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[mesa.git] / src / mesa / program / programopt.c
1 /*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25 /**
26 * \file programopt.c
27 * Vertex/Fragment program optimizations and transformations for program
28 * options, etc.
29 *
30 * \author Brian Paul
31 */
32
33
34 #include "main/glheader.h"
35 #include "main/context.h"
36 #include "prog_parameter.h"
37 #include "prog_statevars.h"
38 #include "program.h"
39 #include "programopt.h"
40 #include "prog_instruction.h"
41
42
43 /**
44 * This function inserts instructions for coordinate modelview * projection
45 * into a vertex program.
46 * May be used to implement the position_invariant option.
47 */
48 static void
49 _mesa_insert_mvp_dp4_code(struct gl_context *ctx, struct gl_program *vprog)
50 {
51 struct prog_instruction *newInst;
52 const GLuint origLen = vprog->NumInstructions;
53 const GLuint newLen = origLen + 4;
54 GLuint i;
55
56 /*
57 * Setup state references for the modelview/projection matrix.
58 * XXX we should check if these state vars are already declared.
59 */
60 static const gl_state_index mvpState[4][STATE_LENGTH] = {
61 { STATE_MVP_MATRIX, 0, 0, 0, 0 }, /* state.matrix.mvp.row[0] */
62 { STATE_MVP_MATRIX, 0, 1, 1, 0 }, /* state.matrix.mvp.row[1] */
63 { STATE_MVP_MATRIX, 0, 2, 2, 0 }, /* state.matrix.mvp.row[2] */
64 { STATE_MVP_MATRIX, 0, 3, 3, 0 }, /* state.matrix.mvp.row[3] */
65 };
66 GLint mvpRef[4];
67
68 for (i = 0; i < 4; i++) {
69 mvpRef[i] = _mesa_add_state_reference(vprog->Parameters, mvpState[i]);
70 }
71
72 /* Alloc storage for new instructions */
73 newInst = _mesa_alloc_instructions(newLen);
74 if (!newInst) {
75 _mesa_error(ctx, GL_OUT_OF_MEMORY,
76 "glProgramString(inserting position_invariant code)");
77 return;
78 }
79
80 /*
81 * Generated instructions:
82 * newInst[0] = DP4 result.position.x, mvp.row[0], vertex.position;
83 * newInst[1] = DP4 result.position.y, mvp.row[1], vertex.position;
84 * newInst[2] = DP4 result.position.z, mvp.row[2], vertex.position;
85 * newInst[3] = DP4 result.position.w, mvp.row[3], vertex.position;
86 */
87 _mesa_init_instructions(newInst, 4);
88 for (i = 0; i < 4; i++) {
89 newInst[i].Opcode = OPCODE_DP4;
90 newInst[i].DstReg.File = PROGRAM_OUTPUT;
91 newInst[i].DstReg.Index = VARYING_SLOT_POS;
92 newInst[i].DstReg.WriteMask = (WRITEMASK_X << i);
93 newInst[i].SrcReg[0].File = PROGRAM_STATE_VAR;
94 newInst[i].SrcReg[0].Index = mvpRef[i];
95 newInst[i].SrcReg[0].Swizzle = SWIZZLE_NOOP;
96 newInst[i].SrcReg[1].File = PROGRAM_INPUT;
97 newInst[i].SrcReg[1].Index = VERT_ATTRIB_POS;
98 newInst[i].SrcReg[1].Swizzle = SWIZZLE_NOOP;
99 }
100
101 /* Append original instructions after new instructions */
102 _mesa_copy_instructions (newInst + 4, vprog->Instructions, origLen);
103
104 /* free old instructions */
105 _mesa_free_instructions(vprog->Instructions, origLen);
106
107 /* install new instructions */
108 vprog->Instructions = newInst;
109 vprog->NumInstructions = newLen;
110 vprog->InputsRead |= VERT_BIT_POS;
111 vprog->OutputsWritten |= BITFIELD64_BIT(VARYING_SLOT_POS);
112 }
113
114
115 static void
116 _mesa_insert_mvp_mad_code(struct gl_context *ctx, struct gl_program *vprog)
117 {
118 struct prog_instruction *newInst;
119 const GLuint origLen = vprog->NumInstructions;
120 const GLuint newLen = origLen + 4;
121 GLuint hposTemp;
122 GLuint i;
123
124 /*
125 * Setup state references for the modelview/projection matrix.
