Imported QtWebKit TP3 (git b57bc6801f1876c3220d5a4bfea33d620d477443)

Change-Id: I3b1d8a2808782c9f34d50240000e20cb38d3680f
Reviewed-by: Konstantin Tokarev <annulen@yandex.ru>

1 files changed, 2220 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/dfg/DFGObjectAllocationSinkingPhase.cpp b/Source/JavaScriptCore/dfg/DFGObjectAllocationSinkingPhase.cpp
new file mode 100644
index 000000000..743a314d4
--- /dev/null
+++ b/Source/JavaScriptCore/dfg/DFGObjectAllocationSinkingPhase.cpp
@@ -0,0 +1,2220 @@
+/*
+ * Copyright (C) 2015 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 "DFGObjectAllocationSinkingPhase.h"
+
+#if ENABLE(DFG_JIT)
+
+#include "DFGBlockMapInlines.h"
+#include "DFGClobbersExitState.h"
+#include "DFGCombinedLiveness.h"
+#include "DFGGraph.h"
+#include "DFGInsertionSet.h"
+#include "DFGLazyNode.h"
+#include "DFGLivenessAnalysisPhase.h"
+#include "DFGOSRAvailabilityAnalysisPhase.h"
+#include "DFGPhase.h"
+#include "DFGPromotedHeapLocation.h"
+#include "DFGSSACalculator.h"
+#include "DFGValidate.h"
+#include "JSCInlines.h"
+
+#include <list>
+
+namespace JSC { namespace DFG {
+
+namespace {
+
+bool verbose = false;
+
+// In order to sink object cycles, we use a points-to analysis coupled
+// with an escape analysis. This analysis is actually similar to an
+// abstract interpreter focused on local allocations and ignoring
+// everything else.
+//
+// We represent the local heap using two mappings:
+//
+// - A set of the local allocations present in the function, where
+//   each of those have a further mapping from
+//   PromotedLocationDescriptor to local allocations they must point
+//   to.
+//
+// - A "pointer" mapping from nodes to local allocations, if they must
+//   be equal to said local allocation and are currently live. This
+//   can be because the node is the actual node that created the
+//   allocation, or any other node that must currently point to it -
+//   we don't make a difference.
+//
+// The following graph is a motivation for why we separate allocations
+// from pointers:
+//
+// Block #0
+//  0: NewObject({})
+//  1: NewObject({})
+//  -: PutByOffset(@0, @1, x)
+//  -: PutStructure(@0, {x:0})
+//  2: GetByOffset(@0, x)
+//  -: Jump(#1)
+//
+// Block #1
+//  -: Return(@2)
+//
+// Here, we need to remember in block #1 that @2 points to a local
+// allocation with appropriate fields and structures information
+// (because we should be able to place a materialization on top of
+// block #1 here), even though @1 is dead. We *could* just keep @1
+// artificially alive here, but there is no real reason to do it:
+// after all, by the end of block #0, @1 and @2 should be completely
+// interchangeable, and there is no reason for us to artificially make
+// @1 more important.
+//
+// An important point to consider to understand this separation is
+// that we should think of the local heap as follow: we have a
+// bunch of nodes that are pointers to "allocations" that live
+// someplace on the heap, and those allocations can have pointers in
+// between themselves as well. We shouldn't care about whatever
+// names we give to the allocations ; what matters when
+// comparing/merging two heaps is the isomorphism/comparison between
+// the allocation graphs as seen by the nodes.
+//
+// For instance, in the following graph:
+//
+// Block #0
+//  0: NewObject({})
+//  -: Branch(#1, #2)
+//
+// Block #1
+//  1: NewObject({})
+//  -: PutByOffset(@0, @1, x)
+//  -: PutStructure(@0, {x:0})
+//  -: Jump(#3)
+//
+// Block #2
+//  2: NewObject({})
+//  -: PutByOffset(@2, undefined, x)
+//  -: PutStructure(@2, {x:0})
+//  -: PutByOffset(@0, @2, x)
+//  -: PutStructure(@0, {x:0})
+//  -: Jump(#3)
+//
+// Block #3
+//  -: Return(@0)
+//
+// we should think of the heaps at tail of blocks #1 and #2 as being
+// exactly the same, even though one has @0.x pointing to @1 and the
+// other has @0.x pointing to @2, because in essence this should not
+// be different from the graph where we hoisted @1 and @2 into a
+// single allocation in block #0. We currently will not handle this
+// case, because we merge allocations based on the node they are
+// coming from, but this is only a technicality for the sake of
+// simplicity that shouldn't hide the deeper idea outlined here.
+
+class Allocation {
+public:
+    // We use Escaped as a special allocation kind because when we
+    // decide to sink an allocation, we still need to keep track of it
+    // once it is escaped if it still has pointers to it in order to
+    // replace any use of those pointers by the corresponding
+    // materialization
+    enum class Kind { Escaped, Object, Activation, Function, ArrowFunction, GeneratorFunction };
+
+    explicit Allocation(Node* identifier = nullptr, Kind kind = Kind::Escaped)
+        : m_identifier(identifier)
+        , m_kind(kind)
+    {
+    }
+
+
+    const HashMap<PromotedLocationDescriptor, Node*>& fields() const
+    {
+        return m_fields;
+    }
+
+    Node* get(PromotedLocationDescriptor descriptor)
+    {
+        return m_fields.get(descriptor);
+    }
+
+    Allocation& set(PromotedLocationDescriptor descriptor, Node* value)
+    {
+        // Pointing to anything else than an unescaped local
+        // allocation is represented by simply not having the
+        // field
+        if (value)
+            m_fields.set(descriptor, value);
+        else
+            m_fields.remove(descriptor);
+        return *this;
+    }
+
+    void remove(PromotedLocationDescriptor descriptor)
+    {
+        set(descriptor, nullptr);
+    }
+
+    bool hasStructures() const
+    {
+        switch (kind()) {
+        case Kind::Object:
+            return true;
+
+        default:
+            return false;
+        }
+    }
+
+    Allocation& setStructures(const StructureSet& structures)
+    {
+        ASSERT(hasStructures() && !structures.isEmpty());
+        m_structures = structures;
+        return *this;
+    }
+
+    Allocation& mergeStructures(const StructureSet& structures)
+    {
+        ASSERT(hasStructures() || structures.isEmpty());
+        m_structures.merge(structures);
+        return *this;
+    }
+
+    Allocation& filterStructures(const StructureSet& structures)
+    {
+        ASSERT(hasStructures());
+        m_structures.filter(structures);
+        return *this;
+    }
+
+    const StructureSet& structures() const
+    {
+        return m_structures;
+    }
+
+    Node* identifier() const { return m_identifier; }
+
+    Kind kind() const { return m_kind; }
+
+    bool isEscapedAllocation() const
+    {
+        return kind() == Kind::Escaped;
+    }
+
+    bool isObjectAllocation() const
+    {
+        return m_kind == Kind::Object;
+    }
+
+    bool isActivationAllocation() const
+    {
+        return m_kind == Kind::Activation;
+    }
+
+    bool isFunctionAllocation() const
+    {
+        return m_kind == Kind::Function || m_kind == Kind::ArrowFunction || m_kind == Kind::GeneratorFunction;
+    }
+
+    bool operator==(const Allocation& other) const
+    {
+        return m_identifier == other.m_identifier
+            && m_kind == other.m_kind
+            && m_fields == other.m_fields
+            && m_structures == other.m_structures;
+    }
+
+    bool operator!=(const Allocation& other) const
+    {
+        return !(*this == other);
+    }
+
+    void dump(PrintStream& out) const
+    {
+        dumpInContext(out, nullptr);
+    }
+
+    void dumpInContext(PrintStream& out, DumpContext* context) const
+    {
+        switch (m_kind) {
+        case Kind::Escaped:
+            out.print("Escaped");
+            break;
+
+        case Kind::Object:
+            out.print("Object");
+            break;
+
+        case Kind::Function:
+            out.print("Function");
+            break;
+                
+        case Kind::ArrowFunction:
+            out.print("ArrowFunction");
+            break;
+
+        case Kind::GeneratorFunction:
+            out.print("GeneratorFunction");
+            break;
+
+        case Kind::Activation:
+            out.print("Activation");
+            break;
+        }
+        out.print("Allocation(");
+        if (!m_structures.isEmpty())
+            out.print(inContext(m_structures, context));
+        if (!m_fields.isEmpty()) {
+            if (!m_structures.isEmpty())
+                out.print(", ");
+            out.print(mapDump(m_fields, " => #", ", "));
+        }
+        out.print(")");
+    }
+
+private:
+    Node* m_identifier; // This is the actual node that created the allocation
+    Kind m_kind;
+    HashMap<PromotedLocationDescriptor, Node*> m_fields;
+    StructureSet m_structures;
+};
+
+class LocalHeap {
+public:
+    Allocation& newAllocation(Node* node, Allocation::Kind kind)
+    {
+        ASSERT(!m_pointers.contains(node) && !isAllocation(node));
+        m_pointers.add(node, node);
+        return m_allocations.set(node, Allocation(node, kind)).iterator->value;
+    }
+
+    bool isAllocation(Node* identifier) const
+    {
+        return m_allocations.contains(identifier);
+    }
+
+    // Note that this is fundamentally different from
+    // onlyLocalAllocation() below. getAllocation() takes as argument
+    // a node-as-identifier, that is, an allocation node. This
+    // allocation node doesn't have to be alive; it may only be
+    // pointed to by other nodes or allocation fields.
+    // For instance, in the following graph:
+    //
+    // Block #0
+    //  0: NewObject({})
+    //  1: NewObject({})
+    //  -: PutByOffset(@0, @1, x)
+    //  -: PutStructure(@0, {x:0})
+    //  2: GetByOffset(@0, x)
+    //  -: Jump(#1)
+    //
+    // Block #1
+    //  -: Return(@2)
+    //
+    // At head of block #1, the only reachable allocation is #@1,
+    // which can be reached through node @2. Thus, getAllocation(#@1)
+    // contains the appropriate metadata for this allocation, but
+    // onlyLocalAllocation(@1) is null, as @1 is no longer a pointer
+    // to #@1 (since it is dead). Conversely, onlyLocalAllocation(@2)
+    // is the same as getAllocation(#@1), while getAllocation(#@2)
+    // does not make sense since @2 is not an allocation node.
+    //
+    // This is meant to be used when the node is already known to be
+    // an identifier (i.e. an allocation) - probably because it was
+    // found as value of a field or pointer in the current heap, or
+    // was the result of a call to follow(). In any other cases (such
+    // as when doing anything while traversing the graph), the
+    // appropriate function to call is probably onlyLocalAllocation.
+    Allocation& getAllocation(Node* identifier)
+    {
+        auto iter = m_allocations.find(identifier);
+        ASSERT(iter != m_allocations.end());
+        return iter->value;
+    }
+
+    void newPointer(Node* node, Node* identifier)
+    {
+        ASSERT(!m_allocations.contains(node) && !m_pointers.contains(node));
+        ASSERT(isAllocation(identifier));
+        m_pointers.add(node, identifier);
+    }
+
+    // follow solves the points-to problem. Given a live node, which
+    // may be either an allocation itself or a heap read (e.g. a
+    // GetByOffset node), it returns the corresponding allocation
+    // node, if there is one. If the argument node is neither an
+    // allocation or a heap read, or may point to different nodes,
+    // nullptr will be returned. Note that a node that points to
+    // different nodes can never point to an unescaped local
+    // allocation.
+    Node* follow(Node* node) const
+    {
+        auto iter = m_pointers.find(node);
+        ASSERT(iter == m_pointers.end() || m_allocations.contains(iter->value));
+        return iter == m_pointers.end() ? nullptr : iter->value;
+    }
+
+    Node* follow(PromotedHeapLocation location) const
+    {
+        const Allocation& base = m_allocations.find(location.base())->value;
+        auto iter = base.fields().find(location.descriptor());
+
+        if (iter == base.fields().end())
+            return nullptr;
+
+        return iter->value;
+    }
+
+    // onlyLocalAllocation find the corresponding allocation metadata
+    // for any live node. onlyLocalAllocation(node) is essentially
+    // getAllocation(follow(node)), with appropriate null handling.
+    Allocation* onlyLocalAllocation(Node* node)
+    {
+        Node* identifier = follow(node);
+        if (!identifier)
+            return nullptr;
+
+        return &getAllocation(identifier);
+    }
+
+    Allocation* onlyLocalAllocation(PromotedHeapLocation location)
+    {
+        Node* identifier = follow(location);
+        if (!identifier)
+            return nullptr;
+
+        return &getAllocation(identifier);
+    }
+
+    // This allows us to store the escapees only when necessary. If
+    // set, the current escapees can be retrieved at any time using
+    // takeEscapees(), which will clear the cached set of escapees;
+    // otherwise the heap won't remember escaping allocations.
+    void setWantEscapees()
+    {
+        m_wantEscapees = true;
+    }
+
+    HashMap<Node*, Allocation> takeEscapees()
+    {
+        return WTFMove(m_escapees);
+    }
+
+    void escape(Node* node)
+    {
+        Node* identifier = follow(node);
+        if (!identifier)
+            return;
+
+        escapeAllocation(identifier);
+    }
+
+    void merge(const LocalHeap& other)
+    {
+        assertIsValid();
+        other.assertIsValid();
+        ASSERT(!m_wantEscapees);
+
+        if (!reached()) {
+            ASSERT(other.reached());
+            *this = other;
+            return;
+        }
+
+        HashSet<Node*> toEscape;
+
+        for (auto& allocationEntry : other.m_allocations)
+            m_allocations.add(allocationEntry.key, allocationEntry.value);
+        for (auto& allocationEntry : m_allocations) {
+            auto allocationIter = other.m_allocations.find(allocationEntry.key);
+
+            // If we have it and they don't, it died for them but we
+            // are keeping it alive from another field somewhere.
+            // There is nothing to do - we will be escaped
+            // automatically when we handle that other field.
+            // This will also happen for allocation that we have and
+            // they don't, and all of those will get pruned.
+            if (allocationIter == other.m_allocations.end())
+                continue;
+
+            if (allocationEntry.value.kind() != allocationIter->value.kind()) {
+                toEscape.add(allocationEntry.key);
+                for (const auto& fieldEntry : allocationIter->value.fields())
+                    toEscape.add(fieldEntry.value);
+            } else {
+                mergePointerSets(
+                    allocationEntry.value.fields(), allocationIter->value.fields(),
+                    [&] (Node* identifier) {
+                        toEscape.add(identifier);
+                    },
+                    [&] (PromotedLocationDescriptor field) {
+                        allocationEntry.value.remove(field);
+                    });
+                allocationEntry.value.mergeStructures(allocationIter->value.structures());
+            }
+        }
+
+        mergePointerSets(m_pointers, other.m_pointers,
+            [&] (Node* identifier) {
+                toEscape.add(identifier);
+            },
+            [&] (Node* field) {
+                m_pointers.remove(field);
+            });
+
+        for (Node* identifier : toEscape)
+            escapeAllocation(identifier);
+
+        if (!ASSERT_DISABLED) {
+            for (const auto& entry : m_allocations)
+                ASSERT_UNUSED(entry, entry.value.isEscapedAllocation() || other.m_allocations.contains(entry.key));
+        }
+
+        // If there is no remaining pointer to an allocation, we can
+        // remove it. This should only happen for escaped allocations,
+        // because we only merge liveness-pruned heaps in the first
+        // place.
+        prune();
+
+        assertIsValid();
+    }
+
+    void pruneByLiveness(const HashSet<Node*>& live)
+    {
+        Vector<Node*> toRemove;
+        for (const auto& entry : m_pointers) {
+            if (!live.contains(entry.key))
+                toRemove.append(entry.key);
+        }
+        for (Node* node : toRemove)
+            m_pointers.remove(node);
+
+        prune();
+    }
+
+    void assertIsValid() const
+    {
+        if (ASSERT_DISABLED)
+            return;
+
+        // Pointers should point to an actual allocation
+        for (const auto& entry : m_pointers) {
+            ASSERT_UNUSED(entry, entry.value);
+            ASSERT(m_allocations.contains(entry.value));
+        }
+
+        for (const auto& allocationEntry : m_allocations) {
+            // Fields should point to an actual allocation
+            for (const auto& fieldEntry : allocationEntry.value.fields()) {
+                ASSERT_UNUSED(fieldEntry, fieldEntry.value);
+                ASSERT(m_allocations.contains(fieldEntry.value));
+            }
+        }
+    }
+
+    bool operator==(const LocalHeap& other) const
+    {
+        assertIsValid();
+        other.assertIsValid();
+        return m_allocations == other.m_allocations
+            && m_pointers == other.m_pointers;
+    }
+
+    bool operator!=(const LocalHeap& other) const
+    {
+        return !(*this == other);
+    }
+
+    const HashMap<Node*, Allocation>& allocations() const
+    {
+        return m_allocations;
+    }
+
+    const HashMap<Node*, Node*>& pointers() const
+    {
+        return m_pointers;
+    }
+
+    void dump(PrintStream& out) const
+    {
+        out.print("  Allocations:\n");
+        for (const auto& entry : m_allocations)
+            out.print("    #", entry.key, ": ", entry.value, "\n");
+        out.print("  Pointers:\n");
+        for (const auto& entry : m_pointers)
+            out.print("    ", entry.key, " => #", entry.value, "\n");
+    }
+
+    bool reached() const
+    {
+        return m_reached;
+    }
+
+    void setReached()
+    {
+        m_reached = true;
+    }
+
+private:
+    // When we merge two heaps, we escape all fields of allocations,
+    // unless they point to the same thing in both heaps.
+    // The reason for this is that it allows us not to do extra work
+    // for diamond graphs where we would otherwise have to check
+    // whether we have a single definition or not, which would be
+    // cumbersome.
