+ # Do link tests if possible, instead asm tests, limited to some platforms
+ # see discussion in PR target/40134, PR libstdc++/40133 and the thread
+ # starting at http://gcc.gnu.org/ml/gcc-patches/2009-07/msg00322.html
+ atomic_builtins_link_tests=no
+ if test x$gcc_no_link != xyes; then
+ # Can do link tests. Limit to some tested platforms
+ case "$host" in
+ *-*-linux* | *-*-uclinux* | *-*-kfreebsd*-gnu | *-*-gnu*)
+ atomic_builtins_link_tests=yes
+ ;;
+ esac
+ fi
+
+ if test x$atomic_builtins_link_tests = xyes; then
+
+ # Do link tests.
+
+ CXXFLAGS="$CXXFLAGS -fno-exceptions"
+
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for atomic builtins for bool" >&5
+$as_echo_n "checking for atomic builtins for bool... " >&6; }
+ if test "${glibcxx_cv_atomic_bool+set}" = set; then :
+ $as_echo_n "(cached) " >&6
+else
+
+ if test x$gcc_no_link = xyes; then
+ as_fn_error "Link tests are not allowed after GCC_NO_EXECUTABLES." "$LINENO" 5
+fi
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+int
+main ()
+{
+typedef bool atomic_type;
+ atomic_type c1;
+ atomic_type c2;
+ const atomic_type c3(0);
+ __sync_fetch_and_add(&c1, c2);
+ __sync_val_compare_and_swap(&c1, c3, c2);
+ __sync_lock_test_and_set(&c1, c3);
+ __sync_lock_release(&c1);
+ __sync_synchronize();
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"; then :
+ glibcxx_cv_atomic_bool=yes
+else
+ glibcxx_cv_atomic_bool=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+
+fi
+
+ if test $glibcxx_cv_atomic_bool = yes; then
+
+$as_echo "#define _GLIBCXX_ATOMIC_BUILTINS_1 1" >>confdefs.h
+
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_atomic_bool" >&5
+$as_echo "$glibcxx_cv_atomic_bool" >&6; }
+
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for atomic builtins for short" >&5
+$as_echo_n "checking for atomic builtins for short... " >&6; }
+ if test "${glibcxx_cv_atomic_short+set}" = set; then :
+ $as_echo_n "(cached) " >&6
+else
+
+ if test x$gcc_no_link = xyes; then
+ as_fn_error "Link tests are not allowed after GCC_NO_EXECUTABLES." "$LINENO" 5
+fi
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+int
+main ()
+{
+typedef short atomic_type;
+ atomic_type c1;
+ atomic_type c2;
+ const atomic_type c3(0);
+ __sync_fetch_and_add(&c1, c2);
+ __sync_val_compare_and_swap(&c1, c3, c2);
+ __sync_lock_test_and_set(&c1, c3);
+ __sync_lock_release(&c1);
+ __sync_synchronize();
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"; then :
+ glibcxx_cv_atomic_short=yes
+else
+ glibcxx_cv_atomic_short=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+
+fi
+
+ if test $glibcxx_cv_atomic_short = yes; then
+
+$as_echo "#define _GLIBCXX_ATOMIC_BUILTINS_2 1" >>confdefs.h
+
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_atomic_short" >&5
+$as_echo "$glibcxx_cv_atomic_short" >&6; }
+
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for atomic builtins for int" >&5
+$as_echo_n "checking for atomic builtins for int... " >&6; }
+ if test "${glibcxx_cv_atomic_int+set}" = set; then :
+ $as_echo_n "(cached) " >&6
+else
+
+ if test x$gcc_no_link = xyes; then
+ as_fn_error "Link tests are not allowed after GCC_NO_EXECUTABLES." "$LINENO" 5
+fi
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+int
+main ()
+{
+typedef int atomic_type;
+ atomic_type c1;
+ atomic_type c2;
+ const atomic_type c3(0);
+ __sync_fetch_and_add(&c1, c2);
+ __sync_val_compare_and_swap(&c1, c3, c2);
+ __sync_lock_test_and_set(&c1, c3);
+ __sync_lock_release(&c1);
+ __sync_synchronize();
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"; then :
+ glibcxx_cv_atomic_int=yes
+else
+ glibcxx_cv_atomic_int=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+
+fi
+
+ if test $glibcxx_cv_atomic_int = yes; then
+
+$as_echo "#define _GLIBCXX_ATOMIC_BUILTINS_4 1" >>confdefs.h
+
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_atomic_int" >&5
+$as_echo "$glibcxx_cv_atomic_int" >&6; }
+
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for atomic builtins for long long" >&5
+$as_echo_n "checking for atomic builtins for long long... " >&6; }
+ if test "${glibcxx_cv_atomic_long_long+set}" = set; then :
+ $as_echo_n "(cached) " >&6
+else
+
+ if test x$gcc_no_link = xyes; then
+ as_fn_error "Link tests are not allowed after GCC_NO_EXECUTABLES." "$LINENO" 5
+fi
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+int
+main ()
+{
+typedef long long atomic_type;
+ atomic_type c1;
+ atomic_type c2;
+ const atomic_type c3(0);
+ __sync_fetch_and_add(&c1, c2);
+ __sync_val_compare_and_swap(&c1, c3, c2);
+ __sync_lock_test_and_set(&c1, c3);
+ __sync_lock_release(&c1);
+ __sync_synchronize();
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"; then :
+ glibcxx_cv_atomic_long_long=yes
+else
+ glibcxx_cv_atomic_long_long=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+
+fi
+
+ if test $glibcxx_cv_atomic_long_long = yes; then
+
+$as_echo "#define _GLIBCXX_ATOMIC_BUILTINS_8 1" >>confdefs.h
+
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_atomic_long_long" >&5
+$as_echo "$glibcxx_cv_atomic_long_long" >&6; }
+
+ else
+
+ # Do asm tests.
+