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Diffstat (limited to 'tests/test-printf-frexpl.c')
| -rw-r--r-- | tests/test-printf-frexpl.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/tests/test-printf-frexpl.c b/tests/test-printf-frexpl.c new file mode 100644 index 0000000..c4c156a --- /dev/null +++ b/tests/test-printf-frexpl.c @@ -0,0 +1,147 @@ +/* Test of splitting a 'long double' into fraction and mantissa. + Copyright (C) 2007-2008 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/>. */ + +/* Written by Bruno Haible <bruno@clisp.org>, 2007. */ + +#include <config.h> + +#include "printf-frexpl.h" + +#include <float.h> +#include <stdio.h> +#include <stdlib.h> + +#include "fpucw.h" + +#define ASSERT(expr) \ + do \ + { \ + if (!(expr)) \ + { \ + fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \ + fflush (stderr); \ + abort (); \ + } \ + } \ + while (0) + +/* On MIPS IRIX machines, LDBL_MIN_EXP is -1021, but the smallest reliable + exponent for 'long double' is -964. Similarly, on PowerPC machines, + LDBL_MIN_EXP is -1021, but the smallest reliable exponent for 'long double' + is -968. For exponents below that, the precision may be truncated to the + precision used for 'double'. */ +#ifdef __sgi +# define MIN_NORMAL_EXP (LDBL_MIN_EXP + 57) +# define MIN_SUBNORMAL_EXP MIN_NORMAL_EXP +#elif defined __ppc || defined __ppc__ || defined __powerpc || defined __powerpc__ +# define MIN_NORMAL_EXP (LDBL_MIN_EXP + 53) +# define MIN_SUBNORMAL_EXP MIN_NORMAL_EXP +#else +# define MIN_NORMAL_EXP LDBL_MIN_EXP +# define MIN_SUBNORMAL_EXP (LDBL_MIN_EXP - 100) +#endif + +static long double +my_ldexp (long double x, int d) +{ + for (; d > 0; d--) + x *= 2.0L; + for (; d < 0; d++) + x *= 0.5L; + return x; +} + +int +main () +{ + int i; + long double x; + DECL_LONG_DOUBLE_ROUNDING + + BEGIN_LONG_DOUBLE_ROUNDING (); + + for (i = 1, x = 1.0L; i <= LDBL_MAX_EXP; i++, x *= 2.0L) + { + int exp = -9999; + long double mantissa = printf_frexpl (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.0L); + } + for (i = 1, x = 1.0L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L) + { + int exp = -9999; + long double mantissa = printf_frexpl (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.0L); + } + for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L) + { + int exp = -9999; + long double mantissa = printf_frexpl (x, &exp); + ASSERT (exp == LDBL_MIN_EXP - 1); + ASSERT (mantissa == my_ldexp (1.0L, i - LDBL_MIN_EXP)); + } + + for (i = 1, x = 1.01L; i <= LDBL_MAX_EXP; i++, x *= 2.0L) + { + int exp = -9999; + long double mantissa = printf_frexpl (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.01L); + } + for (i = 1, x = 1.01L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L) + { + int exp = -9999; + long double mantissa = printf_frexpl (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.01L); + } + for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L) + { + int exp = -9999; + long double mantissa = printf_frexpl (x, &exp); + ASSERT (exp == LDBL_MIN_EXP - 1); + ASSERT (mantissa >= my_ldexp (1.0L, i - LDBL_MIN_EXP)); + ASSERT (mantissa <= my_ldexp (2.0L, i - LDBL_MIN_EXP)); + ASSERT (mantissa == my_ldexp (x, - exp)); + } + + for (i = 1, x = 1.73205L; i <= LDBL_MAX_EXP; i++, x *= 2.0L) + { + int exp = -9999; + long double mantissa = printf_frexpl (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.73205L); + } + for (i = 1, x = 1.73205L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L) + { + int exp = -9999; + long double mantissa = printf_frexpl (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.73205L); + } + for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L) + { + int exp = -9999; + long double mantissa = printf_frexpl (x, &exp); + ASSERT (exp == LDBL_MIN_EXP - 1); + ASSERT (mantissa >= my_ldexp (1.0L, i - LDBL_MIN_EXP)); + ASSERT (mantissa <= my_ldexp (2.0L, i - LDBL_MIN_EXP)); + ASSERT (mantissa == my_ldexp (x, - exp)); + } + + return 0; +} |