我目前正忙着做作业,并请求一些帮助。我们的任务是实现x ^ 4/4!在手臂组装。我已成功计算出x ^ 4和4!的正确值,但我仍然坚持如何计算显然有浮点的除法。我已经实现了一个简单的除法算法,但是根据我的理解,这只适用于整数除法,不是吗?
CMP R2, #0
BEQ divide_end
MOV R0,#0 ;clear R0 to accumulate result
MOV R3,#1 ;set bit 0 in R3, which will be
;shifted left then right
.start
CMP R2,R1
MOVLS R2,R2,LSL#1
MOVLS R3,R3,LSL#1
BLS start
;shift R2 left until it is about to
;be bigger than R1
;shift R3 left in parallel in order
;to flag how far we have to go
.next
CMP R1,R2 ;carry set if R1>R2
SUBCS R1,R1,R2 ;subtract R2 from R1 if this would
;give a positive answer
ADDCS R0,R0,R3 ;and add the current bit in R3 to
;the accumulating answer in R0
MOVS R3,R3,LSR#1 ;Shift R3 right into carry flag
MOVCC R2,R2,LSR#1 ;and if bit 0 of R3 was zero, also
;shift R2 right
BCC next ;If carry not clear, R3 has shifted
;back to where it started, and we
;can end
.divide_end
也许我在这里真的很蠢,但任何帮助都会受到赞赏 非常感谢
答案 0 :(得分:0)
我只是愚蠢。我们被允许使用FPU指令。所以我可以使用VDIV!