diff --git a/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp b/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
index 7c630a2b0da08..0bff1884933d8 100644
--- a/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
+++ b/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
@@ -80,13 +80,13 @@ SDValue X86SelectionDAGInfo::EmitTargetCodeForMemset(
     uint64_t Val = ValC->getZExtValue() & 255;
 
     // If the value is a constant, then we can potentially use larger sets.
-    if (Alignment > Align(2)) {
+    if (Alignment >= Align(4)) {
       // DWORD aligned
       AVT = MVT::i32;
       ValReg = X86::EAX;
       Val = (Val << 8)  | Val;
       Val = (Val << 16) | Val;
-      if (Subtarget.is64Bit() && Alignment > Align(8)) { // QWORD aligned
+      if (Subtarget.is64Bit() && Alignment >= Align(8)) { // QWORD aligned
         AVT = MVT::i64;
         ValReg = X86::RAX;
         Val = (Val << 32) | Val;
diff --git a/llvm/test/CodeGen/X86/memset-minsize.ll b/llvm/test/CodeGen/X86/memset-minsize.ll
index 76d2928db3a9e..cc0f2156262bb 100644
--- a/llvm/test/CodeGen/X86/memset-minsize.ll
+++ b/llvm/test/CodeGen/X86/memset-minsize.ll
@@ -136,4 +136,17 @@ entry:
   ret void
 }
 
+define void @small_memset_to_rep_stos_64(ptr %ptr) minsize nounwind {
+; CHECK-LABEL: small_memset_to_rep_stos_64:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    pushq $16
+; CHECK-NEXT:    popq %rcx
+; CHECK-NEXT:    xorl %eax, %eax
+; CHECK-NEXT:    rep;stosq %rax, %es:(%rdi)
+; CHECK-NEXT:    retq
+entry:
+  call void @llvm.memset.p0.i64(ptr align 8 %ptr, i8 0, i64 128, i1 false)
+  ret void
+}
+
 declare void @llvm.memset.p0.i32(ptr nocapture writeonly, i8, i32, i1)