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 #include "main/macros.h"
30 #include "main/streaming-load-memcpy.h"
31 #include <smmintrin.h>
32
33 /* Copies memory from src to dst, using SSE 4.1's MOVNTDQA to get streaming
34 * read performance from uncached memory.
35 */
36 void
_mesa_streaming_load_memcpy(void * restrict dst,void * restrict src,size_t len)37 _mesa_streaming_load_memcpy(void *restrict dst, void *restrict src, size_t len)
38 {
39 char *restrict d = dst;
40 char *restrict s = src;
41
42 /* If dst and src are not co-aligned, fallback to memcpy(). */
43 if (((uintptr_t)d & 15) != ((uintptr_t)s & 15)) {
44 memcpy(d, s, len);
45 return;
46 }
47
48 /* memcpy() the misaligned header. At the end of this if block, <d> and <s>
49 * are aligned to a 16-byte boundary or <len> == 0.
50 */
51 if ((uintptr_t)d & 15) {
52 uintptr_t bytes_before_alignment_boundary = 16 - ((uintptr_t)d & 15);
53 assert(bytes_before_alignment_boundary < 16);
54
55 memcpy(d, s, MIN2(bytes_before_alignment_boundary, len));
56
57 d = (char *)ALIGN((uintptr_t)d, 16);
58 s = (char *)ALIGN((uintptr_t)s, 16);
59 len -= MIN2(bytes_before_alignment_boundary, len);
60 }
61
62 if (len >= 64)
63 _mm_mfence();
64
65 while (len >= 64) {
66 __m128i *dst_cacheline = (__m128i *)d;
67 __m128i *src_cacheline = (__m128i *)s;
68
69 __m128i temp1 = _mm_stream_load_si128(src_cacheline + 0);
70 __m128i temp2 = _mm_stream_load_si128(src_cacheline + 1);
71 __m128i temp3 = _mm_stream_load_si128(src_cacheline + 2);
72 __m128i temp4 = _mm_stream_load_si128(src_cacheline + 3);
73
74 _mm_store_si128(dst_cacheline + 0, temp1);
75 _mm_store_si128(dst_cacheline + 1, temp2);
76 _mm_store_si128(dst_cacheline + 2, temp3);
77 _mm_store_si128(dst_cacheline + 3, temp4);
78
79 d += 64;
80 s += 64;
81 len -= 64;
82 }
83
84 /* memcpy() the tail. */
85 if (len) {
86 memcpy(d, s, len);
87 }
88 }
89