Move llama in a cargo-examples directory.

1 files changed, 572 insertions, 0 deletions

diff --git a/candle-examples/examples/llama/main.rs b/candle-examples/examples/llama/main.rs
new file mode 100644
index 00000000..73db15e0
--- /dev/null
+++ b/candle-examples/examples/llama/main.rs
@@ -0,0 +1,572 @@
+// An implementation of LLaMA https://github.com/facebookresearch/llama
+//
+// This is based on nanoGPT in a similar way to:
+// https://github.com/Lightning-AI/lit-llama/blob/main/lit_llama/model.py
+//
+// The tokenizer config can be retrieved from:
+// https://huggingface.co/hf-internal-testing/llama-tokenizer/raw/main/tokenizer.json
+//
+// In order to convert the llama weights to a .npz file, run:
+// python examples/llama/convert_checkpoint.py ..../LLaMA/7B/consolidated.00.pth
+
+// TODO: This does not use a batch dimension. If adding it back, be cautious about the
+// transposition operations.
+use anyhow::{Error as E, Result};
+use clap::Parser;
+use rand::{distributions::Distribution, SeedableRng};
+
+use candle::{DType, Device, Tensor};
+use candle_hub::{api::Api, Repo, RepoType};
+use std::collections::HashMap;
+use std::sync::{Arc, Mutex};
+
+mod var_store;
+mod weights;
+
+const MAX_SEQ_LEN: usize = 4096;
+const DTYPE: DType = DType::F16;
+const DEFAULT_PROMPT: &str = r"
+EDWARD:
+I wonder how our princely father 'scaped,
+Or whether he be 'scaped away or no
+From Clifford's and Northumberland's pursuit:
+Had he been ta'en, we should have heard the news;
+Had he been slain, we should have heard the news;
+Or had he 'scaped, methinks we should have heard
+The happy tidings of his good escape.
+How fares my brother? why is he so sad?
+
+RICHARD:
+I cannot joy, until I be resolved
+Where our right valiant father is become.
+I saw him in the battle range about;
+And watch'd him how he singled Clifford forth.
+Methought he bore him in the thickest troop
+As doth a lion in a herd of neat;
+Or as a bear, encompass'd round with dogs,
+Who having pinch'd a few and made them cry,
+The rest stand all aloof, and bark at him.
+So fared our father with his enemies;
+So fled his enemies my warlike father:
+Methinks, 'tis prize enough to be his son.
+See how the morning opes her golden gates,
+And takes her farewell of the glorious sun!
+How well resembles it the prime of youth,
+Trimm'd like a younker prancing to his love!
+
+EDWARD:
+Dazzle mine eyes, or do I see three suns?
+
+RICHARD:
+Three glorious suns, each one a perfect sun;
+Not separated with the racking clouds,
+But sever'd in a pale clear-shining sky.
+See, see! they join, embrace, and seem to kiss,
+As if they vow'd some league inviolable:
+Now are they but one lamp, one light, one sun.
+In this the heaven figures some event.
+
+EDWARD:
+'Tis wondrous strange, the like yet never heard of.
+I think it cites us, brother, to the field,
+That we, the sons of brave Plantagenet,
+Each one already blazing by our meeds,
+Should notwithstanding join our lights together
+And over-shine the earth as this the world.
+Whate'er it bodes, henceforward will I bear
+Upon my target three fair-shining suns.
+";
+
+#[allow(dead_code)]
+struct Config {
+    block_size: usize,
+    vocab_size: usize,
+    n_layer: usize,
+    n_head: usize,
+    n_embd: usize,
+}
+
+#[allow(dead_code)]
+impl Config {
+    fn config_7b() -> Self {
+        Self {
+            block_size: 4096,
+            vocab_size: 32000,
+            n_layer: 32,
+            n_head: 32,
+            n_embd: 4096,
+        }
+    }
+
+    fn config_13b() -> Self {
+        Self {
+            block_size: 4096,
+            vocab_size: 32000,
+            n_layer: 40,
+            n_head: 40,
+            n_embd: 5120,
+        }
+    }
+
+    fn config_30b() -> Self {
+        Self {
+            block_size: 4096,
+            vocab_size: 32000,
+            n_layer: 60,
+            n_head: 52,
+            n_embd: 6656,
+        }
+    }
+
+    fn config_65b() -> Self {
+        Self {
+            block_size: 4096,
+            vocab_size: 32000,
+            n_layer: 80,
+            n_head: 64,
+            n_embd: 8192,
+        }
+    }
+}
+
+struct Embedding {
+    embeddings: Tensor,
+}
+
+impl Embedding {
+    fn new(embeddings: Tensor) -> Self {
+        Self { embeddings }
+    }
+
+    fn forward(&self, indexes: &Tensor) -> Result<Tensor> {
+        let embeddings = self.embeddings.to_dtype(DTYPE)?;
+        Ok(Tensor::embedding(indexes, &embeddings)?)
