Removed static type inference and add a dynamic test for string addition.

src/ia32/codegen-ia32.cc

 // Copyright 2006-2009 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 901 matching lines @@
       flags = ((loop_nesting() > 0) && type->IsLikelySmi())
               ? SMI_CODE_INLINED
               : SMI_CODE_IN_STUB;
       break;
   }
 
   Result right = frame_->Pop();
   Result left = frame_->Pop();
 
   if (op == Token::ADD) {
-    bool left_is_string = left.static_type().is_jsstring();
-    bool right_is_string = right.static_type().is_jsstring();
+    bool left_is_string = left.is_constant() && left.handle()->IsString();
+    bool right_is_string = right.is_constant() && right.handle()->IsString();
     if (left_is_string || right_is_string) {
       frame_->Push(&left);
       frame_->Push(&right);
       Result answer;
       if (left_is_string) {
         if (right_is_string) {
-          // TODO(lrn): if (left.is_constant() && right.is_constant())
+          // TODO(lrn): if both are constant strings
           // -- do a compile time cons, if allocation during codegen is allowed.
           answer = frame_->CallRuntime(Runtime::kStringAdd, 2);
         } else {
           answer =
             frame_->InvokeBuiltin(Builtins::STRING_ADD_LEFT, CALL_FUNCTION, 2);

[Erik Corry, 2009/06/24 11:46:35]

I wonder whether the stub is faster here.  It doesn't have to do the IS_STRING
test in js.

[Lasse Reichstein, 2009/06/24 12:33:07]

Good idea.
I'll commit this for now, and make a test afterwards.

         }
       } else if (right_is_string) {
         answer =
           frame_->InvokeBuiltin(Builtins::STRING_ADD_RIGHT, CALL_FUNCTION, 2);
       }
-      answer.set_static_type(StaticType::jsstring());
       frame_->Push(&answer);
       return;
     }
     // Neither operand is known to be a string.
   }
 
   bool left_is_smi = left.is_constant() && left.handle()->IsSmi();
   bool left_is_non_smi = left.is_constant() && !left.handle()->IsSmi();
   bool right_is_smi = right.is_constant() && right.handle()->IsSmi();
   bool right_is_non_smi = right.is_constant() && !right.handle()->IsSmi();
@@ skipping 5895 matching lines @@
       __ mov(edx, Operand(esp, 2 * kPointerSize));
       break;
     }
     default: UNREACHABLE(); break;
   }
 
   // If all else fails, use the runtime system to get the correct
   // result.
   __ bind(&call_runtime);
   switch (op_) {
-    case Token::ADD:
+    case Token::ADD: {
+      // Test for string arguments before calling runtime.
+      Label not_strings, both_strings, not_string1, string1;
+      Result answer;
+      __ mov(eax, Operand(esp, 2 * kPointerSize));  // First argument.
+      __ mov(edx, Operand(esp, 1 * kPointerSize));  // Second argument.
+      __ test(eax, Immediate(kSmiTagMask));
+      __ j(zero, &not_string1);
+      __ CmpObjectType(eax, FIRST_NONSTRING_TYPE, eax);
+      __ j(above_equal, &not_string1);
+
+      // First argument is a a string, test second.
+      __ test(edx, Immediate(kSmiTagMask));
+      __ j(zero, &string1);
+      __ CmpObjectType(edx, FIRST_NONSTRING_TYPE, edx);
+      __ j(above_equal, &string1);
+
+      // First and second argument are strings.
+      __ TailCallRuntime(ExternalReference(Runtime::kStringAdd), 2);
+
+      // Only first argument is a string.
+      __ bind(&string1);
+      __ InvokeBuiltin(Builtins::STRING_ADD_LEFT, JUMP_FUNCTION);
+
+      // First argument was not a string, test second.
+      __ bind(&not_string1);
+      __ test(edx, Immediate(kSmiTagMask));
+      __ j(zero, &not_strings);
+      __ CmpObjectType(edx, FIRST_NONSTRING_TYPE, edx);
+      __ j(above_equal, &not_strings);
+
+      // Only second argument is a string.
+      __ InvokeBuiltin(Builtins::STRING_ADD_RIGHT, JUMP_FUNCTION);
+
+      __ bind(&not_strings);
+      // Neither argument is a string.
       __ InvokeBuiltin(Builtins::ADD, JUMP_FUNCTION);
       break;
+    }
     case Token::SUB:
       __ InvokeBuiltin(Builtins::SUB, JUMP_FUNCTION);
       break;
     case Token::MUL:
       __ InvokeBuiltin(Builtins::MUL, JUMP_FUNCTION);
         break;
     case Token::DIV:
       __ InvokeBuiltin(Builtins::DIV, JUMP_FUNCTION);
       break;
     case Token::MOD:
@@ skipping 932 matching lines @@
 
   // Slow-case: Go through the JavaScript implementation.
   __ bind(&slow);
   __ InvokeBuiltin(Builtins::INSTANCE_OF, JUMP_FUNCTION);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal