Current File : //glibc-2.29/sysdeps/ieee754/dbl-64/math_config.h
/* Configuration for double precision math routines.
Copyright (C) 2018-2019 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_CONFIG_H
#define _MATH_CONFIG_H
#include <math.h>
#include <math_private.h>
#include <nan-high-order-bit.h>
#include <stdint.h>
#ifndef WANT_ROUNDING
/* Correct special case results in non-nearest rounding modes. */
# define WANT_ROUNDING 1
#endif
#ifndef WANT_ERRNO
/* Set errno according to ISO C with (math_errhandling & MATH_ERRNO) != 0. */
# define WANT_ERRNO 1
#endif
#ifndef WANT_ERRNO_UFLOW
/* Set errno to ERANGE if result underflows to 0 (in all rounding modes). */
# define WANT_ERRNO_UFLOW (WANT_ROUNDING && WANT_ERRNO)
#endif
#ifndef TOINT_INTRINSICS
/* When set, the roundtoint and converttoint functions are provided with
the semantics documented below. */
# define TOINT_INTRINSICS 0
#endif
#if TOINT_INTRINSICS
/* Round x to nearest int in all rounding modes, ties have to be rounded
consistently with converttoint so the results match. If the result
would be outside of [-2^31, 2^31-1] then the semantics is unspecified. */
static inline double_t
roundtoint (double_t x);
/* Convert x to nearest int in all rounding modes, ties have to be rounded
consistently with roundtoint. If the result is not representible in an
int32_t then the semantics is unspecified. */
static inline int32_t
converttoint (double_t x);
#endif
static inline uint64_t
asuint64 (double f)
{
union
{
double f;
uint64_t i;
} u = {f};
return u.i;
}
static inline double
asdouble (uint64_t i)
{
union
{
uint64_t i;
double f;
} u = {i};
return u.f;
}
static inline int
issignaling_inline (double x)
{
uint64_t ix = asuint64 (x);
if (HIGH_ORDER_BIT_IS_SET_FOR_SNAN)
return (ix & 0x7ff8000000000000) == 0x7ff8000000000000;
return 2 * (ix ^ 0x0008000000000000) > 2 * 0x7ff8000000000000ULL;
}
#define NOINLINE __attribute__ ((noinline))
/* Error handling tail calls for special cases, with a sign argument.
The sign of the return value is set if the argument is non-zero. */
/* The result overflows. */
attribute_hidden double __math_oflow (uint32_t);
/* The result underflows to 0 in nearest rounding mode. */
attribute_hidden double __math_uflow (uint32_t);
/* The result underflows to 0 in some directed rounding mode only. */
attribute_hidden double __math_may_uflow (uint32_t);
/* Division by zero. */
attribute_hidden double __math_divzero (uint32_t);
/* Error handling using input checking. */
/* Invalid input unless it is a quiet NaN. */
attribute_hidden double __math_invalid (double);
/* Error handling using output checking, only for errno setting. */
/* Check if the result overflowed to infinity. */
attribute_hidden double __math_check_oflow (double);
/* Check if the result underflowed to 0. */
attribute_hidden double __math_check_uflow (double);
/* Check if the result overflowed to infinity. */
static inline double
check_oflow (double x)
{
return WANT_ERRNO ? __math_check_oflow (x) : x;
}
/* Check if the result underflowed to 0. */
static inline double
check_uflow (double x)
{
return WANT_ERRNO ? __math_check_uflow (x) : x;
}
#define EXP_TABLE_BITS 7
#define EXP_POLY_ORDER 5
#define EXP2_POLY_ORDER 5
extern const struct exp_data
{
double invln2N;
double shift;
double negln2hiN;
double negln2loN;
double poly[4]; /* Last four coefficients. */
double exp2_shift;
double exp2_poly[EXP2_POLY_ORDER];
uint64_t tab[2*(1 << EXP_TABLE_BITS)];
} __exp_data attribute_hidden;
#define LOG_TABLE_BITS 7
#define LOG_POLY_ORDER 6
#define LOG_POLY1_ORDER 12
extern const struct log_data
{
double ln2hi;
double ln2lo;
double poly[LOG_POLY_ORDER - 1]; /* First coefficient is 1. */
double poly1[LOG_POLY1_ORDER - 1];
/* See e_log_data.c for details. */
struct {double invc, logc;} tab[1 << LOG_TABLE_BITS];
#ifndef __FP_FAST_FMA
struct {double chi, clo;} tab2[1 << LOG_TABLE_BITS];
#endif
} __log_data attribute_hidden;
#define LOG2_TABLE_BITS 6
#define LOG2_POLY_ORDER 7
#define LOG2_POLY1_ORDER 11
extern const struct log2_data
{
double invln2hi;
double invln2lo;
double poly[LOG2_POLY_ORDER - 1];
double poly1[LOG2_POLY1_ORDER - 1];
/* See e_log2_data.c for details. */
struct {double invc, logc;} tab[1 << LOG2_TABLE_BITS];
#ifndef __FP_FAST_FMA
struct {double chi, clo;} tab2[1 << LOG2_TABLE_BITS];
#endif
} __log2_data attribute_hidden;
#define POW_LOG_TABLE_BITS 7
#define POW_LOG_POLY_ORDER 8
extern const struct pow_log_data
{
double ln2hi;
double ln2lo;
double poly[POW_LOG_POLY_ORDER - 1]; /* First coefficient is 1. */
/* Note: the pad field is unused, but allows slightly faster indexing. */
/* See e_pow_log_data.c for details. */
struct {double invc, pad, logc, logctail;} tab[1 << POW_LOG_TABLE_BITS];
} __pow_log_data attribute_hidden;
#endif
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