Avoid a smi check when comparing an unknown to a constant smi for equality on...

src/ia32/codegen-ia32.h

 // Copyright 2010 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
@@ skipping 542 matching lines @@
 
   // Emit code to perform a binary operation on two untagged int32 values.
   // The values are on top of the frame, and the result is pushed on the frame.
   void Int32BinaryOperation(BinaryOperation* node);
 
 
   void Comparison(AstNode* node,
                   Condition cc,
                   bool strict,
                   ControlDestination* destination);
+
+  // If at least one of the sides is a constant smi, generate optimized code.
+  void ConstantSmiComparison(Condition cc,
+                             bool strict,
+                             ControlDestination* destination,
+                             Result* left_side,
+                             Result* right_side,
+                             bool left_side_constant_smi,
+                             bool right_side_constant_smi,
+                             bool is_loop_condition);
+
   void GenerateInlineNumberComparison(Result* left_side,
                                       Result* right_side,
                                       Condition cc,
                                       ControlDestination* dest);
 
   // To prevent long attacker-controlled byte sequences, integer constants
   // from the JavaScript source are loaded in two parts if they are larger
   // than 17 bits.
   static const int kMaxSmiInlinedBits = 17;
   bool IsUnsafeSmi(Handle<Object> value);
@@ skipping 494 matching lines @@
   void Print() {
     PrintF("NumberToStringStub\n");
   }
 #endif
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_CODEGEN_IA32_H_