1 /*
2  Copyright (C) Intel Corp.  2006.  All Rights Reserved.
3  Intel funded Tungsten Graphics (http://www.tungstengraphics.com) 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 <keith@tungstengraphics.com>
30   */
31 
32 #include "brw_context.h"
33 #include "brw_wm.h"
34 #include "brw_state.h"
35 #include "main/formats.h"
36 #include "main/fbobject.h"
37 #include "main/samplerobj.h"
38 #include "program/prog_parameter.h"
39 
40 #include "glsl/ralloc.h"
41 
42 /** Return number of src args for given instruction */
brw_wm_nr_args(GLuint opcode)43 GLuint brw_wm_nr_args( GLuint opcode )
44 {
45    switch (opcode) {
46    case WM_FRONTFACING:
47    case WM_PIXELXY:
48       return 0;
49    case WM_CINTERP:
50    case WM_WPOSXY:
51    case WM_DELTAXY:
52       return 1;
53    case WM_LINTERP:
54    case WM_PIXELW:
55       return 2;
56    case WM_FB_WRITE:
57    case WM_PINTERP:
58       return 3;
59    default:
60       assert(opcode < MAX_OPCODE);
61       return _mesa_num_inst_src_regs(opcode);
62    }
63 }
64 
65 
brw_wm_is_scalar_result(GLuint opcode)66 GLuint brw_wm_is_scalar_result( GLuint opcode )
67 {
68    switch (opcode) {
69    case OPCODE_COS:
70    case OPCODE_EX2:
71    case OPCODE_LG2:
72    case OPCODE_POW:
73    case OPCODE_RCP:
74    case OPCODE_RSQ:
75    case OPCODE_SIN:
76    case OPCODE_DP2:
77    case OPCODE_DP3:
78    case OPCODE_DP4:
79    case OPCODE_DPH:
80    case OPCODE_DST:
81       return 1;
82 
83    default:
84       return 0;
85    }
86 }
87 
88 
89 /**
90  * Do GPU code generation for non-GLSL shader.  non-GLSL shaders have
91  * no flow control instructions so we can more readily do SSA-style
92  * optimizations.
93  */
94 static void
brw_wm_non_glsl_emit(struct brw_context * brw,struct brw_wm_compile * c)95 brw_wm_non_glsl_emit(struct brw_context *brw, struct brw_wm_compile *c)
96 {
97    /* Augment fragment program.  Add instructions for pre- and
98     * post-fragment-program tasks such as interpolation and fogging.
99     */
100    brw_wm_pass_fp(c);
101 
102    /* Translate to intermediate representation.  Build register usage
103     * chains.
104     */
105    brw_wm_pass0(c);
106 
107    /* Dead code removal.
108     */
109    brw_wm_pass1(c);
110 
111    /* Register allocation.
112     * Divide by two because we operate on 16 pixels at a time and require
113     * two GRF entries for each logical shader register.
114     */
115    c->grf_limit = BRW_WM_MAX_GRF / 2;
116 
117    brw_wm_pass2(c);
118 
119    /* how many general-purpose registers are used */
120    c->prog_data.reg_blocks = brw_register_blocks(c->max_wm_grf);
121 
122    /* Emit GEN4 code.
123     */
124    brw_wm_emit(c);
125 }
126 
127 
128 /**
129  * Return a bitfield where bit n is set if barycentric interpolation mode n
130  * (see enum brw_wm_barycentric_interp_mode) is needed by the fragment shader.
131  */
132 static unsigned
brw_compute_barycentric_interp_modes(struct brw_context * brw,bool shade_model_flat,const struct gl_fragment_program * fprog)133 brw_compute_barycentric_interp_modes(struct brw_context *brw,
134                                      bool shade_model_flat,
135                                      const struct gl_fragment_program *fprog)
136 {
137    unsigned barycentric_interp_modes = 0;
138    int attr;
139 
140    /* Loop through all fragment shader inputs to figure out what interpolation
141     * modes are in use, and set the appropriate bits in
142     * barycentric_interp_modes.
