memcpy_avx.h

Go to the documentation of this file.

/*
 * Copyright (c) 2016 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*-
 *   BSD LICENSE
 *
 *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef included_clib_memcpy_avx_h
#define included_clib_memcpy_avx_h

#include <stdint.h>
#include <x86intrin.h>

static inline void
clib_mov16(u8 *dst, const u8 *src)
{
        __m128i xmm0;

        xmm0 = _mm_loadu_si128((const __m128i *)src);
        _mm_storeu_si128((__m128i *)dst, xmm0);
}

static inline void
clib_mov32(u8 *dst, const u8 *src)
{
        __m256i ymm0;

        ymm0 = _mm256_loadu_si256((const __m256i *)src);
        _mm256_storeu_si256((__m256i *)dst, ymm0);
}

static inline void
clib_mov64(u8 *dst, const u8 *src)
{
        clib_mov32((u8 *)dst + 0 * 32, (const u8 *)src + 0 * 32);
        clib_mov32((u8 *)dst + 1 * 32, (const u8 *)src + 1 * 32);
}

static inline void
clib_mov128(u8 *dst, const u8 *src)
{
        clib_mov64((u8 *)dst + 0 * 64, (const u8 *)src + 0 * 64);
        clib_mov64((u8 *)dst + 1 * 64, (const u8 *)src + 1 * 64);
}

static inline void
clib_mov256(u8 *dst, const u8 *src)
{
        clib_mov128((u8 *)dst + 0 * 128, (const u8 *)src + 0 * 128);
        clib_mov128((u8 *)dst + 1 * 128, (const u8 *)src + 1 * 128);
}

static inline void
clib_mov64blocks(u8 *dst, const u8 *src, size_t n)
{
        __m256i ymm0, ymm1;

        while (n >= 64) {
                ymm0 = _mm256_loadu_si256((const __m256i *)((const u8 *)src + 0 * 32));
                n -= 64;
                ymm1 = _mm256_loadu_si256((const __m256i *)((const u8 *)src + 1 * 32));
                src = (const u8 *)src + 64;
                _mm256_storeu_si256((__m256i *)((u8 *)dst + 0 * 32), ymm0);
                _mm256_storeu_si256((__m256i *)((u8 *)dst + 1 * 32), ymm1);
                dst = (u8 *)dst + 64;
        }
}

static inline void
clib_mov256blocks(u8 *dst, const u8 *src, size_t n)
{
        __m256i ymm0, ymm1, ymm2, ymm3, ymm4, ymm5, ymm6, ymm7;

        while (n >= 256) {
                ymm0 = _mm256_loadu_si256((const __m256i *)((const u8 *)src + 0 * 32));
                n -= 256;
                ymm1 = _mm256_loadu_si256((const __m256i *)((const u8 *)src + 1 * 32));
                ymm2 = _mm256_loadu_si256((const __m256i *)((const u8 *)src + 2 * 32));
                ymm3 = _mm256_loadu_si256((const __m256i *)((const u8 *)src + 3 * 32));
                ymm4 = _mm256_loadu_si256((const __m256i *)((const u8 *)src + 4 * 32));
                ymm5 = _mm256_loadu_si256((const __m256i *)((const u8 *)src + 5 * 32));
                ymm6 = _mm256_loadu_si256((const __m256i *)((const u8 *)src + 6 * 32));
                ymm7 = _mm256_loadu_si256((const __m256i *)((const u8 *)src + 7 * 32));
                src = (const u8 *)src + 256;
                _mm256_storeu_si256((__m256i *)((u8 *)dst + 0 * 32), ymm0);
                _mm256_storeu_si256((__m256i *)((u8 *)dst + 1 * 32), ymm1);
                _mm256_storeu_si256((__m256i *)((u8 *)dst + 2 * 32), ymm2);
                _mm256_storeu_si256((__m256i *)((u8 *)dst + 3 * 32), ymm3);
                _mm256_storeu_si256((__m256i *)((u8 *)dst + 4 * 32), ymm4);
                _mm256_storeu_si256((__m256i *)((u8 *)dst + 5 * 32), ymm5);
                _mm256_storeu_si256((__m256i *)((u8 *)dst + 6 * 32), ymm6);
                _mm256_storeu_si256((__m256i *)((u8 *)dst + 7 * 32), ymm7);
                dst = (u8 *)dst + 256;
        }
}

static inline void *
clib_memcpy(void *dst, const void *src, size_t n)
{
        uword dstu = (uword)dst;
        uword srcu = (uword)src;
        void *ret = dst;
        size_t dstofss;
        size_t bits;

