[WinEH] Make FuncletLayout more robust against catchret

Catchret transfers control from a catch funclet to an earlier funclet.
However, it is not completely clear which funclet the catchret target is
part of.  Make this clear by stapling the catchret target's funclet
membership onto the CATCHRET SDAG node.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249052 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
David Majnemer 2015-10-01 18:44:59 +00:00
parent 40fed821f0
commit 68754da26d
13 changed files with 249 additions and 50 deletions

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@ -161,6 +161,8 @@ struct WinEHTryBlockMapEntry {
struct WinEHFuncInfo {
DenseMap<const Instruction *, int> EHPadStateMap;
DenseMap<const CatchReturnInst *, const BasicBlock *>
CatchRetSuccessorColorMap;
DenseMap<MCSymbol *, std::pair<int, MCSymbol *>> InvokeToStateMap;
SmallVector<WinEHUnwindMapEntry, 4> UnwindMap;
SmallVector<WinEHTryBlockMapEntry, 4> TryBlockMap;
@ -191,5 +193,8 @@ void calculateWinCXXEHStateNumbers(const Function *ParentFn,
void calculateSEHStateNumbers(const Function *ParentFn,
WinEHFuncInfo &FuncInfo);
void calculateCatchReturnSuccessorColors(const Function *Fn,
WinEHFuncInfo &FuncInfo);
}
#endif // LLVM_CODEGEN_WINEHFUNCINFO_H

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@ -54,10 +54,11 @@ class TargetInstrInfo : public MCInstrInfo {
TargetInstrInfo(const TargetInstrInfo &) = delete;
void operator=(const TargetInstrInfo &) = delete;
public:
TargetInstrInfo(unsigned CFSetupOpcode = ~0u, unsigned CFDestroyOpcode = ~0u)
: CallFrameSetupOpcode(CFSetupOpcode),
CallFrameDestroyOpcode(CFDestroyOpcode) {
}
TargetInstrInfo(unsigned CFSetupOpcode = ~0u, unsigned CFDestroyOpcode = ~0u,
unsigned CatchRetOpcode = ~0u)
: CallFrameSetupOpcode(CFSetupOpcode),
CallFrameDestroyOpcode(CFDestroyOpcode),
CatchRetOpcode(CatchRetOpcode) {}
virtual ~TargetInstrInfo();
@ -146,6 +147,8 @@ public:
unsigned getCallFrameSetupOpcode() const { return CallFrameSetupOpcode; }
unsigned getCallFrameDestroyOpcode() const { return CallFrameDestroyOpcode; }
unsigned getCatchReturnOpcode() const { return CatchRetOpcode; }
/// Returns the actual stack pointer adjustment made by an instruction
/// as part of a call sequence. By default, only call frame setup/destroy
/// instructions adjust the stack, but targets may want to override this
@ -1398,6 +1401,7 @@ public:
private:
unsigned CallFrameSetupOpcode, CallFrameDestroyOpcode;
unsigned CatchRetOpcode;
};
/// \brief Provide DenseMapInfo for TargetInstrInfo::RegSubRegPair.

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@ -186,6 +186,10 @@ def SDTBrind : SDTypeProfile<0, 1, [ // brind
SDTCisPtrTy<0>
]>;
def SDTCatchret : SDTypeProfile<0, 2, [ // catchret
SDTCisVT<0, OtherVT>, SDTCisVT<1, OtherVT>
]>;
def SDTNone : SDTypeProfile<0, 0, []>; // ret, trap
def SDTLoad : SDTypeProfile<1, 1, [ // load
@ -451,7 +455,7 @@ def brcc : SDNode<"ISD::BR_CC" , SDTBrCC, [SDNPHasChain]>;
def brcond : SDNode<"ISD::BRCOND" , SDTBrcond, [SDNPHasChain]>;
def brind : SDNode<"ISD::BRIND" , SDTBrind, [SDNPHasChain]>;
def br : SDNode<"ISD::BR" , SDTBr, [SDNPHasChain]>;
def catchret : SDNode<"ISD::CATCHRET" , SDTBr, [SDNPHasChain]>;
def catchret : SDNode<"ISD::CATCHRET" , SDTCatchret, [SDNPHasChain]>;
def cleanupret : SDNode<"ISD::CLEANUPRET" , SDTNone, [SDNPHasChain]>;
def trap : SDNode<"ISD::TRAP" , SDTNone,

