s390x: add single-instruction math functions

these were introduced in z196 and not available in the baseline (z900)
ISA level. use __HTM__ as an alternate indicator for ISA level, since
gcc did not define __ARCH__ until 7.x.

patch by David Edelsohn.

1 files changed, 15 insertions, 0 deletions

diff --git a/src/math/s390x/nearbyintl.c b/src/math/s390x/nearbyintl.c
new file mode 100644
index 00000000..b4bd5523
--- /dev/null
+++ b/src/math/s390x/nearbyintl.c
@@ -0,0 +1,15 @@
+#include <math.h>
+
+#if defined(__HTM__) || __ARCH__ >= 9
+
+long double nearbyintl(long double x)
+{
+	__asm__ ("fixbra %0, 0, %1, 4" : "=f"(x) : "f"(x));
+	return x;
+}
+
+#else
+
+#include "../nearbyintl.c"
+
+#endif