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3dc2d62d04
postgresql/config/c-compiler.m4
Heikki Linnakangas 3dc2d62d04 Use Intel SSE 4.2 CRC instructions where available. 
Modern x86 and x86-64 processors with SSE 4.2 support have special
instructions, crc32b and crc32q, for calculating CRC-32C. They greatly
speed up CRC calculation.

Whether the instructions can be used or not depends on the compiler and the
target architecture. If generation of SSE 4.2 instructions is allowed for
the target (-msse4.2 flag on gcc and clang), use them. If they are not
allowed by default, but the compiler supports the -msse4.2 flag to enable
them, compile just the CRC-32C function with -msse4.2 flag, and check at
runtime whether the processor we're running on supports it. If it doesn't,
fall back to the slicing-by-8 algorithm. (With the common defaults on
current operating systems, the runtime-check variant is what you get in
practice.)

Abhijit Menon-Sen, heavily modified by me, reviewed by Andres Freund.
2015-04-14 17:05:03 +03:00

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# Macros to detect C compiler features
# config/c-compiler.m4
# PGAC_C_SIGNED
# -------------
# Check if the C compiler understands signed types.
AC_DEFUN([PGAC_C_SIGNED],
[AC_CACHE_CHECK(for signed types, pgac_cv_c_signed,
[AC_TRY_COMPILE([],
[signed char c; signed short s; signed int i;],
[pgac_cv_c_signed=yes],
[pgac_cv_c_signed=no])])
if test x"$pgac_cv_c_signed" = xno ; then
AC_DEFINE(signed,, [Define to empty if the C compiler does not understand signed types.])
fi])# PGAC_C_SIGNED
# PGAC_C_INLINE
# -------------
# Check if the C compiler understands inline functions without being
# noisy about unused static inline functions. Some older compilers
# understand inline functions (as tested by AC_C_INLINE) but warn about
# them if they aren't used in a translation unit.
#
# This test used to just define an inline function, but some compilers
# (notably clang) got too smart and now warn about unused static
# inline functions when defined inside a .c file, but not when defined
# in an included header. Since the latter is what we want to use, test
# to see if the warning appears when the function is in a header file.
# Not pretty, but it works.
#
# Defines: inline, PG_USE_INLINE
AC_DEFUN([PGAC_C_INLINE],
[AC_C_INLINE
AC_CACHE_CHECK([for quiet inline (no complaint if unreferenced)], pgac_cv_c_inline_quietly,
[pgac_cv_c_inline_quietly=no
if test "$ac_cv_c_inline" != no; then
pgac_c_inline_save_werror=$ac_c_werror_flag
ac_c_werror_flag=yes
AC_LINK_IFELSE([AC_LANG_PROGRAM([#include "$srcdir/config/test_quiet_include.h"],[])],
[pgac_cv_c_inline_quietly=yes])
ac_c_werror_flag=$pgac_c_inline_save_werror
fi])
if test "$pgac_cv_c_inline_quietly" != no; then
AC_DEFINE_UNQUOTED([PG_USE_INLINE], 1,
[Define to 1 if "static inline" works without unwanted warnings from ]
[compilations where static inline functions are defined but not called.])
fi
])# PGAC_C_INLINE
# PGAC_C_PRINTF_ARCHETYPE
# -----------------------
# Set the format archetype used by gcc to check printf type functions. We
# prefer "gnu_printf", which includes what glibc uses, such as %m for error
# strings and %lld for 64 bit long longs. GCC 4.4 introduced it. It makes a
# dramatic difference on Windows.
AC_DEFUN([PGAC_PRINTF_ARCHETYPE],
[AC_CACHE_CHECK([for printf format archetype], pgac_cv_printf_archetype,
[ac_save_c_werror_flag=$ac_c_werror_flag
ac_c_werror_flag=yes
AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
[extern int
pgac_write(int ignore, const char *fmt,...)
__attribute__((format(gnu_printf, 2, 3)));], [])],
[pgac_cv_printf_archetype=gnu_printf],
[pgac_cv_printf_archetype=printf])
ac_c_werror_flag=$ac_save_c_werror_flag])
AC_DEFINE_UNQUOTED([PG_PRINTF_ATTRIBUTE], [$pgac_cv_printf_archetype],
[Define to gnu_printf if compiler supports it, else printf.])
