[libc] [llvm] Add vector-based strlen implementation for x86_64 and aarch64 (PR #152389)

[via llvm-commits]

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@@ -0,0 +1,38 @@
+//===-- Strlen implementation -----------------------------------*- C++ -*-===//
+//
+// 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 LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_STRLEN_H
+#define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_STRLEN_H
+
+#include "src/__support/macros/attributes.h"               // LIBC_INLINE
+#include "src/__support/macros/properties/architectures.h" // LIBC_TARGET_ARCH_IS_
+
+#include <stddef.h> // size_t
+
+#if defined(LIBC_COPT_STRING_UNSAFE_WIDE_READ)
+#if defined(LIBC_TARGET_ARCH_IS_X86)
+#include "src/string/memory_utils/x86_64/inline_strlen.h"
+#define LIBC_SRC_STRING_MEMORY_UTILS_STRLEN_WIDE_READ string_length_x86
+#elif defined(LIBC_TARGET_ARCH_IS_AARCH64)
+#include "src/string/memory_utils/aarch64/inline_memcpy.h"
+#define LIBC_SRC_STRING_MEMORY_UTILS_STRLEN_WIDE_READ string_length_aarch64
+#else
+#define LIBC_SRC_STRING_MEMORY_UTILS_STRLEN_WIDE_READ string_length_wide_read
+#endif
+
+namespace LIBC_NAMESPACE_DECL {
+
+[[gnu::flatten]] LIBC_INLINE void
+inline_memcpy(void *__restrict dst, const void *__restrict src, size_t count) {
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lntue wrote:

why is `inline_memcpy` defined here?

https://github.com/llvm/llvm-project/pull/152389