Hi Andrew, On 27 June 2016 at 19:32, Pinski, Andrew <andrew.pin...@cavium.com> wrote: >> No gain expected in implementing an Ifunc'ed version of the library. > > How did you prove that? What hardware did you run this on to prove it? > Also have you thought at least doing an ifunc version for 128bit atomics?
up to 64bits, the calls to the libatomic routines are inlined and armv8.1 CAS and load-operate version are used when the application is build for armv8.1 architecture. For 128bits, a call to the lib is made which uses the same LL/SC implementation with or without LSE support, as CAS and load-operate instruction don't support this data size. I don't have armv8.1 hardware and made the analysis on the generated assembler. Do you have use case on your side where an ifunc version can be useful ? I'm not aware of an algorithm which can replace effectively LL/SC implementation with shorter CAS, do you have any pointers ? Maybe CASP can be used in some cases, I'll investigate it. Thanks Yvan > Thanks, > Andrew > > -----Original Message----- > From: linaro-toolchain [mailto:linaro-toolchain-boun...@lists.linaro.org] On > Behalf Of Yvan Roux > Sent: Monday, June 27, 2016 1:40 AM > To: Linaro Toolchain Mailman List <linaro-toolchain@lists.linaro.org> > Subject: [ACTIVITY] Week 25 > > == Progress == > o Extended Validation (1/10) > - Benchmarking job babysitting. > > o Upstream GCC (4/10) > - ARMv8.1 libatomic: Analysis completed. > No gain expected in implementing an Ifunc'ed version of the library. > - Working on __sync buitlins potential fix. > > o Misc (5/10) > * Various meetings and discussions. > * Internal appraisal > > == Plan == > o Continue on-going tasks (__sync, benchmarking) > _______________________________________________ > linaro-toolchain mailing list > linaro-toolchain@lists.linaro.org > https://lists.linaro.org/mailman/listinfo/linaro-toolchain _______________________________________________ linaro-toolchain mailing list linaro-toolchain@lists.linaro.org https://lists.linaro.org/mailman/listinfo/linaro-toolchain
