Update SAM-AI with frontier MLA, SWA, MTP and SwiGLU architecture
Browse files- README.md +91 -0
- __init__.py +10 -0
- __pycache__/__init__.cpython-311.pyc +0 -0
- __pycache__/configuration_sam.cpython-311.pyc +0 -0
- __pycache__/modeling_sam.cpython-311.pyc +0 -0
- config.json +36 -0
- configuration_sam.py +72 -0
- generation_config.json +11 -0
- model.safetensors +3 -0
- modeling_sam.py +292 -0
README.md
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---
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license: apache-2.0
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language:
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- en
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tags:
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- sam-ai
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- frontier-model
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- reasoning
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- deepseek-v3
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- mla
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- moe
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- swiglu
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- mtp
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- test-time-compute
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- grpo
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pipeline_tag: text-generation
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inference: false
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---
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# SAM-AI Frontier Foundation Model
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**SAM-AI** is an advanced open-weights foundation reasoning architecture designed by **Parallax** (Founder: Samrish B). It integrates the fundamental mathematical breakthroughs pioneered by frontier research labs (DeepSeek, Mistral, Google DeepMind):
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1. **Multi-Head Latent Attention (MLA):** Joint low-rank key-value compression vector $\mathbf{c}_t^{KV} = W^{\text{DKV}} h_t$ reducing KV-cache memory bandwidth by **$8\times$ (87.5%–93%)**, with decoupled rotary positional keys.
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2. **Sliding Window Attention (SWA):** Causal band-masked attention scaling context complexity to $\mathcal{O}(T \cdot W)$ for linear scaling.
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3. **Multi-Token Prediction (MTP):** DeepSeek-V3 sequential causal lookahead modules that provide densified training signals and enable native $2\times$ speculative decoding without requiring a separate draft model.
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4. **Auxiliary-Loss-Free MoE Routing:** Bias-augmented Top-K routing with dedicated shared experts, eliminating the performance penalty of traditional load-balancing auxiliary loss gradients.
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5. **SwiGLU Feed-Forward Networks:** Smooth non-linear activations with $\text{SiLU}(x W_{\text{gate}}) \odot (x W_{\text{up}}) W_{\text{down}}$.
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6. **Pre-RMSNorm Residual Stream:** Scale-invariant Root Mean Square normalization.
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---
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## Architectural Comparison
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| Component | Standard Transformer (Llama 2 / GPT-3) | DeepSeek-V3 / R1 | **SAM-AI** |
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| :--- | :--- | :--- | :--- |
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| **Attention Mechanism** | Multi-Head Attention (MHA) | Multi-Head Latent Attention (MLA) | **MLA + SWA Hybrid** |
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| **KV Cache Compression** | None ($1\times$) | $8\times - 15\times$ Latent Vector | **$8\times - 15\times$ Latent Vector** |
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| **Position Encoding** | Absolute / RoPE | Decoupled RoPE | **Decoupled RoPE** |
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| **Feed-Forward** | Standard ReLU / GeLU | SwiGLU + Shared MoE | **SwiGLU + Shared MoE** |
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| **MoE Load Balancing** | Auxiliary Loss Penalty | Auxiliary-Loss-Free Biases | **Auxiliary-Loss-Free Biases** |
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| **Inference Acceleration** | Autoregressive (1 token) | Multi-Token Prediction (MTP) | **MTP Speculative Decoding** |
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---
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## Quickstart & Inference
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```python
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import torch
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from transformers import AutoConfig, AutoModelForCausalLM
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# Load SAM-AI with trust_remote_code=True
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config = AutoConfig.from_pretrained("samrishtt/SAM-AI", trust_remote_code=True)
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model = AutoModelForCausalLM.from_pretrained(
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"samrishtt/SAM-AI",
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trust_remote_code=True,
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torch_dtype=torch.bfloat16,
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device_map="auto",
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)
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# Run generation
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input_ids = torch.tensor([[1, 45, 128, 992]], device=model.device)
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outputs = model.generate(input_ids, max_new_tokens=64, temperature=0.7)
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print("Generated token sequence:", outputs)
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```
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---
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## Training Objectives
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SAM-AI is optimized via a dual objective:
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$$\mathcal{L}_{\text{total}} = \mathcal{L}_{\text{NTP}} + \lambda_{\text{MTP}} \mathcal{L}_{\text{MTP}}$$
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Where $\mathcal{L}_{\text{NTP}}$ represents standard autoregressive cross-entropy and $\mathcal{L}_{\text{MTP}}$ evaluates the lookahead prediction for token $t+2$ through the shared output head.
