octave-lojdl/gnulib-hg: lib/printf-frexp.c annotate

annotate lib/printf-frexp.c @ 17464:290d581e2e24

autoupdate

author	Karl Berry <karl@freefriends.org>
date	Sat, 10 Aug 2013 07:10:55 -0700
parents	e542fd46ad6f
children

rev	line source
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	1 /* Split a double into fraction and mantissa, for hexadecimal printf.
17249 e542fd46ad6f maint: update all copyright year number ranges Eric Blake <eblake@redhat.com> parents: 16201 diff changeset	2 Copyright (C) 2007, 2009-2013 Free Software Foundation, Inc.
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	3
9309 bbbbbf4cd1c5 Change copyright notice from GPLv2+ to GPLv3+. Bruno Haible <bruno@clisp.org> parents: 8648 diff changeset	4 This program is free software: you can redistribute it and/or modify
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	5 it under the terms of the GNU General Public License as published by
9309 bbbbbf4cd1c5 Change copyright notice from GPLv2+ to GPLv3+. Bruno Haible <bruno@clisp.org> parents: 8648 diff changeset	6 the Free Software Foundation; either version 3 of the License, or
bbbbbf4cd1c5 Change copyright notice from GPLv2+ to GPLv3+. Bruno Haible <bruno@clisp.org> parents: 8648 diff changeset	7 (at your option) any later version.
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	8
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	9 This program is distributed in the hope that it will be useful,
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	10 but WITHOUT ANY WARRANTY; without even the implied warranty of
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	12 GNU General Public License for more details.
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	13
9309 bbbbbf4cd1c5 Change copyright notice from GPLv2+ to GPLv3+. Bruno Haible <bruno@clisp.org> parents: 8648 diff changeset	14 You should have received a copy of the GNU General Public License
bbbbbf4cd1c5 Change copyright notice from GPLv2+ to GPLv3+. Bruno Haible <bruno@clisp.org> parents: 8648 diff changeset	15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	16
15933 6860d9f2e394 printf-frexpl: Simplify for platforms where 'long double' == 'double'. Bruno Haible <bruno@clisp.org> parents: 14079 diff changeset	17 #if ! defined USE_LONG_DOUBLE
6860d9f2e394 printf-frexpl: Simplify for platforms where 'long double' == 'double'. Bruno Haible <bruno@clisp.org> parents: 14079 diff changeset	18 # include <config.h>
6860d9f2e394 printf-frexpl: Simplify for platforms where 'long double' == 'double'. Bruno Haible <bruno@clisp.org> parents: 14079 diff changeset	19 #endif
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	20
8648 359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	21 /* Specification. */
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	22 #ifdef USE_LONG_DOUBLE
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	23 # include "printf-frexpl.h"
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	24 #else
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	25 # include "printf-frexp.h"
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	26 #endif
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	27
8648 359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	28 #include <float.h>
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	29 #include <math.h>
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	30 #ifdef USE_LONG_DOUBLE
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	31 # include "fpucw.h"
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	32 #endif
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	33
8253 c59696ff6dbc Add comment about FLT_RADIX. Bruno Haible <bruno@clisp.org> parents: 8252 diff changeset	34 /* This file assumes FLT_RADIX = 2. If FLT_RADIX is a power of 2 greater
c59696ff6dbc Add comment about FLT_RADIX. Bruno Haible <bruno@clisp.org> parents: 8252 diff changeset	35 than 2, or not even a power of 2, some rounding errors can occur, so that
c59696ff6dbc Add comment about FLT_RADIX. Bruno Haible <bruno@clisp.org> parents: 8252 diff changeset	36 then the returned mantissa is only guaranteed to be <= 2.0, not < 2.0. */
c59696ff6dbc Add comment about FLT_RADIX. Bruno Haible <bruno@clisp.org> parents: 8252 diff changeset	37
8648 359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	38 #ifdef USE_LONG_DOUBLE
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	39 # define FUNC printf_frexpl
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	40 # define DOUBLE long double
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	41 # define MIN_EXP LDBL_MIN_EXP
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	42 # if HAVE_FREXPL_IN_LIBC && HAVE_LDEXPL_IN_LIBC
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	43 # define USE_FREXP_LDEXP
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	44 # define FREXP frexpl
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	45 # define LDEXP ldexpl
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	46 # endif
8648 359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	47 # define DECL_ROUNDING DECL_LONG_DOUBLE_ROUNDING
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	48 # define BEGIN_ROUNDING() BEGIN_LONG_DOUBLE_ROUNDING ()
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	49 # define END_ROUNDING() END_LONG_DOUBLE_ROUNDING ()
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	50 # define L_(literal) literal##L
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	51 #else
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	52 # define FUNC printf_frexp
