1#ifdef LIBC_SCCS 2 .asciz "@(#)udiv.s 5.2 (Berkeley) 03/09/86" 3#endif LIBC_SCCS 4 5/* 6 * udiv - unsigned division for vax-11 7 * 8 * arguments: dividend, divisor. 9 * result: quotient. 10 * uses r0-r2 11 * 12 * If 1 < divisor <= 2147483647, zero-extend the dividend 13 * to 64 bits and let ediv do the work. If the divisor is 1, 14 * ediv will overflow if bit 31 of the dividend is on, so 15 * just return the dividend unchanged. If the divisor is 0, 16 * do the ediv also, so it will generate the proper exception. 17 * All other values of the divisor have bit 31 on: in this case 18 * the quotient must be 0 if divisor > dividend, and 1 otherwise, 19 * provided that the comparison is made as unsigned. 20 */ 21 22#include "DEFS.h" 23 24ASENTRY(udiv, 0) 25 movl 4(ap),r0 /* dividend */ 26 movl 8(ap),r2 /* divisor */ 27 jeql 1f /* if divisor=0, force exception */ 28 cmpl r2,$1 /* if divisor <= 1 (signed), */ 29 jleq 2f /* no division is necessary */ 301: 31 clrl r1 /* zero-extend the dividend */ 32 ediv r2,r0,r0,r2 /* divide. q->r0, r->r2 (discarded) */ 33 ret 342: 35 jeql 1f /* if divisor=1, return dividend */ 36 cmpl r0,r2 /* unsigned comparison between */ 37 jgequ 2f /* dividend and divisor */ 38 clrl r0 /* dividend < divisor, return 0 */ 39 ret 402: 41 movl $1,r0 /* dividend >= divisor, return 1 */ 421: 43 ret 44 45/* 46 * audiv - unsigned division for vax-11 47 * 48 * arguments: *dividend, divisor. 49 * result: quotient in r0 and *dividend. 50 * uses r0-r2 51 */ 52 53#include "DEFS.h" 54 55ASENTRY(audiv, 0) 56 movl *4(ap),r0 /* dividend */ 57 movl 8(ap),r2 /* divisor */ 58 jeql 1f /* if divisor=0, force exception */ 59 cmpl r2,$1 /* if divisor <= 1 (signed), */ 60 jleq 2f /* no division is necessary */ 611: 62 clrl r1 /* zero-extend the dividend */ 63 ediv r2,r0,r0,r2 /* divide. q->r0, r->r2 (discarded) */ 64 movl r0,*4(ap) /* save result */ 65 ret 662: 67 jeql 1f /* if divisor=1, return dividend */ 68 cmpl r0,r2 /* unsigned comparison between */ 69 jgequ 2f /* dividend and divisor */ 70 clrl r0 /* dividend < divisor, return 0 */ 71 clrl *4(ap) /* save result */ 72 ret 732: 74 movl $1,r0 /* dividend >= divisor, return 1 */ 751: 76 movl r0,*4(ap) /* save result */ 77 ret 78