[aarch64-port-dev ] RFR: AArch64: -XX:-UseOnStackReplacement does not work together with -XX:+TieredCompilation.

[Ningsheng Jian]

Hi,

Seems that this is still open. Test failure can be found from latest
Linaro test results:
http://openjdk.linaro.org/jdk9/openjdk-jtreg-nightly-tests/

I created a bug for it to track:
https://bugs.openjdk.java.net/browse/JDK-8173100

Webrev: http://cr.openjdk.java.net/~njian/8173100/webrev.00/

Thanks,
Ningsheng

On 25 July 2016 at 17:22, Ningsheng Jian <ningsheng.jian at linaro.org> wrote:
> Hi,
>
> Hotspot patch [1] introduces a test case
> hotspot/test/compiler/interpreter/DisableOSRTest.java which also
> exposes the same issue on aarch64.
>
> I.e. with -XX:-UseOnStackReplacement and -XX:+TieredCompilation
> options, there are still OSR compilations found from
> -XX:+PrintCompilation.
>
> On x86, the increment_mask_and_jump just jumps to the next instruction
> if backedge_counter_overflow is not generated. So there is no such
> issue - but is it intended?
>
> The following fix on AArch64 is to revert [2] to align with x86 code
> and assign the correct branch target based on the
> UseOnStackReplacement option.
>
> http://people.linaro.org/~ningsheng.jian/disable-osr/webrev.00/
>
> Tested with jtreg.
>
> [1] http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/fd222df9f27c
> [2] http://hg.openjdk.java.net/aarch64-port/jdk8/hotspot/rev/18e5cbbe8abf