1 /**************************************************************************
2 *
3 * Copyright 2009 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 * Texture sampling -- common code.
31 *
32 * @author Jose Fonseca <jfonseca@vmware.com>
33 */
34
35 #include "pipe/p_defines.h"
36 #include "pipe/p_state.h"
37 #include "util/u_format.h"
38 #include "util/u_math.h"
39 #include "util/u_cpu_detect.h"
40 #include "lp_bld_arit.h"
41 #include "lp_bld_const.h"
42 #include "lp_bld_debug.h"
43 #include "lp_bld_printf.h"
44 #include "lp_bld_flow.h"
45 #include "lp_bld_sample.h"
46 #include "lp_bld_swizzle.h"
47 #include "lp_bld_type.h"
48 #include "lp_bld_logic.h"
49 #include "lp_bld_pack.h"
50 #include "lp_bld_quad.h"
51 #include "lp_bld_bitarit.h"
52
53
54 /*
55 * Bri-linear factor. Should be greater than one.
56 */
57 #define BRILINEAR_FACTOR 2
58
59 /**
60 * Does the given texture wrap mode allow sampling the texture border color?
61 * XXX maybe move this into gallium util code.
62 */
63 boolean
lp_sampler_wrap_mode_uses_border_color(unsigned mode,unsigned min_img_filter,unsigned mag_img_filter)64 lp_sampler_wrap_mode_uses_border_color(unsigned mode,
65 unsigned min_img_filter,
66 unsigned mag_img_filter)
67 {
68 switch (mode) {
69 case PIPE_TEX_WRAP_REPEAT:
70 case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
71 case PIPE_TEX_WRAP_MIRROR_REPEAT:
72 case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
73 return FALSE;
74 case PIPE_TEX_WRAP_CLAMP:
75 case PIPE_TEX_WRAP_MIRROR_CLAMP:
76 if (min_img_filter == PIPE_TEX_FILTER_NEAREST &&
77 mag_img_filter == PIPE_TEX_FILTER_NEAREST) {
78 return FALSE;
79 } else {
80 return TRUE;
81 }
82 case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
83 case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
84 return TRUE;
85 default:
86 assert(0 && "unexpected wrap mode");
87 return FALSE;
88 }
89 }
90
91
92 /**
93 * Initialize lp_sampler_static_texture_state object with the gallium
94 * texture/sampler_view state (this contains the parts which are
95 * considered static).
96 */
97 void
lp_sampler_static_texture_state(struct lp_static_texture_state * state,const struct pipe_sampler_view * view)98 lp_sampler_static_texture_state(struct lp_static_texture_state *state,
99 const struct pipe_sampler_view *view)
100 {
101 const struct pipe_resource *texture;
102
103 memset(state, 0, sizeof *state);
104
105 if (!view || !view->texture)
106 return;
107
108 texture = view->texture;
109
110 state->format = view->format;
111 state->swizzle_r = view->swizzle_r;
112 state->swizzle_g = view->swizzle_g;
113 state->swizzle_b = view->swizzle_b;
114 state->swizzle_a = view->swizzle_a;
115
116 state->target = view->target;
117 state->pot_width = util_is_power_of_two(texture->width0);
118 state->pot_height = util_is_power_of_two(texture->height0);
119 state->pot_depth = util_is_power_of_two(texture->depth0);
120 state->level_zero_only = !view->u.tex.last_level;
121
122 /*
123 * the layer / element / level parameters are all either dynamic
124 * state or handled transparently wrt execution.
125 */
126 }
127
128
129 /**
130 * Initialize lp_sampler_static_sampler_state object with the gallium sampler
131 * state (this contains the parts which are considered static).
132 */
133 void
lp_sampler_static_sampler_state(struct lp_static_sampler_state * state,const struct pipe_sampler_state * sampler)134 lp_sampler_static_sampler_state(struct lp_static_sampler_state *state,
135 const struct pipe_sampler_state *sampler)
136 {
137 memset(state, 0, sizeof *state);
138
139 if (!sampler)
140 return;
141
142 /*
143 * We don't copy sampler state over unless it is actually enabled, to avoid
144 * spurious recompiles, as the sampler static state is part of the shader
145 * key.
146 *
147 * Ideally the state tracker or cso_cache module would make all state
148 * canonical, but until that happens it's better to be safe than sorry here.
149 *
150 * XXX: Actually there's much more than can be done here, especially
151 * regarding 1D/2D/3D/CUBE textures, wrap modes, etc.
152 */
153
154 state->wrap_s = sampler->wrap_s;
155 state->wrap_t = sampler->wrap_t;
156 state->wrap_r = sampler->wrap_r;
157 state->min_img_filter = sampler->min_img_filter;
158 state->mag_img_filter = sampler->mag_img_filter;
159 state->seamless_cube_map = sampler->seamless_cube_map;
160
161 if (sampler->max_lod > 0.0f) {
162 state->min_mip_filter = sampler->min_mip_filter;
163 } else {
164 state->min_mip_filter = PIPE_TEX_MIPFILTER_NONE;
165 }
166
167 if (state->min_mip_filter != PIPE_TEX_MIPFILTER_NONE ||
168 state->min_img_filter != state->mag_img_filter) {
169 if (sampler->lod_bias != 0.0f) {
170 state->lod_bias_non_zero = 1;
171 }
172
173 /* If min_lod == max_lod we can greatly simplify mipmap selection.
174 * This is a case that occurs during automatic mipmap generation.
175 */
176 if (sampler->min_lod == sampler->max_lod) {
177 state->min_max_lod_equal = 1;
178 } else {
179 if (sampler->min_lod > 0.0f) {
180 state->apply_min_lod = 1;
181 }
182
183 /*
184 * XXX this won't do anything with the mesa state tracker which always
185 * sets max_lod to not more than actually present mip maps...
186 */
187 if (sampler->max_lod < (PIPE_MAX_TEXTURE_LEVELS - 1)) {
188 state->apply_max_lod = 1;
189 }
190 }
191 }
192
193 state->compare_mode = sampler->compare_mode;
194 if (sampler->compare_mode != PIPE_TEX_COMPARE_NONE) {
195 state->compare_func = sampler->compare_func;
196 }
197
198 state->normalized_coords = sampler->normalized_coords;
199 }
200
201
202 /**
203 * Generate code to compute coordinate gradient (rho).
204 * \param derivs partial derivatives of (s, t, r, q) with respect to X and Y
205 *
206 * The resulting rho has bld->levelf format (per quad or per element).
207 */
208 static LLVMValueRef
lp_build_rho(struct lp_build_sample_context * bld,unsigned texture_unit,LLVMValueRef s,LLVMValueRef t,LLVMValueRef r,LLVMValueRef cube_rho,const struct lp_derivatives * derivs)209 lp_build_rho(struct lp_build_sample_context *bld,
210 unsigned texture_unit,
211 LLVMValueRef s,
212 LLVMValueRef t,
213 LLVMValueRef r,
214 LLVMValueRef cube_rho,
215 const struct lp_derivatives *derivs)
216 {
217 struct gallivm_state *gallivm = bld->gallivm;
218 struct lp_build_context *int_size_bld = &bld->int_size_in_bld;
219 struct lp_build_context *float_size_bld = &bld->float_size_in_bld;
220 struct lp_build_context *float_bld = &bld->float_bld;
221 struct lp_build_context *coord_bld = &bld->coord_bld;
222 struct lp_build_context *rho_bld = &bld->lodf_bld;
223 const unsigned dims = bld->dims;
224 LLVMValueRef ddx_ddy[2] = {NULL};
225 LLVMBuilderRef builder = bld->gallivm->builder;
226 LLVMTypeRef i32t = LLVMInt32TypeInContext(bld->gallivm->context);
227 LLVMValueRef index0 = LLVMConstInt(i32t, 0, 0);
228 LLVMValueRef index1 = LLVMConstInt(i32t, 1, 0);
229 LLVMValueRef index2 = LLVMConstInt(i32t, 2, 0);
230 LLVMValueRef rho_vec;
231 LLVMValueRef int_size, float_size;
232 LLVMValueRef rho;
233 LLVMValueRef first_level, first_level_vec;
234 unsigned length = coord_bld->type.length;
235 unsigned num_quads = length / 4;
236 boolean rho_per_quad = rho_bld->type.length != length;
237 boolean no_rho_opt = (gallivm_debug & GALLIVM_DEBUG_NO_RHO_APPROX) && (dims > 1);
238 unsigned i;
239 LLVMValueRef i32undef = LLVMGetUndef(LLVMInt32TypeInContext(gallivm->context));
240 LLVMValueRef rho_xvec, rho_yvec;
241
242 /* Note that all simplified calculations will only work for isotropic filtering */
243
244 /*
245 * rho calcs are always per quad except for explicit derivs (excluding
246 * the messy cube maps for now) when requested.
247 */
248
249 first_level = bld->dynamic_state->first_level(bld->dynamic_state, bld->gallivm,
250 bld->context_ptr, texture_unit);
251 first_level_vec = lp_build_broadcast_scalar(int_size_bld, first_level);
252 int_size = lp_build_minify(int_size_bld, bld->int_size, first_level_vec, TRUE);
253 float_size = lp_build_int_to_float(float_size_bld, int_size);
254
255 if (cube_rho) {
256 LLVMValueRef cubesize;
257 LLVMValueRef index0 = lp_build_const_int32(gallivm, 0);
258
259 /*
260 * Cube map code did already everything except size mul and per-quad extraction.
261 * Luckily cube maps are always quadratic!
262 */
263 if (rho_per_quad) {
264 rho = lp_build_pack_aos_scalars(bld->gallivm, coord_bld->type,
265 rho_bld->type, cube_rho, 0);
266 }
267 else {
268 rho = lp_build_swizzle_scalar_aos(coord_bld, cube_rho, 0, 4);
269 }
270 /* Could optimize this for single quad just skip the broadcast */
271 cubesize = lp_build_extract_broadcast(gallivm, bld->float_size_in_type,
272 rho_bld->type, float_size, index0);
273 /* skipping sqrt hence returning rho squared */
274 cubesize = lp_build_mul(rho_bld, cubesize, cubesize);
275 rho = lp_build_mul(rho_bld, cubesize, rho);
276 }
277 else if (derivs) {
278 LLVMValueRef ddmax[3], ddx[3], ddy[3];
279 for (i = 0; i < dims; i++) {
280 LLVMValueRef floatdim;
281 LLVMValueRef indexi = lp_build_const_int32(gallivm, i);
282
283 floatdim = lp_build_extract_broadcast(gallivm, bld->float_size_in_type,
284 coord_bld->type, float_size, indexi);
285
286 /*
287 * note that for rho_per_quad case could reduce math (at some shuffle
288 * cost), but for now use same code to per-pixel lod case.
289 */
290 if (no_rho_opt) {
291 ddx[i] = lp_build_mul(coord_bld, floatdim, derivs->ddx[i]);
292 ddy[i] = lp_build_mul(coord_bld, floatdim, derivs->ddy[i]);
293 ddx[i] = lp_build_mul(coord_bld, ddx[i], ddx[i]);
294 ddy[i] = lp_build_mul(coord_bld, ddy[i], ddy[i]);
295 }
296 else {
297 LLVMValueRef tmpx, tmpy;
298 tmpx = lp_build_abs(coord_bld, derivs->ddx[i]);
299 tmpy = lp_build_abs(coord_bld, derivs->ddy[i]);
300 ddmax[i] = lp_build_max(coord_bld, tmpx, tmpy);
301 ddmax[i] = lp_build_mul(coord_bld, floatdim, ddmax[i]);
302 }
303 }
304 if (no_rho_opt) {
305 rho_xvec = lp_build_add(coord_bld, ddx[0], ddx[1]);
306 rho_yvec = lp_build_add(coord_bld, ddy[0], ddy[1]);
307 if (dims > 2) {
308 rho_xvec = lp_build_add(coord_bld, rho_xvec, ddx[2]);
309 rho_yvec = lp_build_add(coord_bld, rho_yvec, ddy[2]);
310 }
311 rho = lp_build_max(coord_bld, rho_xvec, rho_yvec);
312 /* skipping sqrt hence returning rho squared */
313 }
314 else {
315 rho = ddmax[0];
316 if (dims > 1) {
317 rho = lp_build_max(coord_bld, rho, ddmax[1]);
318 if (dims > 2) {
319 rho = lp_build_max(coord_bld, rho, ddmax[2]);
320 }
321 }
322 }
323 if (rho_per_quad) {
324 /*
325 * rho_vec contains per-pixel rho, convert to scalar per quad.
