[Mesa-dev] [PATCH 27/74] glsl: Lower shader storage buffer object writes to ir_ssbo_store
Iago Toral Quiroga
itoral at igalia.com
Thu May 14 07:06:30 PDT 2015
Extend the existing lower_ubo_reference pass to also detect SSBO writes
and lower them to ir_ssbo_store nodes.
---
src/glsl/lower_ubo_reference.cpp | 412 +++++++++++++++++++++++++++++++--------
1 file changed, 336 insertions(+), 76 deletions(-)
diff --git a/src/glsl/lower_ubo_reference.cpp b/src/glsl/lower_ubo_reference.cpp
index fb8a890..8cb28f5 100644
--- a/src/glsl/lower_ubo_reference.cpp
+++ b/src/glsl/lower_ubo_reference.cpp
@@ -139,12 +139,34 @@ public:
}
void handle_rvalue(ir_rvalue **rvalue);
+ ir_visitor_status visit_enter(ir_assignment *ir);
+
+ void setup_for_load_or_write(ir_variable *var,
+ ir_dereference *deref,
+ ir_rvalue **offset,
+ unsigned *const_offset,
+ bool *row_major,
+ int *matrix_columns,
+ bool *is_buffer);
+
void emit_ubo_loads(ir_dereference *deref, ir_variable *base_offset,
unsigned int deref_offset, bool row_major,
int matrix_columns);
ir_expression *ubo_load(const struct glsl_type *type,
ir_rvalue *offset);
+
+ void check_for_ssbo_write(ir_assignment *ir);
+ void write_to_memory(ir_dereference *deref,
+ ir_variable *var,
+ ir_variable *write_var,
+ unsigned write_mask);
+ void emit_ssbo_writes(ir_dereference *deref, ir_variable *base_offset,
+ unsigned int deref_offset, bool row_major,
+ int matrix_columns, unsigned write_mask);
+ ir_ssbo_store *ssbo_write(ir_rvalue *deref, ir_rvalue *offset,
+ unsigned write_mask);
+
void *mem_ctx;
struct gl_shader *shader;
struct gl_uniform_buffer_variable *ubo_var;
@@ -219,26 +241,21 @@ interface_field_name(void *mem_ctx, char *base_name, ir_dereference *d,
}
void
-lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
+lower_ubo_reference_visitor::setup_for_load_or_write(ir_variable *var,
+ ir_dereference *deref,
+ ir_rvalue **offset,
+ unsigned *const_offset,
+ bool *row_major,
+ int *matrix_columns,
+ bool *is_buffer)
{
- if (!*rvalue)
- return;
-
- ir_dereference *deref = (*rvalue)->as_dereference();
- if (!deref)
- return;
-
- ir_variable *var = deref->variable_referenced();
- if (!var || !var->is_in_uniform_block())
- return;
-
- mem_ctx = ralloc_parent(*rvalue);
-
+ /* Fix out 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 ubo block by interface name */
this->uniform_block = NULL;
for (unsigned i = 0; i < shader->NumUniformBlocks; i++) {
if (strcmp(field_name, shader->UniformBlocks[i].Name) == 0) {
@@ -253,10 +270,7 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
this->uniform_block = index;
}
- if (shader->UniformBlocks[i].IsBuffer)
- this->opcode = ir_binop_ssbo_load;
- else
- this->opcode = ir_binop_ubo_load;
+ *is_buffer = shader->UniformBlocks[i].IsBuffer;
struct gl_uniform_block *block = &shader->UniformBlocks[i];
@@ -269,10 +283,10 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
assert(this->uniform_block);
- ir_rvalue *offset = new(mem_ctx) ir_constant(0u);
- unsigned const_offset = 0;
- bool row_major = is_dereferenced_thing_row_major(deref);
- int matrix_columns = 1;
+ *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
@@ -281,76 +295,76 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
while (deref) {
switch (deref->ir_type) {
case ir_type_dereference_variable: {
- const_offset += ubo_var->Offset;
- deref = NULL;
- break;
+ *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_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;
+ ir_dereference_array *deref_array = (ir_dereference_array *) deref;
+ unsigned array_stride;
+ 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;
+ *matrix_columns = deref_array->array->type->matrix_columns;
} else if (deref_array->type->is_interface()) {
/* We're processing an array dereference of an interface instance
- * array. The thing being dereferenced *must* be a variable
- * dereference because intefaces cannot be embedded an 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.
+ * 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.
