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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 "ir.h"
#include "ir_builder.h"
#include "ir_rvalue_visitor.h"
#include "main/macros.h"
#include "glsl_parser_extras.h"
using namespace ir_builder;
/**
* Determine if a thing being dereferenced is row-major
*
* There is some trickery here.
*
* If the thing being dereferenced is a member of uniform block \b without an
* instance name, then the name of the \c ir_variable is the field name of an
* interface type. If this field is row-major, then the thing referenced is
* row-major.
*
* If the thing being dereferenced is a member of uniform block \b with an
* instance name, then the last dereference in the tree will be an
* \c ir_dereference_record. If that record field is row-major, then the
* thing referenced is row-major.
*/
static bool
is_dereferenced_thing_row_major(const ir_rvalue *deref)
{
bool matrix = false;
const ir_rvalue *ir = deref;
while (true) {
matrix = matrix || ir->type->without_array()->is_matrix();
switch (ir->ir_type) {
case ir_type_dereference_array: {
const ir_dereference_array *const array_deref =
(const ir_dereference_array *) ir;
ir = array_deref->array;
break;
}
case ir_type_dereference_record: {
const ir_dereference_record *const record_deref =
(const ir_dereference_record *) ir;
ir = record_deref->record;
const int idx = ir->type->field_index(record_deref->field);
assert(idx >= 0);
const enum glsl_matrix_layout matrix_layout =
glsl_matrix_layout(ir->type->fields.structure[idx].matrix_layout);
switch (matrix_layout) {
case GLSL_MATRIX_LAYOUT_INHERITED:
break;
case GLSL_MATRIX_LAYOUT_COLUMN_MAJOR:
return false;
case GLSL_MATRIX_LAYOUT_ROW_MAJOR:
return matrix || deref->type->without_array()->is_record();
}
break;
}
case ir_type_dereference_variable: {
const ir_dereference_variable *const var_deref =
(const ir_dereference_variable *) ir;
const enum glsl_matrix_layout matrix_layout =
glsl_matrix_layout(var_deref->var->data.matrix_layout);
switch (matrix_layout) {
case GLSL_MATRIX_LAYOUT_INHERITED:
assert(!matrix);
return false;
case GLSL_MATRIX_LAYOUT_COLUMN_MAJOR:
return false;
case GLSL_MATRIX_LAYOUT_ROW_MAJOR:
return matrix || deref->type->without_array()->is_record();
}
unreachable("invalid matrix layout");
break;
}
default:
return false;
}
}
/* The tree must have ended with a dereference that wasn't an
* ir_dereference_variable. That is invalid, and it should be impossible.
*/
unreachable("invalid dereference tree");
return false;
}
namespace {
class lower_ubo_reference_visitor : public ir_rvalue_enter_visitor {
public:
lower_ubo_reference_visitor(struct gl_shader *shader)
: shader(shader)
{
}
void handle_rvalue(ir_rvalue **rvalue);
ir_visitor_status visit_enter(ir_assignment *ir);
void setup_for_load_or_store(ir_variable *var,
ir_rvalue *deref,
ir_rvalue **offset,
unsigned *const_offset,
bool *row_major,
int *matrix_columns,
unsigned packing);
ir_expression *ubo_load(const struct glsl_type *type,
ir_rvalue *offset);
ir_call *ssbo_load(const struct glsl_type *type,
ir_rvalue *offset);
void check_for_ssbo_store(ir_assignment *ir);
void write_to_memory(ir_dereference *deref,
ir_variable *var,
ir_variable *write_var,
unsigned write_mask);
ir_call *ssbo_store(ir_rvalue *deref, ir_rvalue *offset,
unsigned write_mask);
void emit_access(bool is_write, ir_dereference *deref,
ir_variable *base_offset, unsigned int deref_offset,
bool row_major, int matrix_columns,
unsigned packing, unsigned write_mask);
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();
unsigned calculate_unsized_array_stride(ir_dereference *deref,
unsigned 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);
void *mem_ctx;
struct gl_shader *shader;
struct gl_uniform_buffer_variable *ubo_var;
ir_rvalue *uniform_block;
bool progress;
bool is_shader_storage;
};
/**
* 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;
}
void
lower_ubo_reference_visitor::setup_for_load_or_store(ir_variable *var,
ir_rvalue *deref,
ir_rvalue **offset,
unsigned *const_offset,
bool *row_major,
int *matrix_columns,
unsigned 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);
/* Locate the block by interface name */
this->is_shader_storage = var->is_in_shader_storage_block();
unsigned num_blocks;
struct gl_uniform_block **blocks;
if (this->is_shader_storage) {
num_blocks = shader->NumShaderStorageBlocks;
blocks = shader->ShaderStorageBlocks;
} else {
num_blocks = shader->NumUniformBlocks;
blocks = shader->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;
}
this->ubo_var = var->is_interface_instance()
? &blocks[i]->Uniforms[0] : &blocks[i]->Uniforms[var->data.location];
break;
}
}
assert(this->uniform_block);
*offset = new(mem_ctx) ir_constant(0u);
*const_offset = 0;
*row_major = is_dereferenced_thing_row_major(deref);
*matrix_columns = 1;
/* Calculate the offset to the start of the region of the UBO
* dereferenced by *rvalue. This may be a variable offset if an
* array dereference has a variable index.
