• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /**************************************************************************
2  *
3  * Copyright 2009-2010 VMware, Inc.
4  * All Rights Reserved.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sub license, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25  *
26  **************************************************************************/
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  * Since we're using linear layout for everything, but we need to deal with
40  * 2x2 quads, we need to load/store multiple values and swizzle them into
41  * place (we could avoid this by doing depth/stencil testing in linear format,
42  * which would be easy for late depth/stencil test as we could do that after
43  * the fragment shader loop just as we do for color buffers, but more tricky
44  * for early depth test as we'd need both masks and interpolated depth in
45  * linear format).
46  *
47  *
48  * @author Jose Fonseca <jfonseca@vmware.com>
49  * @author Brian Paul <jfonseca@vmware.com>
50  */
51 
52 #include "pipe/p_state.h"
53 #include "util/format/u_format.h"
54 #include "util/u_cpu_detect.h"
55 
56 #include "gallivm/lp_bld_type.h"
57 #include "gallivm/lp_bld_arit.h"
58 #include "gallivm/lp_bld_bitarit.h"
59 #include "gallivm/lp_bld_const.h"
60 #include "gallivm/lp_bld_conv.h"
61 #include "gallivm/lp_bld_logic.h"
62 #include "gallivm/lp_bld_flow.h"
63 #include "gallivm/lp_bld_intr.h"
64 #include "gallivm/lp_bld_debug.h"
65 #include "gallivm/lp_bld_swizzle.h"
66 #include "gallivm/lp_bld_pack.h"
67 
68 #include "lp_bld_depth.h"
69 #include "lp_state_fs.h"
70 
71 
72 /** Used to select fields from pipe_stencil_state */
73 enum stencil_op {
74    S_FAIL_OP,
75    Z_FAIL_OP,
76    Z_PASS_OP
77 };
78 
79 
80 
81 /**
82  * Do the stencil test comparison (compare FB stencil values against ref value).
83  * This will be used twice when generating two-sided stencil code.
84  * \param stencil  the front/back stencil state
85  * \param stencilRef  the stencil reference value, replicated as a vector
86  * \param stencilVals  vector of stencil values from framebuffer
87  * \return vector mask of pass/fail values (~0 or 0)
88  */
89 static LLVMValueRef
lp_build_stencil_test_single(struct lp_build_context * bld,const struct pipe_stencil_state * stencil,LLVMValueRef stencilRef,LLVMValueRef stencilVals)90 lp_build_stencil_test_single(struct lp_build_context *bld,
91                              const struct pipe_stencil_state *stencil,
92                              LLVMValueRef stencilRef,
93                              LLVMValueRef stencilVals)
94 {
95    LLVMBuilderRef builder = bld->gallivm->builder;
96    const unsigned stencilMax = 255; /* XXX fix */
97    struct lp_type type = bld->type;
98    LLVMValueRef res;
99 
100    /*
101     * SSE2 has intrinsics for signed comparisons, but not unsigned ones. Values
102     * are between 0..255 so ensure we generate the fastest comparisons for
103     * wider elements.
104     */
105    if (type.width <= 8) {
106       assert(!type.sign);
107    } else {
108       assert(type.sign);
109    }
110 
111    assert(stencil->enabled);
112 
113    if (stencil->valuemask != stencilMax) {
114       /* compute stencilRef = stencilRef & valuemask */
115       LLVMValueRef valuemask = lp_build_const_int_vec(bld->gallivm, type, stencil->valuemask);
116       stencilRef = LLVMBuildAnd(builder, stencilRef, valuemask, "");
117       /* compute stencilVals = stencilVals & valuemask */
118       stencilVals = LLVMBuildAnd(builder, stencilVals, valuemask, "");
119    }
120 
121    res = lp_build_cmp(bld, stencil->func, stencilRef, stencilVals);
122 
123    return res;
124 }
125 
126 
127 /**
128  * Do the one or two-sided stencil test comparison.
129  * \sa lp_build_stencil_test_single
130  * \param front_facing  an integer vector mask, indicating front (~0) or back
131  *                      (0) facing polygon. If NULL, assume front-facing.
132  */
133 static LLVMValueRef
lp_build_stencil_test(struct lp_build_context * bld,const struct pipe_stencil_state stencil[2],LLVMValueRef stencilRefs[2],LLVMValueRef stencilVals,LLVMValueRef front_facing)134 lp_build_stencil_test(struct lp_build_context *bld,
135                       const struct pipe_stencil_state stencil[2],
136                       LLVMValueRef stencilRefs[2],
137                       LLVMValueRef stencilVals,
138                       LLVMValueRef front_facing)
139 {
140    LLVMValueRef res;
141 
142    assert(stencil[0].enabled);
143 
144    /* do front face test */
145    res = lp_build_stencil_test_single(bld, &stencil[0],
146                                       stencilRefs[0], stencilVals);
147 
148    if (stencil[1].enabled && front_facing != NULL) {
149       /* do back face test */
150       LLVMValueRef back_res;
151 
152       back_res = lp_build_stencil_test_single(bld, &stencil[1],
153                                               stencilRefs[1], stencilVals);
154 
155       res = lp_build_select(bld, front_facing, res, back_res);
156    }
157 
158    return res;
159 }
160 
161 
162 /**
163  * Apply the stencil operator (add/sub/keep/etc) to the given vector
164  * of stencil values.
