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authorJason Ekstrand <[email protected]>2016-02-05 15:03:04 -0800
committerJason Ekstrand <[email protected]>2016-02-05 15:03:44 -0800
commit741744f691d6ef63e9f9a4c03136f969f2ffb0bf (patch)
tree7c9192a0648c2d90bb08efbc21ebcb7a6e2b873a /src/compiler/glsl/lower_buffer_access.cpp
parent9645b8eb1f1b79e537ad8ddb683507df7bc9da58 (diff)
parenteb63640c1d38a200a7b1540405051d3ff79d0d8a (diff)
Merge commit mesa-public/master into vulkan
This pulls in the patches that move all of the compiler stuff around
Diffstat (limited to 'src/compiler/glsl/lower_buffer_access.cpp')
-rw-r--r--src/compiler/glsl/lower_buffer_access.cpp490
1 files changed, 490 insertions, 0 deletions
diff --git a/src/compiler/glsl/lower_buffer_access.cpp b/src/compiler/glsl/lower_buffer_access.cpp
new file mode 100644
index 00000000000..f8c8d140ea8
--- /dev/null
+++ b/src/compiler/glsl/lower_buffer_access.cpp
@@ -0,0 +1,490 @@
+/*
+ * Copyright (c) 2015 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_buffer_access.cpp
+ *
+ * Helper for IR lowering pass to replace dereferences of buffer object based
+ * shader variables with intrinsic function calls.
+ *
+ * This helper is used by lowering passes for UBOs, SSBOs and compute shader
+ * shared variables.
+ */
+
+#include "lower_buffer_access.h"
+#include "ir_builder.h"
+#include "main/macros.h"
+#include "util/list.h"
+#include "glsl_parser_extras.h"
+
+using namespace ir_builder;
+
+namespace lower_buffer_access {
+
+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_buffer_access::emit_access(void *mem_ctx,
+ bool is_write,
+ ir_dereference *deref,
+ ir_variable *base_offset,
+ unsigned int deref_offset,
+ bool row_major,
+ int matrix_columns,
+ unsigned int packing,
+ unsigned int 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(mem_ctx, 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(mem_ctx, 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(mem_ctx, 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(mem_ctx, 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));
+ unsigned mask =
+ is_write ? write_mask : (1 << deref->type->vector_elements) - 1;
+ insert_buffer_access(mem_ctx, deref, deref->type, offset, mask, -1);
+ } 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 || ((1U << i) & write_mask))
+ insert_buffer_access(mem_ctx, deref, deref_type, chan_offset,
+ (1U << i), i);
+ }
+ }
+}
+
+/**
+ * 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.
+ */
+bool
+lower_buffer_access::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: {
+ /* For interface block matrix variables we handle inherited
+ * layouts at HIR generation time, but we don't do that for shared
+ * variables, which are always column-major
+ */
+ ir_variable *var = deref->variable_referenced();
+ assert((var->is_in_buffer_block() && !matrix) ||
+ var->data.mode == ir_var_shader_shared);
+ 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;
+}
+
+/**
+ * This function initializes various values that will be used later by
+ * emit_access when actually emitting loads or stores.
+ *
+ * Note: const_offset is an input as well as an output, clients must
+ * initialize it to the offset of the variable in the underlying block, and
+ * this function will adjust it by adding the constant offset of the member
+ * being accessed into that variable.
+ */
+void
+lower_buffer_access::setup_buffer_access(void *mem_ctx,
+ ir_variable *var,
+ ir_rvalue *deref,
+ ir_rvalue **offset,
+ unsigned *const_offset,
+ bool *row_major,
+ int *matrix_columns,
+ unsigned packing)
+{
+ *offset = new(mem_ctx) ir_constant(0u);
+ *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: {
+ 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;
+ }
+ }
+}
+
+} /* namespace lower_buffer_access */