Revert "Revert r241570, it caused PR24053"

This reverts commit r241602.  We had a latent bug in SCCP where we would
make a basic block empty and then proceed to ask questions about it's
terminator.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241616 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
David Majnemer 2015-07-07 18:49:41 +00:00
parent a77796487b
commit 0148a4c854
2 changed files with 23 additions and 31 deletions

View File

@ -163,47 +163,40 @@ CallInst *BasicBlock::getTerminatingMustTailCall() {
}
Instruction* BasicBlock::getFirstNonPHI() {
BasicBlock::iterator i = begin();
// All valid basic blocks should have a terminator,
// which is not a PHINode. If we have an invalid basic
// block we'll get an assertion failure when dereferencing
// a past-the-end iterator.
while (isa<PHINode>(i)) ++i;
return &*i;
for (Instruction &I : *this)
if (!isa<PHINode>(I))
return &I;
return nullptr;
}
Instruction* BasicBlock::getFirstNonPHIOrDbg() {
BasicBlock::iterator i = begin();
// All valid basic blocks should have a terminator,
// which is not a PHINode. If we have an invalid basic
// block we'll get an assertion failure when dereferencing
// a past-the-end iterator.
while (isa<PHINode>(i) || isa<DbgInfoIntrinsic>(i)) ++i;
return &*i;
for (Instruction &I : *this)
if (!isa<PHINode>(I) && !isa<DbgInfoIntrinsic>(I))
return &I;
return nullptr;
}
Instruction* BasicBlock::getFirstNonPHIOrDbgOrLifetime() {
// All valid basic blocks should have a terminator,
// which is not a PHINode. If we have an invalid basic
// block we'll get an assertion failure when dereferencing
// a past-the-end iterator.
BasicBlock::iterator i = begin();
for (;; ++i) {
if (isa<PHINode>(i) || isa<DbgInfoIntrinsic>(i))
for (Instruction &I : *this) {
if (isa<PHINode>(I) || isa<DbgInfoIntrinsic>(I))
continue;
const IntrinsicInst *II = dyn_cast<IntrinsicInst>(i);
if (!II)
break;
if (II->getIntrinsicID() != Intrinsic::lifetime_start &&
II->getIntrinsicID() != Intrinsic::lifetime_end)
break;
if (auto *II = dyn_cast<IntrinsicInst>(&I))
if (II->getIntrinsicID() == Intrinsic::lifetime_start ||
II->getIntrinsicID() == Intrinsic::lifetime_end)
continue;
return &I;
}
return &*i;
return nullptr;
}
BasicBlock::iterator BasicBlock::getFirstInsertionPt() {
iterator InsertPt = getFirstNonPHI();
Instruction *FirstNonPHI = getFirstNonPHI();
if (!FirstNonPHI)
return end();
iterator InsertPt = FirstNonPHI;
if (isa<LandingPadInst>(InsertPt)) ++InsertPt;
return InsertPt;
}

View File

@ -1799,11 +1799,10 @@ bool IPSCCP::runOnModule(Module &M) {
if (!TI->use_empty())
TI->replaceAllUsesWith(UndefValue::get(TI->getType()));
TI->eraseFromParent();
new UnreachableInst(M.getContext(), BB);
if (&*BB != &F->front())
BlocksToErase.push_back(BB);
else
new UnreachableInst(M.getContext(), BB);
continue;
}