Merge pull request #11 from maiqingqiang/feat-qwen2

feat: Qwen2 support

Libraries/LLM/Configuration.swift

@@ -31,6 +31,7 @@ public enum ModelType: String, Codable {
     case llama
     case phi
     case gemma
+    case qwen2
 
     func createModel(configuration: URL) throws -> LLMModel {
         switch self {
@@ -46,6 +47,10 @@ public enum ModelType: String, Codable {
             let configuration = try JSONDecoder().decode(
                 GemmaConfiguration.self, from: Data(contentsOf: configuration))
             return GemmaModel(configuration)
+        case .qwen2:
+            let configuration = try JSONDecoder().decode(
+                Qwen2Configuration.self, from: Data(contentsOf: configuration))
+            return Qwen2Model(configuration)
         }
     }
 }

Libraries/LLM/Models.swift

@@ -84,6 +84,13 @@ extension ModelConfiguration {
     ) { prompt in
         "<start_of_turn>user \(prompt)<end_of_turn><start_of_turn>model"
     }
+    
+    public static let qwen205b4bit = ModelConfiguration(
+        id: "mlx-community/Qwen1.5-0.5B-Chat-4bit",
+        overrideTokenizer: "PreTrainedTokenizer"
+    ) { prompt in
+        "<|im_start|>user \(prompt)<|im_end|><|im_start|>assistant"
+    }
 
     private enum BootstrapState {
         case idle
@@ -102,6 +109,7 @@ extension ModelConfiguration {
                 codeLlama13b4bit,
                 phi4bit,
                 gemma2bQuantized,
+                qwen205b4bit,
             ])
             bootstrapState = .bootstrapped
 