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	53 # define DOUBLE double
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	54 # define MIN_EXP DBL_MIN_EXP
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	55 # if HAVE_FREXP_IN_LIBC && HAVE_LDEXP_IN_LIBC
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	56 # define USE_FREXP_LDEXP
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	57 # define FREXP frexp
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	58 # define LDEXP ldexp
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	59 # endif
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	60 # define DECL_ROUNDING
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	61 # define BEGIN_ROUNDING()
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	62 # define END_ROUNDING()
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	63 # define L_(literal) literal
359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	64 #endif
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	65
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	66 DOUBLE
9312 bec01fc15c2f Rename parameter 'exp' to 'expptr', to avoid gcc warnings. Bruno Haible <bruno@clisp.org> parents: 9309 diff changeset	67 FUNC (DOUBLE x, int *expptr)
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	68 {
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	69 int exponent;
8531 52719799a90e New module 'fpucw'. Bruno Haible <bruno@clisp.org> parents: 8362 diff changeset	70 DECL_ROUNDING
52719799a90e New module 'fpucw'. Bruno Haible <bruno@clisp.org> parents: 8362 diff changeset	71
52719799a90e New module 'fpucw'. Bruno Haible <bruno@clisp.org> parents: 8362 diff changeset	72 BEGIN_ROUNDING ();
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	73
8648 359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	74 #ifdef USE_FREXP_LDEXP
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	75 /* frexp and ldexp are usually faster than the loop below. */
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	76 x = FREXP (x, &exponent);
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	77
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	78 x = x + x;
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	79 exponent -= 1;
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	80
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	81 if (exponent < MIN_EXP - 1)
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	82 {
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	83 x = LDEXP (x, exponent - (MIN_EXP - 1));
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	84 exponent = MIN_EXP - 1;
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	85 }
8648 359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	86 #else
8535 530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	87 {
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	88 /* Since the exponent is an 'int', it fits in 64 bits. Therefore the
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	89 loops are executed no more than 64 times. */
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	90 DOUBLE pow2[64]; /* pow2[i] = 2^2^i */
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	91 DOUBLE powh[64]; /* powh[i] = 2^-2^i */
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	92 int i;
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	93
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	94 exponent = 0;
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	95 if (x >= L_(1.0))
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	96 {
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	97 /* A nonnegative exponent. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	98 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	99 DOUBLE pow2_i; /* = pow2[i] */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	100 DOUBLE powh_i; /* = powh[i] */
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	101
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	102 /* Invariants: pow2_i = 2^2^i, powh_i = 2^-2^i,
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	103 x * 2^exponent = argument, x >= 1.0. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	104 for (i = 0, pow2_i = L_(2.0), powh_i = L_(0.5);
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	105 ;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	106 i++, pow2_i = pow2_i * pow2_i, powh_i = powh_i * powh_i)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	107 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	108 if (x >= pow2_i)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	109 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	110 exponent += (1 << i);
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	111 x *= powh_i;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	112 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	113 else
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	114 break;
8535 530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	115
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	116 pow2[i] = pow2_i;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	117 powh[i] = powh_i;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	118 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	119 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	120 /* Here 1.0 <= x < 2^2^i. */
8535 530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	121 }
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	122 else
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	123 {
