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 */
63boolean
64lp_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 */
97void
98lp_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_or_zero(texture->width0);
118   state->pot_height        = util_is_power_of_two_or_zero(texture->height0);
119   state->pot_depth         = util_is_power_of_two_or_zero(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 */
133void
134lp_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->min_mip_filter    = sampler->min_mip_filter;
160   state->seamless_cube_map = sampler->seamless_cube_map;
161
162   if (sampler->max_lod > 0.0f) {
163      state->max_lod_pos = 1;
164   }
165
166   if (sampler->lod_bias != 0.0f) {
167      state->lod_bias_non_zero = 1;
168   }
169
170   if (state->min_mip_filter != PIPE_TEX_MIPFILTER_NONE ||
171       state->min_img_filter != state->mag_img_filter) {
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 */
208static LLVMValueRef
209lp_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 = bld->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] = { NULL }, ddx[3] = { NULL }, ddy[3] = { NULL };
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 */
563static void
564lp_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 */
609static void
610lp_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 */
662static LLVMValueRef
663lp_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 */
695void
696lp_build_lod_selector(struct lp_build_sample_context *bld,
697                      boolean is_lodq,
698                      unsigned texture_unit,
699                      unsigned sampler_unit,
700                      LLVMValueRef s,
701                      LLVMValueRef t,
702                      LLVMValueRef r,
703                      LLVMValueRef cube_rho,
704                      const struct lp_derivatives *derivs,
705                      LLVMValueRef lod_bias, /* optional */
706                      LLVMValueRef explicit_lod, /* optional */
707                      unsigned mip_filter,
708                      LLVMValueRef *out_lod,
709                      LLVMValueRef *out_lod_ipart,
710                      LLVMValueRef *out_lod_fpart,
711                      LLVMValueRef *out_lod_positive)
712
713{
714   LLVMBuilderRef builder = bld->gallivm->builder;
715   struct lp_sampler_dynamic_state *dynamic_state = bld->dynamic_state;
716   struct lp_build_context *lodf_bld = &bld->lodf_bld;
717   LLVMValueRef lod;
718
719   *out_lod_ipart = bld->lodi_bld.zero;
720   *out_lod_positive = bld->lodi_bld.zero;
721   *out_lod_fpart = lodf_bld->zero;
722
723   /*
724    * For determining min/mag, we follow GL 4.1 spec, 3.9.12 Texture Magnification:
725    * "Implementations may either unconditionally assume c = 0 for the minification
726    * vs. magnification switch-over point, or may choose to make c depend on the
727    * combination of minification and magnification modes as follows: if the
728    * magnification filter is given by LINEAR and the minification filter is given
729    * by NEAREST_MIPMAP_NEAREST or NEAREST_MIPMAP_LINEAR, then c = 0.5. This is
730    * done to ensure that a minified texture does not appear "sharper" than a
731    * magnified texture. Otherwise c = 0."
732    * And 3.9.11 Texture Minification:
733    * "If lod is less than or equal to the constant c (see section 3.9.12) the
734    * texture is said to be magnified; if it is greater, the texture is minified."
735    * So, using 0 as switchover point always, and using magnification for lod == 0.
736    * Note that the always c = 0 behavior is new (first appearing in GL 3.1 spec),
737    * old GL versions required 0.5 for the modes listed above.
738    * I have no clue about the (undocumented) wishes of d3d9/d3d10 here!
739    */
740
741   if (bld->static_sampler_state->min_max_lod_equal && !is_lodq) {
742      /* User is forcing sampling from a particular mipmap level.
743       * This is hit during mipmap generation.
744       */
745      LLVMValueRef min_lod =
746         dynamic_state->min_lod(dynamic_state, bld->gallivm,
747                                bld->context_ptr, sampler_unit);
748
749      lod = lp_build_broadcast_scalar(lodf_bld, min_lod);
750   }
751   else {
752      if (explicit_lod) {
753         if (bld->num_lods != bld->coord_type.length)
754            lod = lp_build_pack_aos_scalars(bld->gallivm, bld->coord_bld.type,
755                                            lodf_bld->type, explicit_lod, 0);
756         else
757            lod = explicit_lod;
758      }
759      else {
760         LLVMValueRef rho;
761         boolean rho_squared = (bld->no_rho_approx &&
762                                (bld->dims > 1)) || cube_rho;
763
764         rho = lp_build_rho(bld, texture_unit, s, t, r, cube_rho, derivs);
765
766         /*
767          * Compute lod = log2(rho)
768          */
769
770         if (!lod_bias && !is_lodq &&
771             !bld->static_sampler_state->lod_bias_non_zero &&
772             !bld->static_sampler_state->apply_max_lod &&
773             !bld->static_sampler_state->apply_min_lod) {
774            /*
775             * Special case when there are no post-log2 adjustments, which
776             * saves instructions but keeping the integer and fractional lod
777             * computations separate from the start.
778             */
779
780            if (mip_filter == PIPE_TEX_MIPFILTER_NONE ||
781                mip_filter == PIPE_TEX_MIPFILTER_NEAREST) {
782               /*
783                * Don't actually need both values all the time, lod_ipart is
784                * needed for nearest mipfilter, lod_positive if min != mag.
785                */
786               if (rho_squared) {
787                  *out_lod_ipart = lp_build_ilog2_sqrt(lodf_bld, rho);
788               }
789               else {
790                  *out_lod_ipart = lp_build_ilog2(lodf_bld, rho);
791               }
792               *out_lod_positive = lp_build_cmp(lodf_bld, PIPE_FUNC_GREATER,
793                                                rho, lodf_bld->one);
794               return;
795            }
796            if (mip_filter == PIPE_TEX_MIPFILTER_LINEAR &&
797                !bld->no_brilinear && !rho_squared) {
798               /*
799                * This can't work if rho is squared. Not sure if it could be
800                * fixed while keeping it worthwile, could also do sqrt here
801                * but brilinear and no_rho_opt seems like a combination not
802                * making much sense anyway so just use ordinary path below.
803                */
804               lp_build_brilinear_rho(lodf_bld, rho, BRILINEAR_FACTOR,
805                                      out_lod_ipart, out_lod_fpart);
806               *out_lod_positive = lp_build_cmp(lodf_bld, PIPE_FUNC_GREATER,
807                                                rho, lodf_bld->one);
808               return;
809            }
810         }
811
812         if (0) {
813            lod = lp_build_log2(lodf_bld, rho);
814         }
815         else {
816            lod = lp_build_fast_log2(lodf_bld, rho);
817         }
818         if (rho_squared) {
819            /* log2(x^2) == 0.5*log2(x) */
820            lod = lp_build_mul(lodf_bld, lod,
821                               lp_build_const_vec(bld->gallivm, lodf_bld->type, 0.5F));
822         }
823
824         /* add shader lod bias */
825         if (lod_bias) {
826            if (bld->num_lods != bld->coord_type.length)
827               lod_bias = lp_build_pack_aos_scalars(bld->gallivm, bld->coord_bld.type,
828                                                    lodf_bld->type, lod_bias, 0);
829            lod = LLVMBuildFAdd(builder, lod, lod_bias, "shader_lod_bias");
830         }
831      }
832
833      /* add sampler lod bias */
834      if (bld->static_sampler_state->lod_bias_non_zero) {
835         LLVMValueRef sampler_lod_bias =
836            dynamic_state->lod_bias(dynamic_state, bld->gallivm,
837                                    bld->context_ptr, sampler_unit);
838         sampler_lod_bias = lp_build_broadcast_scalar(lodf_bld,
839                                                      sampler_lod_bias);
840         lod = LLVMBuildFAdd(builder, lod, sampler_lod_bias, "sampler_lod_bias");
841      }
842
843      if (is_lodq) {
844         *out_lod = lod;
845      }
846
847      /* clamp lod */
848      if (bld->static_sampler_state->apply_max_lod) {
849         LLVMValueRef max_lod =
850            dynamic_state->max_lod(dynamic_state, bld->gallivm,
851                                   bld->context_ptr, sampler_unit);
852         max_lod = lp_build_broadcast_scalar(lodf_bld, max_lod);
853
854         lod = lp_build_min(lodf_bld, lod, max_lod);
855      }
856      if (bld->static_sampler_state->apply_min_lod) {
857         LLVMValueRef min_lod =
858            dynamic_state->min_lod(dynamic_state, bld->gallivm,
859                                   bld->context_ptr, sampler_unit);
860         min_lod = lp_build_broadcast_scalar(lodf_bld, min_lod);
861
862         lod = lp_build_max(lodf_bld, lod, min_lod);
863      }
864
865      if (is_lodq) {
866         *out_lod_fpart = lod;
867         return;
868      }
869   }
870
871   *out_lod_positive = lp_build_cmp(lodf_bld, PIPE_FUNC_GREATER,
872                                    lod, lodf_bld->zero);
873
874   if (mip_filter == PIPE_TEX_MIPFILTER_LINEAR) {
875      if (!bld->no_brilinear) {
876         lp_build_brilinear_lod(lodf_bld, lod, BRILINEAR_FACTOR,
877                                out_lod_ipart, out_lod_fpart);
878      }
879      else {
880         lp_build_ifloor_fract(lodf_bld, lod, out_lod_ipart, out_lod_fpart);
881      }
882
883      lp_build_name(*out_lod_fpart, "lod_fpart");
884   }
885   else {
886      *out_lod_ipart = lp_build_iround(lodf_bld, lod);
887   }
888
889   lp_build_name(*out_lod_ipart, "lod_ipart");
890
891   return;
892}
893
894
895/**
896 * For PIPE_TEX_MIPFILTER_NEAREST, convert int part of lod
897 * to actual mip level.
