minix/common/lib/libc/arch/m68k/gen/mulsi3.S

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/* $NetBSD: mulsi3.S,v 1.2 2006/01/05 22:33:34 he Exp $ */
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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. 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 <machine/asm.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
RCSID("from: @(#)mulsi3.s 5.1 (Berkeley) 6/7/90")
#else
RCSID("$NetBSD: mulsi3.S,v 1.2 2006/01/05 22:33:34 he Exp $")
#endif
#endif /* LIBC_SCCS and not lint */
/* int * int */
ENTRY(__mulsi3)
#ifndef __mc68010__
movel %sp@(4),%d0
mulsl %sp@(8),%d0
#else
| NB: this requires that __udivsi3 preserve %a0 and return
| the modulus in %d1:
movew %sp@(6), %d0
movel %d0, %a0 | save B
muluw %sp@(8), %d0 | %d0 holds B * C
movew %sp@(10), %d1
movel %d1, %a1 | save D
muluw %sp@(4), %d1 | %d1 holds A * D
addw %d1, %d0 | %d0 holds (B * C) + (A * D)
swap %d0
clrw %d0 | %d0 holds ((B * C) + (A * D)) << 16
exg %a0, %d0 | restore B
movel %a1, %d1 | restore D
muluw %d1, %d0 | %d0 holds B * D
addl %a0, %d0 | final result
#endif /* __mc68010__ */
rts