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/*
* Copyright © 2012 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.
*/
/**
* \file lower_ubo_reference.cpp
*
* IR lower pass to replace dereferences of variables in a uniform
* buffer object with usage of ir_binop_ubo_load expressions, each of
* which can read data up to the size of a vec4.
*
* This relieves drivers of the responsibility to deal with tricky UBO
* layout issues like std140 structures and row_major matrices on
* their own.
*/
#include "lower_buffer_access.h"
#include "ir_builder.h"
#include "main/macros.h"
#include "glsl_parser_extras.h"
#include "main/mtypes.h"
using namespace ir_builder;
namespace {
class lower_ubo_reference_visitor :
public lower_buffer_access::lower_buffer_access {
public:
lower_ubo_reference_visitor(struct gl_linked_shader *shader,
bool clamp_block_indices,
bool use_std430_as_default)
: shader(shader), clamp_block_indices(clamp_block_indices),
struct_field(NULL), variable(NULL)
{
this->use_std430_as_default = use_std430_as_default;
}
void handle_rvalue(ir_rvalue **rvalue);
ir_visitor_status visit_enter(ir_assignment *ir);
void setup_for_load_or_store(void *mem_ctx,
ir_variable *var,
ir_rvalue *deref,
ir_rvalue **offset,
unsigned *const_offset,
bool *row_major,
const glsl_type **matrix_type,
enum glsl_interface_packing packing);
uint32_t ssbo_access_params();
ir_expression *ubo_load(void *mem_ctx, const struct glsl_type *type,
ir_rvalue *offset);
ir_call *ssbo_load(void *mem_ctx, const struct glsl_type *type,
ir_rvalue *offset);
bool check_for_buffer_array_copy(ir_assignment *ir);
bool check_for_buffer_struct_copy(ir_assignment *ir);
void check_for_ssbo_store(ir_assignment *ir);
void write_to_memory(void *mem_ctx, ir_dereference *deref, ir_variable *var,
ir_variable *write_var, unsigned write_mask);
ir_call *ssbo_store(void *mem_ctx, ir_rvalue *deref, ir_rvalue *offset,
unsigned write_mask);
enum {
ubo_load_access,
ssbo_load_access,
ssbo_store_access,
ssbo_unsized_array_length_access,
ssbo_atomic_access,
} buffer_access_type;
void insert_buffer_access(void *mem_ctx, ir_dereference *deref,
const glsl_type *type, ir_rvalue *offset,
unsigned mask, int channel);
ir_visitor_status visit_enter(class ir_expression *);
ir_expression *calculate_ssbo_unsized_array_length(ir_expression *expr);
void check_ssbo_unsized_array_length_expression(class ir_expression *);
void check_ssbo_unsized_array_length_assignment(ir_assignment *ir);
ir_expression *process_ssbo_unsized_array_length(ir_rvalue **,
ir_dereference *,
ir_variable *);
ir_expression *emit_ssbo_get_buffer_size(void *mem_ctx);
unsigned calculate_unsized_array_stride(ir_dereference *deref,
enum glsl_interface_packing packing);
ir_call *lower_ssbo_atomic_intrinsic(ir_call *ir);
ir_call *check_for_ssbo_atomic_intrinsic(ir_call *ir);
ir_visitor_status visit_enter(ir_call *ir);
ir_visitor_status visit_enter(ir_texture *ir);
struct gl_linked_shader *shader;
bool clamp_block_indices;
const struct glsl_struct_field *struct_field;
ir_variable *variable;
ir_rvalue *uniform_block;
bool progress;
};
/**
* Determine the name of the interface block field
*
* This is the name of the specific member as it would appear in the
* \c gl_uniform_buffer_variable::Name field in the shader's
* \c UniformBlocks array.
*/
static const char *
interface_field_name(void *mem_ctx, char *base_name, ir_rvalue *d,
ir_rvalue **nonconst_block_index)
{
*nonconst_block_index = NULL;
char *name_copy = NULL;
size_t base_length = 0;
/* Loop back through the IR until we find the uniform block */
ir_rvalue *ir = d;
while (ir != NULL) {
switch (ir->ir_type) {
case ir_type_dereference_variable: {
/* Exit loop */
ir = NULL;
break;
}
case ir_type_dereference_record: {
ir_dereference_record *r = (ir_dereference_record *) ir;
ir = r->record->as_dereference();
/* If we got here it means any previous array subscripts belong to
* block members and not the block itself so skip over them in the
* next pass.