126 * XXX we should check if these state vars are already declared.
127 */
128 static const gl_state_index mvpState[4][STATE_LENGTH] = {
129 { STATE_MVP_MATRIX, 0, 0, 0, STATE_MATRIX_TRANSPOSE },
130 { STATE_MVP_MATRIX, 0, 1, 1, STATE_MATRIX_TRANSPOSE },
131 { STATE_MVP_MATRIX, 0, 2, 2, STATE_MATRIX_TRANSPOSE },
132 { STATE_MVP_MATRIX, 0, 3, 3, STATE_MATRIX_TRANSPOSE },
133 };
134 GLint mvpRef[4];
135
136 for (i = 0; i < 4; i++) {
137 mvpRef[i] = _mesa_add_state_reference(vprog->Parameters, mvpState[i]);
138 }
139
140 /* Alloc storage for new instructions */
141 newInst = _mesa_alloc_instructions(newLen);
142 if (!newInst) {
143 _mesa_error(ctx, GL_OUT_OF_MEMORY,
144 "glProgramString(inserting position_invariant code)");
145 return;
146 }
147
148 /* TEMP hposTemp; */
149 hposTemp = vprog->NumTemporaries++;
150
151 /*
152 * Generated instructions:
153 * emit_op2(p, OPCODE_MUL, tmp, 0, swizzle1(src,X), mat[0]);
154 * emit_op3(p, OPCODE_MAD, tmp, 0, swizzle1(src,Y), mat[1], tmp);
155 * emit_op3(p, OPCODE_MAD, tmp, 0, swizzle1(src,Z), mat[2], tmp);
156 * emit_op3(p, OPCODE_MAD, dest, 0, swizzle1(src,W), mat[3], tmp);
157 */
158 _mesa_init_instructions(newInst, 4);
159
160 newInst[0].Opcode = OPCODE_MUL;
161 newInst[0].DstReg.File = PROGRAM_TEMPORARY;
162 newInst[0].DstReg.Index = hposTemp;
163 newInst[0].DstReg.WriteMask = WRITEMASK_XYZW;
164 newInst[0].SrcReg[0].File = PROGRAM_INPUT;
165 newInst[0].SrcReg[0].Index = VERT_ATTRIB_POS;
166 newInst[0].SrcReg[0].Swizzle = SWIZZLE_XXXX;
167 newInst[0].SrcReg[1].File = PROGRAM_STATE_VAR;
168 newInst[0].SrcReg[1].Index = mvpRef[0];
169 newInst[0].SrcReg[1].Swizzle = SWIZZLE_NOOP;
170
171 for (i = 1; i <= 2; i++) {
172 newInst[i].Opcode = OPCODE_MAD;
173 newInst[i].DstReg.File = PROGRAM_TEMPORARY;
174 newInst[i].DstReg.Index = hposTemp;
175 newInst[i].DstReg.WriteMask = WRITEMASK_XYZW;
176 newInst[i].SrcReg[0].File = PROGRAM_INPUT;
177 newInst[i].SrcReg[0].Index = VERT_ATTRIB_POS;
178 newInst[i].SrcReg[0].Swizzle = MAKE_SWIZZLE4(i,i,i,i);
179 newInst[i].SrcReg[1].File = PROGRAM_STATE_VAR;
180 newInst[i].SrcReg[1].Index = mvpRef[i];
181 newInst[i].SrcReg[1].Swizzle = SWIZZLE_NOOP;