*/
while (deref) {
switch (deref->ir_type) {
case ir_type_dereference_variable: {
*const_offset += ubo_var->Offset;
deref = NULL;
break;
}
case ir_type_dereference_array: {
ir_dereference_array *deref_array = (ir_dereference_array *) deref;
unsigned array_stride;
if (deref_array->array->type->is_vector()) {
/* We get this when storing or loading a component out of a vector
* with a non-constant index. This happens for v[i] = f where v is
* a vector (or m[i][j] = f where m is a matrix). If we don't
* lower that here, it gets turned into v = vector_insert(v, i,
* f), which loads the entire vector, modifies one component and
* then write the entire thing back. That breaks if another
* thread or SIMD channel is modifying the same vector.
*/
array_stride = 4;
if (deref_array->array->type->is_double())
array_stride *= 2;
} else if (deref_array->array->type->is_matrix() && *row_major) {
/* When loading a vector out of a row major matrix, the
* step between the columns (vectors) is the size of a
* float, while the step between the rows (elements of a
* vector) is handled below in emit_ubo_loads.
*/
array_stride = 4;
if (deref_array->array->type->is_double())
array_stride *= 2;
*matrix_columns = deref_array->array->type->matrix_columns;
} else if (deref_array->type->without_array()->is_interface()) {
/* We're processing an array dereference of an interface instance
* array. The thing being dereferenced *must* be a variable
* dereference because interfaces cannot be embedded in other
* types. In terms of calculating the offsets for the lowering
* pass, we don't care about the array index. All elements of an
* interface instance array will have the same offsets relative to
* the base of the block that backs them.
*/
deref = deref_array->array->as_dereference();
break;
} else {
/* 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_array);
/* The array type will give the correct interface packing
* information
*/
if (packing == GLSL_INTERFACE_PACKING_STD430) {
array_stride = deref_array->type->std430_array_stride(array_row_major);
} else {
array_stride = deref_array->type->std140_size(array_row_major);
array_stride = glsl_align(array_stride, 16);
}
}
ir_rvalue *array_index = deref_array->array_index;
if (array_index->type->base_type == GLSL_TYPE_INT)
array_index = i2u(array_index);
ir_constant *const_index =
array_index->constant_expression_value(NULL);
if (const_index) {
*const_offset += array_stride * const_index->value.u[0];
} else {
*offset = add(*offset,
mul(array_index,
new(mem_ctx) ir_constant(array_stride)));
}
deref = deref_array->array->as_dereference();
break;
}
case ir_type_dereference_record: {
ir_dereference_record *deref_record = (ir_dereference_record *) deref;
const glsl_type *struct_type = deref_record->record->type;
unsigned intra_struct_offset = 0;
for (unsigned int i = 0; i < struct_type->length; i++) {
const glsl_type *type = struct_type->fields.structure[i].type;
ir_dereference_record *field_deref = new(mem_ctx)
ir_dereference_record(deref_record->record,
struct_type->fields.structure[i].name);
const bool field_row_major =
is_dereferenced_thing_row_major(field_deref);
ralloc_free(field_deref);
unsigned field_align = 0;
if (packing == GLSL_INTERFACE_PACKING_STD430)
field_align = type->std430_base_alignment(field_row_major);
else
field_align = type->std140_base_alignment(field_row_major);
intra_struct_offset = glsl_align(intra_struct_offset, field_align);
if (strcmp(struct_type->fields.structure[i].name,
deref_record->field) == 0)
break;
if (packing == GLSL_INTERFACE_PACKING_STD430)
intra_struct_offset += type->std430_size(field_row_major);
else
intra_struct_offset += type->std140_size(field_row_major);
/* If the field just examined was itself a structure, apply rule
* #9:
*
* "The structure may have padding at the end; the base offset
* of the member following the sub-structure is rounded up to
* the next multiple of the base alignment of the structure."
