263 lines
8.9 KiB
C
263 lines
8.9 KiB
C
/* 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; \
|
|
})
|
|
|
|
/* Check for error conditions from a narrowing add function returning
|
|
RET with arguments X and Y and set errno as needed. Overflow and
|
|
underflow can occur for finite arguments and a domain error for
|
|
infinite ones. */
|
|
#define CHECK_NARROW_ADD(RET, X, Y) \
|
|
do \
|
|
{ \
|
|
if (!isfinite (RET)) \
|
|
{ \
|
|
if (isnan (RET)) \
|
|
{ \
|
|
if (!isnan (X) && !isnan (Y)) \
|
|
__set_errno (EDOM); \
|
|
} \
|
|
else if (isfinite (X) && isfinite (Y)) \
|
|
__set_errno (ERANGE); \
|
|
} \
|
|
else if ((RET) == 0 && (X) != -(Y)) \
|
|
__set_errno (ERANGE); \
|
|
} \
|
|
while (0)
|
|
|
|
/* Implement narrowing add using round-to-odd. The arguments are X
|
|
and Y, the return type is TYPE and UNION, MANTISSA and SUFFIX are
|
|
as for ROUND_TO_ODD. */
|
|
#define NARROW_ADD_ROUND_TO_ODD(X, Y, TYPE, UNION, SUFFIX, MANTISSA) \
|
|
do \
|
|
{ \
|
|
TYPE ret; \
|
|
\
|
|
/* Ensure a zero result is computed in the original rounding \
|
|
mode. */ \
|
|
if ((X) == -(Y)) \
|
|
ret = (TYPE) ((X) + (Y)); \
|
|
else \
|
|
ret = (TYPE) ROUND_TO_ODD (math_opt_barrier (X) + (Y), \
|
|
UNION, SUFFIX, MANTISSA); \
|
|
\
|
|
CHECK_NARROW_ADD (ret, (X), (Y)); \
|
|
return ret; \
|
|
} \
|
|
while (0)
|
|
|
|
/* Implement a narrowing add function that is not actually narrowing
|
|
or where no attempt is made to be correctly rounding (the latter
|
|
only applies to IBM long double). The arguments are X and Y and
|
|
the return type is TYPE. */
|
|
#define NARROW_ADD_TRIVIAL(X, Y, TYPE) \
|
|
do \
|
|
{ \
|
|
TYPE ret; \
|
|
\
|
|
ret = (TYPE) ((X) + (Y)); \
|
|
CHECK_NARROW_ADD (ret, (X), (Y)); \
|
|
return ret; \
|
|
} \
|
|
while (0)
|
|
|
|
/* Check for error conditions from a narrowing subtract function
|
|
returning RET with arguments X and Y and set errno as needed.
|
|
Overflow and underflow can occur for finite arguments and a domain
|
|
error for infinite ones. */
|
|
#define CHECK_NARROW_SUB(RET, X, Y) \
|
|
do \
|
|
{ \
|
|
if (!isfinite (RET)) \
|
|
{ \
|
|
if (isnan (RET)) \
|
|
{ \
|
|
if (!isnan (X) && !isnan (Y)) \
|
|
__set_errno (EDOM); \
|
|
} \
|
|
else if (isfinite (X) && isfinite (Y)) \
|
|
__set_errno (ERANGE); \
|
|
} \
|
|
else if ((RET) == 0 && (X) != (Y)) \
|
|
__set_errno (ERANGE); \
|
|
} \
|
|
while (0)
|
|
|
|
/* Implement narrowing subtract using round-to-odd. The arguments are
|
|
X and Y, the return type is TYPE and UNION, MANTISSA and SUFFIX are
|
|
as for ROUND_TO_ODD. */
|
|
#define NARROW_SUB_ROUND_TO_ODD(X, Y, TYPE, UNION, SUFFIX, MANTISSA) \
|
|
do \
|
|
{ \
|
|
TYPE ret; \
|
|
\
|
|
/* Ensure a zero result is computed in the original rounding \
|
|
mode. */ \
|
|
if ((X) == (Y)) \
|
|
ret = (TYPE) ((X) - (Y)); \
|
|
else \
|
|
ret = (TYPE) ROUND_TO_ODD (math_opt_barrier (X) - (Y), \
|
|
UNION, SUFFIX, MANTISSA); \
|
|
\
|
|
CHECK_NARROW_SUB (ret, (X), (Y)); \
|
|
return ret; \
|
|
} \
|
|
while (0)
|
|
|
|
/* Implement a narrowing subtract function that is not actually
|
|
narrowing or where no attempt is made to be correctly rounding (the
|
|
latter only applies to IBM long double). The arguments are X and Y
|
|
and the return type is TYPE. */
|
|
#define NARROW_SUB_TRIVIAL(X, Y, TYPE) \
|
|
do \
|
|
{ \
|
|
TYPE ret; \
|
|
\
|
|
ret = (TYPE) ((X) - (Y)); \
|
|
CHECK_NARROW_SUB (ret, (X), (Y)); \
|
|
return ret; \
|
|
} \
|
|
while (0)
|
|
|
|
/* 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. */
|