Eliminate temporary locals for some expressions

runtime/vm/intermediate_language.h

 // Copyright (c) 2013, 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 511 matching lines @@
   M(AssertAssignable)                                                          \
   M(AssertBoolean)                                                             \
   M(ArgumentDefinitionTest)                                                    \
   M(CurrentContext)                                                            \
   M(StoreContext)                                                              \
   M(ClosureCall)                                                               \
   M(InstanceCall)                                                              \
   M(PolymorphicInstanceCall)                                                   \
   M(StaticCall)                                                                \
   M(LoadLocal)                                                                 \
+  M(PushTemp)                                                                  \
+  M(DropTemps)                                                                 \
   M(StoreLocal)                                                                \
   M(StrictCompare)                                                             \
   M(EqualityCompare)                                                           \
   M(RelationalOp)                                                              \
   M(NativeCall)                                                                \
   M(LoadIndexed)                                                               \
   M(StoreIndexed)                                                              \
   M(StoreInstanceField)                                                        \
   M(LoadStaticField)                                                           \
   M(StoreStaticField)                                                          \
@@ skipping 2596 matching lines @@
   }
 
  private:
   const LocalVariable& local_;
   bool is_last_;
 
   DISALLOW_COPY_AND_ASSIGN(LoadLocalInstr);
 };
 
 
+class PushTempInstr : public TemplateDefinition<1> {
+ public:
+  explicit PushTempInstr(Value* value) {
+    SetInputAt(0, value);
+  }
+
+  DECLARE_INSTRUCTION(PushTemp)
+
+  Value* value() const { return inputs_[0]; }
+
+  virtual CompileType ComputeType() const;
+
+  virtual bool CanDeoptimize() const { return false; }
+
+  virtual EffectSet Effects() const {
+    UNREACHABLE();  // Eliminated by SSA construction.
+    return EffectSet::None();
+  }
+
+  virtual bool MayThrow() const {
+    UNREACHABLE();
+    return false;
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(PushTempInstr);
+};
+
+
+class DropTempsInstr : public TemplateDefinition<1> {
+ public:
+  explicit DropTempsInstr(intptr_t num_temps, Value* value)
+      : num_temps_(num_temps) {
+    SetInputAt(0, value);
+  }
+
+  DECLARE_INSTRUCTION(DropTemps)
+
+  Value* value() const { return inputs_[0]; }
+
+  intptr_t num_temps() const { return num_temps_; }
+
+  virtual CompileType ComputeType() const;
+
+  virtual bool CanDeoptimize() const { return false; }
+
+  virtual EffectSet Effects() const {
+    UNREACHABLE();  // Eliminated by SSA construction.
+    return EffectSet::None();
+  }
+
+  virtual bool MayThrow() const {
+    UNREACHABLE();
+    return false;
+  }
+
+ private:
+  intptr_t num_temps_;
+
+  DISALLOW_COPY_AND_ASSIGN(DropTempsInstr);
+};
+
+
 class StoreLocalInstr : public TemplateDefinition<1> {
  public:
   StoreLocalInstr(const LocalVariable& local, Value* value)
       : local_(local), is_dead_(false), is_last_(false) {
     SetInputAt(0, value);
   }
 
   DECLARE_INSTRUCTION(StoreLocal)
   virtual CompileType* ComputeInitialType() const;
 
@@ skipping 3252 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_