1 files changed, 56 insertions, 0 deletions
diff --git a/sysdeps/ieee754/dbl-64/s_nextup.c b/sysdeps/ieee754/dbl-64/s_nextup.c
new file mode 100644
index 0000000000..d37a2b6657
--- /dev/null
+++ b/sysdeps/ieee754/dbl-64/s_nextup.c
@@ -0,0 +1,56 @@
+/* Return the least floating-point number greater than X.
+   Copyright (C) 2016-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <float.h>
+#include <math.h>
+#include <math_private.h>
+#include <libm-alias-double.h>
+
+/* Return the least floating-point number greater than X.  */
+double
+__nextup (double x)
+{
+  int32_t hx, ix;
+  uint32_t lx;
+
+  EXTRACT_WORDS (hx, lx, x);
+  ix = hx & 0x7fffffff;
+
+  if (((ix >= 0x7ff00000) && ((ix - 0x7ff00000) | lx) != 0))  /* x is nan.  */
+    return x + x;
+  if ((ix | lx) == 0)
+    return DBL_TRUE_MIN;
+  if (hx >= 0)
+    {				/* x > 0.  */
+      if (isinf (x))
+        return x;
+      lx += 1;
+      if (lx == 0)
+        hx += 1;
+    }
+  else
+    {				/* x < 0.  */
+      if (lx == 0)
+        hx -= 1;
+      lx -= 1;
+    }
+  INSERT_WORDS (x, hx, lx);
+  return x;
+}
+
+libm_alias_double (__nextup, nextup)