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Fixed up nostd support, verified that sqrt and cbrt routines work to within 1ULP

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This commit is contained in:
TQ Hirsch
2022-04-25 22:36:05 +02:00
parent 8016a8c7f8
commit 1e1cac4f06
7 changed files with 75 additions and 39 deletions
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33
firmware/motion-tester/src/bin/math_test.rs
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@@ -5,43 +5,30 @@ fn ulp(f: f32) -> f32 {
}
fn fn_err(actual: f32, calc: f32) -> f32 {
(calc - actual).abs() / actual
(calc - actual).abs() / ulp(actual)
}
fn test_all(fname: &str, actual: fn(f32) -> f32, calc: fn(f32) -> f32) {
let mut max_err = 0f32;
let mut max_err_value = 0f32;
(0x01..=0xfe).into_par_iter()
let errors =
(0x01..=0xfe).into_par_iter()
.map(|exp| {
(0x0..=0x7f_ffff).map(|mant| f32::from_bits((exp << 23) + mant))
let max_err_place = (0x0..=0x7f_ffff).map(|mant| f32::from_bits((exp << 23) + mant))
.max_by_key(|value| fn_err(actual(*value), calc(*value)).to_bits())
.unwrap()
.unwrap();
(exp, max_err_place, fn_err(actual(max_err_place), calc(max_err_place)))
})
.map(|value| (value,fn_err(actual(value), calc(value))))
.collect::<Vec<_>>();
for i in (0x0400_0000..0x0f7f_ffffu32).map(f32::from_bits) {
// range of normalized floats...
let err = fn_err(actual(i), calc(i));
if err > max_err {
max_err = err;
max_err_value = i;
}
for (exp, base, err) in errors {
println!("{},{},{}", exp as i32 - 127,base, err);
}
let max_err_pct = max_err * 100f32;
println!("{}: {}% @ {}", fname, max_err_pct, max_err_value);
println!(
"Value: 0x{:08x}\n
Calculated: 0x{:08x}\n
Actual: 0x{:08x}",
max_err_value.to_bits(),
calc(max_err_value).to_bits(), actual(max_err_value).to_bits())
}
fn main() {
// test_all("sqrt", f32::sqrt, jerk_control::math_ext::Roots::sqrt);
//test_all("sqrt", f32::sqrt, jerk_control::math_ext::Roots::sqrt);
test_all("cbrt", f32::cbrt, jerk_control::math_ext::Roots::cbrt);
}
}