src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c

   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 -- SoA.
  31  *
  32  * @author Jose Fonseca <jfonseca@vmware.com>
  33  * @author Brian Paul <brianp@vmware.com>
  34  */
  35
  36 #include "pipe/p_defines.h"
  37 #include "pipe/p_state.h"
  38 #include "util/u_debug.h"
  39 #include "util/u_dump.h"
  40 #include "util/u_memory.h"
  41 #include "util/u_math.h"
  42 #include "util/u_format.h"
  43 #include "lp_bld_debug.h"
  44 #include "lp_bld_type.h"
  45 #include "lp_bld_const.h"
  46 #include "lp_bld_conv.h"
  47 #include "lp_bld_arit.h"
  48 #include "lp_bld_bitarit.h"
  49 #include "lp_bld_logic.h"
  50 #include "lp_bld_printf.h"
  51 #include "lp_bld_swizzle.h"
  52 #include "lp_bld_flow.h"
  53 #include "lp_bld_gather.h"
  54 #include "lp_bld_format.h"
  55 #include "lp_bld_sample.h"
  56 #include "lp_bld_sample_aos.h"
  57 #include "lp_bld_struct.h"
  58 #include "lp_bld_quad.h"
  59
  60
  61 /**
  62  * Generate code to fetch a texel from a texture at int coords (x, y, z).
  63  * The computation depends on whether the texture is 1D, 2D or 3D.
  64  * The result, texel, will be float vectors:
  65  *   texel[0] = red values
  66  *   texel[1] = green values
  67  *   texel[2] = blue values
  68  *   texel[3] = alpha values
  69  */
  70 static void
  71 lp_build_sample_texel_soa(struct lp_build_sample_context *bld,
  72                           unsigned unit,
  73                           LLVMValueRef width,
  74                           LLVMValueRef height,
  75                           LLVMValueRef depth,
  76                           LLVMValueRef x,
  77                           LLVMValueRef y,
  78                           LLVMValueRef z,
  79                           LLVMValueRef y_stride,
  80                           LLVMValueRef z_stride,
  81                           LLVMValueRef data_ptr,
  82                           LLVMValueRef texel_out[4])
  83 {
  84    const struct lp_sampler_static_state *static_state = bld->static_state;
  85    const unsigned dims = bld->dims;
  86    struct lp_build_context *int_coord_bld = &bld->int_coord_bld;
  87    LLVMValueRef offset;
  88    LLVMValueRef i, j;
  89    LLVMValueRef use_border = NULL;
  90
  91    /* use_border = x < 0 || x >= width || y < 0 || y >= height */
  92    if (lp_sampler_wrap_mode_uses_border_color(static_state->wrap_s,
  93                                               static_state->min_img_filter,
  94                                               static_state->mag_img_filter)) {
  95       LLVMValueRef b1, b2;
  96       b1 = lp_build_cmp(int_coord_bld, PIPE_FUNC_LESS, x, int_coord_bld->zero);
  97       b2 = lp_build_cmp(int_coord_bld, PIPE_FUNC_GEQUAL, x, width);
  98       use_border = LLVMBuildOr(bld->builder, b1, b2, "b1_or_b2");
  99    }
 100
 101    if (dims >= 2 &&
 102        lp_sampler_wrap_mode_uses_border_color(static_state->wrap_t,
 103                                               static_state->min_img_filter,
 104                                               static_state->mag_img_filter)) {
 105       LLVMValueRef b1, b2;
 106       b1 = lp_build_cmp(int_coord_bld, PIPE_FUNC_LESS, y, int_coord_bld->zero);
 107       b2 = lp_build_cmp(int_coord_bld, PIPE_FUNC_GEQUAL, y, height);
 108       if (use_border) {
 109          use_border = LLVMBuildOr(bld->builder, use_border, b1, "ub_or_b1");
 110          use_border = LLVMBuildOr(bld->builder, use_border, b2, "ub_or_b2");
 111       }
 112       else {
 113          use_border = LLVMBuildOr(bld->builder, b1, b2, "b1_or_b2");
 114       }
 115    }
 116
 117    if (dims == 3 &&
 118        lp_sampler_wrap_mode_uses_border_color(static_state->wrap_r,
 119                                               static_state->min_img_filter,
 120                                               static_state->mag_img_filter)) {
 121       LLVMValueRef b1, b2;
 122       b1 = lp_build_cmp(int_coord_bld, PIPE_FUNC_LESS, z, int_coord_bld->zero);
 123       b2 = lp_build_cmp(int_coord_bld, PIPE_FUNC_GEQUAL, z, depth);
 124       if (use_border) {
 125          use_border = LLVMBuildOr(bld->builder, use_border, b1, "ub_or_b1");
 126          use_border = LLVMBuildOr(bld->builder, use_border, b2, "ub_or_b2");
 127       }
 128       else {
 129          use_border = LLVMBuildOr(bld->builder, b1, b2, "b1_or_b2");
 130       }
 131    }
 132
 133    /* convert x,y,z coords to linear offset from start of texture, in bytes */
 134    lp_build_sample_offset(&bld->int_coord_bld,
 135                           bld->format_desc,
 136                           x, y, z, y_stride, z_stride,
 137                           &offset, &i, &j);
 138
 139    if (use_border) {
 140       /* If we can sample the border color, it means that texcoords may
 141        * lie outside the bounds of the texture image.  We need to do
 142        * something to prevent reading out of bounds and causing a segfault.
 143        *
 144        * Simply AND the texture coords with !use_border.  This will cause
 145        * coords which are out of bounds to become zero.  Zero's guaranteed
 146        * to be inside the texture image.
 147        */
 148       offset = lp_build_andnot(&bld->int_coord_bld, offset, use_border);
 149    }
 150
 151    lp_build_fetch_rgba_soa(bld->builder,
 152                            bld->format_desc,
 153                            bld->texel_type,
 154                            data_ptr, offset,
 155                            i, j,
 156                            texel_out);
 157
 158    /*
 159     * Note: if we find an app which frequently samples the texture border
 160     * we might want to implement a true conditional here to avoid sampling
 161     * the texture whenever possible (since that's quite a bit of code).
 162     * Ex:
 163     *   if (use_border) {
 164     *      texel = border_color;
 165     *   }
 166     *   else {
 167     *      texel = sample_texture(coord);
 168     *   }
 169     * As it is now, we always sample the texture, then selectively replace
 170     * the texel color results with the border color.
