StarCoder 2 and The Stack v2: The Next Generation

StarCoder 2 and The Stack v2: The Next Generation

• Thesis:
• Methods:
  • Models: 3B, 7B, 15B
  • Two-stage training:
    • First base models are trained with 4K context windows
    • Then fine-tuned with 16K context windows
  • At most 5 epochs over the dataset during training, why?
  • BPE tokenizer
  • RoPE
  • GQA
  • Data:
    • GH pull requests, Kaggle notebooks, code documentation
    • Stack v2, which includes 619 programming languages
    • Intermediate representations (LLVM). This is useful for low-resource languages
    • Math and coding datasets
    • Tailor training dataset composition of programming languages to model size as smaller models have less capacity and languages compete for model capacity. Therefore, 17 most widely used programming languages are used to train the 3B and 7B models while the full dataset is used to train the 15B model
    • Models were trained with repository context, but files within the same repository are in random order
    • Code is prepended with some metadata with 50% probability.
      • Metadata example: <repo_name>reponamefilepath1filepath2 … <|endoftext|>`
      • No metadata example: <file_sep>code1<file_sep>code2 ... <|endoftext|>
    • FIM 50% at the repo-context file level. So each repository is subjected to be FIM transformed with 50% probability.
      • Example: <repo_name>reponame<file_sep>filepath0\ncode0<file_sep><fim_prefix>filepath1\n code1_pre<fim_suffix>code1_suf<fim_middle>code1_mid<file_sep> ...<|endoftext|>
• Contribution:
  • The Stack v2
  • Detailed description and source code of preparing and processing training data
  • Detailed description and source code for training
• Takeaways:
• Improvements:
• Notes:
  • StarCoder2-15B outperforms DeepSeekCoder-33B on math and code reasoning but DeepSeekCoder-33B is still the best for code completion on high resource languages
  • StarCoder2 beats any open code LLMs of similar size
  • StarCoder2-7B doesn’t perform well compared with other open code LLMs of its size. So pick StarCoder2-15B or StarCoder2-3B for deployment

#nlp #llm #code-llm