])# PGAC_PRINTF_ARCHETYPE
# PGAC_TYPE_64BIT_INT(TYPE)
# -------------------------
# Check if TYPE is a working 64 bit integer type. Set HAVE_TYPE_64 to
# yes or no respectively, and define HAVE_TYPE_64 if yes.
AC_DEFUN([PGAC_TYPE_64BIT_INT],
[define([Ac_define], [translit([have_$1_64], [a-z *], [A-Z_P])])dnl
define([Ac_cachevar], [translit([pgac_cv_type_$1_64], [ *], [_p])])dnl
AC_CACHE_CHECK([whether $1 is 64 bits], [Ac_cachevar],
[AC_TRY_RUN(
[typedef $1 ac_int64;
/*
* These are globals to discourage the compiler from folding all the
* arithmetic tests down to compile-time constants.
*/
ac_int64 a = 20000001;
ac_int64 b = 40000005;
int does_int64_work()
{
ac_int64 c,d;
if (sizeof(ac_int64) != 8)
return 0; /* definitely not the right size */
/* Do perfunctory checks to see if 64-bit arithmetic seems to work */
c = a * b;
d = (c + b) / b;
if (d != a+1)
return 0;
return 1;
}
main() {
exit(! does_int64_work());
}],
[Ac_cachevar=yes],
[Ac_cachevar=no],
[# If cross-compiling, check the size reported by the compiler and
# trust that the arithmetic works.
AC_COMPILE_IFELSE([AC_LANG_BOOL_COMPILE_TRY([], [sizeof($1) == 8])],
Ac_cachevar=yes,
Ac_cachevar=no)])])
Ac_define=$Ac_cachevar
if test x"$Ac_cachevar" = xyes ; then
AC_DEFINE(Ac_define, 1, [Define to 1 if `]$1[' works and is 64 bits.])
fi
undefine([Ac_define])dnl
undefine([Ac_cachevar])dnl
])# PGAC_TYPE_64BIT_INT
# PGAC_TYPE_128BIT_INT
# ---------------------
# Check if __int128 is a working 128 bit integer type, and if so
# define PG_INT128_TYPE to that typename. This currently only detects
# a GCC/clang extension, but support for different environments may be
# added in the future.
#
# For the moment we only test for support for 128bit math; support for
# 128bit literals and snprintf is not required.
AC_DEFUN([PGAC_TYPE_128BIT_INT],
[AC_CACHE_CHECK([for __int128], [pgac_cv__128bit_int],
[AC_LINK_IFELSE([AC_LANG_PROGRAM([
/*
* These are globals to discourage the compiler from folding all the
* arithmetic tests down to compile-time constants. We do not have
* convenient support for 64bit literals at this point...
*/
__int128 a = 48828125;
__int128 b = 97656255;
],[
__int128 c,d;
a = (a << 12) + 1; /* 200000000001 */
b = (b << 12) + 5; /* 400000000005 */
/* use the most relevant arithmetic ops */
c = a * b;
d = (c + b) / b;
/* return different values, to prevent optimizations */
if (d != a+1)
return 0;
return 1;
])],
[pgac_cv__128bit_int=yes],
[pgac_cv__128bit_int=no])])
if test x"$pgac_cv__128bit_int" = xyes ; then
AC_DEFINE(PG_INT128_TYPE, __int128, [Define to the name of a signed 128-bit integer type.])
fi])# PGAC_TYPE_128BIT_INT
# PGAC_C_FUNCNAME_SUPPORT
# -----------------------
# Check if the C compiler understands __func__ (C99) or __FUNCTION__ (gcc).
# Define HAVE_FUNCNAME__FUNC or HAVE_FUNCNAME__FUNCTION accordingly.
AC_DEFUN([PGAC_C_FUNCNAME_SUPPORT],
[AC_CACHE_CHECK(for __func__, pgac_cv_funcname_func_support,
[AC_TRY_COMPILE([#include <stdio.h>],
[printf("%s\n", __func__);],
[pgac_cv_funcname_func_support=yes],
[pgac_cv_funcname_func_support=no])])
if test x"$pgac_cv_funcname_func_support" = xyes ; then
AC_DEFINE(HAVE_FUNCNAME__FUNC, 1,
[Define to 1 if your compiler understands __func__.])
else
AC_CACHE_CHECK(for __FUNCTION__, pgac_cv_funcname_function_support,
[AC_TRY_COMPILE([#include <stdio.h>],
[printf("%s\n", __FUNCTION__);],
[pgac_cv_funcname_function_support=yes],
[pgac_cv_funcname_function_support=no])])
if test x"$pgac_cv_funcname_function_support" = xyes ; then
AC_DEFINE(HAVE_FUNCNAME__FUNCTION, 1,
[Define to 1 if your compiler understands __FUNCTION__.])
