Merge all Hydrogen phase declarations into hydrogen-phases.h.

src/hydrogen-phases.h

+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * 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.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "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 THE COPYRIGHT
+// OWNER 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.
+
+#ifndef V8_HYDROGEN_PHASES_H_
+#define V8_HYDROGEN_PHASES_H_
+
+#include "hydrogen.h"
+
+namespace v8 {
+namespace internal {
+
+
+class BoundsCheckBbData;
+class BoundsCheckKey;
+class BoundsCheckTable : private ZoneHashMap {
+ public:
+  explicit BoundsCheckTable(Zone* zone);
+
+  INLINE(BoundsCheckBbData** LookupOrInsert(BoundsCheckKey* key, Zone* zone));
+  INLINE(void Insert(BoundsCheckKey* key, BoundsCheckBbData* data, Zone* zone));
+  INLINE(void Delete(BoundsCheckKey* key));
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(BoundsCheckTable);
+};
+
+
+class HBoundsCheckEliminationPhase : public HPhase {
+ public:
+  explicit HBoundsCheckEliminationPhase(HGraph* graph)
+      : HPhase("H_Bounds checks elimination", graph), table_(zone()) { }
+
+  void Run() { EliminateRedundantBoundsChecks(graph()->entry_block()); }
+
+ private:
+  void EliminateRedundantBoundsChecks(HBasicBlock* bb);
+
+  BoundsCheckTable table_;
+
+  DISALLOW_COPY_AND_ASSIGN(HBoundsCheckEliminationPhase);
+};
+
+
+class HCanonicalizePhase : public HPhase {
+ public:
+  explicit HCanonicalizePhase(HGraph* graph)
+      : HPhase("H_Canonicalize", graph) { }
+
+  void Run();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HCanonicalizePhase);
+};
+
+
+class HDeadCodeEliminationPhase : public HPhase {
+ public:
+  explicit HDeadCodeEliminationPhase(HGraph* graph)
+      : HPhase("H_Dead code elimination", graph) { }
+
+  void Run() {
+    MarkLiveInstructions();
+    RemoveDeadInstructions();
+  }
+
+ private:
+  bool MarkLive(HValue* ref, HValue* instr);
+  void MarkLiveInstructions();
+  void RemoveDeadInstructions();
+
+  DISALLOW_COPY_AND_ASSIGN(HDeadCodeEliminationPhase);
+};
+
+
+class HDehoistIndexComputationsPhase : public HPhase {
+ public:
+  explicit HDehoistIndexComputationsPhase(HGraph* graph)
+      : HPhase("H_Dehoist index computations", graph) { }
+
+  void Run();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HDehoistIndexComputationsPhase);
+};
+
+
+// Mark all blocks that are dominated by an unconditional soft deoptimize to
+// prevent code motion across those blocks.
+class HPropagateDeoptimizingMarkPhase : public HPhase {
+ public:
+  explicit HPropagateDeoptimizingMarkPhase(HGraph* graph)
+      : HPhase("H_Propagate deoptimizing mark", graph) { }
+
+  void Run();
+
+ private:
+  void MarkAsDeoptimizing();
+  void NullifyUnreachableInstructions();
+
+  DISALLOW_COPY_AND_ASSIGN(HPropagateDeoptimizingMarkPhase);
+};
+
+
+// Trims live ranges of environment slots by doing explicit liveness analysis.
+// Values in the environment are kept alive by every subsequent LInstruction
+// that is assigned an LEnvironment, which creates register pressure and
+// unnecessary spill slot moves. Therefore it is beneficial to trim the
+// live ranges of environment slots by zapping them with a constant after
+// the last lookup that refers to them.
+// Slots are identified by their index and only affected if whitelisted in
+// HOptimizedGraphBuilder::IsEligibleForEnvironmentLivenessAnalysis().
+class HEnvironmentLivenessAnalysisPhase : public HPhase {
+ public:
+  explicit HEnvironmentLivenessAnalysisPhase(HGraph* graph);
+
+  void Run();
+
+ private:
+  void ZapEnvironmentSlot(int index, HSimulate* simulate);
+  void ZapEnvironmentSlotsInSuccessors(HBasicBlock* block, BitVector* live);
+  void ZapEnvironmentSlotsForInstruction(HEnvironmentMarker* marker);
+  void UpdateLivenessAtBlockEnd(HBasicBlock* block, BitVector* live);
+  void UpdateLivenessAtInstruction(HInstruction* instr, BitVector* live);
+
+  int block_count_;
+
+  // Largest number of local variables in any environment in the graph
+  // (including inlined environments).
