Mesa (glsl2): glsl2: Always emit matrix constructors inline
Ian Romanick
idr at kemper.freedesktop.org
Tue Jun 29 18:54:42 UTC 2010
Module: Mesa
Branch: glsl2
Commit: 81c7e94466da19f9295b8eb5e4b5e587fea96284
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=81c7e94466da19f9295b8eb5e4b5e587fea96284
Author: Ian Romanick <ian.d.romanick at intel.com>
Date: Fri Jun 25 16:10:43 2010 -0700
glsl2: Always emit matrix constructors inline
---
src/glsl/ast_function.cpp | 322 ++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 321 insertions(+), 1 deletions(-)
diff --git a/src/glsl/ast_function.cpp b/src/glsl/ast_function.cpp
index f1ab6f0..3828d32 100644
--- a/src/glsl/ast_function.cpp
+++ b/src/glsl/ast_function.cpp
@@ -26,6 +26,11 @@
#include "glsl_types.h"
#include "ir.h"
+inline unsigned min(unsigned a, unsigned b)
+{
+ return (a < b) ? a : b;
+}
+
static unsigned
process_parameters(exec_list *instructions, exec_list *actual_parameters,
exec_list *parameters,
@@ -536,6 +541,318 @@ emit_inline_vector_constructor(const glsl_type *type,
}
+/**
+ * Generate assignment of a portion of a vector to a portion of a matrix column
+ *
+ * \param src_base First component of the source to be used in assignment
+ * \param column Column of destination to be assiged
+ * \param row_base First component of the destination column to be assigned
+ * \param count Number of components to be assigned
+ *
+ * \note
+ * \c src_base + \c count must be less than or equal to the number of components
+ * in the source vector.
+ */
+ir_instruction *
+assign_to_matrix_column(ir_variable *var, unsigned column, unsigned row_base,
+ ir_rvalue *src, unsigned src_base, unsigned count,
+ TALLOC_CTX *ctx)
+{
+ const unsigned mask[8] = { 0, 1, 2, 3, 0, 0, 0, 0 };
+
+ ir_constant *col_idx = new(ctx) ir_constant(column);
+ ir_rvalue *column_ref = new(ctx) ir_dereference_array(var, col_idx);
+
+ assert(column_ref->type->components() >= (row_base + count));
+ ir_rvalue *lhs = new(ctx) ir_swizzle(column_ref, &mask[row_base], count);
+
+ assert(src->type->components() >= (src_base + count));
+ ir_rvalue *rhs = new(ctx) ir_swizzle(src, &mask[src_base], count);
+
+ return new(ctx) ir_assignment(lhs, rhs, NULL);
+}
+
+
+/**
+ * Generate inline code for a matrix constructor
+ *
+ * The generated constructor code will consist of a temporary variable
+ * declaration of the same type as the constructor. A sequence of assignments
+ * from constructor parameters to the temporary will follow.
+ *
+ * \return
+ * An \c ir_dereference_variable of the temprorary generated in the constructor
+ * body.
+ */
+ir_rvalue *
+emit_inline_matrix_constructor(const glsl_type *type,
+ exec_list *instructions,
+ exec_list *parameters,
+ void *ctx)
+{
+ assert(!parameters->is_empty());
+
+ ir_variable *var = new(ctx) ir_variable(type, strdup("mat_ctor"));
+ instructions->push_tail(var);
+
+ /* There are three kinds of matrix constructors.
+ *
+ * - Construct a matrix from a single scalar by replicating that scalar to
+ * along the diagonal of the matrix and setting all other components to
+ * zero.
+ *
+ * - Construct a matrix from an arbirary combination of vectors and
+ * scalars. The components of the constructor parameters are assigned
+ * to the matrix in colum-major order until the matrix is full.
+ *
+ * - Construct a matrix from a single matrix. The source matrix is copied
+ * to the upper left portion of the constructed matrix, and the remaining
+ * elements take values from the identity matrix.
+ */
+ ir_rvalue *const first_param = (ir_rvalue *) parameters->head;
+ if (single_scalar_parameter(parameters)) {
+ /* Assign the scalar to the X component of a vec4, and fill the remaining
+ * components with zero.
+ */
+ ir_variable *rhs_var = new(ctx) ir_variable(glsl_type::vec4_type,
+ strdup("mat_ctor_vec"));
+ instructions->push_tail(rhs_var);
+
+ ir_constant_data zero;
+ zero.f[0] = 0.0;
+ zero.f[1] = 0.0;
+ zero.f[2] = 0.0;
+ zero.f[3] = 0.0;
+
+ ir_instruction *inst =
+ new(ctx) ir_assignment(new(ctx) ir_dereference_variable(rhs_var),
+ new(ctx) ir_constant(rhs_var->type, &zero),
+ NULL);
+ instructions->push_tail(inst);
+
+ ir_rvalue *const rhs_ref = new(ctx) ir_dereference_variable(rhs_var);
+ ir_rvalue *const x_of_rhs = new(ctx) ir_swizzle(rhs_ref, 0, 0, 0, 0, 1);
+
+ inst = new(ctx) ir_assignment(x_of_rhs, first_param, NULL);
+ instructions->push_tail(inst);
+
+ /* Assign the temporary vector to each column of the destination matrix
+ * with a swizzle that puts the X component on the diagonal of the
+ * matrix. In some cases this may mean that the X component does not
+ * get assigned into the column at all (i.e., when the matrix has more
+ * columns than rows).
