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Diffstat (limited to 'tests/soft_float_test.c')
-rw-r--r-- | tests/soft_float_test.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/tests/soft_float_test.c b/tests/soft_float_test.c new file mode 100644 index 00000000..58b4dac0 --- /dev/null +++ b/tests/soft_float_test.c @@ -0,0 +1,119 @@ +/* + Copyright 2011-2019 David Robillard <http://drobilla.net> + + Permission to use, copy, modify, and/or distribute this software for any + purpose with or without fee is hereby granted, provided that the above + copyright notice and this permission notice appear in all copies. + + THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +*/ + +#undef NDEBUG + +#include "test_data.h" + +#include "../src/ieee_float.h" +#include "../src/soft_float.h" + +#include <assert.h> +#include <math.h> +#include <stdbool.h> +#include <stdint.h> + +static uint64_t +ulp_distance(const double a, const double b) +{ + assert(a >= 0.0); + assert(b >= 0.0); + + if (a == b) { + return 0; + } else if (isnan(a) || isnan(b)) { + return UINT64_MAX; + } else if (isinf(a) || isinf(b)) { + return UINT64_MAX; + } + + const uint64_t ia = double_to_rep(a); + const uint64_t ib = double_to_rep(b); + + return ia > ib ? ia - ib : ib - ia; +} + +static bool +check_multiply(const double lhs, const double rhs) +{ + assert(lhs >= 0.0); + assert(rhs >= 0.0); + + const SerdSoftFloat sl = soft_float_normalize(soft_float_from_double(lhs)); + const SerdSoftFloat sr = soft_float_normalize(soft_float_from_double(rhs)); + const SerdSoftFloat sp = soft_float_multiply(sl, sr); + const double ep = lhs * rhs; + const double dp = soft_float_to_double(sp); + + return ulp_distance(dp, ep) <= 1; +} + +static void +test_multiply(void) +{ + assert(check_multiply(1.0, 1.0)); + assert(check_multiply(1.0, 8.0)); + assert(check_multiply(8.0, 1.0)); + assert(check_multiply(2.0, 4.0)); + assert(check_multiply(1e100, 1e-100)); + + uint64_t seed = 1; + for (int i = 0; i < 1000000; ++i) { + const double l = fabs(double_from_rep(seed = lcg64(seed))); + const double r = fabs(double_from_rep(seed = lcg64(seed))); + if (isfinite(l) && isfinite(r)) { + assert(check_multiply(l, r)); + } + } +} + +static void +test_exact_pow10(void) +{ + for (int i = 1; i < dec_expt_step; ++i) { + const SerdSoftFloat power = soft_float_exact_pow10(i); + + const double d = soft_float_to_double(power); + const double p = pow(10, i); + assert(ulp_distance(d, p) <= 1); + } +} + +static void +test_pow10_under(void) +{ + for (int i = min_dec_expt; i < max_dec_expt + dec_expt_step; ++i) { + int expt10 = 0; + const SerdSoftFloat power = soft_float_pow10_under(i, &expt10); + + assert(expt10 <= i); + assert(i - expt10 < dec_expt_step); + + const double d = soft_float_to_double(power); + const double p = pow(10, expt10); + assert(ulp_distance(d, p) <= 1); + } +} + +int +main(void) +{ + test_multiply(); + test_exact_pow10(); + test_pow10_under(); + + return 0; +} |