fi
fi])# PGAC_C_FUNCNAME_SUPPORT
# PGAC_C_STATIC_ASSERT
# --------------------
# Check if the C compiler understands _Static_assert(),
# and define HAVE__STATIC_ASSERT if so.
#
# We actually check the syntax ({ _Static_assert(...) }), because we need
# gcc-style compound expressions to be able to wrap the thing into macros.
AC_DEFUN([PGAC_C_STATIC_ASSERT],
[AC_CACHE_CHECK(for _Static_assert, pgac_cv__static_assert,
[AC_TRY_LINK([],
[({ _Static_assert(1, "foo"); })],
[pgac_cv__static_assert=yes],
[pgac_cv__static_assert=no])])
if test x"$pgac_cv__static_assert" = xyes ; then
AC_DEFINE(HAVE__STATIC_ASSERT, 1,
[Define to 1 if your compiler understands _Static_assert.])
fi])# PGAC_C_STATIC_ASSERT
# PGAC_C_TYPES_COMPATIBLE
# -----------------------
# Check if the C compiler understands __builtin_types_compatible_p,
# and define HAVE__BUILTIN_TYPES_COMPATIBLE_P if so.
#
# We check usage with __typeof__, though it's unlikely any compiler would
# have the former and not the latter.
AC_DEFUN([PGAC_C_TYPES_COMPATIBLE],
[AC_CACHE_CHECK(for __builtin_types_compatible_p, pgac_cv__types_compatible,
[AC_TRY_COMPILE([],
[ int x; static int y[__builtin_types_compatible_p(__typeof__(x), int)]; ],
[pgac_cv__types_compatible=yes],
[pgac_cv__types_compatible=no])])
if test x"$pgac_cv__types_compatible" = xyes ; then
AC_DEFINE(HAVE__BUILTIN_TYPES_COMPATIBLE_P, 1,
[Define to 1 if your compiler understands __builtin_types_compatible_p.])
fi])# PGAC_C_TYPES_COMPATIBLE
# PGAC_C_BUILTIN_BSWAP32
# -------------------------
# Check if the C compiler understands __builtin_bswap32(),
# and define HAVE__BUILTIN_BSWAP32 if so.
AC_DEFUN([PGAC_C_BUILTIN_BSWAP32],
[AC_CACHE_CHECK(for __builtin_bswap32, pgac_cv__builtin_bswap32,
[AC_TRY_COMPILE([static unsigned long int x = __builtin_bswap32(0xaabbccdd);],
[],
[pgac_cv__builtin_bswap32=yes],
[pgac_cv__builtin_bswap32=no])])
if test x"$pgac_cv__builtin_bswap32" = xyes ; then
AC_DEFINE(HAVE__BUILTIN_BSWAP32, 1,
[Define to 1 if your compiler understands __builtin_bswap32.])
fi])# PGAC_C_BUILTIN_BSWAP32
# PGAC_C_BUILTIN_CONSTANT_P
# -------------------------
# Check if the C compiler understands __builtin_constant_p(),
# and define HAVE__BUILTIN_CONSTANT_P if so.
AC_DEFUN([PGAC_C_BUILTIN_CONSTANT_P],
[AC_CACHE_CHECK(for __builtin_constant_p, pgac_cv__builtin_constant_p,
[AC_TRY_COMPILE([static int x; static int y[__builtin_constant_p(x) ? x : 1];],
[],
[pgac_cv__builtin_constant_p=yes],
[pgac_cv__builtin_constant_p=no])])
if test x"$pgac_cv__builtin_constant_p" = xyes ; then
AC_DEFINE(HAVE__BUILTIN_CONSTANT_P, 1,
[Define to 1 if your compiler understands __builtin_constant_p.])
