[llvm-commits] [llvm] r142800 - /llvm/trunk/lib/CodeGen/SjLjEHPrepare.cpp
Bill Wendling
isanbard at gmail.com
Mon Oct 24 10:12:36 PDT 2011
Author: void
Date: Mon Oct 24 12:12:36 2011
New Revision: 142800
URL: http://llvm.org/viewvc/llvm-project?rev=142800&view=rev
Log:
Cleanup. Get rid of the old SjLj EH lowering code. No functionality change.
Modified:
llvm/trunk/lib/CodeGen/SjLjEHPrepare.cpp
Modified: llvm/trunk/lib/CodeGen/SjLjEHPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SjLjEHPrepare.cpp?rev=142800&r1=142799&r2=142800&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SjLjEHPrepare.cpp (original)
+++ llvm/trunk/lib/CodeGen/SjLjEHPrepare.cpp Mon Oct 24 12:12:36 2011
@@ -30,17 +30,13 @@
#include "llvm/Support/Debug.h"
#include "llvm/Support/IRBuilder.h"
#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include <set>
using namespace llvm;
-static cl::opt<bool> DisableOldSjLjEH("disable-old-sjlj-eh", cl::Hidden,
- cl::init(true),
- cl::desc("Disable the old SjLj EH preparation pass"));
-
STATISTIC(NumInvokes, "Number of invokes replaced");
-STATISTIC(NumUnwinds, "Number of unwinds replaced");
STATISTIC(NumSpilled, "Number of registers live across unwind edges");
namespace {
@@ -52,16 +48,12 @@
Constant *BuiltinSetjmpFn;
Constant *FrameAddrFn;
Constant *StackAddrFn;
- Constant *StackRestoreFn;
Constant *LSDAAddrFn;
Value *PersonalityFn;
- Constant *SelectorFn;
- Constant *ExceptionFn;
Constant *CallSiteFn;
Constant *DispatchSetupFn;
Constant *FuncCtxFn;
Value *CallSite;
- DenseMap<InvokeInst*, BasicBlock*> LPadSuccMap;
public:
static char ID; // Pass identification, replacement for typeid
explicit SjLjEHPass(const TargetLowering *tli = NULL)
@@ -79,13 +71,7 @@
Value *setupFunctionContext(Function &F, ArrayRef<LandingPadInst*> LPads);
void lowerIncomingArguments(Function &F);
void lowerAcrossUnwindEdges(Function &F, ArrayRef<InvokeInst*> Invokes);
-
void insertCallSiteStore(Instruction *I, int Number, Value *CallSite);
- void markInvokeCallSite(InvokeInst *II, int InvokeNo, Value *CallSite,
- SwitchInst *CatchSwitch);
- void splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes);
- void splitLandingPad(InvokeInst *II);
- bool insertSjLjEHSupport(Function &F);
};
} // end anonymous namespace
@@ -121,11 +107,8 @@
(Type *)0);
FrameAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::frameaddress);
StackAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::stacksave);
- StackRestoreFn = Intrinsic::getDeclaration(&M, Intrinsic::stackrestore);
BuiltinSetjmpFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setjmp);
LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda);
- SelectorFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_selector);
- ExceptionFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_exception);
CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite);
DispatchSetupFn
= Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_dispatch_setup);
@@ -145,572 +128,16 @@
new StoreInst(CallSiteNoC, CallSite, true, I); // volatile
}
-/// splitLandingPad - Split a landing pad. This takes considerable care because
-/// of PHIs and other nasties. The problem is that the jump table needs to jump
-/// to the landing pad block. However, the landing pad block can be jumped to
-/// only by an invoke instruction. So we clone the landingpad instruction into
-/// its own basic block, have the invoke jump to there. The landingpad
-/// instruction's basic block's successor is now the target for the jump table.
-///
-/// But because of PHI nodes, we need to create another basic block for the jump
-/// table to jump to. This is definitely a hack, because the values for the PHI
-/// nodes may not be defined on the edge from the jump table. But that's okay,
-/// because the jump table is simply a construct to mimic what is happening in
-/// the CFG. So the values are mysteriously there, even though there is no value
-/// for the PHI from the jump table's edge (hence calling this a hack).