898 * Note: this is all scalar per quad code.
899 * \param lod_ipart  int texture level of detail
900 * \param level_out  returns integer
901 * \param out_of_bounds returns per coord out_of_bounds mask if provided
902 */
903void
904lp_build_nearest_mip_level(struct lp_build_sample_context *bld,
905                           unsigned texture_unit,
906                           LLVMValueRef lod_ipart,
907                           LLVMValueRef *level_out,
908                           LLVMValueRef *out_of_bounds)
909{
910   struct lp_build_context *leveli_bld = &bld->leveli_bld;
911   struct lp_sampler_dynamic_state *dynamic_state = bld->dynamic_state;
912   LLVMValueRef first_level, last_level, level;
913
914   first_level = dynamic_state->first_level(dynamic_state, bld->gallivm,
915                                            bld->context_ptr, texture_unit);
916   last_level = dynamic_state->last_level(dynamic_state, bld->gallivm,
917                                          bld->context_ptr, texture_unit);
918   first_level = lp_build_broadcast_scalar(leveli_bld, first_level);
919   last_level = lp_build_broadcast_scalar(leveli_bld, last_level);
920
921   level = lp_build_add(leveli_bld, lod_ipart, first_level);
922
923   if (out_of_bounds) {
924      LLVMValueRef out, out1;
925      out = lp_build_cmp(leveli_bld, PIPE_FUNC_LESS, level, first_level);
926      out1 = lp_build_cmp(leveli_bld, PIPE_FUNC_GREATER, level, last_level);
927      out = lp_build_or(leveli_bld, out, out1);
928      if (bld->num_mips == bld->coord_bld.type.length) {
929         *out_of_bounds = out;
930      }
931      else if (bld->num_mips == 1) {
932         *out_of_bounds = lp_build_broadcast_scalar(&bld->int_coord_bld, out);
933      }
934      else {
935         assert(bld->num_mips == bld->coord_bld.type.length / 4);
936         *out_of_bounds = lp_build_unpack_broadcast_aos_scalars(bld->gallivm,
937                                                                leveli_bld->type,
938                                                                bld->int_coord_bld.type,
939                                                                out);
940      }
941      level = lp_build_andnot(&bld->int_coord_bld, level, *out_of_bounds);
942      *level_out = level;
943   }
944   else {
945      /* clamp level to legal range of levels */
946      *level_out = lp_build_clamp(leveli_bld, level, first_level, last_level);
947
948   }
949}
950
951
952/**
953 * For PIPE_TEX_MIPFILTER_LINEAR, convert per-quad (or per element) int LOD(s)
954 * to two (per-quad) (adjacent) mipmap level indexes, and fix up float lod
955 * part accordingly.
956 * Later, we'll sample from those two mipmap levels and interpolate between them.
957 */
958void
959lp_build_linear_mip_levels(struct lp_build_sample_context *bld,
960                           unsigned texture_unit,
961                           LLVMValueRef lod_ipart,
962                           LLVMValueRef *lod_fpart_inout,
963                           LLVMValueRef *level0_out,
964                           LLVMValueRef *level1_out)
965{
966   LLVMBuilderRef builder = bld->gallivm->builder;
967   struct lp_sampler_dynamic_state *dynamic_state = bld->dynamic_state;
968   struct lp_build_context *leveli_bld = &bld->leveli_bld;
969   struct lp_build_context *levelf_bld = &bld->levelf_bld;
970   LLVMValueRef first_level, last_level;
971   LLVMValueRef clamp_min;
972   LLVMValueRef clamp_max;
973
974   assert(bld->num_lods == bld->num_mips);
975
976   first_level = dynamic_state->first_level(dynamic_state, bld->gallivm,
977                                            bld->context_ptr, texture_unit);
978   last_level = dynamic_state->last_level(dynamic_state, bld->gallivm,
979                                          bld->context_ptr, texture_unit);
980   first_level = lp_build_broadcast_scalar(leveli_bld, first_level);
981   last_level = lp_build_broadcast_scalar(leveli_bld, last_level);
982
983   *level0_out = lp_build_add(leveli_bld, lod_ipart, first_level);
984   *level1_out = lp_build_add(leveli_bld, *level0_out, leveli_bld->one);
985
986   /*
987    * Clamp both *level0_out and *level1_out to [first_level, last_level], with
988    * the minimum number of comparisons, and zeroing lod_fpart in the extreme
989    * ends in the process.
990    */
991
992   /* *level0_out < first_level */
993   clamp_min = LLVMBuildICmp(builder, LLVMIntSLT,
994                             *level0_out, first_level,
995                             "clamp_lod_to_first");
996
997   *level0_out = LLVMBuildSelect(builder, clamp_min,
998                                 first_level, *level0_out, "");
999
1000   *level1_out = LLVMBuildSelect(builder, clamp_min,
1001                                 first_level, *level1_out, "");
1002
1003   *lod_fpart_inout = LLVMBuildSelect(builder, clamp_min,
1004                                      levelf_bld->zero, *lod_fpart_inout, "");
1005
1006   /* *level0_out >= last_level */
1007   clamp_max = LLVMBuildICmp(builder, LLVMIntSGE,
1008                             *level0_out, last_level,
1009                             "clamp_lod_to_last");
1010
1011   *level0_out = LLVMBuildSelect(builder, clamp_max,
1012                                 last_level, *level0_out, "");
1013
1014   *level1_out = LLVMBuildSelect(builder, clamp_max,
1015                                 last_level, *level1_out, "");
1016
1017   *lod_fpart_inout = LLVMBuildSelect(builder, clamp_max,
1018                                      levelf_bld->zero, *lod_fpart_inout, "");
1019
1020   lp_build_name(*level0_out, "texture%u_miplevel0", texture_unit);
1021   lp_build_name(*level1_out, "texture%u_miplevel1", texture_unit);
1022   lp_build_name(*lod_fpart_inout, "texture%u_mipweight", texture_unit);
1023}
1024
1025
1026/**
1027 * Return pointer to a single mipmap level.
1028 * \param level  integer mipmap level
1029 */
1030LLVMValueRef
1031lp_build_get_mipmap_level(struct lp_build_sample_context *bld,
1032                          LLVMValueRef level)
1033{
1034   LLVMBuilderRef builder = bld->gallivm->builder;
1035   LLVMValueRef indexes[2], data_ptr, mip_offset;
1036
1037   indexes[0] = lp_build_const_int32(bld->gallivm, 0);
1038   indexes[1] = level;
1039   mip_offset = LLVMBuildGEP(builder, bld->mip_offsets, indexes, 2, "");
1040   mip_offset = LLVMBuildLoad(builder, mip_offset, "");
1041   data_ptr = LLVMBuildGEP(builder, bld->base_ptr, &mip_offset, 1, "");
1042   return data_ptr;
1043}
1044
1045/**
1046 * Return (per-pixel) offsets to mip levels.
