gc: fix msvc not using libatomic_ops (#15418)

thirdparty/libatomic_ops/atomic_ops/sysdeps/gcc/cris.h

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2004 Hewlett-Packard Development Company, L.P.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/* FIXME: seems to be untested.         */
+
+#include "../all_atomic_load_store.h"
+
+#include "../ordered.h"  /* There are no multiprocessor implementations. */
+
+#include "../test_and_set_t_is_ao_t.h"
+
+/*
+ * The architecture apparently supports an "f" flag which is
+ * set on preemption.  This essentially gives us load-locked,
+ * store-conditional primitives, though I'm not quite sure how
+ * this would work on a hypothetical multiprocessor.  -HB
+ *
+ * For details, see
+ * http://developer.axis.com/doc/hardware/etrax100lx/prog_man/
+ *      1_architectural_description.pdf
+ *
+ * TODO: Presumably many other primitives (notably CAS, including the double-
+ * width versions) could be implemented in this manner, if someone got
+ * around to it.
+ */
+
+AO_INLINE AO_TS_VAL_t
+AO_test_and_set_full(volatile AO_TS_t *addr) {
+    /* Ripped from linuxthreads/sysdeps/cris/pt-machine.h */
+    register unsigned long int ret;
+
+    /* Note the use of a dummy output of *addr to expose the write.  The
+       memory barrier is to stop *other* writes being moved past this code.  */
+      __asm__ __volatile__("clearf\n"
+                           "0:\n\t"
+                           "movu.b [%2],%0\n\t"
+                           "ax\n\t"
+                           "move.b %3,[%2]\n\t"
+                           "bwf 0b\n\t"
+                           "clearf"
+                           : "=&r" (ret), "=m" (*addr)
+                           : "r" (addr), "r" ((int) 1), "m" (*addr)
+                           : "memory");
+    return ret;
+}
+#define AO_HAVE_test_and_set_full