165  * \return  new stencil values vector
166  */
167 static LLVMValueRef
lp_build_stencil_op_single(struct lp_build_context * bld,const struct pipe_stencil_state * stencil,enum stencil_op op,LLVMValueRef stencilRef,LLVMValueRef stencilVals)168 lp_build_stencil_op_single(struct lp_build_context *bld,
169                            const struct pipe_stencil_state *stencil,
170                            enum stencil_op op,
171                            LLVMValueRef stencilRef,
172                            LLVMValueRef stencilVals)
173 
174 {
175    LLVMBuilderRef builder = bld->gallivm->builder;
176    struct lp_type type = bld->type;
177    LLVMValueRef res;
178    LLVMValueRef max = lp_build_const_int_vec(bld->gallivm, type, 0xff);
179    unsigned stencil_op;
180 
181    assert(type.sign);
182 
183    switch (op) {
184    case S_FAIL_OP:
185       stencil_op = stencil->fail_op;
186       break;
187    case Z_FAIL_OP:
188       stencil_op = stencil->zfail_op;
189       break;
190    case Z_PASS_OP:
191       stencil_op = stencil->zpass_op;
192       break;
193    default:
194       assert(0 && "Invalid stencil_op mode");
195       stencil_op = PIPE_STENCIL_OP_KEEP;
196    }
197 
198    switch (stencil_op) {
199    case PIPE_STENCIL_OP_KEEP:
200       res = stencilVals;
201       /* we can return early for this case */
202       return res;
203    case PIPE_STENCIL_OP_ZERO:
204       res = bld->zero;
205       break;
206    case PIPE_STENCIL_OP_REPLACE:
207       res = stencilRef;
208       break;
209    case PIPE_STENCIL_OP_INCR:
210       res = lp_build_add(bld, stencilVals, bld->one);
211       res = lp_build_min(bld, res, max);
212       break;
213    case PIPE_STENCIL_OP_DECR:
214       res = lp_build_sub(bld, stencilVals, bld->one);
215       res = lp_build_max(bld, res, bld->zero);
216       break;
217    case PIPE_STENCIL_OP_INCR_WRAP:
218       res = lp_build_add(bld, stencilVals, bld->one);
219       res = LLVMBuildAnd(builder, res, max, "");
220       break;
221    case PIPE_STENCIL_OP_DECR_WRAP:
222       res = lp_build_sub(bld, stencilVals, bld->one);
223       res = LLVMBuildAnd(builder, res, max, "");
224       break;
225    case PIPE_STENCIL_OP_INVERT:
226       res = LLVMBuildNot(builder, stencilVals, "");
227       res = LLVMBuildAnd(builder, res, max, "");
228       break;
229    default:
230       assert(0 && "bad stencil op mode");
231       res = bld->undef;
232    }
233 
234    return res;
235 }
236 
237 
238 /**
239  * Do the one or two-sided stencil test op/update.
240  */
241 static LLVMValueRef
lp_build_stencil_op(struct lp_build_context * bld,const struct pipe_stencil_state stencil[2],enum stencil_op op,LLVMValueRef stencilRefs[2],LLVMValueRef stencilVals,LLVMValueRef mask,LLVMValueRef front_facing)242 lp_build_stencil_op(struct lp_build_context *bld,
243                     const struct pipe_stencil_state stencil[2],
244                     enum stencil_op op,
245                     LLVMValueRef stencilRefs[2],
246                     LLVMValueRef stencilVals,
247                     LLVMValueRef mask,
248                     LLVMValueRef front_facing)
249 
250 {
251    LLVMBuilderRef builder = bld->gallivm->builder;
252    LLVMValueRef res;
253 
254    assert(stencil[0].enabled);
255 
256    /* do front face op */
257    res = lp_build_stencil_op_single(bld, &stencil[0], op,
258                                      stencilRefs[0], stencilVals);
259 
260    if (stencil[1].enabled && front_facing != NULL) {
261       /* do back face op */
262       LLVMValueRef back_res;
263 
264       back_res = lp_build_stencil_op_single(bld, &stencil[1], op,
265                                             stencilRefs[1], stencilVals);
266 
267       res = lp_build_select(bld, front_facing, res, back_res);
268    }
269 
270    if (stencil[0].writemask != 0xff ||
271        (stencil[1].enabled && front_facing != NULL &&
272         stencil[1].writemask != 0xff)) {
273       /* mask &= stencil[0].writemask */
274       LLVMValueRef writemask = lp_build_const_int_vec(bld->gallivm, bld->type,
275                                                       stencil[0].writemask);
276       if (stencil[1].enabled &&
277           stencil[1].writemask != stencil[0].writemask &&
278           front_facing != NULL) {
279          LLVMValueRef back_writemask =
280             lp_build_const_int_vec(bld->gallivm, bld->type,
281                                    stencil[1].writemask);
282          writemask = lp_build_select(bld, front_facing,
283                                      writemask, back_writemask);
284       }
285 
286       mask = LLVMBuildAnd(builder, mask, writemask, "");
287       /* res = (res & mask) | (stencilVals & ~mask) */
288       res = lp_build_select_bitwise(bld, mask, res, stencilVals);
289    }
290    else {
291       /* res = mask ? res : stencilVals */
292       res = lp_build_select(bld, mask, res, stencilVals);
293    }
294 
295    return res;
296 }
297 
298 
299 
300 /**
301  * Return a type that matches the depth/stencil format.
302  */
303 struct lp_type
lp_depth_type(const struct util_format_description * format_desc,unsigned length)304 lp_depth_type(const struct util_format_description *format_desc,
305               unsigned length)
306 {
307    struct lp_type type;
308    unsigned z_swizzle;
309 
310    assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS);
311    assert(format_desc->block.width == 1);
312    assert(format_desc->block.height == 1);
313 
314    memset(&type, 0, sizeof type);
315    type.width = format_desc->block.bits;
316 
317    z_swizzle = format_desc->swizzle[0];
318    if (z_swizzle < 4) {
319       if (format_desc->channel[z_swizzle].type == UTIL_FORMAT_TYPE_FLOAT) {
320          type.floating = TRUE;
321          assert(z_swizzle == 0);
322          assert(format_desc->channel[z_swizzle].size == 32);
323       }
324       else if (format_desc->channel[z_swizzle].type == UTIL_FORMAT_TYPE_UNSIGNED) {
325          assert(format_desc->block.bits <= 32);
326          assert(format_desc->channel[z_swizzle].normalized);
327          if (format_desc->channel[z_swizzle].size < format_desc->block.bits) {
328             /* Prefer signed integers when possible, as SSE has less support
329              * for unsigned comparison;
330              */
331             type.sign = TRUE;
332          }
333       }
334       else
335          assert(0);
336    }
337 
338    type.length = length;
339 
340    return type;
341 }
342 
343 
344 /**
345  * Compute bitmask and bit shift to apply to the incoming fragment Z values
346  * and the Z buffer values needed before doing the Z comparison.
347  *
348  * Note that we leave the Z bits in the position that we find them
349  * in the Z buffer (typically 0xffffff00 or 0x00ffffff).  That lets us
350  * get by with fewer bit twiddling steps.
