+ (inst jmp done)
+ ZERO
+ (inst xor res res)
+ DONE))
+
+(define-vop (unsigned-byte-32-len)
+ (:translate integer-length)
+ (:note "inline (unsigned-byte 32) integer-length")
+ (:policy :fast-safe)
+ (:args (arg :scs (unsigned-reg)))
+ (:arg-types unsigned-num)
+ (:results (res :scs (unsigned-reg)))
+ (:result-types unsigned-num)
+ (:generator 26
+ (inst bsr res arg)
+ (inst jmp :z zero)
+ (inst inc res)