1 files changed, 127 insertions, 0 deletions
diff --git a/js/src/jit/ValueNumbering.h b/js/src/jit/ValueNumbering.h
new file mode 100644
index 000000000..c55abeb9d
--- /dev/null
+++ b/js/src/jit/ValueNumbering.h
@@ -0,0 +1,127 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef jit_ValueNumbering_h
+#define jit_ValueNumbering_h
+
+#include "jit/JitAllocPolicy.h"
+#include "js/HashTable.h"
+
+namespace js {
+namespace jit {
+
+class MDefinition;
+class MBasicBlock;
+class MIRGraph;
+class MPhi;
+class MIRGenerator;
+class MResumePoint;
+
+class ValueNumberer
+{
+    // Value numbering data.
+    class VisibleValues
+    {
+        // Hash policy for ValueSet.
+        struct ValueHasher
+        {
+            typedef const MDefinition* Lookup;
+            typedef MDefinition* Key;
+            static HashNumber hash(Lookup ins);
+            static bool match(Key k, Lookup l);
+            static void rekey(Key& k, Key newKey);
+        };
+
+        typedef HashSet<MDefinition*, ValueHasher, JitAllocPolicy> ValueSet;
+
+        ValueSet set_;        // Set of visible values
+
+      public:
+        explicit VisibleValues(TempAllocator& alloc);
+        MOZ_MUST_USE bool init();
+
+        typedef ValueSet::Ptr Ptr;
+        typedef ValueSet::AddPtr AddPtr;
+
+        Ptr findLeader(const MDefinition* def) const;
+        AddPtr findLeaderForAdd(MDefinition* def);
+        MOZ_MUST_USE bool add(AddPtr p, MDefinition* def);
+        void overwrite(AddPtr p, MDefinition* def);
+        void forget(const MDefinition* def);
+        void clear();
+#ifdef DEBUG
+        bool has(const MDefinition* def) const;
+#endif
+    };
+
+    typedef Vector<MBasicBlock*, 4, JitAllocPolicy> BlockWorklist;
+    typedef Vector<MDefinition*, 4, JitAllocPolicy> DefWorklist;
+
+    MIRGenerator* const mir_;
+    MIRGraph& graph_;
+    VisibleValues values_;            // Numbered values
+    DefWorklist deadDefs_;            // Worklist for deleting values
+    BlockWorklist remainingBlocks_;   // Blocks remaining with fewer preds
+    MDefinition* nextDef_;            // The next definition; don't discard
+    size_t totalNumVisited_;          // The number of blocks visited
+    bool rerun_;                      // Should we run another GVN iteration?
+    bool blocksRemoved_;              // Have any blocks been removed?
+    bool updateAliasAnalysis_;        // Do we care about AliasAnalysis?
+    bool dependenciesBroken_;         // Have we broken AliasAnalysis?
+    bool hasOSRFixups_;               // Have we created any OSR fixup blocks?
+
+    enum UseRemovedOption {
+        DontSetUseRemoved,
+        SetUseRemoved
+    };
+
+    MOZ_MUST_USE bool handleUseReleased(MDefinition* def, UseRemovedOption useRemovedOption);
+    MOZ_MUST_USE bool discardDefsRecursively(MDefinition* def);
+    MOZ_MUST_USE bool releaseResumePointOperands(MResumePoint* resume);
+    MOZ_MUST_USE bool releaseAndRemovePhiOperands(MPhi* phi);
+    MOZ_MUST_USE bool releaseOperands(MDefinition* def);
+    MOZ_MUST_USE bool discardDef(MDefinition* def);
+    MOZ_MUST_USE bool processDeadDefs();
+
+    MOZ_MUST_USE bool fixupOSROnlyLoop(MBasicBlock* block, MBasicBlock* backedge);
+    MOZ_MUST_USE bool removePredecessorAndDoDCE(MBasicBlock* block, MBasicBlock* pred,
+                                                size_t predIndex);
+    MOZ_MUST_USE bool removePredecessorAndCleanUp(MBasicBlock* block, MBasicBlock* pred);
+
+    MDefinition* simplified(MDefinition* def) const;
+    MDefinition* leader(MDefinition* def);
+    bool hasLeader(const MPhi* phi, const MBasicBlock* phiBlock) const;
+    bool loopHasOptimizablePhi(MBasicBlock* header) const;
+
+    MOZ_MUST_USE bool visitDefinition(MDefinition* def);
+    MOZ_MUST_USE bool visitControlInstruction(MBasicBlock* block, const MBasicBlock* root);
+    MOZ_MUST_USE bool visitUnreachableBlock(MBasicBlock* block);
+    MOZ_MUST_USE bool visitBlock(MBasicBlock* block, const MBasicBlock* root);
+    MOZ_MUST_USE bool visitDominatorTree(MBasicBlock* root);
+    MOZ_MUST_USE bool visitGraph();
+
+    MOZ_MUST_USE bool insertOSRFixups();
+    MOZ_MUST_USE bool cleanupOSRFixups();
+
+  public:
+    ValueNumberer(MIRGenerator* mir, MIRGraph& graph);
+    MOZ_MUST_USE bool init();
+
+    enum UpdateAliasAnalysisFlag {
+        DontUpdateAliasAnalysis,
+        UpdateAliasAnalysis
+    };
+
+    // Optimize the graph, performing expression simplification and
+    // canonicalization, eliminating statically fully-redundant expressions,
+    // deleting dead instructions, and removing unreachable blocks.
+    MOZ_MUST_USE bool run(UpdateAliasAnalysisFlag updateAliasAnalysis);
+};
+
+} // namespace jit
+} // namespace js
+
+#endif /* jit_ValueNumbering_h */