//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "sjljehprepare"
#include "llvm/CodeGen/Passes.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetLowering.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Local.h"
#include <set>
using namespace llvm;
+#define DEBUG_TYPE "sjljehprepare"
+
STATISTIC(NumInvokes, "Number of invokes replaced");
STATISTIC(NumSpilled, "Number of registers live across unwind edges");
namespace {
- class SjLjEHPrepare : public FunctionPass {
- const TargetMachine *TM;
- Type *FunctionContextTy;
- Constant *RegisterFn;
- Constant *UnregisterFn;
- Constant *BuiltinSetjmpFn;
- Constant *FrameAddrFn;
- Constant *StackAddrFn;
- Constant *StackRestoreFn;
- Constant *LSDAAddrFn;
- Value *PersonalityFn;
- Constant *CallSiteFn;
- Constant *FuncCtxFn;
- AllocaInst *FuncCtx;
- public:
- static char ID; // Pass identification, replacement for typeid
- explicit SjLjEHPrepare(const TargetMachine *TM)
- : FunctionPass(ID), TM(TM) { }
- bool doInitialization(Module &M);
- bool runOnFunction(Function &F);
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {}
- const char *getPassName() const {
- return "SJLJ Exception Handling preparation";
- }
+class SjLjEHPrepare : public FunctionPass {
+ const TargetMachine *TM;
+ Type *doubleUnderDataTy;
+ Type *doubleUnderJBufTy;
+ Type *FunctionContextTy;
+ Constant *RegisterFn;
+ Constant *UnregisterFn;
+ Constant *BuiltinSetjmpFn;
+ Constant *FrameAddrFn;
+ Constant *StackAddrFn;
+ Constant *StackRestoreFn;
+ Constant *LSDAAddrFn;
+ Value *PersonalityFn;
+ Constant *CallSiteFn;
+ Constant *FuncCtxFn;
+ AllocaInst *FuncCtx;
+
+public:
+ static char ID; // Pass identification, replacement for typeid
+ explicit SjLjEHPrepare(const TargetMachine *TM) : FunctionPass(ID), TM(TM) {}
+ bool doInitialization(Module &M) override;
+ bool runOnFunction(Function &F) override;
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override {}
+ const char *getPassName() const override {
+ return "SJLJ Exception Handling preparation";
+ }
- private:
- bool setupEntryBlockAndCallSites(Function &F);
- void substituteLPadValues(LandingPadInst *LPI, Value *ExnVal,
- Value *SelVal);
- Value *setupFunctionContext(Function &F, ArrayRef<LandingPadInst*> LPads);
- void lowerIncomingArguments(Function &F);
- void lowerAcrossUnwindEdges(Function &F, ArrayRef<InvokeInst*> Invokes);
- void insertCallSiteStore(Instruction *I, int Number);
- };
+private:
+ bool setupEntryBlockAndCallSites(Function &F);
+ void substituteLPadValues(LandingPadInst *LPI, Value *ExnVal, Value *SelVal);
+ Value *setupFunctionContext(Function &F, ArrayRef<LandingPadInst *> LPads);
+ void lowerIncomingArguments(Function &F);
+ void lowerAcrossUnwindEdges(Function &F, ArrayRef<InvokeInst *> Invokes);
+ void insertCallSiteStore(Instruction *I, int Number);
+};
} // end anonymous namespace
char SjLjEHPrepare::ID = 0;
// builtin_setjmp uses a five word jbuf
Type *VoidPtrTy = Type::getInt8PtrTy(M.getContext());
Type *Int32Ty = Type::getInt32Ty(M.getContext());
- FunctionContextTy =
- StructType::get(VoidPtrTy, // __prev
- Int32Ty, // call_site
- ArrayType::get(Int32Ty, 4), // __data
- VoidPtrTy, // __personality
- VoidPtrTy, // __lsda
- ArrayType::get(VoidPtrTy, 5), // __jbuf
- NULL);
- RegisterFn = M.getOrInsertFunction("_Unwind_SjLj_Register",
- Type::getVoidTy(M.getContext()),
- PointerType::getUnqual(FunctionContextTy),
- (Type *)0);
- UnregisterFn =
- M.getOrInsertFunction("_Unwind_SjLj_Unregister",
- Type::getVoidTy(M.getContext()),
- PointerType::getUnqual(FunctionContextTy),
- (Type *)0);
+ doubleUnderDataTy = ArrayType::get(Int32Ty, 4);
