33
44#![ feature( const_float_bits_conv) ]
55#![ feature( const_float_classify) ]
6+ #![ feature( f16) ]
7+ #![ feature( f128) ]
68#![ allow( unused_macro_rules) ]
7-
89// Don't promote
910const fn nop < T > ( x : T ) -> T { x }
1011
@@ -28,6 +29,37 @@ fn has_broken_floats() -> bool {
2829 std:: env:: var ( "TARGET" ) . is_ok_and ( |v| v. contains ( "i586" ) )
2930}
3031
32+ #[ cfg( target_arch = "x86_64" ) ]
33+ fn f16 ( ) {
34+ const_assert ! ( ( 1 f16) . to_bits( ) , 0x3c00 ) ;
35+ const_assert ! ( u16 :: from_be_bytes( 1 f16. to_be_bytes( ) ) , 0x3c00 ) ;
36+ const_assert ! ( ( 12.5f16 ) . to_bits( ) , 0x4a40 ) ;
37+ const_assert ! ( u16 :: from_le_bytes( 12.5f16 . to_le_bytes( ) ) , 0x4a40 ) ;
38+ const_assert ! ( ( 1337 f16) . to_bits( ) , 0x6539 ) ;
39+ const_assert ! ( u16 :: from_ne_bytes( 1337 f16. to_ne_bytes( ) ) , 0x6539 ) ;
40+ const_assert ! ( ( -14.25f16 ) . to_bits( ) , 0xcb20 ) ;
41+ const_assert ! ( f16:: from_bits( 0x3c00 ) , 1.0 ) ;
42+ const_assert ! ( f16:: from_be_bytes( 0x3c00u16 . to_be_bytes( ) ) , 1.0 ) ;
43+ const_assert ! ( f16:: from_bits( 0x4a40 ) , 12.5 ) ;
44+ const_assert ! ( f16:: from_le_bytes( 0x4a40u16 . to_le_bytes( ) ) , 12.5 ) ;
45+ const_assert ! ( f16:: from_bits( 0x5be0 ) , 252.0 ) ;
46+ const_assert ! ( f16:: from_ne_bytes( 0x5be0u16 . to_ne_bytes( ) ) , 252.0 ) ;
47+ const_assert ! ( f16:: from_bits( 0xcb20 ) , -14.25 ) ;
48+
49+ // Check that NaNs roundtrip their bits regardless of signalingness
50+ // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits
51+ // NOTE: These names assume `f{BITS}::NAN` is a quiet NAN and IEEE754-2008's NaN rules apply!
52+ const QUIET_NAN : u16 = f16:: NAN . to_bits ( ) ^ 0x0155 ;
53+ const SIGNALING_NAN : u16 = f16:: NAN . to_bits ( ) ^ 0x02AA ;
54+
55+ const_assert ! ( f16:: from_bits( QUIET_NAN ) . is_nan( ) ) ;
56+ const_assert ! ( f16:: from_bits( SIGNALING_NAN ) . is_nan( ) ) ;
57+ const_assert ! ( f16:: from_bits( QUIET_NAN ) . to_bits( ) , QUIET_NAN ) ;
58+ if !has_broken_floats ( ) {
59+ const_assert ! ( f16:: from_bits( SIGNALING_NAN ) . to_bits( ) , SIGNALING_NAN ) ;
60+ }
61+ }
62+
3163fn f32 ( ) {
3264 const_assert ! ( ( 1f32 ) . to_bits( ) , 0x3f800000 ) ;
3365 const_assert ! ( u32 :: from_be_bytes( 1f32 . to_be_bytes( ) ) , 0x3f800000 ) ;
@@ -88,7 +120,43 @@ fn f64() {
88120 }
89121}
90122
123+ #[ cfg( target_arch = "x86_64" ) ]
124+ fn f128 ( ) {
125+ const_assert ! ( ( 1 f128) . to_bits( ) , 0x3fff0000000000000000000000000000 ) ;
126+ const_assert ! ( u128 :: from_be_bytes( 1 f128. to_be_bytes( ) ) , 0x3fff0000000000000000000000000000 ) ;
127+ const_assert ! ( ( 12.5f128 ) . to_bits( ) , 0x40029000000000000000000000000000 ) ;
128+ const_assert ! ( u128 :: from_le_bytes( 12.5f128 . to_le_bytes( ) ) , 0x40029000000000000000000000000000 ) ;
129+ const_assert ! ( ( 1337 f128) . to_bits( ) , 0x40094e40000000000000000000000000 ) ;
130+ const_assert ! ( u128 :: from_ne_bytes( 1337 f128. to_ne_bytes( ) ) , 0x40094e40000000000000000000000000 ) ;
131+ const_assert ! ( ( -14.25f128 ) . to_bits( ) , 0xc002c800000000000000000000000000 ) ;
132+ const_assert ! ( f128:: from_bits( 0x3fff0000000000000000000000000000 ) , 1.0 ) ;
133+ const_assert ! ( f128:: from_be_bytes( 0x3fff0000000000000000000000000000u128 . to_be_bytes( ) ) , 1.0 ) ;
134+ const_assert ! ( f128:: from_bits( 0x40029000000000000000000000000000 ) , 12.5 ) ;
135+ const_assert ! ( f128:: from_le_bytes( 0x40029000000000000000000000000000u128 . to_le_bytes( ) ) , 12.5 ) ;
136+ const_assert ! ( f128:: from_bits( 0x40094e40000000000000000000000000 ) , 1337.0 ) ;
137+ assert_eq ! ( f128:: from_ne_bytes( 0x40094e40000000000000000000000000u128 . to_ne_bytes( ) ) , 1337.0 ) ;
138+ const_assert ! ( f128:: from_bits( 0xc002c800000000000000000000000000 ) , -14.25 ) ;
139+
140+ // Check that NaNs roundtrip their bits regardless of signalingness
141+ // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits
142+ // NOTE: These names assume `f{BITS}::NAN` is a quiet NAN and IEEE754-2008's NaN rules apply!
143+ const QUIET_NAN : u128 = f128:: NAN . to_bits ( ) | 0x0000_AAAA_AAAA_AAAA_AAAA_AAAA_AAAA_AAAA ;
144+ const SIGNALING_NAN : u128 = f128:: NAN . to_bits ( ) ^ 0x0000_5555_5555_5555_5555_5555_5555_5555 ;
145+
146+ const_assert ! ( f128:: from_bits( QUIET_NAN ) . is_nan( ) ) ;
147+ const_assert ! ( f128:: from_bits( SIGNALING_NAN ) . is_nan( ) ) ;
148+ const_assert ! ( f128:: from_bits( QUIET_NAN ) . to_bits( ) , QUIET_NAN ) ;
149+ if !has_broken_floats ( ) {
150+ const_assert ! ( f128:: from_bits( SIGNALING_NAN ) . to_bits( ) , SIGNALING_NAN ) ;
151+ }
152+ }
153+
91154fn main ( ) {
155+ #[ cfg( target_arch = "x86_64" ) ]
156+ {
157+ f16 ( ) ;
158+ f128 ( ) ;
159+ }
92160 f32 ( ) ;
93161 f64 ( ) ;
94162}
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