Libraries/LLM/Qwen2.swift

@@ -0,0 +1,263 @@
+//
+//  Qwen2.swift
+//  LLM
+//
+//  Created by John Mai on 2024/3/3.
+//
+
+import Foundation
+import MLX
+import MLXNN
+
+// port of https://github.com/ml-explore/mlx-examples/blob/main/llms/mlx_lm/models/qwen2.py
+
+private class Attention: Module {
+    let args: Qwen2Configuration
+    let repeats: Int
+    let scale: Float
+
+    @ModuleInfo(key: "q_proj") var wq: Linear
+    @ModuleInfo(key: "k_proj") var wk: Linear
+    @ModuleInfo(key: "v_proj") var wv: Linear
+    @ModuleInfo(key: "o_proj") var wo: Linear
+
+    let rope: RoPE
+
+    public init(_ args: Qwen2Configuration) {
+        self.args = args
+
+        let dim = args.hiddenSize
+        let heads = args.attentionHeads
+        let kvHeads = args.kvHeads
+
+        self.repeats = heads / kvHeads
+
+        let headDim = args.hiddenSize / heads
+        self.scale = pow(Float(headDim), -0.5)
+
+        _wq.wrappedValue = Linear(dim, heads * headDim, bias: true)
+        _wk.wrappedValue = Linear(dim, kvHeads * headDim, bias: true)
+        _wv.wrappedValue = Linear(dim, kvHeads * headDim, bias: true)
+        _wo.wrappedValue = Linear(heads * headDim, dim, bias: false)
+
+        let ropeScale: Float
+        if let ropeScaling = args.ropeScaling, ropeScaling["type"] == .string("linear"),
+           let factor = ropeScaling["factor"]
+        {
+            switch factor {
+            case .string:
+                fatalError("ropeScaling.factor must be a float")
+            case .float(let v):
+                ropeScale = 1 / v
+            }
+        } else {
+            ropeScale = 1
+        }
+
+        self.rope = RoPE(
+            dimensions: headDim, traditional: args.ropeTraditional, base: args.ropeTheta,
+            scale: ropeScale)
+    }
+
+    public func callAsFunction(
+        _ x: MLXArray, mask: MLXArray? = nil, cache: (MLXArray, MLXArray)? = nil) -> (MLXArray, (MLXArray, MLXArray))
+    {
+        let (B, L) = (x.dim(0), x.dim(1))
+
+        var queries = wq(x)
+        var keys = wk(x)
+        var values = wv(x)
+
+        // prepare the queries, keys and values for the attention computation
+        queries = queries.reshaped(B, L, args.attentionHeads, -1).transposed(0, 2, 1, 3)
+        keys = keys.reshaped(B, L, args.kvHeads, -1).transposed(0, 2, 1, 3)
+        values = values.reshaped(B, L, args.kvHeads, -1).transposed(0, 2, 1, 3)
+
+        if repeats > 1 {
+            keys = MLXArray.repeat(keys, count: repeats, axis: 1)
+            values = MLXArray.repeat(values, count: repeats, axis: 1)
+        }
+
+        if let (keyCache, valueCache) = cache {
+            queries = rope(queries, offset: keyCache.dim(2))
+            keys = rope(keys, offset: keyCache.dim(2))
+            keys = concatenated([keyCache, keys], axis: 2)
+            values = concatenated([valueCache, values], axis: 2)
+        } else {
+            queries = rope(queries)
+            keys = rope(keys)
+        }
+
+        var scores = (queries * scale).matmul(keys.transposed(0, 1, 3, 2))
+        if let mask {
+            scores = scores + mask
+        }
+
+        scores = softMax(scores.asType(.float32), axis: -1).asType(scores.dtype)
+
+        let output = matmul(scores, values).transposed(0, 2, 1, 3).reshaped(B, L, -1)
+
+        return (wo(output), (keys, values))
+    }
+}
+
+private class MLP: Module, UnaryLayer {
+    @ModuleInfo(key: "gate_proj") var gate: Linear
+    @ModuleInfo(key: "down_proj") var down: Linear
+    @ModuleInfo(key: "up_proj") var up: Linear
+
+    public init(dimensions: Int, hiddenDimensions: Int) {
+        _gate.wrappedValue = Linear(dimensions, hiddenDimensions, bias: false)
+        _down.wrappedValue = Linear(hiddenDimensions, dimensions, bias: false)
+        _up.wrappedValue = Linear(dimensions, hiddenDimensions, bias: false)
+    }
+
+    public func callAsFunction(_ x: MLXArray) -> MLXArray {
+        down(silu(gate(x)) * up(x))
+    }
+}
+
+private class TransformerBlock: Module {
+    @ModuleInfo(key: "self_attn") var attention: Attention
+    let mlp: MLP
+
+    @ModuleInfo(key: "input_layernorm") var inputLayerNorm: RMSNorm
+    @ModuleInfo(key: "post_attention_layernorm") var postAttentionLayerNorm: RMSNorm
+
+    public init(_ args: Qwen2Configuration) {
+        _attention.wrappedValue = Attention(args)
+        self.mlp = MLP(dimensions: args.hiddenSize, hiddenDimensions: args.intermediateSize)
+        _inputLayerNorm.wrappedValue = RMSNorm(
+            dimensions: args.hiddenSize, eps: args.rmsNormEps)
+        _postAttentionLayerNorm.wrappedValue = RMSNorm(
+            dimensions: args.hiddenSize, eps: args.rmsNormEps)
+    }
+
+    public func callAsFunction(
+        _ x: MLXArray, mask: MLXArray? = nil, cache: (MLXArray, MLXArray)? = nil) -> (MLXArray, (MLXArray, MLXArray))
