--- a/gcc/config/avr32/lib1funcs.S
+++ b/gcc/config/avr32/lib1funcs.S
@@ -1036,6 +1036,7 @@ __avr32_f64_add_opL_nan_or_inf:
         brne    __avr32_f64_add_return_nan
         mov     r10, 0  /* Generate Inf in r11, r10 */
 	mov_imm r11, 0x7ff00000
+        or      r11, r12 /* Put sign bit back */
         ldm     sp++, r5, r6, r7, pc/* opL Inf, return Inf */
 __avr32_f64_add_return_nan:     
         mov     r10, -1 /* Generate NaN in r11, r10 */
