cosmopolitan/test/math/powf_test.c
Justine Tunney 592f6ebc20
Make quality improvements
- Write some more unit tests
- memcpy() on ARM is now faster
- Address the Musl complex math FIXME comments
- Some libm funcs like pow() now support setting errno
- Import the latest and greatest math functions from ARM
- Use more accurate atan2f() and log1pf() implementations
- atoi() and atol() will no longer saturate or clobber errno
2024-02-25 19:08:43 -08:00

104 lines
3.7 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2024 Justine Alexandra Roberts Tunney │
│ │
│ 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. │
│ │
│ THE 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. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include <errno.h>
#include <float.h>
#include <math.h>
#define OK 0
#define MAX_ERROR_ULP 1
#define CHECK(x) \
if (!(x)) return __LINE__
#define TEST(e, x) \
errno = 0; \
CHECK(x); \
CHECK(errno == e)
int rando(void) {
static unsigned long s;
s *= 6364136223846793005;
s += 1442695040888963407;
return s >> 32;
}
int main() {
// test base cases
TEST(OK, !powf(0, 5));
TEST(OK, powf(0, 0) == 1);
TEST(OK, powf(1, 0) == 1);
TEST(OK, powf(2, 0) == 1);
TEST(OK, powf(0, 2) == 0);
TEST(OK, powf(5, 0) == 1);
TEST(OK, powf(1, 5) == 1);
TEST(OK, powf(2, 3) == 8);
TEST(OK, powf(-2, 3) == -8);
TEST(OK, powf(-2, 2) == 4);
TEST(OK, powf(2, -2) == 0.25);
// test edge cases
TEST(OK, powf(-2, -2) == 0.25);
TEST(OK, powf(2, .5) == sqrtf(2));
TEST(OK, powf(2, -.5) == M_SQRT1_2f);
// test special values
TEST(OK, powf(NAN, 0) == 1);
TEST(OK, !powf(INFINITY, -2));
TEST(OK, isnan(powf(NAN, 2)));
TEST(OK, isnan(powf(2, NAN)));
TEST(OK, powf(INFINITY, -1) == 0);
TEST(OK, powf(INFINITY, 2) == INFINITY);
TEST(OK, powf(-INFINITY, 2) == INFINITY);
TEST(OK, powf(-INFINITY, 3) == -INFINITY);
// test domain errors
TEST(EDOM, isnan(powf(-1, 0.5)));
// test pole errors
TEST(ERANGE, isinf(powf(0, -1)));
TEST(ERANGE, isinf(powf(0, -.5)));
// test underflow and overflow
TEST(ERANGE, powf(1e-38, 2) == 0);
TEST(ERANGE, powf(FLT_MAX, 2) == INFINITY);
// test accuracy assuming pow() is correct
union {
int i;
float f;
} x, y, a, b;
int n = 1000;
for (int i = 0; i < n; ++i) {
for (int j = 0; j < n; ++j) {
x.i = rando();
y.i = rando();
a.f = pow(x.f, y.f);
b.f = powf(x.f, y.f);
if (isnan(a.f) || isnan(b.f)) {
CHECK(isnan(a.f) == isnan(b.f));
continue;
}
int e = b.i - a.i;
if (e < 0) e = -e;
CHECK(e <= MAX_ERROR_ULP);
}
}
}