fi])# PGAC_C_BUILTIN_CONSTANT_P
# PGAC_C_BUILTIN_UNREACHABLE
# --------------------------
# Check if the C compiler understands __builtin_unreachable(),
# and define HAVE__BUILTIN_UNREACHABLE if so.
#
# NB: Don't get the idea of putting a for(;;); or such before the
# __builtin_unreachable() call. Some compilers would remove it before linking
# and only a warning instead of an error would be produced.
AC_DEFUN([PGAC_C_BUILTIN_UNREACHABLE],
[AC_CACHE_CHECK(for __builtin_unreachable, pgac_cv__builtin_unreachable,
[AC_TRY_LINK([],
[__builtin_unreachable();],
[pgac_cv__builtin_unreachable=yes],
[pgac_cv__builtin_unreachable=no])])
if test x"$pgac_cv__builtin_unreachable" = xyes ; then
AC_DEFINE(HAVE__BUILTIN_UNREACHABLE, 1,
[Define to 1 if your compiler understands __builtin_unreachable.])
fi])# PGAC_C_BUILTIN_UNREACHABLE
# PGAC_C_VA_ARGS
# --------------
# Check if the C compiler understands C99-style variadic macros,
# and define HAVE__VA_ARGS if so.
AC_DEFUN([PGAC_C_VA_ARGS],
[AC_CACHE_CHECK(for __VA_ARGS__, pgac_cv__va_args,
[AC_TRY_COMPILE([#include <stdio.h>],
[#define debug(...) fprintf(stderr, __VA_ARGS__)
debug("%s", "blarg");
],
[pgac_cv__va_args=yes],
[pgac_cv__va_args=no])])
if test x"$pgac_cv__va_args" = xyes ; then
AC_DEFINE(HAVE__VA_ARGS, 1,
[Define to 1 if your compiler understands __VA_ARGS__ in macros.])
fi])# PGAC_C_VA_ARGS
# PGAC_PROG_CC_CFLAGS_OPT
# -----------------------
# Given a string, check if the compiler supports the string as a
# command-line option. If it does, add the string to CFLAGS.
AC_DEFUN([PGAC_PROG_CC_CFLAGS_OPT],
[define([Ac_cachevar], [AS_TR_SH([pgac_cv_prog_cc_cflags_$1])])dnl
AC_CACHE_CHECK([whether $CC supports $1], [Ac_cachevar],
[pgac_save_CFLAGS=$CFLAGS
CFLAGS="$pgac_save_CFLAGS $1"
ac_save_c_werror_flag=$ac_c_werror_flag
ac_c_werror_flag=yes
_AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
[Ac_cachevar=yes],
[Ac_cachevar=no])
ac_c_werror_flag=$ac_save_c_werror_flag
CFLAGS="$pgac_save_CFLAGS"])
if test x"$Ac_cachevar" = x"yes"; then
CFLAGS="$CFLAGS $1"
fi
undefine([Ac_cachevar])dnl
])# PGAC_PROG_CC_CFLAGS_OPT
# PGAC_PROG_CC_VAR_OPT
# -----------------------
# Given a variable name and a string, check if the compiler supports
# the string as a command-line option. If it does, add the string to
# the given variable.
AC_DEFUN([PGAC_PROG_CC_VAR_OPT],
[define([Ac_cachevar], [AS_TR_SH([pgac_cv_prog_cc_cflags_$2])])dnl
AC_CACHE_CHECK([whether $CC supports $2], [Ac_cachevar],
[pgac_save_CFLAGS=$CFLAGS
CFLAGS="$pgac_save_CFLAGS $2"
ac_save_c_werror_flag=$ac_c_werror_flag
ac_c_werror_flag=yes
_AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
[Ac_cachevar=yes],
[Ac_cachevar=no])
ac_c_werror_flag=$ac_save_c_werror_flag
CFLAGS="$pgac_save_CFLAGS"])
if test x"$Ac_cachevar" = x"yes"; then
$1="${$1} $2"
