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llvm-project/llvm/lib/CodeGen/MachineFunction.cpp

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//===- MachineFunction.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
//
//===----------------------------------------------------------------------===//
//
// Collect native machine code information for a function. This allows
// target-specific information about the generated code to be stored with each
// function.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/EHPersonalities.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/CodeGen/WasmEHFuncInfo.h"
#include "llvm/CodeGen/WinEHFuncInfo.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/ModuleSlotTracker.h"
#include "llvm/IR/Value.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/SectionKind.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/DOTGraphTraits.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/GraphWriter.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <iterator>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>
using namespace llvm;
#define DEBUG_TYPE "codegen"
static cl::opt<unsigned> AlignAllFunctions(
"align-all-functions",
cl::desc("Force the alignment of all functions in log2 format (e.g. 4 "
"means align on 16B boundaries)."),
cl::init(0), cl::Hidden);
static const char *getPropertyName(MachineFunctionProperties::Property Prop) {
using P = MachineFunctionProperties::Property;
switch(Prop) {
case P::FailedISel: return "FailedISel";
case P::IsSSA: return "IsSSA";
case P::Legalized: return "Legalized";
case P::NoPHIs: return "NoPHIs";
case P::NoVRegs: return "NoVRegs";
case P::RegBankSelected: return "RegBankSelected";
case P::Selected: return "Selected";
case P::TracksLiveness: return "TracksLiveness";
}
llvm_unreachable("Invalid machine function property");
}
// Pin the vtable to this file.
void MachineFunction::Delegate::anchor() {}
void MachineFunctionProperties::print(raw_ostream &OS) const {
const char *Separator = "";
for (BitVector::size_type I = 0; I < Properties.size(); ++I) {
if (!Properties[I])
continue;
OS << Separator << getPropertyName(static_cast<Property>(I));
Separator = ", ";
}
}
//===----------------------------------------------------------------------===//
// MachineFunction implementation
//===----------------------------------------------------------------------===//
// Out-of-line virtual method.
MachineFunctionInfo::~MachineFunctionInfo() = default;
void ilist_alloc_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
MBB->getParent()->DeleteMachineBasicBlock(MBB);
}
static inline unsigned getFnStackAlignment(const TargetSubtargetInfo *STI,
const Function &F) {
if (F.hasFnAttribute(Attribute::StackAlignment))
return F.getFnStackAlignment();
return STI->getFrameLowering()->getStackAlign().value();
}
MachineFunction::MachineFunction(Function &F, const LLVMTargetMachine &Target,
const TargetSubtargetInfo &STI,
unsigned FunctionNum, MachineModuleInfo &mmi)
: F(F), Target(Target), STI(&STI), Ctx(mmi.getContext()), MMI(mmi) {
FunctionNumber = FunctionNum;
init();
}
void MachineFunction::handleInsertion(MachineInstr &MI) {
if (TheDelegate)
TheDelegate->MF_HandleInsertion(MI);
}
void MachineFunction::handleRemoval(MachineInstr &MI) {
if (TheDelegate)
TheDelegate->MF_HandleRemoval(MI);
}
void MachineFunction::init() {
// Assume the function starts in SSA form with correct liveness.
Properties.set(MachineFunctionProperties::Property::IsSSA);
Properties.set(MachineFunctionProperties::Property::TracksLiveness);
if (STI->getRegisterInfo())
RegInfo = new (Allocator) MachineRegisterInfo(this);
else
RegInfo = nullptr;
MFInfo = nullptr;
// We can realign the stack if the target supports it and the user hasn't
// explicitly asked us not to.
bool CanRealignSP = STI->getFrameLowering()->isStackRealignable() &&
!F.hasFnAttribute("no-realign-stack");
FrameInfo = new (Allocator) MachineFrameInfo(
getFnStackAlignment(STI, F), /*StackRealignable=*/CanRealignSP,
/*ForcedRealign=*/CanRealignSP &&
F.hasFnAttribute(Attribute::StackAlignment));
if (F.hasFnAttribute(Attribute::StackAlignment))
FrameInfo->ensureMaxAlignment(*F.getFnStackAlign());
ConstantPool = new (Allocator) MachineConstantPool(getDataLayout());
Alignment = STI->getTargetLowering()->getMinFunctionAlignment();
// FIXME: Shouldn't use pref alignment if explicit alignment is set on F.
// FIXME: Use Function::hasOptSize().
if (!F.hasFnAttribute(Attribute::OptimizeForSize))
Alignment = std::max(Alignment,
STI->getTargetLowering()->getPrefFunctionAlignment());
if (AlignAllFunctions)
Alignment = Align(1ULL << AlignAllFunctions);
JumpTableInfo = nullptr;
if (isFuncletEHPersonality(classifyEHPersonality(
F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) {
WinEHInfo = new (Allocator) WinEHFuncInfo();
}
if (isScopedEHPersonality(classifyEHPersonality(
F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) {
WasmEHInfo = new (Allocator) WasmEHFuncInfo();
}
assert(Target.isCompatibleDataLayout(getDataLayout()) &&
"Can't create a MachineFunction using a Module with a "
"Target-incompatible DataLayout attached\n");
PSVManager =
std::make_unique<PseudoSourceValueManager>(*(getSubtarget().
getInstrInfo()));
}
MachineFunction::~MachineFunction() {
clear();
}
void MachineFunction::clear() {
Properties.reset();
// Don't call destructors on MachineInstr and MachineOperand. All of their
// memory comes from the BumpPtrAllocator which is about to be purged.
//
// Do call MachineBasicBlock destructors, it contains std::vectors.
for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I))
I->Insts.clearAndLeakNodesUnsafely();
MBBNumbering.clear();
InstructionRecycler.clear(Allocator);
OperandRecycler.clear(Allocator);
BasicBlockRecycler.clear(Allocator);
CodeViewAnnotations.clear();
VariableDbgInfos.clear();
if (RegInfo) {
RegInfo->~MachineRegisterInfo();
Allocator.Deallocate(RegInfo);
}
if (MFInfo) {
MFInfo->~MachineFunctionInfo();
Allocator.Deallocate(MFInfo);
}
FrameInfo->~MachineFrameInfo();
Allocator.Deallocate(FrameInfo);
ConstantPool->~MachineConstantPool();
Allocator.Deallocate(ConstantPool);
if (JumpTableInfo) {
JumpTableInfo->~MachineJumpTableInfo();
Allocator.Deallocate(JumpTableInfo);
}
if (WinEHInfo) {
WinEHInfo->~WinEHFuncInfo();
Allocator.Deallocate(WinEHInfo);
}
if (WasmEHInfo) {
WasmEHInfo->~WasmEHFuncInfo();
Allocator.Deallocate(WasmEHInfo);
}
}
const DataLayout &MachineFunction::getDataLayout() const {
return F.getParent()->getDataLayout();
}
/// Get the JumpTableInfo for this function.
/// If it does not already exist, allocate one.
MachineJumpTableInfo *MachineFunction::
getOrCreateJumpTableInfo(unsigned EntryKind) {
if (JumpTableInfo) return JumpTableInfo;
JumpTableInfo = new (Allocator)
MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
return JumpTableInfo;
}
DenormalMode MachineFunction::getDenormalMode(const fltSemantics &FPType) const {
if (&FPType == &APFloat::IEEEsingle()) {
Attribute Attr = F.getFnAttribute("denormal-fp-math-f32");
StringRef Val = Attr.getValueAsString();
if (!Val.empty())
return parseDenormalFPAttribute(Val);
// If the f32 variant of the attribute isn't specified, try to use the
// generic one.
}
// TODO: Should probably avoid the connection to the IR and store directly
// in the MachineFunction.
Attribute Attr = F.getFnAttribute("denormal-fp-math");
return parseDenormalFPAttribute(Attr.getValueAsString());
}
/// Should we be emitting segmented stack stuff for the function
bool MachineFunction::shouldSplitStack() const {
return getFunction().hasFnAttribute("split-stack");
}
LLVM_NODISCARD unsigned
MachineFunction::addFrameInst(const MCCFIInstruction &Inst) {
FrameInstructions.push_back(Inst);
return FrameInstructions.size() - 1;
}
/// This discards all of the MachineBasicBlock numbers and recomputes them.
/// This guarantees that the MBB numbers are sequential, dense, and match the
/// ordering of the blocks within the function. If a specific MachineBasicBlock
/// is specified, only that block and those after it are renumbered.
void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
if (empty()) { MBBNumbering.clear(); return; }
MachineFunction::iterator MBBI, E = end();
if (MBB == nullptr)
MBBI = begin();
else
MBBI = MBB->getIterator();
// Figure out the block number this should have.
unsigned BlockNo = 0;
if (MBBI != begin())
BlockNo = std::prev(MBBI)->getNumber() + 1;
for (; MBBI != E; ++MBBI, ++BlockNo) {
if (MBBI->getNumber() != (int)BlockNo) {
// Remove use of the old number.
if (MBBI->getNumber() != -1) {
assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
"MBB number mismatch!");
MBBNumbering[MBBI->getNumber()] = nullptr;
}
// If BlockNo is already taken, set that block's number to -1.
if (MBBNumbering[BlockNo])
MBBNumbering[BlockNo]->setNumber(-1);
MBBNumbering[BlockNo] = &*MBBI;
MBBI->setNumber(BlockNo);
}
}
// Okay, all the blocks are renumbered. If we have compactified the block
// numbering, shrink MBBNumbering now.
assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
MBBNumbering.resize(BlockNo);
}
/// This sets the section ranges of cold or exception section with basic block
/// sections.
void MachineFunction::setSectionRange() {
// Compute the Section Range of cold and exception basic blocks. Find the
// first and last block of each range.
auto SectionRange =
([&](llvm::MachineBasicBlockSection S) -> std::pair<int, int> {
auto MBBP =
std::find_if(begin(), end(), [&](MachineBasicBlock &MBB) -> bool {
return MBB.getSectionType() == S;
});
if (MBBP == end())
return std::make_pair(-1, -1);
auto MBBQ =
std::find_if(rbegin(), rend(), [&](MachineBasicBlock &MBB) -> bool {
return MBB.getSectionType() == S;
});
assert(MBBQ != rend() && "Section end not found!");
return std::make_pair(MBBP->getNumber(), MBBQ->getNumber());
});
ExceptionSectionRange = SectionRange(MBBS_Exception);
ColdSectionRange = SectionRange(llvm::MBBS_Cold);
}
/// This is used with -fbasicblock-sections or -fbasicblock-labels option.
/// A unary encoding of basic block labels is done to keep ".strtab" sizes
/// small.
void MachineFunction::createBBLabels() {
const TargetInstrInfo *TII = getSubtarget().getInstrInfo();
this->BBSectionsSymbolPrefix.resize(getNumBlockIDs(), 'a');
for (auto MBBI = begin(), E = end(); MBBI != E; ++MBBI) {
assert(
(MBBI->getNumber() >= 0 && MBBI->getNumber() < (int)getNumBlockIDs()) &&
"BasicBlock number was out of range!");
// 'a' - Normal block.
// 'r' - Return block.
// 'l' - Landing Pad.
// 'L' - Return and landing pad.
bool isEHPad = MBBI->isEHPad();
bool isRetBlock = MBBI->isReturnBlock() && !TII->isTailCall(MBBI->back());
char type = 'a';
if (isEHPad && isRetBlock)
type = 'L';
else if (isEHPad)
type = 'l';
else if (isRetBlock)
type = 'r';
BBSectionsSymbolPrefix[MBBI->getNumber()] = type;
}
}
/// Allocate a new MachineInstr. Use this instead of `new MachineInstr'.
MachineInstr *MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
const DebugLoc &DL,
bool NoImp) {
return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
MachineInstr(*this, MCID, DL, NoImp);
}
/// Create a new MachineInstr which is a copy of the 'Orig' instruction,
/// identical in all ways except the instruction has no parent, prev, or next.
MachineInstr *
MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
MachineInstr(*this, *Orig);
}
MachineInstr &MachineFunction::CloneMachineInstrBundle(MachineBasicBlock &MBB,
MachineBasicBlock::iterator InsertBefore, const MachineInstr &Orig) {
MachineInstr *FirstClone = nullptr;
MachineBasicBlock::const_instr_iterator I = Orig.getIterator();
while (true) {
MachineInstr *Cloned = CloneMachineInstr(&*I);
MBB.insert(InsertBefore, Cloned);
if (FirstClone == nullptr) {
FirstClone = Cloned;
} else {
Cloned->bundleWithPred();
}
if (!I->isBundledWithSucc())
break;
++I;
}
// Copy over call site info to the cloned instruction if needed. If Orig is in
// a bundle, copyCallSiteInfo takes care of finding the call instruction in
// the bundle.
if (Orig.shouldUpdateCallSiteInfo())
copyCallSiteInfo(&Orig, FirstClone);
return *FirstClone;
}
/// Delete the given MachineInstr.
///
/// This function also serves as the MachineInstr destructor - the real
/// ~MachineInstr() destructor must be empty.
void
MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
// Verify that a call site info is at valid state. This assertion should
// be triggered during the implementation of support for the
// call site info of a new architecture. If the assertion is triggered,
// back trace will tell where to insert a call to updateCallSiteInfo().
assert((!MI->isCandidateForCallSiteEntry() ||
CallSitesInfo.find(MI) == CallSitesInfo.end()) &&
"Call site info was not updated!");
// Strip it for parts. The operand array and the MI object itself are
// independently recyclable.
if (MI->Operands)
deallocateOperandArray(MI->CapOperands, MI->Operands);
// Don't call ~MachineInstr() which must be trivial anyway because
// ~MachineFunction drops whole lists of MachineInstrs wihout calling their
// destructors.
InstructionRecycler.Deallocate(Allocator, MI);
}
/// Allocate a new MachineBasicBlock. Use this instead of
/// `new MachineBasicBlock'.
MachineBasicBlock *
MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
MachineBasicBlock(*this, bb);
}
/// Delete the given MachineBasicBlock.
void
MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
assert(MBB->getParent() == this && "MBB parent mismatch!");
MBB->~MachineBasicBlock();
BasicBlockRecycler.Deallocate(Allocator, MBB);
}
MachineMemOperand *MachineFunction::getMachineMemOperand(
MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, uint64_t s,
Align base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges,
SyncScope::ID SSID, AtomicOrdering Ordering,
AtomicOrdering FailureOrdering) {
return new (Allocator)
MachineMemOperand(PtrInfo, f, s, base_alignment, AAInfo, Ranges,
SSID, Ordering, FailureOrdering);
}
MachineMemOperand *
MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
int64_t Offset, uint64_t Size) {
const MachinePointerInfo &PtrInfo = MMO->getPointerInfo();
// If there is no pointer value, the offset isn't tracked so we need to adjust
// the base alignment.
Align Alignment = PtrInfo.V.isNull()
? commonAlignment(MMO->getBaseAlign(), Offset)
: MMO->getBaseAlign();
return new (Allocator)
MachineMemOperand(PtrInfo.getWithOffset(Offset), MMO->getFlags(), Size,
Alignment, AAMDNodes(), nullptr, MMO->getSyncScopeID(),
MMO->getOrdering(), MMO->getFailureOrdering());
}
MachineMemOperand *
MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
const AAMDNodes &AAInfo) {
MachinePointerInfo MPI = MMO->getValue() ?
MachinePointerInfo(MMO->getValue(), MMO->getOffset()) :
MachinePointerInfo(MMO->getPseudoValue(), MMO->getOffset());
return new (Allocator) MachineMemOperand(
MPI, MMO->getFlags(), MMO->getSize(), MMO->getBaseAlign(), AAInfo,
MMO->getRanges(), MMO->getSyncScopeID(), MMO->getOrdering(),
MMO->getFailureOrdering());
}
MachineMemOperand *
MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
MachineMemOperand::Flags Flags) {
return new (Allocator) MachineMemOperand(
MMO->getPointerInfo(), Flags, MMO->getSize(), MMO->getBaseAlign(),
MMO->getAAInfo(), MMO->getRanges(), MMO->getSyncScopeID(),
MMO->getOrdering(), MMO->getFailureOrdering());
}
MachineInstr::ExtraInfo *MachineFunction::createMIExtraInfo(
ArrayRef<MachineMemOperand *> MMOs, MCSymbol *PreInstrSymbol,
MCSymbol *PostInstrSymbol, MDNode *HeapAllocMarker) {
return MachineInstr::ExtraInfo::create(Allocator, MMOs, PreInstrSymbol,
PostInstrSymbol, HeapAllocMarker);
}
const char *MachineFunction::createExternalSymbolName(StringRef Name) {
char *Dest = Allocator.Allocate<char>(Name.size() + 1);
llvm::copy(Name, Dest);
Dest[Name.size()] = 0;
return Dest;
}
uint32_t *MachineFunction::allocateRegMask() {
unsigned NumRegs = getSubtarget().getRegisterInfo()->getNumRegs();
unsigned Size = MachineOperand::getRegMaskSize(NumRegs);
uint32_t *Mask = Allocator.Allocate<uint32_t>(Size);
memset(Mask, 0, Size * sizeof(Mask[0]));
return Mask;
}
ArrayRef<int> MachineFunction::allocateShuffleMask(ArrayRef<int> Mask) {
int* AllocMask = Allocator.Allocate<int>(Mask.size());
copy(Mask, AllocMask);
return {AllocMask, Mask.size()};
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void MachineFunction::dump() const {
print(dbgs());
}
#endif
StringRef MachineFunction::getName() const {
return getFunction().getName();
}
void MachineFunction::print(raw_ostream &OS, const SlotIndexes *Indexes) const {
OS << "# Machine code for function " << getName() << ": ";
getProperties().print(OS);
OS << '\n';
// Print Frame Information
FrameInfo->print(*this, OS);
// Print JumpTable Information
if (JumpTableInfo)
JumpTableInfo->print(OS);
// Print Constant Pool
ConstantPool->print(OS);
const TargetRegisterInfo *TRI = getSubtarget().getRegisterInfo();
if (RegInfo && !RegInfo->livein_empty()) {
OS << "Function Live Ins: ";
for (MachineRegisterInfo::livein_iterator
I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
OS << printReg(I->first, TRI);
if (I->second)
OS << " in " << printReg(I->second, TRI);
if (std::next(I) != E)
OS << ", ";
}
OS << '\n';
}
ModuleSlotTracker MST(getFunction().getParent());
MST.incorporateFunction(getFunction());
for (const auto &BB : *this) {
OS << '\n';
// If we print the whole function, print it at its most verbose level.
BB.print(OS, MST, Indexes, /*IsStandalone=*/true);
}
OS << "\n# End machine code for function " << getName() << ".\n\n";
}
/// True if this function needs frame moves for debug or exceptions.
bool MachineFunction::needsFrameMoves() const {
return getMMI().hasDebugInfo() ||
getTarget().Options.ForceDwarfFrameSection ||
F.needsUnwindTableEntry();
}
namespace llvm {
template<>
struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
static std::string getGraphName(const MachineFunction *F) {
return ("CFG for '" + F->getName() + "' function").str();
}
std::string getNodeLabel(const MachineBasicBlock *Node,
const MachineFunction *Graph) {
std::string OutStr;
{
raw_string_ostream OSS(OutStr);
if (isSimple()) {
OSS << printMBBReference(*Node);
if (const BasicBlock *BB = Node->getBasicBlock())
OSS << ": " << BB->getName();
} else
Node->print(OSS);
}
if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
// Process string output to make it nicer...
