Merge branch 'ml-explore:main' into adding-GRPO-training

ACKNOWLEDGMENTS.md

@@ -14,4 +14,4 @@ MLX Examples was developed with contributions from the following individuals:
 - Markus Enzweiler: Added the `cvae` examples.
 - Prince Canuma: Helped add support for `Starcoder2` models.
 - Shiyu Li: Added the `Segment Anything Model`.
-- Gökdeniz Gülmez: Added support for `MiniCPM`, `Mamba` and support for `full-fine-tuning`.
+- Gökdeniz Gülmez: Added support for `MiniCPM`, `Helium`, `Mamba version 1` and support for `full-fine-tuning`.

llms/mlx_lm/models/deepseek_v3.py

@@ -2,6 +2,7 @@
 
 import math
 from dataclasses import dataclass
+from functools import partial
 from typing import Any, Dict, Optional, Tuple
 
 import mlx.core as mx
@@ -125,6 +126,12 @@ class DeepseekV3YarnRotaryEmbedding(nn.Module):
         )
 
 
+# A clipped silu to prevent fp16 from overflowing
+@partial(mx.compile, shapeless=True)
+def clipped_silu(x):
+    return mx.clip(x * mx.sigmoid(x), a_min=-100, a_max=100)
+
+
 class DeepseekV3Attention(nn.Module):
     def __init__(self, config: ModelArgs):
         super().__init__()
@@ -312,7 +319,10 @@ class DeepseekV3MoE(nn.Module):
         self.config = config
         self.num_experts_per_tok = config.num_experts_per_tok
         self.switch_mlp = SwitchGLU(
-            config.hidden_size, config.moe_intermediate_size, config.n_routed_experts
+            config.hidden_size,
+            config.moe_intermediate_size,
+            config.n_routed_experts,
+            activation=clipped_silu,
         )
 
         self.gate = MoEGate(config)
@@ -359,11 +369,7 @@ class DeepseekV3DecoderLayer(nn.Module):
         r = self.self_attn(self.input_layernorm(x), mask, cache)
         h = x + r
         r = self.mlp(self.post_attention_layernorm(h))
-        out = h + r
-        # Protect against overflow for fp16
-        if out.dtype == mx.float16:
-            out = mx.clip(out, a_min=None, a_max=mx.finfo(mx.float16).max - 1000)
-        return out
+        return h + r
 
 
 class DeepseekV3Model(nn.Module):