-void SjLjEHPass::splitLandingPad(InvokeInst *II) {
- SmallVector<BasicBlock*, 2> NewBBs;
- SplitLandingPadPredecessors(II->getUnwindDest(), II->getParent(),
- ".1", ".2", this, NewBBs);
-
- // Create an empty block so that the jump table has something to jump to
- // which doesn't have any PHI nodes.
- BasicBlock *LPad = NewBBs[0];
- BasicBlock *Succ = *succ_begin(LPad);
- BasicBlock *JumpTo = BasicBlock::Create(II->getContext(), "jt.land",
- LPad->getParent(), Succ);
- LPad->getTerminator()->eraseFromParent();
- BranchInst::Create(JumpTo, LPad);
- BranchInst::Create(Succ, JumpTo);
- LPadSuccMap[II] = JumpTo;
-
- for (BasicBlock::iterator I = Succ->begin(); isa<PHINode>(I); ++I) {
- PHINode *PN = cast<PHINode>(I);
- Value *Val = PN->removeIncomingValue(LPad, false);
- PN->addIncoming(Val, JumpTo);
- }
-}
-
-/// markInvokeCallSite - Insert code to mark the call_site for this invoke
-void SjLjEHPass::markInvokeCallSite(InvokeInst *II, int InvokeNo,
- Value *CallSite,
- SwitchInst *CatchSwitch) {
- ConstantInt *CallSiteNoC= ConstantInt::get(Type::getInt32Ty(II->getContext()),
- InvokeNo);
- // The runtime comes back to the dispatcher with the call_site - 1 in
- // the context. Odd, but there it is.
- ConstantInt *SwitchValC = ConstantInt::get(Type::getInt32Ty(II->getContext()),
- InvokeNo - 1);
-
- // If the unwind edge has phi nodes, split the edge.
- if (isa<PHINode>(II->getUnwindDest()->begin())) {
- // FIXME: New EH - This if-condition will be always true in the new scheme.
- if (II->getUnwindDest()->isLandingPad())
- splitLandingPad(II);
- else
- SplitCriticalEdge(II, 1, this);
-
- // If there are any phi nodes left, they must have a single predecessor.
- while (PHINode *PN = dyn_cast<PHINode>(II->getUnwindDest()->begin())) {
- PN->replaceAllUsesWith(PN->getIncomingValue(0));
- PN->eraseFromParent();
- }
- }
-
- // Insert the store of the call site value
- insertCallSiteStore(II, InvokeNo, CallSite);
-
- // Record the call site value for the back end so it stays associated with
- // the invoke.
- CallInst::Create(CallSiteFn, CallSiteNoC, "", II);
-
- // Add a switch case to our unwind block.
- if (BasicBlock *SuccBB = LPadSuccMap[II]) {
- CatchSwitch->addCase(SwitchValC, SuccBB);
- } else {
- CatchSwitch->addCase(SwitchValC, II->getUnwindDest());
- }
-
- // We still want this to look like an invoke so we emit the LSDA properly,
- // so we don't transform the invoke into a call here.
-}
-
/// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until
/// we reach blocks we've already seen.
-static void MarkBlocksLiveIn(BasicBlock *BB, std::set<BasicBlock*> &LiveBBs) {
- if (!LiveBBs.insert(BB).second) return; // already been here.
+static void MarkBlocksLiveIn(BasicBlock *BB,
+ SmallPtrSet<BasicBlock*, 64> &LiveBBs) {
+ if (!LiveBBs.insert(BB)) return; // already been here.
for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
MarkBlocksLiveIn(*PI, LiveBBs);
}
-/// splitLiveRangesAcrossInvokes - Each value that is live across an unwind edge
-/// we spill into a stack location, guaranteeing that there is nothing live
-/// across the unwind edge. This process also splits all critical edges
-/// coming out of invoke's.
