1/**************************************************************************
2 *
3 * Copyright 2009-2010 VMware, Inc.
4 * All Rights Reserved.
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7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
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11 * permit persons to whom the Software is furnished to do so, subject to
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13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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27
28/**
29 * @file
30 * Depth/stencil testing to LLVM IR translation.
31 *
32 * To be done accurately/efficiently the depth/stencil test must be done with
33 * the same type/format of the depth/stencil buffer, which implies massaging
34 * the incoming depths to fit into place. Using a more straightforward
35 * type/format for depth/stencil values internally and only convert when
36 * flushing would avoid this, but it would most likely result in depth fighting
37 * artifacts.
38 *
39 * We are free to use a different pixel layout though. Since our basic
40 * processing unit is a quad (2x2 pixel block) we store the depth/stencil
41 * values tiled, a quad at time. That is, a depth buffer containing
42 *
43 *  Z11 Z12 Z13 Z14 ...
44 *  Z21 Z22 Z23 Z24 ...
45 *  Z31 Z32 Z33 Z34 ...
46 *  Z41 Z42 Z43 Z44 ...
47 *  ... ... ... ... ...
48 *
49 * will actually be stored in memory as
50 *
51 *  Z11 Z12 Z21 Z22 Z13 Z14 Z23 Z24 ...
52 *  Z31 Z32 Z41 Z42 Z33 Z34 Z43 Z44 ...
53 *  ... ... ... ... ... ... ... ... ...
54 *
55 *
56 * @author Jose Fonseca <jfonseca@vmware.com>
57 * @author Brian Paul <jfonseca@vmware.com>
58 */
59
60#include "pipe/p_state.h"
61#include "util/u_format.h"
62#include "util/u_cpu_detect.h"
63
64#include "gallivm/lp_bld_type.h"
65#include "gallivm/lp_bld_arit.h"
66#include "gallivm/lp_bld_bitarit.h"
67#include "gallivm/lp_bld_const.h"
68#include "gallivm/lp_bld_conv.h"
69#include "gallivm/lp_bld_logic.h"
70#include "gallivm/lp_bld_flow.h"
71#include "gallivm/lp_bld_intr.h"
72#include "gallivm/lp_bld_debug.h"
73#include "gallivm/lp_bld_swizzle.h"
74
75#include "lp_bld_depth.h"
76
77
78/** Used to select fields from pipe_stencil_state */
79enum stencil_op {
80   S_FAIL_OP,
81   Z_FAIL_OP,
82   Z_PASS_OP
83};
84
85
86
87/**
88 * Do the stencil test comparison (compare FB stencil values against ref value).
89 * This will be used twice when generating two-sided stencil code.
90 * \param stencil  the front/back stencil state
91 * \param stencilRef  the stencil reference value, replicated as a vector
92 * \param stencilVals  vector of stencil values from framebuffer
93 * \return vector mask of pass/fail values (~0 or 0)
94 */
95static LLVMValueRef
96lp_build_stencil_test_single(struct lp_build_context *bld,
97                             const struct pipe_stencil_state *stencil,
98                             LLVMValueRef stencilRef,
99                             LLVMValueRef stencilVals)
100{
101   LLVMBuilderRef builder = bld->gallivm->builder;
102   const unsigned stencilMax = 255; /* XXX fix */
103   struct lp_type type = bld->type;
104   LLVMValueRef res;
105
106   /*
107    * SSE2 has intrinsics for signed comparisons, but not unsigned ones. Values
108    * are between 0..255 so ensure we generate the fastest comparisons for
109    * wider elements.
110    */
111   if (type.width <= 8) {
112      assert(!type.sign);
113   } else {
114      assert(type.sign);
115   }
116
117   assert(stencil->enabled);
118
119   if (stencil->valuemask != stencilMax) {
120      /* compute stencilRef = stencilRef & valuemask */
121      LLVMValueRef valuemask = lp_build_const_int_vec(bld->gallivm, type, stencil->valuemask);
122      stencilRef = LLVMBuildAnd(builder, stencilRef, valuemask, "");
123      /* compute stencilVals = stencilVals & valuemask */
124      stencilVals = LLVMBuildAnd(builder, stencilVals, valuemask, "");
125   }
126
127   res = lp_build_cmp(bld, stencil->func, stencilRef, stencilVals);
128
129   return res;
130}
131
132
133/**
134 * Do the one or two-sided stencil test comparison.
