diff --git a/llvm/include/llvm/Object/ELF.h b/llvm/include/llvm/Object/ELF.h
index 4f0e5b8db8ff..b36460ca52cf 100644
--- a/llvm/include/llvm/Object/ELF.h
+++ b/llvm/include/llvm/Object/ELF.h
@@ -682,6 +682,7 @@ protected:
   virtual error_code getSymbolName(DataRefImpl Symb, StringRef &Res) const;
   virtual error_code getSymbolFileOffset(DataRefImpl Symb, uint64_t &Res) const;
   virtual error_code getSymbolAddress(DataRefImpl Symb, uint64_t &Res) const;
+  virtual error_code getSymbolAlignment(DataRefImpl Symb, uint32_t &Res) const;
   virtual error_code getSymbolSize(DataRefImpl Symb, uint64_t &Res) const;
   virtual error_code getSymbolNMTypeChar(DataRefImpl Symb, char &Res) const;
   virtual error_code getSymbolFlags(DataRefImpl Symb, uint32_t &Res) const;
@@ -1114,6 +1115,21 @@ error_code ELFObjectFile<ELFT>::getSymbolAddress(DataRefImpl Symb,
   }
 }
 
+template<class ELFT>
+error_code ELFObjectFile<ELFT>::getSymbolAlignment(DataRefImpl Symb,
+                                                   uint32_t &Res) const {
+  uint32_t flags;
+  getSymbolFlags(Symb, flags);
+  if (flags & SymbolRef::SF_Common) {
+    uint64_t Value;
+    getSymbolValue(Symb, Value);
+    Res = Value;
+  } else {
+    Res = 0;
+  }
+  return object_error::success;
+}
+
 template<class ELFT>
 error_code ELFObjectFile<ELFT>::getSymbolSize(DataRefImpl Symb,
                                               uint64_t &Result) const {
diff --git a/llvm/include/llvm/Object/MachO.h b/llvm/include/llvm/Object/MachO.h
index 98d3788e44ca..17a8fc2bff7a 100644
--- a/llvm/include/llvm/Object/MachO.h
+++ b/llvm/include/llvm/Object/MachO.h
@@ -39,6 +39,7 @@ public:
   virtual error_code getSymbolName(DataRefImpl Symb, StringRef &Res) const;
   virtual error_code getSymbolAddress(DataRefImpl Symb, uint64_t &Res) const;
   virtual error_code getSymbolFileOffset(DataRefImpl Symb, uint64_t &Res) const;
+  virtual error_code getSymbolAlignment(DataRefImpl Symb, uint32_t &Res) const;
   virtual error_code getSymbolSize(DataRefImpl Symb, uint64_t &Res) const;
   virtual error_code getSymbolType(DataRefImpl Symb,
                                    SymbolRef::Type &Res) const;
diff --git a/llvm/include/llvm/Object/ObjectFile.h b/llvm/include/llvm/Object/ObjectFile.h
index cbe7ec92d3c5..eb53cc0aab58 100644
--- a/llvm/include/llvm/Object/ObjectFile.h
+++ b/llvm/include/llvm/Object/ObjectFile.h
@@ -217,6 +217,8 @@ public:
   /// mapped).
   error_code getAddress(uint64_t &Result) const;
   error_code getFileOffset(uint64_t &Result) const;
+  /// @brief Get the alignment of this symbol as the actual value (not log 2).
+  error_code getAlignment(uint32_t &Result) const;
   error_code getSize(uint64_t &Result) const;
   error_code getType(SymbolRef::Type &Result) const;
 
@@ -292,6 +294,7 @@ protected:
   virtual error_code getSymbolName(DataRefImpl Symb, StringRef &Res) const = 0;
   virtual error_code getSymbolAddress(DataRefImpl Symb, uint64_t &Res) const = 0;
   virtual error_code getSymbolFileOffset(DataRefImpl Symb, uint64_t &Res)const=0;
+  virtual error_code getSymbolAlignment(DataRefImpl Symb, uint32_t &Res) const;
   virtual error_code getSymbolSize(DataRefImpl Symb, uint64_t &Res) const = 0;
   virtual error_code getSymbolType(DataRefImpl Symb,
                                    SymbolRef::Type &Res) const = 0;
@@ -425,6 +428,10 @@ inline error_code SymbolRef::getFileOffset(uint64_t &Result) const {
   return OwningObject->getSymbolFileOffset(SymbolPimpl, Result);
 }
 
+inline error_code SymbolRef::getAlignment(uint32_t &Result) const {
+  return OwningObject->getSymbolAlignment(SymbolPimpl, Result);
+}
+
 inline error_code SymbolRef::getSize(uint64_t &Result) const {
   return OwningObject->getSymbolSize(SymbolPimpl, Result);
 }
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index 354795dc5f85..7b32db7f0e05 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -96,7 +96,8 @@ ObjectImage *RuntimeDyldImpl::loadObject(ObjectBuffer *InputBuffer) {
     bool isCommon = flags & SymbolRef::SF_Common;
     if (isCommon) {
       // Add the common symbols to a list.  We'll allocate them all below.
-      uint64_t Align = getCommonSymbolAlignment(*i);
+      uint32_t Align;
+      Check(i->getAlignment(Align));
       uint64_t Size = 0;
       Check(i->getSize(Size));
       CommonSize += Size + Align;
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
index ef4a4050e9ef..c5bad8e41640 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
@@ -848,13 +848,6 @@ void RuntimeDyldELF::processRelocationRef(unsigned SectionID,
   }
 }
 
