1*13421Sroot/* urem.s 4.1 83/06/27 */ 2*13421Sroot 3*13421Sroot/* 4*13421Sroot * urem - unsigned remainder for vax-11 5*13421Sroot * 6*13421Sroot * arguments: dividend, divisor 7*13421Sroot * result: remainder 8*13421Sroot * uses r0-r2 9*13421Sroot * 10*13421Sroot * if 1 < divisor <= 2147483647, zero-extend the dividend 11*13421Sroot * to 64 bits and let ediv do the work. If the divisor is 1, 12*13421Sroot * ediv will overflow if bit 31 of the dividend is on, so 13*13421Sroot * just return 0. If the divisor is 0, do the ediv also, 14*13421Sroot * so it will generate the proper exception. All other values 15*13421Sroot * of the divisor have bit 31 on: in this case the remainder 16*13421Sroot * must be the dividend if divisor > dividend, and the dividend 17*13421Sroot * minus the divisor otherwise. The comparison must be unsigned. 18*13421Sroot */ 19*13421Sroot#include "DEFS.h" 20*13421Sroot 21*13421SrootENTRY(urem) 22*13421Sroot movl 4(ap),r0 /* dividend */ 23*13421Sroot movl 8(ap),r2 /* divisor */ 24*13421Sroot jeql 1f /* if divisor=0, force exception */ 25*13421Sroot cmpl r2,$1 /* if divisor <= 1 (signed), */ 26*13421Sroot jleq 2f /* no division is necessary */ 27*13421Sroot1: 28*13421Sroot clrl r1 /* zero-extend the dividend */ 29*13421Sroot ediv r2,r0,r2,r0 /* divide. q->r2 (discarded), r->r0 */ 30*13421Sroot ret 31*13421Sroot2: 32*13421Sroot jneq 1f /* if divisor=1, return 0 */ 33*13421Sroot clrl r0 /* (because doing the divide will overflow */ 34*13421Sroot ret /* if the dividend has its high bit on) */ 35*13421Sroot1: 36*13421Sroot cmpl r0,r2 /* if dividend < divisor (unsigned) */ 37*13421Sroot jlssu 1f /* remainder is dividend */ 38*13421Sroot subl2 r2,r0 /* else remainder is dividend - divisor */ 39*13421Sroot1: 40*13421Sroot ret 41