1/*
2 * Copyright (C) 2013 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#ifndef MaxFrameExtentForSlowPathCall_h
27#define MaxFrameExtentForSlowPathCall_h
28
29#include "JSStack.h"
30#include "Register.h"
31#include "StackAlignment.h"
32#include <wtf/Assertions.h>
33
34namespace JSC {
35
36// The maxFrameExtentForSlowPathCall is the max amount of stack space (in bytes)
37// that can be used for outgoing args when calling a slow path C function
38// from JS code.
39
40#if !ENABLE(JIT)
41static const size_t maxFrameExtentForSlowPathCall = 0;
42
43#elif CPU(X86_64) && OS(WINDOWS)
44// 4 args in registers, but stack space needs to be allocated for all args.
45static const size_t maxFrameExtentForSlowPathCall = 64;
46
47#elif CPU(X86_64)
48// All args in registers.
49static const size_t maxFrameExtentForSlowPathCall = 0;
50
51#elif CPU(X86)
52// 7 args on stack (28 bytes).
53static const size_t maxFrameExtentForSlowPathCall = 40;
54
55#elif CPU(ARM64)
56// All args in registers.
57static const size_t maxFrameExtentForSlowPathCall = 0;
58
59#elif CPU(ARM)
60// First four args in registers, remaining 4 args on stack.
61static const size_t maxFrameExtentForSlowPathCall = 24;
62
63#elif CPU(SH4)
64// First four args in registers, remaining 4 args on stack.
65static const size_t maxFrameExtentForSlowPathCall = 24;
66
67#elif CPU(MIPS)
68// Though args are in registers, there need to be space on the stack for all args.
69static const size_t maxFrameExtentForSlowPathCall = 40;
70
71#else
72#error "Unsupported CPU: need value for maxFrameExtentForSlowPathCall"
73
74#endif
75
76COMPILE_ASSERT(!(maxFrameExtentForSlowPathCall % sizeof(Register)), extent_must_be_in_multiples_of_registers);
77
78#if ENABLE(JIT)
79// Make sure that cfr - maxFrameExtentForSlowPathCall bytes will make the stack pointer aligned
80COMPILE_ASSERT((maxFrameExtentForSlowPathCall % 16) == 16 - sizeof(CallerFrameAndPC), extent_must_align_stack_from_callframe_pointer);
81#endif
82
83static const size_t maxFrameExtentForSlowPathCallInRegisters = maxFrameExtentForSlowPathCall / sizeof(Register);
84
85} // namespace JSC
86
87#endif // MaxFrameExtentForSlowPathCall_h
88
89