unikernel/duniverse/Zarith/tests/setround.c

@@ -0,0 +1,27 @@
+/* Auxiliary function to control FP rounding mode.  Assumes ISO C99. */
+
+#include <fenv.h>
+#include <caml/mlvalues.h>
+
+#ifndef FE_DOWNWARD
+#define FE_DOWNWARD (-1)
+#endif
+#ifndef FE_TONEAREST
+#define FE_TONEAREST (-1)
+#endif
+#ifndef FE_TOWARDZERO
+#define FE_TOWARDZERO (-1)
+#endif
+#ifndef FE_UPWARD
+#define FE_UPWARD (-1)
+#endif
+
+static int modes[4] = {
+  FE_DOWNWARD, FE_TONEAREST, FE_TOWARDZERO, FE_UPWARD
+};
+
+CAMLprim value caml_ztest_setround(value vmode)
+{
+  int rc = fesetround(modes[Int_val(vmode)]);
+  return Val_bool(rc == 0);
+}