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-rw-r--r--math/w_pow_template.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/math/w_pow_template.c b/math/w_pow_template.c
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+/* Wrapper to set errno for pow.
+   Copyright (C) 2017 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/>.  */
+
+/* Only build wrappers from the templates for the types that define the macro
+   below.  This macro is set in math-type-macros-<type>.h in sysdeps/generic
+   for each floating-point type.  */
+#if __USE_WRAPPER_TEMPLATE
+
+# include <fenv.h>
+# include <math.h>
+# include <math_private.h>
+
+FLOAT
+M_DECL_FUNC (__pow) (FLOAT x, FLOAT y)
+{
+  FLOAT z = M_SUF (__ieee754_pow) (x, y);
+  if (__glibc_unlikely (!isfinite (z)))
+    {
+      if (isfinite (x) && isfinite (y))
+	{
+	  if (isnan (z))
+	    /* Domain error: pow(x<0,y=non-integer).  */
+	    __set_errno (EDOM);
+	  else
+	    /* Pole error: pow(x=0,y<0).  Or overflow.  */
+	    __set_errno (ERANGE);
+	}
+    }
+  else if (__glibc_unlikely (z == 0) && isfinite (x) && x != 0 && isfinite (y))
+    /* Underflow.  */
+    __set_errno (ERANGE);
+  return z;
+}
+declare_mgen_alias (__pow, pow)
+
+#endif /* __USE_WRAPPER_TEMPLATE.  */