*/
d = ir;
break;
}
case ir_type_dereference_array: {
ir_dereference_array *a = (ir_dereference_array *) ir;
ir = a->array->as_dereference();
break;
}
case ir_type_swizzle: {
ir_swizzle *s = (ir_swizzle *) ir;
ir = s->val->as_dereference();
/* Skip swizzle in the next pass */
d = ir;
break;
}
default:
assert(!"Should not get here.");
break;
}
}
while (d != NULL) {
switch (d->ir_type) {
case ir_type_dereference_variable: {
ir_dereference_variable *v = (ir_dereference_variable *) d;
if (name_copy != NULL &&
v->var->is_interface_instance() &&
v->var->type->is_array()) {
return name_copy;
} else {
*nonconst_block_index = NULL;
return base_name;
}
break;
}
case ir_type_dereference_array: {
ir_dereference_array *a = (ir_dereference_array *) d;
size_t new_length;
if (name_copy == NULL) {
name_copy = ralloc_strdup(mem_ctx, base_name);
base_length = strlen(name_copy);
}
/* For arrays of arrays we start at the innermost array and work our
* way out so we need to insert the subscript at the base of the
* name string rather than just attaching it to the end.
*/
new_length = base_length;
ir_constant *const_index = a->array_index->as_constant();
char *end = ralloc_strdup(NULL, &name_copy[new_length]);
if (!const_index) {
ir_rvalue *array_index = a->array_index;
if (array_index->type != glsl_type::uint_type)
array_index = i2u(array_index);
if (a->array->type->is_array() &&
a->array->type->fields.array->is_array()) {
ir_constant *base_size = new(mem_ctx)
ir_constant(a->array->type->fields.array->arrays_of_arrays_size());
array_index = mul(array_index, base_size);
}
if (*nonconst_block_index) {
*nonconst_block_index = add(*nonconst_block_index, array_index);
} else {
*nonconst_block_index = array_index;
}
ralloc_asprintf_rewrite_tail(&name_copy, &new_length, "[0]%s",
end);
} else {
ralloc_asprintf_rewrite_tail(&name_copy, &new_length, "[%d]%s",
const_index->get_uint_component(0),
end);
}
ralloc_free(end);
d = a->array->as_dereference();
break;
}
default:
assert(!"Should not get here.");
break;
}
}
assert(!"Should not get here.");
return NULL;
}
static ir_rvalue *
clamp_to_array_bounds(void *mem_ctx, ir_rvalue *index, const glsl_type *type)
{
assert(type->is_array());
const unsigned array_size = type->arrays_of_arrays_size();
ir_constant *max_index = new(mem_ctx) ir_constant(array_size - 1);
max_index->type = index->type;
ir_constant *zero = new(mem_ctx) ir_constant(0);
zero->type = index->type;
if (index->type->base_type == GLSL_TYPE_INT)
index = max2(index, zero);
index = min2(index, max_index);
return index;
}
void
lower_ubo_reference_visitor::setup_for_load_or_store(void *mem_ctx,
ir_variable *var,
ir_rvalue *deref,
ir_rvalue **offset,
unsigned *const_offset,
bool *row_major,
const glsl_type **matrix_type,
enum glsl_interface_packing packing)
{
/* Determine the name of the interface block */
ir_rvalue *nonconst_block_index;
const char *const field_name =
interface_field_name(mem_ctx, (char *) var->get_interface_type()->name,
deref, &nonconst_block_index);
if (nonconst_block_index && clamp_block_indices) {
nonconst_block_index =
clamp_to_array_bounds(mem_ctx, nonconst_block_index, var->type);
}
/* Locate the block by interface name */
unsigned num_blocks;
struct gl_uniform_block **blocks;
if (this->buffer_access_type != ubo_load_access) {
num_blocks = shader->Program->info.num_ssbos;
blocks = shader->Program->sh.ShaderStorageBlocks;
} else {
num_blocks = shader->Program->info.num_ubos;
blocks = shader->Program->sh.UniformBlocks;
}
this->uniform_block = NULL;
for (unsigned i = 0; i < num_blocks; i++) {
if (strcmp(field_name, blocks[i]->Name) == 0) {
ir_constant *index = new(mem_ctx) ir_constant(i);
if (nonconst_block_index) {
this->uniform_block = add(nonconst_block_index, index);
} else {
this->uniform_block = index;
}
if (var->is_interface_instance()) {
*const_offset = 0;
} else {
*const_offset = blocks[i]->Uniforms[var->data.location].Offset;
}
break;
}
}
assert(this->uniform_block);
this->struct_field = NULL;
setup_buffer_access(mem_ctx, deref, offset, const_offset, row_major,
matrix_type, &this->struct_field, packing);
}
void
lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
{
if (!*rvalue)
return;
ir_dereference *deref = (*rvalue)->as_dereference();
if (!deref)
return;
ir_variable *var = deref->variable_referenced();
if (!var || !var->is_in_buffer_block())
return;
void *mem_ctx = ralloc_parent(shader->ir);
ir_rvalue *offset = NULL;
unsigned const_offset;
bool row_major;
const glsl_type *matrix_type;
enum glsl_interface_packing packing =
var->get_interface_type()->
get_internal_ifc_packing(use_std430_as_default);
this->buffer_access_type =
var->is_in_shader_storage_block() ?
