Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

implement the rounding intrinsics using apfloat rounding #3256

Merged
merged 3 commits into from
Jan 7, 2024
Merged

implement the rounding intrinsics using apfloat rounding #3256

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
ff43f1c
implement the rounding intrinsics using apfloat rounding
RalfJung Jan 6, 2024
796a712
merge intrinsics-math into float tests
RalfJung Jan 6, 2024
88dd5d9
these should be exact
RalfJung Jan 6, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
52 changes: 30 additions & 22 deletions src/shims/intrinsics/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -145,17 +145,30 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
"fabsf32" => {
let [f] = check_arg_count(args)?;
let f = this.read_scalar(f)?.to_f32()?;
// Can be implemented in soft-floats.
// This is a "bitwise" operation, so there's no NaN non-determinism.
this.write_scalar(Scalar::from_f32(f.abs()), dest)?;
}
"fabsf64" => {
let [f] = check_arg_count(args)?;
let f = this.read_scalar(f)?.to_f64()?;
// Can be implemented in soft-floats.
// This is a "bitwise" operation, so there's no NaN non-determinism.
this.write_scalar(Scalar::from_f64(f.abs()), dest)?;
}
"floorf32" | "ceilf32" | "truncf32" | "roundf32" | "rintf32" => {
let [f] = check_arg_count(args)?;
let f = this.read_scalar(f)?.to_f32()?;
let mode = match intrinsic_name {
"floorf32" => Round::TowardNegative,
"ceilf32" => Round::TowardPositive,
"truncf32" => Round::TowardZero,
"roundf32" => Round::NearestTiesToAway,
"rintf32" => Round::NearestTiesToEven,
_ => bug!(),
};
let res = f.round_to_integral(mode).value;
let res = this.adjust_nan(res, &[f]);
this.write_scalar(res, dest)?;
}
#[rustfmt::skip]
| "sinf32"
| "cosf32"
Expand All @@ -165,11 +178,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
| "logf32"
| "log10f32"
| "log2f32"
| "floorf32"
| "ceilf32"
| "truncf32"
| "roundf32"
| "rintf32"
=> {
let [f] = check_arg_count(args)?;
let f = this.read_scalar(f)?.to_f32()?;
Expand All @@ -184,18 +192,28 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
"logf32" => f_host.ln(),
"log10f32" => f_host.log10(),
"log2f32" => f_host.log2(),
"floorf32" => f_host.floor(),
"ceilf32" => f_host.ceil(),
"truncf32" => f_host.trunc(),
"roundf32" => f_host.round(),
"rintf32" => f_host.round_ties_even(),
_ => bug!(),
};
let res = res.to_soft();
let res = this.adjust_nan(res, &[f]);
this.write_scalar(res, dest)?;
}

"floorf64" | "ceilf64" | "truncf64" | "roundf64" | "rintf64" => {
let [f] = check_arg_count(args)?;
let f = this.read_scalar(f)?.to_f64()?;
let mode = match intrinsic_name {
"floorf64" => Round::TowardNegative,
"ceilf64" => Round::TowardPositive,
"truncf64" => Round::TowardZero,
"roundf64" => Round::NearestTiesToAway,
"rintf64" => Round::NearestTiesToEven,
_ => bug!(),
};
let res = f.round_to_integral(mode).value;
let res = this.adjust_nan(res, &[f]);
this.write_scalar(res, dest)?;
}
#[rustfmt::skip]
| "sinf64"
| "cosf64"
Expand All @@ -205,11 +223,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
| "logf64"
| "log10f64"
| "log2f64"
| "floorf64"
| "ceilf64"
| "truncf64"
| "roundf64"
| "rintf64"
=> {
let [f] = check_arg_count(args)?;
let f = this.read_scalar(f)?.to_f64()?;
Expand All @@ -224,11 +237,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
"logf64" => f_host.ln(),
"log10f64" => f_host.log10(),
"log2f64" => f_host.log2(),
"floorf64" => f_host.floor(),
"ceilf64" => f_host.ceil(),
"truncf64" => f_host.trunc(),
"roundf64" => f_host.round(),
"rintf64" => f_host.round_ties_even(),
_ => bug!(),
};
let res = res.to_soft();
Expand Down
163 changes: 161 additions & 2 deletions tests/pass/float.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,8 +1,18 @@
#![feature(stmt_expr_attributes)]
#![feature(round_ties_even)]
#![feature(float_gamma)]
#![allow(arithmetic_overflow)]