-/// FIXME: Move this function to a common utility file (Local.cpp?) so
-/// both SjLj and LowerInvoke can use it.
-void SjLjEHPass::
-splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes) {
- // First step, split all critical edges from invoke instructions.
- for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
- InvokeInst *II = Invokes[i];
- SplitCriticalEdge(II, 0, this);
-
- // FIXME: New EH - This if-condition will be always true in the new scheme.
- if (II->getUnwindDest()->isLandingPad())
- splitLandingPad(II);
- else
- SplitCriticalEdge(II, 1, this);
-
- assert(!isa<PHINode>(II->getNormalDest()) &&
- !isa<PHINode>(II->getUnwindDest()) &&
- "Critical edge splitting left single entry phi nodes?");
- }
-
- Function *F = Invokes.back()->getParent()->getParent();
-
- // To avoid having to handle incoming arguments specially, we lower each arg
- // to a copy instruction in the entry block. This ensures that the argument
- // value itself cannot be live across the entry block.
- BasicBlock::iterator AfterAllocaInsertPt = F->begin()->begin();
- while (isa<AllocaInst>(AfterAllocaInsertPt) &&
- isa<ConstantInt>(cast<AllocaInst>(AfterAllocaInsertPt)->getArraySize()))
- ++AfterAllocaInsertPt;
- for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
- AI != E; ++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, "",AfterAllocaInsertPt);
- 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", AfterAllocaInsertPt);
- 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);
- }
- }
-
- // Finally, scan the code looking for instructions with bad live ranges.
- for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
- for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E; ++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->hasOneUse() &&
- cast<Instruction>(Inst->use_back())->getParent() == BB &&
- !isa<PHINode>(Inst->use_back())) continue;
-
- // If this is an alloca in the entry block, it's not a real register
- // value.
- if (AllocaInst *AI = dyn_cast<AllocaInst>(Inst))
- if (isa<ConstantInt>(AI->getArraySize()) && BB == F->begin())
- 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);
- }
-
- // Find all of the blocks that this value is live in.
- std::set<BasicBlock*> LiveBBs;
- LiveBBs.insert(Inst->getParent());
- while (!Users.empty()) {
- Instruction *U = Users.back();
- Users.pop_back();
-
- if (!isa<PHINode>(U)) {
- MarkBlocksLiveIn(U->getParent(), LiveBBs);
- } else {
- // Uses for a PHI node occur in their predecessor block.
- PHINode *PN = cast<PHINode>(U);
- for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
- if (PN->getIncomingValue(i) == Inst)
- MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs);
- }
- }
-
- // Now that we know all of the blocks that this thing is live in, see if
- // it includes any of the unwind locations.
- bool NeedsSpill = false;
- for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
- BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest();
- if (UnwindBlock != BB && LiveBBs.count(UnwindBlock))
- NeedsSpill = true;
- }
-
- // If we decided we need a spill, do it.
- // FIXME: Spilling this way is overkill, as it forces all uses of
- // the value to be reloaded from the stack slot, even those that aren't
- // in the unwind blocks. We should be more selective.
- if (NeedsSpill) {
- ++NumSpilled;
- DemoteRegToStack(*Inst, true);
- }
- }
-}
-
-/// CreateLandingPadLoad - Load the exception handling values and insert them
-/// into a structure.
-static Instruction *CreateLandingPadLoad(Function &F, Value *ExnAddr,
- Value *SelAddr,
- BasicBlock::iterator InsertPt) {
- Value *Exn = new LoadInst(ExnAddr, "exn", false,
- InsertPt);
- Type *Ty = Type::getInt8PtrTy(F.getContext());
- Exn = CastInst::Create(Instruction::IntToPtr, Exn, Ty, "", InsertPt);
- Value *Sel = new LoadInst(SelAddr, "sel", false, InsertPt);
-
- Ty = StructType::get(Exn->getType(), Sel->getType(), NULL);
- InsertValueInst *LPadVal = InsertValueInst::Create(llvm::UndefValue::get(Ty),
- Exn, 0,
- "lpad.val", InsertPt);
- return InsertValueInst::Create(LPadVal, Sel, 1, "lpad.val", InsertPt);
-}
-
-/// ReplaceLandingPadVal - Replace the landingpad instruction's value with a
-/// load from the stored values (via CreateLandingPadLoad). This looks through
-/// PHI nodes, and removes them if they are dead.