182 newInst[i].SrcReg[2].File = PROGRAM_TEMPORARY;
183 newInst[i].SrcReg[2].Index = hposTemp;
184 newInst[1].SrcReg[2].Swizzle = SWIZZLE_NOOP;
185 }
186
187 newInst[3].Opcode = OPCODE_MAD;
188 newInst[3].DstReg.File = PROGRAM_OUTPUT;
189 newInst[3].DstReg.Index = VARYING_SLOT_POS;
190 newInst[3].DstReg.WriteMask = WRITEMASK_XYZW;
191 newInst[3].SrcReg[0].File = PROGRAM_INPUT;
192 newInst[3].SrcReg[0].Index = VERT_ATTRIB_POS;
193 newInst[3].SrcReg[0].Swizzle = SWIZZLE_WWWW;
194 newInst[3].SrcReg[1].File = PROGRAM_STATE_VAR;
195 newInst[3].SrcReg[1].Index = mvpRef[3];
196 newInst[3].SrcReg[1].Swizzle = SWIZZLE_NOOP;
197 newInst[3].SrcReg[2].File = PROGRAM_TEMPORARY;
198 newInst[3].SrcReg[2].Index = hposTemp;
199 newInst[3].SrcReg[2].Swizzle = SWIZZLE_NOOP;
200
201
202 /* Append original instructions after new instructions */
203 _mesa_copy_instructions (newInst + 4, vprog->Instructions, origLen);
204
205 /* free old instructions */
206 _mesa_free_instructions(vprog->Instructions, origLen);
207
208 /* install new instructions */
209 vprog->Instructions = newInst;
210 vprog->NumInstructions = newLen;
211 vprog->InputsRead |= VERT_BIT_POS;
212 vprog->OutputsWritten |= BITFIELD64_BIT(VARYING_SLOT_POS);
213 }
214
215
216 void
217 _mesa_insert_mvp_code(struct gl_context *ctx, struct gl_program *vprog)
218 {
219 if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].OptimizeForAOS)
220 _mesa_insert_mvp_dp4_code( ctx, vprog );
221 else
222 _mesa_insert_mvp_mad_code( ctx, vprog );
223 }
224
225
226
227
228
229
230 /**
231 * Append instructions to implement fog
232 *
233 * The \c fragment.fogcoord input is used to compute the fog blend factor.
234 *
235 * \param ctx The GL context
236 * \param fprog Fragment program that fog instructions will be appended to.
237 * \param fog_mode Fog mode. One of \c GL_EXP, \c GL_EXP2, or \c GL_LINEAR.
238 * \param saturate True if writes to color outputs should be clamped to [0, 1]
239 *
240 * \note
241 * This function sets \c VARYING_BIT_FOGC in \c fprog->Base.InputsRead.
242 *
243 * \todo With a little work, this function could be adapted to add fog code
244 * to vertex programs too.
