src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c

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  27
  28
  29 /**
  30  * @file
  31  * Blend LLVM IR generation -- AoS layout.
  32  *
  33  * AoS blending is in general much slower than SoA, but there are some cases
  34  * where it might be faster. In particular, if a pixel is rendered only once
  35  * then the overhead of tiling and untiling will dominate over the speedup that
  36  * SoA gives. So we might want to detect such cases and fallback to AoS in the
  37  * future, but for now this function is here for historical/benchmarking
  38  * purposes.
  39  *
  40  * Run lp_blend_test after any change to this file.
  41  *
  42  * @author Jose Fonseca <jfonseca@vmware.com>
  43  */
  44
  45
  46 #include "pipe/p_state.h"
  47
  48 #include "lp_bld_type.h"
  49 #include "lp_bld_const.h"
  50 #include "lp_bld_arit.h"
  51 #include "lp_bld_logic.h"
  52 #include "lp_bld_swizzle.h"
  53 #include "lp_bld_blend.h"
  54 #include "lp_bld_debug.h"
  55
  56
  57 /**
  58  * We may the same values several times, so we keep them here to avoid
  59  * recomputing them. Also reusing the values allows us to do simplifications
  60  * that LLVM optimization passes wouldn't normally be able to do.
  61  */
  62 struct lp_build_blend_aos_context
  63 {
  64    struct lp_build_context base;
  65
  66    LLVMValueRef src;
  67    LLVMValueRef dst;
  68    LLVMValueRef const_;
  69
  70    LLVMValueRef inv_src;
  71    LLVMValueRef inv_dst;
  72    LLVMValueRef inv_const;
  73    LLVMValueRef saturate;
  74
  75    LLVMValueRef rgb_src_factor;
  76    LLVMValueRef alpha_src_factor;
  77    LLVMValueRef rgb_dst_factor;
  78    LLVMValueRef alpha_dst_factor;
  79 };
  80
  81
  82 static LLVMValueRef
  83 lp_build_blend_factor_unswizzled(struct lp_build_blend_aos_context *bld,
  84                                  unsigned factor,
  85                                  boolean alpha)
  86 {
  87    switch (factor) {
  88    case PIPE_BLENDFACTOR_ZERO:
  89       return bld->base.zero;
  90    case PIPE_BLENDFACTOR_ONE:
  91       return bld->base.one;
  92    case PIPE_BLENDFACTOR_SRC_COLOR:
  93    case PIPE_BLENDFACTOR_SRC_ALPHA:
  94       return bld->src;
  95    case PIPE_BLENDFACTOR_DST_COLOR:
  96    case PIPE_BLENDFACTOR_DST_ALPHA:
  97       return bld->dst;
  98    case PIPE_BLENDFACTOR_SRC_ALPHA_SATURATE:
  99       if(alpha)
 100          return bld->base.one;
 101       else {
 102          if(!bld->inv_dst)
 103             bld->inv_dst = lp_build_comp(&bld->base, bld->dst);
 104          if(!bld->saturate)
 105             bld->saturate = lp_build_min(&bld->base, bld->src, bld->inv_dst);
 106          return bld->saturate;
 107       }
 108    case PIPE_BLENDFACTOR_CONST_COLOR:
 109    case PIPE_BLENDFACTOR_CONST_ALPHA:
 110       return bld->const_;
 111    case PIPE_BLENDFACTOR_SRC1_COLOR:
 112    case PIPE_BLENDFACTOR_SRC1_ALPHA:
 113       /* TODO */
 114       assert(0);
 115       return bld->base.zero;
 116    case PIPE_BLENDFACTOR_INV_SRC_COLOR:
 117    case PIPE_BLENDFACTOR_INV_SRC_ALPHA:
 118       if(!bld->inv_src)
 119          bld->inv_src = lp_build_comp(&bld->base, bld->src);
 120       return bld->inv_src;
 121    case PIPE_BLENDFACTOR_INV_DST_COLOR:
 122    case PIPE_BLENDFACTOR_INV_DST_ALPHA:
 123       if(!bld->inv_dst)
 124          bld->inv_dst = lp_build_comp(&bld->base, bld->dst);
 125       return bld->inv_dst;
 126    case PIPE_BLENDFACTOR_INV_CONST_COLOR:
 127    case PIPE_BLENDFACTOR_INV_CONST_ALPHA:
 128       if(!bld->inv_const)
 129          bld->inv_const = lp_build_comp(&bld->base, bld->const_);
 130       return bld->inv_const;
 131    case PIPE_BLENDFACTOR_INV_SRC1_COLOR:
 132    case PIPE_BLENDFACTOR_INV_SRC1_ALPHA:
 133       /* TODO */
 134       assert(0);
 135       return bld->base.zero;
 136    default:
 137       assert(0);
 138       return bld->base.zero;
 139    }
 140 }
 141
 142
 143 enum lp_build_blend_swizzle {
 144    LP_BUILD_BLEND_SWIZZLE_RGBA = 0,
 145    LP_BUILD_BLEND_SWIZZLE_AAAA = 1,
 146 };
 147
 148
 149 /**
 150  * How should we shuffle the base factor.
