Skip to content

Commit

Permalink
Add f16 and f128 to tests/ui/consts/const-float-bits-conv.rs
Browse files Browse the repository at this point in the history
  • Loading branch information
rezwanahmedsami committed Aug 17, 2024
1 parent 9b318d2 commit 803cbaf
Showing 1 changed file with 64 additions and 1 deletion.
65 changes: 64 additions & 1 deletion tests/ui/consts/const-float-bits-conv.rs
Original file line number Diff line number Diff line change
Expand Up @@ -3,8 +3,9 @@

#![feature(const_float_bits_conv)]
#![feature(const_float_classify)]
#![feature(f16)]
#![feature(f128)]
#![allow(unused_macro_rules)]

// Don't promote
const fn nop<T>(x: T) -> T { x }

Expand All @@ -28,6 +29,36 @@ fn has_broken_floats() -> bool {
std::env::var("TARGET").is_ok_and(|v| v.contains("i586"))
}

fn f16(){
const_assert!((1f16).to_bits(), 0x3c00);
const_assert!(u16::from_be_bytes(1f16.to_be_bytes()), 0x3c00);
const_assert!((12.5f16).to_bits(), 0x4a40);
const_assert!(u16::from_le_bytes(12.5f16.to_le_bytes()), 0x4a40);
const_assert!((1337f16).to_bits(), 0x6539);
const_assert!(u16::from_ne_bytes(1337f16.to_ne_bytes()), 0x6539);
const_assert!((-14.25f16).to_bits(), 0xcb20);
const_assert!(f16::from_bits(0x3c00), 1.0);
const_assert!(f16::from_be_bytes(0x3c00u16.to_be_bytes()), 1.0);
const_assert!(f16::from_bits(0x4a40), 12.5);
const_assert!(f16::from_le_bytes(0x4a40u16.to_le_bytes()), 12.5);
const_assert!(f16::from_bits(0x5be0), 252.0);
const_assert!(f16::from_ne_bytes(0x5be0u16.to_ne_bytes()), 252.0);
const_assert!(f16::from_bits(0xcb20), -14.25);

// Check that NaNs roundtrip their bits regardless of signalingness
// 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits
// NOTE: These names assume `f{BITS}::NAN` is a quiet NAN and IEEE754-2008's NaN rules apply!
const QUIET_NAN: u16 = f16::NAN.to_bits() ^ 0x0155;
const SIGNALING_NAN: u16 = f16::NAN.to_bits() ^ 0x02AA;

const_assert!(f16::from_bits(QUIET_NAN).is_nan());
const_assert!(f16::from_bits(SIGNALING_NAN).is_nan());
const_assert!(f16::from_bits(QUIET_NAN).to_bits(), QUIET_NAN);
if !has_broken_floats() {
const_assert!(f16::from_bits(SIGNALING_NAN).to_bits(), SIGNALING_NAN);
}
}

fn f32() {
const_assert!((1f32).to_bits(), 0x3f800000);
const_assert!(u32::from_be_bytes(1f32.to_be_bytes()), 0x3f800000);
Expand Down Expand Up @@ -88,7 +119,39 @@ fn f64() {
}
}

fn f128() {
const_assert!((1f128).to_bits(), 0x3fff0000000000000000000000000000);
const_assert!(u128::from_be_bytes(1f128.to_be_bytes()), 0x3fff0000000000000000000000000000);
const_assert!((12.5f128).to_bits(), 0x40029000000000000000000000000000);
const_assert!(u128::from_le_bytes(12.5f128.to_le_bytes()), 0x40029000000000000000000000000000);
const_assert!((1337f128).to_bits(), 0x40094e40000000000000000000000000);
const_assert!(u128::from_ne_bytes(1337f128.to_ne_bytes()), 0x40094e40000000000000000000000000);
const_assert!((-14.25f128).to_bits(), 0xc002c800000000000000000000000000);
const_assert!(f128::from_bits(0x3fff0000000000000000000000000000), 1.0);
const_assert!(f128::from_be_bytes(0x3fff0000000000000000000000000000u128.to_be_bytes()), 1.0);
const_assert!(f128::from_bits(0x40029000000000000000000000000000), 12.5);
const_assert!(f128::from_le_bytes(0x40029000000000000000000000000000u128.to_le_bytes()), 12.5);
const_assert!(f128::from_bits(0x40094e40000000000000000000000000), 1337.0);
assert_eq!(f128::from_ne_bytes(0x40094e40000000000000000000000000u128.to_ne_bytes()), 1337.0);
const_assert!(f128::from_bits(0xc002c800000000000000000000000000), -14.25);

// Check that NaNs roundtrip their bits regardless of signalingness
// 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits
// NOTE: These names assume `f{BITS}::NAN` is a quiet NAN and IEEE754-2008's NaN rules apply!
const QUIET_NAN: u128 = f128::NAN.to_bits() | 0x0000_AAAA_AAAA_AAAA_AAAA_AAAA_AAAA_AAAA;
const SIGNALING_NAN: u128 = f128::NAN.to_bits() ^ 0x0000_5555_5555_5555_5555_5555_5555_5555;

const_assert!(f128::from_bits(QUIET_NAN).is_nan());
const_assert!(f128::from_bits(SIGNALING_NAN).is_nan());
const_assert!(f128::from_bits(QUIET_NAN).to_bits(), QUIET_NAN);
if !has_broken_floats() {
const_assert!(f128::from_bits(SIGNALING_NAN).to_bits(), SIGNALING_NAN);
}
}

fn main() {
f16();
f32();
f64();
f128();
}

0 comments on commit 803cbaf

Please sign in to comment.