src/compiler/nir/nir_lower_64bit_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(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(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 bool
  52 lower_64bit_pack_impl(nir_function_impl *impl)
  53 {
  54    nir_builder b;
  55    nir_builder_init(&b, impl);
  56    bool progress = false;
  57
  58    nir_foreach_block(block, impl) {
  59       nir_foreach_instr_safe(instr, block) {
  60          if (instr->type != nir_instr_type_alu)
  61             continue;
  62
  63          nir_alu_instr *alu_instr = (nir_alu_instr *) instr;
  64
  65          if (alu_instr->op != nir_op_pack_64_2x32 &&
  66              alu_instr->op != nir_op_unpack_64_2x32)
  67             continue;
  68
  69          b.cursor = nir_before_instr(&alu_instr->instr);
  70
  71          nir_ssa_def *src = nir_ssa_for_alu_src(&b, alu_instr, 0);
  72          nir_ssa_def *dest;
  73
  74          switch (alu_instr->op) {
  75          case nir_op_pack_64_2x32:
  76             dest = lower_pack_64(&b, src);
  77             break;
  78          case nir_op_unpack_64_2x32:
  79             dest = lower_unpack_64(&b, src);
  80             break;
  81          default:
  82             unreachable("Impossible opcode");
  83          }
  84
  85          nir_ssa_def_rewrite_uses(&alu_instr->dest.dest.ssa, nir_src_for_ssa(dest));
  86          nir_instr_remove(&alu_instr->instr);
  87          nir_metadata_preserve(impl, nir_metadata_block_index |
  88                                      nir_metadata_dominance);
  89          progress = true;
  90       }
  91    }
  92
  93    return progress;
  94 }
  95
  96 bool
  97 nir_lower_64bit_pack(nir_shader *shader)
  98 {
  99    bool progress = false;
 100
 101    nir_foreach_function(function, shader) {
 102       if (function->impl)
 103          progress |= lower_64bit_pack_impl(function->impl);
 104    }
 105
 106    return false;
 107 }