[Mesa-dev] [PATCH 18/18] glsl: Assign locations for uniforms in UBOs using the std140 rules.
Eric Anholt
eric at anholt.net
Mon Jul 2 17:38:27 PDT 2012
Fixes piglit layout-std140.
---
src/glsl/glsl_types.cpp | 220 ++++++++++++++++++++++++++++++++++++++++++++
src/glsl/glsl_types.h | 13 +++
src/glsl/link_uniforms.cpp | 34 ++++++-
src/glsl/linker.cpp | 2 +
src/glsl/linker.h | 3 +
5 files changed, 270 insertions(+), 2 deletions(-)
diff --git a/src/glsl/glsl_types.cpp b/src/glsl/glsl_types.cpp
index 8a34b8e..3d78660 100644
--- a/src/glsl/glsl_types.cpp
+++ b/src/glsl/glsl_types.cpp
@@ -628,3 +628,223 @@ glsl_type::can_implicitly_convert_to(const glsl_type *desired) const
&& this->is_integer()
&& this->vector_elements == desired->vector_elements;
}
+
+unsigned
+glsl_type::std140_base_alignment(bool row_major) const
+{
+ /* (1) If the member is a scalar consuming <N> basic machine units, the
+ * base alignment is <N>.
+ *
+ * (2) If the member is a two- or four-component vector with components
+ * consuming <N> basic machine units, the base alignment is 2<N> or
+ * 4<N>, respectively.
+ *
+ * (3) If the member is a three-component vector with components consuming
+ * <N> basic machine units, the base alignment is 4<N>.
+ */
+ if (this->is_scalar() || this->is_vector()) {
+ switch (this->vector_elements) {
+ case 1:
+ return 4;
+ case 2:
+ return 8;
+ case 3:
+ case 4:
+ return 16;
+ }
+ }
+
+ /* (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. The array may have padding at the
+ * end; the base offset of the member following the array is rounded up
+ * to the next multiple of the base alignment.
+ *
+ * (6) If the member is an array of <S> column-major matrices with <C>
+ * columns and <R> rows, the matrix is stored identically to a row of
+ * <S>*<C> column vectors with <R> components each, according to rule
+ * (4).
+ *
+ * (8) If the member is an array of <S> row-major matrices with <C> columns
+ * and <R> rows, the matrix is stored identically to a row of <S>*<R>
+ * row vectors with <C> components each, according to rule (4).
+ *
+ * (10) If the member is an array of <S> structures, the <S> elements of
+ * the array are laid out in order, according to rule (9).
+ */
+ if (this->is_array()) {
+ if (this->fields.array->is_scalar() ||
+ this->fields.array->is_vector() ||
+ this->fields.array->is_matrix()) {
+ return MAX2(this->fields.array->std140_base_alignment(row_major), 16);
+ } else {
+ assert(this->fields.array->is_record());
+ return this->fields.array->std140_base_alignment(row_major);
+ }
+ }
+
+ /* (5) If the member is a column-major matrix with <C> columns and
+ * <R> rows, the matrix is stored identically to an array of
+ * <C> column vectors with <R> components each, according to
+ * rule (4).
+ *
+ * (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).
+ */
+ if (this->is_matrix()) {
+ const struct glsl_type *vec_type;
+ if (row_major) {
+ vec_type = get_instance(GLSL_TYPE_FLOAT, this->vector_elements, 1);
+ } else {
+ vec_type = get_instance(GLSL_TYPE_FLOAT, this->matrix_columns, 1);
+ }
+
+ return vec_type->std140_base_alignment(false);
+ }
+
+ /* (9) If the member is a structure, the base alignment of the
+ * structure is <N>, where <N> is the largest base alignment
+ * value of any of its members, and rounded up to the base
+ * alignment of a vec4. The individual members of this
+ * sub-structure are then assigned offsets by applying this set
+ * of rules recursively, where the base offset of the first
+ * member of the sub-structure is equal to the aligned offset
+ * of the structure. 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 (this->is_record()) {
+ unsigned base_alignment = 16;
+ for (unsigned i = 0; i < this->length; i++) {
+ const struct glsl_type *field_type = this->fields.structure[i].type;
+ base_alignment = MAX2(base_alignment,
+ field_type->std140_base_alignment(row_major));
+ }
+ return base_alignment;
+ }
+
+ assert(!"not reached");
+ return -1;
+}
+
+static unsigned
+align(unsigned val, unsigned align)
+{
+ return (val + align - 1) / align * align;
+}
+
+unsigned
+glsl_type::std140_size(bool row_major) const
+{
+ /* (1) If the member is a scalar consuming <N> basic machine units, the
+ * base alignment is <N>.
