[9] RFR(S): 8160651: StubRoutines::_dtan does not restore callee save register rbx

[Vladimir Ivanov]

Looks good.

Best regards,
Vladimir Ivanov

On 6/30/16 4:15 PM, Tobias Hartmann wrote:
> Hi,
>
> please review the following patch:
>
> https://bugs.openjdk.java.net/browse/JDK-8160651
> http://cr.openjdk.java.net/~thartmann/8160651/webrev.00/
>
> StubRoutines::_dtan overwrites the callee save register $rbx but does not restore the original value before returning. The problem is in MacroAssembler::fast_tan() introduced by JDK-8152907 [1]: we set $rbx to 32768 (0x8000) but do not pop the saved value from the stack before returning. This causes several test failures (see linked bugs) because $rbx contains incorrect values. The implementations of MacroAssembler::fast_cos() are MacroAssembler::fast_sin() are similar, but correctly restore $rbx [2].
>
> I also removed the unused LibraryCallKit::inline_trig().
>
> Tested with failing tests, JPRT and RBT (running).
>
> Thanks,
> Tobias
>
> [1] http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/33f10a35ce20#l16.1052
> [2] http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/33f10a35ce20#l8.3947
>