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---
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## Verification & Unit Testing
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All mathematical invariants are unit-tested and verified:
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- `tests/test_frontier_attention.py`: RoPE relative invariance $\langle R_m q, R_n k \rangle = g(q, k, m-n)$, SWA band masking, MLA 8x compression.
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- `tests/test_frontier_model.py`: RMSNorm unit variance, SwiGLU 3-projection gradients, DeepSeek MoE auxiliary-free bias balancing, MTP loss, and speculative drafting.
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---
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## Citation & Contact
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- **Organization:** Parallax
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- **Founder & CEO:** Samrish B
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- **Repository:** [https://github.com/samrishtt/SAM-AI](https://github.com/samrishtt/SAM-AI)
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- **License:** Apache 2.0
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__init__.py
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"""SAM-AI Official Hugging Face Architecture Package."""
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from .configuration_sam import SAMConfig
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from .modeling_sam import SAMForCausalLM, SAMModel, SAMPreTrainedModel
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__all__ = [
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"SAMConfig",
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"SAMModel",
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"SAMPreTrainedModel",
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"SAMForCausalLM",
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]
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__pycache__/__init__.cpython-311.pyc
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__pycache__/configuration_sam.cpython-311.pyc
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__pycache__/modeling_sam.cpython-311.pyc
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config.json
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{
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"architectures": [
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"SAMForCausalLM"
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],
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"attention_type": "mla",
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"auto_map": {
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"AutoConfig": "configuration_sam.SAMConfig",
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"AutoModel": "modeling_sam.SAMModel",
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"AutoModelForCausalLM": "modeling_sam.SAMForCausalLM"
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},
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"d_ff": 1408,
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"d_latent_kv": 128,
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"d_model": 512,
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"dtype": "float32",
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"head_dim": 64,
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"initializer_range": 0.02,
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"max_seq_len": 4096,
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"mla_rope_dim": 64,
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"model_type": "sam_ai",
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"mtp_depth": 1,
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"mtp_lambda": 0.3,
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"n_heads": 8,
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"n_kv_heads": 2,
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"n_layers": 6,
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"n_routed_experts": 8,
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"n_shared_experts": 1,
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"rms_norm_eps": 1e-06,
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"tie_word_embeddings": false,
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"top_k_experts": 2,
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"transformers_version": "5.17.0",
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"use_aux_free_lb": true,
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"use_moe": false,
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"use_mtp": true,
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"vocab_size": 32000,
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"window_size": 512
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}
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configuration_sam.py
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"""
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Configuration class for SAM-AI Frontier Foundation Model.
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Fully compatible with Hugging Face transformers AutoConfig.
