llvm-project/llvm/lib/CodeGen/GlobalISel/CSEInfo.cpp

444 lines
13 KiB
C++

//===- CSEInfo.cpp ------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/GlobalISel/CSEInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/InitializePasses.h"
#include "llvm/Support/Error.h"
#define DEBUG_TYPE "cseinfo"
using namespace llvm;
char llvm::GISelCSEAnalysisWrapperPass::ID = 0;
GISelCSEAnalysisWrapperPass::GISelCSEAnalysisWrapperPass()
: MachineFunctionPass(ID) {
initializeGISelCSEAnalysisWrapperPassPass(*PassRegistry::getPassRegistry());
}
INITIALIZE_PASS_BEGIN(GISelCSEAnalysisWrapperPass, DEBUG_TYPE,
"Analysis containing CSE Info", false, true)
INITIALIZE_PASS_END(GISelCSEAnalysisWrapperPass, DEBUG_TYPE,
"Analysis containing CSE Info", false, true)
/// -------- UniqueMachineInstr -------------//
void UniqueMachineInstr::Profile(FoldingSetNodeID &ID) {
GISelInstProfileBuilder(ID, MI->getMF()->getRegInfo()).addNodeID(MI);
}
/// -----------------------------------------
/// --------- CSEConfigFull ---------- ///
bool CSEConfigFull::shouldCSEOpc(unsigned Opc) {
switch (Opc) {
default:
break;
case TargetOpcode::G_ADD:
case TargetOpcode::G_AND:
case TargetOpcode::G_ASHR:
case TargetOpcode::G_LSHR:
case TargetOpcode::G_MUL:
case TargetOpcode::G_OR:
case TargetOpcode::G_SHL:
case TargetOpcode::G_SUB:
case TargetOpcode::G_XOR:
case TargetOpcode::G_UDIV:
case TargetOpcode::G_SDIV:
case TargetOpcode::G_UREM:
case TargetOpcode::G_SREM:
case TargetOpcode::G_CONSTANT:
case TargetOpcode::G_FCONSTANT:
case TargetOpcode::G_IMPLICIT_DEF:
case TargetOpcode::G_ZEXT:
case TargetOpcode::G_SEXT:
case TargetOpcode::G_ANYEXT:
case TargetOpcode::G_UNMERGE_VALUES:
case TargetOpcode::G_TRUNC:
case TargetOpcode::G_PTR_ADD:
case TargetOpcode::G_EXTRACT:
return true;
}
return false;
}
bool CSEConfigConstantOnly::shouldCSEOpc(unsigned Opc) {
return Opc == TargetOpcode::G_CONSTANT || Opc == TargetOpcode::G_FCONSTANT ||
Opc == TargetOpcode::G_IMPLICIT_DEF;
}
std::unique_ptr<CSEConfigBase>
llvm::getStandardCSEConfigForOpt(CodeGenOpt::Level Level) {
std::unique_ptr<CSEConfigBase> Config;
if (Level == CodeGenOpt::None)
Config = std::make_unique<CSEConfigConstantOnly>();
else
Config = std::make_unique<CSEConfigFull>();
return Config;
}
/// -----------------------------------------
/// -------- GISelCSEInfo -------------//
void GISelCSEInfo::setMF(MachineFunction &MF) {
this->MF = &MF;
this->MRI = &MF.getRegInfo();
}
GISelCSEInfo::~GISelCSEInfo() = default;
bool GISelCSEInfo::isUniqueMachineInstValid(
const UniqueMachineInstr &UMI) const {
// Should we check here and assert that the instruction has been fully
// constructed?
// FIXME: Any other checks required to be done here? Remove this method if
// none.
return true;
}
void GISelCSEInfo::invalidateUniqueMachineInstr(UniqueMachineInstr *UMI) {
bool Removed = CSEMap.RemoveNode(UMI);
(void)Removed;
assert(Removed && "Invalidation called on invalid UMI");
// FIXME: Should UMI be deallocated/destroyed?
