/* $NetBSD: byte_swap_4.S,v 1.9 2020/12/11 09:02:33 dholland Exp $ */ /*- * Copyright (c) 1997 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Neil A. Carson * * 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. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 #if defined(_KERNEL) || defined(_STANDALONE) #define FUNC _C_LABEL(bswap32) #else #define FUNC _C_LABEL(__bswap32) #endif ENTRY(FUNC) #ifdef _ARM_ARCH_6 rev r0, r0 #elif !defined(__thumb__) eor r1, r0, r0, ror #16 /* d.c.b.a -> db.ca.db.ca */ bic r1, r1, #0x00FF0000 /* db.ca.db.ca -> db.0.db.ca */ mov r0, r0, ror #8 /* d.c.b.a -> a.d.c.b */ eor r0, r0, r1, lsr #8 /* a.d.c.b ^ 0.db.0.db -> a.b.c.d */ #else movs r3, #16 lsls r1, r0, #8 /* d.c.b.a -> c.b.a.0 */ lsrs r0, r0, #8 /* d.c.b.a -> 0.d.c.b */ rors r1, r3 /* c.b.a.0 -> a.0.c.b */ rors r0, r3 /* 0.d.c.b -> c.b.0.d */ lsrs r1, r1, #8 /* a.0.c.b -> 0.a.0.c */ lsls r1, r1, #8 /* 0.a.0.c -> a.0.c.0 */ lsls r0, r0, #8 /* c.b.0.d -> b.0.d.0 */ lsrs r0, r0, #8 /* b.0.d.0 -> 0.b.0.d */ orrs r0, r0, r1 /* a.0.c.0 | 0.b.0.d -> a.b.c.d */ #endif RET END(FUNC) #if BYTE_ORDER == LITTLE_ENDIAN STRONG_ALIAS(_C_LABEL(ntohl), FUNC) STRONG_ALIAS(_C_LABEL(htonl), FUNC) #endif