ssbo_load_access : ubo_load_access;
this->variable = var;
/* Compute the offset to the start if the dereference as well as other
* information we need to configure the write
*/
setup_for_load_or_store(mem_ctx, var, deref,
&offset, &const_offset,
&row_major, &matrix_type,
packing);
assert(offset);
/* Now that we've calculated the offset to the start of the
* dereference, walk over the type and emit loads into a temporary.
*/
const glsl_type *type = (*rvalue)->type;
ir_variable *load_var = new(mem_ctx) ir_variable(type,
"ubo_load_temp",
ir_var_temporary);
base_ir->insert_before(load_var);
ir_variable *load_offset = new(mem_ctx) ir_variable(glsl_type::uint_type,
"ubo_load_temp_offset",
ir_var_temporary);
base_ir->insert_before(load_offset);
base_ir->insert_before(assign(load_offset, offset));
deref = new(mem_ctx) ir_dereference_variable(load_var);
emit_access(mem_ctx, false, deref, load_offset, const_offset,
row_major, matrix_type, packing, 0);
*rvalue = deref;
progress = true;
}
ir_expression *
lower_ubo_reference_visitor::ubo_load(void *mem_ctx,
const glsl_type *type,
ir_rvalue *offset)
{
ir_rvalue *block_ref = this->uniform_block->clone(mem_ctx, NULL);
return new(mem_ctx)
ir_expression(ir_binop_ubo_load,
type,
block_ref,
offset);
}
static bool
shader_storage_buffer_object(const _mesa_glsl_parse_state *state)
{
return state->has_shader_storage_buffer_objects();
}
uint32_t
lower_ubo_reference_visitor::ssbo_access_params()
{
assert(variable);
if (variable->is_interface_instance()) {
assert(struct_field);
return ((struct_field->memory_coherent ? ACCESS_COHERENT : 0) |
(struct_field->memory_restrict ? ACCESS_RESTRICT : 0) |
(struct_field->memory_volatile ? ACCESS_VOLATILE : 0));
} else {
return ((variable->data.memory_coherent ? ACCESS_COHERENT : 0) |
(variable->data.memory_restrict ? ACCESS_RESTRICT : 0) |
(variable->data.memory_volatile ? ACCESS_VOLATILE : 0));
}
}
ir_call *
lower_ubo_reference_visitor::ssbo_store(void *mem_ctx,
ir_rvalue *deref,
ir_rvalue *offset,
unsigned write_mask)
{
exec_list sig_params;
ir_variable *block_ref = new(mem_ctx)
ir_variable(glsl_type::uint_type, "block_ref" , ir_var_function_in);
sig_params.push_tail(block_ref);
ir_variable *offset_ref = new(mem_ctx)
ir_variable(glsl_type::uint_type, "offset" , ir_var_function_in);
sig_params.push_tail(offset_ref);
ir_variable *val_ref = new(mem_ctx)
ir_variable(deref->type, "value" , ir_var_function_in);
sig_params.push_tail(val_ref);
ir_variable *writemask_ref = new(mem_ctx)
ir_variable(glsl_type::uint_type, "write_mask" , ir_var_function_in);
sig_params.push_tail(writemask_ref);
ir_variable *access_ref = new(mem_ctx)
ir_variable(glsl_type::uint_type, "access" , ir_var_function_in);
sig_params.push_tail(access_ref);
ir_function_signature *sig = new(mem_ctx)
ir_function_signature(glsl_type::void_type, shader_storage_buffer_object);
assert(sig);
sig->replace_parameters(&sig_params);
sig->intrinsic_id = ir_intrinsic_ssbo_store;
ir_function *f = new(mem_ctx) ir_function("__intrinsic_store_ssbo");
f->add_signature(sig);
exec_list call_params;
call_params.push_tail(this->uniform_block->clone(mem_ctx, NULL));
call_params.push_tail(offset->clone(mem_ctx, NULL));
call_params.push_tail(deref->clone(mem_ctx, NULL));
call_params.push_tail(new(mem_ctx) ir_constant(write_mask));
call_params.push_tail(new(mem_ctx) ir_constant(ssbo_access_params()));
return new(mem_ctx) ir_call(sig, NULL, &call_params);
}
ir_call *
lower_ubo_reference_visitor::ssbo_load(void *mem_ctx,
const struct glsl_type *type,
ir_rvalue *offset)
{
exec_list sig_params;
ir_variable *block_ref = new(mem_ctx)
ir_variable(glsl_type::uint_type, "block_ref" , ir_var_function_in);
sig_params.push_tail(block_ref);
ir_variable *offset_ref = new(mem_ctx)
ir_variable(glsl_type::uint_type, "offset_ref" , ir_var_function_in);
sig_params.push_tail(offset_ref);