 171     */
 172
 173    if (use_border) {
 174       /* select texel color or border color depending on use_border */
 175       LLVMValueRef border_color_ptr =
 176          bld->dynamic_state->border_color(bld->dynamic_state,
 177                                           bld->builder, unit);
 178       int chan;
 179       for (chan = 0; chan < 4; chan++) {
 180          LLVMValueRef border_chan =
 181             lp_build_array_get(bld->builder, border_color_ptr,
 182                                lp_build_const_int32(chan));
 183          LLVMValueRef border_chan_vec =
 184             lp_build_broadcast_scalar(&bld->float_vec_bld, border_chan);
 185          texel_out[chan] = lp_build_select(&bld->texel_bld, use_border,
 186                                            border_chan_vec, texel_out[chan]);
 187       }
 188    }
 189
 190    apply_sampler_swizzle(bld, texel_out);
 191 }
 192
 193
 194 /**
 195  * Helper to compute the mirror function for the PIPE_WRAP_MIRROR modes.
 196  */
 197 static LLVMValueRef
 198 lp_build_coord_mirror(struct lp_build_sample_context *bld,
 199                       LLVMValueRef coord)
 200 {
 201    struct lp_build_context *coord_bld = &bld->coord_bld;
 202    struct lp_build_context *int_coord_bld = &bld->int_coord_bld;
 203    LLVMValueRef fract, flr, isOdd;
 204
 205    lp_build_ifloor_fract(coord_bld, coord, &flr, &fract);
 206
 207    /* isOdd = flr & 1 */
 208    isOdd = LLVMBuildAnd(bld->builder, flr, int_coord_bld->one, "");
 209
 210    /* make coord positive or negative depending on isOdd */
 211    coord = lp_build_set_sign(coord_bld, fract, isOdd);
 212
 213    /* convert isOdd to float */
 214    isOdd = lp_build_int_to_float(coord_bld, isOdd);
 215
 216    /* add isOdd to coord */
 217    coord = lp_build_add(coord_bld, coord, isOdd);
 218
 219    return coord;
 220 }
 221
 222
 223 /**
 224  * Build LLVM code for texture wrap mode for linear filtering.
 225  * \param x0_out  returns first integer texcoord
 226  * \param x1_out  returns second integer texcoord
 227  * \param weight_out  returns linear interpolation weight
 228  */
 229 static void
 230 lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
 231                             LLVMValueRef coord,
 232                             LLVMValueRef length,
 233                             LLVMValueRef length_f,
 234                             boolean is_pot,
 235                             unsigned wrap_mode,
 236                             LLVMValueRef *x0_out,
 237                             LLVMValueRef *x1_out,
 238                             LLVMValueRef *weight_out)
 239 {
 240    struct lp_build_context *coord_bld = &bld->coord_bld;
 241    struct lp_build_context *int_coord_bld = &bld->int_coord_bld;
 242    LLVMValueRef half = lp_build_const_vec(coord_bld->type, 0.5);
 243    LLVMValueRef length_minus_one = lp_build_sub(int_coord_bld, length, int_coord_bld->one);
 244    LLVMValueRef coord0, coord1, weight;
 245
 246    switch(wrap_mode) {
 247    case PIPE_TEX_WRAP_REPEAT:
 248       /* mul by size and subtract 0.5 */
 249       coord = lp_build_mul(coord_bld, coord, length_f);
 250       coord = lp_build_sub(coord_bld, coord, half);
 251       /* convert to int, compute lerp weight */
 252       lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
 253       /* repeat wrap */
 254       if (is_pot) {
 255          coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
 256          coord0 = LLVMBuildAnd(bld->builder, coord0, length_minus_one, "");
 257          coord1 = LLVMBuildAnd(bld->builder, coord1, length_minus_one, "");
 258       }
 259       else {
 260          /* Add a bias to the texcoord to handle negative coords */
 261          LLVMValueRef bias = lp_build_mul_imm(int_coord_bld, length, 1024);
 262          LLVMValueRef mask;
 263          coord0 = LLVMBuildAdd(bld->builder, coord0, bias, "");
 264          coord0 = LLVMBuildURem(bld->builder, coord0, length, "");
 265          mask = lp_build_compare(bld->builder, int_coord_bld->type,
 266                                  PIPE_FUNC_NOTEQUAL, coord0, length_minus_one);
 267          coord1 = LLVMBuildAnd(bld->builder,
 268                               lp_build_add(int_coord_bld, coord0, int_coord_bld->one),
 269                               mask, "");
 270       }
 271       break;
 272
 273    case PIPE_TEX_WRAP_CLAMP:
 274       if (bld->static_state->normalized_coords) {
 275          /* scale coord to length */
 276          coord = lp_build_mul(coord_bld, coord, length_f);
 277       }
 278
 279       /* clamp to [0, length] */
 280       coord = lp_build_clamp(coord_bld, coord, coord_bld->zero, length_f);
 281
 282       coord = lp_build_sub(coord_bld, coord, half);
 283
 284       /* convert to int, compute lerp weight */
 285       lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
 286       coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
 287       break;
 288
 289    case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
 290       {
 291          struct lp_build_context abs_coord_bld = bld->coord_bld;
 292          abs_coord_bld.type.sign = FALSE;
 293
 294          if (bld->static_state->normalized_coords) {
 295             /* mul by tex size */
 296             coord = lp_build_mul(coord_bld, coord, length_f);
 297          }
 298          /* clamp to length max */
 299          coord = lp_build_min(coord_bld, coord, length_f);
 300          /* subtract 0.5 */
 301          coord = lp_build_sub(coord_bld, coord, half);
 302          /* clamp to [0, length - 0.5] */
 303          coord = lp_build_max(coord_bld, coord, coord_bld->zero);
 304          /* convert to int, compute lerp weight */
 305          lp_build_ifloor_fract(&abs_coord_bld, coord, &coord0, &weight);
 306          coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
 307          /* coord1 = min(coord1, length-1) */
 308          coord1 = lp_build_min(int_coord_bld, coord1, length_minus_one);
 309          break;
 310       }
 311
 312    case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
 313       {
 314          LLVMValueRef min;
 315          if (bld->static_state->normalized_coords) {
 316             /* scale coord to length */
 317             coord = lp_build_mul(coord_bld, coord, length_f);
 318          }
 319          /* was: clamp to [-0.5, length + 0.5], then sub 0.5 */
 320          coord = lp_build_sub(coord_bld, coord, half);
 321          min = lp_build_const_vec(coord_bld->type, -1.0F);
 322          coord = lp_build_clamp(coord_bld, coord, min, length_f);
 323          /* convert to int, compute lerp weight */
 324          lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
 325          coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
 326       }
 327       break;
 328
 329    case PIPE_TEX_WRAP_MIRROR_REPEAT:
 330       /* compute mirror function */
 331       coord = lp_build_coord_mirror(bld, coord);
 332
 333       /* scale coord to length */
 334       coord = lp_build_mul(coord_bld, coord, length_f);
 335       coord = lp_build_sub(coord_bld, coord, half);
 336
 337       /* convert to int, compute lerp weight */
 338       lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
 339       coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
 340
 341       /* coord0 = max(coord0, 0) */
 342       coord0 = lp_build_max(int_coord_bld, coord0, int_coord_bld->zero);
 343       /* coord1 = min(coord1, length-1) */
 344       coord1 = lp_build_min(int_coord_bld, coord1, length_minus_one);