+    //
+    // Note that we should try to unify nodes even when they are not
+    // from the same allocation; for instance we should be able to
+    // completely eliminate all allocations from the following graph:
+    //
+    // Block #0
+    //  0: NewObject({})
+    //  -: Branch(#1, #2)
+    //
+    // Block #1
+    //  1: NewObject({})
+    //  -: PutByOffset(@1, "left", val)
+    //  -: PutStructure(@1, {val:0})
+    //  -: PutByOffset(@0, @1, x)
+    //  -: PutStructure(@0, {x:0})
+    //  -: Jump(#3)
+    //
+    // Block #2
+    //  2: NewObject({})
+    //  -: PutByOffset(@2, "right", val)
+    //  -: PutStructure(@2, {val:0})
+    //  -: PutByOffset(@0, @2, x)
+    //  -: PutStructure(@0, {x:0})
+    //  -: Jump(#3)
+    //
+    // Block #3:
+    //  3: GetByOffset(@0, x)
+    //  4: GetByOffset(@3, val)
+    //  -: Return(@4)
+    template<typename Key, typename EscapeFunctor, typename RemoveFunctor>
+    void mergePointerSets(
+        const HashMap<Key, Node*>& my, const HashMap<Key, Node*>& their,
+        const EscapeFunctor& escape, const RemoveFunctor& remove)
+    {
+        Vector<Key> toRemove;
+        for (const auto& entry : my) {
+            auto iter = their.find(entry.key);
+            if (iter == their.end()) {
+                toRemove.append(entry.key);
+                escape(entry.value);
+            } else if (iter->value != entry.value) {
+                toRemove.append(entry.key);
+                escape(entry.value);
+                escape(iter->value);
+            }
+        }
+        for (const auto& entry : their) {
+            if (my.contains(entry.key))
+                continue;
+            escape(entry.value);
+        }
+        for (Key key : toRemove)
+            remove(key);
+    }
+
+    void escapeAllocation(Node* identifier)
+    {
+        Allocation& allocation = getAllocation(identifier);
+        if (allocation.isEscapedAllocation())
+            return;
+
+        Allocation unescaped = WTFMove(allocation);
+        allocation = Allocation(unescaped.identifier(), Allocation::Kind::Escaped);
+
+        for (const auto& entry : unescaped.fields())
+            escapeAllocation(entry.value);
+
+        if (m_wantEscapees)
+            m_escapees.add(unescaped.identifier(), WTFMove(unescaped));
+    }
+
+    void prune()
+    {
+        HashSet<Node*> reachable;
+        for (const auto& entry : m_pointers)
+            reachable.add(entry.value);
+
+        // Repeatedly mark as reachable allocations in fields of other
+        // reachable allocations
+        {
+            Vector<Node*> worklist;
+            worklist.appendRange(reachable.begin(), reachable.end());
+
+            while (!worklist.isEmpty()) {
+                Node* identifier = worklist.takeLast();
+                Allocation& allocation = m_allocations.find(identifier)->value;
+                for (const auto& entry : allocation.fields()) {
+                    if (reachable.add(entry.value).isNewEntry)
+                        worklist.append(entry.value);
+                }
+            }
+        }
+
+        // Remove unreachable allocations
+        {
+            Vector<Node*> toRemove;
+            for (const auto& entry : m_allocations) {
+                if (!reachable.contains(entry.key))
+                    toRemove.append(entry.key);
+            }
+            for (Node* identifier : toRemove)
+                m_allocations.remove(identifier);
+        }
+    }
+
+    bool m_reached = false;
+    HashMap<Node*, Node*> m_pointers;
+    HashMap<Node*, Allocation> m_allocations;
+
+    bool m_wantEscapees = false;
+    HashMap<Node*, Allocation> m_escapees;
+};
+
+class ObjectAllocationSinkingPhase : public Phase {
+public:
+    ObjectAllocationSinkingPhase(Graph& graph)
+        : Phase(graph, "object allocation elimination")
+        , m_pointerSSA(graph)
+        , m_allocationSSA(graph)
+        , m_insertionSet(graph)
+    {
+    }
+
+    bool run()
+    {
+        ASSERT(m_graph.m_form == SSA);
+        ASSERT(m_graph.m_fixpointState == FixpointNotConverged);
+
+        if (!performSinking())
+            return false;
+
+        if (verbose) {
+            dataLog("Graph after elimination:\n");
+            m_graph.dump();
+        }
+
+        return true;
+    }
+
+private:
+    bool performSinking()
+    {
+        m_graph.computeRefCounts();
+        m_graph.initializeNodeOwners();
+        m_graph.ensureDominators();
+        performLivenessAnalysis(m_graph);
+        performOSRAvailabilityAnalysis(m_graph);
+        m_combinedLiveness = CombinedLiveness(m_graph);
+
+        CString graphBeforeSinking;
+        if (Options::verboseValidationFailure() && Options::validateGraphAtEachPhase()) {
+            StringPrintStream out;
+            m_graph.dump(out);
+            graphBeforeSinking = out.toCString();
+        }
+
+        if (verbose) {
+            dataLog("Graph before elimination:\n");
+            m_graph.dump();
+        }
+
+        performAnalysis();
+
+        if (!determineSinkCandidates())
+            return false;
+
+        if (verbose) {
+            for (BasicBlock* block : m_graph.blocksInNaturalOrder()) {
+                dataLog("Heap at head of ", *block, ": \n", m_heapAtHead[block]);
+                dataLog("Heap at tail of ", *block, ": \n", m_heapAtTail[block]);
+            }
+        }
+
+        promoteLocalHeap();
+
+        if (Options::validateGraphAtEachPhase())
+            DFG::validate(m_graph, DumpGraph, graphBeforeSinking);
+        return true;
+    }
+
+    void performAnalysis()
+    {
+        m_heapAtHead = BlockMap<LocalHeap>(m_graph);
+        m_heapAtTail = BlockMap<LocalHeap>(m_graph);
+
+        bool changed;
+        do {
+            if (verbose)
+                dataLog("Doing iteration of escape analysis.\n");
+            changed = false;
+
+            for (BasicBlock* block : m_graph.blocksInPreOrder()) {
+                m_heapAtHead[block].setReached();
+                m_heap = m_heapAtHead[block];
+
+                for (Node* node : *block) {
+                    handleNode(
+                        node,
+                        [] (PromotedHeapLocation, LazyNode) { },
+                        [&] (PromotedHeapLocation) -> Node* {
+                            return nullptr;
+                        });
+                }
+
+                if (m_heap == m_heapAtTail[block])
+                    continue;
+
+                m_heapAtTail[block] = m_heap;
+                changed = true;
+
+                m_heap.assertIsValid();
+
+                // We keep only pointers that are live, and only
+                // allocations that are either live, pointed to by a
+                // live pointer, or (recursively) stored in a field of
+                // a live allocation.
+                //
+                // This means we can accidentaly leak non-dominating
+                // nodes into the successor. However, due to the
+                // non-dominance property, we are guaranteed that the
+                // successor has at least one predecessor that is not
+                // dominated either: this means any reference to a
+                // non-dominating allocation in the successor will
+                // trigger an escape and get pruned during the merge.
+                m_heap.pruneByLiveness(m_combinedLiveness.liveAtTail[block]);
+
+                for (BasicBlock* successorBlock : block->successors())
+                    m_heapAtHead[successorBlock].merge(m_heap);
+            }
+        } while (changed);
+    }
+
+    template<typename WriteFunctor, typename ResolveFunctor>
+    void handleNode(
+        Node* node,
+        const WriteFunctor& heapWrite,
+        const ResolveFunctor& heapResolve)
+    {
+        m_heap.assertIsValid();
+        ASSERT(m_heap.takeEscapees().isEmpty());
+
+        Allocation* target = nullptr;
+        HashMap<PromotedLocationDescriptor, LazyNode> writes;
+        PromotedLocationDescriptor exactRead;
+
+        switch (node->op()) {
+        case NewObject:
+            target = &m_heap.newAllocation(node, Allocation::Kind::Object);
+            target->setStructures(node->structure());
+            writes.add(
+                StructurePLoc, LazyNode(m_graph.freeze(node->structure())));
+            break;
+
+        case NewFunction:
+        case NewArrowFunction:
+        case NewGeneratorFunction: {
+            if (isStillValid(node->castOperand<FunctionExecutable*>()->singletonFunction())) {
+                m_heap.escape(node->child1().node());
+                break;
+            }
+            
+            if (node->op() == NewGeneratorFunction)
+                target = &m_heap.newAllocation(node, Allocation::Kind::GeneratorFunction);
+            else if (node->op() == NewArrowFunction)
+                target = &m_heap.newAllocation(node, Allocation::Kind::ArrowFunction);
+            else
+                target = &m_heap.newAllocation(node, Allocation::Kind::Function);
+            writes.add(FunctionExecutablePLoc, LazyNode(node->cellOperand()));
+            writes.add(FunctionActivationPLoc, LazyNode(node->child1().node()));
+            break;
+        }
+
+        case CreateActivation: {
+            if (isStillValid(node->castOperand<SymbolTable*>()->singletonScope())) {
+                m_heap.escape(node->child1().node());
+                break;
+            }
+            target = &m_heap.newAllocation(node, Allocation::Kind::Activation);
+            writes.add(ActivationSymbolTablePLoc, LazyNode(node->cellOperand()));
+            writes.add(ActivationScopePLoc, LazyNode(node->child1().node()));
+            {
+                SymbolTable* symbolTable = node->castOperand<SymbolTable*>();
+                ConcurrentJITLocker locker(symbolTable->m_lock);
+                LazyNode initialValue(m_graph.freeze(node->initializationValueForActivation()));
+                for (auto iter = symbolTable->begin(locker), end = symbolTable->end(locker); iter != end; ++iter) {
+                    writes.add(
+                        PromotedLocationDescriptor(ClosureVarPLoc, iter->value.scopeOffset().offset()),
+                        initialValue);
+                }
+            }
+            break;
+        }
+
+        case PutStructure:
+            target = m_heap.onlyLocalAllocation(node->child1().node());
+            if (target && target->isObjectAllocation()) {
+                writes.add(StructurePLoc, LazyNode(m_graph.freeze(JSValue(node->transition()->next))));
+                target->setStructures(node->transition()->next);
+            } else
+                m_heap.escape(node->child1().node());
+            break;
+
+        case CheckStructure: {
+            Allocation* allocation = m_heap.onlyLocalAllocation(node->child1().node());
+            if (allocation && allocation->isObjectAllocation()) {
+                allocation->filterStructures(node->structureSet());
+                if (Node* value = heapResolve(PromotedHeapLocation(allocation->identifier(), StructurePLoc)))
+                    node->convertToCheckStructureImmediate(value);
+            } else
+                m_heap.escape(node->child1().node());
+            break;
+        }
+
+        case GetByOffset:
+        case GetGetterSetterByOffset:
+            target = m_heap.onlyLocalAllocation(node->child2().node());
+            if (target && target->isObjectAllocation()) {
+                unsigned identifierNumber = node->storageAccessData().identifierNumber;
+                exactRead = PromotedLocationDescriptor(NamedPropertyPLoc, identifierNumber);
+            } else {
+                m_heap.escape(node->child1().node());
+                m_heap.escape(node->child2().node());
+            }
+            break;
+
+        case MultiGetByOffset: {
+            Allocation* allocation = m_heap.onlyLocalAllocation(node->child1().node());
+            if (allocation && allocation->isObjectAllocation()) {
+                MultiGetByOffsetData& data = node->multiGetByOffsetData();
+                StructureSet validStructures;
+                bool hasInvalidStructures = false;
+                for (const auto& multiGetByOffsetCase : data.cases) {
+                    if (!allocation->structures().overlaps(multiGetByOffsetCase.set()))
+                        continue;
+
+                    switch (multiGetByOffsetCase.method().kind()) {
+                    case GetByOffsetMethod::LoadFromPrototype: // We need to escape those
+                    case GetByOffsetMethod::Constant: // We don't really have a way of expressing this
+                        hasInvalidStructures = true;
+                        break;
+
+                    case GetByOffsetMethod::Load: // We're good
+                        validStructures.merge(multiGetByOffsetCase.set());
+                        break;
+
+                    default:
+                        RELEASE_ASSERT_NOT_REACHED();
+                    }
+                }
+                if (hasInvalidStructures) {
+                    m_heap.escape(node->child1().node());
+                    break;
+                }
+                unsigned identifierNumber = data.identifierNumber;
+                PromotedHeapLocation location(NamedPropertyPLoc, allocation->identifier(), identifierNumber);
+                if (Node* value = heapResolve(location)) {
+                    if (allocation->structures().isSubsetOf(validStructures))
+                        node->replaceWith(value);
+                    else {
+                        Node* structure = heapResolve(PromotedHeapLocation(allocation->identifier(), StructurePLoc));
+                        ASSERT(structure);
+                        allocation->filterStructures(validStructures);
+                        node->convertToCheckStructure(m_graph.addStructureSet(allocation->structures()));
+                        node->convertToCheckStructureImmediate(structure);
+                        node->setReplacement(value);
+                    }
+                } else if (!allocation->structures().isSubsetOf(validStructures)) {
+                    // Even though we don't need the result here, we still need
+                    // to make the call to tell our caller that we could need
+                    // the StructurePLoc.
