1/*
2 * Copyright (C) 2014 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 "FloatingPointEnvironment.h"
28
29#include <wtf/MainThread.h>
30#include <wtf/NeverDestroyed.h>
31
32#if PLATFORM(IOS)
33
34namespace WebCore {
35
36FloatingPointEnvironment& FloatingPointEnvironment::shared()
37{
38    static NeverDestroyed<FloatingPointEnvironment> floatingPointEnvironment;
39    return floatingPointEnvironment;
40}
41
42FloatingPointEnvironment::FloatingPointEnvironment()
43    : m_isInitialized(false)
44{
45}
46
47void FloatingPointEnvironment::enableDenormalSupport()
48{
49    RELEASE_ASSERT(isUIThread());
50#if defined _ARM_ARCH_7
51    fenv_t env;
52    fegetenv(&env);
53    env.__fpscr &= ~0x01000000U;
54    fesetenv(&env);
55#endif
56    // Supporting denormal mode is already the default on x86, x86_64, and ARM64.
57}
58
59void FloatingPointEnvironment::saveMainThreadEnvironment()
60{
61    RELEASE_ASSERT(!m_isInitialized);
62    RELEASE_ASSERT(isUIThread());
63    fegetenv(&m_mainThreadEnvironment);
64    m_isInitialized = true;
65}
66
67void FloatingPointEnvironment::propagateMainThreadEnvironment()
68{
69    RELEASE_ASSERT(m_isInitialized);
70    RELEASE_ASSERT(!isUIThread());
71    fesetenv(&m_mainThreadEnvironment);
72}
73
74} // namespace WebCore
75
76#endif // PLATFORM(IOS)
77