-static void ReplaceLandingPadVal(Function &F, Instruction *Inst, Value *ExnAddr,
- Value *SelAddr) {
- if (Inst->use_empty()) return;
-
- while (!Inst->use_empty()) {
- Instruction *I = cast<Instruction>(Inst->use_back());
-
- if (PHINode *PN = dyn_cast<PHINode>(I)) {
- ReplaceLandingPadVal(F, PN, ExnAddr, SelAddr);
- if (PN->use_empty()) PN->eraseFromParent();
- continue;
- }
-
- I->replaceUsesOfWith(Inst, CreateLandingPadLoad(F, ExnAddr, SelAddr, I));
- }
-}
-
-bool SjLjEHPass::insertSjLjEHSupport(Function &F) {
- SmallVector<ReturnInst*,16> Returns;
- SmallVector<UnwindInst*,16> Unwinds;
- SmallVector<InvokeInst*,16> Invokes;
-
- // Look through the terminators of the basic blocks to find invokes, returns
- // and unwinds.
- for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
- if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
- // Remember all return instructions in case we insert an invoke into this
- // function.
- Returns.push_back(RI);
- } else if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
- Invokes.push_back(II);
- } else if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
- Unwinds.push_back(UI);
- }
- }
-
- NumInvokes += Invokes.size();
- NumUnwinds += Unwinds.size();
-
- // If we don't have any invokes, there's nothing to do.
- if (Invokes.empty()) return false;
-
- // Find the eh.selector.*, eh.exception and alloca calls.
- //
- // Remember any allocas() that aren't in the entry block, as the
- // jmpbuf saved SP will need to be updated for them.
- //
- // We'll use the first eh.selector to determine the right personality
- // function to use. For SJLJ, we always use the same personality for the
- // whole function, not on a per-selector basis.
- // FIXME: That's a bit ugly. Better way?
- SmallVector<CallInst*,16> EH_Selectors;
- SmallVector<CallInst*,16> EH_Exceptions;
- SmallVector<Instruction*,16> JmpbufUpdatePoints;
-
- for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
- // Note: Skip the entry block since there's nothing there that interests
- // us. eh.selector and eh.exception shouldn't ever be there, and we
- // want to disregard any allocas that are there.
- //
- // FIXME: This is awkward. The new EH scheme won't need to skip the entry
- // block.
- if (BB == F.begin()) {
- if (InvokeInst *II = dyn_cast<InvokeInst>(F.begin()->getTerminator())) {
- // FIXME: This will be always non-NULL in the new EH.
- if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst())
- if (!PersonalityFn) PersonalityFn = LPI->getPersonalityFn();
- }
-
- continue;
- }
-
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
- if (CallInst *CI = dyn_cast<CallInst>(I)) {
- if (CI->getCalledFunction() == SelectorFn) {
- if (!PersonalityFn) PersonalityFn = CI->getArgOperand(1);
- EH_Selectors.push_back(CI);
- } else if (CI->getCalledFunction() == ExceptionFn) {
- EH_Exceptions.push_back(CI);
- } else if (CI->getCalledFunction() == StackRestoreFn) {
- JmpbufUpdatePoints.push_back(CI);
- }
- } else if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
- JmpbufUpdatePoints.push_back(AI);
- } else if (InvokeInst *II = dyn_cast<InvokeInst>(I)) {
- // FIXME: This will be always non-NULL in the new EH.
- if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst())
- if (!PersonalityFn) PersonalityFn = LPI->getPersonalityFn();
- }
- }
- }
-
- // If we don't have any eh.selector calls, we can't determine the personality
- // function. Without a personality function, we can't process exceptions.
- if (!PersonalityFn) return false;
-
- // We have invokes, so we need to add register/unregister calls to get this
- // function onto the global unwind stack.