1047 * \param level  integer mipmap level
1048 */
1049LLVMValueRef
1050lp_build_get_mip_offsets(struct lp_build_sample_context *bld,
1051                         LLVMValueRef level)
1052{
1053   LLVMBuilderRef builder = bld->gallivm->builder;
1054   LLVMValueRef indexes[2], offsets, offset1;
1055
1056   indexes[0] = lp_build_const_int32(bld->gallivm, 0);
1057   if (bld->num_mips == 1) {
1058      indexes[1] = level;
1059      offset1 = LLVMBuildGEP(builder, bld->mip_offsets, indexes, 2, "");
1060      offset1 = LLVMBuildLoad(builder, offset1, "");
1061      offsets = lp_build_broadcast_scalar(&bld->int_coord_bld, offset1);
1062   }
1063   else if (bld->num_mips == bld->coord_bld.type.length / 4) {
1064      unsigned i;
1065
1066      offsets = bld->int_coord_bld.undef;
1067      for (i = 0; i < bld->num_mips; i++) {
1068         LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1069         LLVMValueRef indexo = lp_build_const_int32(bld->gallivm, 4 * i);
1070         indexes[1] = LLVMBuildExtractElement(builder, level, indexi, "");
1071         offset1 = LLVMBuildGEP(builder, bld->mip_offsets, indexes, 2, "");
1072         offset1 = LLVMBuildLoad(builder, offset1, "");
1073         offsets = LLVMBuildInsertElement(builder, offsets, offset1, indexo, "");
1074      }
1075      offsets = lp_build_swizzle_scalar_aos(&bld->int_coord_bld, offsets, 0, 4);
1076   }
1077   else {
1078      unsigned i;
1079
1080      assert (bld->num_mips == bld->coord_bld.type.length);
1081
1082      offsets = bld->int_coord_bld.undef;
1083      for (i = 0; i < bld->num_mips; i++) {
1084         LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1085         indexes[1] = LLVMBuildExtractElement(builder, level, indexi, "");
1086         offset1 = LLVMBuildGEP(builder, bld->mip_offsets, indexes, 2, "");
1087         offset1 = LLVMBuildLoad(builder, offset1, "");
1088         offsets = LLVMBuildInsertElement(builder, offsets, offset1, indexi, "");
1089      }
1090   }
1091   return offsets;
1092}
1093
1094
1095/**
1096 * Codegen equivalent for u_minify().
1097 * @param lod_scalar  if lod is a (broadcasted) scalar
1098 * Return max(1, base_size >> level);
1099 */
1100LLVMValueRef
1101lp_build_minify(struct lp_build_context *bld,
1102                LLVMValueRef base_size,
1103                LLVMValueRef level,
1104                boolean lod_scalar)
1105{
1106   LLVMBuilderRef builder = bld->gallivm->builder;
1107   assert(lp_check_value(bld->type, base_size));
1108   assert(lp_check_value(bld->type, level));
1109
1110   if (level == bld->zero) {
1111      /* if we're using mipmap level zero, no minification is needed */
1112      return base_size;
1113   }
1114   else {
1115      LLVMValueRef size;
1116      assert(bld->type.sign);
1117      if (lod_scalar ||
1118         (util_cpu_caps.has_avx2 || !util_cpu_caps.has_sse)) {
1119         size = LLVMBuildLShr(builder, base_size, level, "minify");
1120         size = lp_build_max(bld, size, bld->one);
1121      }
1122      else {
1123         /*
1124          * emulate shift with float mul, since intel "forgot" shifts with
1125          * per-element shift count until avx2, which results in terrible
1126          * scalar extraction (both count and value), scalar shift,
1127          * vector reinsertion. Should not be an issue on any non-x86 cpu
1128          * with a vector instruction set.
1129          * On cpus with AMD's XOP this should also be unnecessary but I'm
1130          * not sure if llvm would emit this with current flags.
1131          */
1132         LLVMValueRef const127, const23, lf;
1133         struct lp_type ftype;
1134         struct lp_build_context fbld;
1135         ftype = lp_type_float_vec(32, bld->type.length * bld->type.width);
1136         lp_build_context_init(&fbld, bld->gallivm, ftype);
1137         const127 = lp_build_const_int_vec(bld->gallivm, bld->type, 127);
1138         const23 = lp_build_const_int_vec(bld->gallivm, bld->type, 23);
1139
1140         /* calculate 2^(-level) float */
1141         lf = lp_build_sub(bld, const127, level);
1142         lf = lp_build_shl(bld, lf, const23);
1143         lf = LLVMBuildBitCast(builder, lf, fbld.vec_type, "");
1144
1145         /* finish shift operation by doing float mul */
1146         base_size = lp_build_int_to_float(&fbld, base_size);
1147         size = lp_build_mul(&fbld, base_size, lf);
1148         /*
1149          * do the max also with floats because
1150          * a) non-emulated int max requires sse41
1151          *    (this is actually a lie as we could cast to 16bit values
1152          *    as 16bit is sufficient and 16bit int max is sse2)
1153          * b) with avx we can do int max 4-wide but float max 8-wide
1154          */
1155         size = lp_build_max(&fbld, size, fbld.one);
1156         size = lp_build_itrunc(&fbld, size);
1157      }
1158      return size;
1159   }
1160}
1161
1162
1163/**
1164 * Dereference stride_array[mipmap_level] array to get a stride.
1165 * Return stride as a vector.
1166 */
1167static LLVMValueRef
1168lp_build_get_level_stride_vec(struct lp_build_sample_context *bld,
1169                              LLVMValueRef stride_array, LLVMValueRef level)
1170{
1171   LLVMBuilderRef builder = bld->gallivm->builder;
1172   LLVMValueRef indexes[2], stride, stride1;
1173   indexes[0] = lp_build_const_int32(bld->gallivm, 0);
1174   if (bld->num_mips == 1) {
1175      indexes[1] = level;
1176      stride1 = LLVMBuildGEP(builder, stride_array, indexes, 2, "");
1177      stride1 = LLVMBuildLoad(builder, stride1, "");
1178      stride = lp_build_broadcast_scalar(&bld->int_coord_bld, stride1);
1179   }
1180   else if (bld->num_mips == bld->coord_bld.type.length / 4) {
1181      LLVMValueRef stride1;
1182      unsigned i;
1183
1184      stride = bld->int_coord_bld.undef;
1185      for (i = 0; i < bld->num_mips; i++) {
1186         LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1187         LLVMValueRef indexo = lp_build_const_int32(bld->gallivm, 4 * i);
1188         indexes[1] = LLVMBuildExtractElement(builder, level, indexi, "");
1189         stride1 = LLVMBuildGEP(builder, stride_array, indexes, 2, "");
1190         stride1 = LLVMBuildLoad(builder, stride1, "");
1191         stride = LLVMBuildInsertElement(builder, stride, stride1, indexo, "");
1192      }
1193      stride = lp_build_swizzle_scalar_aos(&bld->int_coord_bld, stride, 0, 4);
1194   }
1195   else {
1196      LLVMValueRef stride1;
1197      unsigned i;
1198
1199      assert (bld->num_mips == bld->coord_bld.type.length);
1200
1201      stride = bld->int_coord_bld.undef;
1202      for (i = 0; i < bld->coord_bld.type.length; i++) {
1203         LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1204         indexes[1] = LLVMBuildExtractElement(builder, level, indexi, "");
1205         stride1 = LLVMBuildGEP(builder, stride_array, indexes, 2, "");
1206         stride1 = LLVMBuildLoad(builder, stride1, "");
1207         stride = LLVMBuildInsertElement(builder, stride, stride1, indexi, "");
1208      }
1209   }
1210   return stride;
1211}
1212
1213
1214/**
1215 * When sampling a mipmap, we need to compute the width, height, depth
1216 * of the source levels from the level indexes.  This helper function
1217 * does that.
1218 */
1219void
1220lp_build_mipmap_level_sizes(struct lp_build_sample_context *bld,
1221                            LLVMValueRef ilevel,
1222                            LLVMValueRef *out_size,
1223                            LLVMValueRef *row_stride_vec,
1224                            LLVMValueRef *img_stride_vec)
1225{
1226   const unsigned dims = bld->dims;
1227   LLVMValueRef ilevel_vec;
1228
1229   /*
1230    * Compute width, height, depth at mipmap level 'ilevel'
1231    */
1232   if (bld->num_mips == 1) {
1233      ilevel_vec = lp_build_broadcast_scalar(&bld->int_size_bld, ilevel);
1234      *out_size = lp_build_minify(&bld->int_size_bld, bld->int_size, ilevel_vec, TRUE);
1235   }
1236   else {
1237      LLVMValueRef int_size_vec;
1238      LLVMValueRef tmp[LP_MAX_VECTOR_LENGTH];
1239      unsigned num_quads = bld->coord_bld.type.length / 4;
1240      unsigned i;
1241
1242      if (bld->num_mips == num_quads) {
1243         /*
1244          * XXX: this should be #ifndef SANE_INSTRUCTION_SET.
1245          * intel "forgot" the variable shift count instruction until avx2.
1246          * A harmless 8x32 shift gets translated into 32 instructions
1247          * (16 extracts, 8 scalar shifts, 8 inserts), llvm is apparently
1248          * unable to recognize if there are really just 2 different shift
1249          * count values. So do the shift 4-wide before expansion.
