mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-19 18:24:14 +08:00
77 lines
1.5 KiB
ArmAsm
77 lines
1.5 KiB
ArmAsm
#include "libgcc.h"
|
|
|
|
;; This function also computes the remainder and stores it in er3.
|
|
.global __udivsi3
|
|
__udivsi3:
|
|
mov.w A1E,A1E ; denominator top word 0?
|
|
bne DenHighNonZero
|
|
|
|
; do it the easy way, see page 107 in manual
|
|
mov.w A0E,A2
|
|
extu.l A2P
|
|
divxu.w A1,A2P
|
|
mov.w A2E,A0E
|
|
divxu.w A1,A0P
|
|
mov.w A0E,A3
|
|
mov.w A2,A0E
|
|
extu.l A3P
|
|
rts
|
|
|
|
; er0 = er0 / er1
|
|
; er3 = er0 % er1
|
|
; trashes er1 er2
|
|
; expects er1 >= 2^16
|
|
DenHighNonZero:
|
|
mov.l er0,er3
|
|
mov.l er1,er2
|
|
#ifdef CONFIG_CPU_H8300H
|
|
divmod_L21:
|
|
shlr.l er0
|
|
shlr.l er2 ; make divisor < 2^16
|
|
mov.w e2,e2
|
|
bne divmod_L21
|
|
#else
|
|
shlr.l #2,er2 ; make divisor < 2^16
|
|
mov.w e2,e2
|
|
beq divmod_L22A
|
|
divmod_L21:
|
|
shlr.l #2,er0
|
|
divmod_L22:
|
|
shlr.l #2,er2 ; make divisor < 2^16
|
|
mov.w e2,e2
|
|
bne divmod_L21
|
|
divmod_L22A:
|
|
rotxl.w r2
|
|
bcs divmod_L23
|
|
shlr.l er0
|
|
bra divmod_L24
|
|
divmod_L23:
|
|
rotxr.w r2
|
|
shlr.l #2,er0
|
|
divmod_L24:
|
|
#endif
|
|
;; At this point,
|
|
;; er0 contains shifted dividend
|
|
;; er1 contains divisor
|
|
;; er2 contains shifted divisor
|
|
;; er3 contains dividend, later remainder
|
|
divxu.w r2,er0 ; r0 now contains the approximate quotient (AQ)
|
|
extu.l er0
|
|
beq divmod_L25
|
|
subs #1,er0 ; er0 = AQ - 1
|
|
mov.w e1,r2
|
|
mulxu.w r0,er2 ; er2 = upper (AQ - 1) * divisor
|
|
sub.w r2,e3 ; dividend - 65536 * er2
|
|
mov.w r1,r2
|
|
mulxu.w r0,er2 ; compute er3 = remainder (tentative)
|
|
sub.l er2,er3 ; er3 = dividend - (AQ - 1) * divisor
|
|
divmod_L25:
|
|
cmp.l er1,er3 ; is divisor < remainder?
|
|
blo divmod_L26
|
|
adds #1,er0
|
|
sub.l er1,er3 ; correct the remainder
|
|
divmod_L26:
|
|
rts
|
|
|
|
.end
|