src/compiler/nir/nir_lower_packing.c

   1 /*
   2  * Copyright © 2015 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  */
  24
  25 #include "nir.h"
  26 #include "nir_builder.h"
  27
  28 /*
  29  * lowers:
  30  *
  31  * packDouble2x32(foo) -> packDouble2x32Split(foo.x, foo.y)
  32  * unpackDouble2x32(foo) -> vec2(unpackDouble2x32_x(foo), unpackDouble2x32_y(foo))
  33  * packInt2x32(foo) -> packInt2x32Split(foo.x, foo.y)
  34  * unpackInt2x32(foo) -> vec2(unpackInt2x32_x(foo), unpackInt2x32_y(foo))
  35  */
  36
  37 static nir_ssa_def *
  38 lower_pack_64_from_32(nir_builder *b, nir_ssa_def *src)
  39 {
  40    return nir_pack_64_2x32_split(b, nir_channel(b, src, 0),
  41                                     nir_channel(b, src, 1));
  42 }
  43
  44 static nir_ssa_def *
  45 lower_unpack_64_to_32(nir_builder *b, nir_ssa_def *src)
  46 {
  47    return nir_vec2(b, nir_unpack_64_2x32_split_x(b, src),
  48                       nir_unpack_64_2x32_split_y(b, src));
  49 }
  50
  51 static nir_ssa_def *
  52 lower_pack_32_from_16(nir_builder *b, nir_ssa_def *src)
  53 {
  54    return nir_pack_32_2x16_split(b, nir_channel(b, src, 0),
  55                                     nir_channel(b, src, 1));
  56 }
  57
  58 static nir_ssa_def *
  59 lower_unpack_32_to_16(nir_builder *b, nir_ssa_def *src)
  60 {
  61    return nir_vec2(b, nir_unpack_32_2x16_split_x(b, src),
  62                       nir_unpack_32_2x16_split_y(b, src));
  63 }
  64
  65 static nir_ssa_def *
  66 lower_pack_64_from_16(nir_builder *b, nir_ssa_def *src)
  67 {
  68    nir_ssa_def *xy = nir_pack_32_2x16_split(b, nir_channel(b, src, 0),
  69                                                nir_channel(b, src, 1));
  70
  71    nir_ssa_def *zw = nir_pack_32_2x16_split(b, nir_channel(b, src, 2),
  72                                                nir_channel(b, src, 3));
  73
  74    return nir_pack_64_2x32_split(b, xy, zw);
  75 }
  76
  77 static nir_ssa_def *
  78 lower_unpack_64_to_16(nir_builder *b, nir_ssa_def *src)
  79 {
  80    nir_ssa_def *xy = nir_unpack_64_2x32_split_x(b, src);
  81    nir_ssa_def *zw = nir_unpack_64_2x32_split_y(b, src);
  82
  83    return nir_vec4(b, nir_unpack_32_2x16_split_x(b, xy),
  84                       nir_unpack_32_2x16_split_y(b, xy),
  85                       nir_unpack_32_2x16_split_x(b, zw),
  86                       nir_unpack_32_2x16_split_y(b, zw));
  87 }
  88
  89 static bool
  90 lower_pack_impl(nir_function_impl *impl)
  91 {
  92    nir_builder b;
  93    nir_builder_init(&b, impl);
  94    bool progress = false;
  95
  96    nir_foreach_block(block, impl) {
  97       nir_foreach_instr_safe(instr, block) {
  98          if (instr->type != nir_instr_type_alu)
  99             continue;
 100
 101          nir_alu_instr *alu_instr = (nir_alu_instr *) instr;
 102
 103          if (alu_instr->op != nir_op_pack_64_2x32 &&
 104              alu_instr->op != nir_op_unpack_64_2x32 &&
 105              alu_instr->op != nir_op_pack_64_4x16 &&
 106              alu_instr->op != nir_op_unpack_64_4x16 &&
 107              alu_instr->op != nir_op_pack_32_2x16 &&
 108              alu_instr->op != nir_op_unpack_32_2x16)
 109             continue;
 110
 111          b.cursor = nir_before_instr(&alu_instr->instr);
 112
 113          nir_ssa_def *src = nir_ssa_for_alu_src(&b, alu_instr, 0);
 114          nir_ssa_def *dest;
 115
 116          switch (alu_instr->op) {
 117          case nir_op_pack_64_2x32:
 118             dest = lower_pack_64_from_32(&b, src);
 119             break;
 120          case nir_op_unpack_64_2x32:
 121             dest = lower_unpack_64_to_32(&b, src);
 122             break;
 123          case nir_op_pack_64_4x16:
 124             dest = lower_pack_64_from_16(&b, src);
 125             break;
 126          case nir_op_unpack_64_4x16:
 127             dest = lower_unpack_64_to_16(&b, src);
 128             break;
 129          case nir_op_pack_32_2x16:
 130             dest = lower_pack_32_from_16(&b, src);
 131             break;
 132          case nir_op_unpack_32_2x16:
 133             dest = lower_unpack_32_to_16(&b, src);
 134             break;
 135          default:
 136             unreachable("Impossible opcode");
 137          }
 138
 139          nir_ssa_def_rewrite_uses(&alu_instr->dest.dest.ssa, nir_src_for_ssa(dest));
 140          nir_instr_remove(&alu_instr->instr);
 141          progress = true;
 142       }
 143    }
 144
 145    if (progress) {
 146       nir_metadata_preserve(impl, nir_metadata_block_index |
 147                                   nir_metadata_dominance);
 148    } else {
 149       nir_metadata_preserve(impl, nir_metadata_all);
 150    }
 151
 152    return progress;
 153 }
 154
 155 bool
 156 nir_lower_pack(nir_shader *shader)
 157 {
 158    bool progress = false;
 159
 160    nir_foreach_function(function, shader) {
 161       if (function->impl)
 162          progress |= lower_pack_impl(function->impl);
 163    }
 164
 165    return false;
 166 }