-#ifdef LIBC_SCCS
- .asciz "@(#)udiv.s 5.2 (Berkeley) 3/9/86"
-#endif LIBC_SCCS
-
-/*
- * udiv - unsigned division for vax-11
+/*-
+ * Copyright (c) 1991, 1993
+ * The Regents of the University of California. All rights reserved.
*
- * arguments: dividend, divisor.
- * result: quotient.
- * uses r0-r2
+ * This code is derived from software contributed to Berkeley by
+ * Donn Seeley at UUNET Technologies, Inc.
*
- * 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.
+ * 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.
+ *
+ * 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(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
+#if defined(LIBC_SCCS) && !defined(lint)
+ .asciz "@(#)udiv.s 8.1 (Berkeley) 6/4/93"
+#endif /* LIBC_SCCS and not lint */
/*
- * audiv - unsigned division for vax-11
- *
- * arguments: *dividend, divisor.
- * result: quotient in r0 and *dividend.
- * uses r0-r2
+ * Unsigned division, PCC flavor.
+ * udiv() takes an ordinary dividend/divisor pair;
+ * audiv() takes a pointer to a dividend and an ordinary divisor.
*/
#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 */
+#define DIVIDEND 4(ap)
+#define DIVISOR 8(ap)
+
+ASENTRY(udiv,0)
+ movl DIVISOR,r2
+ jlss Leasy # big divisor: settle by comparison
+ movl DIVIDEND,r0
+ jlss Lhard # big dividend: extended division
+ divl2 r2,r0 # small divisor and dividend: signed division
+ ret
+Lhard:
+ clrl r1
+ ediv r2,r0,r0,r1
+ ret
+Leasy:
+ cmpl DIVIDEND,r2
+ jgequ Lone # if dividend is as big or bigger, return 1
+ clrl r0 # else return 0
+ ret
+Lone:
+ movl $1,r0
+ ret
+
+ASENTRY(audiv,0)
+ movl DIVIDEND,r3
+ movl DIVISOR,r2
+ jlss La_easy # big divisor: settle by comparison
+ movl (r3),r0
+ jlss La_hard # big dividend: extended division
+ divl2 r2,r0 # small divisor and dividend: signed division
+ movl r0,(r3) # leave the value of the assignment in r0
+ ret
+La_hard:
+ clrl r1
+ ediv r2,r0,r0,r1
+ movl r0,(r3)
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 */
+La_easy:
+ cmpl (r3),r2
+ jgequ La_one # if dividend is as big or bigger, return 1
+ clrl r0 # else return 0
+ clrl (r3)
ret
-2:
- movl $1,r0 /* dividend >= divisor, return 1 */
-1:
- movl r0,*4(ap) /* save result */
+La_one:
+ movl $1,r0
+ movl r0,(r3)
ret