1250          */
1251         struct lp_build_context bld4;
1252         struct lp_type type4;
1253
1254         type4 = bld->int_coord_bld.type;
1255         type4.length = 4;
1256
1257         lp_build_context_init(&bld4, bld->gallivm, type4);
1258
1259         if (bld->dims == 1) {
1260            assert(bld->int_size_in_bld.type.length == 1);
1261            int_size_vec = lp_build_broadcast_scalar(&bld4,
1262                                                     bld->int_size);
1263         }
1264         else {
1265            assert(bld->int_size_in_bld.type.length == 4);
1266            int_size_vec = bld->int_size;
1267         }
1268
1269         for (i = 0; i < num_quads; i++) {
1270            LLVMValueRef ileveli;
1271            LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1272
1273            ileveli = lp_build_extract_broadcast(bld->gallivm,
1274                                                 bld->leveli_bld.type,
1275                                                 bld4.type,
1276                                                 ilevel,
1277                                                 indexi);
1278            tmp[i] = lp_build_minify(&bld4, int_size_vec, ileveli, TRUE);
1279         }
1280         /*
1281          * out_size is [w0, h0, d0, _, w1, h1, d1, _, ...] vector for dims > 1,
1282          * [w0, w0, w0, w0, w1, w1, w1, w1, ...] otherwise.
1283          */
1284         *out_size = lp_build_concat(bld->gallivm,
1285                                     tmp,
1286                                     bld4.type,
1287                                     num_quads);
1288      }
1289      else {
1290        /* FIXME: this is terrible and results in _huge_ vector
1291         * (for the dims > 1 case).
1292         * Should refactor this (together with extract_image_sizes) and do
1293         * something more useful. Could for instance if we have width,height
1294         * with 4-wide vector pack all elements into a 8xi16 vector
1295         * (on which we can still do useful math) instead of using a 16xi32
1296         * vector.
1297         * For dims == 1 this will create [w0, w1, w2, w3, ...] vector.
1298         * For dims > 1 this will create [w0, h0, d0, _, w1, h1, d1, _, ...] vector.
1299         */
1300         assert(bld->num_mips == bld->coord_bld.type.length);
1301         if (bld->dims == 1) {
1302            assert(bld->int_size_in_bld.type.length == 1);
1303            int_size_vec = lp_build_broadcast_scalar(&bld->int_coord_bld,
1304                                                     bld->int_size);
1305            *out_size = lp_build_minify(&bld->int_coord_bld, int_size_vec, ilevel, FALSE);
1306         }
1307         else {
1308            LLVMValueRef ilevel1;
1309            for (i = 0; i < bld->num_mips; i++) {
1310               LLVMValueRef indexi = lp_build_const_int32(bld->gallivm, i);
1311               ilevel1 = lp_build_extract_broadcast(bld->gallivm, bld->int_coord_type,
1312                                                    bld->int_size_in_bld.type, ilevel, indexi);
1313               tmp[i] = bld->int_size;
1314               tmp[i] = lp_build_minify(&bld->int_size_in_bld, tmp[i], ilevel1, TRUE);
1315            }
1316            *out_size = lp_build_concat(bld->gallivm, tmp,
1317                                        bld->int_size_in_bld.type,
1318                                        bld->num_mips);
1319         }
1320      }
1321   }
1322
1323   if (dims >= 2) {
1324      *row_stride_vec = lp_build_get_level_stride_vec(bld,
1325                                                      bld->row_stride_array,
1326                                                      ilevel);
1327   }
1328   if (dims == 3 || has_layer_coord(bld->static_texture_state->target)) {
1329      *img_stride_vec = lp_build_get_level_stride_vec(bld,
1330                                                      bld->img_stride_array,
1331                                                      ilevel);
1332   }
1333}
1334
1335
1336/**
1337 * Extract and broadcast texture size.
1338 *
1339 * @param size_type   type of the texture size vector (either
1340 *                    bld->int_size_type or bld->float_size_type)
1341 * @param coord_type  type of the texture size vector (either
1342 *                    bld->int_coord_type or bld->coord_type)
1343 * @param size        vector with the texture size (width, height, depth)
1344 */
1345void
1346lp_build_extract_image_sizes(struct lp_build_sample_context *bld,
1347                             struct lp_build_context *size_bld,
1348                             struct lp_type coord_type,
1349                             LLVMValueRef size,
1350                             LLVMValueRef *out_width,
1351                             LLVMValueRef *out_height,
1352                             LLVMValueRef *out_depth)
1353{
1354   const unsigned dims = bld->dims;
1355   LLVMTypeRef i32t = LLVMInt32TypeInContext(bld->gallivm->context);
1356   struct lp_type size_type = size_bld->type;
1357
1358   if (bld->num_mips == 1) {
1359      *out_width = lp_build_extract_broadcast(bld->gallivm,
1360                                              size_type,
1361                                              coord_type,
1362                                              size,
1363                                              LLVMConstInt(i32t, 0, 0));
1364      if (dims >= 2) {
1365         *out_height = lp_build_extract_broadcast(bld->gallivm,
1366                                                  size_type,
1367                                                  coord_type,
1368                                                  size,
1369                                                  LLVMConstInt(i32t, 1, 0));
1370         if (dims == 3) {
1371            *out_depth = lp_build_extract_broadcast(bld->gallivm,
1372                                                    size_type,
1373                                                    coord_type,
1374                                                    size,
1375                                                    LLVMConstInt(i32t, 2, 0));
1376         }
1377      }
1378   }
1379   else {
1380      unsigned num_quads = bld->coord_bld.type.length / 4;
1381
1382      if (dims == 1) {
1383         *out_width = size;
1384      }
1385      else if (bld->num_mips == num_quads) {
1386         *out_width = lp_build_swizzle_scalar_aos(size_bld, size, 0, 4);
1387         if (dims >= 2) {
1388            *out_height = lp_build_swizzle_scalar_aos(size_bld, size, 1, 4);
1389            if (dims == 3) {
1390               *out_depth = lp_build_swizzle_scalar_aos(size_bld, size, 2, 4);
1391            }
1392         }
1393      }
1394      else {
1395         assert(bld->num_mips == bld->coord_type.length);
1396         *out_width = lp_build_pack_aos_scalars(bld->gallivm, size_type,
1397                                                coord_type, size, 0);
1398         if (dims >= 2) {
1399            *out_height = lp_build_pack_aos_scalars(bld->gallivm, size_type,
1400                                                    coord_type, size, 1);
1401            if (dims == 3) {
1402               *out_depth = lp_build_pack_aos_scalars(bld->gallivm, size_type,
1403                                                      coord_type, size, 2);
1404            }
1405         }
1406      }
1407   }
1408}
1409
1410
1411/**
1412 * Unnormalize coords.
1413 *
1414 * @param flt_size  vector with the integer texture size (width, height, depth)
1415 */
1416void
1417lp_build_unnormalized_coords(struct lp_build_sample_context *bld,
1418                             LLVMValueRef flt_size,
1419                             LLVMValueRef *s,
1420                             LLVMValueRef *t,
1421                             LLVMValueRef *r)
1422{
1423   const unsigned dims = bld->dims;
1424   LLVMValueRef width;
1425   LLVMValueRef height = NULL;
1426   LLVMValueRef depth = NULL;
1427
1428   lp_build_extract_image_sizes(bld,
1429                                &bld->float_size_bld,
1430                                bld->coord_type,
1431                                flt_size,
1432                                &width,
1433                                &height,
1434                                &depth);
1435
1436   /* s = s * width, t = t * height */
1437   *s = lp_build_mul(&bld->coord_bld, *s, width);
1438   if (dims >= 2) {
1439      *t = lp_build_mul(&bld->coord_bld, *t, height);
1440      if (dims >= 3) {
1441         *r = lp_build_mul(&bld->coord_bld, *r, depth);
1442      }
1443   }
1444}
1445
1446/**
1447 * Generate new coords and faces for cubemap texels falling off the face.
1448 *
1449 * @param face   face (center) of the pixel
1450 * @param x0     lower x coord
1451 * @param x1     higher x coord (must be x0 + 1)
1452 * @param y0     lower y coord
1453 * @param y1     higher y coord (must be x0 + 1)
1454 * @param max_coord     texture cube (level) size - 1
1455 * @param next_faces    new face values when falling off
1456 * @param next_xcoords  new x coord values when falling off
1457 * @param next_ycoords  new y coord values when falling off
1458 *
1459 * The arrays hold the new values when under/overflow of
1460 * lower x, higher x, lower y, higher y coord would occur (in this order).
