Mercurial > gnulib
changeset 36308:72724c833084
Tests for module 'exp2'.
* modules/exp2-tests: New file.
* tests/test-exp2.c: New file.
* tests/test-exp2.h: New file.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Wed, 07 Mar 2012 03:29:46 +0100 |
parents | 5edfd2edc02f |
children | 4b5581d0b884 |
files | ChangeLog modules/exp2-tests tests/test-exp2.c tests/test-exp2.h |
diffstat | 4 files changed, 197 insertions(+), 0 deletions(-) [+] |
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--- a/ChangeLog Wed Mar 07 03:29:32 2012 +0100 +++ b/ChangeLog Wed Mar 07 03:29:46 2012 +0100 @@ -1,5 +1,10 @@ 2012-03-08 Bruno Haible <bruno@clisp.org> + Tests for module 'exp2'. + * modules/exp2-tests: New file. + * tests/test-exp2.c: New file. + * tests/test-exp2.h: New file. + New module 'exp2'. * lib/math.in.h (exp2): New declaration. * lib/exp2.c: New file.
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/modules/exp2-tests Wed Mar 07 03:29:46 2012 +0100 @@ -0,0 +1,16 @@ +Files: +tests/test-exp2.c +tests/test-exp2.h +tests/signature.h +tests/macros.h +tests/randomd.c + +Depends-on: + +configure.ac: + +Makefile.am: +TESTS += test-exp2 +check_PROGRAMS += test-exp2 +test_exp2_SOURCES = test-exp2.c randomd.c +test_exp2_LDADD = $(LDADD) @EXP2_LIBM@
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/tests/test-exp2.c Wed Mar 07 03:29:46 2012 +0100 @@ -0,0 +1,48 @@ +/* Test of exp2() function. + Copyright (C) 2010-2012 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>, 2010. */ + +#include <config.h> + +#include <math.h> + +#include "signature.h" +SIGNATURE_CHECK (exp2, double, (double)); + +#include <float.h> + +#include "macros.h" + +#define DOUBLE double +#define L_(literal) literal +#define MANT_DIG DBL_MANT_DIG +#define EXP2 exp2 +#define RANDOM randomd +#include "test-exp2.h" + +int +main () +{ + /* A particular value. */ + x = 0.6; + y = exp2 (x); + ASSERT (y >= 1.515716566 && y <= 1.515716567); + + test_function (); + + return 0; +}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/tests/test-exp2.h Wed Mar 07 03:29:46 2012 +0100 @@ -0,0 +1,128 @@ +/* Test of exp2*() function family. + Copyright (C) 2012 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)); + + /* Small integral arguments. */ + { + DOUBLE x = L_(0.0); + DOUBLE y = EXP2 (x); + ASSERT (y == L_(1.0)); + } + { + DOUBLE x = L_(1.0); + DOUBLE y = EXP2 (x); + ASSERT (y == L_(2.0)); + } + { + DOUBLE x = L_(2.0); + DOUBLE y = EXP2 (x); + ASSERT (y == L_(4.0)); + } + /* <http://sourceware.org/bugzilla/show_bug.cgi?id=13824> */ +#if !(defined __linux__ && defined __sparc__) + { + DOUBLE x = L_(3.0); + DOUBLE y = EXP2 (x); + ASSERT (y == L_(8.0)); + } + { + DOUBLE x = L_(4.0); + DOUBLE y = EXP2 (x); + ASSERT (y == L_(16.0)); + } +#endif + { + DOUBLE x = - L_(1.0); + DOUBLE y = EXP2 (x); + ASSERT (y == L_(0.5)); + } + { + DOUBLE x = - L_(2.0); + DOUBLE y = EXP2 (x); + ASSERT (y == L_(0.25)); + } + + /* Randomized tests. */ + { + /* Error bound, in ulps. */ + const DOUBLE err_bound = + (sizeof (DOUBLE) == sizeof (long 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 exp2l.c to + 53 bits of precision. */ + L_(1350.0) +#else + L_(3.0) +#endif + : L_(3.0)); + + for (i = 0; i < SIZEOF (RANDOM); i++) + { + DOUBLE x = L_(16.0) * RANDOM[i]; /* 0.0 <= x <= 16.0 */ + DOUBLE y = EXP2 (x); + DOUBLE z = EXP2 (- x); + DOUBLE err = y * z - L_(1.0); + 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 (long double) ? +#if defined __i386__ && defined __FreeBSD__ + L_(2300.0) +#else + L_(29.0) +#endif + : L_(11.0)); + + for (i = 0; i < SIZEOF (RANDOM) / 5; i++) + for (j = 0; j < SIZEOF (RANDOM) / 5; j++) + { + DOUBLE x = L_(32.0) * RANDOM[i] - L_(16.0); /* -16.0 <= x <= 16.0 */ + DOUBLE y = L_(32.0) * RANDOM[j] - L_(16.0); /* -16.0 <= y <= 16.0 */ + DOUBLE z = - x - y; + /* Approximately x + y + z = 0. */ + DOUBLE err = EXP2 (x) * EXP2 (y) * EXP2 (z) - L_(1.0); + ASSERT (err > - err_bound / TWO_MANT_DIG + && err < err_bound / TWO_MANT_DIG); + } + } +} + +volatile DOUBLE x; +DOUBLE y;