brw_fs_visitor.cpp revision febad1779ae5cb5c85d66c2635baea62da52d2fa
1/*
2 * Copyright © 2010 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24/** @file brw_fs_visitor.cpp
25 *
26 * This file supports generating the FS LIR from the GLSL IR.  The LIR
27 * makes it easier to do backend-specific optimizations than doing so
28 * in the GLSL IR or in the native code.
29 */
30extern "C" {
31
32#include <sys/types.h>
33
34#include "main/macros.h"
35#include "main/shaderobj.h"
36#include "main/uniforms.h"
37#include "program/prog_parameter.h"
38#include "program/prog_print.h"
39#include "program/prog_optimize.h"
40#include "program/register_allocate.h"
41#include "program/sampler.h"
42#include "program/hash_table.h"
43#include "brw_context.h"
44#include "brw_eu.h"
45#include "brw_wm.h"
46}
47#include "brw_shader.h"
48#include "brw_fs.h"
49#include "glsl/glsl_types.h"
50#include "glsl/ir_optimization.h"
51#include "glsl/ir_print_visitor.h"
52
53void
54fs_visitor::visit(ir_variable *ir)
55{
56   fs_reg *reg = NULL;
57
58   if (variable_storage(ir))
59      return;
60
61   if (ir->mode == ir_var_in) {
62      if (!strcmp(ir->name, "gl_FragCoord")) {
63	 reg = emit_fragcoord_interpolation(ir);
64      } else if (!strcmp(ir->name, "gl_FrontFacing")) {
65	 reg = emit_frontfacing_interpolation(ir);
66      } else {
67	 reg = emit_general_interpolation(ir);
68      }
69      assert(reg);
70      hash_table_insert(this->variable_ht, reg, ir);
71      return;
72   } else if (ir->mode == ir_var_out) {
73      reg = new(this->mem_ctx) fs_reg(this, ir->type);
74
75      if (ir->location == FRAG_RESULT_COLOR) {
76	 /* Writing gl_FragColor outputs to all color regions. */
77	 for (int i = 0; i < MAX2(c->key.nr_color_regions, 1); i++) {
78	    this->outputs[i] = *reg;
79	 }
80      } else if (ir->location == FRAG_RESULT_DEPTH) {
81	 this->frag_depth = ir;
82      } else {
83	 /* gl_FragData or a user-defined FS output */
84	 assert(ir->location >= FRAG_RESULT_DATA0 &&
85		ir->location < FRAG_RESULT_DATA0 + BRW_MAX_DRAW_BUFFERS);
86
87	 /* General color output. */
88	 for (unsigned int i = 0; i < MAX2(1, ir->type->length); i++) {
89	    int output = ir->location - FRAG_RESULT_DATA0 + i;
90	    this->outputs[output] = *reg;
91	    this->outputs[output].reg_offset += 4 * i;
92	 }
93      }
94   } else if (ir->mode == ir_var_uniform) {
95      int param_index = c->prog_data.nr_params;
96
97      if (c->dispatch_width == 16) {
98	 if (!variable_storage(ir)) {
99	    fail("Failed to find uniform '%s' in 16-wide\n", ir->name);
100	 }
101	 return;
102      }
103
104      if (!strncmp(ir->name, "gl_", 3)) {
105	 setup_builtin_uniform_values(ir);
106      } else {
107	 setup_uniform_values(ir->location, ir->type);
108      }
109
110      reg = new(this->mem_ctx) fs_reg(UNIFORM, param_index);
111      reg->type = brw_type_for_base_type(ir->type);
112   }
113
114   if (!reg)
115      reg = new(this->mem_ctx) fs_reg(this, ir->type);
116
117   hash_table_insert(this->variable_ht, reg, ir);
118}
119
120void
121fs_visitor::visit(ir_dereference_variable *ir)
122{
123   fs_reg *reg = variable_storage(ir->var);
124   this->result = *reg;
125}
126
127void
128fs_visitor::visit(ir_dereference_record *ir)
129{
130   const glsl_type *struct_type = ir->record->type;
131
132   ir->record->accept(this);
133
134   unsigned int offset = 0;
135   for (unsigned int i = 0; i < struct_type->length; i++) {
136      if (strcmp(struct_type->fields.structure[i].name, ir->field) == 0)
137	 break;
138      offset += type_size(struct_type->fields.structure[i].type);
139   }
140   this->result.reg_offset += offset;
141   this->result.type = brw_type_for_base_type(ir->type);
142}
143
144void
145fs_visitor::visit(ir_dereference_array *ir)
146{
147   ir_constant *index;
148   int element_size;
149
150   ir->array->accept(this);
151   index = ir->array_index->as_constant();
152
153   element_size = type_size(ir->type);
154   this->result.type = brw_type_for_base_type(ir->type);
155
156   if (index) {
157      assert(this->result.file == UNIFORM || this->result.file == GRF);
158      this->result.reg_offset += index->value.i[0] * element_size;
159   } else {
160      assert(!"FINISHME: non-constant array element");
161   }
162}
163
164/* Instruction selection: Produce a MOV.sat instead of
165 * MIN(MAX(val, 0), 1) when possible.
166 */
167bool
168fs_visitor::try_emit_saturate(ir_expression *ir)
169{
170   ir_rvalue *sat_val = ir->as_rvalue_to_saturate();
171
172   if (!sat_val)
173      return false;
174
175   sat_val->accept(this);
176   fs_reg src = this->result;
177
178   this->result = fs_reg(this, ir->type);
179   fs_inst *inst = emit(BRW_OPCODE_MOV, this->result, src);
180   inst->saturate = true;
181
182   return true;
183}
184
185void
186fs_visitor::visit(ir_expression *ir)
187{
188   unsigned int operand;
189   fs_reg op[2], temp;
190   fs_inst *inst;
191
192   assert(ir->get_num_operands() <= 2);
193
194   if (try_emit_saturate(ir))
195      return;
196
197   for (operand = 0; operand < ir->get_num_operands(); operand++) {
198      ir->operands[operand]->accept(this);
199      if (this->result.file == BAD_FILE) {
200	 ir_print_visitor v;
201	 fail("Failed to get tree for expression operand:\n");
202	 ir->operands[operand]->accept(&v);
203      }
204      op[operand] = this->result;
205
206      /* Matrix expression operands should have been broken down to vector
207       * operations already.
208       */
209      assert(!ir->operands[operand]->type->is_matrix());
210      /* And then those vector operands should have been broken down to scalar.
211       */
212      assert(!ir->operands[operand]->type->is_vector());
213   }
214
215   /* Storage for our result.  If our result goes into an assignment, it will
216    * just get copy-propagated out, so no worries.
217    */
218   this->result = fs_reg(this, ir->type);
219
220   switch (ir->operation) {
221   case ir_unop_logic_not:
222      /* Note that BRW_OPCODE_NOT is not appropriate here, since it is
223       * ones complement of the whole register, not just bit 0.
224       */
225      emit(BRW_OPCODE_XOR, this->result, op[0], fs_reg(1));
226      break;
227   case ir_unop_neg:
228      op[0].negate = !op[0].negate;
229      this->result = op[0];
230      break;
231   case ir_unop_abs:
232      op[0].abs = true;
233      op[0].negate = false;
234      this->result = op[0];
235      break;
236   case ir_unop_sign:
237      temp = fs_reg(this, ir->type);
238
239      emit(BRW_OPCODE_MOV, this->result, fs_reg(0.0f));
240
241      inst = emit(BRW_OPCODE_CMP, reg_null_f, op[0], fs_reg(0.0f));
242      inst->conditional_mod = BRW_CONDITIONAL_G;
243      inst = emit(BRW_OPCODE_MOV, this->result, fs_reg(1.0f));
244      inst->predicated = true;
245
246      inst = emit(BRW_OPCODE_CMP, reg_null_f, op[0], fs_reg(0.0f));
247      inst->conditional_mod = BRW_CONDITIONAL_L;
248      inst = emit(BRW_OPCODE_MOV, this->result, fs_reg(-1.0f));
249      inst->predicated = true;
250
251      break;
252   case ir_unop_rcp:
253      emit_math(SHADER_OPCODE_RCP, this->result, op[0]);
254      break;
255
256   case ir_unop_exp2:
257      emit_math(SHADER_OPCODE_EXP2, this->result, op[0]);
258      break;
259   case ir_unop_log2:
260      emit_math(SHADER_OPCODE_LOG2, this->result, op[0]);
261      break;
262   case ir_unop_exp:
263   case ir_unop_log:
264      assert(!"not reached: should be handled by ir_explog_to_explog2");
265      break;
266   case ir_unop_sin:
267   case ir_unop_sin_reduced:
268      emit_math(SHADER_OPCODE_SIN, this->result, op[0]);
269      break;
270   case ir_unop_cos:
271   case ir_unop_cos_reduced:
272      emit_math(SHADER_OPCODE_COS, this->result, op[0]);
273      break;
274
275   case ir_unop_dFdx:
276      emit(FS_OPCODE_DDX, this->result, op[0]);
277      break;
278   case ir_unop_dFdy:
279      emit(FS_OPCODE_DDY, this->result, op[0]);
280      break;
281
282   case ir_binop_add:
283      emit(BRW_OPCODE_ADD, this->result, op[0], op[1]);
284      break;
285   case ir_binop_sub:
286      assert(!"not reached: should be handled by ir_sub_to_add_neg");
287      break;
288
289   case ir_binop_mul:
290      if (ir->type->is_integer()) {
291	 /* For integer multiplication, the MUL uses the low 16 bits
292	  * of one of the operands (src0 on gen6, src1 on gen7).  The
293	  * MACH accumulates in the contribution of the upper 16 bits
294	  * of that operand.