326 */
327 rho = lp_build_pack_aos_scalars(bld->gallivm, coord_bld->type,
328 rho_bld->type, rho, 0);
329 }
330 }
331 else {
332 /*
333 * This looks all a bit complex, but it's not that bad
334 * (the shuffle code makes it look worse than it is).
335 * Still, might not be ideal for all cases.
336 */
337 static const unsigned char swizzle0[] = { /* no-op swizzle */
338 0, LP_BLD_SWIZZLE_DONTCARE,
339 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
340 };
341 static const unsigned char swizzle1[] = {
342 1, LP_BLD_SWIZZLE_DONTCARE,
343 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
344 };
345 static const unsigned char swizzle2[] = {
346 2, LP_BLD_SWIZZLE_DONTCARE,
347 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
348 };
349
350 if (dims < 2) {
351 ddx_ddy[0] = lp_build_packed_ddx_ddy_onecoord(coord_bld, s);
352 }
353 else if (dims >= 2) {
354 ddx_ddy[0] = lp_build_packed_ddx_ddy_twocoord(coord_bld, s, t);
355 if (dims > 2) {
356 ddx_ddy[1] = lp_build_packed_ddx_ddy_onecoord(coord_bld, r);
357 }
358 }
359
360 if (no_rho_opt) {
361 static const unsigned char swizzle01[] = { /* no-op swizzle */
362 0, 1,
363 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
364 };
365 static const unsigned char swizzle23[] = {
366 2, 3,
367 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
368 };
369 LLVMValueRef ddx_ddys, ddx_ddyt, floatdim, shuffles[LP_MAX_VECTOR_LENGTH / 4];
370
371 for (i = 0; i < num_quads; i++) {
372 shuffles[i*4+0] = shuffles[i*4+1] = index0;
373 shuffles[i*4+2] = shuffles[i*4+3] = index1;
374 }
375 floatdim = LLVMBuildShuffleVector(builder, float_size, float_size,
376 LLVMConstVector(shuffles, length), "");
377 ddx_ddy[0] = lp_build_mul(coord_bld, ddx_ddy[0], floatdim);
378 ddx_ddy[0] = lp_build_mul(coord_bld, ddx_ddy[0], ddx_ddy[0]);
379 ddx_ddys = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle01);
380 ddx_ddyt = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle23);
381 rho_vec = lp_build_add(coord_bld, ddx_ddys, ddx_ddyt);
382
383 if (dims > 2) {
384 static const unsigned char swizzle02[] = {
385 0, 2,
386 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
387 };
388 floatdim = lp_build_extract_broadcast(gallivm, bld->float_size_in_type,
389 coord_bld->type, float_size, index2);
390 ddx_ddy[1] = lp_build_mul(coord_bld, ddx_ddy[1], floatdim);
391 ddx_ddy[1] = lp_build_mul(coord_bld, ddx_ddy[1], ddx_ddy[1]);
392 ddx_ddy[1] = lp_build_swizzle_aos(coord_bld, ddx_ddy[1], swizzle02);
393 rho_vec = lp_build_add(coord_bld, rho_vec, ddx_ddy[1]);
394 }
395
396 rho_xvec = lp_build_swizzle_aos(coord_bld, rho_vec, swizzle0);
397 rho_yvec = lp_build_swizzle_aos(coord_bld, rho_vec, swizzle1);
398 rho = lp_build_max(coord_bld, rho_xvec, rho_yvec);
399
400 if (rho_per_quad) {
401 rho = lp_build_pack_aos_scalars(bld->gallivm, coord_bld->type,
402 rho_bld->type, rho, 0);
403 }
404 else {
405 rho = lp_build_swizzle_scalar_aos(coord_bld, rho, 0, 4);
406 }
407 /* skipping sqrt hence returning rho squared */
408 }
409 else {
410 ddx_ddy[0] = lp_build_abs(coord_bld, ddx_ddy[0]);
411 if (dims > 2) {
412 ddx_ddy[1] = lp_build_abs(coord_bld, ddx_ddy[1]);
413 }
414 else {
415 ddx_ddy[1] = NULL; /* silence compiler warning */
416 }
417
418 if (dims < 2) {
419 rho_xvec = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle0);
420 rho_yvec = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle2);
421 }
422 else if (dims == 2) {
423 static const unsigned char swizzle02[] = {
424 0, 2,
425 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
426 };
427 static const unsigned char swizzle13[] = {
428 1, 3,
429 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
430 };
431 rho_xvec = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle02);
432 rho_yvec = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle13);
433 }
434 else {
435 LLVMValueRef shuffles1[LP_MAX_VECTOR_LENGTH];
436 LLVMValueRef shuffles2[LP_MAX_VECTOR_LENGTH];
437 assert(dims == 3);
438 for (i = 0; i < num_quads; i++) {
439 shuffles1[4*i + 0] = lp_build_const_int32(gallivm, 4*i);
440 shuffles1[4*i + 1] = lp_build_const_int32(gallivm, 4*i + 2);
441 shuffles1[4*i + 2] = lp_build_const_int32(gallivm, length + 4*i);
442 shuffles1[4*i + 3] = i32undef;
443 shuffles2[4*i + 0] = lp_build_const_int32(gallivm, 4*i + 1);
444 shuffles2[4*i + 1] = lp_build_const_int32(gallivm, 4*i + 3);
445 shuffles2[4*i + 2] = lp_build_const_int32(gallivm, length + 4*i + 2);
446 shuffles2[4*i + 3] = i32undef;
447 }
448 rho_xvec = LLVMBuildShuffleVector(builder, ddx_ddy[0], ddx_ddy[1],
449 LLVMConstVector(shuffles1, length), "");
450 rho_yvec = LLVMBuildShuffleVector(builder, ddx_ddy[0], ddx_ddy[1],
451 LLVMConstVector(shuffles2, length), "");
452 }
453
454 rho_vec = lp_build_max(coord_bld, rho_xvec, rho_yvec);
455
456 if (bld->coord_type.length > 4) {
457 /* expand size to each quad */
458 if (dims > 1) {
459 /* could use some broadcast_vector helper for this? */
460 LLVMValueRef src[LP_MAX_VECTOR_LENGTH/4];
461 for (i = 0; i < num_quads; i++) {
462 src[i] = float_size;
463 }
464 float_size = lp_build_concat(bld->gallivm, src, float_size_bld->type, num_quads);
465 }
466 else {
467 float_size = lp_build_broadcast_scalar(coord_bld, float_size);
468 }
469 rho_vec = lp_build_mul(coord_bld, rho_vec, float_size);
470
471 if (dims <= 1) {
472 rho = rho_vec;
473 }
474 else {
475 if (dims >= 2) {
476 LLVMValueRef rho_s, rho_t, rho_r;
477
478 rho_s = lp_build_swizzle_aos(coord_bld, rho_vec, swizzle0);
479 rho_t = lp_build_swizzle_aos(coord_bld, rho_vec, swizzle1);
480
481 rho = lp_build_max(coord_bld, rho_s, rho_t);
482
483 if (dims >= 3) {
484 rho_r = lp_build_swizzle_aos(coord_bld, rho_vec, swizzle2);
485 rho = lp_build_max(coord_bld, rho, rho_r);
486 }
487 }
488 }
489 if (rho_per_quad) {
490 rho = lp_build_pack_aos_scalars(bld->gallivm, coord_bld->type,
491 rho_bld->type, rho, 0);
492 }
493 else {
494 rho = lp_build_swizzle_scalar_aos(coord_bld, rho, 0, 4);
495 }
496 }
497 else {
498 if (dims <= 1) {
499 rho_vec = LLVMBuildExtractElement(builder, rho_vec, index0, "");
500 }
501 rho_vec = lp_build_mul(float_size_bld, rho_vec, float_size);
502
503 if (dims <= 1) {
504 rho = rho_vec;
505 }
506 else {
507 if (dims >= 2) {
508 LLVMValueRef rho_s, rho_t, rho_r;
509
510 rho_s = LLVMBuildExtractElement(builder, rho_vec, index0, "");
511 rho_t = LLVMBuildExtractElement(builder, rho_vec, index1, "");
512
513 rho = lp_build_max(float_bld, rho_s, rho_t);
514
515 if (dims >= 3) {
516 rho_r = LLVMBuildExtractElement(builder, rho_vec, index2, "");
517 rho = lp_build_max(float_bld, rho, rho_r);
518 }
519 }
520 }
521 if (!rho_per_quad) {
522 rho = lp_build_broadcast_scalar(rho_bld, rho);
523 }
524 }
525 }
526 }
527
528 return rho;
529 }
530
531
532 /*
533 * Bri-linear lod computation
534 *
535 * Use a piece-wise linear approximation of log2 such that:
536 * - round to nearest, for values in the neighborhood of -1, 0, 1, 2, etc.
537 * - linear approximation for values in the neighborhood of 0.5, 1.5., etc,
538 * with the steepness specified in 'factor'
539 * - exact result for 0.5, 1.5, etc.
540 *
541 *
542 * 1.0 - /----*
543 * /
544 * /
545 * /
546 * 0.5 - *
547 * /
548 * /
549 * /
550 * 0.0 - *----/
551 *
552 * | |
553 * 2^0 2^1
554 *
555 * This is a technique also commonly used in hardware:
556 * - http://ixbtlabs.com/articles2/gffx/nv40-rx800-3.html
557 *
558 * TODO: For correctness, this should only be applied when texture is known to
559 * have regular mipmaps, i.e., mipmaps derived from the base level.
560 *
561 * TODO: This could be done in fixed point, where applicable.
562 */
563 static void
lp_build_brilinear_lod(struct lp_build_context * bld,LLVMValueRef lod,double factor,LLVMValueRef * out_lod_ipart,LLVMValueRef * out_lod_fpart)564 lp_build_brilinear_lod(struct lp_build_context *bld,
565 LLVMValueRef lod,
566 double factor,
567 LLVMValueRef *out_lod_ipart,
568 LLVMValueRef *out_lod_fpart)
569 {
570 LLVMValueRef lod_fpart;
571 double pre_offset = (factor - 0.5)/factor - 0.5;
572 double post_offset = 1 - factor;
573
574 if (0) {
575 lp_build_printf(bld->gallivm, "lod = %f\n", lod);
576 }
577
578 lod = lp_build_add(bld, lod,
579 lp_build_const_vec(bld->gallivm, bld->type, pre_offset));
580
581 lp_build_ifloor_fract(bld, lod, out_lod_ipart, &lod_fpart);
582
583 lod_fpart = lp_build_mad(bld, lod_fpart,
584 lp_build_const_vec(bld->gallivm, bld->type, factor),
585 lp_build_const_vec(bld->gallivm, bld->type, post_offset));
586
587 /*
588 * It's not necessary to clamp lod_fpart since:
589 * - the above expression will never produce numbers greater than one.
590 * - the mip filtering branch is only taken if lod_fpart is positive
591 */
592
593 *out_lod_fpart = lod_fpart;
594
595 if (0) {
596 lp_build_printf(bld->gallivm, "lod_ipart = %i\n", *out_lod_ipart);
597 lp_build_printf(bld->gallivm, "lod_fpart = %f\n\n", *out_lod_fpart);
598 }
599 }
600
601
602 /*
603 * Combined log2 and brilinear lod computation.
604 *
605 * It's in all identical to calling lp_build_fast_log2() and
606 * lp_build_brilinear_lod() above, but by combining we can compute the integer
607 * and fractional part independently.
608 */
609 static void
lp_build_brilinear_rho(struct lp_build_context * bld,LLVMValueRef rho,double factor,LLVMValueRef * out_lod_ipart,LLVMValueRef * out_lod_fpart)610 lp_build_brilinear_rho(struct lp_build_context *bld,
611 LLVMValueRef rho,
612 double factor,
613 LLVMValueRef *out_lod_ipart,
614 LLVMValueRef *out_lod_fpart)
615 {
616 LLVMValueRef lod_ipart;
617 LLVMValueRef lod_fpart;
618
619 const double pre_factor = (2*factor - 0.5)/(M_SQRT2*factor);
620 const double post_offset = 1 - 2*factor;
621
622 assert(bld->type.floating);
623
624 assert(lp_check_value(bld->type, rho));
625
626 /*
627 * The pre factor will make the intersections with the exact powers of two
628 * happen precisely where we want them to be, which means that the integer
629 * part will not need any post adjustments.
