src/test/run-pass/issue-50811.rs

   1 // Copyright 2018 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.
   4 //
   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.
  10
  11 #![feature(test)]
  12
  13 extern crate test;
  14
  15 use std::f64::{NAN, NEG_INFINITY, INFINITY, MAX};
  16 use std::mem::size_of;
  17 use test::black_box;
  18
  19 // Ensure the const-eval result and runtime result of float comparison are equivalent.
  20
  21 macro_rules! compare {
  22     ($op:tt) => {
  23         compare!(
  24             [NEG_INFINITY, -MAX, -1.0, -0.0, 0.0, 1.0, MAX, INFINITY, NAN],
  25             $op
  26         );
  27     };
  28     ([$($lhs:expr),+], $op:tt) => {
  29         $(compare!(
  30             $lhs,
  31             $op,
  32             [NEG_INFINITY, -MAX, -1.0, -0.0, 0.0, 1.0, MAX, INFINITY, NAN]
  33         );)+
  34     };
  35     ($lhs:expr, $op:tt, [$($rhs:expr),+]) => {
  36         $({
  37             // Wrap the check in its own function to reduce time needed to borrowck.
  38             fn check() {
  39                 static CONST_EVAL: bool = $lhs $op $rhs;
  40                 let runtime_eval = black_box($lhs) $op black_box($rhs);
  41                 assert_eq!(CONST_EVAL, runtime_eval, stringify!($lhs $op $rhs));
  42                 assert_eq!(
  43                     size_of::<[u8; ($lhs $op $rhs) as usize]>(),
  44                     runtime_eval as usize,
  45                     stringify!($lhs $op $rhs (forced const eval))
  46                 );
  47             }
  48             check();
  49         })+
  50     };
  51 }
  52
  53 fn main() {
  54     assert_eq!(0.0/0.0 < 0.0/0.0, false);
  55     assert_eq!(0.0/0.0 > 0.0/0.0, false);
  56     assert_eq!(NAN < NAN, false);
  57     assert_eq!(NAN > NAN, false);
  58
  59     compare!(==);
  60     compare!(!=);
  61     compare!(<);
  62     compare!(<=);
  63     compare!(>);
  64     compare!(>=);
  65 }