openwall / openwall/john

Optimize intrinsic functions with pre-processor-fu

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enhancement
Dominant language
C
Stars
13.6k
Forks
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PR merge metrics
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Description

I'm pretty sure we can drop most branches in the SIMD functions using some clever rewrites and macros. The OpenCL functions does that. Well, that's not really a fair comparison since everything is always inlined but anyway.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by locating the SIMD functions mentioned in the issue and comparing them with the corresponding OpenCL functions. Determine which branches could be replaced with preprocessor rewrites or macros, then verify that the optimized functions preserve existing behavior and measure whether branching is reduced.

Written by the indexing model from the issue text.

Assessment

Tech stack
c
Domain
performance
Issue type
Refactor
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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