+    {
+        var (r, cache) = attention(inputLayerNorm(x), mask: mask, cache: cache)
+        let h = x + r
+        r = mlp(postAttentionLayerNorm(h))
+        let out = h + r
+        return (out, cache)
+    }
+}
+
+public class Qwen2ModelInner: Module {
+    @ModuleInfo(key: "embed_tokens") var embedTokens: Embedding
+
+    fileprivate let layers: [TransformerBlock]
+    let norm: RMSNorm
+
+    public init(_ args: Qwen2Configuration) {
+        precondition(args.vocabularySize > 0)
+
+        _embedTokens.wrappedValue = Embedding(
+            embeddingCount: args.vocabularySize, dimensions: args.hiddenSize)
+
+        self.layers = (0 ..< args.hiddenLayers)
+            .map { _ in
+                TransformerBlock(args)
+            }
+        self.norm = RMSNorm(dimensions: args.hiddenSize, eps: args.rmsNormEps)
+    }
+
+    public func callAsFunction(_ inputs: MLXArray, cache: [(MLXArray, MLXArray)]? = nil) -> (
+        MLXArray, [(MLXArray, MLXArray)])
+    {
+        var h = embedTokens(inputs)
+
+        var mask: MLXArray? = nil
+        if h.dim(1) > 1 {
+            mask = MultiHeadAttention.createAdditiveCausalMask(h.dim(1))
+            mask = mask?.asType(h.dtype)
+        }
+
+        var newCache = [(MLXArray, MLXArray)]()
+
+        for (i, layer) in layers.enumerated() {
+            var cacheUpdate: (MLXArray, MLXArray)
+            (h, cacheUpdate) = layer(h, mask: mask, cache: cache?[i])
+            newCache.append(cacheUpdate)
+        }
+
+        return (norm(h), newCache)
+    }
+}
+
+public class Qwen2Model: Module, LLMModel {
+    public let vocabularySize: Int
+    let model: Qwen2ModelInner
+
+    @ModuleInfo(key: "lm_head") var lmHead: Linear
+
+    public init(_ args: Qwen2Configuration) {
+        self.vocabularySize = args.vocabularySize
+        self.model = Qwen2ModelInner(args)
+        _lmHead.wrappedValue = Linear(args.hiddenSize, args.vocabularySize, bias: false)
+    }
+
+    public func callAsFunction(_ inputs: MLXArray, cache: [(MLXArray, MLXArray)]?) -> (
+        MLXArray, [(MLXArray, MLXArray)])
+    {
+        let (out, cache) = model(inputs, cache: cache)
+        return (lmHead(out), cache)
+    }
+}
+
+public struct Qwen2Configuration: Codable {
+    var hiddenSize: Int
+    var hiddenLayers: Int
+    var intermediateSize: Int
+    var attentionHeads: Int
+    var rmsNormEps: Float
+    var vocabularySize: Int
+    var kvHeads: Int
+    var ropeTheta: Float = 1_000_000
+    var ropeTraditional: Bool = false
+    var ropeScaling: [String: StringOrNumber]? = nil
+
+    enum CodingKeys: String, CodingKey {
+        case hiddenSize = "hidden_size"
+        case hiddenLayers = "num_hidden_layers"
+        case intermediateSize = "intermediate_size"
+        case attentionHeads = "num_attention_heads"
+        case rmsNormEps = "rms_norm_eps"
+        case vocabularySize = "vocab_size"
+        case kvHeads = "num_key_value_heads"
+        case ropeTheta = "rope_theta"
+        case ropeTraditional = "rope_traditional"
+        case ropeScaling = "rope_scaling"
+    }
+
+    public init(from decoder: Decoder) throws {
+        // custom implementation to handle optional keys with required values
+        let container: KeyedDecodingContainer<Qwen2Configuration.CodingKeys> =
+            try decoder.container(
+                keyedBy: Qwen2Configuration.CodingKeys.self)
+
+        self.hiddenSize = try container.decode(
+            Int.self, forKey: Qwen2Configuration.CodingKeys.hiddenSize)
+        self.hiddenLayers = try container.decode(
+            Int.self, forKey: Qwen2Configuration.CodingKeys.hiddenLayers)
+        self.intermediateSize = try container.decode(
+            Int.self, forKey: Qwen2Configuration.CodingKeys.intermediateSize)
+        self.attentionHeads = try container.decode(
+            Int.self, forKey: Qwen2Configuration.CodingKeys.attentionHeads)
+        self.rmsNormEps = try container.decode(
+            Float.self, forKey: Qwen2Configuration.CodingKeys.rmsNormEps)
+        self.vocabularySize = try container.decode(
+            Int.self, forKey: Qwen2Configuration.CodingKeys.vocabularySize)
+        self.kvHeads = try container.decode(Int.self, forKey: Qwen2Configuration.CodingKeys.kvHeads)
+        self.ropeTheta =
+            try container.decodeIfPresent(
+                Float.self, forKey: Qwen2Configuration.CodingKeys.ropeTheta)
+            ?? 1_000_000
+        self.ropeTraditional =
+            try container.decodeIfPresent(
+                Bool.self, forKey: Qwen2Configuration.CodingKeys.ropeTraditional) ?? false
+        self.ropeScaling = try container.decodeIfPresent(
+            [String: StringOrNumber].self, forKey: Qwen2Configuration.CodingKeys.ropeScaling)
+    }
+}

