MergeFunctions: Don't replace a weak function use by another equivalent weak function
We don't know whether the weak functions definition is the definitive definition.
rdar://21303727
llvm-svn: 239422
diff --git a/llvm/lib/Transforms/IPO/MergeFunctions.cpp b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
index 052f1b4..2e3519e 100644
--- a/llvm/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
@@ -1397,28 +1397,26 @@
if (F->mayBeOverridden()) {
assert(G->mayBeOverridden());
+ // Make them both thunks to the same internal function.
+ Function *H = Function::Create(F->getFunctionType(), F->getLinkage(), "",
+ F->getParent());
+ H->copyAttributesFrom(F);
+ H->takeName(F);
+ removeUsers(F);
+ F->replaceAllUsesWith(H);
+
+ unsigned MaxAlignment = std::max(G->getAlignment(), H->getAlignment());
+
if (HasGlobalAliases) {
- // Make them both thunks to the same internal function.
- Function *H = Function::Create(F->getFunctionType(), F->getLinkage(), "",
- F->getParent());
- H->copyAttributesFrom(F);
- H->takeName(F);
- removeUsers(F);
- F->replaceAllUsesWith(H);
-
- unsigned MaxAlignment = std::max(G->getAlignment(), H->getAlignment());
-
writeAlias(F, G);
writeAlias(F, H);
-
- F->setAlignment(MaxAlignment);
- F->setLinkage(GlobalValue::PrivateLinkage);
} else {
- // We can't merge them. Instead, pick one and update all direct callers
- // to call it and hope that we improve the instruction cache hit rate.
- replaceDirectCallers(G, F);
+ writeThunk(F, G);
+ writeThunk(F, H);
}
+ F->setAlignment(MaxAlignment);
+ F->setLinkage(GlobalValue::PrivateLinkage);
++NumDoubleWeak;
} else {
writeThunkOrAlias(F, G);