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Diffstat (limited to 'src/glsl/ir_constant_folding.cpp')
| -rw-r--r-- | src/glsl/ir_constant_folding.cpp | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/src/glsl/ir_constant_folding.cpp b/src/glsl/ir_constant_folding.cpp new file mode 100644 index 00000000000..11260423d90 --- /dev/null +++ b/src/glsl/ir_constant_folding.cpp @@ -0,0 +1,273 @@ +/* + * 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; +} |