ir_variable *access_ref = new(mem_ctx)
ir_variable(glsl_type::uint_type, "access" , ir_var_function_in);
sig_params.push_tail(access_ref);
ir_function_signature *sig =
new(mem_ctx) ir_function_signature(type, shader_storage_buffer_object);
assert(sig);
sig->replace_parameters(&sig_params);
sig->intrinsic_id = ir_intrinsic_ssbo_load;
ir_function *f = new(mem_ctx) ir_function("__intrinsic_load_ssbo");
f->add_signature(sig);
ir_variable *result = new(mem_ctx)
ir_variable(type, "ssbo_load_result", ir_var_temporary);
base_ir->insert_before(result);
ir_dereference_variable *deref_result = new(mem_ctx)
ir_dereference_variable(result);
exec_list call_params;
call_params.push_tail(this->uniform_block->clone(mem_ctx, NULL));
call_params.push_tail(offset->clone(mem_ctx, NULL));
call_params.push_tail(new(mem_ctx) ir_constant(ssbo_access_params()));
return new(mem_ctx) ir_call(sig, deref_result, &call_params);
}
void
lower_ubo_reference_visitor::insert_buffer_access(void *mem_ctx,
ir_dereference *deref,
const glsl_type *type,
ir_rvalue *offset,
unsigned mask,
int channel)
{
switch (this->buffer_access_type) {
case ubo_load_access:
base_ir->insert_before(assign(deref->clone(mem_ctx, NULL),
ubo_load(mem_ctx, type, offset),
mask));
break;
case ssbo_load_access: {
ir_call *load_ssbo = ssbo_load(mem_ctx, type, offset);
base_ir->insert_before(load_ssbo);
ir_rvalue *value = load_ssbo->return_deref->as_rvalue()->clone(mem_ctx, NULL);
ir_assignment *assignment =
assign(deref->clone(mem_ctx, NULL), value, mask);
base_ir->insert_before(assignment);
break;
}
case ssbo_store_access:
if (channel >= 0) {
base_ir->insert_after(ssbo_store(mem_ctx,
swizzle(deref, channel, 1),
offset, 1));
} else {
base_ir->insert_after(ssbo_store(mem_ctx, deref, offset, mask));
}
break;
default:
unreachable("invalid buffer_access_type in insert_buffer_access");
}
}
void
lower_ubo_reference_visitor::write_to_memory(void *mem_ctx,
ir_dereference *deref,
ir_variable *var,
ir_variable *write_var,
unsigned write_mask)
{
ir_rvalue *offset = NULL;
unsigned const_offset;
bool row_major;
const glsl_type *matrix_type;
enum glsl_interface_packing packing =
var->get_interface_type()->
get_internal_ifc_packing(use_std430_as_default);
this->buffer_access_type = ssbo_store_access;
this->variable = var;
/* Compute the offset to the start if the dereference as well as other
* information we need to configure the write
*/
setup_for_load_or_store(mem_ctx, var, deref,
&offset, &const_offset,
&row_major, &matrix_type,
packing);
assert(offset);
/* Now emit writes from the temporary to memory */
ir_variable *write_offset =
new(mem_ctx) ir_variable(glsl_type::uint_type,
"ssbo_store_temp_offset",
ir_var_temporary);
base_ir->insert_before(write_offset);
base_ir->insert_before(assign(write_offset, offset));
deref = new(mem_ctx) ir_dereference_variable(write_var);
emit_access(mem_ctx, true, deref, write_offset, const_offset,
row_major, matrix_type, packing, write_mask);
}
ir_visitor_status
lower_ubo_reference_visitor::visit_enter(ir_expression *ir)
{
check_ssbo_unsized_array_length_expression(ir);
return rvalue_visit(ir);
}
ir_expression *
lower_ubo_reference_visitor::calculate_ssbo_unsized_array_length(ir_expression *expr)
{
if (expr->operation !=
ir_expression_operation(ir_unop_ssbo_unsized_array_length))
return NULL;
ir_rvalue *rvalue = expr->operands[0]->as_rvalue();
if (!rvalue ||
!rvalue->type->is_array() || !rvalue->type->is_unsized_array())
return NULL;
ir_dereference *deref = expr->operands[0]->as_dereference();
if (!deref)
return NULL;
ir_variable *var = expr->operands[0]->variable_referenced();
if (!var || !var->is_in_shader_storage_block())
return NULL;
return process_ssbo_unsized_array_length(&rvalue, deref, var);
}
void
lower_ubo_reference_visitor::check_ssbo_unsized_array_length_expression(ir_expression *ir)
