src/mesa/drivers/dri/i965/brw_wm.c

   1 /*
   2  Copyright (C) Intel Corp.  2006.  All Rights Reserved.
   3  Intel funded Tungsten Graphics to
   4  develop this 3D driver.
   5
   6  Permission is hereby granted, free of charge, to any person obtaining
   7  a 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, sublicense, 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 above copyright notice and this permission notice (including the
  15  next paragraph) shall be included in all copies or substantial
  16  portions of the Software.
  17
  18  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  21  IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
  22  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  23  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  24  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25
  26  **********************************************************************/
  27  /*
  28   * Authors:
  29   *   Keith Whitwell <keithw@vmware.com>
  30   */
  31
  32 #include "brw_context.h"
  33 #include "brw_wm.h"
  34 #include "brw_state.h"
  35 #include "main/enums.h"
  36 #include "main/formats.h"
  37 #include "main/fbobject.h"
  38 #include "main/samplerobj.h"
  39 #include "main/framebuffer.h"
  40 #include "program/prog_parameter.h"
  41 #include "program/program.h"
  42 #include "intel_mipmap_tree.h"
  43
  44 #include "util/ralloc.h"
  45
  46 /**
  47  * Return a bitfield where bit n is set if barycentric interpolation mode n
  48  * (see enum brw_wm_barycentric_interp_mode) is needed by the fragment shader.
  49  */
  50 static unsigned
  51 brw_compute_barycentric_interp_modes(struct brw_context *brw,
  52                                      bool shade_model_flat,
  53                                      bool persample_shading,
  54                                      const struct gl_fragment_program *fprog)
  55 {
  56    unsigned barycentric_interp_modes = 0;
  57    int attr;
  58
  59    /* Loop through all fragment shader inputs to figure out what interpolation
  60     * modes are in use, and set the appropriate bits in
  61     * barycentric_interp_modes.
  62     */
  63    for (attr = 0; attr < VARYING_SLOT_MAX; ++attr) {
  64       enum glsl_interp_qualifier interp_qualifier =
  65          fprog->InterpQualifier[attr];
  66       bool is_centroid = (fprog->IsCentroid & BITFIELD64_BIT(attr)) &&
  67          !persample_shading;
  68       bool is_sample = (fprog->IsSample & BITFIELD64_BIT(attr)) ||
  69          persample_shading;
  70       bool is_gl_Color = attr == VARYING_SLOT_COL0 || attr == VARYING_SLOT_COL1;
  71
  72       /* Ignore unused inputs. */
  73       if (!(fprog->Base.InputsRead & BITFIELD64_BIT(attr)))
  74          continue;
  75
  76       /* Ignore WPOS and FACE, because they don't require interpolation. */
  77       if (attr == VARYING_SLOT_POS || attr == VARYING_SLOT_FACE)
  78          continue;
  79
  80       /* Determine the set (or sets) of barycentric coordinates needed to
  81        * interpolate this variable.  Note that when
  82        * brw->needs_unlit_centroid_workaround is set, centroid interpolation
  83        * uses PIXEL interpolation for unlit pixels and CENTROID interpolation
  84        * for lit pixels, so we need both sets of barycentric coordinates.