+ doubleUnderJBufTy = ArrayType::get(VoidPtrTy, 5);
+ FunctionContextTy = StructType::get(VoidPtrTy, // __prev
+ Int32Ty, // call_site
+ doubleUnderDataTy, // __data
+ VoidPtrTy, // __personality
+ VoidPtrTy, // __lsda
+ doubleUnderJBufTy, // __jbuf
+ nullptr);
+ RegisterFn = M.getOrInsertFunction(
+ "_Unwind_SjLj_Register", Type::getVoidTy(M.getContext()),
+ PointerType::getUnqual(FunctionContextTy), (Type *)nullptr);
+ UnregisterFn = M.getOrInsertFunction(
+ "_Unwind_SjLj_Unregister", Type::getVoidTy(M.getContext()),
+ PointerType::getUnqual(FunctionContextTy), (Type *)nullptr);
FrameAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::frameaddress);
StackAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::stacksave);
StackRestoreFn = Intrinsic::getDeclaration(&M, Intrinsic::stackrestore);
LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda);
CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite);
FuncCtxFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_functioncontext);
- PersonalityFn = 0;
+ PersonalityFn = nullptr;
return true;
}
Value *Zero = ConstantInt::get(Int32Ty, 0);
Value *One = ConstantInt::get(Int32Ty, 1);
Value *Idxs[2] = { Zero, One };
- Value *CallSite = Builder.CreateGEP(FuncCtx, Idxs, "call_site");
+ Value *CallSite =
+ Builder.CreateGEP(FunctionContextTy, FuncCtx, Idxs, "call_site");
// Insert a store of the call-site number
- ConstantInt *CallSiteNoC = ConstantInt::get(Type::getInt32Ty(I->getContext()),
- Number);
- Builder.CreateStore(CallSiteNoC, CallSite, true/*volatile*/);
+ ConstantInt *CallSiteNoC =
+ ConstantInt::get(Type::getInt32Ty(I->getContext()), Number);
+ Builder.CreateStore(CallSiteNoC, CallSite, true /*volatile*/);
}
/// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until
/// we reach blocks we've already seen.
static void MarkBlocksLiveIn(BasicBlock *BB,
- SmallPtrSet<BasicBlock*, 64> &LiveBBs) {
- if (!LiveBBs.insert(BB)) return; // already been here.
+ SmallPtrSetImpl<BasicBlock *> &LiveBBs) {
+ if (!LiveBBs.insert(BB).second)
+ return; // already been here.
for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
MarkBlocksLiveIn(*PI, LiveBBs);
/// instruction with those returned by the personality function.
void SjLjEHPrepare::substituteLPadValues(LandingPadInst *LPI, Value *ExnVal,
Value *SelVal) {
- SmallVector<Value*, 8> UseWorkList(LPI->use_begin(), LPI->use_end());
+ SmallVector<Value *, 8> UseWorkList(LPI->user_begin(), LPI->user_end());
while (!UseWorkList.empty()) {
Value *Val = UseWorkList.pop_back_val();
ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(Val);
- if (!EVI) continue;
- if (EVI->getNumIndices() != 1) continue;
+ if (!EVI)
+ continue;
+ if (EVI->getNumIndices() != 1)
+ continue;
if (*EVI->idx_begin() == 0)
EVI->replaceAllUsesWith(ExnVal);
else if (*EVI->idx_begin() == 1)
EVI->eraseFromParent();
}
- if (LPI->getNumUses() == 0) return;
+ if (LPI->getNumUses() == 0)
+ return;
// There are still some uses of LPI. Construct an aggregate with the exception
// values and replace the LPI with that aggregate.
Type *LPadType = LPI->getType();
Value *LPadVal = UndefValue::get(LPadType);
- IRBuilder<>
- Builder(llvm::next(BasicBlock::iterator(cast<Instruction>(SelVal))));
+ IRBuilder<> Builder(
+ std::next(BasicBlock::iterator(cast<Instruction>(SelVal))));
LPadVal = Builder.CreateInsertValue(LPadVal, ExnVal, 0, "lpad.val");
LPadVal = Builder.CreateInsertValue(LPadVal, SelVal, 1, "lpad.val");
/// setupFunctionContext - Allocate the function context on the stack and fill
/// it with all of the data that we know at this point.