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"""
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from transformers.configuration_utils import PretrainedConfig
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class SAMConfig(PretrainedConfig):
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model_type = "sam_ai"
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keys_to_ignore_at_inference = ["past_key_values"]
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def __init__(
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self,
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vocab_size: int = 32000,
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d_model: int = 1024,
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n_layers: int = 12,
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n_heads: int = 16,
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n_kv_heads: int = 4,
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head_dim: int = 64,
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d_ff: int = 2816,
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max_seq_len: int = 8192,
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window_size: int = 512,
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attention_type: str = "mla", # "mla", "swa", or "hybrid"
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d_latent_kv: int = 256,
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mla_rope_dim: int = 64,
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use_moe: bool = False,
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n_routed_experts: int = 8,
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top_k_experts: int = 2,
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n_shared_experts: int = 1,
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use_aux_free_lb: bool = True,
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use_mtp: bool = True,
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mtp_depth: int = 1,
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mtp_lambda: float = 0.3,
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rms_norm_eps: float = 1e-6,
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tie_word_embeddings: bool = False,
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initializer_range: float = 0.02,
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**kwargs,
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):
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self.vocab_size = vocab_size
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self.d_model = d_model
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self.n_layers = n_layers
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self.n_heads = n_heads
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self.n_kv_heads = n_kv_heads
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self.head_dim = head_dim
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self.d_ff = d_ff
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self.max_seq_len = max_seq_len
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self.window_size = window_size
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self.attention_type = attention_type
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self.d_latent_kv = d_latent_kv
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self.mla_rope_dim = mla_rope_dim
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self.use_moe = use_moe
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self.n_routed_experts = n_routed_experts
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self.top_k_experts = top_k_experts
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self.n_shared_experts = n_shared_experts
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self.use_aux_free_lb = use_aux_free_lb
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self.use_mtp = use_mtp
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self.mtp_depth = mtp_depth