  85        */
  86       if (interp_qualifier == INTERP_QUALIFIER_NOPERSPECTIVE) {
  87          if (is_centroid) {
  88             barycentric_interp_modes |=
  89                1 << BRW_WM_NONPERSPECTIVE_CENTROID_BARYCENTRIC;
  90          } else if (is_sample) {
  91             barycentric_interp_modes |=
  92                1 << BRW_WM_NONPERSPECTIVE_SAMPLE_BARYCENTRIC;
  93          }
  94          if ((!is_centroid && !is_sample) ||
  95              brw->needs_unlit_centroid_workaround) {
  96             barycentric_interp_modes |=
  97                1 << BRW_WM_NONPERSPECTIVE_PIXEL_BARYCENTRIC;
  98          }
  99       } else if (interp_qualifier == INTERP_QUALIFIER_SMOOTH ||
 100                  (!(shade_model_flat && is_gl_Color) &&
 101                   interp_qualifier == INTERP_QUALIFIER_NONE)) {
 102          if (is_centroid) {
 103             barycentric_interp_modes |=
 104                1 << BRW_WM_PERSPECTIVE_CENTROID_BARYCENTRIC;
 105          } else if (is_sample) {
 106             barycentric_interp_modes |=
 107                1 << BRW_WM_PERSPECTIVE_SAMPLE_BARYCENTRIC;
 108          }
 109          if ((!is_centroid && !is_sample) ||
 110              brw->needs_unlit_centroid_workaround) {
 111             barycentric_interp_modes |=
 112                1 << BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC;
 113          }
 114       }
 115    }
 116
 117    return barycentric_interp_modes;
 118 }
 119
 120 static uint8_t
 121 computed_depth_mode(struct gl_fragment_program *fp)
 122 {
 123    if (fp->Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
 124       switch (fp->FragDepthLayout) {
 125       case FRAG_DEPTH_LAYOUT_NONE:
 126       case FRAG_DEPTH_LAYOUT_ANY:
 127          return BRW_PSCDEPTH_ON;
 128       case FRAG_DEPTH_LAYOUT_GREATER:
 129          return BRW_PSCDEPTH_ON_GE;
 130       case FRAG_DEPTH_LAYOUT_LESS:
 131          return BRW_PSCDEPTH_ON_LE;
 132       case FRAG_DEPTH_LAYOUT_UNCHANGED:
 133          return BRW_PSCDEPTH_OFF;
 134       }
 135    }
 136    return BRW_PSCDEPTH_OFF;
 137 }
 138
 139 bool
 140 brw_wm_prog_data_compare(const void *in_a, const void *in_b)
 141 {
 142    const struct brw_wm_prog_data *a = in_a;
 143    const struct brw_wm_prog_data *b = in_b;
 144
 145    /* Compare the base structure. */
 146    if (!brw_stage_prog_data_compare(&a->base, &b->base))
 147       return false;
 148
 149    /* Compare the rest of the structure. */
 150    const unsigned offset = sizeof(struct brw_stage_prog_data);
 151    if (memcmp(((char *) a) + offset, ((char *) b) + offset,
 152               sizeof(struct brw_wm_prog_data) - offset))
 153       return false;
 154
 155    return true;
 156 }
 157
 158 /**
 159  * All Mesa program -> GPU code generation goes through this function.
 160  * Depending on the instructions used (i.e. flow control instructions)
 161  * we'll use one of two code generators.
 162  */
 163 bool
 164 brw_codegen_wm_prog(struct brw_context *brw,
 165                     struct gl_shader_program *prog,
 166                     struct brw_fragment_program *fp,
 167                     struct brw_wm_prog_key *key)
 168 {
 169    struct gl_context *ctx = &brw->ctx;
 170    void *mem_ctx = ralloc_context(NULL);
 171    struct brw_wm_prog_data prog_data;
 172    const GLuint *program;
 173    struct gl_shader *fs = NULL;
 174    GLuint program_size;
 175
 176    if (prog)
 177       fs = prog->_LinkedShaders[MESA_SHADER_FRAGMENT];
 178
 179    memset(&prog_data, 0, sizeof(prog_data));
 180    /* key->alpha_test_func means simulating alpha testing via discards,
 181     * so the shader definitely kills pixels.
 182     */
 183    prog_data.uses_kill = fp->program.UsesKill || key->alpha_test_func;
 184    prog_data.uses_omask =
 185       fp->program.Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_SAMPLE_MASK);
 186    prog_data.computed_depth_mode = computed_depth_mode(&fp->program);
 187
 188    /* Use ALT floating point mode for ARB programs so that 0^0 == 1. */
 189    if (!prog)
 190       prog_data.base.use_alt_mode = true;
 191
 192    /* Allocate the references to the uniforms that will end up in the
 193     * prog_data associated with the compiled program, and which will be freed
 194     * by the state cache.
