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runtime/models_v2/
granite.rs

1//! Granite Model V2 - Clean implementation
2//!
3//! Granite (IBM's decoder model) features:
4//! - Standard transformer decoder architecture
5//! - RoPE embeddings
6//! - Grouped Query Attention (GQA)
7//! - SwiGLU activation
8
9use crate::model_config;
10use super::traits::*;
11use anyhow::Result;
12use serde::{Serialize, Deserialize};
13
14/// Granite model configuration
15model_config!(GraniteConfig {
16    vocab_size: usize = 32000,
17    hidden_size: usize = 4096,
18    intermediate_size: usize = 11008,
19    num_hidden_layers: usize = 32,
20    num_attention_heads: usize = 32,
21    num_key_value_heads: usize = 8,
22    hidden_act: String = "silu".to_string(),
23    max_position_embeddings: usize = 8192,
24    initializer_range: f32 = 0.02,
25    rms_norm_eps: f32 = 1e-5,
26    use_cache: bool = true,
27    pad_token_id: i64 = 0,
28    bos_token_id: i64 = 1,
29    eos_token_id: i64 = 2,
30    tie_word_embeddings: bool = false,
31    rope_theta: f32 = 10000.0,
32    attention_multiplier: f32 = 1.0,
33    residual_multiplier: f32 = 1.0,
34});
35
36impl GraniteConfig {
37    pub fn from_gguf_config(gguf: &crate::weight_loader_core::GGUFModelConfig) -> Self {
38        Self {
39            vocab_size: gguf.vocab_size,
40            hidden_size: gguf.hidden_size,
41            intermediate_size: gguf.intermediate_size,
42            num_hidden_layers: gguf.num_hidden_layers,
43            num_attention_heads: gguf.num_attention_heads,
44            num_key_value_heads: gguf.num_key_value_heads,
45            max_position_embeddings: gguf.max_position_embeddings,
46            rope_theta: gguf.rope_theta,
47            ..Default::default()
48        }
49    }
50}
51
52pub struct GraniteModelV2 {
53    config: GraniteConfig,
54    device: Device,
55    embed_tokens: Tensor,
56    layers: Vec<GraniteLayer>,
57    norm: Tensor,
58    lm_head: Tensor,
59}
60
61pub struct GraniteLayer {
62    self_attn: GraniteAttention,
63    mlp: GraniteMLP,
64    input_layernorm: Tensor,
65    post_attention_layernorm: Tensor,
66}
67
68pub struct GraniteAttention {
69    q_proj: Tensor,
70    k_proj: Tensor,
71    v_proj: Tensor,
72    o_proj: Tensor,
73    num_heads: usize,
74    num_kv_heads: usize,
75    head_dim: usize,
76    scale: f32,
77}
78
79pub struct GraniteMLP {
80    gate_proj: Tensor,
81    up_proj: Tensor,
82    down_proj: Tensor,
83}
84
85fn apply_rope_granite(
86    q: &candle_core::Tensor,
87    k: &candle_core::Tensor,
88    seq_len: usize,
89    head_dim: usize,
90    rope_theta: f32,
91) -> Result<(candle_core::Tensor, candle_core::Tensor)> {
92    let device = q.device();
93    let half_dim = head_dim / 2;
94    let inv_freq: Vec<f32> = (0..half_dim)
95        .map(|i| 1.0 / rope_theta.powf((2 * i) as f32 / head_dim as f32))
96        .collect();
97
98    let positions: Vec<f32> = (0..seq_len).map(|p| p as f32).collect();
99    let mut angles = Vec::with_capacity(seq_len * half_dim);
100    for pos in &positions {
101        for freq in &inv_freq {
102            angles.push(pos * freq);
103        }
104    }
105
106    let angles_tensor = candle_core::Tensor::from_vec(angles, &[seq_len, half_dim], device)?;
107    let cos = angles_tensor.cos()?.unsqueeze(0)?.unsqueeze(0)?;
108    let sin = angles_tensor.sin()?.unsqueeze(0)?.unsqueeze(0)?;
109
110    let q_half1 = q.narrow(3, 0, half_dim)?;
111    let q_half2 = q.narrow(3, half_dim, half_dim)?;
112    let k_half1 = k.narrow(3, 0, half_dim)?;
113    let k_half2 = k.narrow(3, half_dim, half_dim)?;
114
115    let q_rot1 = (q_half1.broadcast_mul(&cos)? - q_half2.broadcast_mul(&sin)?)?;
116    let q_rot2 = (q_half1.broadcast_mul(&sin)? + q_half2.broadcast_mul(&cos)?)?;
117    let k_rot1 = (k_half1.broadcast_mul(&cos)? - k_half2.broadcast_mul(&sin)?)?;
118    let k_rot2 = (k_half1.broadcast_mul(&sin)? + k_half2.broadcast_mul(&cos)?)?;
119
120    Ok((
121        candle_core::Tensor::cat(&[&q_rot1, &q_rot2], 3)?,
122        candle_core::Tensor::cat(&[&k_rot1, &k_rot2], 3)?
