Date: Sun, 25 Sep 2022 22:46:47 +0200 From: Dimitry Andric <dim@FreeBSD.org> To: Jan Beich <jbeich@FreeBSD.org> Cc: Christian Weisgerber <naddy@mips.inka.de>, freebsd-current@freebsd.org Subject: Re: Did clang 14 lose some intrinsics support? Message-ID: <1A903FD8-D904-4B91-ABC4-2F704F0E2CF4@FreeBSD.org> In-Reply-To: <zgen-6zwv-wny@FreeBSD.org> References: <YzCL/%2BUEhLy7kHaL@lorvorc.mips.inka.de> <zgen-6zwv-wny@FreeBSD.org>
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--Apple-Mail=_6A6C5323-8673-47D3-90AB-FAAB7E847848 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii On 25 Sep 2022, at 21:02, Jan Beich <jbeich@FreeBSD.org> wrote: > > Christian Weisgerber <naddy@mips.inka.de> writes: > >> Did we lose support for SSSE3 and AVX2 intrinsics on amd64 with >> clang 14? > > __builtin_* appear unstable unlike _mm* intrinsics. Clang 15 seems > to hide more but I'm not sure about the cause (need bisecting). Yeah, these internal names are constantly changing. I don't know the reason for it, but it's terribly annoying when diagnosing failures with preprocessed files, as these tend to break when compiled with a much earlier or later copy of clang. > ===> clang version 15.0.1 > #define SSE2_SUPPORTED 1 > #define SSE_SUPPORTED 1 > > ===> clang version 15.0.1 with -march=native > #define AVX_SUPPORTED 1 > #define FMA_SUPPORTED 1 > #define SSE2_SUPPORTED 1 > #define SSE4_1_SUPPORTED 1 > #define SSE_SUPPORTED 1 > >> #if __has_builtin(__builtin_ia32_pabsd128) >> #define SSSE3_SUPPORTED 1 >> #endif > [...] >> #if __has_builtin(__builtin_ia32_pabsd256) >> #define AVX2_SUPPORTED 1 >> #endif > > See https://github.com/llvm/llvm-project/commit/e5147f82e1cb > > - Instead of __builtin_ia32_pabsd128 maybe use _mm_abs_epi32 > - Instead of __builtin_ia32_pabsd256 maybe use _mm256_abs_epi32 > I'm wondering why this rather fragile method is chosen? If you want to know whether SSE is supported, you check for __SSE__, and similarly __SSE2__, __AVX__ and a bunch of others. That is also portable to gcc. -Dimitry --Apple-Mail=_6A6C5323-8673-47D3-90AB-FAAB7E847848 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.2 iF0EARECAB0WIQR6tGLSzjX8bUI5T82wXqMKLiCWowUCYzC+NwAKCRCwXqMKLiCW o7zLAJ4+KxyghfjJZriIcC2tPbhcZPQ7eACg8KGwhFatN/7MdCi+EC0cliBs9v8= =XJ7C -----END PGP SIGNATURE----- --Apple-Mail=_6A6C5323-8673-47D3-90AB-FAAB7E847848--
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