#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 |