Avoid inserting noop's in the middle of a loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60141 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LoopAligner.cpp b/lib/CodeGen/LoopAligner.cpp
index b8d0059..b67f5c3 100644
--- a/lib/CodeGen/LoopAligner.cpp
+++ b/lib/CodeGen/LoopAligner.cpp
@@ -64,8 +64,14 @@
for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) {
MachineBasicBlock *MBB = I;
- if (MLI->isLoopHeader(MBB))
+ if (MLI->isLoopHeader(MBB)) {
+ MachineBasicBlock *PredBB = prior(I);
+ if (MLI->getLoopFor(MBB) == MLI->getLoopFor(PredBB))
+ // If previously BB is in the same loop, don't align this BB. We want
+ // to prevent adding noop's inside a loop.
+ continue;
MBB->setAlignment(Align);
+ }
}
return true;