Move math_narrow_eval to separate math-narrow-eval.h.

This patch continues cleaning up the math_private.h header, which
contains lots of different definitions many of which are only needed
by a limited subset of files using that header (and some of which are
overridden by architectures that only want to override selected parts
of the header), by moving the math_narrow_eval macro out to a separate
math-narrow-eval.h header, only included by those files that need it.
That header is placed in include/ (since it's used in stdlib/, not
just files built in math/, but no sysdeps variants are needed at
present).

Tested for x86_64, and with build-many-glibcs.py.  (Installed stripped
shared libraries change because of line numbers in assertions in
strtod_l.c.)

	* include/math-narrow-eval.h: New file.  Contents moved from ....
	* sysdeps/generic/math_private.h: ... here.
	(math_narrow_eval): Remove macro.  Moved to math-narrow-eval.h.
	[FLT_EVAL_METHOD != 0] (excess_precision): Likewise.
	* math/s_fdim_template.c: Include <math-narrow-eval.h>.
	* stdlib/strtod_l.c: Likewise.
	* sysdeps/i386/fpu/s_f32xaddf64.c: Likewise.
	* sysdeps/i386/fpu/s_f32xsubf64.c: Likewise.
	* sysdeps/i386/fpu/s_fdim.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_cosh.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_gamma_r.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_j1.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_jn.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_sinh.c: Likewise.
	* sysdeps/ieee754/dbl-64/gamma_productf.c: Likewise.
	* sysdeps/ieee754/dbl-64/k_rem_pio2.c: Likewise.
	* sysdeps/ieee754/dbl-64/lgamma_neg.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_erf.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_llrint.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_lrint.c: Likewise.
	* sysdeps/ieee754/flt-32/e_coshf.c: Likewise.
	* sysdeps/ieee754/flt-32/e_exp2f.c: Likewise.
	* sysdeps/ieee754/flt-32/e_expf.c: Likewise.
	* sysdeps/ieee754/flt-32/e_gammaf_r.c: Likewise.
	* sysdeps/ieee754/flt-32/e_j1f.c: Likewise.
	* sysdeps/ieee754/flt-32/e_jnf.c: Likewise.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c: Likewise.
	* sysdeps/ieee754/flt-32/e_sinhf.c: Likewise.
	* sysdeps/ieee754/flt-32/k_rem_pio2f.c: Likewise.
	* sysdeps/ieee754/flt-32/lgamma_negf.c: Likewise.
	* sysdeps/ieee754/flt-32/s_erff.c: Likewise.
	* sysdeps/ieee754/flt-32/s_llrintf.c: Likewise.
	* sysdeps/ieee754/flt-32/s_lrintf.c: Likewise.
	* sysdeps/ieee754/ldbl-96/gamma_product.c: Likewise.

1 files changed, 47 insertions, 0 deletions

diff --git a/include/math-narrow-eval.h b/include/math-narrow-eval.h
new file mode 100644
index 0000000000..4361aa06c0
--- /dev/null
+++ b/include/math-narrow-eval.h
@@ -0,0 +1,47 @@
+/* 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 */