+                    // The reason for this is that when we decide not to sink a
+                    // node, we will still lower any read to its fields before
+                    // it escapes (which are usually reads across a function
+                    // call that DFGClobberize can't handle) - but we only do
+                    // this for PromotedHeapLocations that we have seen read
+                    // during the analysis!
+                    heapResolve(PromotedHeapLocation(allocation->identifier(), StructurePLoc));
+                    allocation->filterStructures(validStructures);
+                }
+                Node* identifier = allocation->get(location.descriptor());
+                if (identifier)
+                    m_heap.newPointer(node, identifier);
+            } else
+                m_heap.escape(node->child1().node());
+            break;
+        }
+
+        case PutByOffset:
+            target = m_heap.onlyLocalAllocation(node->child2().node());
+            if (target && target->isObjectAllocation()) {
+                unsigned identifierNumber = node->storageAccessData().identifierNumber;
+                writes.add(
+                    PromotedLocationDescriptor(NamedPropertyPLoc, identifierNumber),
+                    LazyNode(node->child3().node()));
+            } else {
+                m_heap.escape(node->child1().node());
+                m_heap.escape(node->child2().node());
+                m_heap.escape(node->child3().node());
+            }
+            break;
+
+        case GetClosureVar:
+            target = m_heap.onlyLocalAllocation(node->child1().node());
+            if (target && target->isActivationAllocation()) {
+                exactRead =
+                    PromotedLocationDescriptor(ClosureVarPLoc, node->scopeOffset().offset());
+            } else
+                m_heap.escape(node->child1().node());
+            break;
+
+        case PutClosureVar:
+            target = m_heap.onlyLocalAllocation(node->child1().node());
+            if (target && target->isActivationAllocation()) {
+                writes.add(
+                    PromotedLocationDescriptor(ClosureVarPLoc, node->scopeOffset().offset()),
+                    LazyNode(node->child2().node()));
+            } else {
+                m_heap.escape(node->child1().node());
+                m_heap.escape(node->child2().node());
+            }
+            break;
+
+        case SkipScope:
+            target = m_heap.onlyLocalAllocation(node->child1().node());
+            if (target && target->isActivationAllocation())
+                exactRead = ActivationScopePLoc;
+            else
+                m_heap.escape(node->child1().node());
+            break;
+
+        case GetExecutable:
+            target = m_heap.onlyLocalAllocation(node->child1().node());
+            if (target && target->isFunctionAllocation())
+                exactRead = FunctionExecutablePLoc;
+            else
+                m_heap.escape(node->child1().node());
+            break;
+
+        case GetScope:
+            target = m_heap.onlyLocalAllocation(node->child1().node());
+            if (target && target->isFunctionAllocation())
+                exactRead = FunctionActivationPLoc;
+            else
+                m_heap.escape(node->child1().node());
+            break;
+
+        case Check:
+            m_graph.doToChildren(
+                node,
+                [&] (Edge edge) {
+                    if (edge.willNotHaveCheck())
+                        return;
+
+                    if (alreadyChecked(edge.useKind(), SpecObject))
+                        return;
+
+                    m_heap.escape(edge.node());
+                });
+            break;
+
+        case MovHint:
+        case PutHint:
+            // Handled by OSR availability analysis
+            break;
+
+        default:
+            m_graph.doToChildren(
+                node,
+                [&] (Edge edge) {
+                    m_heap.escape(edge.node());
+                });
+            break;
+        }
+
+        if (exactRead) {
+            ASSERT(target);
+            ASSERT(writes.isEmpty());
+            if (Node* value = heapResolve(PromotedHeapLocation(target->identifier(), exactRead))) {
+                ASSERT(!value->replacement());
+                node->replaceWith(value);
+            }
+            Node* identifier = target->get(exactRead);
+            if (identifier)
+                m_heap.newPointer(node, identifier);
+        }
+
+        for (auto entry : writes) {
+            ASSERT(target);
+            if (entry.value.isNode())
+                target->set(entry.key, m_heap.follow(entry.value.asNode()));
+            else
+                target->remove(entry.key);
+            heapWrite(PromotedHeapLocation(target->identifier(), entry.key), entry.value);
+        }
+
+        m_heap.assertIsValid();
+    }
+
+    bool determineSinkCandidates()
+    {
+        m_sinkCandidates.clear();
+        m_materializationToEscapee.clear();
+        m_materializationSiteToMaterializations.clear();
+        m_materializationSiteToRecoveries.clear();
+
+        // Logically we wish to consider every allocation and sink
+        // it. However, it is probably not profitable to sink an
+        // allocation that will always escape. So, we only sink an
+        // allocation if one of the following is true:
+        //
+        // 1) There exists a basic block with only backwards outgoing
+        //    edges (or no outgoing edges) in which the node wasn't
+        //    materialized. This is meant to catch
+        //    effectively-infinite loops in which we don't need to
+        //    have allocated the object.
+        //
+        // 2) There exists a basic block at the tail of which the node
+        //    is dead and not materialized.
+        //
+        // 3) The sum of execution counts of the materializations is
+        //    less than the sum of execution counts of the original
+        //    node.
+        //
+        // We currently implement only rule #2.
+        // FIXME: Implement the two other rules.
+        // https://bugs.webkit.org/show_bug.cgi?id=137073 (rule #1)
+        // https://bugs.webkit.org/show_bug.cgi?id=137074 (rule #3)
+        //
+        // However, these rules allow for a sunk object to be put into
+        // a non-sunk one, which we don't support. We could solve this
+        // by supporting PutHints on local allocations, making these
+        // objects only partially correct, and we would need to adapt
+        // the OSR availability analysis and OSR exit to handle
+        // this. This would be totally doable, but would create a
+        // super rare, and thus bug-prone, code path.
+        // So, instead, we need to implement one of the following
+        // closure rules:
+        //
+        // 1) If we put a sink candidate into a local allocation that
+        //    is not a sink candidate, change our minds and don't
+        //    actually sink the sink candidate.
+        //
+        // 2) If we put a sink candidate into a local allocation, that
+        //    allocation becomes a sink candidate as well.
+        //
+        // We currently choose to implement closure rule #2.
