Fix EnforceKnownAlignment so that it doesn't ever reduce the alignment
of an alloca or global variable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64693 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 76b5566..8bdeb7f 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -9237,15 +9237,23 @@
// If there is a large requested alignment and we can, bump up the alignment
// of the global.
if (!GV->isDeclaration()) {
- GV->setAlignment(PrefAlign);
- Align = PrefAlign;
+ if (GV->getAlignment() >= PrefAlign)
+ Align = GV->getAlignment();
+ else {
+ GV->setAlignment(PrefAlign);
+ Align = PrefAlign;
+ }
}
} else if (AllocationInst *AI = dyn_cast<AllocationInst>(V)) {
// If there is a requested alignment and if this is an alloca, round up. We
// don't do this for malloc, because some systems can't respect the request.
if (isa<AllocaInst>(AI)) {
- AI->setAlignment(PrefAlign);
- Align = PrefAlign;
+ if (AI->getAlignment() >= PrefAlign)
+ Align = AI->getAlignment();
+ else {
+ AI->setAlignment(PrefAlign);
+ Align = PrefAlign;
+ }
}
}