darling-JavaScriptCore/dfg/DFGEdge.h

250 lines
7.4 KiB
C++

/*
* Copyright (C) 2011, 2013, 2014 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.
*/
#pragma once
#if ENABLE(DFG_JIT)
#include "DFGCommon.h"
#include "DFGUseKind.h"
namespace JSC { namespace DFG {
class AdjacencyList;
class Edge {
public:
explicit Edge(Node* node = nullptr, UseKind useKind = UntypedUse, ProofStatus proofStatus = NeedsCheck, KillStatus killStatus = DoesNotKill)
#if USE(JSVALUE64)
: m_encodedWord(makeWord(node, useKind, proofStatus, killStatus))
#else
: m_node(node)
, m_encodedWord(makeWord(useKind, proofStatus, killStatus))
#endif
{
}
#if USE(JSVALUE64)
Node* node() const { return bitwise_cast<Node*>(m_encodedWord >> shift()); }
#else
Node* node() const { return m_node; }
#endif
Node& operator*() const { return *node(); }
Node* operator->() const { return node(); }
void setNode(Node* node)
{
#if USE(JSVALUE64)
m_encodedWord = makeWord(node, useKind(), proofStatus(), killStatus());
#else
m_node = node;
#endif
}
UseKind useKindUnchecked() const
{
#if USE(JSVALUE64)
unsigned masked = m_encodedWord & (((1 << shift()) - 1));
unsigned shifted = masked >> 2;
#else
unsigned shifted = static_cast<UseKind>(m_encodedWord) >> 2;
#endif
ASSERT(shifted < static_cast<unsigned>(LastUseKind));
UseKind result = static_cast<UseKind>(shifted);
ASSERT(node() || result == UntypedUse);
return result;
}
UseKind useKind() const
{
ASSERT(node());
return useKindUnchecked();
}
void setUseKind(UseKind useKind)
{
ASSERT(node());
#if USE(JSVALUE64)
m_encodedWord = makeWord(node(), useKind, proofStatus(), killStatus());
#else
m_encodedWord = makeWord(useKind, proofStatus(), killStatus());
#endif
}
ProofStatus proofStatusUnchecked() const
{
return proofStatusForIsProved(m_encodedWord & 1);
}
ProofStatus proofStatus() const
{
ASSERT(node());
return proofStatusUnchecked();
}
void setProofStatus(ProofStatus proofStatus)
{
ASSERT(node());
#if USE(JSVALUE64)
m_encodedWord = makeWord(node(), useKind(), proofStatus, killStatus());
#else
m_encodedWord = makeWord(useKind(), proofStatus, killStatus());
#endif
}
bool isProved() const
{
return proofStatus() == IsProved;
}
bool willNotHaveCheck() const
{
return isProved() || shouldNotHaveTypeCheck(useKind());
}
bool willHaveCheck() const
{
return !willNotHaveCheck();
}
KillStatus killStatusUnchecked() const
{
return killStatusForDoesKill(m_encodedWord & 2);
}
KillStatus killStatus() const
{
ASSERT(node());
return killStatusUnchecked();
}
void setKillStatus(KillStatus killStatus)
{
ASSERT(node());
#if USE(JSVALUE64)
m_encodedWord = makeWord(node(), useKind(), proofStatus(), killStatus);
#else
m_encodedWord = makeWord(useKind(), proofStatus(), killStatus);
#endif
}
bool doesKill() const { return DFG::doesKill(killStatus()); }
bool isSet() const { return !!node(); }
Edge sanitized() const
{
Edge result = *this;
#if USE(JSVALUE64)
result.m_encodedWord = makeWord(node(), useKindUnchecked(), NeedsCheck, DoesNotKill);
#else
result.m_encodedWord = makeWord(useKindUnchecked(), NeedsCheck, DoesNotKill);
#endif
return result;
}
bool operator!() const { return !isSet(); }
explicit operator bool() const { return isSet(); }
bool operator==(Edge other) const
{
#if USE(JSVALUE64)
return m_encodedWord == other.m_encodedWord;
#else
return m_node == other.m_node && m_encodedWord == other.m_encodedWord;
#endif
}
bool operator!=(Edge other) const
{
return !(*this == other);
}
void dump(PrintStream&) const;
unsigned hash() const
{
#if USE(JSVALUE64)
return IntHash<uintptr_t>::hash(m_encodedWord);
#else
return PtrHash<Node*>::hash(m_node) + m_encodedWord;
#endif
}
private:
friend class AdjacencyList;
#if USE(JSVALUE64)
static constexpr uint32_t shift() { return 8; }
static uintptr_t makeWord(Node* node, UseKind useKind, ProofStatus proofStatus, KillStatus killStatus)
{
ASSERT(sizeof(node) == 8);
uintptr_t shiftedValue = bitwise_cast<uintptr_t>(node) << shift();
ASSERT((shiftedValue >> shift()) == bitwise_cast<uintptr_t>(node));
ASSERT(useKind >= 0 && useKind < LastUseKind);
static_assert((static_cast<uintptr_t>(LastUseKind) << 2) < (static_cast<uintptr_t>(1) << shift()), "We rely on this being true to not clobber the node pointer.");
uintptr_t result = shiftedValue | (static_cast<uintptr_t>(useKind) << 2) | (DFG::doesKill(killStatus) << 1) | static_cast<uintptr_t>(DFG::isProved(proofStatus));
if (ASSERT_ENABLED) {
union U {
U() { word = 0; }
uintptr_t word;
Edge edge;
} u;
u.word = result;
ASSERT(u.edge.useKindUnchecked() == useKind);
ASSERT(u.edge.node() == node);
ASSERT(u.edge.proofStatusUnchecked() == proofStatus);
ASSERT(u.edge.killStatusUnchecked() == killStatus);
}
return result;
}
#else
static uintptr_t makeWord(UseKind useKind, ProofStatus proofStatus, KillStatus killStatus)
{
return (static_cast<uintptr_t>(useKind) << 2) | (DFG::doesKill(killStatus) << 1) | static_cast<uintptr_t>(DFG::isProved(proofStatus));
}
Node* m_node;
#endif
// On 64-bit this holds both the pointer and the use kind, while on 32-bit
// this just holds the use kind. In both cases this may be hijacked by
// AdjacencyList for storing firstChild and numChildren.
uintptr_t m_encodedWord;
};
inline bool operator==(Edge edge, Node* node)
{
return edge.node() == node;
}
inline bool operator==(Node* node, Edge edge)
{
return edge.node() == node;
}
inline bool operator!=(Edge edge, Node* node)
{
return edge.node() != node;
}
inline bool operator!=(Node* node, Edge edge)
{
return edge.node() != node;
}
} } // namespace JSC::DFG
#endif // ENABLE(DFG_JIT)