135 * \sa lp_build_stencil_test_single
136 * \param front_facing  an integer vector mask, indicating front (~0) or back
137 *                      (0) facing polygon. If NULL, assume front-facing.
138 */
139static LLVMValueRef
140lp_build_stencil_test(struct lp_build_context *bld,
141                      const struct pipe_stencil_state stencil[2],
142                      LLVMValueRef stencilRefs[2],
143                      LLVMValueRef stencilVals,
144                      LLVMValueRef front_facing)
145{
146   LLVMValueRef res;
147
148   assert(stencil[0].enabled);
149
150   /* do front face test */
151   res = lp_build_stencil_test_single(bld, &stencil[0],
152                                      stencilRefs[0], stencilVals);
153
154   if (stencil[1].enabled && front_facing != NULL) {
155      /* do back face test */
156      LLVMValueRef back_res;
157
158      back_res = lp_build_stencil_test_single(bld, &stencil[1],
159                                              stencilRefs[1], stencilVals);
160
161      res = lp_build_select(bld, front_facing, res, back_res);
162   }
163
164   return res;
165}
166
167
168/**
169 * Apply the stencil operator (add/sub/keep/etc) to the given vector
170 * of stencil values.
171 * \return  new stencil values vector
172 */
173static LLVMValueRef
174lp_build_stencil_op_single(struct lp_build_context *bld,
175                           const struct pipe_stencil_state *stencil,
176                           enum stencil_op op,
177                           LLVMValueRef stencilRef,
178                           LLVMValueRef stencilVals)
179
180{
181   LLVMBuilderRef builder = bld->gallivm->builder;
182   struct lp_type type = bld->type;
183   LLVMValueRef res;
184   LLVMValueRef max = lp_build_const_int_vec(bld->gallivm, type, 0xff);
185   unsigned stencil_op;
186
187   assert(type.sign);
188
189   switch (op) {
190   case S_FAIL_OP:
191      stencil_op = stencil->fail_op;
192      break;
193   case Z_FAIL_OP:
194      stencil_op = stencil->zfail_op;
195      break;
196   case Z_PASS_OP:
197      stencil_op = stencil->zpass_op;
198      break;
199   default:
200      assert(0 && "Invalid stencil_op mode");
201      stencil_op = PIPE_STENCIL_OP_KEEP;
202   }
203
204   switch (stencil_op) {
205   case PIPE_STENCIL_OP_KEEP:
206      res = stencilVals;
207      /* we can return early for this case */
208      return res;
209   case PIPE_STENCIL_OP_ZERO:
210      res = bld->zero;
211      break;
212   case PIPE_STENCIL_OP_REPLACE:
213      res = stencilRef;
214      break;
215   case PIPE_STENCIL_OP_INCR:
216      res = lp_build_add(bld, stencilVals, bld->one);
217      res = lp_build_min(bld, res, max);
218      break;
219   case PIPE_STENCIL_OP_DECR:
220      res = lp_build_sub(bld, stencilVals, bld->one);
221      res = lp_build_max(bld, res, bld->zero);
222      break;
223   case PIPE_STENCIL_OP_INCR_WRAP:
224      res = lp_build_add(bld, stencilVals, bld->one);
225      res = LLVMBuildAnd(builder, res, max, "");
226      break;
227   case PIPE_STENCIL_OP_DECR_WRAP:
228      res = lp_build_sub(bld, stencilVals, bld->one);
229      res = LLVMBuildAnd(builder, res, max, "");
230      break;
231   case PIPE_STENCIL_OP_INVERT:
232      res = LLVMBuildNot(builder, stencilVals, "");
233      res = LLVMBuildAnd(builder, res, max, "");
234      break;
235   default:
236      assert(0 && "bad stencil op mode");
237      res = bld->undef;
238   }
239
240   return res;
241}
242
243
244/**
245 * Do the one or two-sided stencil test op/update.