295	  *
296	  * FINISHME: Emit just the MUL if we know an operand is small
297	  * enough.
298	  */
299	 struct brw_reg acc = retype(brw_acc_reg(), BRW_REGISTER_TYPE_D);
300
301	 emit(BRW_OPCODE_MUL, acc, op[0], op[1]);
302	 emit(BRW_OPCODE_MACH, reg_null_d, op[0], op[1]);
303	 emit(BRW_OPCODE_MOV, this->result, fs_reg(acc));
304      } else {
305	 emit(BRW_OPCODE_MUL, this->result, op[0], op[1]);
306      }
307      break;
308   case ir_binop_div:
309      /* Floating point should be lowered by DIV_TO_MUL_RCP in the compiler. */
310      assert(ir->type->is_integer());
311      emit_math(SHADER_OPCODE_INT_QUOTIENT, this->result, op[0], op[1]);
312      break;
313   case ir_binop_mod:
314      /* Floating point should be lowered by MOD_TO_FRACT in the compiler. */
315      assert(ir->type->is_integer());
316      emit_math(SHADER_OPCODE_INT_REMAINDER, this->result, op[0], op[1]);
317      break;
318
319   case ir_binop_less:
320   case ir_binop_greater:
321   case ir_binop_lequal:
322   case ir_binop_gequal:
323   case ir_binop_equal:
324   case ir_binop_all_equal:
325   case ir_binop_nequal:
326   case ir_binop_any_nequal:
327      temp = this->result;
328      /* original gen4 does implicit conversion before comparison. */
329      if (intel->gen < 5)
330	 temp.type = op[0].type;
331
332      resolve_ud_negate(&op[0]);
333      resolve_ud_negate(&op[1]);
334
335      inst = emit(BRW_OPCODE_CMP, temp, op[0], op[1]);
336      inst->conditional_mod = brw_conditional_for_comparison(ir->operation);
337      emit(BRW_OPCODE_AND, this->result, this->result, fs_reg(0x1));
338      break;
339
340   case ir_binop_logic_xor:
341      emit(BRW_OPCODE_XOR, this->result, op[0], op[1]);
342      break;
343
344   case ir_binop_logic_or:
345      emit(BRW_OPCODE_OR, this->result, op[0], op[1]);
346      break;
347
348   case ir_binop_logic_and:
349      emit(BRW_OPCODE_AND, this->result, op[0], op[1]);
350      break;
351
352   case ir_binop_dot:
353   case ir_unop_any:
354      assert(!"not reached: should be handled by brw_fs_channel_expressions");
355      break;
356
357   case ir_unop_noise:
358      assert(!"not reached: should be handled by lower_noise");
359      break;
360
361   case ir_quadop_vector:
362      assert(!"not reached: should be handled by lower_quadop_vector");
363      break;
364
365   case ir_unop_sqrt:
366      emit_math(SHADER_OPCODE_SQRT, this->result, op[0]);
367      break;
368
369   case ir_unop_rsq:
370      emit_math(SHADER_OPCODE_RSQ, this->result, op[0]);
371      break;
372
373   case ir_unop_i2u:
374      op[0].type = BRW_REGISTER_TYPE_UD;
375      this->result = op[0];
376      break;
377   case ir_unop_u2i:
378      op[0].type = BRW_REGISTER_TYPE_D;
379      this->result = op[0];
380      break;
381   case ir_unop_i2f:
382   case ir_unop_u2f:
383   case ir_unop_b2f:
384   case ir_unop_b2i:
385   case ir_unop_f2i:
386      emit(BRW_OPCODE_MOV, this->result, op[0]);
387      break;
388   case ir_unop_f2b:
389   case ir_unop_i2b:
390      temp = this->result;
391      /* original gen4 does implicit conversion before comparison. */
392      if (intel->gen < 5)
393	 temp.type = op[0].type;
394
395      resolve_ud_negate(&op[0]);
396
397      inst = emit(BRW_OPCODE_CMP, temp, op[0], fs_reg(0.0f));
398      inst->conditional_mod = BRW_CONDITIONAL_NZ;
399      inst = emit(BRW_OPCODE_AND, this->result, this->result, fs_reg(1));
400      break;
401
402   case ir_unop_trunc:
403      emit(BRW_OPCODE_RNDZ, this->result, op[0]);
404      break;
405   case ir_unop_ceil:
406      op[0].negate = !op[0].negate;
407      inst = emit(BRW_OPCODE_RNDD, this->result, op[0]);
408      this->result.negate = true;
409      break;
410   case ir_unop_floor:
411      inst = emit(BRW_OPCODE_RNDD, this->result, op[0]);
412      break;
413   case ir_unop_fract:
414      inst = emit(BRW_OPCODE_FRC, this->result, op[0]);
415      break;
416   case ir_unop_round_even:
417      emit(BRW_OPCODE_RNDE, this->result, op[0]);
418      break;
419
420   case ir_binop_min:
421      resolve_ud_negate(&op[0]);
422      resolve_ud_negate(&op[1]);
423
424      if (intel->gen >= 6) {
425	 inst = emit(BRW_OPCODE_SEL, this->result, op[0], op[1]);
426	 inst->conditional_mod = BRW_CONDITIONAL_L;
427      } else {
428	 /* Unalias the destination */
429	 this->result = fs_reg(this, ir->type);
430
431	 inst = emit(BRW_OPCODE_CMP, this->result, op[0], op[1]);
432	 inst->conditional_mod = BRW_CONDITIONAL_L;
433
434	 inst = emit(BRW_OPCODE_SEL, this->result, op[0], op[1]);
435	 inst->predicated = true;
436      }
437      break;
438   case ir_binop_max:
439      resolve_ud_negate(&op[0]);
440      resolve_ud_negate(&op[1]);
441
442      if (intel->gen >= 6) {
443	 inst = emit(BRW_OPCODE_SEL, this->result, op[0], op[1]);
444	 inst->conditional_mod = BRW_CONDITIONAL_GE;
445      } else {
446	 /* Unalias the destination */
447	 this->result = fs_reg(this, ir->type);
448
449	 inst = emit(BRW_OPCODE_CMP, this->result, op[0], op[1]);
450	 inst->conditional_mod = BRW_CONDITIONAL_G;
451
452	 inst = emit(BRW_OPCODE_SEL, this->result, op[0], op[1]);
453	 inst->predicated = true;
454      }
455      break;
456
457   case ir_binop_pow:
458      emit_math(SHADER_OPCODE_POW, this->result, op[0], op[1]);
459      break;
460
461   case ir_unop_bit_not:
462      inst = emit(BRW_OPCODE_NOT, this->result, op[0]);
463      break;
464   case ir_binop_bit_and:
465      inst = emit(BRW_OPCODE_AND, this->result, op[0], op[1]);
466      break;
467   case ir_binop_bit_xor:
468      inst = emit(BRW_OPCODE_XOR, this->result, op[0], op[1]);
469      break;
470   case ir_binop_bit_or:
471      inst = emit(BRW_OPCODE_OR, this->result, op[0], op[1]);
472      break;
473
474   case ir_binop_lshift:
475      inst = emit(BRW_OPCODE_SHL, this->result, op[0], op[1]);
476      break;
477
478   case ir_binop_rshift:
479      if (ir->type->base_type == GLSL_TYPE_INT)
480	 inst = emit(BRW_OPCODE_ASR, this->result, op[0], op[1]);
481      else
482	 inst = emit(BRW_OPCODE_SHR, this->result, op[0], op[1]);
483      break;
484   }
485}
486
487void
488fs_visitor::emit_assignment_writes(fs_reg &l, fs_reg &r,
489				   const glsl_type *type, bool predicated)
490{
491   switch (type->base_type) {
492   case GLSL_TYPE_FLOAT:
493   case GLSL_TYPE_UINT:
494   case GLSL_TYPE_INT:
495   case GLSL_TYPE_BOOL:
496      for (unsigned int i = 0; i < type->components(); i++) {
497	 l.type = brw_type_for_base_type(type);
498	 r.type = brw_type_for_base_type(type);
499
500	 if (predicated || !l.equals(&r)) {
501	    fs_inst *inst = emit(BRW_OPCODE_MOV, l, r);
502	    inst->predicated = predicated;
503	 }
504
505	 l.reg_offset++;
506	 r.reg_offset++;
507      }
508      break;
509   case GLSL_TYPE_ARRAY:
510      for (unsigned int i = 0; i < type->length; i++) {
511	 emit_assignment_writes(l, r, type->fields.array, predicated);
512      }
513      break;
514
515   case GLSL_TYPE_STRUCT:
516      for (unsigned int i = 0; i < type->length; i++) {
517	 emit_assignment_writes(l, r, type->fields.structure[i].type,
518				predicated);
519      }
520      break;
521
522   case GLSL_TYPE_SAMPLER:
523      break;
524
525   default:
526      assert(!"not reached");
527      break;
528   }
529}
530
531/* If the RHS processing resulted in an instruction generating a
532 * temporary value, and it would be easy to rewrite the instruction to
533 * generate its result right into the LHS instead, do so.  This ends
534 * up reliably removing instructions where it can be tricky to do so
535 * later without real UD chain information.
