SPIRV-Tools/source/opt/optimizer.cpp
GregF 9de4e69856 Add AggressiveDCEPass
Create aggressive dead code elimination pass
This pass eliminates unused code from functions. In addition,
it detects and eliminates code which may have spurious uses but which do
not contribute to the output of the function. The most common cause of
such code sequences is summations in loops whose result is no longer used
due to dead code elimination. This optimization has additional compile
time cost over standard dead code elimination.

This pass only processes entry point functions. It also only processes
shaders with logical addressing. It currently will not process functions
with function calls. It currently only supports the GLSL.std.450 extended
instruction set. It currently does not support any extensions.

This pass will be made more effective by first running passes that remove
dead control flow and inlines function calls.

This pass can be especially useful after running Local Access Chain
Conversion, which tends to cause cycles of dead code to be left after
Store/Load elimination passes are completed. These cycles cannot be
eliminated with standard dead code elimination.

Additionally: This transform uses a whitelist of instructions that it
knows do have side effects, (a.k.a. combinators).  It assumes other
instructions have side effects: it will not remove them, and assumes
they have side effects via their ID operands.
2017-07-10 11:30:25 -04:00

185 lines
6.0 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 "spirv-tools/optimizer.hpp"
#include "build_module.h"
#include "make_unique.h"
#include "pass_manager.h"
#include "passes.h"
namespace spvtools {
struct Optimizer::PassToken::Impl {
Impl(std::unique_ptr<opt::Pass> p) : pass(std::move(p)) {}
std::unique_ptr<opt::Pass> pass; // Internal implementation pass.
};
Optimizer::PassToken::PassToken(
std::unique_ptr<Optimizer::PassToken::Impl> impl)
: impl_(std::move(impl)) {}
Optimizer::PassToken::PassToken(PassToken&& that)
: impl_(std::move(that.impl_)) {}
Optimizer::PassToken& Optimizer::PassToken::operator=(PassToken&& that) {
impl_ = std::move(that.impl_);
return *this;
}
Optimizer::PassToken::~PassToken() {}
struct Optimizer::Impl {
explicit Impl(spv_target_env env) : target_env(env), pass_manager() {}
const spv_target_env target_env; // Target environment.
opt::PassManager pass_manager; // Internal implementation pass manager.
};
Optimizer::Optimizer(spv_target_env env) : impl_(new Impl(env)) {}
Optimizer::~Optimizer() {}
void Optimizer::SetMessageConsumer(MessageConsumer c) {
// All passes' message consumer needs to be updated.
for (uint32_t i = 0; i < impl_->pass_manager.NumPasses(); ++i) {
impl_->pass_manager.GetPass(i)->SetMessageConsumer(c);
}
impl_->pass_manager.SetMessageConsumer(std::move(c));
}
Optimizer& Optimizer::RegisterPass(PassToken&& p) {
// Change to use the pass manager's consumer.
p.impl_->pass->SetMessageConsumer(impl_->pass_manager.consumer());
impl_->pass_manager.AddPass(std::move(p.impl_->pass));
return *this;
}
bool Optimizer::Run(const uint32_t* original_binary,
const size_t original_binary_size,
std::vector<uint32_t>* optimized_binary) const {
std::unique_ptr<ir::Module> module =
BuildModule(impl_->target_env, impl_->pass_manager.consumer(),
original_binary, original_binary_size);
if (module == nullptr) return false;
auto status = impl_->pass_manager.Run(module.get());
if (status == opt::Pass::Status::SuccessWithChange ||
(status == opt::Pass::Status::SuccessWithoutChange &&
(optimized_binary->data() != original_binary ||
optimized_binary->size() != original_binary_size))) {
optimized_binary->clear();
module->ToBinary(optimized_binary, /* skip_nop = */ true);
}
return status != opt::Pass::Status::Failure;
}
Optimizer::PassToken CreateNullPass() {
return MakeUnique<Optimizer::PassToken::Impl>(MakeUnique<opt::NullPass>());
}
Optimizer::PassToken CreateStripDebugInfoPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::StripDebugInfoPass>());
}
Optimizer::PassToken CreateSetSpecConstantDefaultValuePass(
const std::unordered_map<uint32_t, std::string>& id_value_map) {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::SetSpecConstantDefaultValuePass>(id_value_map));
}
Optimizer::PassToken CreateSetSpecConstantDefaultValuePass(
const std::unordered_map<uint32_t, std::vector<uint32_t>>& id_value_map) {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::SetSpecConstantDefaultValuePass>(id_value_map));
}
Optimizer::PassToken CreateFlattenDecorationPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::FlattenDecorationPass>());
}
Optimizer::PassToken CreateFreezeSpecConstantValuePass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::FreezeSpecConstantValuePass>());
}
Optimizer::PassToken CreateFoldSpecConstantOpAndCompositePass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::FoldSpecConstantOpAndCompositePass>());
}
Optimizer::PassToken CreateUnifyConstantPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::UnifyConstantPass>());
}
Optimizer::PassToken CreateEliminateDeadConstantPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::EliminateDeadConstantPass>());
}
Optimizer::PassToken CreateBlockMergePass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::BlockMergePass>());
}
Optimizer::PassToken CreateInlinePass() {
return MakeUnique<Optimizer::PassToken::Impl>(MakeUnique<opt::InlinePass>());
}
Optimizer::PassToken CreateLocalAccessChainConvertPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::LocalAccessChainConvertPass>());
}
Optimizer::PassToken CreateLocalSingleBlockLoadStoreElimPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::LocalSingleBlockLoadStoreElimPass>());
}
Optimizer::PassToken CreateLocalSingleStoreElimPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::LocalSingleStoreElimPass>());
}
Optimizer::PassToken CreateInsertExtractElimPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::InsertExtractElimPass>());
}
Optimizer::PassToken CreateDeadBranchElimPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::DeadBranchElimPass>());
}
Optimizer::PassToken CreateLocalMultiStoreElimPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::LocalMultiStoreElimPass>());
}
Optimizer::PassToken CreateAggressiveDCEPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::AggressiveDCEPass>());
}
Optimizer::PassToken CreateCompactIdsPass() {
return MakeUnique<Optimizer::PassToken::Impl>(
MakeUnique<opt::CompactIdsPass>());
}
} // namespace spvtools