107 lines
3.1 KiB
C
107 lines
3.1 KiB
C
/*
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* Copyright (c) 2021-2021 Huawei Device Co., Ltd. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice, this list of
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* conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice, this list
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* of conditions and the following disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* 3. Neither the name of the copyright holder nor the names of its contributors may be used
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* to endorse or promote products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <stdint.h>
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void *memset(void *dest, int c, size_t n)
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{
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char *pos = dest;
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uint32_t c32 = 0;
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uint64_t c64 = 0;
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if (n == 0) return dest;
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c = c & 0xFF;
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if (c) {
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c32 = c;
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c32 |= c32 << 8;
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c32 |= c32 << 16;
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c64 = c32;
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c64 |= c64 << 32;
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}
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if (((uintptr_t)(pos) & 7) != 0) {
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int unalignedCnt = 8 - ((uintptr_t)(pos) & 7);
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if (n >= unalignedCnt) {
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n = n - unalignedCnt;
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} else {
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unalignedCnt = n;
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n = 0;
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}
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for (int loop = 1; loop <= unalignedCnt; ++loop) {
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*pos = (char)c;
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pos++;
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}
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}
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/* L32_byte_aligned */
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while (n >= 32) {
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*(uint64_t *)(pos) = c64;
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*(uint64_t *)(pos + 8) = c64;
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*(uint64_t *)(pos + 16) = c64;
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*(uint64_t *)(pos + 24) = c64;
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n -= 32;
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pos += 32;
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}
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if (n == 0) return dest;
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/* L16_byte_aligned */
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if (n >= 16) {
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*(uint64_t *)(pos) = c64;
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*(uint64_t *)(pos + 8) = c64;
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n -= 16;
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pos += 16;
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if (n == 0) return dest;
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}
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/* L8_byte_aligned */
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if (n >= 8) {
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*(uint64_t *)(pos) = c64;
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n -= 8;
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pos += 8;
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if (n == 0) return dest;
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}
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/* L4_byte_aligned */
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if (n >= 4) {
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*(uint32_t *)(pos) = c32;
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n -= 4;
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pos += 4;
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if (n == 0) return dest;
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}
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while (n--) {
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*pos++ = c;
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}
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return dest;
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} |