490      *
 491      * Introduce a small fragment at the start of the program that will be
 492      * the only code that directly reads the WPOS input.
 493      * All other code pieces that reference that input will be rewritten
 494      * to read from a newly allocated temporary. */
 495     if (wpos != ATTR_UNUSED) {
 496         /* Moving the input to some other reg is not really necessary. */
 497         rc_transform_fragment_wpos(&compiler.Base, wpos, wpos, TRUE);
 498     }
 499
 500     if (face != ATTR_UNUSED) {
 501         rc_transform_fragment_face(&compiler.Base, face);
 502     }
 503
 504     /* Invoke the compiler */
 505     r3xx_compile_fragment_program(&compiler);
 506
 507     if (compiler.Base.Error) {
 508         fprintf(stderr, "r300 FP: Compiler Error:\n%sUsing a dummy shader"
 509                 " instead.\n", compiler.Base.ErrorMsg);
 510
 511         if (shader->dummy) {
 512             fprintf(stderr, "r300 FP: Cannot compile the dummy shader! "
 513                     "Giving up...\n");
 514             abort();
 515         }
 516
 517         rc_destroy(&compiler.Base);
 518         r300_dummy_fragment_shader(r300, shader);
 519         return;
 520     }
 521
 522     /* Shaders with zero instructions are invalid,
 523      * use the dummy shader instead. */
 524     if (shader->code.code.r500.inst_end == -1) {
 525         rc_destroy(&compiler.Base);
 526         r300_dummy_fragment_shader(r300, shader);
 527         return;
 528     }
 529
 530     /* Initialize numbers of constants for each type. */
 531     shader->externals_count = 0;
 532     for (i = 0;
 533          i < shader->code.constants.Count &&
 534          shader->code.constants.Constants[i].Type == RC_CONSTANT_EXTERNAL; i++) {
 535         shader->externals_count = i+1;
 536     }
 537     shader->immediates_count = 0;
 538     shader->rc_state_count = 0;
 539
 540     for (i = shader->externals_count; i < shader->code.constants.Count; i++) {
 541         switch (shader->code.constants.Constants[i].Type) {
 542             case RC_CONSTANT_IMMEDIATE:
 543                 ++shader->immediates_count;
 544                 break;
 545             case RC_CONSTANT_STATE:
 546                 ++shader->rc_state_count;
 547                 break;
 548             default:
 549                 assert(0);
 550         }
 551     }
 552
 553     /* Setup shader depth output. */
 554     if (shader->code.writes_depth) {
 555         shader->fg_depth_src = R300_FG_DEPTH_SRC_SHADER;
 556         shader->us_out_w = R300_W_FMT_W24 | R300_W_SRC_US;
 557     } else {
 558         shader->fg_depth_src = R300_FG_DEPTH_SRC_SCAN;
 559         shader->us_out_w = R300_W_FMT_W0 | R300_W_SRC_US;
 560     }
 561
 562     /* And, finally... */
 563     rc_destroy(&compiler.Base);
 564
 565     /* Build the command buffer. */
 566     r300_emit_fs_code_to_buffer(r300, shader);
 567 }
 568
 569 boolean r300_pick_fragment_shader(struct r300_context* r300)
 570 {
 571     struct r300_fragment_shader* fs = r300_fs(r300);
 572     struct r300_fragment_program_external_state state = {{{ 0 }}};
 573     struct r300_fragment_shader_code* ptr;
 574
 575     get_external_state(r300, &state);
 576
 577     if (!fs->first) {
 578         /* Build the fragment shader for the first time. */
 579         fs->first = fs->shader = CALLOC_STRUCT(r300_fragment_shader_code);
 580
 581         memcpy(&fs->shader->compare_state, &state,
 582             sizeof(struct r300_fragment_program_external_state));
 583         r300_translate_fragment_shader(r300, fs->shader, fs->state.tokens);
 584         return TRUE;
 585
 586     } else {
 587         /* Check if the currently-bound shader has been compiled
 588          * with the texture-compare state we need. */
 589         if (memcmp(&fs->shader->compare_state, &state, sizeof(state)) != 0) {
 590             /* Search for the right shader. */
 591             ptr = fs->first;
 592             while (ptr) {
 593                 if (memcmp(&ptr->compare_state, &state, sizeof(state)) == 0) {
 594                     if (fs->shader != ptr) {
 595                         fs->shader = ptr;
 596                         return TRUE;
 597                     }
 598                     /* The currently-bound one is OK. */
 599                     return FALSE;
 600                 }
 601                 ptr = ptr->next;
 602             }
 603
 604             /* Not found, gotta compile a new one. */
 605             ptr = CALLOC_STRUCT(r300_fragment_shader_code);
 606             ptr->next = fs->first;
 607             fs->first = fs->shader = ptr;
 608
 609             ptr->compare_state = state;
 610             r300_translate_fragment_shader(r300, ptr, fs->state.tokens);
 611             return TRUE;
 612         }
 613     }
 614
 615     return FALSE;
 616 }