diff options
Diffstat (limited to 'config/c-compiler.m4')
| -rw-r--r-- | config/c-compiler.m4 | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/config/c-compiler.m4 b/config/c-compiler.m4 index b518851441b..ba5c40db01c 100644 --- a/config/c-compiler.m4 +++ b/config/c-compiler.m4 @@ -667,3 +667,37 @@ if test x"$Ac_cachevar" = x"yes"; then fi undefine([Ac_cachevar])dnl ])# PGAC_SSE42_CRC32_INTRINSICS + + +# PGAC_ARMV8_CRC32C_INTRINSICS +# ----------------------- +# Check if the compiler supports the CRC32C instructions using the __crc32cb, +# __crc32ch, __crc32cw, and __crc32cd intrinsic functions. These instructions +# were first introduced in ARMv8 in the optional CRC Extension, and became +# mandatory in ARMv8.1. +# +# An optional compiler flag can be passed as argument (e.g. +# -march=armv8-a+crc). If the intrinsics are supported, sets +# pgac_armv8_crc32c_intrinsics, and CFLAGS_ARMV8_CRC32C. +AC_DEFUN([PGAC_ARMV8_CRC32C_INTRINSICS], +[define([Ac_cachevar], [AS_TR_SH([pgac_cv_armv8_crc32c_intrinsics_$1])])dnl +AC_CACHE_CHECK([for __crc32cb, __crc32ch, __crc32cw, and __crc32cd with CFLAGS=$1], [Ac_cachevar], +[pgac_save_CFLAGS=$CFLAGS +CFLAGS="$pgac_save_CFLAGS $1" +AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <arm_acle.h>], + [unsigned int crc = 0; + crc = __crc32cb(crc, 0); + crc = __crc32ch(crc, 0); + crc = __crc32cw(crc, 0); + crc = __crc32cd(crc, 0); + /* return computed value, to prevent the above being optimized away */ + return crc == 0;])], + [Ac_cachevar=yes], + [Ac_cachevar=no]) +CFLAGS="$pgac_save_CFLAGS"]) +if test x"$Ac_cachevar" = x"yes"; then + CFLAGS_ARMV8_CRC32C="$1" + pgac_armv8_crc32c_intrinsics=yes +fi +undefine([Ac_cachevar])dnl +])# PGAC_ARMV8_CRC32C_INTRINSICS |