 345       break;
 346
 347    case PIPE_TEX_WRAP_MIRROR_CLAMP:
 348       coord = lp_build_abs(coord_bld, coord);
 349
 350       if (bld->static_state->normalized_coords) {
 351          /* scale coord to length */
 352          coord = lp_build_mul(coord_bld, coord, length_f);
 353       }
 354
 355       /* clamp to [0, length] */
 356       coord = lp_build_min(coord_bld, coord, length_f);
 357
 358       coord = lp_build_sub(coord_bld, coord, half);
 359
 360       /* convert to int, compute lerp weight */
 361       lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
 362       coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
 363       break;
 364
 365    case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
 366       {
 367          LLVMValueRef min, max;
 368          struct lp_build_context abs_coord_bld = bld->coord_bld;
 369          abs_coord_bld.type.sign = FALSE;
 370          coord = lp_build_abs(coord_bld, coord);
 371
 372          if (bld->static_state->normalized_coords) {
 373             /* scale coord to length */
 374             coord = lp_build_mul(coord_bld, coord, length_f);
 375          }
 376
 377          /* clamp to [0.5, length - 0.5] */
 378          min = half;
 379          max = lp_build_sub(coord_bld, length_f, min);
 380          coord = lp_build_clamp(coord_bld, coord, min, max);
 381
 382          coord = lp_build_sub(coord_bld, coord, half);
 383
 384          /* convert to int, compute lerp weight */
 385          lp_build_ifloor_fract(&abs_coord_bld, coord, &coord0, &weight);
 386          coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
 387       }
 388       break;
 389
 390    case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
 391       {
 392          coord = lp_build_abs(coord_bld, coord);
 393
 394          if (bld->static_state->normalized_coords) {
 395             /* scale coord to length */
 396             coord = lp_build_mul(coord_bld, coord, length_f);
 397          }
 398
 399          /* was: clamp to [-0.5, length + 0.5] then sub 0.5 */
 400          /* skip -0.5 clamp (always positive), do sub first */
 401          coord = lp_build_sub(coord_bld, coord, half);
 402          coord = lp_build_min(coord_bld, coord, length_f);
 403
 404          /* convert to int, compute lerp weight */
 405          lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
 406          coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
 407       }
 408       break;
 409
 410    default:
 411       assert(0);
 412       coord0 = NULL;
 413       coord1 = NULL;
 414       weight = NULL;
 415    }
 416
 417    *x0_out = coord0;
 418    *x1_out = coord1;
 419    *weight_out = weight;
 420 }
 421
 422
 423 /**
 424  * Build LLVM code for texture wrap mode for nearest filtering.
 425  * \param coord  the incoming texcoord (nominally in [0,1])
 426  * \param length  the texture size along one dimension, as int vector
 427  * \param is_pot  if TRUE, length is a power of two
 428  * \param wrap_mode  one of PIPE_TEX_WRAP_x
 429  */
 430 static LLVMValueRef
 431 lp_build_sample_wrap_nearest(struct lp_build_sample_context *bld,
 432                              LLVMValueRef coord,
 433                              LLVMValueRef length,
 434                              LLVMValueRef length_f,
 435                              boolean is_pot,
 436                              unsigned wrap_mode)
 437 {
 438    struct lp_build_context *coord_bld = &bld->coord_bld;
 439    struct lp_build_context *int_coord_bld = &bld->int_coord_bld;
 440    LLVMValueRef length_minus_one = lp_build_sub(int_coord_bld, length, int_coord_bld->one);
 441    LLVMValueRef icoord;
 442
 443    switch(wrap_mode) {
 444    case PIPE_TEX_WRAP_REPEAT:
 445       coord = lp_build_mul(coord_bld, coord, length_f);
 446       icoord = lp_build_ifloor(coord_bld, coord);
 447       if (is_pot)
 448          icoord = LLVMBuildAnd(bld->builder, icoord, length_minus_one, "");
 449       else {
 450          /* Add a bias to the texcoord to handle negative coords */
 451          LLVMValueRef bias = lp_build_mul_imm(int_coord_bld, length, 1024);
 452          icoord = LLVMBuildAdd(bld->builder, icoord, bias, "");
 453          icoord = LLVMBuildURem(bld->builder, icoord, length, "");
 454       }
 455       break;
 456
 457    case PIPE_TEX_WRAP_CLAMP:
 458    case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
 459       if (bld->static_state->normalized_coords) {
 460          /* scale coord to length */
 461          coord = lp_build_mul(coord_bld, coord, length_f);
 462       }
 463
 464       /* floor */
 465       /* use itrunc instead since we clamp to 0 anyway */
 466       icoord = lp_build_itrunc(coord_bld, coord);
 467
 468       /* clamp to [0, length - 1]. */
 469       icoord = lp_build_clamp(int_coord_bld, icoord, int_coord_bld->zero,
 470                               length_minus_one);
 471       break;
 472
 473    case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
 474       /* Note: this is the same as CLAMP_TO_EDGE, except min = -min */
 475       {
 476          LLVMValueRef min, max;
 477
 478          if (bld->static_state->normalized_coords) {
 479             /* scale coord to length */
 480             coord = lp_build_mul(coord_bld, coord, length_f);
 481          }
 482
 483          icoord = lp_build_ifloor(coord_bld, coord);
 484
 485          /* clamp to [-1, length] */
 486          min = lp_build_negate(int_coord_bld, int_coord_bld->one);
 487          max = length;
 488          icoord = lp_build_clamp(int_coord_bld, icoord, min, max);
 489       }
 490       break;
 491
 492    case PIPE_TEX_WRAP_MIRROR_REPEAT:
 493       /* compute mirror function */
 494       coord = lp_build_coord_mirror(bld, coord);
 495
 496       /* scale coord to length */
 497       assert(bld->static_state->normalized_coords);
 498       coord = lp_build_mul(coord_bld, coord, length_f);
 499
 500       /* itrunc == ifloor here */
 501       icoord = lp_build_itrunc(coord_bld, coord);
 502
 503       /* clamp to [0, length - 1] */
 504       icoord = lp_build_min(int_coord_bld, icoord, length_minus_one);
 505       break;
 506
 507    case PIPE_TEX_WRAP_MIRROR_CLAMP:
 508    case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
 509       coord = lp_build_abs(coord_bld, coord);
 510
 511       if (bld->static_state->normalized_coords) {
 512          /* scale coord to length */
 513          coord = lp_build_mul(coord_bld, coord, length_f);
 514       }
 515
 516       /* itrunc == ifloor here */
 517       icoord = lp_build_itrunc(coord_bld, coord);
 518
 519       /* clamp to [0, length - 1] */
 520       icoord = lp_build_min(int_coord_bld, icoord, length_minus_one);
 521       break;
 522
 523    case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
 524       coord = lp_build_abs(coord_bld, coord);
 525
 526       if (bld->static_state->normalized_coords) {
 527          /* scale coord to length */
 528          coord = lp_build_mul(coord_bld, coord, length_f);
 529       }
 530
 531       /* itrunc == ifloor here */
 532       icoord = lp_build_itrunc(coord_bld, coord);
 533
 534       /* clamp to [0, length] */
 535       icoord = lp_build_min(int_coord_bld, icoord, length);
 536       break;
 537
 538    default:
 539       assert(0);
 540       icoord = NULL;
 541    }
 542
 543    return icoord;
 544 }
 545
 546
 547 /**
 548  * Generate code to sample a mipmap level with nearest filtering.