use std::fmt::Debug;
use std::hint::black_box;
use std::{f32, f64};

macro_rules! assert_approx_eq {
($a:expr, $b:expr) => {{
let (a, b) = (&$a, &$b);
assert!((*a - *b).abs() < 1.0e-6, "{} is not approximately equal to {}", *a, *b);
}};
}

fn main() {
basic();
Expand All @@ -11,6 +21,8 @@ fn main() {
ops();
nan_casts();
rounding();
mul_add();
libm();
}

// Helper function to avoid promotion so that this tests "run-time" casts, not CTFE.
Expand Down Expand Up @@ -148,8 +160,6 @@ fn basic() {
assert_ne!({ 5.0_f32 / 0.0 }, { -5.0_f32 / 0.0 });
assert!((5.0_f64 / 0.0).is_infinite());
assert_ne!({ 5.0_f64 / 0.0 }, { 5.0_f64 / -0.0 });
assert!((-5.0_f32).sqrt().is_nan());
assert!((-5.0_f64).sqrt().is_nan());
assert_ne!(f32::NAN, f32::NAN);
assert_ne!(f64::NAN, f64::NAN);
// negative zero
Expand Down Expand Up @@ -178,6 +188,9 @@ fn basic() {
assert!((black_box(1.0f64) % -1.0).is_sign_positive());
assert!((black_box(-1.0f64) % 1.0).is_sign_negative());
assert!((black_box(-1.0f64) % -1.0).is_sign_negative());

assert_eq!((-1.0f32).abs(), 1.0f32);
assert_eq!(34.2f64.abs(), 34.2f64);
}

/// Many of these test values are taken from
Expand Down Expand Up @@ -592,4 +605,150 @@ fn rounding() {
assert_eq((-1.3f64).round_ties_even(), -1.0f64);
assert_eq((-1.5f64).round_ties_even(), -2.0f64);
assert_eq((-1.7f64).round_ties_even(), -2.0f64);

assert_eq!(3.8f32.floor(), 3.0f32);
assert_eq!((-1.1f64).floor(), -2.0f64);

assert_eq!((-2.3f32).ceil(), -2.0f32);
assert_eq!(3.8f64.ceil(), 4.0f64);

assert_eq!(0.1f32.trunc(), 0.0f32);
assert_eq!((-0.1f64).trunc(), 0.0f64);

assert_eq!(3.3_f32.round(), 3.0);
assert_eq!(2.5_f32.round(), 3.0);
assert_eq!(3.9_f64.round(), 4.0);
assert_eq!(2.5_f64.round(), 3.0);
}

fn mul_add() {
assert_eq!(3.0f32.mul_add(2.0f32, 5.0f32), 11.0);
assert_eq!(0.0f32.mul_add(-2.0, f32::consts::E), f32::consts::E);
assert_eq!(3.0f64.mul_add(2.0, 5.0), 11.0);
assert_eq!(0.0f64.mul_add(-2.0f64, f64::consts::E), f64::consts::E);
assert_eq!((-3.2f32).mul_add(2.4, f32::NEG_INFINITY), f32::NEG_INFINITY);
assert_eq!((-3.2f64).mul_add(2.4, f64::NEG_INFINITY), f64::NEG_INFINITY);

let f = f32::mul_add(
-0.000000000000000000000000000000000000014728589,
0.0000037105144,
0.000000000000000000000000000000000000000000055,
);
assert_eq!(f.to_bits(), f32::to_bits(-0.0));
}