630 */
631 rho = lp_build_mul(bld, rho,
632 lp_build_const_vec(bld->gallivm, bld->type, pre_factor));
633
634 /* ipart = ifloor(log2(rho)) */
635 lod_ipart = lp_build_extract_exponent(bld, rho, 0);
636
637 /* fpart = rho / 2**ipart */
638 lod_fpart = lp_build_extract_mantissa(bld, rho);
639
640 lod_fpart = lp_build_mad(bld, lod_fpart,
641 lp_build_const_vec(bld->gallivm, bld->type, factor),
642 lp_build_const_vec(bld->gallivm, bld->type, post_offset));
643
644 /*
645 * Like lp_build_brilinear_lod, it's not necessary to clamp lod_fpart since:
646 * - the above expression will never produce numbers greater than one.
647 * - the mip filtering branch is only taken if lod_fpart is positive
648 */
649
650 *out_lod_ipart = lod_ipart;
651 *out_lod_fpart = lod_fpart;
652 }
653
654
655 /**
656 * Fast implementation of iround(log2(sqrt(x))), based on
657 * log2(x^n) == n*log2(x).
658 *
659 * Gives accurate results all the time.
660 * (Could be trivially extended to handle other power-of-two roots.)
661 */
662 static LLVMValueRef
lp_build_ilog2_sqrt(struct lp_build_context * bld,LLVMValueRef x)663 lp_build_ilog2_sqrt(struct lp_build_context *bld,
664 LLVMValueRef x)
665 {
666 LLVMBuilderRef builder = bld->gallivm->builder;
667 LLVMValueRef ipart;
668 struct lp_type i_type = lp_int_type(bld->type);
669 LLVMValueRef one = lp_build_const_int_vec(bld->gallivm, i_type, 1);
670
671 assert(bld->type.floating);
672
673 assert(lp_check_value(bld->type, x));
674
675 /* ipart = log2(x) + 0.5 = 0.5*(log2(x^2) + 1.0) */
676 ipart = lp_build_extract_exponent(bld, x, 1);
677 ipart = LLVMBuildAShr(builder, ipart, one, "");
678
679 return ipart;
680 }
681
682
683 /**
684 * Generate code to compute texture level of detail (lambda).
685 * \param derivs partial derivatives of (s, t, r, q) with respect to X and Y
686 * \param lod_bias optional float vector with the shader lod bias
687 * \param explicit_lod optional float vector with the explicit lod
688 * \param cube_rho rho calculated by cube coord mapping (optional)
689 * \param out_lod_ipart integer part of lod
690 * \param out_lod_fpart float part of lod (never larger than 1 but may be negative)
691 * \param out_lod_positive (mask) if lod is positive (i.e. texture is minified)
692 *
693 * The resulting lod can be scalar per quad or be per element.
694 */
695 void
lp_build_lod_selector(struct lp_build_sample_context * bld,unsigned texture_unit,unsigned sampler_unit,LLVMValueRef s,LLVMValueRef t,LLVMValueRef r,LLVMValueRef cube_rho,const struct lp_derivatives * derivs,LLVMValueRef lod_bias,LLVMValueRef explicit_lod,unsigned mip_filter,LLVMValueRef * out_lod_ipart,LLVMValueRef * out_lod_fpart,LLVMValueRef * out_lod_positive)696 lp_build_lod_selector(struct lp_build_sample_context *bld,
697 unsigned texture_unit,
698 unsigned sampler_unit,
699 LLVMValueRef s,
700 LLVMValueRef t,
701 LLVMValueRef r,
702 LLVMValueRef cube_rho,
703 const struct lp_derivatives *derivs,
704 LLVMValueRef lod_bias, /* optional */
705 LLVMValueRef explicit_lod, /* optional */
706 unsigned mip_filter,
707 LLVMValueRef *out_lod_ipart,
708 LLVMValueRef *out_lod_fpart,
709 LLVMValueRef *out_lod_positive)
710
711 {
712 LLVMBuilderRef builder = bld->gallivm->builder;
713 struct lp_sampler_dynamic_state *dynamic_state = bld->dynamic_state;
714 struct lp_build_context *lodf_bld = &bld->lodf_bld;
715 LLVMValueRef lod;
716
717 *out_lod_ipart = bld->lodi_bld.zero;
718 *out_lod_positive = bld->lodi_bld.zero;
719 *out_lod_fpart = lodf_bld->zero;
720
721 /*
722 * For determining min/mag, we follow GL 4.1 spec, 3.9.12 Texture Magnification:
723 * "Implementations may either unconditionally assume c = 0 for the minification
724 * vs. magnification switch-over point, or may choose to make c depend on the
725 * combination of minification and magnification modes as follows: if the
726 * magnification filter is given by LINEAR and the minification filter is given
727 * by NEAREST_MIPMAP_NEAREST or NEAREST_MIPMAP_LINEAR, then c = 0.5. This is
728 * done to ensure that a minified texture does not appear "sharper" than a
729 * magnified texture. Otherwise c = 0."
730 * And 3.9.11 Texture Minification:
731 * "If lod is less than or equal to the constant c (see section 3.9.12) the
732 * texture is said to be magnified; if it is greater, the texture is minified."
733 * So, using 0 as switchover point always, and using magnification for lod == 0.
734 * Note that the always c = 0 behavior is new (first appearing in GL 3.1 spec),
735 * old GL versions required 0.5 for the modes listed above.
736 * I have no clue about the (undocumented) wishes of d3d9/d3d10 here!
737 */
738
739 if (bld->static_sampler_state->min_max_lod_equal) {
740 /* User is forcing sampling from a particular mipmap level.
741 * This is hit during mipmap generation.
742 */
743 LLVMValueRef min_lod =
744 dynamic_state->min_lod(dynamic_state, bld->gallivm,
745 bld->context_ptr, sampler_unit);
746
747 lod = lp_build_broadcast_scalar(lodf_bld, min_lod);
748 }
749 else {
750 if (explicit_lod) {
751 if (bld->num_lods != bld->coord_type.length)
752 lod = lp_build_pack_aos_scalars(bld->gallivm, bld->coord_bld.type,
753 lodf_bld->type, explicit_lod, 0);
754 else
755 lod = explicit_lod;
756 }
757 else {
758 LLVMValueRef rho;
759 boolean rho_squared = ((gallivm_debug & GALLIVM_DEBUG_NO_RHO_APPROX) &&
760 (bld->dims > 1)) || cube_rho;
761
762 rho = lp_build_rho(bld, texture_unit, s, t, r, cube_rho, derivs);
763
764 /*
765 * Compute lod = log2(rho)
766 */
767
768 if (!lod_bias &&
769 !bld->static_sampler_state->lod_bias_non_zero &&
770 !bld->static_sampler_state->apply_max_lod &&
771 !bld->static_sampler_state->apply_min_lod) {
772 /*
773 * Special case when there are no post-log2 adjustments, which
774 * saves instructions but keeping the integer and fractional lod
775 * computations separate from the start.
776 */
777
778 if (mip_filter == PIPE_TEX_MIPFILTER_NONE ||
779 mip_filter == PIPE_TEX_MIPFILTER_NEAREST) {
780 /*
781 * Don't actually need both values all the time, lod_ipart is
782 * needed for nearest mipfilter, lod_positive if min != mag.
783 */
784 if (rho_squared) {
785 *out_lod_ipart = lp_build_ilog2_sqrt(lodf_bld, rho);
786 }
787 else {
788 *out_lod_ipart = lp_build_ilog2(lodf_bld, rho);
789 }
790 *out_lod_positive = lp_build_cmp(lodf_bld, PIPE_FUNC_GREATER,
791 rho, lodf_bld->one);
792 return;
793 }
794 if (mip_filter == PIPE_TEX_MIPFILTER_LINEAR &&
795 !(gallivm_debug & GALLIVM_DEBUG_NO_BRILINEAR) &&
796 !rho_squared) {
797 /*
798 * This can't work if rho is squared. Not sure if it could be
799 * fixed while keeping it worthwile, could also do sqrt here
800 * but brilinear and no_rho_opt seems like a combination not
801 * making much sense anyway so just use ordinary path below.
802 */
803 lp_build_brilinear_rho(lodf_bld, rho, BRILINEAR_FACTOR,
804 out_lod_ipart, out_lod_fpart);
805 *out_lod_positive = lp_build_cmp(lodf_bld, PIPE_FUNC_GREATER,
806 rho, lodf_bld->one);
807 return;
808 }
809 }
810
811 if (0) {
812 lod = lp_build_log2(lodf_bld, rho);
813 }
814 else {
815 lod = lp_build_fast_log2(lodf_bld, rho);
816 }
817 if (rho_squared) {
818 /* log2(x^2) == 0.5*log2(x) */
819 lod = lp_build_mul(lodf_bld, lod,
820 lp_build_const_vec(bld->gallivm, lodf_bld->type, 0.5F));
821 }
822
823 /* add shader lod bias */
824 if (lod_bias) {
825 if (bld->num_lods != bld->coord_type.length)
826 lod_bias = lp_build_pack_aos_scalars(bld->gallivm, bld->coord_bld.type,
827 lodf_bld->type, lod_bias, 0);
828 lod = LLVMBuildFAdd(builder, lod, lod_bias, "shader_lod_bias");
829 }
830 }
831
832 /* add sampler lod bias */
833 if (bld->static_sampler_state->lod_bias_non_zero) {
834 LLVMValueRef sampler_lod_bias =
835 dynamic_state->lod_bias(dynamic_state, bld->gallivm,
836 bld->context_ptr, sampler_unit);
837 sampler_lod_bias = lp_build_broadcast_scalar(lodf_bld,
838 sampler_lod_bias);
839 lod = LLVMBuildFAdd(builder, lod, sampler_lod_bias, "sampler_lod_bias");
840 }
841
842 /* clamp lod */
843 if (bld->static_sampler_state->apply_max_lod) {
844 LLVMValueRef max_lod =
845 dynamic_state->max_lod(dynamic_state, bld->gallivm,
846 bld->context_ptr, sampler_unit);
847 max_lod = lp_build_broadcast_scalar(lodf_bld, max_lod);
848
849 lod = lp_build_min(lodf_bld, lod, max_lod);
850 }
851 if (bld->static_sampler_state->apply_min_lod) {
852 LLVMValueRef min_lod =
853 dynamic_state->min_lod(dynamic_state, bld->gallivm,
854 bld->context_ptr, sampler_unit);
855 min_lod = lp_build_broadcast_scalar(lodf_bld, min_lod);
856
857 lod = lp_build_max(lodf_bld, lod, min_lod);
858 }
859 }
860
861 *out_lod_positive = lp_build_cmp(lodf_bld, PIPE_FUNC_GREATER,
862 lod, lodf_bld->zero);
863
864 if (mip_filter == PIPE_TEX_MIPFILTER_LINEAR) {
865 if (!(gallivm_debug & GALLIVM_DEBUG_NO_BRILINEAR)) {
866 lp_build_brilinear_lod(lodf_bld, lod, BRILINEAR_FACTOR,
867 out_lod_ipart, out_lod_fpart);
868 }
869 else {
870 lp_build_ifloor_fract(lodf_bld, lod, out_lod_ipart, out_lod_fpart);
871 }
872
873 lp_build_name(*out_lod_fpart, "lod_fpart");
874 }
875 else {
876 *out_lod_ipart = lp_build_iround(lodf_bld, lod);
877 }
878
879 lp_build_name(*out_lod_ipart, "lod_ipart");
880
881 return;
882 }
883
884
885 /**
886 * For PIPE_TEX_MIPFILTER_NEAREST, convert int part of lod
887 * to actual mip level.
888 * Note: this is all scalar per quad code.
889 * \param lod_ipart int texture level of detail
890 * \param level_out returns integer
891 * \param out_of_bounds returns per coord out_of_bounds mask if provided
892 */
893 void
lp_build_nearest_mip_level(struct lp_build_sample_context * bld,unsigned texture_unit,LLVMValueRef lod_ipart,LLVMValueRef * level_out,LLVMValueRef * out_of_bounds)894 lp_build_nearest_mip_level(struct lp_build_sample_context *bld,
895 unsigned texture_unit,
896 LLVMValueRef lod_ipart,
897 LLVMValueRef *level_out,
898 LLVMValueRef *out_of_bounds)
899 {
900 struct lp_build_context *leveli_bld = &bld->leveli_bld;
901 struct lp_sampler_dynamic_state *dynamic_state = bld->dynamic_state;
902 LLVMValueRef first_level, last_level, level;
903
904 first_level = dynamic_state->first_level(dynamic_state, bld->gallivm,
905 bld->context_ptr, texture_unit);
906 last_level = dynamic_state->last_level(dynamic_state, bld->gallivm,
907 bld->context_ptr, texture_unit);
908 first_level = lp_build_broadcast_scalar(leveli_bld, first_level);
909 last_level = lp_build_broadcast_scalar(leveli_bld, last_level);
910
911 level = lp_build_add(leveli_bld, lod_ipart, first_level);
912
913 if (out_of_bounds) {
914 LLVMValueRef out, out1;
915 out = lp_build_cmp(leveli_bld, PIPE_FUNC_LESS, level, first_level);
916 out1 = lp_build_cmp(leveli_bld, PIPE_FUNC_GREATER, level, last_level);
917 out = lp_build_or(leveli_bld, out, out1);
918 if (bld->num_mips == bld->coord_bld.type.length) {
919 *out_of_bounds = out;
920 }
921 else if (bld->num_mips == 1) {
922 *out_of_bounds = lp_build_broadcast_scalar(&bld->int_coord_bld, out);
923 }
924 else {
925 assert(bld->num_mips == bld->coord_bld.type.length / 4);
926 *out_of_bounds = lp_build_unpack_broadcast_aos_scalars(bld->gallivm,
927 leveli_bld->type,
928 bld->int_coord_bld.type,
929 out);
930 }
931 level = lp_build_andnot(&bld->int_coord_bld, level, *out_of_bounds);
932 *level_out = level;
933 }
934 else {
935 /* clamp level to legal range of levels */
936 *level_out = lp_build_clamp(leveli_bld, level, first_level, last_level);
937
938 }
939 }
940
941
942 /**
943 * For PIPE_TEX_MIPFILTER_LINEAR, convert per-quad (or per element) int LOD(s)
944 * to two (per-quad) (adjacent) mipmap level indexes, and fix up float lod
945 * part accordingly.
946 * Later, we'll sample from those two mipmap levels and interpolate between them.
947 */
948 void
lp_build_linear_mip_levels(struct lp_build_sample_context * bld,unsigned texture_unit,LLVMValueRef lod_ipart,LLVMValueRef * lod_fpart_inout,LLVMValueRef * level0_out,LLVMValueRef * level1_out)949 lp_build_linear_mip_levels(struct lp_build_sample_context *bld,
950 unsigned texture_unit,
951 LLVMValueRef lod_ipart,
952 LLVMValueRef *lod_fpart_inout,
953 LLVMValueRef *level0_out,
954 LLVMValueRef *level1_out)
955 {
956 LLVMBuilderRef builder = bld->gallivm->builder;
957 struct lp_sampler_dynamic_state *dynamic_state = bld->dynamic_state;
958 struct lp_build_context *leveli_bld = &bld->leveli_bld;
959 struct lp_build_context *levelf_bld = &bld->levelf_bld;
960 LLVMValueRef first_level, last_level;
961 LLVMValueRef clamp_min;
962 LLVMValueRef clamp_max;
963
964 assert(bld->num_lods == bld->num_mips);
965
966 first_level = dynamic_state->first_level(dynamic_state, bld->gallivm,
967 bld->context_ptr, texture_unit);
968 last_level = dynamic_state->last_level(dynamic_state, bld->gallivm,
969 bld->context_ptr, texture_unit);
970 first_level = lp_build_broadcast_scalar(leveli_bld, first_level);
971 last_level = lp_build_broadcast_scalar(leveli_bld, last_level);
972
973 *level0_out = lp_build_add(leveli_bld, lod_ipart, first_level);
974 *level1_out = lp_build_add(leveli_bld, *level0_out, leveli_bld->one);
975
976 /*
977 * Clamp both *level0_out and *level1_out to [first_level, last_level], with
978 * the minimum number of comparisons, and zeroing lod_fpart in the extreme
979 * ends in the process.
980 */
981
982 /* *level0_out < first_level */
983 clamp_min = LLVMBuildICmp(builder, LLVMIntSLT,
984 *level0_out, first_level,
985 "clamp_lod_to_first");
986
987 *level0_out = LLVMBuildSelect(builder, clamp_min,
988 first_level, *level0_out, "");
989
990 *level1_out = LLVMBuildSelect(builder, clamp_min,
991 first_level, *level1_out, "");
992
993 *lod_fpart_inout = LLVMBuildSelect(builder, clamp_min,
994 levelf_bld->zero, *lod_fpart_inout, "");
995
996 /* *level0_out >= last_level */
997 clamp_max = LLVMBuildICmp(builder, LLVMIntSGE,
998 *level0_out, last_level,
999 "clamp_lod_to_last");
1000
1001 *level0_out = LLVMBuildSelect(builder, clamp_max,
1002 last_level, *level0_out, "");
1003
1004 *level1_out = LLVMBuildSelect(builder, clamp_max,
1005 last_level, *level1_out, "");
1006
1007 *lod_fpart_inout = LLVMBuildSelect(builder, clamp_max,
1008 levelf_bld->zero, *lod_fpart_inout, "");
1009
1010 lp_build_name(*level0_out, "texture%u_miplevel0", texture_unit);
1011 lp_build_name(*level1_out, "texture%u_miplevel1", texture_unit);
1012 lp_build_name(*lod_fpart_inout, "texture%u_mipweight", texture_unit);
1013 }
1014
1015
1016 /**
1017 * Return pointer to a single mipmap level.
1018 * \param level integer mipmap level
1019 */
1020 LLVMValueRef
lp_build_get_mipmap_level(struct lp_build_sample_context * bld,LLVMValueRef level)1021 lp_build_get_mipmap_level(struct lp_build_sample_context *bld,
1022 LLVMValueRef level)
1023 {
1024 LLVMBuilderRef builder = bld->gallivm->builder;
1025 LLVMValueRef indexes[2], data_ptr, mip_offset;
1026
1027 indexes[0] = lp_build_const_int32(bld->gallivm, 0);
1028 indexes[1] = level;
1029 mip_offset = LLVMBuildGEP(builder, bld->mip_offsets, indexes, 2, "");
1030 mip_offset = LLVMBuildLoad(builder, mip_offset, "");
1031 data_ptr = LLVMBuildGEP(builder, bld->base_ptr, &mip_offset, 1, "");
1032 return data_ptr;
1033 }
1034
1035 /**
1036 * Return (per-pixel) offsets to mip levels.
1037 * \param level integer mipmap level
1038 */
1039 LLVMValueRef
lp_build_get_mip_offsets(struct lp_build_sample_context * bld,LLVMValueRef level)1040 lp_build_get_mip_offsets(struct lp_build_sample_context *bld,
1041 LLVMValueRef level)
1042 {
1043 LLVMBuilderRef builder = bld->gallivm->builder;
1044 LLVMValueRef indexes[2], offsets, offset1;
1045
1046 indexes[0] = lp_build_const_int32(bld->gallivm, 0);
1047 if (bld->num_mips == 1) {
1048 indexes[1] = level;
1049 offset1 = LLVMBuildGEP(builder, bld->mip_offsets, indexes, 2, "");
1050 offset1 = LLVMBuildLoad(builder, offset1, "");
1051 offsets = lp_build_broadcast_scalar(&bld->int_coord_bld, offset1);
1052 }
1053 else if (bld->num_mips == bld->coord_bld.type.length / 4) {
1054 unsigned i;
1055
1056 offsets = bld->int_coord_bld.undef;
1057 for (i = 0; i < bld->num_mips; i++) {
1058 LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1059 LLVMValueRef indexo = lp_build_const_int32(bld->gallivm, 4 * i);
1060 indexes[1] = LLVMBuildExtractElement(builder, level, indexi, "");
1061 offset1 = LLVMBuildGEP(builder, bld->mip_offsets, indexes, 2, "");
1062 offset1 = LLVMBuildLoad(builder, offset1, "");
1063 offsets = LLVMBuildInsertElement(builder, offsets, offset1, indexo, "");
1064 }
1065 offsets = lp_build_swizzle_scalar_aos(&bld->int_coord_bld, offsets, 0, 4);
1066 }
1067 else {
1068 unsigned i;
1069
1070 assert (bld->num_mips == bld->coord_bld.type.length);
1071
1072 offsets = bld->int_coord_bld.undef;
1073 for (i = 0; i < bld->num_mips; i++) {
1074 LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1075 indexes[1] = LLVMBuildExtractElement(builder, level, indexi, "");
1076 offset1 = LLVMBuildGEP(builder, bld->mip_offsets, indexes, 2, "");
1077 offset1 = LLVMBuildLoad(builder, offset1, "");
1078 offsets = LLVMBuildInsertElement(builder, offsets, offset1, indexi, "");
1079 }
1080 }
1081 return offsets;
1082 }
1083
1084
1085 /**
1086 * Codegen equivalent for u_minify().
1087 * @param lod_scalar if lod is a (broadcasted) scalar
1088 * Return max(1, base_size >> level);
1089 */
1090 LLVMValueRef
lp_build_minify(struct lp_build_context * bld,LLVMValueRef base_size,LLVMValueRef level,boolean lod_scalar)1091 lp_build_minify(struct lp_build_context *bld,
1092 LLVMValueRef base_size,
1093 LLVMValueRef level,
1094 boolean lod_scalar)
1095 {
1096 LLVMBuilderRef builder = bld->gallivm->builder;
1097 assert(lp_check_value(bld->type, base_size));
1098 assert(lp_check_value(bld->type, level));
1099
1100 if (level == bld->zero) {
1101 /* if we're using mipmap level zero, no minification is needed */
1102 return base_size;
1103 }
1104 else {
1105 LLVMValueRef size;
1106 assert(bld->type.sign);
1107 if (lod_scalar ||
1108 (util_cpu_caps.has_avx2 || !util_cpu_caps.has_sse)) {
1109 size = LLVMBuildLShr(builder, base_size, level, "minify");
1110 size = lp_build_max(bld, size, bld->one);
1111 }
1112 else {
1113 /*
1114 * emulate shift with float mul, since intel "forgot" shifts with
1115 * per-element shift count until avx2, which results in terrible
1116 * scalar extraction (both count and value), scalar shift,
1117 * vector reinsertion. Should not be an issue on any non-x86 cpu
1118 * with a vector instruction set.
1119 * On cpus with AMD's XOP this should also be unnecessary but I'm
1120 * not sure if llvm would emit this with current flags.
1121 */
1122 LLVMValueRef const127, const23, lf;
1123 struct lp_type ftype;
1124 struct lp_build_context fbld;
1125 ftype = lp_type_float_vec(32, bld->type.length * bld->type.width);
1126 lp_build_context_init(&fbld, bld->gallivm, ftype);
1127 const127 = lp_build_const_int_vec(bld->gallivm, bld->type, 127);
1128 const23 = lp_build_const_int_vec(bld->gallivm, bld->type, 23);
1129
1130 /* calculate 2^(-level) float */
1131 lf = lp_build_sub(bld, const127, level);
1132 lf = lp_build_shl(bld, lf, const23);
1133 lf = LLVMBuildBitCast(builder, lf, fbld.vec_type, "");
1134
1135 /* finish shift operation by doing float mul */
1136 base_size = lp_build_int_to_float(&fbld, base_size);
1137 size = lp_build_mul(&fbld, base_size, lf);
1138 /*
1139 * do the max also with floats because
1140 * a) non-emulated int max requires sse41
1141 * (this is actually a lie as we could cast to 16bit values
1142 * as 16bit is sufficient and 16bit int max is sse2)
1143 * b) with avx we can do int max 4-wide but float max 8-wide
1144 */
1145 size = lp_build_max(&fbld, size, fbld.one);
1146 size = lp_build_itrunc(&fbld, size);
1147 }
1148 return size;
1149 }
1150 }
1151
1152
1153 /**
1154 * Dereference stride_array[mipmap_level] array to get a stride.
1155 * Return stride as a vector.
1156 */
1157 static LLVMValueRef
lp_build_get_level_stride_vec(struct lp_build_sample_context * bld,LLVMValueRef stride_array,LLVMValueRef level)1158 lp_build_get_level_stride_vec(struct lp_build_sample_context *bld,
1159 LLVMValueRef stride_array, LLVMValueRef level)
1160 {
1161 LLVMBuilderRef builder = bld->gallivm->builder;
1162 LLVMValueRef indexes[2], stride, stride1;
1163 indexes[0] = lp_build_const_int32(bld->gallivm, 0);
1164 if (bld->num_mips == 1) {
1165 indexes[1] = level;
1166 stride1 = LLVMBuildGEP(builder, stride_array, indexes, 2, "");
1167 stride1 = LLVMBuildLoad(builder, stride1, "");
1168 stride = lp_build_broadcast_scalar(&bld->int_coord_bld, stride1);
1169 }
1170 else if (bld->num_mips == bld->coord_bld.type.length / 4) {
1171 LLVMValueRef stride1;
1172 unsigned i;
1173
1174 stride = bld->int_coord_bld.undef;
1175 for (i = 0; i < bld->num_mips; i++) {
1176 LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1177 LLVMValueRef indexo = lp_build_const_int32(bld->gallivm, 4 * i);
1178 indexes[1] = LLVMBuildExtractElement(builder, level, indexi, "");
1179 stride1 = LLVMBuildGEP(builder, stride_array, indexes, 2, "");
1180 stride1 = LLVMBuildLoad(builder, stride1, "");
1181 stride = LLVMBuildInsertElement(builder, stride, stride1, indexo, "");
1182 }
1183 stride = lp_build_swizzle_scalar_aos(&bld->int_coord_bld, stride, 0, 4);
1184 }
1185 else {
1186 LLVMValueRef stride1;
1187 unsigned i;
1188
1189 assert (bld->num_mips == bld->coord_bld.type.length);
1190
1191 stride = bld->int_coord_bld.undef;
1192 for (i = 0; i < bld->coord_bld.type.length; i++) {
1193 LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1194 indexes[1] = LLVMBuildExtractElement(builder, level, indexi, "");
1195 stride1 = LLVMBuildGEP(builder, stride_array, indexes, 2, "");
1196 stride1 = LLVMBuildLoad(builder, stride1, "");
1197 stride = LLVMBuildInsertElement(builder, stride, stride1, indexi, "");
1198 }
1199 }
1200 return stride;
1201 }
1202
1203
1204 /**
1205 * When sampling a mipmap, we need to compute the width, height, depth
1206 * of the source levels from the level indexes. This helper function
1207 * does that.
1208 */
1209 void
lp_build_mipmap_level_sizes(struct lp_build_sample_context * bld,LLVMValueRef ilevel,LLVMValueRef * out_size,LLVMValueRef * row_stride_vec,LLVMValueRef * img_stride_vec)1210 lp_build_mipmap_level_sizes(struct lp_build_sample_context *bld,
1211 LLVMValueRef ilevel,
1212 LLVMValueRef *out_size,
1213 LLVMValueRef *row_stride_vec,
1214 LLVMValueRef *img_stride_vec)
1215 {
1216 const unsigned dims = bld->dims;
1217 LLVMValueRef ilevel_vec;
1218
1219 /*
1220 * Compute width, height, depth at mipmap level 'ilevel'
1221 */
1222 if (bld->num_mips == 1) {
1223 ilevel_vec = lp_build_broadcast_scalar(&bld->int_size_bld, ilevel);
1224 *out_size = lp_build_minify(&bld->int_size_bld, bld->int_size, ilevel_vec, TRUE);
1225 }
1226 else {
1227 LLVMValueRef int_size_vec;
1228 LLVMValueRef tmp[LP_MAX_VECTOR_LENGTH];
1229 unsigned num_quads = bld->coord_bld.type.length / 4;
1230 unsigned i;
1231
1232 if (bld->num_mips == num_quads) {
1233 /*
1234 * XXX: this should be #ifndef SANE_INSTRUCTION_SET.
1235 * intel "forgot" the variable shift count instruction until avx2.
1236 * A harmless 8x32 shift gets translated into 32 instructions
1237 * (16 extracts, 8 scalar shifts, 8 inserts), llvm is apparently
1238 * unable to recognize if there are really just 2 different shift
1239 * count values. So do the shift 4-wide before expansion.
1240 */
1241 struct lp_build_context bld4;
1242 struct lp_type type4;
1243
1244 type4 = bld->int_coord_bld.type;
1245 type4.length = 4;
1246
1247 lp_build_context_init(&bld4, bld->gallivm, type4);
1248
1249 if (bld->dims == 1) {
1250 assert(bld->int_size_in_bld.type.length == 1);
1251 int_size_vec = lp_build_broadcast_scalar(&bld4,
1252 bld->int_size);
1253 }
1254 else {
1255 assert(bld->int_size_in_bld.type.length == 4);
1256 int_size_vec = bld->int_size;
1257 }
1258
1259 for (i = 0; i < num_quads; i++) {
1260 LLVMValueRef ileveli;
1261 LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1262
1263 ileveli = lp_build_extract_broadcast(bld->gallivm,
1264 bld->leveli_bld.type,
1265 bld4.type,
1266 ilevel,
1267 indexi);
1268 tmp[i] = lp_build_minify(&bld4, int_size_vec, ileveli, TRUE);
1269 }
1270 /*
1271 * out_size is [w0, h0, d0, _, w1, h1, d1, _, ...] vector for dims > 1,
1272 * [w0, w0, w0, w0, w1, w1, w1, w1, ...] otherwise.
1273 */
1274 *out_size = lp_build_concat(bld->gallivm,
1275 tmp,
1276 bld4.type,
1277 num_quads);
1278 }
1279 else {
1280 /* FIXME: this is terrible and results in _huge_ vector
1281 * (for the dims > 1 case).
1282 * Should refactor this (together with extract_image_sizes) and do
1283 * something more useful. Could for instance if we have width,height
1284 * with 4-wide vector pack all elements into a 8xi16 vector
1285 * (on which we can still do useful math) instead of using a 16xi32
1286 * vector.
1287 * For dims == 1 this will create [w0, w1, w2, w3, ...] vector.
1288 * For dims > 1 this will create [w0, h0, d0, _, w1, h1, d1, _, ...] vector.
1289 */
1290 assert(bld->num_mips == bld->coord_bld.type.length);
1291 if (bld->dims == 1) {
1292 assert(bld->int_size_in_bld.type.length == 1);
1293 int_size_vec = lp_build_broadcast_scalar(&bld->int_coord_bld,
1294 bld->int_size);
1295 *out_size = lp_build_minify(&bld->int_coord_bld, int_size_vec, ilevel, FALSE);
1296 }
1297 else {
1298 LLVMValueRef ilevel1;
1299 for (i = 0; i < bld->num_mips; i++) {
1300 LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1301 ilevel1 = lp_build_extract_broadcast(bld->gallivm, bld->int_coord_type,
1302 bld->int_size_in_bld.type, ilevel, indexi);
1303 tmp[i] = bld->int_size;
1304 tmp[i] = lp_build_minify(&bld->int_size_in_bld, tmp[i], ilevel1, TRUE);
1305 }
1306 *out_size = lp_build_concat(bld->gallivm, tmp,
1307 bld->int_size_in_bld.type,
1308 bld->num_mips);
1309 }
1310 }
1311 }
1312
1313 if (dims >= 2) {
1314 *row_stride_vec = lp_build_get_level_stride_vec(bld,
1315 bld->row_stride_array,
1316 ilevel);
1317 }
1318 if (dims == 3 || has_layer_coord(bld->static_texture_state->target)) {
1319 *img_stride_vec = lp_build_get_level_stride_vec(bld,
1320 bld->img_stride_array,
1321 ilevel);
1322 }
1323 }
1324
1325
1326 /**
1327 * Extract and broadcast texture size.
1328 *
1329 * @param size_type type of the texture size vector (either
1330 * bld->int_size_type or bld->float_size_type)
1331 * @param coord_type type of the texture size vector (either
1332 * bld->int_coord_type or bld->coord_type)
1333 * @param size vector with the texture size (width, height, depth)
1334 */
1335 void
lp_build_extract_image_sizes(struct lp_build_sample_context * bld,struct lp_build_context * size_bld,struct lp_type coord_type,LLVMValueRef size,LLVMValueRef * out_width,LLVMValueRef * out_height,LLVMValueRef * out_depth)1336 lp_build_extract_image_sizes(struct lp_build_sample_context *bld,
1337 struct lp_build_context *size_bld,
1338 struct lp_type coord_type,
1339 LLVMValueRef size,
1340 LLVMValueRef *out_width,
1341 LLVMValueRef *out_height,
1342 LLVMValueRef *out_depth)
1343 {
1344 const unsigned dims = bld->dims;
1345 LLVMTypeRef i32t = LLVMInt32TypeInContext(bld->gallivm->context);
1346 struct lp_type size_type = size_bld->type;
1347
1348 if (bld->num_mips == 1) {
1349 *out_width = lp_build_extract_broadcast(bld->gallivm,
1350 size_type,
1351 coord_type,
1352 size,
1353 LLVMConstInt(i32t, 0, 0));
1354 if (dims >= 2) {
1355 *out_height = lp_build_extract_broadcast(bld->gallivm,
1356 size_type,
1357 coord_type,
1358 size,
1359 LLVMConstInt(i32t, 1, 0));
1360 if (dims == 3) {
1361 *out_depth = lp_build_extract_broadcast(bld->gallivm,
1362 size_type,
1363 coord_type,
1364 size,
1365 LLVMConstInt(i32t, 2, 0));
1366 }
1367 }
1368 }
1369 else {
1370 unsigned num_quads = bld->coord_bld.type.length / 4;
1371
1372 if (dims == 1) {
1373 *out_width = size;
1374 }
1375 else if (bld->num_mips == num_quads) {
1376 *out_width = lp_build_swizzle_scalar_aos(size_bld, size, 0, 4);
1377 if (dims >= 2) {
1378 *out_height = lp_build_swizzle_scalar_aos(size_bld, size, 1, 4);
1379 if (dims == 3) {
1380 *out_depth = lp_build_swizzle_scalar_aos(size_bld, size, 2, 4);
1381 }
1382 }
1383 }
1384 else {
1385 assert(bld->num_mips == bld->coord_type.length);
1386 *out_width = lp_build_pack_aos_scalars(bld->gallivm, size_type,
1387 coord_type, size, 0);
1388 if (dims >= 2) {
1389 *out_height = lp_build_pack_aos_scalars(bld->gallivm, size_type,
1390 coord_type, size, 1);
1391 if (dims == 3) {
1392 *out_depth = lp_build_pack_aos_scalars(bld->gallivm, size_type,
1393 coord_type, size, 2);
1394 }
1395 }
1396 }
1397 }
1398 }
1399
1400
1401 /**
1402 * Unnormalize coords.
1403 *
1404 * @param flt_size vector with the integer texture size (width, height, depth)
1405 */
1406 void
lp_build_unnormalized_coords(struct lp_build_sample_context * bld,LLVMValueRef flt_size,LLVMValueRef * s,LLVMValueRef * t,LLVMValueRef * r)1407 lp_build_unnormalized_coords(struct lp_build_sample_context *bld,
1408 LLVMValueRef flt_size,
1409 LLVMValueRef *s,
1410 LLVMValueRef *t,
1411 LLVMValueRef *r)
1412 {
1413 const unsigned dims = bld->dims;
1414 LLVMValueRef width;
1415 LLVMValueRef height;
1416 LLVMValueRef depth;
1417
1418 lp_build_extract_image_sizes(bld,
1419 &bld->float_size_bld,
1420 bld->coord_type,
1421 flt_size,
1422 &width,
1423 &height,
1424 &depth);
1425
1426 /* s = s * width, t = t * height */
1427 *s = lp_build_mul(&bld->coord_bld, *s, width);
1428 if (dims >= 2) {
1429 *t = lp_build_mul(&bld->coord_bld, *t, height);
1430 if (dims >= 3) {
1431 *r = lp_build_mul(&bld->coord_bld, *r, depth);
1432 }
1433 }
1434 }
1435
1436 /**
1437 * Generate new coords and faces for cubemap texels falling off the face.