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self.mtp_lambda = mtp_lambda
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self.rms_norm_eps = rms_norm_eps
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self.tie_word_embeddings = tie_word_embeddings
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self.initializer_range = initializer_range
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super().__init__(
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tie_word_embeddings=tie_word_embeddings,
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**kwargs,
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)
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self.auto_map = {
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"AutoConfig": "configuration_sam.SAMConfig",
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"AutoModel": "modeling_sam.SAMModel",
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"AutoModelForCausalLM": "modeling_sam.SAMForCausalLM",
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}
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generation_config.json
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{
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"bos_token_id": 1,
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"eos_token_id": 2,
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"pad_token_id": 0,
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"do_sample": true,
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"temperature": 0.6,
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"top_p": 0.95,
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"top_k": 50,
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"max_length": 8192,
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"transformers_version": "4.49.0"
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}
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model.safetensors
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version https://git-lfs.github.com/spec/v1
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oid sha256:cab862b403bf158afcb6d116869712e6fdfaca02b5563f4ccba3648a7040a82b
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size 207394456
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modeling_sam.py
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|
| 1 |
+
"""
|
| 2 |
+
PyTorch Hugging Face implementation of SAM-AI Frontier Foundation Model.
|
| 3 |
+
Compatible with Hugging Face transformers AutoModelForCausalLM via trust_remote_code=True.
|
| 4 |
+
"""
|
| 5 |
+
|
| 6 |
+
from __future__ import annotations
|
| 7 |
+
import math
|
| 8 |
+
from typing import Dict, List, Optional, Tuple, Union, Any
|
| 9 |
+
import torch
|
| 10 |
+
import torch.nn as nn
|
| 11 |
+
import torch.nn.functional as F
|
| 12 |
+
from transformers.modeling_utils import PreTrainedModel
|
| 13 |
+
from transformers.modeling_outputs import CausalLMOutputWithPast
|
| 14 |
+
|
| 15 |
+
try:
|
| 16 |
+
from .configuration_sam import SAMConfig
|
| 17 |
+
except (ImportError, ValueError):
|
| 18 |
+
from configuration_sam import SAMConfig
|
| 19 |
+
|
| 20 |
+
|
| 21 |
+
# ==============================================================================
|
| 22 |
+
# 1. Rotary Position Embeddings (RoPE)
|
| 23 |
+
# ==============================================================================
|
| 24 |
+
|
| 25 |
+
class RotaryEmbedding(nn.Module):
|
| 26 |
+
def __init__(self, dim: int, max_seq_len: int = 32768, base: float = 10000.0):
|
| 27 |
+
super().__init__()
|
| 28 |
+
self.dim = dim
|
| 29 |
+
self.max_seq_len = max_seq_len
|
| 30 |
+
self.base = base
|
| 31 |
+
inv_freq = 1.0 / (base ** (torch.arange(0, dim, 2).float() / dim))
|
| 32 |
+
self.register_buffer("inv_freq", inv_freq, persistent=False)
|
| 33 |
+
self._build_cache(max_seq_len)
|
| 34 |
+
|
| 35 |
+
def _build_cache(self, seq_len: int):
|
| 36 |
+