 195     */
 196    int param_count;
 197    if (fs) {
 198       param_count = fs->num_uniform_components;
 199    } else {
 200       param_count = fp->program.Base.Parameters->NumParameters * 4;
 201    }
 202    /* The backend also sometimes adds params for texture size. */
 203    param_count += 2 * ctx->Const.Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits;
 204    prog_data.base.param =
 205       rzalloc_array(NULL, const gl_constant_value *, param_count);
 206    prog_data.base.pull_param =
 207       rzalloc_array(NULL, const gl_constant_value *, param_count);
 208    prog_data.base.nr_params = param_count;
 209
 210    prog_data.barycentric_interp_modes =
 211       brw_compute_barycentric_interp_modes(brw, key->flat_shade,
 212                                            key->persample_shading,
 213                                            &fp->program);
 214
 215    program = brw_wm_fs_emit(brw, mem_ctx, key, &prog_data,
 216                             &fp->program, prog, &program_size);
 217    if (program == NULL) {
 218       ralloc_free(mem_ctx);
 219       return false;
 220    }
 221
 222    if (prog_data.base.total_scratch) {
 223       brw_get_scratch_bo(brw, &brw->wm.base.scratch_bo,
 224                          prog_data.base.total_scratch * brw->max_wm_threads);
 225    }
 226
 227    if (unlikely(INTEL_DEBUG & DEBUG_WM))
 228       fprintf(stderr, "\n");
 229
 230    brw_upload_cache(&brw->cache, BRW_CACHE_FS_PROG,
 231                     key, sizeof(struct brw_wm_prog_key),
 232                     program, program_size,
 233                     &prog_data, sizeof(prog_data),
 234                     &brw->wm.base.prog_offset, &brw->wm.prog_data);
 235
 236    ralloc_free(mem_ctx);
 237
 238    return true;
 239 }
 240
 241 static bool
 242 key_debug(struct brw_context *brw, const char *name, int a, int b)
 243 {
 244    if (a != b) {
 245       perf_debug("  %s %d->%d\n", name, a, b);
 246       return true;
 247    } else {
 248       return false;
 249    }
 250 }
 251
 252 bool
 253 brw_debug_recompile_sampler_key(struct brw_context *brw,
 254                                 const struct brw_sampler_prog_key_data *old_key,
 255                                 const struct brw_sampler_prog_key_data *key)
 256 {
 257    bool found = false;
 258
 259    for (unsigned int i = 0; i < MAX_SAMPLERS; i++) {
 260       found |= key_debug(brw, "EXT_texture_swizzle or DEPTH_TEXTURE_MODE",
 261                          old_key->swizzles[i], key->swizzles[i]);
 262    }
 263    found |= key_debug(brw, "GL_CLAMP enabled on any texture unit's 1st coordinate",
 264                       old_key->gl_clamp_mask[0], key->gl_clamp_mask[0]);
 265    found |= key_debug(brw, "GL_CLAMP enabled on any texture unit's 2nd coordinate",
 266                       old_key->gl_clamp_mask[1], key->gl_clamp_mask[1]);
 267    found |= key_debug(brw, "GL_CLAMP enabled on any texture unit's 3rd coordinate",
 268                       old_key->gl_clamp_mask[2], key->gl_clamp_mask[2]);
 269    found |= key_debug(brw, "gather channel quirk on any texture unit",
 270                       old_key->gather_channel_quirk_mask, key->gather_channel_quirk_mask);
 271    found |= key_debug(brw, "compressed multisample layout",
 272                       old_key->compressed_multisample_layout_mask,
 273                       key->compressed_multisample_layout_mask);
 274
 275    for (unsigned int i = 0; i < MAX_SAMPLERS; i++) {
 276       found |= key_debug(brw, "textureGather workarounds",
 277                          old_key->gen6_gather_wa[i], key->gen6_gather_wa[i]);
 278    }
 279
 280    return found;
 281 }
 282
 283 void
 284 brw_wm_debug_recompile(struct brw_context *brw,
 285                        struct gl_shader_program *prog,
 286                        const struct brw_wm_prog_key *key)
 287 {
 288    struct brw_cache_item *c = NULL;
 289    const struct brw_wm_prog_key *old_key = NULL;
 290    bool found = false;
 291
 292    perf_debug("Recompiling fragment shader for program %d\n", prog->Name);
 293
 294    for (unsigned int i = 0; i < brw->cache.size; i++) {
 295       for (c = brw->cache.items[i]; c; c = c->next) {
 296          if (c->cache_id == BRW_CACHE_FS_PROG) {
