Skip to main content

tract_transformers/
lib.rs

1pub mod ops;
2mod rewriter;
3use std::collections::HashSet;
4
5use rewriter::*;
6use tract_nnef::internal::*;
7
8register_simple_model_transform!("detect_apply_rope", ApplyRopeTransform);
9register_simple_model_transform!("detect_diag_gather", DetectDiagGatherTransform);
10register_simple_model_transform!("detect_scaled_masked_softmax", ScaledMaskedSoftmaxTransform);
11register_simple_model_transform!("detect_kv_cache", KeyValueCacheTransform);
12register_simple_model_transform!(
13    "detect_sdpa_kv_cache_broadcast",
14    SdpaFuseKvCacheBroadcastTransform
15);
16register_simple_model_transform!("unfold_kv_cache", UnfoldKeyValueCacheTransform);
17register_simple_model_transform!("transformers_detect_all", TransformersTransform);
18
19pub fn register(registry: &mut Registry) {
20    ops::apply_rope::register(registry);
21    ops::scaled_masked_softmax::register(registry);
22    ops::sdpa::register(registry);
23    ops::dyn_kv_cache::register(registry);
24    ops::window_kv_cache::register(registry);
25}
26
27pub trait WithTractTransformers {
28    fn enable_tract_transformers(&mut self);
29    fn with_tract_transformers(self) -> Self;
30}
31
32impl WithTractTransformers for tract_nnef::framework::Nnef {
33    fn enable_tract_transformers(&mut self) {
34        self.registries.push(tract_transformers_registry());
35    }
36
37    fn with_tract_transformers(mut self) -> Self {
38        self.enable_tract_transformers();
39        self
40    }
41}
42
43pub fn tract_transformers_registry() -> Registry {
44    let mut reg = Registry::new("tract_transformers")
45        .with_doc("Extension `tract_transformers` extends NNEF with operators")
46        .with_doc("for transformer networks.")
47        .with_doc("")
48        .with_doc("Add `extension tract_transformers` to `graph.nnef`");
49
50    register(&mut reg);
51    reg
52}
53
54pub fn figure_out_causal_llm_b_s_p(
55    model: &TypedModel,
56) -> TractResult<(Option<Symbol>, Option<Symbol>, Option<Symbol>)> {
57    // expectations:
58    // - one input is for tokens, so integer dt (i64 ?) and typically of shape S or 1,S, or B,S
59    // - other inputs are kv cache, some kind of float. shape features both S and P, and B if B is present in tokens
60    let token_input = model
61        .inputs
62        .iter()
63        .position(|i| model.outlet_fact(*i).unwrap().datum_type.is_integer())
64        .context("No token input found")?;
65    let tokens_symbols = model.input_fact(token_input)?.shape.volume().symbols();
66    let kv_symbols = if let Some(kv_input) =
67        model.inputs.iter().position(|i| model.outlet_fact(*i).unwrap().datum_type.is_float())
68    {
69        model.input_fact(kv_input)?.shape.volume().symbols()
70    } else {
71        // Look for KVCache Op
72        let dummy_session_state = TurnState::default();
73        let mut symbols = HashSet::new();
74        for node in &model.nodes {
75            if let Some((_, fact)) =
76                node.op.state(&dummy_session_state, 0)?.and_then(|state| state.init_tensor_fact())
77            {
78                symbols = fact.shape.volume().symbols();
79                break;
80            }
81        }
82        symbols
83    };
84
85    let b = tokens_symbols.intersection(&kv_symbols).cloned().collect::<HashSet<_>>();
86    let s = tokens_symbols.difference(&b).cloned().collect::<HashSet<_>>();
87    let p = kv_symbols.difference(&b).cloned().collect::<HashSet<_>>();
88    Ok((b.into_iter().next(), s.into_iter().next(), p.into_iter().next()))
89}
90
91pub fn memory_arena_hints_for_causal_llm(model: &TypedModel) -> TractResult<SymbolValues> {
92    let (b, s, p) = figure_out_causal_llm_b_s_p(model)?;
93    let mut values = SymbolValues::default()
94        .with(&s.context("Could not determine sequence_len (S)")?, 1024)
95        .with(&p.context("Could not determine past_sequence_len (P)")?, 0);
96    if let Some(b) = b {
97        values = values.with(&b, 1);
98    }
99    Ok(values)
100}