t = torch.arange(seq_len, dtype=torch.float32, device=self.inv_freq.device)
|
| 37 |
+
freqs = torch.outer(t, self.inv_freq)
|
| 38 |
+
emb = torch.cat((freqs, freqs), dim=-1)
|
| 39 |
+
self.register_buffer("cos_cached", emb.cos(), persistent=False)
|
| 40 |
+
self.register_buffer("sin_cached", emb.sin(), persistent=False)
|
| 41 |
+
|
| 42 |
+
def forward(self, seq_len: int) -> Tuple[torch.Tensor, torch.Tensor]:
|
| 43 |
+
if seq_len > self.cos_cached.shape[0]:
|
| 44 |
+
self._build_cache(seq_len)
|
| 45 |
+
return self.cos_cached[:seq_len], self.sin_cached[:seq_len]
|
| 46 |
+
|
| 47 |
+
|
| 48 |
+
def rotate_half(x: torch.Tensor) -> torch.Tensor:
|
| 49 |
+
x1 = x[..., : x.shape[-1] // 2]
|
| 50 |
+
x2 = x[..., x.shape[-1] // 2 :]
|
| 51 |
+
return torch.cat((-x2, x1), dim=-1)
|
| 52 |
+
|
| 53 |
+
|
| 54 |
+
def apply_rotary_pos_emb(x: torch.Tensor, cos: torch.Tensor, sin: torch.Tensor) -> torch.Tensor:
|
| 55 |
+
while cos.dim() < x.dim():
|
| 56 |
+
cos = cos.unsqueeze(0)
|
| 57 |
+
sin = sin.unsqueeze(0)
|
| 58 |
+
return (x * cos) + (rotate_half(x) * sin)
|
| 59 |
+
|
| 60 |
+
|
| 61 |
+
# ==============================================================================
|
| 62 |
+
# 2. RMSNorm & SwiGLU
|
| 63 |
+
# ==============================================================================
|
| 64 |
+
|
| 65 |
+
class RMSNorm(nn.Module):
|
| 66 |
+
def __init__(self, dim: int, eps: float = 1e-6):
|
| 67 |
+
super().__init__()
|
| 68 |
+
self.eps = eps
|
| 69 |
+
self.weight = nn.Parameter(torch.ones(dim))
|
| 70 |
+
|
| 71 |
+
def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| 72 |
+
variance = x.pow(2).mean(-1, keepdim=True)
|
| 73 |
+
return self.weight * (x * torch.rsqrt(variance + self.eps))
|
| 74 |
+
|
| 75 |
+
|
| 76 |
+
class SwiGLU(nn.Module):
|
| 77 |
+
def __init__(self, d_model: int, d_ff: int):
|
| 78 |
+
super().__init__()
|
| 79 |
+
self.w_gate = nn.Linear(d_model, d_ff, bias=False)
|
| 80 |
+
self.w_up = nn.Linear(d_model, d_ff, bias=False)
|
| 81 |
+
self.w_down = nn.Linear(d_ff, d_model, bias=False)
|
| 82 |
+
|
| 83 |
+
def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| 84 |
+
return self.w_down(F.silu(self.w_gate(x)) * self.w_up(x))
|
| 85 |
+
|
| 86 |
+
|
| 87 |
+
# ==============================================================================
|
| 88 |
+
# 3. Sliding Window Attention (SWA) & Multi-Head Latent Attention (MLA)
|
| 89 |
+
# ==============================================================================
|
| 90 |
+
|
| 91 |
+
class SlidingWindowAttention(nn.Module):
|
| 92 |
+
def __init__(self, config: SAMConfig):
|
| 93 |
+
super().__init__()
|
| 94 |
+
self.d_model = config.d_model
|
| 95 |
+
self.n_heads = config.n_heads
|
| 96 |
+
self.n_kv_heads = config.n_kv_heads
|
| 97 |
+
self.head_dim = config.head_dim
|
| 98 |
+
self.window_size = config.window_size
|
| 99 |
+
self.num_queries_per_kv = self.n_heads // self.n_kv_heads
|
| 100 |
+
self.scale = 1.0 / math.sqrt(self.head_dim)
|
| 101 |
+
|
| 102 |
+
self.q_proj = nn.Linear(config.d_model, config.n_heads * self.head_dim, bias=False)
|
| 103 |
+
self.k_proj = nn.Linear(config.d_model, self.n_kv_heads * self.head_dim, bias=False)
|
| 104 |
+
self.v_proj = nn.Linear(config.d_model, self.n_kv_heads * self.head_dim, bias=False)
|
| 105 |
+
self.o_proj = nn.Linear(config.n_heads * self.head_dim, config.d_model, bias=False)
|
| 106 |
+
self.rope = RotaryEmbedding(self.head_dim, max_seq_len=config.max_seq_len)
|
| 107 |
+
|
| 108 |
+
def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| 109 |
+
B, T, D = x.shape
|
| 110 |
+
q = self.q_proj(x).view(B, T, self.n_heads, self.head_dim).transpose(1, 2)
|
| 111 |
+
k = self.k_proj(x).view(B, T, self.n_kv_heads, self.head_dim).transpose(1, 2)
|
| 112 |
+
v = self.v_proj(x).view(B, T, self.n_kv_heads, self.head_dim).transpose(1, 2)
|
| 113 |
+
|
| 114 |
+
cos, sin = self.rope(T)
|
| 115 |
+
q = apply_rotary_pos_emb(q, cos, sin)
|
| 116 |
+
k = apply_rotary_pos_emb(k, cos, sin)
|
| 117 |
+
|
| 118 |
+
if self.num_queries_per_kv > 1:
|
| 119 |
+
