X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=m4%2Fae_cc_atomic_builtins.m4;fp=m4%2Fae_cc_atomic_builtins.m4;h=2efbde39864293d2fbc8613af29eedb4470b0c18;hp=0000000000000000000000000000000000000000;hb=3afcf5a0407c69b32603a249e8e7b3d309584a85;hpb=c92c99041415698b57ca123e58a19b05189ae398

diff --git a/m4/ae_cc_atomic_builtins.m4 b/m4/ae_cc_atomic_builtins.m4
new file mode 100644
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+++ b/m4/ae_cc_atomic_builtins.m4
@@ -0,0 +1,78 @@
+# SYNOPSIS
+#
+#   AE_CC_ATOMIC_BUILTINS([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
+#
+# LICENSE
+#
+#   Copyright (c) 2023 Michael Jeanson <mjeanson@efficios.com>
+#
+#   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 2 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 <https://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([AE_CC_ATOMIC_BUILTINS], [
+AC_REQUIRE([AC_PROG_CC])
+AC_LANG_PUSH([C])
+
+AC_CACHE_CHECK(
+  [whether $CC supports atomic builtins],
+  [ae_cv_cc_atomic_builtins],
+  [
+    AC_LINK_IFELSE([
+      AC_LANG_PROGRAM([
+        int x, y;
+      ],[
+        __atomic_store_n(&x, 0, __ATOMIC_RELAXED);
+        __atomic_load_n(&x, __ATOMIC_RELAXED);
+        y = __atomic_exchange_n(&x, 1, __ATOMIC_RELAXED);
+        __atomic_compare_exchange_n(&x, &y, 0, 0, __ATOMIC_RELAXED, __ATOMIC_RELAXED);
+        __atomic_add_fetch(&x, 1, __ATOMIC_RELAXED);
+        __atomic_sub_fetch(&x, 1, __ATOMIC_RELAXED);
+        __atomic_and_fetch(&x, 0x01, __ATOMIC_RELAXED);
+        __atomic_or_fetch(&x, 0x01, __ATOMIC_RELAXED);
+        __atomic_thread_fence(__ATOMIC_RELAXED);
+        __atomic_signal_fence(__ATOMIC_RELAXED);
+      ])
+    ],[
+      ae_cv_cc_atomic_builtins=yes
+    ],[
+      ae_cv_cc_atomic_builtins=no
+    ])
+  ]
+)
+
+# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
+if test "x$ae_cv_cc_atomic_builtins" = "xyes"; then
+  $1
+  :
+else
+  $2
+  :
+fi
+
+AC_LANG_POP
+])dnl AE_CC_ATOMIC_BUILTINS