1/* urem.s 4.4 85/01/16 */ 2 3/* 4 * urem - unsigned remainder for vax-11 5 * 6 * arguments: dividend, divisor 7 * result: remainder 8 * uses r0-r2 9 * 10 * if 1 < divisor <= 2147483647, zero-extend the dividend 11 * to 64 bits and let ediv do the work. If the divisor is 1, 12 * ediv will overflow if bit 31 of the dividend is on, so 13 * just return 0. If the divisor is 0, do the ediv also, 14 * so it will generate the proper exception. All other values 15 * of the divisor have bit 31 on: in this case the remainder 16 * must be the dividend if divisor > dividend, and the dividend 17 * minus the divisor otherwise. The comparison must be unsigned. 18 */ 19#include "DEFS.h" 20 21ASENTRY(urem, 0) 22 movl 4(ap),r0 /* dividend */ 23 movl 8(ap),r2 /* divisor */ 24 jeql 1f /* if divisor=0, force exception */ 25 cmpl r2,$1 /* if divisor <= 1 (signed), */ 26 jleq 2f /* no division is necessary */ 271: 28 clrl r1 /* zero-extend the dividend */ 29 ediv r2,r0,r2,r0 /* divide. q->r2 (discarded), r->r0 */ 30 ret 312: 32 jneq 1f /* if divisor=1, return 0 */ 33 clrl r0 /* (because doing the divide will overflow */ 34 ret /* if the dividend has its high bit on) */ 351: 36 cmpl r0,r2 /* if dividend < divisor (unsigned) */ 37 jlssu 1f /* remainder is dividend */ 38 subl2 r2,r0 /* else remainder is dividend - divisor */ 391: 40 ret 41 42/* 43 * aurem - unsigned remainder for vax-11 44 * 45 * arguments: *dividend, divisor 46 * result: remainder in r0 and *dividend 47 * uses r0-r2 48 */ 49#include "DEFS.h" 50 51ASENTRY(aurem, 0) 52 movl *4(ap),r0 /* dividend */ 53 movl 8(ap),r2 /* divisor */ 54 jeql 1f /* if divisor=0, force exception */ 55 cmpl r2,$1 /* if divisor <= 1 (signed), */ 56 jleq 2f /* no division is necessary */ 571: 58 clrl r1 /* zero-extend the dividend */ 59 ediv r2,r0,r2,r0 /* divide. q->r2 (discarded), r->r0 */ 60 movl r0,*4(ap) /* save result */ 61 ret 622: 63 jneq 1f /* if divisor=1, return 0 */ 64 clrl r0 /* (because doing the divide will overflow */ 65 clrl *4(ap) /* if the dividend has its high bit on) */ 66 ret 671: 68 cmpl r0,r2 /* if dividend < divisor (unsigned) */ 69 jlssu 1f /* remainder is dividend */ 70 subl2 r2,r0 /* else remainder is dividend - divisor */ 711: 72 movl r0,*4(ap) /* save result */ 73 ret 74