246 */
247static LLVMValueRef
248lp_build_stencil_op(struct lp_build_context *bld,
249                    const struct pipe_stencil_state stencil[2],
250                    enum stencil_op op,
251                    LLVMValueRef stencilRefs[2],
252                    LLVMValueRef stencilVals,
253                    LLVMValueRef mask,
254                    LLVMValueRef front_facing)
255
256{
257   LLVMBuilderRef builder = bld->gallivm->builder;
258   LLVMValueRef res;
259
260   assert(stencil[0].enabled);
261
262   /* do front face op */
263   res = lp_build_stencil_op_single(bld, &stencil[0], op,
264                                     stencilRefs[0], stencilVals);
265
266   if (stencil[1].enabled && front_facing != NULL) {
267      /* do back face op */
268      LLVMValueRef back_res;
269
270      back_res = lp_build_stencil_op_single(bld, &stencil[1], op,
271                                            stencilRefs[1], stencilVals);
272
273      res = lp_build_select(bld, front_facing, res, back_res);
274   }
275
276   if (stencil[0].writemask != 0xff ||
277       (stencil[1].enabled && front_facing != NULL && stencil[1].writemask != 0xff)) {
278      /* mask &= stencil[0].writemask */
279      LLVMValueRef writemask = lp_build_const_int_vec(bld->gallivm, bld->type,
280                                                      stencil[0].writemask);
281      if (stencil[1].enabled && stencil[1].writemask != stencil[0].writemask && front_facing != NULL) {
282         LLVMValueRef back_writemask = lp_build_const_int_vec(bld->gallivm, bld->type,
283                                                         stencil[1].writemask);
284         writemask = lp_build_select(bld, front_facing, writemask, back_writemask);
285      }
286
287      mask = LLVMBuildAnd(builder, mask, writemask, "");
288      /* res = (res & mask) | (stencilVals & ~mask) */
289      res = lp_build_select_bitwise(bld, mask, res, stencilVals);
290   }
291   else {
292      /* res = mask ? res : stencilVals */
293      res = lp_build_select(bld, mask, res, stencilVals);
294   }
295
296   return res;
297}
298
299
300
301/**
302 * Return a type appropriate for depth/stencil testing.
303 */
304struct lp_type
305lp_depth_type(const struct util_format_description *format_desc,
306              unsigned length)
307{
308   struct lp_type type;
309   unsigned swizzle;
310
311   assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS);
312   assert(format_desc->block.width == 1);
313   assert(format_desc->block.height == 1);
314
315   swizzle = format_desc->swizzle[0];
316   assert(swizzle < 4);
317
318   memset(&type, 0, sizeof type);
319   type.width = format_desc->block.bits;
320
321   if(format_desc->channel[swizzle].type == UTIL_FORMAT_TYPE_FLOAT) {
322      type.floating = TRUE;
323      assert(swizzle == 0);
324      assert(format_desc->channel[swizzle].size == format_desc->block.bits);
325   }
326   else if(format_desc->channel[swizzle].type == UTIL_FORMAT_TYPE_UNSIGNED) {
327      assert(format_desc->block.bits <= 32);
328      assert(format_desc->channel[swizzle].normalized);
329      if (format_desc->channel[swizzle].size < format_desc->block.bits) {
330         /* Prefer signed integers when possible, as SSE has less support
331          * for unsigned comparison;
332          */
333         type.sign = TRUE;
334      }
335   }
336   else
337      assert(0);
338
339   assert(type.width <= length);
340   type.length = length / type.width;
341
342   return type;
343}
344
345
346/**
347 * Compute bitmask and bit shift to apply to the incoming fragment Z values
348 * and the Z buffer values needed before doing the Z comparison.
349 *
350 * Note that we leave the Z bits in the position that we find them
351 * in the Z buffer (typically 0xffffff00 or 0x00ffffff).  That lets us
352 * get by with fewer bit twiddling steps.
353 */
354static boolean
355get_z_shift_and_mask(const struct util_format_description *format_desc,
356                     unsigned *shift, unsigned *width, unsigned *mask)
357{
358   const unsigned total_bits = format_desc->block.bits;
359   unsigned z_swizzle;
360   unsigned chan;
361   unsigned padding_left, padding_right;
362
363   assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS);
364   assert(format_desc->block.width == 1);
365   assert(format_desc->block.height == 1);
366
367   z_swizzle = format_desc->swizzle[0];
368
369   if (z_swizzle == UTIL_FORMAT_SWIZZLE_NONE)
370      return FALSE;
371
372   *width = format_desc->channel[z_swizzle].size;
373
374   padding_right = 0;
375   for (chan = 0; chan < z_swizzle; ++chan)
376      padding_right += format_desc->channel[chan].size;
377
378   padding_left =
379      total_bits - (padding_right + *width);
380
381   if (padding_left || padding_right) {
382      unsigned long long mask_left = (1ULL << (total_bits - padding_left)) - 1;
383      unsigned long long mask_right = (1ULL << (padding_right)) - 1;
384      *mask = mask_left ^ mask_right;
385   }
386   else {
387      *mask = 0xffffffff;
388   }
389
390   *shift = padding_right;
391
392   return TRUE;
393}
394
395
396/**
397 * Compute bitmask and bit shift to apply to the framebuffer pixel values
398 * to put the stencil bits in the least significant position.
399 * (i.e. 0x000000ff)
400 */
401static boolean
402get_s_shift_and_mask(const struct util_format_description *format_desc,
403                     unsigned *shift, unsigned *mask)
404{
405   unsigned s_swizzle;
406   unsigned chan, sz;
407
408   s_swizzle = format_desc->swizzle[1];
409
410   if (s_swizzle == UTIL_FORMAT_SWIZZLE_NONE)
411      return FALSE;
412
413   *shift = 0;
414   for (chan = 0; chan < s_swizzle; chan++)
415      *shift += format_desc->channel[chan].size;
416
417   sz = format_desc->channel[s_swizzle].size;
418   *mask = (1U << sz) - 1U;
419
420   return TRUE;
421}
422
423
424/**
425 * Perform the occlusion test and increase the counter.
426 * Test the depth mask. Add the number of channel which has none zero mask
427 * into the occlusion counter. e.g. maskvalue is {-1, -1, -1, -1}.
428 * The counter will add 4.
429 *
430 * \param type holds element type of the mask vector.
431 * \param maskvalue is the depth test mask.
432 * \param counter is a pointer of the uint32 counter.
433 */
434void
435lp_build_occlusion_count(struct gallivm_state *gallivm,
436                         struct lp_type type,
437                         LLVMValueRef maskvalue,
438                         LLVMValueRef counter)
439{
440   LLVMBuilderRef builder = gallivm->builder;
441   LLVMContextRef context = gallivm->context;
442   LLVMValueRef countmask = lp_build_const_int_vec(gallivm, type, 1);
443   LLVMValueRef count, newcount;
444
445   assert(type.length <= 16);
446   assert(type.floating);
447
448   if(util_cpu_caps.has_sse && type.length == 4) {
449      const char *movmskintr = "llvm.x86.sse.movmsk.ps";
450      const char *popcntintr = "llvm.ctpop.i32";
451      LLVMValueRef bits = LLVMBuildBitCast(builder, maskvalue,
452                                           lp_build_vec_type(gallivm, type), "");
453      bits = lp_build_intrinsic_unary(builder, movmskintr,
454                                      LLVMInt32TypeInContext(context), bits);
455      count = lp_build_intrinsic_unary(builder, popcntintr,
456                                       LLVMInt32TypeInContext(context), bits);
457   }
458   else if(util_cpu_caps.has_avx && type.length == 8) {
459      const char *movmskintr = "llvm.x86.avx.movmsk.ps.256";
460      const char *popcntintr = "llvm.ctpop.i32";
461      LLVMValueRef bits = LLVMBuildBitCast(builder, maskvalue,
462                                           lp_build_vec_type(gallivm, type), "");
463      bits = lp_build_intrinsic_unary(builder, movmskintr,
464                                      LLVMInt32TypeInContext(context), bits);
465      count = lp_build_intrinsic_unary(builder, popcntintr,
466                                       LLVMInt32TypeInContext(context), bits);
467   }
468   else {
469      unsigned i;
470      LLVMValueRef countv = LLVMBuildAnd(builder, maskvalue, countmask, "countv");
471      LLVMTypeRef counttype = LLVMIntTypeInContext(context, type.length * 8);
472      LLVMTypeRef i8vntype = LLVMVectorType(LLVMInt8TypeInContext(context), type.length * 4);
473      LLVMValueRef shufflev, countd;
474      LLVMValueRef shuffles[16];
475      const char *popcntintr = NULL;
476
477      countv = LLVMBuildBitCast(builder, countv, i8vntype, "");
478
479       for (i = 0; i < type.length; i++) {
480          shuffles[i] = lp_build_const_int32(gallivm, 4*i);
481       }
482
483       shufflev = LLVMConstVector(shuffles, type.length);
484       countd = LLVMBuildShuffleVector(builder, countv, LLVMGetUndef(i8vntype), shufflev, "");
485       countd = LLVMBuildBitCast(builder, countd, counttype, "countd");
486
487       /*
488        * XXX FIXME
489        * this is bad on cpus without popcount (on x86 supported by intel
490        * nehalem, amd barcelona, and up - not tied to sse42).