pub fn libm() {
fn ldexp(a: f64, b: i32) -> f64 {
extern "C" {
fn ldexp(x: f64, n: i32) -> f64;
}
unsafe { ldexp(a, b) }
}

assert_approx_eq!(64f32.sqrt(), 8f32);
assert_approx_eq!(64f64.sqrt(), 8f64);
assert!((-5.0_f32).sqrt().is_nan());
assert!((-5.0_f64).sqrt().is_nan());

assert_approx_eq!(25f32.powi(-2), 0.0016f32);
assert_approx_eq!(23.2f64.powi(2), 538.24f64);

assert_approx_eq!(25f32.powf(-2f32), 0.0016f32);
assert_approx_eq!(400f64.powf(0.5f64), 20f64);

assert_approx_eq!(1f32.exp(), f32::consts::E);
assert_approx_eq!(1f64.exp(), f64::consts::E);

assert_approx_eq!(1f32.exp_m1(), f32::consts::E - 1.0);
assert_approx_eq!(1f64.exp_m1(), f64::consts::E - 1.0);

assert_approx_eq!(10f32.exp2(), 1024f32);
assert_approx_eq!(50f64.exp2(), 1125899906842624f64);

assert_approx_eq!(f32::consts::E.ln(), 1f32);
assert_approx_eq!(1f64.ln(), 0f64);

assert_approx_eq!(0f32.ln_1p(), 0f32);
assert_approx_eq!(0f64.ln_1p(), 0f64);

assert_approx_eq!(10f32.log10(), 1f32);
assert_approx_eq!(f64::consts::E.log10(), f64::consts::LOG10_E);

assert_approx_eq!(8f32.log2(), 3f32);
assert_approx_eq!(f64::consts::E.log2(), f64::consts::LOG2_E);

#[allow(deprecated)]
{
assert_approx_eq!(5.0f32.abs_sub(3.0), 2.0);
assert_approx_eq!(3.0f64.abs_sub(5.0), 0.0);
}

assert_approx_eq!(27.0f32.cbrt(), 3.0f32);
assert_approx_eq!(27.0f64.cbrt(), 3.0f64);

assert_approx_eq!(3.0f32.hypot(4.0f32), 5.0f32);
assert_approx_eq!(3.0f64.hypot(4.0f64), 5.0f64);

assert_eq!(ldexp(0.65f64, 3i32), 5.2f64);
assert_eq!(ldexp(1.42, 0xFFFF), f64::INFINITY);
assert_eq!(ldexp(1.42, -0xFFFF), 0f64);

// Trigonometric functions.

assert_approx_eq!(0f32.sin(), 0f32);
assert_approx_eq!((f64::consts::PI / 2f64).sin(), 1f64);
assert_approx_eq!(f32::consts::FRAC_PI_6.sin(), 0.5);
assert_approx_eq!(f64::consts::FRAC_PI_6.sin(), 0.5);
assert_approx_eq!(f32::consts::FRAC_PI_4.sin().asin(), f32::consts::FRAC_PI_4);
assert_approx_eq!(f64::consts::FRAC_PI_4.sin().asin(), f64::consts::FRAC_PI_4);

assert_approx_eq!(1.0f32.sinh(), 1.1752012f32);
assert_approx_eq!(1.0f64.sinh(), 1.1752012f64);
assert_approx_eq!(2.0f32.asinh(), 1.443635475178810342493276740273105f32);
assert_approx_eq!((-2.0f64).asinh(), -1.443635475178810342493276740273105f64);

assert_approx_eq!(0f32.cos(), 1f32);
assert_approx_eq!((f64::consts::PI * 2f64).cos(), 1f64);
assert_approx_eq!(f32::consts::FRAC_PI_3.cos(), 0.5);
assert_approx_eq!(f64::consts::FRAC_PI_3.cos(), 0.5);
assert_approx_eq!(f32::consts::FRAC_PI_4.cos().acos(), f32::consts::FRAC_PI_4);
assert_approx_eq!(f64::consts::FRAC_PI_4.cos().acos(), f64::consts::FRAC_PI_4);