245 */
246 void
247 _mesa_append_fog_code(struct gl_context *ctx,
248 struct gl_fragment_program *fprog, GLenum fog_mode,
249 GLboolean saturate)
250 {
251 static const gl_state_index fogPStateOpt[STATE_LENGTH]
252 = { STATE_INTERNAL, STATE_FOG_PARAMS_OPTIMIZED, 0, 0, 0 };
253 static const gl_state_index fogColorState[STATE_LENGTH]
254 = { STATE_FOG_COLOR, 0, 0, 0, 0};
255 struct prog_instruction *newInst, *inst;
256 const GLuint origLen = fprog->Base.NumInstructions;
257 const GLuint newLen = origLen + 5;
258 GLuint i;
259 GLint fogPRefOpt, fogColorRef; /* state references */
260 GLuint colorTemp, fogFactorTemp; /* temporary registerss */
261
262 if (fog_mode == GL_NONE) {
263 _mesa_problem(ctx, "_mesa_append_fog_code() called for fragment program"
264 " with fog_mode == GL_NONE");
265 return;
266 }
267
268 if (!(fprog->Base.OutputsWritten & (1 << FRAG_RESULT_COLOR))) {
269 /* program doesn't output color, so nothing to do */
270 return;
271 }
272
273 /* Alloc storage for new instructions */
274 newInst = _mesa_alloc_instructions(newLen);
275 if (!newInst) {
276 _mesa_error(ctx, GL_OUT_OF_MEMORY,
277 "glProgramString(inserting fog_option code)");
278 return;
279 }
280
281 /* Copy orig instructions into new instruction buffer */
282 _mesa_copy_instructions(newInst, fprog->Base.Instructions, origLen);
283
284 /* PARAM fogParamsRefOpt = internal optimized fog params; */
285 fogPRefOpt
286 = _mesa_add_state_reference(fprog->Base.Parameters, fogPStateOpt);
287 /* PARAM fogColorRef = state.fog.color; */
288 fogColorRef
289 = _mesa_add_state_reference(fprog->Base.Parameters, fogColorState);
290
291 /* TEMP colorTemp; */
292 colorTemp = fprog->Base.NumTemporaries++;
293 /* TEMP fogFactorTemp; */
294 fogFactorTemp = fprog->Base.NumTemporaries++;
295
296 /* Scan program to find where result.color is written */
297 inst = newInst;
298 for (i = 0; i < fprog->Base.NumInstructions; i++) {
299 if (inst->Opcode == OPCODE_END)
300 break;
301 if (inst->DstReg.File == PROGRAM_OUTPUT &&
302 inst->DstReg.Index == FRAG_RESULT_COLOR) {
303 /* change the instruction to write to colorTemp w/ clamping */
304 inst->DstReg.File = PROGRAM_TEMPORARY;
305 inst->DstReg.Index = colorTemp;
306 inst->Saturate = saturate;
307 /* don't break (may be several writes to result.color) */
308 }
309 inst++;
310 }
311 assert(inst->Opcode == OPCODE_END); /* we'll overwrite this inst */
312
313 _mesa_init_instructions(inst, 5);
314
315 /* emit instructions to compute fog blending factor */
316 /* this is always clamped to [0, 1] regardless of fragment clamping */
317 if (fog_mode == GL_LINEAR) {
318 /* MAD fogFactorTemp.x, fragment.fogcoord.x, fogPRefOpt.x, fogPRefOpt.y; */
319 inst->Opcode = OPCODE_MAD;
320 inst->DstReg.File = PROGRAM_TEMPORARY;
321 inst->DstReg.Index = fogFactorTemp;
322 inst->DstReg.WriteMask = WRITEMASK_X;
323 inst->SrcReg[0].File = PROGRAM_INPUT;
324 inst->SrcReg[0].Index = VARYING_SLOT_FOGC;
325 inst->SrcReg[0].Swizzle = SWIZZLE_XXXX;
326 inst->SrcReg[1].File = PROGRAM_STATE_VAR;
327 inst->SrcReg[1].Index = fogPRefOpt;
328 inst->SrcReg[1].Swizzle = SWIZZLE_XXXX;
329 inst->SrcReg[2].File = PROGRAM_STATE_VAR;
330 inst->SrcReg[2].Index = fogPRefOpt;
331 inst->SrcReg[2].Swizzle = SWIZZLE_YYYY;
332 inst->Saturate = GL_TRUE;
333 inst++;
334 }
335 else {
336 assert(fog_mode == GL_EXP || fog_mode == GL_EXP2);
337 /* fogPRefOpt.z = d/ln(2), fogPRefOpt.w = d/sqrt(ln(2) */