{
if (ir->operation ==
ir_expression_operation(ir_unop_ssbo_unsized_array_length)) {
/* Don't replace this unop if it is found alone. It is going to be
* removed by the optimization passes or replaced if it is part of
* an ir_assignment or another ir_expression.
*/
return;
}
for (unsigned i = 0; i < ir->num_operands; i++) {
if (ir->operands[i]->ir_type != ir_type_expression)
continue;
ir_expression *expr = (ir_expression *) ir->operands[i];
ir_expression *temp = calculate_ssbo_unsized_array_length(expr);
if (!temp)
continue;
delete expr;
ir->operands[i] = temp;
}
}
void
lower_ubo_reference_visitor::check_ssbo_unsized_array_length_assignment(ir_assignment *ir)
{
if (!ir->rhs || ir->rhs->ir_type != ir_type_expression)
return;
ir_expression *expr = (ir_expression *) ir->rhs;
ir_expression *temp = calculate_ssbo_unsized_array_length(expr);
if (!temp)
return;
delete expr;
ir->rhs = temp;
return;
}
ir_expression *
lower_ubo_reference_visitor::emit_ssbo_get_buffer_size(void *mem_ctx)
{
ir_rvalue *block_ref = this->uniform_block->clone(mem_ctx, NULL);
return new(mem_ctx) ir_expression(ir_unop_get_buffer_size,
glsl_type::int_type,
block_ref);
}
unsigned
lower_ubo_reference_visitor::calculate_unsized_array_stride(ir_dereference *deref,
enum glsl_interface_packing packing)
{
unsigned array_stride = 0;
switch (deref->ir_type) {
case ir_type_dereference_variable:
{
ir_dereference_variable *deref_var = (ir_dereference_variable *)deref;
const struct glsl_type *unsized_array_type = NULL;
/* An unsized array can be sized by other lowering passes, so pick
* the first field of the array which has the data type of the unsized
* array.
*/
unsized_array_type = deref_var->var->type->fields.array;
/* Whether or not the field is row-major (because it might be a
* bvec2 or something) does not affect the array itself. We need
* to know whether an array element in its entirety is row-major.
*/
const bool array_row_major =
is_dereferenced_thing_row_major(deref_var);
if (packing == GLSL_INTERFACE_PACKING_STD430) {
array_stride = unsized_array_type->std430_array_stride(array_row_major);
} else {
array_stride = unsized_array_type->std140_size(array_row_major);
array_stride = glsl_align(array_stride, 16);
}
break;
}
case ir_type_dereference_record:
{
ir_dereference_record *deref_record = (ir_dereference_record *) deref;
ir_dereference *interface_deref =
deref_record->record->as_dereference();
assert(interface_deref != NULL);
const struct glsl_type *interface_type = interface_deref->type;
unsigned record_length = interface_type->length;
/* Unsized array is always the last element of the interface */
const struct glsl_type *unsized_array_type =
interface_type->fields.structure[record_length - 1].type->fields.array;
const bool array_row_major =
is_dereferenced_thing_row_major(deref_record);
if (packing == GLSL_INTERFACE_PACKING_STD430) {
array_stride = unsized_array_type->std430_array_stride(array_row_major);
} else {
array_stride = unsized_array_type->std140_size(array_row_major);
array_stride = glsl_align(array_stride, 16);
}
break;
}
default:
unreachable("Unsupported dereference type");
}
return array_stride;
}
ir_expression *
lower_ubo_reference_visitor::process_ssbo_unsized_array_length(ir_rvalue **rvalue,
ir_dereference *deref,
ir_variable *var)
{
void *mem_ctx = ralloc_parent(*rvalue);
ir_rvalue *base_offset = NULL;
unsigned const_offset;
bool row_major;
const glsl_type *matrix_type;
enum glsl_interface_packing packing =
var->get_interface_type()->
get_internal_ifc_packing(use_std430_as_default);
int unsized_array_stride =
calculate_unsized_array_stride(deref, packing);
this->buffer_access_type = ssbo_unsized_array_length_access;
this->variable = var;
/* Compute the offset to the start if the dereference as well as other
* information we need to calculate the length.
