aboutsummaryrefslogtreecommitdiff
path: root/math/math-narrow.h
diff options
context:
space:
mode:
Diffstat (limited to 'math/math-narrow.h')
-rw-r--r--math/math-narrow.h146
1 files changed, 146 insertions, 0 deletions
diff --git a/math/math-narrow.h b/math/math-narrow.h
new file mode 100644
index 0000000000..1a3a5c57d7
--- /dev/null
+++ b/math/math-narrow.h
@@ -0,0 +1,146 @@
+/* Helper macros for functions returning a narrower type.
+ Copyright (C) 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_H
+#define _MATH_NARROW_H 1
+
+#include <bits/floatn.h>
+#include <bits/long-double.h>
+#include <errno.h>
+#include <fenv.h>
+#include <ieee754.h>
+#include <math_private.h>
+
+/* Carry out a computation using round-to-odd. The computation is
+ EXPR; the union type in which to store the result is UNION and the
+ subfield of the "ieee" field of that union with the low part of the
+ mantissa is MANTISSA; SUFFIX is the suffix for the libc_fe* macros
+ to ensure that the correct rounding mode is used, for platforms
+ with multiple rounding modes where those macros set only the
+ relevant mode. This macro does not work correctly if the sign of
+ an exact zero result depends on the rounding mode, so that case
+ must be checked for separately. */
+#define ROUND_TO_ODD(EXPR, UNION, SUFFIX, MANTISSA) \
+ ({ \
+ fenv_t env; \
+ UNION u; \
+ \
+ libc_feholdexcept_setround ## SUFFIX (&env, FE_TOWARDZERO); \
+ u.d = (EXPR); \
+ math_force_eval (u.d); \
+ u.ieee.MANTISSA \
+ |= libc_feupdateenv_test ## SUFFIX (&env, FE_INEXACT) != 0; \
+ \
+ u.d; \
+ })
+
+/* The following macros declare aliases for a narrowing function. The
+ sole argument is the base name of a family of functions, such as
+ "add". If any platform changes long double format after the
+ introduction of narrowing functions, in a way requiring symbol
+ versioning compatibility, additional variants of these macros will
+ be needed. */
+
+#define libm_alias_float_double_main(func) \
+ weak_alias (__f ## func, f ## func) \
+ weak_alias (__f ## func, f32 ## func ## f64) \
+ weak_alias (__f ## func, f32 ## func ## f32x)
+
+#ifdef NO_LONG_DOUBLE
+# define libm_alias_float_double(func) \
+ libm_alias_float_double_main (func) \
+ weak_alias (__f ## func, f ## func ## l)
+#else
+# define libm_alias_float_double(func) \
+ libm_alias_float_double_main (func)
+#endif
+
+#define libm_alias_float32x_float64_main(func) \
+ weak_alias (__f32x ## func ## f64, f32x ## func ## f64)
+
+#ifdef NO_LONG_DOUBLE
+# define libm_alias_float32x_float64(func) \
+ libm_alias_float32x_float64_main (func) \
+ weak_alias (__f32x ## func ## f64, d ## func ## l)
+#elif defined __LONG_DOUBLE_MATH_OPTIONAL
+# define libm_alias_float32x_float64(func) \
+ libm_alias_float32x_float64_main (func) \
+ weak_alias (__f32x ## func ## f64, __nldbl_d ## func ## l)
+#else
+# define libm_alias_float32x_float64(func) \
+ libm_alias_float32x_float64_main (func)
+#endif
+
+#if __HAVE_FLOAT128 && !__HAVE_DISTINCT_FLOAT128
+# define libm_alias_float_ldouble_f128(func) \
+ weak_alias (__f ## func ## l, f32 ## func ## f128)
+# define libm_alias_double_ldouble_f128(func) \
+ weak_alias (__d ## func ## l, f32x ## func ## f128) \
+ weak_alias (__d ## func ## l, f64 ## func ## f128)
+#else
+# define libm_alias_float_ldouble_f128(func)
+# define libm_alias_double_ldouble_f128(func)
+#endif
+
+#if __HAVE_FLOAT64X_LONG_DOUBLE
+# define libm_alias_float_ldouble_f64x(func) \
+ weak_alias (__f ## func ## l, f32 ## func ## f64x)
+# define libm_alias_double_ldouble_f64x(func) \
+ weak_alias (__d ## func ## l, f32x ## func ## f64x) \
+ weak_alias (__d ## func ## l, f64 ## func ## f64x)
+#else
+# define libm_alias_float_ldouble_f64x(func)
+# define libm_alias_double_ldouble_f64x(func)
+#endif
+
+#define libm_alias_float_ldouble(func) \
+ weak_alias (__f ## func ## l, f ## func ## l) \
+ libm_alias_float_ldouble_f128 (func) \
+ libm_alias_float_ldouble_f64x (func)
+
+#define libm_alias_double_ldouble(func) \
+ weak_alias (__d ## func ## l, d ## func ## l) \
+ libm_alias_double_ldouble_f128 (func) \
+ libm_alias_double_ldouble_f64x (func)
+
+#define libm_alias_float64x_float128(func) \
+ weak_alias (__f64x ## func ## f128, f64x ## func ## f128)
+
+#define libm_alias_float32_float128_main(func) \
+ weak_alias (__f32 ## func ## f128, f32 ## func ## f128)
+
+#define libm_alias_float64_float128_main(func) \
+ weak_alias (__f64 ## func ## f128, f64 ## func ## f128) \
+ weak_alias (__f64 ## func ## f128, f32x ## func ## f128)
+
+#if __HAVE_FLOAT64X_LONG_DOUBLE
+# define libm_alias_float32_float128(func) \
+ libm_alias_float32_float128_main (func)
+# define libm_alias_float64_float128(func) \
+ libm_alias_float64_float128_main (func)
+#else
+# define libm_alias_float32_float128(func) \
+ libm_alias_float32_float128_main (func) \
+ weak_alias (__f32 ## func ## f128, f32 ## func ## f64x)
+# define libm_alias_float64_float128(func) \
+ libm_alias_float64_float128_main (func) \
+ weak_alias (__f64 ## func ## f128, f64 ## func ## f64x) \
+ weak_alias (__f64 ## func ## f128, f32x ## func ## f64x)
+#endif
+
+#endif /* math-narrow.h. */