Teach MachineBasicBlock::updateTerminator() to handle a failing TII->ReverseBranchCondition(Cond) call.
This fixes the MallocBench/cfrac test case regression.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89608 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 2e6bd8a..e6a1878 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -279,8 +279,9 @@
// successors is its layout successor, rewrite it to a fallthrough
// conditional branch.
if (isLayoutSuccessor(TBB)) {
+ if (TII->ReverseBranchCondition(Cond))
+ return;
TII->RemoveBranch(*this);
- TII->ReverseBranchCondition(Cond);
TII->InsertBranch(*this, FBB, 0, Cond);
} else if (isLayoutSuccessor(FBB)) {
TII->RemoveBranch(*this);
@@ -292,8 +293,13 @@
MachineBasicBlock *MBBB = *next(succ_begin());
if (MBBA == TBB) std::swap(MBBB, MBBA);
if (isLayoutSuccessor(TBB)) {
+ if (TII->ReverseBranchCondition(Cond)) {
+ // We can't reverse the condition, add an unconditional branch.
+ Cond.clear();
+ TII->InsertBranch(*this, MBBA, 0, Cond);
+ return;
+ }
TII->RemoveBranch(*this);
- TII->ReverseBranchCondition(Cond);
TII->InsertBranch(*this, MBBA, 0, Cond);
} else if (!isLayoutSuccessor(MBBA)) {
TII->RemoveBranch(*this);