Fix const merging when an alias of a const is llvm.used.

We used to disable constant merging not only if a constant is llvm.used, but
also if an alias of a constant is llvm.used. This change fixes that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181175 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 4 deletions

diff --git a/lib/Transforms/IPO/ConstantMerge.cpp b/lib/Transforms/IPO/ConstantMerge.cpp
index b63495b968..a7bf18896b 100644
--- a/lib/Transforms/IPO/ConstantMerge.cpp
+++ b/lib/Transforms/IPO/ConstantMerge.cpp
@@ -27,6 +27,7 @@
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Module.h"
+#include "llvm/IR/Operator.h"
 #include "llvm/Pass.h"
 using namespace llvm;
 
@@ -68,10 +69,11 @@ static void FindUsedValues(GlobalVariable *LLVMUsed,
   if (LLVMUsed == 0) return;
   ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
 
-  for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i)
-    if (GlobalValue *GV = 
-        dyn_cast<GlobalValue>(Inits->getOperand(i)->stripPointerCasts()))
-      UsedValues.insert(GV);
+  for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i) {
+    Value *Operand = Inits->getOperand(i)->stripPointerCastsNoFollowAliases();
+    GlobalValue *GV = cast<GlobalValue>(Operand);
+    UsedValues.insert(GV);
+  }
 }
 
 // True if A is better than B.