RFR: Remove ShWB from formssel.cpp

[Aleksey Shipilev]

On 09/26/2018 04:38 PM, Roman Kennke wrote:
> We no longer expand ShenandoahWriteBarrier in the .ad files, and
> therefore don't need the matchers in formssel.cpp:
> 
> diff --git a/src/hotspot/share/adlc/formssel.cpp
> b/src/hotspot/share/adlc/formssel.cpp
> --- a/src/hotspot/share/adlc/formssel.cpp
> +++ b/src/hotspot/share/adlc/formssel.cpp
> @@ -778,8 +778,7 @@
>         !strcmp(_matrule->_rChild->_opType,"CompareAndExchangeN") ||
> 
> !strcmp(_matrule->_rChild->_opType,"ShenandoahCompareAndExchangeP") ||
> 
> !strcmp(_matrule->_rChild->_opType,"ShenandoahCompareAndExchangeN") ||
> -       !strcmp(_matrule->_rChild->_opType,"ShenandoahReadBarrier") ||
> -       !strcmp(_matrule->_rChild->_opType,"ShenandoahWriteBarrier")) )
> return true;
> +       !strcmp(_matrule->_rChild->_opType,"ShenandoahReadBarrier")))
> return true;
>    else if ( is_ideal_load() == Form::idealP )                return true;
>    else if ( is_ideal_store() != Form::none  )                return true;
> 
> @@ -3504,7 +3503,7 @@
>      "ClearArray",
>      "GetAndSetB", "GetAndSetS", "GetAndAddI", "GetAndSetI", "GetAndSetP",
>      "GetAndAddB", "GetAndAddS", "GetAndAddL", "GetAndSetL", "GetAndSetN",
> -    "ShenandoahReadBarrier", "ShenandoahWriteBarrier",
> +    "ShenandoahReadBarrier",
>      "LoadBarrierSlowReg", "LoadBarrierWeakSlowReg"
>    };
>    int cnt = sizeof(needs_ideal_memory_list)/sizeof(char*);

Seems fine. Roland needs to ack this.

-Aleksey