+  int maximum_environment_size_;
+
+  // Per-block data. All these lists are indexed by block_id.
+  ZoneList<BitVector*> live_at_block_start_;
+  ZoneList<HSimulate*> first_simulate_;
+  ZoneList<BitVector*> first_simulate_invalid_for_index_;
+
+  // List of all HEnvironmentMarker instructions for quick iteration/deletion.
+  // It is populated during the first pass over the graph, controlled by
+  // |collect_markers_|.
+  ZoneList<HEnvironmentMarker*> markers_;
+  bool collect_markers_;
+
+  // Keeps track of the last simulate seen, as well as the environment slots
+  // for which a new live range has started since (so they must not be zapped
+  // in that simulate when the end of another live range of theirs is found).
+  HSimulate* last_simulate_;
+  BitVector went_live_since_last_simulate_;
+
+  DISALLOW_COPY_AND_ASSIGN(HEnvironmentLivenessAnalysisPhase);
+};
+
+
+class HEscapeAnalysisPhase : public HPhase {
+ public:
+  explicit HEscapeAnalysisPhase(HGraph* graph)
+      : HPhase("H_Escape analysis", graph), captured_(0, zone()) { }
+
+  void Run() { CollectCapturedValues(); }
+
+ private:
+  void CollectCapturedValues();
+  void CollectIfNoEscapingUses(HInstruction* instr);
+
+  ZoneList<HValue*> captured_;
+
+  DISALLOW_COPY_AND_ASSIGN(HEscapeAnalysisPhase);
+};
+
+
+class HInferRepresentationPhase : public HPhase {
+ public:
+  explicit HInferRepresentationPhase(HGraph* graph)
+      : HPhase("H_Infer representations", graph),
+        worklist_(8, zone()),
+        in_worklist_(graph->GetMaximumValueID(), zone()) { }
+
+  void Run();
+  void AddToWorklist(HValue* current);
+
+ private:
+  ZoneList<HValue*> worklist_;
+  BitVector in_worklist_;
+
+  DISALLOW_COPY_AND_ASSIGN(HInferRepresentationPhase);
+};
+
+
+class HInferTypesPhase : public HPhase {
+ public:
+  explicit HInferTypesPhase(HGraph* graph)
+      : HPhase("H_Inferring types", graph), worklist_(8, zone()),
+        in_worklist_(graph->GetMaximumValueID(), zone()) { }
+
+  void Run() { InferTypes(0, graph()->blocks()->length() - 1); }
+
+ private:
+  void InferTypes(int from_inclusive, int to_inclusive);
+
+  ZoneList<HValue*> worklist_;
+  BitVector in_worklist_;
+
+  DISALLOW_COPY_AND_ASSIGN(HInferTypesPhase);
+};
+
+
+// Perform common subexpression elimination and loop-invariant code motion.
+class HGlobalValueNumberingPhase : public HPhase {
+ public:
+  explicit HGlobalValueNumberingPhase(HGraph* graph);
+
+  void Run() {
+    Analyze();
+    // Trigger a second analysis pass to further eliminate duplicate values
+    // that could only be discovered by removing side-effect-generating
+    // instructions during the first pass.
+    if (FLAG_smi_only_arrays && removed_side_effects_) {
+      Analyze();
+      ASSERT(!removed_side_effects_);
+    }
+  }
+
+ private:
+  void Analyze();
+  GVNFlagSet CollectSideEffectsOnPathsToDominatedBlock(
+      HBasicBlock* dominator,
+      HBasicBlock* dominated);
+  void AnalyzeGraph();
+  void ComputeBlockSideEffects();
+  void LoopInvariantCodeMotion();
+  void ProcessLoopBlock(HBasicBlock* block,
+                        HBasicBlock* before_loop,
+                        GVNFlagSet loop_kills,
+                        GVNFlagSet* accumulated_first_time_depends,
+                        GVNFlagSet* accumulated_first_time_changes);
+  bool AllowCodeMotion();
+  bool ShouldMove(HInstruction* instr, HBasicBlock* loop_header);
+
+  bool removed_side_effects_;
+
+  // A map of block IDs to their side effects.
