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weir/
scc_query.rs

1//! `scc_query`  -  strongly-connected-component membership query.
2//!
3//! Given the SCC label of every node (host-supplied via Tarjan or
4//! the GPU SCC primitive), return the set of nodes belonging to the
5//! same component as a query target. Used for cycle-detection rules
6//! and recursion-aware static analysis.
7
8use vyre::ir::Program;
9use vyre_primitives::bitset::and::bitset_and;
10use vyre_primitives::graph::csr_forward_traverse::bitset_words;
11
12pub(crate) const OP_ID: &str = "weir::scc_query";
13
14/// Build an SCC-membership Program.
15///
16/// Inputs:
17/// - `same_scc_buf`: per-node bitset where bit `m` is set iff `m`
18///   belongs to the SAME SCC as the query target
19///   (host-built from the SCC label vector).
20/// - `query_set`:    per-node bitset of nodes being queried.
21/// - `out`:          per-node bitset; bit `n` set iff `n` is in
22///   `query_set` AND in the same SCC as the target.
23#[must_use]
24pub fn scc_query(node_count: u32, same_scc_buf: &str, query_set: &str, out: &str) -> Program {
25    let words = bitset_words(node_count);
26    vyre_harness::region::tag_program(OP_ID, bitset_and(same_scc_buf, query_set, out, words))
27}
28
29/// reference oracle.
30#[must_use]
31#[cfg(any(test, feature = "cpu-parity"))]
32#[deprecated(
33    note = "reference oracle only; production code must dispatch the Weir Program on a concrete GPU backend or use weir::oracle for parity evidence"
34)]
35pub(crate) fn cpu_ref(same_scc: &[u32], query_set: &[u32]) -> Vec<u32> {
36    vyre_primitives::bitset::and::cpu_ref(same_scc, query_set)
37}
38
39/// Soundness marker for [`scc_query`].
40#[derive(Clone, Copy, Debug, PartialEq, Eq)]
41pub struct SccQuery;
42impl super::soundness::SoundnessTagged for SccQuery {
43    fn soundness(&self) -> super::soundness::Soundness {
44        super::soundness::Soundness::Exact
45    }
46}
47
48inventory::submit! {
49    vyre_harness::OpEntry::new(
50        OP_ID,
51        || scc_query(4, "same", "query", "out"),
52        Some(|| {
53            let u32s = crate::dispatch_decode::pack_u32;
54            vec![vec![u32s(&[0b1100]), u32s(&[0b1010]), u32s(&[0])]]
55        }),
56        Some(|| {
57            let u32s = crate::dispatch_decode::pack_u32;
58            vec![vec![u32s(&[0b1000])]]
59        }),
60    )
61}
62
63#[cfg(test)]
64#[allow(deprecated)]
65mod tests {
66    use super::*;
67
68    #[test]
69    fn same_scc_query_intersects() {
70        assert_eq!(cpu_ref(&[0b1100], &[0b1010]), vec![0b1000]);
71    }
72
73    #[test]
74    fn no_match_yields_empty() {
75        assert_eq!(cpu_ref(&[0b0011], &[0b1100]), vec![0]);
76    }
77
78    #[test]
79    fn singleton_scc_self_match() {
80        assert_eq!(cpu_ref(&[0b0001], &[0b0001]), vec![0b0001]);
81    }
82
83    #[test]
84    fn distributes_per_word() {
85        assert_eq!(
86            cpu_ref(&[0xFF00, 0xF00F], &[0x0FF0, 0x0F0F]),
87            vec![0x0F00, 0x000F]
88        );
89    }
90}