+ *
+ * (2) If the member is a two- or four-component vector with components
+ * consuming <N> basic machine units, the base alignment is 2<N> or
+ * 4<N>, respectively.
+ *
+ * (3) If the member is a three-component vector with components consuming
+ * <N> basic machine units, the base alignment is 4<N>.
+ */
+ if (this->is_scalar() || this->is_vector()) {
+ return this->vector_elements * 4;
+ }
+
+ /* (5) If the member is a column-major matrix with <C> columns and
+ * <R> rows, the matrix is stored identically to an array of
+ * <C> column vectors with <R> components each, according to
+ * rule (4).
+ *
+ * (6) If the member is an array of <S> column-major matrices with <C>
+ * columns and <R> rows, the matrix is stored identically to a row of
+ * <S>*<C> column vectors with <R> components each, according to rule
+ * (4).
+ *
+ * (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).
+ *
+ * (8) If the member is an array of <S> row-major matrices with <C> columns
+ * and <R> rows, the matrix is stored identically to a row of <S>*<R>
+ * row vectors with <C> components each, according to rule (4).
+ */
+ if (this->is_matrix() || (this->is_array() &&
+ this->fields.array->is_matrix())) {
+ const struct glsl_type *element_type;
+ const struct glsl_type *vec_type;
+ unsigned int array_len;
+
+ if (this->is_array()) {
+ element_type = this->fields.array;
+ array_len = this->length;
+ } else {
+ element_type = this;
+ array_len = 1;
+ }
+
+ if (row_major) {
+ vec_type = get_instance(GLSL_TYPE_FLOAT,
+ element_type->matrix_columns, 1);
+ array_len *= element_type->vector_elements;
+ } else {
+ vec_type = get_instance(GLSL_TYPE_FLOAT,
+ element_type->vector_elements, 1);
+ array_len *= element_type->matrix_columns;
+ }
+ const glsl_type *array_type = glsl_type::get_array_instance(vec_type,
+ array_len);
+
+ return array_type->std140_size(false);
+ }
+
+ /* (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. The array may have padding at the
+ * end; the base offset of the member following the array is rounded up
+ * to the next multiple of the base alignment.
+ *
+ * (10) If the member is an array of <S> structures, the <S> elements of
+ * the array are laid out in order, according to rule (9).
+ */
+ if (this->is_array()) {
+ if (this->fields.array->is_record()) {
+ return this->length * this->fields.array->std140_size(row_major);
+ } else {
+ unsigned element_base_align =
+ this->fields.array->std140_base_alignment(row_major);
+ return this->length * MAX2(element_base_align, 16);
+ }
+ }
+
+ /* (9) If the member is a structure, the base alignment of the
+ * structure is <N>, where <N> is the largest base alignment
+ * value of any of its members, and rounded up to the base
+ * alignment of a vec4. The individual members of this
+ * sub-structure are then assigned offsets by applying this set
+ * of rules recursively, where the base offset of the first
+ * member of the sub-structure is equal to the aligned offset
+ * of the structure. 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 (this->is_record()) {
+ unsigned size = 0;
+ for (unsigned i = 0; i < this->length; i++) {
+ const struct glsl_type *field_type = this->fields.structure[i].type;
+ unsigned align = field_type->std140_base_alignment(row_major);
+ size = (size + align - 1) / align * align;
+ size += field_type->std140_size(row_major);
+ }
+ size = align(size,
+ this->fields.structure[0].type->std140_base_alignment(row_major));
+ return size;
+ }
+
+ assert(!"not reached");
+ return -1;
+}
diff --git a/src/glsl/glsl_types.h b/src/glsl/glsl_types.h
index 48d41d7..bbc524d 100644
--- a/src/glsl/glsl_types.h
+++ b/src/glsl/glsl_types.h
@@ -243,6 +243,19 @@ struct glsl_type {
unsigned component_slots() const;
/**
+ * Alignment in bytes of the start of this type in a std140 uniform
+ * block.