536 */
537bool
538fs_visitor::try_rewrite_rhs_to_dst(ir_assignment *ir,
539                                   fs_reg dst,
540                                   fs_reg src,
541                                   fs_inst *pre_rhs_inst,
542                                   fs_inst *last_rhs_inst)
543{
544   if (pre_rhs_inst == last_rhs_inst)
545      return false; /* No instructions generated to work with. */
546
547   /* Only attempt if we're doing a direct assignment. */
548   if (ir->condition ||
549       !(ir->lhs->type->is_scalar() ||
550        (ir->lhs->type->is_vector() &&
551         ir->write_mask == (1 << ir->lhs->type->vector_elements) - 1)))
552      return false;
553
554   /* Make sure the last instruction generated our source reg. */
555   if (last_rhs_inst->predicated ||
556       last_rhs_inst->force_uncompressed ||
557       last_rhs_inst->force_sechalf ||
558       !src.equals(&last_rhs_inst->dst))
559      return false;
560
561   /* Success!  Rewrite the instruction. */
562   last_rhs_inst->dst = dst;
563
564   return true;
565}
566
567void
568fs_visitor::visit(ir_assignment *ir)
569{
570   fs_reg l, r;
571   fs_inst *inst;
572
573   /* FINISHME: arrays on the lhs */
574   ir->lhs->accept(this);
575   l = this->result;
576
577   fs_inst *pre_rhs_inst = (fs_inst *) this->instructions.get_tail();
578
579   ir->rhs->accept(this);
580   r = this->result;
581
582   fs_inst *last_rhs_inst = (fs_inst *) this->instructions.get_tail();
583
584   assert(l.file != BAD_FILE);
585   assert(r.file != BAD_FILE);
586
587   if (try_rewrite_rhs_to_dst(ir, l, r, pre_rhs_inst, last_rhs_inst))
588      return;
589
590   if (ir->condition) {
591      emit_bool_to_cond_code(ir->condition);
592   }
593
594   if (ir->lhs->type->is_scalar() ||
595       ir->lhs->type->is_vector()) {
596      for (int i = 0; i < ir->lhs->type->vector_elements; i++) {
597	 if (ir->write_mask & (1 << i)) {
598	    inst = emit(BRW_OPCODE_MOV, l, r);
599	    if (ir->condition)
600	       inst->predicated = true;
601	    r.reg_offset++;
602	 }
603	 l.reg_offset++;
604      }
605   } else {
606      emit_assignment_writes(l, r, ir->lhs->type, ir->condition != NULL);
607   }
608}
609
610fs_inst *
611fs_visitor::emit_texture_gen4(ir_texture *ir, fs_reg dst, fs_reg coordinate,
612			      int sampler)
613{
614   int mlen;
615   int base_mrf = 1;
616   bool simd16 = false;
617   fs_reg orig_dst;
618
619   /* g0 header. */
620   mlen = 1;
621
622   if (ir->shadow_comparitor && ir->op != ir_txd) {
623      for (int i = 0; i < ir->coordinate->type->vector_elements; i++) {
624	 fs_inst *inst = emit(BRW_OPCODE_MOV,
625			      fs_reg(MRF, base_mrf + mlen + i), coordinate);
626	 if (i < 3 && c->key.gl_clamp_mask[i] & (1 << sampler))
627	    inst->saturate = true;
628
629	 coordinate.reg_offset++;
630      }
631      /* gen4's SIMD8 sampler always has the slots for u,v,r present. */
632      mlen += 3;
633
634      if (ir->op == ir_tex) {
635	 /* There's no plain shadow compare message, so we use shadow
636	  * compare with a bias of 0.0.
637	  */
638	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), fs_reg(0.0f));
639	 mlen++;
640      } else if (ir->op == ir_txb) {
641	 ir->lod_info.bias->accept(this);
642	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), this->result);
643	 mlen++;
644      } else {
645	 assert(ir->op == ir_txl);
646	 ir->lod_info.lod->accept(this);
647	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), this->result);
648	 mlen++;
649      }
650
651      ir->shadow_comparitor->accept(this);
652      emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), this->result);
653      mlen++;
654   } else if (ir->op == ir_tex) {
655      for (int i = 0; i < ir->coordinate->type->vector_elements; i++) {
656	 fs_inst *inst = emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen + i),
657			      coordinate);
658	 if (i < 3 && c->key.gl_clamp_mask[i] & (1 << sampler))
659	    inst->saturate = true;
660	 coordinate.reg_offset++;
661      }
662      /* gen4's SIMD8 sampler always has the slots for u,v,r present. */
663      mlen += 3;
664   } else if (ir->op == ir_txd) {
665      ir->lod_info.grad.dPdx->accept(this);
666      fs_reg dPdx = this->result;
667
668      ir->lod_info.grad.dPdy->accept(this);
669      fs_reg dPdy = this->result;
670
671      for (int i = 0; i < ir->coordinate->type->vector_elements; i++) {
672	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen + i), coordinate);
673	 coordinate.reg_offset++;
674      }
675      /* the slots for u and v are always present, but r is optional */
676      mlen += MAX2(ir->coordinate->type->vector_elements, 2);
677
678      /*  P   = u, v, r
679       * dPdx = dudx, dvdx, drdx
680       * dPdy = dudy, dvdy, drdy
681       *
682       * 1-arg: Does not exist.
683       *
684       * 2-arg: dudx   dvdx   dudy   dvdy
685       *        dPdx.x dPdx.y dPdy.x dPdy.y
686       *        m4     m5     m6     m7
687       *
688       * 3-arg: dudx   dvdx   drdx   dudy   dvdy   drdy
689       *        dPdx.x dPdx.y dPdx.z dPdy.x dPdy.y dPdy.z
690       *        m5     m6     m7     m8     m9     m10
691       */
692      for (int i = 0; i < ir->lod_info.grad.dPdx->type->vector_elements; i++) {
693	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), dPdx);
694	 dPdx.reg_offset++;
695      }
696      mlen += MAX2(ir->lod_info.grad.dPdx->type->vector_elements, 2);
697
698      for (int i = 0; i < ir->lod_info.grad.dPdy->type->vector_elements; i++) {
699	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), dPdy);
700	 dPdy.reg_offset++;
701      }
702      mlen += MAX2(ir->lod_info.grad.dPdy->type->vector_elements, 2);
703   } else if (ir->op == ir_txs) {
704      /* There's no SIMD8 resinfo message on Gen4.  Use SIMD16 instead. */
705      simd16 = true;
706      ir->lod_info.lod->accept(this);
707      emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen, BRW_REGISTER_TYPE_UD), this->result);
708      mlen += 2;
709   } else {
710      /* Oh joy.  gen4 doesn't have SIMD8 non-shadow-compare bias/lod
711       * instructions.  We'll need to do SIMD16 here.
712       */
713      simd16 = true;
714      assert(ir->op == ir_txb || ir->op == ir_txl || ir->op == ir_txf);
715
716      for (int i = 0; i < ir->coordinate->type->vector_elements; i++) {
717	 fs_inst *inst = emit(BRW_OPCODE_MOV, fs_reg(MRF,
718						     base_mrf + mlen + i * 2,
719						     coordinate.type),
720			      coordinate);
721	 if (i < 3 && c->key.gl_clamp_mask[i] & (1 << sampler))
722	    inst->saturate = true;
723	 coordinate.reg_offset++;
724      }
725
726      /* Initialize the rest of u/v/r with 0.0.  Empirically, this seems to
727       * be necessary for TXF (ld), but seems wise to do for all messages.
728       */
729      for (int i = ir->coordinate->type->vector_elements; i < 3; i++) {
730	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen + i * 2), fs_reg(0.0f));
731      }
732
733      /* lod/bias appears after u/v/r. */
734      mlen += 6;
735
736      if (ir->op == ir_txb) {
737	 ir->lod_info.bias->accept(this);
738	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), this->result);
739	 mlen++;
740      } else {
741	 ir->lod_info.lod->accept(this);
742	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen, this->result.type),
743			      this->result);
744	 mlen++;
745      }
746
747      /* The unused upper half. */
748      mlen++;
749   }
750
751   if (simd16) {
752      /* Now, since we're doing simd16, the return is 2 interleaved
753       * vec4s where the odd-indexed ones are junk. We'll need to move
754       * this weirdness around to the expected layout.
755       */
756      orig_dst = dst;
757      const glsl_type *vec_type =
758	 glsl_type::get_instance(ir->type->base_type, 4, 1);
759      dst = fs_reg(this, glsl_type::get_array_instance(vec_type, 2));
760      dst.type = intel->is_g4x ? brw_type_for_base_type(ir->type)
761			       : BRW_REGISTER_TYPE_F;
762   }
763
764   fs_inst *inst = NULL;
765   switch (ir->op) {
766   case ir_tex:
767      inst = emit(SHADER_OPCODE_TEX, dst);
768      break;
769   case ir_txb:
770      inst = emit(FS_OPCODE_TXB, dst);
771      break;
772   case ir_txl:
773      inst = emit(SHADER_OPCODE_TXL, dst);
774      break;
775   case ir_txd:
776      inst = emit(SHADER_OPCODE_TXD, dst);
777      break;
778   case ir_txs:
779      inst = emit(SHADER_OPCODE_TXS, dst);
780      break;
781   case ir_txf:
782      inst = emit(SHADER_OPCODE_TXF, dst);
783      break;
784   }
785   inst->base_mrf = base_mrf;
786   inst->mlen = mlen;
787   inst->header_present = true;
788
789   if (simd16) {
790      for (int i = 0; i < 4; i++) {
791	 emit(BRW_OPCODE_MOV, orig_dst, dst);
792	 orig_dst.reg_offset++;
793	 dst.reg_offset += 2;
794      }
795   }
796
797   return inst;
798}
799
800/* gen5's sampler has slots for u, v, r, array index, then optional
801 * parameters like shadow comparitor or LOD bias.  If optional
802 * parameters aren't present, those base slots are optional and don't
803 * need to be included in the message.
804 *
805 * We don't fill in the unnecessary slots regardless, which may look
806 * surprising in the disassembly.