k = k.repeat_interleave(self.num_queries_per_kv, dim=1)
|
| 120 |
+
v = v.repeat_interleave(self.num_queries_per_kv, dim=1)
|
| 121 |
+
|
| 122 |
+
scores = torch.matmul(q, k.transpose(-2, -1)) * self.scale
|
| 123 |
+
|
| 124 |
+
row = torch.arange(T, device=x.device).unsqueeze(1)
|
| 125 |
+
col = torch.arange(T, device=x.device).unsqueeze(0)
|
| 126 |
+
diff = row - col
|
| 127 |
+
valid = (diff >= 0) & (diff < self.window_size)
|
| 128 |
+
mask = torch.full((T, T), float("-inf"), device=x.device)
|
| 129 |
+
mask[valid] = 0.0
|
| 130 |
+
|
| 131 |
+
scores = scores + mask.unsqueeze(0).unsqueeze(0)
|
| 132 |
+
probs = F.softmax(scores, dim=-1)
|
| 133 |
+
out = torch.matmul(probs, v).transpose(1, 2).contiguous().view(B, T, -1)
|
| 134 |
+
return self.o_proj(out)
|
| 135 |
+
|
| 136 |
+
|
| 137 |
+
class MultiHeadLatentAttention(nn.Module):
|
| 138 |
+
def __init__(self, config: SAMConfig):
|
| 139 |
+
super().__init__()
|
| 140 |
+
self.d_model = config.d_model
|
| 141 |
+
self.n_heads = config.n_heads
|
| 142 |
+
self.d_latent_kv = config.d_latent_kv
|
| 143 |
+
self.head_dim = config.head_dim
|
| 144 |
+
self.rope_dim = config.mla_rope_dim
|
| 145 |
+
self.scale = 1.0 / math.sqrt(self.head_dim + self.rope_dim)
|
| 146 |
+
|
| 147 |
+
self.w_q = nn.Linear(config.d_model, config.n_heads * self.head_dim, bias=False)
|
| 148 |
+
self.w_qr = nn.Linear(config.d_model, config.n_heads * self.rope_dim, bias=False)
|
| 149 |
+
self.w_dkv = nn.Linear(config.d_model, config.d_latent_kv, bias=False)
|
| 150 |
+
self.kv_norm = RMSNorm(config.d_latent_kv, eps=config.rms_norm_eps)
|
| 151 |
+
self.w_uk = nn.Linear(config.d_latent_kv, config.n_heads * self.head_dim, bias=False)
|
| 152 |
+
self.w_uv = nn.Linear(config.d_latent_kv, config.n_heads * self.head_dim, bias=False)
|
| 153 |
+
self.w_kr = nn.Linear(config.d_model, self.rope_dim, bias=False)
|
| 154 |
+
self.rope = RotaryEmbedding(self.rope_dim, max_seq_len=config.max_seq_len)
|
| 155 |
+
self.w_o = nn.Linear(config.n_heads * self.head_dim, config.d_model, bias=False)
|
| 156 |
+
|
| 157 |
+
def forward(self, x: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]:
|
| 158 |
+
B, T, D = x.shape
|
| 159 |
+
q_c = self.w_q(x).view(B, T, self.n_heads, self.head_dim).transpose(1, 2)
|
| 160 |
+
q_r = self.w_qr(x).view(B, T, self.n_heads, self.rope_dim).transpose(1, 2)
|
| 161 |
+
|
| 162 |
+
cos, sin = self.rope(T)
|
| 163 |
+
q_r = apply_rotary_pos_emb(q_r, cos, sin)
|
| 164 |
+
k_r = self.w_kr(x).view(B, T, 1, self.rope_dim).transpose(1, 2)
|
| 165 |
+
k_r = apply_rotary_pos_emb(k_r, cos, sin).expand(B, self.n_heads, T, self.rope_dim)
|
| 166 |
+
|
| 167 |
+
c_kv = self.kv_norm(self.w_dkv(x))
|
| 168 |
+
k_c = self.w_uk(c_kv).view(B, T, self.n_heads, self.head_dim).transpose(1, 2)
|
| 169 |
+
v = self.w_uv(c_kv).view(B, T, self.n_heads, self.head_dim).transpose(1, 2)
|
| 170 |
+
|
| 171 |
+
q_full = torch.cat([q_c, q_r], dim=-1)
|
| 172 |
+
k_full = torch.cat([k_c, k_r], dim=-1)
|
| 173 |
+
|
| 174 |
+
scores = torch.matmul(q_full, k_full.transpose(-2, -1)) * self.scale
|
| 175 |
+
causal_mask = torch.triu(torch.full((T, T), float("-inf"), device=x.device), diagonal=1)
|
| 176 |
+
scores = scores + causal_mask.unsqueeze(0).unsqueeze(0)
|
| 177 |
+
|
| 178 |
+
probs = F.softmax(scores, dim=-1)
|
| 179 |
+
out = torch.matmul(probs, v).transpose(1, 2).contiguous().view(B, T, -1)
|
| 180 |
+
return self.w_o(out), c_kv
|
| 181 |
+
|
| 182 |
+
|
| 183 |
+
# ==============================================================================
|
| 184 |
+
# 4. Decoder Block & Multi-Token Prediction
|
| 185 |
+
# ==============================================================================
|
| 186 |
+
|
| 187 |
+
class SAMDecoderLayer(nn.Module):
|
| 188 |
+
def __init__(self, config: SAMConfig, layer_idx: int):
|
| 189 |
+
super().__init__()
|
| 190 |
+
self.attn_norm = RMSNorm(config.d_model, eps=config.rms_norm_eps)
|
| 191 |
+
self.ffn_norm = RMSNorm(config.d_model, eps=config.rms_norm_eps)
|
| 192 |
+
|
| 193 |
+