351  */
352 static boolean
get_z_shift_and_mask(const struct util_format_description * format_desc,unsigned * shift,unsigned * width,unsigned * mask)353 get_z_shift_and_mask(const struct util_format_description *format_desc,
354                      unsigned *shift, unsigned *width, unsigned *mask)
355 {
356    unsigned total_bits;
357    unsigned z_swizzle;
358 
359    assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS);
360    assert(format_desc->block.width == 1);
361    assert(format_desc->block.height == 1);
362 
363    /* 64bit d/s format is special already extracted 32 bits */
364    total_bits = format_desc->block.bits > 32 ? 32 : format_desc->block.bits;
365 
366    z_swizzle = format_desc->swizzle[0];
367 
368    if (z_swizzle == PIPE_SWIZZLE_NONE)
369       return FALSE;
370 
371    *width = format_desc->channel[z_swizzle].size;
372    /* & 31 is for the same reason as the 32-bit limit above */
373    *shift = format_desc->channel[z_swizzle].shift & 31;
374 
375    if (*width == total_bits) {
376       *mask = 0xffffffff;
377    } else {
378       *mask = ((1 << *width) - 1) << *shift;
379    }
380 
381    return TRUE;
382 }
383 
384 
385 /**
386  * Compute bitmask and bit shift to apply to the framebuffer pixel values
387  * to put the stencil bits in the least significant position.
388  * (i.e. 0x000000ff)
389  */
390 static boolean
get_s_shift_and_mask(const struct util_format_description * format_desc,unsigned * shift,unsigned * mask)391 get_s_shift_and_mask(const struct util_format_description *format_desc,
392                      unsigned *shift, unsigned *mask)
393 {
394    const unsigned s_swizzle = format_desc->swizzle[1];
395 
396    if (s_swizzle == PIPE_SWIZZLE_NONE)
397       return FALSE;
398 
399    /* just special case 64bit d/s format */
400    if (format_desc->block.bits > 32) {
401       /* XXX big-endian? */
402       assert(format_desc->format == PIPE_FORMAT_Z32_FLOAT_S8X24_UINT);
403       *shift = 0;
404       *mask = 0xff;
405       return TRUE;
406    }
407 
408    *shift = format_desc->channel[s_swizzle].shift;
409    const unsigned sz = format_desc->channel[s_swizzle].size;
410    *mask = (1U << sz) - 1U;
411 
412    return TRUE;
413 }
414 
415 
416 /**
417  * Perform the occlusion test and increase the counter.
418  * Test the depth mask. Add the number of channel which has none zero mask
419  * into the occlusion counter. e.g. maskvalue is {-1, -1, -1, -1}.
420  * The counter will add 4.
421  * TODO: could get that out of the fs loop.
422  *
423  * \param type holds element type of the mask vector.
424  * \param maskvalue is the depth test mask.
425  * \param counter is a pointer of the uint32 counter.
426  */
427 void
lp_build_occlusion_count(struct gallivm_state * gallivm,struct lp_type type,LLVMValueRef maskvalue,LLVMValueRef counter)428 lp_build_occlusion_count(struct gallivm_state *gallivm,
429                          struct lp_type type,
430                          LLVMValueRef maskvalue,
431                          LLVMValueRef counter)
432 {
433    LLVMBuilderRef builder = gallivm->builder;
434    LLVMContextRef context = gallivm->context;
435    LLVMValueRef countmask = lp_build_const_int_vec(gallivm, type, 1);
436    LLVMValueRef count, newcount;
437 
438    assert(type.length <= 16);
439    assert(type.floating);
440 
441    if (util_get_cpu_caps()->has_sse && type.length == 4) {
442       const char *movmskintr = "llvm.x86.sse.movmsk.ps";
443       const char *popcntintr = "llvm.ctpop.i32";
444       LLVMValueRef bits = LLVMBuildBitCast(builder, maskvalue,
445                                            lp_build_vec_type(gallivm, type), "");
446       bits = lp_build_intrinsic_unary(builder, movmskintr,
447                                       LLVMInt32TypeInContext(context), bits);
448       count = lp_build_intrinsic_unary(builder, popcntintr,
449                                        LLVMInt32TypeInContext(context), bits);
450       count = LLVMBuildZExt(builder, count, LLVMIntTypeInContext(context, 64), "");
451    }
452    else if (util_get_cpu_caps()->has_avx && type.length == 8) {
453       const char *movmskintr = "llvm.x86.avx.movmsk.ps.256";
454       const char *popcntintr = "llvm.ctpop.i32";
455       LLVMValueRef bits = LLVMBuildBitCast(builder, maskvalue,
456                                            lp_build_vec_type(gallivm, type), "");
457       bits = lp_build_intrinsic_unary(builder, movmskintr,
458                                       LLVMInt32TypeInContext(context), bits);
459       count = lp_build_intrinsic_unary(builder, popcntintr,
460                                        LLVMInt32TypeInContext(context), bits);
461       count = LLVMBuildZExt(builder, count, LLVMIntTypeInContext(context, 64), "");
462    }
463    else {
464       LLVMValueRef countv = LLVMBuildAnd(builder, maskvalue, countmask, "countv");
465       LLVMTypeRef counttype = LLVMIntTypeInContext(context, type.length * 8);
466       LLVMTypeRef i8vntype = LLVMVectorType(LLVMInt8TypeInContext(context), type.length * 4);
467       LLVMValueRef shufflev, countd;
468       LLVMValueRef shuffles[16];
469       const char *popcntintr = NULL;
470 
471       countv = LLVMBuildBitCast(builder, countv, i8vntype, "");
472 
473        for (unsigned i = 0; i < type.length; i++) {
474 #if UTIL_ARCH_LITTLE_ENDIAN
475           shuffles[i] = lp_build_const_int32(gallivm, 4*i);
476 #else
477           shuffles[i] = lp_build_const_int32(gallivm, (4*i) + 3);
478 #endif
479        }
480 
481        shufflev = LLVMConstVector(shuffles, type.length);
482        countd = LLVMBuildShuffleVector(builder, countv, LLVMGetUndef(i8vntype), shufflev, "");
483        countd = LLVMBuildBitCast(builder, countd, counttype, "countd");
484 
485        /*
486         * XXX FIXME
487         * this is bad on cpus without popcount (on x86 supported by intel
488         * nehalem, amd barcelona, and up - not tied to sse42).
489         * Would be much faster to just sum the 4 elements of the vector with
490         * some horizontal add (shuffle/add/shuffle/add after the initial and).