+        HashMap<Node*, Vector<Node*>> dependencies;
+        bool hasUnescapedReads = false;
+        for (BasicBlock* block : m_graph.blocksInPreOrder()) {
+            m_heap = m_heapAtHead[block];
+
+            for (Node* node : *block) {
+                handleNode(
+                    node,
+                    [&] (PromotedHeapLocation location, LazyNode value) {
+                        if (!value.isNode())
+                            return;
+
+                        Allocation* allocation = m_heap.onlyLocalAllocation(value.asNode());
+                        if (allocation && !allocation->isEscapedAllocation())
+                            dependencies.add(allocation->identifier(), Vector<Node*>()).iterator->value.append(location.base());
+                    },
+                    [&] (PromotedHeapLocation) -> Node* {
+                        hasUnescapedReads = true;
+                        return nullptr;
+                    });
+            }
+
+            // The sink candidates are initially the unescaped
+            // allocations dying at tail of blocks
+            HashSet<Node*> allocations;
+            for (const auto& entry : m_heap.allocations()) {
+                if (!entry.value.isEscapedAllocation())
+                    allocations.add(entry.key);
+            }
+
+            m_heap.pruneByLiveness(m_combinedLiveness.liveAtTail[block]);
+
+            for (Node* identifier : allocations) {
+                if (!m_heap.isAllocation(identifier))
+                    m_sinkCandidates.add(identifier);
+            }
+        }
+
+        // Ensure that the set of sink candidates is closed for put operations
+        Vector<Node*> worklist;
+        worklist.appendRange(m_sinkCandidates.begin(), m_sinkCandidates.end());
+
+        while (!worklist.isEmpty()) {
+            for (Node* identifier : dependencies.get(worklist.takeLast())) {
+                if (m_sinkCandidates.add(identifier).isNewEntry)
+                    worklist.append(identifier);
+            }
+        }
+
+        if (m_sinkCandidates.isEmpty())
+            return hasUnescapedReads;
+
+        if (verbose)
+            dataLog("Candidates: ", listDump(m_sinkCandidates), "\n");
+
+        // Create the materialization nodes
+        for (BasicBlock* block : m_graph.blocksInNaturalOrder()) {
+            m_heap = m_heapAtHead[block];
+            m_heap.setWantEscapees();
+
+            for (Node* node : *block) {
+                handleNode(
+                    node,
+                    [] (PromotedHeapLocation, LazyNode) { },
+                    [] (PromotedHeapLocation) -> Node* {
+                        return nullptr;
+                    });
+                auto escapees = m_heap.takeEscapees();
+                if (!escapees.isEmpty())
+                    placeMaterializations(escapees, node);
+            }
+
+            m_heap.pruneByLiveness(m_combinedLiveness.liveAtTail[block]);
+
+            {
+                HashMap<Node*, Allocation> escapingOnEdge;
+                for (const auto& entry : m_heap.allocations()) {
+                    if (entry.value.isEscapedAllocation())
+                        continue;
+
+                    bool mustEscape = false;
+                    for (BasicBlock* successorBlock : block->successors()) {
+                        if (!m_heapAtHead[successorBlock].isAllocation(entry.key)
+                            || m_heapAtHead[successorBlock].getAllocation(entry.key).isEscapedAllocation())
+                            mustEscape = true;
+                    }
+
+                    if (mustEscape)
+                        escapingOnEdge.add(entry.key, entry.value);
+                }
+                placeMaterializations(WTFMove(escapingOnEdge), block->terminal());
+            }
+        }
+
+        return hasUnescapedReads || !m_sinkCandidates.isEmpty();
+    }
+
+    void placeMaterializations(HashMap<Node*, Allocation> escapees, Node* where)
+    {
+        // We don't create materializations if the escapee is not a
+        // sink candidate
+        Vector<Node*> toRemove;
+        for (const auto& entry : escapees) {
+            if (!m_sinkCandidates.contains(entry.key))
+                toRemove.append(entry.key);
+        }
+        for (Node* identifier : toRemove)
+            escapees.remove(identifier);
+
+        if (escapees.isEmpty())
+            return;
+
+        // First collect the hints that will be needed when the node
+        // we materialize is still stored into other unescaped sink candidates
+        Vector<PromotedHeapLocation> hints;
+        for (const auto& entry : m_heap.allocations()) {
+            if (escapees.contains(entry.key))
+                continue;
+
+            for (const auto& field : entry.value.fields()) {
+                ASSERT(m_sinkCandidates.contains(entry.key) || !escapees.contains(field.value));
+                if (escapees.contains(field.value) && !field.key.neededForMaterialization())
+                    hints.append(PromotedHeapLocation(entry.key, field.key));
+            }
+        }
+
+        // Now we need to order the materialization. Any order is
+        // valid (as long as we materialize a node first if it is
+        // needed for the materialization of another node, e.g. a
+        // function's activation must be materialized before the
+        // function itself), but we want to try minimizing the number
+        // of times we have to place Puts to close cycles after a
+        // materialization. In other words, we are trying to find the
+        // minimum number of materializations to remove from the
+        // materialization graph to make it a DAG, known as the
+        // (vertex) feedback set problem. Unfortunately, this is a
+        // NP-hard problem, which we don't want to solve exactly.
+        //
+        // Instead, we use a simple greedy procedure, that procedes as
+        // follow:
+        //  - While there is at least one node with no outgoing edge
+        //    amongst the remaining materializations, materialize it
+        //    first
+        //
+        //  - Similarily, while there is at least one node with no
+        //    incoming edge amongst the remaining materializations,
+        //    materialize it last.
+        //
+        //  - When both previous conditions are false, we have an
+        //    actual cycle, and we need to pick a node to
+        //    materialize. We try greedily to remove the "pressure" on
+        //    the remaining nodes by choosing the node with maximum
+        //    |incoming edges| * |outgoing edges| as a measure of how
+        //    "central" to the graph it is. We materialize it first,
+        //    so that all the recoveries will be Puts of things into
+        //    it (rather than Puts of the materialization into other
+        //    objects), which means we will have a single
+        //    StoreBarrier.
+
+
+        // Compute dependencies between materializations
+        HashMap<Node*, HashSet<Node*>> dependencies;
+        HashMap<Node*, HashSet<Node*>> reverseDependencies;
+        HashMap<Node*, HashSet<Node*>> forMaterialization;
+        for (const auto& entry : escapees) {
+            auto& myDependencies = dependencies.add(entry.key, HashSet<Node*>()).iterator->value;
+            auto& myDependenciesForMaterialization = forMaterialization.add(entry.key, HashSet<Node*>()).iterator->value;
+            reverseDependencies.add(entry.key, HashSet<Node*>());
+            for (const auto& field : entry.value.fields()) {
+                if (escapees.contains(field.value) && field.value != entry.key) {
+                    myDependencies.add(field.value);
+                    reverseDependencies.add(field.value, HashSet<Node*>()).iterator->value.add(entry.key);
+                    if (field.key.neededForMaterialization())
+                        myDependenciesForMaterialization.add(field.value);
+                }
+            }
+        }
+
+        // Helper function to update the materialized set and the
+        // dependencies
+        HashSet<Node*> materialized;
+        auto materialize = [&] (Node* identifier) {
+            materialized.add(identifier);
+            for (Node* dep : dependencies.get(identifier))
+                reverseDependencies.find(dep)->value.remove(identifier);
+            for (Node* rdep : reverseDependencies.get(identifier)) {
+                dependencies.find(rdep)->value.remove(identifier);
+                forMaterialization.find(rdep)->value.remove(identifier);
+            }
+            dependencies.remove(identifier);
+            reverseDependencies.remove(identifier);
+            forMaterialization.remove(identifier);
+        };
+
+        // Nodes without remaining unmaterialized fields will be
+        // materialized first - amongst the remaining unmaterialized
+        // nodes
+        std::list<Allocation> toMaterialize;
+        auto firstPos = toMaterialize.begin();
+        auto materializeFirst = [&] (Allocation&& allocation) {
+            materialize(allocation.identifier());
+            // We need to insert *after* the current position
+            if (firstPos != toMaterialize.end())
+                ++firstPos;
+            firstPos = toMaterialize.insert(firstPos, WTFMove(allocation));
+        };
+
+        // Nodes that no other unmaterialized node points to will be
+        // materialized last - amongst the remaining unmaterialized
+        // nodes
+        auto lastPos = toMaterialize.end();
+        auto materializeLast = [&] (Allocation&& allocation) {
+            materialize(allocation.identifier());
+            lastPos = toMaterialize.insert(lastPos, WTFMove(allocation));
+        };
+
+        // These are the promoted locations that contains some of the
+        // allocations we are currently escaping. If they are a location on
+        // some other allocation we are currently materializing, we will need
+        // to "recover" their value with a real put once the corresponding
+        // allocation is materialized; if they are a location on some other
+        // not-yet-materialized allocation, we will need a PutHint.
+        Vector<PromotedHeapLocation> toRecover;
+
+        // This loop does the actual cycle breaking
+        while (!escapees.isEmpty()) {
+            materialized.clear();
+
+            // Materialize nodes that won't require recoveries if we can
+            for (auto& entry : escapees) {
+                if (!forMaterialization.find(entry.key)->value.isEmpty())
+                    continue;
+
+                if (dependencies.find(entry.key)->value.isEmpty()) {
+                    materializeFirst(WTFMove(entry.value));
+                    continue;
+                }
+
+                if (reverseDependencies.find(entry.key)->value.isEmpty()) {
+                    materializeLast(WTFMove(entry.value));
+                    continue;
+                }
+            }
+
+            // We reach this only if there is an actual cycle that needs
+            // breaking. Because we do not want to solve a NP-hard problem
+            // here, we just heuristically pick a node and materialize it
+            // first.
+            if (materialized.isEmpty()) {
+                uint64_t maxEvaluation = 0;
+                Allocation* bestAllocation;
+                for (auto& entry : escapees) {
+                    if (!forMaterialization.find(entry.key)->value.isEmpty())
+                        continue;
+
+                    uint64_t evaluation =
+                        static_cast<uint64_t>(dependencies.get(entry.key).size()) * reverseDependencies.get(entry.key).size();
+                    if (evaluation > maxEvaluation) {
+                        maxEvaluation = evaluation;
+                        bestAllocation = &entry.value;
+                    }
+                }
+                RELEASE_ASSERT(maxEvaluation > 0);
+
+                materializeFirst(WTFMove(*bestAllocation));
+            }
+            RELEASE_ASSERT(!materialized.isEmpty());
+
+            for (Node* identifier : materialized)
+                escapees.remove(identifier);
+        }
+
+        materialized.clear();
+
+        HashSet<Node*> escaped;
+        for (const Allocation& allocation : toMaterialize)
+            escaped.add(allocation.identifier());
+        for (const Allocation& allocation : toMaterialize) {
+            for (const auto& field : allocation.fields()) {
+                if (escaped.contains(field.value) && !materialized.contains(field.value))
+                    toRecover.append(PromotedHeapLocation(allocation.identifier(), field.key));
+            }
+            materialized.add(allocation.identifier());
+        }
+
+        Vector<Node*>& materializations = m_materializationSiteToMaterializations.add(
+            where, Vector<Node*>()).iterator->value;
+
+        for (const Allocation& allocation : toMaterialize) {
+            Node* materialization = createMaterialization(allocation, where);
+            materializations.append(materialization);
+            m_materializationToEscapee.add(materialization, allocation.identifier());
+        }
+
+        if (!toRecover.isEmpty()) {
+            m_materializationSiteToRecoveries.add(
+                where, Vector<PromotedHeapLocation>()).iterator->value.appendVector(toRecover);
+        }
+
+        // The hints need to be after the "real" recoveries so that we
+        // don't hint not-yet-complete objects
+        if (!hints.isEmpty()) {
+            m_materializationSiteToRecoveries.add(
+                where, Vector<PromotedHeapLocation>()).iterator->value.appendVector(hints);
+        }
+    }
+
+    Node* createMaterialization(const Allocation& allocation, Node* where)
+    {
+        // FIXME: This is the only place where we actually use the
+        // fact that an allocation's identifier is indeed the node
+        // that created the allocation.
