1 /* Copyright (C) 2011-2014 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library. If not, see
17 <http://www.gnu.org/licenses/>. */
23 #include <arch/chip.h>
25 /* How many cache lines ahead should we prefetch? */
26 #define PREFETCH_LINES_AHEAD 3
29 __memcpy (void *__restrict dstv, const void *__restrict srcv, size_t n)
31 char *__restrict dst1 = (char *) dstv;
32 const char *__restrict src1 = (const char *) srcv;
33 const char *__restrict src1_end;
34 const char *__restrict prefetch;
35 op_t *__restrict dst8; /* 8-byte pointer to destination memory. */
36 op_t final; /* Final bytes to write to trailing word, if any */
46 /* Locate the end of source memory we will copy. Don't prefetch
48 src1_end = src1 + n - 1;
50 /* Prefetch ahead a few cache lines, but not past the end. */
52 for (i = 0; i < PREFETCH_LINES_AHEAD; i++)
54 __insn_prefetch (prefetch);
55 prefetch += CHIP_L2_LINE_SIZE ();
56 prefetch = (prefetch < src1_end) ? prefetch : src1;
59 /* Copy bytes until dst is word-aligned. */
60 for (; (uintptr_t) dst1 & (sizeof (op_t) - 1); n--)
63 /* 8-byte pointer to destination memory. */
66 if (__builtin_expect ((uintptr_t) src1 & (sizeof (op_t) - 1), 0))
68 /* Misaligned copy. Use glibc's _wordcopy_fwd_dest_aligned, but
69 inline it to avoid prologue/epilogue. TODO: Consider
70 prefetching and using wh64 as well. */
73 long int dstp = (long int) dst1;
74 long int srcp = (long int) src1;
75 long int len = n / OPSIZ;
77 /* Save the initial source pointer so we know the number of
78 bytes to shift for merging two unaligned results. */
81 /* Make SRCP aligned by rounding it down to the beginning of the
82 `op_t' it points in the middle of. */
88 a1 = ((op_t *) srcp)[0];
89 a2 = ((op_t *) srcp)[1];
94 a0 = ((op_t *) srcp)[0];
95 a1 = ((op_t *) srcp)[1];
100 if (OP_T_THRES <= 3 * OPSIZ && len == 0)
102 a3 = ((op_t *) srcp)[0];
103 a0 = ((op_t *) srcp)[1];
108 a2 = ((op_t *) srcp)[0];
109 a3 = ((op_t *) srcp)[1];
112 if (OP_T_THRES <= 3 * OPSIZ && len == 0)
114 goto do4; /* No-op. */
120 a0 = ((op_t *) srcp)[0];
121 a2 = __insn_dblalign (a2, a3, srci);
122 ((op_t *) dstp)[0] = a2;
126 a1 = ((op_t *) srcp)[0];
127 a3 = __insn_dblalign (a3, a0, srci);
128 ((op_t *) dstp)[0] = a3;
132 a2 = ((op_t *) srcp)[0];
133 a0 = __insn_dblalign (a0, a1, srci);
134 ((op_t *) dstp)[0] = a0;
138 a3 = ((op_t *) srcp)[0];
139 a1 = __insn_dblalign (a1, a2, srci);
140 ((op_t *) dstp)[0] = a1;
147 /* This is the right position for do0. Please don't move
150 ((op_t *) dstp)[0] = __insn_dblalign (a2, a3, srci);
156 a0 = ((const char *) srcp <= src1_end) ? ((op_t *) srcp)[0] : 0;
158 final = __insn_dblalign (a3, a0, srci);
159 dst8 = (op_t *)(dstp + OPSIZ);
165 const op_t *__restrict src8 = (const op_t *) src1;
167 /* src8 and dst8 are both word-aligned. */
168 if (n >= CHIP_L2_LINE_SIZE ())
170 /* Copy until 'dst' is cache-line-aligned. */
171 for (; (uintptr_t) dst8 & (CHIP_L2_LINE_SIZE () - 1);
175 for (; n >= CHIP_L2_LINE_SIZE ();)
177 op_t tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
179 /* Prefetch and advance to next line to prefetch, but
180 don't go past the end. */
181 __insn_prefetch (prefetch);
182 prefetch += CHIP_L2_LINE_SIZE ();
183 prefetch = (prefetch < src1_end) ? prefetch :
186 /* Do all the loads before wh64. This is necessary if
187 [src8, src8+7] and [dst8, dst8+7] share the same
188 cache line and dst8 <= src8, as can be the case when
189 called from memmove, or with code tested on x86 whose
190 memcpy always works with forward copies. */
213 #if CHIP_L2_LINE_SIZE() != 64
214 # error "Fix code that assumes particular L2 cache line size."
218 for (; n >= sizeof (op_t); n -= sizeof (op_t))
221 if (__builtin_expect (n == 0, 1))
227 /* n != 0 if we get here. Write out any trailing bytes. */
228 dst1 = (char *) dst8;
229 #ifndef __BIG_ENDIAN__
232 *(uint32_t *) dst1 = final;
239 *(uint16_t *) dst1 = final;
245 *(uint8_t *) dst1 = final;
249 *(uint32_t *) dst1 = final >> 32;
258 *(uint16_t *) dst1 = final >> 16;
266 *(uint8_t *) dst1 = final >> 8;
271 weak_alias (__memcpy, memcpy)
272 libc_hidden_builtin_def (memcpy)