807 */
808fs_inst *
809fs_visitor::emit_texture_gen5(ir_texture *ir, fs_reg dst, fs_reg coordinate,
810			      int sampler)
811{
812   int mlen = 0;
813   int base_mrf = 2;
814   int reg_width = c->dispatch_width / 8;
815   bool header_present = false;
816   const int vector_elements =
817      ir->coordinate ? ir->coordinate->type->vector_elements : 0;
818
819   if (ir->offset) {
820      /* The offsets set up by the ir_texture visitor are in the
821       * m1 header, so we can't go headerless.
822       */
823      header_present = true;
824      mlen++;
825      base_mrf--;
826   }
827
828   for (int i = 0; i < vector_elements; i++) {
829      fs_inst *inst = emit(BRW_OPCODE_MOV,
830			   fs_reg(MRF, base_mrf + mlen + i * reg_width,
831				  coordinate.type),
832			   coordinate);
833      if (i < 3 && c->key.gl_clamp_mask[i] & (1 << sampler))
834	 inst->saturate = true;
835      coordinate.reg_offset++;
836   }
837   mlen += vector_elements * reg_width;
838
839   if (ir->shadow_comparitor && ir->op != ir_txd) {
840      mlen = MAX2(mlen, header_present + 4 * reg_width);
841
842      ir->shadow_comparitor->accept(this);
843      emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), this->result);
844      mlen += reg_width;
845   }
846
847   fs_inst *inst = NULL;
848   switch (ir->op) {
849   case ir_tex:
850      inst = emit(SHADER_OPCODE_TEX, dst);
851      break;
852   case ir_txb:
853      ir->lod_info.bias->accept(this);
854      mlen = MAX2(mlen, header_present + 4 * reg_width);
855      emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), this->result);
856      mlen += reg_width;
857
858      inst = emit(FS_OPCODE_TXB, dst);
859
860      break;
861   case ir_txl:
862      ir->lod_info.lod->accept(this);
863      mlen = MAX2(mlen, header_present + 4 * reg_width);
864      emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), this->result);
865      mlen += reg_width;
866
867      inst = emit(SHADER_OPCODE_TXL, dst);
868      break;
869   case ir_txd: {
870      ir->lod_info.grad.dPdx->accept(this);
871      fs_reg dPdx = this->result;
872
873      ir->lod_info.grad.dPdy->accept(this);
874      fs_reg dPdy = this->result;
875
876      mlen = MAX2(mlen, header_present + 4 * reg_width); /* skip over 'ai' */
877
878      /**
879       *  P   =  u,    v,    r
880       * dPdx = dudx, dvdx, drdx
881       * dPdy = dudy, dvdy, drdy
882       *
883       * Load up these values:
884       * - dudx   dudy   dvdx   dvdy   drdx   drdy
885       * - dPdx.x dPdy.x dPdx.y dPdy.y dPdx.z dPdy.z
886       */
887      for (int i = 0; i < ir->lod_info.grad.dPdx->type->vector_elements; i++) {
888	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), dPdx);
889	 dPdx.reg_offset++;
890	 mlen += reg_width;
891
892	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), dPdy);
893	 dPdy.reg_offset++;
894	 mlen += reg_width;
895      }
896
897      inst = emit(SHADER_OPCODE_TXD, dst);
898      break;
899   }
900   case ir_txs:
901      ir->lod_info.lod->accept(this);
902      emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen, BRW_REGISTER_TYPE_UD), this->result);
903      mlen += reg_width;
904      inst = emit(SHADER_OPCODE_TXS, dst);
905      break;
906   case ir_txf:
907      mlen = header_present + 4 * reg_width;
908
909      ir->lod_info.lod->accept(this);
910      emit(BRW_OPCODE_MOV,
911	   fs_reg(MRF, base_mrf + mlen - reg_width, BRW_REGISTER_TYPE_UD),
912	   this->result);
913      inst = emit(SHADER_OPCODE_TXF, dst);
914      break;
915   }
916   inst->base_mrf = base_mrf;
917   inst->mlen = mlen;
918   inst->header_present = header_present;
919
920   if (mlen > 11) {
921      fail("Message length >11 disallowed by hardware\n");
922   }
923
924   return inst;
925}
926
927fs_inst *
928fs_visitor::emit_texture_gen7(ir_texture *ir, fs_reg dst, fs_reg coordinate,
929			      int sampler)
930{
931   int mlen = 0;
932   int base_mrf = 2;
933   int reg_width = c->dispatch_width / 8;
934   bool header_present = false;
935
936   if (ir->offset) {
937      /* The offsets set up by the ir_texture visitor are in the
938       * m1 header, so we can't go headerless.
939       */
940      header_present = true;
941      mlen++;
942      base_mrf--;
943   }
944
945   if (ir->shadow_comparitor && ir->op != ir_txd) {
946      ir->shadow_comparitor->accept(this);
947      emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), this->result);
948      mlen += reg_width;
949   }
950
951   /* Set up the LOD info */
952   switch (ir->op) {
953   case ir_tex:
954      break;
955   case ir_txb:
956      ir->lod_info.bias->accept(this);
957      emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), this->result);
958      mlen += reg_width;
959      break;
960   case ir_txl:
961      ir->lod_info.lod->accept(this);
962      emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), this->result);
963      mlen += reg_width;
964      break;
965   case ir_txd: {
966      if (c->dispatch_width == 16)
967	 fail("Gen7 does not support sample_d/sample_d_c in SIMD16 mode.");
968
969      ir->lod_info.grad.dPdx->accept(this);
970      fs_reg dPdx = this->result;
971
972      ir->lod_info.grad.dPdy->accept(this);
973      fs_reg dPdy = this->result;
974
975      /* Load dPdx and the coordinate together:
976       * [hdr], [ref], x, dPdx.x, dPdy.x, y, dPdx.y, dPdy.y, z, dPdx.z, dPdy.z
977       */
978      for (int i = 0; i < ir->coordinate->type->vector_elements; i++) {
979	 fs_inst *inst = emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen),
980			      coordinate);
981	 if (i < 3 && c->key.gl_clamp_mask[i] & (1 << sampler))
982	    inst->saturate = true;
983	 coordinate.reg_offset++;
984	 mlen += reg_width;
985
986	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), dPdx);
987	 dPdx.reg_offset++;
988	 mlen += reg_width;
989
990	 emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), dPdy);
991	 dPdy.reg_offset++;
992	 mlen += reg_width;
993      }
994      break;
995   }
996   case ir_txs:
997      ir->lod_info.lod->accept(this);
998      emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen, BRW_REGISTER_TYPE_UD), this->result);
999      mlen += reg_width;
1000      break;
1001   case ir_txf:
1002      /* Unfortunately, the parameters for LD are intermixed: u, lod, v, r. */
1003      emit(BRW_OPCODE_MOV,
1004	   fs_reg(MRF, base_mrf + mlen, BRW_REGISTER_TYPE_D), coordinate);
1005      coordinate.reg_offset++;
1006      mlen += reg_width;
1007
1008      ir->lod_info.lod->accept(this);
1009      emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen, BRW_REGISTER_TYPE_D), this->result);
1010      mlen += reg_width;
1011
1012      for (int i = 1; i < ir->coordinate->type->vector_elements; i++) {
1013	 emit(BRW_OPCODE_MOV,
1014	      fs_reg(MRF, base_mrf + mlen, BRW_REGISTER_TYPE_D), coordinate);
1015	 coordinate.reg_offset++;
1016	 mlen += reg_width;
1017      }
1018      break;
1019   }
1020
1021   /* Set up the coordinate (except for cases where it was done above) */
1022   if (ir->op != ir_txd && ir->op != ir_txs && ir->op != ir_txf) {
1023      for (int i = 0; i < ir->coordinate->type->vector_elements; i++) {
1024	 fs_inst *inst = emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen),
1025			      coordinate);
1026	 if (i < 3 && c->key.gl_clamp_mask[i] & (1 << sampler))
1027	    inst->saturate = true;
1028	 coordinate.reg_offset++;
1029	 mlen += reg_width;
1030      }
1031   }
1032
1033   /* Generate the SEND */
1034   fs_inst *inst = NULL;
1035   switch (ir->op) {
1036   case ir_tex: inst = emit(SHADER_OPCODE_TEX, dst); break;
1037   case ir_txb: inst = emit(FS_OPCODE_TXB, dst); break;
1038   case ir_txl: inst = emit(SHADER_OPCODE_TXL, dst); break;
1039   case ir_txd: inst = emit(SHADER_OPCODE_TXD, dst); break;
1040   case ir_txf: inst = emit(SHADER_OPCODE_TXF, dst); break;
1041   case ir_txs: inst = emit(SHADER_OPCODE_TXS, dst); break;
1042   }
1043   inst->base_mrf = base_mrf;
1044   inst->mlen = mlen;
1045   inst->header_present = header_present;
1046
1047   if (mlen > 11) {
1048      fail("Message length >11 disallowed by hardware\n");
1049   }
1050
1051   return inst;
1052}
1053
1054void
1055fs_visitor::visit(ir_texture *ir)
1056{
1057   fs_inst *inst = NULL;
1058
1059   int sampler = _mesa_get_sampler_uniform_value(ir->sampler, prog, &fp->Base);
1060   sampler = fp->Base.SamplerUnits[sampler];
1061
1062   /* Our hardware doesn't have a sample_d_c message, so shadow compares
1063    * for textureGrad/TXD need to be emulated with instructions.
