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#![cfg(not(target_arch = "wasm32"))]
use std::mem::MaybeUninit;
use std::str;
use core::num::flt2dec::strategy::grisu::format_exact_opt;
use core::num::flt2dec::strategy::grisu::format_shortest_opt;
use core::num::flt2dec::MAX_SIG_DIGITS;
use core::num::flt2dec::{decode, DecodableFloat, Decoded, FullDecoded};
use rand::distributions::{Distribution, Uniform};
use rand::rngs::StdRng;
use rand::SeedableRng;
pub fn decode_finite<T: DecodableFloat>(v: T) -> Decoded {
match decode(v).1 {
FullDecoded::Finite(decoded) => decoded,
full_decoded => panic!("expected finite, got {full_decoded:?} instead"),
}
}
fn iterate<F, G, V>(func: &str, k: usize, n: usize, mut f: F, mut g: G, mut v: V) -> (usize, usize)
where
F: for<'a> FnMut(&Decoded, &'a mut [MaybeUninit<u8>]) -> Option<(&'a [u8], i16)>,
G: for<'a> FnMut(&Decoded, &'a mut [MaybeUninit<u8>]) -> (&'a [u8], i16),
V: FnMut(usize) -> Decoded,
{
assert!(k <= 1024);
let mut npassed = 0; // f(x) = Some(g(x))
let mut nignored = 0; // f(x) = None
for i in 0..n {
if (i & 0xfffff) == 0 {
println!(
"in progress, {:x}/{:x} (ignored={} passed={} failed={})",
i,
n,
nignored,
npassed,
i - nignored - npassed
);
}
let decoded = v(i);
let mut buf1 = [MaybeUninit::new(0); 1024];
if let Some((buf1, e1)) = f(&decoded, &mut buf1[..k]) {
let mut buf2 = [MaybeUninit::new(0); 1024];
let (buf2, e2) = g(&decoded, &mut buf2[..k]);
if e1 == e2 && buf1 == buf2 {
npassed += 1;
} else {
println!(
"equivalence test failed, {:x}/{:x}: {:?} f(i)={}e{} g(i)={}e{}",
i,
n,
decoded,
str::from_utf8(buf1).unwrap(),
e1,
str::from_utf8(buf2).unwrap(),
e2
);
}
} else {
nignored += 1;
}
}
println!(
"{}({}): done, ignored={} passed={} failed={}",
func,
k,
nignored,
npassed,
n - nignored - npassed
);
assert!(
nignored + npassed == n,
"{}({}): {} out of {} values returns an incorrect value!",
func,
k,
n - nignored - npassed,
n
);
(npassed, nignored)
}
pub fn f32_random_equivalence_test<F, G>(f: F, g: G, k: usize, n: usize)
where
F: for<'a> FnMut(&Decoded, &'a mut [MaybeUninit<u8>]) -> Option<(&'a [u8], i16)>,
G: for<'a> FnMut(&Decoded, &'a mut [MaybeUninit<u8>]) -> (&'a [u8], i16),
{
if cfg!(target_os = "emscripten") {
return; // using rng pulls in i128 support, which doesn't work
}
let mut rng = StdRng::from_entropy();
let f32_range = Uniform::new(0x0000_0001u32, 0x7f80_0000);
iterate("f32_random_equivalence_test", k, n, f, g, |_| {
let x = f32::from_bits(f32_range.sample(&mut rng));
decode_finite(x)
});
}
pub fn f64_random_equivalence_test<F, G>(f: F, g: G, k: usize, n: usize)
where
F: for<'a> FnMut(&Decoded, &'a mut [MaybeUninit<u8>]) -> Option<(&'a [u8], i16)>,
G: for<'a> FnMut(&Decoded, &'a mut [MaybeUninit<u8>]) -> (&'a [u8], i16),
{
if cfg!(target_os = "emscripten") {
return; // using rng pulls in i128 support, which doesn't work
}
let mut rng = StdRng::from_entropy();
let f64_range = Uniform::new(0x0000_0000_0000_0001u64, 0x7ff0_0000_0000_0000);
iterate("f64_random_equivalence_test", k, n, f, g, |_| {
let x = f64::from_bits(f64_range.sample(&mut rng));
decode_finite(x)
});
}
pub fn f32_exhaustive_equivalence_test<F, G>(f: F, g: G, k: usize)
where
F: for<'a> FnMut(&Decoded, &'a mut [MaybeUninit<u8>]) -> Option<(&'a [u8], i16)>,
G: for<'a> FnMut(&Decoded, &'a mut [MaybeUninit<u8>]) -> (&'a [u8], i16),
{
// we have only 2^23 * (2^8 - 1) - 1 = 2,139,095,039 positive finite f32 values,
// so why not simply testing all of them?
//
// this is of course very stressful (and thus should be behind an `#[ignore]` attribute),
// but with `-C opt-level=3 -C lto` this only takes about an hour or so.
// iterate from 0x0000_0001 to 0x7f7f_ffff, i.e., all finite ranges
let (npassed, nignored) =
iterate("f32_exhaustive_equivalence_test", k, 0x7f7f_ffff, f, g, |i: usize| {
let x = f32::from_bits(i as u32 + 1);
decode_finite(x)
});
assert_eq!((npassed, nignored), (2121451881, 17643158));
}
#[test]
fn shortest_random_equivalence_test() {
use core::num::flt2dec::strategy::dragon::format_shortest as fallback;
// Miri is too slow
let n = if cfg!(miri) { 10 } else { 10_000 };
f64_random_equivalence_test(format_shortest_opt, fallback, MAX_SIG_DIGITS, n);
f32_random_equivalence_test(format_shortest_opt, fallback, MAX_SIG_DIGITS, n);
}
#[test]
#[ignore] // it is too expensive
fn shortest_f32_exhaustive_equivalence_test() {
// it is hard to directly test the optimality of the output, but we can at least test if
// two different algorithms agree to each other.
//
// this reports the progress and the number of f32 values returned `None`.
// with `--nocapture` (and plenty of time and appropriate rustc flags), this should print:
// `done, ignored=17643158 passed=2121451881 failed=0`.
use core::num::flt2dec::strategy::dragon::format_shortest as fallback;
f32_exhaustive_equivalence_test(format_shortest_opt, fallback, MAX_SIG_DIGITS);
}
#[test]
#[ignore] // it is too expensive
fn shortest_f64_hard_random_equivalence_test() {
// this again probably has to use appropriate rustc flags.
use core::num::flt2dec::strategy::dragon::format_shortest as fallback;
f64_random_equivalence_test(format_shortest_opt, fallback, MAX_SIG_DIGITS, 100_000_000);
}
#[test]
fn exact_f32_random_equivalence_test() {
use core::num::flt2dec::strategy::dragon::format_exact as fallback;
// Miri is too slow
let n = if cfg!(miri) { 3 } else { 1_000 };
for k in 1..21 {
f32_random_equivalence_test(
|d, buf| format_exact_opt(d, buf, i16::MIN),
|d, buf| fallback(d, buf, i16::MIN),
k,
n,
);
}
}
#[test]
fn exact_f64_random_equivalence_test() {
use core::num::flt2dec::strategy::dragon::format_exact as fallback;
// Miri is too slow
let n = if cfg!(miri) { 2 } else { 1_000 };
for k in 1..21 {
f64_random_equivalence_test(
|d, buf| format_exact_opt(d, buf, i16::MIN),
|d, buf| fallback(d, buf, i16::MIN),
k,
n,
);
}
}
|