 297             old_key = c->key;
 298
 299             if (old_key->program_string_id == key->program_string_id)
 300                break;
 301          }
 302       }
 303       if (c)
 304          break;
 305    }
 306
 307    if (!c) {
 308       perf_debug("  Didn't find previous compile in the shader cache for debug\n");
 309       return;
 310    }
 311
 312    found |= key_debug(brw, "alphatest, computed depth, depth test, or "
 313                       "depth write",
 314                       old_key->iz_lookup, key->iz_lookup);
 315    found |= key_debug(brw, "depth statistics",
 316                       old_key->stats_wm, key->stats_wm);
 317    found |= key_debug(brw, "flat shading",
 318                       old_key->flat_shade, key->flat_shade);
 319    found |= key_debug(brw, "per-sample shading",
 320                       old_key->persample_shading, key->persample_shading);
 321    found |= key_debug(brw, "per-sample shading and 2x MSAA",
 322                       old_key->persample_2x, key->persample_2x);
 323    found |= key_debug(brw, "number of color buffers",
 324                       old_key->nr_color_regions, key->nr_color_regions);
 325    found |= key_debug(brw, "MRT alpha test or alpha-to-coverage",
 326                       old_key->replicate_alpha, key->replicate_alpha);
 327    found |= key_debug(brw, "rendering to FBO",
 328                       old_key->render_to_fbo, key->render_to_fbo);
 329    found |= key_debug(brw, "fragment color clamping",
 330                       old_key->clamp_fragment_color, key->clamp_fragment_color);
 331    found |= key_debug(brw, "line smoothing",
 332                       old_key->line_aa, key->line_aa);
 333    found |= key_debug(brw, "renderbuffer height",
 334                       old_key->drawable_height, key->drawable_height);
 335    found |= key_debug(brw, "input slots valid",
 336                       old_key->input_slots_valid, key->input_slots_valid);
 337    found |= key_debug(brw, "mrt alpha test function",
 338                       old_key->alpha_test_func, key->alpha_test_func);
 339    found |= key_debug(brw, "mrt alpha test reference value",
 340                       old_key->alpha_test_ref, key->alpha_test_ref);
 341
 342    found |= brw_debug_recompile_sampler_key(brw, &old_key->tex, &key->tex);
 343
 344    if (!found) {
 345       perf_debug("  Something else\n");
 346    }
 347 }
 348
 349 static uint8_t
 350 gen6_gather_workaround(GLenum internalformat)
 351 {
 352    switch (internalformat) {
 353       case GL_R8I: return WA_SIGN | WA_8BIT;
 354       case GL_R8UI: return WA_8BIT;
 355       case GL_R16I: return WA_SIGN | WA_16BIT;
 356       case GL_R16UI: return WA_16BIT;
 357       /* note that even though GL_R32I and GL_R32UI have format overrides
 358        * in the surface state, there is no shader w/a required */
 359       default: return 0;
 360    }
 361 }
 362
 363 void
 364 brw_populate_sampler_prog_key_data(struct gl_context *ctx,
 365                                    const struct gl_program *prog,
 366                                    unsigned sampler_count,
 367                                    struct brw_sampler_prog_key_data *key)
 368 {
 369    struct brw_context *brw = brw_context(ctx);
 370
 371    for (int s = 0; s < sampler_count; s++) {
 372       key->swizzles[s] = SWIZZLE_NOOP;
 373
 374       if (!(prog->SamplersUsed & (1 << s)))
 375          continue;
 376
 377       int unit_id = prog->SamplerUnits[s];
 378       const struct gl_texture_unit *unit = &ctx->Texture.Unit[unit_id];
 379
 380       if (unit->_Current && unit->_Current->Target != GL_TEXTURE_BUFFER) {
 381          const struct gl_texture_object *t = unit->_Current;
 382          const struct gl_texture_image *img = t->Image[0][t->BaseLevel];
 383          struct gl_sampler_object *sampler = _mesa_get_samplerobj(ctx, unit_id);
 384
 385          const bool alpha_depth = t->DepthMode == GL_ALPHA &&
 386             (img->_BaseFormat == GL_DEPTH_COMPONENT ||
 387              img->_BaseFormat == GL_DEPTH_STENCIL);
 388
 389          /* Haswell handles texture swizzling as surface format overrides
 390           * (except for GL_ALPHA); all other platforms need MOVs in the shader.
