libhermit-rs 0.6.3

A Rust-based library operating system
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167

#![feature(test)]
#![feature(bench_black_box)]
#![no_std]
#![no_main]
#![test_runner(common::test_case_runner)]
#![feature(custom_test_frameworks)]
#![reexport_test_harness_main = "test_main"]

/// Regarding `#[test]` and `#[test_case]` this comment explains the current implementation
/// https://github.com/rust-lang/rust/issues/50297#issuecomment-524180479
/// This is of course subject to change, since the whole feature is not stable
///
//extern crate hermit;
//extern crate x86_64;
#[macro_use]
extern crate float_cmp;

//use common::*;
use core::hint::black_box;

use common::exit;

// Either use black_box from core::hint or the value_fence definition
// core hint is a nop, but possibly only prevents dead code elimination
// value_fence has higher overhead but should be a bit safer regarding preventing optimizations
// pub fn black_box<T>(x: T) -> T {
// 	common::value_fence::<T>(x)
// }
mod common;

#[test_case]
fn add1() {
	let x = black_box(1) + black_box(2);
	assert_eq!(x, 3);
}

#[test_case]
fn subtest() {
	int_test::<u8>();
	int_test::<u16>();
	int_test::<u32>();
	int_test::<u64>();
	int_test::<u128>();
	int_test::<i8>();
	int_test::<i16>();
	int_test::<i32>();
	int_test::<i64>();
	int_test::<i128>();

	sint_test::<i8>();
	sint_test::<i16>();
	sint_test::<i32>();
	sint_test::<i64>();
	sint_test::<i128>();
}

fn int_test<T>()
where
	T: core::fmt::Debug,
	T: num_traits::int::PrimInt,
{
	let fifteen = T::from(15).unwrap();
	let ten = T::from(10).unwrap();
	let r_five: T = black_box(fifteen) - black_box(ten);
	let r_zero: T = black_box(fifteen) - black_box(fifteen);
	assert_eq!(r_five, T::from(5).unwrap());
	assert_eq!(r_zero, T::from(0).unwrap());

	let r_twentyfive: T = black_box(fifteen) + black_box(ten);
	let r_twentyfive2: T = black_box(r_zero) + black_box(r_twentyfive);
	assert_eq!(r_twentyfive, T::from(25).unwrap());
	assert_eq!(r_twentyfive2, r_twentyfive);

	let r_hundred: T = black_box(ten) * black_box(ten);
	let r_hundred2: T = black_box(ten).pow(2);
	let r_zero: T = black_box(r_hundred) * black_box(r_zero);
	assert_eq!(r_hundred, T::from(100).unwrap());
	assert_eq!(r_hundred, r_hundred2);
	assert_eq!(r_zero, T::from(0).unwrap());

	let r_ten: T = black_box(r_hundred) / black_box(ten);
	let r_one: T = black_box(r_ten) / black_box(ten);
	let r_zero: T = black_box(r_one) / black_box(ten);
	assert_eq!(r_ten, ten);
	assert_eq!(r_one, T::from(1).unwrap());
	assert_eq!(r_zero, T::from(0).unwrap());
}

fn sint_test<T>()
where
	T: core::fmt::Debug,
	T: num_traits::sign::Signed,
	T: num_traits::int::PrimInt,
{
	let fifteen = T::from(15).unwrap();
	let ten = T::from(10).unwrap();
	let r_minusfive: T = black_box(ten) - black_box(fifteen);
	assert_eq!(r_minusfive, T::from(-5).unwrap());
	let r_minusfifteen: T = black_box(r_minusfive) - black_box(ten);
	assert_eq!(r_minusfifteen, T::from(-15).unwrap());
	let r_fifteen: T = black_box(r_minusfifteen) + black_box(fifteen) + black_box(fifteen);
	assert_eq!(r_fifteen, fifteen);

	let r_minusseventyfive: T = black_box(r_minusfive) * black_box(fifteen);
	let r_zero: T = black_box(r_minusseventyfive) * black_box(T::from(0).unwrap());
	assert_eq!(r_minusseventyfive, T::from(-75).unwrap());
	assert_eq!(r_zero, T::from(0).unwrap());
	assert_eq!(r_zero, T::from(-0).unwrap());

	let r_minusseven: T = black_box(r_minusseventyfive) / black_box(ten);
	assert_eq!(r_minusseven, T::from(-7).unwrap());

	let r_fortynine: T = black_box(r_minusseven).pow(2);
	let r_fortynine2: T = black_box(r_minusseven) * black_box(r_minusseven);
	assert_eq!(r_fortynine, T::from(49).unwrap());
	assert_eq!(r_fortynine, r_fortynine2);
}

#[test_case]
fn test_f64_arithmetic() {
	let x = black_box::<f64>(65.2);
	let y = black_box::<f64>(89.123);
	let z = x * y;
	assert!(approx_eq!(f64, z, 5810.8196f64, ulps = 1));
	let z = z * y;
	assert!(approx_eq!(f64, z, 517877.6752108f64, ulps = 1));
	let z = z * y;
	assert!(approx_eq!(f64, z, 46_154_812.047_812_13_f64, ulps = 2));
	let z = z * y;
	assert!(approx_eq!(f64, z, 4_113_455_314.137_160_3_f64, ulps = 3));

	let z = black_box(z) / y;
	assert!(approx_eq!(f64, z, 46_154_812.047_812_13_f64, ulps = 2));
	assert!(!approx_eq!(f64, z, 46_154_812.047_812_13_f64, ulps = 1)); // If we haven't lost any precision, the something is fishy

	let z = black_box(z) / y;
	assert!(approx_eq!(f64, z, 517877.6752108f64, ulps = 2));
	assert!(!approx_eq!(f64, z, 517877.6752108f64, ulps = 1));

	// Division
	let x = black_box::<f64>(4.0);
	let y = black_box::<f64>(5.0);
	let z = x / y;
	assert!(approx_eq!(f64, z, 0.8f64, ulps = 0));
	let z = black_box(z) / y;
	assert!(approx_eq!(f64, z, 0.16f64, ulps = 0));
	// 0100011110101110000101000111101011100001010001111011 exp 01111111100
	let z = black_box(z) / y;
	assert!(approx_eq!(f64, z, 0.032f64, ulps = 0));
	let z = black_box(z) / y;
	assert!(approx_eq!(f64, z, 0.0064f64, ulps = 0));
	//1010001101101110001011101011000111000100001100101101 exp 01111110111
	let z = black_box(z) / y;
	assert!(approx_eq!(f64, z, 0.00128f64, ulps = 0));
	//0b0011111101010100111110001011010110001000111000110110100011110001

	let z = black_box(z) * black_box(y) * black_box(y) * black_box(y);
	assert!(approx_eq!(f64, z, 0.16f64, ulps = 0));
	let z = black_box(z * y);
	assert!(approx_eq!(f64, z, 0.8f64, ulps = 0));
}

#[no_mangle]
extern "C" fn runtime_entry(_argc: i32, _argv: *const *const u8, _env: *const *const u8) -> ! {
	test_main();
	exit(false);
}