diff options
Diffstat (limited to 'tests/fp')
| -rw-r--r-- | tests/fp/fp-test-log2.c | 118 | ||||
| -rw-r--r-- | tests/fp/meson.build | 11 |
2 files changed, 129 insertions, 0 deletions
diff --git a/tests/fp/fp-test-log2.c b/tests/fp/fp-test-log2.c new file mode 100644 index 0000000000..4eae93eb7c --- /dev/null +++ b/tests/fp/fp-test-log2.c @@ -0,0 +1,118 @@ +/* + * fp-test-log2.c - test QEMU's softfloat log2 + * + * Copyright (C) 2020, Linaro, Ltd. + * + * License: GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ +#ifndef HW_POISON_H +#error Must define HW_POISON_H to work around TARGET_* poisoning +#endif + +#include "qemu/osdep.h" +#include "qemu/cutils.h" +#include <math.h> +#include "fpu/softfloat.h" + +typedef union { + double d; + float64 i; +} ufloat64; + +static int errors; + +static void compare(ufloat64 test, ufloat64 real, ufloat64 soft, bool exact) +{ + int msb; + uint64_t ulp = UINT64_MAX; + + if (real.i == soft.i) { + return; + } + msb = 63 - __builtin_clzll(real.i ^ soft.i); + + if (msb < 52) { + if (real.i > soft.i) { + ulp = real.i - soft.i; + } else { + ulp = soft.i - real.i; + } + } + + /* glibc allows 3 ulp error in its libm-test-ulps; allow 4 here */ + if (!exact && ulp <= 4) { + return; + } + + printf("test: %016" PRIx64 " %+.13a\n" + " sf: %016" PRIx64 " %+.13a\n" + "libm: %016" PRIx64 " %+.13a\n", + test.i, test.d, soft.i, soft.d, real.i, real.d); + + if (msb == 63) { + printf("Error in sign!\n\n"); + } else if (msb >= 52) { + printf("Error in exponent: %d\n\n", + (int)(soft.i >> 52) - (int)(real.i >> 52)); + } else { + printf("Error in fraction: %" PRIu64 " ulp\n\n", ulp); + } + + if (++errors == 20) { + exit(1); + } +} + +int main(int ac, char **av) +{ + ufloat64 test, real, soft; + float_status qsf = {0}; + int i; + + set_float_rounding_mode(float_round_nearest_even, &qsf); + + test.d = 0.0; + real.d = -__builtin_inf(); + soft.i = float64_log2(test.i, &qsf); + compare(test, real, soft, true); + + test.d = 1.0; + real.d = 0.0; + soft.i = float64_log2(test.i, &qsf); + compare(test, real, soft, true); + + test.d = 2.0; + real.d = 1.0; + soft.i = float64_log2(test.i, &qsf); + compare(test, real, soft, true); + + test.d = 4.0; + real.d = 2.0; + soft.i = float64_log2(test.i, &qsf); + compare(test, real, soft, true); + + test.d = 0x1p64; + real.d = 64.0; + soft.i = float64_log2(test.i, &qsf); + compare(test, real, soft, true); + + test.d = __builtin_inf(); + real.d = __builtin_inf(); + soft.i = float64_log2(test.i, &qsf); + compare(test, real, soft, true); + + for (i = 0; i < 10000; ++i) { + test.d = drand48() + 1.0; /* [1.0, 2.0) */ + real.d = log2(test.d); + soft.i = float64_log2(test.i, &qsf); + compare(test, real, soft, false); + + test.d = drand48() * 100; /* [0.0, 100) */ + real.d = log2(test.d); + soft.i = float64_log2(test.i, &qsf); + compare(test, real, soft, false); + } + + return 0; +} diff --git a/tests/fp/meson.build b/tests/fp/meson.build index 1c3eee9955..9218bfd3b0 100644 --- a/tests/fp/meson.build +++ b/tests/fp/meson.build @@ -634,3 +634,14 @@ fpbench = executable( include_directories: [sfinc, include_directories(tfdir)], c_args: fpcflags, ) + +fptestlog2 = executable( + 'fp-test-log2', + ['fp-test-log2.c', '../../fpu/softfloat.c'], + link_with: [libsoftfloat], + dependencies: [qemuutil], + include_directories: [sfinc], + c_args: fpcflags, +) +test('fp-test-log2', fptestlog2, + suite: ['softfloat', 'softfloat-ops']) |