-unsigned RuntimeDyldELF::getCommonSymbolAlignment(const SymbolRef &Sym) {
-  // In ELF, the value of an SHN_COMMON symbol is its alignment requirement.
-  uint64_t Align;
-  Check(Sym.getValue(Align));
-  return Align;
-}
-
 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
   if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
     return false;
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
index b6ddf2d6a7ae..102b1c6b593e 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
@@ -68,9 +68,6 @@ class RuntimeDyldELF : public RuntimeDyldImpl {
                               int64_t Addend);
 
 
-  unsigned getCommonSymbolAlignment(const SymbolRef &Sym);
-
-
   uint64_t findPPC64TOC() const;
   void findOPDEntrySection(ObjectImage &Obj,
                            ObjSectionToIDMap &LocalSections,
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
index 3211a1c7eafd..51873b1f4bf0 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
@@ -194,13 +194,6 @@ protected:
     return (uint8_t*)Sections[SectionID].Address;
   }
 
-  // Subclasses can override this method to get the alignment requirement of
-  // a common symbol. Returns no alignment requirement if not implemented.
-  virtual unsigned getCommonSymbolAlignment(const SymbolRef &Sym) {
-    return 0;
-  }
-
-
   void writeInt16BE(uint8_t *Addr, uint16_t Value) {
     if (sys::IsLittleEndianHost)
       Value = sys::SwapByteOrder(Value);
diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index bb6ca93176dd..f6840b8c15d5 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -495,6 +495,19 @@ MachOObjectFile::getSymbolFileOffset(DataRefImpl Symb,
   return object_error::success;
 }
 
+error_code MachOObjectFile::getSymbolAlignment(DataRefImpl DRI,
+                                               uint32_t &Result) const {
+  uint32_t flags;
+  this->getSymbolFlags(DRI, flags);
+  if (flags & SymbolRef::SF_Common) {
+    SymbolTableEntryBase Entry = getSymbolTableEntryBase(this, DRI);
+    Result = 1 << MachO::GET_COMM_ALIGN(Entry.Flags);
+  } else {
+    Result = 0;
+  }
+  return object_error::success;
+}
+
 error_code MachOObjectFile::getSymbolSize(DataRefImpl DRI,
                                           uint64_t &Result) const {
   uint64_t BeginOffset;
@@ -609,8 +622,12 @@ error_code MachOObjectFile::getSymbolFlags(DataRefImpl DRI,
 
   if (MachOType & MachO::NlistMaskExternal) {
     Result |= SymbolRef::SF_Global;
-    if ((MachOType & MachO::NlistMaskType) == MachO::NListTypeUndefined)
-      Result |= SymbolRef::SF_Common;
+    if ((MachOType & MachO::NlistMaskType) == MachO::NListTypeUndefined) {
+      uint64_t Value;
+      getSymbolAddress(DRI, Value);
+      if (Value)
+        Result |= SymbolRef::SF_Common;
+    }
   }
 
   if (MachOFlags & (MachO::NListDescWeakRef | MachO::NListDescWeakDef))
diff --git a/llvm/lib/Object/ObjectFile.cpp b/llvm/lib/Object/ObjectFile.cpp
index 518959aa059d..77fd995cf0e4 100644
--- a/llvm/lib/Object/ObjectFile.cpp
+++ b/llvm/lib/Object/ObjectFile.cpp
@@ -27,6 +27,12 @@ ObjectFile::ObjectFile(unsigned int Type, MemoryBuffer *source)
   : Binary(Type, source) {
 }
 
+error_code ObjectFile::getSymbolAlignment(DataRefImpl DRI,
+                                          uint32_t &Result) const {
+  Result = 0;
+  return object_error::success;
+}
+
 ObjectFile *ObjectFile::createObjectFile(MemoryBuffer *Object) {
   if (!Object || Object->getBufferSize() < 64)
     return 0;
diff --git a/llvm/test/ExecutionEngine/MCJIT/test-common-symbols-alignment.ll b/llvm/test/ExecutionEngine/MCJIT/test-common-symbols-alignment.ll
index 43256c4492c2..989a47342339 100644
--- a/llvm/test/ExecutionEngine/MCJIT/test-common-symbols-alignment.ll
+++ b/llvm/test/ExecutionEngine/MCJIT/test-common-symbols-alignment.ll
@@ -1,5 +1,4 @@
 ; RUN: %lli_mcjit -O0 %s
-; XFAIL: darwin
 
 ; This test checks that common symbols have been allocated addresses honouring
 ; the alignment requirement.