If a constant or a function has linkonce_odr linkage and unnamed_addr, mark it

hidden. Being linkonce_odr guarantees that it is available in every dso that
needs it. Being a constant/function with unnamed_addr guarantees that the
copies don't have to be merged.

llvm-svn: 159136

1 files changed, 11 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
index 35f98b22653..2f1af187f92 100644
--- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -1731,6 +1731,12 @@ bool GlobalOpt::ProcessGlobal(GlobalVariable *GV,
     return true;
   }
 
+  if (GV->hasLinkOnceODRLinkage() && GV->hasUnnamedAddr() && GV->isConstant() &&
+      GV->getVisibility() != GlobalValue::HiddenVisibility) {
+    GV->setVisibility(GlobalValue::HiddenVisibility);
+    return true;
+  }
+
   if (!GV->hasLocalLinkage())
     return false;
 
@@ -1743,6 +1749,7 @@ bool GlobalOpt::ProcessGlobal(GlobalVariable *GV,
   if (!GS.isCompared && !GV->hasUnnamedAddr()) {
     GV->setUnnamedAddr(true);
     NumUnnamed++;
+    return true;
   }
 
   if (GV->isConstant() || !GV->hasInitializer())
@@ -1917,6 +1924,10 @@ bool GlobalOpt::OptimizeFunctions(Module &M) {
       F->eraseFromParent();
       Changed = true;
       ++NumFnDeleted;
+    } else if (F->hasLinkOnceODRLinkage() && F->hasUnnamedAddr() &&
+               F->getVisibility() != GlobalValue::HiddenVisibility) {
+      F->setVisibility(GlobalValue::HiddenVisibility);
+      Changed = true;
     } else if (F->hasLocalLinkage()) {
       if (F->getCallingConv() == CallingConv::C && !F->isVarArg() &&
           !F->hasAddressTaken()) {