src/gallium/auxiliary/gallivm/lp_bld_format_aos_array.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2012 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
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
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  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include "lp_bld_const.h"
  29 #include "lp_bld_struct.h"
  30 #include "lp_bld_format.h"
  31 #include "lp_bld_debug.h"
  32 #include "lp_bld_type.h"
  33 #include "lp_bld_conv.h"
  34 #include "lp_bld_pack.h"
  35 #include "lp_bld_intr.h"
  36 #include "lp_bld_gather.h"
  37
  38 #include "util/u_memory.h"
  39 #include "util/u_format.h"
  40 #include "pipe/p_state.h"
  41
  42
  43
  44 /**
  45  * @brief lp_build_fetch_rgba_aos_array
  46  *
  47  * \param format_desc   describes format of the image we're fetching from
  48  * \param dst_type      output type
  49  * \param base_ptr      address of the pixel block (or the texel if uncompressed)
  50  * \param offset        ptr offset
  51  */
  52 LLVMValueRef
  53 lp_build_fetch_rgba_aos_array(struct gallivm_state *gallivm,
  54                               const struct util_format_description *format_desc,
  55                               struct lp_type dst_type,
  56                               LLVMValueRef base_ptr,
  57                               LLVMValueRef offset)
  58 {
  59    struct lp_build_context bld;
  60    LLVMBuilderRef builder = gallivm->builder;
  61    LLVMTypeRef src_vec_type;
  62    LLVMValueRef ptr, res = NULL;
  63    struct lp_type src_type;
  64    boolean pure_integer = format_desc->channel[0].pure_integer;
  65    struct lp_type tmp_type;
  66
  67    lp_type_from_format_desc(&src_type, format_desc);
  68
  69    assert(src_type.length <= dst_type.length);
  70
  71    src_vec_type  = lp_build_vec_type(gallivm,  src_type);
  72
  73    /*
  74     * Read whole vector from memory, unaligned.
  75     * XXX: Note it's actually aligned to element type. Not sure if all
  76     * callers are able to guarantee that (whereas for others, we should
  77     * be able to use full alignment when there's 2 or 4 channels).
  78     * (If all callers can guarantee element type alignment, we should
  79     * relax alignment restrictions elsewhere.)
  80     */
  81    ptr = LLVMBuildGEP(builder, base_ptr, &offset, 1, "");
  82    ptr = LLVMBuildPointerCast(builder, ptr, LLVMPointerType(src_vec_type, 0), "");
  83    res = LLVMBuildLoad(builder, ptr, "");
  84    LLVMSetAlignment(res, src_type.width / 8);
  85
  86    /* Truncate doubles to float */
  87    if (src_type.floating && src_type.width == 64) {
  88       src_type.width = 32;
  89       src_vec_type  = lp_build_vec_type(gallivm,  src_type);
  90
  91       res = LLVMBuildFPTrunc(builder, res, src_vec_type, "");
  92    }
  93
  94    /* Expand to correct length */
  95    if (src_type.length < dst_type.length) {
  96       res = lp_build_pad_vector(gallivm, res, dst_type.length);
  97       src_type.length = dst_type.length;
  98    }
  99
 100    tmp_type = dst_type;
 101    if (pure_integer) {
 102        /* some callers expect (fake) floats other real ints. */
 103       tmp_type.floating = 0;
 104       tmp_type.sign = src_type.sign;
 105    }
 106
 107    /* Convert to correct format */
 108    lp_build_conv(gallivm, src_type, tmp_type, &res, 1, &res, 1);
 109
 110    /* Swizzle it */
 111    lp_build_context_init(&bld, gallivm, tmp_type);
 112    res = lp_build_format_swizzle_aos(format_desc, &bld, res);
 113
 114    /* Bitcast to floats (for pure integers) when requested */
 115    if (pure_integer && dst_type.floating) {
 116       res = LLVMBuildBitCast(builder, res, lp_build_vec_type(gallivm, dst_type), "");
 117    }
 118
 119    return res;
 120 }