 549  * If sampling a cube texture, r = cube face in [0,5].
 550  */
 551 static void
 552 lp_build_sample_image_nearest(struct lp_build_sample_context *bld,
 553                               unsigned unit,
 554                               LLVMValueRef size,
 555                               LLVMValueRef row_stride_vec,
 556                               LLVMValueRef img_stride_vec,
 557                               LLVMValueRef data_ptr,
 558                               LLVMValueRef s,
 559                               LLVMValueRef t,
 560                               LLVMValueRef r,
 561                               LLVMValueRef colors_out[4])
 562 {
 563    const unsigned dims = bld->dims;
 564    LLVMValueRef width_vec;
 565    LLVMValueRef height_vec;
 566    LLVMValueRef depth_vec;
 567    LLVMValueRef flt_size;
 568    LLVMValueRef flt_width_vec;
 569    LLVMValueRef flt_height_vec;
 570    LLVMValueRef flt_depth_vec;
 571    LLVMValueRef x, y, z;
 572
 573    lp_build_extract_image_sizes(bld,
 574                                 bld->int_size_type,
 575                                 bld->int_coord_type,
 576                                 size,
 577                                 &width_vec, &height_vec, &depth_vec);
 578
 579    flt_size = lp_build_int_to_float(&bld->float_size_bld, size);
 580
 581    lp_build_extract_image_sizes(bld,
 582                                 bld->float_size_type,
 583                                 bld->coord_type,
 584                                 flt_size,
 585                                 &flt_width_vec, &flt_height_vec, &flt_depth_vec);
 586
 587    /*
 588     * Compute integer texcoords.
 589     */
 590    x = lp_build_sample_wrap_nearest(bld, s, width_vec, flt_width_vec,
 591                                     bld->static_state->pot_width,
 592                                     bld->static_state->wrap_s);
 593    lp_build_name(x, "tex.x.wrapped");
 594
 595    if (dims >= 2) {
 596       y = lp_build_sample_wrap_nearest(bld, t, height_vec, flt_height_vec,
 597                                        bld->static_state->pot_height,
 598                                        bld->static_state->wrap_t);
 599       lp_build_name(y, "tex.y.wrapped");
 600
 601       if (dims == 3) {
 602          z = lp_build_sample_wrap_nearest(bld, r, depth_vec, flt_depth_vec,
 603                                           bld->static_state->pot_depth,
 604                                           bld->static_state->wrap_r);
 605          lp_build_name(z, "tex.z.wrapped");
 606       }
 607       else if (bld->static_state->target == PIPE_TEXTURE_CUBE) {
 608          z = r;
 609       }
 610       else {
 611          z = NULL;
 612       }
 613    }
 614    else {
 615       y = z = NULL;
 616    }
 617
 618    /*
 619     * Get texture colors.
 620     */
 621    lp_build_sample_texel_soa(bld, unit,
 622                              width_vec, height_vec, depth_vec,
 623                              x, y, z,
 624                              row_stride_vec, img_stride_vec,
 625                              data_ptr, colors_out);
 626 }
 627
 628
 629 /**
 630  * Generate code to sample a mipmap level with linear filtering.
 631  * If sampling a cube texture, r = cube face in [0,5].
 632  */
 633 static void
 634 lp_build_sample_image_linear(struct lp_build_sample_context *bld,
 635                              unsigned unit,
 636                              LLVMValueRef size,
 637                              LLVMValueRef row_stride_vec,
 638                              LLVMValueRef img_stride_vec,
 639                              LLVMValueRef data_ptr,
 640                              LLVMValueRef s,
 641                              LLVMValueRef t,
 642                              LLVMValueRef r,
 643                              LLVMValueRef colors_out[4])
 644 {
 645    const unsigned dims = bld->dims;
 646    LLVMValueRef width_vec;
 647    LLVMValueRef height_vec;
 648    LLVMValueRef depth_vec;
 649    LLVMValueRef flt_size;
 650    LLVMValueRef flt_width_vec;
 651    LLVMValueRef flt_height_vec;
 652    LLVMValueRef flt_depth_vec;
 653    LLVMValueRef x0, y0, z0, x1, y1, z1;
 654    LLVMValueRef s_fpart, t_fpart, r_fpart;
 655    LLVMValueRef neighbors[2][2][4];
 656    int chan;
 657
 658    lp_build_extract_image_sizes(bld,
 659                                 bld->int_size_type,
 660                                 bld->int_coord_type,
 661                                 size,
 662                                 &width_vec, &height_vec, &depth_vec);
 663
 664    flt_size = lp_build_int_to_float(&bld->float_size_bld, size);
 665
 666    lp_build_extract_image_sizes(bld,
 667                                 bld->float_size_type,
 668                                 bld->coord_type,
 669                                 flt_size,
 670                                 &flt_width_vec, &flt_height_vec, &flt_depth_vec);
 671
 672    /*
 673     * Compute integer texcoords.