- //
- // First thing we need to do is scan the whole function for values that are
- // live across unwind edges. Each value that is live across an unwind edge we
- // spill into a stack location, guaranteeing that there is nothing live across
- // the unwind edge. This process also splits all critical edges coming out of
- // invoke's.
- splitLiveRangesAcrossInvokes(Invokes);
-
-
- SmallVector<LandingPadInst*, 16> LandingPads;
- for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
- if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator()))
- // FIXME: This will be always non-NULL in the new EH.
- if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst())
- LandingPads.push_back(LPI);
- }
-
-
- 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.
- unsigned Align = 4; // FIXME: Should be a TLI check?
- AllocaInst *FunctionContext =
- new AllocaInst(FunctionContextTy, 0, Align,
- "fcn_context", F.begin()->begin());
-
- Value *Idxs[2];
- Type *Int32Ty = Type::getInt32Ty(F.getContext());
- Value *Zero = ConstantInt::get(Int32Ty, 0);
- // We need to also keep around a reference to the call_site field
- Idxs[0] = Zero;
- Idxs[1] = ConstantInt::get(Int32Ty, 1);
- CallSite = GetElementPtrInst::Create(FunctionContext, Idxs, "call_site",
- EntryBB->getTerminator());
-
- // The exception selector comes back in context->data[1]
- Idxs[1] = ConstantInt::get(Int32Ty, 2);
- Value *FCData = GetElementPtrInst::Create(FunctionContext, Idxs, "fc_data",
- EntryBB->getTerminator());
- Idxs[1] = ConstantInt::get(Int32Ty, 1);
- Value *SelectorAddr = GetElementPtrInst::Create(FCData, Idxs,
- "exc_selector_gep",
- EntryBB->getTerminator());
- // The exception value comes back in context->data[0]
- Idxs[1] = Zero;
- Value *ExceptionAddr = GetElementPtrInst::Create(FCData, Idxs,
- "exception_gep",
- EntryBB->getTerminator());
-
- // The result of the eh.selector call will be replaced with a a reference to
- // the selector value returned in the function context. We leave the selector
- // itself so the EH analysis later can use it.
- for (int i = 0, e = EH_Selectors.size(); i < e; ++i) {
- CallInst *I = EH_Selectors[i];
- Value *SelectorVal = new LoadInst(SelectorAddr, "select_val", true, I);
- I->replaceAllUsesWith(SelectorVal);
- }
-
- // eh.exception calls are replaced with references to the proper location in
- // the context. Unlike eh.selector, the eh.exception calls are removed
- // entirely.
- for (int i = 0, e = EH_Exceptions.size(); i < e; ++i) {
- CallInst *I = EH_Exceptions[i];
- // Possible for there to be duplicates, so check to make sure the
- // instruction hasn't already been removed.
- if (!I->getParent()) continue;
- Value *Val = new LoadInst(ExceptionAddr, "exception", true, I);
- Type *Ty = Type::getInt8PtrTy(F.getContext());
- Val = CastInst::Create(Instruction::IntToPtr, Val, Ty, "", I);
-
- I->replaceAllUsesWith(Val);
- I->eraseFromParent();
- }
-
- for (unsigned i = 0, e = LandingPads.size(); i != e; ++i)
- ReplaceLandingPadVal(F, LandingPads[i], ExceptionAddr, SelectorAddr);
-
- // The entry block changes to have the eh.sjlj.setjmp, with a conditional
- // branch to a dispatch block for non-zero returns. If we return normally,
- // we're not handling an exception and just register the function context and
- // continue.
-
- // Create the dispatch block. The dispatch block is basically a big switch
- // statement that goes to all of the invoke landing pads.
- BasicBlock *DispatchBlock =
- BasicBlock::Create(F.getContext(), "eh.sjlj.setjmp.catch", &F);
-
- // Insert a load of the callsite in the dispatch block, and a switch on its
- // value. By default, we issue a trap statement.