491        * Would be much faster to just sum the 4 elements of the vector with
492        * some horizontal add (shuffle/add/shuffle/add after the initial and).
493        */
494       switch (type.length) {
495       case 4:
496          popcntintr = "llvm.ctpop.i32";
497          break;
498       case 8:
499          popcntintr = "llvm.ctpop.i64";
500          break;
501       case 16:
502          popcntintr = "llvm.ctpop.i128";
503          break;
504       default:
505          assert(0);
506       }
507       count = lp_build_intrinsic_unary(builder, popcntintr, counttype, countd);
508
509       if (type.length > 4) {
510          count = LLVMBuildTrunc(builder, count, LLVMIntTypeInContext(context, 32), "");
511       }
512   }
513   newcount = LLVMBuildLoad(builder, counter, "origcount");
514   newcount = LLVMBuildAdd(builder, newcount, count, "newcount");
515   LLVMBuildStore(builder, newcount, counter);
516}
517
518
519
520/**
521 * Generate code for performing depth and/or stencil tests.
522 * We operate on a vector of values (typically n 2x2 quads).
523 *
524 * \param depth  the depth test state
525 * \param stencil  the front/back stencil state
526 * \param type  the data type of the fragment depth/stencil values
527 * \param format_desc  description of the depth/stencil surface
528 * \param mask  the alive/dead pixel mask for the quad (vector)
529 * \param stencil_refs  the front/back stencil ref values (scalar)
530 * \param z_src  the incoming depth/stencil values (n 2x2 quad values, float32)
531 * \param zs_dst_ptr  pointer to depth/stencil values in framebuffer
532 * \param face  contains boolean value indicating front/back facing polygon
533 */
534void
535lp_build_depth_stencil_test(struct gallivm_state *gallivm,
536                            const struct pipe_depth_state *depth,
537                            const struct pipe_stencil_state stencil[2],
538                            struct lp_type z_src_type,
539                            const struct util_format_description *format_desc,
540                            struct lp_build_mask_context *mask,
541                            LLVMValueRef stencil_refs[2],
542                            LLVMValueRef z_src,
543                            LLVMValueRef zs_dst_ptr,
544                            LLVMValueRef face,
545                            LLVMValueRef *zs_value,
546                            boolean do_branch)
547{
548   LLVMBuilderRef builder = gallivm->builder;
549   struct lp_type z_type;
550   struct lp_build_context z_bld;
551   struct lp_build_context s_bld;
552   struct lp_type s_type;
553   unsigned z_shift = 0, z_width = 0, z_mask = 0;
554   LLVMValueRef zs_dst, z_dst = NULL;
555   LLVMValueRef stencil_vals = NULL;
556   LLVMValueRef z_bitmask = NULL, stencil_shift = NULL;
557   LLVMValueRef z_pass = NULL, s_pass_mask = NULL;
558   LLVMValueRef orig_mask = lp_build_mask_value(mask);
559   LLVMValueRef front_facing = NULL;
560
561
562   /*
563    * Depths are expected to be between 0 and 1, even if they are stored in
564    * floats. Setting these bits here will ensure that the lp_build_conv() call
565    * below won't try to unnecessarily clamp the incoming values.