+    }
+}
+
+struct Linear {
+    weight: Tensor,
+}
+
+impl Linear {
+    fn new(weight: Tensor) -> Self {
+        Self { weight }
+    }
+
+    fn forward(&self, x: &Tensor) -> Result<Tensor> {
+        let weight = self.weight.to_dtype(DTYPE)?;
+        let x = x.matmul(&weight.t()?)?;
+        Ok(x)
+    }
+}
+
+struct RmsNorm {
+    scale: Tensor,
+}
+
+impl RmsNorm {
+    fn new(scale: Tensor) -> Self {
+        Self { scale }
+    }
+
+    fn forward(&self, x: &Tensor) -> Result<Tensor> {
+        // This is a no-op if x's dtype is already f32.
+        let x = x.to_dtype(DType::F32)?;
+        let (seq_len, hidden_size) = x.shape().r2()?;
+        let norm_x = ((&x * &x)?.sum(&[1])? / hidden_size as f64)?;
+        let norm_x = norm_x.broadcast_as((seq_len, hidden_size))?;
+        let x_normed = (x / (norm_x + 1e-5)?.sqrt()?)?;
+        let size = self.scale.shape().r1()?;
+        let scale = self
+            .scale
+            .to_dtype(DType::F32)?
+            .broadcast_as((seq_len, size))?;
+        let x = (scale * x_normed)?;
+        let x = x.to_dtype(DTYPE)?;
+        Ok(x)
+    }
+}
+
+struct Mlp {
+    c_fc1: Linear,
+    c_fc2: Linear,
+    c_proj: Linear,
+}
+
+fn silu(xs: &Tensor) -> Result<Tensor> {
+    Ok((xs / (xs.neg()?.exp()? + 1.0)?)?)
+}
+
+impl Mlp {
+    fn new(c_fc1: Linear, c_fc2: Linear, c_proj: Linear) -> Self {
+        Self {
+            c_fc1,
+            c_fc2,
+            c_proj,
+        }
+    }
+
+    fn forward(&self, x: &Tensor) -> Result<Tensor> {
+        let x = (silu(&self.c_fc1.forward(x)?)? * self.c_fc2.forward(x)?)?;
+        self.c_proj.forward(&x)
+    }
+}
+
+fn masked_fill(on_false: &Tensor, mask: &Tensor, on_true: f32) -> Result<Tensor> {
+    let shape = mask.shape();
+    let on_true = Tensor::new(on_true, &on_false.device())?.broadcast_as(shape.dims())?;
+    let m = mask.where_cond(&on_true, on_false)?;
+    Ok(m)
+}
+
+#[derive(Clone)]
+struct Cache {
+    masks: Arc<Mutex<HashMap<usize, Tensor>>>,
+    use_kv_cache: bool,
+    #[allow(clippy::type_complexity)]
+    kvs: Arc<Mutex<Vec<Option<(Tensor, Tensor)>>>>,
+    device: Device,
+}
+
+impl Cache {
+    fn new(use_kv_cache: bool, config: &Config, device: &Device) -> Self {
+        Self {
+            masks: Arc::new(Mutex::new(HashMap::new())),
+            use_kv_cache,
+            kvs: Arc::new(Mutex::new(vec![None; config.n_layer])),
+            device: device.clone(),
+        }
+    }
+
+    fn mask(&self, t: usize) -> Result<Tensor> {
+        let mut masks = self.masks.lock().unwrap();
+        if let Some(mask) = masks.get(&t) {
+            Ok(mask.clone())
+        } else {
+            // TODO: If we support bool or u8 tensors, this would be better.
