+ old_CXXFLAGS="$CXXFLAGS"
+
+ # Do link tests if possible, instead asm tests, limited to some platforms
+ # see discussion in PR target/40134, PR libstdc++/40133 and the thread
+ # starting at http://gcc.gnu.org/ml/gcc-patches/2009-07/msg00322.html
+ atomic_builtins_link_tests=no
+ if test x$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"
+
+ AC_MSG_CHECKING([for atomic builtins for bool])
+ AC_CACHE_VAL(glibcxx_cv_atomic_bool, [
+ AC_TRY_LINK(
+ [ ],
+ [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();],
+ [glibcxx_cv_atomic_bool=yes],
+ [glibcxx_cv_atomic_bool=no])
+ ])
+ if test $glibcxx_cv_atomic_bool = yes; then
+ AC_DEFINE(_GLIBCXX_ATOMIC_BUILTINS_1, 1,
+ [Define if builtin atomic operations for bool are supported on this host.])
+ fi
+ AC_MSG_RESULT($glibcxx_cv_atomic_bool)
+
+ AC_MSG_CHECKING([for atomic builtins for short])
+ AC_CACHE_VAL(glibcxx_cv_atomic_short, [
+ AC_TRY_LINK(
+ [ ],
+ [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();],
+ [glibcxx_cv_atomic_short=yes],
+ [glibcxx_cv_atomic_short=no])
+ ])
+ if test $glibcxx_cv_atomic_short = yes; then
+ AC_DEFINE(_GLIBCXX_ATOMIC_BUILTINS_2, 1,
+ [Define if builtin atomic operations for short are supported on this host.])
+ fi
+ AC_MSG_RESULT($glibcxx_cv_atomic_short)
+
+ AC_MSG_CHECKING([for atomic builtins for int])
+ AC_CACHE_VAL(glibcxx_cv_atomic_int, [
+ AC_TRY_LINK(
+ [ ],
+ [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();],
+ [glibcxx_cv_atomic_int=yes],
+ [glibcxx_cv_atomic_int=no])
+ ])
+ if test $glibcxx_cv_atomic_int = yes; then
+ AC_DEFINE(_GLIBCXX_ATOMIC_BUILTINS_4, 1,
+ [Define if builtin atomic operations for int are supported on this host.])
+ fi
+ AC_MSG_RESULT($glibcxx_cv_atomic_int)
+
+ AC_MSG_CHECKING([for atomic builtins for long long])
+ AC_CACHE_VAL(glibcxx_cv_atomic_long_long, [
+ AC_TRY_LINK(
+ [ ],
+ [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();],
+ [glibcxx_cv_atomic_long_long=yes],
+ [glibcxx_cv_atomic_long_long=no])
+ ])
+ if test $glibcxx_cv_atomic_long_long = yes; then
+ AC_DEFINE(_GLIBCXX_ATOMIC_BUILTINS_8, 1,
+ [Define if builtin atomic operations for long long are supported on this host.])
+ fi
+ AC_MSG_RESULT($glibcxx_cv_atomic_long_long)
+
+ else
+
+ # Do asm tests.
+
+ # Compile unoptimized.
+ CXXFLAGS='-O0 -S'
+
+ # Fake what AC_TRY_COMPILE does.
+
+ cat > conftest.$ac_ext << EOF
+[#]line __oline__ "configure"
+int main()
+{
+ typedef bool atomic_type;
+ atomic_type c1;
+ atomic_type c2;
+ const atomic_type c3(0);
+ __sync_fetch_and_add(&c1, c2);
+ __sync_val_compare_and_swap(&c1, c3, c2);
+ __sync_lock_test_and_set(&c1, c3);
+ __sync_lock_release(&c1);
+ __sync_synchronize();
+ return 0;
+}
+EOF
+
+ AC_MSG_CHECKING([for atomic builtins for bool])
+ if AC_TRY_EVAL(ac_compile); then
+ if grep __sync_ conftest.s >/dev/null 2>&1 ; then
+ glibcxx_cv_atomic_bool=no
+ else
+ AC_DEFINE(_GLIBCXX_ATOMIC_BUILTINS_1, 1,
+ [Define if builtin atomic operations for bool are supported on this host.])
+ glibcxx_cv_atomic_bool=yes
+ fi
+ fi
+ AC_MSG_RESULT($glibcxx_cv_atomic_bool)
+ rm -f conftest*
+
+ cat > conftest.$ac_ext << EOF
+[#]line __oline__ "configure"
+int main()
+{
+ typedef short atomic_type;
+ atomic_type c1;
+ atomic_type c2;
+ const atomic_type c3(0);
+ __sync_fetch_and_add(&c1, c2);
+ __sync_val_compare_and_swap(&c1, c3, c2);
+ __sync_lock_test_and_set(&c1, c3);
+ __sync_lock_release(&c1);
+ __sync_synchronize();
+ return 0;
+}
+EOF
+
+ AC_MSG_CHECKING([for atomic builtins for short])
+ if AC_TRY_EVAL(ac_compile); then
+ if grep __sync_ conftest.s >/dev/null 2>&1 ; then
+ glibcxx_cv_atomic_short=no
+ else
+ AC_DEFINE(_GLIBCXX_ATOMIC_BUILTINS_2, 1,
+ [Define if builtin atomic operations for short are supported on this host.])
+ glibcxx_cv_atomic_short=yes
+ fi
+ fi
+ AC_MSG_RESULT($glibcxx_cv_atomic_short)
+ rm -f conftest*