143     */
144    for (attr = 0; attr < FRAG_ATTRIB_MAX; ++attr) {
145       enum glsl_interp_qualifier interp_qualifier =
146          fprog->InterpQualifier[attr];
147       bool is_centroid = fprog->IsCentroid & BITFIELD64_BIT(attr);
148       bool is_gl_Color = attr == FRAG_ATTRIB_COL0 || attr == FRAG_ATTRIB_COL1;
149 
150       /* Ignore unused inputs. */
151       if (!(fprog->Base.InputsRead & BITFIELD64_BIT(attr)))
152          continue;
153 
154       /* Ignore WPOS and FACE, because they don't require interpolation. */
155       if (attr == FRAG_ATTRIB_WPOS || attr == FRAG_ATTRIB_FACE)
156          continue;
157 
158       /* Determine the set (or sets) of barycentric coordinates needed to
159        * interpolate this variable.  Note that when
160        * brw->needs_unlit_centroid_workaround is set, centroid interpolation
161        * uses PIXEL interpolation for unlit pixels and CENTROID interpolation
162        * for lit pixels, so we need both sets of barycentric coordinates.
163        */
164       if (interp_qualifier == INTERP_QUALIFIER_NOPERSPECTIVE) {
165          if (is_centroid) {
166             barycentric_interp_modes |=
167                1 << BRW_WM_NONPERSPECTIVE_CENTROID_BARYCENTRIC;
168          }
169          if (!is_centroid || brw->needs_unlit_centroid_workaround) {
170             barycentric_interp_modes |=
171                1 << BRW_WM_NONPERSPECTIVE_PIXEL_BARYCENTRIC;
172          }
173       } else if (interp_qualifier == INTERP_QUALIFIER_SMOOTH ||
174                  (!(shade_model_flat && is_gl_Color) &&
175                   interp_qualifier == INTERP_QUALIFIER_NONE)) {
176          if (is_centroid) {
177             barycentric_interp_modes |=
178                1 << BRW_WM_PERSPECTIVE_CENTROID_BARYCENTRIC;
179          }
180          if (!is_centroid || brw->needs_unlit_centroid_workaround) {
181             barycentric_interp_modes |=
182                1 << BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC;
183          }
184       }
185    }
186 
187    return barycentric_interp_modes;
188 }
189 
190 
191 void
brw_wm_payload_setup(struct brw_context * brw,struct brw_wm_compile * c)192 brw_wm_payload_setup(struct brw_context *brw,
193 		     struct brw_wm_compile *c)
194 {
195    struct intel_context *intel = &brw->intel;
196    bool uses_depth = (c->fp->program.Base.InputsRead &
197 		      (1 << FRAG_ATTRIB_WPOS)) != 0;
198    unsigned barycentric_interp_modes = c->prog_data.barycentric_interp_modes;
199    int i;
200 
201    if (intel->gen >= 6) {
202       /* R0-1: masks, pixel X/Y coordinates. */
203       c->nr_payload_regs = 2;
204       /* R2: only for 32-pixel dispatch.*/
205 
206       /* R3-26: barycentric interpolation coordinates.  These appear in the
207        * same order that they appear in the brw_wm_barycentric_interp_mode
208        * enum.  Each set of coordinates occupies 2 registers if dispatch width
209        * == 8 and 4 registers if dispatch width == 16.  Coordinates only
210        * appear if they were enabled using the "Barycentric Interpolation
211        * Mode" bits in WM_STATE.
