(cond ((integerp src)
(maybe-emit-rex-prefix segment size nil nil dst)
(cond ((and (eq size :qword)
- (typep src '(signed-byte 31)))
+ (typep src '(signed-byte 32)))
;; When loading small immediates to a qword register
;; using B8 wastes 3 bytes compared to C7.
(emit-byte segment #b11000111)