 674     */
 675    lp_build_sample_wrap_linear(bld, s, width_vec, flt_width_vec,
 676                                bld->static_state->pot_width,
 677                                bld->static_state->wrap_s,
 678                                &x0, &x1, &s_fpart);
 679    lp_build_name(x0, "tex.x0.wrapped");
 680    lp_build_name(x1, "tex.x1.wrapped");
 681
 682    if (dims >= 2) {
 683       lp_build_sample_wrap_linear(bld, t, height_vec, flt_height_vec,
 684                                   bld->static_state->pot_height,
 685                                   bld->static_state->wrap_t,
 686                                   &y0, &y1, &t_fpart);
 687       lp_build_name(y0, "tex.y0.wrapped");
 688       lp_build_name(y1, "tex.y1.wrapped");
 689
 690       if (dims == 3) {
 691          lp_build_sample_wrap_linear(bld, r, depth_vec, flt_depth_vec,
 692                                      bld->static_state->pot_depth,
 693                                      bld->static_state->wrap_r,
 694                                      &z0, &z1, &r_fpart);
 695          lp_build_name(z0, "tex.z0.wrapped");
 696          lp_build_name(z1, "tex.z1.wrapped");
 697       }
 698       else if (bld->static_state->target == PIPE_TEXTURE_CUBE) {
 699          z0 = z1 = r;  /* cube face */
 700          r_fpart = NULL;
 701       }
 702       else {
 703          z0 = z1 = NULL;
 704          r_fpart = NULL;
 705       }
 706    }
 707    else {
 708       y0 = y1 = t_fpart = NULL;
 709       z0 = z1 = r_fpart = NULL;
 710    }
 711
 712    /*
 713     * Get texture colors.
 714     */
 715    /* get x0/x1 texels */
 716    lp_build_sample_texel_soa(bld, unit,
 717                              width_vec, height_vec, depth_vec,
 718                              x0, y0, z0,
 719                              row_stride_vec, img_stride_vec,
 720                              data_ptr, neighbors[0][0]);
 721    lp_build_sample_texel_soa(bld, unit,
 722                              width_vec, height_vec, depth_vec,
 723                              x1, y0, z0,
 724                              row_stride_vec, img_stride_vec,
 725                              data_ptr, neighbors[0][1]);
 726
 727    if (dims == 1) {
 728       /* Interpolate two samples from 1D image to produce one color */
 729       for (chan = 0; chan < 4; chan++) {
 730          colors_out[chan] = lp_build_lerp(&bld->texel_bld, s_fpart,
 731                                           neighbors[0][0][chan],
 732                                           neighbors[0][1][chan]);
 733       }
 734    }
 735    else {
 736       /* 2D/3D texture */
 737       LLVMValueRef colors0[4];
 738
 739       /* get x0/x1 texels at y1 */
 740       lp_build_sample_texel_soa(bld, unit,
 741                                 width_vec, height_vec, depth_vec,
 742                                 x0, y1, z0,
 743                                 row_stride_vec, img_stride_vec,
 744                                 data_ptr, neighbors[1][0]);
 745       lp_build_sample_texel_soa(bld, unit,
 746                                 width_vec, height_vec, depth_vec,
 747                                 x1, y1, z0,
 748                                 row_stride_vec, img_stride_vec,
 749                                 data_ptr, neighbors[1][1]);
 750
 751       /* Bilinear interpolate the four samples from the 2D image / 3D slice */
 752       for (chan = 0; chan < 4; chan++) {
 753          colors0[chan] = lp_build_lerp_2d(&bld->texel_bld,
 754                                           s_fpart, t_fpart,
 755                                           neighbors[0][0][chan],
 756                                           neighbors[0][1][chan],
 757                                           neighbors[1][0][chan],
 758                                           neighbors[1][1][chan]);
 759       }
 760
 761       if (dims == 3) {
 762          LLVMValueRef neighbors1[2][2][4];
 763          LLVMValueRef colors1[4];
 764
 765          /* get x0/x1/y0/y1 texels at z1 */
 766          lp_build_sample_texel_soa(bld, unit,
 767                                    width_vec, height_vec, depth_vec,
 768                                    x0, y0, z1,
 769                                    row_stride_vec, img_stride_vec,
 770                                    data_ptr, neighbors1[0][0]);
 771          lp_build_sample_texel_soa(bld, unit,
 772                                    width_vec, height_vec, depth_vec,
 773                                    x1, y0, z1,
 774                                    row_stride_vec, img_stride_vec,
 775                                    data_ptr, neighbors1[0][1]);
 776          lp_build_sample_texel_soa(bld, unit,
 777                                    width_vec, height_vec, depth_vec,
 778                                    x0, y1, z1,
 779                                    row_stride_vec, img_stride_vec,
 780                                    data_ptr, neighbors1[1][0]);
 781          lp_build_sample_texel_soa(bld, unit,
 782                                    width_vec, height_vec, depth_vec,
 783                                    x1, y1, z1,
 784                                    row_stride_vec, img_stride_vec,
 785                                    data_ptr, neighbors1[1][1]);
 786
 787          /* Bilinear interpolate the four samples from the second Z slice */
 788          for (chan = 0; chan < 4; chan++) {
 789             colors1[chan] = lp_build_lerp_2d(&bld->texel_bld,
 790                                              s_fpart, t_fpart,
 791                                              neighbors1[0][0][chan],
 792                                              neighbors1[0][1][chan],
 793                                              neighbors1[1][0][chan],
 794                                              neighbors1[1][1][chan]);
 795          }
 796
 797          /* Linearly interpolate the two samples from the two 3D slices */
 798          for (chan = 0; chan < 4; chan++) {
 799             colors_out[chan] = lp_build_lerp(&bld->texel_bld,
 800                                              r_fpart,
 801                                              colors0[chan], colors1[chan]);
 802          }
 803       }
 804       else {
 805          /* 2D tex */
 806          for (chan = 0; chan < 4; chan++) {
 807             colors_out[chan] = colors0[chan];
 808          }
 809       }
 810    }
 811 }
 812
 813
 814 /**
 815  * Sample the texture/mipmap using given image filter and mip filter.
 816  * data0_ptr and data1_ptr point to the two mipmap levels to sample
 817  * from.  width0/1_vec, height0/1_vec, depth0/1_vec indicate their sizes.