*/
if (type->without_array()->is_record()) {
intra_struct_offset = glsl_align(intra_struct_offset,
field_align);
}
}
*const_offset += intra_struct_offset;
deref = deref_record->record->as_dereference();
break;
}
case ir_type_swizzle: {
ir_swizzle *deref_swizzle = (ir_swizzle *) deref;
assert(deref_swizzle->mask.num_components == 1);
*const_offset += deref_swizzle->mask.x * sizeof(int);
deref = deref_swizzle->val->as_dereference();
break;
}
default:
assert(!"not reached");
deref = NULL;
break;
}
}
}
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;
mem_ctx = ralloc_parent(shader->ir);
ir_rvalue *offset = NULL;
unsigned const_offset;
bool row_major;
int matrix_columns;
unsigned packing = var->get_interface_type()->interface_packing;
/* 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(var, deref,
&offset, &const_offset,
&row_major, &matrix_columns,
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(false, deref, load_offset, const_offset,
row_major, matrix_columns, packing, 0);
*rvalue = deref;
progress = true;
}
ir_expression *
lower_ubo_reference_visitor::ubo_load(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->ARB_shader_storage_buffer_object_enable;
}
ir_call *
lower_ubo_reference_visitor::ssbo_store(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_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->is_intrinsic = true;
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));
return new(mem_ctx) ir_call(sig, NULL, &call_params);
}
ir_call *
lower_ubo_reference_visitor::ssbo_load(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_function_signature *sig =
new(mem_ctx) ir_function_signature(type, shader_storage_buffer_object);
assert(sig);
sig->replace_parameters(&sig_params);
sig->is_intrinsic = true;
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));
return new(mem_ctx) ir_call(sig, deref_result, &call_params);
}
static inline int
writemask_for_size(unsigned n)
{
return ((1 << n) - 1);
}
/**
* Takes a deref and recursively calls itself to break the deref down to the
* point that the reads or writes generated are contiguous scalars or vectors.
*/
void
lower_ubo_reference_visitor::emit_access(bool is_write,
ir_dereference *deref,
ir_variable *base_offset,
unsigned int deref_offset,
bool row_major,
int matrix_columns,
unsigned packing,
unsigned write_mask)
{
if (deref->type->is_record()) {
unsigned int field_offset = 0;
for (unsigned i = 0; i < deref->type->length; i++) {
const struct glsl_struct_field *field =
&deref->type->fields.structure[i];
ir_dereference *field_deref =
new(mem_ctx) ir_dereference_record(deref->clone(mem_ctx, NULL),
field->name);
field_offset =
glsl_align(field_offset,
field->type->std140_base_alignment(row_major));
emit_access(is_write, field_deref, base_offset,
deref_offset + field_offset,
row_major, 1, packing,
writemask_for_size(field_deref->type->vector_elements));
field_offset += field->type->std140_size(row_major);
}
return;
}
if (deref->type->is_array()) {
unsigned array_stride = packing == GLSL_INTERFACE_PACKING_STD430 ?
deref->type->fields.array->std430_array_stride(row_major) :
glsl_align(deref->type->fields.array->std140_size(row_major), 16);
for (unsigned i = 0; i < deref->type->length; i++) {
ir_constant *element = new(mem_ctx) ir_constant(i);
ir_dereference *element_deref =
new(mem_ctx) ir_dereference_array(deref->clone(mem_ctx, NULL),
element);
emit_access(is_write, element_deref, base_offset,
deref_offset + i * array_stride,
row_major, 1, packing,
writemask_for_size(element_deref->type->vector_elements));
}
return;
}
if (deref->type->is_matrix()) {
for (unsigned i = 0; i < deref->type->matrix_columns; i++) {
ir_constant *col = new(mem_ctx) ir_constant(i);
ir_dereference *col_deref =
new(mem_ctx) ir_dereference_array(deref->clone(mem_ctx, NULL), col);
if (row_major) {
/* For a row-major matrix, the next column starts at the next
* element.