+        switch (allocation.kind()) {
+        case Allocation::Kind::Object: {
+            ObjectMaterializationData* data = m_graph.m_objectMaterializationData.add();
+            StructureSet* set = m_graph.addStructureSet(allocation.structures());
+
+            return m_graph.addNode(
+                allocation.identifier()->prediction(), Node::VarArg, MaterializeNewObject,
+                where->origin.withSemantic(allocation.identifier()->origin.semantic),
+                OpInfo(set), OpInfo(data), 0, 0);
+        }
+
+        case Allocation::Kind::ArrowFunction:
+        case Allocation::Kind::GeneratorFunction:
+        case Allocation::Kind::Function: {
+            FrozenValue* executable = allocation.identifier()->cellOperand();
+            
+            NodeType nodeType =
+                allocation.kind() == Allocation::Kind::ArrowFunction ? NewArrowFunction :
+                allocation.kind() == Allocation::Kind::GeneratorFunction ? NewGeneratorFunction : NewFunction;
+            
+            return m_graph.addNode(
+                allocation.identifier()->prediction(), nodeType,
+                where->origin.withSemantic(
+                    allocation.identifier()->origin.semantic),
+                OpInfo(executable));
+            break;
+        }
+
+        case Allocation::Kind::Activation: {
+            ObjectMaterializationData* data = m_graph.m_objectMaterializationData.add();
+            FrozenValue* symbolTable = allocation.identifier()->cellOperand();
+
+            return m_graph.addNode(
+                allocation.identifier()->prediction(), Node::VarArg, MaterializeCreateActivation,
+                where->origin.withSemantic(
+                    allocation.identifier()->origin.semantic),
+                OpInfo(symbolTable), OpInfo(data), 0, 0);
+        }
+
+        default:
+            DFG_CRASH(m_graph, allocation.identifier(), "Bad allocation kind");
+        }
+    }
+
+    void promoteLocalHeap()
+    {
+        // Collect the set of heap locations that we will be operating
+        // over.
+        HashSet<PromotedHeapLocation> locations;
+        for (BasicBlock* block : m_graph.blocksInNaturalOrder()) {
+            m_heap = m_heapAtHead[block];
+
+            for (Node* node : *block) {
+                handleNode(
+                    node,
+                    [&] (PromotedHeapLocation location, LazyNode) {
+                        // If the location is not on a sink candidate,
+                        // we only sink it if it is read
+                        if (m_sinkCandidates.contains(location.base()))
+                            locations.add(location);
+                    },
+                    [&] (PromotedHeapLocation location) -> Node* {
+                        locations.add(location);
+                        return nullptr;
+                    });
+            }
+        }
+
+        // Figure out which locations belong to which allocations.
+        m_locationsForAllocation.clear();
+        for (PromotedHeapLocation location : locations) {
+            auto result = m_locationsForAllocation.add(
+                location.base(),
+                Vector<PromotedHeapLocation>());
+            ASSERT(!result.iterator->value.contains(location));
+            result.iterator->value.append(location);
+        }
+
+        m_pointerSSA.reset();
+        m_allocationSSA.reset();
+
+        // Collect the set of "variables" that we will be sinking.
+        m_locationToVariable.clear();
+        m_nodeToVariable.clear();
+        Vector<Node*> indexToNode;
+        Vector<PromotedHeapLocation> indexToLocation;
+
+        for (Node* index : m_sinkCandidates) {
+            SSACalculator::Variable* variable = m_allocationSSA.newVariable();
+            m_nodeToVariable.add(index, variable);
+            ASSERT(indexToNode.size() == variable->index());
+            indexToNode.append(index);
+        }
+
+        for (PromotedHeapLocation location : locations) {
+            SSACalculator::Variable* variable = m_pointerSSA.newVariable();
+            m_locationToVariable.add(location, variable);
+            ASSERT(indexToLocation.size() == variable->index());
+            indexToLocation.append(location);
+        }
+
+        // We insert all required constants at top of block 0 so that
+        // they are inserted only once and we don't clutter the graph
+        // with useless constants everywhere
+        HashMap<FrozenValue*, Node*> lazyMapping;
+        if (!m_bottom)
+            m_bottom = m_insertionSet.insertConstant(0, m_graph.block(0)->at(0)->origin, jsNumber(1927));
+        for (BasicBlock* block : m_graph.blocksInNaturalOrder()) {
+            m_heap = m_heapAtHead[block];
+
+            for (unsigned nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) {
+                Node* node = block->at(nodeIndex);
+
+                // Some named properties can be added conditionally,
+                // and that would necessitate bottoms
+                for (PromotedHeapLocation location : m_locationsForAllocation.get(node)) {
+                    if (location.kind() != NamedPropertyPLoc)
+                        continue;
+
+                    SSACalculator::Variable* variable = m_locationToVariable.get(location);
+                    m_pointerSSA.newDef(variable, block, m_bottom);
+                }
+
+                for (Node* materialization : m_materializationSiteToMaterializations.get(node)) {
+                    Node* escapee = m_materializationToEscapee.get(materialization);
+                    m_allocationSSA.newDef(m_nodeToVariable.get(escapee), block, materialization);
+                }
+
+                if (m_sinkCandidates.contains(node))
+                    m_allocationSSA.newDef(m_nodeToVariable.get(node), block, node);
+
+                handleNode(
+                    node,
+                    [&] (PromotedHeapLocation location, LazyNode value) {
+                        if (!locations.contains(location))
+                            return;
+
+                        Node* nodeValue;
+                        if (value.isNode())
+                            nodeValue = value.asNode();
+                        else {
+                            auto iter = lazyMapping.find(value.asValue());
+                            if (iter != lazyMapping.end())
+                                nodeValue = iter->value;
+                            else {
+                                nodeValue = value.ensureIsNode(
+                                    m_insertionSet, m_graph.block(0), 0);
+                                lazyMapping.add(value.asValue(), nodeValue);
+                            }
+                        }
+
+                        SSACalculator::Variable* variable = m_locationToVariable.get(location);
+                        m_pointerSSA.newDef(variable, block, nodeValue);
+                    },
+                    [] (PromotedHeapLocation) -> Node* {
+                        return nullptr;
+                    });
+            }
+        }
+        m_insertionSet.execute(m_graph.block(0));
+
+        // Run the SSA calculators to create Phis
+        m_pointerSSA.computePhis(
+            [&] (SSACalculator::Variable* variable, BasicBlock* block) -> Node* {
+                PromotedHeapLocation location = indexToLocation[variable->index()];
+
+                // Don't create Phi nodes for fields of dead allocations
+                if (!m_heapAtHead[block].isAllocation(location.base()))
+                    return nullptr;
+
+                // Don't create Phi nodes once we are escaped
+                if (m_heapAtHead[block].getAllocation(location.base()).isEscapedAllocation())
+                    return nullptr;
+
+                // If we point to a single allocation, we will
+                // directly use its materialization
+                if (m_heapAtHead[block].follow(location))
+                    return nullptr;
+
+                Node* phiNode = m_graph.addNode(SpecHeapTop, Phi, block->at(0)->origin.withInvalidExit());
+                phiNode->mergeFlags(NodeResultJS);
+                return phiNode;
+            });
+
+        m_allocationSSA.computePhis(
+            [&] (SSACalculator::Variable* variable, BasicBlock* block) -> Node* {
+                Node* identifier = indexToNode[variable->index()];
+
+                // Don't create Phi nodes for dead allocations
+                if (!m_heapAtHead[block].isAllocation(identifier))
+                    return nullptr;
+
+                // Don't create Phi nodes until we are escaped
+                if (!m_heapAtHead[block].getAllocation(identifier).isEscapedAllocation())
+                    return nullptr;
+
+                Node* phiNode = m_graph.addNode(SpecHeapTop, Phi, block->at(0)->origin.withInvalidExit());
+                phiNode->mergeFlags(NodeResultJS);
+                return phiNode;
+            });
+
+        // Place Phis in the right places, replace all uses of any load with the appropriate
+        // value, and create the materialization nodes.
+        LocalOSRAvailabilityCalculator availabilityCalculator;
+        m_graph.clearReplacements();
+        for (BasicBlock* block : m_graph.blocksInPreOrder()) {
+            m_heap = m_heapAtHead[block];
+            availabilityCalculator.beginBlock(block);
+
+            // These mapping tables are intended to be lazy. If
+            // something is omitted from the table, it means that
+            // there haven't been any local stores to the promoted
+            // heap location (or any local materialization).
+            m_localMapping.clear();
+            m_escapeeToMaterialization.clear();
+
+            // Insert the Phi functions that we had previously
+            // created.