llms/mlx_lm/models/helium.py

@@ -0,0 +1,183 @@
+from dataclasses import dataclass
+from typing import Any, Optional, Tuple
+
+import mlx.core as mx
+import mlx.nn as nn
+
+from .base import BaseModelArgs, create_attention_mask, scaled_dot_product_attention
+
+
+@dataclass
+class ModelArgs(BaseModelArgs):
+    hidden_size: int
+    num_hidden_layers: int
+    intermediate_size: int
+    num_attention_heads: int
+    num_key_value_heads: int
+    rms_norm_eps: float
+    vocab_size: int
+    attention_bias: bool
+    head_dim: int
+    max_position_embeddings: int
+    mlp_bias: bool
+    model_type: str
+    rope_theta: float
+    tie_word_embeddings: bool
+
+
+class HeliumAttention(nn.Module):
+    def __init__(self, args: ModelArgs):
+        super().__init__()
+
+        dim = args.hidden_size
+        self.n_heads = n_heads = args.num_attention_heads
+        assert args.num_key_value_heads is not None
+        self.n_kv_heads = n_kv_heads = args.num_key_value_heads
+
+        head_dim = args.hidden_size // n_heads
+        self.scale = head_dim**-0.5
+
+        self.q_proj = nn.Linear(dim, n_heads * head_dim, bias=args.attention_bias)
+        self.k_proj = nn.Linear(dim, n_kv_heads * head_dim, bias=args.attention_bias)
+        self.v_proj = nn.Linear(dim, n_kv_heads * head_dim, bias=args.attention_bias)
+        self.o_proj = nn.Linear(n_heads * head_dim, dim, bias=False)
+        self.rope = nn.RoPE(head_dim, traditional=True, base=args.rope_theta)
+
+    def __call__(
+        self,
+        x: mx.array,
+        mask: Optional[mx.array] = None,
+        cache: Optional[Any] = None,
+    ) -> mx.array:
+        B, L, D = x.shape
+
+        queries, keys, values = self.q_proj(x), self.k_proj(x), self.v_proj(x)
+
+        # Prepare the queries, keys and values for the attention computation
+        queries = queries.reshape(B, L, self.n_heads, -1).transpose(0, 2, 1, 3)
+        keys = keys.reshape(B, L, self.n_kv_heads, -1).transpose(0, 2, 1, 3)
+        values = values.reshape(B, L, self.n_kv_heads, -1).transpose(0, 2, 1, 3)
+
+        if cache is not None:
+            queries = self.rope(queries, offset=cache.offset)
+            keys = self.rope(keys, offset=cache.offset)
+            keys, values = cache.update_and_fetch(keys, values)
+        else:
+            queries = self.rope(queries)
+            keys = self.rope(keys)
+
+        output = scaled_dot_product_attention(
+            queries, keys, values, cache=cache, scale=self.scale, mask=mask
+        )
+        output = output.transpose(0, 2, 1, 3).reshape(B, L, -1)
+        return self.o_proj(output)
+
+
+class HeliumMLP(nn.Module):
+    def __init__(self, args: ModelArgs):
+        super().__init__()
+        self.hidden_size = args.hidden_size
+        self.intermediate_size = args.intermediate_size
+
+        self.gate_proj = nn.Linear(
+            self.hidden_size, self.intermediate_size, bias=args.mlp_bias
+        )
+        self.up_proj = nn.Linear(
+            self.hidden_size, self.intermediate_size, bias=args.mlp_bias
+        )
+        self.down_proj = nn.Linear(
+            self.intermediate_size, self.hidden_size, bias=args.mlp_bias
+        )
+
+    def __call__(self, x: mx.array) -> mx.array:
+        return self.down_proj(nn.silu(self.gate_proj(x)) * self.up_proj(x))
+
+
+class HeliumDecoderLayer(nn.Module):
+    def __init__(self, args: ModelArgs):
+        super().__init__()
+        self.hidden_size = args.hidden_size
+
+        self.self_attn = HeliumAttention(args)
+        self.mlp = HeliumMLP(args)
+        self.input_layernorm = nn.RMSNorm(args.hidden_size, eps=args.rms_norm_eps)
+        self.post_attention_layernorm = nn.RMSNorm(
+            args.hidden_size, eps=args.rms_norm_eps
+        )
+
+    def __call__(
+        self,
+        x: mx.array,
+        mask: Optional[mx.array] = None,
+        cache: Optional[Any] = None,
+    ) -> mx.array:
+        r = self.self_attn(self.input_layernorm(x), mask, cache)
+        h = x + r
+        r = self.mlp(self.post_attention_layernorm(h))
+        out = h + r
+        return out
+
+
+class HeliumModel(nn.Module):
+    def __init__(self, args: ModelArgs):
+        super().__init__()
+        self.num_hidden_layers = args.num_hidden_layers
+        self.vocab_size = args.vocab_size
+
+        assert self.vocab_size > 0
+        self.embed_tokens = nn.Embedding(args.vocab_size, args.hidden_size)
+
+        self.layers = [HeliumDecoderLayer(args) for _ in range(args.num_hidden_layers)]
+
+        self.norm = nn.RMSNorm(args.hidden_size, eps=args.rms_norm_eps)
+
+    def __call__(
+        self,
+        inputs: mx.array,
+        mask: mx.array = None,
+        cache=None,
+    ) -> mx.array:
+        h = self.embed_tokens(inputs)
+
+        if mask is None:
+            mask = create_attention_mask(h, cache)
+
+        if cache is None:
+            cache = [None] * len(self.layers)
+
+        for layer, c in zip(self.layers, cache):
+            h = layer(h, mask, c)
+
+        return self.norm(h)
+
+
+class Model(nn.Module):
+    def __init__(self, args: ModelArgs):
+        super().__init__()
+        self.args = args
+        self.model_type = args.model_type
+
+        self.model = HeliumModel(args)
+
+        self.vocab_size = args.vocab_size
+        self.lm_head = nn.Linear(args.hidden_size, args.vocab_size, bias=False)
+
+        if not args.tie_word_embeddings:
+            self.lm_head = nn.Linear(args.hidden_size, args.vocab_size, bias=False)
+
+    def __call__(
+        self,
+        inputs: mx.array,
+        mask: mx.array = None,
+        cache=None,
+    ) -> mx.array:
+        out = self.model(inputs, mask, cache)
+        if self.args.tie_word_embeddings:
+            out = self.model.embed_tokens.as_linear(out)
+        else:
+            out = self.lm_head(out)
+        return out
+
+    @property
+    def layers(self):
+        return self.model.layers

