When no SIMD is found, configure must deactivate SIMD support
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bug
enhancement
- Dominant language
- C
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Description
When no SIMD is found, configure should behave as if the user had set --disable-simd:
- set that no SIMD is avaiblable;
- define JOHN_NO_SIMD;
- ...
That's not what's happening on Android.
The lines below will include the header even when SIMD is not supported (in my example).
checking special compiler flags... ARM
checking for NEON... no
checking for ASIMD... no
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the configure checks for NEON and ASIMD and inspect src/pseudo_intrinsics.h at the linked lines. Reproduce the Android case where both checks report no, then verify that configuration marks SIMD unavailable, defines JOHN_NO_SIMD, and does not include the SIMD header.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- c
- Domain
- build-system, performance
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100