1438 *
1439 * @param face face (center) of the pixel
1440 * @param x0 lower x coord
1441 * @param x1 higher x coord (must be x0 + 1)
1442 * @param y0 lower y coord
1443 * @param y1 higher y coord (must be x0 + 1)
1444 * @param max_coord texture cube (level) size - 1
1445 * @param next_faces new face values when falling off
1446 * @param next_xcoords new x coord values when falling off
1447 * @param next_ycoords new y coord values when falling off
1448 *
1449 * The arrays hold the new values when under/overflow of
1450 * lower x, higher x, lower y, higher y coord would occur (in this order).
1451 * next_xcoords/next_ycoords have two entries each (for both new lower and
1452 * higher coord).
1453 */
1454 void
lp_build_cube_new_coords(struct lp_build_context * ivec_bld,LLVMValueRef face,LLVMValueRef x0,LLVMValueRef x1,LLVMValueRef y0,LLVMValueRef y1,LLVMValueRef max_coord,LLVMValueRef next_faces[4],LLVMValueRef next_xcoords[4][2],LLVMValueRef next_ycoords[4][2])1455 lp_build_cube_new_coords(struct lp_build_context *ivec_bld,
1456 LLVMValueRef face,
1457 LLVMValueRef x0,
1458 LLVMValueRef x1,
1459 LLVMValueRef y0,
1460 LLVMValueRef y1,
1461 LLVMValueRef max_coord,
1462 LLVMValueRef next_faces[4],
1463 LLVMValueRef next_xcoords[4][2],
1464 LLVMValueRef next_ycoords[4][2])
1465 {
1466 /*
1467 * Lookup tables aren't nice for simd code hence try some logic here.
1468 * (Note that while it would not be necessary to do per-sample (4) lookups
1469 * when using a LUT as it's impossible that texels fall off of positive
1470 * and negative edges simultaneously, it would however be necessary to
1471 * do 2 lookups for corner handling as in this case texels both fall off
1472 * of x and y axes.)
1473 */
1474 /*
1475 * Next faces (for face 012345):
1476 * x < 0.0 : 451110
1477 * x >= 1.0 : 540001
1478 * y < 0.0 : 225422
1479 * y >= 1.0 : 334533
1480 * Hence nfx+ (and nfy+) == nfx- (nfy-) xor 1
1481 * nfx-: face > 1 ? (face == 5 ? 0 : 1) : (4 + face & 1)
1482 * nfy+: face & ~4 > 1 ? face + 2 : 3;
1483 * This could also use pshufb instead, but would need (manually coded)
1484 * ssse3 intrinsic (llvm won't do non-constant shuffles).
1485 */
1486 struct gallivm_state *gallivm = ivec_bld->gallivm;
1487 LLVMValueRef sel, sel_f2345, sel_f23, sel_f2, tmpsel, tmp;
1488 LLVMValueRef faceand1, sel_fand1, maxmx0, maxmx1, maxmy0, maxmy1;
1489 LLVMValueRef c2 = lp_build_const_int_vec(gallivm, ivec_bld->type, 2);
1490 LLVMValueRef c3 = lp_build_const_int_vec(gallivm, ivec_bld->type, 3);
1491 LLVMValueRef c4 = lp_build_const_int_vec(gallivm, ivec_bld->type, 4);
1492 LLVMValueRef c5 = lp_build_const_int_vec(gallivm, ivec_bld->type, 5);
1493
1494 sel = lp_build_cmp(ivec_bld, PIPE_FUNC_EQUAL, face, c5);
1495 tmpsel = lp_build_select(ivec_bld, sel, ivec_bld->zero, ivec_bld->one);
1496 sel_f2345 = lp_build_cmp(ivec_bld, PIPE_FUNC_GREATER, face, ivec_bld->one);
1497 faceand1 = lp_build_and(ivec_bld, face, ivec_bld->one);
1498 tmp = lp_build_add(ivec_bld, faceand1, c4);
1499 next_faces[0] = lp_build_select(ivec_bld, sel_f2345, tmpsel, tmp);
1500 next_faces[1] = lp_build_xor(ivec_bld, next_faces[0], ivec_bld->one);
1501
1502 tmp = lp_build_andnot(ivec_bld, face, c4);
1503 sel_f23 = lp_build_cmp(ivec_bld, PIPE_FUNC_GREATER, tmp, ivec_bld->one);
1504 tmp = lp_build_add(ivec_bld, face, c2);
1505 next_faces[3] = lp_build_select(ivec_bld, sel_f23, tmp, c3);
1506 next_faces[2] = lp_build_xor(ivec_bld, next_faces[3], ivec_bld->one);
1507
1508 /*
1509 * new xcoords (for face 012345):
1510 * x < 0.0 : max max t max-t max max
1511 * x >= 1.0 : 0 0 max-t t 0 0
1512 * y < 0.0 : max 0 max-s s s max-s
1513 * y >= 1.0 : max 0 s max-s s max-s
1514 *
1515 * ncx[1] = face & ~4 > 1 ? (face == 2 ? max-t : t) : 0
1516 * ncx[0] = max - ncx[1]
1517 * ncx[3] = face > 1 ? (face & 1 ? max-s : s) : (face & 1) ? 0 : max
1518 * ncx[2] = face & ~4 > 1 ? max - ncx[3] : ncx[3]
1519 */
1520 sel_f2 = lp_build_cmp(ivec_bld, PIPE_FUNC_EQUAL, face, c2);
1521 maxmy0 = lp_build_sub(ivec_bld, max_coord, y0);
1522 tmp = lp_build_select(ivec_bld, sel_f2, maxmy0, y0);
1523 next_xcoords[1][0] = lp_build_select(ivec_bld, sel_f23, tmp, ivec_bld->zero);
1524 next_xcoords[0][0] = lp_build_sub(ivec_bld, max_coord, next_xcoords[1][0]);
1525 maxmy1 = lp_build_sub(ivec_bld, max_coord, y1);
1526 tmp = lp_build_select(ivec_bld, sel_f2, maxmy1, y1);
1527 next_xcoords[1][1] = lp_build_select(ivec_bld, sel_f23, tmp, ivec_bld->zero);
1528 next_xcoords[0][1] = lp_build_sub(ivec_bld, max_coord, next_xcoords[1][1]);
1529
1530 sel_fand1 = lp_build_cmp(ivec_bld, PIPE_FUNC_EQUAL, faceand1, ivec_bld->one);
1531
1532 tmpsel = lp_build_select(ivec_bld, sel_fand1, ivec_bld->zero, max_coord);
1533 maxmx0 = lp_build_sub(ivec_bld, max_coord, x0);
1534 tmp = lp_build_select(ivec_bld, sel_fand1, maxmx0, x0);
1535 next_xcoords[3][0] = lp_build_select(ivec_bld, sel_f2345, tmp, tmpsel);
1536 tmp = lp_build_sub(ivec_bld, max_coord, next_xcoords[3][0]);
1537 next_xcoords[2][0] = lp_build_select(ivec_bld, sel_f23, tmp, next_xcoords[3][0]);
1538 maxmx1 = lp_build_sub(ivec_bld, max_coord, x1);
1539 tmp = lp_build_select(ivec_bld, sel_fand1, maxmx1, x1);
1540 next_xcoords[3][1] = lp_build_select(ivec_bld, sel_f2345, tmp, tmpsel);
1541 tmp = lp_build_sub(ivec_bld, max_coord, next_xcoords[3][1]);
1542 next_xcoords[2][1] = lp_build_select(ivec_bld, sel_f23, tmp, next_xcoords[3][1]);
1543
1544 /*
1545 * new ycoords (for face 012345):
1546 * x < 0.0 : t t 0 max t t
1547 * x >= 1.0 : t t 0 max t t
1548 * y < 0.0 : max-s s 0 max max 0
1549 * y >= 1.0 : s max-s 0 max 0 max
1550 *
1551 * ncy[0] = face & ~4 > 1 ? (face == 2 ? 0 : max) : t
1552 * ncy[1] = ncy[0]
1553 * ncy[3] = face > 1 ? (face & 1 ? max : 0) : (face & 1) ? max-s : max
1554 * ncx[2] = face & ~4 > 1 ? max - ncx[3] : ncx[3]
1555 */
1556 tmp = lp_build_select(ivec_bld, sel_f2, ivec_bld->zero, max_coord);
1557 next_ycoords[0][0] = lp_build_select(ivec_bld, sel_f23, tmp, y0);
1558 next_ycoords[1][0] = next_ycoords[0][0];
1559 next_ycoords[0][1] = lp_build_select(ivec_bld, sel_f23, tmp, y1);
1560 next_ycoords[1][1] = next_ycoords[0][1];
1561
1562 tmpsel = lp_build_select(ivec_bld, sel_fand1, maxmx0, x0);
1563 tmp = lp_build_select(ivec_bld, sel_fand1, max_coord, ivec_bld->zero);
1564 next_ycoords[3][0] = lp_build_select(ivec_bld, sel_f2345, tmp, tmpsel);
1565 tmp = lp_build_sub(ivec_bld, max_coord, next_ycoords[3][0]);
1566 next_ycoords[2][0] = lp_build_select(ivec_bld, sel_f23, next_ycoords[3][0], tmp);
1567 tmpsel = lp_build_select(ivec_bld, sel_fand1, maxmx1, x1);
1568 tmp = lp_build_select(ivec_bld, sel_fand1, max_coord, ivec_bld->zero);
1569 next_ycoords[3][1] = lp_build_select(ivec_bld, sel_f2345, tmp, tmpsel);
1570 tmp = lp_build_sub(ivec_bld, max_coord, next_ycoords[3][1]);
1571 next_ycoords[2][1] = lp_build_select(ivec_bld, sel_f23, next_ycoords[3][1], tmp);
1572 }
1573
1574
1575 /** Helper used by lp_build_cube_lookup() */
1576 static LLVMValueRef
lp_build_cube_imapos(struct lp_build_context * coord_bld,LLVMValueRef coord)1577 lp_build_cube_imapos(struct lp_build_context *coord_bld, LLVMValueRef coord)
1578 {
1579 /* ima = +0.5 / abs(coord); */
1580 LLVMValueRef posHalf = lp_build_const_vec(coord_bld->gallivm, coord_bld->type, 0.5);
1581 LLVMValueRef absCoord = lp_build_abs(coord_bld, coord);
1582 LLVMValueRef ima = lp_build_div(coord_bld, posHalf, absCoord);
1583 return ima;
1584 }
1585
1586
1587 /** Helper for doing 3-wise selection.
1588 * Returns sel1 ? val2 : (sel0 ? val0 : val1).
1589 */
1590 static LLVMValueRef
lp_build_select3(struct lp_build_context * sel_bld,LLVMValueRef sel0,LLVMValueRef sel1,LLVMValueRef val0,LLVMValueRef val1,LLVMValueRef val2)1591 lp_build_select3(struct lp_build_context *sel_bld,
1592 LLVMValueRef sel0,
1593 LLVMValueRef sel1,
1594 LLVMValueRef val0,
1595 LLVMValueRef val1,
1596 LLVMValueRef val2)
1597 {
1598 LLVMValueRef tmp;
1599 tmp = lp_build_select(sel_bld, sel0, val0, val1);
1600 return lp_build_select(sel_bld, sel1, val2, tmp);
1601 }
1602
1603
1604 /**
1605 * Generate code to do cube face selection and compute per-face texcoords.
