SPIRV-Tools/source/opt/eliminate_dead_functions_pass.cpp
Alastair Donaldson 34c5ac614c
Fixes #2358. Added to the reducer the ability to remove a function t… (#2361)
* Fixes #2358.  Added to the reducer the ability to remove a function that is not directly called.  Factored out some code from the optimizer to help with this.
2019-02-08 16:20:29 +00:00

53 lines
1.6 KiB
C++

// Copyright (c) 2017 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 "source/opt/eliminate_dead_functions_pass.h"
#include "source/opt/eliminate_dead_functions_util.h"
#include <unordered_set>
#include "source/opt/ir_context.h"
namespace spvtools {
namespace opt {
Pass::Status EliminateDeadFunctionsPass::Process() {
// Identify live functions first. Those that are not live
// are dead.
std::unordered_set<const Function*> live_function_set;
ProcessFunction mark_live = [&live_function_set](Function* fp) {
live_function_set.insert(fp);
return false;
};
context()->ProcessReachableCallTree(mark_live);
bool modified = false;
for (auto funcIter = get_module()->begin();
funcIter != get_module()->end();) {
if (live_function_set.count(&*funcIter) == 0) {
modified = true;
funcIter =
eliminatedeadfunctionsutil::EliminateFunction(context(), &funcIter);
} else {
++funcIter;
}
}
return modified ? Pass::Status::SuccessWithChange
: Pass::Status::SuccessWithoutChange;
}
} // namespace opt
} // namespace spvtools