491         */
492        switch (type.length) {
493        case 4:
494           popcntintr = "llvm.ctpop.i32";
495           break;
496        case 8:
497           popcntintr = "llvm.ctpop.i64";
498           break;
499        case 16:
500           popcntintr = "llvm.ctpop.i128";
501           break;
502        default:
503           assert(0);
504        }
505        count = lp_build_intrinsic_unary(builder, popcntintr, counttype, countd);
506 
507        if (type.length > 8) {
508           count = LLVMBuildTrunc(builder, count, LLVMIntTypeInContext(context, 64), "");
509        }
510        else if (type.length < 8) {
511           count = LLVMBuildZExt(builder, count, LLVMIntTypeInContext(context, 64), "");
512        }
513    }
514    newcount = LLVMBuildLoad2(builder, LLVMTypeOf(count), counter, "origcount");
515    newcount = LLVMBuildAdd(builder, newcount, count, "newcount");
516    LLVMBuildStore(builder, newcount, counter);
517 }
518 
519 
520 /**
521  * Load depth/stencil values.
522  * The stored values are linear, swizzle them.
523  *
524  * \param type  the data type of the fragment depth/stencil values
525  * \param format_desc  description of the depth/stencil surface
526  * \param is_1d  whether this resource has only one dimension
527  * \param loop_counter  the current loop iteration
528  * \param depth_ptr  pointer to the depth/stencil values of this 4x4 block
529  * \param depth_stride  stride of the depth/stencil buffer
530  * \param z_fb  contains z values loaded from fb (may include padding)
531  * \param s_fb  contains s values loaded from fb (may include padding)
532  */
533 void
lp_build_depth_stencil_load_swizzled(struct gallivm_state * gallivm,struct lp_type z_src_type,const struct util_format_description * format_desc,boolean is_1d,LLVMValueRef depth_ptr,LLVMValueRef depth_stride,LLVMValueRef * z_fb,LLVMValueRef * s_fb,LLVMValueRef loop_counter)534 lp_build_depth_stencil_load_swizzled(struct gallivm_state *gallivm,
535                                      struct lp_type z_src_type,
536                                      const struct util_format_description *format_desc,
537                                      boolean is_1d,
538                                      LLVMValueRef depth_ptr,
539                                      LLVMValueRef depth_stride,
540                                      LLVMValueRef *z_fb,
541                                      LLVMValueRef *s_fb,
542                                      LLVMValueRef loop_counter)
543 {
544    LLVMBuilderRef builder = gallivm->builder;
545    LLVMValueRef shuffles[LP_MAX_VECTOR_LENGTH / 4];
546    LLVMValueRef depth_offset1, depth_offset2;
547    const unsigned depth_bytes = format_desc->block.bits / 8;
548    struct lp_type zs_type = lp_depth_type(format_desc, z_src_type.length);
549 
550    struct lp_type zs_load_type = zs_type;
551    zs_load_type.length = zs_load_type.length / 2;
552 
553    LLVMTypeRef zs_dst_type = lp_build_vec_type(gallivm, zs_load_type);
554 
555    if (z_src_type.length == 4) {
556       LLVMValueRef looplsb = LLVMBuildAnd(builder, loop_counter,
557                                           lp_build_const_int32(gallivm, 1), "");
558       LLVMValueRef loopmsb = LLVMBuildAnd(builder, loop_counter,
559                                           lp_build_const_int32(gallivm, 2), "");
560       LLVMValueRef offset2 = LLVMBuildMul(builder, loopmsb,
561                                           depth_stride, "");
562       depth_offset1 = LLVMBuildMul(builder, looplsb,
563                                    lp_build_const_int32(gallivm, depth_bytes * 2), "");
564       depth_offset1 = LLVMBuildAdd(builder, depth_offset1, offset2, "");
565 
566       /* just concatenate the loaded 2x2 values into 4-wide vector */
567       for (unsigned i = 0; i < 4; i++) {
568          shuffles[i] = lp_build_const_int32(gallivm, i);
569       }
570    }
571    else {
572       unsigned i;
573       LLVMValueRef loopx2 = LLVMBuildShl(builder, loop_counter,
574                                          lp_build_const_int32(gallivm, 1), "");
575       assert(z_src_type.length == 8);
576       depth_offset1 = LLVMBuildMul(builder, loopx2, depth_stride, "");
577       /*
578        * We load 2x4 values, and need to swizzle them (order
579        * 0,1,4,5,2,3,6,7) - not so hot with avx unfortunately.
580        */
581       for (i = 0; i < 8; i++) {
582          shuffles[i] = lp_build_const_int32(gallivm, (i&1) + (i&2) * 2 + (i&4) / 2);
583       }
584    }
585 
586    depth_offset2 = LLVMBuildAdd(builder, depth_offset1, depth_stride, "");
587 
588    /* Load current z/stencil values from z/stencil buffer */
589    LLVMTypeRef load_ptr_type = LLVMPointerType(zs_dst_type, 0);
590    LLVMValueRef zs_dst_ptr =
591       LLVMBuildGEP(builder, depth_ptr, &depth_offset1, 1, "");
592    zs_dst_ptr = LLVMBuildBitCast(builder, zs_dst_ptr, load_ptr_type, "");
593    LLVMValueRef zs_dst1 = LLVMBuildLoad2(builder, zs_dst_type, zs_dst_ptr, "");
594    LLVMValueRef zs_dst2;
595    if (is_1d) {
596       zs_dst2 = lp_build_undef(gallivm, zs_load_type);
597    }
598    else {
599       zs_dst_ptr = LLVMBuildGEP(builder, depth_ptr, &depth_offset2, 1, "");
600       zs_dst_ptr = LLVMBuildBitCast(builder, zs_dst_ptr, load_ptr_type, "");
601       zs_dst2 = LLVMBuildLoad2(builder, zs_dst_type, zs_dst_ptr, "");
602    }
603 
604    *z_fb = LLVMBuildShuffleVector(builder, zs_dst1, zs_dst2,
605                                   LLVMConstVector(shuffles, zs_type.length), "");
606    *s_fb = *z_fb;
607 
608    if (format_desc->block.bits == 8) {
609       /* Extend stencil-only 8 bit values (S8_UINT) */
610       *s_fb = LLVMBuildZExt(builder, *s_fb,
611                             lp_build_int_vec_type(gallivm, z_src_type), "");
612    }
613 
614    if (format_desc->block.bits < z_src_type.width) {
615       /* Extend destination ZS values (e.g., when reading from Z16_UNORM) */
616       *z_fb = LLVMBuildZExt(builder, *z_fb,
617                             lp_build_int_vec_type(gallivm, z_src_type), "");
618    }
619 
620    else if (format_desc->block.bits > 32) {
621       /* rely on llvm to handle too wide vector we have here nicely */
622       struct lp_type typex2 = zs_type;
623       struct lp_type s_type = zs_type;
624       LLVMValueRef shuffles1[LP_MAX_VECTOR_LENGTH / 4];
625       LLVMValueRef shuffles2[LP_MAX_VECTOR_LENGTH / 4];
626       LLVMValueRef tmp;
627 
628       typex2.width = typex2.width / 2;
629       typex2.length = typex2.length * 2;
630       s_type.width = s_type.width / 2;
631       s_type.floating = 0;
632 
633       tmp = LLVMBuildBitCast(builder, *z_fb,
634                              lp_build_vec_type(gallivm, typex2), "");
635 
636       for (unsigned i = 0; i < zs_type.length; i++) {
637          shuffles1[i] = lp_build_const_int32(gallivm, i * 2);
638          shuffles2[i] = lp_build_const_int32(gallivm, i * 2 + 1);
639       }
640       *z_fb = LLVMBuildShuffleVector(builder, tmp, tmp,
641                                      LLVMConstVector(shuffles1, zs_type.length), "");
642       *s_fb = LLVMBuildShuffleVector(builder, tmp, tmp,
643                                      LLVMConstVector(shuffles2, zs_type.length), "");
644       *s_fb = LLVMBuildBitCast(builder, *s_fb,
645                                lp_build_vec_type(gallivm, s_type), "");
646       lp_build_name(*s_fb, "s_dst");
647    }
648 
649    lp_build_name(*z_fb, "z_dst");
650    lp_build_name(*s_fb, "s_dst");
651    lp_build_name(*z_fb, "z_dst");
652 }
653 
654 
655 /**
656  * Store depth/stencil values.
