glsl: move to compiler/

Signed-off-by: Emil Velikov <[email protected]>
Acked-by: Matt Turner <[email protected]>
Acked-by: Jose Fonseca <[email protected]>

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 */