1064    */
1065   bool hw_compare_supported = ir->op != ir_txd;
1066   if (ir->shadow_comparitor && !hw_compare_supported) {
1067      assert(c->key.compare_funcs[sampler] != GL_NONE);
1068      /* No need to even sample for GL_ALWAYS or GL_NEVER...bail early */
1069      if (c->key.compare_funcs[sampler] == GL_ALWAYS)
1070	 return swizzle_result(ir, fs_reg(1.0f), sampler);
1071      else if (c->key.compare_funcs[sampler] == GL_NEVER)
1072	 return swizzle_result(ir, fs_reg(0.0f), sampler);
1073   }
1074
1075   if (ir->coordinate)
1076      ir->coordinate->accept(this);
1077   fs_reg coordinate = this->result;
1078
1079   if (ir->offset != NULL) {
1080      ir_constant *offset = ir->offset->as_constant();
1081      assert(offset != NULL);
1082
1083      signed char offsets[3];
1084      for (unsigned i = 0; i < ir->offset->type->vector_elements; i++)
1085	 offsets[i] = (signed char) offset->value.i[i];
1086
1087      /* Combine all three offsets into a single unsigned dword:
1088       *
1089       *    bits 11:8 - U Offset (X component)
1090       *    bits  7:4 - V Offset (Y component)
1091       *    bits  3:0 - R Offset (Z component)
1092       */
1093      unsigned offset_bits = 0;
1094      for (unsigned i = 0; i < ir->offset->type->vector_elements; i++) {
1095	 const unsigned shift = 4 * (2 - i);
1096	 offset_bits |= (offsets[i] << shift) & (0xF << shift);
1097      }
1098
1099      /* Explicitly set up the message header by copying g0 to msg reg m1. */
1100      emit(BRW_OPCODE_MOV, fs_reg(MRF, 1, BRW_REGISTER_TYPE_UD),
1101	   fs_reg(retype(brw_vec8_grf(0, 0), BRW_REGISTER_TYPE_UD)));
1102
1103      /* Then set the offset bits in DWord 2 of the message header. */
1104      emit(BRW_OPCODE_MOV,
1105	   fs_reg(retype(brw_vec1_reg(BRW_MESSAGE_REGISTER_FILE, 1, 2),
1106			 BRW_REGISTER_TYPE_UD)),
1107	   fs_reg(brw_imm_uw(offset_bits)));
1108   }
1109
1110   /* Should be lowered by do_lower_texture_projection */
1111   assert(!ir->projector);
1112
1113   /* The 965 requires the EU to do the normalization of GL rectangle
1114    * texture coordinates.  We use the program parameter state
1115    * tracking to get the scaling factor.
1116    */
1117   if (intel->gen < 6 &&
1118       ir->sampler->type->sampler_dimensionality == GLSL_SAMPLER_DIM_RECT) {
1119      struct gl_program_parameter_list *params = c->fp->program.Base.Parameters;
1120      int tokens[STATE_LENGTH] = {
1121	 STATE_INTERNAL,
1122	 STATE_TEXRECT_SCALE,
1123	 sampler,
1124	 0,
1125	 0
1126      };
1127
1128      if (c->dispatch_width == 16) {
1129	 fail("rectangle scale uniform setup not supported on 16-wide\n");
1130	 this->result = fs_reg(this, ir->type);
1131	 return;
1132      }
1133
1134      c->prog_data.param_convert[c->prog_data.nr_params] =
1135	 PARAM_NO_CONVERT;
1136      c->prog_data.param_convert[c->prog_data.nr_params + 1] =
1137	 PARAM_NO_CONVERT;
1138
1139      fs_reg scale_x = fs_reg(UNIFORM, c->prog_data.nr_params);
1140      fs_reg scale_y = fs_reg(UNIFORM, c->prog_data.nr_params + 1);
1141      GLuint index = _mesa_add_state_reference(params,
1142					       (gl_state_index *)tokens);
1143
1144      this->param_index[c->prog_data.nr_params] = index;
1145      this->param_offset[c->prog_data.nr_params] = 0;
1146      c->prog_data.nr_params++;
1147      this->param_index[c->prog_data.nr_params] = index;
1148      this->param_offset[c->prog_data.nr_params] = 1;
1149      c->prog_data.nr_params++;
1150
1151      fs_reg dst = fs_reg(this, ir->coordinate->type);
1152      fs_reg src = coordinate;
1153      coordinate = dst;
1154
1155      emit(BRW_OPCODE_MUL, dst, src, scale_x);
1156      dst.reg_offset++;
1157      src.reg_offset++;
1158      emit(BRW_OPCODE_MUL, dst, src, scale_y);
1159   }
1160
1161   /* Writemasking doesn't eliminate channels on SIMD8 texture
1162    * samples, so don't worry about them.
1163    */
1164   fs_reg dst = fs_reg(this, glsl_type::get_instance(ir->type->base_type, 4, 1));
1165
1166   if (intel->gen >= 7) {
1167      inst = emit_texture_gen7(ir, dst, coordinate, sampler);
1168   } else if (intel->gen >= 5) {
1169      inst = emit_texture_gen5(ir, dst, coordinate, sampler);
1170   } else {
1171      inst = emit_texture_gen4(ir, dst, coordinate, sampler);
1172   }
1173
1174   /* If there's an offset, we already set up m1.  To avoid the implied move,
1175    * use the null register.  Otherwise, we want an implied move from g0.
1176    */
1177   if (ir->offset != NULL || !inst->header_present)
1178      inst->src[0] = reg_undef;
1179   else
1180      inst->src[0] = fs_reg(retype(brw_vec8_grf(0, 0), BRW_REGISTER_TYPE_UW));
1181
1182   inst->sampler = sampler;
1183
1184   if (ir->shadow_comparitor) {
1185      if (hw_compare_supported) {
1186	 inst->shadow_compare = true;
1187      } else {
1188	 ir->shadow_comparitor->accept(this);
1189	 fs_reg ref = this->result;
1190
1191	 fs_reg value = dst;
1192	 dst = fs_reg(this, glsl_type::vec4_type);
1193
1194	 /* FINISHME: This needs to be done pre-filtering. */
1195
1196	 uint32_t conditional = 0;
1197	 switch (c->key.compare_funcs[sampler]) {
1198	 /* GL_ALWAYS and GL_NEVER were handled at the top of the function */
1199	 case GL_LESS:     conditional = BRW_CONDITIONAL_L;   break;
1200	 case GL_GREATER:  conditional = BRW_CONDITIONAL_G;   break;
1201	 case GL_LEQUAL:   conditional = BRW_CONDITIONAL_LE;  break;
1202	 case GL_GEQUAL:   conditional = BRW_CONDITIONAL_GE;  break;
1203	 case GL_EQUAL:    conditional = BRW_CONDITIONAL_EQ;  break;
1204	 case GL_NOTEQUAL: conditional = BRW_CONDITIONAL_NEQ; break;
1205	 default: assert(!"Should not get here: bad shadow compare function");
1206	 }
1207
1208	 /* Use conditional moves to load 0 or 1 as the result */
1209	 this->current_annotation = "manual shadow comparison";
1210	 for (int i = 0; i < 4; i++) {
1211	    inst = emit(BRW_OPCODE_MOV, dst, fs_reg(0.0f));
1212
1213	    inst = emit(BRW_OPCODE_CMP, reg_null_f, ref, value);
1214	    inst->conditional_mod = conditional;
1215
1216	    inst = emit(BRW_OPCODE_MOV, dst, fs_reg(1.0f));
1217	    inst->predicated = true;
1218
1219	    dst.reg_offset++;
1220	    value.reg_offset++;
1221	 }
1222	 dst.reg_offset = 0;
1223      }
1224   }
1225
1226   swizzle_result(ir, dst, sampler);
1227}
1228
1229/**
1230 * Swizzle the result of a texture result.  This is necessary for
1231 * EXT_texture_swizzle as well as DEPTH_TEXTURE_MODE for shadow comparisons.
1232 */
1233void
1234fs_visitor::swizzle_result(ir_texture *ir, fs_reg orig_val, int sampler)
1235{
1236   this->result = orig_val;
1237
1238   if (ir->op == ir_txs)
1239      return;
1240
1241   if (ir->type == glsl_type::float_type) {
1242      /* Ignore DEPTH_TEXTURE_MODE swizzling. */
1243      assert(ir->sampler->type->sampler_shadow);
1244   } else if (c->key.tex_swizzles[sampler] != SWIZZLE_NOOP) {
1245      fs_reg swizzled_result = fs_reg(this, glsl_type::vec4_type);
1246
1247      for (int i = 0; i < 4; i++) {
1248	 int swiz = GET_SWZ(c->key.tex_swizzles[sampler], i);
1249	 fs_reg l = swizzled_result;
1250	 l.reg_offset += i;
1251
1252	 if (swiz == SWIZZLE_ZERO) {
1253	    emit(BRW_OPCODE_MOV, l, fs_reg(0.0f));
1254	 } else if (swiz == SWIZZLE_ONE) {
1255	    emit(BRW_OPCODE_MOV, l, fs_reg(1.0f));
1256	 } else {
1257	    fs_reg r = orig_val;
1258	    r.reg_offset += GET_SWZ(c->key.tex_swizzles[sampler], i);
1259	    emit(BRW_OPCODE_MOV, l, r);
1260	 }
1261      }
1262      this->result = swizzled_result;
1263   }
1264}
1265
1266void
1267fs_visitor::visit(ir_swizzle *ir)
1268{
1269   ir->val->accept(this);
1270   fs_reg val = this->result;
1271
1272   if (ir->type->vector_elements == 1) {
1273      this->result.reg_offset += ir->mask.x;
1274      return;
1275   }
1276
1277   fs_reg result = fs_reg(this, ir->type);
1278   this->result = result;
1279
1280   for (unsigned int i = 0; i < ir->type->vector_elements; i++) {
1281      fs_reg channel = val;
1282      int swiz = 0;
1283
1284      switch (i) {
1285      case 0:
1286	 swiz = ir->mask.x;
1287	 break;
1288      case 1:
1289	 swiz = ir->mask.y;
1290	 break;
1291      case 2:
1292	 swiz = ir->mask.z;
1293	 break;
1294      case 3:
1295	 swiz = ir->mask.w;
1296	 break;
1297      }
1298
1299      channel.reg_offset += swiz;
1300      emit(BRW_OPCODE_MOV, result, channel);
1301      result.reg_offset++;
1302   }
1303}
1304
1305void
1306fs_visitor::visit(ir_discard *ir)
1307{
1308   assert(ir->condition == NULL); /* FINISHME */
1309
1310   emit(FS_OPCODE_DISCARD);
1311   kill_emitted = true;
1312}
1313
1314void
1315fs_visitor::visit(ir_constant *ir)
1316{
1317   /* Set this->result to reg at the bottom of the function because some code
1318    * paths will cause this visitor to be applied to other fields.  This will
1319    * cause the value stored in this->result to be modified.
