diff options
Diffstat (limited to 'gl/printf-frexp.c')
| -rw-r--r-- | gl/printf-frexp.c | 190 |
1 files changed, 0 insertions, 190 deletions
diff --git a/gl/printf-frexp.c b/gl/printf-frexp.c deleted file mode 100644 index 1a7b0c438e..0000000000 --- a/gl/printf-frexp.c +++ /dev/null @@ -1,190 +0,0 @@ -/* Split a double into fraction and mantissa, for hexadecimal printf. - Copyright (C) 2007, 2009-2013 Free Software Foundation, Inc. - - This program is free software: you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 3 of the License, or - (at your option) any later version. - - This program 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 General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program. If not, see <http://www.gnu.org/licenses/>. */ - -#if ! defined USE_LONG_DOUBLE -# include <config.h> -#endif - -/* Specification. */ -#ifdef USE_LONG_DOUBLE -# include "printf-frexpl.h" -#else -# include "printf-frexp.h" -#endif - -#include <float.h> -#include <math.h> -#ifdef USE_LONG_DOUBLE -# include "fpucw.h" -#endif - -/* This file assumes FLT_RADIX = 2. If FLT_RADIX is a power of 2 greater - than 2, or not even a power of 2, some rounding errors can occur, so that - then the returned mantissa is only guaranteed to be <= 2.0, not < 2.0. */ - -#ifdef USE_LONG_DOUBLE -# define FUNC printf_frexpl -# define DOUBLE long double -# define MIN_EXP LDBL_MIN_EXP -# if HAVE_FREXPL_IN_LIBC && HAVE_LDEXPL_IN_LIBC -# define USE_FREXP_LDEXP -# define FREXP frexpl -# define LDEXP ldexpl -# endif -# define DECL_ROUNDING DECL_LONG_DOUBLE_ROUNDING -# define BEGIN_ROUNDING() BEGIN_LONG_DOUBLE_ROUNDING () -# define END_ROUNDING() END_LONG_DOUBLE_ROUNDING () -# define L_(literal) literal##L -#else -# define FUNC printf_frexp -# define DOUBLE double -# define MIN_EXP DBL_MIN_EXP -# if HAVE_FREXP_IN_LIBC && HAVE_LDEXP_IN_LIBC -# define USE_FREXP_LDEXP -# define FREXP frexp -# define LDEXP ldexp -# endif -# define DECL_ROUNDING -# define BEGIN_ROUNDING() -# define END_ROUNDING() -# define L_(literal) literal -#endif - -DOUBLE -FUNC (DOUBLE x, int *expptr) -{ - int exponent; - DECL_ROUNDING - - BEGIN_ROUNDING (); - -#ifdef USE_FREXP_LDEXP - /* frexp and ldexp are usually faster than the loop below. */ - x = FREXP (x, &exponent); - - x = x + x; - exponent -= 1; - - if (exponent < MIN_EXP - 1) - { - x = LDEXP (x, exponent - (MIN_EXP - 1)); - exponent = MIN_EXP - 1; - } -#else - { - /* Since the exponent is an 'int', it fits in 64 bits. Therefore the - loops are executed no more than 64 times. */ - DOUBLE pow2[64]; /* pow2[i] = 2^2^i */ - DOUBLE powh[64]; /* powh[i] = 2^-2^i */ - int i; - - exponent = 0; - if (x >= L_(1.0)) - { - /* A nonnegative exponent. */ - { - DOUBLE pow2_i; /* = pow2[i] */ - DOUBLE powh_i; /* = powh[i] */ - - /* Invariants: pow2_i = 2^2^i, powh_i = 2^-2^i, - x * 2^exponent = argument, x >= 1.0. */ - for (i = 0, pow2_i = L_(2.0), powh_i = L_(0.5); - ; - i++, pow2_i = pow2_i * pow2_i, powh_i = powh_i * powh_i) - { - if (x >= pow2_i) - { - exponent += (1 << i); - x *= powh_i; - } - else - break; - - pow2[i] = pow2_i; - powh[i] = powh_i; - } - } - /* Here 1.0 <= x < 2^2^i. */ - } - else - { - /* A negative exponent. */ - { - DOUBLE pow2_i; /* = pow2[i] */ - DOUBLE powh_i; /* = powh[i] */ - - /* Invariants: pow2_i = 2^2^i, powh_i = 2^-2^i, - x * 2^exponent = argument, x < 1.0, exponent >= MIN_EXP - 1. */ - for (i = 0, pow2_i = L_(2.0), powh_i = L_(0.5); - ; - i++, pow2_i = pow2_i * pow2_i, powh_i = powh_i * powh_i) - { - if (exponent - (1 << i) < MIN_EXP - 1) - break; - - exponent -= (1 << i); - x *= pow2_i; - if (x >= L_(1.0)) - break; - - pow2[i] = pow2_i; - powh[i] = powh_i; - } - } - /* Here either x < 1.0 and exponent - 2^i < MIN_EXP - 1 <= exponent, - or 1.0 <= x < 2^2^i and exponent >= MIN_EXP - 1. */ - - if (x < L_(1.0)) - /* Invariants: x * 2^exponent = argument, x < 1.0 and - exponent - 2^i < MIN_EXP - 1 <= exponent. */ - while (i > 0) - { - i--; - if (exponent - (1 << i) >= MIN_EXP - 1) - { - exponent -= (1 << i); - x *= pow2[i]; - if (x >= L_(1.0)) - break; - } - } - - /* Here either x < 1.0 and exponent = MIN_EXP - 1, - or 1.0 <= x < 2^2^i and exponent >= MIN_EXP - 1. */ - } - - /* Invariants: x * 2^exponent = argument, and - either x < 1.0 and exponent = MIN_EXP - 1, - or 1.0 <= x < 2^2^i and exponent >= MIN_EXP - 1. */ - while (i > 0) - { - i--; - if (x >= pow2[i]) - { - exponent += (1 << i); - x *= powh[i]; - } - } - /* Here either x < 1.0 and exponent = MIN_EXP - 1, - or 1.0 <= x < 2.0 and exponent >= MIN_EXP - 1. */ - } -#endif - - END_ROUNDING (); - - *expptr = exponent; - return x; -} |