*/
int size_mul = deref->type->is_double() ? 8 : 4;
emit_access(is_write, col_deref, base_offset,
deref_offset + i * size_mul,
row_major, deref->type->matrix_columns, packing,
writemask_for_size(col_deref->type->vector_elements));
} else {
int size_mul;
/* std430 doesn't round up vec2 size to a vec4 size */
if (packing == GLSL_INTERFACE_PACKING_STD430 &&
deref->type->vector_elements == 2 &&
!deref->type->is_double()) {
size_mul = 8;
} else {
/* std140 always rounds the stride of arrays (and matrices) to a
* vec4, so matrices are always 16 between columns/rows. With
* doubles, they will be 32 apart when there are more than 2 rows.
*
* For both std140 and std430, if the member is a
* three-'component vector with components consuming N basic
* machine units, the base alignment is 4N. For vec4, base
* alignment is 4N.
*/
size_mul = (deref->type->is_double() &&
deref->type->vector_elements > 2) ? 32 : 16;
}
emit_access(is_write, col_deref, base_offset,
deref_offset + i * size_mul,
row_major, deref->type->matrix_columns, packing,
writemask_for_size(col_deref->type->vector_elements));
}
}
return;
}
assert(deref->type->is_scalar() || deref->type->is_vector());
if (!row_major) {
ir_rvalue *offset =
add(base_offset, new(mem_ctx) ir_constant(deref_offset));
if (is_write)
base_ir->insert_after(ssbo_store(deref, offset, write_mask));
else {
if (!this->is_shader_storage) {
base_ir->insert_before(assign(deref->clone(mem_ctx, NULL),
ubo_load(deref->type, offset)));
} else {
ir_call *load_ssbo = ssbo_load(deref->type, offset);
base_ir->insert_before(load_ssbo);
ir_rvalue *value = load_ssbo->return_deref->as_rvalue()->clone(mem_ctx, NULL);
base_ir->insert_before(assign(deref->clone(mem_ctx, NULL), value));
}
}
} else {
unsigned N = deref->type->is_double() ? 8 : 4;
/* We're dereffing a column out of a row-major matrix, so we
* gather the vector from each stored row.
*/
assert(deref->type->base_type == GLSL_TYPE_FLOAT ||
deref->type->base_type == GLSL_TYPE_DOUBLE);
/* Matrices, row_major or not, are stored as if they were
* arrays of vectors of the appropriate size in std140.
* Arrays have their strides rounded up to a vec4, so the
* matrix stride is always 16. However a double matrix may either be 16
* or 32 depending on the number of columns.
*/
assert(matrix_columns <= 4);
unsigned matrix_stride = 0;
/* Matrix stride for std430 mat2xY matrices are not rounded up to
* vec4 size. From OpenGL 4.3 spec, section 7.6.2.2 "Standard Uniform
* Block Layout":
*
* "2. If the member is a two- or four-component vector with components
* consuming N basic machine units, the base alignment is 2N or 4N,
* respectively." [...]
* "4. If the member is an array of scalars or vectors, the base alignment
* and array stride are set to match the base alignment of a single array
* element, according to rules (1), (2), and (3), and rounded up to the
* base alignment of a vec4." [...]
* "7. If the member is a row-major matrix with C columns and R rows, the
* matrix is stored identically to an array of R row vectors with C
* components each, according to rule (4)." [...]
* "When using the std430 storage layout, shader storage blocks will be
* laid out in buffer storage identically to uniform and shader storage
* blocks using the std140 layout, except that the base alignment and
* stride of arrays of scalars and vectors in rule 4 and of structures in
* rule 9 are not rounded up a multiple of the base alignment of a vec4."
