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// 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
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
#include <algorithm>
#include <map>
#include <memory>
#include <queue>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#include "source/opt/basic_block.h"
#include "source/opt/def_use_manager.h"
#include "source/opt/mem_pass.h"
#include "source/opt/module.h"
namespace spvtools {
namespace opt {
// See optimizer.hpp for documentation.
class LocalAccessChainConvertPass : public MemPass {
const char* name() const override { return "convert-local-access-chains"; }
Status Process() override;
IRContext::Analysis GetPreservedAnalyses() override {
return IRContext::kAnalysisDefUse | IRContext::kAnalysisConstants |
using ProcessFunction = std::function<bool(Function*)>;
// 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(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<Operand>& in_opnds,
std::vector<std::unique_ptr<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 Instruction* ptrInst, uint32_t* varId, uint32_t* varPteTypeId,
std::vector<std::unique_ptr<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 Instruction* ptrInst,
std::vector<Operand>* in_opnds);
// Create a load/insert/store equivalent to a store of
// |valId| through (constant index) access chain |ptrInst|.
// Append to |newInsts|. Returns true if successful.
bool GenAccessChainStoreReplacement(
const Instruction* ptrInst, uint32_t valId,
std::vector<std::unique_ptr<Instruction>>* newInsts);
// For the (constant index) access chain |address_inst|, create an
// equivalent load and extract that replaces |original_load|. The result id
// of the extract will be the same as the original result id of
// |original_load|. Returns true if successful.
bool ReplaceAccessChainLoad(const Instruction* address_inst,
Instruction* original_load);
// Return true if all indices of access chain |acp| are OpConstant integers
// whose values can fit into an unsigned 32-bit value.
bool Is32BitConstantIndexAccessChain(const 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.
// Returns a status to indicate success or failure, and change or no change.
Status ConvertLocalAccessChains(Function* func);
// Returns true one of the indexes in the |access_chain_inst| is definitly out
// of bounds. If the size of the type or the value of the index is unknown,
// then it will be considered in-bounds.
bool AnyIndexIsOutOfBounds(const Instruction* access_chain_inst);
// Returns true if getting element |index| from |type| would be out-of-bounds.
// If |index| is nullptr or the size of the type are unknown, then it will be
// considered in-bounds.
bool IsIndexOutOfBounds(const analysis::Constant* index,
const analysis::Type* type) const;
// Initialize extensions allowlist
void InitExtensions();
// Return true if all extensions in this module are allowed by this pass.
bool AllExtensionsSupported() const;
void Initialize();
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_allowlist_;
} // namespace opt
} // namespace spvtools