 391           */
 392          if (alpha_depth || (brw->gen < 8 && !brw->is_haswell))
 393             key->swizzles[s] = brw_get_texture_swizzle(ctx, t);
 394
 395          if (brw->gen < 8 &&
 396              sampler->MinFilter != GL_NEAREST &&
 397              sampler->MagFilter != GL_NEAREST) {
 398             if (sampler->WrapS == GL_CLAMP)
 399                key->gl_clamp_mask[0] |= 1 << s;
 400             if (sampler->WrapT == GL_CLAMP)
 401                key->gl_clamp_mask[1] |= 1 << s;
 402             if (sampler->WrapR == GL_CLAMP)
 403                key->gl_clamp_mask[2] |= 1 << s;
 404          }
 405
 406          /* gather4's channel select for green from RG32F is broken;
 407           * requires a shader w/a on IVB; fixable with just SCS on HSW. */
 408          if (brw->gen == 7 && !brw->is_haswell && prog->UsesGather) {
 409             if (img->InternalFormat == GL_RG32F)
 410                key->gather_channel_quirk_mask |= 1 << s;
 411          }
 412
 413          /* Gen6's gather4 is broken for UINT/SINT; we treat them as
 414           * UNORM/FLOAT instead and fix it in the shader.
 415           */
 416          if (brw->gen == 6 && prog->UsesGather) {
 417             key->gen6_gather_wa[s] = gen6_gather_workaround(img->InternalFormat);
 418          }
 419
 420          /* If this is a multisample sampler, and uses the CMS MSAA layout,
 421           * then we need to emit slightly different code to first sample the
 422           * MCS surface.
 423           */
 424          struct intel_texture_object *intel_tex =
 425             intel_texture_object((struct gl_texture_object *)t);
 426
 427          if (brw->gen >= 7 &&
 428              intel_tex->mt->msaa_layout == INTEL_MSAA_LAYOUT_CMS) {
 429             key->compressed_multisample_layout_mask |= 1 << s;
 430          }
 431       }
 432    }
 433 }
 434
 435 static bool
 436 brw_wm_state_dirty (struct brw_context *brw)
 437 {
 438    return brw_state_dirty(brw,
 439                           _NEW_BUFFERS |
 440                           _NEW_COLOR |
 441                           _NEW_DEPTH |
 442                           _NEW_FRAG_CLAMP |
 443                           _NEW_HINT |
 444                           _NEW_LIGHT |
 445                           _NEW_LINE |
 446                           _NEW_MULTISAMPLE |
 447                           _NEW_POLYGON |
 448                           _NEW_STENCIL |
 449                           _NEW_TEXTURE,
 450                           BRW_NEW_FRAGMENT_PROGRAM |
 451                           BRW_NEW_REDUCED_PRIMITIVE |
 452                           BRW_NEW_STATS_WM |
 453                           BRW_NEW_VUE_MAP_GEOM_OUT);
 454 }
 455
 456 static void brw_wm_populate_key( struct brw_context *brw,
 457                                  struct brw_wm_prog_key *key )
 458 {
 459    struct gl_context *ctx = &brw->ctx;
 460    /* BRW_NEW_FRAGMENT_PROGRAM */
 461    const struct brw_fragment_program *fp =
 462       (struct brw_fragment_program *)brw->fragment_program;
 463    const struct gl_program *prog = (struct gl_program *) brw->fragment_program;
 464    GLuint lookup = 0;
 465    GLuint line_aa;
 466    bool program_uses_dfdy = fp->program.UsesDFdy;
 467    const bool multisample_fbo = _mesa_geometric_samples(ctx->DrawBuffer) > 1;
 468
 469    memset(key, 0, sizeof(*key));
 470
 471    /* Build the index for table lookup
