1 // Copyright 2017 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // ignore-emscripten u128 not supported
13 #![feature(test, i128)]
14 #![deny(overflowing_literals)]
22 ($val:expr, $src_ty:ident -> $dest_ty:ident, $expected:expr) => ({
24 const X: $src_ty = $val;
25 const Y: $dest_ty = X as $dest_ty;
26 assert_eq!(Y, $expected,
27 "const eval {} -> {}", stringify!($src_ty), stringify!($dest_ty));
29 // black_box disables constant evaluation to test run-time conversions:
30 assert_eq!(black_box::<$src_ty>($val) as $dest_ty, $expected,
31 "run-time {} -> {}", stringify!($src_ty), stringify!($dest_ty));
36 // nextDown(f32::MAX) = 2^128 - 2 * 2^104
37 const SECOND_LARGEST_F32: f32 = 340282326356119256160033759537265639424.;
39 // f32::MAX - 0.5 ULP and smaller should be rounded down
40 test!(0xfffffe00000000000000000000000000, u128 -> f32, SECOND_LARGEST_F32);
41 test!(0xfffffe7fffffffffffffffffffffffff, u128 -> f32, SECOND_LARGEST_F32);
42 test!(0xfffffe80000000000000000000000000, u128 -> f32, SECOND_LARGEST_F32);
43 // numbers within < 0.5 ULP of f32::MAX it should be rounded to f32::MAX
44 test!(0xfffffe80000000000000000000000001, u128 -> f32, f32::MAX);
45 test!(0xfffffeffffffffffffffffffffffffff, u128 -> f32, f32::MAX);
46 test!(0xffffff00000000000000000000000000, u128 -> f32, f32::MAX);
47 test!(0xffffff00000000000000000000000001, u128 -> f32, f32::MAX);
48 test!(0xffffff7fffffffffffffffffffffffff, u128 -> f32, f32::MAX);
49 // f32::MAX + 0.5 ULP and greater should be rounded to infinity
50 test!(0xffffff80000000000000000000000000, u128 -> f32, f32::INFINITY);
51 test!(0xffffff80000000f00000000000000000, u128 -> f32, f32::INFINITY);
52 test!(0xffffff87ffffffffffffffff00000001, u128 -> f32, f32::INFINITY);
54 // u128->f64 should not be affected by the u128->f32 checks
55 test!(0xffffff80000000000000000000000000, u128 -> f64,
56 340282356779733661637539395458142568448.0);
57 test!(u128::MAX, u128 -> f64, 340282366920938463463374607431768211455.0);