Generate smaller unoptimized code for certain expressions.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
===================================================================
--- runtime/vm/intermediate_language.h	(revision 33576)
+++ runtime/vm/intermediate_language.h	(working copy)
@@ -3430,17 +3430,25 @@
 };
 
 
-class DropTempsInstr : public TemplateDefinition<1> {
+class DropTempsInstr : public Definition {
  public:
-  explicit DropTempsInstr(intptr_t num_temps, Value* value)
-      : num_temps_(num_temps) {
-    SetInputAt(0, value);
+  explicit DropTempsInstr(intptr_t num_temps, Value* value = NULL)
+      : num_temps_(num_temps), value_(NULL) {
+    if (value != NULL) {
+      SetInputAt(0, value);

[srdjan, 2014/03/12 18:18:30]

I think it would be better do add a private method SetValue which would do:
value->set_instruction(this);
value->set_use_index(i)

[Florian Schneider, 2014/03/13 08:56:15]

I would still need RawSetInputAt since it is used by SetInputAt. I'll rather
have  the use-list book-keeping in once place.

+    }
   }
 
   DECLARE_INSTRUCTION(DropTemps)
 
-  Value* value() const { return inputs_[0]; }
+  virtual intptr_t InputCount() const { return value_ != NULL ? 1 : 0; }
+  virtual Value* InputAt(intptr_t i) const {
+    ASSERT((value_ != NULL) && (i == 0));
+    return value_;
+  }
 
+  Value* value() const { return value_; }
+
   intptr_t num_temps() const { return num_temps_; }
 
   virtual CompileType* ComputeInitialType() const;
@@ -3460,7 +3468,12 @@
   }
 
  private:
+  virtual void RawSetInputAt(intptr_t i, Value* value) {
+    value_ = value;
+  }
+
   intptr_t num_temps_;

[srdjan, 2014/03/12 18:18:30]

const ?

[Florian Schneider, 2014/03/13 08:56:15]

Done.

+  Value* value_;
 
   DISALLOW_COPY_AND_ASSIGN(DropTempsInstr);
 };