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	124 /* A negative exponent. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	125 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	126 DOUBLE pow2_i; /* = pow2[i] */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	127 DOUBLE powh_i; /* = powh[i] */
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	128
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	129 /* Invariants: pow2_i = 2^2^i, powh_i = 2^-2^i,
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	130 x * 2^exponent = argument, x < 1.0, exponent >= MIN_EXP - 1. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	131 for (i = 0, pow2_i = L_(2.0), powh_i = L_(0.5);
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	132 ;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	133 i++, pow2_i = pow2_i * pow2_i, powh_i = powh_i * powh_i)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	134 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	135 if (exponent - (1 << i) < MIN_EXP - 1)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	136 break;
8535 530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	137
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	138 exponent -= (1 << i);
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	139 x *= pow2_i;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	140 if (x >= L_(1.0))
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	141 break;
8535 530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	142
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	143 pow2[i] = pow2_i;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	144 powh[i] = powh_i;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	145 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	146 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	147 /* Here either x < 1.0 and exponent - 2^i < MIN_EXP - 1 <= exponent,
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	148 or 1.0 <= x < 2^2^i and exponent >= MIN_EXP - 1. */
8535 530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	149
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	150 if (x < L_(1.0))
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	151 /* Invariants: x * 2^exponent = argument, x < 1.0 and
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	152 exponent - 2^i < MIN_EXP - 1 <= exponent. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	153 while (i > 0)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	154 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	155 i--;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	156 if (exponent - (1 << i) >= MIN_EXP - 1)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	157 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	158 exponent -= (1 << i);
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	159 x *= pow2[i];
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	160 if (x >= L_(1.0))
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	161 break;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	162 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	163 }
8535 530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	164
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	165 /* Here either x < 1.0 and exponent = MIN_EXP - 1,
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	166 or 1.0 <= x < 2^2^i and exponent >= MIN_EXP - 1. */
8535 530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	167 }
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	168
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	169 /* Invariants: x * 2^exponent = argument, and
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	170 either x < 1.0 and exponent = MIN_EXP - 1,
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	171 or 1.0 <= x < 2^2^i and exponent >= MIN_EXP - 1. */
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	172 while (i > 0)
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	173 {
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	174 i--;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	175 if (x >= pow2[i])
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	176 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	177 exponent += (1 << i);
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	178 x *= powh[i];
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 9312 diff changeset	179 }
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	180 }
8535 530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	181 /* Here either x < 1.0 and exponent = MIN_EXP - 1,
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	182 or 1.0 <= x < 2.0 and exponent >= MIN_EXP - 1. */
530583a3b054 Oops, fix ANSI C syntax error introduced in last patch. Bruno Haible <bruno@clisp.org> parents: 8531 diff changeset	183 }
8648 359d135f748c Assume 'long double' exists. Bruno Haible <bruno@clisp.org> parents: 8535 diff changeset	184 #endif
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	185
8531 52719799a90e New module 'fpucw'. Bruno Haible <bruno@clisp.org> parents: 8362 diff changeset	186 END_ROUNDING ();
52719799a90e New module 'fpucw'. Bruno Haible <bruno@clisp.org> parents: 8362 diff changeset	187
9312 bec01fc15c2f Rename parameter 'exp' to 'expptr', to avoid gcc warnings. Bruno Haible <bruno@clisp.org> parents: 9309 diff changeset	188 *expptr = exponent;
8240 536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	189 return x;
536315dcb204 New module 'printf-frexp'. Bruno Haible <bruno@clisp.org> parents: diff changeset	190 }

Mercurial > hg > octave-lojdl > gnulib-hg

annotate lib/printf-frexp.c @ 17464:290d581e2e24