mesa/src/compiler/nir/nir_opt_access.c

382 lines
14 KiB
C

/*
* Copyright © 2019 Valve 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"
/* This pass optimizes GL access qualifiers. So far it does three things:
*
* - Infer readonly when it's missing.
* - Infer writeonly when it's missing.
* - Infer ACCESS_CAN_REORDER when the following are true:
* - Either there are no writes, or ACCESS_NON_WRITEABLE is set. In either
* case there are no writes to the underlying memory.
* - ACCESS_VOLATILE is not set.
*
* If these conditions are true, then image and buffer reads may be treated as
* if they were uniform buffer reads, i.e. they may be arbitrarily moved,
* combined, rematerialized etc.
*/
struct access_state {
nir_shader *shader;
bool infer_non_readable;
struct set *vars_written;
struct set *vars_read;
bool images_written;
bool buffers_written;
bool images_read;
bool buffers_read;
};
static void
gather_buffer_access(struct access_state *state, nir_ssa_def *def, bool read, bool write)
{
state->buffers_read |= read;
state->buffers_written |= write;
if (!def)
return;
const nir_variable *var = nir_get_binding_variable(
state->shader, nir_chase_binding(nir_src_for_ssa(def)));
if (var) {
if (read)
_mesa_set_add(state->vars_read, var);
if (write)
_mesa_set_add(state->vars_written, var);
} else {
nir_foreach_variable_with_modes(possible_var, state->shader, nir_var_mem_ssbo) {
if (read)
_mesa_set_add(state->vars_read, possible_var);
if (write)
_mesa_set_add(state->vars_written, possible_var);
}
}
}
static void
gather_intrinsic(struct access_state *state, nir_intrinsic_instr *instr)
{
const nir_variable *var;
bool read, write;
switch (instr->intrinsic) {
case nir_intrinsic_image_deref_load:
case nir_intrinsic_image_deref_store:
case nir_intrinsic_image_deref_sparse_load:
case nir_intrinsic_image_deref_atomic_add:
case nir_intrinsic_image_deref_atomic_imin:
case nir_intrinsic_image_deref_atomic_umin:
case nir_intrinsic_image_deref_atomic_imax:
case nir_intrinsic_image_deref_atomic_umax:
case nir_intrinsic_image_deref_atomic_and:
case nir_intrinsic_image_deref_atomic_or:
case nir_intrinsic_image_deref_atomic_xor:
case nir_intrinsic_image_deref_atomic_exchange:
case nir_intrinsic_image_deref_atomic_comp_swap:
case nir_intrinsic_image_deref_atomic_fadd:
case nir_intrinsic_image_deref_atomic_fmin:
case nir_intrinsic_image_deref_atomic_fmax:
var = nir_intrinsic_get_var(instr, 0);
read = instr->intrinsic != nir_intrinsic_image_deref_store;
write = instr->intrinsic != nir_intrinsic_image_deref_load &&
instr->intrinsic != nir_intrinsic_image_deref_sparse_load;
/* In OpenGL, buffer images use normal buffer objects, whereas other
* image types use textures which cannot alias with buffer objects.
* Therefore we have to group buffer samplers together with SSBO's.