566    */
567   if(z_src_type.floating) {
568      z_src_type.sign = FALSE;
569      z_src_type.norm = TRUE;
570   }
571   else {
572      assert(!z_src_type.sign);
573      assert(z_src_type.norm);
574   }
575
576   /* Pick the depth type. */
577   z_type = lp_depth_type(format_desc, z_src_type.width*z_src_type.length);
578
579   /* FIXME: Cope with a depth test type with a different bit width. */
580   assert(z_type.width == z_src_type.width);
581   assert(z_type.length == z_src_type.length);
582
583   /* FIXME: for non-float depth/stencil might generate better code
584    * if we'd always split it up to use 128bit operations.
585    * For stencil we'd almost certainly want to pack to 8xi16 values,
586    * for z just run twice.
587    */
588
589   /* Sanity checking */
590   {
591      const unsigned z_swizzle = format_desc->swizzle[0];
592      const unsigned s_swizzle = format_desc->swizzle[1];
593
594      assert(z_swizzle != UTIL_FORMAT_SWIZZLE_NONE ||
595             s_swizzle != UTIL_FORMAT_SWIZZLE_NONE);
596
597      assert(depth->enabled || stencil[0].enabled);
598
599      assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS);
600      assert(format_desc->block.width == 1);
601      assert(format_desc->block.height == 1);
602
603      if (stencil[0].enabled) {
604         assert(format_desc->format == PIPE_FORMAT_Z24_UNORM_S8_UINT ||
605                format_desc->format == PIPE_FORMAT_S8_UINT_Z24_UNORM);
606      }
607
608      assert(z_swizzle < 4);
609      assert(format_desc->block.bits == z_type.width);
610      if (z_type.floating) {
611         assert(z_swizzle == 0);
612         assert(format_desc->channel[z_swizzle].type ==
613                UTIL_FORMAT_TYPE_FLOAT);
614         assert(format_desc->channel[z_swizzle].size ==
615                format_desc->block.bits);
616      }
617      else {
618         assert(format_desc->channel[z_swizzle].type ==
619                UTIL_FORMAT_TYPE_UNSIGNED);
620         assert(format_desc->channel[z_swizzle].normalized);
621         assert(!z_type.fixed);
622      }
623   }
624
625
626   /* Setup build context for Z vals */
627   lp_build_context_init(&z_bld, gallivm, z_type);
628
629   /* Setup build context for stencil vals */
630   s_type = lp_int_type(z_type);
631   lp_build_context_init(&s_bld, gallivm, s_type);
632
633   /* Load current z/stencil value from z/stencil buffer */
634   zs_dst_ptr = LLVMBuildBitCast(builder,
635                                 zs_dst_ptr,
636                                 LLVMPointerType(z_bld.vec_type, 0), "");
637   zs_dst = LLVMBuildLoad(builder, zs_dst_ptr, "");
638
639   lp_build_name(zs_dst, "zs_dst");
640
641
642   /* Compute and apply the Z/stencil bitmasks and shifts.
643    */
644   {
645      unsigned s_shift, s_mask;
646
647      if (get_z_shift_and_mask(format_desc, &z_shift, &z_width, &z_mask)) {
648         if (z_mask != 0xffffffff) {
649            z_bitmask = lp_build_const_int_vec(gallivm, z_type, z_mask);
650         }
651
652         /*
653          * Align the framebuffer Z 's LSB to the right.