338 /* EXP: MUL fogFactorTemp.x, fogPRefOpt.z, fragment.fogcoord.x; */
339 /* EXP2: MUL fogFactorTemp.x, fogPRefOpt.w, fragment.fogcoord.x; */
340 inst->Opcode = OPCODE_MUL;
341 inst->DstReg.File = PROGRAM_TEMPORARY;
342 inst->DstReg.Index = fogFactorTemp;
343 inst->DstReg.WriteMask = WRITEMASK_X;
344 inst->SrcReg[0].File = PROGRAM_STATE_VAR;
345 inst->SrcReg[0].Index = fogPRefOpt;
346 inst->SrcReg[0].Swizzle
347 = (fog_mode == GL_EXP) ? SWIZZLE_ZZZZ : SWIZZLE_WWWW;
348 inst->SrcReg[1].File = PROGRAM_INPUT;
349 inst->SrcReg[1].Index = VARYING_SLOT_FOGC;
350 inst->SrcReg[1].Swizzle = SWIZZLE_XXXX;
351 inst++;
352 if (fog_mode == GL_EXP2) {
353 /* MUL fogFactorTemp.x, fogFactorTemp.x, fogFactorTemp.x; */
354 inst->Opcode = OPCODE_MUL;
355 inst->DstReg.File = PROGRAM_TEMPORARY;
356 inst->DstReg.Index = fogFactorTemp;
357 inst->DstReg.WriteMask = WRITEMASK_X;
358 inst->SrcReg[0].File = PROGRAM_TEMPORARY;
359 inst->SrcReg[0].Index = fogFactorTemp;
360 inst->SrcReg[0].Swizzle = SWIZZLE_XXXX;
361 inst->SrcReg[1].File = PROGRAM_TEMPORARY;
362 inst->SrcReg[1].Index = fogFactorTemp;
363 inst->SrcReg[1].Swizzle = SWIZZLE_XXXX;
364 inst++;
365 }
366 /* EX2_SAT fogFactorTemp.x, -fogFactorTemp.x; */
367 inst->Opcode = OPCODE_EX2;
368 inst->DstReg.File = PROGRAM_TEMPORARY;
369 inst->DstReg.Index = fogFactorTemp;
370 inst->DstReg.WriteMask = WRITEMASK_X;
371 inst->SrcReg[0].File = PROGRAM_TEMPORARY;
372 inst->SrcReg[0].Index = fogFactorTemp;
373 inst->SrcReg[0].Negate = NEGATE_XYZW;
374 inst->SrcReg[0].Swizzle = SWIZZLE_XXXX;
375 inst->Saturate = GL_TRUE;
376 inst++;
377 }
378 /* LRP result.color.xyz, fogFactorTemp.xxxx, colorTemp, fogColorRef; */
379 inst->Opcode = OPCODE_LRP;
380 inst->DstReg.File = PROGRAM_OUTPUT;
381 inst->DstReg.Index = FRAG_RESULT_COLOR;
382 inst->DstReg.WriteMask = WRITEMASK_XYZ;
383 inst->SrcReg[0].File = PROGRAM_TEMPORARY;
384 inst->SrcReg[0].Index = fogFactorTemp;
385 inst->SrcReg[0].Swizzle = SWIZZLE_XXXX;
386 inst->SrcReg[1].File = PROGRAM_TEMPORARY;
387 inst->SrcReg[1].Index = colorTemp;
388 inst->SrcReg[1].Swizzle = SWIZZLE_NOOP;
389 inst->SrcReg[2].File = PROGRAM_STATE_VAR;
390 inst->SrcReg[2].Index = fogColorRef;
391 inst->SrcReg[2].Swizzle = SWIZZLE_NOOP;
392 inst++;
393 /* MOV result.color.w, colorTemp.x; # copy alpha */
394 inst->Opcode = OPCODE_MOV;
395 inst->DstReg.File = PROGRAM_OUTPUT;
396 inst->DstReg.Index = FRAG_RESULT_COLOR;
397 inst->DstReg.WriteMask = WRITEMASK_W;
398 inst->SrcReg[0].File = PROGRAM_TEMPORARY;
399 inst->SrcReg[0].Index = colorTemp;
400 inst->SrcReg[0].Swizzle = SWIZZLE_NOOP;
401 inst++;
402 /* END; */
403 inst->Opcode = OPCODE_END;
404 inst++;
405
406 /* free old instructions */
407 _mesa_free_instructions(fprog->Base.Instructions, origLen);
408
409 /* install new instructions */
410 fprog->Base.Instructions = newInst;
411 fprog->Base.NumInstructions = inst - newInst;
412 fprog->Base.InputsRead |= VARYING_BIT_FOGC;
413 assert(fprog->Base.OutputsWritten & (1 << FRAG_RESULT_COLOR));
414 }
415
416
417
418 static GLboolean
419 is_texture_instruction(const struct prog_instruction *inst)
420 {
421 switch (inst->Opcode) {
422 case OPCODE_TEX:
423 case OPCODE_TXB:
424 case OPCODE_TXD:
425 case OPCODE_TXL:
426 case OPCODE_TXP:
427 return GL_TRUE;
428 default:
429 return GL_FALSE;
430 }
431 }
432
433
434 /**
435 * Count the number of texure indirections in the given program.