*/
setup_for_load_or_store(mem_ctx, var, deref,
&base_offset, &const_offset,
&row_major, &matrix_type,
packing);
/* array.length() =
* max((buffer_object_size - offset_of_array) / stride_of_array, 0)
*/
ir_expression *buffer_size = emit_ssbo_get_buffer_size(mem_ctx);
ir_expression *offset_of_array = new(mem_ctx)
ir_expression(ir_binop_add, base_offset,
new(mem_ctx) ir_constant(const_offset));
ir_expression *offset_of_array_int = new(mem_ctx)
ir_expression(ir_unop_u2i, offset_of_array);
ir_expression *sub = new(mem_ctx)
ir_expression(ir_binop_sub, buffer_size, offset_of_array_int);
ir_expression *div = new(mem_ctx)
ir_expression(ir_binop_div, sub,
new(mem_ctx) ir_constant(unsized_array_stride));
ir_expression *max = new(mem_ctx)
ir_expression(ir_binop_max, div, new(mem_ctx) ir_constant(0));
return max;
}
void
lower_ubo_reference_visitor::check_for_ssbo_store(ir_assignment *ir)
{
if (!ir || !ir->lhs)
return;
ir_rvalue *rvalue = ir->lhs->as_rvalue();
if (!rvalue)
return;
ir_dereference *deref = ir->lhs->as_dereference();
if (!deref)
return;
ir_variable *var = ir->lhs->variable_referenced();
if (!var || !var->is_in_shader_storage_block())
return;
/* We have a write to a buffer variable, so declare a temporary and rewrite
* the assignment so that the temporary is the LHS.
*/
void *mem_ctx = ralloc_parent(shader->ir);
const glsl_type *type = rvalue->type;
ir_variable *write_var = new(mem_ctx) ir_variable(type,
"ssbo_store_temp",
ir_var_temporary);
base_ir->insert_before(write_var);
ir->lhs = new(mem_ctx) ir_dereference_variable(write_var);
/* Now we have to write the value assigned to the temporary back to memory */
write_to_memory(mem_ctx, deref, var, write_var, ir->write_mask);
progress = true;
}
static bool
is_buffer_backed_variable(ir_variable *var)
{
return var->is_in_buffer_block() ||
var->data.mode == ir_var_shader_shared;
}
bool
lower_ubo_reference_visitor::check_for_buffer_array_copy(ir_assignment *ir)
{
if (!ir || !ir->lhs || !ir->rhs)
return false;
/* LHS and RHS must be arrays
* FIXME: arrays of arrays?
*/
if (!ir->lhs->type->is_array() || !ir->rhs->type->is_array())
return false;
/* RHS must be a buffer-backed variable. This is what can cause the problem
* since it would lead to a series of loads that need to live until we
* see the writes to the LHS.
*/
ir_variable *rhs_var = ir->rhs->variable_referenced();
if (!rhs_var || !is_buffer_backed_variable(rhs_var))
return false;
/* Split the array copy into individual element copies to reduce
* register pressure
*/
ir_dereference *rhs_deref = ir->rhs->as_dereference();
if (!rhs_deref)
return false;
ir_dereference *lhs_deref = ir->lhs->as_dereference();
if (!lhs_deref)
return false;
assert(lhs_deref->type->length == rhs_deref->type->length);
void *mem_ctx = ralloc_parent(shader->ir);
for (unsigned i = 0; i < lhs_deref->type->length; i++) {
ir_dereference *lhs_i =
new(mem_ctx) ir_dereference_array(lhs_deref->clone(mem_ctx, NULL),
new(mem_ctx) ir_constant(i));
ir_dereference *rhs_i =
new(mem_ctx) ir_dereference_array(rhs_deref->clone(mem_ctx, NULL),
new(mem_ctx) ir_constant(i));
ir->insert_after(assign(lhs_i, rhs_i));
}
ir->remove();
progress = true;
return true;
}
bool
lower_ubo_reference_visitor::check_for_buffer_struct_copy(ir_assignment *ir)
{
if (!ir || !ir->lhs || !ir->rhs)
return false;
/* LHS and RHS must be records */
if (!ir->lhs->type->is_struct() || !ir->rhs->type->is_struct())
return false;
/* RHS must be a buffer-backed variable. This is what can cause the problem
* since it would lead to a series of loads that need to live until we
* see the writes to the LHS.
