pg_crc32c_sse42_choose.c File Reference

#include "c.h"
#include "port/pg_crc32c.h"

Include dependency graph for pg_crc32c_sse42_choose.c:

Go to the source code of this file.

Functions
static bool	zmm_regs_available (void)
static pg_crc32c	pg_comp_crc32c_choose (pg_crc32c crc, const void *data, size_t len)

Variables
pg_crc32c(*	pg_comp_crc32c )(pg_crc32c crc, const void *data, size_t len) = pg_comp_crc32c_choose

Function Documentation

pg_comp_crc32c_choose()

static pg_crc32c pg_comp_crc32c_choose ( pg_crc32c  crc, const void *  data, size_t  len  )

static

Definition at line 61 of file pg_crc32c_sse42_choose.c.

{
    unsigned int exx[4] = {0, 0, 0, 0};
 
    /*
     * Set fallback. We must guard since slicing-by-8 is not visible
     * everywhere.
     */
#ifdef USE_SSE42_CRC32C_WITH_RUNTIME_CHECK
    pg_comp_crc32c = pg_comp_crc32c_sb8;
#endif
 
#if defined(HAVE__GET_CPUID)
    __get_cpuid(1, &exx[0], &exx[1], &exx[2], &exx[3]);
#elif defined(HAVE__CPUID)
    __cpuid(exx, 1);
#else
#error cpuid instruction not available
#endif
 
    if ((exx[2] & (1 << 20)) != 0)  /* SSE 4.2 */
    {
        pg_comp_crc32c = pg_comp_crc32c_sse42;
 
        if (exx[2] & (1 << 27) &&   /* OSXSAVE */
            zmm_regs_available())
        {
            /* second cpuid call on leaf 7 to check extended AVX-512 support */
 
            memset(exx, 0, 4 * sizeof(exx[0]));
 
#if defined(HAVE__GET_CPUID_COUNT)
            __get_cpuid_count(7, 0, &exx[0], &exx[1], &exx[2], &exx[3]);
#elif defined(HAVE__CPUIDEX)
            __cpuidex(exx, 7, 0);
#endif
 
#ifdef USE_AVX512_CRC32C_WITH_RUNTIME_CHECK
            if (exx[2] & (1 << 10) &&   /* VPCLMULQDQ */
                exx[1] & (1 << 31)) /* AVX512-VL */
                pg_comp_crc32c = pg_comp_crc32c_avx512;
#endif
        }
    }
 
    return pg_comp_crc32c(crc, data, len);
}

References crc, data, len, pg_comp_crc32c, pg_comp_crc32c_sb8(), and zmm_regs_available().

zmm_regs_available()

static bool zmm_regs_available ( void  )

static

Definition at line 47 of file pg_crc32c_sse42_choose.c.

{
#ifdef HAVE_XSAVE_INTRINSICS
    return (_xgetbv(0) & 0xe6) == 0xe6;
#else
    return false;
#endif
}

Referenced by pg_comp_crc32c_choose().

Variable Documentation

pg_comp_crc32c

pg_crc32c(* pg_comp_crc32c) (pg_crc32c crc, const void *data, size_t len)	(	pg_crc32c	crc,
		const void *	data,
		size_t	len
	)		= pg_comp_crc32c_choose

Definition at line 109 of file pg_crc32c_sse42_choose.c.

Referenced by pg_comp_crc32c_choose().