1 files changed, 10 insertions, 75 deletions

diff --git a/llvm/lib/Transforms/Scalar/GlobalMerge.cpp b/llvm/lib/Transforms/Scalar/GlobalMerge.cpp
index 98061f5b9a8..dd9c3784cc2 100644
--- a/llvm/lib/Transforms/Scalar/GlobalMerge.cpp
+++ b/llvm/lib/Transforms/Scalar/GlobalMerge.cpp
@@ -72,7 +72,7 @@ using namespace llvm;
 #define DEBUG_TYPE "global-merge"
 
 static cl::opt<bool>
-EnableGlobalMerge("enable-global-merge", cl::NotHidden,
+EnableGlobalMerge("global-merge", cl::Hidden,
                   cl::desc("Enable global merge pass"),
                   cl::init(true));
 
@@ -81,16 +81,6 @@ EnableGlobalMergeOnConst("global-merge-on-const", cl::Hidden,
                          cl::desc("Enable global merge pass on constants"),
                          cl::init(false));
 
-static cl::opt<bool>
-EnableGlobalMergeOnExternal("global-merge-on-external", cl::Hidden,
-                   cl::desc("Enable global merge pass on external linkage"),
-                   cl::init(false));
-
-static cl::opt<bool>
-EnableGlobalMergeAligned("global-merge-aligned", cl::Hidden,
-                   cl::desc("Set target specific alignment for global merge pass"),
-                   cl::init(false));
-
 STATISTIC(NumMerged      , "Number of globals merged");
 namespace {
   class GlobalMerge : public FunctionPass {
@@ -139,21 +129,9 @@ namespace {
 } // end anonymous namespace
 
 char GlobalMerge::ID = 0;
+INITIALIZE_PASS(GlobalMerge, "global-merge",
+                "Global Merge", false, false)
 
-static void *initializeGlobalMergePassOnce(PassRegistry &Registry) {
-  PassInfo *PI = new PassInfo(
-      "Merge global variables",
-      "global-merge", &GlobalMerge::ID,
-      PassInfo::NormalCtor_t(callDefaultCtor<GlobalMerge>), false,
-      false, PassInfo::TargetMachineCtor_t(
-                 callTargetMachineCtor<GlobalMerge>));
-  Registry.registerPass(*PI, true);
-  return PI;
-}
-
-void llvm::initializeGlobalMergePass(PassRegistry &Registry) {
-  CALL_ONCE_INITIALIZATION(initializeGlobalMergePassOnce)
-}
 
 bool GlobalMerge::doMerge(SmallVectorImpl<GlobalVariable*> &Globals,
                           Module &M, bool isConst, unsigned AddrSpace) const {
@@ -176,16 +154,11 @@ bool GlobalMerge::doMerge(SmallVectorImpl<GlobalVariable*> &Globals,
 
   Type *Int32Ty = Type::getInt32Ty(M.getContext());
 
-  assert (Globals.size() > 1);
-  
   for (size_t i = 0, e = Globals.size(); i != e; ) {
     size_t j = 0;
     uint64_t MergedSize = 0;
     std::vector<Type*> Tys;
     std::vector<Constant*> Inits;
-
-    bool HasExternal = false;
-    GlobalVariable *TheFirstExternal = 0;
     for (j = i; j != e; ++j) {
       Type *Ty = Globals[j]->getType()->getElementType();
       MergedSize += DL->getTypeAllocSize(Ty);
@@ -194,45 +167,17 @@ bool GlobalMerge::doMerge(SmallVectorImpl<GlobalVariable*> &Globals,
       }
       Tys.push_back(Ty);
       Inits.push_back(Globals[j]->getInitializer());
-
-      if (Globals[j]->hasExternalLinkage() && !HasExternal) {
-        HasExternal = true;
-        TheFirstExternal = Globals[j];
-      }
     }
 
-    // If merged variables doesn't have external linkage, we needn't to expose
-    // the symbol after merging.
-    GlobalValue::LinkageTypes Linkage = HasExternal ?
-                                          GlobalValue::ExternalLinkage :
-                                          GlobalValue::InternalLinkage ;
-
-    // If merged variables have external linkage, we use symbol name of the
-    // first variable merged as the suffix of global symbol name. This would
-    // be able to avoid the link-time naming conflict for globalm symbols.
-    Twine MergedGVName = HasExternal ?
-                           "_MergedGlobals_" + TheFirstExternal->getName() :
-                           "_MergedGlobals" ;
-
     StructType *MergedTy = StructType::get(M.getContext(), Tys);
     Constant *MergedInit = ConstantStruct::get(MergedTy, Inits);
-
     GlobalVariable *MergedGV = new GlobalVariable(M, MergedTy, isConst,
-                                     Linkage, MergedInit, MergedGVName,
-                                     nullptr, GlobalVariable::NotThreadLocal,
-                                     AddrSpace);
-
-    if (EnableGlobalMergeAligned) {
-      unsigned Align = TLI->getGlobalMergeAlignment(MergedTy);
-      assert(((Align % DL->getABITypeAlignment(MergedTy)) == 0) &&
-        "Specified alignment doesn't meet natural alignment requirement.");
-      MergedGV->setAlignment(Align);
-    }
-
+                                                  GlobalValue::InternalLinkage,
+                                                  MergedInit, "_MergedGlobals",
+                                                  nullptr,
+                                                  GlobalVariable::NotThreadLocal,
+                                                  AddrSpace);
     for (size_t k = i; k < j; ++k) {
-      GlobalValue::LinkageTypes Linkage = Globals[k]->getLinkage();
-      std::string Name = Globals[k]->getName();
-
       Constant *Idx[2] = {
         ConstantInt::get(Int32Ty, 0),
         ConstantInt::get(Int32Ty, k-i)
@@ -240,12 +185,6 @@ bool GlobalMerge::doMerge(SmallVectorImpl<GlobalVariable*> &Globals,
       Constant *GEP = ConstantExpr::getInBoundsGetElementPtr(MergedGV, Idx);
       Globals[k]->replaceAllUsesWith(GEP);
       Globals[k]->eraseFromParent();
-
-      if (Linkage != GlobalValue::InternalLinkage) {
-        // Generate a new alias...
-        new GlobalAlias(GEP->getType(), Linkage, Name, GEP, &M);
-      }
-
       NumMerged++;
     }
     i = j;
@@ -306,12 +245,8 @@ bool GlobalMerge::doInitialization(Module &M) {
   // Grab all non-const globals.
   for (Module::global_iterator I = M.global_begin(),
          E = M.global_end(); I != E; ++I) {
-    // Merge is safe for "normal" internal or external globals only
-    if (I->isDeclaration() || I->isThreadLocal() || I->hasSection())
-      continue;
-
-    if (!(EnableGlobalMergeOnExternal && I->hasExternalLinkage())
-          && !I->hasInternalLinkage())
+    // Merge is safe for "normal" internal globals only
+    if (!I->hasLocalLinkage() || I->isThreadLocal() || I->hasSection())
       continue;
 
     PointerType *PT = dyn_cast<PointerType>(I->getType());