+ */
+ static const unsigned rhs_swiz[4][4] = {
+ { 0, 1, 1, 1 },
+ { 1, 0, 1, 1 },
+ { 1, 1, 0, 1 },
+ { 1, 1, 1, 0 }
+ };
+
+ const unsigned cols_to_init = min(type->matrix_columns,
+ type->vector_elements);
+ for (unsigned i = 0; i < cols_to_init; i++) {
+ ir_constant *const col_idx = new(ctx) ir_constant(i);
+ ir_rvalue *const col_ref = new(ctx) ir_dereference_array(var, col_idx);
+
+ ir_rvalue *const rhs_ref = new(ctx) ir_dereference_variable(rhs_var);
+ ir_rvalue *const rhs = new(ctx) ir_swizzle(rhs_ref, rhs_swiz[i],
+ type->vector_elements);
+
+ inst = new(ctx) ir_assignment(col_ref, rhs, NULL);
+ instructions->push_tail(inst);
+ }
+
+ for (unsigned i = cols_to_init; i < type->matrix_columns; i++) {
+ ir_constant *const col_idx = new(ctx) ir_constant(i);
+ ir_rvalue *const col_ref = new(ctx) ir_dereference_array(var, col_idx);
+
+ ir_rvalue *const rhs_ref = new(ctx) ir_dereference_variable(rhs_var);
+ ir_rvalue *const rhs = new(ctx) ir_swizzle(rhs_ref, 1, 1, 1, 1,
+ type->vector_elements);
+
+ inst = new(ctx) ir_assignment(col_ref, rhs, NULL);
+ instructions->push_tail(inst);
+ }
+ } else if (first_param->type->is_matrix()) {
+ /* From page 50 (56 of the PDF) of the GLSL 1.50 spec:
+ *
+ * "If a matrix is constructed from a matrix, then each component
+ * (column i, row j) in the result that has a corresponding
+ * component (column i, row j) in the argument will be initialized
+ * from there. All other components will be initialized to the
+ * identity matrix. If a matrix argument is given to a matrix
+ * constructor, it is an error to have any other arguments."
+ */
+ assert(first_param->next->is_tail_sentinal());
+ ir_rvalue *const src_matrix = first_param;
+
+ /* If the source matrix is smaller, pre-initialize the relavent parts of
+ * the destination matrix to the identity matrix.
+ */
+ if ((src_matrix->type->matrix_columns < var->type->matrix_columns)
+ || (src_matrix->type->vector_elements < var->type->vector_elements)) {
+
+ /* If the source matrix has fewer rows, every column of the destination
+ * must be initialized. Otherwise only the columns in the destination
+ * that do not exist in the source must be initialized.
+ */
+ unsigned col =
+ (src_matrix->type->vector_elements < var->type->vector_elements)
+ ? 0 : src_matrix->type->matrix_columns;
+
+ const glsl_type *const col_type = var->type->column_type();
+ for (/* empty */; col < var->type->matrix_columns; col++) {
+ ir_constant_data ident;
+
+ ident.f[0] = 0.0;
+ ident.f[1] = 0.0;
+ ident.f[2] = 0.0;
+ ident.f[3] = 0.0;
+
+ ident.f[col] = 1.0;
+
+ ir_rvalue *const rhs = new(ctx) ir_constant(col_type, &ident);
+
+ ir_rvalue *const lhs =
+ new(ctx) ir_dereference_array(var, new(ctx) ir_constant(col));
+
+ ir_instruction *inst = new(ctx) ir_assignment(lhs, rhs, NULL);
+ instructions->push_tail(inst);
+ }
+ }
+
+ /* Assign columns from the source matrix to the destination matrix.
+ *
+ * Since the parameter will be used in the RHS of multiple assignments,
+ * generate a temporary and copy the paramter there.