123    ))
124}
125
126impl Model for GraniteModelV2 {
127    type Config = GraniteConfig;
128
129    fn new(config: GraniteConfig) -> Result<Self> {
130        let device = Device::CPU;
131        let embed_tokens = ops_fn::zeros(&[config.vocab_size, config.hidden_size], DataType::Float32, &device)?;
132        let norm = ops_fn::zeros(&[config.hidden_size], DataType::Float32, &device)?;
133        let lm_head = ops_fn::zeros(&[config.vocab_size, config.hidden_size], DataType::Float32, &device)?;
134
135        let mut layers = Vec::with_capacity(config.num_hidden_layers);
136        for _ in 0..config.num_hidden_layers {
137            layers.push(GraniteLayer::new(&config, &device)?);
138        }
139
140        Ok(Self { config, device, embed_tokens, layers, norm, lm_head })
141    }
142
143    fn from_weights(config: GraniteConfig, weights: ModelWeights) -> Result<Self> {
144        let mut model = Self::new(config)?;
145        if let Some(w) = weights.get("model.embed_tokens.weight") { model.embed_tokens = w.clone(); }
146        if let Some(w) = weights.get("model.norm.weight") { model.norm = w.clone(); }
147        if model.config.tie_word_embeddings {
148            model.lm_head = model.embed_tokens.clone();
149        } else if let Some(w) = weights.get("lm_head.weight") {
150            model.lm_head = w.clone();
151        }
152        for (i, layer) in model.layers.iter_mut().enumerate() { layer.load_weights(&weights, i)?; }
153        Ok(model)
154    }
155
156    fn forward(&self, inputs: &ModelInputs) -> Result<ModelOutputs> {
157        match inputs {
158            ModelInputs::Text { input_ids, .. } => {
159                let seq_len = input_ids.shape()[1];
160                let mut hidden = ops_fn::embedding(input_ids, &self.embed_tokens)?;
161
162                for layer in &self.layers {
163                    hidden = layer.forward(&hidden, seq_len, self.config.rope_theta, self.config.residual_multiplier)?;
164                }
165
166                hidden = ops_fn::rms_norm(&hidden, &self.norm, self.config.rms_norm_eps)?;
167                let logits = ops_fn::matmul(&hidden, &ops_fn::transpose(&self.lm_head)?)?;
168
169                Ok(ModelOutputs::Logits { logits, hidden_states: None })
170            }
171            _ => Err(anyhow::anyhow!("Granite only supports text inputs")),
172        }
173    }
174
175    fn generate(&self, prompt: &str, config: &GenerationConfig) -> Result<String> {
176        use crate::tokenizer::Tokenizer;
177        use rand::Rng;
178        let tokenizer = Tokenizer::new();
179        let mut tokens: Vec<u32> = tokenizer.encode(prompt);
180        for _ in 0..config.max_new_tokens {
181            let tokens_i64: Vec<i64> = tokens.iter().map(|&t| t as i64).collect();
182            let input = Tensor::from_i64_slice(&tokens_i64, &[1, tokens.len()], &self.device)?;
183            let outputs = self.forward(&ModelInputs::text(input))?;
184            let logits = match outputs { ModelOutputs::Logits { logits, .. } => logits, _ => return Err(anyhow::anyhow!("Expected logits")) };
185            let logits_candle = logits.to_candle()?;
186            let last = logits_candle.narrow(1, logits_candle.dims()[1] - 1, 1)?.squeeze(1)?.squeeze(0)?;
187            let logits_vec: Vec<f32> = last.to_vec1()?;
