0,0 → 1,84 |
/* |
* 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 opt_if_simplification.cpp |
* |
* Moves constant branches of if statements out to the surrounding |
* instruction stream. |
*/ |
|
#include "ir.h" |
|
class ir_if_simplification_visitor : public ir_hierarchical_visitor { |
public: |
ir_if_simplification_visitor() |
{ |
this->made_progress = false; |
} |
|
ir_visitor_status visit_leave(ir_if *); |
|
bool made_progress; |
}; |
|
bool |
do_if_simplification(exec_list *instructions) |
{ |
ir_if_simplification_visitor v; |
|
v.run(instructions); |
return v.made_progress; |
} |
|
|
ir_visitor_status |
ir_if_simplification_visitor::visit_leave(ir_if *ir) |
{ |
/* FINISHME: Ideally there would be a way to note that the condition results |
* FINISHME: in a constant before processing both of the other subtrees. |
* FINISHME: This can probably be done with some flags, but it would take |
* FINISHME: some work to get right. |
*/ |
ir_constant *condition_constant = ir->condition->constant_expression_value(); |
if (condition_constant) { |
/* Move the contents of the one branch of the conditional |
* that matters out. |
*/ |
if (condition_constant->value.b[0]) { |
foreach_iter(exec_list_iterator, then_iter, ir->then_instructions) { |
ir_instruction *then_ir = (ir_instruction *)then_iter.get(); |
ir->insert_before(then_ir); |
} |
} else { |
foreach_iter(exec_list_iterator, else_iter, ir->else_instructions) { |
ir_instruction *else_ir = (ir_instruction *)else_iter.get(); |
ir->insert_before(else_ir); |
} |
} |
ir->remove(); |
this->made_progress = true; |
} |
|
return visit_continue; |
} |