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+/* Narrow floating-point values to their semantic type.
+ Copyright (C) 2015-2018 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/>. */
+
+#ifndef _MATH_NARROW_EVAL_H
+#define _MATH_NARROW_EVAL_H 1
+
+#include <float.h>
+
+/* math_narrow_eval reduces its floating-point argument to the range
+ and precision of its semantic type. (The original evaluation may
+ still occur with excess range and precision, so the result may be
+ affected by double rounding.) */
+#if FLT_EVAL_METHOD == 0
+# define math_narrow_eval(x) (x)
+#else
+# if FLT_EVAL_METHOD == 1
+# define excess_precision(type) __builtin_types_compatible_p (type, float)
+# else
+# define excess_precision(type) (__builtin_types_compatible_p (type, float) \
+ || __builtin_types_compatible_p (type, \
+ double))
+# endif
+# define math_narrow_eval(x) \
+ ({ \
+ __typeof (x) math_narrow_eval_tmp = (x); \
+ if (excess_precision (__typeof (math_narrow_eval_tmp))) \
+ __asm__ ("" : "+m" (math_narrow_eval_tmp)); \
+ math_narrow_eval_tmp; \
+ })
+#endif
+
+#endif /* math-narrow-eval.h */