+            for (SSACalculator::Def* phiDef : m_pointerSSA.phisForBlock(block)) {
+                SSACalculator::Variable* variable = phiDef->variable();
+                m_insertionSet.insert(0, phiDef->value());
+
+                PromotedHeapLocation location = indexToLocation[variable->index()];
+                m_localMapping.set(location, phiDef->value());
+
+                if (m_sinkCandidates.contains(location.base())) {
+                    m_insertionSet.insert(
+                        0,
+                        location.createHint(
+                            m_graph, block->at(0)->origin.withInvalidExit(), phiDef->value()));
+                }
+            }
+
+            for (SSACalculator::Def* phiDef : m_allocationSSA.phisForBlock(block)) {
+                SSACalculator::Variable* variable = phiDef->variable();
+                m_insertionSet.insert(0, phiDef->value());
+
+                Node* identifier = indexToNode[variable->index()];
+                m_escapeeToMaterialization.add(identifier, phiDef->value());
+                bool canExit = false;
+                insertOSRHintsForUpdate(
+                    0, block->at(0)->origin, canExit,
+                    availabilityCalculator.m_availability, identifier, phiDef->value());
+            }
+
+            if (verbose) {
+                dataLog("Local mapping at ", pointerDump(block), ": ", mapDump(m_localMapping), "\n");
+                dataLog("Local materializations at ", pointerDump(block), ": ", mapDump(m_escapeeToMaterialization), "\n");
+            }
+
+            for (unsigned nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) {
+                Node* node = block->at(nodeIndex);
+                bool canExit = true;
+                bool nextCanExit = node->origin.exitOK;
+                for (PromotedHeapLocation location : m_locationsForAllocation.get(node)) {
+                    if (location.kind() != NamedPropertyPLoc)
+                        continue;
+
+                    m_localMapping.set(location, m_bottom);
+
+                    if (m_sinkCandidates.contains(node)) {
+                        m_insertionSet.insert(
+                            nodeIndex + 1,
+                            location.createHint(
+                                m_graph, node->origin.takeValidExit(nextCanExit), m_bottom));
+                    }
+                }
+
+                for (Node* materialization : m_materializationSiteToMaterializations.get(node)) {
+                    materialization->origin.exitOK &= canExit;
+                    Node* escapee = m_materializationToEscapee.get(materialization);
+                    populateMaterialization(block, materialization, escapee);
+                    m_escapeeToMaterialization.set(escapee, materialization);
+                    m_insertionSet.insert(nodeIndex, materialization);
+                    if (verbose)
+                        dataLog("Materializing ", escapee, " => ", materialization, " at ", node, "\n");
+                }
+
+                for (PromotedHeapLocation location : m_materializationSiteToRecoveries.get(node))
+                    m_insertionSet.insert(nodeIndex, createRecovery(block, location, node, canExit));
+
+                // We need to put the OSR hints after the recoveries,
+                // because we only want the hints once the object is
+                // complete
+                for (Node* materialization : m_materializationSiteToMaterializations.get(node)) {
+                    Node* escapee = m_materializationToEscapee.get(materialization);
+                    insertOSRHintsForUpdate(
+                        nodeIndex, node->origin, canExit,
+                        availabilityCalculator.m_availability, escapee, materialization);
+                }
+
+                if (node->origin.exitOK && !canExit) {
+                    // We indicate that the exit state is fine now. It is OK because we updated the
+                    // state above. We need to indicate this manually because the validation doesn't
+                    // have enough information to infer that the exit state is fine.
+                    m_insertionSet.insertNode(nodeIndex, SpecNone, ExitOK, node->origin);
+                }
+
+                if (m_sinkCandidates.contains(node))
+                    m_escapeeToMaterialization.set(node, node);
+
+                availabilityCalculator.executeNode(node);
+
+                bool desiredNextExitOK = node->origin.exitOK && !clobbersExitState(m_graph, node);
+
+                bool doLower = false;
+                handleNode(
+                    node,
+                    [&] (PromotedHeapLocation location, LazyNode value) {
+                        if (!locations.contains(location))
+                            return;
+
+                        Node* nodeValue;
+                        if (value.isNode())
+                            nodeValue = value.asNode();
+                        else
+                            nodeValue = lazyMapping.get(value.asValue());
+
+                        nodeValue = resolve(block, nodeValue);
+
+                        m_localMapping.set(location, nodeValue);
+
+                        if (!m_sinkCandidates.contains(location.base()))
+                            return;
+
+                        doLower = true;
+
+                        m_insertionSet.insert(
+                            nodeIndex + 1,
+                            location.createHint(
+                                m_graph, node->origin.takeValidExit(nextCanExit), nodeValue));
+                    },
+                    [&] (PromotedHeapLocation location) -> Node* {
+                        return resolve(block, location);
+                    });
+
+                if (!nextCanExit && desiredNextExitOK) {
+                    // We indicate that the exit state is fine now. We need to do this because we
+                    // emitted hints that appear to invalidate the exit state.
+                    m_insertionSet.insertNode(nodeIndex + 1, SpecNone, ExitOK, node->origin);
+                }
+
+                if (m_sinkCandidates.contains(node) || doLower) {
+                    switch (node->op()) {
+                    case NewObject:
+                        node->convertToPhantomNewObject();
+                        break;
+
+                    case NewArrowFunction:
+                    case NewFunction:
+                        node->convertToPhantomNewFunction();
+                        break;
+
+                    case NewGeneratorFunction:
+                        node->convertToPhantomNewGeneratorFunction();
+                        break;
+
+                    case CreateActivation:
+                        node->convertToPhantomCreateActivation();
+                        break;
+
+                    default:
+                        node->remove();
+                        break;
+                    }
+                }
+
+                m_graph.doToChildren(
+                    node,
+                    [&] (Edge& edge) {
+                        edge.setNode(resolve(block, edge.node()));
+                    });
+            }
+
+            // Gotta drop some Upsilons.
+            NodeAndIndex terminal = block->findTerminal();
+            size_t upsilonInsertionPoint = terminal.index;
+            NodeOrigin upsilonOrigin = terminal.node->origin;
+            for (BasicBlock* successorBlock : block->successors()) {
+                for (SSACalculator::Def* phiDef : m_pointerSSA.phisForBlock(successorBlock)) {
+                    Node* phiNode = phiDef->value();
+                    SSACalculator::Variable* variable = phiDef->variable();
+                    PromotedHeapLocation location = indexToLocation[variable->index()];
+                    Node* incoming = resolve(block, location);
+
+                    m_insertionSet.insertNode(
+                        upsilonInsertionPoint, SpecNone, Upsilon, upsilonOrigin,
+                        OpInfo(phiNode), incoming->defaultEdge());
+                }
+
+                for (SSACalculator::Def* phiDef : m_allocationSSA.phisForBlock(successorBlock)) {
+                    Node* phiNode = phiDef->value();
+                    SSACalculator::Variable* variable = phiDef->variable();
+                    Node* incoming = getMaterialization(block, indexToNode[variable->index()]);
+
+                    m_insertionSet.insertNode(
+                        upsilonInsertionPoint, SpecNone, Upsilon, upsilonOrigin,
+                        OpInfo(phiNode), incoming->defaultEdge());
+                }
+            }
+
+            m_insertionSet.execute(block);
+        }
+    }
+
+    Node* resolve(BasicBlock* block, PromotedHeapLocation location)
+    {
+        // If we are currently pointing to a single local allocation,
+        // simply return the associated materialization.
+        if (Node* identifier = m_heap.follow(location))
+            return getMaterialization(block, identifier);
+
+        if (Node* result = m_localMapping.get(location))
+            return result;
+
+        // This implies that there is no local mapping. Find a non-local mapping.
+        SSACalculator::Def* def = m_pointerSSA.nonLocalReachingDef(
+            block, m_locationToVariable.get(location));
+        ASSERT(def);
+        ASSERT(def->value());
+
+        Node* result = def->value();
+
+        ASSERT(!result->replacement());
+
+        m_localMapping.add(location, result);
+        return result;
+    }
+
+    Node* resolve(BasicBlock* block, Node* node)
+    {
+        // If we are currently pointing to a single local allocation,
+        // simply return the associated materialization.
+        if (Node* identifier = m_heap.follow(node))
+            return getMaterialization(block, identifier);
+
+        if (node->replacement())
+            node = node->replacement();
+        ASSERT(!node->replacement());
+
+        return node;
+    }
+
+    Node* getMaterialization(BasicBlock* block, Node* identifier)
+    {
+        ASSERT(m_heap.isAllocation(identifier));
+        if (!m_sinkCandidates.contains(identifier))
+            return identifier;
+
+        if (Node* materialization = m_escapeeToMaterialization.get(identifier))
+            return materialization;
+
+        SSACalculator::Def* def = m_allocationSSA.nonLocalReachingDef(
+            block, m_nodeToVariable.get(identifier));
+        ASSERT(def && def->value());
+        m_escapeeToMaterialization.add(identifier, def->value());
+        ASSERT(!def->value()->replacement());
+        return def->value();
+    }
+
+    void insertOSRHintsForUpdate(unsigned nodeIndex, NodeOrigin origin, bool& canExit, AvailabilityMap& availability, Node* escapee, Node* materialization)
+    {
+        // We need to follow() the value in the heap.
+        // Consider the following graph:
+        //
+        // Block #0
+        //   0: NewObject({})
+        //   1: NewObject({})
+        //   -: PutByOffset(@0, @1, x:0)
+        //   -: PutStructure(@0, {x:0})
+        //   2: GetByOffset(@0, x:0)
+        //   -: MovHint(@2, loc1)
+        //   -: Branch(#1, #2)
+        //
+        // Block #1
+        //   3: Call(f, @1)
+        //   4: Return(@0)
+        //
+        // Block #2
+        //   -: Return(undefined)
+        //
+        // We need to materialize @1 at @3, and when doing so we need
+        // to insert a MovHint for the materialization into loc1 as
+        // well.
+        // In order to do this, we say that we need to insert an
+        // update hint for any availability whose node resolve()s to
+        // the materialization.
