vyre-conform 0.1.0

Conformance suite for vyre backends — proves byte-identical output to CPU reference
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

//! Checkers for one-sided identity and zero-absorbing laws.

use crate::proof::algebra::checker::support::{
    call_binary, engine_failure_violation, simple_rng, violation,
};
use crate::spec::law::LawViolation;

/// Side of the binary operation constrained by the law.
#[derive(Clone, Copy)]
pub(crate) enum Side {
    /// Fixed element is the left argument.
    Left,
    /// Fixed element is the right argument.
    Right,
}

/// Verify a one-sided identity over exhaustive u8 inputs.
#[inline]
pub(crate) fn check_identity_exhaustive_u8(
    op_id: &str,
    f: fn(&[u8]) -> Vec<u8>,
    side: Side,
    element: u32,
) -> Result<(u64, Option<LawViolation>), LawViolation> {
    let mut cases = 0;
    for a in 0u32..256 {
        cases += 1;
        if let Some(v) = identity_case(op_id, f, side, element, a)? {
            return Ok((cases, Some(v)));
        }
    }
    Ok((cases, None))
}

/// Verify a one-sided identity over deterministic u32 witnesses.
#[inline]
pub(crate) fn check_identity_witnessed_u32(
    op_id: &str,
    f: fn(&[u8]) -> Vec<u8>,
    side: Side,
    element: u32,
    count: u64,
) -> Result<(u64, Option<LawViolation>), LawViolation> {
    let mut rng = simple_rng(op_id, identity_law_name(side));
    for i in 0..count {
        if let Some(v) = identity_case(op_id, f, side, element, rng.next_u32())? {
            return Ok((i + 1, Some(v)));
        }
    }
    Ok((count, None))
}

/// Verify a one-sided absorbing law over exhaustive u8 inputs.
#[inline]
pub(crate) fn check_absorbing_exhaustive_u8(
    op_id: &str,
    f: fn(&[u8]) -> Vec<u8>,
    side: Side,
    element: u32,
) -> Result<(u64, Option<LawViolation>), LawViolation> {
    let mut cases = 0;
    for a in 0u32..256 {
        cases += 1;
        if let Some(v) = absorbing_case(op_id, f, side, element, a)? {
            return Ok((cases, Some(v)));
        }
    }
    Ok((cases, None))
}

/// Verify a one-sided absorbing law over deterministic u32 witnesses.
#[inline]
pub(crate) fn check_absorbing_witnessed_u32(
    op_id: &str,
    f: fn(&[u8]) -> Vec<u8>,
    side: Side,
    element: u32,
    count: u64,
) -> Result<(u64, Option<LawViolation>), LawViolation> {
    let mut rng = simple_rng(op_id, absorbing_law_name(side));
    for i in 0..count {
        if let Some(v) = absorbing_case(op_id, f, side, element, rng.next_u32())? {
            return Ok((i + 1, Some(v)));
        }
    }
    Ok((count, None))
}

fn identity_case(
    op_id: &str,
    f: fn(&[u8]) -> Vec<u8>,
    side: Side,
    element: u32,
    a: u32,
) -> Result<Option<LawViolation>, LawViolation> {
    let actual = match side {
        Side::Left => call_binary(f, element, a).map_err(|e| engine_failure_violation(op_id, e))?,
        Side::Right => {
            call_binary(f, a, element).map_err(|e| engine_failure_violation(op_id, e))?
        }
    };
    if actual == a {
        Ok(None)
    } else {
        let (left, right) = match side {
            Side::Left => (element, a),
            Side::Right => (a, element),
        };
        Ok(Some(violation(
            op_id,
            identity_law_name(side),
            left,
            right,
            0,
            actual,
            a,
        )))
    }
}

fn absorbing_case(
    op_id: &str,
    f: fn(&[u8]) -> Vec<u8>,
    side: Side,
    element: u32,
    a: u32,
) -> Result<Option<LawViolation>, LawViolation> {
    let actual = match side {
        Side::Left => call_binary(f, element, a).map_err(|e| engine_failure_violation(op_id, e))?,
        Side::Right => {
            call_binary(f, a, element).map_err(|e| engine_failure_violation(op_id, e))?
        }
    };
    if actual == element {
        Ok(None)
    } else {
        let (left, right) = match side {
            Side::Left => (element, a),
            Side::Right => (a, element),
        };
        Ok(Some(violation(
            op_id,
            absorbing_law_name(side),
            left,
            right,
            0,
            actual,
            element,
        )))
    }
}

fn identity_law_name(side: Side) -> &'static str {
    match side {
        Side::Left => "left-identity",
        Side::Right => "right-identity",
    }
}

fn absorbing_law_name(side: Side) -> &'static str {
    match side {
        Side::Left => "left-absorbing",
        Side::Right => "right-absorbing",
    }
}