vyre 0.4.0

GPU compute intermediate representation with a standard operation library
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

// Portable GPU kernel for string_matching.substring_find_first.
//
// Bindings:
// 0 params: len_a, len_b, param_c, param_d
// 1 haystack_words: little-endian packed bytes
// 2 needle_words: little-endian packed bytes
// 3 result: atomic u32 first offset, initialized to 0xffffffff

struct Params {
    haystack_len: u32,
    needle_len: u32,
    reserved0: u32,
    reserved1: u32,
}

const NOT_FOUND: u32 = 0xffffffffu;

@group(0) @binding(0) var<uniform> params: Params;
@group(0) @binding(1) var<storage, read> haystack_words: array<u32>;
@group(0) @binding(2) var<storage, read> needle_words: array<u32>;
@group(0) @binding(3) var<storage, read_write> result: atomic<u32>;

fn packed_byte(words: ptr<storage, array<u32>, read>, index: u32) -> u32 {
    let word = (*words)[index >> 2u];
    let shift = (index & 3u) << 3u;
    return (word >> shift) & 0xffu;
}

fn haystack_byte(index: u32) -> u32 {
    return packed_byte(&haystack_words, index);
}

fn needle_byte(index: u32) -> u32 {
    return packed_byte(&needle_words, index);
}

fn candidate_matches(start: u32) -> bool {
    var offset = 0u;
    loop {
        if (offset >= params.len_b) {
            break;
        }
        if (haystack_byte(start + offset) != needle_byte(offset)) {
            return false;
        }
        offset = offset + 1u;
    }
    return true;
}

@compute @workgroup_size(256, 1, 1)
fn string_matching_substring_find_first(@builtin(global_invocation_id) id: vec3<u32>) {
    if (params.len_b == 0u) {
        atomicMin(&result, 0u);
        return;
    }
    if (params.len_b > params.len_a) {
        return;
    }

    let start = id.x;
    if (start > params.len_a - params.len_b) {
        return;
    }
    if (start >= atomicLoad(&result)) {
        return;
    }
    if (candidate_matches(start)) {
        atomicMin(&result, start);
    }
}