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@ -16,6 +16,8 @@
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;
#define DEBUG_TYPE "funclet-layout"
@ -36,8 +38,21 @@ static void
collectFuncletMembers(DenseMap<MachineBasicBlock *, int> &FuncletMembership,
int Funclet, MachineBasicBlock *MBB) {
// Don't revisit blocks.
if (FuncletMembership.count(MBB) > 0)
if (FuncletMembership.count(MBB) > 0) {
// FIXME: This is a hack, we need to assert this unconditionally.
bool IsProbablyUnreachableBlock =
MBB->empty() ||
(MBB->succ_empty() && !MBB->getFirstTerminator()->isReturn() &&
MBB->size() == 1);
if (!IsProbablyUnreachableBlock) {
if (FuncletMembership[MBB] != Funclet) {
assert(false && "MBB is part of two funclets!");
report_fatal_error("MBB is part of two funclets!");
}
}
return;
}
// Add this MBB to our funclet.
FuncletMembership[MBB] = Funclet;
@ -71,18 +86,36 @@ bool FuncletLayout::runOnMachineFunction(MachineFunction &F) {
if (!F.getMMI().hasEHFunclets())
return false;
const TargetInstrInfo *TII = F.getSubtarget().getInstrInfo();
SmallVector<MachineBasicBlock *, 16> FuncletBlocks;
for (MachineBasicBlock &MBB : F)
SmallVector<std::pair<MachineBasicBlock *, int>, 16> CatchRetSuccessors;
for (MachineBasicBlock &MBB : F) {
if (MBB.isEHFuncletEntry())
FuncletBlocks.push_back(&MBB);
MachineBasicBlock::iterator MBBI = MBB.getFirstTerminator();
if (MBBI->getOpcode() != TII->getCatchReturnOpcode())
continue;
MachineBasicBlock *Successor = MBBI->getOperand(0).getMBB();
MachineBasicBlock *SuccessorColor = MBBI->getOperand(1).getMBB();
CatchRetSuccessors.push_back({Successor, SuccessorColor->getNumber()});
}
// We don't have anything to do if there aren't any EH pads.
if (FuncletBlocks.empty())
return false;
DenseMap<MachineBasicBlock *, int> FuncletMembership;
// Identify all the basic blocks reachable from the function entry.
collectFuncletMembers(FuncletMembership, F.front().getNumber(), F.begin());
// Next, identify all the blocks inside the funclets.
for (MachineBasicBlock *MBB : FuncletBlocks)
collectFuncletMembers(FuncletMembership, MBB->getNumber(), MBB);
// Finally, identify all the targets of a catchret.
for (std::pair<MachineBasicBlock *, int> CatchRetPair : CatchRetSuccessors)
collectFuncletMembers(FuncletMembership, CatchRetPair.second,
CatchRetPair.first);
F.sort([&](MachineBasicBlock &x, MachineBasicBlock &y) {
return FuncletMembership[&x] < FuncletMembership[&y];

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@ -290,9 +290,11 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
const Function *WinEHParentFn = MMI.getWinEHParent(&fn);
if (Personality == EHPersonality::MSVC_CXX)
calculateWinCXXEHStateNumbers(WinEHParentFn, EHInfo);
else
else if (isAsynchronousEHPersonality(Personality))
calculateSEHStateNumbers(WinEHParentFn, EHInfo);
calculateCatchReturnSuccessorColors(WinEHParentFn, EHInfo);
// Map all BB references in the WinEH data to MBBs.
for (WinEHTryBlockMapEntry &TBME : EHInfo.TryBlockMap) {
for (WinEHHandlerType &H : TBME.HandlerArray) {