212        */
213       for (i = 0; i < BRW_WM_BARYCENTRIC_INTERP_MODE_COUNT; ++i) {
214          if (barycentric_interp_modes & (1 << i)) {
215             c->barycentric_coord_reg[i] = c->nr_payload_regs;
216             c->nr_payload_regs += 2;
217             if (c->dispatch_width == 16) {
218                c->nr_payload_regs += 2;
219             }
220          }
221       }
222 
223       /* R27: interpolated depth if uses source depth */
224       if (uses_depth) {
225 	 c->source_depth_reg = c->nr_payload_regs;
226 	 c->nr_payload_regs++;
227 	 if (c->dispatch_width == 16) {
228 	    /* R28: interpolated depth if not 8-wide. */
229 	    c->nr_payload_regs++;
230 	 }
231       }
232       /* R29: interpolated W set if GEN6_WM_USES_SOURCE_W.
233        */
234       if (uses_depth) {
235 	 c->source_w_reg = c->nr_payload_regs;
236 	 c->nr_payload_regs++;
237 	 if (c->dispatch_width == 16) {
238 	    /* R30: interpolated W if not 8-wide. */
239 	    c->nr_payload_regs++;
240 	 }
241       }
242       /* R31: MSAA position offsets. */
243       /* R32-: bary for 32-pixel. */
244       /* R58-59: interp W for 32-pixel. */
245 
246       if (c->fp->program.Base.OutputsWritten &
247 	  BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
248 	 c->source_depth_to_render_target = true;
249 	 c->computes_depth = true;
250       }
251    } else {
252       brw_wm_lookup_iz(intel, c);
253    }
254 }
255 
256 /**
257  * All Mesa program -> GPU code generation goes through this function.
258  * Depending on the instructions used (i.e. flow control instructions)
259  * we'll use one of two code generators.
260  */
do_wm_prog(struct brw_context * brw,struct gl_shader_program * prog,struct brw_fragment_program * fp,struct brw_wm_prog_key * key)261 bool do_wm_prog(struct brw_context *brw,
262 		struct gl_shader_program *prog,
263 		struct brw_fragment_program *fp,
264 		struct brw_wm_prog_key *key)
265 {
266    struct intel_context *intel = &brw->intel;
267    struct brw_wm_compile *c;
268    const GLuint *program;
269    GLuint program_size;
270 
271    c = brw->wm.compile_data;
272    if (c == NULL) {
273       brw->wm.compile_data = rzalloc(NULL, struct brw_wm_compile);
274       c = brw->wm.compile_data;
275       if (c == NULL) {
276          /* Ouch - big out of memory problem.  Can't continue
277           * without triggering a segfault, no way to signal,
278           * so just return.
279           */
280          return false;
281       }
282    } else {
283       void *instruction = c->instruction;
284       void *prog_instructions = c->prog_instructions;
285       void *vreg = c->vreg;
286       void *refs = c->refs;
287       memset(c, 0, sizeof(*brw->wm.compile_data));
288       c->instruction = instruction;
289       c->prog_instructions = prog_instructions;
290       c->vreg = vreg;
291       c->refs = refs;
292    }
293    memcpy(&c->key, key, sizeof(*key));
294 
295    c->fp = fp;
296    c->env_param = brw->intel.ctx.FragmentProgram.Parameters;
297 
298    brw_init_compile(brw, &c->func, c);
299 
300    c->prog_data.barycentric_interp_modes =
301       brw_compute_barycentric_interp_modes(brw, c->key.flat_shade,
302                                            &fp->program);
303 
304    if (prog && prog->_LinkedShaders[MESA_SHADER_FRAGMENT]) {
305       if (!brw_wm_fs_emit(brw, c, prog))