1320    *
1321    * Make reg constant so that it doesn't get accidentally modified along the
1322    * way.  Yes, I actually had this problem. :(
1323    */
1324   const fs_reg reg(this, ir->type);
1325   fs_reg dst_reg = reg;
1326
1327   if (ir->type->is_array()) {
1328      const unsigned size = type_size(ir->type->fields.array);
1329
1330      for (unsigned i = 0; i < ir->type->length; i++) {
1331	 ir->array_elements[i]->accept(this);
1332	 fs_reg src_reg = this->result;
1333
1334	 dst_reg.type = src_reg.type;
1335	 for (unsigned j = 0; j < size; j++) {
1336	    emit(BRW_OPCODE_MOV, dst_reg, src_reg);
1337	    src_reg.reg_offset++;
1338	    dst_reg.reg_offset++;
1339	 }
1340      }
1341   } else if (ir->type->is_record()) {
1342      foreach_list(node, &ir->components) {
1343	 ir_instruction *const field = (ir_instruction *) node;
1344	 const unsigned size = type_size(field->type);
1345
1346	 field->accept(this);
1347	 fs_reg src_reg = this->result;
1348
1349	 dst_reg.type = src_reg.type;
1350	 for (unsigned j = 0; j < size; j++) {
1351	    emit(BRW_OPCODE_MOV, dst_reg, src_reg);
1352	    src_reg.reg_offset++;
1353	    dst_reg.reg_offset++;
1354	 }
1355      }
1356   } else {
1357      const unsigned size = type_size(ir->type);
1358
1359      for (unsigned i = 0; i < size; i++) {
1360	 switch (ir->type->base_type) {
1361	 case GLSL_TYPE_FLOAT:
1362	    emit(BRW_OPCODE_MOV, dst_reg, fs_reg(ir->value.f[i]));
1363	    break;
1364	 case GLSL_TYPE_UINT:
1365	    emit(BRW_OPCODE_MOV, dst_reg, fs_reg(ir->value.u[i]));
1366	    break;
1367	 case GLSL_TYPE_INT:
1368	    emit(BRW_OPCODE_MOV, dst_reg, fs_reg(ir->value.i[i]));
1369	    break;
1370	 case GLSL_TYPE_BOOL:
1371	    emit(BRW_OPCODE_MOV, dst_reg, fs_reg((int)ir->value.b[i]));
1372	    break;
1373	 default:
1374	    assert(!"Non-float/uint/int/bool constant");
1375	 }
1376	 dst_reg.reg_offset++;
1377      }
1378   }
1379
1380   this->result = reg;
1381}
1382
1383void
1384fs_visitor::emit_bool_to_cond_code(ir_rvalue *ir)
1385{
1386   ir_expression *expr = ir->as_expression();
1387
1388   if (expr) {
1389      fs_reg op[2];
1390      fs_inst *inst;
1391
1392      assert(expr->get_num_operands() <= 2);
1393      for (unsigned int i = 0; i < expr->get_num_operands(); i++) {
1394	 assert(expr->operands[i]->type->is_scalar());
1395
1396	 expr->operands[i]->accept(this);
1397	 op[i] = this->result;
1398
1399	 resolve_ud_negate(&op[i]);
1400      }
1401
1402      switch (expr->operation) {
1403      case ir_unop_logic_not:
1404	 inst = emit(BRW_OPCODE_AND, reg_null_d, op[0], fs_reg(1));
1405	 inst->conditional_mod = BRW_CONDITIONAL_Z;
1406	 break;
1407
1408      case ir_binop_logic_xor:
1409	 inst = emit(BRW_OPCODE_XOR, reg_null_d, op[0], op[1]);
1410	 inst->conditional_mod = BRW_CONDITIONAL_NZ;
1411	 break;
1412
1413      case ir_binop_logic_or:
1414	 inst = emit(BRW_OPCODE_OR, reg_null_d, op[0], op[1]);
1415	 inst->conditional_mod = BRW_CONDITIONAL_NZ;
1416	 break;
1417
1418      case ir_binop_logic_and:
1419	 inst = emit(BRW_OPCODE_AND, reg_null_d, op[0], op[1]);
1420	 inst->conditional_mod = BRW_CONDITIONAL_NZ;
1421	 break;
1422
1423      case ir_unop_f2b:
1424	 if (intel->gen >= 6) {
1425	    inst = emit(BRW_OPCODE_CMP, reg_null_d, op[0], fs_reg(0.0f));
1426	 } else {
1427	    inst = emit(BRW_OPCODE_MOV, reg_null_f, op[0]);
1428	 }
1429	 inst->conditional_mod = BRW_CONDITIONAL_NZ;
1430	 break;
1431
1432      case ir_unop_i2b:
1433	 if (intel->gen >= 6) {
1434	    inst = emit(BRW_OPCODE_CMP, reg_null_d, op[0], fs_reg(0));
1435	 } else {
1436	    inst = emit(BRW_OPCODE_MOV, reg_null_d, op[0]);
1437	 }
1438	 inst->conditional_mod = BRW_CONDITIONAL_NZ;
1439	 break;
1440
1441      case ir_binop_greater:
1442      case ir_binop_gequal:
1443      case ir_binop_less:
1444      case ir_binop_lequal:
1445      case ir_binop_equal:
1446      case ir_binop_all_equal:
1447      case ir_binop_nequal:
1448      case ir_binop_any_nequal:
1449	 inst = emit(BRW_OPCODE_CMP, reg_null_cmp, op[0], op[1]);
1450	 inst->conditional_mod =
1451	    brw_conditional_for_comparison(expr->operation);
1452	 break;
1453
1454      default:
1455	 assert(!"not reached");
1456	 fail("bad cond code\n");
1457	 break;
1458      }
1459      return;
1460   }
1461
1462   ir->accept(this);
1463
1464   if (intel->gen >= 6) {
1465      fs_inst *inst = emit(BRW_OPCODE_AND, reg_null_d, this->result, fs_reg(1));
1466      inst->conditional_mod = BRW_CONDITIONAL_NZ;
1467   } else {
1468      fs_inst *inst = emit(BRW_OPCODE_MOV, reg_null_d, this->result);
1469      inst->conditional_mod = BRW_CONDITIONAL_NZ;
1470   }
1471}
1472
1473/**
1474 * Emit a gen6 IF statement with the comparison folded into the IF
1475 * instruction.
1476 */
1477void
1478fs_visitor::emit_if_gen6(ir_if *ir)
1479{
1480   ir_expression *expr = ir->condition->as_expression();
1481
1482   if (expr) {
1483      fs_reg op[2];
1484      fs_inst *inst;
1485      fs_reg temp;
1486
1487      assert(expr->get_num_operands() <= 2);
1488      for (unsigned int i = 0; i < expr->get_num_operands(); i++) {
1489	 assert(expr->operands[i]->type->is_scalar());
1490
1491	 expr->operands[i]->accept(this);
1492	 op[i] = this->result;
1493      }
1494
1495      switch (expr->operation) {
1496      case ir_unop_logic_not:
1497	 inst = emit(BRW_OPCODE_IF, temp, op[0], fs_reg(0));
1498	 inst->conditional_mod = BRW_CONDITIONAL_Z;
1499	 return;
1500
1501      case ir_binop_logic_xor:
1502	 inst = emit(BRW_OPCODE_IF, reg_null_d, op[0], op[1]);
1503	 inst->conditional_mod = BRW_CONDITIONAL_NZ;
1504	 return;
1505
1506      case ir_binop_logic_or:
1507	 temp = fs_reg(this, glsl_type::bool_type);
1508	 emit(BRW_OPCODE_OR, temp, op[0], op[1]);
1509	 inst = emit(BRW_OPCODE_IF, reg_null_d, temp, fs_reg(0));
1510	 inst->conditional_mod = BRW_CONDITIONAL_NZ;
1511	 return;
1512
1513      case ir_binop_logic_and:
1514	 temp = fs_reg(this, glsl_type::bool_type);
1515	 emit(BRW_OPCODE_AND, temp, op[0], op[1]);
1516	 inst = emit(BRW_OPCODE_IF, reg_null_d, temp, fs_reg(0));
1517	 inst->conditional_mod = BRW_CONDITIONAL_NZ;
1518	 return;
1519
1520      case ir_unop_f2b:
1521	 inst = emit(BRW_OPCODE_IF, reg_null_f, op[0], fs_reg(0));
1522	 inst->conditional_mod = BRW_CONDITIONAL_NZ;
1523	 return;
1524
1525      case ir_unop_i2b:
1526	 inst = emit(BRW_OPCODE_IF, reg_null_d, op[0], fs_reg(0));
1527	 inst->conditional_mod = BRW_CONDITIONAL_NZ;
1528	 return;
1529
1530      case ir_binop_greater:
1531      case ir_binop_gequal:
1532      case ir_binop_less:
1533      case ir_binop_lequal:
1534      case ir_binop_equal:
1535      case ir_binop_all_equal:
1536      case ir_binop_nequal:
1537      case ir_binop_any_nequal:
1538	 inst = emit(BRW_OPCODE_IF, reg_null_d, op[0], op[1]);
1539	 inst->conditional_mod =
1540	    brw_conditional_for_comparison(expr->operation);
1541	 return;
1542      default:
1543	 assert(!"not reached");
1544	 inst = emit(BRW_OPCODE_IF, reg_null_d, op[0], fs_reg(0));
1545	 inst->conditional_mod = BRW_CONDITIONAL_NZ;
1546	 fail("bad condition\n");
1547	 return;
1548      }
1549      return;
1550   }
1551
1552   ir->condition->accept(this);
1553
1554   fs_inst *inst = emit(BRW_OPCODE_IF, reg_null_d, this->result, fs_reg(0));
1555   inst->conditional_mod = BRW_CONDITIONAL_NZ;
1556}
1557
1558void
1559fs_visitor::visit(ir_if *ir)
1560{
1561   fs_inst *inst;
1562
1563   if (intel->gen < 6 && c->dispatch_width == 16) {
1564      fail("Can't support (non-uniform) control flow on 16-wide\n");
1565   }
1566
1567   /* Don't point the annotation at the if statement, because then it plus
1568    * the then and else blocks get printed.
