Add DoubleToSmi optimistically, preventing boxing/unboxing of doubles and propagate smi-nessof the …

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 235 matching lines @@
   M(ExtractConstructorInstantiator)                                            \
   M(AllocateContext)                                                           \
   M(ChainContext)                                                              \
   M(CloneContext)                                                              \
   M(CatchEntry)                                                                \
   M(BinarySmiOp)                                                               \
   M(UnarySmiOp)                                                                \
   M(CheckStackOverflow)                                                        \
   M(SmiToDouble)                                                               \
   M(DoubleToInteger)                                                           \
+  M(DoubleToSmi)                                                               \
   M(CheckClass)                                                                \
   M(CheckSmi)                                                                  \
   M(Constant)                                                                  \
   M(CheckEitherNonSmi)                                                         \
   M(BinaryDoubleOp)                                                            \
   M(MathSqrt)                                                                  \
   M(UnboxDouble)                                                               \
   M(BoxDouble)                                                                 \
   M(UnboxInteger)                                                              \
   M(BoxInteger)                                                                \
@@ skipping 261 matching lines @@
   friend class UnarySmiOpInstr;
   friend class ShiftMintOpInstr;
   friend class UnaryMintOpInstr;
   friend class MathSqrtInstr;
   friend class CheckClassInstr;
   friend class CheckSmiInstr;
   friend class CheckArrayBoundInstr;
   friend class CheckEitherNonSmiInstr;
   friend class StringCharCodeAtInstr;
   friend class LICM;
+  friend class DoubleToSmiInstr;
 
   intptr_t deopt_id_;
   intptr_t lifetime_position_;  // Position used by register allocator.
   Instruction* previous_;
   Instruction* next_;
   Environment* env_;
   intptr_t expr_id_;
 
   DISALLOW_COPY_AND_ASSIGN(Instruction);
 };
@@ skipping 3421 matching lines @@
 
  private:
   InstanceCallInstr* instance_call_;
 
   DISALLOW_COPY_AND_ASSIGN(SmiToDoubleInstr);
 };
 
 
 class DoubleToIntegerInstr : public TemplateDefinition<1> {
  public:
-  explicit DoubleToIntegerInstr(Value* value, InstanceCallInstr* instance_call)
+  DoubleToIntegerInstr(Value* value, InstanceCallInstr* instance_call)
       : instance_call_(instance_call) {
     ASSERT(value != NULL);
     inputs_[0] = value;
   }
 
   Value* value() const { return inputs_[0]; }
   InstanceCallInstr* instance_call() const { return instance_call_; }
 
   DECLARE_INSTRUCTION(DoubleToInteger)
   virtual RawAbstractType* CompileType() const;
 
   virtual intptr_t ArgumentCount() const { return 1; }

[Vyacheslav Egorov (Google), 2012/12/17 12:53:44]

I think this should be 0 because pusharguments are dropped.

 
   virtual bool CanDeoptimize() const { return true; }
 
   virtual bool HasSideEffect() const { return false; }
 
   // Result could be any of the int types.
   virtual intptr_t ResultCid() const { return kDynamicCid; }
 
  private:
   InstanceCallInstr* instance_call_;
 
   DISALLOW_COPY_AND_ASSIGN(DoubleToIntegerInstr);
 };
 
 
+// Similar to 'DoubleToIntegerInstr' but expects unboxed double as input
+// and creates a Smi.
+class DoubleToSmiInstr : public TemplateDefinition<1> {
+ public:
+  DoubleToSmiInstr(Value* value, InstanceCallInstr* instance_call) {
+    ASSERT(value != NULL);
+    inputs_[0] = value;
+    deopt_id_ = instance_call->deopt_id();
+  }
+
+  Value* value() const { return inputs_[0]; }
+
+  DECLARE_INSTRUCTION(DoubleToSmi)
+  virtual RawAbstractType* CompileType() const;
+
+  virtual intptr_t ArgumentCount() const { return 1; }

[Vyacheslav Egorov (Google), 2012/12/17 12:53:44]

I think this should be zero because this instruction does not contain a call
inside and pushargument is dropped in optimizer.

[srdjan, 2012/12/18 00:12:47]

Done.

[Vyacheslav Egorov (Google), 2012/12/18 11:45:10]

Actually Definition has a default implementation that returns 0 so you can just
remove it.

[srdjan, 2012/12/18 16:29:47]

Done, thanks. 

+
+  virtual bool CanDeoptimize() const { return true; }
+
+  virtual bool HasSideEffect() const { return false; }
+
+  // Result could be any of the int types.
+  virtual intptr_t ResultCid() const { return kSmiCid; }

[Vyacheslav Egorov (Google), 2012/12/17 12:53:44]

Comment does not match implementation.

[srdjan, 2012/12/18 00:12:47]

Removed comment.

+
+  virtual Representation RequiredInputRepresentation(intptr_t idx) const {
+    ASSERT(idx == 0);
+    return kUnboxedDouble;
+  }
+
+  virtual intptr_t DeoptimizationTarget() const { return deopt_id_; }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DoubleToSmiInstr);
+};
+
+
 class CheckClassInstr : public TemplateInstruction<1> {
  public:
   CheckClassInstr(Value* value,
                   intptr_t deopt_id,
                   const ICData& unary_checks);
 
   DECLARE_INSTRUCTION(CheckClass)
   virtual RawAbstractType* CompileType() const;
 
   virtual intptr_t ArgumentCount() const { return 0; }
@@ skipping 303 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_