/*
* Copyright © 2017 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "nir.h"
#include "nir_builder.h"
/**
* \file nir_opt_intrinsics.c
*/
static bool
src_is_single_use_shuffle(nir_src src, nir_ssa_def **data, nir_ssa_def **index)
{
nir_intrinsic_instr *shuffle = nir_src_as_intrinsic(src);
if (shuffle == NULL || shuffle->intrinsic != nir_intrinsic_shuffle)
return false;
/* This is only called when src is part of an ALU op so requiring no if
* uses is reasonable. If we ever want to use this from an if statement,
* we can change it then.
*/
if (!list_is_empty(&shuffle->dest.ssa.if_uses) ||
!list_is_singular(&shuffle->dest.ssa.uses))
return false;
assert(shuffle->src[0].is_ssa);
assert(shuffle->src[1].is_ssa);
*data = shuffle->src[0].ssa;
*index = shuffle->src[1].ssa;
return true;
}
static nir_ssa_def *
try_opt_bcsel_of_shuffle(nir_builder *b, nir_alu_instr *alu,
bool block_has_discard)
{
assert(alu->op == nir_op_bcsel);
/* If we've seen a discard in this block, don't do the optimization. We
* could try to do something fancy where we check if the shuffle is on our
* side of the discard or not but this is good enough for correctness for
* now and subgroup ops in the presence of discard aren't common.
*/
if (block_has_discard)
return false;
if (!nir_alu_src_is_trivial_ssa(alu, 0))
return NULL;
nir_ssa_def *data1, *index1;
if (!nir_alu_src_is_trivial_ssa(alu, 1) ||
alu->src[1].src.ssa->parent_instr->block != alu->instr.block ||
!src_is_single_use_shuffle(alu->src[1].src, &data1, &index1))
return NULL;
nir_ssa_def *data2, *index2;
if (!nir_alu_src_is_trivial_ssa(alu, 2) ||
alu->src[2].src.ssa->parent_instr->block != alu->instr.block ||
!src_is_single_use_shuffle(alu->src[2].src, &data2, &index2))
return NULL;
if (data1 != data2)
return NULL;
nir_ssa_def *index = nir_bcsel(b, alu->src[0].src.ssa, index1, index2);
nir_ssa_def *shuffle = nir_shuffle(b, data1, index);
return shuffle;
}
static bool
opt_intrinsics_alu(nir_builder *b, nir_alu_instr *alu,
bool block_has_discard)
{
nir_ssa_def *replacement = NULL;
switch (alu->op) {
case nir_op_bcsel:
replacement = try_opt_bcsel_of_shuffle(b, alu, block_has_discard);
break;
default:
break;
}
if (replacement) {
nir_ssa_def_rewrite_uses(&alu->dest.dest.ssa,
replacement);
nir_instr_remove(&alu->instr);
return true;
} else {
return false;
}
}
static bool
opt_intrinsics_intrin(nir_builder *b, nir_intrinsic_instr *intrin,
const struct nir_shader_compiler_options *options)
{
switch (intrin->intrinsic) {
case nir_intrinsic_load_sample_mask_in: {
/* Transform:
* gl_SampleMaskIn == 0 ---> gl_HelperInvocation
* gl_SampleMaskIn != 0 ---> !gl_HelperInvocation
*/
if (!options->optimize_sample_mask_in)
return false;
bool progress = false;
nir_foreach_use_safe(use_src, &intrin->dest.ssa) {
if (use_src->parent_instr->type == nir_instr_type_alu) {
nir_alu_instr *alu = nir_instr_as_alu(use_src->parent_instr);
if (alu->op == nir_op_ieq ||
alu->op == nir_op_ine) {
/* Check for 0 in either operand. */
nir_const_value *const_val =
nir_src_as_const_value(alu->src[0].src);
if (!const_val)
const_val = nir_src_as_const_value(alu->src[1].src);
if (!const_val || const_val->i32 != 0)
continue;
nir_ssa_def *new_expr = nir_load_helper_invocation(b, 1);
if (alu->op == nir_op_ine)
new_expr = nir_inot(b, new_expr);
nir_ssa_def_rewrite_uses(&alu->dest.dest.ssa,
new_expr);
nir_instr_remove(&alu->instr);
progress = true;
}
}
}
return progress;
}
default:
return false;
}
}
static bool
opt_intrinsics_impl(nir_function_impl *impl,
const struct nir_shader_compiler_options *options)
{
nir_builder b;
nir_builder_init(&b, impl);
bool progress = false;
nir_foreach_block(block, impl) {
bool block_has_discard = false;
nir_foreach_instr_safe(instr, block) {
b.cursor = nir_before_instr(instr);
switch (instr->type) {
case nir_instr_type_alu:
if (opt_intrinsics_alu(&b, nir_instr_as_alu(instr),
block_has_discard))
progress = true;
break;
case nir_instr_type_intrinsic: {
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
if (intrin->intrinsic == nir_intrinsic_discard ||
intrin->intrinsic == nir_intrinsic_discard_if ||
intrin->intrinsic == nir_intrinsic_demote ||
intrin->intrinsic == nir_intrinsic_demote_if ||
intrin->intrinsic == nir_intrinsic_terminate ||
intrin->intrinsic == nir_intrinsic_terminate_if)
block_has_discard = true;
if (opt_intrinsics_intrin(&b, intrin, options))
progress = true;
break;
}
default:
break;
}
}
}
return progress;
}
bool
nir_opt_intrinsics(nir_shader *shader)
{
bool progress = false;
nir_foreach_function(function, shader) {
if (!function->impl)
continue;
if (opt_intrinsics_impl(function->impl, shader->options)) {
progress = true;
nir_metadata_preserve(function->impl, nir_metadata_block_index |
nir_metadata_dominance);
} else {
nir_metadata_preserve(function->impl, nir_metadata_all);
}
}
return progress;
}