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.
llvm-svn: 241616
diff --git a/llvm/lib/IR/BasicBlock.cpp b/llvm/lib/IR/BasicBlock.cpp
index 77cb10d..0a04494 100644
--- a/llvm/lib/IR/BasicBlock.cpp
+++ b/llvm/lib/IR/BasicBlock.cpp
@@ -163,47 +163,40 @@
}
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;
}