+            let mask: Vec<_> = (0..t)
+                .flat_map(|i| (0..t).map(move |j| u32::from(j > i)))
+                .collect();
+            let mask = Tensor::from_slice(&mask, (t, t), &self.device)?;
+            masks.insert(t, mask.clone());
+            Ok(mask)
+        }
+    }
+}
+
+struct CausalSelfAttention {
+    c_attn: Linear,
+    c_proj: Linear,
+    n_head: usize,
+    cache: Cache,
+}
+
+impl CausalSelfAttention {
+    fn new(c_attn: Linear, c_proj: Linear, n_head: usize, cache: &Cache) -> Self {
+        Self {
+            c_attn,
+            c_proj,
+            n_head,
+            cache: cache.clone(),
+        }
+    }
+
+    fn apply_rotary_emb(&self, x: &Tensor, freqs_cis: &Tensor) -> Result<Tensor> {
+        let mut dims = x.dims().to_vec();
+        let fcis_dims = freqs_cis.dims();
+        let freqs_cis = if dims[1] < fcis_dims[1] {
+            freqs_cis.narrow(1, 0, dims[1])?
+        } else {
+            freqs_cis.clone()
+        };
+        let v = dims.pop().unwrap();
+        dims.push(v / 2);
+        dims.push(2);
+        let x = x.reshape(dims)?;
+        let rank = x.rank();
+        let re_x = x.narrow(rank - 1, 0, 1)?;
+        let im_x = x.narrow(rank - 1, 1, 1)?;
+        let re_f = freqs_cis
+            .narrow(rank - 1, 0, 1)?
+            .broadcast_as(re_x.shape())?;
+        let im_f = freqs_cis
+            .narrow(rank - 1, 1, 1)?
+            .broadcast_as(im_x.shape())?;
+        let re = ((&re_x * &re_f)? - (&im_x * &im_f)?)?;
+        let im = ((&re_x * &im_f)? + (&im_x * &re_f)?)?;
+        let rope = Tensor::cat(&[&re, &im], rank - 1)?;
+        let rope = rope.flatten(Some(rope.rank() - 2), None)?;
+        Ok(rope)
+    }
+
+    fn forward(&self, x: &Tensor, freqs_cis: &Tensor, block_idx: usize) -> Result<Tensor> {
+        let (t, c) = x.shape().r2()?;
+        let qkv = self.c_attn.forward(x)?;
+        let qkv = qkv.to_dtype(DType::F32)?;
+        let n_embd = c;
+        let q = qkv.narrow(1, 0, n_embd)?;
+        let k = qkv.narrow(1, n_embd, n_embd)?;
+        let v = qkv.narrow(1, 2 * n_embd, n_embd)?;
+        let target_dim = [t, self.n_head, c / self.n_head];
+        let k = k.reshape(target_dim.as_slice())?.transpose(0, 1)?;
+        let q = q.reshape(target_dim.as_slice())?.transpose(0, 1)?;
+        let mut v = v.reshape(target_dim.as_slice())?.transpose(0, 1)?;
+        let q = self.apply_rotary_emb(&q, freqs_cis)?;
+        let mut k = self.apply_rotary_emb(&k, freqs_cis)?;
+
+        if self.cache.use_kv_cache {
+            let mut cache = self.cache.kvs.lock().unwrap();
+            if let Some((cache_k, cache_v)) = &cache[block_idx] {
+                k = Tensor::cat(&[cache_k, &k], 1)?.contiguous()?;
+                v = Tensor::cat(&[cache_v, &v], 1)?.contiguous()?;
+                let k_seq_len = k.dims()[1];
+                if k_seq_len > MAX_SEQ_LEN {
+                    k = k
+                        .narrow(1, k_seq_len - MAX_SEQ_LEN, MAX_SEQ_LEN)?
+                        .contiguous()?
+                }
+                let v_seq_len = v.dims()[1];
+                if v_seq_len > 2 * MAX_SEQ_LEN {
+                    v = v
+                        .narrow(1, v_seq_len - MAX_SEQ_LEN, MAX_SEQ_LEN)?
+                        .contiguous()?
+                }
+            }
+            cache[block_idx] = Some((k.clone(), v.clone()))
+        }
+
+        let k_shape = k.shape();
+        let att = (q.matmul(&k.t()?)? / (*k_shape.dims().last().unwrap() as f64).sqrt())?;
+        let mask = self.cache.mask(t)?.broadcast_as(att.shape())?;
+        let att = masked_fill(&att, &mask, f32::NEG_INFINITY)?;
+        let att = att.softmax(att.rank() - 1)?;
+        // Convert to contiguous as matmul doesn't support strided vs for now.
