Prep for merging 3.4: Undo changes from 3.3 branch

lib/Transforms/IPO/GlobalOpt.cpp

Index: lib/Transforms/IPO/GlobalOpt.cpp
diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index 6cab6ed0ffa82e7d3b266b5f7d07357b75f659f9..70b066d64bf486ef4414d2b4a820a7371124f09c 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -3062,105 +3062,6 @@ bool GlobalOpt::OptimizeGlobalCtorsList(GlobalVariable *&GCL) {
   return true;
 }
 
-static Value::use_iterator getFirst(Value *V, SmallPtrSet<Use*, 8> &Tried) {
-  for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I) {
-    Use *U = &I.getUse();
-    if (Tried.count(U))
-      continue;
-
-    User *Usr = *I;
-    GlobalVariable *GV = dyn_cast<GlobalVariable>(Usr);
-    if (!GV || !GV->hasName()) {
-      Tried.insert(U);
-      return I;
-    }
-
-    StringRef Name = GV->getName();
-    if (Name != "llvm.used" && Name != "llvm.compiler_used") {
-      Tried.insert(U);
-      return I;
-    }
-  }
-  return V->use_end();
-}
-
-static bool replaceAllNonLLVMUsedUsesWith(Constant *Old, Constant *New);
-
-static bool replaceUsesOfWithOnConstant(ConstantArray *CA, Value *From,
-                                        Value *ToV, Use *U) {
-  Constant *To = cast<Constant>(ToV);
-
-  SmallVector<Constant*, 8> NewOps;
-  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
-    Constant *Op = CA->getOperand(i);
-    NewOps.push_back(Op == From ? To : Op);
-  }
-
-  Constant *Replacement = ConstantArray::get(CA->getType(), NewOps);
-  assert(Replacement != CA && "CA didn't contain From!");
-
-  bool Ret = replaceAllNonLLVMUsedUsesWith(CA, Replacement);
-  if (Replacement->use_empty())
-    Replacement->destroyConstant();
-  if (CA->use_empty())
-    CA->destroyConstant();
-  return Ret;
-}
-
-static bool replaceUsesOfWithOnConstant(ConstantExpr *CE, Value *From,
-                                        Value *ToV, Use *U) {
-  Constant *To = cast<Constant>(ToV);
-  SmallVector<Constant*, 8> NewOps;
-  for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
-    Constant *Op = CE->getOperand(i);
-    NewOps.push_back(Op == From ? To : Op);
-  }
-
-  Constant *Replacement = CE->getWithOperands(NewOps);
-  assert(Replacement != CE && "CE didn't contain From!");
-
-  bool Ret = replaceAllNonLLVMUsedUsesWith(CE, Replacement);
-  if (Replacement->use_empty())
-    Replacement->destroyConstant();
-  if (CE->use_empty())
-    CE->destroyConstant();
-  return Ret;
-}
-
-static bool replaceUsesOfWithOnConstant(Constant *C, Value *From, Value *To,
-                                        Use *U) {
-  if (ConstantArray *CA = dyn_cast<ConstantArray>(C))
-    return replaceUsesOfWithOnConstant(CA, From, To, U);
-  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
-    return replaceUsesOfWithOnConstant(CE, From, To, U);
-  C->replaceUsesOfWithOnConstant(From, To, U);
-  return true;
-}
-
-static bool replaceAllNonLLVMUsedUsesWith(Constant *Old, Constant *New) {
-  SmallPtrSet<Use*, 8> Tried;
-  bool Ret = false;
-  for (;;) {
-    Value::use_iterator I = getFirst(Old, Tried);
-    if (I == Old->use_end())
-      break;
-    Use &U = I.getUse();
-
-    // Must handle Constants specially, we cannot call replaceUsesOfWith on a
-    // constant because they are uniqued.
-    if (Constant *C = dyn_cast<Constant>(U.getUser())) {
-      if (!isa<GlobalValue>(C)) {
-        Ret |= replaceUsesOfWithOnConstant(C, Old, New, &U);
-        continue;
-      }
-    }
-
-    U.set(New);
-    Ret = true;
-  }
-  return Ret;
-}
-
 bool GlobalOpt::OptimizeGlobalAliases(Module &M) {
   bool Changed = false;
 
@@ -3180,12 +3081,11 @@ bool GlobalOpt::OptimizeGlobalAliases(Module &M) {
     bool hasOneUse = Target->hasOneUse() && Aliasee->hasOneUse();
 
     // Make all users of the alias use the aliasee instead.
-    if (replaceAllNonLLVMUsedUsesWith(J, Aliasee)) {
+    if (!J->use_empty()) {
+      J->replaceAllUsesWith(Aliasee);
       ++NumAliasesResolved;
       Changed = true;
     }
-    if (!J->use_empty())
-      continue;
 
     // If the alias is externally visible, we may still be able to simplify it.
     if (!J->hasLocalLinkage()) {