436 * The program's NumTexIndirections field will be updated.
437 * See the GL_ARB_fragment_program spec (issue 24) for details.
438 * XXX we count texture indirections in texenvprogram.c (maybe use this code
439 * instead and elsewhere).
440 */
441 void
442 _mesa_count_texture_indirections(struct gl_program *prog)
443 {
444 GLuint indirections = 1;
445 GLbitfield tempsOutput = 0x0;
446 GLbitfield aluTemps = 0x0;
447 GLuint i;
448
449 for (i = 0; i < prog->NumInstructions; i++) {
450 const struct prog_instruction *inst = prog->Instructions + i;
451
452 if (is_texture_instruction(inst)) {
453 if (((inst->SrcReg[0].File == PROGRAM_TEMPORARY) &&
454 (tempsOutput & (1 << inst->SrcReg[0].Index))) ||
455 ((inst->Opcode != OPCODE_KIL) &&
456 (inst->DstReg.File == PROGRAM_TEMPORARY) &&
457 (aluTemps & (1 << inst->DstReg.Index))))
458 {
459 indirections++;
460 tempsOutput = 0x0;
461 aluTemps = 0x0;
462 }
463 }
464 else {
465 GLuint j;
466 for (j = 0; j < 3; j++) {
467 if (inst->SrcReg[j].File == PROGRAM_TEMPORARY)
468 aluTemps |= (1 << inst->SrcReg[j].Index);
469 }
470 if (inst->DstReg.File == PROGRAM_TEMPORARY)
471 aluTemps |= (1 << inst->DstReg.Index);
472 }
473
474 if ((inst->Opcode != OPCODE_KIL) && (inst->DstReg.File == PROGRAM_TEMPORARY))
475 tempsOutput |= (1 << inst->DstReg.Index);
476 }
477
478 prog->NumTexIndirections = indirections;
479 }
480
481
482 /**
483 * Count number of texture instructions in given program and update the
484 * program's NumTexInstructions field.
485 */
486 void
487 _mesa_count_texture_instructions(struct gl_program *prog)
488 {
489 GLuint i;
490 prog->NumTexInstructions = 0;
491 for (i = 0; i < prog->NumInstructions; i++) {
492 prog->NumTexInstructions += is_texture_instruction(prog->Instructions + i);
493 }
494 }
495
496
497 /**
498 * Scan/rewrite program to remove reads of custom (output) registers.
499 * The passed type has to be PROGRAM_OUTPUT.
500 * On some hardware, trying to read an output register causes trouble.
501 * So, rewrite the program to use a temporary register in this case.