1461 * next_xcoords/next_ycoords have two entries each (for both new lower and
1462 * higher coord).
1463 */
1464void
1465lp_build_cube_new_coords(struct lp_build_context *ivec_bld,
1466                        LLVMValueRef face,
1467                        LLVMValueRef x0,
1468                        LLVMValueRef x1,
1469                        LLVMValueRef y0,
1470                        LLVMValueRef y1,
1471                        LLVMValueRef max_coord,
1472                        LLVMValueRef next_faces[4],
1473                        LLVMValueRef next_xcoords[4][2],
1474                        LLVMValueRef next_ycoords[4][2])
1475{
1476   /*
1477    * Lookup tables aren't nice for simd code hence try some logic here.
1478    * (Note that while it would not be necessary to do per-sample (4) lookups
1479    * when using a LUT as it's impossible that texels fall off of positive
1480    * and negative edges simultaneously, it would however be necessary to
1481    * do 2 lookups for corner handling as in this case texels both fall off
1482    * of x and y axes.)
1483    */
1484   /*
1485    * Next faces (for face 012345):
1486    * x < 0.0  : 451110
1487    * x >= 1.0 : 540001
1488    * y < 0.0  : 225422
1489    * y >= 1.0 : 334533
1490    * Hence nfx+ (and nfy+) == nfx- (nfy-) xor 1
1491    * nfx-: face > 1 ? (face == 5 ? 0 : 1) : (4 + face & 1)
1492    * nfy+: face & ~4 > 1 ? face + 2 : 3;
1493    * This could also use pshufb instead, but would need (manually coded)
1494    * ssse3 intrinsic (llvm won't do non-constant shuffles).
1495    */
1496   struct gallivm_state *gallivm = ivec_bld->gallivm;
1497   LLVMValueRef sel, sel_f2345, sel_f23, sel_f2, tmpsel, tmp;
1498   LLVMValueRef faceand1, sel_fand1, maxmx0, maxmx1, maxmy0, maxmy1;
1499   LLVMValueRef c2 = lp_build_const_int_vec(gallivm, ivec_bld->type, 2);
1500   LLVMValueRef c3 = lp_build_const_int_vec(gallivm, ivec_bld->type, 3);
1501   LLVMValueRef c4 = lp_build_const_int_vec(gallivm, ivec_bld->type, 4);
1502   LLVMValueRef c5 = lp_build_const_int_vec(gallivm, ivec_bld->type, 5);
1503
1504   sel = lp_build_cmp(ivec_bld, PIPE_FUNC_EQUAL, face, c5);
1505   tmpsel = lp_build_select(ivec_bld, sel, ivec_bld->zero, ivec_bld->one);
1506   sel_f2345 = lp_build_cmp(ivec_bld, PIPE_FUNC_GREATER, face, ivec_bld->one);
1507   faceand1 = lp_build_and(ivec_bld, face, ivec_bld->one);
1508   tmp = lp_build_add(ivec_bld, faceand1, c4);
1509   next_faces[0] = lp_build_select(ivec_bld, sel_f2345, tmpsel, tmp);
1510   next_faces[1] = lp_build_xor(ivec_bld, next_faces[0], ivec_bld->one);
1511
1512   tmp = lp_build_andnot(ivec_bld, face, c4);
1513   sel_f23 = lp_build_cmp(ivec_bld, PIPE_FUNC_GREATER, tmp, ivec_bld->one);
1514   tmp = lp_build_add(ivec_bld, face, c2);
1515   next_faces[3] = lp_build_select(ivec_bld, sel_f23, tmp, c3);
1516   next_faces[2] = lp_build_xor(ivec_bld, next_faces[3], ivec_bld->one);
1517
1518   /*
1519    * new xcoords (for face 012345):
1520    * x < 0.0  : max   max   t     max-t max  max
1521    * x >= 1.0 : 0     0     max-t t     0    0
1522    * y < 0.0  : max   0     max-s s     s    max-s
1523    * y >= 1.0 : max   0     s     max-s s    max-s
1524    *
1525    * ncx[1] = face & ~4 > 1 ? (face == 2 ? max-t : t) : 0
1526    * ncx[0] = max - ncx[1]
1527    * ncx[3] = face > 1 ? (face & 1 ? max-s : s) : (face & 1) ? 0 : max
1528    * ncx[2] = face & ~4 > 1 ? max - ncx[3] : ncx[3]
1529    */
1530   sel_f2 = lp_build_cmp(ivec_bld, PIPE_FUNC_EQUAL, face, c2);
1531   maxmy0 = lp_build_sub(ivec_bld, max_coord, y0);
1532   tmp = lp_build_select(ivec_bld, sel_f2, maxmy0, y0);
1533   next_xcoords[1][0] = lp_build_select(ivec_bld, sel_f23, tmp, ivec_bld->zero);
1534   next_xcoords[0][0] = lp_build_sub(ivec_bld, max_coord, next_xcoords[1][0]);
1535   maxmy1 = lp_build_sub(ivec_bld, max_coord, y1);
1536   tmp = lp_build_select(ivec_bld, sel_f2, maxmy1, y1);
1537   next_xcoords[1][1] = lp_build_select(ivec_bld, sel_f23, tmp, ivec_bld->zero);
1538   next_xcoords[0][1] = lp_build_sub(ivec_bld, max_coord, next_xcoords[1][1]);
1539
1540   sel_fand1 = lp_build_cmp(ivec_bld, PIPE_FUNC_EQUAL, faceand1, ivec_bld->one);
1541
1542   tmpsel = lp_build_select(ivec_bld, sel_fand1, ivec_bld->zero, max_coord);
1543   maxmx0 = lp_build_sub(ivec_bld, max_coord, x0);
1544   tmp = lp_build_select(ivec_bld, sel_fand1, maxmx0, x0);
1545   next_xcoords[3][0] = lp_build_select(ivec_bld, sel_f2345, tmp, tmpsel);
1546   tmp = lp_build_sub(ivec_bld, max_coord, next_xcoords[3][0]);
1547   next_xcoords[2][0] = lp_build_select(ivec_bld, sel_f23, tmp, next_xcoords[3][0]);
1548   maxmx1 = lp_build_sub(ivec_bld, max_coord, x1);
1549   tmp = lp_build_select(ivec_bld, sel_fand1, maxmx1, x1);
1550   next_xcoords[3][1] = lp_build_select(ivec_bld, sel_f2345, tmp, tmpsel);
1551   tmp = lp_build_sub(ivec_bld, max_coord, next_xcoords[3][1]);
1552   next_xcoords[2][1] = lp_build_select(ivec_bld, sel_f23, tmp, next_xcoords[3][1]);
1553
1554   /*
1555    * new ycoords (for face 012345):
1556    * x < 0.0  : t     t     0     max   t    t
1557    * x >= 1.0 : t     t     0     max   t    t
1558    * y < 0.0  : max-s s     0     max   max  0
1559    * y >= 1.0 : s     max-s 0     max   0    max
1560    *
1561    * ncy[0] = face & ~4 > 1 ? (face == 2 ? 0 : max) : t
1562    * ncy[1] = ncy[0]
1563    * ncy[3] = face > 1 ? (face & 1 ? max : 0) : (face & 1) ? max-s : max
1564    * ncx[2] = face & ~4 > 1 ? max - ncx[3] : ncx[3]
1565    */
1566   tmp = lp_build_select(ivec_bld, sel_f2, ivec_bld->zero, max_coord);
1567   next_ycoords[0][0] = lp_build_select(ivec_bld, sel_f23, tmp, y0);
1568   next_ycoords[1][0] = next_ycoords[0][0];
1569   next_ycoords[0][1] = lp_build_select(ivec_bld, sel_f23, tmp, y1);
1570   next_ycoords[1][1] = next_ycoords[0][1];
1571
1572   tmpsel = lp_build_select(ivec_bld, sel_fand1, maxmx0, x0);
1573   tmp = lp_build_select(ivec_bld, sel_fand1, max_coord, ivec_bld->zero);
1574   next_ycoords[3][0] = lp_build_select(ivec_bld, sel_f2345, tmp, tmpsel);
1575   tmp = lp_build_sub(ivec_bld, max_coord, next_ycoords[3][0]);
1576   next_ycoords[2][0] = lp_build_select(ivec_bld, sel_f23, next_ycoords[3][0], tmp);
1577   tmpsel = lp_build_select(ivec_bld, sel_fand1, maxmx1, x1);
1578   tmp = lp_build_select(ivec_bld, sel_fand1, max_coord, ivec_bld->zero);
1579   next_ycoords[3][1] = lp_build_select(ivec_bld, sel_f2345, tmp, tmpsel);
1580   tmp = lp_build_sub(ivec_bld, max_coord, next_ycoords[3][1]);
1581   next_ycoords[2][1] = lp_build_select(ivec_bld, sel_f23, next_ycoords[3][1], tmp);
1582}
1583
1584
1585/** Helper used by lp_build_cube_lookup() */
1586static LLVMValueRef
1587lp_build_cube_imapos(struct lp_build_context *coord_bld, LLVMValueRef coord)
1588{
1589   /* ima = +0.5 / abs(coord); */
1590   LLVMValueRef posHalf = lp_build_const_vec(coord_bld->gallivm, coord_bld->type, 0.5);
1591   LLVMValueRef absCoord = lp_build_abs(coord_bld, coord);
1592   LLVMValueRef ima = lp_build_div(coord_bld, posHalf, absCoord);
1593   return ima;
1594}
1595
1596
1597/** Helper for doing 3-wise selection.
