RFR (M) 8157726: VarHandles/Unsafe should support sub-word atomic ops [RESEND]

[Aleksey Shipilev]

On 05/30/2016 01:32 PM, Vladimir Ivanov wrote:
> Looks good.

Thanks!

> src/share/vm/opto/c2compiler.cpp:
> 
> +  case vmIntrinsics::_weakCompareAndSwapObjectVolatile:
> 
> +  case vmIntrinsics::_weakCompareAndSwapLongVolatile:
> 
> +  case vmIntrinsics::_weakCompareAndSwapIntVolatile:
> 
> Was it overlooked in one of previous VH-related changes?

Yes, we apparently missed that in JDK-8155965, added here for
consistency reasons. It is a bug waiting to happen: while we currently
"fail" the compilation when C2 cannot match the nodes, we should check
it routinely in c2compiler.cpp.

Thanks,
-Aleksey