+        for (auto entry : availability.m_heap) {
+            if (!entry.value.hasNode())
+                continue;
+            if (m_heap.follow(entry.value.node()) != escapee)
+                continue;
+
+            m_insertionSet.insert(
+                nodeIndex,
+                entry.key.createHint(m_graph, origin.takeValidExit(canExit), materialization));
+        }
+
+        for (unsigned i = availability.m_locals.size(); i--;) {
+            if (!availability.m_locals[i].hasNode())
+                continue;
+            if (m_heap.follow(availability.m_locals[i].node()) != escapee)
+                continue;
+
+            int operand = availability.m_locals.operandForIndex(i);
+            m_insertionSet.insertNode(
+                nodeIndex, SpecNone, MovHint, origin.takeValidExit(canExit), OpInfo(operand),
+                materialization->defaultEdge());
+        }
+    }
+
+    void populateMaterialization(BasicBlock* block, Node* node, Node* escapee)
+    {
+        Allocation& allocation = m_heap.getAllocation(escapee);
+        switch (node->op()) {
+        case MaterializeNewObject: {
+            ObjectMaterializationData& data = node->objectMaterializationData();
+            unsigned firstChild = m_graph.m_varArgChildren.size();
+
+            Vector<PromotedHeapLocation> locations = m_locationsForAllocation.get(escapee);
+
+            PromotedHeapLocation structure(StructurePLoc, allocation.identifier());
+            ASSERT(locations.contains(structure));
+
+            m_graph.m_varArgChildren.append(Edge(resolve(block, structure), KnownCellUse));
+
+            for (PromotedHeapLocation location : locations) {
+                switch (location.kind()) {
+                case StructurePLoc:
+                    ASSERT(location == structure);
+                    break;
+
+                case NamedPropertyPLoc: {
+                    ASSERT(location.base() == allocation.identifier());
+                    data.m_properties.append(PhantomPropertyValue(location.info()));
+                    Node* value = resolve(block, location);
+                    if (m_sinkCandidates.contains(value))
+                        m_graph.m_varArgChildren.append(m_bottom);
+                    else
+                        m_graph.m_varArgChildren.append(value);
+                    break;
+                }
+
+                default:
+                    DFG_CRASH(m_graph, node, "Bad location kind");
+                }
+            }
+
+            node->children = AdjacencyList(
+                AdjacencyList::Variable,
+                firstChild, m_graph.m_varArgChildren.size() - firstChild);
+            break;
+        }
+
+        case MaterializeCreateActivation: {
+            ObjectMaterializationData& data = node->objectMaterializationData();
+
+            unsigned firstChild = m_graph.m_varArgChildren.size();
+
+            Vector<PromotedHeapLocation> locations = m_locationsForAllocation.get(escapee);
+
+            PromotedHeapLocation symbolTable(ActivationSymbolTablePLoc, allocation.identifier());
+            ASSERT(locations.contains(symbolTable));
+            ASSERT(node->cellOperand() == resolve(block, symbolTable)->constant());
+            m_graph.m_varArgChildren.append(Edge(resolve(block, symbolTable), KnownCellUse));
+
+            PromotedHeapLocation scope(ActivationScopePLoc, allocation.identifier());
+            ASSERT(locations.contains(scope));
+            m_graph.m_varArgChildren.append(Edge(resolve(block, scope), KnownCellUse));
+
+            for (PromotedHeapLocation location : locations) {
+                switch (location.kind()) {
+                case ActivationScopePLoc: {
+                    ASSERT(location == scope);
+                    break;
+                }
+
+                case ActivationSymbolTablePLoc: {
+                    ASSERT(location == symbolTable);
+                    break;
+                }
+
+                case ClosureVarPLoc: {
+                    ASSERT(location.base() == allocation.identifier());
+                    data.m_properties.append(PhantomPropertyValue(location.info()));
+                    Node* value = resolve(block, location);
+                    if (m_sinkCandidates.contains(value))
+                        m_graph.m_varArgChildren.append(m_bottom);
+                    else
+                        m_graph.m_varArgChildren.append(value);
+                    break;
+                }
+
+                default:
+                    DFG_CRASH(m_graph, node, "Bad location kind");
+                }
+            }
+
+            node->children = AdjacencyList(
+                AdjacencyList::Variable,
+                firstChild, m_graph.m_varArgChildren.size() - firstChild);
+            break;
+        }
+        
+        case NewFunction:
+        case NewArrowFunction:
+        case NewGeneratorFunction: {
+            Vector<PromotedHeapLocation> locations = m_locationsForAllocation.get(escapee);
+            ASSERT(locations.size() == 2);
+                
+            PromotedHeapLocation executable(FunctionExecutablePLoc, allocation.identifier());
+            ASSERT_UNUSED(executable, locations.contains(executable));
+                
+            PromotedHeapLocation activation(FunctionActivationPLoc, allocation.identifier());
+            ASSERT(locations.contains(activation));
+
+            node->child1() = Edge(resolve(block, activation), KnownCellUse);
+            break;
+        }
+
+        default:
+            DFG_CRASH(m_graph, node, "Bad materialize op");
+        }
+    }
+
+    Node* createRecovery(BasicBlock* block, PromotedHeapLocation location, Node* where, bool& canExit)
+    {
+        if (verbose)
+            dataLog("Recovering ", location, " at ", where, "\n");
+        ASSERT(location.base()->isPhantomAllocation());
+        Node* base = getMaterialization(block, location.base());
+        Node* value = resolve(block, location);
+
+        NodeOrigin origin = where->origin.withSemantic(base->origin.semantic);
+
+        if (verbose)
+            dataLog("Base is ", base, " and value is ", value, "\n");
+
+        if (base->isPhantomAllocation()) {
+            return PromotedHeapLocation(base, location.descriptor()).createHint(
+                m_graph, origin.takeValidExit(canExit), value);
+        }
+
+        switch (location.kind()) {
+        case NamedPropertyPLoc: {
+            Allocation& allocation = m_heap.getAllocation(location.base());
+
+            Vector<Structure*> structures;
+            structures.appendRange(allocation.structures().begin(), allocation.structures().end());
+            unsigned identifierNumber = location.info();
+            UniquedStringImpl* uid = m_graph.identifiers()[identifierNumber];
+
+            std::sort(
+                structures.begin(),
+                structures.end(),
+                [uid] (Structure *a, Structure* b) -> bool {
+                    return a->getConcurrently(uid) < b->getConcurrently(uid);
+                });
+
+            PropertyOffset firstOffset = structures[0]->getConcurrently(uid);
+
+            if (firstOffset == structures.last()->getConcurrently(uid)) {
+                Node* storage = base;
+                // FIXME: When we decide to sink objects with a
+                // property storage, we should handle non-inline offsets.
+                RELEASE_ASSERT(isInlineOffset(firstOffset));
+
+                StorageAccessData* data = m_graph.m_storageAccessData.add();
+                data->offset = firstOffset;
+                data->identifierNumber = identifierNumber;
+
+                return m_graph.addNode(
+                    SpecNone,
+                    PutByOffset,
+                    origin.takeValidExit(canExit),
+                    OpInfo(data),
+                    Edge(storage, KnownCellUse),
+                    Edge(base, KnownCellUse),
+                    value->defaultEdge());
+            }
+
+            MultiPutByOffsetData* data = m_graph.m_multiPutByOffsetData.add();
+            data->identifierNumber = identifierNumber;
+
+            {
+                PropertyOffset currentOffset = firstOffset;
+                StructureSet currentSet;
+                for (Structure* structure : structures) {
+                    PropertyOffset offset = structure->getConcurrently(uid);
+                    if (offset != currentOffset) {
+                        // Because our analysis treats MultiPutByOffset like an escape, we only have to
+                        // deal with storing results that would have been previously stored by PutByOffset
+                        // nodes. Those nodes were guarded by the appropriate type checks. This means that
+                        // at this point, we can simply trust that the incoming value has the right type
+                        // for whatever structure we are using.
+                        data->variants.append(
+                            PutByIdVariant::replace(currentSet, currentOffset, InferredType::Top));
+                        currentOffset = offset;
+                        currentSet.clear();
+                    }
+                    currentSet.add(structure);
+                }
+                data->variants.append(
+                    PutByIdVariant::replace(currentSet, currentOffset, InferredType::Top));
+            }
+
+            return m_graph.addNode(
+                SpecNone,
+                MultiPutByOffset,
+                origin.takeValidExit(canExit),
+                OpInfo(data),
+                Edge(base, KnownCellUse),
+                value->defaultEdge());
+            break;
+        }
+
+        case ClosureVarPLoc: {
+            return m_graph.addNode(
+                SpecNone,
+                PutClosureVar,
+                origin.takeValidExit(canExit),
+                OpInfo(location.info()),
+                Edge(base, KnownCellUse),
+                value->defaultEdge());
+            break;
+        }
+
+        default:
+            DFG_CRASH(m_graph, base, "Bad location kind");
+            break;
+        }
+    }
+
+    // This is a great way of asking value->isStillValid() without having to worry about getting
+    // different answers. It turns out that this analysis works OK regardless of what this
+    // returns but breaks badly if this changes its mind for any particular InferredValue. This
+    // method protects us from that.
+    bool isStillValid(InferredValue* value)
+    {
+        return m_validInferredValues.add(value, value->isStillValid()).iterator->value;
+    }
+
+    SSACalculator m_pointerSSA;
+    SSACalculator m_allocationSSA;
+    HashSet<Node*> m_sinkCandidates;
+    HashMap<PromotedHeapLocation, SSACalculator::Variable*> m_locationToVariable;
+    HashMap<Node*, SSACalculator::Variable*> m_nodeToVariable;
+    HashMap<PromotedHeapLocation, Node*> m_localMapping;
+    HashMap<Node*, Node*> m_escapeeToMaterialization;
+    InsertionSet m_insertionSet;
+    CombinedLiveness m_combinedLiveness;
+
+    HashMap<InferredValue*, bool> m_validInferredValues;
+
+    HashMap<Node*, Node*> m_materializationToEscapee;
+    HashMap<Node*, Vector<Node*>> m_materializationSiteToMaterializations;
+    HashMap<Node*, Vector<PromotedHeapLocation>> m_materializationSiteToRecoveries;
+
+    HashMap<Node*, Vector<PromotedHeapLocation>> m_locationsForAllocation;
+
+    BlockMap<LocalHeap> m_heapAtHead;
+    BlockMap<LocalHeap> m_heapAtTail;
+    LocalHeap m_heap;
+
+    Node* m_bottom = nullptr;
+};
+
+}
+
+bool performObjectAllocationSinking(Graph& graph)
+{
+    SamplingRegion samplingRegion("DFG Object Allocation Sinking Phase");
+    return runPhase<ObjectAllocationSinkingPhase>(graph);
+}
+
+} } // namespace JSC::DFG
+
+#endif // ENABLE(DFG_JIT)