-Value *SjLjEHPrepare::
-setupFunctionContext(Function &F, ArrayRef<LandingPadInst*> LPads) {
+Value *SjLjEHPrepare::setupFunctionContext(Function &F,
+ ArrayRef<LandingPadInst *> LPads) {
BasicBlock *EntryBB = F.begin();
// Create an alloca for the incoming jump buffer ptr and the new jump buffer
// that needs to be restored on all exits from the function. This is an alloca
// because the value needs to be added to the global context list.
- const TargetLowering *TLI = TM->getTargetLowering();
+ const TargetLowering *TLI = TM->getSubtargetImpl(F)->getTargetLowering();
unsigned Align =
- TLI->getDataLayout()->getPrefTypeAlignment(FunctionContextTy);
- FuncCtx =
- new AllocaInst(FunctionContextTy, 0, Align, "fn_context", EntryBB->begin());
+ TLI->getDataLayout()->getPrefTypeAlignment(FunctionContextTy);
+ FuncCtx = new AllocaInst(FunctionContextTy, nullptr, Align, "fn_context",
+ EntryBB->begin());
// Fill in the function context structure.
for (unsigned I = 0, E = LPads.size(); I != E; ++I) {
IRBuilder<> Builder(LPI->getParent()->getFirstInsertionPt());
// Reference the __data field.
- Value *FCData = Builder.CreateConstGEP2_32(FuncCtx, 0, 2, "__data");
+ Value *FCData =
+ Builder.CreateConstGEP2_32(FunctionContextTy, FuncCtx, 0, 2, "__data");
// The exception values come back in context->__data[0].
- Value *ExceptionAddr = Builder.CreateConstGEP2_32(FCData, 0, 0,
- "exception_gep");
+ Value *ExceptionAddr = Builder.CreateConstGEP2_32(doubleUnderDataTy, FCData,
+ 0, 0, "exception_gep");
Value *ExnVal = Builder.CreateLoad(ExceptionAddr, true, "exn_val");
ExnVal = Builder.CreateIntToPtr(ExnVal, Builder.getInt8PtrTy());
- Value *SelectorAddr = Builder.CreateConstGEP2_32(FCData, 0, 1,
- "exn_selector_gep");
+ Value *SelectorAddr = Builder.CreateConstGEP2_32(doubleUnderDataTy, FCData,
+ 0, 1, "exn_selector_gep");
Value *SelVal = Builder.CreateLoad(SelectorAddr, true, "exn_selector_val");
substituteLPadValues(LPI, ExnVal, SelVal);
IRBuilder<> Builder(EntryBB->getTerminator());
if (!PersonalityFn)
PersonalityFn = LPads[0]->getPersonalityFn();
- Value *PersonalityFieldPtr = Builder.CreateConstGEP2_32(FuncCtx, 0, 3,
- "pers_fn_gep");
- Builder.CreateStore(Builder.CreateBitCast(PersonalityFn,
- Builder.getInt8PtrTy()),
- PersonalityFieldPtr, /*isVolatile=*/true);
+ Value *PersonalityFieldPtr = Builder.CreateConstGEP2_32(
+ FunctionContextTy, FuncCtx, 0, 3, "pers_fn_gep");
+ Builder.CreateStore(
+ Builder.CreateBitCast(PersonalityFn, Builder.getInt8PtrTy()),
+ PersonalityFieldPtr, /*isVolatile=*/true);
// LSDA address
Value *LSDA = Builder.CreateCall(LSDAAddrFn, "lsda_addr");
- Value *LSDAFieldPtr = Builder.CreateConstGEP2_32(FuncCtx, 0, 4, "lsda_gep");
+ Value *LSDAFieldPtr =
+ Builder.CreateConstGEP2_32(FunctionContextTy, FuncCtx, 0, 4, "lsda_gep");
Builder.CreateStore(LSDA, LSDAFieldPtr, /*isVolatile=*/true);
return FuncCtx;
isa<ConstantInt>(cast<AllocaInst>(AfterAllocaInsPt)->getArraySize()))
++AfterAllocaInsPt;
- for (Function::arg_iterator
- AI = F.arg_begin(), AE = F.arg_end(); AI != AE; ++AI) {
+ for (Function::arg_iterator AI = F.arg_begin(), AE = F.arg_end(); AI != AE;
+ ++AI) {
Type *Ty = AI->getType();
- // Aggregate types can't be cast, but are legal argument types, so we have
- // to handle them differently. We use an extract/insert pair as a
- // lightweight method to achieve the same goal.
