66 lines
2.5 KiB
ArmAsm
66 lines
2.5 KiB
ArmAsm
/* $NetBSD: byte_swap_4.S,v 1.7 2013/08/19 03:44:47 matt Exp $ */
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/*-
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* Copyright (c) 1997 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Neil A. Carson
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <machine/asm.h>
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#if defined(_KERNEL) || defined(_STANDALONE)
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#define FUNC _C_LABEL(bswap32)
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#else
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#define FUNC _C_LABEL(__bswap32)
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#endif
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ENTRY(FUNC)
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#ifdef _ARM_ARCH_6
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rev r0, r0
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#elif !defined(__thumb__)
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eor r1, r0, r0, ror #16 /* 4.3.2.1 -> 42.31.42.31 */
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bic r1, r1, #0x00FF0000 /* 42.31.42.31 -> 42.0.42.31 */
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mov r0, r0, ror #8 /* 4.3.2.1 -> 1.4.3.2 */
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eor r0, r0, r1, lsr #8 /* 1.4.3.2 ^ 0.42.0.42 -> 1.2.3.4 */
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#else
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movs r3, #16
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lsls r1, r0, #8 /* 4.3.2.1 -> 3.2.1.0 /*
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lsrs r0, r0, #8 /* 4.3.2.1 -> 0.4.3.2 */
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rors r1, r3 /* 3.2.1.0 -> 1.0.3.2 */
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rors r0, r3 /* 0.4.3.2 -> 3.2.0.4 */
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lsrs r1, r1, #8 /* 1.0.3.2 -> 0.1.0.3 */
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lsls r1, r1, #8 /* 0.1.0.3 -> 1.0.3.0 */
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lsls r0, r0, #8 /* 3.2.0.4 -> 2.0.4.0 */
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lsrs r0, r0, #8 /* 2.0.4.0 -> 0.2.0.4 */
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orrs r0, r0, r1 /* 1.0.3.0 | 0.2.0.4 -> 1.2.3.4 */
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#endif
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RET
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END(FUNC)
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#if BYTE_ORDER == LITTLE_ENDIAN
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STRONG_ALIAS(_C_LABEL(ntohl), FUNC)
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STRONG_ALIAS(_C_LABEL(htonl), FUNC)
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#endif
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