1/*
2 * Copyright (C) 2016-2017 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 "WasmMemoryInformation.h"
28
29#if ENABLE(WEBASSEMBLY)
30
31#include "WasmCallingConvention.h"
32#include "WasmContextInlines.h"
33#include "WasmMemory.h"
34#include <wtf/NeverDestroyed.h>
35
36namespace JSC { namespace Wasm {
37
38static Vector<GPRReg> getPinnedRegisters(unsigned remainingPinnedRegisters)
39{
40 Vector<GPRReg> registers;
41 jscCallingConvention().m_calleeSaveRegisters.forEach([&] (Reg reg) {
42 if (!reg.isGPR())
43 return;
44 GPRReg gpr = reg.gpr();
45 if (!remainingPinnedRegisters || RegisterSet::stackRegisters().get(reg))
46 return;
47 if (RegisterSet::runtimeTagRegisters().get(reg)) {
48 // Since we don't need to, we currently don't pick from the tag registers to allow
49 // JS->Wasm stubs to freely use these registers.
50 return;
51 }
52 --remainingPinnedRegisters;
53 registers.append(gpr);
54 });
55 return registers;
56}
57
58const PinnedRegisterInfo& PinnedRegisterInfo::get()
59{
60 static LazyNeverDestroyed<PinnedRegisterInfo> staticPinnedRegisterInfo;
61 static std::once_flag staticPinnedRegisterInfoFlag;
62 std::call_once(staticPinnedRegisterInfoFlag, [] () {
63 unsigned numberOfPinnedRegisters = 2;
64 if (!Context::useFastTLS())
65 ++numberOfPinnedRegisters;
66 Vector<GPRReg> pinnedRegs = getPinnedRegisters(numberOfPinnedRegisters);
67
68 GPRReg baseMemoryPointer = pinnedRegs.takeLast();
69 GPRReg sizeRegister = pinnedRegs.takeLast();
70 GPRReg wasmContextInstancePointer = InvalidGPRReg;
71 if (!Context::useFastTLS())
72 wasmContextInstancePointer = pinnedRegs.takeLast();
73
74 staticPinnedRegisterInfo.construct(sizeRegister, baseMemoryPointer, wasmContextInstancePointer);
75 });
76
77 return staticPinnedRegisterInfo.get();
78}
79
80PinnedRegisterInfo::PinnedRegisterInfo(GPRReg sizeRegister, GPRReg baseMemoryPointer, GPRReg wasmContextInstancePointer)
81 : sizeRegister(sizeRegister)
82 , baseMemoryPointer(baseMemoryPointer)
83 , wasmContextInstancePointer(wasmContextInstancePointer)
84{
85}
86
87MemoryInformation::MemoryInformation(PageCount initial, PageCount maximum, bool isImport)
88 : m_initial(initial)
89 , m_maximum(maximum)
90 , m_isImport(isImport)
91{
92 RELEASE_ASSERT(!!m_initial);
93 RELEASE_ASSERT(!m_maximum || m_maximum >= m_initial);
94 ASSERT(!!*this);
95}
96
97} } // namespace JSC::Wasm
98
99#endif // ENABLE(WEBASSEMBLY)
100