306 	 return false;
307    } else {
308       if (!c->instruction) {
309 	 c->instruction = rzalloc_array(c, struct brw_wm_instruction, BRW_WM_MAX_INSN);
310 	 c->prog_instructions = rzalloc_array(c, struct prog_instruction, BRW_WM_MAX_INSN);
311 	 c->vreg = rzalloc_array(c, struct brw_wm_value, BRW_WM_MAX_VREG);
312 	 c->refs = rzalloc_array(c, struct brw_wm_ref, BRW_WM_MAX_REF);
313       }
314 
315       /* Fallback for fixed function and ARB_fp shaders. */
316       c->dispatch_width = 16;
317       brw_wm_payload_setup(brw, c);
318       brw_wm_non_glsl_emit(brw, c);
319       c->prog_data.dispatch_width = 16;
320    }
321 
322    /* Scratch space is used for register spilling */
323    if (c->last_scratch) {
324       perf_debug("Fragment shader triggered register spilling.  "
325                  "Try reducing the number of live scalar values to "
326                  "improve performance.\n");
327 
328       c->prog_data.total_scratch = brw_get_scratch_size(c->last_scratch);
329 
330       brw_get_scratch_bo(intel, &brw->wm.scratch_bo,
331 			 c->prog_data.total_scratch * brw->max_wm_threads);
332    }
333 
334    if (unlikely(INTEL_DEBUG & DEBUG_WM))
335       fprintf(stderr, "\n");
336 
337    /* get the program
338     */
339    program = brw_get_program(&c->func, &program_size);
340 
341    brw_upload_cache(&brw->cache, BRW_WM_PROG,
342 		    &c->key, sizeof(c->key),
343 		    program, program_size,
344 		    &c->prog_data, sizeof(c->prog_data),
345 		    &brw->wm.prog_offset, &brw->wm.prog_data);
346 
347    return true;
348 }
349 
350 static bool
key_debug(const char * name,int a,int b)351 key_debug(const char *name, int a, int b)
352 {
353    if (a != b) {
354       perf_debug("  %s %d->%d\n", name, a, b);
355       return true;
356    } else {
357       return false;
358    }
359 }
360 
361 bool
brw_debug_recompile_sampler_key(const struct brw_sampler_prog_key_data * old_key,const struct brw_sampler_prog_key_data * key)362 brw_debug_recompile_sampler_key(const struct brw_sampler_prog_key_data *old_key,
363                                 const struct brw_sampler_prog_key_data *key)
364 {
365    bool found = false;
366 
367    for (unsigned int i = 0; i < MAX_SAMPLERS; i++) {
368       found |= key_debug("EXT_texture_swizzle or DEPTH_TEXTURE_MODE",
369                          old_key->swizzles[i], key->swizzles[i]);
370    }
371    found |= key_debug("GL_CLAMP enabled on any texture unit's 1st coordinate",
372                       old_key->gl_clamp_mask[0], key->gl_clamp_mask[0]);
373    found |= key_debug("GL_CLAMP enabled on any texture unit's 2nd coordinate",
374                       old_key->gl_clamp_mask[1], key->gl_clamp_mask[1]);
375    found |= key_debug("GL_CLAMP enabled on any texture unit's 3rd coordinate",
376                       old_key->gl_clamp_mask[2], key->gl_clamp_mask[2]);
377    found |= key_debug("GL_MESA_ycbcr texturing\n",
378                       old_key->yuvtex_mask, key->yuvtex_mask);
379    found |= key_debug("GL_MESA_ycbcr UV swapping\n",
380                       old_key->yuvtex_swap_mask, key->yuvtex_swap_mask);
381 
382    return found;
383 }
384 
385 void
brw_wm_debug_recompile(struct brw_context * brw,struct gl_shader_program * prog,const struct brw_wm_prog_key * key)386 brw_wm_debug_recompile(struct brw_context *brw,
