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fix applying an error to infinities

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This commit is contained in:
Ralf Jung 2025-09-03 21:22:43 +02:00
parent 18683c20ae
commit 8667034718
2 changed files with 8 additions and 0 deletions
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4
src/tools/miri/src/math.rs
View file

@ -15,6 +15,8 @@ pub(crate) fn apply_random_float_error<F: rustc_apfloat::Float>(
|| matches!(ecx.machine.float_rounding_error, FloatRoundingErrorMode::None)
// relative errors don't do anything to zeros... avoid messing up the sign
|| val.is_zero()
// The logic below makes no sense if the input is already non-finite.
|| !val.is_finite()
{
return val;
}
@ -54,6 +56,8 @@ pub(crate) fn apply_random_float_error_ulp<F: rustc_apfloat::Float>(
// FIXME: also disturb zeros? That requires a lot more cases in `fixed_float_value`
// and might make the std test suite quite unhappy.
|| val.is_zero()
// The logic below makes no sense if the input is already non-finite.
|| !val.is_finite()
{
return val;
}

4
src/tools/miri/tests/pass/float.rs
View file

@ -1052,6 +1052,10 @@ pub fn libm() {
assert_eq!(42f64.powf(0.0), 1.0);
assert_eq!(f32::INFINITY.powf(0.0), 1.0);
assert_eq!(f64::INFINITY.powf(0.0), 1.0);
assert_eq!(f32::NEG_INFINITY.powi(3), f32::NEG_INFINITY);
assert_eq!(f32::NEG_INFINITY.powi(2), f32::INFINITY);
assert_eq!(f64::INFINITY.powi(3), f64::INFINITY);
assert_eq!(f64::INFINITY.powi(2), f64::INFINITY);
// f*::NAN is a quiet NAN and should return 1 as well.
assert_eq!(f32::NAN.powi(0), 1.0);