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Diffstat (limited to 'vendor/cfitsio/swapproc.c')
| -rw-r--r-- | vendor/cfitsio/swapproc.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/vendor/cfitsio/swapproc.c b/vendor/cfitsio/swapproc.c new file mode 100644 index 00000000..cc69d6e6 --- /dev/null +++ b/vendor/cfitsio/swapproc.c @@ -0,0 +1,247 @@ +/* This file, swapproc.c, contains general utility routines that are */ +/* used by other FITSIO routines to swap bytes. */ + +/* The FITSIO software was written by William Pence at the High Energy */ +/* Astrophysic Science Archive Research Center (HEASARC) at the NASA */ +/* Goddard Space Flight Center. */ + +/* The fast SSE2 and SSSE3 functions were provided by Julian Taylor, ESO */ + +#include <string.h> +#include <stdlib.h> +#include "fitsio2.h" + +/* bswap builtin is available since GCC 4.3 */ +#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) +#define HAVE_BSWAP +#endif + +#ifdef __SSSE3__ +#include <tmmintrin.h> +/* swap 16 bytes according to mask, values must be 16 byte aligned */ +static inline void swap_ssse3(char * values, __m128i mask) +{ + __m128i v = _mm_load_si128((__m128i *)values); + __m128i s = _mm_shuffle_epi8(v, mask); + _mm_store_si128((__m128i*)values, s); +} +#endif +#ifdef __SSE2__ +#include <emmintrin.h> +/* swap 8 shorts, values must be 16 byte aligned + * faster than ssse3 variant for shorts */ +static inline void swap2_sse2(char * values) +{ + __m128i r1 = _mm_load_si128((__m128i *)values); + __m128i r2 = r1; + r1 = _mm_srli_epi16(r1, 8); + r2 = _mm_slli_epi16(r2, 8); + r1 = _mm_or_si128(r1, r2); + _mm_store_si128((__m128i*)values, r1); +} +/* the three shuffles required for 4 and 8 byte variants make + * SSE2 slower than bswap */ + + +/* get number of elements to peel to reach alignment */ +static inline size_t get_peel(void * addr, size_t esize, size_t nvals, + size_t alignment) +{ + const size_t offset = (size_t)addr % alignment; + size_t peel = offset ? (alignment - offset) / esize : 0; + peel = nvals < peel ? nvals : peel; + return peel; +} +#endif + +/*--------------------------------------------------------------------------*/ +static void ffswap2_slow(short *svalues, long nvals) +{ + register long ii; + unsigned short * usvalues; + + usvalues = (unsigned short *) svalues; + + for (ii = 0; ii < nvals; ii++) + { + usvalues[ii] = (usvalues[ii]>>8) | (usvalues[ii]<<8); + } +} +/*--------------------------------------------------------------------------*/ +#if __SSE2__ +void ffswap2(short *svalues, /* IO - pointer to shorts to be swapped */ + long nvals) /* I - number of shorts to be swapped */ +/* + swap the bytes in the input short integers: ( 0 1 -> 1 0 ) +*/ +{ + if ((long)svalues % 2 != 0) { /* should not happen */ + ffswap2_slow(svalues, nvals); + return; + } + + long ii; + size_t peel = get_peel((void*)&svalues[0], sizeof(svalues[0]), nvals, 16); + + ffswap2_slow(svalues, peel); + for (ii = peel; ii < (nvals - peel - (nvals - peel) % 8); ii+=8) { + swap2_sse2((char*)&svalues[ii]); + } + ffswap2_slow(&svalues[ii], nvals - ii); +} +#else +void ffswap2(short *svalues, /* IO - pointer to shorts to be swapped */ + long nvals) /* I - number of shorts to be swapped */ +/* + swap the bytes in the input 4-byte integer: ( 0 1 2 3 -> 3 2 1 0 ) +*/ +{ + ffswap2_slow(svalues, nvals); +} +#endif +/*--------------------------------------------------------------------------*/ +static void ffswap4_slow(INT32BIT *ivalues, long nvals) +{ + register long ii; + +#if defined(HAVE_BSWAP) + for (ii = 0; ii < nvals; ii++) + { + ivalues[ii] = __builtin_bswap32(ivalues[ii]); + } +#elif defined(_MSC_VER) && (_MSC_VER >= 1400) + /* intrinsic byte swapping function