*/
assert(deref_array->array->as_dereference_variable());
deref = deref_array->array->as_dereference();
break;
- } else {
+ } 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
+ * 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);
- array_stride = deref_array->type->std140_size(array_row_major);
- array_stride = glsl_align(array_stride, 16);
- }
+ 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 =
+ 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;
+ 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;
+ 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;
+ 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);
+ 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);
@@ -358,11 +372,12 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
unsigned field_align = type->std140_base_alignment(field_row_major);
- intra_struct_offset = glsl_align(intra_struct_offset, field_align);
+ intra_struct_offset = glsl_align(intra_struct_offset, field_align);
+
+ if (strcmp(struct_type->fields.structure[i].name,
+ deref_record->field) == 0)
+ break;
- if (strcmp(struct_type->fields.structure[i].name,
- deref_record->field) == 0)
- break;
intra_struct_offset += type->std140_size(field_row_major);
/* If the field just examined was itself a structure, apply rule
@@ -377,19 +392,56 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
field_align);
}
- }
-
- const_offset += intra_struct_offset;
+ }
- deref = deref_record->record->as_dereference();
- break;
+ *const_offset += intra_struct_offset;
+ deref = deref_record->record->as_dereference();
+ break;
}
+
default:
- assert(!"not reached");
- deref = NULL;
- break;
+ 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_uniform_block())
+ return;
+
+ mem_ctx = ralloc_parent(*rvalue);
+
+ ir_rvalue *offset = NULL;
+ unsigned const_offset;
+ bool row_major;
+ int matrix_columns;
+ bool is_buffer;
+
+ /* Compute the offset to the start if the dereference as well as other
+ * information we need to configure the write
+ */
+ setup_for_load_or_write(var, deref,
+ &offset, &const_offset,
+ &row_major, &matrix_columns,
+ &is_buffer);
+ assert(offset);
+
+ if (is_buffer)
+ this->opcode = ir_binop_ssbo_load;
+ else
+ this->opcode = ir_binop_ubo_load;
/* Now that we've calculated the offset to the start of the
* dereference, walk over the type and emit loads into a temporary.
@@ -549,6 +601,214 @@ lower_ubo_reference_visitor::emit_ubo_loads(ir_dereference *deref,
}
}
+ir_ssbo_store *
+lower_ubo_reference_visitor::ssbo_write(ir_rvalue *deref,
+ ir_rvalue *offset,
+ unsigned write_mask)
+{
+ ir_rvalue *block_ref = this->uniform_block->clone(mem_ctx, NULL);
+ ir_rvalue *val_ref = deref->clone(mem_ctx, NULL);
+ return new(mem_ctx) ir_ssbo_store(block_ref, offset, val_ref, write_mask);
+}
+
+static inline int
+writemask_for_size(unsigned n)
+{
+ return ((1 << n) - 1);
+}
+
+void
+lower_ubo_reference_visitor::emit_ssbo_writes(ir_dereference *deref,
+ ir_variable *base_offset,
+ unsigned int deref_offset,
+ bool row_major,
+ int matrix_columns,
+ 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_ssbo_writes(field_deref, base_offset,
+ deref_offset + field_offset,
+ row_major, 1,
+ 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 =
+ 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_ssbo_writes(element_deref, base_offset,
+ deref_offset + i * array_stride,
+ row_major, 1,
+ 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_ssbo_writes(col_deref, base_offset,
+ deref_offset + i * size_mul,
+ row_major, deref->type->matrix_columns,
+ writemask_for_size(col_deref->type->vector_elements));
+ } 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.
+ */
+ int size_mul = (deref->type->is_double() &&
+ deref->type->vector_elements > 2) ? 32 : 16;
+ emit_ssbo_writes(col_deref, base_offset,
+ deref_offset + i * size_mul,
+ row_major, deref->type->matrix_columns,
+ 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));
+ base_ir->insert_after(ssbo_write(deref, offset, write_mask));
+ } 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 = glsl_align(matrix_columns * N, 16);
+
+ 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));
+
+ base_ir->insert_after(ssbo_write(swizzle(deref, i, 1), chan_offset, 1));
+ }
+ }
+}
+
+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;
+ bool is_buffer;
+
+ /* Compute the offset to the start if the dereference as well as other
+ * information we need to configure the write
+ */
+ setup_for_load_or_write(var, deref,
+ &offset, &const_offset,
+ &row_major, &matrix_columns,
+ &is_buffer);
+ assert(offset);
+ assert(is_buffer);
+
+ /* Now emit writes from the temporary to memory */
+ ir_variable *write_offset =
+ new(mem_ctx) ir_variable(glsl_type::uint_type,
+ "ssbo_write_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_ssbo_writes(deref, write_offset, const_offset,
+ row_major, matrix_columns, write_mask);
+}
+
+void
+lower_ubo_reference_visitor::check_for_ssbo_write(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_uniform_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(rvalue);
+
+ const glsl_type *type = rvalue->type;
+ ir_variable *write_var = new(mem_ctx) ir_variable(type,
+ "ssbo_write_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_for_ssbo_write(ir);
+ return rvalue_visit(ir);
+}
+
} /* unnamed namespace */
void
--
1.9.1
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