FastDup/ext/htslib/htscodecs/htscodecs/htscodecs_endian.h

94 lines
3.5 KiB
C

/*
* Copyright (c) 2020 Genome Research Ltd.
* Author(s): James Bonfield
*
* 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 names Genome Research Ltd and Wellcome Trust Sanger
* Institute 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 GENOME RESEARCH LTD 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 GENOME RESEARCH
* LTD 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.
*/
#ifndef HTSCODECS_ENDIAN_H
#define HTSCODECS_ENDIAN_H
// Endianness checking.
// Sets HTSCODECS_ENDIAN_KNOWN if system type detected and either
// HTSCODECS_LITTLE_ENDIAN or HTSCODECS_BIG_ENDIAN.
/*
* In general our preferred route is to write code in an endian agnostic
* fashion, but our data formats are natively little endian. Therefore
* in time critical code it's sometimes best to exploit that.
*
* Therefore we'll optimise code along the lines of:
*
* #ifdef HTSCODECS_LITTLE_ENDIAN
* // do something little endian specific
* #else
* // do something in an endian agnostic fashion
* #endif
*
* This means our code works even if we fail to recognise the
* specific machine type.
*/
#if (defined(__i386__) \
|| defined(__i386) \
|| defined(__amd64__) \
|| defined(__amd64) \
|| defined(__x86_64__) \
|| defined(__x86_64) \
|| defined(__i686__) \
|| defined(__i686)) \
|| (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) \
|| defined(__LITTLE_ENDIAN__) \
|| defined(__ARMEL__) \
|| defined(__THUMBEL__) \
|| defined(__AARCH64EL__) \
|| defined(_MIPSEL) \
|| defined(__MIPSEL) \
|| defined(__MIPSEL__)
// Little endian
# define HTSCODECS_LITTLE_ENDIAN
# define HTSCODECS_ENDIAN_KNOWN
#elif (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) \
|| defined(__BIG_ENDIAN__) \
|| defined(__ARMEB__) \
|| defined(__THUMBEB__) \
|| defined(__AAARCHEB__) \
|| defined(_MIPSEB) \
|| defined(__MIPSEB) \
|| defined(__MIPSEB__)
// Big endian
# define HTSCODECS_BIG_ENDIAN
# define HTSCODECS_ENDIAN_KNOWN
#else
// Unknown - code will need to check HTSCODES_ENDIAN_KNOWN and do endian agnostic
#endif
#endif /* HTSCODECS_ENDIAN_H */