From: Bruno Haible Date: Tue, 21 Dec 2010 16:16:09 +0000 (+0100) Subject: Tests for module 'floor'. X-Git-Tag: v0.1~3513 X-Git-Url: http://erislabs.org.uk/gitweb/?a=commitdiff_plain;h=de3f6e3f012bbaa9e536592318d5925a12bb2288;p=gnulib.git Tests for module 'floor'. * modules/floor-tests: New file. * tests/test-floor1.c: New file, based on tests/test-floorl.c. * tests/test-floor2.c: New file, based on tests/test-floorf2.c. --- diff --git a/ChangeLog b/ChangeLog index b5e2efe97..667fb215e 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,12 @@ 2010-12-21 Bruno Haible + Tests for module 'floor'. + * modules/floor-tests: New file. + * tests/test-floor1.c: New file, based on tests/test-floorl.c. + * tests/test-floor2.c: New file, based on tests/test-floorf2.c. + +2010-12-21 Bruno Haible + math: Fix indentation. * lib/math.in.h (floorf): Fix indentation. diff --git a/modules/floor-tests b/modules/floor-tests new file mode 100644 index 000000000..9d5fbe8bb --- /dev/null +++ b/modules/floor-tests @@ -0,0 +1,21 @@ +Files: +tests/test-floor1.c +tests/test-floor2.c +tests/minus-zero.h +tests/nan.h +tests/signature.h +tests/macros.h + +Depends-on: +float +isnand-nolibm +stdbool +stdint + +configure.ac: + +Makefile.am: +TESTS += test-floor1 test-floor2 +check_PROGRAMS += test-floor1 test-floor2 +test_floor1_LDADD = $(LDADD) @FLOOR_LIBM@ +test_floor2_LDADD = $(LDADD) @FLOOR_LIBM@ diff --git a/tests/test-floor1.c b/tests/test-floor1.c new file mode 100644 index 000000000..cd165d851 --- /dev/null +++ b/tests/test-floor1.c @@ -0,0 +1,65 @@ +/* Test of rounding towards negative infinity. + Copyright (C) 2007-2010 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 . */ + +/* Written by Bruno Haible , 2007. */ + +#include + +#include + +#include "signature.h" +SIGNATURE_CHECK (floor, double, (double)); + +#include "isnand-nolibm.h" +#include "minus-zero.h" +#include "nan.h" +#include "macros.h" + +int +main (int argc, char **argv _GL_UNUSED) +{ + /* Zero. */ + ASSERT (floor (0.0) == 0.0); + ASSERT (floor (minus_zerod) == 0.0); + /* Positive numbers. */ + ASSERT (floor (0.3) == 0.0); + ASSERT (floor (0.7) == 0.0); + ASSERT (floor (1.0) == 1.0); + ASSERT (floor (1.5) == 1.0); + ASSERT (floor (1.999) == 1.0); + ASSERT (floor (2.0) == 2.0); + ASSERT (floor (65535.999) == 65535.0); + ASSERT (floor (65536.0) == 65536.0); + ASSERT (floor (2.341e31) == 2.341e31); + /* Negative numbers. */ + ASSERT (floor (-0.3) == -1.0); + ASSERT (floor (-0.7) == -1.0); + ASSERT (floor (-1.0) == -1.0); + ASSERT (floor (-1.001) == -2.0); + ASSERT (floor (-1.5) == -2.0); + ASSERT (floor (-1.999) == -2.0); + ASSERT (floor (-2.0) == -2.0); + ASSERT (floor (-65535.999) == -65536.0); + ASSERT (floor (-65536.0) == -65536.0); + ASSERT (floor (-2.341e31) == -2.341e31); + /* Infinite numbers. */ + ASSERT (floor (1.0 / 0.0) == 1.0 / 0.0); + ASSERT (floor (-1.0 / 0.0) == -1.0 / 0.0); + /* NaNs. */ + ASSERT (isnand (floor (NaNd ()))); + + return 0; +} diff --git a/tests/test-floor2.c b/tests/test-floor2.c new file mode 100644 index 000000000..1aca8ab5f --- /dev/null +++ b/tests/test-floor2.c @@ -0,0 +1,164 @@ +/* Test of rounding towards negative infinity. + Copyright (C) 2007-2010 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 . */ + +/* Written by Bruno Haible , 2007. */ + +/* When this test fails on some platform, build it together with the gnulib + module 'fprintf-posix' for optimal debugging output. */ + +#include + +#include + +#include +#include +#include +#include + +#include "isnand-nolibm.h" +#include "macros.h" + + +/* The reference implementation, taken from lib/floor.c. */ + +#define DOUBLE double +#define MANT_DIG DBL_MANT_DIG +#define L_(literal) literal + +/* 2^(MANT_DIG-1). */ +static 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)); + +DOUBLE +floor_reference (DOUBLE x) +{ + /* The use of 'volatile' guarantees that excess precision bits are dropped + at each addition step and before the following comparison at the caller's + site. 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 y = x; + volatile DOUBLE z = y; + + if (z > L_(0.0)) + { + /* Avoid rounding errors for values near 2^k, where k >= MANT_DIG-1. */ + if (z < TWO_MANT_DIG) + { + /* Round to the next integer (nearest or up or down, doesn't matter). */ + z += TWO_MANT_DIG; + z -= TWO_MANT_DIG; + /* Enforce rounding down. */ + if (z > y) + z -= L_(1.0); + } + } + else if (z < L_(0.0)) + { + /* Work around ICC's desire to optimize denormal floats to 0. */ + if (z > -DBL_MIN) + return L_(-1.0); + /* Avoid rounding errors for values near -2^k, where k >= MANT_DIG-1. */ + if (z > - TWO_MANT_DIG) + { + /* Round to the next integer (nearest or up or down, doesn't matter). */ + z -= TWO_MANT_DIG; + z += TWO_MANT_DIG; + /* Enforce rounding down. */ + if (z > y) + z -= L_(1.0); + } + } + return z; +} + + +/* Test for equality. */ +static int +equal (DOUBLE x, DOUBLE y) +{ + return (isnand (x) ? isnand (y) : x == y); +} + +/* Test whether the result for a given argument is correct. */ +static bool +correct_result_p (DOUBLE x, DOUBLE result) +{ + return + (x < 0 && x >= -1 ? result == - L_(1.0) : + x - 1 < x ? result <= x && result >= x - 1 && x - result < 1 : + equal (result, x)); +} + +/* Test the function for a given argument. */ +static int +check (double x) +{ + /* If the reference implementation is incorrect, bail out immediately. */ + double reference = floor_reference (x); + ASSERT (correct_result_p (x, reference)); + /* If the actual implementation is wrong, return an error code. */ + { + double result = floor (x); + if (correct_result_p (x, result)) + return 0; + else + { +#if GNULIB_TEST_FPRINTF_POSIX + fprintf (stderr, "floor %g(%a) = %g(%a) or %g(%a)?\n", + x, x, reference, reference, result, result); +#endif + return 1; + } + } +} + +#define NUM_HIGHBITS 15 +#define NUM_LOWBITS 4 + +int +main () +{ +#if UINT64_MAX + unsigned int highbits; + unsigned int lowbits; + int error = 0; + for (highbits = 0; highbits < (1 << NUM_HIGHBITS); highbits++) + for (lowbits = 0; lowbits < (1 << NUM_LOWBITS); lowbits++) + { + /* Combine highbits and lowbits into a floating-point number, + sign-extending the lowbits to 64-NUM_HIGHBITS bits. */ + union { double f; uint64_t i; } janus; + janus.i = ((uint64_t) highbits << (64 - NUM_HIGHBITS)) + | ((uint64_t) ((int64_t) ((uint64_t) lowbits << (64 - NUM_LOWBITS)) + >> (64 - NUM_LOWBITS - NUM_HIGHBITS)) + >> NUM_HIGHBITS); + error |= check (janus.f); + } + return (error ? 1 : 0); +#else + fprintf (stderr, "Skipping test: no 64-bit integer type available\n"); + return 77; +#endif +}