Fuse comparisons that are used by branches together.

runtime/vm/intermediate_language.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 61 matching lines @@
   M(CheckStackOverflow, CheckStackOverflowComp)                                \
   M(ToDouble, ToDoubleComp)                                                    \
 
 
 #define FORWARD_DECLARATION(ShortName, ClassName) class ClassName;
 FOR_EACH_COMPUTATION(FORWARD_DECLARATION)
 #undef FORWARD_DECLARATION
 
 // Forward declarations.
 class BufferFormatter;
+class BranchInstr;
 class Instruction;
 class Value;
 
 
 class Computation : public ZoneAllocated {
  public:
   static const int kNoCid = -1;
 
   Computation() : cid_(-1), ic_data_(NULL), instr_(NULL), locs_(NULL) {
     Isolate* isolate = Isolate::Current();
@@ skipping 399 matching lines @@
   const intptr_t try_index_;
   const String& function_name_;
   ZoneGrowableArray<Value*>* const arguments_;
   const Array& argument_names_;
   const intptr_t checked_argument_count_;
 
   DISALLOW_COPY_AND_ASSIGN(InstanceCallComp);
 };
 
 
-class StrictCompareComp : public TemplateComputation<2> {
+class ComparisonComp : public TemplateComputation<2> {
+ public:
+  ComparisonComp(Value* left, Value* right)
+      : fused_with_branch_(NULL) {
+    ASSERT(left != NULL);
+    ASSERT(right != NULL);
+    inputs_[0] = left;
+    inputs_[1] = right;
+  }
+
+  void MarkFusedWithBranch(BranchInstr* branch) {
+    fused_with_branch_ = branch;
+  }
+
+  BranchInstr* fused_with_branch() const {
+    return fused_with_branch_;
+  }

[srdjan, 2012/06/13 15:29:35]

Maybe also is_fused_with_branch => fused_with_branch_ != NULL, then add an
assert to fused_with_branch that it must not be NULL.

[Vyacheslav Egorov (Google), 2012/06/13 16:23:43]

Done.

+
+  Value* left() const { return inputs_[0]; }
+  Value* right() const { return inputs_[1]; }
+
+ private:
+  BranchInstr* fused_with_branch_;
+};
+
+
+class StrictCompareComp : public ComparisonComp {
  public:
   StrictCompareComp(Token::Kind kind, Value* left, Value* right)
-      : kind_(kind) {
+      : ComparisonComp(left, right), kind_(kind) {
     ASSERT((kind_ == Token::kEQ_STRICT) || (kind_ == Token::kNE_STRICT));
-    inputs_[0] = left;
-    inputs_[1] = right;
   }
 
   DECLARE_COMPUTATION(StrictCompare)
 
   Token::Kind kind() const { return kind_; }
-  Value* left() const { return inputs_[0]; }
-  Value* right() const { return inputs_[1]; }
 
   virtual void PrintOperandsTo(BufferFormatter* f) const;
 
  private:
   const Token::Kind kind_;
 
   DISALLOW_COPY_AND_ASSIGN(StrictCompareComp);
 };
 
 
-class EqualityCompareComp : public TemplateComputation<2> {
+class EqualityCompareComp : public ComparisonComp {
  public:
   EqualityCompareComp(intptr_t token_index,
                       intptr_t try_index,
                       Value* left,
                       Value* right)
-      : token_index_(token_index),
+      : ComparisonComp(left, right),
+        token_index_(token_index),
         try_index_(try_index) {
-    ASSERT(left != NULL);
-    ASSERT(right != NULL);
-    inputs_[0] = left;
-    inputs_[1] = right;
   }
 
   DECLARE_COMPUTATION(EqualityCompare)
 
   intptr_t token_index() const { return token_index_; }
   intptr_t try_index() const { return try_index_; }
-  Value* left() const { return inputs_[0]; }
-  Value* right() const { return inputs_[1]; }
 
   virtual void PrintOperandsTo(BufferFormatter* f) const;
 
  private:
   const intptr_t token_index_;
   const intptr_t try_index_;
 
   DISALLOW_COPY_AND_ASSIGN(EqualityCompareComp);
 };
 