1606 */
1607 void
lp_build_cube_lookup(struct lp_build_sample_context * bld,LLVMValueRef * coords,const struct lp_derivatives * derivs_in,LLVMValueRef * rho,struct lp_derivatives * derivs_out,boolean need_derivs)1608 lp_build_cube_lookup(struct lp_build_sample_context *bld,
1609 LLVMValueRef *coords,
1610 const struct lp_derivatives *derivs_in, /* optional */
1611 LLVMValueRef *rho,
1612 struct lp_derivatives *derivs_out, /* optional */
1613 boolean need_derivs)
1614 {
1615 struct lp_build_context *coord_bld = &bld->coord_bld;
1616 LLVMBuilderRef builder = bld->gallivm->builder;
1617 struct gallivm_state *gallivm = bld->gallivm;
1618 LLVMValueRef si, ti, ri;
1619
1620 /*
1621 * Do per-pixel face selection. We cannot however (as we used to do)
1622 * simply calculate the derivs afterwards (which is very bogus for
1623 * explicit derivs btw) because the values would be "random" when
1624 * not all pixels lie on the same face. So what we do here is just
1625 * calculate the derivatives after scaling the coords by the absolute
1626 * value of the inverse major axis, and essentially do rho calculation
1627 * steps as if it were a 3d texture. This is perfect if all pixels hit
1628 * the same face, but not so great at edges, I believe the max error
1629 * should be sqrt(2) with no_rho_approx or 2 otherwise (essentially measuring
1630 * the 3d distance between 2 points on the cube instead of measuring up/down
1631 * the edge). Still this is possibly a win over just selecting the same face
1632 * for all pixels. Unfortunately, something like that doesn't work for
1633 * explicit derivatives.
1634 */
1635 struct lp_build_context *cint_bld = &bld->int_coord_bld;
1636 struct lp_type intctype = cint_bld->type;
1637 LLVMTypeRef coord_vec_type = coord_bld->vec_type;
1638 LLVMTypeRef cint_vec_type = cint_bld->vec_type;
1639 LLVMValueRef as, at, ar, face, face_s, face_t;
1640 LLVMValueRef as_ge_at, maxasat, ar_ge_as_at;
1641 LLVMValueRef snewx, tnewx, snewy, tnewy, snewz, tnewz;
1642 LLVMValueRef tnegi, rnegi;
1643 LLVMValueRef ma, mai, signma, signmabit, imahalfpos;
1644 LLVMValueRef posHalf = lp_build_const_vec(gallivm, coord_bld->type, 0.5);
1645 LLVMValueRef signmask = lp_build_const_int_vec(gallivm, intctype,
1646 1LL << (intctype.width - 1));
1647 LLVMValueRef signshift = lp_build_const_int_vec(gallivm, intctype,
1648 intctype.width -1);
1649 LLVMValueRef facex = lp_build_const_int_vec(gallivm, intctype, PIPE_TEX_FACE_POS_X);
1650 LLVMValueRef facey = lp_build_const_int_vec(gallivm, intctype, PIPE_TEX_FACE_POS_Y);
1651 LLVMValueRef facez = lp_build_const_int_vec(gallivm, intctype, PIPE_TEX_FACE_POS_Z);
1652 LLVMValueRef s = coords[0];
1653 LLVMValueRef t = coords[1];
1654 LLVMValueRef r = coords[2];
1655
1656 assert(PIPE_TEX_FACE_NEG_X == PIPE_TEX_FACE_POS_X + 1);
1657 assert(PIPE_TEX_FACE_NEG_Y == PIPE_TEX_FACE_POS_Y + 1);
1658 assert(PIPE_TEX_FACE_NEG_Z == PIPE_TEX_FACE_POS_Z + 1);
1659
1660 /*
1661 * get absolute value (for x/y/z face selection) and sign bit
1662 * (for mirroring minor coords and pos/neg face selection)
1663 * of the original coords.
1664 */
1665 as = lp_build_abs(&bld->coord_bld, s);
1666 at = lp_build_abs(&bld->coord_bld, t);
1667 ar = lp_build_abs(&bld->coord_bld, r);
1668
1669 /*
1670 * major face determination: select x if x > y else select y
1671 * select z if z >= max(x,y) else select previous result
1672 * if some axis are the same we chose z over y, y over x - the
1673 * dx10 spec seems to ask for it while OpenGL doesn't care (if we
1674 * wouldn't care could save a select or two if using different
1675 * compares and doing at_g_as_ar last since tnewx and tnewz are the
1676 * same).
1677 */
1678 as_ge_at = lp_build_cmp(coord_bld, PIPE_FUNC_GREATER, as, at);
1679 maxasat = lp_build_max(coord_bld, as, at);
1680 ar_ge_as_at = lp_build_cmp(coord_bld, PIPE_FUNC_GEQUAL, ar, maxasat);
1681
1682 if (need_derivs && (derivs_in ||
1683 ((gallivm_debug & GALLIVM_DEBUG_NO_QUAD_LOD) &&
1684 (gallivm_debug & GALLIVM_DEBUG_NO_RHO_APPROX)))) {
1685 /*
1686 * XXX: This is really really complex.
1687 * It is a bit overkill to use this for implicit derivatives as well,
1688 * no way this is worth the cost in practice, but seems to be the
1689 * only way for getting accurate and per-pixel lod values.
1690 */
1691 LLVMValueRef ima, imahalf, tmp, ddx[3], ddy[3];
1692 LLVMValueRef madx, mady, madxdivma, madydivma;
1693 LLVMValueRef sdxi, tdxi, rdxi, sdyi, tdyi, rdyi;
1694 LLVMValueRef tdxnegi, rdxnegi, tdynegi, rdynegi;
1695 LLVMValueRef sdxnewx, sdxnewy, sdxnewz, tdxnewx, tdxnewy, tdxnewz;
1696 LLVMValueRef sdynewx, sdynewy, sdynewz, tdynewx, tdynewy, tdynewz;
1697 LLVMValueRef face_sdx, face_tdx, face_sdy, face_tdy;
1698 /*
1699 * s = 1/2 * ( sc / ma + 1)
1700 * t = 1/2 * ( tc / ma + 1)
1701 *
1702 * s' = 1/2 * (sc' * ma - sc * ma') / ma^2
1703 * t' = 1/2 * (tc' * ma - tc * ma') / ma^2
1704 *
1705 * dx.s = 0.5 * (dx.sc - sc * dx.ma / ma) / ma
1706 * dx.t = 0.5 * (dx.tc - tc * dx.ma / ma) / ma
1707 * dy.s = 0.5 * (dy.sc - sc * dy.ma / ma) / ma
1708 * dy.t = 0.5 * (dy.tc - tc * dy.ma / ma) / ma
1709 */
1710
1711 /* select ma, calculate ima */
1712 ma = lp_build_select3(coord_bld, as_ge_at, ar_ge_as_at, s, t, r);
1713 mai = LLVMBuildBitCast(builder, ma, cint_vec_type, "");
1714 signmabit = LLVMBuildAnd(builder, mai, signmask, "");
1715 ima = lp_build_div(coord_bld, coord_bld->one, ma);
1716 imahalf = lp_build_mul(coord_bld, posHalf, ima);
1717 imahalfpos = lp_build_abs(coord_bld, imahalf);
1718
1719 if (!derivs_in) {
1720 ddx[0] = lp_build_ddx(coord_bld, s);
1721 ddx[1] = lp_build_ddx(coord_bld, t);
1722 ddx[2] = lp_build_ddx(coord_bld, r);
1723 ddy[0] = lp_build_ddy(coord_bld, s);
1724 ddy[1] = lp_build_ddy(coord_bld, t);
1725 ddy[2] = lp_build_ddy(coord_bld, r);
1726 }
1727 else {
1728 ddx[0] = derivs_in->ddx[0];
1729 ddx[1] = derivs_in->ddx[1];
1730 ddx[2] = derivs_in->ddx[2];
1731 ddy[0] = derivs_in->ddy[0];
1732 ddy[1] = derivs_in->ddy[1];
1733 ddy[2] = derivs_in->ddy[2];
1734 }
1735
1736 /* select major derivatives */
1737 madx = lp_build_select3(coord_bld, as_ge_at, ar_ge_as_at, ddx[0], ddx[1], ddx[2]);
1738 mady = lp_build_select3(coord_bld, as_ge_at, ar_ge_as_at, ddy[0], ddy[1], ddy[2]);
1739
1740 si = LLVMBuildBitCast(builder, s, cint_vec_type, "");
1741 ti = LLVMBuildBitCast(builder, t, cint_vec_type, "");
1742 ri = LLVMBuildBitCast(builder, r, cint_vec_type, "");
1743
1744 sdxi = LLVMBuildBitCast(builder, ddx[0], cint_vec_type, "");
1745 tdxi = LLVMBuildBitCast(builder, ddx[1], cint_vec_type, "");
1746 rdxi = LLVMBuildBitCast(builder, ddx[2], cint_vec_type, "");
1747
1748 sdyi = LLVMBuildBitCast(builder, ddy[0], cint_vec_type, "");
1749 tdyi = LLVMBuildBitCast(builder, ddy[1], cint_vec_type, "");
1750 rdyi = LLVMBuildBitCast(builder, ddy[2], cint_vec_type, "");
1751
1752 /*
1753 * compute all possible new s/t coords, which does the mirroring,
1754 * and do the same for derivs minor axes.
1755 * snewx = signma * -r;
1756 * tnewx = -t;
1757 * snewy = s;
1758 * tnewy = signma * r;
1759 * snewz = signma * s;
1760 * tnewz = -t;
1761 */
1762 tnegi = LLVMBuildXor(builder, ti, signmask, "");
1763 rnegi = LLVMBuildXor(builder, ri, signmask, "");
1764 tdxnegi = LLVMBuildXor(builder, tdxi, signmask, "");
1765 rdxnegi = LLVMBuildXor(builder, rdxi, signmask, "");
1766 tdynegi = LLVMBuildXor(builder, tdyi, signmask, "");
1767 rdynegi = LLVMBuildXor(builder, rdyi, signmask, "");
1768
1769 snewx = LLVMBuildXor(builder, signmabit, rnegi, "");
1770 tnewx = tnegi;
1771 sdxnewx = LLVMBuildXor(builder, signmabit, rdxnegi, "");
1772 tdxnewx = tdxnegi;
1773 sdynewx = LLVMBuildXor(builder, signmabit, rdynegi, "");
1774 tdynewx = tdynegi;
1775
1776 snewy = si;
1777 tnewy = LLVMBuildXor(builder, signmabit, ri, "");
1778 sdxnewy = sdxi;
1779 tdxnewy = LLVMBuildXor(builder, signmabit, rdxi, "");
1780 sdynewy = sdyi;
1781 tdynewy = LLVMBuildXor(builder, signmabit, rdyi, "");
1782
1783 snewz = LLVMBuildXor(builder, signmabit, si, "");
1784 tnewz = tnegi;
1785 sdxnewz = LLVMBuildXor(builder, signmabit, sdxi, "");
1786 tdxnewz = tdxnegi;
1787 sdynewz = LLVMBuildXor(builder, signmabit, sdyi, "");
1788 tdynewz = tdynegi;
1789
1790 /* select the mirrored values */
1791 face = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, facex, facey, facez);
1792 face_s = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, snewx, snewy, snewz);
1793 face_t = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, tnewx, tnewy, tnewz);
1794 face_sdx = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, sdxnewx, sdxnewy, sdxnewz);
1795 face_tdx = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, tdxnewx, tdxnewy, tdxnewz);
1796 face_sdy = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, sdynewx, sdynewy, sdynewz);
1797 face_tdy = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, tdynewx, tdynewy, tdynewz);
1798
1799 face_s = LLVMBuildBitCast(builder, face_s, coord_vec_type, "");
1800 face_t = LLVMBuildBitCast(builder, face_t, coord_vec_type, "");
1801 face_sdx = LLVMBuildBitCast(builder, face_sdx, coord_vec_type, "");
1802 face_tdx = LLVMBuildBitCast(builder, face_tdx, coord_vec_type, "");
1803 face_sdy = LLVMBuildBitCast(builder, face_sdy, coord_vec_type, "");
1804 face_tdy = LLVMBuildBitCast(builder, face_tdy, coord_vec_type, "");
1805
1806 /* deriv math, dx.s = 0.5 * (dx.sc - sc * dx.ma / ma) / ma */
1807 madxdivma = lp_build_mul(coord_bld, madx, ima);
1808 tmp = lp_build_mul(coord_bld, madxdivma, face_s);
1809 tmp = lp_build_sub(coord_bld, face_sdx, tmp);
1810 derivs_out->ddx[0] = lp_build_mul(coord_bld, tmp, imahalf);
1811
1812 /* dx.t = 0.5 * (dx.tc - tc * dx.ma / ma) / ma */
1813 tmp = lp_build_mul(coord_bld, madxdivma, face_t);
1814 tmp = lp_build_sub(coord_bld, face_tdx, tmp);
1815 derivs_out->ddx[1] = lp_build_mul(coord_bld, tmp, imahalf);
1816
1817 /* dy.s = 0.5 * (dy.sc - sc * dy.ma / ma) / ma */
1818 madydivma = lp_build_mul(coord_bld, mady, ima);
1819 tmp = lp_build_mul(coord_bld, madydivma, face_s);
1820 tmp = lp_build_sub(coord_bld, face_sdy, tmp);
1821 derivs_out->ddy[0] = lp_build_mul(coord_bld, tmp, imahalf);
1822
1823 /* dy.t = 0.5 * (dy.tc - tc * dy.ma / ma) / ma */
1824 tmp = lp_build_mul(coord_bld, madydivma, face_t);
1825 tmp = lp_build_sub(coord_bld, face_tdy, tmp);
1826 derivs_out->ddy[1] = lp_build_mul(coord_bld, tmp, imahalf);
1827
1828 signma = LLVMBuildLShr(builder, mai, signshift, "");
1829 coords[2] = LLVMBuildOr(builder, face, signma, "face");
1830
1831 /* project coords */
1832 face_s = lp_build_mul(coord_bld, face_s, imahalfpos);
1833 face_t = lp_build_mul(coord_bld, face_t, imahalfpos);
1834
1835 coords[0] = lp_build_add(coord_bld, face_s, posHalf);
1836 coords[1] = lp_build_add(coord_bld, face_t, posHalf);
1837
1838 return;
1839 }
1840
1841 else if (need_derivs) {
1842 LLVMValueRef ddx_ddy[2], tmp[3], rho_vec;
1843 static const unsigned char swizzle0[] = { /* no-op swizzle */
1844 0, LP_BLD_SWIZZLE_DONTCARE,
1845 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
1846 };
1847 static const unsigned char swizzle1[] = {
1848 1, LP_BLD_SWIZZLE_DONTCARE,
1849 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
1850 };
1851 static const unsigned char swizzle01[] = { /* no-op swizzle */
1852 0, 1,
1853 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
1854 };
1855 static const unsigned char swizzle23[] = {
1856 2, 3,
1857 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
1858 };
1859 static const unsigned char swizzle02[] = {
1860 0, 2,
1861 LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
1862 };
1863
1864 /*
1865 * scale the s/t/r coords pre-select/mirror so we can calculate
1866 * "reasonable" derivs.