*/
if (packing == GLSL_INTERFACE_PACKING_STD430 && matrix_columns == 2)
matrix_stride = 2 * N;
else
matrix_stride = glsl_align(matrix_columns * N, 16);
const glsl_type *deref_type = deref->type->base_type == GLSL_TYPE_FLOAT ?
glsl_type::float_type : glsl_type::double_type;
for (unsigned i = 0; i < deref->type->vector_elements; i++) {
ir_rvalue *chan_offset =
add(base_offset,
new(mem_ctx) ir_constant(deref_offset + i * matrix_stride));
if (is_write) {
/* If the component is not in the writemask, then don't
* store any value.
*/
if (!((1 << i) & write_mask))
continue;
base_ir->insert_after(ssbo_store(swizzle(deref, i, 1), chan_offset, 1));
} else {
if (!this->is_shader_storage) {
base_ir->insert_before(assign(deref->clone(mem_ctx, NULL),
ubo_load(deref_type, chan_offset),
(1U << i)));
} else {
ir_call *load_ssbo = ssbo_load(deref_type, chan_offset);
base_ir->insert_before(load_ssbo);
ir_rvalue *value = load_ssbo->return_deref->as_rvalue()->clone(mem_ctx, NULL);
base_ir->insert_before(assign(deref->clone(mem_ctx, NULL),
value,
(1U << i)));
}
}
}
}
}
void
lower_ubo_reference_visitor::write_to_memory(ir_dereference *deref,
ir_variable *var,
ir_variable *write_var,
unsigned write_mask)
{
ir_rvalue *offset = NULL;
unsigned const_offset;
bool row_major;
int matrix_columns;
unsigned packing = var->get_interface_type()->interface_packing;
/* 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(var, deref,
&offset, &const_offset,
&row_major, &matrix_columns,
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(true, deref, write_offset, const_offset,
row_major, matrix_columns, 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->get_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()
{
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,
unsigned 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)
{
mem_ctx = ralloc_parent(*rvalue);
ir_rvalue *base_offset = NULL;
unsigned const_offset;
bool row_major;
int matrix_columns;
unsigned packing = var->get_interface_type()->interface_packing;
int unsized_array_stride = calculate_unsized_array_stride(deref, packing);
/* 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(var, deref,
&base_offset, &const_offset,
&row_major, &matrix_columns,
packing);
/* array.length() =
* max((buffer_object_size - offset_of_array) / stride_of_array, 0)
*/
ir_expression *buffer_size = emit_ssbo_get_buffer_size();
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_buffer_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.
*/
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(deref, var, write_var, ir->write_mask);
progress = true;
}
ir_visitor_status
lower_ubo_reference_visitor::visit_enter(ir_assignment *ir)
{
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());
ir_variable *var = deref->variable_referenced();
assert(var);
/* Compute the offset to the start if the dereference and the
* block index
*/
mem_ctx = ralloc_parent(shader->ir);
ir_rvalue *offset = NULL;
unsigned const_offset;
bool row_major;
int matrix_columns;
unsigned packing = var->get_interface_type()->interface_packing;
setup_for_load_or_store(var, deref,
&offset, &const_offset,
&row_major, &matrix_columns,
packing);
assert(offset);
assert(!row_major);
assert(matrix_columns == 1);
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->base_type == GLSL_TYPE_INT ?
glsl_type::int_type : glsl_type::uint_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);
sig->is_intrinsic = true;
char func_name[64];
sprintf(func_name, "%s_internal", 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)
{
const char *callee = ir->callee_name();
if (!strcmp("__intrinsic_ssbo_atomic_add", callee) ||
!strcmp("__intrinsic_ssbo_atomic_min", callee) ||
!strcmp("__intrinsic_ssbo_atomic_max", callee) ||
!strcmp("__intrinsic_ssbo_atomic_and", callee) ||
!strcmp("__intrinsic_ssbo_atomic_or", callee) ||
!strcmp("__intrinsic_ssbo_atomic_xor", callee) ||
!strcmp("__intrinsic_ssbo_atomic_exchange", callee) ||
!strcmp("__intrinsic_ssbo_atomic_comp_swap", callee)) {
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);
}
} /* unnamed namespace */
void
lower_ubo_reference(struct gl_shader *shader)
{
lower_ubo_reference_visitor v(shader);
/* 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);
}
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