for (unsigned i = 0; i != OutStr.length(); ++i)
if (OutStr[i] == '\n') { // Left justify
OutStr[i] = '\\';
OutStr.insert(OutStr.begin()+i+1, 'l');
}
return OutStr;
}
};
} // end namespace llvm
void MachineFunction::viewCFG() const
{
#ifndef NDEBUG
ViewGraph(this, "mf" + getName());
#else
errs() << "MachineFunction::viewCFG is only available in debug builds on "
<< "systems with Graphviz or gv!\n";
#endif // NDEBUG
}
void MachineFunction::viewCFGOnly() const
{
#ifndef NDEBUG
ViewGraph(this, "mf" + getName(), true);
#else
errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
<< "systems with Graphviz or gv!\n";
#endif // NDEBUG
}
/// Add the specified physical register as a live-in value and
/// create a corresponding virtual register for it.
unsigned MachineFunction::addLiveIn(unsigned PReg,
const TargetRegisterClass *RC) {
MachineRegisterInfo &MRI = getRegInfo();
unsigned VReg = MRI.getLiveInVirtReg(PReg);
if (VReg) {
const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg);
(void)VRegRC;
// A physical register can be added several times.
// Between two calls, the register class of the related virtual register
// may have been constrained to match some operation constraints.
// In that case, check that the current register class includes the
// physical register and is a sub class of the specified RC.
assert((VRegRC == RC || (VRegRC->contains(PReg) &&
RC->hasSubClassEq(VRegRC))) &&
"Register class mismatch!");
return VReg;
}
VReg = MRI.createVirtualRegister(RC);
MRI.addLiveIn(PReg, VReg);
return VReg;
}
/// Return the MCSymbol for the specified non-empty jump table.
/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
/// normal 'L' label is returned.
MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
bool isLinkerPrivate) const {
const DataLayout &DL = getDataLayout();
assert(JumpTableInfo && "No jump tables");
assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
StringRef Prefix = isLinkerPrivate ? DL.getLinkerPrivateGlobalPrefix()
: DL.getPrivateGlobalPrefix();
SmallString<60> Name;
raw_svector_ostream(Name)
<< Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
return Ctx.getOrCreateSymbol(Name);
}
/// Return a function-local symbol to represent the PIC base.
MCSymbol *MachineFunction::getPICBaseSymbol() const {
const DataLayout &DL = getDataLayout();
return Ctx.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
Twine(getFunctionNumber()) + "$pb");
}
/// \name Exception Handling
/// \{
LandingPadInfo &
MachineFunction::getOrCreateLandingPadInfo(MachineBasicBlock *LandingPad) {
unsigned N = LandingPads.size();
for (unsigned i = 0; i < N; ++i) {
LandingPadInfo &LP = LandingPads[i];
if (LP.LandingPadBlock == LandingPad)
return LP;
}
LandingPads.push_back(LandingPadInfo(LandingPad));
return LandingPads[N];
}
void MachineFunction::addInvoke(MachineBasicBlock *LandingPad,
MCSymbol *BeginLabel, MCSymbol *EndLabel) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.BeginLabels.push_back(BeginLabel);
LP.EndLabels.push_back(EndLabel);
}
MCSymbol *MachineFunction::addLandingPad(MachineBasicBlock *LandingPad) {
MCSymbol *LandingPadLabel = Ctx.createTempSymbol();
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.LandingPadLabel = LandingPadLabel;
const Instruction *FirstI = LandingPad->getBasicBlock()->getFirstNonPHI();
if (const auto *LPI = dyn_cast<LandingPadInst>(FirstI)) {
if (const auto *PF =
dyn_cast<Function>(F.getPersonalityFn()->stripPointerCasts()))
getMMI().addPersonality(PF);
if (LPI->isCleanup())
addCleanup(LandingPad);
// FIXME: New EH - Add the clauses in reverse order. This isn't 100%
// correct, but we need to do it this way because of how the DWARF EH
// emitter processes the clauses.
for (unsigned I = LPI->getNumClauses(); I != 0; --I) {
Value *Val = LPI->getClause(I - 1);
if (LPI->isCatch(I - 1)) {
addCatchTypeInfo(LandingPad,
dyn_cast<GlobalValue>(Val->stripPointerCasts()));
} else {
// Add filters in a list.