387                        struct gl_shader_program *prog,
388                        const struct brw_wm_prog_key *key)
389 {
390    struct brw_cache_item *c = NULL;
391    const struct brw_wm_prog_key *old_key = NULL;
392    bool found = false;
393 
394    perf_debug("Recompiling fragment shader for program %d\n", prog->Name);
395 
396    for (unsigned int i = 0; i < brw->cache.size; i++) {
397       for (c = brw->cache.items[i]; c; c = c->next) {
398          if (c->cache_id == BRW_WM_PROG) {
399             old_key = c->key;
400 
401             if (old_key->program_string_id == key->program_string_id)
402                break;
403          }
404       }
405       if (c)
406          break;
407    }
408 
409    if (!c) {
410       perf_debug("  Didn't find previous compile in the shader cache for "
411                  "debug\n");
412       return;
413    }
414 
415    found |= key_debug("alphatest, computed depth, depth test, or depth write",
416                       old_key->iz_lookup, key->iz_lookup);
417    found |= key_debug("depth statistics", old_key->stats_wm, key->stats_wm);
418    found |= key_debug("flat shading", old_key->flat_shade, key->flat_shade);
419    found |= key_debug("number of color buffers", old_key->nr_color_regions, key->nr_color_regions);
420    found |= key_debug("rendering to FBO", old_key->render_to_fbo, key->render_to_fbo);
421    found |= key_debug("fragment color clamping", old_key->clamp_fragment_color, key->clamp_fragment_color);
422    found |= key_debug("line smoothing", old_key->line_aa, key->line_aa);
423    found |= key_debug("proj_attrib_mask", old_key->proj_attrib_mask, key->proj_attrib_mask);
424    found |= key_debug("renderbuffer height", old_key->drawable_height, key->drawable_height);
425    found |= key_debug("vertex shader outputs", old_key->vp_outputs_written, key->vp_outputs_written);
426 
427    found |= brw_debug_recompile_sampler_key(&old_key->tex, &key->tex);
428 
429    if (!found) {
430       perf_debug("  Something else\n");
431    }
432 }
433 
434 void
brw_populate_sampler_prog_key_data(struct gl_context * ctx,const struct gl_program * prog,struct brw_sampler_prog_key_data * key)435 brw_populate_sampler_prog_key_data(struct gl_context *ctx,
436 				   const struct gl_program *prog,
437 				   struct brw_sampler_prog_key_data *key)
438 {
439    struct intel_context *intel = intel_context(ctx);
440 
441    for (int s = 0; s < MAX_SAMPLERS; s++) {
442       key->swizzles[s] = SWIZZLE_NOOP;
443 
444       if (!(prog->SamplersUsed & (1 << s)))
445 	 continue;
446 
447       int unit_id = prog->SamplerUnits[s];
448       const struct gl_texture_unit *unit = &ctx->Texture.Unit[unit_id];
449 
450       if (unit->_ReallyEnabled && unit->_Current->Target != GL_TEXTURE_BUFFER) {
451 	 const struct gl_texture_object *t = unit->_Current;
452 	 const struct gl_texture_image *img = t->Image[0][t->BaseLevel];
453 	 struct gl_sampler_object *sampler = _mesa_get_samplerobj(ctx, unit_id);
454 
455          const bool alpha_depth = t->DepthMode == GL_ALPHA &&
456             (img->_BaseFormat == GL_DEPTH_COMPONENT ||
457              img->_BaseFormat == GL_DEPTH_STENCIL);
458 
459          /* Haswell handles texture swizzling as surface format overrides
460           * (except for GL_ALPHA); all other platforms need MOVs in the shader.
