RFR(S): 8201368: IfNode::fold_compares() may lead to incorrect execution

[Vladimir Kozlov]

Changes looks good.

To avoid running test with -Xcomp add:

@requires vm.compMode == "Xmixed"

Vladimir

On 4/12/18 7:41 AM, Roland Westrelin wrote:
> 
> Hi Nils,
> 
> Thanks for reviewing this.
> 
>> Add "-Xmixed" to the test commandline to disable -Xcomp for this test.
>> -XX:-BackgroundCompilation is costly in combination with -Xcomp.
> 
> -Xcomp causes BackgroundCompilation to be set to false AFAICT:
> 
> void Arguments::set_mode_flags(Mode mode) {
> ...
>    switch (mode) {
>    default:
>      ShouldNotReachHere();
>      break;
>    case _int:
>      UseCompiler              = false;
>      UseLoopCounter           = false;
>      AlwaysCompileLoopMethods = false;
>      UseOnStackReplacement    = false;
>      break;
>    case _mixed:
>      // same as default
>      break;
>    case _comp:
>      UseInterpreter           = false;
>      BackgroundCompilation    = false;
> 
> Roland.
>