}
UniqueMachineInstr *GISelCSEInfo::getNodeIfExists(FoldingSetNodeID &ID,
MachineBasicBlock *MBB,
void *&InsertPos) {
auto *Node = CSEMap.FindNodeOrInsertPos(ID, InsertPos);
if (Node) {
if (!isUniqueMachineInstValid(*Node)) {
invalidateUniqueMachineInstr(Node);
return nullptr;
}
if (Node->MI->getParent() != MBB)
return nullptr;
}
return Node;
}
void GISelCSEInfo::insertNode(UniqueMachineInstr *UMI, void *InsertPos) {
handleRecordedInsts();
assert(UMI);
UniqueMachineInstr *MaybeNewNode = UMI;
if (InsertPos)
CSEMap.InsertNode(UMI, InsertPos);
else
MaybeNewNode = CSEMap.GetOrInsertNode(UMI);
if (MaybeNewNode != UMI) {
// A similar node exists in the folding set. Let's ignore this one.
return;
}
assert(InstrMapping.count(UMI->MI) == 0 &&
"This instruction should not be in the map");
InstrMapping[UMI->MI] = MaybeNewNode;
}
UniqueMachineInstr *GISelCSEInfo::getUniqueInstrForMI(const MachineInstr *MI) {
assert(shouldCSE(MI->getOpcode()) && "Trying to CSE an unsupported Node");
auto *Node = new (UniqueInstrAllocator) UniqueMachineInstr(MI);
return Node;
}
void GISelCSEInfo::insertInstr(MachineInstr *MI, void *InsertPos) {
assert(MI);
// If it exists in temporary insts, remove it.
TemporaryInsts.remove(MI);
auto *Node = getUniqueInstrForMI(MI);
insertNode(Node, InsertPos);
}
MachineInstr *GISelCSEInfo::getMachineInstrIfExists(FoldingSetNodeID &ID,
MachineBasicBlock *MBB,
void *&InsertPos) {
handleRecordedInsts();
if (auto *Inst = getNodeIfExists(ID, MBB, InsertPos)) {
LLVM_DEBUG(dbgs() << "CSEInfo::Found Instr " << *Inst->MI;);
return const_cast<MachineInstr *>(Inst->MI);
}
return nullptr;
}
void GISelCSEInfo::countOpcodeHit(unsigned Opc) {
#ifndef NDEBUG
if (OpcodeHitTable.count(Opc))
OpcodeHitTable[Opc] += 1;
else
OpcodeHitTable[Opc] = 1;
#endif
// Else do nothing.
}
void GISelCSEInfo::recordNewInstruction(MachineInstr *MI) {
if (shouldCSE(MI->getOpcode())) {
TemporaryInsts.insert(MI);
LLVM_DEBUG(dbgs() << "CSEInfo::Recording new MI " << *MI);
}
}
void GISelCSEInfo::handleRecordedInst(MachineInstr *MI) {
assert(shouldCSE(MI->getOpcode()) && "Invalid instruction for CSE");
auto *UMI = InstrMapping.lookup(MI);
LLVM_DEBUG(dbgs() << "CSEInfo::Handling recorded MI " << *MI);
if (UMI) {
// Invalidate this MI.
invalidateUniqueMachineInstr(UMI);
InstrMapping.erase(MI);
}
/// Now insert the new instruction.
if (UMI) {
/// We'll reuse the same UniqueMachineInstr to avoid the new
/// allocation.
