minix/common/lib/libc/arch/mips/gen/byte_swap_4.S
Gianluca Guida b6cbf7203b Import unmodified NetBSD libc in trunk
This patch imports the unmodified current version of NetBSD libc.
The NetBSD includes are in /nbsd_include, while the libc code itself is 
split between lib/nbsd_libc and common/lib/libc.
2011-02-14 19:36:03 +00:00

87 lines
2.9 KiB
ArmAsm

/* $NetBSD: byte_swap_4.S,v 1.3 2009/12/14 00:39:00 matt Exp $ */
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Ralph Campbell.
*
* 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 <mips/asm.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
RCSID("from: @(#)htonl.s 8.1 (Berkeley) 6/4/93")
#else
RCSID("$NetBSD: byte_swap_4.S,v 1.3 2009/12/14 00:39:00 matt Exp $")
#endif
#endif /* LIBC_SCCS and not lint */
#undef _LOCORE
#define _LOCORE /* XXX not really, just assembly-code source */
#include <machine/endian.h>
#if defined(_KERNEL) || defined(_STANDALONE)
#define BSWAP32_NAME bswap32
#else
#define BSWAP32_NAME __bswap32
#endif
NLEAF(BSWAP32_NAME) # a0 = 0x11223344, return 0x44332211
#if BYTE_ORDER == LITTLE_ENDIAN
ALEAF(htonl) # a0 = 0x11223344, return 0x44332211
ALEAF(ntohl)
#endif
#if (__mips == 32 || __mips == 64) && __mips_isa_rev == 2
/*
* If we are on MIPS32R2 or MIPS64R2 it's much easier
*/
wsbh a0, a0 # word swap bytes within halfwords
rotr v0, a0, 16 # rotate word 16bits
j ra
#else
srl v1, a0, 24 # v1 = 0x00000011
sll v0, a0, 24 # v0 = 0x44000000
or v0, v0, v1
and v1, a0, 0xff00
sll v1, v1, 8 # v1 = 0x00330000
or v0, v0, v1
srl v1, a0, 8
and v1, v1, 0xff00 # v1 = 0x00002200
or v0, v0, v1
j ra
#endif
END(BSWAP32_NAME)
#if BYTE_ORDER == BIG_ENDIAN
NLEAF(htonl) # a0 = 0x11223344, return 0x44332211
ALEAF(ntohl)
move v0, a0
j ra
END(htonl)
#endif