Papers › Superposed Decoding: Multiple Generations from a Single Autoregressive Inference Pass

Superposed Decoding: Multiple Generations from a Single Autoregressive Inference Pass

28 May 2024arXiv:2405.18400archive 2025-07-28

Ethan Shen, Alan Fan, Sarah M. Pratt, Jae Sung Park, Matthew Wallingford, Sham M. Kakade, Ari Holtzman, Ranjay Krishna, Ali Farhadi, Aditya Kusupati

Many applications today provide users with multiple auto-complete drafts as they type, including GitHub's code completion, Gmail's smart compose, and Apple's messaging auto-suggestions. Under the hood, language models support this by running an autoregressive inference pass to provide a draft. Consequently, providing k drafts to the user requires running an expensive language model k times. To alleviate the computation cost of running k inference passes, we propose Superposed Decoding, a new decoding algorithm that generates k drafts at the computation cost of one autoregressive inference pass. We achieve this by feeding a superposition of the most recent token embeddings from the k drafts as input to the next decoding step of the language model. At every inference step we combine the k drafts with the top-k tokens to get k² new drafts and cache the k most likely options, using an n-gram interpolation with minimal compute overhead to filter out incoherent generations. Our experiments show that k drafts from Superposed Decoding are at least as coherent and factual as Nucleus Sampling and Greedy Decoding respectively, while being at least 2.44× faster for k≥3. In a compute-normalized setting, user evaluations demonstrably favor text generated by Superposed Decoding over Nucleus Sampling. Superposed Decoding can also be combined with other decoding strategies, resulting in universal coverage gains when scaling inference time compute. Code and more examples open-sourced at https://github.com/RAIVNLab/SuperposedDecoding.

PaperPDFCodeCode Syntology ran

In Syntology Open this paper in Syntology's Atlas, the map of the papers in Syntology's graph and their citations.

For agents, Syntology's MCP tool lists every function and class Syntology harvested from this paper and whether it ran (how to connect): get_harvested_code_for_paper(arxiv_id="2405.18400")

Code

Syntology Ran 11 of 11 code samples harvested from 1 repository linked to this paper; 0 have no recorded run. Of those that ran: 1 ran · violated contract; 2 ran · fixture could not drive it; 8 ran with no contract checked.

By repository: official repository: 11 samples from 1 repository, 11 ran. The run record, sample by sample. “Ran” means executed on a synthesized input, not that the code is correct or reproduces the paper.

raivnlab/superposeddecoding officialmentioned in papermentioned on GitHubpytorchNOASSERTION report

Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.

Code Syntology ran Syntology

11 samples harvested; 11 ran; 0 honoured the contract we drafted; 0 have no recorded run. Read from Syntology's graph 2026-09-24; that is when this build read the record, not when the samples ran.

1ran · violated contract
2ran · fixture could not drive it
8ran

Licence: 11 of the 11 samples are pointer only, meaning Syntology does not serve that copy's text. This page shows no code text for any sample; each one links to its file in the repository.

Harvested from raivnlab/superposeddecoding. “Ran” means the sample executed on a synthesized input. It does not mean the output is correct, and nothing here reproduces the paper's results. “Honoured” and “violated” refer to a contract Syntology drafted from the code itself; “our draft was wrong” and “fixture could not drive it” are failures of Syntology's instrument, not of the code.

Each sample ends with its code_sha256, Syntology's identity for that exact code. An agent fetches the stored sample with Syntology's MCP tool get_code(code_sha256="…") (how to connect); click an identity to copy that call.

Repository labels, per sample. official repository: The archive marks this repository official for the paper. named in the paper: The archive records that the paper mentions this repository; it is not marked official. community (archive-listed): In the archive's code links for this paper, not marked official and not recorded as mentioned in the paper. found in paper text by Syntology: Syntology found this repository in the paper's own text; whether it is the authors' implementation is not asserted. community: Not in the archive's code links for this paper; a community repository Syntology harvested. Samples from a repository marked official are listed first. Licence labels name the repository's licence as recorded at harvest. “Pointer only” means Syntology does not serve that copy's text, for one of four reasons: no licence file was found; the licence was not identified; the licence is recorded as permissive but that copy's record is not marked cleared; or the licence is outside the permissive list Syntology serves text under (MIT, Apache-2.0, BSD and similar). Some licences outside that list permit redistribution, such as WTFPL, and GPL-3.0 under its conditions; they are simply not on the list. Hover a licence label for the reason. File links open the file on GitHub at the default branch, which may have changed since the harvest.

Superpose raivnlab/superposeddecoding/superposed/llama/superpose.py official repository ran · metamorphic tier: deterministic licence not identified · pointer only · e0a9aeb41260db1a · report
apply_rotary_emb RAIVNLab/SuperposedDecoding/superposed/llama/model.py official repository ran · fixture could not drive it no licence file found · pointer only · d7b6dcfe63bfe59b · report
calculate_diversity RAIVNLab/SuperposedDecoding/superposed/llama/metrics.py official repository ran licence not identified · pointer only · 457061e09e882aba · report
calculate_ngram_repetition RAIVNLab/SuperposedDecoding/superposed/llama/metrics.py official repository ran licence not identified · pointer only · 6201ed24380afb6e · report
calculate_perplexity RAIVNLab/SuperposedDecoding/superposed/llama/metrics.py official repository ran licence not identified · pointer only · 9844eb34712feeb4 · report
decode RAIVNLab/SuperposedDecoding/superposed/llama/utils.py official repository ran licence not identified · pointer only · 96a252f312cd6f36 · report
log_prob_to_prob RAIVNLab/SuperposedDecoding/superposed/llama/utils.py official repository ran fingerprinted licence not identified · pointer only · fb61d23822857703 · report
make_models RAIVNLab/SuperposedDecoding/superposed/ngrams/ngram_models.py official repository ran licence not identified · pointer only · 301fbabe02f250fd · report
precompute_freqs_cis RAIVNLab/SuperposedDecoding/superposed/llama/model.py official repository ran · violated contract no licence file found · pointer only · 04a1fa63d6d4b8e4 · report
reshape_for_broadcast RAIVNLab/SuperposedDecoding/superposed/llama/model.py official repository ran · fixture could not drive it no licence file found · pointer only · 5a639d78ada17fee · report
sample_top_p RAIVNLab/SuperposedDecoding/superposed/llama/generation.py official repository ran licence not identified · pointer only · 128a40bb8f1f26ef · report

Tasks

Code CompletionLanguage ModelingLanguage Modelling

Results from the paper archive 2025-07-28

No leaderboard rows for this paper in the archive.

Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections