1 files changed, 51 insertions, 0 deletions
diff --git a/libquadmath/math/exp2q.c b/libquadmath/math/exp2q.c
new file mode 100644
index 00000000000..f012264a3df
--- /dev/null
+++ b/libquadmath/math/exp2q.c
@@ -0,0 +1,51 @@
+/* Compute 2^x.
+   Copyright (C) 2012-2018 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 "quadmath-imp.h"
+
+__float128
+exp2q (__float128 x)
+{
+  if (__glibc_likely (__builtin_isless (x, (__float128) FLT128_MAX_EXP)))
+    {
+      if (__builtin_expect (__builtin_isgreaterequal (x, (__float128) (FLT128_MIN_EXP - FLT128_MANT_DIG
+							- 1)), 1))
+	{
+	  int intx = (int) x;
+	  __float128 fractx = x - intx;
+	  __float128 result;
+	  if (fabsq (fractx) < FLT128_EPSILON / 4)
+	    result = scalbnq (1 + fractx, intx);
+	  else
+	    result = scalbnq (expq (M_LN2q * fractx), intx);
+	  math_check_force_underflow_nonneg (result);
+	  return result;
+	}
+      else
+	{
+	  /* Underflow or exact zero.  */
+	  if (isinfq (x))
+	    return 0;
+	  else
+	    return FLT128_MIN * FLT128_MIN;
+	}
+    }
+  else
+    /* Infinity, NaN or overflow.  */
+    return FLT128_MAX * x;
+}