--- old/src/hotspot/cpu/x86/macroAssembler_x86.hpp	2019-03-06 22:35:24.615132922 +0100
+++ new/src/hotspot/cpu/x86/macroAssembler_x86.hpp	2019-03-06 22:35:24.405133019 +0100
@@ -165,6 +165,7 @@
 
   // Support optimal SSE move instructions.
   void movflt(XMMRegister dst, XMMRegister src) {
+    if (dst-> encoding() == src->encoding()) return;
     if (UseXmmRegToRegMoveAll) { movaps(dst, src); return; }
     else                       { movss (dst, src); return; }
   }
@@ -173,6 +174,7 @@
   void movflt(Address dst, XMMRegister src) { movss(dst, src); }
 
   void movdbl(XMMRegister dst, XMMRegister src) {
+    if (dst-> encoding() == src->encoding()) return;
     if (UseXmmRegToRegMoveAll) { movapd(dst, src); return; }
     else                       { movsd (dst, src); return; }
   }