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@ -1168,9 +1168,21 @@ void SelectionDAGBuilder::visitCatchRet(const CatchReturnInst &I) {
MachineBasicBlock *TargetMBB = FuncInfo.MBBMap[I.getSuccessor()];
FuncInfo.MBB->addSuccessor(TargetMBB);
// Figure out the funclet membership for the catchret's successor.
// This will be used by the FuncletLayout pass to determine how to order the
// BB's.
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
WinEHFuncInfo &EHInfo =
MMI.getWinEHFuncInfo(DAG.getMachineFunction().getFunction());
const BasicBlock *SuccessorColor = EHInfo.CatchRetSuccessorColorMap[&I];
assert(SuccessorColor && "No parent funclet for catchret!");
MachineBasicBlock *SuccessorColorMBB = FuncInfo.MBBMap[SuccessorColor];
assert(SuccessorColorMBB && "No MBB for SuccessorColor!");
// Create the terminator node.
SDValue Ret = DAG.getNode(ISD::CATCHRET, getCurSDLoc(), MVT::Other,
getControlRoot(), DAG.getBasicBlock(TargetMBB));
getControlRoot(), DAG.getBasicBlock(TargetMBB),
DAG.getBasicBlock(SuccessorColorMBB));
DAG.setRoot(Ret);
}