assert_approx_eq!(1.0f32.cosh(), 1.54308f32);
assert_approx_eq!(1.0f64.cosh(), 1.54308f64);
assert_approx_eq!(2.0f32.acosh(), 1.31695789692481670862504634730796844f32);
assert_approx_eq!(3.0f64.acosh(), 1.76274717403908605046521864995958461f64);

assert_approx_eq!(1.0f32.tan(), 1.557408f32);
assert_approx_eq!(1.0f64.tan(), 1.557408f64);
assert_approx_eq!(1.0_f32, 1.0_f32.tan().atan());
assert_approx_eq!(1.0_f64, 1.0_f64.tan().atan());
assert_approx_eq!(1.0f32.atan2(2.0f32), 0.46364761f32);
assert_approx_eq!(1.0f32.atan2(2.0f32), 0.46364761f32);

assert_approx_eq!(
1.0f32.tanh(),
(1.0 - f32::consts::E.powi(-2)) / (1.0 + f32::consts::E.powi(-2))
);
assert_approx_eq!(
1.0f64.tanh(),
(1.0 - f64::consts::E.powi(-2)) / (1.0 + f64::consts::E.powi(-2))
);
assert_approx_eq!(0.5f32.atanh(), 0.54930614433405484569762261846126285f32);
assert_approx_eq!(0.5f64.atanh(), 0.54930614433405484569762261846126285f64);

assert_approx_eq!(5.0f32.gamma(), 24.0);
assert_approx_eq!(5.0f64.gamma(), 24.0);
assert_approx_eq!((-0.5f32).gamma(), (-2.0) * f32::consts::PI.sqrt());
assert_approx_eq!((-0.5f64).gamma(), (-2.0) * f64::consts::PI.sqrt());

assert_eq!(2.0f32.ln_gamma(), (0.0, 1));
assert_eq!(2.0f64.ln_gamma(), (0.0, 1));
// Gamma(-0.5) = -2*sqrt(π)
let (val, sign) = (-0.5f32).ln_gamma();
assert_approx_eq!(val, (2.0 * f32::consts::PI.sqrt()).ln());
assert_eq!(sign, -1);
let (val, sign) = (-0.5f64).ln_gamma();
assert_approx_eq!(val, (2.0 * f64::consts::PI.sqrt()).ln());
assert_eq!(sign, -1);
}
8 changes: 8 additions & 0 deletions tests/pass/float_nan.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -264,6 +264,10 @@ fn test_f32() {
HashSet::from_iter([F32::nan(Pos, Quiet, 0), F32::nan(Neg, Quiet, 0)]),
|| F32::from(f32::min(nan, nan)),
);
check_all_outcomes(
HashSet::from_iter([F32::nan(Pos, Quiet, 0), F32::nan(Neg, Quiet, 0)]),
|| F32::from(nan.floor()),
);
check_all_outcomes(
HashSet::from_iter([F32::nan(Pos, Quiet, 0), F32::nan(Neg, Quiet, 0)]),
|| F32::from(nan.sin()),
Expand Down Expand Up @@ -376,6 +380,10 @@ fn test_f64() {
HashSet::from_iter([F64::nan(Pos, Quiet, 0), F64::nan(Neg, Quiet, 0)]),
|| F64::from(f64::min(nan, nan)),
);
check_all_outcomes(
HashSet::from_iter([F64::nan(Pos, Quiet, 0), F64::nan(Neg, Quiet, 0)]),
|| F64::from(nan.floor()),
);
check_all_outcomes(
HashSet::from_iter([F64::nan(Pos, Quiet, 0), F64::nan(Neg, Quiet, 0)]),
|| F64::from(nan.sin()),
Expand Down