auto *CVal = cast<Constant>(Val);
SmallVector<const GlobalValue *, 4> FilterList;
for (User::op_iterator II = CVal->op_begin(), IE = CVal->op_end();
II != IE; ++II)
FilterList.push_back(cast<GlobalValue>((*II)->stripPointerCasts()));
addFilterTypeInfo(LandingPad, FilterList);
}
}
} else if (const auto *CPI = dyn_cast<CatchPadInst>(FirstI)) {
for (unsigned I = CPI->getNumArgOperands(); I != 0; --I) {
Value *TypeInfo = CPI->getArgOperand(I - 1)->stripPointerCasts();
addCatchTypeInfo(LandingPad, dyn_cast<GlobalValue>(TypeInfo));
}
} else {
assert(isa<CleanupPadInst>(FirstI) && "Invalid landingpad!");
}
return LandingPadLabel;
}
void MachineFunction::addCatchTypeInfo(MachineBasicBlock *LandingPad,
ArrayRef<const GlobalValue *> TyInfo) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
for (unsigned N = TyInfo.size(); N; --N)
LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1]));
}
void MachineFunction::addFilterTypeInfo(MachineBasicBlock *LandingPad,
ArrayRef<const GlobalValue *> TyInfo) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
std::vector<unsigned> IdsInFilter(TyInfo.size());
for (unsigned I = 0, E = TyInfo.size(); I != E; ++I)
IdsInFilter[I] = getTypeIDFor(TyInfo[I]);
LP.TypeIds.push_back(getFilterIDFor(IdsInFilter));
}
void MachineFunction::tidyLandingPads(DenseMap<MCSymbol *, uintptr_t> *LPMap,
bool TidyIfNoBeginLabels) {
for (unsigned i = 0; i != LandingPads.size(); ) {
LandingPadInfo &LandingPad = LandingPads[i];
if (LandingPad.LandingPadLabel &&
!LandingPad.LandingPadLabel->isDefined() &&
(!LPMap || (*LPMap)[LandingPad.LandingPadLabel] == 0))
LandingPad.LandingPadLabel = nullptr;
// Special case: we *should* emit LPs with null LP MBB. This indicates
// "nounwind" case.
if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) {
LandingPads.erase(LandingPads.begin() + i);
continue;
}
if (TidyIfNoBeginLabels) {
for (unsigned j = 0, e = LandingPads[i].BeginLabels.size(); j != e; ++j) {
MCSymbol *BeginLabel = LandingPad.BeginLabels[j];
MCSymbol *EndLabel = LandingPad.EndLabels[j];
if ((BeginLabel->isDefined() || (LPMap && (*LPMap)[BeginLabel] != 0)) &&
(EndLabel->isDefined() || (LPMap && (*LPMap)[EndLabel] != 0)))
continue;
LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
--j;
--e;
}
// Remove landing pads with no try-ranges.
if (LandingPads[i].BeginLabels.empty()) {
LandingPads.erase(LandingPads.begin() + i);
continue;
}
}
// If there is no landing pad, ensure that the list of typeids is empty.
// If the only typeid is a cleanup, this is the same as having no typeids.
if (!LandingPad.LandingPadBlock ||
(LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0]))
LandingPad.TypeIds.clear();
++i;
}
}
void MachineFunction::addCleanup(MachineBasicBlock *LandingPad) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.TypeIds.push_back(0);
}
void MachineFunction::addSEHCatchHandler(MachineBasicBlock *LandingPad,
const Function *Filter,
const BlockAddress *RecoverBA) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
SEHHandler Handler;
Handler.FilterOrFinally = Filter;
Handler.RecoverBA = RecoverBA;
LP.SEHHandlers.push_back(Handler);
}
void MachineFunction::addSEHCleanupHandler(MachineBasicBlock *LandingPad,
const Function *Cleanup) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
SEHHandler Handler;
Handler.FilterOrFinally = Cleanup;
Handler.RecoverBA = nullptr;
LP.SEHHandlers.push_back(Handler);
}
void MachineFunction::setCallSiteLandingPad(MCSymbol *Sym,
ArrayRef<unsigned> Sites) {
LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end());
}
unsigned MachineFunction::getTypeIDFor(const GlobalValue *TI) {
for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)
if (TypeInfos[i] == TI) return i + 1;
TypeInfos.push_back(TI);
return TypeInfos.size();
}
int MachineFunction::getFilterIDFor(std::vector<unsigned> &TyIds) {
// If the new filter coincides with the tail of an existing filter, then
// re-use the existing filter. Folding filters more than this requires
// re-ordering filters and/or their elements - probably not worth it.
for (std::vector<unsigned>::iterator I = FilterEnds.begin(),
E = FilterEnds.end(); I != E; ++I) {
unsigned i = *I, j = TyIds.size();
while (i && j)
if (FilterIds[--i] != TyIds[--j])
goto try_next;
if (!j)
// The new filter coincides with range [i, end) of the existing filter.
return -(1 + i);
try_next:;
}
// Add the new filter.
int FilterID = -(1 + FilterIds.size());
FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
FilterIds.insert(FilterIds.end(), TyIds.begin(), TyIds.end());
FilterEnds.push_back(FilterIds.size());
FilterIds.push_back(0); // terminator
return FilterID;
}
MachineFunction::CallSiteInfoMap::iterator
MachineFunction::getCallSiteInfo(const MachineInstr *MI) {
assert(MI->isCandidateForCallSiteEntry() &&
"Call site info refers only to call (MI) candidates");
if (!Target.Options.EmitCallSiteInfo)
return CallSitesInfo.end();
return CallSitesInfo.find(MI);
}
/// Return the call machine instruction or find a call within bundle.