        /**
         * Copy less than 16 bytes
         */
        if (n < 16) {
                if (n & 0x01) {
                        *(u8 *)dstu = *(const u8 *)srcu;
                        srcu = (uword)((const u8 *)srcu + 1);
                        dstu = (uword)((u8 *)dstu + 1);
                }
                if (n & 0x02) {
                        *(uint16_t *)dstu = *(const uint16_t *)srcu;
                        srcu = (uword)((const uint16_t *)srcu + 1);
                        dstu = (uword)((uint16_t *)dstu + 1);
                }
                if (n & 0x04) {
                        *(uint32_t *)dstu = *(const uint32_t *)srcu;
                        srcu = (uword)((const uint32_t *)srcu + 1);
                        dstu = (uword)((uint32_t *)dstu + 1);
                }
                if (n & 0x08) {
                        *(uint64_t *)dstu = *(const uint64_t *)srcu;
                }
                return ret;
        }

        /**
         * Fast way when copy size doesn't exceed 512 bytes
         */
        if (n <= 32) {
                clib_mov16((u8 *)dst, (const u8 *)src);
                clib_mov16((u8 *)dst - 16 + n, (const u8 *)src - 16 + n);
                return ret;
        }
        if (n <= 64) {
                clib_mov32((u8 *)dst, (const u8 *)src);
                clib_mov32((u8 *)dst - 32 + n, (const u8 *)src - 32 + n);
                return ret;
        }
        if (n <= 512) {
                if (n >= 256) {
                        n -= 256;
                        clib_mov256((u8 *)dst, (const u8 *)src);
                        src = (const u8 *)src + 256;
                        dst = (u8 *)dst + 256;
                }
                if (n >= 128) {
                        n -= 128;
                        clib_mov128((u8 *)dst, (const u8 *)src);
                        src = (const u8 *)src + 128;
                        dst = (u8 *)dst + 128;
                }
                if (n >= 64) {
                        n -= 64;
                        clib_mov64((u8 *)dst, (const u8 *)src);
                        src = (const u8 *)src + 64;
                        dst = (u8 *)dst + 64;
                }
COPY_BLOCK_64_BACK31:
                if (n > 32) {
                        clib_mov32((u8 *)dst, (const u8 *)src);
                        clib_mov32((u8 *)dst - 32 + n, (const u8 *)src - 32 + n);
                        return ret;
                }
                if (n > 0) {
                        clib_mov32((u8 *)dst - 32 + n, (const u8 *)src - 32 + n);
                }
                return ret;
        }

        /**
         * Make store aligned when copy size exceeds 512 bytes
         */
        dstofss = (uword)dst & 0x1F;
        if (dstofss > 0) {
                dstofss = 32 - dstofss;
                n -= dstofss;
                clib_mov32((u8 *)dst, (const u8 *)src);
                src = (const u8 *)src + dstofss;
                dst = (u8 *)dst + dstofss;
        }

        /**
         * Copy 256-byte blocks.
         * Use copy block function for better instruction order control,
         * which is important when load is unaligned.
         */
        clib_mov256blocks((u8 *)dst, (const u8 *)src, n);
        bits = n;
        n = n & 255;
        bits -= n;
        src = (const u8 *)src + bits;
        dst = (u8 *)dst + bits;

        /**
         * Copy 64-byte blocks.
         * Use copy block function for better instruction order control,
         * which is important when load is unaligned.
         */
        if (n >= 64) {
                clib_mov64blocks((u8 *)dst, (const u8 *)src, n);
                bits = n;
                n = n & 63;
                bits -= n;
                src = (const u8 *)src + bits;
                dst = (u8 *)dst + bits;
        }

        /**
         * Copy whatever left
         */
        goto COPY_BLOCK_64_BACK31;
}


#endif /* included_clib_mamcpy_avx_h */