346c172b32
This new libc is mostly from scratch, with *printf() functions provided by Marco Paland and Eyal Rozenberg's tiny printf library, and malloc and friends provided by dlmalloc.
56 lines
1.4 KiB
C++
56 lines
1.4 KiB
C++
#pragma once
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/** \file j6libc/copy.h
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* Internal implementations to aid in implementing mem* functions
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*
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* This file is part of the C standard library for the jsix operating
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* system.
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at https://mozilla.org/MPL/2.0/.
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*/
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#ifndef __cplusplus
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#error "__j6libc/copy.h included by non-C++ code"
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#endif
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#include <stddef.h>
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#include <__j6libc/size_t.h>
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namespace __j6libc {
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template <size_t N>
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inline void do_copy(char *s1, const char *s2) {
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#if __has_builtin(__builtin_memcpy_inline)
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__builtin_memcpy_inline(s1, s2, N);
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#else
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#warn "Not using __builtin_memcpy_inline for memcpy"
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for (size_t i = 0; i < N; ++i)
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s1[i] = s2[i];
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#endif
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}
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template <size_t N>
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inline void do_double_copy(char *s1, const char *s2, size_t n) {
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do_copy<N>(s1, s2);
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ptrdiff_t off = n - N;
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if (!off) return;
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do_copy<N>(s1+off, s2+off);
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}
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__attribute__((always_inline))
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inline void do_large_copy(char *s1, const char *s2, size_t n) {
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asm volatile ("rep movsb" : "+D"(s1), "+S"(s2), "+c"(n) :: "memory");
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}
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__attribute__((always_inline))
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inline void do_backward_copy(char *s1, const char *s2, size_t n) {
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for (size_t i = n - 1; i < n; --i)
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s1[i] = s2[i];
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}
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} // namespace __j6libc
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