 151  */
 152 static enum lp_build_blend_swizzle
 153 lp_build_blend_factor_swizzle(unsigned factor)
 154 {
 155    switch (factor) {
 156    case PIPE_BLENDFACTOR_ONE:
 157    case PIPE_BLENDFACTOR_ZERO:
 158    case PIPE_BLENDFACTOR_SRC_COLOR:
 159    case PIPE_BLENDFACTOR_DST_COLOR:
 160    case PIPE_BLENDFACTOR_CONST_COLOR:
 161    case PIPE_BLENDFACTOR_SRC1_COLOR:
 162    case PIPE_BLENDFACTOR_INV_SRC_COLOR:
 163    case PIPE_BLENDFACTOR_INV_DST_COLOR:
 164    case PIPE_BLENDFACTOR_INV_CONST_COLOR:
 165    case PIPE_BLENDFACTOR_INV_SRC1_COLOR:
 166       return LP_BUILD_BLEND_SWIZZLE_RGBA;
 167    case PIPE_BLENDFACTOR_SRC_ALPHA:
 168    case PIPE_BLENDFACTOR_DST_ALPHA:
 169    case PIPE_BLENDFACTOR_SRC_ALPHA_SATURATE:
 170    case PIPE_BLENDFACTOR_SRC1_ALPHA:
 171    case PIPE_BLENDFACTOR_CONST_ALPHA:
 172    case PIPE_BLENDFACTOR_INV_SRC_ALPHA:
 173    case PIPE_BLENDFACTOR_INV_DST_ALPHA:
 174    case PIPE_BLENDFACTOR_INV_CONST_ALPHA:
 175    case PIPE_BLENDFACTOR_INV_SRC1_ALPHA:
 176       return LP_BUILD_BLEND_SWIZZLE_AAAA;
 177    default:
 178       assert(0);
 179       return LP_BUILD_BLEND_SWIZZLE_RGBA;
 180    }
 181 }
 182
 183
 184 static LLVMValueRef
 185 lp_build_blend_swizzle(struct lp_build_blend_aos_context *bld,
 186                        LLVMValueRef rgb,
 187                        LLVMValueRef alpha,
 188                        enum lp_build_blend_swizzle rgb_swizzle,
 189                        unsigned alpha_swizzle)
 190 {
 191    if(rgb == alpha) {
 192       if(rgb_swizzle == LP_BUILD_BLEND_SWIZZLE_RGBA)
 193          return rgb;
 194       if(rgb_swizzle == LP_BUILD_BLEND_SWIZZLE_AAAA)
 195          return lp_build_broadcast_aos(&bld->base, rgb, alpha_swizzle);
 196    }
 197    else {
 198       if(rgb_swizzle == LP_BUILD_BLEND_SWIZZLE_RGBA) {
 199          boolean cond[4] = {0, 0, 0, 0};
 200          cond[alpha_swizzle] = 1;
 201          return lp_build_select_aos(&bld->base, alpha, rgb, cond);
 202       }
 203       if(rgb_swizzle == LP_BUILD_BLEND_SWIZZLE_AAAA) {
 204          unsigned char swizzle[4];
 205          swizzle[0] = alpha_swizzle;
 206          swizzle[1] = alpha_swizzle;
 207          swizzle[2] = alpha_swizzle;
 208          swizzle[3] = alpha_swizzle;
 209          swizzle[alpha_swizzle] += 4;
 210          return lp_build_swizzle2_aos(&bld->base, rgb, alpha, swizzle);
 211       }
 212    }
 213    assert(0);
 214    return bld->base.undef;
 215 }
 216
 217
 218 /**
 219  * @sa http://www.opengl.org/sdk/docs/man/xhtml/glBlendFuncSeparate.xml
 220  */
 221 static LLVMValueRef
 222 lp_build_blend_factor(struct lp_build_blend_aos_context *bld,
 223                       LLVMValueRef factor1,
 224                       unsigned rgb_factor,
 225                       unsigned alpha_factor,
 226                       unsigned alpha_swizzle)
 227 {
 228    LLVMValueRef rgb_factor_;
 229    LLVMValueRef alpha_factor_;
 230    LLVMValueRef factor2;
 231    enum lp_build_blend_swizzle rgb_swizzle;
 232
 233    rgb_factor_   = lp_build_blend_factor_unswizzled(bld, rgb_factor,   FALSE);
 234    alpha_factor_ = lp_build_blend_factor_unswizzled(bld, alpha_factor, TRUE);
 235
 236    rgb_swizzle = lp_build_blend_factor_swizzle(rgb_factor);
 237
 238    factor2 = lp_build_blend_swizzle(bld, rgb_factor_, alpha_factor_, rgb_swizzle, alpha_swizzle);
 239
 240    return lp_build_mul(&bld->base, factor1, factor2);
 241 }
 242
 243
 244 boolean
 245 lp_build_blend_func_commutative(unsigned func)
 246 {
 247    switch (func) {
 248    case PIPE_BLEND_ADD:
 249    case PIPE_BLEND_MIN:
