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-rw-r--r--math/w_pow_compat.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/math/w_pow_compat.c b/math/w_pow_compat.c
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+++ b/math/w_pow_compat.c
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+/* Copyright (C) 2011-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
+
+   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 <math.h>
+#include <math_private.h>
+
+
+/* wrapper pow */
+double
+__pow (double x, double y)
+{
+  double z = __ieee754_pow (x, y);
+  if (__glibc_unlikely (!isfinite (z)))
+    {
+      if (_LIB_VERSION != _IEEE_)
+	{
+	  if (isfinite (x) && isfinite (y))
+	    {
+	      if (isnan (z))
+		/* pow neg**non-int */
+		return __kernel_standard (x, y, 24);
+	      else if (x == 0.0 && y < 0.0)
+		{
+		  if (signbit (x) && signbit (z))
+		    /* pow(-0.0,negative) */
+		    return __kernel_standard (x, y, 23);
+		  else
+		    /* pow(+0.0,negative) */
+		    return __kernel_standard (x, y, 43);
+		}
+	      else
+		/* pow overflow */
+		return __kernel_standard (x, y, 21);
+	    }
+	}
+    }
+  else if (__builtin_expect (z == 0.0, 0)
+	   && isfinite (x) && x != 0 && isfinite (y)
+	   && _LIB_VERSION != _IEEE_)
+    /* pow underflow */
+    return __kernel_standard (x, y, 22);
+
+  return z;
+}
+weak_alias (__pow, pow)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__pow, __powl)
+weak_alias (__pow, powl)
+#endif