src/gallium/drivers/llvmpipe/lp_bld_pack.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
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  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
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  25  *
  26  **************************************************************************/
  27
  28
  29 #include "util/u_format.h"
  30
  31 #include "lp_bld.h"
  32
  33
  34 void
  35 lp_build_pack_rgba(LLVMBuilderRef builder,
  36                    enum pipe_format format,
  37                    LLVMValueRef ptr,
  38                    LLVMValueRef rgba)
  39 {
  40    const struct util_format_description *desc;
  41    LLVMTypeRef type;
  42    LLVMValueRef packed = NULL;
  43    unsigned shift = 0;
  44    unsigned i, j;
  45
  46    desc = util_format_description(format);
  47
  48    assert(desc->layout == UTIL_FORMAT_LAYOUT_RGBA);
  49    assert(desc->block.width == 1);
  50    assert(desc->block.height == 1);
  51
  52    type = LLVMIntType(desc->block.bits);
  53
  54    LLVMValueRef swizzles[4];
  55    LLVMValueRef shifted, casted, scaled, unswizzled;
  56
  57
  58    /* Unswizzle the color components into the source vector. */
  59    for (i = 0; i < 4; ++i) {
  60       for (j = 0; j < 4; ++j) {
  61          if (desc->swizzle[j] == i)
  62             break;
  63       }
  64       if (j < 4)
  65          swizzles[i] = LLVMConstInt(LLVMInt32Type(), j, 0);
  66       else
  67          swizzles[i] = LLVMGetUndef(LLVMInt32Type());
  68    }
  69
  70    unswizzled = LLVMBuildShuffleVector(builder, rgba,
  71                                        LLVMGetUndef(LLVMVectorType(LLVMFloatType(), 4)),
  72                                        LLVMConstVector(swizzles, 4), "");
  73
  74    LLVMValueRef shifts[4];
  75    LLVMValueRef scales[4];
  76    bool normalized = FALSE;
  77
  78    for (i = 0; i < 4; ++i) {
  79       unsigned bits = desc->channel[i].size;
  80
  81       if (desc->channel[i].type == UTIL_FORMAT_TYPE_VOID) {
  82          shifts[i] = LLVMGetUndef(LLVMInt32Type());
  83          scales[i] =  LLVMGetUndef(LLVMFloatType());
  84       }
  85       else {
  86          unsigned mask = (1 << bits) - 1;
  87
  88          assert(desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED);
  89          assert(bits < 32);
  90
  91          shifts[i] = LLVMConstInt(LLVMInt32Type(), shift, 0);
  92
  93          if (desc->channel[i].normalized) {
  94             scales[i] = LLVMConstReal(LLVMFloatType(), mask);
  95             normalized = TRUE;
  96          }
  97          else
  98             scales[i] =  LLVMConstReal(LLVMFloatType(), 1.0);
  99       }
 100
 101       shift += bits;
 102    }
 103
 104    if (normalized)
 105       scaled = LLVMBuildMul(builder, unswizzled, LLVMConstVector(scales, 4), "");
 106    else
 107       scaled = unswizzled;
 108
 109    casted = LLVMBuildFPToSI(builder, scaled, LLVMVectorType(LLVMInt32Type(), 4), "");
 110
 111    shifted = LLVMBuildShl(builder, casted, LLVMConstVector(shifts, 4), "");
 112
 113    /* Bitwise or all components */
 114    for (i = 0; i < 4; ++i) {
 115       if (desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED) {
 116          LLVMValueRef component = LLVMBuildExtractElement(builder, shifted, LLVMConstInt(LLVMInt32Type(), i, 0), "");
 117          if (packed)
 118             packed = LLVMBuildOr(builder, packed, component, "");
 119          else
 120             packed = component;
 121       }
 122    }
 123
 124    if (packed) {
 125
 126       if (desc->block.bits < 32)
 127          packed = LLVMBuildTrunc(builder, packed, type, "");
 128
 129       LLVMBuildStore(builder, packed, LLVMBuildBitCast(builder, ptr, LLVMPointerType(type, 0), ""));
 130    }
 131 }
 132