 818  * If we're using nearest miplevel sampling the '1' values will be null/unused.
 819  */
 820 static void
 821 lp_build_sample_mipmap(struct lp_build_sample_context *bld,
 822                        unsigned unit,
 823                        unsigned img_filter,
 824                        unsigned mip_filter,
 825                        LLVMValueRef s,
 826                        LLVMValueRef t,
 827                        LLVMValueRef r,
 828                        LLVMValueRef ilevel0,
 829                        LLVMValueRef ilevel1,
 830                        LLVMValueRef lod_fpart,
 831                        LLVMValueRef *colors_out)
 832 {
 833    LLVMBuilderRef builder = bld->builder;
 834    LLVMValueRef size0;
 835    LLVMValueRef size1;
 836    LLVMValueRef row_stride0_vec;
 837    LLVMValueRef row_stride1_vec;
 838    LLVMValueRef img_stride0_vec;
 839    LLVMValueRef img_stride1_vec;
 840    LLVMValueRef data_ptr0;
 841    LLVMValueRef data_ptr1;
 842    LLVMValueRef colors0[4], colors1[4];
 843    unsigned chan;
 844
 845    /* sample the first mipmap level */
 846    lp_build_mipmap_level_sizes(bld, ilevel0,
 847                                &size0,
 848                                &row_stride0_vec, &img_stride0_vec);
 849    data_ptr0 = lp_build_get_mipmap_level(bld, ilevel0);
 850    if (img_filter == PIPE_TEX_FILTER_NEAREST) {
 851       lp_build_sample_image_nearest(bld, unit,
 852                                     size0,
 853                                     row_stride0_vec, img_stride0_vec,
 854                                     data_ptr0, s, t, r,
 855                                     colors0);
 856    }
 857    else {
 858       assert(img_filter == PIPE_TEX_FILTER_LINEAR);
 859       lp_build_sample_image_linear(bld, unit,
 860                                    size0,
 861                                    row_stride0_vec, img_stride0_vec,
 862                                    data_ptr0, s, t, r,
 863                                    colors0);
 864    }
 865
 866    /* Store the first level's colors in the output variables */
 867    for (chan = 0; chan < 4; chan++) {
 868        LLVMBuildStore(builder, colors0[chan], colors_out[chan]);
 869    }
 870
 871    if (mip_filter == PIPE_TEX_MIPFILTER_LINEAR) {
 872       struct lp_build_if_state if_ctx;
 873       LLVMValueRef need_lerp;
 874
 875       /* need_lerp = lod_fpart > 0 */
 876       need_lerp = LLVMBuildFCmp(builder, LLVMRealUGT,
 877                                 lod_fpart,
 878                                 bld->float_bld.zero,
 879                                 "need_lerp");
 880
 881       lp_build_if(&if_ctx, builder, need_lerp);
 882       {
 883          /* sample the second mipmap level */
 884          lp_build_mipmap_level_sizes(bld, ilevel1,
 885                                      &size1,
 886                                      &row_stride1_vec, &img_stride1_vec);
 887          data_ptr1 = lp_build_get_mipmap_level(bld, ilevel1);
 888          if (img_filter == PIPE_TEX_FILTER_NEAREST) {
 889             lp_build_sample_image_nearest(bld, unit,
 890                                           size1,
 891                                           row_stride1_vec, img_stride1_vec,
 892                                           data_ptr1, s, t, r,
 893                                           colors1);
 894          }
 895          else {
 896             lp_build_sample_image_linear(bld, unit,
 897                                          size1,
 898                                          row_stride1_vec, img_stride1_vec,
 899                                          data_ptr1, s, t, r,
 900                                          colors1);
 901          }
 902
 903          /* interpolate samples from the two mipmap levels */
 904
 905          lod_fpart = lp_build_broadcast_scalar(&bld->texel_bld, lod_fpart);
 906
 907          for (chan = 0; chan < 4; chan++) {
 908             colors0[chan] = lp_build_lerp(&bld->texel_bld, lod_fpart,
 909                                           colors0[chan], colors1[chan]);
 910             LLVMBuildStore(builder, colors0[chan], colors_out[chan]);
 911          }
 912       }
 913       lp_build_endif(&if_ctx);
 914    }
 915 }
 916
 917
 918
 919 /**
 920  * General texture sampling codegen.
 921  * This function handles texture sampling for all texture targets (1D,
 922  * 2D, 3D, cube) and all filtering modes.
 923  */
 924 static void
 925 lp_build_sample_general(struct lp_build_sample_context *bld,
 926                         unsigned unit,
 927                         LLVMValueRef s,
 928                         LLVMValueRef t,
 929                         LLVMValueRef r,
 930                         const LLVMValueRef *ddx,
 931                         const LLVMValueRef *ddy,
 932                         LLVMValueRef lod_bias, /* optional */
 933                         LLVMValueRef explicit_lod, /* optional */
 934                         LLVMValueRef *colors_out)
 935 {
 936    struct lp_build_context *int_bld = &bld->int_bld;
 937    LLVMBuilderRef builder = bld->builder;
 938    const unsigned mip_filter = bld->static_state->min_mip_filter;
 939    const unsigned min_filter = bld->static_state->min_img_filter;
 940    const unsigned mag_filter = bld->static_state->mag_img_filter;
 941    LLVMValueRef lod_ipart = NULL, lod_fpart = NULL;
 942    LLVMValueRef ilevel0, ilevel1 = NULL;
 943    LLVMValueRef face_ddx[4], face_ddy[4];
 944    LLVMValueRef texels[4];
 945    LLVMTypeRef i32t = LLVMInt32Type();
 946    LLVMValueRef i32t_zero = LLVMConstInt(i32t, 0, 0);
 947    unsigned chan;
 948
 949    /*
 950    printf("%s mip %d  min %d  mag %d\n", __FUNCTION__,
 951           mip_filter, min_filter, mag_filter);
 952    */
 953
 954    /*
 955     * Choose cube face, recompute texcoords and derivatives for the chosen face.