1598 * Returns sel1 ? val2 : (sel0 ? val0 : val1).
1599 */
1600static LLVMValueRef
1601lp_build_select3(struct lp_build_context *sel_bld,
1602                 LLVMValueRef sel0,
1603                 LLVMValueRef sel1,
1604                 LLVMValueRef val0,
1605                 LLVMValueRef val1,
1606                 LLVMValueRef val2)
1607{
1608   LLVMValueRef tmp;
1609   tmp = lp_build_select(sel_bld, sel0, val0, val1);
1610   return lp_build_select(sel_bld, sel1, val2, tmp);
1611}
1612
1613
1614/**
1615 * Generate code to do cube face selection and compute per-face texcoords.
1616 */
1617void
1618lp_build_cube_lookup(struct lp_build_sample_context *bld,
1619                     LLVMValueRef *coords,
1620                     const struct lp_derivatives *derivs_in, /* optional */
1621                     LLVMValueRef *rho,
1622                     struct lp_derivatives *derivs_out, /* optional */
1623                     boolean need_derivs)
1624{
1625   struct lp_build_context *coord_bld = &bld->coord_bld;
1626   LLVMBuilderRef builder = bld->gallivm->builder;
1627   struct gallivm_state *gallivm = bld->gallivm;
1628   LLVMValueRef si, ti, ri;
1629
1630   /*
1631    * Do per-pixel face selection. We cannot however (as we used to do)
1632    * simply calculate the derivs afterwards (which is very bogus for
1633    * explicit derivs btw) because the values would be "random" when
1634    * not all pixels lie on the same face. So what we do here is just
1635    * calculate the derivatives after scaling the coords by the absolute
1636    * value of the inverse major axis, and essentially do rho calculation
1637    * steps as if it were a 3d texture. This is perfect if all pixels hit
1638    * the same face, but not so great at edges, I believe the max error
1639    * should be sqrt(2) with no_rho_approx or 2 otherwise (essentially measuring
1640    * the 3d distance between 2 points on the cube instead of measuring up/down
1641    * the edge). Still this is possibly a win over just selecting the same face
1642    * for all pixels. Unfortunately, something like that doesn't work for
1643    * explicit derivatives.
1644    */
1645   struct lp_build_context *cint_bld = &bld->int_coord_bld;
1646   struct lp_type intctype = cint_bld->type;
1647   LLVMTypeRef coord_vec_type = coord_bld->vec_type;
1648   LLVMTypeRef cint_vec_type = cint_bld->vec_type;
1649   LLVMValueRef as, at, ar, face, face_s, face_t;
1650   LLVMValueRef as_ge_at, maxasat, ar_ge_as_at;
1651   LLVMValueRef snewx, tnewx, snewy, tnewy, snewz, tnewz;
1652   LLVMValueRef tnegi, rnegi;
1653   LLVMValueRef ma, mai, signma, signmabit, imahalfpos;
1654   LLVMValueRef posHalf = lp_build_const_vec(gallivm, coord_bld->type, 0.5);
1655   LLVMValueRef signmask = lp_build_const_int_vec(gallivm, intctype,
1656                                                  1LL << (intctype.width - 1));
1657   LLVMValueRef signshift = lp_build_const_int_vec(gallivm, intctype,
1658                                                   intctype.width -1);
1659   LLVMValueRef facex = lp_build_const_int_vec(gallivm, intctype, PIPE_TEX_FACE_POS_X);
1660   LLVMValueRef facey = lp_build_const_int_vec(gallivm, intctype, PIPE_TEX_FACE_POS_Y);
1661   LLVMValueRef facez = lp_build_const_int_vec(gallivm, intctype, PIPE_TEX_FACE_POS_Z);
1662   LLVMValueRef s = coords[0];
1663   LLVMValueRef t = coords[1];
1664   LLVMValueRef r = coords[2];
1665
1666   assert(PIPE_TEX_FACE_NEG_X == PIPE_TEX_FACE_POS_X + 1);
1667   assert(PIPE_TEX_FACE_NEG_Y == PIPE_TEX_FACE_POS_Y + 1);
1668   assert(PIPE_TEX_FACE_NEG_Z == PIPE_TEX_FACE_POS_Z + 1);
1669
1670   /*
1671    * get absolute value (for x/y/z face selection) and sign bit
1672    * (for mirroring minor coords and pos/neg face selection)
1673    * of the original coords.
1674    */
1675   as = lp_build_abs(&bld->coord_bld, s);
1676   at = lp_build_abs(&bld->coord_bld, t);
1677   ar = lp_build_abs(&bld->coord_bld, r);
1678
1679   /*
1680    * major face determination: select x if x > y else select y
1681    * select z if z >= max(x,y) else select previous result
1682    * if some axis are the same we chose z over y, y over x - the
1683    * dx10 spec seems to ask for it while OpenGL doesn't care (if we
1684    * wouldn't care could save a select or two if using different
1685    * compares and doing at_g_as_ar last since tnewx and tnewz are the
1686    * same).
1687    */
1688   as_ge_at = lp_build_cmp(coord_bld, PIPE_FUNC_GREATER, as, at);
1689   maxasat = lp_build_max(coord_bld, as, at);
1690   ar_ge_as_at = lp_build_cmp(coord_bld, PIPE_FUNC_GEQUAL, ar, maxasat);
1691
1692   if (need_derivs && (derivs_in || (bld->no_quad_lod && bld->no_rho_approx))) {
1693      /*
1694       * XXX: This is really really complex.
1695       * It is a bit overkill to use this for implicit derivatives as well,
1696       * no way this is worth the cost in practice, but seems to be the
1697       * only way for getting accurate and per-pixel lod values.
1698       */
1699      LLVMValueRef ima, imahalf, tmp, ddx[3], ddy[3];
1700      LLVMValueRef madx, mady, madxdivma, madydivma;
1701      LLVMValueRef sdxi, tdxi, rdxi, sdyi, tdyi, rdyi;
1702      LLVMValueRef tdxnegi, rdxnegi, tdynegi, rdynegi;
1703      LLVMValueRef sdxnewx, sdxnewy, sdxnewz, tdxnewx, tdxnewy, tdxnewz;
1704      LLVMValueRef sdynewx, sdynewy, sdynewz, tdynewx, tdynewy, tdynewz;
1705      LLVMValueRef face_sdx, face_tdx, face_sdy, face_tdy;
1706      /*
1707       * s = 1/2 * ( sc / ma + 1)
1708       * t = 1/2 * ( tc / ma + 1)
1709       *
1710       * s' = 1/2 * (sc' * ma - sc * ma') / ma^2
1711       * t' = 1/2 * (tc' * ma - tc * ma') / ma^2
1712       *
1713       * dx.s = 0.5 * (dx.sc - sc * dx.ma / ma) / ma
1714       * dx.t = 0.5 * (dx.tc - tc * dx.ma / ma) / ma
1715       * dy.s = 0.5 * (dy.sc - sc * dy.ma / ma) / ma
1716       * dy.t = 0.5 * (dy.tc - tc * dy.ma / ma) / ma
1717       */
1718
1719      /* select ma, calculate ima */
1720      ma = lp_build_select3(coord_bld, as_ge_at, ar_ge_as_at, s, t, r);
1721      mai = LLVMBuildBitCast(builder, ma, cint_vec_type, "");
1722      signmabit = LLVMBuildAnd(builder, mai, signmask, "");
1723      ima = lp_build_div(coord_bld, coord_bld->one, ma);
1724      imahalf = lp_build_mul(coord_bld, posHalf, ima);
1725      imahalfpos = lp_build_abs(coord_bld, imahalf);
1726
1727      if (!derivs_in) {
1728         ddx[0] = lp_build_ddx(coord_bld, s);
1729         ddx[1] = lp_build_ddx(coord_bld, t);
1730         ddx[2] = lp_build_ddx(coord_bld, r);
1731         ddy[0] = lp_build_ddy(coord_bld, s);
1732         ddy[1] = lp_build_ddy(coord_bld, t);
1733         ddy[2] = lp_build_ddy(coord_bld, r);
1734      }
1735      else {
1736         ddx[0] = derivs_in->ddx[0];
1737         ddx[1] = derivs_in->ddx[1];
1738         ddx[2] = derivs_in->ddx[2];
1739         ddy[0] = derivs_in->ddy[0];
1740         ddy[1] = derivs_in->ddy[1];
1741         ddy[2] = derivs_in->ddy[2];
1742      }
1743
1744      /* select major derivatives */
1745      madx = lp_build_select3(coord_bld, as_ge_at, ar_ge_as_at, ddx[0], ddx[1], ddx[2]);
1746      mady = lp_build_select3(coord_bld, as_ge_at, ar_ge_as_at, ddy[0], ddy[1], ddy[2]);
1747
1748      si = LLVMBuildBitCast(builder, s, cint_vec_type, "");
1749      ti = LLVMBuildBitCast(builder, t, cint_vec_type, "");
1750      ri = LLVMBuildBitCast(builder, r, cint_vec_type, "");
1751
1752      sdxi = LLVMBuildBitCast(builder, ddx[0], cint_vec_type, "");
1753      tdxi = LLVMBuildBitCast(builder, ddx[1], cint_vec_type, "");
1754      rdxi = LLVMBuildBitCast(builder, ddx[2], cint_vec_type, "");
1755
1756      sdyi = LLVMBuildBitCast(builder, ddy[0], cint_vec_type, "");
1757      tdyi = LLVMBuildBitCast(builder, ddy[1], cint_vec_type, "");
1758      rdyi = LLVMBuildBitCast(builder, ddy[2], cint_vec_type, "");
1759
1760      /*
1761       * compute all possible new s/t coords, which does the mirroring,
1762       * and do the same for derivs minor axes.