llms/mlx_lm/sample_utils.py

@@ -147,11 +147,11 @@ def min_p_sampling(
     logprobs = logprobs * (1 / temperature)
 
     # Indices sorted in decreasing order
-    sorted_indices = mx.argsort(-logprobs).squeeze(0)
-    sorted_logprobs = logprobs[..., sorted_indices]
+    sorted_indices = mx.argsort(-logprobs, axis=-1)
+    sorted_logprobs = mx.take_along_axis(logprobs, sorted_indices, axis=-1)
 
     # Top probability
-    top_logprobs = logprobs[..., sorted_indices[0]]
+    top_logprobs = sorted_logprobs[:, 0:1]
 
     # Calculate the min_p threshold
     scaled_min_p = top_logprobs + math.log(min_p)
@@ -163,9 +163,9 @@ def min_p_sampling(
     # Create pool of tokens with probability less than scaled min_p
     selected_logprobs = mx.where(tokens_to_remove, -float("inf"), sorted_logprobs)
 
-    # Return sampled token
-    sorted_token = mx.random.categorical(selected_logprobs)
-    return sorted_indices[sorted_token]
+    # Return sampled tokens
+    sorted_tokens = mx.random.categorical(selected_logprobs, axis=-1)[:, None]
+    return mx.take_along_axis(sorted_indices, sorted_tokens, axis=-1).squeeze(1)
 
 
 @partial(mx.compile, inputs=mx.random.state, outputs=mx.random.state)
@@ -185,7 +185,7 @@ def top_p_sampling(logits: mx.array, top_p: float, temperature: float) -> mx.arr
 
     # sort probs in ascending order
     sorted_indices = mx.argsort(probs, axis=-1)
-    sorted_probs = probs[..., sorted_indices.squeeze(0)]
+    sorted_probs = mx.take_along_axis(probs, sorted_indices, axis=-1)
 
     cumulative_probs = mx.cumsum(sorted_probs, axis=-1)
 
@@ -196,10 +196,8 @@ def top_p_sampling(logits: mx.array, top_p: float, temperature: float) -> mx.arr
         0,
     )
 
-    sorted_token = mx.random.categorical(mx.log(top_probs))
-    token = sorted_indices.squeeze(0)[sorted_token]
-
-    return token
+    sorted_tokens = mx.random.categorical(mx.log(top_probs), axis=-1)[:, None]
+    return mx.take_along_axis(sorted_indices, sorted_tokens, axis=-1).squeeze(1)
 
 
 @partial(mx.compile, inputs=mx.random.state, outputs=mx.random.state)

llms/mlx_lm/server.py

@@ -114,6 +114,33 @@ def convert_chat(messages: List[dict], role_mapping: Optional[dict] = None):
     return prompt.rstrip()
 