fi
undefine([Ac_cachevar])dnl
])# PGAC_PROG_CC_CFLAGS_OPT
# PGAC_PROG_CC_LDFLAGS_OPT
# ------------------------
# Given a string, check if the compiler supports the string as a
# command-line option. If it does, add the string to LDFLAGS.
# For reasons you'd really rather not know about, this checks whether
# you can link to a particular function, not just whether you can link.
# In fact, we must actually check that the resulting program runs :-(
AC_DEFUN([PGAC_PROG_CC_LDFLAGS_OPT],
[define([Ac_cachevar], [AS_TR_SH([pgac_cv_prog_cc_ldflags_$1])])dnl
AC_CACHE_CHECK([whether $CC supports $1], [Ac_cachevar],
[pgac_save_LDFLAGS=$LDFLAGS
LDFLAGS="$pgac_save_LDFLAGS $1"
AC_RUN_IFELSE([AC_LANG_PROGRAM([extern void $2 (); void (*fptr) () = $2;],[])],
[Ac_cachevar=yes],
[Ac_cachevar=no],
[Ac_cachevar="assuming no"])
LDFLAGS="$pgac_save_LDFLAGS"])
if test x"$Ac_cachevar" = x"yes"; then
LDFLAGS="$LDFLAGS $1"
fi
undefine([Ac_cachevar])dnl
])# PGAC_PROG_CC_LDFLAGS_OPT
# PGAC_HAVE_GCC__SYNC_CHAR_TAS
# -------------------------
# Check if the C compiler understands __sync_lock_test_and_set(char),
# and define HAVE_GCC__SYNC_CHAR_TAS
#
# NB: There are platforms where test_and_set is available but compare_and_swap
# is not, so test this separately.
# NB: Some platforms only do 32bit tas, others only do 8bit tas. Test both.
AC_DEFUN([PGAC_HAVE_GCC__SYNC_CHAR_TAS],
[AC_CACHE_CHECK(for builtin __sync char locking functions, pgac_cv_gcc_sync_char_tas,
[AC_TRY_LINK([],
[char lock = 0;
__sync_lock_test_and_set(&lock, 1);
__sync_lock_release(&lock);],
[pgac_cv_gcc_sync_char_tas="yes"],
[pgac_cv_gcc_sync_char_tas="no"])])
if test x"$pgac_cv_gcc_sync_char_tas" = x"yes"; then
AC_DEFINE(HAVE_GCC__SYNC_CHAR_TAS, 1, [Define to 1 if you have __sync_lock_test_and_set(char *) and friends.])
fi])# PGAC_HAVE_GCC__SYNC_CHAR_TAS
# PGAC_HAVE_GCC__SYNC_INT32_TAS
# -------------------------
# Check if the C compiler understands __sync_lock_test_and_set(),
# and define HAVE_GCC__SYNC_INT32_TAS
AC_DEFUN([PGAC_HAVE_GCC__SYNC_INT32_TAS],
[AC_CACHE_CHECK(for builtin __sync int32 locking functions, pgac_cv_gcc_sync_int32_tas,
[AC_TRY_LINK([],
[int lock = 0;
__sync_lock_test_and_set(&lock, 1);
__sync_lock_release(&lock);],
[pgac_cv_gcc_sync_int32_tas="yes"],
[pgac_cv_gcc_sync_int32_tas="no"])])
if test x"$pgac_cv_gcc_sync_int32_tas" = x"yes"; then
AC_DEFINE(HAVE_GCC__SYNC_INT32_TAS, 1, [Define to 1 if you have __sync_lock_test_and_set(int *) and friends.])
fi])# PGAC_HAVE_GCC__SYNC_INT32_TAS
# PGAC_HAVE_GCC__SYNC_INT32_CAS
# -------------------------
# Check if the C compiler understands __sync_compare_and_swap() for 32bit
# types, and define HAVE_GCC__SYNC_INT32_CAS if so.
AC_DEFUN([PGAC_HAVE_GCC__SYNC_INT32_CAS],
[AC_CACHE_CHECK(for builtin __sync int32 atomic operations, pgac_cv_gcc_sync_int32_cas,
[AC_TRY_LINK([],
[int val = 0;
__sync_val_compare_and_swap(&val, 0, 37);],
[pgac_cv_gcc_sync_int32_cas="yes"],
[pgac_cv_gcc_sync_int32_cas="no"])])
if test x"$pgac_cv_gcc_sync_int32_cas" = x"yes"; then
AC_DEFINE(HAVE_GCC__SYNC_INT32_CAS, 1, [Define to 1 if you have __sync_compare_and_swap(int *, int, int).])
fi])# PGAC_HAVE_GCC__SYNC_INT32_CAS
# PGAC_HAVE_GCC__SYNC_INT64_CAS
# -------------------------
# Check if the C compiler understands __sync_compare_and_swap() for 64bit
# types, and define HAVE_GCC__SYNC_INT64_CAS if so.
AC_DEFUN([PGAC_HAVE_GCC__SYNC_INT64_CAS],
[AC_CACHE_CHECK(for builtin __sync int64 atomic operations, pgac_cv_gcc_sync_int64_cas,
[AC_TRY_LINK([],
[PG_INT64_TYPE lock = 0;
__sync_val_compare_and_swap(&lock, 0, (PG_INT64_TYPE) 37);],
[pgac_cv_gcc_sync_int64_cas="yes"],
[pgac_cv_gcc_sync_int64_cas="no"])])
if test x"$pgac_cv_gcc_sync_int64_cas" = x"yes"; then
AC_DEFINE(HAVE_GCC__SYNC_INT64_CAS, 1, [Define to 1 if you have __sync_compare_and_swap(int64 *, int64, int64).])