188            let next = if config.do_sample && config.temperature > 0.0 {
189                let scaled: Vec<f32> = logits_vec.iter().map(|&x| x / config.temperature).collect();
190                let max_v = scaled.iter().cloned().fold(f32::NEG_INFINITY, f32::max);
191                let exp_sum: f32 = scaled.iter().map(|&x| (x - max_v).exp()).sum();
192                let probs: Vec<f32> = scaled.iter().map(|&x| (x - max_v).exp() / exp_sum).collect();
193                let mut rng = rand::thread_rng();
194                let r: f32 = rng.gen();
195                let mut cum = 0.0;
196                let mut s = 0u32;
197                for (i, &p) in probs.iter().enumerate() { cum += p; if r <= cum { s = i as u32; break; } }
198                s
199            } else {
200                logits_vec.iter().enumerate().max_by(|a, b| a.1.partial_cmp(b.1).unwrap()).map(|(i, _)| i as u32).unwrap_or(0)
201            };
202            if next == config.eos_token_id { break; }
203            tokens.push(next);
204        }
205        Ok(tokenizer.decode(&tokens))
206    }
207
208    fn config(&self) -> &Self::Config { &self.config }
209    fn memory_requirements(&self) -> MemoryRequirements {
210        let p = self.config.vocab_size * self.config.hidden_size + self.config.num_hidden_layers * 8 * self.config.hidden_size.pow(2);
211        MemoryRequirements { gpu_memory: p * 4, cpu_memory: p, kv_cache_memory: 2 * self.config.num_hidden_layers * self.config.max_position_embeddings * self.config.hidden_size * 4, peak_memory: p * 5 }
212    }
213    fn to_device(&mut self, device: &Device) -> Result<()> {
214        self.embed_tokens = self.embed_tokens.to_device(device)?;
215        self.norm = self.norm.to_device(device)?;
216        self.lm_head = self.lm_head.to_device(device)?;
217        for layer in &mut self.layers { layer.to_device(device)?; }
218        self.device = device.clone();
219        Ok(())
220    }
221}
222
223impl GraniteLayer {
224    fn new(config: &GraniteConfig, device: &Device) -> Result<Self> {
225        Ok(Self {
226            self_attn: GraniteAttention::new(config, device)?,
227            mlp: GraniteMLP::new(config, device)?,
228            input_layernorm: ops_fn::zeros(&[config.hidden_size], DataType::Float32, device)?,
229            post_attention_layernorm: ops_fn::zeros(&[config.hidden_size], DataType::Float32, device)?,
230        })
231    }
232
233    fn forward(&self, hidden_states: &Tensor, seq_len: usize, rope_theta: f32, residual_multiplier: f32) -> Result<Tensor> {
234        let residual = hidden_states.clone();
235        let h = ops_fn::rms_norm(hidden_states, &self.input_layernorm, 1e-5)?;
236        let attn_out = self.self_attn.forward(&h, seq_len, rope_theta)?;
237        let attn_scaled = if residual_multiplier != 1.0 {
238            ops_fn::scale(&attn_out, residual_multiplier)?
239        } else {
240            attn_out
241        };
242        let h = ops_fn::add(&residual, &attn_scaled)?;
243
244        let residual = h.clone();
245        let h = ops_fn::rms_norm(&h, &self.post_attention_layernorm, 1e-5)?;
246        let mlp_out = self.mlp.forward(&h)?;
247        let mlp_scaled = if residual_multiplier != 1.0 {
248            ops_fn::scale(&mlp_out, residual_multiplier)?