1763       * snewx = signma * -r;
1764       * tnewx = -t;
1765       * snewy = s;
1766       * tnewy = signma * r;
1767       * snewz = signma * s;
1768       * tnewz = -t;
1769       */
1770      tnegi = LLVMBuildXor(builder, ti, signmask, "");
1771      rnegi = LLVMBuildXor(builder, ri, signmask, "");
1772      tdxnegi = LLVMBuildXor(builder, tdxi, signmask, "");
1773      rdxnegi = LLVMBuildXor(builder, rdxi, signmask, "");
1774      tdynegi = LLVMBuildXor(builder, tdyi, signmask, "");
1775      rdynegi = LLVMBuildXor(builder, rdyi, signmask, "");
1776
1777      snewx = LLVMBuildXor(builder, signmabit, rnegi, "");
1778      tnewx = tnegi;
1779      sdxnewx = LLVMBuildXor(builder, signmabit, rdxnegi, "");
1780      tdxnewx = tdxnegi;
1781      sdynewx = LLVMBuildXor(builder, signmabit, rdynegi, "");
1782      tdynewx = tdynegi;
1783
1784      snewy = si;
1785      tnewy = LLVMBuildXor(builder, signmabit, ri, "");
1786      sdxnewy = sdxi;
1787      tdxnewy = LLVMBuildXor(builder, signmabit, rdxi, "");
1788      sdynewy = sdyi;
1789      tdynewy = LLVMBuildXor(builder, signmabit, rdyi, "");
1790
1791      snewz = LLVMBuildXor(builder, signmabit, si, "");
1792      tnewz = tnegi;
1793      sdxnewz = LLVMBuildXor(builder, signmabit, sdxi, "");
1794      tdxnewz = tdxnegi;
1795      sdynewz = LLVMBuildXor(builder, signmabit, sdyi, "");
1796      tdynewz = tdynegi;
1797
1798      /* select the mirrored values */
1799      face = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, facex, facey, facez);
1800      face_s = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, snewx, snewy, snewz);
1801      face_t = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, tnewx, tnewy, tnewz);
1802      face_sdx = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, sdxnewx, sdxnewy, sdxnewz);
1803      face_tdx = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, tdxnewx, tdxnewy, tdxnewz);
1804      face_sdy = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, sdynewx, sdynewy, sdynewz);
1805      face_tdy = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, tdynewx, tdynewy, tdynewz);
1806
1807      face_s = LLVMBuildBitCast(builder, face_s, coord_vec_type, "");
1808      face_t = LLVMBuildBitCast(builder, face_t, coord_vec_type, "");
1809      face_sdx = LLVMBuildBitCast(builder, face_sdx, coord_vec_type, "");
1810      face_tdx = LLVMBuildBitCast(builder, face_tdx, coord_vec_type, "");
1811      face_sdy = LLVMBuildBitCast(builder, face_sdy, coord_vec_type, "");
1812      face_tdy = LLVMBuildBitCast(builder, face_tdy, coord_vec_type, "");
1813
1814      /* deriv math, dx.s = 0.5 * (dx.sc - sc * dx.ma / ma) / ma */
1815      madxdivma = lp_build_mul(coord_bld, madx, ima);
1816      tmp = lp_build_mul(coord_bld, madxdivma, face_s);
1817      tmp = lp_build_sub(coord_bld, face_sdx, tmp);
1818      derivs_out->ddx[0] = lp_build_mul(coord_bld, tmp, imahalf);
1819
1820      /* dx.t = 0.5 * (dx.tc - tc * dx.ma / ma) / ma */
1821      tmp = lp_build_mul(coord_bld, madxdivma, face_t);
1822      tmp = lp_build_sub(coord_bld, face_tdx, tmp);
1823      derivs_out->ddx[1] = lp_build_mul(coord_bld, tmp, imahalf);
1824
1825      /* dy.s = 0.5 * (dy.sc - sc * dy.ma / ma) / ma */
1826      madydivma = lp_build_mul(coord_bld, mady, ima);
1827      tmp = lp_build_mul(coord_bld, madydivma, face_s);
1828      tmp = lp_build_sub(coord_bld, face_sdy, tmp);
1829      derivs_out->ddy[0] = lp_build_mul(coord_bld, tmp, imahalf);
1830
1831      /* dy.t = 0.5 * (dy.tc - tc * dy.ma / ma) / ma */
1832      tmp = lp_build_mul(coord_bld, madydivma, face_t);
1833      tmp = lp_build_sub(coord_bld, face_tdy, tmp);
1834      derivs_out->ddy[1] = lp_build_mul(coord_bld, tmp, imahalf);
1835
1836      signma = LLVMBuildLShr(builder, mai, signshift, "");
1837      coords[2] = LLVMBuildOr(builder, face, signma, "face");
1838
1839      /* project coords */
1840      face_s = lp_build_mul(coord_bld, face_s, imahalfpos);
1841      face_t = lp_build_mul(coord_bld, face_t, imahalfpos);
1842
1843      coords[0] = lp_build_add(coord_bld, face_s, posHalf);
1844      coords[1] = lp_build_add(coord_bld, face_t, posHalf);
1845
1846      return;
1847   }
1848
1849   else if (need_derivs) {
1850      LLVMValueRef ddx_ddy[2], tmp[3], rho_vec;
1851      static const unsigned char swizzle0[] = { /* no-op swizzle */
1852         0, LP_BLD_SWIZZLE_DONTCARE,
1853         LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
1854      };
1855      static const unsigned char swizzle1[] = {
1856         1, LP_BLD_SWIZZLE_DONTCARE,
1857         LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
1858      };
1859      static const unsigned char swizzle01[] = { /* no-op swizzle */
1860         0, 1,
1861         LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
1862      };
1863      static const unsigned char swizzle23[] = {
1864         2, 3,
1865         LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
1866      };
1867      static const unsigned char swizzle02[] = {
1868         0, 2,
1869         LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE
1870      };
1871
1872      /*
1873       * scale the s/t/r coords pre-select/mirror so we can calculate
1874       * "reasonable" derivs.
1875       */
1876      ma = lp_build_select3(coord_bld, as_ge_at, ar_ge_as_at, s, t, r);
1877      imahalfpos = lp_build_cube_imapos(coord_bld, ma);
1878      s = lp_build_mul(coord_bld, s, imahalfpos);
1879      t = lp_build_mul(coord_bld, t, imahalfpos);
1880      r = lp_build_mul(coord_bld, r, imahalfpos);
1881
1882      /*
1883       * This isn't quite the same as the "ordinary" (3d deriv) path since we
1884       * know the texture is square which simplifies things (we can omit the
1885       * size mul which happens very early completely here and do it at the
1886       * very end).
