Messages in this thread | | | Subject | Re: [PATCH v2 10/30] Add x86-specific parity functions | From | Zeng Zhaoxiu <> | Date | Thu, 7 Apr 2016 11:56:12 +0800 |
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在 2016年04月07日 03:45, Andi Kleen 写道: > zengzhaoxiu@163.com writes: > >> From: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com> >> >> Use alternatives, lifted from arch_hweight > Is there actually anything performance critical in the kernel that uses > parity? > > FWIW the arch hweight custom calling convention is a problem for LTO > because it needs different special flags, so I usually have to disable > it. Likely other reasonable usages, such as automatic source code > analysis, and other tool chain based usages have similar problems. > > As far as I can tell both for hweight and likely for parity it is > badly overengineering and normal calling conventions would work as well, > and cause much less problems. > > So if parity is really worth adding here (which I find doubtful, > but you may have numbers), please add it without these magic > calling hacks. > > -Andi >
Thanks. I will instead use __arch_hweight.
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