657  * Incoming values are swizzled (typically n 2x2 quads), stored linear.
658  * If there's a mask it will do select/store otherwise just store.
659  *
660  * \param type  the data type of the fragment depth/stencil values
661  * \param format_desc  description of the depth/stencil surface
662  * \param is_1d  whether this resource has only one dimension
663  * \param mask_value the alive/dead pixel mask for the quad (vector)
664  * \param z_fb  z values read from fb (with padding)
665  * \param s_fb  s values read from fb (with padding)
666  * \param loop_counter  the current loop iteration
667  * \param depth_ptr  pointer to the depth/stencil values of this 4x4 block
668  * \param depth_stride  stride of the depth/stencil buffer
669  * \param z_value the depth values to store (with padding)
670  * \param s_value the stencil values to store (with padding)
671  */
672 void
lp_build_depth_stencil_write_swizzled(struct gallivm_state * gallivm,struct lp_type z_src_type,const struct util_format_description * format_desc,boolean is_1d,LLVMValueRef mask_value,LLVMValueRef z_fb,LLVMValueRef s_fb,LLVMValueRef loop_counter,LLVMValueRef depth_ptr,LLVMValueRef depth_stride,LLVMValueRef z_value,LLVMValueRef s_value)673 lp_build_depth_stencil_write_swizzled(struct gallivm_state *gallivm,
674                                       struct lp_type z_src_type,
675                                       const struct util_format_description *format_desc,
676                                       boolean is_1d,
677                                       LLVMValueRef mask_value,
678                                       LLVMValueRef z_fb,
679                                       LLVMValueRef s_fb,
680                                       LLVMValueRef loop_counter,
681                                       LLVMValueRef depth_ptr,
682                                       LLVMValueRef depth_stride,
683                                       LLVMValueRef z_value,
684                                       LLVMValueRef s_value)
685 {
686    struct lp_build_context z_bld;
687    LLVMValueRef shuffles[LP_MAX_VECTOR_LENGTH / 4];
688    LLVMBuilderRef builder = gallivm->builder;
689    LLVMValueRef zs_dst1, zs_dst2;
690    LLVMValueRef zs_dst_ptr1, zs_dst_ptr2;
691    LLVMValueRef depth_offset1, depth_offset2;
692    LLVMTypeRef load_ptr_type;
693    unsigned depth_bytes = format_desc->block.bits / 8;
694    struct lp_type zs_type = lp_depth_type(format_desc, z_src_type.length);
695    struct lp_type z_type = zs_type;
696    struct lp_type zs_load_type = zs_type;
697 
698    zs_load_type.length = zs_load_type.length / 2;
699    load_ptr_type = LLVMPointerType(lp_build_vec_type(gallivm, zs_load_type), 0);
700 
701    z_type.width = z_src_type.width;
702 
703    lp_build_context_init(&z_bld, gallivm, z_type);
704 
705    /*
706     * This is far from ideal, at least for late depth write we should do this
707     * outside the fs loop to avoid all the swizzle stuff.
708     */
709    if (z_src_type.length == 4) {
710       LLVMValueRef looplsb = LLVMBuildAnd(builder, loop_counter,
711                                           lp_build_const_int32(gallivm, 1), "");
712       LLVMValueRef loopmsb = LLVMBuildAnd(builder, loop_counter,
713                                           lp_build_const_int32(gallivm, 2), "");
714       LLVMValueRef offset2 = LLVMBuildMul(builder, loopmsb,
715                                           depth_stride, "");
716       depth_offset1 = LLVMBuildMul(builder, looplsb,
717                                    lp_build_const_int32(gallivm, depth_bytes * 2), "");
718       depth_offset1 = LLVMBuildAdd(builder, depth_offset1, offset2, "");
719    }
720    else {
721       LLVMValueRef loopx2 = LLVMBuildShl(builder, loop_counter,
722                                          lp_build_const_int32(gallivm, 1), "");
723       assert(z_src_type.length == 8);
724       depth_offset1 = LLVMBuildMul(builder, loopx2, depth_stride, "");
725       /*
726        * We load 2x4 values, and need to swizzle them (order
727        * 0,1,4,5,2,3,6,7) - not so hot with avx unfortunately.
