src/compiler/nir/nir_lower_double_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  */
  34
  35 static nir_ssa_def *
  36 lower_pack_double(nir_builder *b, nir_ssa_def *src)
  37 {
  38    return nir_pack_double_2x32_split(b, nir_channel(b, src, 0),
  39                                         nir_channel(b, src, 1));
  40 }
  41
  42 static nir_ssa_def *
  43 lower_unpack_double(nir_builder *b, nir_ssa_def *src)
  44 {
  45    return nir_vec2(b, nir_unpack_double_2x32_split_x(b, src),
  46                       nir_unpack_double_2x32_split_y(b, src));
  47 }
  48
  49 static bool
  50 lower_double_pack_block(nir_block *block, void *ctx)
  51 {
  52    nir_builder *b = (nir_builder *) ctx;
  53
  54    nir_foreach_instr_safe(block, instr) {
  55       if (instr->type != nir_instr_type_alu)
  56          continue;
  57
  58       nir_alu_instr *alu_instr = (nir_alu_instr *) instr;
  59
  60       if (alu_instr->op != nir_op_pack_double_2x32 &&
  61           alu_instr->op != nir_op_unpack_double_2x32)
  62          continue;
  63
  64       b->cursor = nir_before_instr(&alu_instr->instr);
  65
  66       nir_ssa_def *src = nir_ssa_for_alu_src(b, alu_instr, 0);
  67       nir_ssa_def *dest =
  68          alu_instr->op == nir_op_pack_double_2x32 ?
  69          lower_pack_double(b, src) :
  70          lower_unpack_double(b, src);
  71
  72       nir_ssa_def_rewrite_uses(&alu_instr->dest.dest.ssa, nir_src_for_ssa(dest));
  73       nir_instr_remove(&alu_instr->instr);
  74    }
  75
  76    return true;
  77 }
  78
  79 static void
  80 lower_double_pack_impl(nir_function_impl *impl)
  81 {
  82    nir_builder b;
  83    nir_builder_init(&b, impl);
  84    nir_foreach_block_call(impl, lower_double_pack_block, &b);
  85 }
  86
  87 void
  88 nir_lower_double_pack(nir_shader *shader)
  89 {
  90    nir_foreach_function(shader, function) {
  91       if (function->impl)
  92          lower_double_pack_impl(function->impl);
  93    }
  94 }
  95