 472     */
 473    if (brw->gen < 6) {
 474       /* _NEW_COLOR */
 475       if (fp->program.UsesKill || ctx->Color.AlphaEnabled)
 476          lookup |= IZ_PS_KILL_ALPHATEST_BIT;
 477
 478       if (fp->program.Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH))
 479          lookup |= IZ_PS_COMPUTES_DEPTH_BIT;
 480
 481       /* _NEW_DEPTH */
 482       if (ctx->Depth.Test)
 483          lookup |= IZ_DEPTH_TEST_ENABLE_BIT;
 484
 485       if (ctx->Depth.Test && ctx->Depth.Mask) /* ?? */
 486          lookup |= IZ_DEPTH_WRITE_ENABLE_BIT;
 487
 488       /* _NEW_STENCIL | _NEW_BUFFERS */
 489       if (ctx->Stencil._Enabled) {
 490          lookup |= IZ_STENCIL_TEST_ENABLE_BIT;
 491
 492          if (ctx->Stencil.WriteMask[0] ||
 493              ctx->Stencil.WriteMask[ctx->Stencil._BackFace])
 494             lookup |= IZ_STENCIL_WRITE_ENABLE_BIT;
 495       }
 496       key->iz_lookup = lookup;
 497    }
 498
 499    line_aa = AA_NEVER;
 500
 501    /* _NEW_LINE, _NEW_POLYGON, BRW_NEW_REDUCED_PRIMITIVE */
 502    if (ctx->Line.SmoothFlag) {
 503       if (brw->reduced_primitive == GL_LINES) {
 504          line_aa = AA_ALWAYS;
 505       }
 506       else if (brw->reduced_primitive == GL_TRIANGLES) {
 507          if (ctx->Polygon.FrontMode == GL_LINE) {
 508             line_aa = AA_SOMETIMES;
 509
 510             if (ctx->Polygon.BackMode == GL_LINE ||
 511                 (ctx->Polygon.CullFlag &&
 512                  ctx->Polygon.CullFaceMode == GL_BACK))
 513                line_aa = AA_ALWAYS;
 514          }
 515          else if (ctx->Polygon.BackMode == GL_LINE) {
 516             line_aa = AA_SOMETIMES;
 517
 518             if ((ctx->Polygon.CullFlag &&
 519                  ctx->Polygon.CullFaceMode == GL_FRONT))
 520                line_aa = AA_ALWAYS;
 521          }
 522       }
 523    }
 524
 525    key->line_aa = line_aa;
 526
 527    /* _NEW_HINT */
 528    key->high_quality_derivatives =
 529       ctx->Hint.FragmentShaderDerivative == GL_NICEST;
 530
 531    if (brw->gen < 6)
 532       key->stats_wm = brw->stats_wm;
 533
 534    /* _NEW_LIGHT */
 535    key->flat_shade = (ctx->Light.ShadeModel == GL_FLAT);
 536
 537    /* _NEW_FRAG_CLAMP | _NEW_BUFFERS */
 538    key->clamp_fragment_color = ctx->Color._ClampFragmentColor;
 539
 540    /* _NEW_TEXTURE */
 541    brw_populate_sampler_prog_key_data(ctx, prog, brw->wm.base.sampler_count,
 542                                       &key->tex);
 543
 544    /* _NEW_BUFFERS */
 545    /*
 546     * Include the draw buffer origin and height so that we can calculate
 547     * fragment position values relative to the bottom left of the drawable,
 548     * from the incoming screen origin relative position we get as part of our
 549     * payload.
 550     *
 551     * This is only needed for the WM_WPOSXY opcode when the fragment program
 552     * uses the gl_FragCoord input.
 553     *
 554     * We could avoid recompiling by including this as a constant referenced by
 555     * our program, but if we were to do that it would also be nice to handle
 556     * getting that constant updated at batchbuffer submit time (when we
 557     * hold the lock and know where the buffer really is) rather than at emit
 558     * time when we don't hold the lock and are just guessing.  We could also
 559     * just avoid using this as key data if the program doesn't use
 560     * fragment.position.