- BasicBlock *TrapBlock =
- BasicBlock::Create(F.getContext(), "trapbb", &F);
- CallInst::Create(Intrinsic::getDeclaration(F.getParent(), Intrinsic::trap),
- "", TrapBlock);
- new UnreachableInst(F.getContext(), TrapBlock);
-
- Value *DispatchLoad = new LoadInst(CallSite, "invoke.num", true,
- DispatchBlock);
- SwitchInst *DispatchSwitch =
- SwitchInst::Create(DispatchLoad, TrapBlock, Invokes.size(),
- DispatchBlock);
- // Split the entry block to insert the conditional branch for the setjmp.
- BasicBlock *ContBlock = EntryBB->splitBasicBlock(EntryBB->getTerminator(),
- "eh.sjlj.setjmp.cont");
-
- // Populate the Function Context
- // 1. LSDA address
- // 2. Personality function address
- // 3. jmpbuf (save SP, FP and call eh.sjlj.setjmp)
-
- // LSDA address
- Idxs[0] = Zero;
- Idxs[1] = ConstantInt::get(Int32Ty, 4);
- Value *LSDAFieldPtr =
- GetElementPtrInst::Create(FunctionContext, Idxs, "lsda_gep",
- EntryBB->getTerminator());
- Value *LSDA = CallInst::Create(LSDAAddrFn, "lsda_addr",
- EntryBB->getTerminator());
- new StoreInst(LSDA, LSDAFieldPtr, true, EntryBB->getTerminator());
-
- Idxs[1] = ConstantInt::get(Int32Ty, 3);
- Value *PersonalityFieldPtr =
- GetElementPtrInst::Create(FunctionContext, Idxs, "lsda_gep",
- EntryBB->getTerminator());
- new StoreInst(PersonalityFn, PersonalityFieldPtr, true,
- EntryBB->getTerminator());
-
- // Save the frame pointer.
- Idxs[1] = ConstantInt::get(Int32Ty, 5);
- Value *JBufPtr
- = GetElementPtrInst::Create(FunctionContext, Idxs, "jbuf_gep",
- EntryBB->getTerminator());
- Idxs[1] = ConstantInt::get(Int32Ty, 0);
- Value *FramePtr =
- GetElementPtrInst::Create(JBufPtr, Idxs, "jbuf_fp_gep",
- EntryBB->getTerminator());
-
- Value *Val = CallInst::Create(FrameAddrFn,
- ConstantInt::get(Int32Ty, 0),
- "fp",
- EntryBB->getTerminator());
- new StoreInst(Val, FramePtr, true, EntryBB->getTerminator());
-
- // Save the stack pointer.
- Idxs[1] = ConstantInt::get(Int32Ty, 2);
- Value *StackPtr =
- GetElementPtrInst::Create(JBufPtr, Idxs, "jbuf_sp_gep",
- EntryBB->getTerminator());
-
- Val = CallInst::Create(StackAddrFn, "sp", EntryBB->getTerminator());
- new StoreInst(Val, StackPtr, true, EntryBB->getTerminator());
-
- // Call the setjmp instrinsic. It fills in the rest of the jmpbuf.
- Value *SetjmpArg =
- CastInst::Create(Instruction::BitCast, JBufPtr,
- Type::getInt8PtrTy(F.getContext()), "",
- EntryBB->getTerminator());
- Value *DispatchVal = CallInst::Create(BuiltinSetjmpFn, SetjmpArg,
- "",
- EntryBB->getTerminator());
-
- // Add a call to dispatch_setup after the setjmp call. This is expanded to any
- // target-specific setup that needs to be done.
- CallInst::Create(DispatchSetupFn, DispatchVal, "", EntryBB->getTerminator());
-
- // check the return value of the setjmp. non-zero goes to dispatcher.
- Value *IsNormal = new ICmpInst(EntryBB->getTerminator(),
- ICmpInst::ICMP_EQ, DispatchVal, Zero,
- "notunwind");
- // Nuke the uncond branch.
- EntryBB->getTerminator()->eraseFromParent();
-
- // Put in a new condbranch in its place.
