src/mesa/main/streaming-load-memcpy.c

   1 /*
   2  * Copyright © 2013 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  *    Matt Turner <mattst88@gmail.com>
  26  *
  27  */
  28
  29 #ifdef __SSE4_1__
  30 #include "main/macros.h"
  31 #include "main/streaming-load-memcpy.h"
  32 #include <smmintrin.h>
  33
  34 /* Copies memory from src to dst, using SSE 4.1's MOVNTDQA to get streaming
  35  * read performance from uncached memory.
  36  */
  37 void
  38 _mesa_streaming_load_memcpy(void *restrict dst, void *restrict src, size_t len)
  39 {
  40    char *restrict d = dst;
  41    char *restrict s = src;
  42
  43    /* If dst and src are not co-aligned, fallback to memcpy(). */
  44    if (((uintptr_t)d & 15) != ((uintptr_t)s & 15)) {
  45       memcpy(d, s, len);
  46       return;
  47    }
  48
  49    /* memcpy() the misaligned header. At the end of this if block, <d> and <s>
  50     * are aligned to a 16-byte boundary or <len> == 0.
  51     */
  52    if ((uintptr_t)d & 15) {
  53       uintptr_t bytes_before_alignment_boundary = 16 - ((uintptr_t)d & 15);
  54       assert(bytes_before_alignment_boundary < 16);
  55
  56       memcpy(d, s, MIN2(bytes_before_alignment_boundary, len));
  57
  58       d = (char *)ALIGN((uintptr_t)d, 16);
  59       s = (char *)ALIGN((uintptr_t)s, 16);
  60       len -= MIN2(bytes_before_alignment_boundary, len);
  61    }
  62
  63    while (len >= 64) {
  64       __m128i *dst_cacheline = (__m128i *)d;
  65       __m128i *src_cacheline = (__m128i *)s;
  66
  67       __m128i temp1 = _mm_stream_load_si128(src_cacheline + 0);
  68       __m128i temp2 = _mm_stream_load_si128(src_cacheline + 1);
  69       __m128i temp3 = _mm_stream_load_si128(src_cacheline + 2);
  70       __m128i temp4 = _mm_stream_load_si128(src_cacheline + 3);
  71
  72       _mm_store_si128(dst_cacheline + 0, temp1);
  73       _mm_store_si128(dst_cacheline + 1, temp2);
  74       _mm_store_si128(dst_cacheline + 2, temp3);
  75       _mm_store_si128(dst_cacheline + 3, temp4);
  76
  77       d += 64;
  78       s += 64;
  79       len -= 64;
  80    }
  81
  82    /* memcpy() the tail. */
  83    if (len) {
  84       memcpy(d, s, len);
  85    }
  86 }
  87
  88 #endif