+        let y = att.matmul(&v.contiguous()?)?;
+        let y = y.transpose(0, 1)?.reshape(&[t, c])?;
+        let y = y.to_dtype(DTYPE)?;
+        let y = self.c_proj.forward(&y)?;
+        Ok(y)
+    }
+}
+
+struct Block {
+    rms_1: RmsNorm,
+    attn: CausalSelfAttention,
+    rms_2: RmsNorm,
+    mlp: Mlp,
+}
+
+impl Block {
+    fn new(rms_1: RmsNorm, attn: CausalSelfAttention, rms_2: RmsNorm, mlp: Mlp) -> Self {
+        Self {
+            rms_1,
+            attn,
+            rms_2,
+            mlp,
+        }
+    }
+
+    fn forward(&self, x: &Tensor, freqs_cis: &Tensor, block_idx: usize) -> Result<Tensor> {
+        let x = (self
+            .attn
+            .forward(&self.rms_1.forward(x)?, freqs_cis, block_idx)?
+            + x)?;
+        let x = (self.mlp.forward(&self.rms_2.forward(&x)?)? + x)?;
+        Ok(x)
+    }
+}
+
+struct Llama {
+    wte: Embedding,
+    blocks: Vec<Block>,
+    ln_f: RmsNorm,
+    lm_head: Linear,
+}
+
+impl Llama {
+    fn new(wte: Embedding, blocks: Vec<Block>, ln_f: RmsNorm, lm_head: Linear) -> Self {
+        Self {
+            wte,
+            blocks,
+            ln_f,
+            lm_head,
+        }
+    }
+
+    fn forward(&self, x: &Tensor, freqs_cis: &Tensor) -> Result<Tensor> {
+        // TODO: Support for mini-batches? (i.e. r2)
+        let t = x.shape().r1()?;
+        let mut x = self.wte.forward(x)?;
+        for (block_idx, block) in self.blocks.iter().enumerate() {
+            x = block.forward(&x, freqs_cis, block_idx)?;
+        }
+        let x = self.ln_f.forward(&x)?;
+        let x = x.narrow(0, t - 1, 1)?;
+        let logits = self.lm_head.forward(&x)?;
+        let logits = logits.to_dtype(DType::F32)?;
+        let (b, vocab_size) = logits.shape().r2()?;
+        assert_eq!(b, 1);
+        Ok(logits.reshape(vocab_size)?)
+    }
+}
+
+fn precompute_freqs_cis(config: &Config, device: &Device) -> Result<Tensor> {
+    let n_elem = config.n_embd / config.n_head;
+    let theta: Vec<_> = (0..n_elem)
+        .step_by(2)
+        .map(|i| 1f32 / 10000f32.powf(i as f32 / n_elem as f32))
+        .collect();
+    let arange: Vec<_> = (0..MAX_SEQ_LEN).map(|c| c as f32).collect();
+    let theta = Tensor::new(theta.as_slice(), device)?;
+    let arange = Tensor::new(arange.as_slice(), device)?;
+    let idx_theta = arange
+        .reshape((arange.elem_count(), 1))?
+        .matmul(&theta.reshape((1, theta.elem_count()))?)?;
+    let shape = [1, MAX_SEQ_LEN, n_elem / 2, 1];
+    let idx_theta_cos = idx_theta.cos()?.reshape(&shape)?;
+    let idx_theta_sin = idx_theta.sin()?.reshape(&shape)?;
+    let last_dim = idx_theta_cos.rank() - 1;
+    Ok(Tensor::cat(&[&idx_theta_cos, &idx_theta_sin], last_dim)?)
+}
+
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about = None)]
+struct Args {
+    /// Run on CPU rather than on GPU.
+    #[arg(long)]
+    cpu: bool,
+
+    /// Use npy instead of safetensors
+    #[arg(long)]
+    npy: Option<String>,
+
+    /// The temperature used to generate samples.
+    #[arg(long)]
+    temperature: Option<f64>,
+
+    /// The seed to use when generating random samples.
+    #[arg(long, default_value_t = 299792458)]
+    seed: u64,
+
+    /// The length of the sample to generate (in tokens).
+    #[arg(long, default_value_t = 100)]
+    sample_len: usize,
+
+    /// Disable the key-value cache.
