/*
* Copyright © 2014 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.
*
* Authors:
* Connor Abbott (cwabbott0@gmail.com)
*
*/
#include "nir.h"
#include <main/imports.h>
/**
* SSA-based copy propagation
*/
static bool is_move(nir_alu_instr *instr)
{
if (instr->op != nir_op_fmov &&
instr->op != nir_op_imov)
return false;
if (instr->dest.saturate)
return false;
/* we handle modifiers in a separate pass */
if (instr->src[0].abs || instr->src[0].negate)
return false;
if (!instr->src[0].src.is_ssa)
return false;
return true;
}
static bool is_vec(nir_alu_instr *instr)
{
for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
if (!instr->src[i].src.is_ssa)
return false;
/* we handle modifiers in a separate pass */
if (instr->src[i].abs || instr->src[i].negate)
return false;
}
return instr->op == nir_op_vec2 ||
instr->op == nir_op_vec3 ||
instr->op == nir_op_vec4;
}
static bool
is_swizzleless_move(nir_alu_instr *instr)
{
if (is_move(instr)) {
for (unsigned i = 0; i < 4; i++) {
if (!((instr->dest.write_mask >> i) & 1))
break;
if (instr->src[0].swizzle[i] != i)
return false;
}
return true;
} else if (is_vec(instr)) {
nir_ssa_def *def = NULL;
for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
if (instr->src[i].swizzle[0] != i)
return false;
if (def == NULL) {
def = instr->src[i].src.ssa;
} else if (instr->src[i].src.ssa != def) {
return false;
}
}
return true;
} else {
return false;
}
}
static bool
copy_prop_src(nir_src *src, nir_instr *parent_instr, nir_if *parent_if,
unsigned num_components)
{
if (!src->is_ssa) {
if (src->reg.indirect)
return copy_prop_src(src->reg.indirect, parent_instr, parent_if, 1);
return false;
}
nir_instr *src_instr = src->ssa->parent_instr;
if (src_instr->type != nir_instr_type_alu)
return false;
nir_alu_instr *alu_instr = nir_instr_as_alu(src_instr);
if (!is_swizzleless_move(alu_instr))
return false;
if (alu_instr->src[0].src.ssa->num_components != num_components)
return false;
if (parent_instr) {
nir_instr_rewrite_src(parent_instr, src,
nir_src_for_ssa(alu_instr->src[0].src.ssa));
} else {
assert(src == &parent_if->condition);
nir_if_rewrite_condition(parent_if,
nir_src_for_ssa(alu_instr->src[0].src.ssa));
}
return true;
}
static bool
copy_prop_alu_src(nir_alu_instr *parent_alu_instr, unsigned index)
{
nir_alu_src *src = &parent_alu_instr->src[index];
if (!src->src.is_ssa) {
if (src->src.reg.indirect)
return copy_prop_src(src->src.reg.indirect, &parent_alu_instr->instr,
NULL, 1);
return false;
}
nir_instr *src_instr = src->src.ssa->parent_instr;
if (src_instr->type != nir_instr_type_alu)
return false;
nir_alu_instr *alu_instr = nir_instr_as_alu(src_instr);
if (!is_move(alu_instr) && !is_vec(alu_instr))
return false;
nir_ssa_def *def;
unsigned new_swizzle[4] = {0, 0, 0, 0};
if (alu_instr->op == nir_op_fmov ||
alu_instr->op == nir_op_imov) {
for (unsigned i = 0; i < 4; i++)
new_swizzle[i] = alu_instr->src[0].swizzle[src->swizzle[i]];
def = alu_instr->src[0].src.ssa;
} else {
def = NULL;
for (unsigned i = 0; i < 4; i++) {
if (!nir_alu_instr_channel_used(parent_alu_instr, index, i))
continue;
nir_ssa_def *new_def = alu_instr->src[src->swizzle[i]].src.ssa;
if (def == NULL)
def = new_def;
else {
if (def != new_def)
return false;
}
new_swizzle[i] = alu_instr->src[src->swizzle[i]].swizzle[0];
}
}
for (unsigned i = 0; i < 4; i++)
src->swizzle[i] = new_swizzle[i];