*/
ir_variable *rhs_var = ir->rhs->variable_referenced();
if (!rhs_var || !is_buffer_backed_variable(rhs_var))
return false;
/* Split the struct copy into individual element copies to reduce
* register pressure
*/
ir_dereference *rhs_deref = ir->rhs->as_dereference();
if (!rhs_deref)
return false;
ir_dereference *lhs_deref = ir->lhs->as_dereference();
if (!lhs_deref)
return false;
assert(lhs_deref->type == rhs_deref->type);
void *mem_ctx = ralloc_parent(shader->ir);
for (unsigned i = 0; i < lhs_deref->type->length; i++) {
const char *field_name = lhs_deref->type->fields.structure[i].name;
ir_dereference *lhs_field =
new(mem_ctx) ir_dereference_record(lhs_deref->clone(mem_ctx, NULL),
field_name);
ir_dereference *rhs_field =
new(mem_ctx) ir_dereference_record(rhs_deref->clone(mem_ctx, NULL),
field_name);
ir->insert_after(assign(lhs_field, rhs_field));
}
ir->remove();
progress = true;
return true;
}
ir_visitor_status
lower_ubo_reference_visitor::visit_enter(ir_assignment *ir)
{
/* Array and struct copies could involve large amounts of load/store
* operations. To improve register pressure we want to special-case
* these and split them into individual element copies.
* This way we avoid emitting all the loads for the RHS first and
* all the writes for the LHS second and register usage is more
* efficient.
*/
if (check_for_buffer_array_copy(ir))
return visit_continue_with_parent;
if (check_for_buffer_struct_copy(ir))
return visit_continue_with_parent;
check_ssbo_unsized_array_length_assignment(ir);
check_for_ssbo_store(ir);
return rvalue_visit(ir);
}
/* Lowers the intrinsic call to a new internal intrinsic that swaps the
* access to the buffer variable in the first parameter by an offset
* and block index. This involves creating the new internal intrinsic
* (i.e. the new function signature).
*/
ir_call *
lower_ubo_reference_visitor::lower_ssbo_atomic_intrinsic(ir_call *ir)
{
/* SSBO atomics usually have 2 parameters, the buffer variable and an
* integer argument. The exception is CompSwap, that has an additional
* integer parameter.
*/
int param_count = ir->actual_parameters.length();
assert(param_count == 2 || param_count == 3);
/* First argument must be a scalar integer buffer variable */
exec_node *param = ir->actual_parameters.get_head();
ir_instruction *inst = (ir_instruction *) param;
assert(inst->ir_type == ir_type_dereference_variable ||
inst->ir_type == ir_type_dereference_array ||
inst->ir_type == ir_type_dereference_record ||
inst->ir_type == ir_type_swizzle);
ir_rvalue *deref = (ir_rvalue *) inst;
assert(deref->type->is_scalar() &&
(deref->type->is_integer_32() || deref->type->is_float()));
ir_variable *var = deref->variable_referenced();
assert(var);
/* Compute the offset to the start if the dereference and the
* block index
*/
void *mem_ctx = ralloc_parent(shader->ir);
ir_rvalue *offset = NULL;
unsigned const_offset;
bool row_major;
const glsl_type *matrix_type;
enum glsl_interface_packing packing =
var->get_interface_type()->
get_internal_ifc_packing(use_std430_as_default);
this->buffer_access_type = ssbo_atomic_access;
this->variable = var;
setup_for_load_or_store(mem_ctx, var, deref,
&offset, &const_offset,
&row_major, &matrix_type,
packing);
assert(offset);
assert(!row_major);
assert(matrix_type == NULL);
ir_rvalue *deref_offset =
add(offset, new(mem_ctx) ir_constant(const_offset));
ir_rvalue *block_index = this->uniform_block->clone(mem_ctx, NULL);
/* Create the new internal function signature that will take a block
* index and offset instead of a buffer variable
*/
exec_list sig_params;
ir_variable *sig_param = new(mem_ctx)
