Simplify double to number convertion.

src/runtime.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 5394 matching lines @@
   return Heap::AllocateHeapNumber(-x);
 }
 
 
 static Object* Runtime_NumberDiv(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
   CONVERT_DOUBLE_CHECKED(x, args[0]);
   CONVERT_DOUBLE_CHECKED(y, args[1]);
-  return Heap::NewNumberFromDouble(x / y);
+  return Heap::NumberFromDouble(x / y);
 }
 
 
 static Object* Runtime_NumberMod(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
   CONVERT_DOUBLE_CHECKED(x, args[0]);
   CONVERT_DOUBLE_CHECKED(y, args[1]);
 
   x = modulo(x, y);
-  // NewNumberFromDouble may return a Smi instead of a Number object
-  return Heap::NewNumberFromDouble(x);
+  // NumberFromDouble may return a Smi instead of a Number object
+  return Heap::NumberFromDouble(x);
 }
 
 
 static Object* Runtime_StringAdd(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
   CONVERT_CHECKED(String, str1, args[0]);
   CONVERT_CHECKED(String, str2, args[1]);
   Counters::string_add_runtime.Increment();
   return Heap::AllocateConsString(str1, str2);
@@ skipping 633 matching lines @@
   }
 
   // If the magnitude is big enough, there's no place for fraction part. If we
   // try to add 0.5 to this number, 1.0 will be added instead.
   if (exponent >= 52) {
     return number;
   }
 
   if (sign && value >= -0.5) return Heap::minus_zero_value();
 
-  return Heap::NumberFromDouble(floor(value + 0.5));
+  // Do not call NumberFromDouble() to avoid extra checks.
+  return Heap::AllocateHeapNumber(floor(value + 0.5));
 }
 
 
 static Object* Runtime_Math_sin(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
   Counters::math_sin.Increment();
 
   CONVERT_DOUBLE_CHECKED(x, args[0]);
   return TranscendentalCache::Get(TranscendentalCache::SIN, x);
@@ skipping 4149 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal