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Merged
merged 2 commits into from
Jun 10, 2025
+386 −107
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Enable Non-determinism of float operations in Miri and change std tests #138062

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5bafe9d
Enable Float non-determinism in miri. Update and add tests and change
LorrensP-2158466 Mar 5, 2025
00452bd
change tests to use fixed constants to let them pass with miri
LorrensP-2158466 May 30, 2025
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2 changes: 1 addition & 1 deletion library/core/src/num/f32.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1879,7 +1879,7 @@ pub mod math {
///
/// let x = 2.0_f32;
/// let abs_difference = (f32::math::powi(x, 2) - (x * x)).abs();
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-5);
///
/// assert_eq!(f32::math::powi(f32::NAN, 0), 1.0);
/// ```
Expand Down
2 changes: 1 addition & 1 deletion library/core/src/num/f64.rs
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Expand Up @@ -1877,7 +1877,7 @@ pub mod math {
///
/// let x = 2.0_f64;
/// let abs_difference = (f64::math::powi(x, 2) - (x * x)).abs();
/// assert!(abs_difference <= f64::EPSILON);
/// assert!(abs_difference <= 1e-6);
///
/// assert_eq!(f64::math::powi(f64::NAN, 0), 1.0);
/// ```
Expand Down
9 changes: 7 additions & 2 deletions library/coretests/tests/floats/f32.rs
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Expand Up @@ -23,6 +23,11 @@ const NAN_MASK1: u32 = 0x002a_aaaa;
/// Second pattern over the mantissa
const NAN_MASK2: u32 = 0x0055_5555;

/// Miri adds some extra errors to float functions; make sure the tests still pass.
/// These values are purely used as a canary to test against and are thus not a stable guarantee Rust provides.
/// They serve as a way to get an idea of the real precision of floating point operations on different platforms.
const APPROX_DELTA: f32 = if cfg!(miri) { 1e-4 } else { 1e-6 };
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I only use this once in this file, but it's the same reason as in library/std/tests/floats/f32.rs.


#[test]
fn test_num_f32() {
super::test_num(10f32, 2f32);
Expand Down Expand Up @@ -437,8 +442,8 @@ fn test_powi() {
let nan: f32 = f32::NAN;
let inf: f32 = f32::INFINITY;
let neg_inf: f32 = f32::NEG_INFINITY;
assert_biteq!(1.0f32.powi(1), 1.0);
assert_approx_eq!((-3.1f32).powi(2), 9.61);
assert_approx_eq!(1.0f32.powi(1), 1.0);
assert_approx_eq!((-3.1f32).powi(2), 9.61, APPROX_DELTA);
assert_approx_eq!(5.9f32.powi(-2), 0.028727);
assert_biteq!(8.3f32.powi(0), 1.0);
assert!(nan.powi(2).is_nan());
Expand Down
2 changes: 1 addition & 1 deletion library/coretests/tests/floats/f64.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -422,7 +422,7 @@ fn test_powi() {
let nan: f64 = f64::NAN;
let inf: f64 = f64::INFINITY;
let neg_inf: f64 = f64::NEG_INFINITY;
assert_biteq!(1.0f64.powi(1), 1.0);
assert_approx_eq!(1.0f64.powi(1), 1.0);
assert_approx_eq!((-3.1f64).powi(2), 9.61);
assert_approx_eq!(5.9f64.powi(-2), 0.028727);
assert_biteq!(8.3f64.powi(0), 1.0);
Expand Down
6 changes: 4 additions & 2 deletions library/coretests/tests/num/dec2flt/float.rs
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Expand Up @@ -23,7 +23,8 @@ fn test_f16_integer_decode() {
fn test_f32_integer_decode() {
assert_eq!(3.14159265359f32.integer_decode(), (13176795, -22, 1));
assert_eq!((-8573.5918555f32).integer_decode(), (8779358, -10, -1));
assert_eq!(2f32.powf(100.0).integer_decode(), (8388608, 77, 1));
// Set 2^100 directly instead of using powf, because it doesn't guarentee precision
assert_eq!(1.2676506e30_f32.integer_decode(), (8388608, 77, 1));
assert_eq!(0f32.integer_decode(), (0, -150, 1));
assert_eq!((-0f32).integer_decode(), (0, -150, -1));
assert_eq!(f32::INFINITY.integer_decode(), (8388608, 105, 1));
Expand All @@ -39,7 +40,8 @@ fn test_f32_integer_decode() {
fn test_f64_integer_decode() {
assert_eq!(3.14159265359f64.integer_decode(), (7074237752028906, -51, 1));
assert_eq!((-8573.5918555f64).integer_decode(), (4713381968463931, -39, -1));
assert_eq!(2f64.powf(100.0).integer_decode(), (4503599627370496, 48, 1));
// Set 2^100 directly instead of using powf, because it doesn't guarentee precision
assert_eq!(1.2676506002282294e30_f64.integer_decode(), (4503599627370496, 48, 1));
assert_eq!(0f64.integer_decode(), (0, -1075, 1));
assert_eq!((-0f64).integer_decode(), (0, -1075, -1));
assert_eq!(f64::INFINITY.integer_decode(), (4503599627370496, 972, 1));
Expand Down
34 changes: 17 additions & 17 deletions library/std/src/num/f32.rs
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Expand Up @@ -304,7 +304,7 @@ impl f32 {
/// ```
/// let x = 2.0_f32;
/// let abs_difference = (x.powi(2) - (x * x)).abs();
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-5);
///
/// assert_eq!(f32::powi(f32::NAN, 0), 1.0);
/// ```
Expand All @@ -328,7 +328,7 @@ impl f32 {
/// ```
/// let x = 2.0_f32;
/// let abs_difference = (x.powf(2.0) - (x * x)).abs();
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-5);
///
/// assert_eq!(f32::powf(1.0, f32::NAN), 1.0);
/// assert_eq!(f32::powf(f32::NAN, 0.0), 1.0);
Expand Down Expand Up @@ -388,7 +388,7 @@ impl f32 {
/// // ln(e) - 1 == 0
/// let abs_difference = (e.ln() - 1.0).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-6);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
Expand All @@ -413,7 +413,7 @@ impl f32 {
/// // 2^2 - 4 == 0
/// let abs_difference = (f.exp2() - 4.0).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-5);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
Expand Down Expand Up @@ -442,7 +442,7 @@ impl f32 {
/// // ln(e) - 1 == 0
/// let abs_difference = (e.ln() - 1.0).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-6);
/// ```
///
/// Non-positive values:
Expand Down Expand Up @@ -479,7 +479,7 @@ impl f32 {
/// // log5(5) - 1 == 0
/// let abs_difference = (five.log(5.0) - 1.0).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-6);
/// ```
///
/// Non-positive values:
Expand Down Expand Up @@ -512,7 +512,7 @@ impl f32 {
/// // log2(2) - 1 == 0
/// let abs_difference = (two.log2() - 1.0).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-6);
/// ```
///
/// Non-positive values:
Expand Down Expand Up @@ -545,7 +545,7 @@ impl f32 {
/// // log10(10) - 1 == 0
/// let abs_difference = (ten.log10() - 1.0).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-6);
/// ```
///
/// Non-positive values:
Expand Down Expand Up @@ -652,7 +652,7 @@ impl f32 {
/// // sqrt(x^2 + y^2)
/// let abs_difference = (x.hypot(y) - (x.powi(2) + y.powi(2)).sqrt()).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-6);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
Expand All @@ -676,7 +676,7 @@ impl f32 {
///
/// let abs_difference = (x.sin() - 1.0).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-6);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
Expand All @@ -700,7 +700,7 @@ impl f32 {
///
/// let abs_difference = (x.cos() - 1.0).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-6);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
Expand Down Expand Up @@ -754,7 +754,7 @@ impl f32 {
/// // asin(sin(pi/2))
/// let abs_difference = (f.sin().asin() - std::f32::consts::FRAC_PI_2).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-3);
/// ```
#[doc(alias = "arcsin")]
#[rustc_allow_incoherent_impl]
Expand Down Expand Up @@ -784,7 +784,7 @@ impl f32 {
/// // acos(cos(pi/4))
/// let abs_difference = (f.cos().acos() - std::f32::consts::FRAC_PI_4).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-6);
/// ```
#[doc(alias = "arccos")]
#[rustc_allow_incoherent_impl]
Expand Down Expand Up @@ -884,8 +884,8 @@ impl f32 {
/// let abs_difference_0 = (f.0 - x.sin()).abs();
/// let abs_difference_1 = (f.1 - x.cos()).abs();
///
/// assert!(abs_difference_0 <= f32::EPSILON);
/// assert!(abs_difference_1 <= f32::EPSILON);
/// assert!(abs_difference_0 <= 1e-6);
/// assert!(abs_difference_1 <= 1e-6);
/// ```
#[doc(alias = "sincos")]
#[rustc_allow_incoherent_impl]
Expand Down Expand Up @@ -1067,7 +1067,7 @@ impl f32 {
///
/// let abs_difference = (f - x).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-7);
/// ```
#[doc(alias = "arcsinh")]
#[rustc_allow_incoherent_impl]
Expand Down Expand Up @@ -1095,7 +1095,7 @@ impl f32 {
///
/// let abs_difference = (f - x).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference <= 1e-6);
/// ```
#[doc(alias = "arccosh")]
#[rustc_allow_incoherent_impl]
Expand Down
6 changes: 3 additions & 3 deletions library/std/src/num/f64.rs
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Expand Up @@ -304,7 +304,7 @@ impl f64 {
/// ```
/// let x = 2.0_f64;
/// let abs_difference = (x.powi(2) - (x * x)).abs();
/// assert!(abs_difference <= f64::EPSILON);
/// assert!(abs_difference <= 1e-14);
///
/// assert_eq!(f64::powi(f64::NAN, 0), 1.0);
/// ```
Expand All @@ -328,7 +328,7 @@ impl f64 {
/// ```
/// let x = 2.0_f64;
/// let abs_difference = (x.powf(2.0) - (x * x)).abs();
/// assert!(abs_difference <= f64::EPSILON);
/// assert!(abs_difference <= 1e-14);
///
/// assert_eq!(f64::powf(1.0, f64::NAN), 1.0);
/// assert_eq!(f64::powf(f64::NAN, 0.0), 1.0);
Expand Down Expand Up @@ -754,7 +754,7 @@ impl f64 {
/// // asin(sin(pi/2))
/// let abs_difference = (f.sin().asin() - std::f64::consts::FRAC_PI_2).abs();
///
/// assert!(abs_difference < 1e-10);
/// assert!(abs_difference < 1e-7);
/// ```
#[doc(alias = "arcsin")]
#[rustc_allow_incoherent_impl]
Expand Down
33 changes: 19 additions & 14 deletions library/std/tests/floats/f32.rs
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@@ -1,5 +1,10 @@
use std::f32::consts;

/// Miri adds some extra errors to float functions; make sure the tests still pass.
/// These values are purely used as a canary to test against and are thus not a stable guarantee Rust provides.
/// They serve as a way to get an idea of the real precision of floating point operations on different platforms.
const APPROX_DELTA: f32 = if cfg!(miri) { 1e-3 } else { 1e-6 };

#[allow(unused_macros)]
macro_rules! assert_f32_biteq {
($left : expr, $right : expr) => {
Expand All @@ -17,9 +22,9 @@ fn test_powf() {
let inf: f32 = f32::INFINITY;
let neg_inf: f32 = f32::NEG_INFINITY;
assert_eq!(1.0f32.powf(1.0), 1.0);
assert_approx_eq!(3.4f32.powf(4.5), 246.408218);
assert_approx_eq!(3.4f32.powf(4.5), 246.408218, APPROX_DELTA);
assert_approx_eq!(2.7f32.powf(-3.2), 0.041652);
assert_approx_eq!((-3.1f32).powf(2.0), 9.61);
assert_approx_eq!((-3.1f32).powf(2.0), 9.61, APPROX_DELTA);
assert_approx_eq!(5.9f32.powf(-2.0), 0.028727);
assert_eq!(8.3f32.powf(0.0), 1.0);
assert!(nan.powf(2.0).is_nan());
Expand All @@ -30,8 +35,8 @@ fn test_powf() {
#[test]
fn test_exp() {
assert_eq!(1.0, 0.0f32.exp());
assert_approx_eq!(2.718282, 1.0f32.exp());
assert_approx_eq!(148.413162, 5.0f32.exp());
assert_approx_eq!(2.718282, 1.0f32.exp(), APPROX_DELTA);
assert_approx_eq!(148.413162, 5.0f32.exp(), APPROX_DELTA);

let inf: f32 = f32::INFINITY;
let neg_inf: f32 = f32::NEG_INFINITY;
Expand All @@ -43,7 +48,7 @@ fn test_exp() {

#[test]
fn test_exp2() {
assert_eq!(32.0, 5.0f32.exp2());
assert_approx_eq!(32.0, 5.0f32.exp2(), APPROX_DELTA);
assert_eq!(1.0, 0.0f32.exp2());

let inf: f32 = f32::INFINITY;
Expand All @@ -66,17 +71,17 @@ fn test_ln() {
assert!((-2.3f32).ln().is_nan());
assert_eq!((-0.0f32).ln(), neg_inf);
assert_eq!(0.0f32.ln(), neg_inf);
assert_approx_eq!(4.0f32.ln(), 1.386294);
assert_approx_eq!(4.0f32.ln(), 1.386294, APPROX_DELTA);
}

#[test]
fn test_log() {
let nan: f32 = f32::NAN;
let inf: f32 = f32::INFINITY;
let neg_inf: f32 = f32::NEG_INFINITY;
assert_eq!(10.0f32.log(10.0), 1.0);
assert_approx_eq!(10.0f32.log(10.0), 1.0);
assert_approx_eq!(2.3f32.log(3.5), 0.664858);
assert_eq!(1.0f32.exp().log(1.0f32.exp()), 1.0);
assert_approx_eq!(1.0f32.exp().log(1.0f32.exp()), 1.0, APPROX_DELTA);
assert!(1.0f32.log(1.0).is_nan());
assert!(1.0f32.log(-13.9).is_nan());
assert!(nan.log(2.3).is_nan());
Expand All @@ -92,9 +97,9 @@ fn test_log2() {
let nan: f32 = f32::NAN;
let inf: f32 = f32::INFINITY;
let neg_inf: f32 = f32::NEG_INFINITY;
assert_approx_eq!(10.0f32.log2(), 3.321928);
assert_approx_eq!(10.0f32.log2(), 3.321928, APPROX_DELTA);
assert_approx_eq!(2.3f32.log2(), 1.201634);
assert_approx_eq!(1.0f32.exp().log2(), 1.442695);
assert_approx_eq!(1.0f32.exp().log2(), 1.442695, APPROX_DELTA);
assert!(nan.log2().is_nan());
assert_eq!(inf.log2(), inf);
assert!(neg_inf.log2().is_nan());
Expand All @@ -108,7 +113,7 @@ fn test_log10() {
let nan: f32 = f32::NAN;
let inf: f32 = f32::INFINITY;
let neg_inf: f32 = f32::NEG_INFINITY;
assert_eq!(10.0f32.log10(), 1.0);
assert_approx_eq!(10.0f32.log10(), 1.0);
assert_approx_eq!(2.3f32.log10(), 0.361728);
assert_approx_eq!(1.0f32.exp().log10(), 0.434294);
assert_eq!(1.0f32.log10(), 0.0);
Expand Down Expand Up @@ -158,7 +163,7 @@ fn test_acosh() {
assert_approx_eq!(3.0f32.acosh(), 1.76274717403908605046521864995958461f32);

// test for low accuracy from issue 104548
assert_approx_eq!(60.0f32, 60.0f32.cosh().acosh());
assert_approx_eq!(60.0f32, 60.0f32.cosh().acosh(), APPROX_DELTA);
}

#[test]
Expand Down Expand Up @@ -237,7 +242,7 @@ fn test_real_consts() {
let ln_10: f32 = consts::LN_10;

assert_approx_eq!(frac_pi_2, pi / 2f32);
assert_approx_eq!(frac_pi_3, pi / 3f32);
assert_approx_eq!(frac_pi_3, pi / 3f32, APPROX_DELTA);
assert_approx_eq!(frac_pi_4, pi / 4f32);
assert_approx_eq!(frac_pi_6, pi / 6f32);
assert_approx_eq!(frac_pi_8, pi / 8f32);
Expand All @@ -249,5 +254,5 @@ fn test_real_consts() {
assert_approx_eq!(log2_e, e.log2());
assert_approx_eq!(log10_e, e.log10());
assert_approx_eq!(ln_2, 2f32.ln());
assert_approx_eq!(ln_10, 10f32.ln());
assert_approx_eq!(ln_10, 10f32.ln(), APPROX_DELTA);
}
8 changes: 4 additions & 4 deletions library/std/tests/floats/f64.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -43,7 +43,7 @@ fn test_exp() {

#[test]
fn test_exp2() {
assert_eq!(32.0, 5.0f64.exp2());
assert_approx_eq!(32.0, 5.0f64.exp2());
assert_eq!(1.0, 0.0f64.exp2());

let inf: f64 = f64::INFINITY;
Expand Down Expand Up @@ -74,9 +74,9 @@ fn test_log() {
let nan: f64 = f64::NAN;
let inf: f64 = f64::INFINITY;
let neg_inf: f64 = f64::NEG_INFINITY;
assert_eq!(10.0f64.log(10.0), 1.0);
assert_approx_eq!(10.0f64.log(10.0), 1.0);
assert_approx_eq!(2.3f64.log(3.5), 0.664858);
assert_eq!(1.0f64.exp().log(1.0f64.exp()), 1.0);
assert_approx_eq!(1.0f64.exp().log(1.0f64.exp()), 1.0);
assert!(1.0f64.log(1.0).is_nan());
assert!(1.0f64.log(-13.9).is_nan());
assert!(nan.log(2.3).is_nan());
Expand Down Expand Up @@ -108,7 +108,7 @@ fn test_log10() {
let nan: f64 = f64::NAN;
let inf: f64 = f64::INFINITY;
let neg_inf: f64 = f64::NEG_INFINITY;
assert_eq!(10.0f64.log10(), 1.0);
assert_approx_eq!(10.0f64.log10(), 1.0);
assert_approx_eq!(2.3f64.log10(), 0.361728);
assert_approx_eq!(1.0f64.exp().log10(), 0.434294);
assert_eq!(1.0f64.log10(), 0.0);
Expand Down
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