Optimize 3 Number2Integer functions in runtime.cc: remove the check that was ...

src/runtime.cc

Index: src/runtime.cc
===================================================================
--- src/runtime.cc	(revision 3939)
+++ src/runtime.cc	(working copy)
@@ -4152,10 +4152,13 @@
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
-  Object* obj = args[0];
-  if (obj->IsSmi()) return obj;
-  CONVERT_DOUBLE_CHECKED(number, obj);
-  return Heap::NumberFromDouble(DoubleToInteger(number));
+  CONVERT_DOUBLE_CHECKED(number, args[0]);
+
+  // We do not include 0 so that we didn't have to treat +0 / -0 cases.

[Mads Ager (chromium), 2010/02/25 15:11:03]

didn't -> don't

[Oleg Eterevsky, 2010/02/25 15:30:43]

Done.

+  if (number > 0 && number <= Smi::kMaxValue)

[Mads Ager (chromium), 2010/02/25 15:11:03]

Please use braces around both the if and the else body.

if (...) {
  ...
} else {
  ...
}

[Oleg Eterevsky, 2010/02/25 15:30:43]

Done.

+    return Smi::FromInt(static_cast<int>(number));
+  else
+    return Heap::NumberFromDouble(DoubleToInteger(number));
 }
 
 
@@ -4164,7 +4167,6 @@
   ASSERT(args.length() == 1);
 
   Object* obj = args[0];

[Mads Ager (chromium), 2010/02/25 15:11:03]

Just use args[0] in the CONVERT_NUMBER_CHECKED below?

[Oleg Eterevsky, 2010/02/25 15:30:43]

Done.

-  if (obj->IsSmi() && Smi::cast(obj)->value() >= 0) return obj;
   CONVERT_NUMBER_CHECKED(int32_t, number, Uint32, obj);
   return Heap::NumberFromUint32(number);
 }
@@ -4174,10 +4176,11 @@
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
-  Object* obj = args[0];
-  if (obj->IsSmi()) return obj;
-  CONVERT_DOUBLE_CHECKED(number, obj);
-  return Heap::NumberFromInt32(DoubleToInt32(number));
+  CONVERT_DOUBLE_CHECKED(number, args[0]);
+  if (number > 0 && number <= Smi::kMaxValue)

[Mads Ager (chromium), 2010/02/25 15:11:03]

Please use braces here as well.  Repeat the comment about not handling 0 because
of the -0/+0 complications?

[Oleg Eterevsky, 2010/02/25 15:30:43]

Done.

+    return Smi::FromInt(static_cast<int>(number));
+  else
+    return Heap::NumberFromInt32(DoubleToInt32(number));
 }