728        */
729       for (unsigned i = 0; i < 8; i++) {
730          shuffles[i] = lp_build_const_int32(gallivm, (i&1) + (i&2) * 2 + (i&4) / 2);
731       }
732    }
733 
734    depth_offset2 = LLVMBuildAdd(builder, depth_offset1, depth_stride, "");
735 
736    zs_dst_ptr1 = LLVMBuildGEP(builder, depth_ptr, &depth_offset1, 1, "");
737    zs_dst_ptr1 = LLVMBuildBitCast(builder, zs_dst_ptr1, load_ptr_type, "");
738    zs_dst_ptr2 = LLVMBuildGEP(builder, depth_ptr, &depth_offset2, 1, "");
739    zs_dst_ptr2 = LLVMBuildBitCast(builder, zs_dst_ptr2, load_ptr_type, "");
740 
741    if (format_desc->block.bits > 32) {
742       s_value = LLVMBuildBitCast(builder, s_value, z_bld.vec_type, "");
743    }
744 
745    if (mask_value) {
746       z_value = lp_build_select(&z_bld, mask_value, z_value, z_fb);
747       if (format_desc->block.bits > 32) {
748          s_fb = LLVMBuildBitCast(builder, s_fb, z_bld.vec_type, "");
749          s_value = lp_build_select(&z_bld, mask_value, s_value, s_fb);
750       }
751    }
752 
753    if (zs_type.width < z_src_type.width) {
754       /* Truncate ZS values (e.g., when writing to Z16_UNORM) */
755       z_value = LLVMBuildTrunc(builder, z_value,
756                                lp_build_int_vec_type(gallivm, zs_type), "");
757    }
758 
759    if (format_desc->block.bits <= 32) {
760       if (z_src_type.length == 4) {
761          zs_dst1 = lp_build_extract_range(gallivm, z_value, 0, 2);
762          zs_dst2 = lp_build_extract_range(gallivm, z_value, 2, 2);
763       }
764       else {
765          assert(z_src_type.length == 8);
766          zs_dst1 = LLVMBuildShuffleVector(builder, z_value, z_value,
767                                           LLVMConstVector(&shuffles[0],
768                                                           zs_load_type.length), "");
769          zs_dst2 = LLVMBuildShuffleVector(builder, z_value, z_value,
770                                           LLVMConstVector(&shuffles[4],
771                                                           zs_load_type.length), "");
772       }
773    }
774    else {
775       if (z_src_type.length == 4) {
776          zs_dst1 = lp_build_interleave2(gallivm, z_type,
777                                         z_value, s_value, 0);
778          zs_dst2 = lp_build_interleave2(gallivm, z_type,
779                                         z_value, s_value, 1);
780       }
781       else {
782          LLVMValueRef shuffles[LP_MAX_VECTOR_LENGTH / 2];
783          assert(z_src_type.length == 8);
784          for (unsigned i = 0; i < 8; i++) {
785             shuffles[i*2] = lp_build_const_int32(gallivm, (i&1) + (i&2) * 2 + (i&4) / 2);
786             shuffles[i*2+1] = lp_build_const_int32(gallivm, (i&1) + (i&2) * 2 + (i&4) / 2 +
787                                                    z_src_type.length);
788          }
789          zs_dst1 = LLVMBuildShuffleVector(builder, z_value, s_value,
790                                           LLVMConstVector(&shuffles[0],
791                                                           z_src_type.length), "");
792          zs_dst2 = LLVMBuildShuffleVector(builder, z_value, s_value,
793                                           LLVMConstVector(&shuffles[8],
794                                                           z_src_type.length), "");
795       }
796       zs_dst1 = LLVMBuildBitCast(builder, zs_dst1,
797                                  lp_build_vec_type(gallivm, zs_load_type), "");
798       zs_dst2 = LLVMBuildBitCast(builder, zs_dst2,
799                                  lp_build_vec_type(gallivm, zs_load_type), "");
800    }
801 
802    LLVMBuildStore(builder, zs_dst1, zs_dst_ptr1);
803    if (!is_1d) {
804       LLVMBuildStore(builder, zs_dst2, zs_dst_ptr2);
805    }
806 }
807 
808 
809 /**
810  * Generate code for performing depth and/or stencil tests.
811  * We operate on a vector of values (typically n 2x2 quads).
812  *
813  * \param depth  the depth test state
814  * \param stencil  the front/back stencil state
815  * \param type  the data type of the fragment depth/stencil values
816  * \param format_desc  description of the depth/stencil surface
817  * \param mask  the alive/dead pixel mask for the quad (vector)
818  * \param cov_mask coverage mask
819  * \param stencil_refs  the front/back stencil ref values (scalar)
820  * \param z_src  the incoming depth/stencil values (n 2x2 quad values, float32)
821  * \param zs_dst  the depth/stencil values in framebuffer
822  * \param face  contains boolean value indicating front/back facing polygon
823  */
824 void
lp_build_depth_stencil_test(struct gallivm_state * gallivm,const struct lp_depth_state * depth,const struct pipe_stencil_state stencil[2],struct lp_type z_src_type,const struct util_format_description * format_desc,struct lp_build_mask_context * mask,LLVMValueRef * cov_mask,LLVMValueRef stencil_refs[2],LLVMValueRef z_src,LLVMValueRef z_fb,LLVMValueRef s_fb,LLVMValueRef face,LLVMValueRef * z_value,LLVMValueRef * s_value,boolean do_branch,bool restrict_depth)825 lp_build_depth_stencil_test(struct gallivm_state *gallivm,
826                             const struct lp_depth_state *depth,
827                             const struct pipe_stencil_state stencil[2],
828                             struct lp_type z_src_type,
829                             const struct util_format_description *format_desc,
830                             struct lp_build_mask_context *mask,
831                             LLVMValueRef *cov_mask,
832                             LLVMValueRef stencil_refs[2],
833                             LLVMValueRef z_src,
834                             LLVMValueRef z_fb,
835                             LLVMValueRef s_fb,
836                             LLVMValueRef face,
837                             LLVMValueRef *z_value,
838                             LLVMValueRef *s_value,
839                             boolean do_branch,
840                             bool restrict_depth)
841 {
842    LLVMBuilderRef builder = gallivm->builder;
843    struct lp_type z_type;
844    struct lp_build_context z_bld;
845    struct lp_build_context s_bld;
846    struct lp_type s_type;
847    unsigned z_shift = 0, z_width = 0, z_mask = 0;
848    LLVMValueRef z_dst = NULL;
849    LLVMValueRef stencil_vals = NULL;
850    LLVMValueRef z_bitmask = NULL, stencil_shift = NULL;
851    LLVMValueRef z_pass = NULL, s_pass_mask = NULL;
852    LLVMValueRef current_mask = mask ? lp_build_mask_value(mask) : *cov_mask;
853    LLVMValueRef front_facing = NULL;
854    boolean have_z, have_s;
855 
856    /*
857     * Depths are expected to be between 0 and 1, even if they are stored in
858     * floats. Setting these bits here will ensure that the lp_build_conv() call
859     * below won't try to unnecessarily clamp the incoming values.
860     * If depths are expected outside 0..1 don't set these bits.