 956     */
 957    if (bld->static_state->target == PIPE_TEXTURE_CUBE) {
 958       LLVMValueRef face, face_s, face_t;
 959       lp_build_cube_lookup(bld, s, t, r, &face, &face_s, &face_t);
 960       s = face_s; /* vec */
 961       t = face_t; /* vec */
 962       /* use 'r' to indicate cube face */
 963       r = lp_build_broadcast_scalar(&bld->int_coord_bld, face); /* vec */
 964
 965       /* recompute ddx, ddy using the new (s,t) face texcoords */
 966       face_ddx[0] = lp_build_ddx(&bld->coord_bld, s);
 967       face_ddx[1] = lp_build_ddx(&bld->coord_bld, t);
 968       face_ddx[2] = NULL;
 969       face_ddx[3] = NULL;
 970       face_ddy[0] = lp_build_ddy(&bld->coord_bld, s);
 971       face_ddy[1] = lp_build_ddy(&bld->coord_bld, t);
 972       face_ddy[2] = NULL;
 973       face_ddy[3] = NULL;
 974       ddx = face_ddx;
 975       ddy = face_ddy;
 976    }
 977
 978    /*
 979     * Compute the level of detail (float).
 980     */
 981    if (min_filter != mag_filter ||
 982        mip_filter != PIPE_TEX_MIPFILTER_NONE) {
 983       /* Need to compute lod either to choose mipmap levels or to
 984        * distinguish between minification/magnification with one mipmap level.
 985        */
 986       lp_build_lod_selector(bld, unit, ddx, ddy,
 987                             lod_bias, explicit_lod,
 988                             mip_filter,
 989                             &lod_ipart, &lod_fpart);
 990    } else {
 991       lod_ipart = i32t_zero;
 992    }
 993
 994    /*
 995     * Compute integer mipmap level(s) to fetch texels from: ilevel0, ilevel1
 996     */
 997    switch (mip_filter) {
 998    default:
 999       assert(0 && "bad mip_filter value in lp_build_sample_soa()");
1000       /* fall-through */
1001    case PIPE_TEX_MIPFILTER_NONE:
1002       /* always use mip level 0 */
1003       if (bld->static_state->target == PIPE_TEXTURE_CUBE) {
1004          /* XXX this is a work-around for an apparent bug in LLVM 2.7.
1005           * We should be able to set ilevel0 = const(0) but that causes
1006           * bad x86 code to be emitted.
1007           */
1008          assert(lod_ipart);
1009          lp_build_nearest_mip_level(bld, unit, lod_ipart, &ilevel0);
1010       }
1011       else {
1012          ilevel0 = i32t_zero;
1013       }
1014       break;
1015    case PIPE_TEX_MIPFILTER_NEAREST:
1016       assert(lod_ipart);
1017       lp_build_nearest_mip_level(bld, unit, lod_ipart, &ilevel0);
1018       break;
1019    case PIPE_TEX_MIPFILTER_LINEAR:
1020       assert(lod_ipart);
1021       assert(lod_fpart);
1022       lp_build_linear_mip_levels(bld, unit,
1023                                  lod_ipart, &lod_fpart,
1024                                  &ilevel0, &ilevel1);
1025       break;
1026    }
1027
1028    /*
1029     * Get/interpolate texture colors.
1030     */
1031
1032    for (chan = 0; chan < 4; ++chan) {
1033      texels[chan] = lp_build_alloca(builder, bld->texel_bld.vec_type, "");
1034      lp_build_name(texels[chan], "sampler%u_texel_%c_var", unit, "xyzw"[chan]);
1035    }
1036
1037    if (min_filter == mag_filter) {
1038       /* no need to distinquish between minification and magnification */
1039       lp_build_sample_mipmap(bld, unit,
1040                              min_filter, mip_filter,
1041                              s, t, r,
1042                              ilevel0, ilevel1, lod_fpart,
1043                              texels);
1044    }
1045    else {
1046       /* Emit conditional to choose min image filter or mag image filter
1047        * depending on the lod being > 0 or <= 0, respectively.
1048        */
1049       struct lp_build_if_state if_ctx;
1050       LLVMValueRef minify;
1051
1052       /* minify = lod >= 0.0 */
1053       minify = LLVMBuildICmp(builder, LLVMIntSGE,
1054                              lod_ipart, int_bld->zero, "");
1055
1056       lp_build_if(&if_ctx, builder, minify);
1057       {
1058          /* Use the minification filter */
1059          lp_build_sample_mipmap(bld, unit,
1060                                 min_filter, mip_filter,
1061                                 s, t, r,
1062                                 ilevel0, ilevel1, lod_fpart,
1063                                 texels);
1064       }
1065       lp_build_else(&if_ctx);
1066       {
1067          /* Use the magnification filter */
1068          lp_build_sample_mipmap(bld, unit,
1069                                 mag_filter, PIPE_TEX_MIPFILTER_NONE,
1070                                 s, t, r,
1071                                 i32t_zero, NULL, NULL,
1072                                 texels);
1073       }
1074       lp_build_endif(&if_ctx);
1075    }
1076
1077    for (chan = 0; chan < 4; ++chan) {
1078      colors_out[chan] = LLVMBuildLoad(builder, texels[chan], "");
1079      lp_build_name(colors_out[chan], "sampler%u_texel_%c", unit, "xyzw"[chan]);
1080    }
1081 }
1082
1083
1084 /**
1085  * Do shadow test/comparison.
1086  * \param p  the texcoord Z (aka R, aka P) component
1087  * \param texel  the texel to compare against (use the X channel)
1088  */
1089 static void
1090 lp_build_sample_compare(struct lp_build_sample_context *bld,
1091                         LLVMValueRef p,
1092                         LLVMValueRef texel[4])
1093 {
1094    struct lp_build_context *texel_bld = &bld->texel_bld;
1095    LLVMValueRef res;
1096    const unsigned chan = 0;
1097
1098    if (bld->static_state->compare_mode == PIPE_TEX_COMPARE_NONE)
1099       return;
1100
1101    /* debug code */
1102    if (0) {
1103       LLVMValueRef indx = lp_build_const_int32(0);
1104       LLVMValueRef coord = LLVMBuildExtractElement(bld->builder, p, indx, "");
1105       LLVMValueRef tex = LLVMBuildExtractElement(bld->builder,
1106                                                  texel[chan], indx, "");
1107       lp_build_printf(bld->builder, "shadow compare coord %f to texture %f\n",
1108                       coord, tex);
1109    }
1110
1111    /* result = (p FUNC texel) ? 1 : 0 */
1112    res = lp_build_cmp(texel_bld, bld->static_state->compare_func,
1113                       p, texel[chan]);
1114    res = lp_build_select(texel_bld, res, texel_bld->one, texel_bld->zero);
1115
1116    /* XXX returning result for default GL_DEPTH_TEXTURE_MODE = GL_LUMINANCE */
1117    texel[0] =
1118    texel[1] =
1119    texel[2] = res;
1120    texel[3] = texel_bld->one;
1121 }
1122
1123
1124 /**
1125  * Just set texels to white instead of actually sampling the texture.