static const MachineInstr *getCallInstr(const MachineInstr *MI) {
if (!MI->isBundle())
return MI;
for (auto &BMI : make_range(getBundleStart(MI->getIterator()),
getBundleEnd(MI->getIterator())))
if (BMI.isCandidateForCallSiteEntry())
return &BMI;
llvm_unreachable("Unexpected bundle without a call site candidate");
}
void MachineFunction::eraseCallSiteInfo(const MachineInstr *MI) {
assert(MI->shouldUpdateCallSiteInfo() &&
"Call site info refers only to call (MI) candidates or "
"candidates inside bundles");
const MachineInstr *CallMI = getCallInstr(MI);
CallSiteInfoMap::iterator CSIt = getCallSiteInfo(CallMI);
if (CSIt == CallSitesInfo.end())
return;
CallSitesInfo.erase(CSIt);
}
void MachineFunction::copyCallSiteInfo(const MachineInstr *Old,
const MachineInstr *New) {
assert(Old->shouldUpdateCallSiteInfo() &&
"Call site info refers only to call (MI) candidates or "
"candidates inside bundles");
if (!New->isCandidateForCallSiteEntry())
return eraseCallSiteInfo(Old);
const MachineInstr *OldCallMI = getCallInstr(Old);
CallSiteInfoMap::iterator CSIt = getCallSiteInfo(OldCallMI);
if (CSIt == CallSitesInfo.end())
return;
CallSiteInfo CSInfo = CSIt->second;
CallSitesInfo[New] = CSInfo;
}
void MachineFunction::moveCallSiteInfo(const MachineInstr *Old,
const MachineInstr *New) {
assert(Old->shouldUpdateCallSiteInfo() &&
"Call site info refers only to call (MI) candidates or "
"candidates inside bundles");
if (!New->isCandidateForCallSiteEntry())
return eraseCallSiteInfo(Old);
const MachineInstr *OldCallMI = getCallInstr(Old);
CallSiteInfoMap::iterator CSIt = getCallSiteInfo(OldCallMI);
if (CSIt == CallSitesInfo.end())
return;
CallSiteInfo CSInfo = std::move(CSIt->second);
CallSitesInfo.erase(CSIt);
CallSitesInfo[New] = CSInfo;
}
/// \}
//===----------------------------------------------------------------------===//
// MachineJumpTableInfo implementation
//===----------------------------------------------------------------------===//
/// Return the size of each entry in the jump table.
unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
// The size of a jump table entry is 4 bytes unless the entry is just the
// address of a block, in which case it is the pointer size.
switch (getEntryKind()) {
case MachineJumpTableInfo::EK_BlockAddress:
return TD.getPointerSize();
case MachineJumpTableInfo::EK_GPRel64BlockAddress:
return 8;
case MachineJumpTableInfo::EK_GPRel32BlockAddress:
case MachineJumpTableInfo::EK_LabelDifference32:
case MachineJumpTableInfo::EK_Custom32:
return 4;
case MachineJumpTableInfo::EK_Inline:
return 0;
}
llvm_unreachable("Unknown jump table encoding!");
}
/// Return the alignment of each entry in the jump table.
unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
// The alignment of a jump table entry is the alignment of int32 unless the
// entry is just the address of a block, in which case it is the pointer
// alignment.
switch (getEntryKind()) {
case MachineJumpTableInfo::EK_BlockAddress:
return TD.getPointerABIAlignment(0).value();
case MachineJumpTableInfo::EK_GPRel64BlockAddress:
return TD.getABIIntegerTypeAlignment(64).value();
case MachineJumpTableInfo::EK_GPRel32BlockAddress:
case MachineJumpTableInfo::EK_LabelDifference32:
case MachineJumpTableInfo::EK_Custom32:
return TD.getABIIntegerTypeAlignment(32).value();
case MachineJumpTableInfo::EK_Inline:
return 1;
}
llvm_unreachable("Unknown jump table encoding!");
}
/// Create a new jump table entry in the jump table info.
unsigned MachineJumpTableInfo::createJumpTableIndex(
const std::vector<MachineBasicBlock*> &DestBBs) {
assert(!DestBBs.empty() && "Cannot create an empty jump table!");
JumpTables.push_back(MachineJumpTableEntry(DestBBs));
return JumpTables.size()-1;
}
/// If Old is the target of any jump tables, update the jump tables to branch
/// to New instead.
bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
MachineBasicBlock *New) {
assert(Old != New && "Not making a change?");
bool MadeChange = false;
for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
ReplaceMBBInJumpTable(i, Old, New);
return MadeChange;
}
/// If Old is a target of the jump tables, update the jump table to branch to
/// New instead.
bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
MachineBasicBlock *Old,
MachineBasicBlock *New) {
assert(Old != New && "Not making a change?");
bool MadeChange = false;
MachineJumpTableEntry &JTE = JumpTables[Idx];
for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
if (JTE.MBBs[j] == Old) {
JTE.MBBs[j] = New;
MadeChange = true;
}
return MadeChange;
}
void MachineJumpTableInfo::print(raw_ostream &OS) const {
if (JumpTables.empty()) return;
OS << "Jump Tables:\n";
for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
OS << printJumpTableEntryReference(i) << ':';
for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
OS << ' ' << printMBBReference(*JumpTables[i].MBBs[j]);
if (i != e)
OS << '\n';
}
OS << '\n';
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void MachineJumpTableInfo::dump() const { print(dbgs()); }
#endif
Printable llvm::printJumpTableEntryReference(unsigned Idx) {
return Printable([Idx](raw_ostream &OS) { OS << "%jump-table." << Idx; });
}
//===----------------------------------------------------------------------===//
// MachineConstantPool implementation
//===----------------------------------------------------------------------===//
void MachineConstantPoolValue::anchor() {}
Type *MachineConstantPoolEntry::getType() const {
if (isMachineConstantPoolEntry())
return Val.MachineCPVal->getType();
return Val.ConstVal->getType();
}
bool MachineConstantPoolEntry::needsRelocation() const {
if (isMachineConstantPoolEntry())
return true;
return Val.ConstVal->needsRelocation();
}
SectionKind
MachineConstantPoolEntry::getSectionKind(const DataLayout *DL) const {
if (needsRelocation())
return SectionKind::getReadOnlyWithRel();
switch (DL->getTypeAllocSize(getType())) {
case 4:
return SectionKind::getMergeableConst4();
case 8:
return SectionKind::getMergeableConst8();
case 16:
return SectionKind::getMergeableConst16();
case 32:
return SectionKind::getMergeableConst32();
default:
return SectionKind::getReadOnly();
}
}
MachineConstantPool::~MachineConstantPool() {
// A constant may be a member of both Constants and MachineCPVsSharingEntries,
// so keep track of which we've deleted to avoid double deletions.
DenseSet<MachineConstantPoolValue*> Deleted;
for (unsigned i = 0, e = Constants.size(); i != e; ++i)
if (Constants[i].isMachineConstantPoolEntry()) {
Deleted.insert(Constants[i].Val.MachineCPVal);
delete Constants[i].Val.MachineCPVal;
}
for (DenseSet<MachineConstantPoolValue*>::iterator I =
MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
I != E; ++I) {
if (Deleted.count(*I) == 0)
delete *I;
}
}
/// Test whether the given two constants can be allocated the same constant pool
/// entry.
static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
const DataLayout &DL) {
// Handle the trivial case quickly.
if (A == B) return true;
// If they have the same type but weren't the same constant, quickly
// reject them.
if (A->getType() == B->getType()) return false;
// We can't handle structs or arrays.
if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
return false;
// For now, only support constants with the same size.
uint64_t StoreSize = DL.getTypeStoreSize(A->getType());
if (StoreSize != DL.getTypeStoreSize(B->getType()) || StoreSize > 128)
return false;
Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
// Try constant folding a bitcast of both instructions to an integer. If we
// get two identical ConstantInt's, then we are good to share them. We use
// the constant folding APIs to do this so that we get the benefit of
// DataLayout.
if (isa<PointerType>(A->getType()))
A = ConstantFoldCastOperand(Instruction::PtrToInt,
const_cast<Constant *>(A), IntTy, DL);
else if (A->getType() != IntTy)
A = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(A),
IntTy, DL);
if (isa<PointerType>(B->getType()))
B = ConstantFoldCastOperand(Instruction::PtrToInt,
const_cast<Constant *>(B), IntTy, DL);
else if (B->getType() != IntTy)
B = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(B),
IntTy, DL);
return A == B;
}
/// Create a new entry in the constant pool or return an existing one.
/// User must specify the log2 of the minimum required alignment for the object.
unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
unsigned Alignment) {
assert(Alignment && "Alignment must be specified!");
if (Alignment > PoolAlignment) PoolAlignment = Alignment;
// Check to see if we already have this constant.
//
// FIXME, this could be made much more efficient for large constant pools.
for (unsigned i = 0, e = Constants.size(); i != e; ++i)
if (!Constants[i].isMachineConstantPoolEntry() &&
CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, DL)) {
if ((unsigned)Constants[i].getAlignment() < Alignment)
Constants[i].Alignment = Alignment;
return i;
}
Constants.push_back(MachineConstantPoolEntry(C, Alignment));
return Constants.size()-1;
}
unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
unsigned Alignment) {
assert(Alignment && "Alignment must be specified!");
if (Alignment > PoolAlignment) PoolAlignment = Alignment;
// Check to see if we already have this constant.
//
// FIXME, this could be made much more efficient for large constant pools.
int Idx = V->getExistingMachineCPValue(this, Alignment);
if (Idx != -1) {
MachineCPVsSharingEntries.insert(V);
return (unsigned)Idx;
}
Constants.push_back(MachineConstantPoolEntry(V, Alignment));
return Constants.size()-1;
}
void MachineConstantPool::print(raw_ostream &OS) const {
if (Constants.empty()) return;
OS << "Constant Pool:\n";
for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
OS << " cp#" << i << ": ";
if (Constants[i].isMachineConstantPoolEntry())
Constants[i].Val.MachineCPVal->print(OS);
else
Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false);
OS << ", align=" << Constants[i].getAlignment();
OS << "\n";
}
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void MachineConstantPool::dump() const { print(dbgs()); }
#endif
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