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Diffstat (limited to 'math/math-narrow.h')
| -rw-r--r-- | math/math-narrow.h | 146 |
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. */ |