llvm-project/llvm/lib/CodeGen/MIRPrinter.cpp
Reid Kleckner 5ff5ddd0ad [Win64] Insert int3 into trailing empty BBs
Otherwise, the Win64 unwinder considers direct branches to such empty
trailing BBs to be a branch out of the function. It treats such a branch
as a tail call, which can only be part of an epilogue. If the unwinder
misclassifies such a branch as part of the epilogue, it will fail to
unwind the stack further. This can lead to bad stack traces, or failure
to handle exceptions properly. This is described in
https://llvm.org/PR45064#c4, and by the comment at the top of the
X86AvoidTrailingCallPass.cpp file.

It should be safe to insert int3 for such blocks. An empty trailing BB
that reaches this pass is pretty much guaranteed to be unreachable.  If
a program executed such a block, it would fall off the end of the
function.

Most of the complexity in this patch comes from threading through the
"EHFuncletEntry" boolean on the MIRParser and registering the pass so we
can stop and start codegen around it. I used an MIR test because we
should teach LLVM to optimize away these branches as a follow-up.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D76531
2020-03-23 08:50:37 -07:00

945 lines
32 KiB
C++

//===- MIRPrinter.cpp - MIR serialization format printer ------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements the class that prints out the LLVM IR and machine
// functions using the MIR serialization format.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MIRPrinter.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/None.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallBitVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/CodeGen/GlobalISel/RegisterBank.h"
#include "llvm/CodeGen/MIRYamlMapping.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/IRPrintingPasses.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/ModuleSlotTracker.h"
#include "llvm/IR/Value.h"
#include "llvm/MC/LaneBitmask.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/AtomicOrdering.h"
#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/LowLevelTypeImpl.h"
#include "llvm/Support/YAMLTraits.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetIntrinsicInfo.h"
#include "llvm/Target/TargetMachine.h"
#include <algorithm>
#include <cassert>
#include <cinttypes>
#include <cstdint>
#include <iterator>
#include <string>
#include <utility>
#include <vector>
using namespace llvm;
static cl::opt<bool> SimplifyMIR(
"simplify-mir", cl::Hidden,
cl::desc("Leave out unnecessary information when printing MIR"));
namespace {
/// This structure describes how to print out stack object references.
struct FrameIndexOperand {
std::string Name;
unsigned ID;
bool IsFixed;
FrameIndexOperand(StringRef Name, unsigned ID, bool IsFixed)
: Name(Name.str()), ID(ID), IsFixed(IsFixed) {}
/// Return an ordinary stack object reference.
static FrameIndexOperand create(StringRef Name, unsigned ID) {
return FrameIndexOperand(Name, ID, /*IsFixed=*/false);
}
/// Return a fixed stack object reference.
static FrameIndexOperand createFixed(unsigned ID) {
return FrameIndexOperand("", ID, /*IsFixed=*/true);
}
};
} // end anonymous namespace
namespace llvm {
/// This class prints out the machine functions using the MIR serialization
/// format.
class MIRPrinter {
raw_ostream &OS;
DenseMap<const uint32_t *, unsigned> RegisterMaskIds;
/// Maps from stack object indices to operand indices which will be used when
/// printing frame index machine operands.
DenseMap<int, FrameIndexOperand> StackObjectOperandMapping;
public:
MIRPrinter(raw_ostream &OS) : OS(OS) {}
void print(const MachineFunction &MF);
void convert(yaml::MachineFunction &MF, const MachineRegisterInfo &RegInfo,
const TargetRegisterInfo *TRI);
void convert(ModuleSlotTracker &MST, yaml::MachineFrameInfo &YamlMFI,
const MachineFrameInfo &MFI);
void convert(yaml::MachineFunction &MF,
const MachineConstantPool &ConstantPool);
void convert(ModuleSlotTracker &MST, yaml::MachineJumpTable &YamlJTI,
const MachineJumpTableInfo &JTI);
void convertStackObjects(yaml::MachineFunction &YMF,
const MachineFunction &MF, ModuleSlotTracker &MST);
void convertCallSiteObjects(yaml::MachineFunction &YMF,
const MachineFunction &MF,
ModuleSlotTracker &MST);
private:
void initRegisterMaskIds(const MachineFunction &MF);
};
/// This class prints out the machine instructions using the MIR serialization
/// format.
class MIPrinter {
raw_ostream &OS;
ModuleSlotTracker &MST;
const DenseMap<const uint32_t *, unsigned> &RegisterMaskIds;
const DenseMap<int, FrameIndexOperand> &StackObjectOperandMapping;
/// Synchronization scope names registered with LLVMContext.
SmallVector<StringRef, 8> SSNs;
bool canPredictBranchProbabilities(const MachineBasicBlock &MBB) const;
bool canPredictSuccessors(const MachineBasicBlock &MBB) const;
public:
MIPrinter(raw_ostream &OS, ModuleSlotTracker &MST,
const DenseMap<const uint32_t *, unsigned> &RegisterMaskIds,
const DenseMap<int, FrameIndexOperand> &StackObjectOperandMapping)
: OS(OS), MST(MST), RegisterMaskIds(RegisterMaskIds),
StackObjectOperandMapping(StackObjectOperandMapping) {}
void print(const MachineBasicBlock &MBB);
void print(const MachineInstr &MI);
void printStackObjectReference(int FrameIndex);
void print(const MachineInstr &MI, unsigned OpIdx,
const TargetRegisterInfo *TRI, const TargetInstrInfo *TII,
bool ShouldPrintRegisterTies, LLT TypeToPrint,
bool PrintDef = true);
};
} // end namespace llvm
namespace llvm {
namespace yaml {
/// This struct serializes the LLVM IR module.
template <> struct BlockScalarTraits<Module> {
static void output(const Module &Mod, void *Ctxt, raw_ostream &OS) {
Mod.print(OS, nullptr);
}
static StringRef input(StringRef Str, void *Ctxt, Module &Mod) {
llvm_unreachable("LLVM Module is supposed to be parsed separately");
return "";
}
};
} // end namespace yaml
} // end namespace llvm
static void printRegMIR(unsigned Reg, yaml::StringValue &Dest,
const TargetRegisterInfo *TRI) {
raw_string_ostream OS(Dest.Value);
OS << printReg(Reg, TRI);
}
void MIRPrinter::print(const MachineFunction &MF) {
initRegisterMaskIds(MF);
yaml::MachineFunction YamlMF;
YamlMF.Name = MF.getName();
YamlMF.Alignment = MF.getAlignment().value();
YamlMF.ExposesReturnsTwice = MF.exposesReturnsTwice();
YamlMF.HasWinCFI = MF.hasWinCFI();
YamlMF.Legalized = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::Legalized);
YamlMF.RegBankSelected = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::RegBankSelected);
YamlMF.Selected = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::Selected);
YamlMF.FailedISel = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::FailedISel);
convert(YamlMF, MF.getRegInfo(), MF.getSubtarget().getRegisterInfo());
ModuleSlotTracker MST(MF.getFunction().getParent());
MST.incorporateFunction(MF.getFunction());
convert(MST, YamlMF.FrameInfo, MF.getFrameInfo());
convertStackObjects(YamlMF, MF, MST);
convertCallSiteObjects(YamlMF, MF, MST);
if (const auto *ConstantPool = MF.getConstantPool())
convert(YamlMF, *ConstantPool);
if (const auto *JumpTableInfo = MF.getJumpTableInfo())
convert(MST, YamlMF.JumpTableInfo, *JumpTableInfo);
const TargetMachine &TM = MF.getTarget();
YamlMF.MachineFuncInfo =
std::unique_ptr<yaml::MachineFunctionInfo>(TM.convertFuncInfoToYAML(MF));
raw_string_ostream StrOS(YamlMF.Body.Value.Value);
bool IsNewlineNeeded = false;
for (const auto &MBB : MF) {
if (IsNewlineNeeded)
StrOS << "\n";
MIPrinter(StrOS, MST, RegisterMaskIds, StackObjectOperandMapping)
.print(MBB);
IsNewlineNeeded = true;
}
StrOS.flush();
yaml::Output Out(OS);
if (!SimplifyMIR)
Out.setWriteDefaultValues(true);
Out << YamlMF;
}
static void printCustomRegMask(const uint32_t *RegMask, raw_ostream &OS,
const TargetRegisterInfo *TRI) {
assert(RegMask && "Can't print an empty register mask");
OS << StringRef("CustomRegMask(");
bool IsRegInRegMaskFound = false;
for (int I = 0, E = TRI->getNumRegs(); I < E; I++) {
// Check whether the register is asserted in regmask.
if (RegMask[I / 32] & (1u << (I % 32))) {
if (IsRegInRegMaskFound)
OS << ',';
OS << printReg(I, TRI);
IsRegInRegMaskFound = true;
}
}
OS << ')';
}
static void printRegClassOrBank(unsigned Reg, yaml::StringValue &Dest,
const MachineRegisterInfo &RegInfo,
const TargetRegisterInfo *TRI) {
raw_string_ostream OS(Dest.Value);
OS << printRegClassOrBank(Reg, RegInfo, TRI);
}
template <typename T>
static void
printStackObjectDbgInfo(const MachineFunction::VariableDbgInfo &DebugVar,
T &Object, ModuleSlotTracker &MST) {
std::array<std::string *, 3> Outputs{{&Object.DebugVar.Value,
&Object.DebugExpr.Value,
&Object.DebugLoc.Value}};
std::array<const Metadata *, 3> Metas{{DebugVar.Var,
DebugVar.Expr,
DebugVar.Loc}};
for (unsigned i = 0; i < 3; ++i) {
raw_string_ostream StrOS(*Outputs[i]);
Metas[i]->printAsOperand(StrOS, MST);
}
}
void MIRPrinter::convert(yaml::MachineFunction &MF,
const MachineRegisterInfo &RegInfo,
const TargetRegisterInfo *TRI) {
MF.TracksRegLiveness = RegInfo.tracksLiveness();
// Print the virtual register definitions.
for (unsigned I = 0, E = RegInfo.getNumVirtRegs(); I < E; ++I) {
unsigned Reg = Register::index2VirtReg(I);
yaml::VirtualRegisterDefinition VReg;
VReg.ID = I;
if (RegInfo.getVRegName(Reg) != "")
continue;
::printRegClassOrBank(Reg, VReg.Class, RegInfo, TRI);
unsigned PreferredReg = RegInfo.getSimpleHint(Reg);
if (PreferredReg)
printRegMIR(PreferredReg, VReg.PreferredRegister, TRI);
MF.VirtualRegisters.push_back(VReg);
}
// Print the live ins.
for (std::pair<unsigned, unsigned> LI : RegInfo.liveins()) {
yaml::MachineFunctionLiveIn LiveIn;
printRegMIR(LI.first, LiveIn.Register, TRI);
if (LI.second)
printRegMIR(LI.second, LiveIn.VirtualRegister, TRI);
MF.LiveIns.push_back(LiveIn);
}
// Prints the callee saved registers.
if (RegInfo.isUpdatedCSRsInitialized()) {
const MCPhysReg *CalleeSavedRegs = RegInfo.getCalleeSavedRegs();
std::vector<yaml::FlowStringValue> CalleeSavedRegisters;
for (const MCPhysReg *I = CalleeSavedRegs; *I; ++I) {
yaml::FlowStringValue Reg;
printRegMIR(*I, Reg, TRI);
CalleeSavedRegisters.push_back(Reg);
}
MF.CalleeSavedRegisters = CalleeSavedRegisters;
}
}
void MIRPrinter::convert(ModuleSlotTracker &MST,
yaml::MachineFrameInfo &YamlMFI,
const MachineFrameInfo &MFI) {
YamlMFI.IsFrameAddressTaken = MFI.isFrameAddressTaken();
YamlMFI.IsReturnAddressTaken = MFI.isReturnAddressTaken();
YamlMFI.HasStackMap = MFI.hasStackMap();
YamlMFI.HasPatchPoint = MFI.hasPatchPoint();
YamlMFI.StackSize = MFI.getStackSize();
YamlMFI.OffsetAdjustment = MFI.getOffsetAdjustment();
YamlMFI.MaxAlignment = MFI.getMaxAlign().value();
YamlMFI.AdjustsStack = MFI.adjustsStack();
YamlMFI.HasCalls = MFI.hasCalls();
YamlMFI.MaxCallFrameSize = MFI.isMaxCallFrameSizeComputed()
? MFI.getMaxCallFrameSize() : ~0u;
YamlMFI.CVBytesOfCalleeSavedRegisters =
MFI.getCVBytesOfCalleeSavedRegisters();
YamlMFI.HasOpaqueSPAdjustment = MFI.hasOpaqueSPAdjustment();
YamlMFI.HasVAStart = MFI.hasVAStart();
YamlMFI.HasMustTailInVarArgFunc = MFI.hasMustTailInVarArgFunc();
YamlMFI.LocalFrameSize = MFI.getLocalFrameSize();
if (MFI.getSavePoint()) {
raw_string_ostream StrOS(YamlMFI.SavePoint.Value);
StrOS << printMBBReference(*MFI.getSavePoint());
}
if (MFI.getRestorePoint()) {
raw_string_ostream StrOS(YamlMFI.RestorePoint.Value);
StrOS << printMBBReference(*MFI.getRestorePoint());
}
}
void MIRPrinter::convertStackObjects(yaml::MachineFunction &YMF,
const MachineFunction &MF,
ModuleSlotTracker &MST) {
const MachineFrameInfo &MFI = MF.getFrameInfo();
const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
// Process fixed stack objects.
unsigned ID = 0;
for (int I = MFI.getObjectIndexBegin(); I < 0; ++I, ++ID) {
if (MFI.isDeadObjectIndex(I))
continue;
yaml::FixedMachineStackObject YamlObject;
YamlObject.ID = ID;
YamlObject.Type = MFI.isSpillSlotObjectIndex(I)
? yaml::FixedMachineStackObject::SpillSlot
: yaml::FixedMachineStackObject::DefaultType;
YamlObject.Offset = MFI.getObjectOffset(I);
YamlObject.Size = MFI.getObjectSize(I);
YamlObject.Alignment = MFI.getObjectAlignment(I);
YamlObject.StackID = (TargetStackID::Value)MFI.getStackID(I);
YamlObject.IsImmutable = MFI.isImmutableObjectIndex(I);
YamlObject.IsAliased = MFI.isAliasedObjectIndex(I);
YMF.FixedStackObjects.push_back(YamlObject);
StackObjectOperandMapping.insert(
std::make_pair(I, FrameIndexOperand::createFixed(ID)));
}
// Process ordinary stack objects.
ID = 0;
for (int I = 0, E = MFI.getObjectIndexEnd(); I < E; ++I, ++ID) {
if (MFI.isDeadObjectIndex(I))
continue;
yaml::MachineStackObject YamlObject;
YamlObject.ID = ID;
if (const auto *Alloca = MFI.getObjectAllocation(I))
YamlObject.Name.Value = std::string(
Alloca->hasName() ? Alloca->getName() : "<unnamed alloca>");
YamlObject.Type = MFI.isSpillSlotObjectIndex(I)
? yaml::MachineStackObject::SpillSlot
: MFI.isVariableSizedObjectIndex(I)
? yaml::MachineStackObject::VariableSized
: yaml::MachineStackObject::DefaultType;
YamlObject.Offset = MFI.getObjectOffset(I);
YamlObject.Size = MFI.getObjectSize(I);
YamlObject.Alignment = MFI.getObjectAlignment(I);
YamlObject.StackID = (TargetStackID::Value)MFI.getStackID(I);
YMF.StackObjects.push_back(YamlObject);
StackObjectOperandMapping.insert(std::make_pair(
I, FrameIndexOperand::create(YamlObject.Name.Value, ID)));
}
for (const auto &CSInfo : MFI.getCalleeSavedInfo()) {
if (!CSInfo.isSpilledToReg() && MFI.isDeadObjectIndex(CSInfo.getFrameIdx()))
continue;
yaml::StringValue Reg;
printRegMIR(CSInfo.getReg(), Reg, TRI);
if (!CSInfo.isSpilledToReg()) {
auto StackObjectInfo = StackObjectOperandMapping.find(CSInfo.getFrameIdx());
assert(StackObjectInfo != StackObjectOperandMapping.end() &&
"Invalid stack object index");
const FrameIndexOperand &StackObject = StackObjectInfo->second;
if (StackObject.IsFixed) {
YMF.FixedStackObjects[StackObject.ID].CalleeSavedRegister = Reg;
YMF.FixedStackObjects[StackObject.ID].CalleeSavedRestored =
CSInfo.isRestored();
} else {
YMF.StackObjects[StackObject.ID].CalleeSavedRegister = Reg;
YMF.StackObjects[StackObject.ID].CalleeSavedRestored =
CSInfo.isRestored();
}
}
}
for (unsigned I = 0, E = MFI.getLocalFrameObjectCount(); I < E; ++I) {
auto LocalObject = MFI.getLocalFrameObjectMap(I);
auto StackObjectInfo = StackObjectOperandMapping.find(LocalObject.first);
assert(StackObjectInfo != StackObjectOperandMapping.end() &&
"Invalid stack object index");
const FrameIndexOperand &StackObject = StackObjectInfo->second;
assert(!StackObject.IsFixed && "Expected a locally mapped stack object");
YMF.StackObjects[StackObject.ID].LocalOffset = LocalObject.second;
}
// Print the stack object references in the frame information class after
// converting the stack objects.
if (MFI.hasStackProtectorIndex()) {
raw_string_ostream StrOS(YMF.FrameInfo.StackProtector.Value);
MIPrinter(StrOS, MST, RegisterMaskIds, StackObjectOperandMapping)
.printStackObjectReference(MFI.getStackProtectorIndex());
}
// Print the debug variable information.
