[libcxx-commits] [libcxx] [libc++] Vectorize mismatch (PR #73255)

[Nikolas Klauser via libcxx-commits]

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@@ -0,0 +1,114 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___ALGORITHM_SIMD_UTILS_H
+#define _LIBCPP___ALGORITHM_SIMD_UTILS_H
+
+#include <__bit/bit_cast.h>
+#include <__bit/countr.h>
+#include <__config>
+#include <__type_traits/is_arithmetic.h>
+#include <__type_traits/is_same.h>
+#include <__utility/integer_sequence.h>
+#include <cstddef>
+#include <cstdint>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER >= 14 && __has_attribute(__ext_vector_type__) && __has_builtin(__builtin_reduce_and) &&            \
+    __has_builtin(__builtin_convertvector)
+#  define _LIBCPP_HAS_ALGORITHM_VECTOR_UTILS 1
+#else
+#  define _LIBCPP_HAS_ALGORITHM_VECTOR_UTILS 0
+#endif
+
+#if _LIBCPP_HAS_ALGORITHM_VECTOR_UTILS && !defined(__OPTIMIZE_SIZE__)
+#  define _LIBCPP_VECTORIZE_ALGORIHTMS 1
+#else
+#  define _LIBCPP_VECTORIZE_ALGORIHTMS 0
+#endif
+
+#if _LIBCPP_HAS_ALGORITHM_VECTOR_UTILS
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#  if defined(__AVX512F__)
+template <class _Tp>
+inline constexpr size_t __native_vector_size = 64 / sizeof(_Tp);
----------------
philnik777 wrote:

I'm pretty sure there is no way to get the value of `-mprefer-vector-width`. Since I don't really expect a performance difference for now anyways I'm just going to remove the 64 byte vector for now. Maybe I'll reintroduce it at some point if there is any evidence that it makes a difference for some algorithm.

https://github.com/llvm/llvm-project/pull/73255