 250    case PIPE_BLEND_MAX:
 251       return TRUE;
 252    case PIPE_BLEND_SUBTRACT:
 253    case PIPE_BLEND_REVERSE_SUBTRACT:
 254       return FALSE;
 255    default:
 256       assert(0);
 257       return TRUE;
 258    }
 259 }
 260
 261
 262 boolean
 263 lp_build_blend_func_reverse(unsigned rgb_func, unsigned alpha_func)
 264 {
 265    if(rgb_func == alpha_func)
 266       return FALSE;
 267    if(rgb_func == PIPE_BLEND_SUBTRACT && alpha_func == PIPE_BLEND_REVERSE_SUBTRACT)
 268       return TRUE;
 269    if(rgb_func == PIPE_BLEND_REVERSE_SUBTRACT && alpha_func == PIPE_BLEND_SUBTRACT)
 270       return TRUE;
 271    return FALSE;
 272 }
 273
 274
 275 /**
 276  * @sa http://www.opengl.org/sdk/docs/man/xhtml/glBlendEquationSeparate.xml
 277  */
 278 LLVMValueRef
 279 lp_build_blend_func(struct lp_build_context *bld,
 280                     unsigned func,
 281                     LLVMValueRef term1,
 282                     LLVMValueRef term2)
 283 {
 284    switch (func) {
 285    case PIPE_BLEND_ADD:
 286       return lp_build_add(bld, term1, term2);
 287       break;
 288    case PIPE_BLEND_SUBTRACT:
 289       return lp_build_sub(bld, term1, term2);
 290    case PIPE_BLEND_REVERSE_SUBTRACT:
 291       return lp_build_sub(bld, term2, term1);
 292    case PIPE_BLEND_MIN:
 293       return lp_build_min(bld, term1, term2);
 294    case PIPE_BLEND_MAX:
 295       return lp_build_max(bld, term1, term2);
 296    default:
 297       assert(0);
 298       return bld->zero;
 299    }
 300 }
 301
 302
 303 LLVMValueRef
 304 lp_build_blend_aos(LLVMBuilderRef builder,
 305                    const struct pipe_blend_state *blend,
 306                    union lp_type type,
 307                    LLVMValueRef src,
 308                    LLVMValueRef dst,
 309                    LLVMValueRef const_,
 310                    unsigned alpha_swizzle)
 311 {
 312    struct lp_build_blend_aos_context bld;
 313    LLVMValueRef src_term;
 314    LLVMValueRef dst_term;
 315
 316    /* FIXME */
 317    assert(blend->colormask == 0xf);
 318
 319    if(!blend->blend_enable)
 320       return src;
 321
 322    /* It makes no sense to blend unless values are normalized */
 323    assert(type.norm);
 324
 325    /* Setup build context */
 326    memset(&bld, 0, sizeof bld);
 327    lp_build_context_init(&bld.base, builder, type);
 328    bld.src = src;
 329    bld.dst = dst;
 330    bld.const_ = const_;
 331
 332    /* TODO: There are still a few optimization opportunities here. For certain
 333     * combinations it is possible to reorder the operations and therefore saving
 334     * some instructions. */
 335
 336    src_term = lp_build_blend_factor(&bld, src, blend->rgb_src_factor, blend->alpha_src_factor, alpha_swizzle);
 337    dst_term = lp_build_blend_factor(&bld, dst, blend->rgb_dst_factor, blend->alpha_dst_factor, alpha_swizzle);
 338
 339    lp_build_name(src_term, "src_term");
 340    lp_build_name(dst_term, "dst_term");
 341
 342    if(blend->rgb_func == blend->alpha_func) {
 343       return lp_build_blend_func(&bld.base, blend->rgb_func, src_term, dst_term);
 344    }
 345    else {
 346       /* Seperate RGB / A functions */
 347
 348       LLVMValueRef rgb;
 349       LLVMValueRef alpha;
 350
 351       rgb   = lp_build_blend_func(&bld.base, blend->rgb_func,   src_term, dst_term);
 352       alpha = lp_build_blend_func(&bld.base, blend->alpha_func, src_term, dst_term);
 353
 354       return lp_build_blend_swizzle(&bld, rgb, alpha, LP_BUILD_BLEND_SWIZZLE_RGBA, alpha_swizzle);
 355    }
 356 }