Constant-fold !<number>

src/parser.cc

 // Copyright 2011 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 2537 matching lines @@
     if (expression != NULL && expression->AsLiteral() &&
         expression->AsLiteral()->handle()->IsNumber()) {
       double value = expression->AsLiteral()->handle()->Number();
       switch (op) {
         case Token::ADD:
           return expression;
         case Token::SUB:
           return NewNumberLiteral(-value);
         case Token::BIT_NOT:
           return NewNumberLiteral(~DoubleToInt32(value));
+        case Token::NOT:
+          if (!isnan(value)) {

[Kevin Millikin (Chromium), 2011/06/14 08:40:35]

Does:

bool cond = isnan(value) || (value == 0);
Handle<Object> boolean(isolate()->heap()->ToBoolean(cond));

Handle the NaN case as well?

+            Handle<Object> boolean(isolate()->heap()->ToBoolean(value == 0));
+            return new(zone()) Literal(boolean);
+          }
+          break;
         default: break;
       }
     }
 
     // "delete identifier" is a syntax error in strict mode.
     if (op == Token::DELETE && top_scope_->is_strict_mode()) {
       VariableProxy* operand = expression->AsVariableProxy();
       if (operand != NULL && !operand->is_this()) {
         ReportMessage("strict_delete", Vector<const char*>::empty());
         *ok = false;
@@ skipping 2423 matching lines @@
                                    info->is_global(),
                                    info->StrictMode());
     }
   }
 
   info->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal