third_party_spirv-tools/source/opt/local_access_chain_convert_pass.h
Steven Perron 65046eca7c Change IRContext::KillInst to delete instructions.
The current method of removing an instruction is to call ToNop.  The
problem with this is that it leaves around an instruction that later
passes will look at.  We should just delete the instruction.

In MemPass there is a utility routine called DCEInst.  It can delete
essentially any instruction, which can invalidate pointers now that they
are actually deleted.  The interface was changed to add a call back that
can be used to update any local data structures that contain
ir::Intruction*.
2017-12-04 11:07:45 -05:00

127 lines
4.7 KiB
C++

// Copyright (c) 2017 The Khronos Group Inc.
// Copyright (c) 2017 Valve Corporation
// Copyright (c) 2017 LunarG 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.
#ifndef LIBSPIRV_OPT_LOCAL_ACCESS_CHAIN_CONVERT_PASS_H_
#define LIBSPIRV_OPT_LOCAL_ACCESS_CHAIN_CONVERT_PASS_H_
#include <algorithm>
#include <map>
#include <queue>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include "basic_block.h"
#include "def_use_manager.h"
#include "mem_pass.h"
#include "module.h"
namespace spvtools {
namespace opt {
// See optimizer.hpp for documentation.
class LocalAccessChainConvertPass : public MemPass {
public:
LocalAccessChainConvertPass();
const char* name() const override { return "convert-local-access-chains"; }
Status Process(ir::IRContext* c) override;
ir::IRContext::Analysis GetPreservedAnalyses() override {
return ir::IRContext::kAnalysisDefUse;
}
using ProcessFunction = std::function<bool(ir::Function*)>;
private:
// Return true if all refs through |ptrId| are only loads or stores and
// cache ptrId in supported_ref_ptrs_. TODO(dnovillo): This function is
// replicated in other passes and it's slightly different in every pass. Is it
// possible to make one common implementation?
bool HasOnlySupportedRefs(uint32_t ptrId);
// Search |func| and cache function scope variables of target type that are
// not accessed with non-constant-index access chains. Also cache non-target
// variables.
void FindTargetVars(ir::Function* func);
// Build instruction from |opcode|, |typeId|, |resultId|, and |in_opnds|.
// Append to |newInsts|.
void BuildAndAppendInst(
SpvOp opcode, uint32_t typeId, uint32_t resultId,
const std::vector<ir::Operand>& in_opnds,
std::vector<std::unique_ptr<ir::Instruction>>* newInsts);
// Build load of variable in |ptrInst| and append to |newInsts|.
// Return var in |varId| and its pointee type in |varPteTypeId|.
uint32_t BuildAndAppendVarLoad(
const ir::Instruction* ptrInst, uint32_t* varId, uint32_t* varPteTypeId,
std::vector<std::unique_ptr<ir::Instruction>>* newInsts);
// Append literal integer operands to |in_opnds| corresponding to constant
// integer operands from access chain |ptrInst|. Assumes all indices in
// access chains are OpConstant.
void AppendConstantOperands(const ir::Instruction* ptrInst,
std::vector<ir::Operand>* in_opnds);
// Create a load/insert/store equivalent to a store of
// |valId| through (constant index) access chaing |ptrInst|.
// Append to |newInsts|.
void GenAccessChainStoreReplacement(
const ir::Instruction* ptrInst, uint32_t valId,
std::vector<std::unique_ptr<ir::Instruction>>* newInsts);
// For the (constant index) access chain |ptrInst|, create an
// equivalent load and extract. Append to |newInsts|.
uint32_t GenAccessChainLoadReplacement(
const ir::Instruction* ptrInst,
std::vector<std::unique_ptr<ir::Instruction>>* newInsts);
// Return true if all indices of access chain |acp| are OpConstant integers
bool IsConstantIndexAccessChain(const ir::Instruction* acp) const;
// Identify all function scope variables of target type which are
// accessed only with loads, stores and access chains with constant
// indices. Convert all loads and stores of such variables into equivalent
// loads, stores, extracts and inserts. This unifies access to these
// variables to a single mode and simplifies analysis and optimization.
// See IsTargetType() for targeted types.
//
// Nested access chains and pointer access chains are not currently
// converted.
bool ConvertLocalAccessChains(ir::Function* func);
// Initialize extensions whitelist
void InitExtensions();
// Return true if all extensions in this module are allowed by this pass.
bool AllExtensionsSupported() const;
void Initialize(ir::IRContext* c);
Pass::Status ProcessImpl();
// Variables with only supported references, ie. loads and stores using
// variable directly or through non-ptr access chains.
std::unordered_set<uint32_t> supported_ref_ptrs_;
// Extensions supported by this pass.
std::unordered_set<std::string> extensions_whitelist_;
};
} // namespace opt
} // namespace spvtools
#endif // LIBSPIRV_OPT_LOCAL_ACCESS_CHAIN_CONVERT_PASS_H_