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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:11:47 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:11:47 +0000 |
commit | 758f820bcc0f68aeebac1717e537ca13a320b909 (patch) | |
tree | 48111ece75cf4f98316848b37a7e26356e00669e /gnulib-tests/test-printf-frexp.c | |
parent | Initial commit. (diff) | |
download | coreutils-758f820bcc0f68aeebac1717e537ca13a320b909.tar.xz coreutils-758f820bcc0f68aeebac1717e537ca13a320b909.zip |
Adding upstream version 9.1.upstream/9.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gnulib-tests/test-printf-frexp.c')
-rw-r--r-- | gnulib-tests/test-printf-frexp.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/gnulib-tests/test-printf-frexp.c b/gnulib-tests/test-printf-frexp.c new file mode 100644 index 0000000..01b34a5 --- /dev/null +++ b/gnulib-tests/test-printf-frexp.c @@ -0,0 +1,119 @@ +/* Test of splitting a double into fraction and mantissa. + Copyright (C) 2007-2022 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 <https://www.gnu.org/licenses/>. */ + +/* Written by Bruno Haible <bruno@clisp.org>, 2007. */ + +#include <config.h> + +#include "printf-frexp.h" + +#include <float.h> + +#include "macros.h" + +static double +my_ldexp (double x, int d) +{ + for (; d > 0; d--) + x *= 2.0; + for (; d < 0; d++) + x *= 0.5; + return x; +} + +int +main () +{ + int i; + /* The use of 'volatile' guarantees that excess precision bits are dropped + when dealing with denormalized numbers. It is necessary on x86 systems + where double-floats are not IEEE compliant by default, to avoid that the + results become platform and compiler option dependent. 'volatile' is a + portable alternative to gcc's -ffloat-store option. */ + volatile double x; + + for (i = 1, x = 1.0; i <= DBL_MAX_EXP; i++, x *= 2.0) + { + int exp = -9999; + double mantissa = printf_frexp (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.0); + } + for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5) + { + int exp = -9999; + double mantissa = printf_frexp (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.0); + } + for (; i >= DBL_MIN_EXP - 100 && x > 0.0; i--, x *= 0.5) + { + int exp = -9999; + double mantissa = printf_frexp (x, &exp); + ASSERT (exp == DBL_MIN_EXP - 1); + ASSERT (mantissa == my_ldexp (1.0, i - DBL_MIN_EXP)); + } + + for (i = 1, x = 1.01; i <= DBL_MAX_EXP; i++, x *= 2.0) + { + int exp = -9999; + double mantissa = printf_frexp (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.01); + } + for (i = 1, x = 1.01; i >= DBL_MIN_EXP; i--, x *= 0.5) + { + int exp = -9999; + double mantissa = printf_frexp (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.01); + } + for (; i >= DBL_MIN_EXP - 100 && x > 0.0; i--, x *= 0.5) + { + int exp = -9999; + double mantissa = printf_frexp (x, &exp); + ASSERT (exp == DBL_MIN_EXP - 1); + ASSERT (mantissa >= my_ldexp (1.0, i - DBL_MIN_EXP)); + ASSERT (mantissa <= my_ldexp (2.0, i - DBL_MIN_EXP)); + ASSERT (mantissa == my_ldexp (x, - exp)); + } + + for (i = 1, x = 1.73205; i <= DBL_MAX_EXP; i++, x *= 2.0) + { + int exp = -9999; + double mantissa = printf_frexp (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.73205); + } + for (i = 1, x = 1.73205; i >= DBL_MIN_EXP; i--, x *= 0.5) + { + int exp = -9999; + double mantissa = printf_frexp (x, &exp); + ASSERT (exp == i - 1); + ASSERT (mantissa == 1.73205); + } + for (; i >= DBL_MIN_EXP - 100 && x > 0.0; i--, x *= 0.5) + { + int exp = -9999; + double mantissa = printf_frexp (x, &exp); + ASSERT (exp == DBL_MIN_EXP - 1); + ASSERT (mantissa >= my_ldexp (1.0, i - DBL_MIN_EXP)); + ASSERT (mantissa <= my_ldexp (2.0, i - DBL_MIN_EXP)); + ASSERT (mantissa == my_ldexp (x, - exp)); + } + + return 0; +} |