1 // compile-flags: -Zmir-opt-level=0
4 #![feature(const_panic)]
5 #![feature(const_float_bits_conv)]
6 #![feature(const_float_classify)]
9 const fn nop<T>(x: T) -> T { x }
11 macro_rules! const_assert {
14 const _: () = assert!($a);
18 ($a:expr, $b:expr) => {
20 const _: () = assert!($a == $b);
21 assert_eq!(nop($a), nop($b));
27 const_assert!((1f32).to_bits(), 0x3f800000);
28 const_assert!(u32::from_be_bytes(1f32.to_be_bytes()), 0x3f800000);
29 const_assert!((12.5f32).to_bits(), 0x41480000);
30 const_assert!(u32::from_le_bytes(12.5f32.to_le_bytes()), 0x41480000);
31 const_assert!((1337f32).to_bits(), 0x44a72000);
32 const_assert!(u32::from_ne_bytes(1337f32.to_ne_bytes()), 0x44a72000);
33 const_assert!((-14.25f32).to_bits(), 0xc1640000);
34 const_assert!(f32::from_bits(0x3f800000), 1.0);
35 const_assert!(f32::from_be_bytes(0x3f800000u32.to_be_bytes()), 1.0);
36 const_assert!(f32::from_bits(0x41480000), 12.5);
37 const_assert!(f32::from_le_bytes(0x41480000u32.to_le_bytes()), 12.5);
38 const_assert!(f32::from_bits(0x44a72000), 1337.0);
39 const_assert!(f32::from_ne_bytes(0x44a72000u32.to_ne_bytes()), 1337.0);
40 const_assert!(f32::from_bits(0xc1640000), -14.25);
42 // Check that NaNs roundtrip their bits regardless of signalingness
43 // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits
44 const MASKED_NAN1: u32 = f32::NAN.to_bits() ^ 0x002A_AAAA;
45 const MASKED_NAN2: u32 = f32::NAN.to_bits() ^ 0x0055_5555;
47 const_assert!(f32::from_bits(MASKED_NAN1).is_nan());
48 const_assert!(f32::from_bits(MASKED_NAN1).is_nan());
50 // LLVM does not guarantee that loads and stores of NaNs preserve their exact bit pattern.
51 // In practice, this seems to only cause a problem on x86, since the most widely used calling
52 // convention mandates that floating point values are returned on the x87 FPU stack. See #73328.
53 if !cfg!(target_arch = "x86") {
54 const_assert!(f32::from_bits(MASKED_NAN1).to_bits(), MASKED_NAN1);
55 const_assert!(f32::from_bits(MASKED_NAN2).to_bits(), MASKED_NAN2);
60 const_assert!((1f64).to_bits(), 0x3ff0000000000000);
61 const_assert!(u64::from_be_bytes(1f64.to_be_bytes()), 0x3ff0000000000000);
62 const_assert!((12.5f64).to_bits(), 0x4029000000000000);
63 const_assert!(u64::from_le_bytes(12.5f64.to_le_bytes()), 0x4029000000000000);
64 const_assert!((1337f64).to_bits(), 0x4094e40000000000);
65 const_assert!(u64::from_ne_bytes(1337f64.to_ne_bytes()), 0x4094e40000000000);
66 const_assert!((-14.25f64).to_bits(), 0xc02c800000000000);
67 const_assert!(f64::from_bits(0x3ff0000000000000), 1.0);
68 const_assert!(f64::from_be_bytes(0x3ff0000000000000u64.to_be_bytes()), 1.0);
69 const_assert!(f64::from_bits(0x4029000000000000), 12.5);
70 const_assert!(f64::from_le_bytes(0x4029000000000000u64.to_le_bytes()), 12.5);
71 const_assert!(f64::from_bits(0x4094e40000000000), 1337.0);
72 const_assert!(f64::from_ne_bytes(0x4094e40000000000u64.to_ne_bytes()), 1337.0);
73 const_assert!(f64::from_bits(0xc02c800000000000), -14.25);
75 // Check that NaNs roundtrip their bits regardless of signalingness
76 // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits
77 const MASKED_NAN1: u64 = f64::NAN.to_bits() ^ 0x000A_AAAA_AAAA_AAAA;
78 const MASKED_NAN2: u64 = f64::NAN.to_bits() ^ 0x0005_5555_5555_5555;
80 const_assert!(f64::from_bits(MASKED_NAN1).is_nan());
81 const_assert!(f64::from_bits(MASKED_NAN1).is_nan());
84 if !cfg!(target_arch = "x86") {
85 const_assert!(f64::from_bits(MASKED_NAN1).to_bits(), MASKED_NAN1);
86 const_assert!(f64::from_bits(MASKED_NAN2).to_bits(), MASKED_NAN2);