SPIRV-Tools/source/opt/reduce_load_size.h
Steven Perron a1f9e1342e Preserve inst-to-block and def-use in passes.
The following passes are updated to preserve the inst-to-block and
def-use analysies:

	private-to-local
	aggressive dead-code elimination
	dead branch elimination
	local-single-block elimination
	local-single-store elimination
	reduce load size
	compact ids (inst-to-block only)
	merge block
	dead-insert elimination
	ccp

The one execption is that compact ids still kills the def-use manager.
This is because it changes so many ids it is faster to kill and rebuild.

Does everything in
https://github.com/KhronosGroup/SPIRV-Tools/issues/1593 except for the
changes to merge return.
2018-06-04 13:48:30 -04:00

64 lines
2.4 KiB
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// Copyright (c) 2018 Google LLC
//
// 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.
#ifndef LIBSPIRV_OPT_REDUCE_LOAD_SIZE_H_
#define LIBSPIRV_OPT_REDUCE_LOAD_SIZE_H_
#include "ir_context.h"
#include "module.h"
#include "pass.h"
namespace spvtools {
namespace opt {
// See optimizer.hpp for documentation.
class ReduceLoadSize : public Pass {
public:
const char* name() const override { return "reduce-load-size"; }
Status Process(ir::IRContext* irContext) override;
// Return the mask of preserved Analyses.
ir::IRContext::Analysis GetPreservedAnalyses() override {
return ir::IRContext::kAnalysisDefUse |
ir::IRContext::kAnalysisInstrToBlockMapping |
ir::IRContext::kAnalysisCombinators | ir::IRContext::kAnalysisCFG |
ir::IRContext::kAnalysisDominatorAnalysis |
ir::IRContext::kAnalysisLoopAnalysis |
ir::IRContext::kAnalysisNameMap;
}
private:
// Replaces |inst|, which must be an OpCompositeExtract instruction, with
// an OpAccessChain and a load if possible. This happens only if it is a load
// feeding |inst|. Returns true if the substitution happened. The position
// of the new instructions will be in the same place as the load feeding the
// extract.
bool ReplaceExtract(ir::Instruction* inst);
// Returns true if the OpCompositeExtract instruction |inst| should be replace
// or not. This is determined by looking at the load that feeds |inst| if
// it is a load. |should_replace_cache_| is used to cache the results based
// on the load feeding |inst|.
bool ShouldReplaceExtract(ir::Instruction* inst);
// Maps the result id of an OpLoad instruction to the result of whether or
// not the OpCompositeExtract that use the id should be replaced.
std::unordered_map<uint32_t, bool> should_replace_cache_;
};
} // namespace opt
} // namespace spvtools
#endif // LIBSPIRV_OPT_REDUCE_LOAD_SIZE_H_