diff --git a/llvm/include/llvm/MC/MCSymbol.h b/llvm/include/llvm/MC/MCSymbol.h
--- a/llvm/include/llvm/MC/MCSymbol.h
+++ b/llvm/include/llvm/MC/MCSymbol.h
@@ -342,14 +342,12 @@
   /// \param Size - The size of the symbol.
   /// \param Align - The alignment of the symbol.
   /// \param Target - Is the symbol a target-specific common-like symbol.
-  void setCommon(uint64_t Size, unsigned Align, bool Target = false) {
+  void setCommon(uint64_t Size, Align Align, bool Target = false) {
     assert(getOffset() == 0);
     CommonSize = Size;
     SymbolContents = Target ? SymContentsTargetCommon : SymContentsCommon;
 
-    assert((!Align || isPowerOf2_32(Align)) &&
-           "Alignment must be a power of 2");
-    unsigned Log2Align = Log2_32(Align) + 1;
+    unsigned Log2Align = encode(Align);
     assert(Log2Align < (1U << NumCommonAlignmentBits) &&
            "Out of range alignment");
     CommonAlignLog2 = Log2Align;
@@ -374,7 +372,7 @@
           isTargetCommon() != Target)
         return true;
     } else
-      setCommon(Size, Align, Target);
+      setCommon(Size, llvm::Align(Align), Target);
     return false;
   }
 
diff --git a/llvm/lib/MC/MCMachOStreamer.cpp b/llvm/lib/MC/MCMachOStreamer.cpp
--- a/llvm/lib/MC/MCMachOStreamer.cpp
+++ b/llvm/lib/MC/MCMachOStreamer.cpp
@@ -436,7 +436,7 @@
 
   getAssembler().registerSymbol(*Symbol);
   Symbol->setExternal(true);
-  Symbol->setCommon(Size, ByteAlignment);
+  Symbol->setCommon(Size, Align(ByteAlignment));
 }
 
 void MCMachOStreamer::emitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
diff --git a/llvm/lib/MC/MCWinCOFFStreamer.cpp b/llvm/lib/MC/MCWinCOFFStreamer.cpp
--- a/llvm/lib/MC/MCWinCOFFStreamer.cpp
+++ b/llvm/lib/MC/MCWinCOFFStreamer.cpp
@@ -276,7 +276,7 @@
 
   getAssembler().registerSymbol(*Symbol);
   Symbol->setExternal(true);
-  Symbol->setCommon(Size, ByteAlignment);
+  Symbol->setCommon(Size, Align(ByteAlignment));
 
   if (!T.isWindowsMSVCEnvironment() && ByteAlignment > 1) {
     SmallString<128> Directive;
diff --git a/llvm/lib/MC/MCXCOFFStreamer.cpp b/llvm/lib/MC/MCXCOFFStreamer.cpp
--- a/llvm/lib/MC/MCXCOFFStreamer.cpp
+++ b/llvm/lib/MC/MCXCOFFStreamer.cpp
@@ -95,7 +95,7 @@
   getAssembler().registerSymbol(*Symbol);
   Symbol->setExternal(cast<MCSymbolXCOFF>(Symbol)->getStorageClass() !=
                       XCOFF::C_HIDEXT);
-  Symbol->setCommon(Size, ByteAlignment);
+  Symbol->setCommon(Size, Align(ByteAlignment));
 
   // Default csect align is 4, but common symbols have explicit alignment values
   // and we should honor it.