fi])# PGAC_HAVE_GCC__SYNC_INT64_CAS
# PGAC_HAVE_GCC__ATOMIC_INT32_CAS
# -------------------------
# Check if the C compiler understands __atomic_compare_exchange_n() for 32bit
# types, and define HAVE_GCC__ATOMIC_INT32_CAS if so.
AC_DEFUN([PGAC_HAVE_GCC__ATOMIC_INT32_CAS],
[AC_CACHE_CHECK(for builtin __atomic int32 atomic operations, pgac_cv_gcc_atomic_int32_cas,
[AC_TRY_LINK([],
[int val = 0;
int expect = 0;
__atomic_compare_exchange_n(&val, &expect, 37, 0, __ATOMIC_SEQ_CST, __ATOMIC_RELAXED);],
[pgac_cv_gcc_atomic_int32_cas="yes"],
[pgac_cv_gcc_atomic_int32_cas="no"])])
if test x"$pgac_cv_gcc_atomic_int32_cas" = x"yes"; then
AC_DEFINE(HAVE_GCC__ATOMIC_INT32_CAS, 1, [Define to 1 if you have __atomic_compare_exchange_n(int *, int *, int).])
fi])# PGAC_HAVE_GCC__ATOMIC_INT32_CAS
# PGAC_HAVE_GCC__ATOMIC_INT64_CAS
# -------------------------
# Check if the C compiler understands __atomic_compare_exchange_n() for 64bit
# types, and define HAVE_GCC__ATOMIC_INT64_CAS if so.
AC_DEFUN([PGAC_HAVE_GCC__ATOMIC_INT64_CAS],
[AC_CACHE_CHECK(for builtin __atomic int64 atomic operations, pgac_cv_gcc_atomic_int64_cas,
[AC_TRY_LINK([],
[PG_INT64_TYPE val = 0;
PG_INT64_TYPE expect = 0;
__atomic_compare_exchange_n(&val, &expect, 37, 0, __ATOMIC_SEQ_CST, __ATOMIC_RELAXED);],
[pgac_cv_gcc_atomic_int64_cas="yes"],
[pgac_cv_gcc_atomic_int64_cas="no"])])
if test x"$pgac_cv_gcc_atomic_int64_cas" = x"yes"; then
AC_DEFINE(HAVE_GCC__ATOMIC_INT64_CAS, 1, [Define to 1 if you have __atomic_compare_exchange_n(int64 *, int *, int64).])
fi])# PGAC_HAVE_GCC__ATOMIC_INT64_CAS
# PGAC_SSE42_CRC32_INTRINSICS
# -----------------------
# Check if the compiler supports _mm_crc32_u8 and _mm_crc32_u64 intrinsics.
# An optional compiler flag can be passed as argument (e.g. -msse4.2). If the
# intrinsics are supported, sets pgac_sse42_crc32_intrinsics, and CFLAGS_SSE42.
AC_DEFUN([PGAC_SSE42_CRC32_INTRINSICS],
[define([Ac_cachevar], [AS_TR_SH([pgac_cv_sse42_crc32_intrinsics_$1])])dnl
AC_CACHE_CHECK([for _mm_crc32_u8 and _mm_crc32_u64 with CFLAGS=$1], [Ac_cachevar],
[pgac_save_CFLAGS=$CFLAGS
CFLAGS="$pgac_save_CFLAGS $1"
ac_save_c_werror_flag=$ac_c_werror_flag
ac_c_werror_flag=yes
AC_TRY_LINK([#include <nmmintrin.h>],
[unsigned int crc = 0;
crc = _mm_crc32_u8(crc, 0);
crc = (unsigned int) _mm_crc32_u64(crc, 0);],
[Ac_cachevar=yes],
[Ac_cachevar=no])
ac_c_werror_flag=$ac_save_c_werror_flag
CFLAGS="$pgac_save_CFLAGS"])
if test x"$Ac_cachevar" = x"yes"; then
CFLAGS_SSE42="$1"
pgac_sse42_crc32_intrinsics=yes
fi
undefine([Ac_cachevar])dnl
])# PGAC_SSE42_CRC32_INTRINSICS
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