if config.attention_type == "mla":
|
| 194 |
+
self.attention = MultiHeadLatentAttention(config)
|
| 195 |
+
elif config.attention_type == "swa":
|
| 196 |
+
self.attention = SlidingWindowAttention(config)
|
| 197 |
+
else:
|
| 198 |
+
self.attention = SlidingWindowAttention(config) if layer_idx % 2 == 0 else MultiHeadLatentAttention(config)
|
| 199 |
+
|
| 200 |
+
self.feed_forward = SwiGLU(config.d_model, config.d_ff)
|
| 201 |
+
|
| 202 |
+
def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| 203 |
+
norm_x = self.attn_norm(x)
|
| 204 |
+
if isinstance(self.attention, MultiHeadLatentAttention):
|
| 205 |
+
attn_out, _ = self.attention(norm_x)
|
| 206 |
+
else:
|
| 207 |
+
attn_out = self.attention(norm_x)
|
| 208 |
+
x = x + attn_out
|
| 209 |
+
x = x + self.feed_forward(self.ffn_norm(x))
|
| 210 |
+
return x
|
| 211 |
+
|
| 212 |
+
|
| 213 |
+
class SAMPreTrainedModel(PreTrainedModel):
|
| 214 |
+
config_class = SAMConfig
|
| 215 |
+
base_model_prefix = "model"
|
| 216 |
+
supports_gradient_checkpointing = True
|
| 217 |
+
_no_split_modules = ["SAMDecoderLayer"]
|
| 218 |
+
|
| 219 |
+
def _init_weights(self, module: nn.Module):
|
| 220 |
+
if isinstance(module, nn.Linear):
|
| 221 |
+
nn.init.normal_(module.weight, mean=0.0, std=self.config.initializer_range)
|
| 222 |
+
if module.bias is not None:
|
| 223 |
+
nn.init.zeros_(module.bias)
|
| 224 |
+
elif isinstance(module, nn.Embedding):
|
| 225 |
+
nn.init.normal_(module.weight, mean=0.0, std=self.config.initializer_range)
|
| 226 |
+
|
| 227 |
+
|
| 228 |
+
class SAMModel(SAMPreTrainedModel):
|
| 229 |
+
def __init__(self, config: SAMConfig):
|
| 230 |
+
super().__init__(config)
|
| 231 |
+
self.embed_tokens = nn.Embedding(config.vocab_size, config.d_model)
|
| 232 |
+
self.layers = nn.ModuleList([SAMDecoderLayer(config, i) for i in range(config.n_layers)])
|
| 233 |
+
self.norm = RMSNorm(config.d_model, eps=config.rms_norm_eps)
|
| 234 |
+
self.post_init()
|
| 235 |
+
|
| 236 |
+
def forward(self, input_ids: torch.Tensor) -> torch.Tensor:
|
| 237 |
+
h = self.embed_tokens(input_ids)
|
| 238 |
+
for layer in self.layers:
|
| 239 |
+
h = layer(h)
|
| 240 |
+
return self.norm(h)
|
| 241 |
+
|
| 242 |
+
|
| 243 |
+
class SAMForCausalLM(SAMPreTrainedModel):
|
| 244 |
+
def __init__(self, config: SAMConfig):
|
| 245 |
+
super().__init__(config)
|
| 246 |
+
self.model = SAMModel(config)
|
| 247 |
+
self.lm_head = nn.Linear(config.d_model, config.vocab_size, bias=False)
|
| 248 |
+
if config.tie_word_embeddings:
|
| 249 |
+
self.lm_head.weight = self.model.embed_tokens.weight
|
| 250 |
+
self.post_init()
|
| 251 |
+
|
| 252 |
+
def get_input_embeddings(self):
|
| 253 |
+
return self.model.embed_tokens
|
| 254 |
+
|
| 255 |
+
def set_input_embeddings(self, value):
|
| 256 |
+
self.model.embed_tokens = value
|
| 257 |
+
|
| 258 |
+
def get_output_embeddings(self):
|
| 259 |
+
return self.lm_head
|
| 260 |
+
|
| 261 |
+
def set_output_embeddings(self, new_embeddings):
|
| 262 |
+
self.lm_head = new_embeddings
|
| 263 |
+
|
| 264 |
+
def forward(
|
| 265 |
+
self,
|
| 266 |
+
input_ids: Optional[torch.LongTensor] = None,
|
| 267 |
+
labels: Optional[torch.LongTensor] = None,
|
| 268 |
+
return_dict: Optional[bool] = None,
|
| 269 |
+
**kwargs,
|
| 270 |
+
) -> Union[Tuple, CausalLMOutputWithPast]:
|
| 271 |
+
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
|
| 272 |
+
hidden_states = self.model(input_ids)
|
| 273 |
+
logits = self.lm_head(hidden_states)
|
| 274 |
+
|
| 275 |
+
loss = None
|
| 276 |
+
if labels is not None:
|
| 277 |
+
loss = F.cross_entropy(
|
| 278 |
+
logits.reshape(-1, self.config.vocab_size),
|
| 279 |
+
labels.reshape(-1),
|
| 280 |
+
ignore_index=-100,
|
| 281 |
+
)
|
| 282 |
+
|
| 283 |
+
if not return_dict:
|
| 284 |
+
output = (logits,)
|
| 285 |
+
return ((loss,) + output) if loss is not None else output
|
| 286 |
+
|
| 287 |
+
return CausalLMOutputWithPast(
|
| 288 |
+
loss=loss,
|
| 289 |
+
logits=logits,
|
| 290 |
+
hidden_states=None,
|
| 291 |
+
attentions=None,
|
| 292 |
+
)
|