rlx-flow 0.2.1

Block assembly-line API for RLX model builders — fusion-first, config-driven
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

// RLX — versatile ML compiler + runtime.
// Copyright (C) 2026 Eugene Hauptmann, Nataliya Kosmyna.

//! [`AttentionStage`] implementations for decode and prefill blocks.

use anyhow::Result;

use super::{BlockStage, LlamaDecodeLayerStage, Qwen3DecodeLayerStage, SelfAttnPrefillStage};
use crate::context::FlowCtx;
use crate::stage_contract::{LayerStage, StageArtifacts};
use crate::stage_interfaces::{AttentionStage, KvCacheContract};
use crate::value::FlowValue;

fn kv_from_decode(ctx: &FlowCtx<'_>, layer_idx: usize) -> Result<KvCacheContract> {
    let decode = ctx
        .state
        .decode
        .as_ref()
        .ok_or_else(|| anyhow::anyhow!("AttentionStage: BindDecodeInputs required"))?;
    let k = ctx.node_shape(decode.past_k[layer_idx])?;
    let v = ctx.node_shape(decode.past_v[layer_idx])?;
    Ok(KvCacheContract { k, v })
}

impl LayerStage for SelfAttnPrefillStage {
    fn name(&self) -> &str {
        "self_attn_prefill"
    }

    fn emit_layer(
        &self,
        ctx: &mut FlowCtx<'_>,
        input: FlowValue,
    ) -> Result<(FlowValue, StageArtifacts)> {
        let out = BlockStage::emit(self, ctx, input.clone())?;
        let value = out.unwrap_or(input);
        Ok((
            value.clone(),
            StageArtifacts::hidden_only(value.shape.clone()),
        ))
    }
}

impl AttentionStage for SelfAttnPrefillStage {
    fn cache_contract(&self, ctx: &FlowCtx<'_>, hidden: &rlx_ir::Shape) -> KvCacheContract {
        let _ = ctx;
        KvCacheContract {
            k: hidden.clone(),
            v: hidden.clone(),
        }
    }
}

impl LayerStage for LlamaDecodeLayerStage {
    fn name(&self) -> &str {
        "llama_decode_layer"
    }

    fn emit_layer(
        &self,
        ctx: &mut FlowCtx<'_>,
        input: FlowValue,
    ) -> Result<(FlowValue, StageArtifacts)> {
        let out = BlockStage::emit(self, ctx, input.clone())?;
        let value = out.unwrap_or(input);
        Ok((
            value.clone(),
            StageArtifacts::hidden_only(value.shape.clone()),
        ))
    }
}

impl AttentionStage for LlamaDecodeLayerStage {
    fn cache_contract(&self, ctx: &FlowCtx<'_>, hidden: &rlx_ir::Shape) -> KvCacheContract {
        let _ = hidden;
        kv_from_decode(ctx, self.layer_idx).unwrap_or_else(|_| KvCacheContract {
            k: self.spec.hidden_shape.clone(),
            v: self.spec.hidden_shape.clone(),
        })
    }
}

impl LayerStage for Qwen3DecodeLayerStage {
    fn name(&self) -> &str {
        "qwen3_decode_layer"
    }

    fn emit_layer(
        &self,
        ctx: &mut FlowCtx<'_>,
        input: FlowValue,
    ) -> Result<(FlowValue, StageArtifacts)> {
        let out = BlockStage::emit(self, ctx, input.clone())?;
        let value = out.unwrap_or(input);
        Ok((
            value.clone(),
            StageArtifacts::hidden_only(value.shape.clone()),
        ))
    }
}

impl AttentionStage for Qwen3DecodeLayerStage {
    fn cache_contract(&self, ctx: &FlowCtx<'_>, hidden: &rlx_ir::Shape) -> KvCacheContract {
        let _ = hidden;
        kv_from_decode(ctx, self.layer_idx).unwrap_or_else(|_| KvCacheContract {
            k: self.spec.hidden_shape.clone(),
            v: self.spec.hidden_shape.clone(),
        })
    }
}