1/*
2 * Copyright (C) 2016 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "ArrayConventions.h"
28
29#include "JSCInlines.h"
30
31namespace JSC {
32
33#if USE(JSVALUE64)
34void clearArrayMemset(WriteBarrier<Unknown>* base, unsigned count)
35{
36#if CPU(X86_64) && COMPILER(GCC_COMPATIBLE)
37 uint64_t zero = 0;
38 asm volatile (
39 "rep stosq\n\t"
40 : "+D"(base), "+c"(count)
41 : "a"(zero)
42 : "memory"
43 );
44#else // not CPU(X86_64)
45 memset(base, 0, count * sizeof(WriteBarrier<Unknown>));
46#endif // generic CPU
47}
48
49void clearArrayMemset(double* base, unsigned count)
50{
51#if CPU(X86_64) && COMPILER(GCC_COMPATIBLE)
52 uint64_t pnan = bitwise_cast<uint64_t>(PNaN);
53 asm volatile (
54 "rep stosq\n\t"
55 : "+D"(base), "+c"(count)
56 : "a"(pnan)
57 : "memory"
58 );
59#else // not CPU(X86_64)
60 // Oh no, we can't actually do any better than this!
61 for (unsigned i = count; i--;)
62 base[i] = PNaN;
63#endif // generic CPU
64}
65#endif // USE(JSVALUE64)
66
67} // namespace JSC
68
69