 
+def process_message_content(messages):
+    """
+    Convert message content to a format suitable for `apply_chat_template`.
+
+    The function operates on messages in place. It converts the 'content' field
+    to a string instead of a list of text fragments.
+
+    Args:
+        message_list (list): A list of dictionaries, where each dictionary may
+          have a 'content' key containing a list of dictionaries with 'type' and
+          'text' keys.
+
+    Raises:
+        ValueError: If the 'content' type is not supported or if 'text' is missing.
+
+    """
+    for message in messages:
+        content = message["content"]
+        if isinstance(content, list):
+            text_fragments = [
+                fragment["text"] for fragment in content if fragment["type"] == "text"
+            ]
+            if len(text_fragments) != len(content):
+                raise ValueError("Only 'text' content type is supported.")
+            message["content"] = "".join(text_fragments)
+
+
 @dataclass
 class PromptCache:
     cache: List[Any] = field(default_factory=list)
@@ -591,8 +618,10 @@ class APIHandler(BaseHTTPRequestHandler):
         self.request_id = f"chatcmpl-{uuid.uuid4()}"
         self.object_type = "chat.completion.chunk" if self.stream else "chat.completion"
         if self.tokenizer.chat_template:
+            messages = body["messages"]
+            process_message_content(messages)
             prompt = self.tokenizer.apply_chat_template(
-                body["messages"],
+                messages,
                 body.get("tools", None),
                 add_generation_prompt=True,
             )

llms/mlx_lm/tuner/utils.py

@@ -94,6 +94,7 @@ def linear_to_lora_layers(
         "phimoe",
         "gemma",
         "gemma2",
+        "helium",
         "starcoder2",
         "cohere",
         "cohere2",

llms/mlx_lm/utils.py

@@ -398,8 +398,9 @@ def speculative_generate_step(
             quantize_cache_fn(cache)
 
             logprobs = logits - mx.logsumexp(logits, keepdims=True)
-            y = sampler(logprobs).squeeze(0)
-            return y, logprobs.squeeze(0)
+            logprobs = logprobs.squeeze(0)
+            y = sampler(logprobs)
+            return y, logprobs
 
     def _prefill(model, cache, y):
         while y.size > prefill_step_size:

llms/tests/test_sample_utils.py

@@ -28,6 +28,12 @@ class TestSampleUtils(unittest.TestCase):
         token = top_p_sampling(logits, 0.95, temperature).item()
         self.assertTrue(token in (1, 2, 3))
 
+        # Batch mode works
+        probs = mx.array([[0.9, 0.0, 0.0, 0.1], [0.0, 0.8, 0.0, 0.1]])
+        logits = mx.log(probs)
+        tokens = top_p_sampling(logits, 0.5, temperature)
+        self.assertEqual(tokens.tolist(), [0, 1])
+
     def test_min_p_sampling(self):
         probs = mx.array([0.9, 0.0, 0.0, 0.1])[None]
         logits = mx.log(probs)
@@ -42,6 +48,12 @@ class TestSampleUtils(unittest.TestCase):
             token = min_p_sampling(logits, 0.05)
             self.assertTrue(token in (0, 3))
 
+        # Batch mode works
+        probs = mx.array([[0.9, 0.0, 0.0, 0.1], [0.0, 0.8, 0.0, 0.1]])
+        logits = mx.log(probs)
+        tokens = min_p_sampling(logits, 0.7)
+        self.assertEqual(tokens.tolist(), [0, 1])
+
     def test_top_k_sampling(self):
         probs = mx.array([0.9, 0.0, 0.0, 0.1])[None]
         logits = mx.log(probs)

llms/tests/test_server.py

@@ -80,6 +80,29 @@ class TestServer(unittest.TestCase):
         self.assertIn("id", response_body)
         self.assertIn("choices", response_body)
 
+    def test_handle_chat_completions_with_content_fragments(self):
+        url = f"http://localhost:{self.port}/v1/chat/completions"
+        chat_post_data = {
+            "model": "chat_model",
+            "max_tokens": 10,
+            "temperature": 0.7,
+            "top_p": 0.85,
+            "repetition_penalty": 1.2,
+            "messages": [
+                {
+                    "role": "system",
+                    "content": [
+                        {"type": "text", "text": "You are a helpful assistant."}
+                    ],
+                },
+                {"role": "user", "content": [{"type": "text", "text": "Hello!"}]},
+            ],
+        }
+        response = requests.post(url, json=chat_post_data)
+        response_body = response.text
+        self.assertIn("id", response_body)
+        self.assertIn("choices", response_body)
+
     def test_handle_models(self):
         url = f"http://localhost:{self.port}/v1/models"
         response = requests.get(url)