src/gallium/drivers/llvmpipe/lp_bld_interp.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2009 VMware, Inc.
   4  * Copyright 2007-2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   5  * All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the
   9  * "Software"), to deal in the Software without restriction, including
  10  * without limitation the rights to use, copy, modify, merge, publish,
  11  * distribute, sub license, and/or sell copies of the Software, and to
  12  * permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the
  16  * next paragraph) shall be included in all copies or substantial portions
  17  * of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  21  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  22  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  23  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  24  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  25  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  **************************************************************************/
  28
  29 /**
  30  * @file
  31  * Position and shader input interpolation.
  32  *
  33  * @author Jose Fonseca <jfonseca@vmware.com>
  34  */
  35
  36 #include "pipe/p_shader_tokens.h"
  37 #include "util/u_debug.h"
  38 #include "util/u_memory.h"
  39 #include "util/u_math.h"
  40 #include "tgsi/tgsi_parse.h"
  41 #include "lp_bld_debug.h"
  42 #include "lp_bld_const.h"
  43 #include "lp_bld_arit.h"
  44 #include "lp_bld_swizzle.h"
  45 #include "lp_bld_interp.h"
  46
  47
  48 static void
  49 attrib_name(LLVMValueRef val, unsigned attrib, unsigned chan, const char *suffix)
  50 {
  51    if(attrib == 0)
  52       lp_build_name(val, "pos.%c%s", "xyzw"[chan], suffix);
  53    else
  54       lp_build_name(val, "input%u.%c%s", attrib - 1, "xyzw"[chan], suffix);
  55 }
  56
  57
  58 static void
  59 coeffs_init(struct lp_build_interp_soa_context *bld,
  60             LLVMValueRef a0_ptr,
  61             LLVMValueRef dadx_ptr,
  62             LLVMValueRef dady_ptr)
  63 {
  64    LLVMBuilderRef builder = bld->base.builder;
  65    unsigned attrib;
  66    unsigned chan;
  67
  68    for(attrib = 0; attrib < bld->num_attribs; ++attrib) {
  69       unsigned mask = bld->mask[attrib];
  70       unsigned mode = bld->mode[attrib];
  71       for(chan = 0; chan < NUM_CHANNELS; ++chan) {
  72          if(mask & (1 << chan)) {
  73             LLVMValueRef index = LLVMConstInt(LLVMInt32Type(), attrib*NUM_CHANNELS + chan, 0);
  74             LLVMValueRef a0 = NULL;
  75             LLVMValueRef dadx = NULL;
  76             LLVMValueRef dady = NULL;
  77
  78             switch( mode ) {
  79             case TGSI_INTERPOLATE_PERSPECTIVE:
  80                /* fall-through */
  81
  82             case TGSI_INTERPOLATE_LINEAR:
  83                dadx = LLVMBuildLoad(builder, LLVMBuildGEP(builder, dadx_ptr, &index, 1, ""), "");
  84                dady = LLVMBuildLoad(builder, LLVMBuildGEP(builder, dady_ptr, &index, 1, ""), "");
  85                dadx = lp_build_broadcast_scalar(&bld->base, dadx);
  86                dady = lp_build_broadcast_scalar(&bld->base, dady);
  87                attrib_name(dadx, attrib, chan, ".dadx");
  88                attrib_name(dady, attrib, chan, ".dady");
  89                /* fall-through */
  90
  91             case TGSI_INTERPOLATE_CONSTANT:
  92                a0 = LLVMBuildLoad(builder, LLVMBuildGEP(builder, a0_ptr, &index, 1, ""), "");
  93                a0 = lp_build_broadcast_scalar(&bld->base, a0);
  94                attrib_name(a0, attrib, chan, ".dady");
  95                break;
  96
  97             default:
  98                assert(0);
  99                break;
 100             }
 101
 102             bld->a0  [attrib][chan] = a0;
 103             bld->dadx[attrib][chan] = dadx;
 104             bld->dady[attrib][chan] = dady;
 105          }
 106       }
 107    }
 108 }
 109
 110
 111 /**
 112  * Small vector x scale multiplication optimization.
 113  *
 114  * TODO: Should be elsewhere.
 115  */
 116 static LLVMValueRef
 117 coeff_multiply(struct lp_build_interp_soa_context *bld,
 118                LLVMValueRef coeff,
 119                int step)
 120 {
 121    LLVMValueRef factor;
 122
 123    switch(step) {
 124    case 0:
 125       return bld->base.zero;
 126    case 1:
 127       return coeff;
 128    case 2:
 129       return lp_build_add(&bld->base, coeff, coeff);
 130    default:
 131       factor = lp_build_const_scalar(bld->base.type, (double)step);
 132       return lp_build_mul(&bld->base, coeff, factor);
 133    }
 134 }
 135
 136
 137 /**
 138  * Multiply the dadx and dady with the xstep and ystep respectively.