+    #[arg(long)]
+    no_kv_cache: bool,
+
+    /// The initial prompt.
+    #[arg(long)]
+    prompt: Option<String>,
+}
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    use tokenizers::Tokenizer;
+
+    let args = Args::parse();
+    let device = if args.cpu {
+        Device::Cpu
+    } else {
+        Device::new_cuda(0)?
+    };
+    let config = Config::config_7b();
+    let cache = Cache::new(!args.no_kv_cache, &config, &device);
+    let start = std::time::Instant::now();
+    let (llama, tokenizer_filename) = match args.npy {
+        Some(npy) => {
+            println!("building the model (NPY)");
+            let weights = Llama::load_npy(&device, &npy, &cache, &config)?;
+            let token_path = std::path::Path::new("llama-tokenizer.json").to_path_buf();
+            (weights, token_path)
+        }
+        None => {
+            let api = Api::new()?;
+            let repo = Repo::new("Narsil/amall-7b".to_string(), RepoType::Model);
+            println!("building the model");
+            let tokenizer_filename = api.get(&repo, "tokenizer.json").await?;
+            let mut filenames = vec![];
+            for rfilename in [
+                "model-00001-of-00002.safetensors",
+                "model-00002-of-00002.safetensors",
+            ] {
+                let filename = api.get(&repo, rfilename).await?;
+                filenames.push(filename);
+            }
+
+            println!("building the model (SF)");
+            (
+                Llama::load(&device, &filenames, &cache, &config)?,
+                tokenizer_filename,
+            )
+        }
+    };
+    println!("Loaded in {:?}", start.elapsed());
+    let tokenizer = Tokenizer::from_file(tokenizer_filename).map_err(E::msg)?;
+    let prompt = args.prompt.as_ref().map_or(DEFAULT_PROMPT, |p| p.as_str());
+    let mut tokens = tokenizer
+        .encode(prompt, true)
+        .map_err(E::msg)?
+        .get_ids()
+        .to_vec();
+
+    println!("pre-computing the positional embeddings");
+    let freqs_cis = precompute_freqs_cis(&config, &device)?;
+    println!("starting the inference loop");
+    let mut new_tokens = vec![];
+    let mut rng = rand::rngs::StdRng::seed_from_u64(args.seed);
+    let start_gen = std::time::Instant::now();
+    let mut index_pos = 0;
+    for index in 0..args.sample_len {
+        let start_gen = std::time::Instant::now();
+        let context_size = if cache.use_kv_cache && index > 0 {
+            1
+        } else {
+            tokens.len()
+        };
+        let ctxt = &tokens[tokens.len().saturating_sub(context_size)..];
+        let input = Tensor::new(ctxt, &device)?;
+        let freqs_cis = if cache.use_kv_cache {
+            freqs_cis.narrow(1, index_pos, ctxt.len())?
+        } else {
+            freqs_cis.clone()
+        };
+        let logits = llama.forward(&input, &freqs_cis)?;
+        index_pos += ctxt.len();
+
+        let next_token = if let Some(temperature) = args.temperature {
+            println!("Sampling with temperature {temperature:?}");
+            let prs = (&logits / temperature)?.softmax(logits.rank() - 1)?;
+            let logits_v: Vec<f32> = prs.to_vec1()?;
+            let distr = rand::distributions::WeightedIndex::new(&logits_v)?;
+
+            distr.sample(&mut rng) as u32
+        } else {
+            let logits_v: Vec<f32> = logits.to_vec1()?;
+            logits_v
+                .iter()
+                .enumerate()
+                .max_by(|(_, u), (_, v)| u.total_cmp(v))
+                .map(|(i, _)| i as u32)
+                .unwrap()
+        };
+        tokens.push(next_token);
+        new_tokens.push(next_token);
+        println!("> {:?}", start_gen.elapsed());
+        println!(
+            "{} token: {} '{}'",
+            index + 1,
+            next_token,
+            tokenizer.decode(vec![next_token], true).map_err(E::msg)?
+        );
+    }
+    let dt = start_gen.elapsed();
+    println!(
+        "{} tokens generated ({} token/s)\n----\n{}\n----",
+        args.sample_len,
+        args.sample_len as f64 / dt.as_secs_f64(),
+        tokenizer.decode(new_tokens, true).map_err(E::msg)?
+    );
+    Ok(())
+}