From: Jonathan Wakely <jwakely@redhat.com>
To: Matthias Kretz <m.kretz@gsi.de>
Cc: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org
Subject: Re: [PATCH 2/2] libstdc++: Fix simd compilation with Clang
Date: Tue, 21 Mar 2023 11:19:35 +0000 [thread overview]
Message-ID: <CACb0b4nf-+u34UiV7DZ=v-06_qjBWVddihSWdTtOyg0c5fvfDg@mail.gmail.com> (raw)
In-Reply-To: <25835488.EfDdHjke4D@minbar>
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On Tue, 21 Mar 2023 at 09:24, Matthias Kretz via Libstdc++ <
libstdc++@gcc.gnu.org> wrote:
>
>
> Clang fails to compile some constant expressions involving simd.
> Therefore, just disable this non-conforming extension for clang.
>
> Fix AVX512 blend implementation for Clang. It was converting the bitmask
> to bool before, which is obviously wrong. Instead use a Clang builtin to
> convert the bitmask to vector-mask before using a vector blend ?:. A
> similar change is required for the masked unary implementation, because
> the GCC builtins do not exist on Clang.
>
> Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
>
> libstdc++-v3/ChangeLog:
>
> * include/experimental/bits/simd_detail.h: Don't declare the
> simd API as constexpr with Clang.
> * include/experimental/bits/simd_x86.h (__movm): New.
> (_S_blend_avx512): Resolve FIXME. Implement blend using __movm
> and ?:.
> (_SimdImplX86::_S_masked_unary): Clang does not implement the
> same builtins. Implement the function using __movm, ?:, and -
> operators on vector_size types instead.
>
+#if (defined __STRICT_ANSI__ && __STRICT_ANSI__) || defined __clang__
We don't generally are about -Wundef so this could be simplified to:
#if __STRICT_ANSI__ || defined __clang__
But it's OK as it is. OK for trunk.
next prev parent reply other threads:[~2023-03-21 11:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-21 9:22 [PATCH 0/2] Make std::experimental::simd (more) usable " Matthias Kretz
2023-03-21 9:23 ` [PATCH 1/2] libstdc++: Fix simd test compilation " Matthias Kretz
2023-03-21 11:16 ` Jonathan Wakely
2023-03-21 9:23 ` [PATCH 2/2] libstdc++: Fix simd " Matthias Kretz
2023-03-21 11:19 ` Jonathan Wakely [this message]
2023-03-21 17:01 ` [committed] " Matthias Kretz
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