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author | Lorry Tar Creator <lorry-tar-importer@lorry> | 2015-12-28 00:06:36 +0000 |
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committer | Lorry Tar Creator <lorry-tar-importer@lorry> | 2015-12-28 00:06:36 +0000 |
commit | 6eb5949dd99d174393465069c2fd0bab32deddcc (patch) | |
tree | d104f72ac2dcb0f592b1c8e06a5af6790bd4080c /gettext-tools/gnulib-tests/test-log10.h | |
parent | 482840e61f86ca321838a91e902c41d40c098bbb (diff) | |
download | gettext-tarball-6eb5949dd99d174393465069c2fd0bab32deddcc.tar.gz |
gettext-0.19.7gettext-0.19.7
Diffstat (limited to 'gettext-tools/gnulib-tests/test-log10.h')
-rw-r--r-- | gettext-tools/gnulib-tests/test-log10.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/gettext-tools/gnulib-tests/test-log10.h b/gettext-tools/gnulib-tests/test-log10.h new file mode 100644 index 0000000..cd51640 --- /dev/null +++ b/gettext-tools/gnulib-tests/test-log10.h @@ -0,0 +1,104 @@ +/* Test of log10*() function family. + Copyright (C) 2012-2015 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/>. */ + +static void +test_function (void) +{ + int i; + int j; + const DOUBLE TWO_MANT_DIG = + /* Assume MANT_DIG <= 5 * 31. + Use the identity + n = floor(n/5) + floor((n+1)/5) + ... + floor((n+4)/5). */ + (DOUBLE) (1U << ((MANT_DIG - 1) / 5)) + * (DOUBLE) (1U << ((MANT_DIG - 1 + 1) / 5)) + * (DOUBLE) (1U << ((MANT_DIG - 1 + 2) / 5)) + * (DOUBLE) (1U << ((MANT_DIG - 1 + 3) / 5)) + * (DOUBLE) (1U << ((MANT_DIG - 1 + 4) / 5)); + + /* Pole. */ + { + DOUBLE z = LOG10 (L_(0.0)); + ASSERT (z == - HUGEVAL); + } + { + DOUBLE z = LOG10 (MINUS_ZERO); + ASSERT (z == - HUGEVAL); + } + + /* Randomized tests. */ + { + /* Error bound, in ulps. */ + const DOUBLE err_bound = + (sizeof (DOUBLE) > sizeof (double) ? +#if defined __i386__ && defined __FreeBSD__ + /* On FreeBSD/x86 6.4, the 'long double' type really has only 53 bits of + precision in the compiler but 64 bits of precision at runtime. See + <http://lists.gnu.org/archive/html/bug-gnulib/2008-07/msg00063.html>. + The compiler has truncated all 'long double' literals in log10l.c to + 53 bits of precision. */ + L_(18.0) +#else + L_(3.0) +#endif + : L_(3.0)); + + for (i = 0; i < SIZEOF (RANDOM); i++) + { + DOUBLE x = L_(16.0) * RANDOM[i] + L_(1.0); /* 1.0 <= x <= 17.0 */ + DOUBLE y = LOG10 (x); + DOUBLE z = LOG10 (L_(1.0) / x); + DOUBLE err = y + z; + ASSERT (y >= L_(0.0)); + ASSERT (z <= L_(0.0)); + ASSERT (err > - err_bound / TWO_MANT_DIG + && err < err_bound / TWO_MANT_DIG); + } + } + + { + /* Error bound, in ulps. */ + const DOUBLE err_bound = + (sizeof (DOUBLE) > sizeof (double) ? +#if defined __i386__ && defined __FreeBSD__ + /* On FreeBSD/x86 6.4, the 'long double' type really has only 53 bits of + precision in the compiler but 64 bits of precision at runtime. See + <http://lists.gnu.org/archive/html/bug-gnulib/2008-07/msg00063.html>. + The compiler has truncated all 'long double' literals in log10l.c to + 53 bits of precision. */ + L_(38.0) +#else + L_(5.0) +#endif + : L_(5.0)); + + for (i = 0; i < SIZEOF (RANDOM) / 5; i++) + for (j = 0; j < SIZEOF (RANDOM) / 5; j++) + { + DOUBLE x = L_(17.0) / (L_(16.0) - L_(15.0) * RANDOM[i]) - L_(1.0); + DOUBLE y = L_(17.0) / (L_(16.0) - L_(15.0) * RANDOM[j]) - L_(1.0); + /* 1/16 <= x,y <= 16 */ + DOUBLE z = L_(1.0) / (x * y); + /* Approximately x * y * z = 1. */ + DOUBLE err = LOG10 (x) + LOG10 (y) + LOG10 (z); + ASSERT (err > - err_bound / TWO_MANT_DIG + && err < err_bound / TWO_MANT_DIG); + } + } +} + +volatile DOUBLE x; +DOUBLE y; |