 139  */
 140 static void
 141 coeffs_update(struct lp_build_interp_soa_context *bld)
 142 {
 143    unsigned attrib;
 144    unsigned chan;
 145
 146    for(attrib = 0; attrib < bld->num_attribs; ++attrib) {
 147       unsigned mask = bld->mask[attrib];
 148       unsigned mode = bld->mode[attrib];
 149       if (mode != TGSI_INTERPOLATE_CONSTANT) {
 150          for(chan = 0; chan < NUM_CHANNELS; ++chan) {
 151             if(mask & (1 << chan)) {
 152                bld->dadx[attrib][chan] = coeff_multiply(bld, bld->dadx[attrib][chan], bld->xstep);
 153                bld->dady[attrib][chan] = coeff_multiply(bld, bld->dady[attrib][chan], bld->ystep);
 154             }
 155          }
 156       }
 157    }
 158 }
 159
 160
 161 static void
 162 attribs_init(struct lp_build_interp_soa_context *bld)
 163 {
 164    LLVMValueRef x = bld->pos[0];
 165    LLVMValueRef y = bld->pos[1];
 166    LLVMValueRef oow = NULL;
 167    unsigned attrib;
 168    unsigned chan;
 169
 170    for(attrib = 0; attrib < bld->num_attribs; ++attrib) {
 171       unsigned mask = bld->mask[attrib];
 172       unsigned mode = bld->mode[attrib];
 173       for(chan = 0; chan < NUM_CHANNELS; ++chan) {
 174          if(mask & (1 << chan)) {
 175             LLVMValueRef a0   = bld->a0  [attrib][chan];
 176             LLVMValueRef dadx = bld->dadx[attrib][chan];
 177             LLVMValueRef dady = bld->dady[attrib][chan];
 178             LLVMValueRef res;
 179
 180             res = a0;
 181
 182             if (mode != TGSI_INTERPOLATE_CONSTANT) {
 183                res = lp_build_add(&bld->base, res, lp_build_mul(&bld->base, x, dadx));
 184                res = lp_build_add(&bld->base, res, lp_build_mul(&bld->base, y, dady));
 185             }
 186
 187             /* Keep the value of the attribue before perspective divide for faster updates */
 188             bld->attribs_pre[attrib][chan] = res;
 189
 190             if (mode == TGSI_INTERPOLATE_PERSPECTIVE) {
 191                LLVMValueRef w = bld->pos[3];
 192                assert(attrib != 0);
 193                if(!oow)
 194                   oow = lp_build_rcp(&bld->base, w);
 195                res = lp_build_mul(&bld->base, res, oow);
 196             }
 197
 198             attrib_name(res, attrib, chan, "");
 199
 200             bld->attribs[attrib][chan] = res;
 201          }
 202       }
 203    }
 204 }
 205
 206
 207 static void
 208 attribs_update(struct lp_build_interp_soa_context *bld)
 209 {
 210    LLVMValueRef oow = NULL;
 211    unsigned attrib;
 212    unsigned chan;
 213
 214    for(attrib = 0; attrib < bld->num_attribs; ++attrib) {
 215       unsigned mask = bld->mask[attrib];
 216       unsigned mode = bld->mode[attrib];
 217
 218       if (mode != TGSI_INTERPOLATE_CONSTANT) {
 219          for(chan = 0; chan < NUM_CHANNELS; ++chan) {
 220             if(mask & (1 << chan)) {
 221                LLVMValueRef dadx = bld->dadx[attrib][chan];
 222                LLVMValueRef dady = bld->dady[attrib][chan];
 223                LLVMValueRef res;
 224
 225                res = bld->attribs_pre[attrib][chan];
 226
 227                if(bld->xstep)
 228                   res = lp_build_add(&bld->base, res, dadx);
 229
 230                if(bld->ystep)
 231                   res = lp_build_add(&bld->base, res, dady);
 232
 233                bld->attribs_pre[attrib][chan] = res;
 234
 235                if (mode == TGSI_INTERPOLATE_PERSPECTIVE) {
 236                   LLVMValueRef w = bld->pos[3];
 237                   assert(attrib != 0);
 238                   if(!oow)
 239                      oow = lp_build_rcp(&bld->base, w);
 240                   res = lp_build_mul(&bld->base, res, oow);
 241                }
 242
 243                attrib_name(res, attrib, chan, "");
 244
 245                bld->attribs[attrib][chan] = res;
 246             }
 247          }
 248       }
 249    }
 250 }
 251
 252
 253 /**
 254  * Generate the position vectors.