1569    */
1570   this->base_ir = ir->condition;
1571
1572   if (intel->gen == 6) {
1573      emit_if_gen6(ir);
1574   } else {
1575      emit_bool_to_cond_code(ir->condition);
1576
1577      inst = emit(BRW_OPCODE_IF);
1578      inst->predicated = true;
1579   }
1580
1581   foreach_list(node, &ir->then_instructions) {
1582      ir_instruction *ir = (ir_instruction *)node;
1583      this->base_ir = ir;
1584
1585      ir->accept(this);
1586   }
1587
1588   if (!ir->else_instructions.is_empty()) {
1589      emit(BRW_OPCODE_ELSE);
1590
1591      foreach_list(node, &ir->else_instructions) {
1592	 ir_instruction *ir = (ir_instruction *)node;
1593	 this->base_ir = ir;
1594
1595	 ir->accept(this);
1596      }
1597   }
1598
1599   emit(BRW_OPCODE_ENDIF);
1600}
1601
1602void
1603fs_visitor::visit(ir_loop *ir)
1604{
1605   fs_reg counter = reg_undef;
1606
1607   if (c->dispatch_width == 16) {
1608      fail("Can't support (non-uniform) control flow on 16-wide\n");
1609   }
1610
1611   if (ir->counter) {
1612      this->base_ir = ir->counter;
1613      ir->counter->accept(this);
1614      counter = *(variable_storage(ir->counter));
1615
1616      if (ir->from) {
1617	 this->base_ir = ir->from;
1618	 ir->from->accept(this);
1619
1620	 emit(BRW_OPCODE_MOV, counter, this->result);
1621      }
1622   }
1623
1624   emit(BRW_OPCODE_DO);
1625
1626   if (ir->to) {
1627      this->base_ir = ir->to;
1628      ir->to->accept(this);
1629
1630      fs_inst *inst = emit(BRW_OPCODE_CMP, reg_null_cmp, counter, this->result);
1631      inst->conditional_mod = brw_conditional_for_comparison(ir->cmp);
1632
1633      inst = emit(BRW_OPCODE_BREAK);
1634      inst->predicated = true;
1635   }
1636
1637   foreach_list(node, &ir->body_instructions) {
1638      ir_instruction *ir = (ir_instruction *)node;
1639
1640      this->base_ir = ir;
1641      ir->accept(this);
1642   }
1643
1644   if (ir->increment) {
1645      this->base_ir = ir->increment;
1646      ir->increment->accept(this);
1647      emit(BRW_OPCODE_ADD, counter, counter, this->result);
1648   }
1649
1650   emit(BRW_OPCODE_WHILE);
1651}
1652
1653void
1654fs_visitor::visit(ir_loop_jump *ir)
1655{
1656   switch (ir->mode) {
1657   case ir_loop_jump::jump_break:
1658      emit(BRW_OPCODE_BREAK);
1659      break;
1660   case ir_loop_jump::jump_continue:
1661      emit(BRW_OPCODE_CONTINUE);
1662      break;
1663   }
1664}
1665
1666void
1667fs_visitor::visit(ir_call *ir)
1668{
1669   assert(!"FINISHME");
1670}
1671
1672void
1673fs_visitor::visit(ir_return *ir)
1674{
1675   assert(!"FINISHME");
1676}
1677
1678void
1679fs_visitor::visit(ir_function *ir)
1680{
1681   /* Ignore function bodies other than main() -- we shouldn't see calls to
1682    * them since they should all be inlined before we get to ir_to_mesa.
1683    */
1684   if (strcmp(ir->name, "main") == 0) {
1685      const ir_function_signature *sig;
1686      exec_list empty;
1687
1688      sig = ir->matching_signature(&empty);
1689
1690      assert(sig);
1691
1692      foreach_list(node, &sig->body) {
1693	 ir_instruction *ir = (ir_instruction *)node;
1694	 this->base_ir = ir;
1695
1696	 ir->accept(this);
1697      }
1698   }
1699}
1700
1701void
1702fs_visitor::visit(ir_function_signature *ir)
1703{
1704   assert(!"not reached");
1705   (void)ir;
1706}
1707
1708fs_inst *
1709fs_visitor::emit(fs_inst inst)
1710{
1711   fs_inst *list_inst = new(mem_ctx) fs_inst;
1712   *list_inst = inst;
1713
1714   if (force_uncompressed_stack > 0)
1715      list_inst->force_uncompressed = true;
1716   else if (force_sechalf_stack > 0)
1717      list_inst->force_sechalf = true;
1718
1719   list_inst->annotation = this->current_annotation;
1720   list_inst->ir = this->base_ir;
1721
1722   this->instructions.push_tail(list_inst);
1723
1724   return list_inst;
1725}
1726
1727/** Emits a dummy fragment shader consisting of magenta for bringup purposes. */
1728void
1729fs_visitor::emit_dummy_fs()
1730{
1731   /* Everyone's favorite color. */
1732   emit(BRW_OPCODE_MOV, fs_reg(MRF, 2), fs_reg(1.0f));
1733   emit(BRW_OPCODE_MOV, fs_reg(MRF, 3), fs_reg(0.0f));
1734   emit(BRW_OPCODE_MOV, fs_reg(MRF, 4), fs_reg(1.0f));
1735   emit(BRW_OPCODE_MOV, fs_reg(MRF, 5), fs_reg(0.0f));
1736
1737   fs_inst *write;
1738   write = emit(FS_OPCODE_FB_WRITE, fs_reg(0), fs_reg(0));
1739   write->base_mrf = 2;
1740}
1741
1742/* The register location here is relative to the start of the URB
1743 * data.  It will get adjusted to be a real location before
1744 * generate_code() time.
1745 */
1746struct brw_reg
1747fs_visitor::interp_reg(int location, int channel)
1748{
1749   int regnr = urb_setup[location] * 2 + channel / 2;
1750   int stride = (channel & 1) * 4;
1751
1752   assert(urb_setup[location] != -1);
1753
1754   return brw_vec1_grf(regnr, stride);
1755}
1756
1757/** Emits the interpolation for the varying inputs. */
1758void
1759fs_visitor::emit_interpolation_setup_gen4()
1760{
1761   this->current_annotation = "compute pixel centers";
1762   this->pixel_x = fs_reg(this, glsl_type::uint_type);
1763   this->pixel_y = fs_reg(this, glsl_type::uint_type);
1764   this->pixel_x.type = BRW_REGISTER_TYPE_UW;
1765   this->pixel_y.type = BRW_REGISTER_TYPE_UW;
1766
1767   emit(FS_OPCODE_PIXEL_X, this->pixel_x);
1768   emit(FS_OPCODE_PIXEL_Y, this->pixel_y);
1769
1770   this->current_annotation = "compute pixel deltas from v0";
1771   if (brw->has_pln) {
1772      this->delta_x[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC] =
1773         fs_reg(this, glsl_type::vec2_type);
1774      this->delta_y[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC] =
1775         this->delta_x[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC];
1776      this->delta_y[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC].reg_offset++;
1777   } else {
1778      this->delta_x[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC] =
1779         fs_reg(this, glsl_type::float_type);
1780      this->delta_y[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC] =
1781         fs_reg(this, glsl_type::float_type);
1782   }
1783   emit(BRW_OPCODE_ADD, this->delta_x[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC],
1784	this->pixel_x, fs_reg(negate(brw_vec1_grf(1, 0))));
1785   emit(BRW_OPCODE_ADD, this->delta_y[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC],
1786	this->pixel_y, fs_reg(negate(brw_vec1_grf(1, 1))));
1787
1788   this->current_annotation = "compute pos.w and 1/pos.w";
1789   /* Compute wpos.w.  It's always in our setup, since it's needed to
1790    * interpolate the other attributes.