*/
if (glsl_get_sampler_dim(glsl_without_array(var->type)) ==
GLSL_SAMPLER_DIM_BUF) {
state->buffers_read |= read;
state->buffers_written |= write;
} else {
state->images_read |= read;
state->images_written |= write;
}
if ((var->data.mode == nir_var_uniform ||
var->data.mode == nir_var_image) && read)
_mesa_set_add(state->vars_read, var);
if ((var->data.mode == nir_var_uniform ||
var->data.mode == nir_var_image) && write)
_mesa_set_add(state->vars_written, var);
break;
case nir_intrinsic_bindless_image_load:
case nir_intrinsic_bindless_image_store:
case nir_intrinsic_bindless_image_sparse_load:
case nir_intrinsic_bindless_image_atomic_add:
case nir_intrinsic_bindless_image_atomic_imin:
case nir_intrinsic_bindless_image_atomic_umin:
case nir_intrinsic_bindless_image_atomic_imax:
case nir_intrinsic_bindless_image_atomic_umax:
case nir_intrinsic_bindless_image_atomic_and:
case nir_intrinsic_bindless_image_atomic_or:
case nir_intrinsic_bindless_image_atomic_xor:
case nir_intrinsic_bindless_image_atomic_exchange:
case nir_intrinsic_bindless_image_atomic_comp_swap:
case nir_intrinsic_bindless_image_atomic_fadd:
case nir_intrinsic_bindless_image_atomic_fmin:
case nir_intrinsic_bindless_image_atomic_fmax:
read = instr->intrinsic != nir_intrinsic_bindless_image_store;
write = instr->intrinsic != nir_intrinsic_bindless_image_load &&
instr->intrinsic != nir_intrinsic_bindless_image_sparse_load;
if (nir_intrinsic_image_dim(instr) == GLSL_SAMPLER_DIM_BUF) {
state->buffers_read |= read;
state->buffers_written |= write;
} else {
state->images_read |= read;
state->images_written |= write;
}
break;
case nir_intrinsic_load_deref:
case nir_intrinsic_store_deref:
case nir_intrinsic_deref_atomic_add:
case nir_intrinsic_deref_atomic_imin:
case nir_intrinsic_deref_atomic_umin:
case nir_intrinsic_deref_atomic_imax:
case nir_intrinsic_deref_atomic_umax:
case nir_intrinsic_deref_atomic_and:
case nir_intrinsic_deref_atomic_or:
case nir_intrinsic_deref_atomic_xor:
case nir_intrinsic_deref_atomic_exchange:
case nir_intrinsic_deref_atomic_comp_swap:
case nir_intrinsic_deref_atomic_fadd:
case nir_intrinsic_deref_atomic_fmin:
case nir_intrinsic_deref_atomic_fmax:
case nir_intrinsic_deref_atomic_fcomp_swap: {
nir_deref_instr *deref = nir_src_as_deref(instr->src[0]);
if (!nir_deref_mode_may_be(deref, nir_var_mem_ssbo | nir_var_mem_global))
break;
bool ssbo = nir_deref_mode_is(deref, nir_var_mem_ssbo);
gather_buffer_access(state, ssbo ? instr->src[0].ssa : NULL,
instr->intrinsic != nir_intrinsic_store_deref,
instr->intrinsic != nir_intrinsic_load_deref);
break;
}
default:
break;
}
}
static bool
process_variable(struct access_state *state, nir_variable *var)
{
const struct glsl_type *type = glsl_without_array(var->type);
if (var->data.mode != nir_var_mem_ssbo &&
!(var->data.mode == nir_var_uniform && glsl_type_is_image(type)) &&
var->data.mode != nir_var_image)
return false;
/* Ignore variables we've already marked */
if (var->data.access & ACCESS_CAN_REORDER)
return false;
unsigned access = var->data.access;
bool is_buffer = var->data.mode == nir_var_mem_ssbo ||
glsl_get_sampler_dim(type) == GLSL_SAMPLER_DIM_BUF;
if (!(access & ACCESS_NON_WRITEABLE)) {
if (is_buffer ? !state->buffers_written : !state->images_written)
access |= ACCESS_NON_WRITEABLE;
else if ((access & ACCESS_RESTRICT) && !_mesa_set_search(state->vars_written, var))
access |= ACCESS_NON_WRITEABLE;
}
if (state->infer_non_readable && !(access & ACCESS_NON_READABLE)) {
if (is_buffer ? !state->buffers_read : !state->images_read)
access |= ACCESS_NON_READABLE;
else if ((access & ACCESS_RESTRICT) && !_mesa_set_search(state->vars_read, var))
access |= ACCESS_NON_READABLE;
}
bool changed = var->data.access != access;
var->data.access = access;
return changed;
}
static bool
update_access(struct access_state *state, nir_intrinsic_instr *instr, bool is_buffer, bool is_global)
{
enum gl_access_qualifier access = nir_intrinsic_access(instr);
bool is_memory_readonly = access & ACCESS_NON_WRITEABLE;
bool is_memory_writeonly = access & ACCESS_NON_READABLE;
if (instr->intrinsic != nir_intrinsic_bindless_image_load &&
instr->intrinsic != nir_intrinsic_bindless_image_store &&
instr->intrinsic != nir_intrinsic_bindless_image_sparse_load &&
!is_global) {
const nir_variable *var = nir_get_binding_variable(
state->shader, nir_chase_binding(instr->src[0]));
is_memory_readonly |= var && (var->data.access & ACCESS_NON_WRITEABLE);
is_memory_writeonly |= var && (var->data.access & ACCESS_NON_READABLE);
}
if (is_global) {
is_memory_readonly |= !state->buffers_written && !state->images_written;
is_memory_writeonly |= !state->buffers_read && !state->images_read;
} else {
is_memory_readonly |= is_buffer ? !state->buffers_written : !state->images_written;
is_memory_writeonly |= is_buffer ? !state->buffers_read : !state->images_read;
}
if (is_memory_readonly)
access |= ACCESS_NON_WRITEABLE;
if (state->infer_non_readable && is_memory_writeonly)
access |= ACCESS_NON_READABLE;
if (!(access & ACCESS_VOLATILE) && is_memory_readonly)
access |= ACCESS_CAN_REORDER;
bool progress = nir_intrinsic_access(instr) != access;
nir_intrinsic_set_access(instr, access);
return progress;
}
static bool
process_intrinsic(struct access_state *state, nir_intrinsic_instr *instr)
{
switch (instr->intrinsic) {
case nir_intrinsic_bindless_image_load:
case nir_intrinsic_bindless_image_store:
case nir_intrinsic_bindless_image_sparse_load:
return update_access(state, instr, nir_intrinsic_image_dim(instr) == GLSL_SAMPLER_DIM_BUF,
false);
case nir_intrinsic_load_deref:
case nir_intrinsic_store_deref: {
if (nir_deref_mode_is(nir_src_as_deref(instr->src[0]), nir_var_mem_global))
return update_access(state, instr, false, true);
else if (nir_deref_mode_is(nir_src_as_deref(instr->src[0]), nir_var_mem_ssbo))
return update_access(state, instr, true, false);
else
return false;
}
case nir_intrinsic_image_deref_load:
case nir_intrinsic_image_deref_store:
case nir_intrinsic_image_deref_sparse_load: {
nir_variable *var = nir_intrinsic_get_var(instr, 0);
bool is_buffer =
glsl_get_sampler_dim(glsl_without_array(var->type)) == GLSL_SAMPLER_DIM_BUF;
return update_access(state, instr, is_buffer, false);
}
default:
return false;
}
}
static bool
opt_access_impl(struct access_state *state,
nir_function_impl *impl)
{
bool progress = false;
nir_foreach_block(block, impl) {
nir_foreach_instr(instr, block) {
if (instr->type == nir_instr_type_intrinsic)
progress |= process_intrinsic(state,
nir_instr_as_intrinsic(instr));
}
}
if (progress) {
nir_metadata_preserve(impl,
nir_metadata_block_index |
nir_metadata_dominance |
nir_metadata_live_ssa_defs |
nir_metadata_loop_analysis);
}
return progress;
}
bool
nir_opt_access(nir_shader *shader, const nir_opt_access_options *options)
{
struct access_state state = {
.shader = shader,
.infer_non_readable = options->infer_non_readable,
.vars_written = _mesa_pointer_set_create(NULL),
.vars_read = _mesa_pointer_set_create(NULL),
};
bool var_progress = false;
bool progress = false;
nir_foreach_function(func, shader) {
if (func->impl) {
nir_foreach_block(block, func->impl) {
nir_foreach_instr(instr, block) {
if (instr->type == nir_instr_type_intrinsic)
gather_intrinsic(&state, nir_instr_as_intrinsic(instr));
}
}
}
}
/* In Vulkan, buffers and images can alias. */
if (options->is_vulkan) {
state.buffers_written |= state.images_written;
state.images_written |= state.buffers_written;
state.buffers_read |= state.images_read;
state.images_read |= state.buffers_read;
}
nir_foreach_variable_with_modes(var, shader, nir_var_uniform |
nir_var_mem_ubo |
nir_var_mem_ssbo |
nir_var_image)
var_progress |= process_variable(&state, var);
nir_foreach_function(func, shader) {
if (func->impl) {
progress |= opt_access_impl(&state, func->impl);
/* If we make a change to the uniforms, update all the impls. */
if (var_progress) {
nir_metadata_preserve(func->impl,
nir_metadata_block_index |
nir_metadata_dominance |
nir_metadata_live_ssa_defs |
nir_metadata_loop_analysis);
}
}
}
progress |= var_progress;
_mesa_set_destroy(state.vars_read, NULL);
_mesa_set_destroy(state.vars_written, NULL);
return progress;
}