1867 */
1868 ma = lp_build_select3(coord_bld, as_ge_at, ar_ge_as_at, s, t, r);
1869 imahalfpos = lp_build_cube_imapos(coord_bld, ma);
1870 s = lp_build_mul(coord_bld, s, imahalfpos);
1871 t = lp_build_mul(coord_bld, t, imahalfpos);
1872 r = lp_build_mul(coord_bld, r, imahalfpos);
1873
1874 /*
1875 * This isn't quite the same as the "ordinary" (3d deriv) path since we
1876 * know the texture is square which simplifies things (we can omit the
1877 * size mul which happens very early completely here and do it at the
1878 * very end).
1879 * Also always do calculations according to GALLIVM_DEBUG_NO_RHO_APPROX
1880 * since the error can get quite big otherwise at edges.
1881 * (With no_rho_approx max error is sqrt(2) at edges, same as it is
1882 * without no_rho_approx for 2d textures, otherwise it would be factor 2.)
1883 */
1884 ddx_ddy[0] = lp_build_packed_ddx_ddy_twocoord(coord_bld, s, t);
1885 ddx_ddy[1] = lp_build_packed_ddx_ddy_onecoord(coord_bld, r);
1886
1887 ddx_ddy[0] = lp_build_mul(coord_bld, ddx_ddy[0], ddx_ddy[0]);
1888 ddx_ddy[1] = lp_build_mul(coord_bld, ddx_ddy[1], ddx_ddy[1]);
1889
1890 tmp[0] = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle01);
1891 tmp[1] = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle23);
1892 tmp[2] = lp_build_swizzle_aos(coord_bld, ddx_ddy[1], swizzle02);
1893
1894 rho_vec = lp_build_add(coord_bld, tmp[0], tmp[1]);
1895 rho_vec = lp_build_add(coord_bld, rho_vec, tmp[2]);
1896
1897 tmp[0] = lp_build_swizzle_aos(coord_bld, rho_vec, swizzle0);
1898 tmp[1] = lp_build_swizzle_aos(coord_bld, rho_vec, swizzle1);
1899 *rho = lp_build_max(coord_bld, tmp[0], tmp[1]);
1900 }
1901
1902 if (!need_derivs) {
1903 ma = lp_build_select3(coord_bld, as_ge_at, ar_ge_as_at, s, t, r);
1904 }
1905 mai = LLVMBuildBitCast(builder, ma, cint_vec_type, "");
1906 signmabit = LLVMBuildAnd(builder, mai, signmask, "");
1907
1908 si = LLVMBuildBitCast(builder, s, cint_vec_type, "");
1909 ti = LLVMBuildBitCast(builder, t, cint_vec_type, "");
1910 ri = LLVMBuildBitCast(builder, r, cint_vec_type, "");
1911
1912 /*
1913 * compute all possible new s/t coords, which does the mirroring
1914 * snewx = signma * -r;
1915 * tnewx = -t;
1916 * snewy = s;
1917 * tnewy = signma * r;
1918 * snewz = signma * s;
1919 * tnewz = -t;
1920 */
1921 tnegi = LLVMBuildXor(builder, ti, signmask, "");
1922 rnegi = LLVMBuildXor(builder, ri, signmask, "");
1923
1924 snewx = LLVMBuildXor(builder, signmabit, rnegi, "");
1925 tnewx = tnegi;
1926
1927 snewy = si;
1928 tnewy = LLVMBuildXor(builder, signmabit, ri, "");
1929
1930 snewz = LLVMBuildXor(builder, signmabit, si, "");
1931 tnewz = tnegi;
1932
1933 /* select the mirrored values */
1934 face_s = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, snewx, snewy, snewz);
1935 face_t = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, tnewx, tnewy, tnewz);
1936 face = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, facex, facey, facez);
1937
1938 face_s = LLVMBuildBitCast(builder, face_s, coord_vec_type, "");
1939 face_t = LLVMBuildBitCast(builder, face_t, coord_vec_type, "");
1940
1941 /* add +1 for neg face */
1942 /* XXX with AVX probably want to use another select here -
1943 * as long as we ensure vblendvps gets used we can actually
1944 * skip the comparison and just use sign as a "mask" directly.
1945 */
1946 signma = LLVMBuildLShr(builder, mai, signshift, "");
1947 coords[2] = LLVMBuildOr(builder, face, signma, "face");
1948
1949 /* project coords */
1950 if (!need_derivs) {
1951 imahalfpos = lp_build_cube_imapos(coord_bld, ma);
1952 face_s = lp_build_mul(coord_bld, face_s, imahalfpos);
1953 face_t = lp_build_mul(coord_bld, face_t, imahalfpos);
1954 }
1955
1956 coords[0] = lp_build_add(coord_bld, face_s, posHalf);
1957 coords[1] = lp_build_add(coord_bld, face_t, posHalf);
1958 }
1959
1960
1961 /**
1962 * Compute the partial offset of a pixel block along an arbitrary axis.
1963 *
1964 * @param coord coordinate in pixels
1965 * @param stride number of bytes between rows of successive pixel blocks
1966 * @param block_length number of pixels in a pixels block along the coordinate
1967 * axis
1968 * @param out_offset resulting relative offset of the pixel block in bytes
1969 * @param out_subcoord resulting sub-block pixel coordinate
1970 */
1971 void
lp_build_sample_partial_offset(struct lp_build_context * bld,unsigned block_length,LLVMValueRef coord,LLVMValueRef stride,LLVMValueRef * out_offset,LLVMValueRef * out_subcoord)1972 lp_build_sample_partial_offset(struct lp_build_context *bld,
1973 unsigned block_length,
1974 LLVMValueRef coord,
1975 LLVMValueRef stride,
1976 LLVMValueRef *out_offset,
1977 LLVMValueRef *out_subcoord)
1978 {
1979 LLVMBuilderRef builder = bld->gallivm->builder;
1980 LLVMValueRef offset;
1981 LLVMValueRef subcoord;
1982
1983 if (block_length == 1) {
1984 subcoord = bld->zero;
1985 }
1986 else {
1987 /*
1988 * Pixel blocks have power of two dimensions. LLVM should convert the
1989 * rem/div to bit arithmetic.
1990 * TODO: Verify this.
1991 * It does indeed BUT it does transform it to scalar (and back) when doing so
1992 * (using roughly extract, shift/and, mov, unpack) (llvm 2.7).
1993 * The generated code looks seriously unfunny and is quite expensive.
1994 */
1995 #if 0
1996 LLVMValueRef block_width = lp_build_const_int_vec(bld->type, block_length);
1997 subcoord = LLVMBuildURem(builder, coord, block_width, "");
1998 coord = LLVMBuildUDiv(builder, coord, block_width, "");
1999 #else
2000 unsigned logbase2 = util_logbase2(block_length);
2001 LLVMValueRef block_shift = lp_build_const_int_vec(bld->gallivm, bld->type, logbase2);
2002 LLVMValueRef block_mask = lp_build_const_int_vec(bld->gallivm, bld->type, block_length - 1);
2003 subcoord = LLVMBuildAnd(builder, coord, block_mask, "");
2004 coord = LLVMBuildLShr(builder, coord, block_shift, "");
2005 #endif
2006 }
2007
2008 offset = lp_build_mul(bld, coord, stride);
2009
2010 assert(out_offset);
2011 assert(out_subcoord);
2012
2013 *out_offset = offset;
2014 *out_subcoord = subcoord;
2015 }
2016
2017
2018 /**
2019 * Compute the offset of a pixel block.
2020 *
2021 * x, y, z, y_stride, z_stride are vectors, and they refer to pixels.
2022 *
2023 * Returns the relative offset and i,j sub-block coordinates
2024 */
2025 void
lp_build_sample_offset(struct lp_build_context * bld,const struct util_format_description * format_desc,LLVMValueRef x,LLVMValueRef y,LLVMValueRef z,LLVMValueRef y_stride,LLVMValueRef z_stride,LLVMValueRef * out_offset,LLVMValueRef * out_i,LLVMValueRef * out_j)2026 lp_build_sample_offset(struct lp_build_context *bld,
2027 const struct util_format_description *format_desc,
2028 LLVMValueRef x,
2029 LLVMValueRef y,
2030 LLVMValueRef z,
2031 LLVMValueRef y_stride,
2032 LLVMValueRef z_stride,
2033 LLVMValueRef *out_offset,
2034 LLVMValueRef *out_i,
2035 LLVMValueRef *out_j)
2036 {
2037 LLVMValueRef x_stride;
2038 LLVMValueRef offset;
2039
2040 x_stride = lp_build_const_vec(bld->gallivm, bld->type,
2041 format_desc->block.bits/8);
2042
2043 lp_build_sample_partial_offset(bld,
2044 format_desc->block.width,
2045 x, x_stride,
2046 &offset, out_i);
2047
2048 if (y && y_stride) {
2049 LLVMValueRef y_offset;
2050 lp_build_sample_partial_offset(bld,
2051 format_desc->block.height,
2052 y, y_stride,
2053 &y_offset, out_j);
2054 offset = lp_build_add(bld, offset, y_offset);
2055 }
2056 else {
2057 *out_j = bld->zero;
2058 }
2059
2060 if (z && z_stride) {
2061 LLVMValueRef z_offset;
2062 LLVMValueRef k;
2063 lp_build_sample_partial_offset(bld,
2064 1, /* pixel blocks are always 2D */
2065 z, z_stride,
2066 &z_offset, &k);
2067 offset = lp_build_add(bld, offset, z_offset);
2068 }
2069
2070 *out_offset = offset;
2071 }
2072