commit ff12f8b9ae10bf7270ec7ead28a479f6105058eb
Author: Segher Boessenkool <segher@kernel.crashing.org>
Date:   Fri Aug 30 16:17:20 2019 +0200

    backport: re PR target/91481 (POWER9 "DARN" RNG intrinsic produces repeated output (CVE-2019-15847))
    
            Backport from trunk
            2019-08-23  Segher Boessenkool  <segher@kernel.crashing.org>
    
    gcc/testsuite/
            PR target/91481
            * gcc.target/powerpc/darn-3.c: New testcase.
    
    From-SVN: r275182

--- /dev/null
+++ gcc/testsuite/gcc.target/powerpc/darn-3.c
@@ -0,0 +1,16 @@
+/* { dg-do compile { target { powerpc*-*-* } } } */
+/* { dg-skip-if "" { powerpc*-*-aix* } } */
+/* { dg-options "-O2 -mdejagnu-cpu=power9" } */
+
+static int darn32(void) { return __builtin_darn_32(); }
+
+int four(void)
+{
+	int sum = 0;
+	int i;
+	for (i = 0; i < 4; i++)
+		sum += darn32();
+	return sum;
+}
+
+/* { dg-final { scan-assembler-times {(?n)\mdarn .*,0\M} 4 } } */