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-rw-r--r--js/src/jit/ValueNumbering.h127
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diff --git a/js/src/jit/ValueNumbering.h b/js/src/jit/ValueNumbering.h
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+/* -*- 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 */