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Late comment, just saw this. Not sure where the momentum is coming from. The proposal has a new maintainer now, new drafts have been released, and there's a st

by geertj 3y ago

Late comment, just saw this. Not sure where the momentum is coming from. The proposal has a new maintainer now, new drafts have been released, and there's a stated goal to get this included in C++26. For me, the appeal for experimental/simd would be it being part of the stdlib. Have you considered proposing Highway for stdlib inclusion? From your description it appears to be a more complete implementation. I realize it's a long and arduous process, but I think it's the only way to make something truly the default implementation. (And thanks for the link. I was not aware that Highway existed.)

janwas 3y ago
Interesting, thanks for sharing :) At the time we open-sourced Highway, the standardization process had already started and there were some discussions. I'm curious why stdlib is the only path you see to default? Compare the activity level of https://github.com/VcDevel/std-simd https://github.com/VcDevel/std-simd vs https://github.com/google/highway https://github.com/google/highway. As to open-source usage, after years of std::experimental, I see <200 search hits [1], vs >400 for Highway [2], even after excluding several library users. But that aside, I'm not convinced standardization is the best path for a SIMD library. We and external users extend Highway on a weekly basis as new use cases arise. What if we deferred those changes to 3-monthly meetings, or had to wait for one meeting per WD, CD, (FCD), DIS, (FDIS) stage before it's standardized? Standardization seems more useful for rarely-changing things. 1: https://sourcegraph.com/search?q=context:global+std::experimental::simd+-path:clang-tidy+count:10000+-path:sycl+-path:highway/+-repo:highway+-path:man/+-path:md%24+-path:rst%24+-path:sh%24+-path:txt%24+-path:testsuite/+-path:tests/+-path:svn-base%24&patternType=standard&sm=1&groupBy=repo https://sourcegraph.com/search?q=context:global+std::experim... 2: https://sourcegraph.com/search?q=context:global+HWY_NAMESPACE+-path:clang-tidy+count:10000+-path:sycl+-path:highway/+-repo:highway+-path:man/+-path:md%24+-path:rst%24+-path:sh%24+-path:txt%24+-path:testsuite/+-path:tests/+-path:svn-base%24+-path:libjxl+-path:jpeg-xl+-path:jxl+-path:jpegli&patternType=standard&sm=1&groupBy=repo https://sourcegraph.com/search?q=context:global+HWY_NAMESPAC...

by geertj 3y ago

janwas 3y ago

Interesting, thanks for sharing :) At the time we open-sourced Highway, the standardization process had already started and there were some discussions. I'm curious why stdlib is the only path you see to default? Compare the activity level of https://github.com/VcDevel/std-simd https://github.com/VcDevel/std-simd vs https://github.com/google/highway https://github.com/google/highway. As to open-source usage, after years of std::experimental, I see <200 search hits [1], vs >400 for Highway [2], even after excluding several library users. But that aside, I'm not convinced standardization is the best path for a SIMD library. We and external users extend Highway on a weekly basis as new use cases arise. What if we deferred those changes to 3-monthly meetings, or had to wait for one meeting per WD, CD, (FCD), DIS, (FDIS) stage before it's standardized? Standardization seems more useful for rarely-changing things. 1: https://sourcegraph.com/search?q=context:global+std::experimental::simd+-path:clang-tidy+count:10000+-path:sycl+-path:highway/+-repo:highway+-path:man/+-path:md%24+-path:rst%24+-path:sh%24+-path:txt%24+-path:testsuite/+-path:tests/+-path:svn-base%24&patternType=standard&sm=1&groupBy=repo https://sourcegraph.com/search?q=context:global+std::experim... 2: https://sourcegraph.com/search?q=context:global+HWY_NAMESPACE+-path:clang-tidy+count:10000+-path:sycl+-path:highway/+-repo:highway+-path:man/+-path:md%24+-path:rst%24+-path:sh%24+-path:txt%24+-path:testsuite/+-path:tests/+-path:svn-base%24+-path:libjxl+-path:jpeg-xl+-path:jxl+-path:jpegli&patternType=standard&sm=1&groupBy=repo https://sourcegraph.com/search?q=context:global+HWY_NAMESPAC...