for (const MachineFunction::VariableDbgInfo &DebugVar :
MF.getVariableDbgInfo()) {
auto StackObjectInfo = StackObjectOperandMapping.find(DebugVar.Slot);
assert(StackObjectInfo != StackObjectOperandMapping.end() &&
"Invalid stack object index");
const FrameIndexOperand &StackObject = StackObjectInfo->second;
if (StackObject.IsFixed) {
auto &Object = YMF.FixedStackObjects[StackObject.ID];
printStackObjectDbgInfo(DebugVar, Object, MST);
} else {
auto &Object = YMF.StackObjects[StackObject.ID];
printStackObjectDbgInfo(DebugVar, Object, MST);
}
}
}
void MIRPrinter::convertCallSiteObjects(yaml::MachineFunction &YMF,
const MachineFunction &MF,
ModuleSlotTracker &MST) {
const auto *TRI = MF.getSubtarget().getRegisterInfo();
for (auto CSInfo : MF.getCallSitesInfo()) {
yaml::CallSiteInfo YmlCS;
yaml::CallSiteInfo::MachineInstrLoc CallLocation;
// Prepare instruction position.
MachineBasicBlock::const_instr_iterator CallI = CSInfo.first->getIterator();
CallLocation.BlockNum = CallI->getParent()->getNumber();
// Get call instruction offset from the beginning of block.
CallLocation.Offset =
std::distance(CallI->getParent()->instr_begin(), CallI);
YmlCS.CallLocation = CallLocation;
// Construct call arguments and theirs forwarding register info.
for (auto ArgReg : CSInfo.second) {
yaml::CallSiteInfo::ArgRegPair YmlArgReg;
YmlArgReg.ArgNo = ArgReg.ArgNo;
printRegMIR(ArgReg.Reg, YmlArgReg.Reg, TRI);
YmlCS.ArgForwardingRegs.emplace_back(YmlArgReg);
}
YMF.CallSitesInfo.push_back(YmlCS);
}
// Sort call info by position of call instructions.
llvm::sort(YMF.CallSitesInfo.begin(), YMF.CallSitesInfo.end(),
[](yaml::CallSiteInfo A, yaml::CallSiteInfo B) {
if (A.CallLocation.BlockNum == B.CallLocation.BlockNum)
return A.CallLocation.Offset < B.CallLocation.Offset;
return A.CallLocation.BlockNum < B.CallLocation.BlockNum;
});
}
void MIRPrinter::convert(yaml::MachineFunction &MF,
const MachineConstantPool &ConstantPool) {
unsigned ID = 0;
for (const MachineConstantPoolEntry &Constant : ConstantPool.getConstants()) {
std::string Str;
raw_string_ostream StrOS(Str);
if (Constant.isMachineConstantPoolEntry()) {
Constant.Val.MachineCPVal->print(StrOS);
} else {
Constant.Val.ConstVal->printAsOperand(StrOS);
}
yaml::MachineConstantPoolValue YamlConstant;
YamlConstant.ID = ID++;
YamlConstant.Value = StrOS.str();
YamlConstant.Alignment = Constant.getAlignment();
YamlConstant.IsTargetSpecific = Constant.isMachineConstantPoolEntry();
MF.Constants.push_back(YamlConstant);
}
}
void MIRPrinter::convert(ModuleSlotTracker &MST,
yaml::MachineJumpTable &YamlJTI,
const MachineJumpTableInfo &JTI) {
YamlJTI.Kind = JTI.getEntryKind();
unsigned ID = 0;
for (const auto &Table : JTI.getJumpTables()) {
std::string Str;
yaml::MachineJumpTable::Entry Entry;
Entry.ID = ID++;
for (const auto *MBB : Table.MBBs) {
raw_string_ostream StrOS(Str);
StrOS << printMBBReference(*MBB);
Entry.Blocks.push_back(StrOS.str());
Str.clear();
}
YamlJTI.Entries.push_back(Entry);
}
}
void MIRPrinter::initRegisterMaskIds(const MachineFunction &MF) {
const auto *TRI = MF.getSubtarget().getRegisterInfo();
unsigned I = 0;
for (const uint32_t *Mask : TRI->getRegMasks())
RegisterMaskIds.insert(std::make_pair(Mask, I++));
}
void llvm::guessSuccessors(const MachineBasicBlock &MBB,
SmallVectorImpl<MachineBasicBlock*> &Result,
bool &IsFallthrough) {
SmallPtrSet<MachineBasicBlock*,8> Seen;
for (const MachineInstr &MI : MBB) {
if (MI.isPHI())
continue;
for (const MachineOperand &MO : MI.operands()) {
if (!MO.isMBB())
continue;
MachineBasicBlock *Succ = MO.getMBB();
auto RP = Seen.insert(Succ);
if (RP.second)