- if (isa<StructType>(Ty) || isa<ArrayType>(Ty) || isa<VectorType>(Ty)) {
- Instruction *EI = ExtractValueInst::Create(AI, 0, "", AfterAllocaInsPt);
- Instruction *NI = InsertValueInst::Create(AI, EI, 0);
- NI->insertAfter(EI);
- AI->replaceAllUsesWith(NI);
-
- // Set the operand of the instructions back to the AllocaInst.
- EI->setOperand(0, AI);
- NI->setOperand(0, AI);
- } else {
- // This is always a no-op cast because we're casting AI to AI->getType()
- // so src and destination types are identical. BitCast is the only
- // possibility.
- CastInst *NC =
- new BitCastInst(AI, AI->getType(), AI->getName() + ".tmp",
- AfterAllocaInsPt);
- AI->replaceAllUsesWith(NC);
-
- // Set the operand of the cast instruction back to the AllocaInst.
- // Normally it's forbidden to replace a CastInst's operand because it
- // could cause the opcode to reflect an illegal conversion. However, we're
- // replacing it here with the same value it was constructed with. We do
- // this because the above replaceAllUsesWith() clobbered the operand, but
- // we want this one to remain.
- NC->setOperand(0, AI);
- }
+ // Use 'select i8 true, %arg, undef' to simulate a 'no-op' instruction.
+ Value *TrueValue = ConstantInt::getTrue(F.getContext());
+ Value *UndefValue = UndefValue::get(Ty);
+ Instruction *SI = SelectInst::Create(TrueValue, AI, UndefValue,
+ AI->getName() + ".tmp",
+ AfterAllocaInsPt);
+ AI->replaceAllUsesWith(SI);
+
+ // Reset the operand, because it was clobbered by the RAUW above.
+ SI->setOperand(1, AI);
}
}
/// lowerAcrossUnwindEdges - Find all variables which are alive across an unwind
/// edge and spill them.
void SjLjEHPrepare::lowerAcrossUnwindEdges(Function &F,
- ArrayRef<InvokeInst*> Invokes) {
+ ArrayRef<InvokeInst *> Invokes) {
// Finally, scan the code looking for instructions with bad live ranges.
- for (Function::iterator
- BB = F.begin(), BBE = F.end(); BB != BBE; ++BB) {
- for (BasicBlock::iterator
- II = BB->begin(), IIE = BB->end(); II != IIE; ++II) {
+ for (Function::iterator BB = F.begin(), BBE = F.end(); BB != BBE; ++BB) {
+ for (BasicBlock::iterator II = BB->begin(), IIE = BB->end(); II != IIE;
+ ++II) {
// Ignore obvious cases we don't have to handle. In particular, most
// instructions either have no uses or only have a single use inside the
// current block. Ignore them quickly.
Instruction *Inst = II;
- if (Inst->use_empty()) continue;
+ if (Inst->use_empty())
+ continue;
if (Inst->hasOneUse() &&
- cast<Instruction>(Inst->use_back())->getParent() == BB &&
- !isa<PHINode>(Inst->use_back())) continue;
+ cast<Instruction>(Inst->user_back())->getParent() == BB &&
+ !isa<PHINode>(Inst->user_back()))
+ continue;
// If this is an alloca in the entry block, it's not a real register
// value.
continue;
// Avoid iterator invalidation by copying users to a temporary vector.
- SmallVector<Instruction*, 16> Users;
- for (Value::use_iterator
- UI = Inst->use_begin(), E = Inst->use_end(); UI != E; ++UI) {
- Instruction *User = cast<Instruction>(*UI);
- if (User->getParent() != BB || isa<PHINode>(User))
- Users.push_back(User);
+ SmallVector<Instruction *, 16> Users;
+ for (User *U : Inst->users()) {
+ Instruction *UI = cast<Instruction>(U);
+ if (UI->getParent() != BB || isa<PHINode>(UI))
+ Users.push_back(UI);
}
// Find all of the blocks that this value is live in.
- SmallPtrSet<BasicBlock*, 64> LiveBBs;
+ SmallPtrSet<BasicBlock *, 64> LiveBBs;
LiveBBs.insert(Inst->getParent());
while (!Users.empty()) {
Instruction *U = Users.back();
BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest();
if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) {
DEBUG(dbgs() << "SJLJ Spill: " << *Inst << " around "
- << UnwindBlock->getName() << "\n");
+ << UnwindBlock->getName() << "\n");
NeedsSpill = true;
break;
}
LandingPadInst *LPI = UnwindBlock->getLandingPadInst();
// Place PHIs into a set to avoid invalidating the iterator.
