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implement sqrt for f16 and f128

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This commit is contained in:
Ralf Jung 2025-09-18 22:02:46 +02:00
parent 19b9676a7f
commit f19b560fa9
2 changed files with 45 additions and 15 deletions
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16
src/tools/miri/src/intrinsics/math.rs
View file

@ -20,6 +20,14 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
match intrinsic_name {
// Operations we can do with soft-floats.
"sqrtf16" => {
let [f] = check_intrinsic_arg_count(args)?;
let f = this.read_scalar(f)?.to_f16()?;
// Sqrt is specified to be fully precise.
let res = math::sqrt(f);
let res = this.adjust_nan(res, &[f]);
this.write_scalar(res, dest)?;
}
"sqrtf32" => {
let [f] = check_intrinsic_arg_count(args)?;
let f = this.read_scalar(f)?.to_f32()?;
@ -36,6 +44,14 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
let res = this.adjust_nan(res, &[f]);
this.write_scalar(res, dest)?;
}
"sqrtf128" => {
let [f] = check_intrinsic_arg_count(args)?;
let f = this.read_scalar(f)?.to_f128()?;
// Sqrt is specified to be fully precise.
let res = math::sqrt(f);
let res = this.adjust_nan(res, &[f]);
this.write_scalar(res, dest)?;
}
"fmaf32" => {
let [a, b, c] = check_intrinsic_arg_count(args)?;

44
src/tools/miri/tests/pass/float.rs
View file

@ -281,6 +281,35 @@ fn basic() {
assert_eq!(34.2f64.abs(), 34.2f64);
assert_eq!((-1.0f128).abs(), 1.0f128);
assert_eq!(34.2f128.abs(), 34.2f128);
assert_eq!(64_f16.sqrt(), 8_f16);
assert_eq!(64_f32.sqrt(), 8_f32);
assert_eq!(64_f64.sqrt(), 8_f64);
assert_eq!(64_f128.sqrt(), 8_f128);
assert_eq!(f16::INFINITY.sqrt(), f16::INFINITY);
assert_eq!(f32::INFINITY.sqrt(), f32::INFINITY);
assert_eq!(f64::INFINITY.sqrt(), f64::INFINITY);
assert_eq!(f128::INFINITY.sqrt(), f128::INFINITY);
assert_eq!(0.0_f16.sqrt().total_cmp(&0.0), std::cmp::Ordering::Equal);
assert_eq!(0.0_f32.sqrt().total_cmp(&0.0), std::cmp::Ordering::Equal);
assert_eq!(0.0_f64.sqrt().total_cmp(&0.0), std::cmp::Ordering::Equal);
assert_eq!(0.0_f128.sqrt().total_cmp(&0.0), std::cmp::Ordering::Equal);
assert_eq!((-0.0_f16).sqrt().total_cmp(&-0.0), std::cmp::Ordering::Equal);
assert_eq!((-0.0_f32).sqrt().total_cmp(&-0.0), std::cmp::Ordering::Equal);
assert_eq!((-0.0_f64).sqrt().total_cmp(&-0.0), std::cmp::Ordering::Equal);
assert_eq!((-0.0_f128).sqrt().total_cmp(&-0.0), std::cmp::Ordering::Equal);
assert!((-5.0_f16).sqrt().is_nan());
assert!((-5.0_f32).sqrt().is_nan());
assert!((-5.0_f64).sqrt().is_nan());
assert!((-5.0_f128).sqrt().is_nan());
assert!(f16::NEG_INFINITY.sqrt().is_nan());
assert!(f32::NEG_INFINITY.sqrt().is_nan());
assert!(f64::NEG_INFINITY.sqrt().is_nan());
assert!(f128::NEG_INFINITY.sqrt().is_nan());
assert!(f16::NAN.sqrt().is_nan());
assert!(f32::NAN.sqrt().is_nan());
assert!(f64::NAN.sqrt().is_nan());
assert!(f128::NAN.sqrt().is_nan());
}
/// Test casts from floats to ints and back
@ -1012,21 +1041,6 @@ pub fn libm() {
unsafe { ldexp(a, b) }
}
assert_eq!(64_f32.sqrt(), 8_f32);
assert_eq!(64_f64.sqrt(), 8_f64);
assert_eq!(f32::INFINITY.sqrt(), f32::INFINITY);
assert_eq!(f64::INFINITY.sqrt(), f64::INFINITY);
assert_eq!(0.0_f32.sqrt().total_cmp(&0.0), std::cmp::Ordering::Equal);
assert_eq!(0.0_f64.sqrt().total_cmp(&0.0), std::cmp::Ordering::Equal);
assert_eq!((-0.0_f32).sqrt().total_cmp(&-0.0), std::cmp::Ordering::Equal);
assert_eq!((-0.0_f64).sqrt().total_cmp(&-0.0), std::cmp::Ordering::Equal);
assert!((-5.0_f32).sqrt().is_nan());
assert!((-5.0_f64).sqrt().is_nan());
assert!(f32::NEG_INFINITY.sqrt().is_nan());
assert!(f64::NEG_INFINITY.sqrt().is_nan());
assert!(f32::NAN.sqrt().is_nan());
assert!(f64::NAN.sqrt().is_nan());
assert_approx_eq!(25f32.powi(-2), 0.0016f32);
assert_approx_eq!(23.2f64.powi(2), 538.24f64);