osmocom
/
libosmocore
mirror of https://gerrit.osmocom.org/libosmocore
11
0
Fork 0
Code Issues Releases Wiki Activity

configure.ac: check for __builtin_cpu_supports call support 

The '__builtin_cpu_supports' is a GCC's built-in function which
returns a positive integer if the run-time CPU supports specified
SIMD feature and returns 0 otherwise. It is required for further
SSE optimization of Viterbi decoder.

This change adds a new check, whether compiler supports this call.
See /gcc/X86-Built-in-Functions.html at gcc.gnu.org for reference.

Change-Id: I5d52cfb3e8fab3eedc0293a2842708cbee0f476a
This commit is contained in:
Vadim Yanitskiy 2017-05-08 00:07:21 +07:00
parent 2c3066e5da
commit a8a5819155
1 changed files with 27 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
configure.ac
View File

@ -242,6 +242,33 @@ else
AM_CONDITIONAL(HAVE_SSE4_1, false)
fi
dnl Check if the compiler supports specified GCC's built-in function
AC_DEFUN([CHECK_BUILTIN_SUPPORT], [
AC_CACHE_CHECK(
[whether ${CC} has $1 built-in],
[osmo_cv_cc_has_builtin], [
AC_LINK_IFELSE([
AC_LANG_PROGRAM([], [
__builtin_cpu_supports("sse");
])
],
[AS_VAR_SET([osmo_cv_cc_has_builtin], [yes])],
[AS_VAR_SET([osmo_cv_cc_has_builtin], [no])])
]
)
AS_IF([test yes = AS_VAR_GET([osmo_cv_cc_has_builtin])], [
AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_$1), 1,
[Define to 1 if compiler has the '$1' built-in function])
], [
AC_MSG_WARN($2)
])
])
dnl Check if the compiler supports runtime SIMD detection
CHECK_BUILTIN_SUPPORT([__builtin_cpu_supports],
[Runtime SIMD detection will be disabled])
AC_OUTPUT(
libosmocore.pc
libosmocodec.pc