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/*
* Copyright (C) 2013-2019 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.
*/
#include "config.h"
#include "DFGSSALoweringPhase.h"
#if ENABLE(DFG_JIT)
#include "DFGGraph.h"
#include "DFGInsertionSet.h"
#include "DFGPhase.h"
#include "JSCJSValueInlines.h"
namespace JSC { namespace DFG {
class SSALoweringPhase : public Phase {
static constexpr bool verbose = false;
public:
SSALoweringPhase(Graph& graph)
: Phase(graph, "SSA lowering"_s)
, m_insertionSet(graph)
{
}
bool run()
{
RELEASE_ASSERT(m_graph.m_form == SSA);
for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
m_block = m_graph.block(blockIndex);
if (!m_block)
continue;
for (m_nodeIndex = 0; m_nodeIndex < m_block->size(); ++m_nodeIndex) {
m_node = m_block->at(m_nodeIndex);
handleNode();
}
m_insertionSet.execute(m_block);
}
return true;
}
private:
void handleNode()
{
switch (m_node->op()) {
case AtomicsAdd:
case AtomicsAnd:
case AtomicsCompareExchange:
case AtomicsExchange:
case AtomicsLoad:
case AtomicsOr:
case AtomicsStore:
case AtomicsSub:
case AtomicsXor: {
unsigned numExtraArgs = numExtraAtomicsArgs(m_node->op());
lowerBoundsCheck(m_graph.child(m_node, 0), m_graph.child(m_node, 1), m_graph.child(m_node, 2 + numExtraArgs));
break;
}
case HasIndexedProperty:
lowerBoundsCheck(m_graph.child(m_node, 0), m_graph.child(m_node, 1), m_graph.child(m_node, 2));
break;
case EnumeratorGetByVal:
case GetByVal: {
lowerBoundsCheck(m_graph.varArgChild(m_node, 0), m_graph.varArgChild(m_node, 1), m_graph.varArgChild(m_node, 2));
break;
}
case EnumeratorPutByVal:
break;
case PutByVal:
case PutByValDirect: {
Edge base = m_graph.varArgChild(m_node, 0);
Edge index = m_graph.varArgChild(m_node, 1);
Edge storage = m_graph.varArgChild(m_node, 3);
if (lowerBoundsCheck(base, index, storage))
break;
if (m_node->arrayMode().isSomeTypedArrayView() && m_node->arrayMode().isOutOfBounds()) {
#if USE(LARGE_TYPED_ARRAYS)
if (m_node->arrayMode().mayBeLargeTypedArray() || m_graph.hasExitSite(m_node->origin.semantic, Overflow)) {
Node* length = m_insertionSet.insertNode(
m_nodeIndex, SpecInt52Any, GetTypedArrayLengthAsInt52, m_node->origin,
OpInfo(m_node->arrayMode().asWord()), base, storage);
length->setResult(NodeResultInt52);
// GetTypedArrayLengthAsInt52 says write(MiscFields) to model concurrent updates. But this does not mean that
// we cannot exit after running GetTypedArrayLengthAsInt52 since exit state is still intact after that.
// To teach DFG / FTL about it, we insert ExitOK node here to make subsequent nodes valid for exits.
if (m_node->arrayMode().mayBeResizableOrGrowableSharedTypedArray())
m_insertionSet.insertNode(m_nodeIndex, SpecNone, ExitOK, m_node->origin.withExitOK(true));
m_graph.varArgChild(m_node, 4) = Edge(length, Int52RepUse);
} else {
#endif
Node* length = m_insertionSet.insertNode(
m_nodeIndex, SpecInt32Only, GetArrayLength, m_node->origin,
OpInfo(m_node->arrayMode().asWord()), base, storage);
if (m_node->arrayMode().mayBeResizableOrGrowableSharedTypedArray())
m_insertionSet.insertNode(m_nodeIndex, SpecNone, ExitOK, m_node->origin.withExitOK(true));
m_graph.varArgChild(m_node, 4) = Edge(length, KnownInt32Use);
#if USE(LARGE_TYPED_ARRAYS)
}
#endif
break;
}
break;
}
default:
break;
}
}
bool lowerBoundsCheck(Edge base, Edge index, Edge storage)
{
if (!m_node->arrayMode().permitsBoundsCheckLowering())
return false;
if (!m_node->arrayMode().lengthNeedsStorage())
storage = Edge();
NodeType op = GetArrayLength;
switch (m_node->arrayMode().type()) {
case Array::ArrayStorage:
case Array::SlowPutArrayStorage:
op = GetVectorLength;
break;
case Array::String:
// When we need to support this, it will require additional code since base's useKind is KnownStringUse.
DFG_CRASH(m_graph, m_node, "Array::String's base.useKind() is KnownStringUse");
break;
default:
break;
}
Node* checkInBounds;
#if USE(LARGE_TYPED_ARRAYS)
if ((op == GetArrayLength) && m_node->arrayMode().isSomeTypedArrayView() && (m_node->arrayMode().mayBeLargeTypedArray() || m_graph.hasExitSite(m_node->origin.semantic, Overflow))) {
Node* length = m_insertionSet.insertNode(
m_nodeIndex, SpecInt52Any, GetTypedArrayLengthAsInt52, m_node->origin,
OpInfo(m_node->arrayMode().asWord()), Edge(base.node(), KnownCellUse), storage);
if (m_node->arrayMode().mayBeResizableOrGrowableSharedTypedArray())
m_insertionSet.insertNode(m_nodeIndex, SpecNone, ExitOK, m_node->origin.withExitOK(true));
// The return type is a dummy since this node does not actually return anything.
checkInBounds = m_insertionSet.insertNode(
m_nodeIndex, SpecInt32Only, CheckInBoundsInt52, m_node->origin,
index, Edge(length, Int52RepUse));
} else {
#endif
Node* length = m_insertionSet.insertNode(
m_nodeIndex, SpecInt32Only, op, m_node->origin,
OpInfo(m_node->arrayMode().asWord()), Edge(base.node(), KnownCellUse), storage);
if (m_node->arrayMode().mayBeResizableOrGrowableSharedTypedArray())
m_insertionSet.insertNode(m_nodeIndex, SpecNone, ExitOK, m_node->origin.withExitOK(true));
checkInBounds = m_insertionSet.insertNode(
m_nodeIndex, SpecInt32Only, CheckInBounds, m_node->origin,
index, Edge(length, KnownInt32Use));
#if USE(LARGE_TYPED_ARRAYS)
}
#endif
AdjacencyList adjacencyList = m_graph.copyVarargChildren(m_node);
m_graph.m_varArgChildren.append(Edge(checkInBounds, UntypedUse));
adjacencyList.setNumChildren(adjacencyList.numChildren() + 1);
m_node->children = adjacencyList;
return true;
}
InsertionSet m_insertionSet;
BasicBlock* m_block;
unsigned m_nodeIndex;
Node* m_node;
};
bool performSSALowering(Graph& graph)
{
return runPhase<SSALoweringPhase>(graph);
}
} } // namespace JSC::DFG
#endif // ENABLE(DFG_JIT)
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