SPIRV-Tools/source/opt/freeze_spec_constant_value_pass.cpp
Steven Perron e8f2890c30 Replace calls to ToNop by KillInst.
Calling `ToNop` leaves around instructions that are pointless.  In
general it is better to remove the instruction completely.  That way
other optimizations will not need to look at them.

Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/1003.
2018-01-04 11:03:04 -05:00

54 lines
1.8 KiB
C++

// Copyright (c) 2016 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "freeze_spec_constant_value_pass.h"
#include "ir_context.h"
namespace spvtools {
namespace opt {
Pass::Status FreezeSpecConstantValuePass::Process(ir::IRContext* irContext) {
bool modified = false;
irContext->module()->ForEachInst(
[&modified, irContext](ir::Instruction* inst) {
switch (inst->opcode()) {
case SpvOp::SpvOpSpecConstant:
inst->SetOpcode(SpvOp::SpvOpConstant);
modified = true;
break;
case SpvOp::SpvOpSpecConstantTrue:
inst->SetOpcode(SpvOp::SpvOpConstantTrue);
modified = true;
break;
case SpvOp::SpvOpSpecConstantFalse:
inst->SetOpcode(SpvOp::SpvOpConstantFalse);
modified = true;
break;
case SpvOp::SpvOpDecorate:
if (inst->GetSingleWordInOperand(1) ==
SpvDecoration::SpvDecorationSpecId) {
irContext->KillInst(inst);
modified = true;
}
break;
default:
break;
}
});
return modified ? Status::SuccessWithChange : Status::SuccessWithoutChange;
}
} // namespace opt
} // namespace spvtools