new file mode 100644
@@ -0,0 +1,93 @@
+/*
+ * Test CDSG instruction.
+ *
+ * Increment the first half of aligned_quadword by 1, and the second half by 2
+ * from 2 threads. Verify that the result is consistent.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include <assert.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+static volatile bool start;
+typedef unsigned long aligned_quadword[2] __attribute__((__aligned__(16)));
+static aligned_quadword val;
+static const int n_iterations = 1000000;
+
+static inline int cdsg(unsigned long *orig0, unsigned long *orig1,
+ unsigned long new0, unsigned long new1,
+ aligned_quadword *mem)
+{
+ register unsigned long r0 asm("r0");
+ register unsigned long r1 asm("r1");
+ register unsigned long r2 asm("r2");
+ register unsigned long r3 asm("r3");
+ int cc;
+
+ r0 = *orig0;
+ r1 = *orig1;
+ r2 = new0;
+ r3 = new1;
+ asm("cdsg %[r0],%[r2],%[db2]\n"
+ "ipm %[cc]"
+ : [r0] "+r" (r0)
+ , [r1] "+r" (r1)
+ , [db2] "+m" (*mem)
+ , [cc] "=r" (cc)
+ : [r2] "r" (r2)
+ , [r3] "r" (r3)
+ : "cc");
+ *orig0 = r0;
+ *orig1 = r1;
+
+ return (cc >> 28) & 3;
+}
+
+void *cdsg_loop(void *arg)
+{
+ unsigned long orig0, orig1, new0, new1;
+ int cc;
+ int i;
+
+ while (!start) {
+ }
+
+ orig0 = val[0];
+ orig1 = val[1];
+ for (i = 0; i < n_iterations;) {
+ new0 = orig0 + 1;
+ new1 = orig1 + 2;
+
+ cc = cdsg(&orig0, &orig1, new0, new1, &val);
+
+ if (cc == 0) {
+ orig0 = new0;
+ orig1 = new1;
+ i++;
+ } else {
+ assert(cc == 1);
+ }
+ }
+
+ return NULL;
+}
+
+int main(void)
+{
+ pthread_t thread;
+ int ret;
+
+ ret = pthread_create(&thread, NULL, cdsg_loop, NULL);
+ assert(ret == 0);
+ start = true;
+ cdsg_loop(NULL);
+ ret = pthread_join(thread, NULL);
+ assert(ret == 0);
+
+ assert(val[0] == n_iterations * 2);
+ assert(val[1] == n_iterations * 4);
+
+ return EXIT_SUCCESS;
+}
@@ -27,6 +27,10 @@ TESTS+=noexec
TESTS+=div
TESTS+=clst
TESTS+=long-double
+TESTS+=cdsg
+
+cdsg: CFLAGS+=-pthread
+cdsg: LDFLAGS+=-pthread
Z13_TESTS=vistr
$(Z13_TESTS): CFLAGS+=-march=z13 -O2