RFR (M): 7023898: Intrinsify AtomicLongFieldUpdater.getAndIncrement()

[John Rose]

On May 15, 2012, at 9:10 AM, Roland Westrelin wrote:

> http://cr.openjdk.java.net/~roland/7023898/

The C2 part looks good.  I have a few small suggestions.

1. Replace push(cas) by push_node(type, load_store).

2. I don't understand why the (kind = cmpxchg) case doesn't push a result.  Does't the original push(cas) do that?

3. In the if/else chain testing 'kind', change the bare 'else' to 'else if (kind ≡ cmpxchg)' and follow up with 'else ShouldNotReachHere()'.  At least put an "assert(kind ≡ cmpxchg)".  This will ease maintenance, in case somebody adds a new case to load_store_kind.

4. Naming:  Consider using a more type-like name for load_store_kind, such as LoadStoreKind.  Compare ReexecuteState and NodeType enums.  Also, the enum names themselves could use a prefix or camel-case, e.g., LS_xadd or _xadd or XAdd.  Since the names are private to library_call.cpp, it doesn't matter as much as in other places, but it still improves readability of code that contains the names.  (Reason:  an all-lower-case simple name like xadd appears at first glance to be a local variable.  Manifest constants should look different.)

Overall, it is a nicely rounded extension, with good reuse of previously existing code.  Thanks!

— John

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