- SmallPtrSet<PHINode*, 8> PHIsToDemote;
- for (BasicBlock::iterator
- PN = UnwindBlock->begin(); isa<PHINode>(PN); ++PN)
+ SmallPtrSet<PHINode *, 8> PHIsToDemote;
+ for (BasicBlock::iterator PN = UnwindBlock->begin(); isa<PHINode>(PN); ++PN)
PHIsToDemote.insert(cast<PHINode>(PN));
- if (PHIsToDemote.empty()) continue;
+ if (PHIsToDemote.empty())
+ continue;
// Demote the PHIs to the stack.
- for (SmallPtrSet<PHINode*, 8>::iterator
- I = PHIsToDemote.begin(), E = PHIsToDemote.end(); I != E; ++I)
- DemotePHIToStack(*I);
+ for (PHINode *PN : PHIsToDemote)
+ DemotePHIToStack(PN);
// Move the landingpad instruction back to the top of the landing pad block.
LPI->moveBefore(UnwindBlock->begin());
/// the function context and marking the call sites with the appropriate
/// values. These values are used by the DWARF EH emitter.
bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) {
- SmallVector<ReturnInst*, 16> Returns;
- SmallVector<InvokeInst*, 16> Invokes;
- SmallSetVector<LandingPadInst*, 16> LPads;
+ SmallVector<ReturnInst *, 16> Returns;
+ SmallVector<InvokeInst *, 16> Invokes;
+ SmallSetVector<LandingPadInst *, 16> LPads;
// Look through the terminators of the basic blocks to find invokes.
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
Returns.push_back(RI);
}
- if (Invokes.empty()) return false;
+ if (Invokes.empty())
+ return false;
NumInvokes += Invokes.size();
lowerAcrossUnwindEdges(F, Invokes);
Value *FuncCtx =
- setupFunctionContext(F, makeArrayRef(LPads.begin(), LPads.end()));
+ setupFunctionContext(F, makeArrayRef(LPads.begin(), LPads.end()));
BasicBlock *EntryBB = F.begin();
IRBuilder<> Builder(EntryBB->getTerminator());
// Get a reference to the jump buffer.
- Value *JBufPtr = Builder.CreateConstGEP2_32(FuncCtx, 0, 5, "jbuf_gep");
+ Value *JBufPtr =
+ Builder.CreateConstGEP2_32(FunctionContextTy, FuncCtx, 0, 5, "jbuf_gep");
// Save the frame pointer.
- Value *FramePtr = Builder.CreateConstGEP2_32(JBufPtr, 0, 0, "jbuf_fp_gep");
+ Value *FramePtr = Builder.CreateConstGEP2_32(doubleUnderJBufTy, JBufPtr, 0, 0,
+ "jbuf_fp_gep");
Value *Val = Builder.CreateCall(FrameAddrFn, Builder.getInt32(0), "fp");
Builder.CreateStore(Val, FramePtr, /*isVolatile=*/true);
// Save the stack pointer.
- Value *StackPtr = Builder.CreateConstGEP2_32(JBufPtr, 0, 2, "jbuf_sp_gep");
+ Value *StackPtr = Builder.CreateConstGEP2_32(doubleUnderJBufTy, JBufPtr, 0, 2,
+ "jbuf_sp_gep");
Val = Builder.CreateCall(StackAddrFn, "sp");
Builder.CreateStore(Val, StackPtr, /*isVolatile=*/true);
insertCallSiteStore(Invokes[I], I + 1);
ConstantInt *CallSiteNum =
- ConstantInt::get(Type::getInt32Ty(F.getContext()), I + 1);
+ ConstantInt::get(Type::getInt32Ty(F.getContext()), I + 1);
// Record the call site value for the back end so it stays associated with
// the invoke.
}
// Register the function context and make sure it's known to not throw
- CallInst *Register = CallInst::Create(RegisterFn, FuncCtx, "",
- EntryBB->getTerminator());
+ CallInst *Register =
+ CallInst::Create(RegisterFn, FuncCtx, "", EntryBB->getTerminator());
Register->setDoesNotThrow();
// Following any allocas not in the entry block, update the saved SP in the
projects / oota-llvm.git / blobdiff