ir_variable(glsl_type::uint_type, "block_ref" , ir_var_function_in);
sig_params.push_tail(sig_param);
sig_param = new(mem_ctx)
ir_variable(glsl_type::uint_type, "offset" , ir_var_function_in);
sig_params.push_tail(sig_param);
const glsl_type *type = deref->type->get_scalar_type();
sig_param = new(mem_ctx)
ir_variable(type, "data1", ir_var_function_in);
sig_params.push_tail(sig_param);
if (param_count == 3) {
sig_param = new(mem_ctx)
ir_variable(type, "data2", ir_var_function_in);
sig_params.push_tail(sig_param);
}
ir_function_signature *sig =
new(mem_ctx) ir_function_signature(deref->type,
shader_storage_buffer_object);
assert(sig);
sig->replace_parameters(&sig_params);
assert(ir->callee->intrinsic_id >= ir_intrinsic_generic_load);
assert(ir->callee->intrinsic_id <= ir_intrinsic_generic_atomic_comp_swap);
sig->intrinsic_id = MAP_INTRINSIC_TO_TYPE(ir->callee->intrinsic_id, ssbo);
char func_name[64];
sprintf(func_name, "%s_ssbo", ir->callee_name());
ir_function *f = new(mem_ctx) ir_function(func_name);
f->add_signature(sig);
/* Now, create the call to the internal intrinsic */
exec_list call_params;
call_params.push_tail(block_index);
call_params.push_tail(deref_offset);
param = ir->actual_parameters.get_head()->get_next();
ir_rvalue *param_as_rvalue = ((ir_instruction *) param)->as_rvalue();
call_params.push_tail(param_as_rvalue->clone(mem_ctx, NULL));
if (param_count == 3) {
param = param->get_next();
param_as_rvalue = ((ir_instruction *) param)->as_rvalue();
call_params.push_tail(param_as_rvalue->clone(mem_ctx, NULL));
}
ir_dereference_variable *return_deref =
ir->return_deref->clone(mem_ctx, NULL);
return new(mem_ctx) ir_call(sig, return_deref, &call_params);
}
ir_call *
lower_ubo_reference_visitor::check_for_ssbo_atomic_intrinsic(ir_call *ir)
{
exec_list& params = ir->actual_parameters;
if (params.length() < 2 || params.length() > 3)
return ir;
ir_rvalue *rvalue =
((ir_instruction *) params.get_head())->as_rvalue();
if (!rvalue)
return ir;
ir_variable *var = rvalue->variable_referenced();
if (!var || !var->is_in_shader_storage_block())
return ir;
const enum ir_intrinsic_id id = ir->callee->intrinsic_id;
if (id == ir_intrinsic_generic_atomic_add ||
id == ir_intrinsic_generic_atomic_min ||
id == ir_intrinsic_generic_atomic_max ||
id == ir_intrinsic_generic_atomic_and ||
id == ir_intrinsic_generic_atomic_or ||
id == ir_intrinsic_generic_atomic_xor ||
id == ir_intrinsic_generic_atomic_exchange ||
id == ir_intrinsic_generic_atomic_comp_swap) {
return lower_ssbo_atomic_intrinsic(ir);
}
return ir;
}
ir_visitor_status
lower_ubo_reference_visitor::visit_enter(ir_call *ir)
{
ir_call *new_ir = check_for_ssbo_atomic_intrinsic(ir);
if (new_ir != ir) {
progress = true;
base_ir->replace_with(new_ir);
return visit_continue_with_parent;
}
return rvalue_visit(ir);
}
ir_visitor_status
lower_ubo_reference_visitor::visit_enter(ir_texture *ir)
{
ir_dereference *sampler = ir->sampler;
if (sampler->ir_type == ir_type_dereference_record) {
handle_rvalue((ir_rvalue **)&ir->sampler);
return visit_continue_with_parent;
}
return rvalue_visit(ir);
}
} /* unnamed namespace */
void
lower_ubo_reference(struct gl_linked_shader *shader,
bool clamp_block_indices, bool use_std430_as_default)
{
lower_ubo_reference_visitor v(shader, clamp_block_indices,
use_std430_as_default);
/* Loop over the instructions lowering references, because we take
* a deref of a UBO array using a UBO dereference as the index will
* produce a collection of instructions all of which have cloned
* UBO dereferences for that array index.
*/
do {
v.progress = false;
visit_list_elements(&v, shader->ir);
} while (v.progress);
}