Result.push_back(Succ);
}
}
MachineBasicBlock::const_iterator I = MBB.getLastNonDebugInstr();
IsFallthrough = I == MBB.end() || !I->isBarrier();
}
bool
MIPrinter::canPredictBranchProbabilities(const MachineBasicBlock &MBB) const {
if (MBB.succ_size() <= 1)
return true;
if (!MBB.hasSuccessorProbabilities())
return true;
SmallVector<BranchProbability,8> Normalized(MBB.Probs.begin(),
MBB.Probs.end());
BranchProbability::normalizeProbabilities(Normalized.begin(),
Normalized.end());
SmallVector<BranchProbability,8> Equal(Normalized.size());
BranchProbability::normalizeProbabilities(Equal.begin(), Equal.end());
return std::equal(Normalized.begin(), Normalized.end(), Equal.begin());
}
bool MIPrinter::canPredictSuccessors(const MachineBasicBlock &MBB) const {
SmallVector<MachineBasicBlock*,8> GuessedSuccs;
bool GuessedFallthrough;
guessSuccessors(MBB, GuessedSuccs, GuessedFallthrough);
if (GuessedFallthrough) {
const MachineFunction &MF = *MBB.getParent();
MachineFunction::const_iterator NextI = std::next(MBB.getIterator());
if (NextI != MF.end()) {
MachineBasicBlock *Next = const_cast<MachineBasicBlock*>(&*NextI);
if (!is_contained(GuessedSuccs, Next))
GuessedSuccs.push_back(Next);
}
}
if (GuessedSuccs.size() != MBB.succ_size())
return false;
return std::equal(MBB.succ_begin(), MBB.succ_end(), GuessedSuccs.begin());
}
void MIPrinter::print(const MachineBasicBlock &MBB) {
assert(MBB.getNumber() >= 0 && "Invalid MBB number");
OS << "bb." << MBB.getNumber();
bool HasAttributes = false;
if (const auto *BB = MBB.getBasicBlock()) {
if (BB->hasName()) {
OS << "." << BB->getName();
} else {
HasAttributes = true;
OS << " (";
int Slot = MST.getLocalSlot(BB);
if (Slot == -1)
OS << "<ir-block badref>";
else
OS << (Twine("%ir-block.") + Twine(Slot)).str();
}
}
if (MBB.hasAddressTaken()) {
OS << (HasAttributes ? ", " : " (");
OS << "address-taken";
HasAttributes = true;
}
if (MBB.isEHPad()) {
OS << (HasAttributes ? ", " : " (");
OS << "landing-pad";
HasAttributes = true;
}
if (MBB.isEHFuncletEntry()) {
OS << (HasAttributes ? ", " : " (");
OS << "ehfunclet-entry";
HasAttributes = true;
}
if (MBB.getAlignment() != Align(1)) {
OS << (HasAttributes ? ", " : " (");
OS << "align " << MBB.getAlignment().value();
HasAttributes = true;
}
if (MBB.getSectionType() != MBBS_None) {
OS << (HasAttributes ? ", " : " (");
OS << "bbsections ";
switch (MBB.getSectionType()) {
case MBBS_Entry:
OS << "Entry";
break;
case MBBS_Exception:
OS << "Exception";
break;
case MBBS_Cold:
OS << "Cold";
break;
case MBBS_Unique:
OS << "Unique";
break;
default:
llvm_unreachable("No such section type");
}
HasAttributes = true;
}
if (HasAttributes)
OS << ")";
OS << ":\n";
bool HasLineAttributes = false;
// Print the successors
bool canPredictProbs = canPredictBranchProbabilities(MBB);
// Even if the list of successors is empty, if we cannot guess it,
// we need to print it to tell the parser that the list is empty.
// This is needed, because MI model unreachable as empty blocks
// with an empty successor list. If the parser would see that
// without the successor list, it would guess the code would
// fallthrough.
if ((!MBB.succ_empty() && !SimplifyMIR) || !canPredictProbs ||
!canPredictSuccessors(MBB)) {
OS.indent(2) << "successors: ";
for (auto I = MBB.succ_begin(), E = MBB.succ_end(); I != E; ++I) {
if (I != MBB.succ_begin())
OS << ", ";
OS << printMBBReference(**I);
if (!SimplifyMIR || !canPredictProbs)
OS << '('
<< format("0x%08" PRIx32, MBB.getSuccProbability(I).getNumerator())
<< ')';
}
OS << "\n";
HasLineAttributes = true;
}
// Print the live in registers.
const MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
if (MRI.tracksLiveness() && !MBB.livein_empty()) {
const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
OS.indent(2) << "liveins: ";
bool First = true;
for (const auto &LI : MBB.liveins()) {
if (!First)
OS << ", ";
First = false;
OS << printReg(LI.PhysReg, &TRI);
if (!LI.LaneMask.all())
OS << ":0x" << PrintLaneMask(LI.LaneMask);
}
OS << "\n";
HasLineAttributes = true;
}
if (HasLineAttributes)
OS << "\n";
bool IsInBundle = false;
for (auto I = MBB.instr_begin(), E = MBB.instr_end(); I != E; ++I) {
const MachineInstr &MI = *I;
if (IsInBundle && !MI.isInsideBundle()) {
OS.indent(2) << "}\n";
IsInBundle = false;
}
OS.indent(IsInBundle ? 4 : 2);
print(MI);
if (!IsInBundle && MI.getFlag(MachineInstr::BundledSucc)) {
OS << " {";
IsInBundle = true;
}
OS << "\n";
}
if (IsInBundle)
OS.indent(2) << "}\n";
}
void MIPrinter::print(const MachineInstr &MI) {
const auto *MF = MI.getMF();
const auto &MRI = MF->getRegInfo();
const auto &SubTarget = MF->getSubtarget();
const auto *TRI = SubTarget.getRegisterInfo();
assert(TRI && "Expected target register info");
const auto *TII = SubTarget.getInstrInfo();
assert(TII && "Expected target instruction info");
if (MI.isCFIInstruction())
assert(MI.getNumOperands() == 1 && "Expected 1 operand in CFI instruction");
SmallBitVector PrintedTypes(8);
bool ShouldPrintRegisterTies = MI.hasComplexRegisterTies();
unsigned I = 0, E = MI.getNumOperands();
for (; I < E && MI.getOperand(I).isReg() && MI.getOperand(I).isDef() &&
!MI.getOperand(I).isImplicit();
++I) {
if (I)
OS << ", ";
print(MI, I, TRI, TII, ShouldPrintRegisterTies,
MI.getTypeToPrint(I, PrintedTypes, MRI),
/*PrintDef=*/false);
}
if (I)
OS << " = ";
if (MI.getFlag(MachineInstr::FrameSetup))
OS << "frame-setup ";
if (MI.getFlag(MachineInstr::FrameDestroy))
OS << "frame-destroy ";
if (MI.getFlag(MachineInstr::FmNoNans))
OS << "nnan ";
if (MI.getFlag(MachineInstr::FmNoInfs))
OS << "ninf ";
if (MI.getFlag(MachineInstr::FmNsz))
OS << "nsz ";
if (MI.getFlag(MachineInstr::FmArcp))
OS << "arcp ";
if (MI.getFlag(MachineInstr::FmContract))
OS << "contract ";
if (MI.getFlag(MachineInstr::FmAfn))
OS << "afn ";
if (MI.getFlag(MachineInstr::FmReassoc))
OS << "reassoc ";
if (MI.getFlag(MachineInstr::NoUWrap))
OS << "nuw ";
if (MI.getFlag(MachineInstr::NoSWrap))
OS << "nsw ";
if (MI.getFlag(MachineInstr::IsExact))
OS << "exact ";
if (MI.getFlag(MachineInstr::NoFPExcept))
OS << "nofpexcept ";
OS << TII->getName(MI.getOpcode());
if (I < E)
OS << ' ';
bool NeedComma = false;
for (; I < E; ++I) {
if (NeedComma)
OS << ", ";
print(MI, I, TRI, TII, ShouldPrintRegisterTies,
MI.getTypeToPrint(I, PrintedTypes, MRI));
NeedComma = true;
}
// Print any optional symbols attached to this instruction as-if they were
// operands.
