luau/CodeGen/include/Luau/IrAnalysis.h
2023-05-05 12:57:12 -07:00

99 lines
2.8 KiB
C++

// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
#pragma once
#include <bitset>
#include <utility>
#include <vector>
#include <stdint.h>
namespace Luau
{
namespace CodeGen
{
struct IrBlock;
struct IrFunction;
void updateUseCounts(IrFunction& function);
void updateLastUseLocations(IrFunction& function);
uint32_t getNextInstUse(IrFunction& function, uint32_t targetInstIdx, uint32_t startInstIdx);
// Returns how many values are coming into the block (live in) and how many are coming out of the block (live out)
std::pair<uint32_t, uint32_t> getLiveInOutValueCount(IrFunction& function, IrBlock& block);
uint32_t getLiveInValueCount(IrFunction& function, IrBlock& block);
uint32_t getLiveOutValueCount(IrFunction& function, IrBlock& block);
struct RegisterSet
{
std::bitset<256> regs;
// If variadic sequence is active, we track register from which it starts
bool varargSeq = false;
uint8_t varargStart = 0;
};
void requireVariadicSequence(RegisterSet& sourceRs, const RegisterSet& defRs, uint8_t varargStart);
struct CfgInfo
{
std::vector<uint32_t> predecessors;
std::vector<uint32_t> predecessorsOffsets;
std::vector<uint32_t> successors;
std::vector<uint32_t> successorsOffsets;
// VM registers that are live when the block is entered
// Additionally, an active variadic sequence can exist at the entry of the block
std::vector<RegisterSet> in;
// VM registers that are defined inside the block
// It can also contain a variadic sequence definition if that hasn't been consumed inside the block
// Note that this means that checking 'def' set might not be enough to say that register has not been written to
std::vector<RegisterSet> def;
// VM registers that are coming out from the block
// These might be registers that are defined inside the block or have been defined at the entry of the block
// Additionally, an active variadic sequence can exist at the exit of the block
std::vector<RegisterSet> out;
// VM registers captured by nested closures
// This set can never have an active variadic sequence
RegisterSet captured;
};
void computeCfgInfo(IrFunction& function);
struct BlockIteratorWrapper
{
const uint32_t* itBegin = nullptr;
const uint32_t* itEnd = nullptr;
bool empty() const
{
return itBegin == itEnd;
}
size_t size() const
{
return size_t(itEnd - itBegin);
}
const uint32_t* begin() const
{
return itBegin;
}
const uint32_t* end() const
{
return itEnd;
}
};
BlockIteratorWrapper predecessors(const CfgInfo& cfg, uint32_t blockIdx);
BlockIteratorWrapper successors(const CfgInfo& cfg, uint32_t blockIdx);
} // namespace CodeGen
} // namespace Luau