 255  *
 256  * Parameter x0, y0 are the integer values with the quad upper left coordinates.
 257  */
 258 static void
 259 pos_init(struct lp_build_interp_soa_context *bld,
 260          LLVMValueRef x0,
 261          LLVMValueRef y0)
 262 {
 263    lp_build_name(x0, "pos.x");
 264    lp_build_name(y0, "pos.y");
 265
 266    bld->attribs[0][0] = x0;
 267    bld->attribs[0][1] = y0;
 268 }
 269
 270
 271 static void
 272 pos_update(struct lp_build_interp_soa_context *bld)
 273 {
 274    LLVMValueRef x = bld->attribs[0][0];
 275    LLVMValueRef y = bld->attribs[0][1];
 276
 277    if(bld->xstep)
 278       x = lp_build_add(&bld->base, x, lp_build_const_scalar(bld->base.type, bld->xstep));
 279
 280    if(bld->ystep)
 281       y = lp_build_add(&bld->base, y, lp_build_const_scalar(bld->base.type, bld->ystep));
 282
 283    lp_build_name(x, "pos.x");
 284    lp_build_name(y, "pos.y");
 285
 286    bld->attribs[0][0] = x;
 287    bld->attribs[0][1] = y;
 288 }
 289
 290
 291 void
 292 lp_build_interp_soa_init(struct lp_build_interp_soa_context *bld,
 293                          const struct tgsi_token *tokens,
 294                          LLVMBuilderRef builder,
 295                          struct lp_type type,
 296                          LLVMValueRef a0_ptr,
 297                          LLVMValueRef dadx_ptr,
 298                          LLVMValueRef dady_ptr,
 299                          LLVMValueRef x0,
 300                          LLVMValueRef y0,
 301                          int xstep,
 302                          int ystep)
 303 {
 304    struct tgsi_parse_context parse;
 305    struct tgsi_full_declaration *decl;
 306
 307    memset(bld, 0, sizeof *bld);
 308
 309    lp_build_context_init(&bld->base, builder, type);
 310
 311    /* For convenience */
 312    bld->pos = bld->attribs[0];
 313    bld->inputs = (const LLVMValueRef (*)[NUM_CHANNELS]) bld->attribs[1];
 314
 315    /* Position */
 316    bld->num_attribs = 1;
 317    bld->mask[0] = TGSI_WRITEMASK_ZW;
 318    bld->mode[0] = TGSI_INTERPOLATE_LINEAR;
 319
 320    /* Inputs */
 321    tgsi_parse_init( &parse, tokens );
 322    while( !tgsi_parse_end_of_tokens( &parse ) ) {
 323       tgsi_parse_token( &parse );
 324
 325       switch( parse.FullToken.Token.Type ) {
 326       case TGSI_TOKEN_TYPE_DECLARATION:
 327          decl = &parse.FullToken.FullDeclaration;
 328          if( decl->Declaration.File == TGSI_FILE_INPUT ) {
 329             unsigned first, last, mask;
 330             unsigned attrib;
 331
 332             first = decl->DeclarationRange.First;
 333             last = decl->DeclarationRange.Last;
 334             mask = decl->Declaration.UsageMask;
 335
 336             for( attrib = first; attrib <= last; ++attrib ) {
 337                bld->mask[1 + attrib] = mask;
 338                bld->mode[1 + attrib] = decl->Declaration.Interpolate;
 339             }
 340
 341             bld->num_attribs = MAX2(bld->num_attribs, 1 + last + 1);
 342          }
 343          break;
 344
 345       case TGSI_TOKEN_TYPE_INSTRUCTION:
 346       case TGSI_TOKEN_TYPE_IMMEDIATE:
 347          break;
 348
 349       default:
 350          assert( 0 );
 351       }
 352    }
 353    tgsi_parse_free( &parse );
 354
 355    coeffs_init(bld, a0_ptr, dadx_ptr, dady_ptr);
 356
 357    pos_init(bld, x0, y0);
 358
 359    attribs_init(bld);
 360
 361    bld->xstep = xstep;
 362    bld->ystep = ystep;
 363
 364    coeffs_update(bld);
 365 }
 366
 367
 368 /**
 369  * Advance the position and inputs with the xstep and ystep.
 370  */
 371 void
 372 lp_build_interp_soa_update(struct lp_build_interp_soa_context *bld)
 373 {
 374    pos_update(bld);
 375
 376    attribs_update(bld);
 377 }