 561     *
 562     * For DRI2 the origin_x/y will always be (0,0) but we still need the
 563     * drawable height in order to invert the Y axis.
 564     */
 565    if (fp->program.Base.InputsRead & VARYING_BIT_POS) {
 566       key->drawable_height = _mesa_geometric_height(ctx->DrawBuffer);
 567    }
 568
 569    if ((fp->program.Base.InputsRead & VARYING_BIT_POS) || program_uses_dfdy) {
 570       key->render_to_fbo = _mesa_is_user_fbo(ctx->DrawBuffer);
 571    }
 572
 573    /* _NEW_BUFFERS */
 574    key->nr_color_regions = ctx->DrawBuffer->_NumColorDrawBuffers;
 575
 576    /* _NEW_MULTISAMPLE, _NEW_COLOR, _NEW_BUFFERS */
 577    key->replicate_alpha = ctx->DrawBuffer->_NumColorDrawBuffers > 1 &&
 578       (ctx->Multisample.SampleAlphaToCoverage || ctx->Color.AlphaEnabled);
 579
 580    /* _NEW_BUFFERS _NEW_MULTISAMPLE */
 581    /* Ignore sample qualifier while computing this flag. */
 582    key->persample_shading =
 583       _mesa_get_min_invocations_per_fragment(ctx, &fp->program, true) > 1;
 584    if (key->persample_shading)
 585       key->persample_2x = _mesa_geometric_samples(ctx->DrawBuffer) == 2;
 586
 587    key->compute_pos_offset =
 588       _mesa_get_min_invocations_per_fragment(ctx, &fp->program, false) > 1 &&
 589       fp->program.Base.SystemValuesRead & SYSTEM_BIT_SAMPLE_POS;
 590
 591    key->compute_sample_id =
 592       multisample_fbo &&
 593       ctx->Multisample.Enabled &&
 594       (fp->program.Base.SystemValuesRead & SYSTEM_BIT_SAMPLE_ID);
 595
 596    /* BRW_NEW_VUE_MAP_GEOM_OUT */
 597    if (brw->gen < 6 || _mesa_bitcount_64(fp->program.Base.InputsRead &
 598                                          BRW_FS_VARYING_INPUT_MASK) > 16)
 599       key->input_slots_valid = brw->vue_map_geom_out.slots_valid;
 600
 601
 602    /* _NEW_COLOR | _NEW_BUFFERS */
 603    /* Pre-gen6, the hardware alpha test always used each render
 604     * target's alpha to do alpha test, as opposed to render target 0's alpha
 605     * like GL requires.  Fix that by building the alpha test into the
 606     * shader, and we'll skip enabling the fixed function alpha test.
 607     */
 608    if (brw->gen < 6 && ctx->DrawBuffer->_NumColorDrawBuffers > 1 && ctx->Color.AlphaEnabled) {
 609       key->alpha_test_func = ctx->Color.AlphaFunc;
 610       key->alpha_test_ref = ctx->Color.AlphaRef;
 611    }
 612
 613    /* The unique fragment program ID */
 614    key->program_string_id = fp->id;
 615 }
 616
 617 void
 618 brw_upload_wm_prog(struct brw_context *brw)
 619 {
 620    struct gl_context *ctx = &brw->ctx;
 621    struct gl_shader_program *current = ctx->_Shader->_CurrentFragmentProgram;
 622    struct brw_wm_prog_key key;
 623    struct brw_fragment_program *fp = (struct brw_fragment_program *)
 624       brw->fragment_program;
 625
 626    if (!brw_wm_state_dirty(brw))
 627       return;
 628
 629    brw_wm_populate_key(brw, &key);
 630
 631    if (!brw_search_cache(&brw->cache, BRW_CACHE_FS_PROG,
 632                          &key, sizeof(key),
 633                          &brw->wm.base.prog_offset, &brw->wm.prog_data)) {
 634       bool success = brw_codegen_wm_prog(brw, current, fp, &key);
 635       (void) success;
 636       assert(success);
 637    }
 638    brw->wm.base.prog_data = &brw->wm.prog_data->base;
 639 }