in Microsoft Visual C++ 8.0 and later */ + unsigned int* uivalues = (unsigned int *) ivalues; + + /* intrinsic byte swapping function in Microsoft Visual C++ */ + for (ii = 0; ii < nvals; ii++) + { + uivalues[ii] = _byteswap_ulong(uivalues[ii]); + } +#else + char *cvalues, tmp; + + for (ii = 0; ii < nvals; ii++) + { + cvalues = (char *)&ivalues[ii]; + tmp = cvalues[0]; + cvalues[0] = cvalues[3]; + cvalues[3] = tmp; + tmp = cvalues[1]; + cvalues[1] = cvalues[2]; + cvalues[2] = tmp; + } +#endif +} +/*--------------------------------------------------------------------------*/ +#ifdef __SSSE3__ +void ffswap4(INT32BIT *ivalues, /* IO - pointer to INT*4 to be swapped */ + long nvals) /* I - number of floats to be swapped */ +/* + swap the bytes in the input 4-byte integer: ( 0 1 2 3 -> 3 2 1 0 ) +*/ +{ + if ((long)ivalues % 4 != 0) { /* should not happen */ + ffswap4_slow(ivalues, nvals); + return; + } + + long ii; + const __m128i cmask4 = _mm_set_epi8(12, 13, 14, 15, + 8, 9, 10, 11, + 4, 5, 6, 7, + 0, 1, 2 ,3); + size_t peel = get_peel((void*)&ivalues[0], sizeof(ivalues[0]), nvals, 16); + ffswap4_slow(ivalues, peel); + for (ii = peel; ii < (nvals - peel - (nvals - peel) % 4); ii+=4) { + swap_ssse3((char*)&ivalues[ii], cmask4); + } + ffswap4_slow(&ivalues[ii], nvals - ii); +} +#else +void ffswap4(INT32BIT *ivalues, /* IO - pointer to INT*4 to be swapped */ + long nvals) /* I - number of floats to be swapped */ +/* + swap the bytes in the input 4-byte integer: ( 0 1 2 3 -> 3 2 1 0 ) +*/ +{ + ffswap4_slow(ivalues, nvals); +} +#endif +/*--------------------------------------------------------------------------*/ +static void ffswap8_slow(double *dvalues, long nvals) +{ + register long ii; +#ifdef HAVE_BSWAP + LONGLONG * llvalues = (LONGLONG*)dvalues; + + for (ii = 0; ii < nvals; ii++) { + llvalues[ii] = __builtin_bswap64(llvalues[ii]); + } +#elif defined(_MSC_VER) && (_MSC_VER >= 1400) + /* intrinsic byte swapping function in Microsoft Visual C++ 8.0 and later */ + unsigned __int64 * llvalues = (unsigned __int64 *) dvalues; + + for (ii = 0; ii < nvals; ii++) + { + llvalues[ii] = _byteswap_uint64(llvalues[ii]); + } +#else + register char *cvalues; + register char temp; + + cvalues = (char *) dvalues; /* copy the pointer value */ + + for (ii = 0; ii < nvals*8; ii += 8) + { + temp = cvalues[ii]; + cvalues[ii] = cvalues[ii+7]; + cvalues[ii+7] = temp; + + temp = cvalues[ii+1]; + cvalues[ii+1] = cvalues[ii+6]; + cvalues[ii+6] = temp; + + temp = cvalues[ii+2]; + cvalues[ii+2] = cvalues[ii+5]; + cvalues[ii+5] = temp; + + temp = cvalues[ii+3]; + cvalues[ii+3] = cvalues[ii+4]; + cvalues[ii+4] = temp; + } +#endif +} +/*--------------------------------------------------------------------------*/ +#ifdef __SSSE3__ +void ffswap8(double *dvalues, /* IO - pointer to doubles to be swapped */ + long nvals) /* I - number of doubles to be swapped */ +/* + swap the bytes in the input doubles: ( 01234567 -> 76543210 ) +*/ +{ + if ((long)dvalues % 8 != 0) { /* should not happen on amd64 */ + ffswap8_slow(dvalues, nvals); + return; + } + + long ii; + const __m128i cmask8 = _mm_set_epi8(8, 9, 10, 11, 12, 13, 14, 15, + 0, 1, 2 ,3, 4, 5, 6, 7); + size_t peel = get_peel((void*)&dvalues[0], sizeof(dvalues[0]), nvals, 16); + ffswap8_slow(dvalues, peel); + for (ii = peel; ii < (nvals - peel - (nvals - peel) % 2); ii+=2) { + swap_ssse3((char*)&dvalues[ii], cmask8); + } + ffswap8_slow(&dvalues[ii], nvals - ii); +} +#else +void ffswap8(double *dvalues, /* IO - pointer to doubles to be swapped */ + long nvals) /* I - number of doubles to be swapped */ +/* + swap the bytes in the input doubles: ( 01234567 -> 76543210 ) +*/ +{ + ffswap8_slow(dvalues, nvals); +} +#endif |