1. Does Qualcomm Centriq 2400 have sve instruction set? The 2400 is armv8.a.
2. how to know whether an arm cpu support sve instruction set?
3. After which year, does arm cpu support sve instruction set?
Have you asked Qualcom ?
Yes. You can see this pdf https://www.qualcomm.com/documents/qualcomm-centriq-2400-processor. After I read your link, I still don't know whether Qualcom centriq 2400 support sve.
Again, for specific details of specific manufacturer's implementations, you need to ask the manufacturer!
The ARM document tells you that SVE is optional - so only the specific manufacturer can tell you whether they implemented that option in their particular product!
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