1126  * For debugging.
1127  */
1128 void
1129 lp_build_sample_nop(struct lp_type type,
1130                     LLVMValueRef texel_out[4])
1131 {
1132    LLVMValueRef one = lp_build_one(type);
1133    unsigned chan;
1134
1135    for (chan = 0; chan < 4; chan++) {
1136       texel_out[chan] = one;
1137    }
1138 }
1139
1140
1141 /**
1142  * Build texture sampling code.
1143  * 'texel' will return a vector of four LLVMValueRefs corresponding to
1144  * R, G, B, A.
1145  * \param type  vector float type to use for coords, etc.
1146  * \param ddx  partial derivatives of (s,t,r,q) with respect to x
1147  * \param ddy  partial derivatives of (s,t,r,q) with respect to y
1148  */
1149 void
1150 lp_build_sample_soa(LLVMBuilderRef builder,
1151                     const struct lp_sampler_static_state *static_state,
1152                     struct lp_sampler_dynamic_state *dynamic_state,
1153                     struct lp_type type,
1154                     unsigned unit,
1155                     unsigned num_coords,
1156                     const LLVMValueRef *coords,
1157                     const LLVMValueRef ddx[4],
1158                     const LLVMValueRef ddy[4],
1159                     LLVMValueRef lod_bias, /* optional */
1160                     LLVMValueRef explicit_lod, /* optional */
1161                     LLVMValueRef texel_out[4])
1162 {
1163    unsigned dims = texture_dims(static_state->target);
1164    struct lp_build_sample_context bld;
1165    LLVMTypeRef i32t = LLVMInt32Type();
1166
1167    LLVMValueRef s;
1168    LLVMValueRef t;
1169    LLVMValueRef r;
1170    struct lp_type float_vec_type;
1171
1172    if (0) {
1173       enum pipe_format fmt = static_state->format;
1174       debug_printf("Sample from %s\n", util_format_name(fmt));
1175    }
1176
1177    assert(type.floating);
1178
1179    /* Setup our build context */
1180    memset(&bld, 0, sizeof bld);
1181    bld.builder = builder;
1182    bld.static_state = static_state;
1183    bld.dynamic_state = dynamic_state;
1184    bld.format_desc = util_format_description(static_state->format);
1185    bld.dims = dims;
1186
1187    bld.float_type = lp_type_float(32);
1188    bld.int_type = lp_type_int(32);
1189    bld.coord_type = type;
1190    bld.int_coord_type = lp_int_type(type);
1191    bld.float_size_type = lp_type_float(32);
1192    bld.float_size_type.length = dims > 1 ? 4 : 1;
1193    bld.int_size_type = lp_int_type(bld.float_size_type);
1194    bld.texel_type = type;
1195
1196    float_vec_type = lp_type_float_vec(32);
1197
1198    lp_build_context_init(&bld.float_bld, builder, bld.float_type);
1199    lp_build_context_init(&bld.float_vec_bld, builder, float_vec_type);
1200    lp_build_context_init(&bld.int_bld, builder, bld.int_type);
1201    lp_build_context_init(&bld.coord_bld, builder, bld.coord_type);
1202    lp_build_context_init(&bld.int_coord_bld, builder, bld.int_coord_type);
1203    lp_build_context_init(&bld.int_size_bld, builder, bld.int_size_type);
1204    lp_build_context_init(&bld.float_size_bld, builder, bld.float_size_type);
1205    lp_build_context_init(&bld.texel_bld, builder, bld.texel_type);
1206
1207    /* Get the dynamic state */
1208    bld.width = dynamic_state->width(dynamic_state, builder, unit);
1209    bld.height = dynamic_state->height(dynamic_state, builder, unit);
1210    bld.depth = dynamic_state->depth(dynamic_state, builder, unit);
1211    bld.row_stride_array = dynamic_state->row_stride(dynamic_state, builder, unit);
1212    bld.img_stride_array = dynamic_state->img_stride(dynamic_state, builder, unit);
1213    bld.data_array = dynamic_state->data_ptr(dynamic_state, builder, unit);
1214    /* Note that data_array is an array[level] of pointers to texture images */
1215
1216    s = coords[0];
1217    t = coords[1];
1218    r = coords[2];
1219
1220    /* width, height, depth as single int vector */
1221    if (dims <= 1) {
1222       bld.int_size = bld.width;
1223    }
1224    else {
1225       bld.int_size = LLVMBuildInsertElement(builder, bld.int_size_bld.undef,
1226                                             bld.width, LLVMConstInt(i32t, 0, 0), "");
1227       if (dims >= 2) {
1228          bld.int_size = LLVMBuildInsertElement(builder, bld.int_size,
1229                                                bld.height, LLVMConstInt(i32t, 1, 0), "");
1230          if (dims >= 3) {
1231             bld.int_size = LLVMBuildInsertElement(builder, bld.int_size,
1232                                                   bld.depth, LLVMConstInt(i32t, 2, 0), "");
1233          }
1234       }
1235    }
1236
1237    if (0) {
1238       /* For debug: no-op texture sampling */
1239       lp_build_sample_nop(bld.texel_type, texel_out);
1240    }
1241    else if (util_format_fits_8unorm(bld.format_desc) &&
1242             lp_is_simple_wrap_mode(static_state->wrap_s) &&
1243             lp_is_simple_wrap_mode(static_state->wrap_t)) {
1244       /* do sampling/filtering with fixed pt arithmetic */
1245       lp_build_sample_aos(&bld, unit, s, t, r, ddx, ddy,
1246                           lod_bias, explicit_lod,
1247                           texel_out);
1248    }
1249
1250    else {
1251       if ((gallivm_debug & GALLIVM_DEBUG_PERF) &&
1252           util_format_fits_8unorm(bld.format_desc)) {
1253          debug_printf("%s: using floating point linear filtering for %s\n",
1254                       __FUNCTION__, bld.format_desc->short_name);
1255          debug_printf("  min_img %d  mag_img %d  mip %d  wraps %d  wrapt %d\n",
1256                       static_state->min_img_filter,
1257                       static_state->mag_img_filter,
1258                       static_state->min_mip_filter,
1259                       static_state->wrap_s,
1260                       static_state->wrap_t);
1261       }
1262
1263       lp_build_sample_general(&bld, unit, s, t, r, ddx, ddy,
1264                               lod_bias, explicit_lod,
1265                               texel_out);
1266    }
1267
1268    lp_build_sample_compare(&bld, r, texel_out);
1269 }