Index: lib/Target/AArch64/AArch64FastISel.cpp
===================================================================
--- lib/Target/AArch64/AArch64FastISel.cpp
+++ lib/Target/AArch64/AArch64FastISel.cpp
@@ -3270,6 +3270,8 @@
     return Len < 32;
 }
 
+// FIXME: MemCpy intrinsic now provides separate alignments for source and
+// dest. Enhance this function to exploit this.
 bool AArch64FastISel::tryEmitSmallMemCpy(Address Dest, Address Src,
                                          uint64_t Len, unsigned Alignment) {
   // Make sure we don't bloat code by inlining very large memcpy's.
@@ -3457,7 +3459,8 @@
       // Small memcpy's are common enough that we want to do them without a call
       // if possible.
       uint64_t Len = cast<ConstantInt>(MTI->getLength())->getZExtValue();
-      unsigned Alignment = MTI->getAlignment();
+      unsigned Alignment = MinAlign(MTI->getDestAlignment(),
+                                    MTI->getSourceAlignment());
       if (isMemCpySmall(Len, Alignment)) {
         Address Dest, Src;
         if (!computeAddress(MTI->getRawDest(), Dest) ||