Try again to teach getFirstTerminator() about debug values.
Fix some callers to better deal with debug values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123419 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index ad1ab28..3696387 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -155,11 +155,22 @@
}
MachineBasicBlock::iterator MachineBasicBlock::getFirstTerminator() {
- iterator I = end();
- while (I != begin() && (--I)->getDesc().isTerminator())
- ; /*noop */
- if (I != end() && !I->getDesc().isTerminator()) ++I;
- return I;
+ iterator B = begin(), I = end();
+ iterator Term = I;
+ while (I != B) {
+ --I;
+ // Ignore any debug values after the first terminator.
+ if (I->isDebugValue())
+ continue;
+ // Stop once we see a non-debug non-terminator.
+ if (!I->getDesc().isTerminator())
+ break;
+ // Earliest terminator so far.
+ Term = I;
+ }
+ // Return the first terminator, or end().
+ // Everything after Term is terminators and debug values.
+ return Term;
}
MachineBasicBlock::iterator MachineBasicBlock::getLastNonDebugInstr() {
diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp
index 923fa21..b940e26 100644
--- a/lib/CodeGen/PHIElimination.cpp
+++ b/lib/CodeGen/PHIElimination.cpp
@@ -339,6 +339,8 @@
#ifndef NDEBUG
for (MachineBasicBlock::iterator TI = llvm::next(Term);
TI != opBlock.end(); ++TI) {
+ if (TI->isDebugValue())
+ continue;
assert(!TI->readsRegister(SrcReg) &&
"Terminator instructions cannot use virtual registers unless"
"they are the first terminator in a block!");
@@ -347,9 +349,13 @@
} else if (reusedIncoming || !IncomingReg) {
// We may have to rewind a bit if we didn't insert a copy this time.
KillInst = Term;
- while (KillInst != opBlock.begin())
- if ((--KillInst)->readsRegister(SrcReg))
+ while (KillInst != opBlock.begin()) {
+ --KillInst;
+ if (KillInst->isDebugValue())
+ continue;
+ if (KillInst->readsRegister(SrcReg))
break;
+ }
} else {
// We just inserted this copy.
KillInst = prior(InsertPos);