--- a/gcc/config/avr32/lib1funcs.S
+++ b/gcc/config/avr32/lib1funcs.S
@@ -2800,6 +2800,7 @@ __extendsfdf_return_op1:        
         lsl     r11,8                   /* check mantissa */
         movne   r11, -1                 /* Return NaN */
         moveq   r11, r10                /* Return inf */
+        mov     r10, 0
         rjmp    __extendsfdf_return_op1
 #endif