On Tue, Dec 15, 2020 at 12:42:24PM +0900, Norbert Preining wrote: > Hi Julian, > > thanks for the suggestion, sounds interesting.
Yeah, I'm looking at this from APT's side of things, because I have a custom Intel CRC32c implementation for cache hashing, and want to optimize and while unoptimized XXH3 is the same - two times faster, optimized XXH3 (AVX2) yields results similar to Mark Adler's 3-way CRC32c code (another 2 times faster or so), just without having all that vendorization :) > > On Mon, 14 Dec 2020, Julian Andres Klode wrote: > > > At the bare minimum, on x86, export DIGEST=1 when building and install > > > xxh_x86dispatch.h header. I'd love to see the xxh_x86dispatch.h also > > Do you have something like the following in mind? > --- a/debian/libxxhash-dev.install > +++ b/debian/libxxhash-dev.install > @@ -4,3 +4,4 @@ usr/include/xxhash.h > usr/include/xxh3.h > usr/lib/*/pkgconfig/libxxhash.pc > doc/xxhash_spec.md usr/share/doc/libxxhash-dev > +xxh_x86dispatch.h /usr/include (1) /usr/include/xxh_x86dispatch.h works for me too (2) might make sense to only ship that file when building with dispatch. So the clever path out seems to be to just say usr/include/xxh*.h, as that will pick up xxh_x86dispatch.h when we're building with DISPATCH=1, and doesn't pick it up when building without :) > diff --git a/debian/rules b/debian/rules > index 2053a97..b6159cd 100755 > --- a/debian/rules > +++ b/debian/rules > @@ -2,7 +2,12 @@ > > #export DH_VERBOSE=1 > > -DEB_HOST_MULTIARCH ?= $(shell dpkg-architecture -qDEB_HOST_MULTIARCH) > +include /usr/share/dpkg/architecture.mk > + > +ifeq ($(DEB_HOST_ARCH),$(filter $(DEB_HOST_ARCH),i386 amd64)) > + export DISPATCH=1 > +endif Maybe Filter for DEB_HOST_ARCH_CPU instead, so it works on non-Linux arch, or use dpkg-architecture --is any-amd64 || dpkg-architecture --is any-i386. But not sure symbols files support wildcards, and: You also need to add various _dispatch symbols to the symbols file for those architectures, like this, but with (arch=amd64 i386) in front of them I suppose. --- debian/libxxhash0.symbols (libxxhash0_0.8.0-1_amd64) +++ dpkg-gensymbolsSwiZXg 2020-12-15 12:38:51.857342147 +0100 @@ -15,20 +15,28 @@ XXH32_update@Base 0.6.5 XXH3_128bits@Base 0.7.0 XXH3_128bits_digest@Base 0.7.1 + XXH3_128bits_dispatch@Base 0.8.0-1 XXH3_128bits_reset@Base 0.7.1 XXH3_128bits_reset_withSecret@Base 0.7.1 XXH3_128bits_reset_withSeed@Base 0.7.1 XXH3_128bits_update@Base 0.7.1 + XXH3_128bits_update_dispatch@Base 0.8.0-1 XXH3_128bits_withSecret@Base 0.7.1 + XXH3_128bits_withSecret_dispatch@Base 0.8.0-1 XXH3_128bits_withSeed@Base 0.7.0 + XXH3_128bits_withSeed_dispatch@Base 0.8.0-1 XXH3_64bits@Base 0.7.0 XXH3_64bits_digest@Base 0.7.1 + XXH3_64bits_dispatch@Base 0.8.0-1 XXH3_64bits_reset@Base 0.7.1 XXH3_64bits_reset_withSecret@Base 0.7.1 XXH3_64bits_reset_withSeed@Base 0.7.1 XXH3_64bits_update@Base 0.7.1 + XXH3_64bits_update_dispatch@Base 0.8.0-1 XXH3_64bits_withSecret@Base 0.7.1 + XXH3_64bits_withSecret_dispatch@Base 0.8.0-1 XXH3_64bits_withSeed@Base 0.7.0 + XXH3_64bits_withSeed_dispatch@Base 0.8.0-1 XXH3_copyState@Base 0.7.1 XXH3_createState@Base 0.7.1 XXH3_freeState@Base 0.7.1 -- debian developer - deb.li/jak | jak-linux.org - free software dev ubuntu core developer i speak de, en