861     */
862    if (z_src_type.floating) {
863       if (restrict_depth) {
864          z_src_type.sign = FALSE;
865          z_src_type.norm = TRUE;
866       }
867    }
868    else {
869       assert(!z_src_type.sign);
870       assert(z_src_type.norm);
871    }
872 
873    /* Pick the type matching the depth-stencil format. */
874    z_type = lp_depth_type(format_desc, z_src_type.length);
875 
876    /* Pick the intermediate type for depth operations. */
877    z_type.width = z_src_type.width;
878    assert(z_type.length == z_src_type.length);
879 
880    /* FIXME: for non-float depth/stencil might generate better code
881     * if we'd always split it up to use 128bit operations.
882     * For stencil we'd almost certainly want to pack to 8xi16 values,
883     * for z just run twice.
884     */
885 
886    /* Sanity checking */
887    {
888       ASSERTED const unsigned z_swizzle = format_desc->swizzle[0];
889       ASSERTED const unsigned s_swizzle = format_desc->swizzle[1];
890 
891       assert(z_swizzle != PIPE_SWIZZLE_NONE ||
892              s_swizzle != PIPE_SWIZZLE_NONE);
893 
894       assert(depth->enabled || stencil[0].enabled);
895 
896       assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS);
897       assert(format_desc->block.width == 1);
898       assert(format_desc->block.height == 1);
899 
900       if (stencil[0].enabled) {
901          assert(s_swizzle < 4);
902          assert(format_desc->channel[s_swizzle].type == UTIL_FORMAT_TYPE_UNSIGNED);
903          assert(format_desc->channel[s_swizzle].pure_integer);
904          assert(!format_desc->channel[s_swizzle].normalized);
905          assert(format_desc->channel[s_swizzle].size == 8);
906       }
907 
908       if (depth->enabled) {
909          assert(z_swizzle < 4);
910          if (z_type.floating) {
911             assert(z_swizzle == 0);
912             assert(format_desc->channel[z_swizzle].type ==
913                    UTIL_FORMAT_TYPE_FLOAT);
914             assert(format_desc->channel[z_swizzle].size == 32);
915          }
916          else {
917             assert(format_desc->channel[z_swizzle].type ==
918                    UTIL_FORMAT_TYPE_UNSIGNED);
919             assert(format_desc->channel[z_swizzle].normalized);
920             assert(!z_type.fixed);
921          }
922       }
923    }
924 
925 
926    /* Setup build context for Z vals */
927    lp_build_context_init(&z_bld, gallivm, z_type);
928 
929    /* Setup build context for stencil vals */
930    s_type = lp_int_type(z_type);
931    lp_build_context_init(&s_bld, gallivm, s_type);
932 
933    /* Compute and apply the Z/stencil bitmasks and shifts.
934     */
935    {
936       unsigned s_shift, s_mask;
937 
938       z_dst = z_fb;
939       stencil_vals = s_fb;
940 
941       have_z = get_z_shift_and_mask(format_desc, &z_shift, &z_width, &z_mask);
942       have_s = get_s_shift_and_mask(format_desc, &s_shift, &s_mask);
943 
944       if (have_z) {
945          if (z_mask != 0xffffffff) {
946             z_bitmask = lp_build_const_int_vec(gallivm, z_type, z_mask);
947          }
948 
949          /*
950           * Align the framebuffer Z 's LSB to the right.
951           */
952          if (z_shift) {
953             LLVMValueRef shift = lp_build_const_int_vec(gallivm, z_type, z_shift);
954             z_dst = LLVMBuildLShr(builder, z_dst, shift, "z_dst");
955          } else if (z_bitmask) {
956             z_dst = LLVMBuildAnd(builder, z_dst, z_bitmask, "z_dst");
957          } else {
958             lp_build_name(z_dst, "z_dst");
959          }
960       }
961 
962       if (have_s) {
963          if (s_shift) {
964             LLVMValueRef shift = lp_build_const_int_vec(gallivm, s_type, s_shift);
965             stencil_vals = LLVMBuildLShr(builder, stencil_vals, shift, "");
966             stencil_shift = shift;  /* used below */
967          }
968 
969          if (s_mask != 0xffffffff) {
970             LLVMValueRef mask = lp_build_const_int_vec(gallivm, s_type, s_mask);
971             stencil_vals = LLVMBuildAnd(builder, stencil_vals, mask, "");
972          }
973 
974          lp_build_name(stencil_vals, "s_dst");
975       }
976    }
977 
978    if (stencil[0].enabled) {
979 
980       if (face) {
981          if (0) {
982             /*
983              * XXX: the scalar expansion below produces atrocious code
984              * (basically producing a 64bit scalar value, then moving the 2
985              * 32bit pieces separately to simd, plus 4 shuffles, which is
986              * seriously lame). But the scalar-simd transitions are always
987              * tricky, so no big surprise there.
988              * This here would be way better, however llvm has some serious
989              * trouble later using it in the select, probably because it will
990              * recognize the expression as constant and move the simd value
991              * away (out of the loop) - and then it will suddenly try
992              * constructing i1 high-bit masks out of it later...
993              * (Try piglit stencil-twoside.)
994              * Note this is NOT due to using SExt/Trunc, it fails exactly the
995              * same even when using native compare/select.
996              * I cannot reproduce this problem when using stand-alone compiler
997              * though, suggesting some problem with optimization passes...
998              * (With stand-alone compilation, the construction of this mask
999              * value, no matter if the easy 3 instruction here or the complex
1000              * 16+ one below, never gets separated from where it's used.)
1001              * The scalar code still has the same problem, but the generated
1002              * code looks a bit better at least for some reason, even if
1003              * mostly by luck (the fundamental issue clearly is the same).