*UMI = UniqueMachineInstr(MI);
insertNode(UMI, nullptr);
} else {
/// This is a new instruction. Allocate a new UniqueMachineInstr and
/// Insert.
insertInstr(MI);
}
}
void GISelCSEInfo::handleRemoveInst(MachineInstr *MI) {
if (auto *UMI = InstrMapping.lookup(MI)) {
invalidateUniqueMachineInstr(UMI);
InstrMapping.erase(MI);
}
TemporaryInsts.remove(MI);
}
void GISelCSEInfo::handleRecordedInsts() {
while (!TemporaryInsts.empty()) {
auto *MI = TemporaryInsts.pop_back_val();
handleRecordedInst(MI);
}
}
bool GISelCSEInfo::shouldCSE(unsigned Opc) const {
assert(CSEOpt.get() && "CSEConfig not set");
return CSEOpt->shouldCSEOpc(Opc);
}
void GISelCSEInfo::erasingInstr(MachineInstr &MI) { handleRemoveInst(&MI); }
void GISelCSEInfo::createdInstr(MachineInstr &MI) { recordNewInstruction(&MI); }
void GISelCSEInfo::changingInstr(MachineInstr &MI) {
// For now, perform erase, followed by insert.
erasingInstr(MI);
createdInstr(MI);
}
void GISelCSEInfo::changedInstr(MachineInstr &MI) { changingInstr(MI); }
void GISelCSEInfo::analyze(MachineFunction &MF) {
setMF(MF);
for (auto &MBB : MF) {
if (MBB.empty())
continue;
for (MachineInstr &MI : MBB) {
if (!shouldCSE(MI.getOpcode()))
continue;
LLVM_DEBUG(dbgs() << "CSEInfo::Add MI: " << MI);
insertInstr(&MI);
}
}
}
void GISelCSEInfo::releaseMemory() {
print();
CSEMap.clear();
InstrMapping.clear();
UniqueInstrAllocator.Reset();
TemporaryInsts.clear();
CSEOpt.reset();
MRI = nullptr;
MF = nullptr;
#ifndef NDEBUG
OpcodeHitTable.clear();
#endif
}
#ifndef NDEBUG
static const char *stringify(const MachineInstr *MI, std::string &S) {
raw_string_ostream OS(S);
OS << *MI;
return OS.str().c_str();
}
#endif
Error GISelCSEInfo::verify() {
#ifndef NDEBUG
std::string S1, S2;
handleRecordedInsts();
// For each instruction in map from MI -> UMI,
// Profile(MI) and make sure UMI is found for that profile.
for (auto &It : InstrMapping) {
FoldingSetNodeID TmpID;
GISelInstProfileBuilder(TmpID, *MRI).addNodeID(It.first);
void *InsertPos;
UniqueMachineInstr *FoundNode =
CSEMap.FindNodeOrInsertPos(TmpID, InsertPos);
if (FoundNode != It.second)
return createStringError(std::errc::not_supported,
"CSEMap mismatch, InstrMapping has MIs without "
"corresponding Nodes in CSEMap:\n%s",
stringify(It.second->MI, S1));
}
// For every node in the CSEMap, make sure that the InstrMapping
// points to it.