249        } else {
250            mlp_out
251        };
252        ops_fn::add(&residual, &mlp_scaled)
253    }
254
255    fn load_weights(&mut self, weights: &ModelWeights, idx: usize) -> Result<()> {
256        let p = format!("model.layers.{}", idx);
257        if let Some(w) = weights.get(&format!("{}.self_attn.q_proj.weight", p)) { self.self_attn.q_proj = ops_fn::transpose(w)?; }
258        if let Some(w) = weights.get(&format!("{}.self_attn.k_proj.weight", p)) { self.self_attn.k_proj = ops_fn::transpose(w)?; }
259        if let Some(w) = weights.get(&format!("{}.self_attn.v_proj.weight", p)) { self.self_attn.v_proj = ops_fn::transpose(w)?; }
260        if let Some(w) = weights.get(&format!("{}.self_attn.o_proj.weight", p)) { self.self_attn.o_proj = ops_fn::transpose(w)?; }
261        if let Some(w) = weights.get(&format!("{}.mlp.gate_proj.weight", p)) { self.mlp.gate_proj = ops_fn::transpose(w)?; }
262        if let Some(w) = weights.get(&format!("{}.mlp.up_proj.weight", p)) { self.mlp.up_proj = ops_fn::transpose(w)?; }
263        if let Some(w) = weights.get(&format!("{}.mlp.down_proj.weight", p)) { self.mlp.down_proj = ops_fn::transpose(w)?; }
264        if let Some(w) = weights.get(&format!("{}.input_layernorm.weight", p)) { self.input_layernorm = w.clone(); }
265        if let Some(w) = weights.get(&format!("{}.post_attention_layernorm.weight", p)) { self.post_attention_layernorm = w.clone(); }
266        Ok(())
267    }
268
269    fn to_device(&mut self, device: &Device) -> Result<()> {
270        self.self_attn.to_device(device)?;
271        self.mlp.to_device(device)?;
272        self.input_layernorm = self.input_layernorm.to_device(device)?;
273        self.post_attention_layernorm = self.post_attention_layernorm.to_device(device)?;
274        Ok(())
275    }
276}
277
278impl GraniteAttention {
279    fn new(config: &GraniteConfig, device: &Device) -> Result<Self> {
280        let head_dim = config.hidden_size / config.num_attention_heads;
281        Ok(Self {
282            q_proj: ops_fn::zeros(&[config.hidden_size, config.num_attention_heads * head_dim], DataType::Float32, device)?,
283            k_proj: ops_fn::zeros(&[config.hidden_size, config.num_key_value_heads * head_dim], DataType::Float32, device)?,
284            v_proj: ops_fn::zeros(&[config.hidden_size, config.num_key_value_heads * head_dim], DataType::Float32, device)?,
285            o_proj: ops_fn::zeros(&[config.num_attention_heads * head_dim, config.hidden_size], DataType::Float32, device)?,
286            num_heads: config.num_attention_heads,
287            num_kv_heads: config.num_key_value_heads,
288            head_dim,
289            scale: 1.0 / (head_dim as f32).sqrt(),
290        })
291    }
292
293    fn forward(&self, hidden_states: &Tensor, seq_len: usize, rope_theta: f32) -> Result<Tensor> {
294        let shape = hidden_states.shape();
295        let batch = shape[0];
296
297        let q = ops_fn::matmul(hidden_states, &self.q_proj)?.to_candle()?;
298        let k = ops_fn::matmul(hidden_states, &self.k_proj)?.to_candle()?;
299        let v = ops_fn::matmul(hidden_states, &self.v_proj)?.to_candle()?;
300
301        let q = q.reshape(&[batch, seq_len, self.num_heads, self.head_dim])?.transpose(1, 2)?;
302        let k = k.reshape(&[batch, seq_len, self.num_kv_heads, self.head_dim])?.transpose(1, 2)?;
303        let v = v.reshape(&[batch, seq_len, self.num_kv_heads, self.head_dim])?.transpose(1, 2)?;
304
305        let (q, k) = apply_rope_granite(&q, &k, seq_len, self.head_dim, rope_theta)?;
306
307        // GQA expansion
308        let num_groups = self.num_heads / self.num_kv_heads;
309        let (k, v) = if num_groups > 1 {
310            let k_exp = k.unsqueeze(2)?.broadcast_as(&[batch, self.num_kv_heads, num_groups, seq_len, self.head_dim])?.reshape(&[batch, self.num_heads, seq_len, self.head_dim])?;
311            let v_exp = v.unsqueeze(2)?.broadcast_as(&[batch, self.num_kv_heads, num_groups, seq_len, self.head_dim])?.reshape(&[batch, self.num_heads, seq_len, self.head_dim])?;
312            (k_exp, v_exp)
313        } else {
314            (k, v)
315        };
316
317        let q = q.contiguous()?;
318        let k_t = k.transpose(2, 3)?.contiguous()?;
319        let scores = (q.matmul(&k_t)? * (self.scale as f64))?;
320
321        let device = scores.device();
322        let mask = {
323            let mut m = vec![0.0f32; seq_len * seq_len];
324            for i in 0..seq_len { for j in (i+1)..seq_len { m[i*seq_len+j] = f32::NEG_INFINITY; } }
325            candle_core::Tensor::from_vec(m, &[1, 1, seq_len, seq_len], device)?