654          */
655         if (z_shift) {
656            LLVMValueRef shift = lp_build_const_int_vec(gallivm, z_type, z_shift);
657            z_dst = LLVMBuildLShr(builder, zs_dst, shift, "z_dst");
658         } else if (z_bitmask) {
659	    /* TODO: Instead of loading a mask from memory and ANDing, it's
660	     * probably faster to just shake the bits with two shifts. */
661            z_dst = LLVMBuildAnd(builder, zs_dst, z_bitmask, "z_dst");
662         } else {
663            z_dst = zs_dst;
664            lp_build_name(z_dst, "z_dst");
665         }
666      }
667
668      if (get_s_shift_and_mask(format_desc, &s_shift, &s_mask)) {
669         if (s_shift) {
670            LLVMValueRef shift = lp_build_const_int_vec(gallivm, s_type, s_shift);
671            stencil_vals = LLVMBuildLShr(builder, zs_dst, shift, "");
672            stencil_shift = shift;  /* used below */
673         }
674         else {
675            stencil_vals = zs_dst;
676         }
677
678         if (s_mask != 0xffffffff) {
679            LLVMValueRef mask = lp_build_const_int_vec(gallivm, s_type, s_mask);
680            stencil_vals = LLVMBuildAnd(builder, stencil_vals, mask, "");
681         }
682
683         lp_build_name(stencil_vals, "s_dst");
684      }
685   }
686
687   if (stencil[0].enabled) {
688
689      if (face) {
690         LLVMValueRef zero = lp_build_const_int32(gallivm, 0);
691
692         /* front_facing = face != 0 ? ~0 : 0 */
693         front_facing = LLVMBuildICmp(builder, LLVMIntNE, face, zero, "");
694         front_facing = LLVMBuildSExt(builder, front_facing,
695                                      LLVMIntTypeInContext(gallivm->context,
696                                             s_bld.type.length*s_bld.type.width),
697                                      "");
698         front_facing = LLVMBuildBitCast(builder, front_facing,
699                                         s_bld.int_vec_type, "");
700      }
701
702      /* convert scalar stencil refs into vectors */
703      stencil_refs[0] = lp_build_broadcast_scalar(&s_bld, stencil_refs[0]);
704      stencil_refs[1] = lp_build_broadcast_scalar(&s_bld, stencil_refs[1]);
705
706      s_pass_mask = lp_build_stencil_test(&s_bld, stencil,
707                                          stencil_refs, stencil_vals,
708                                          front_facing);
709
710      /* apply stencil-fail operator */
711      {
712         LLVMValueRef s_fail_mask = lp_build_andnot(&s_bld, orig_mask, s_pass_mask);
713         stencil_vals = lp_build_stencil_op(&s_bld, stencil, S_FAIL_OP,
714                                            stencil_refs, stencil_vals,
715                                            s_fail_mask, front_facing);
716      }
717   }
718
719   if (depth->enabled) {
720      /*
721       * Convert fragment Z to the desired type, aligning the LSB to the right.
722       */
723
724      assert(z_type.width == z_src_type.width);
725      assert(z_type.length == z_src_type.length);
726      assert(lp_check_value(z_src_type, z_src));
727      if (z_src_type.floating) {
728         /*
729          * Convert from floating point values
730          */
731
732         if (!z_type.floating) {
733            z_src = lp_build_clamped_float_to_unsigned_norm(gallivm,
734                                                            z_src_type,
735                                                            z_width,
736                                                            z_src);
737         }
738      } else {
739         /*
740          * Convert from unsigned normalized values.
741          */
742
743         assert(!z_src_type.sign);
744         assert(!z_src_type.fixed);
745         assert(z_src_type.norm);
746         assert(!z_type.floating);
747         if (z_src_type.width > z_width) {
748            LLVMValueRef shift = lp_build_const_int_vec(gallivm, z_src_type,
749                                                        z_src_type.width - z_width);
750            z_src = LLVMBuildLShr(builder, z_src, shift, "");
751         }
752      }
753      assert(lp_check_value(z_type, z_src));
754
755      lp_build_name(z_src, "z_src");
756
757      /* compare src Z to dst Z, returning 'pass' mask */
758      z_pass = lp_build_cmp(&z_bld, depth->func, z_src, z_dst);
759
760      if (!stencil[0].enabled) {
761         /* We can potentially skip all remaining operations here, but only
762          * if stencil is disabled because we still need to update the stencil
763          * buffer values.  Don't need to update Z buffer values.
764          */
765         lp_build_mask_update(mask, z_pass);
766
767         if (do_branch) {
768            lp_build_mask_check(mask);
769            do_branch = FALSE;
770         }
771      }
772
773      if (depth->writemask) {
774         LLVMValueRef zselectmask;
775
776         /* mask off bits that failed Z test */
777         zselectmask = LLVMBuildAnd(builder, orig_mask, z_pass, "");
778
779         /* mask off bits that failed stencil test */
780         if (s_pass_mask) {
781            zselectmask = LLVMBuildAnd(builder, zselectmask, s_pass_mask, "");
782         }
783
784         /* Mix the old and new Z buffer values.