+  ZoneList<GVNFlagSet> block_side_effects_;
+
+  // A map of loop header block IDs to their loop's side effects.
+  ZoneList<GVNFlagSet> loop_side_effects_;
+
+  // Used when collecting side effects on paths from dominator to
+  // dominated.
+  BitVector visited_on_paths_;
+
+  DISALLOW_COPY_AND_ASSIGN(HGlobalValueNumberingPhase);
+};
+
+
+class HComputeMinusZeroChecksPhase : public HPhase {
+ public:
+  explicit HComputeMinusZeroChecksPhase(HGraph* graph)
+      : HPhase("H_Compute minus zero checks", graph),
+        visited_(graph->GetMaximumValueID(), zone()) { }
+
+  void Run();
+
+ private:
+  void PropagateMinusZeroChecks(HValue* value);
+
+  BitVector visited_;
+
+  DISALLOW_COPY_AND_ASSIGN(HComputeMinusZeroChecksPhase);
+};
+
+
+class HRangeAnalysisPhase : public HPhase {
+ public:
+  explicit HRangeAnalysisPhase(HGraph* graph)
+      : HPhase("H_Range analysis", graph), changed_ranges_(16, zone()) { }
+
+  void Run();
+
+ private:
+  void TraceRange(const char* msg, ...);
+  void InferControlFlowRange(HCompareNumericAndBranch* test,
+                             HBasicBlock* dest);
+  void UpdateControlFlowRange(Token::Value op, HValue* value, HValue* other);
+  void InferRange(HValue* value);
+  void RollBackTo(int index);
+  void AddRange(HValue* value, Range* range);
+
+  ZoneList<HValue*> changed_ranges_;
+
+  DISALLOW_COPY_AND_ASSIGN(HRangeAnalysisPhase);
+};
+
+
+// Replace all phis consisting of a single non-loop operand plus any number of
+// loop operands by that single non-loop operand.
+class HRedundantPhiEliminationPhase : public HPhase {
+ public:
+  explicit HRedundantPhiEliminationPhase(HGraph* graph)
+      : HPhase("H_Redundant phi elimination", graph) { }
+
+  void Run();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HRedundantPhiEliminationPhase);
+};
+
+
+class HMergeRemovableSimulatesPhase : public HPhase {
+ public:
+  explicit HMergeRemovableSimulatesPhase(HGraph* graph)
+      : HPhase("H_Merge removable simulates", graph) { }
+
+  void Run();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HMergeRemovableSimulatesPhase);
+};
+
+
+class HRepresentationChangesPhase : public HPhase {
+ public:
+  explicit HRepresentationChangesPhase(HGraph* graph)
+      : HPhase("H_Representation changes", graph) { }
+
+  void Run();
+
+ private:
+  void InsertRepresentationChangeForUse(HValue* value,
+                                        HValue* use_value,
+                                        int use_index,
+                                        Representation to);
+  void InsertRepresentationChangesForValue(HValue* value);
+
+  DISALLOW_COPY_AND_ASSIGN(HRepresentationChangesPhase);
+};
+
+
+class HStackCheckEliminationPhase : public HPhase {
+ public:
+  explicit HStackCheckEliminationPhase(HGraph* graph)
+      : HPhase("H_Stack check elimination", graph) { }
+
+  void Run();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HStackCheckEliminationPhase);
+};
+
+
+// Discover instructions that can be marked with kUint32 flag allowing
+// them to produce full range uint32 values.
+class HUint32AnalysisPhase : public HPhase {
+ public:
+  explicit HUint32AnalysisPhase(HGraph* graph)
+      : HPhase("H_Compute safe UInt32 operations", graph), phis_(4, zone()) { }
+
+  void Run();
+
+ private:
+  INLINE(bool IsSafeUint32Use(HValue* val, HValue* use));
+  INLINE(bool Uint32UsesAreSafe(HValue* uint32val));
+  INLINE(bool CheckPhiOperands(HPhi* phi));
+  INLINE(void UnmarkPhi(HPhi* phi, ZoneList<HPhi*>* worklist));
+  INLINE(void UnmarkUnsafePhis());
+
+  ZoneList<HPhi*> phis_;
+
+  DISALLOW_COPY_AND_ASSIGN(HUint32AnalysisPhase);
+};
+
+
+} }  // namespace v8::internal
+
+#endif  // V8_HYDROGEN_PHASES_H_