Training Language Models on Synthetic Edit Sequences Improves Code
  Synthesis
Software engineers mainly write code by editing existing programs. In
contrast, large language models (LLMs) autoregressively synthesize programs in
a single pass. One explanation for this is the scarcity of open-sourced edit
data. While high-quality instruction data for code synthesis is already scarce,
high-quality edit data is even scarcer. To fill this gap, we develop a
synthetic data generation algorithm called LintSeq. This algorithm refactors
existing code into a sequence of code edits by using a linter to procedurally
sample across the error-free insertions that can be used to sequentially write
programs. It outputs edit sequences as text strings consisting of consecutive
program diffs. To test LintSeq, we use it to refactor a dataset of instruction
+ program pairs into instruction + program-diff-sequence tuples. Then, we
instruction finetune a series of smaller LLMs ranging from 2.6B to 14B
parameters on both the re-factored and original versions of this dataset,
comparing zero-shot performance on code synthesis benchmarks. We show that
during repeated sampling, edit sequence finetuned models produce more diverse
programs than baselines. This results in better inference-time scaling for
benchmark coverage as a function of samples, i.e. the fraction of problems
"pass@k" solved by any attempt given "k" tries. For example, on HumanEval
pass@50, small LLMs finetuned on synthetic edit sequences are competitive with
GPT-4 and outperform models finetuned on the baseline dataset by +20% (+/-3%)
in absolute score. Finally, we also pretrain our own tiny LMs for code
understanding. We show that finetuning tiny models on synthetic code edits
results in state-of-the-art code synthesis for the on-device model class. Our
150M parameter edit sequence LM matches or outperforms code models with twice
as many parameters, both with and without repeated sampling, including Codex
and AlphaCode.
66ff7b3d43510cc1bd347770
Ulyana Piterbarg
admin_assigned
2024-10-04T09:16:39.075Z
6337054e0267ebcf02637018
/avatars/89ad12d6643f18706050a92efccd92e6.svg
Ulyana Piterbarg
user
upiter
66ff7b3d43510cc1bd347771
Lerrel Pinto
admin_assigned
2024-10-04T09:16:45.575Z
6388cdb6685efaedd15dc0f3
/avatars/b2b74454bf86bf61fd90ba088644f547.svg
Lerrel Pinto
user
lerrel
66ff7b3d43510cc1bd347772
Rob Fergus
Training Language Models on Synthetic Edit Sequences Improves Code
  Synthesis
Software engineers mainly write code by editing existing programs. In
contrast, large language models (LLMs) autoregressively synthesize programs in
a single pass. One explanation for this is the scarcity of open-sourced edit
data. While high-quality instruction data for code synthesis is already scarce,
high-quality edit data is even scarcer. To fill this gap, we develop a
synthetic data generation algorithm called LintSeq. This algorithm refactors
existing code into a sequence of code edits by using a linter to procedurally
sample across the error-free insertions that can be used to sequentially write
programs. It outputs edit sequences as text strings consisting of consecutive
program diffs. To test LintSeq, we use it to refactor a dataset of instruction
+ program pairs into instruction + program-diff-sequence tuples. Then, we
instruction finetune a series of smaller LLMs ranging from 2.6B to 14B
parameters on both the re-factored and original versions of this dataset,
comparing zero-shot performance on code synthesis benchmarks. We show that
during repeated sampling, edit sequence finetuned models produce more diverse
programs than baselines. This results in better inference-time scaling for
benchmark coverage as a function of samples, i.e. the fraction of problems
"pass@k" solved by any attempt given "k" tries. For example, on HumanEval
pass@50, small LLMs finetuned on synthetic edit sequences are competitive with
GPT-4 and outperform models finetuned on the baseline dataset by +20% (+/-3%)
in absolute score. Finally, we also pretrain our own tiny LMs for code
understanding. We show that finetuning tiny models on synthetic code edits
results in state-of-the-art code synthesis for the on-device model class. Our
150M parameter edit sequence LM matches or outperforms code models with twice
as many parameters, both with and without repeated sampling, including Codex
and AlphaCode.
LintSeq generates synthetic code editing data to improve the diversity and performance of LLMs in code synthesis, outperforming models trained on baseline datasets.
large language models LLMs autoregressive synthesis synthetic data generation LintSeq linter program diffs instruction finetuning code synthesis benchmarks Zero-shot performance HumanEval pretraining tiny LMs code understanding Codex AlphaCode