if (MCSymbol *PreInstrSymbol = MI.getPreInstrSymbol()) {
if (NeedComma)
OS << ',';
OS << " pre-instr-symbol ";
MachineOperand::printSymbol(OS, *PreInstrSymbol);
NeedComma = true;
}
if (MCSymbol *PostInstrSymbol = MI.getPostInstrSymbol()) {
if (NeedComma)
OS << ',';
OS << " post-instr-symbol ";
MachineOperand::printSymbol(OS, *PostInstrSymbol);
NeedComma = true;
}
if (MDNode *HeapAllocMarker = MI.getHeapAllocMarker()) {
if (NeedComma)
OS << ',';
OS << " heap-alloc-marker ";
HeapAllocMarker->printAsOperand(OS, MST);
NeedComma = true;
}
if (const DebugLoc &DL = MI.getDebugLoc()) {
if (NeedComma)
OS << ',';
OS << " debug-location ";
DL->printAsOperand(OS, MST);
}
if (!MI.memoperands_empty()) {
OS << " :: ";
const LLVMContext &Context = MF->getFunction().getContext();
const MachineFrameInfo &MFI = MF->getFrameInfo();
bool NeedComma = false;
for (const auto *Op : MI.memoperands()) {
if (NeedComma)
OS << ", ";
Op->print(OS, MST, SSNs, Context, &MFI, TII);
NeedComma = true;
}
}
}
void MIPrinter::printStackObjectReference(int FrameIndex) {
auto ObjectInfo = StackObjectOperandMapping.find(FrameIndex);
assert(ObjectInfo != StackObjectOperandMapping.end() &&
"Invalid frame index");
const FrameIndexOperand &Operand = ObjectInfo->second;
MachineOperand::printStackObjectReference(OS, Operand.ID, Operand.IsFixed,
Operand.Name);
}
static std::string formatOperandComment(std::string Comment) {
if (Comment.empty())
return Comment;
return std::string(" /* " + Comment + " */");
}
void MIPrinter::print(const MachineInstr &MI, unsigned OpIdx,
const TargetRegisterInfo *TRI,
const TargetInstrInfo *TII,
bool ShouldPrintRegisterTies, LLT TypeToPrint,
bool PrintDef) {
const MachineOperand &Op = MI.getOperand(OpIdx);
std::string MOComment = TII->createMIROperandComment(MI, Op, OpIdx);
switch (Op.getType()) {
case MachineOperand::MO_Immediate:
if (MI.isOperandSubregIdx(OpIdx)) {
MachineOperand::printTargetFlags(OS, Op);
MachineOperand::printSubRegIdx(OS, Op.getImm(), TRI);
break;
}
LLVM_FALLTHROUGH;
case MachineOperand::MO_Register:
case MachineOperand::MO_CImmediate:
case MachineOperand::MO_FPImmediate:
case MachineOperand::MO_MachineBasicBlock:
case MachineOperand::MO_ConstantPoolIndex:
case MachineOperand::MO_TargetIndex:
case MachineOperand::MO_JumpTableIndex:
case MachineOperand::MO_ExternalSymbol:
case MachineOperand::MO_GlobalAddress:
case MachineOperand::MO_RegisterLiveOut:
case MachineOperand::MO_Metadata:
case MachineOperand::MO_MCSymbol:
case MachineOperand::MO_CFIIndex:
case MachineOperand::MO_IntrinsicID:
case MachineOperand::MO_Predicate:
case MachineOperand::MO_BlockAddress:
case MachineOperand::MO_ShuffleMask: {
unsigned TiedOperandIdx = 0;
if (ShouldPrintRegisterTies && Op.isReg() && Op.isTied() && !Op.isDef())
TiedOperandIdx = Op.getParent()->findTiedOperandIdx(OpIdx);
const TargetIntrinsicInfo *TII = MI.getMF()->getTarget().getIntrinsicInfo();
Op.print(OS, MST, TypeToPrint, OpIdx, PrintDef, /*IsStandalone=*/false,
ShouldPrintRegisterTies, TiedOperandIdx, TRI, TII);
OS << formatOperandComment(MOComment);
break;
}
case MachineOperand::MO_FrameIndex:
printStackObjectReference(Op.getIndex());
break;
case MachineOperand::MO_RegisterMask: {
auto RegMaskInfo = RegisterMaskIds.find(Op.getRegMask());
if (RegMaskInfo != RegisterMaskIds.end())
OS << StringRef(TRI->getRegMaskNames()[RegMaskInfo->second]).lower();
else
printCustomRegMask(Op.getRegMask(), OS, TRI);
break;
}
}
}
void MIRFormatter::printIRValue(raw_ostream &OS, const Value &V,
ModuleSlotTracker &MST) {
if (isa<GlobalValue>(V)) {
V.printAsOperand(OS, /*PrintType=*/false, MST);
return;
}
if (isa<Constant>(V)) {
// Machine memory operands can load/store to/from constant value pointers.
OS << '`';
V.printAsOperand(OS, /*PrintType=*/true, MST);
OS << '`';
return;
}
OS << "%ir.";
if (V.hasName()) {
printLLVMNameWithoutPrefix(OS, V.getName());
return;
}
int Slot = MST.getCurrentFunction() ? MST.getLocalSlot(&V) : -1;
MachineOperand::printIRSlotNumber(OS, Slot);
}
void llvm::printMIR(raw_ostream &OS, const Module &M) {
yaml::Output Out(OS);
Out << const_cast<Module &>(M);
}
void llvm::printMIR(raw_ostream &OS, const MachineFunction &MF) {
MIRPrinter Printer(OS);
Printer.print(MF);
}