461           */
462          if (!intel->is_haswell || alpha_depth)
463             key->swizzles[s] = brw_get_texture_swizzle(t);
464 
465 	 if (img->InternalFormat == GL_YCBCR_MESA) {
466 	    key->yuvtex_mask |= 1 << s;
467 	    if (img->TexFormat == MESA_FORMAT_YCBCR)
468 		key->yuvtex_swap_mask |= 1 << s;
469 	 }
470 
471 	 if (sampler->MinFilter != GL_NEAREST &&
472 	     sampler->MagFilter != GL_NEAREST) {
473 	    if (sampler->WrapS == GL_CLAMP)
474 	       key->gl_clamp_mask[0] |= 1 << s;
475 	    if (sampler->WrapT == GL_CLAMP)
476 	       key->gl_clamp_mask[1] |= 1 << s;
477 	    if (sampler->WrapR == GL_CLAMP)
478 	       key->gl_clamp_mask[2] |= 1 << s;
479 	 }
480       }
481    }
482 }
483 
brw_wm_populate_key(struct brw_context * brw,struct brw_wm_prog_key * key)484 static void brw_wm_populate_key( struct brw_context *brw,
485 				 struct brw_wm_prog_key *key )
486 {
487    struct gl_context *ctx = &brw->intel.ctx;
488    struct intel_context *intel = &brw->intel;
489    /* BRW_NEW_FRAGMENT_PROGRAM */
490    const struct brw_fragment_program *fp =
491       (struct brw_fragment_program *)brw->fragment_program;
492    const struct gl_program *prog = (struct gl_program *) brw->fragment_program;
493    GLuint lookup = 0;
494    GLuint line_aa;
495    bool program_uses_dfdy = fp->program.UsesDFdy;
496 
497    memset(key, 0, sizeof(*key));
498 
499    /* Build the index for table lookup
500     */
501    if (intel->gen < 6) {
502       /* _NEW_COLOR */
503       if (fp->program.UsesKill || ctx->Color.AlphaEnabled)
504 	 lookup |= IZ_PS_KILL_ALPHATEST_BIT;
505 
506       if (fp->program.Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH))
507 	 lookup |= IZ_PS_COMPUTES_DEPTH_BIT;
508 
509       /* _NEW_DEPTH */
510       if (ctx->Depth.Test)
511 	 lookup |= IZ_DEPTH_TEST_ENABLE_BIT;
512 
513       if (ctx->Depth.Test && ctx->Depth.Mask) /* ?? */
514 	 lookup |= IZ_DEPTH_WRITE_ENABLE_BIT;
515 
516       /* _NEW_STENCIL */
517       if (ctx->Stencil._Enabled) {
518 	 lookup |= IZ_STENCIL_TEST_ENABLE_BIT;
519 
520 	 if (ctx->Stencil.WriteMask[0] ||
521 	     ctx->Stencil.WriteMask[ctx->Stencil._BackFace])
522 	    lookup |= IZ_STENCIL_WRITE_ENABLE_BIT;
523       }
524       key->iz_lookup = lookup;
525    }
526 
527    line_aa = AA_NEVER;
528 
529    /* _NEW_LINE, _NEW_POLYGON, BRW_NEW_REDUCED_PRIMITIVE */
530    if (ctx->Line.SmoothFlag) {
531       if (brw->intel.reduced_primitive == GL_LINES) {
532 	 line_aa = AA_ALWAYS;
533       }
534       else if (brw->intel.reduced_primitive == GL_TRIANGLES) {
535 	 if (ctx->Polygon.FrontMode == GL_LINE) {
536 	    line_aa = AA_SOMETIMES;
537 
538 	    if (ctx->Polygon.BackMode == GL_LINE ||
539 		(ctx->Polygon.CullFlag &&
540 		 ctx->Polygon.CullFaceMode == GL_BACK))
541 	       line_aa = AA_ALWAYS;
542 	 }
543 	 else if (ctx->Polygon.BackMode == GL_LINE) {
544 	    line_aa = AA_SOMETIMES;
545 
546 	    if ((ctx->Polygon.CullFlag &&
547 		 ctx->Polygon.CullFaceMode == GL_FRONT))
548 	       line_aa = AA_ALWAYS;
549 	 }
550       }
551    }
552 
553    key->line_aa = line_aa;
554 
555    if (intel->gen < 6)
556       key->stats_wm = brw->intel.stats_wm;
557 
558    /* BRW_NEW_WM_INPUT_DIMENSIONS */
559    /* Only set this for fixed function.  The optimization it enables isn't
560     * useful for programs using shaders.
