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      1 /*	$OpenBSD: endian.h,v 1.3 2005/12/13 00:35:23 millert Exp $	*/
      2 
      3 /*
      4  * Copyright (C) 2010 The Android Open Source Project
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  *  * Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  *  * Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in
     14  *    the documentation and/or other materials provided with the
     15  *    distribution.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     18  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     20  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
     21  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
     22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     23  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
     24  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     25  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     27  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 #ifndef _ARM_ENDIAN_H_
     32 #define _ARM_ENDIAN_H_
     33 
     34 #ifdef __GNUC__
     35 
     36 /*
     37  * REV and REV16 weren't available on ARM5 or ARM4.
     38  * We don't include <machine/cpu-features.h> because it pollutes the
     39  * namespace with macros like PLD.
     40  */
     41 #if !defined __ARM_ARCH_5__ && !defined __ARM_ARCH_5T__ && \
     42     !defined __ARM_ARCH_5TE__ && !defined __ARM_ARCH_5TEJ__ && \
     43     !defined __ARM_ARCH_4T__ && !defined __ARM_ARCH_4__
     44 
     45 /* According to RealView Assembler User's Guide, REV and REV16 are available
     46  * in Thumb code and 16-bit instructions when used in Thumb-2 code.
     47  *
     48  * REV Rd, Rm
     49  *   Rd and Rm must both be Lo registers.
     50  *
     51  * REV16 Rd, Rm
     52  *   Rd and Rm must both be Lo registers.
     53  *
     54  * The +l constraint takes care of this without constraining us in ARM mode.
     55  */
     56 #define __swap16md(x) ({                                        \
     57     register u_int16_t _x = (x);                                \
     58     __asm volatile ("rev16 %0, %0" : "+l" (_x));                \
     59     _x;                                                         \
     60 })
     61 
     62 #define __swap32md(x) ({                                        \
     63     register u_int32_t _x = (x);                                \
     64     __asm volatile ("rev %0, %0" : "+l" (_x));                  \
     65     _x;                                                         \
     66 })
     67 
     68 #define __swap64md(x) ({                                        \
     69     u_int64_t _swap64md_x = (x);                                \
     70     (u_int64_t) __swap32md(_swap64md_x >> 32) |                 \
     71         (u_int64_t) __swap32md(_swap64md_x & 0xffffffff) << 32; \
     72 })
     73 
     74 /* Tell sys/endian.h we have MD variants of the swap macros.  */
     75 #define MD_SWAP
     76 
     77 #endif  /* __ARM_ARCH__ */
     78 #endif  /* __GNUC__ */
     79 
     80 #if defined(__ARMEB__)
     81 #define _BYTE_ORDER _BIG_ENDIAN
     82 #else
     83 #define _BYTE_ORDER _LITTLE_ENDIAN
     84 #endif
     85 #define __STRICT_ALIGNMENT
     86 #include <sys/types.h>
     87 #include <sys/endian.h>
     88 
     89 #endif  /* !_ARM_ENDIAN_H_ */
     90