Turns out AnalyzeBranch can modify the mbb being analyzed. This is a nasty
suprise to some callers, e.g. register coalescer. For now, add an parameter
that tells AnalyzeBranch whether it's safe to modify the mbb. A better
solution is out there, but I don't have time to deal with it right now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64124 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMInstrInfo.cpp b/lib/Target/ARM/ARMInstrInfo.cpp
index bbe5a10..0c55f93 100644
--- a/lib/Target/ARM/ARMInstrInfo.cpp
+++ b/lib/Target/ARM/ARMInstrInfo.cpp
@@ -335,7 +335,8 @@
// Branch analysis.
bool ARMInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const {
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin() || !isUnpredicatedTerminator(--I))
@@ -385,7 +386,8 @@
(LastOpc == ARM::B || LastOpc == ARM::tB)) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
- I->eraseFromParent();
+ if (AllowModify)
+ I->eraseFromParent();
return false;
}
@@ -396,7 +398,8 @@
SecondLastOpc == ARM::BR_JTadd || SecondLastOpc==ARM::tBR_JTr) &&
(LastOpc == ARM::B || LastOpc == ARM::tB)) {
I = LastInst;
- I->eraseFromParent();
+ if (AllowModify)
+ I->eraseFromParent();
return true;
}