785          * z_dst[i] = zselectmask[i] ? z_src[i] : z_dst[i]
786          */
787         z_dst = lp_build_select(&z_bld, zselectmask, z_src, z_dst);
788      }
789
790      if (stencil[0].enabled) {
791         /* update stencil buffer values according to z pass/fail result */
792         LLVMValueRef z_fail_mask, z_pass_mask;
793
794         /* apply Z-fail operator */
795         z_fail_mask = lp_build_andnot(&z_bld, orig_mask, z_pass);
796         stencil_vals = lp_build_stencil_op(&s_bld, stencil, Z_FAIL_OP,
797                                            stencil_refs, stencil_vals,
798                                            z_fail_mask, front_facing);
799
800         /* apply Z-pass operator */
801         z_pass_mask = LLVMBuildAnd(builder, orig_mask, z_pass, "");
802         stencil_vals = lp_build_stencil_op(&s_bld, stencil, Z_PASS_OP,
803                                            stencil_refs, stencil_vals,
804                                            z_pass_mask, front_facing);
805      }
806   }
807   else {
808      /* No depth test: apply Z-pass operator to stencil buffer values which
809       * passed the stencil test.
810       */
811      s_pass_mask = LLVMBuildAnd(builder, orig_mask, s_pass_mask, "");
812      stencil_vals = lp_build_stencil_op(&s_bld, stencil, Z_PASS_OP,
813                                         stencil_refs, stencil_vals,
814                                         s_pass_mask, front_facing);
815   }
816
817   /* Put Z and ztencil bits in the right place */
818   if (z_dst && z_shift) {
819      LLVMValueRef shift = lp_build_const_int_vec(gallivm, z_type, z_shift);
820      z_dst = LLVMBuildShl(builder, z_dst, shift, "");
821   }
822   if (stencil_vals && stencil_shift)
823      stencil_vals = LLVMBuildShl(builder, stencil_vals,
824                                  stencil_shift, "");
825
826   /* Finally, merge/store the z/stencil values */
827   if ((depth->enabled && depth->writemask) ||
828       (stencil[0].enabled && stencil[0].writemask)) {
829
830      if (z_dst && stencil_vals)
831         zs_dst = LLVMBuildOr(builder, z_dst, stencil_vals, "");
832      else if (z_dst)
833         zs_dst = z_dst;
834      else
835         zs_dst = stencil_vals;
836
837      *zs_value = zs_dst;
838   }
839
840   if (s_pass_mask)
841      lp_build_mask_update(mask, s_pass_mask);
842
843   if (depth->enabled && stencil[0].enabled)
844      lp_build_mask_update(mask, z_pass);
845
846   if (do_branch)
847      lp_build_mask_check(mask);
848
849}
850
851
852void
853lp_build_depth_write(LLVMBuilderRef builder,
854                     const struct util_format_description *format_desc,
855                     LLVMValueRef zs_dst_ptr,
856                     LLVMValueRef zs_value)
857{
858   zs_dst_ptr = LLVMBuildBitCast(builder, zs_dst_ptr,
859                                 LLVMPointerType(LLVMTypeOf(zs_value), 0), "");
860
861   LLVMBuildStore(builder, zs_value, zs_dst_ptr);
862}
863
864
865void
866lp_build_deferred_depth_write(struct gallivm_state *gallivm,
867                              struct lp_type z_src_type,
868                              const struct util_format_description *format_desc,
869                              struct lp_build_mask_context *mask,
870                              LLVMValueRef zs_dst_ptr,
871                              LLVMValueRef zs_value)
872{
873   struct lp_type z_type;
874   struct lp_build_context z_bld;
875   LLVMValueRef z_dst;
876   LLVMBuilderRef builder = gallivm->builder;
877
878   /* XXX: pointlessly redo type logic:
879    */
880   z_type = lp_depth_type(format_desc, z_src_type.width*z_src_type.length);
881   lp_build_context_init(&z_bld, gallivm, z_type);
882
883   zs_dst_ptr = LLVMBuildBitCast(builder, zs_dst_ptr,
884                                 LLVMPointerType(z_bld.vec_type, 0), "");
885
886   z_dst = LLVMBuildLoad(builder, zs_dst_ptr, "zsbufval");
887   z_dst = lp_build_select(&z_bld, lp_build_mask_value(mask), zs_value, z_dst);
888
889   LLVMBuildStore(builder, z_dst, zs_dst_ptr);
890}
891