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Diffstat (limited to 'test-suite/standalone/test-round.c')
-rw-r--r-- | test-suite/standalone/test-round.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/test-suite/standalone/test-round.c b/test-suite/standalone/test-round.c new file mode 100644 index 000000000..c9175b230 --- /dev/null +++ b/test-suite/standalone/test-round.c @@ -0,0 +1,149 @@ +/* Copyright 2004,2006,2008-2009,2011,2014,2018 + Free Software Foundation, Inc. + + This file is part of Guile. + + Guile is free software: you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published + by the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + Guile 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 Lesser General Public + License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with Guile. If not, see + <https://www.gnu.org/licenses/>. */ + +#if HAVE_CONFIG_H +# include <config.h> +#endif + +#undef NDEBUG + +#include <assert.h> +#include <math.h> +#include <stdio.h> + +#if HAVE_FENV_H +# if defined __GNUC__ && defined __GLIBC__ +/* In Glibc 2.17, <bits/fenv.h> defines `feraiseexcept' as an inline + without declaring it first, so ignore the warning. */ +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Wmissing-prototypes" +# endif +# include <fenv.h> +# if defined __GNUC__ && defined __GLIBC__ +# pragma GCC diagnostic pop +# endif +#elif defined HAVE_MACHINE_FPU_H +/* On Tru64 5.1b, the declaration of fesetround(3) is in <machine/fpu.h>. + On NetBSD, this header has to be included along with <sys/types.h>. */ +# ifdef HAVE_SYS_TYPES_H +# include <sys/types.h> +# endif +# include <machine/fpu.h> +#endif + +#include <libguile.h> + + +#define numberof(x) (sizeof (x) / sizeof ((x)[0])) + +static void +test_scm_c_round () +{ + /* FE constants are defined only where supported, in particular for + instance some ARM systems have been seen with only a couple of modes */ + static const int modes[] = { + 0, +#ifdef FE_TONEAREST + FE_TONEAREST, +#endif +#ifdef FE_UPWARD + FE_UPWARD, +#endif +#ifdef FE_DOWNWARD + FE_DOWNWARD, +#endif +#ifdef FE_TOWARDZERO + FE_TOWARDZERO, +#endif + }; + + double x, want; + int i; + + for (i = 0; i < numberof (modes); i++) + { + /* First iteration is the default rounding mode, ie. no call to + fesetround. Subsequent iterations are the FE modes from the + table. */ + if (i != 0) + { +#ifdef HAVE_FESETROUND + fesetround (modes[i]); +#endif + } + + assert (scm_c_round (0.0) == 0.0); + assert (scm_c_round (1.0) == 1.0); + assert (scm_c_round (-1.0) == -1.0); + + assert (scm_c_round (0.5) == 0.0); + assert (scm_c_round (1.5) == 2.0); + assert (scm_c_round (-1.5) == -2.0); + assert (scm_c_round (2.5) == 2.0); + assert (scm_c_round (-2.5) == -2.0); + assert (scm_c_round (3.5) == 4.0); + assert (scm_c_round (-3.5) == -4.0); + + /* 2^(DBL_MANT_DIG-1)-1+0.5 */ + x = ldexp (1.0, DBL_MANT_DIG - 1) - 1.0 + 0.5; + want = ldexp (1.0, DBL_MANT_DIG - 1); + assert (scm_c_round (x) == want); + + /* -(2^(DBL_MANT_DIG-1)-1+0.5) */ + x = - (ldexp (1.0, DBL_MANT_DIG - 1) - 1.0 + 0.5); + want = - ldexp (1.0, DBL_MANT_DIG - 1); + assert (scm_c_round (x) == want); + + /* 2^DBL_MANT_DIG-1 + In the past scm_c_round had incorrectly incremented this value, due + to the way that x+0.5 would round upwards (in the usual default + nearest-even mode on most systems). */ + x = ldexp (1.0, DBL_MANT_DIG) - 1.0; + assert (x == floor (x)); /* should be an integer already */ + assert (scm_c_round (x) == x); /* scm_c_round should return it unchanged */ + + /* -(2^DBL_MANT_DIG-1) */ + x = - (ldexp (1.0, DBL_MANT_DIG) - 1.0); + assert (x == floor (x)); /* should be an integer already */ + assert (scm_c_round (x) == x); /* scm_c_round should return it unchanged */ + + /* 2^64 */ + x = ldexp (1.0, 64); + assert (scm_c_round (x) == x); + + /* -2^64 + In the past scm_c_round had incorrectely gone to the next highest + representable value in FE_UPWARD, due to x+0.5 rounding. */ + x = - ldexp (1.0, 64); + assert (scm_c_round (x) == x); + } +} + +static void +tests (void *data, int argc, char **argv) +{ + test_scm_c_round (); +} + +int +main (int argc, char *argv[]) +{ + scm_boot_guile (argc, argv, tests, NULL); + return 0; +} |