static int trivial_quick(rand_pool *r) { return (-1); }
+#if __GNUC__ && (CPUFAM_X86 || CPUFAM_AMD64)
+static int rdrand_quick(rand_pool *r)
+{
+ unsigned long rr;
+ int i = 16;
+
+ __asm__ ("0: rdrand %0; jc 9f; dec %1; jnz 0b; 9:"
+ : "=r" (rr), "=r" (i) : "1" (i) : "cc");
+ if (!i) return (-1);
+ rand_add(r, &rr, sizeof(rr), 8*sizeof(rr));
+ return (0);
+}
+#endif
+
static quick__functype *pick_quick(void)
{
+#if __GNUC__ && (CPUFAM_X86 || CPUFAM_AMD64)
+ DISPATCH_PICK_COND(rand_quick, rdrand_quick,
+ cpu_feature_p(CPUFEAT_X86_RDRAND));
+#endif
DISPATCH_PICK_FALLBACK(rand_quick, trivial_quick);
}