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/*
* Copyright (C) 2013 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef FTLSlowPathCallKey_h
#define FTLSlowPathCallKey_h
#if ENABLE(FTL_JIT)
#include "RegisterSet.h"
namespace JSC { namespace FTL {
// This is used for creating some sanity in slow-path calls out of the FTL's inline
// caches. The idea is that we don't want all of the register save/restore stuff to
// be generated at each IC site. Instead, the IC slow path call site will just save
// the registers needed for the arguments. It will arrange for there to be enough
// space on top of stack to save the remaining registers and the return PC. Then it
// will call a shared thunk that will save the remaining registers. That thunk needs
// to know the stack offset at which things get saved along with the call target.
// Note that the offset is *not including* the return PC that would be pushed on X86.
class SlowPathCallKey {
public:
SlowPathCallKey()
: m_callTarget(0)
, m_offset(0)
{
}
SlowPathCallKey(const RegisterSet& set, void* callTarget, ptrdiff_t offset)
: m_usedRegisters(set)
, m_callTarget(callTarget)
, m_offset(offset)
{
}
const RegisterSet& usedRegisters() const { return m_usedRegisters; }
void* callTarget() const { return m_callTarget; }
ptrdiff_t offset() const { return m_offset; }
void dump(PrintStream&) const;
enum EmptyValueTag { EmptyValue };
enum DeletedValueTag { DeletedValue };
SlowPathCallKey(EmptyValueTag)
: m_usedRegisters(RegisterSet::EmptyValue)
, m_callTarget(0)
, m_offset(0)
{
}
SlowPathCallKey(DeletedValueTag)
: m_usedRegisters(RegisterSet::DeletedValue)
, m_callTarget(0)
, m_offset(0)
{
}
bool isEmptyValue() const { return m_usedRegisters.isEmptyValue(); }
bool isDeletedValue() const { return m_usedRegisters.isDeletedValue(); }
bool operator==(const SlowPathCallKey& other) const
{
return m_usedRegisters == other.m_usedRegisters
&& m_callTarget == other.m_callTarget
&& m_offset == other.m_offset;
}
unsigned hash() const
{
return m_usedRegisters.hash() + PtrHash<void*>::hash(m_callTarget) + m_offset;
}
private:
RegisterSet m_usedRegisters;
void* m_callTarget;
ptrdiff_t m_offset;
};
struct SlowPathCallKeyHash {
static unsigned hash(const SlowPathCallKey& key) { return key.hash(); }
static bool equal(const SlowPathCallKey& a, const SlowPathCallKey& b) { return a == b; }
static const bool safeToCompareToEmptyOrDeleted = false;
};
} } // namespace JSC::FTL
namespace WTF {
template<typename T> struct DefaultHash;
template<> struct DefaultHash<JSC::FTL::SlowPathCallKey> {
typedef JSC::FTL::SlowPathCallKeyHash Hash;
};
template<typename T> struct HashTraits;
template<> struct HashTraits<JSC::FTL::SlowPathCallKey> : public CustomHashTraits<JSC::FTL::SlowPathCallKey> { };
} // namespace WTF
#endif // ENABLE(FTL_JIT)
#endif // FTLSlowPathCallKey_h