From: Bruno Haible Date: Sat, 31 Mar 2012 18:38:09 +0000 (+0200) Subject: log10 tests: More tests. X-Git-Tag: v0.1~793 X-Git-Url: http://erislabs.org.uk/gitweb/?a=commitdiff_plain;h=70b19129a5169b37d7ac24eab814387ed05a36a1;p=gnulib.git log10 tests: More tests. * tests/test-log10.h: New file. * modules/log10-tests (Files): Add tests/test-log10.h, tests/minus-zero.h, tests/randomd.c. (Makefile.am): Add randomd.c to test_log10_SOURCES. * tests/test-log10.c: Include , minus-zero.h, test-log10.h. (main): Invoke test_function. --- diff --git a/ChangeLog b/ChangeLog index 466c94b9c..f4b570b18 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2012-03-31 Bruno Haible + + log10 tests: More tests. + * tests/test-log10.h: New file. + * modules/log10-tests (Files): Add tests/test-log10.h, + tests/minus-zero.h, tests/randomd.c. + (Makefile.am): Add randomd.c to test_log10_SOURCES. + * tests/test-log10.c: Include , minus-zero.h, test-log10.h. + (main): Invoke test_function. + 2012-03-31 Simon Josefsson fflush: Fix syntax error. diff --git a/modules/log10-tests b/modules/log10-tests index 5fc6e6bcf..16fb55f34 100644 --- a/modules/log10-tests +++ b/modules/log10-tests @@ -1,7 +1,10 @@ Files: tests/test-log10.c +tests/test-log10.h +tests/minus-zero.h tests/signature.h tests/macros.h +tests/randomd.c Depends-on: @@ -10,4 +13,5 @@ configure.ac: Makefile.am: TESTS += test-log10 check_PROGRAMS += test-log10 +test_log10_SOURCES = test-log10.c randomd.c test_log10_LDADD = $(LDADD) @LOG10_LIBM@ diff --git a/tests/test-log10.c b/tests/test-log10.c index 28d0d5391..a6fbc1338 100644 --- a/tests/test-log10.c +++ b/tests/test-log10.c @@ -23,10 +23,19 @@ #include "signature.h" SIGNATURE_CHECK (log10, double, (double)); +#include + +#include "minus-zero.h" #include "macros.h" -volatile double x; -double y; +#define DOUBLE double +#define HUGEVAL HUGE_VAL +#define L_(literal) literal +#define MANT_DIG DBL_MANT_DIG +#define MINUS_ZERO minus_zerod +#define LOG10 log10 +#define RANDOM randomd +#include "test-log10.h" int main () @@ -36,5 +45,7 @@ main () y = log10 (x); ASSERT (y >= -0.2218487497 && y <= -0.2218487496); + test_function (); + return 0; } diff --git a/tests/test-log10.h b/tests/test-log10.h new file mode 100644 index 000000000..fd0c918cf --- /dev/null +++ b/tests/test-log10.h @@ -0,0 +1,104 @@ +/* Test of log10*() 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 . */ + +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 + . + 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 + . + 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); i++) + for (j = 0; j < SIZEOF (RANDOM); 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;