diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c
index 8e14ebb35b..a588435b5e 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -527,8 +527,8 @@ static inline void put_loop_count(
         if ( !amd_like(ctxt) && mode_64bit() && ad_bytes == 4 )         \
         {                                                               \
             _regs.r(cx) = 0;                                            \
-            if ( extend_si ) _regs.r(si) = _regs.esi;                   \
-            if ( extend_di ) _regs.r(di) = _regs.edi;                   \
+            if ( extend_si ) _regs.r(si) = (uint32_t)_regs.r(si);       \
+            if ( extend_di ) _regs.r(di) = (uint32_t)_regs.r(di);       \
         }                                                               \
         goto complete_insn;                                             \
     }                                                                   \
@@ -2029,7 +2029,7 @@ x86_emulate(
         switch ( op_bytes )
         {
         case 2: _regs.ax = (int8_t)_regs.ax; break; /* cbw */
-        case 4: _regs.r(ax) = (uint32_t)(int16_t)_regs.ax; break; /* cwde */
+        case 4: _regs.r(ax) = (uint32_t)(int16_t)_regs.r(ax); break; /* cwde */
         case 8: _regs.r(ax) = (int32_t)_regs.r(ax); break; /* cdqe */
         }
         break;