Libraries/LLM/Tokenizer.swift

@@ -116,4 +116,5 @@ public func discardUnhandledMerges(tokenizerData: Config) -> Config {
 let replacementTokenizers = [
     "CodeLlamaTokenizer": "LlamaTokenizer",
     "GemmaTokenizer": "PreTrainedTokenizer",
+    "Qwen2Tokenizer": "PreTrainedTokenizer",
 ]

Tools/llm-tool/LLMTool.swift

@@ -42,7 +42,9 @@ struct SyncGenerator: AsyncParsableCommand {
 
         let modelConfiguration = ModelConfiguration.configuration(id: model)
         let (model, tokenizer) = try await load(configuration: modelConfiguration)
-
+        
+        print("Model loaded -> \(self.model)")
+        
         let prompt = modelConfiguration.prepare(prompt: self.prompt)
         let promptTokens = tokenizer.encode(text: prompt)
 
@@ -131,6 +133,8 @@ struct AsyncGenerator: AsyncParsableCommand {
 
         let modelConfiguration = ModelConfiguration.configuration(id: model)
         let (model, tokenizer) = try await load(configuration: modelConfiguration)
+        
+        print("Model loaded -> \(self.model)")
 
         let prompt = modelConfiguration.prepare(prompt: self.prompt)
         let promptTokens = tokenizer.encode(text: prompt)

mlx-swift-examples.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		52A776182B94B5EE00AA6E80 /* Qwen2.swift in Sources */ = {isa = PBXBuildFile; fileRef = 52A776172B94B5EE00AA6E80 /* Qwen2.swift */; };
 		C3288D762B6D9313009FF608 /* LinearModelTraining.swift in Sources */ = {isa = PBXBuildFile; fileRef = C3288D752B6D9313009FF608 /* LinearModelTraining.swift */; };
 		C3288D7B2B6D9339009FF608 /* ArgumentParser in Frameworks */ = {isa = PBXBuildFile; productRef = C3288D7A2B6D9339009FF608 /* ArgumentParser */; };
 		C34E48F52B696F0B00FCB841 /* LLMTool.swift in Sources */ = {isa = PBXBuildFile; fileRef = C34E48F42B696F0B00FCB841 /* LLMTool.swift */; };
@@ -180,6 +181,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		52A776172B94B5EE00AA6E80 /* Qwen2.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Qwen2.swift; sourceTree = "<group>"; };
 		C325DE3F2B648CDB00628871 /* README.md */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = net.daringfireball.markdown; path = README.md; sourceTree = "<group>"; };
 		C3288D732B6D9313009FF608 /* LinearModelTraining */ = {isa = PBXFileReference; explicitFileType = "compiled.mach-o.executable"; includeInIndex = 0; path = LinearModelTraining; sourceTree = BUILT_PRODUCTS_DIR; };
 		C3288D752B6D9313009FF608 /* LinearModelTraining.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LinearModelTraining.swift; sourceTree = "<group>"; };
@@ -363,6 +365,7 @@
 				C34E48ED2B696E6500FCB841 /* Load.swift */,
 				C3E786AA2B8D1AEC0004D037 /* Evaluate.swift */,
 				C3E786AC2B8D4AF50004D037 /* Tokenizer.swift */,
+				52A776172B94B5EE00AA6E80 /* Qwen2.swift */,
 			);
 			path = LLM;
 			sourceTree = "<group>";
@@ -829,6 +832,7 @@
 				C3A8B3AC2B9283150002EFB8 /* Models.swift in Sources */,
 				C3E786AB2B8D1AEC0004D037 /* Evaluate.swift in Sources */,
 				C38935CC2B869C870037B833 /* Llama.swift in Sources */,
+				52A776182B94B5EE00AA6E80 /* Qwen2.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

mlx-swift-examples.xcodeproj/xcshareddata/xcschemes/llm-tool.xcscheme

@@ -55,6 +55,10 @@
             argument = "--model mlx-community/CodeLlama-13b-Instruct-hf-4bit-MLX"
             isEnabled = "NO">
          </CommandLineArgument>
+         <CommandLineArgument
+            argument = "--model mlx-community/Qwen1.5-0.5B-Chat-4bit"
+            isEnabled = "YES">
+         </CommandLineArgument>
          <CommandLineArgument
             argument = "--prompt &apos;func sortArray(_ array: [Int]) -&gt; String { &lt;FILL_ME&gt; }&apos;"
             isEnabled = "NO">
@@ -69,7 +73,7 @@
          </CommandLineArgument>
          <CommandLineArgument
             argument = "--model mlx-community/phi-2-hf-4bit-mlx"
-            isEnabled = "YES">
+            isEnabled = "NO">
          </CommandLineArgument>
       </CommandLineArguments>
    </LaunchAction>