561     */
562    if (ctx->Shader.CurrentFragmentProgram)
563       key->proj_attrib_mask = 0xffffffff;
564    else
565       key->proj_attrib_mask = brw->wm.input_size_masks[4-1];
566 
567    /* _NEW_LIGHT */
568    key->flat_shade = (ctx->Light.ShadeModel == GL_FLAT);
569 
570    /* _NEW_FRAG_CLAMP | _NEW_BUFFERS */
571    key->clamp_fragment_color = ctx->Color._ClampFragmentColor;
572 
573    /* _NEW_TEXTURE */
574    brw_populate_sampler_prog_key_data(ctx, prog, &key->tex);
575 
576    /* _NEW_BUFFERS */
577    /*
578     * Include the draw buffer origin and height so that we can calculate
579     * fragment position values relative to the bottom left of the drawable,
580     * from the incoming screen origin relative position we get as part of our
581     * payload.
582     *
583     * This is only needed for the WM_WPOSXY opcode when the fragment program
584     * uses the gl_FragCoord input.
585     *
586     * We could avoid recompiling by including this as a constant referenced by
587     * our program, but if we were to do that it would also be nice to handle
588     * getting that constant updated at batchbuffer submit time (when we
589     * hold the lock and know where the buffer really is) rather than at emit
590     * time when we don't hold the lock and are just guessing.  We could also
591     * just avoid using this as key data if the program doesn't use
592     * fragment.position.
593     *
594     * For DRI2 the origin_x/y will always be (0,0) but we still need the
595     * drawable height in order to invert the Y axis.
596     */
597    if (fp->program.Base.InputsRead & FRAG_BIT_WPOS) {
598       key->drawable_height = ctx->DrawBuffer->Height;
599    }
600 
601    if ((fp->program.Base.InputsRead & FRAG_BIT_WPOS) || program_uses_dfdy) {
602       key->render_to_fbo = _mesa_is_user_fbo(ctx->DrawBuffer);
603    }
604 
605    /* _NEW_BUFFERS */
606    key->nr_color_regions = ctx->DrawBuffer->_NumColorDrawBuffers;
607   /* _NEW_MULTISAMPLE */
608    key->sample_alpha_to_coverage = ctx->Multisample.SampleAlphaToCoverage;
609 
610    /* CACHE_NEW_VS_PROG */
611    if (intel->gen < 6)
612       key->vp_outputs_written = brw->vs.prog_data->outputs_written;
613 
614    /* The unique fragment program ID */
615    key->program_string_id = fp->id;
616 }
617 
618 
619 static void
brw_upload_wm_prog(struct brw_context * brw)620 brw_upload_wm_prog(struct brw_context *brw)
621 {
622    struct intel_context *intel = &brw->intel;
623    struct gl_context *ctx = &intel->ctx;
624    struct brw_wm_prog_key key;
625    struct brw_fragment_program *fp = (struct brw_fragment_program *)
626       brw->fragment_program;
627 
628    brw_wm_populate_key(brw, &key);
629 
630    if (!brw_search_cache(&brw->cache, BRW_WM_PROG,
631 			 &key, sizeof(key),
632 			 &brw->wm.prog_offset, &brw->wm.prog_data)) {
633       bool success = do_wm_prog(brw, ctx->Shader._CurrentFragmentProgram, fp,
634 				&key);
635       (void) success;
636       assert(success);
637    }
638 }
639 
640 
641 const struct brw_tracked_state brw_wm_prog = {
642    .dirty = {
643       .mesa  = (_NEW_COLOR |
644 		_NEW_DEPTH |
645 		_NEW_STENCIL |
646 		_NEW_POLYGON |
647 		_NEW_LINE |
648 		_NEW_LIGHT |
649 		_NEW_FRAG_CLAMP |
650 		_NEW_BUFFERS |
651 		_NEW_TEXTURE |
652 		_NEW_MULTISAMPLE),
653       .brw   = (BRW_NEW_FRAGMENT_PROGRAM |
654 		BRW_NEW_WM_INPUT_DIMENSIONS |
655 		BRW_NEW_REDUCED_PRIMITIVE),
656       .cache = CACHE_NEW_VS_PROG,
657    },
658    .emit = brw_upload_wm_prog
659 };
660 
661