+ */
+ ir_variable *const rhs_var = new(ctx) ir_variable(first_param->type,
+ strdup("mat_ctor_mat"));
+ instructions->push_tail(rhs_var);
+
+ ir_dereference *const rhs_var_ref =
+ new(ctx) ir_dereference_variable(rhs_var);
+ ir_instruction *const inst =
+ new(ctx) ir_assignment(rhs_var_ref, first_param, NULL);
+ instructions->push_tail(inst);
+
+
+ const unsigned swiz[4] = { 0, 1, 2, 3 };
+ const unsigned last_col = min(src_matrix->type->matrix_columns,
+ var->type->matrix_columns);
+ for (unsigned i = 0; i < last_col; i++) {
+ ir_rvalue *const lhs_col =
+ new(ctx) ir_dereference_array(var, new(ctx) ir_constant(i));
+ ir_rvalue *const rhs_col =
+ new(ctx) ir_dereference_array(rhs_var, new(ctx) ir_constant(i));
+
+ /* If one matrix has columns that are smaller than the columns of the
+ * other matrix, wrap the column access of the larger with a swizzle
+ * so that the LHS and RHS of the assignment have the same size (and
+ * therefore have the same type).
+ *
+ * It would be perfectly valid to unconditionally generate the
+ * swizzles, this this will typically result in a more compact IR tree.
+ */
+ ir_rvalue *lhs;
+ ir_rvalue *rhs;
+ if (lhs_col->type->vector_elements < rhs_col->type->vector_elements) {
+ lhs = lhs_col;
+
+ rhs = new(ctx) ir_swizzle(rhs_col, swiz,
+ lhs_col->type->vector_elements);
+ } else if (lhs_col->type->vector_elements
+ > rhs_col->type->vector_elements) {
+ lhs = new(ctx) ir_swizzle(lhs_col, swiz,
+ rhs_col->type->vector_elements);
+ rhs = rhs_col;
+ } else {
+ lhs = lhs_col;
+ rhs = rhs_col;
+ }
+
+ assert(lhs->type == rhs->type);
+
+ ir_instruction *inst = new(ctx) ir_assignment(lhs, rhs, NULL);
+ instructions->push_tail(inst);
+ }
+ } else {
+ const unsigned rows = type->matrix_columns;
+ const unsigned cols = type->vector_elements;
+ unsigned col_idx = 0;
+ unsigned row_idx = 0;
+
+ foreach_list (node, parameters) {
+ ir_rvalue *const rhs = (ir_rvalue *) node;
+ const unsigned components_remaining_this_column = rows - row_idx;
+ unsigned rhs_components = rhs->type->components();
+ unsigned rhs_base = 0;
+
+ /* Since the parameter might be used in the RHS of two assignments,
+ * generate a temporary and copy the paramter there.
+ */
+ ir_variable *rhs_var = new(ctx) ir_variable(rhs->type,
+ strdup("mat_ctor_vec"));
+ instructions->push_tail(rhs_var);
+
+ ir_dereference *rhs_var_ref =
+ new(ctx) ir_dereference_variable(rhs_var);
+ ir_instruction *inst = new(ctx) ir_assignment(rhs_var_ref, rhs, NULL);
+ instructions->push_tail(inst);
+
+ /* Assign the current parameter to as many components of the matrix
+ * as it will fill.
+ *
+ * NOTE: A single vector parameter can span two matrix columns. A
+ * single vec4, for example, can completely fill a mat2.
+ */
+ if (rhs_components >= components_remaining_this_column) {
+ const unsigned count = min(rhs_components,
+ components_remaining_this_column);
+
+ rhs_var_ref = new(ctx) ir_dereference_variable(rhs_var);
+
+ ir_instruction *inst = assign_to_matrix_column(var, col_idx,
+ row_idx,
+ rhs_var_ref, 0,
+ count, ctx);
+ instructions->push_tail(inst);
+
+ rhs_base = count;
+
+ col_idx++;
+ row_idx = 0;
+ }
+
+ /* If there is data left in the parameter and components left to be
+ * set in the destination, emit another assignment. It is possible
+ * that the assignment could be of a vec4 to the last element of the
+ * matrix. In this case col_idx==cols, but there is still data
+ * left in the source parameter. Obviously, don't emit an assignment
+ * to data outside the destination matrix.
+ */
+ if ((col_idx < cols) && (rhs_base < rhs_components)) {
+ const unsigned count = rhs_components - rhs_base;
+
+ rhs_var_ref = new(ctx) ir_dereference_variable(rhs_var);
+
+ ir_instruction *inst = assign_to_matrix_column(var, col_idx,
+ row_idx,
+ rhs_var_ref,
+ rhs_base,
+ count, ctx);
+ instructions->push_tail(inst);
+
+ row_idx += count;
+ }
+ }
+ }
+
+ return new(ctx) ir_dereference_variable(var);
+}
+
+
ir_rvalue *
ast_function_expression::hir(exec_list *instructions,
struct _mesa_glsl_parse_state *state)
@@ -807,7 +1124,10 @@ ast_function_expression::hir(exec_list *instructions,
ctx);
} else {
assert(constructor_type->is_matrix());
- return new(ctx) ir_call(sig, & actual_parameters);
+ return emit_inline_matrix_constructor(constructor_type,
+ instructions,
+ &actual_parameters,
+ ctx);
}
} else {
/* FINISHME: Log a better error message here. G++ will show the
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