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@ -399,6 +399,29 @@ FunctionPass *llvm::createWinEHPass(const TargetMachine *TM) {
return new WinEHPrepare(TM);
}
static bool
findExceptionalConstructs(Function &Fn,
SmallVectorImpl<LandingPadInst *> &LPads,
SmallVectorImpl<ResumeInst *> &Resumes,
SmallVectorImpl<BasicBlock *> &EntryBlocks) {
bool ForExplicitEH = false;
for (BasicBlock &BB : Fn) {
Instruction *First = BB.getFirstNonPHI();
if (auto *LP = dyn_cast<LandingPadInst>(First)) {
LPads.push_back(LP);
} else if (First->isEHPad()) {
if (!ForExplicitEH)
EntryBlocks.push_back(&Fn.getEntryBlock());
if (!isa<CatchEndPadInst>(First) && !isa<CleanupEndPadInst>(First))
EntryBlocks.push_back(&BB);
ForExplicitEH = true;
}
if (auto *Resume = dyn_cast<ResumeInst>(BB.getTerminator()))
Resumes.push_back(Resume);
}
return ForExplicitEH;
}
bool WinEHPrepare::runOnFunction(Function &Fn) {
if (!Fn.hasPersonalityFn())
return false;
@ -417,21 +440,8 @@ bool WinEHPrepare::runOnFunction(Function &Fn) {
SmallVector<LandingPadInst *, 4> LPads;
SmallVector<ResumeInst *, 4> Resumes;
SmallVector<BasicBlock *, 4> EntryBlocks;
bool ForExplicitEH = false;
for (BasicBlock &BB : Fn) {
Instruction *First = BB.getFirstNonPHI();
if (auto *LP = dyn_cast<LandingPadInst>(First)) {
LPads.push_back(LP);
} else if (First->isEHPad()) {
if (!ForExplicitEH)
EntryBlocks.push_back(&Fn.getEntryBlock());
if (!isa<CatchEndPadInst>(First) && !isa<CleanupEndPadInst>(First))
EntryBlocks.push_back(&BB);
ForExplicitEH = true;
}
if (auto *Resume = dyn_cast<ResumeInst>(BB.getTerminator()))
Resumes.push_back(Resume);
}
bool ForExplicitEH =
findExceptionalConstructs(Fn, LPads, Resumes, EntryBlocks);
if (ForExplicitEH)
return prepareExplicitEH(Fn, EntryBlocks);
@ -2878,8 +2888,11 @@ void WinEHPrepare::replaceTerminatePadWithCleanup(Function &F) {
}
}
void WinEHPrepare::colorFunclets(Function &F,
SmallVectorImpl<BasicBlock *> &EntryBlocks) {
static void
colorFunclets(Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks,
std::map<BasicBlock *, std::set<BasicBlock *>> &BlockColors,
std::map<BasicBlock *, std::set<BasicBlock *>> &FuncletBlocks,
std::map<BasicBlock *, std::set<BasicBlock *>> &FuncletChildren) {
SmallVector<std::pair<BasicBlock *, BasicBlock *>, 16> Worklist;
BasicBlock *EntryBlock = &F.getEntryBlock();
@ -2976,6 +2989,56 @@ void WinEHPrepare::colorFunclets(Function &F,
}
}
void WinEHPrepare::colorFunclets(Function &F,
SmallVectorImpl<BasicBlock *> &EntryBlocks) {
::colorFunclets(F, EntryBlocks, BlockColors, FuncletBlocks, FuncletChildren);
}
void llvm::calculateCatchReturnSuccessorColors(const Function *Fn,
WinEHFuncInfo &FuncInfo) {
SmallVector<LandingPadInst *, 4> LPads;
SmallVector<ResumeInst *, 4> Resumes;
SmallVector<BasicBlock *, 4> EntryBlocks;
// colorFunclets needs the set of EntryBlocks, get them using
// findExceptionalConstructs.
bool ForExplicitEH = findExceptionalConstructs(const_cast<Function &>(*Fn),
LPads, Resumes, EntryBlocks);
if (!ForExplicitEH)
return;
std::map<BasicBlock *, std::set<BasicBlock *>> BlockColors;
std::map<BasicBlock *, std::set<BasicBlock *>> FuncletBlocks;
std::map<BasicBlock *, std::set<BasicBlock *>> FuncletChildren;
// Figure out which basic blocks belong to which funclets.
colorFunclets(const_cast<Function &>(*Fn), EntryBlocks, BlockColors,
FuncletBlocks, FuncletChildren);
// We need to find the catchret successors. To do this, we must first find
// all the catchpad funclets.
for (auto &Funclet : FuncletBlocks) {
// Figure out what kind of funclet we are looking at; We only care about
// catchpads.
BasicBlock *FuncletPadBB = Funclet.first;
Instruction *FirstNonPHI = FuncletPadBB->getFirstNonPHI();
auto *CatchPad = dyn_cast<CatchPadInst>(FirstNonPHI);
if (!CatchPad)
continue;
// The users of a catchpad are always catchrets.
for (User *Exit : CatchPad->users()) {
auto *CatchReturn = cast<CatchReturnInst>(Exit);
BasicBlock *CatchRetSuccessor = CatchReturn->getSuccessor();
std::set<BasicBlock *> &SuccessorColors = BlockColors[CatchRetSuccessor];
assert(SuccessorColors.size() == 1 && "Expected BB to be monochrome!");
BasicBlock *Color = *SuccessorColors.begin();
if (auto *CPI = dyn_cast<CatchPadInst>(Color->getFirstNonPHI()))
Color = CPI->getNormalDest();
// Record the catchret successor's funclet membership.
FuncInfo.CatchRetSuccessorColorMap[CatchReturn] = Color;
}
}
}
void WinEHPrepare::demotePHIsOnFunclets(Function &F) {
// Strip PHI nodes off of EH pads.
SmallVector<PHINode *, 16> PHINodes;