1791    */
1792   this->wpos_w = fs_reg(this, glsl_type::float_type);
1793   emit(FS_OPCODE_LINTERP, wpos_w,
1794        this->delta_x[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC],
1795        this->delta_y[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC],
1796	interp_reg(FRAG_ATTRIB_WPOS, 3));
1797   /* Compute the pixel 1/W value from wpos.w. */
1798   this->pixel_w = fs_reg(this, glsl_type::float_type);
1799   emit_math(SHADER_OPCODE_RCP, this->pixel_w, wpos_w);
1800   this->current_annotation = NULL;
1801}
1802
1803/** Emits the interpolation for the varying inputs. */
1804void
1805fs_visitor::emit_interpolation_setup_gen6()
1806{
1807   struct brw_reg g1_uw = retype(brw_vec1_grf(1, 0), BRW_REGISTER_TYPE_UW);
1808
1809   /* If the pixel centers end up used, the setup is the same as for gen4. */
1810   this->current_annotation = "compute pixel centers";
1811   fs_reg int_pixel_x = fs_reg(this, glsl_type::uint_type);
1812   fs_reg int_pixel_y = fs_reg(this, glsl_type::uint_type);
1813   int_pixel_x.type = BRW_REGISTER_TYPE_UW;
1814   int_pixel_y.type = BRW_REGISTER_TYPE_UW;
1815   emit(BRW_OPCODE_ADD,
1816	int_pixel_x,
1817	fs_reg(stride(suboffset(g1_uw, 4), 2, 4, 0)),
1818	fs_reg(brw_imm_v(0x10101010)));
1819   emit(BRW_OPCODE_ADD,
1820	int_pixel_y,
1821	fs_reg(stride(suboffset(g1_uw, 5), 2, 4, 0)),
1822	fs_reg(brw_imm_v(0x11001100)));
1823
1824   /* As of gen6, we can no longer mix float and int sources.  We have
1825    * to turn the integer pixel centers into floats for their actual
1826    * use.
1827    */
1828   this->pixel_x = fs_reg(this, glsl_type::float_type);
1829   this->pixel_y = fs_reg(this, glsl_type::float_type);
1830   emit(BRW_OPCODE_MOV, this->pixel_x, int_pixel_x);
1831   emit(BRW_OPCODE_MOV, this->pixel_y, int_pixel_y);
1832
1833   this->current_annotation = "compute pos.w";
1834   this->pixel_w = fs_reg(brw_vec8_grf(c->source_w_reg, 0));
1835   this->wpos_w = fs_reg(this, glsl_type::float_type);
1836   emit_math(SHADER_OPCODE_RCP, this->wpos_w, this->pixel_w);
1837
1838   for (int i = 0; i < BRW_WM_BARYCENTRIC_INTERP_MODE_COUNT; ++i) {
1839      uint8_t reg = c->barycentric_coord_reg[i];
1840      this->delta_x[i] = fs_reg(brw_vec8_grf(reg, 0));
1841      this->delta_y[i] = fs_reg(brw_vec8_grf(reg + 1, 0));
1842   }
1843
1844   this->current_annotation = NULL;
1845}
1846
1847void
1848fs_visitor::emit_color_write(int target, int index, int first_color_mrf)
1849{
1850   int reg_width = c->dispatch_width / 8;
1851   fs_inst *inst;
1852   fs_reg color = outputs[target];
1853   fs_reg mrf;
1854
1855   /* If there's no color data to be written, skip it. */
1856   if (color.file == BAD_FILE)
1857      return;
1858
1859   color.reg_offset += index;
1860
1861   if (c->dispatch_width == 8 || intel->gen >= 6) {
1862      /* SIMD8 write looks like:
1863       * m + 0: r0
1864       * m + 1: r1
1865       * m + 2: g0
1866       * m + 3: g1
1867       *
1868       * gen6 SIMD16 DP write looks like:
1869       * m + 0: r0
1870       * m + 1: r1
1871       * m + 2: g0
1872       * m + 3: g1
1873       * m + 4: b0
1874       * m + 5: b1
1875       * m + 6: a0
1876       * m + 7: a1
1877       */
1878      inst = emit(BRW_OPCODE_MOV,
1879		  fs_reg(MRF, first_color_mrf + index * reg_width, color.type),
1880		  color);
1881      inst->saturate = c->key.clamp_fragment_color;
1882   } else {
1883      /* pre-gen6 SIMD16 single source DP write looks like:
1884       * m + 0: r0
1885       * m + 1: g0
1886       * m + 2: b0
1887       * m + 3: a0
1888       * m + 4: r1
1889       * m + 5: g1
1890       * m + 6: b1
1891       * m + 7: a1
1892       */
1893      if (brw->has_compr4) {
1894	 /* By setting the high bit of the MRF register number, we
1895	  * indicate that we want COMPR4 mode - instead of doing the
1896	  * usual destination + 1 for the second half we get
1897	  * destination + 4.
1898	  */
1899	 inst = emit(BRW_OPCODE_MOV,
1900		     fs_reg(MRF, BRW_MRF_COMPR4 + first_color_mrf + index,
1901			    color.type),
1902		     color);
1903	 inst->saturate = c->key.clamp_fragment_color;
1904      } else {
1905	 push_force_uncompressed();
1906	 inst = emit(BRW_OPCODE_MOV, fs_reg(MRF, first_color_mrf + index,
1907					    color.type),
1908		     color);
1909	 inst->saturate = c->key.clamp_fragment_color;
1910	 pop_force_uncompressed();
1911
1912	 push_force_sechalf();
1913	 color.sechalf = true;
1914	 inst = emit(BRW_OPCODE_MOV, fs_reg(MRF, first_color_mrf + index + 4,
1915					    color.type),
1916		     color);
1917	 inst->saturate = c->key.clamp_fragment_color;
1918	 pop_force_sechalf();
1919	 color.sechalf = false;
1920      }
1921   }
1922}
1923
1924void
1925fs_visitor::emit_fb_writes()
1926{
1927   this->current_annotation = "FB write header";
1928   bool header_present = true;
1929   int base_mrf = 2;
1930   int nr = base_mrf;
1931   int reg_width = c->dispatch_width / 8;
1932
1933   if (intel->gen >= 6 &&
1934       !this->kill_emitted &&
1935       c->key.nr_color_regions == 1) {
1936      header_present = false;
1937   }
1938
1939   if (header_present) {
1940      /* m2, m3 header */
1941      nr += 2;
1942   }
1943
1944   if (c->aa_dest_stencil_reg) {
1945      push_force_uncompressed();
1946      emit(BRW_OPCODE_MOV, fs_reg(MRF, nr++),
1947	   fs_reg(brw_vec8_grf(c->aa_dest_stencil_reg, 0)));
1948      pop_force_uncompressed();
1949   }
1950
1951   /* Reserve space for color. It'll be filled in per MRT below. */
1952   int color_mrf = nr;
1953   nr += 4 * reg_width;
1954
1955   if (c->source_depth_to_render_target) {
1956      if (intel->gen == 6 && c->dispatch_width == 16) {
1957	 /* For outputting oDepth on gen6, SIMD8 writes have to be
1958	  * used.  This would require 8-wide moves of each half to
1959	  * message regs, kind of like pre-gen5 SIMD16 FB writes.
1960	  * Just bail on doing so for now.
1961	  */
1962	 fail("Missing support for simd16 depth writes on gen6\n");
1963      }
1964
1965      if (c->computes_depth) {
1966	 /* Hand over gl_FragDepth. */
1967	 assert(this->frag_depth);
1968	 fs_reg depth = *(variable_storage(this->frag_depth));
1969
1970	 emit(BRW_OPCODE_MOV, fs_reg(MRF, nr), depth);
1971      } else {
1972	 /* Pass through the payload depth. */
1973	 emit(BRW_OPCODE_MOV, fs_reg(MRF, nr),
1974	      fs_reg(brw_vec8_grf(c->source_depth_reg, 0)));
1975      }
1976      nr += reg_width;
1977   }
1978
1979   if (c->dest_depth_reg) {
1980      emit(BRW_OPCODE_MOV, fs_reg(MRF, nr),
1981	   fs_reg(brw_vec8_grf(c->dest_depth_reg, 0)));
1982      nr += reg_width;
1983   }
1984
1985   for (int target = 0; target < c->key.nr_color_regions; target++) {
1986      this->current_annotation = ralloc_asprintf(this->mem_ctx,
1987						 "FB write target %d",
1988						 target);
1989      for (int i = 0; i < 4; i++)
1990	 emit_color_write(target, i, color_mrf);
1991
1992      fs_inst *inst = emit(FS_OPCODE_FB_WRITE);
1993      inst->target = target;
1994      inst->base_mrf = base_mrf;
1995      inst->mlen = nr - base_mrf;
1996      if (target == c->key.nr_color_regions - 1)
1997	 inst->eot = true;
1998      inst->header_present = header_present;
1999   }
2000
2001   if (c->key.nr_color_regions == 0) {
2002      if (c->key.alpha_test) {
2003	 /* If the alpha test is enabled but there's no color buffer,
2004	  * we still need to send alpha out the pipeline to our null
2005	  * renderbuffer.
2006	  */
2007	 emit_color_write(0, 3, color_mrf);
2008      }
2009
2010      fs_inst *inst = emit(FS_OPCODE_FB_WRITE);
2011      inst->base_mrf = base_mrf;
2012      inst->mlen = nr - base_mrf;
2013      inst->eot = true;
2014      inst->header_present = header_present;
2015   }
2016
2017   this->current_annotation = NULL;
2018}
2019
2020void
2021fs_visitor::resolve_ud_negate(fs_reg *reg)
2022{
2023   if (reg->type != BRW_REGISTER_TYPE_UD ||
2024       !reg->negate)
2025      return;
2026
2027   fs_reg temp = fs_reg(this, glsl_type::uint_type);
2028   emit(BRW_OPCODE_MOV, temp, *reg);
2029   *reg = temp;
2030}
2031