diff --git a/lib/Target/X86/README-MMX.txt b/lib/Target/X86/README-MMX.txt
index f3a625e65dc..57c7c3f48c8 100644
--- a/lib/Target/X86/README-MMX.txt
+++ b/lib/Target/X86/README-MMX.txt
@@ -40,3 +40,30 @@ _qux:
         movl    %edx, 4(%eax)
         addl    $12, %esp
         ret     $4
+
+//===---------------------------------------------------------------------===//
+
+int main() {
+  __m64 A[1] = { _mm_cvtsi32_si64(1)  };
+  __m64 B[1] = { _mm_cvtsi32_si64(10) };
+  __m64 sum = _mm_cvtsi32_si64(0);
+
+  sum = __builtin_ia32_paddq(__builtin_ia32_paddq(A[0], B[0]), sum);
+
+  printf("Sum = %d\n", _mm_cvtsi64_si32(sum));
+  return 0;
+}
+
+Generates:
+
+        movl $11, %eax
+###     movd %eax, %mm0
+###     movq %mm0, 8(%esp)
+###     movl 8(%esp), %eax
+        movl %eax, 4(%esp)
+        movl $_str, (%esp)
+        call L_printf$stub
+        xorl %eax, %eax
+        addl $28, %esp
+
+These instructions are unnecessary.