-#ifdef LIBC_SCCS
- .asciz "@(#)urem.s 5.2 (Berkeley) 3/9/86"
-#endif LIBC_SCCS
-
-/*
- * urem - unsigned remainder for vax-11
+/*-
+ * Copyright (c) 1991, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Donn Seeley at UUNET Technologies, Inc.
*
- * arguments: dividend, divisor
- * result: remainder
- * uses r0-r2
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
*
- * 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 0. 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 remainder
- * must be the dividend if divisor > dividend, and the dividend
- * minus the divisor otherwise. The comparison must be unsigned.
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
*/
-#include "DEFS.h"
-ASENTRY(urem, 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,r2,r0 /* divide. q->r2 (discarded), r->r0 */
- ret
-2:
- jneq 1f /* if divisor=1, return 0 */
- clrl r0 /* (because doing the divide will overflow */
- ret /* if the dividend has its high bit on) */
-1:
- cmpl r0,r2 /* if dividend < divisor (unsigned) */
- jlssu 1f /* remainder is dividend */
- subl2 r2,r0 /* else remainder is dividend - divisor */
-1:
- ret
+#if defined(LIBC_SCCS) && !defined(lint)
+ .asciz "@(#)urem.s 8.1 (Berkeley) 6/4/93"
+#endif /* LIBC_SCCS and not lint */
+
+#include "DEFS.h"
/*
- * aurem - unsigned remainder for vax-11
- *
- * arguments: *dividend, divisor
- * result: remainder in r0 and *dividend
- * uses r0-r2
+ * Unsigned modulus, PCC flavor.
+ * urem() takes an ordinary dividend/divisor pair;
+ * aurem() takes a pointer to a dividend and an ordinary divisor.
*/
-#include "DEFS.h"
-ASENTRY(aurem, 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,r2,r0 /* divide. q->r2 (discarded), r->r0 */
- movl r0,*4(ap) /* save result */
+#define DIVIDEND 4(ap)
+#define DIVISOR 8(ap)
+
+ASENTRY(urem,0)
+ movl DIVISOR,r2
+ jlss Leasy # big divisor: settle by comparison
+ movl DIVIDEND,r0
+ jlss Lhard # big dividend: need extended division
+ divl3 r2,r0,r1 # small divisor and dividend: signed modulus
+ mull2 r2,r1
+ subl2 r1,r0
+ ret
+Lhard:
+ clrl r1
+ ediv r2,r0,r1,r0
+ ret
+Leasy:
+ subl3 r2,DIVIDEND,r0
+ jcc Ldifference # if divisor goes in once, return difference
+ movl DIVIDEND,r0 # if divisor is bigger, return dividend
+Ldifference:
+ ret
+
+ASENTRY(aurem,0)
+ movl DIVIDEND,r3
+ movl DIVISOR,r2
+ jlss La_easy # big divisor: settle by comparison
+ movl (r3),r0
+ jlss La_hard # big dividend: need extended division
+ divl3 r2,r0,r1 # small divisor and dividend: signed modulus
+ mull2 r2,r1
+ subl2 r1,r0
+ movl r0,(r3) # leave the value of the assignment in r0
+ ret
+La_hard:
+ clrl r1
+ ediv r2,r0,r1,r0
+ movl r0,(r3)
+ ret
+La_easy:
+ subl3 r2,(r3),r0
+ jcs La_dividend # if divisor is bigger, leave dividend alone
+ movl r0,(r3) # if divisor goes in once, store difference
ret
-2:
- jneq 1f /* if divisor=1, return 0 */
- clrl r0 /* (because doing the divide will overflow */
- clrl *4(ap) /* if the dividend has its high bit on) */
- ret
-1:
- cmpl r0,r2 /* if dividend < divisor (unsigned) */
- jlssu 1f /* remainder is dividend */
- subl2 r2,r0 /* else remainder is dividend - divisor */
-1:
- movl r0,*4(ap) /* save result */
+La_dividend:
+ movl (r3),r0
ret