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authorIan Romanick <[email protected]>2010-08-16 19:08:53 -0700
committerIan Romanick <[email protected]>2010-08-16 19:08:53 -0700
commit6c03c576cc49bbb008de66d374f4302ff0fe0390 (patch)
tree7ddeb3ee88532d9aef8728b9aa256edf7c125247 /src/glsl/ir_constant_folding.cpp
parent15a3b42e135a3a2cb463ec3cff80a55dd8528051 (diff)
parenta433cd286c60eb9d4c2114f042709eda0f3de676 (diff)
Merge branch 'glsl2'
Conflicts: src/mesa/program/prog_optimize.c
Diffstat (limited to 'src/glsl/ir_constant_folding.cpp')
-rw-r--r--src/glsl/ir_constant_folding.cpp273
1 files changed, 273 insertions, 0 deletions
diff --git a/src/glsl/ir_constant_folding.cpp b/src/glsl/ir_constant_folding.cpp
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+/*
+ * Copyright © 2010 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 ir_constant_folding.cpp
+ * Replace constant-valued expressions with references to constant values.
+ */
+
+#include "ir.h"
+#include "ir_visitor.h"
+#include "ir_optimization.h"
+#include "glsl_types.h"
+
+/**
+ * Visitor class for replacing expressions with ir_constant values.
+ */
+
+class ir_constant_folding_visitor : public ir_visitor {
+public:
+ ir_constant_folding_visitor()
+ {
+ this->progress = false;
+ }
+
+ virtual ~ir_constant_folding_visitor()
+ {
+ /* empty */
+ }
+
+ /**
+ * \name Visit methods
+ *
+ * As typical for the visitor pattern, there must be one \c visit method for
+ * each concrete subclass of \c ir_instruction. Virtual base classes within
+ * the hierarchy should not have \c visit methods.
+ */
+ /*@{*/
+ virtual void visit(ir_variable *);
+ virtual void visit(ir_function_signature *);
+ virtual void visit(ir_function *);
+ virtual void visit(ir_expression *);
+ virtual void visit(ir_texture *);
+ virtual void visit(ir_swizzle *);
+ virtual void visit(ir_dereference_variable *);
+ virtual void visit(ir_dereference_array *);
+ virtual void visit(ir_dereference_record *);
+ virtual void visit(ir_assignment *);
+ virtual void visit(ir_constant *);
+ virtual void visit(ir_call *);
+ virtual void visit(ir_return *);
+ virtual void visit(ir_discard *);
+ virtual void visit(ir_if *);
+ virtual void visit(ir_loop *);
+ virtual void visit(ir_loop_jump *);
+ /*@}*/
+
+ void fold_constant(ir_rvalue **rvalue);
+
+ bool progress;
+};
+
+void
+ir_constant_folding_visitor::fold_constant(ir_rvalue **rvalue)
+{
+ if (*rvalue == NULL || (*rvalue)->ir_type == ir_type_constant)
+ return;
+
+ ir_constant *constant = (*rvalue)->constant_expression_value();
+ if (constant) {
+ *rvalue = constant;
+ this->progress = true;
+ } else {
+ (*rvalue)->accept(this);
+ }
+}
+
+void
+ir_constant_folding_visitor::visit(ir_variable *ir)
+{
+ (void) ir;
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_function_signature *ir)
+{
+ visit_exec_list(&ir->body, this);
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_function *ir)
+{
+ foreach_iter(exec_list_iterator, iter, *ir) {
+ ir_function_signature *const sig = (ir_function_signature *) iter.get();
+ sig->accept(this);
+ }
+}
+
+void
+ir_constant_folding_visitor::visit(ir_expression *ir)
+{
+ unsigned int operand;
+
+ for (operand = 0; operand < ir->get_num_operands(); operand++) {
+ fold_constant(&ir->operands[operand]);
+ }
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_texture *ir)
+{
+ fold_constant(&ir->coordinate);
+ fold_constant(&ir->projector);
+ fold_constant(&ir->shadow_comparitor);
+
+ switch (ir->op) {
+ case ir_tex:
+ break;
+ case ir_txb:
+ fold_constant(&ir->lod_info.bias);
+ break;
+ case ir_txf:
+ case ir_txl:
+ fold_constant(&ir->lod_info.lod);
+ break;
+ case ir_txd:
+ fold_constant(&ir->lod_info.grad.dPdx);
+ fold_constant(&ir->lod_info.grad.dPdy);
+ break;
+ }
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_swizzle *ir)
+{
+ fold_constant(&ir->val);
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_dereference_variable *ir)
+{
+ (void) ir;
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_dereference_array *ir)
+{
+ fold_constant(&ir->array_index);
+ ir->array->accept(this);
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_dereference_record *ir)
+{
+ ir->record->accept(this);
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_assignment *ir)
+{
+ fold_constant(&ir->rhs);
+
+ if (ir->condition) {
+ /* If the condition is constant, either remove the condition or
+ * remove the never-executed assignment.
+ */
+ ir_constant *const_val = ir->condition->constant_expression_value();
+ if (const_val) {
+ if (const_val->value.b[0])
+ ir->condition = NULL;
+ else
+ ir->remove();
+ this->progress = true;
+ }
+ }
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_constant *ir)
+{
+ (void) ir;
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_call *ir)
+{
+ foreach_iter(exec_list_iterator, iter, *ir) {
+ ir_rvalue *param = (ir_rvalue *)iter.get();
+ ir_rvalue *new_param = param;
+ fold_constant(&new_param);
+
+ if (new_param != param) {
+ param->replace_with(new_param);
+ }
+ }
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_return *ir)
+{
+ fold_constant(&ir->value);
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_discard *ir)
+{
+ (void) ir;
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_if *ir)
+{
+ fold_constant(&ir->condition);
+
+ visit_exec_list(&ir->then_instructions, this);
+ visit_exec_list(&ir->else_instructions, this);
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_loop *ir)
+{
+ (void) ir;
+}
+
+
+void
+ir_constant_folding_visitor::visit(ir_loop_jump *ir)
+{
+ (void) ir;
+}
+
+bool
+do_constant_folding(exec_list *instructions)
+{
+ ir_constant_folding_visitor constant_folding;
+
+ visit_exec_list(instructions, &constant_folding);
+
+ return constant_folding.progress;
+}