Qwen MoE model. (#1960)

* Qwen MoE model.

* Add the MoE model to the example.

* Fix the scaling.

* Readme updates.

* Readme tweaks.

candle-examples/examples/qwen/main.rs

@@ -7,7 +7,8 @@ extern crate accelerate_src;
 use anyhow::{Error as E, Result};
 use clap::Parser;
 
-use candle_transformers::models::qwen2::{Config, Model};
+use candle_transformers::models::qwen2::{Config as ConfigBase, Model as ModelBase};
+use candle_transformers::models::qwen2_moe::{Config as ConfigMoe, Model as ModelMoe};
 
 use candle::{DType, Device, Tensor};
 use candle_examples::token_output_stream::TokenOutputStream;
@@ -16,6 +17,20 @@ use candle_transformers::generation::LogitsProcessor;
 use hf_hub::{api::sync::Api, Repo, RepoType};
 use tokenizers::Tokenizer;
 
+enum Model {
+    Base(ModelBase),
+    Moe(ModelMoe),
+}
+
+impl Model {
+    fn forward(&mut self, xs: &Tensor, s: usize) -> candle::Result<Tensor> {
+        match self {
+            Self::Moe(ref mut m) => m.forward(xs, s),
+            Self::Base(ref mut m) => m.forward(xs, s),
+        }
+    }
+}
+
 struct TextGeneration {
     model: Model,
     device: Device,
@@ -127,6 +142,8 @@ enum WhichModel {
     W14b,
     #[value(name = "72b")]
     W72b,
+    #[value(name = "moe-a2.7b")]
+    MoeA27b,
 }
 
 #[derive(Parser, Debug)]
@@ -224,6 +241,7 @@ fn main() -> Result<()> {
                 WhichModel::W7b => "7B",
                 WhichModel::W14b => "14B",
                 WhichModel::W72b => "72B",
+                WhichModel::MoeA27b => "MoE-A2.7B",
             };
             format!("Qwen/Qwen1.5-{size}")
         }
@@ -244,7 +262,11 @@ fn main() -> Result<()> {
             .collect::<Vec<_>>(),
         None => match args.model {
             WhichModel::W0_5b | WhichModel::W1_8b => vec![repo.get("model.safetensors")?],
-            WhichModel::W4b | WhichModel::W7b | WhichModel::W14b | WhichModel::W72b => {
+            WhichModel::W4b
+            | WhichModel::W7b
+            | WhichModel::W14b
+            | WhichModel::W72b
+            | WhichModel::MoeA27b => {
                 candle_examples::hub_load_safetensors(&repo, "model.safetensors.index.json")?
             }
         },
@@ -254,7 +276,6 @@ fn main() -> Result<()> {
 
     let start = std::time::Instant::now();
     let config_file = repo.get("config.json")?;
-    let config: Config = serde_json::from_slice(&std::fs::read(config_file)?)?;
     let device = candle_examples::device(args.cpu)?;
     let dtype = if device.is_cuda() {
         DType::BF16
@@ -262,7 +283,16 @@ fn main() -> Result<()> {
         DType::F32
     };
     let vb = unsafe { VarBuilder::from_mmaped_safetensors(&filenames, dtype, &device)? };
-    let model = Model::new(&config, vb)?;
+    let model = match args.model {
+        WhichModel::MoeA27b => {
+            let config: ConfigMoe = serde_json::from_slice(&std::fs::read(config_file)?)?;
+            Model::Moe(ModelMoe::new(&config, vb)?)
+        }
+        _ => {
+            let config: ConfigBase = serde_json::from_slice(&std::fs::read(config_file)?)?;
+            Model::Base(ModelBase::new(&config, vb)?)
+        }
+    };
 
     println!("loaded the model in {:?}", start.elapsed());