Bring r254336 back:

[oota-llvm.git] / lib / Transforms / Utils / GlobalStatus.cpp

diff --git a/lib/Transforms/Utils/GlobalStatus.cpp b/lib/Transforms/Utils/GlobalStatus.cpp
index 33e34a9941e051b921bb0b5b53156533a3f265f9..3893a752503b6b63600edd6ddd6b7b56461054b5 100644 (file)
--- a/lib/Transforms/Utils/GlobalStatus.cpp
+++ b/lib/Transforms/Utils/GlobalStatus.cpp
@@ -35,6 +35,9 @@ bool llvm::isSafeToDestroyConstant(const Constant *C) {
   if (isa<GlobalValue>(C))
     return false;
 
+  if (isa<ConstantInt>(C) || isa<ConstantFP>(C))
+    return false;
+
   for (const User *U : C->users())
     if (const Constant *CU = dyn_cast<Constant>(U)) {
       if (!isSafeToDestroyConstant(CU))
@@ -46,6 +49,10 @@ bool llvm::isSafeToDestroyConstant(const Constant *C) {
 
 static bool analyzeGlobalAux(const Value *V, GlobalStatus &GS,
                              SmallPtrSetImpl<const PHINode *> &PhiUsers) {
+  if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
+    if (GV->isExternallyInitialized())
+      GS.StoredType = GlobalStatus::StoredOnce;
+
   for (const Use &U : V->uses()) {
     const User *UR = U.getUser();
     if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(UR)) {
@@ -130,7 +137,7 @@ static bool analyzeGlobalAux(const Value *V, GlobalStatus &GS,
       } else if (const PHINode *PN = dyn_cast<PHINode>(I)) {
         // PHI nodes we can check just like select or GEP instructions, but we
         // have to be careful about infinite recursion.
-        if (PhiUsers.insert(PN)) // Not already visited.
+        if (PhiUsers.insert(PN).second) // Not already visited.
           if (analyzeGlobalAux(I, GS, PhiUsers))
             return true;
       } else if (isa<CmpInst>(I)) {
@@ -147,7 +154,7 @@ static bool analyzeGlobalAux(const Value *V, GlobalStatus &GS,
         if (MSI->isVolatile())
           return true;
         GS.StoredType = GlobalStatus::Stored;
-      } else if (ImmutableCallSite C = I) {
+      } else if (auto C = ImmutableCallSite(I)) {
         if (!C.isCallee(&U))
           return true;
         GS.IsLoaded = true;