Commit 6de0cdc1 authored by Debarshi Ray's avatar Debarshi Ray

build: Disable rdtscp by default

... because it is only available in various Core i[357] CPUs and is
not portable across all x86_64 versions. It is not prudent to
automatically enable it during the build because a newer build machine
will cause the application to crash with a SIGILL when run on
something older.

This is also a good time to switch to GB_ENABLE_RDTSCP.

Original patch from Christian Hergert for gnome-builder.

https://bugzilla.gnome.org/show_bug.cgi?id=771995
parent 5de918f7
......@@ -78,17 +78,8 @@ if test "$have_langinfo_measurement" = "yes"; then
[Define if _NL_MEASUREMENT_MEASUREMENT is available])
fi
AC_MSG_CHECKING([for fast counters with rdtscp])
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <x86intrin.h>
int main (int argc, char *argv[]) { int cpu; __builtin_ia32_rdtscp (&cpu); return 0; }]])],
[have_rdtscp=yes],
[have_rdtscp=no])
AC_MSG_RESULT([$have_rdtscp])
AS_IF([test "$have_rdtscp" = "yes"],
[CFLAGS="$CFLAGS -DEGG_HAVE_RDTSCP"])
AS_CASE(["$host"], [*-*-linux*], [CFLAGS="$CFLAGS -D_GNU_SOURCE"], [])
GB_ENABLE_RDTSCP
AS_IF([test "x$enable_rdtscp" = "xyes"], [CFLAGS="$CFLAGS -DEGG_HAVE_RDTSCP"])
AC_CHECK_FUNCS([sched_getcpu])
AC_CHECK_FUNCS([shm_open], [LIBRT=], [AC_CHECK_LIB([rt], [shm_open], [LIBRT=-lrt], [LIBRT=])])
......
#
# SYNOPSIS
#
# GB_ENABLE_RDTSCP
#
# DESCRIPTION
#
# Enables support for rdtscp counters as supported by egg-counter.
#
# Note: This may or may not override some variables such as CFLAGS.
#
# LICENSE
#
# Copyright (c) 2015 Christian Hergert <christian@hergert.me>
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation, either version 3 of the License, or (at your
# option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
# Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.
#
# As a special exception, the respective Autoconf Macro's copyright owner
# gives unlimited permission to copy, distribute and modify the configure
# scripts that are the output of Autoconf when processing the Macro. You
# need not follow the terms of the GNU General Public License when using
# or distributing such scripts, even though portions of the text of the
# Macro appear in them. The GNU General Public License (GPL) does govern
# all other use of the material that constitutes the Autoconf Macro.
#
# This special exception to the GPL applies to versions of the Autoconf
# Macro released by the Autoconf Archive. When you make and distribute a
# modified version of the Autoconf Macro, you may extend this special
# exception to the GPL to apply to your modified version as well.
#serial 1
AC_DEFUN([GB_ENABLE_RDTSCP], [
AC_ARG_ENABLE([rdtscp], [AC_HELP_STRING([--enable-rdtscp], [turn on rdtscp optimizations [default=no]])],
[enable_rdtscp=$enableval], [enable_rdtscp=no])
AS_IF([test "$enable_rdtscp" = "yes"], [
AC_MSG_CHECKING([for fast counters with rdtscp])
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <x86intrin.h>
int main (int argc, char *argv[]) { int cpu; __builtin_ia32_rdtscp (&cpu); return 0; }
]])],
[enable_rdtscp=yes],
[enable_rdtscp=no])
AC_MSG_RESULT(["$enable_rdtscp"])
])
AS_CASE(["$host"],
[*-*-linux*],[CFLAGS="$CFLAGS -D_GNU_SOURCE"],
[])
])
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