nir_instr_rewrite_src(&parent_alu_instr->instr, &src->src,
nir_src_for_ssa(def));
return true;
}
static bool
copy_prop_dest(nir_dest *dest, nir_instr *instr)
{
if (!dest->is_ssa && dest->reg.indirect)
return copy_prop_src(dest->reg.indirect, instr, NULL, 1);
return false;
}
static bool
copy_prop_deref_var(nir_instr *instr, nir_deref_var *deref_var)
{
if (!deref_var)
return false;
bool progress = false;
for (nir_deref *deref = deref_var->deref.child;
deref; deref = deref->child) {
if (deref->deref_type != nir_deref_type_array)
continue;
nir_deref_array *arr = nir_deref_as_array(deref);
if (arr->deref_array_type != nir_deref_array_type_indirect)
continue;
while (copy_prop_src(&arr->indirect, instr, NULL, 1))
progress = true;
}
return progress;
}
static bool
copy_prop_instr(nir_instr *instr)
{
bool progress = false;
switch (instr->type) {
case nir_instr_type_alu: {
nir_alu_instr *alu_instr = nir_instr_as_alu(instr);
for (unsigned i = 0; i < nir_op_infos[alu_instr->op].num_inputs; i++)
while (copy_prop_alu_src(alu_instr, i))
progress = true;
while (copy_prop_dest(&alu_instr->dest.dest, instr))
progress = true;
return progress;
}
case nir_instr_type_tex: {
nir_tex_instr *tex = nir_instr_as_tex(instr);
for (unsigned i = 0; i < tex->num_srcs; i++) {
unsigned num_components = nir_tex_instr_src_size(tex, i);
while (copy_prop_src(&tex->src[i].src, instr, NULL, num_components))
progress = true;
}
if (copy_prop_deref_var(instr, tex->texture))
progress = true;
if (copy_prop_deref_var(instr, tex->sampler))
progress = true;
while (copy_prop_dest(&tex->dest, instr))
progress = true;
return progress;
}
case nir_instr_type_intrinsic: {
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
for (unsigned i = 0;
i < nir_intrinsic_infos[intrin->intrinsic].num_srcs; i++) {
unsigned num_components =
nir_intrinsic_infos[intrin->intrinsic].src_components[i];
if (!num_components)
num_components = intrin->num_components;
while (copy_prop_src(&intrin->src[i], instr, NULL, num_components))
progress = true;
}
for (unsigned i = 0;
i < nir_intrinsic_infos[intrin->intrinsic].num_variables; i++) {
if (copy_prop_deref_var(instr, intrin->variables[i]))
progress = true;
}
if (nir_intrinsic_infos[intrin->intrinsic].has_dest) {
while (copy_prop_dest(&intrin->dest, instr))
progress = true;
}
return progress;
}
case nir_instr_type_phi: {
nir_phi_instr *phi = nir_instr_as_phi(instr);
assert(phi->dest.is_ssa);
unsigned num_components = phi->dest.ssa.num_components;
nir_foreach_phi_src(src, phi) {
while (copy_prop_src(&src->src, instr, NULL, num_components))
progress = true;
}
return progress;
}
default:
return false;
}
}
static bool
copy_prop_if(nir_if *if_stmt)
{
return copy_prop_src(&if_stmt->condition, NULL, if_stmt, 1);
}
static bool
nir_copy_prop_impl(nir_function_impl *impl)
{
bool progress = false;
nir_foreach_block(block, impl) {
nir_foreach_instr(instr, block) {
if (copy_prop_instr(instr))
progress = true;
}
nir_if *if_stmt = nir_block_get_following_if(block);
if (if_stmt && copy_prop_if(if_stmt))
progress = true;
}
if (progress) {
nir_metadata_preserve(impl, nir_metadata_block_index |
nir_metadata_dominance);
}
return progress;
}
bool
nir_copy_prop(nir_shader *shader)
{
bool progress = false;
nir_foreach_function(function, shader) {
if (function->impl && nir_copy_prop_impl(function->impl))
progress = true;
}
return progress;
}