+ */
+ unsigned std140_base_alignment(bool row_major) const;
+
+ /** Size in bytes of this type in a std140 uniform block.
+ *
+ * Note that this is not GL_UNIFORM_SIZE (which is the number of
+ * elements in the array)
+ */
+ unsigned std140_size(bool row_major) const;
+
+ /**
* \brief Can this type be implicitly converted to another?
*
* \return True if the types are identical or if this type can be converted
diff --git a/src/glsl/link_uniforms.cpp b/src/glsl/link_uniforms.cpp
index 4cc97ce..d7ef5d4 100644
--- a/src/glsl/link_uniforms.cpp
+++ b/src/glsl/link_uniforms.cpp
@@ -29,6 +29,12 @@
#include "program/hash_table.h"
#include "program.h"
+static inline unsigned int
+align(unsigned int a, unsigned int align)
+{
+ return (a + align - 1) / align * align;
+}
+
/**
* \file link_uniforms.cpp
* Assign locations for GLSL uniforms.
@@ -317,9 +323,11 @@ private:
if (this->ubo_var) {
this->uniforms[id].block_index = this->ubo_block_index;
- /* FINISHME: Actual std140 offset assignment. */
+ unsigned alignment = type->std140_base_alignment(ubo_var->RowMajor);
+ this->ubo_byte_offset = align(this->ubo_byte_offset, alignment);
this->uniforms[id].offset = this->ubo_byte_offset;
- this->ubo_byte_offset += 4 * type->components();
+ this->ubo_byte_offset += type->std140_size(ubo_var->RowMajor);
+
this->uniforms[id].array_stride = 0;
this->uniforms[id].matrix_stride = 0;
this->uniforms[id].row_major = base_type->is_matrix() &&
@@ -454,6 +462,28 @@ link_update_uniform_buffer_variables(struct gl_shader *shader)
}
void
+link_assign_uniform_block_offsets(struct gl_shader *shader)
+{
+ for (unsigned b = 0; b < shader->NumUniformBlocks; b++) {
+ struct gl_uniform_block *block = &shader->UniformBlocks[b];
+
+ unsigned offset = 0;
+ for (unsigned int i = 0; i < block->NumUniforms; i++) {
+ struct gl_uniform_buffer_variable *ubo_var = &block->Uniforms[i];
+ const struct glsl_type *type = ubo_var->Type;
+
+ unsigned alignment = type->std140_base_alignment(ubo_var->RowMajor);
+ unsigned size = type->std140_size(ubo_var->RowMajor);
+
+ offset = align(offset, alignment);
+ ubo_var->Offset = offset;
+ offset += size;
+ }
+ block->UniformBufferSize = offset;
+ }
+}
+
+void
link_assign_uniform_locations(struct gl_shader_program *prog)
{
ralloc_free(prog->UniformStorage);
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 4267602..dd2a036 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -979,6 +979,8 @@ link_intrastage_shaders(void *mem_ctx,
struct gl_shader *sh = shader_list[i];
for (unsigned j = 0; j < shader_list[i]->NumUniformBlocks; j++) {
+ link_assign_uniform_block_offsets(shader_list[i]);
+
int index = link_cross_validate_uniform_block(mem_ctx,
&uniform_blocks,
&num_uniform_blocks,
diff --git a/src/glsl/linker.h b/src/glsl/linker.h
index 5c54437..7d2e98a 100644
--- a/src/glsl/linker.h
+++ b/src/glsl/linker.h
@@ -46,6 +46,9 @@ link_cross_validate_uniform_block(void *mem_ctx,
unsigned int *num_linked_blocks,
struct gl_uniform_block *new_block);
+void
+link_assign_uniform_block_offsets(struct gl_shader *shader);
+
/**
* Class for processing all of the leaf fields of an uniform
*
--
1.7.10
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