1887       * Also always do calculations according to GALLIVM_DEBUG_NO_RHO_APPROX
1888       * since the error can get quite big otherwise at edges.
1889       * (With no_rho_approx max error is sqrt(2) at edges, same as it is
1890       * without no_rho_approx for 2d textures, otherwise it would be factor 2.)
1891       */
1892      ddx_ddy[0] = lp_build_packed_ddx_ddy_twocoord(coord_bld, s, t);
1893      ddx_ddy[1] = lp_build_packed_ddx_ddy_onecoord(coord_bld, r);
1894
1895      ddx_ddy[0] = lp_build_mul(coord_bld, ddx_ddy[0], ddx_ddy[0]);
1896      ddx_ddy[1] = lp_build_mul(coord_bld, ddx_ddy[1], ddx_ddy[1]);
1897
1898      tmp[0] = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle01);
1899      tmp[1] = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle23);
1900      tmp[2] = lp_build_swizzle_aos(coord_bld, ddx_ddy[1], swizzle02);
1901
1902      rho_vec = lp_build_add(coord_bld, tmp[0], tmp[1]);
1903      rho_vec = lp_build_add(coord_bld, rho_vec, tmp[2]);
1904
1905      tmp[0] = lp_build_swizzle_aos(coord_bld, rho_vec, swizzle0);
1906      tmp[1] = lp_build_swizzle_aos(coord_bld, rho_vec, swizzle1);
1907      *rho = lp_build_max(coord_bld, tmp[0], tmp[1]);
1908   }
1909
1910   if (!need_derivs) {
1911      ma = lp_build_select3(coord_bld, as_ge_at, ar_ge_as_at, s, t, r);
1912   }
1913   mai = LLVMBuildBitCast(builder, ma, cint_vec_type, "");
1914   signmabit = LLVMBuildAnd(builder, mai, signmask, "");
1915
1916   si = LLVMBuildBitCast(builder, s, cint_vec_type, "");
1917   ti = LLVMBuildBitCast(builder, t, cint_vec_type, "");
1918   ri = LLVMBuildBitCast(builder, r, cint_vec_type, "");
1919
1920   /*
1921    * compute all possible new s/t coords, which does the mirroring
1922    * snewx = signma * -r;
1923    * tnewx = -t;
1924    * snewy = s;
1925    * tnewy = signma * r;
1926    * snewz = signma * s;
1927    * tnewz = -t;
1928    */
1929   tnegi = LLVMBuildXor(builder, ti, signmask, "");
1930   rnegi = LLVMBuildXor(builder, ri, signmask, "");
1931
1932   snewx = LLVMBuildXor(builder, signmabit, rnegi, "");
1933   tnewx = tnegi;
1934
1935   snewy = si;
1936   tnewy = LLVMBuildXor(builder, signmabit, ri, "");
1937
1938   snewz = LLVMBuildXor(builder, signmabit, si, "");
1939   tnewz = tnegi;
1940
1941   /* select the mirrored values */
1942   face_s = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, snewx, snewy, snewz);
1943   face_t = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, tnewx, tnewy, tnewz);
1944   face = lp_build_select3(cint_bld, as_ge_at, ar_ge_as_at, facex, facey, facez);
1945
1946   face_s = LLVMBuildBitCast(builder, face_s, coord_vec_type, "");
1947   face_t = LLVMBuildBitCast(builder, face_t, coord_vec_type, "");
1948
1949   /* add +1 for neg face */
1950   /* XXX with AVX probably want to use another select here -
1951    * as long as we ensure vblendvps gets used we can actually
1952    * skip the comparison and just use sign as a "mask" directly.
1953    */
1954   signma = LLVMBuildLShr(builder, mai, signshift, "");
1955   coords[2] = LLVMBuildOr(builder, face, signma, "face");
1956
1957   /* project coords */
1958   if (!need_derivs) {
1959      imahalfpos = lp_build_cube_imapos(coord_bld, ma);
1960      face_s = lp_build_mul(coord_bld, face_s, imahalfpos);
1961      face_t = lp_build_mul(coord_bld, face_t, imahalfpos);
1962   }
1963
1964   coords[0] = lp_build_add(coord_bld, face_s, posHalf);
1965   coords[1] = lp_build_add(coord_bld, face_t, posHalf);
1966}
1967
1968
1969/**
1970 * Compute the partial offset of a pixel block along an arbitrary axis.
1971 *
1972 * @param coord   coordinate in pixels
1973 * @param stride  number of bytes between rows of successive pixel blocks
1974 * @param block_length  number of pixels in a pixels block along the coordinate
1975 *                      axis
1976 * @param out_offset    resulting relative offset of the pixel block in bytes
1977 * @param out_subcoord  resulting sub-block pixel coordinate
1978 */
1979void
1980lp_build_sample_partial_offset(struct lp_build_context *bld,
1981                               unsigned block_length,
1982                               LLVMValueRef coord,
1983                               LLVMValueRef stride,
1984                               LLVMValueRef *out_offset,
1985                               LLVMValueRef *out_subcoord)
1986{
1987   LLVMBuilderRef builder = bld->gallivm->builder;
1988   LLVMValueRef offset;
1989   LLVMValueRef subcoord;
1990
1991   if (block_length == 1) {
1992      subcoord = bld->zero;
1993   }
1994   else {
1995      /*
1996       * Pixel blocks have power of two dimensions. LLVM should convert the
1997       * rem/div to bit arithmetic.
1998       * TODO: Verify this.
1999       * It does indeed BUT it does transform it to scalar (and back) when doing so
2000       * (using roughly extract, shift/and, mov, unpack) (llvm 2.7).
2001       * The generated code looks seriously unfunny and is quite expensive.
2002       */
2003#if 0
2004      LLVMValueRef block_width = lp_build_const_int_vec(bld->type, block_length);
2005      subcoord = LLVMBuildURem(builder, coord, block_width, "");
2006      coord    = LLVMBuildUDiv(builder, coord, block_width, "");
2007#else
2008      unsigned logbase2 = util_logbase2(block_length);
2009      LLVMValueRef block_shift = lp_build_const_int_vec(bld->gallivm, bld->type, logbase2);
2010      LLVMValueRef block_mask = lp_build_const_int_vec(bld->gallivm, bld->type, block_length - 1);
2011      subcoord = LLVMBuildAnd(builder, coord, block_mask, "");
2012      coord = LLVMBuildLShr(builder, coord, block_shift, "");
2013#endif
2014   }
2015
2016   offset = lp_build_mul(bld, coord, stride);
2017
2018   assert(out_offset);
2019   assert(out_subcoord);
2020
2021   *out_offset = offset;
2022   *out_subcoord = subcoord;
2023}
2024
2025
2026/**
2027 * Compute the offset of a pixel block.
2028 *
2029 * x, y, z, y_stride, z_stride are vectors, and they refer to pixels.
2030 *
2031 * Returns the relative offset and i,j sub-block coordinates
2032 */
2033void
2034lp_build_sample_offset(struct lp_build_context *bld,
2035                       const struct util_format_description *format_desc,
2036                       LLVMValueRef x,
2037                       LLVMValueRef y,
2038                       LLVMValueRef z,
2039                       LLVMValueRef y_stride,
2040                       LLVMValueRef z_stride,
2041                       LLVMValueRef *out_offset,
2042                       LLVMValueRef *out_i,
2043                       LLVMValueRef *out_j)
2044{
2045   LLVMValueRef x_stride;
2046   LLVMValueRef offset;
2047
2048   x_stride = lp_build_const_vec(bld->gallivm, bld->type,
2049                                 format_desc->block.bits/8);
2050
2051   lp_build_sample_partial_offset(bld,
2052                                  format_desc->block.width,
2053                                  x, x_stride,
2054                                  &offset, out_i);
2055
2056   if (y && y_stride) {
2057      LLVMValueRef y_offset;
2058      lp_build_sample_partial_offset(bld,
2059                                     format_desc->block.height,
2060                                     y, y_stride,
2061                                     &y_offset, out_j);
2062      offset = lp_build_add(bld, offset, y_offset);
2063   }
2064   else {
2065      *out_j = bld->zero;
2066   }
2067
2068   if (z && z_stride) {
2069      LLVMValueRef z_offset;
2070      LLVMValueRef k;
2071      lp_build_sample_partial_offset(bld,
2072                                     1, /* pixel blocks are always 2D */
2073                                     z, z_stride,
2074                                     &z_offset, &k);
2075      offset = lp_build_add(bld, offset, z_offset);
2076   }
2077
2078   *out_offset = offset;
2079}
2080