+dnl Test for #pragma omp threadprivate
+AC_CACHE_CHECK([for omp support], [gold_cv_c_threadprivate],
+[save_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -fopenmp"
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([
+#include <omp.h>
+int i;
+#pragma omp threadprivate (i)
+])], [gold_cv_c_threadprivate=yes], [gold_cv_c_threadprivate=no])
+CFLAGS="$save_CFLAGS"])
+if test "$gold_cv_c_threadprivate" = "yes"; then
+ AC_DEFINE(HAVE_OMP_SUPPORT, 1,
+ [Define if compiler supports #pragma omp threadprivate])
+fi
+AM_CONDITIONAL(OMP_SUPPORT, test "$gold_cv_c_threadprivate" = "yes")
+
+dnl Test for the -ftls-dialect=gnu2 option.
+dnl Use -Werror in case of compilers that make unknown -m options warnings.
+dnl They would pass the test here, but fail in actual use when $WARN_CFLAGS
+dnl gets set later by default Autoconf magic to include -Werror. (We are
+dnl assuming here that there is no compiler that groks -mtls-dialect=gnu2
+dnl but does not grok -Werror.)
+save_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -Werror -fpic -mtls-dialect=gnu2"
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([
+__thread int i;
+void foo (void)
+{
+ i = 10;
+}
+])], [have_tls_gnu2=yes], [have_tls_gnu2=no])
+CFLAGS="$save_CFLAGS"
+AM_CONDITIONAL(TLS_GNU2_DIALECT, test "$have_tls_gnu2" = "yes")
+
+dnl On GNU/Linux TLS descriptors are supported by the dynamic loader
+dnl only with glibc 2.9 or later.
+AC_CACHE_CHECK([for glibc >= 2.9], [gold_cv_lib_glibc29],
+[AC_COMPILE_IFELSE([AC_LANG_SOURCE([
+#include <features.h>
+#if !defined __GLIBC__
+error
+#elif __GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 9)
+error
+#endif
+])], [gold_cv_lib_glibc29=yes], [gold_cv_lib_glibc29=no])])
+
+AM_CONDITIONAL(TLS_DESCRIPTORS, test "$gold_cv_lib_glibc29" = "yes")
+
+dnl Test for the -frandom-seed option.
+AC_CACHE_CHECK([for -frandom-seed support], [gold_cv_c_random_seed],
+[save_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -frandom-seed=foo"
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([int i;])], [gold_cv_c_random_seed=yes],
+[gold_cv_c_random_seed=no])
+CFLAGS="$save_CFLAGS"])
+if test "$gold_cv_c_random_seed" = "yes"; then
+ # In Makefile, '$@' will be expanded to be the name of the file
+ # being built, providing a unique seed for each file.
+ RANDOM_SEED_CFLAGS=-frandom-seed=\$@
+fi
+AC_SUBST(RANDOM_SEED_CFLAGS)
+
+dnl On GNU/Linux ifunc is supported by the dynamic linker in glibc
+dnl 2.11 or later, and by binutils 2.20.1 or later.
+AC_CACHE_CHECK([for glibc ifunc support], [gold_cv_lib_glibc_ifunc],
+[save_LDFLAGS="$LDFLAGS"
+LDFLAGS="$LDFLAGS -static"
+AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#include <features.h>
+#if !defined __GLIBC__
+error
+#elif __GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 11)
+error
+#endif
+void func (void) { }
+void invoke (void);
+__asm__(".type invoke, %gnu_indirect_function");
+typedef void (*funcptr) (void);
+funcptr dispatch (void) __asm__ ("invoke");
+funcptr dispatch (void) { return &func; }]],
+[[invoke();]])
+], [
+if ${NM} conftest$EXEEXT | grep "__rela\?_iplt_start" >/dev/null 2>&1; then
+ gold_cv_lib_glibc_ifunc=both
+else
+ gold_cv_lib_glibc_ifunc=dyn
+fi], [gold_cv_lib_glibc_ifunc=no])
+LDFLAGS="$save_LDFLAGS"])
+
+AM_CONDITIONAL(IFUNC, test "$gold_cv_lib_glibc_ifunc" != "no")
+AM_CONDITIONAL(IFUNC_STATIC, test "$gold_cv_lib_glibc_ifunc" = "both")
+