 
-class RelationalOpComp : public TemplateComputation<2> {
+class RelationalOpComp : public ComparisonComp {
  public:
   RelationalOpComp(intptr_t token_index,
                    intptr_t try_index,
                    Token::Kind kind,
                    Value* left,
                    Value* right)
-      : token_index_(token_index),
+      : ComparisonComp(left, right),
+        token_index_(token_index),
         try_index_(try_index),
         kind_(kind),
         operands_class_id_(kObject) {
     ASSERT(Token::IsRelationalOperator(kind));
-    ASSERT(left != NULL);
-    ASSERT(right != NULL);
-    inputs_[0] = left;
-    inputs_[1] = right;
   }
 
   DECLARE_COMPUTATION(RelationalOp)
 
   intptr_t token_index() const { return token_index_; }
   intptr_t try_index() const { return try_index_; }
   Token::Kind kind() const { return kind_; }
-  Value* left() const { return inputs_[0]; }
-  Value* right() const { return inputs_[1]; }
 
   // TODO(srdjan): instead of class-id pass an enum that can differentiate
   // between boxed and unboxed doubles and integers.
   void set_operands_class_id(intptr_t value) {
     operands_class_id_ = value;
   }
+
   intptr_t operands_class_id() const { return operands_class_id_; }
 
   virtual void PrintOperandsTo(BufferFormatter* f) const;
 
  private:
   const intptr_t token_index_;
   const intptr_t try_index_;
   const Token::Kind kind_;
   intptr_t operands_class_id_;  // class id of both operands.
 
@@ skipping 1548 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(ReThrowInstr);
 };
 
 
 class BranchInstr : public InstructionWithInputs {
  public:
   explicit BranchInstr(Value* value)
       : InstructionWithInputs(),
         value_(value),
         true_successor_(NULL),
-        false_successor_(NULL) { }
+        false_successor_(NULL),
+        fused_with_comparison_(false) { }
 
   DECLARE_INSTRUCTION(Branch)
 
   Value* value() const { return value_; }
   TargetEntryInstr* true_successor() const { return true_successor_; }
   TargetEntryInstr* false_successor() const { return false_successor_; }
 
   TargetEntryInstr** true_successor_address() { return &true_successor_; }
   TargetEntryInstr** false_successor_address() { return &false_successor_; }
 
   virtual Instruction* StraightLineSuccessor() const { return NULL; }
   virtual void SetSuccessor(Instruction* instr) { UNREACHABLE(); }
 
   virtual intptr_t SuccessorCount() const;
   virtual BlockEntryInstr* SuccessorAt(intptr_t index) const;
 
   virtual void DiscoverBlocks(
       BlockEntryInstr* current_block,
       GrowableArray<BlockEntryInstr*>* preorder,
       GrowableArray<BlockEntryInstr*>* postorder,
       GrowableArray<intptr_t>* parent,
       GrowableArray<BitVector*>* assigned_vars,
       intptr_t variable_count);
 
   virtual LocationSummary* MakeLocationSummary() const;
 
   virtual void EmitNativeCode(FlowGraphCompiler* compiler);
 
+  void EmitBranchOnCondition(FlowGraphCompiler* compiler,
+                             Condition true_condition);
+
+  void MarkFusedWithComparison() {
+    fused_with_comparison_ = true;
+  }
+
+  bool is_fused_with_comparison() const { return fused_with_comparison_; }
+
  private:
   Value* value_;
   TargetEntryInstr* true_successor_;
   TargetEntryInstr* false_successor_;
+  bool fused_with_comparison_;

[srdjan, 2012/06/13 15:29:35]

rename to is_fused_with_comparison_

[Vyacheslav Egorov (Google), 2012/06/13 16:23:43]

Done.

 
   DISALLOW_COPY_AND_ASSIGN(BranchInstr);
 };
 
 #undef DECLARE_INSTRUCTION
 
 
 // Visitor base class to visit each instruction and computation in a flow
 // graph as defined by a reversed list of basic blocks.
 class FlowGraphVisitor : public ValueObject {
@@ skipping 24 matching lines @@
   const GrowableArray<BlockEntryInstr*>& block_order_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_