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@ -1120,24 +1120,12 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
BuildMI(*RestoreMBB, RestoreMBBI, DL, TII.get(X86::JMP_4))
.addMBB(TargetMBB);
}
// Replace CATCHRET with the appropriate RET.
unsigned RetOp = STI.is64Bit() ? X86::RETQ : X86::RETL;
MachineBasicBlock::iterator NewExit =
BuildMI(MBB, MBBI, DL, TII.get(RetOp)).addReg(ReturnReg);
MBBI->eraseFromParent();
MBBI = NewExit;
} else if (MBBI->getOpcode() == X86::CLEANUPRET) {
NumBytes = MFI->getMaxCallFrameSize();
assert(hasFP(MF) && "EH funclets without FP not yet implemented");
BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::POP64r : X86::POP32r),
MachineFramePtr)
.setMIFlag(MachineInstr::FrameDestroy);
// Replace CLEANUPRET with the appropriate RET.
unsigned RetOp = STI.is64Bit() ? X86::RETQ : X86::RETL;
MachineBasicBlock::iterator NewExit =
BuildMI(MBB, MBBI, DL, TII.get(RetOp));
MBBI->eraseFromParent();
MBBI = NewExit;
} else if (hasFP(MF)) {
// Calculate required stack adjustment.
uint64_t FrameSize = StackSize - SlotSize;

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@ -152,10 +152,10 @@ def EH_RETURN64 : I<0xC3, RawFrm, (outs), (ins GR64:$addr),
}
let isTerminator = 1, isBarrier = 1, hasCtrlDep = 1, isCodeGenOnly = 1, isReturn = 1 in {
def CATCHRET : I<0, Pseudo, (outs), (ins brtarget32:$dst),
"# CATCHRET",
[(catchret bb:$dst)]>;
let isTerminator = 1, hasSideEffects = 1, isBarrier = 1, hasCtrlDep = 1, isCodeGenOnly = 1, isReturn = 1 in {
def CATCHRET : I<0, Pseudo, (outs), (ins brtarget32:$dst, brtarget32:$from),
"# CATCHRET",
[(catchret bb:$dst, bb:$from)]>;
def CLEANUPRET : I<0, Pseudo, (outs), (ins), "# CLEANUPRET", [(cleanupret)]>;
}

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@ -101,9 +101,11 @@ struct X86MemoryFoldTableEntry {
void X86InstrInfo::anchor() {}
X86InstrInfo::X86InstrInfo(X86Subtarget &STI)
: X86GenInstrInfo(
(STI.isTarget64BitLP64() ? X86::ADJCALLSTACKDOWN64 : X86::ADJCALLSTACKDOWN32),
(STI.isTarget64BitLP64() ? X86::ADJCALLSTACKUP64 : X86::ADJCALLSTACKUP32)),
: X86GenInstrInfo((STI.isTarget64BitLP64() ? X86::ADJCALLSTACKDOWN64
: X86::ADJCALLSTACKDOWN32),
(STI.isTarget64BitLP64() ? X86::ADJCALLSTACKUP64
: X86::ADJCALLSTACKUP32),
X86::CATCHRET),
Subtarget(STI), RI(STI.getTargetTriple()) {
static const X86MemoryFoldTableEntry MemoryFoldTable2Addr[] = {

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@ -531,6 +531,23 @@ ReSimplify:
break;
}
case X86::CLEANUPRET: {
// Replace CATCHRET with the appropriate RET.
OutMI = MCInst();
OutMI.setOpcode(getRetOpcode(AsmPrinter.getSubtarget()));
break;
}
case X86::CATCHRET: {
// Replace CATCHRET with the appropriate RET.
const X86Subtarget &Subtarget = AsmPrinter.getSubtarget();
unsigned ReturnReg = Subtarget.is64Bit() ? X86::RAX : X86::EAX;
OutMI = MCInst();
OutMI.setOpcode(getRetOpcode(Subtarget));
OutMI.addOperand(MCOperand::createReg(ReturnReg));
break;
}
// TAILJMPd, TAILJMPd64 - Lower to the correct jump instructions.
case X86::TAILJMPr:
case X86::TAILJMPd:
@ -1076,6 +1093,18 @@ void X86AsmPrinter::EmitInstruction(const MachineInstr *MI) {
X86ATTInstPrinter::getRegisterName(Reg));
break;
}
case X86::CLEANUPRET: {
// Lower these as normal, but add some comments.
OutStreamer->AddComment("CLEANUPRET");
break;
}
case X86::CATCHRET: {
// Lower these as normal, but add some comments.
OutStreamer->AddComment("CATCHRET");
break;
}
case X86::TAILJMPr:
case X86::TAILJMPm:
case X86::TAILJMPd:

