#ifdef LIBC_SCCS .asciz "@(#)udiv.s 5.2 (Berkeley) 3/9/86" #endif LIBC_SCCS /* * udiv - unsigned division for vax-11 * * arguments: dividend, divisor. * result: quotient. * uses r0-r2 * * If 1 < divisor <= 2147483647, zero-extend the dividend * to 64 bits and let ediv do the work. If the divisor is 1, * ediv will overflow if bit 31 of the dividend is on, so * just return the dividend unchanged. If the divisor is 0, * do the ediv also, so it will generate the proper exception. * All other values of the divisor have bit 31 on: in this case * the quotient must be 0 if divisor > dividend, and 1 otherwise, * provided that the comparison is made as unsigned. */ #include "DEFS.h" ASENTRY(udiv, 0) movl 4(ap),r0 /* dividend */ movl 8(ap),r2 /* divisor */ jeql 1f /* if divisor=0, force exception */ cmpl r2,$1 /* if divisor <= 1 (signed), */ jleq 2f /* no division is necessary */ 1: clrl r1 /* zero-extend the dividend */ ediv r2,r0,r0,r2 /* divide. q->r0, r->r2 (discarded) */ ret 2: jeql 1f /* if divisor=1, return dividend */ cmpl r0,r2 /* unsigned comparison between */ jgequ 2f /* dividend and divisor */ clrl r0 /* dividend < divisor, return 0 */ ret 2: movl $1,r0 /* dividend >= divisor, return 1 */ 1: ret /* * audiv - unsigned division for vax-11 * * arguments: *dividend, divisor. * result: quotient in r0 and *dividend. * uses r0-r2 */ #include "DEFS.h" ASENTRY(audiv, 0) movl *4(ap),r0 /* dividend */ movl 8(ap),r2 /* divisor */ jeql 1f /* if divisor=0, force exception */ cmpl r2,$1 /* if divisor <= 1 (signed), */ jleq 2f /* no division is necessary */ 1: clrl r1 /* zero-extend the dividend */ ediv r2,r0,r0,r2 /* divide. q->r0, r->r2 (discarded) */ movl r0,*4(ap) /* save result */ ret 2: jeql 1f /* if divisor=1, return dividend */ cmpl r0,r2 /* unsigned comparison between */ jgequ 2f /* dividend and divisor */ clrl r0 /* dividend < divisor, return 0 */ clrl *4(ap) /* save result */ ret 2: movl $1,r0 /* dividend >= divisor, return 1 */ 1: movl r0,*4(ap) /* save result */ ret