for (const UniqueMachineInstr &UMI : CSEMap) {
if (!InstrMapping.count(UMI.MI))
return createStringError(std::errc::not_supported,
"Node in CSE without InstrMapping:\n%s",
stringify(UMI.MI, S1));
if (InstrMapping[UMI.MI] != &UMI)
return createStringError(std::make_error_code(std::errc::not_supported),
"Mismatch in CSE mapping:\n%s\n%s",
stringify(InstrMapping[UMI.MI]->MI, S1),
stringify(UMI.MI, S2));
}
#endif
return Error::success();
}
void GISelCSEInfo::print() {
LLVM_DEBUG(for (auto &It
: OpcodeHitTable) {
dbgs() << "CSEInfo::CSE Hit for Opc " << It.first << " : " << It.second
<< "\n";
};);
}
/// -----------------------------------------
// ---- Profiling methods for FoldingSetNode --- //
const GISelInstProfileBuilder &
GISelInstProfileBuilder::addNodeID(const MachineInstr *MI) const {
addNodeIDMBB(MI->getParent());
addNodeIDOpcode(MI->getOpcode());
for (auto &Op : MI->operands())
addNodeIDMachineOperand(Op);
addNodeIDFlag(MI->getFlags());
return *this;
}
const GISelInstProfileBuilder &
GISelInstProfileBuilder::addNodeIDOpcode(unsigned Opc) const {
ID.AddInteger(Opc);
return *this;
}
const GISelInstProfileBuilder &
GISelInstProfileBuilder::addNodeIDRegType(const LLT Ty) const {
uint64_t Val = Ty.getUniqueRAWLLTData();
ID.AddInteger(Val);
return *this;
}
const GISelInstProfileBuilder &
GISelInstProfileBuilder::addNodeIDRegType(const TargetRegisterClass *RC) const {
ID.AddPointer(RC);
return *this;
}
const GISelInstProfileBuilder &
GISelInstProfileBuilder::addNodeIDRegType(const RegisterBank *RB) const {
ID.AddPointer(RB);
return *this;
}
const GISelInstProfileBuilder &
GISelInstProfileBuilder::addNodeIDImmediate(int64_t Imm) const {
ID.AddInteger(Imm);
return *this;
}
const GISelInstProfileBuilder &
GISelInstProfileBuilder::addNodeIDRegNum(Register Reg) const {
ID.AddInteger(Reg);
return *this;
}
const GISelInstProfileBuilder &
GISelInstProfileBuilder::addNodeIDRegType(const Register Reg) const {
addNodeIDMachineOperand(MachineOperand::CreateReg(Reg, false));
return *this;
}
const GISelInstProfileBuilder &
GISelInstProfileBuilder::addNodeIDMBB(const MachineBasicBlock *MBB) const {
ID.AddPointer(MBB);
return *this;
}
const GISelInstProfileBuilder &
GISelInstProfileBuilder::addNodeIDFlag(unsigned Flag) const {
if (Flag)
ID.AddInteger(Flag);
return *this;
}
const GISelInstProfileBuilder &
GISelInstProfileBuilder::addNodeIDReg(Register Reg) const {
LLT Ty = MRI.getType(Reg);
if (Ty.isValid())
addNodeIDRegType(Ty);
if (const RegClassOrRegBank &RCOrRB = MRI.getRegClassOrRegBank(Reg)) {
if (const auto *RB = RCOrRB.dyn_cast<const RegisterBank *>())
addNodeIDRegType(RB);
else if (const auto *RC = RCOrRB.dyn_cast<const TargetRegisterClass *>())
addNodeIDRegType(RC);
}
return *this;
}
const GISelInstProfileBuilder &GISelInstProfileBuilder::addNodeIDMachineOperand(
const MachineOperand &MO) const {
if (MO.isReg()) {
Register Reg = MO.getReg();
if (!MO.isDef())
addNodeIDRegNum(Reg);
// Profile the register properties.
addNodeIDReg(Reg);
assert(!MO.isImplicit() && "Unhandled case");
} else if (MO.isImm())
ID.AddInteger(MO.getImm());
else if (MO.isCImm())
ID.AddPointer(MO.getCImm());
else if (MO.isFPImm())
ID.AddPointer(MO.getFPImm());
else if (MO.isPredicate())
ID.AddInteger(MO.getPredicate());
else
llvm_unreachable("Unhandled operand type");
// Handle other types
return *this;
}
GISelCSEInfo &
GISelCSEAnalysisWrapper::get(std::unique_ptr<CSEConfigBase> CSEOpt,
bool Recompute) {
if (!AlreadyComputed || Recompute) {
Info.releaseMemory();
Info.setCSEConfig(std::move(CSEOpt));
Info.analyze(*MF);
AlreadyComputed = true;
}
return Info;
}
void GISelCSEAnalysisWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
MachineFunctionPass::getAnalysisUsage(AU);
}
bool GISelCSEAnalysisWrapperPass::runOnMachineFunction(MachineFunction &MF) {
releaseMemory();
Wrapper.setMF(MF);
return false;
}