1004              */
1005             front_facing = lp_build_broadcast(gallivm, s_bld.vec_type, face);
1006             /* front_facing = face != 0 ? ~0 : 0 */
1007             front_facing = lp_build_compare(gallivm, s_bld.type,
1008                                             PIPE_FUNC_NOTEQUAL,
1009                                             front_facing, s_bld.zero);
1010          } else {
1011             LLVMValueRef zero = lp_build_const_int32(gallivm, 0);
1012 
1013             /* front_facing = face != 0 ? ~0 : 0 */
1014             front_facing = LLVMBuildICmp(builder, LLVMIntNE, face, zero, "");
1015             front_facing = LLVMBuildSExt(builder, front_facing,
1016                                          LLVMIntTypeInContext(gallivm->context,
1017                                                 s_bld.type.length*s_bld.type.width),
1018                                          "");
1019             front_facing = LLVMBuildBitCast(builder, front_facing,
1020                                             s_bld.int_vec_type, "");
1021 
1022          }
1023       }
1024 
1025       s_pass_mask = lp_build_stencil_test(&s_bld, stencil,
1026                                           stencil_refs, stencil_vals,
1027                                           front_facing);
1028 
1029       /* apply stencil-fail operator */
1030       {
1031          LLVMValueRef s_fail_mask = lp_build_andnot(&s_bld, current_mask, s_pass_mask);
1032          stencil_vals = lp_build_stencil_op(&s_bld, stencil, S_FAIL_OP,
1033                                             stencil_refs, stencil_vals,
1034                                             s_fail_mask, front_facing);
1035       }
1036    }
1037 
1038    if (depth->enabled) {
1039       /*
1040        * Convert fragment Z to the desired type, aligning the LSB to the right.
1041        */
1042 
1043       assert(z_type.width == z_src_type.width);
1044       assert(z_type.length == z_src_type.length);
1045       assert(lp_check_value(z_src_type, z_src));
1046       if (z_src_type.floating) {
1047          /*
1048           * Convert from floating point values
1049           */
1050 
1051          if (!z_type.floating) {
1052             z_src = lp_build_clamped_float_to_unsigned_norm(gallivm,
1053                                                             z_src_type,
1054                                                             z_width,
1055                                                             z_src);
1056          }
1057       } else {
1058          /*
1059           * Convert from unsigned normalized values.
1060           */
1061 
1062          assert(!z_src_type.sign);
1063          assert(!z_src_type.fixed);
1064          assert(z_src_type.norm);
1065          assert(!z_type.floating);
1066          if (z_src_type.width > z_width) {
1067             LLVMValueRef shift = lp_build_const_int_vec(gallivm, z_src_type,
1068                                                         z_src_type.width - z_width);
1069             z_src = LLVMBuildLShr(builder, z_src, shift, "");
1070          }
1071       }
1072       assert(lp_check_value(z_type, z_src));
1073 
1074       lp_build_name(z_src, "z_src");
1075 
1076       /* compare src Z to dst Z, returning 'pass' mask */
1077       z_pass = lp_build_cmp(&z_bld, depth->func, z_src, z_dst);
1078 
1079       /* mask off bits that failed stencil test */
1080       if (s_pass_mask) {
1081          current_mask = LLVMBuildAnd(builder, current_mask, s_pass_mask, "");
1082       }
1083 
1084       if (!stencil[0].enabled && mask) {
1085          /* We can potentially skip all remaining operations here, but only
1086           * if stencil is disabled because we still need to update the stencil
1087           * buffer values.  Don't need to update Z buffer values.
1088           */
1089          lp_build_mask_update(mask, z_pass);
1090 
1091          if (do_branch) {
1092             lp_build_mask_check(mask);
1093          }
1094       }
1095 
1096       if (depth->writemask) {
1097          LLVMValueRef z_pass_mask;
1098 
1099          /* mask off bits that failed Z test */
1100          z_pass_mask = LLVMBuildAnd(builder, current_mask, z_pass, "");
1101 
1102          /* Mix the old and new Z buffer values.
1103           * z_dst[i] = zselectmask[i] ? z_src[i] : z_dst[i]
1104           */
1105          z_dst = lp_build_select(&z_bld, z_pass_mask, z_src, z_dst);
1106       }
1107 
1108       if (stencil[0].enabled) {
1109          /* update stencil buffer values according to z pass/fail result */
1110          LLVMValueRef z_fail_mask, z_pass_mask;
1111 
1112          /* apply Z-fail operator */
1113          z_fail_mask = lp_build_andnot(&s_bld, current_mask, z_pass);
1114          stencil_vals = lp_build_stencil_op(&s_bld, stencil, Z_FAIL_OP,
1115                                             stencil_refs, stencil_vals,
1116                                             z_fail_mask, front_facing);
1117 
1118          /* apply Z-pass operator */
1119          z_pass_mask = LLVMBuildAnd(builder, current_mask, z_pass, "");
1120          stencil_vals = lp_build_stencil_op(&s_bld, stencil, Z_PASS_OP,
1121                                             stencil_refs, stencil_vals,
1122                                             z_pass_mask, front_facing);
1123       }
1124    }
1125    else {
1126       /* No depth test: apply Z-pass operator to stencil buffer values which
1127        * passed the stencil test.
1128        */
1129       s_pass_mask = LLVMBuildAnd(builder, current_mask, s_pass_mask, "");
1130       stencil_vals = lp_build_stencil_op(&s_bld, stencil, Z_PASS_OP,
1131                                          stencil_refs, stencil_vals,
1132                                          s_pass_mask, front_facing);
1133    }
1134 
1135    /* Put Z and stencil bits in the right place */
1136    if (have_z && z_shift) {
1137       LLVMValueRef shift = lp_build_const_int_vec(gallivm, z_type, z_shift);
1138       z_dst = LLVMBuildShl(builder, z_dst, shift, "");
1139    }
1140    if (stencil_vals && stencil_shift)
1141       stencil_vals = LLVMBuildShl(builder, stencil_vals,
1142                                   stencil_shift, "");
1143 
1144    /* Finally, merge the z/stencil values */
1145    if (format_desc->block.bits <= 32) {
1146       if (have_z && have_s)
1147          *z_value = LLVMBuildOr(builder, z_dst, stencil_vals, "");
1148       else if (have_z)
1149          *z_value = z_dst;
1150       else
1151          *z_value = stencil_vals;
1152       *s_value = *z_value;
1153    }
1154    else {
1155       *z_value = z_dst;
1156       *s_value = stencil_vals;
1157    }
1158 
1159    if (mask) {
1160       if (s_pass_mask)
1161          lp_build_mask_update(mask, s_pass_mask);
1162 
1163       if (depth->enabled && stencil[0].enabled)
1164          lp_build_mask_update(mask, z_pass);
1165    } else {
1166       LLVMValueRef tmp_mask = *cov_mask;
1167       if (s_pass_mask)
1168          tmp_mask = LLVMBuildAnd(builder, tmp_mask, s_pass_mask, "");
1169 
1170       /* for multisample we don't do the stencil optimisation so update always */
1171       if (depth->enabled)
1172          tmp_mask = LLVMBuildAnd(builder, tmp_mask, z_pass, "");
1173       *cov_mask = tmp_mask;
1174    }
1175 }
1176 
1177