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@ -3,7 +3,9 @@
target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-windows-msvc"
define void @f(i1 %B) personality i32 (...)* @__CxxFrameHandler3 {
%eh.ThrowInfo = type { i32, i32, i32, i32 }
define void @test1(i1 %B) personality i32 (...)* @__CxxFrameHandler3 {
entry:
invoke void @g()
to label %unreachable unwind label %catch.dispatch
@ -28,7 +30,7 @@ unreachable:
unreachable
}
; CHECK-LABEL: f:
; CHECK-LABEL: test1:
; The entry funclet contains %entry and %try.cont
; CHECK: # %entry
@ -42,4 +44,59 @@ unreachable:
declare void @g()
define i32 @test2(i1 %B) personality i32 (...)* @__CxxFrameHandler3 {
entry:
invoke void @_CxxThrowException(i8* null, %eh.ThrowInfo* null) #1
to label %unreachable unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchpad [i8* null, i32 64, i8* null]
to label %catch unwind label %catchendblock
catch: ; preds = %catch.dispatch
invoke void @_CxxThrowException(i8* null, %eh.ThrowInfo* null) #1
to label %unreachable unwind label %catch.dispatch.1
catch.dispatch.1: ; preds = %catch
%1 = catchpad [i8* null, i32 64, i8* null]
to label %catch.3 unwind label %catchendblock.2
catch.3: ; preds = %catch.dispatch.1
catchret %1 to label %try.cont
try.cont: ; preds = %catch.3
catchret %0 to label %try.cont.5
try.cont.5: ; preds = %try.cont
ret i32 0
catchendblock.2: ; preds = %catch.dispatch.1
catchendpad unwind label %catchendblock
catchendblock: ; preds = %catchendblock.2, %catch.dispatch
catchendpad unwind to caller
unreachable: ; preds = %catch, %entry
unreachable
}
; CHECK-LABEL: test2:
; The entry funclet contains %entry and %try.cont.5
; CHECK: # %entry
; CHECK: # %try.cont.5
; CHECK: retq
; The inner catch funclet contains %catch.3
; CHECK: # %catch.3
; CHECK: retq
; The outer catch funclet contains %catch and %try.cont
; CHECK: # %catch
; CHECK: # %try.cont
; CHECK: retq
declare void @_CxxThrowException(i8*, %eh.ThrowInfo*)
declare i32 @__CxxFrameHandler3(...)

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@ -430,7 +430,7 @@ void InstrInfoEmitter::run(raw_ostream &OS) {
OS << "namespace llvm {\n";
OS << "struct " << ClassName << " : public TargetInstrInfo {\n"
<< " explicit " << ClassName
<< "(int CFSetupOpcode = -1, int CFDestroyOpcode = -1);\n"
<< "(int CFSetupOpcode = -1, int CFDestroyOpcode = -1, int CatchRetOpcode = -1);\n"
<< " ~" << ClassName << "() override {}\n"
<< "};\n";
OS << "} // end llvm namespace \n";
@ -445,8 +445,8 @@ void InstrInfoEmitter::run(raw_ostream &OS) {
OS << "extern const unsigned " << TargetName << "InstrNameIndices[];\n";
OS << "extern const char " << TargetName << "InstrNameData[];\n";
OS << ClassName << "::" << ClassName
<< "(int CFSetupOpcode, int CFDestroyOpcode)\n"
<< " : TargetInstrInfo(CFSetupOpcode, CFDestroyOpcode) {\n"
<< "(int CFSetupOpcode, int CFDestroyOpcode, int CatchRetOpcode)\n"
<< " : TargetInstrInfo(CFSetupOpcode, CFDestroyOpcode, CatchRetOpcode) {\n"
<< " InitMCInstrInfo(" << TargetName << "Insts, " << TargetName
<< "InstrNameIndices, " << TargetName << "InstrNameData, "
<< NumberedInstructions.size() << ");\n}\n";