1 // compile-flags: -Zmir-opt-level=0
2 // run-pass
3
4 #![feature(const_float_bits_conv)]
5 #![feature(const_float_classify)]
6
7 // Don't promote
nop<T>(x: T) -> T8 const fn nop<T>(x: T) -> T { x }
9
10 macro_rules! const_assert {
11 ($a:expr) => {
12 {
13 const _: () = assert!($a);
14 assert!(nop($a));
15 }
16 };
17 ($a:expr, $b:expr) => {
18 {
19 const _: () = assert!($a == $b);
20 assert_eq!(nop($a), nop($b));
21 }
22 };
23 }
24
f32()25 fn f32() {
26 const_assert!((1f32).to_bits(), 0x3f800000);
27 const_assert!(u32::from_be_bytes(1f32.to_be_bytes()), 0x3f800000);
28 const_assert!((12.5f32).to_bits(), 0x41480000);
29 const_assert!(u32::from_le_bytes(12.5f32.to_le_bytes()), 0x41480000);
30 const_assert!((1337f32).to_bits(), 0x44a72000);
31 const_assert!(u32::from_ne_bytes(1337f32.to_ne_bytes()), 0x44a72000);
32 const_assert!((-14.25f32).to_bits(), 0xc1640000);
33 const_assert!(f32::from_bits(0x3f800000), 1.0);
34 const_assert!(f32::from_be_bytes(0x3f800000u32.to_be_bytes()), 1.0);
35 const_assert!(f32::from_bits(0x41480000), 12.5);
36 const_assert!(f32::from_le_bytes(0x41480000u32.to_le_bytes()), 12.5);
37 const_assert!(f32::from_bits(0x44a72000), 1337.0);
38 const_assert!(f32::from_ne_bytes(0x44a72000u32.to_ne_bytes()), 1337.0);
39 const_assert!(f32::from_bits(0xc1640000), -14.25);
40
41 // Check that NaNs roundtrip their bits regardless of signalingness
42 // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits
43 const MASKED_NAN1: u32 = f32::NAN.to_bits() ^ 0x002A_AAAA;
44 const MASKED_NAN2: u32 = f32::NAN.to_bits() ^ 0x0055_5555;
45
46 const_assert!(f32::from_bits(MASKED_NAN1).is_nan());
47 const_assert!(f32::from_bits(MASKED_NAN1).is_nan());
48
49 // LLVM does not guarantee that loads and stores of NaNs preserve their exact bit pattern.
50 // In practice, this seems to only cause a problem on x86, since the most widely used calling
51 // convention mandates that floating point values are returned on the x87 FPU stack. See #73328.
52 if !cfg!(target_arch = "x86") {
53 const_assert!(f32::from_bits(MASKED_NAN1).to_bits(), MASKED_NAN1);
54 const_assert!(f32::from_bits(MASKED_NAN2).to_bits(), MASKED_NAN2);
55 }
56 }
57
f64()58 fn f64() {
59 const_assert!((1f64).to_bits(), 0x3ff0000000000000);
60 const_assert!(u64::from_be_bytes(1f64.to_be_bytes()), 0x3ff0000000000000);
61 const_assert!((12.5f64).to_bits(), 0x4029000000000000);
62 const_assert!(u64::from_le_bytes(12.5f64.to_le_bytes()), 0x4029000000000000);
63 const_assert!((1337f64).to_bits(), 0x4094e40000000000);
64 const_assert!(u64::from_ne_bytes(1337f64.to_ne_bytes()), 0x4094e40000000000);
65 const_assert!((-14.25f64).to_bits(), 0xc02c800000000000);
66 const_assert!(f64::from_bits(0x3ff0000000000000), 1.0);
67 const_assert!(f64::from_be_bytes(0x3ff0000000000000u64.to_be_bytes()), 1.0);
68 const_assert!(f64::from_bits(0x4029000000000000), 12.5);
69 const_assert!(f64::from_le_bytes(0x4029000000000000u64.to_le_bytes()), 12.5);
70 const_assert!(f64::from_bits(0x4094e40000000000), 1337.0);
71 const_assert!(f64::from_ne_bytes(0x4094e40000000000u64.to_ne_bytes()), 1337.0);
72 const_assert!(f64::from_bits(0xc02c800000000000), -14.25);
73
74 // Check that NaNs roundtrip their bits regardless of signalingness
75 // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits
76 const MASKED_NAN1: u64 = f64::NAN.to_bits() ^ 0x000A_AAAA_AAAA_AAAA;
77 const MASKED_NAN2: u64 = f64::NAN.to_bits() ^ 0x0005_5555_5555_5555;
78
79 const_assert!(f64::from_bits(MASKED_NAN1).is_nan());
80 const_assert!(f64::from_bits(MASKED_NAN1).is_nan());
81
82 // See comment above.
83 if !cfg!(target_arch = "x86") {
84 const_assert!(f64::from_bits(MASKED_NAN1).to_bits(), MASKED_NAN1);
85 const_assert!(f64::from_bits(MASKED_NAN2).to_bits(), MASKED_NAN2);
86 }
87 }
88
main()89 fn main() {
90 f32();
91 f64();
92 }
93