502 */
503 void
504 _mesa_remove_output_reads(struct gl_program *prog, gl_register_file type)
505 {
506 GLuint i;
507 GLint outputMap[VARYING_SLOT_MAX];
508 GLuint numVaryingReads = 0;
509 GLboolean usedTemps[MAX_PROGRAM_TEMPS];
510 GLuint firstTemp = 0;
511
512 _mesa_find_used_registers(prog, PROGRAM_TEMPORARY,
513 usedTemps, MAX_PROGRAM_TEMPS);
514
515 assert(type == PROGRAM_OUTPUT);
516
517 for (i = 0; i < VARYING_SLOT_MAX; i++)
518 outputMap[i] = -1;
519
520 /* look for instructions which read from varying vars */
521 for (i = 0; i < prog->NumInstructions; i++) {
522 struct prog_instruction *inst = prog->Instructions + i;
523 const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
524 GLuint j;
525 for (j = 0; j < numSrc; j++) {
526 if (inst->SrcReg[j].File == type) {
527 /* replace the read with a temp reg */
528 const GLuint var = inst->SrcReg[j].Index;
529 if (outputMap[var] == -1) {
530 numVaryingReads++;
531 outputMap[var] = _mesa_find_free_register(usedTemps,
532 MAX_PROGRAM_TEMPS,
533 firstTemp);
534 firstTemp = outputMap[var] + 1;
535 }
536 inst->SrcReg[j].File = PROGRAM_TEMPORARY;
537 inst->SrcReg[j].Index = outputMap[var];
538 }
539 }
540 }
541
542 if (numVaryingReads == 0)
543 return; /* nothing to be done */
544
545 /* look for instructions which write to the varying vars identified above */
546 for (i = 0; i < prog->NumInstructions; i++) {
547 struct prog_instruction *inst = prog->Instructions + i;
548 if (inst->DstReg.File == type &&
549 outputMap[inst->DstReg.Index] >= 0) {
550 /* change inst to write to the temp reg, instead of the varying */
551 inst->DstReg.File = PROGRAM_TEMPORARY;
552 inst->DstReg.Index = outputMap[inst->DstReg.Index];
553 }
554 }
555
556 /* insert new instructions to copy the temp vars to the varying vars */
557 {
558 struct prog_instruction *inst;
559 GLint endPos, var;
560
561 /* Look for END instruction and insert the new varying writes */
562 endPos = -1;
563 for (i = 0; i < prog->NumInstructions; i++) {
564 struct prog_instruction *inst = prog->Instructions + i;
565 if (inst->Opcode == OPCODE_END) {
566 endPos = i;
567 _mesa_insert_instructions(prog, i, numVaryingReads);
568 break;
569 }
570 }
571
572 assert(endPos >= 0);
573
574 /* insert new MOV instructions here */
575 inst = prog->Instructions + endPos;
576 for (var = 0; var < VARYING_SLOT_MAX; var++) {
577 if (outputMap[var] >= 0) {
578 /* MOV VAR[var], TEMP[tmp]; */
579 inst->Opcode = OPCODE_MOV;
580 inst->DstReg.File = type;
581 inst->DstReg.Index = var;
582 inst->SrcReg[0].File = PROGRAM_TEMPORARY;
583 inst->SrcReg[0].Index = outputMap[var];
584 inst++;
585 }
586 }
587 }
588 }
589
590 void
591 _mesa_program_fragment_position_to_sysval(struct gl_program *prog)
592 {
593 GLuint i;
594
595 if (prog->Target != GL_FRAGMENT_PROGRAM_ARB ||
596 !(prog->InputsRead & BITFIELD64_BIT(VARYING_SLOT_POS)))
597 return;
598
599 prog->InputsRead &= ~BITFIELD64_BIT(VARYING_SLOT_POS);
600 prog->SystemValuesRead |= 1 << SYSTEM_VALUE_FRAG_COORD;
601
602 for (i = 0; i < prog->NumInstructions; i++) {
603 struct prog_instruction *inst = prog->Instructions + i;
604 const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
605 GLuint j;
606
607 for (j = 0; j < numSrc; j++) {
608 if (inst->SrcReg[j].File == PROGRAM_INPUT &&
609 inst->SrcReg[j].Index == VARYING_SLOT_POS) {
610 inst->SrcReg[j].File = PROGRAM_SYSTEM_VALUE;
611 inst->SrcReg[j].Index = SYSTEM_VALUE_FRAG_COORD;
612 }
613 }
614 }
615 }