- BranchInst::Create(ContBlock, DispatchBlock, IsNormal, EntryBB);
-
- // Register the function context and make sure it's known to not throw
- CallInst *Register =
- CallInst::Create(RegisterFn, FunctionContext, "",
- ContBlock->getTerminator());
- Register->setDoesNotThrow();
-
- // At this point, we are all set up, update the invoke instructions to mark
- // their call_site values, and fill in the dispatch switch accordingly.
- for (unsigned i = 0, e = Invokes.size(); i != e; ++i)
- markInvokeCallSite(Invokes[i], i+1, CallSite, DispatchSwitch);
-
- // Mark call instructions that aren't nounwind as no-action (call_site ==
- // -1). Skip the entry block, as prior to then, no function context has been
- // created for this function and any unexpected exceptions thrown will go
- // directly to the caller's context, which is what we want anyway, so no need
- // to do anything here.
- for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;) {
- for (BasicBlock::iterator I = BB->begin(), end = BB->end(); I != end; ++I)
- if (CallInst *CI = dyn_cast<CallInst>(I)) {
- // Ignore calls to the EH builtins (eh.selector, eh.exception)
- Constant *Callee = CI->getCalledFunction();
- if (Callee != SelectorFn && Callee != ExceptionFn
- && !CI->doesNotThrow())
- insertCallSiteStore(CI, -1, CallSite);
- } else if (ResumeInst *RI = dyn_cast<ResumeInst>(I)) {
- insertCallSiteStore(RI, -1, CallSite);
- }
- }
-
- // Replace all unwinds with a branch to the unwind handler.
- // ??? Should this ever happen with sjlj exceptions?
- for (unsigned i = 0, e = Unwinds.size(); i != e; ++i) {
- BranchInst::Create(TrapBlock, Unwinds[i]);
- Unwinds[i]->eraseFromParent();
- }
-
- // Following any allocas not in the entry block, update the saved SP in the
- // jmpbuf to the new value.
- for (unsigned i = 0, e = JmpbufUpdatePoints.size(); i != e; ++i) {
- Instruction *AI = JmpbufUpdatePoints[i];
- Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp");
- StackAddr->insertAfter(AI);
- Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true);
- StoreStackAddr->insertAfter(StackAddr);
- }
-
- // Finally, for any returns from this function, if this function contains an
- // invoke, add a call to unregister the function context.
- for (unsigned i = 0, e = Returns.size(); i != e; ++i)
- CallInst::Create(UnregisterFn, FunctionContext, "", Returns[i]);
-
- return true;
-}
-
/// setupFunctionContext - Allocate the function context on the stack and fill
/// it with all of the data that we know at this point.
Value *SjLjEHPass::
@@ -871,7 +298,7 @@
}
// Find all of the blocks that this value is live in.
- std::set<BasicBlock*> LiveBBs;
+ SmallPtrSet<BasicBlock*, 64> LiveBBs;
LiveBBs.insert(Inst->getParent());
while (!Users.empty()) {
Instruction *U = Users.back();
@@ -895,6 +322,7 @@
BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest();
if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) {
NeedsSpill = true;
+ break;
}
}
@@ -903,8 +331,8 @@
// the value to be reloaded from the stack slot, even those that aren't
// in the unwind blocks. We should be more selective.
if (NeedsSpill) {
- ++NumSpilled;
DemoteRegToStack(*Inst, true);
+ ++NumSpilled;
}
}
}
@@ -950,6 +378,8 @@
if (Invokes.empty()) return false;
+ NumInvokes += Invokes.size();
+
lowerIncomingArguments(F);
lowerAcrossUnwindEdges(F, Invokes);
@@ -1039,10 +469,6 @@
}
bool SjLjEHPass::runOnFunction(Function &F) {
- bool Res = false;
- if (!DisableOldSjLjEH)
- Res = insertSjLjEHSupport(F);
- else
- Res = setupEntryBlockAndCallSites(F);
+ bool Res = setupEntryBlockAndCallSites(F);
return Res;
}
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