148 lines
4.4 KiB
C
148 lines
4.4 KiB
C
/* Test of splitting a 'long double' into fraction and mantissa.
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Copyright (C) 2007-2008 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
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#include <config.h>
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#include "printf-frexpl.h"
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#include <float.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include "fpucw.h"
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#define ASSERT(expr) \
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do \
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{ \
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if (!(expr)) \
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{ \
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fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
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fflush (stderr); \
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abort (); \
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} \
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} \
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while (0)
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/* On MIPS IRIX machines, LDBL_MIN_EXP is -1021, but the smallest reliable
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exponent for 'long double' is -964. Similarly, on PowerPC machines,
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LDBL_MIN_EXP is -1021, but the smallest reliable exponent for 'long double'
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is -968. For exponents below that, the precision may be truncated to the
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precision used for 'double'. */
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#ifdef __sgi
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# define MIN_NORMAL_EXP (LDBL_MIN_EXP + 57)
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# define MIN_SUBNORMAL_EXP MIN_NORMAL_EXP
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#elif defined __ppc || defined __ppc__ || defined __powerpc || defined __powerpc__
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# define MIN_NORMAL_EXP (LDBL_MIN_EXP + 53)
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# define MIN_SUBNORMAL_EXP MIN_NORMAL_EXP
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#else
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# define MIN_NORMAL_EXP LDBL_MIN_EXP
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# define MIN_SUBNORMAL_EXP (LDBL_MIN_EXP - 100)
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#endif
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static long double
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my_ldexp (long double x, int d)
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{
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for (; d > 0; d--)
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x *= 2.0L;
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for (; d < 0; d++)
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x *= 0.5L;
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return x;
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}
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int
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main ()
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{
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int i;
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long double x;
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DECL_LONG_DOUBLE_ROUNDING
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BEGIN_LONG_DOUBLE_ROUNDING ();
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for (i = 1, x = 1.0L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
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{
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int exp = -9999;
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long double mantissa = printf_frexpl (x, &exp);
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ASSERT (exp == i - 1);
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ASSERT (mantissa == 1.0L);
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}
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for (i = 1, x = 1.0L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
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{
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int exp = -9999;
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long double mantissa = printf_frexpl (x, &exp);
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ASSERT (exp == i - 1);
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ASSERT (mantissa == 1.0L);
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}
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for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L)
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{
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int exp = -9999;
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long double mantissa = printf_frexpl (x, &exp);
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ASSERT (exp == LDBL_MIN_EXP - 1);
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ASSERT (mantissa == my_ldexp (1.0L, i - LDBL_MIN_EXP));
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}
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for (i = 1, x = 1.01L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
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{
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int exp = -9999;
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long double mantissa = printf_frexpl (x, &exp);
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ASSERT (exp == i - 1);
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ASSERT (mantissa == 1.01L);
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}
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for (i = 1, x = 1.01L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
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{
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int exp = -9999;
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long double mantissa = printf_frexpl (x, &exp);
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ASSERT (exp == i - 1);
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ASSERT (mantissa == 1.01L);
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}
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for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L)
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{
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int exp = -9999;
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long double mantissa = printf_frexpl (x, &exp);
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ASSERT (exp == LDBL_MIN_EXP - 1);
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ASSERT (mantissa >= my_ldexp (1.0L, i - LDBL_MIN_EXP));
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ASSERT (mantissa <= my_ldexp (2.0L, i - LDBL_MIN_EXP));
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ASSERT (mantissa == my_ldexp (x, - exp));
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}
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for (i = 1, x = 1.73205L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
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{
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int exp = -9999;
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long double mantissa = printf_frexpl (x, &exp);
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ASSERT (exp == i - 1);
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ASSERT (mantissa == 1.73205L);
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}
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for (i = 1, x = 1.73205L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
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{
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int exp = -9999;
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long double mantissa = printf_frexpl (x, &exp);
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ASSERT (exp == i - 1);
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ASSERT (mantissa == 1.73205L);
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}
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for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L)
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{
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int exp = -9999;
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long double mantissa = printf_frexpl (x, &exp);
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ASSERT (exp == LDBL_MIN_EXP - 1);
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ASSERT (mantissa >= my_ldexp (1.0L, i - LDBL_MIN_EXP));
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ASSERT (mantissa <= my_ldexp (2.0L, i - LDBL_MIN_EXP));
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ASSERT (mantissa == my_ldexp (x, - exp));
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}
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return 0;
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}
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