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author | Christopher Haster <chaster@utexas.edu> | 2018-02-02 14:58:43 +0300 |
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committer | Christopher Haster <chaster@utexas.edu> | 2018-02-19 10:39:08 +0300 |
commit | a0a55fb9e5942b51331947b855756abcac42a3c5 (patch) | |
tree | a0b298883add8c0cd4c93497be38c61e2091b780 /lfs_util.h | |
parent | 4f08424b51c6e7fda140b91fd551a35531ca0fc3 (diff) |
Added conversion to/from little-endian on disk
Required to support big-endian processors, with the most notable being
the PowerPC architecture.
On little-endian architectures, these conversions can be optimized out
and have no code impact.
Initial patch provided by gmouchard
Diffstat (limited to 'lfs_util.h')
-rw-r--r-- | lfs_util.h | 23 |
1 files changed, 23 insertions, 0 deletions
@@ -70,6 +70,29 @@ static inline int lfs_scmp(uint32_t a, uint32_t b) { return (int)(unsigned)(a - b); } +static inline uint32_t lfs_fromle32(uint32_t a) { +#if ( \ + (defined( BYTE_ORDER ) && BYTE_ORDER == ORDER_LITTLE_ENDIAN ) || \ + (defined(__BYTE_ORDER ) && __BYTE_ORDER == __ORDER_LITTLE_ENDIAN ) || \ + (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)) + return a; +#elif ( \ + (defined( BYTE_ORDER ) && BYTE_ORDER == ORDER_BIG_ENDIAN ) || \ + (defined(__BYTE_ORDER ) && __BYTE_ORDER == __ORDER_BIG_ENDIAN ) || \ + (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)) + return __builtin_bswap32(a); +#else + return (((uint8_t*)&a)[0] << 0) | + (((uint8_t*)&a)[1] << 8) | + (((uint8_t*)&a)[2] << 16) | + (((uint8_t*)&a)[3] << 24); +#endif +} + +static inline uint32_t lfs_tole32(uint32_t a) { + return lfs_fromle32(a); +} + // CRC-32 with polynomial = 0x04c11db7 void lfs_crc(uint32_t *crc, const void *buffer, size_t size); |