Don't let DeadArgElimination change the return type ({} into void and {T}
into T) when no return values are actually dead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52537 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/DeadArgumentElimination.cpp b/lib/Transforms/IPO/DeadArgumentElimination.cpp
index 6f00c89..3253c54 100644
--- a/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -598,15 +598,21 @@
++NumRetValsEliminated;
Changed = true;
}
- if (RetTypes.size() == 0)
- // No return types? Make it void
- NRetTy = Type::VoidTy;
+ if (RetTypes.size() > 1 || (STy && STy->getNumElements() == RetTypes.size()))
+ // More than one return type? Return a struct with them. Also, if we used
+ // to return a struct and didn't change the number of return values,
+ // return a struct again. This prevents chaning {something} into something
+ // and {} into void.
+ // Make the new struct packed if we used to return a packed struct
+ // already.
+ NRetTy = StructType::get(RetTypes, STy->isPacked());
else if (RetTypes.size() == 1)
- // One return type? Just a simple value then
+ // One return type? Just a simple value then, but only if we didn't use to
+ // return a struct with that simple value before.
NRetTy = RetTypes.front();
- else
- // More return types? Return a struct with them
- NRetTy = StructType::get(RetTypes);
+ else if (RetTypes.size() == 0)
+ // No return types? Make it void, but only if we didn't use to return {}
+ NRetTy = Type::VoidTy;
} else {
NRetTy = Type::VoidTy;
}