326        };
327        let scores = scores.broadcast_add(&mask)?;
328
329        let v = v.contiguous()?;
330        let attn = candle_nn::ops::softmax_last_dim(&scores)?.matmul(&v)?;
331        let out = attn.transpose(1, 2)?.reshape(&[batch, seq_len, self.num_heads * self.head_dim])?;
332        ops_fn::matmul(&Tensor::from_candle(out), &self.o_proj)
333    }
334
335    fn to_device(&mut self, device: &Device) -> Result<()> {
336        self.q_proj = self.q_proj.to_device(device)?;
337        self.k_proj = self.k_proj.to_device(device)?;
338        self.v_proj = self.v_proj.to_device(device)?;
339        self.o_proj = self.o_proj.to_device(device)?;
340        Ok(())
341    }
342}
343
344impl GraniteMLP {
345    fn new(config: &GraniteConfig, device: &Device) -> Result<Self> {
346        Ok(Self {
347            gate_proj: ops_fn::zeros(&[config.hidden_size, config.intermediate_size], DataType::Float32, device)?,
348            up_proj: ops_fn::zeros(&[config.hidden_size, config.intermediate_size], DataType::Float32, device)?,
349            down_proj: ops_fn::zeros(&[config.intermediate_size, config.hidden_size], DataType::Float32, device)?,
350        })
351    }
352    fn forward(&self, x: &Tensor) -> Result<Tensor> {
353        let gate = ops_fn::matmul(x, &self.gate_proj)?;
354        let up = ops_fn::matmul(x, &self.up_proj)?;
355        let h = ops_fn::mul(&ops_fn::silu(&gate)?, &up)?;
356        ops_fn::matmul(&h, &self.down_proj)
357    }
358    fn to_device(&mut self, device: &Device) -> Result<()> {
359        self.gate_proj = self.gate_proj.to_device(device)?;
360        self.up_proj = self.up_proj.to_device(device)?;
361        self.down_proj = self.down_proj.to_device(device)?;
362        Ok(())
363    }
364}
365
366#[cfg(test)]
367mod tests {
368    use super::*;
369    #[test]
370    fn test_granite_creation() {
371        let config = GraniteConfig { vocab_size: 1000, hidden_size: 128, intermediate_size: 512, num_hidden_layers: 2, num_attention_heads: 4, num_key_value_heads: 4, ..Default::default() };
372        let model = GraniteModelV2::new(config).unwrap();
373        assert_eq!(model.config().vocab_size(), 1000);
374    }
375    #[test]
376    fn test_granite_forward() {
377        let config = GraniteConfig { vocab_size: 100, hidden_size: 64, intermediate_size: 256, num_hidden_layers: 1, num_attention_heads: 4, num_key_value_heads: 4, ..Default::default() };
378        let model = GraniteModelV2::new(config).unwrap();
379        let inputs = ModelInputs::text(ops_fn::zeros(&[2, 8], DataType::Int64, &Device::CPU).unwrap());
380        match model.forward(&inputs).unwrap() { ModelOutputs::Logits { logits, .. } => assert_eq!(logits.shape(), &[2, 8, 100]), _ => panic!() }
381    }
382}