[aarch64-port-dev ] RFR (XS) 8221725: AArch64 build failures after JDK-8221408 (Windows 32bit build build errors/warnings in hotspot)

[Thomas Stüfe]

Hi Dmitry,

Kim would be in a better position to answer this, I'm not part of Oracle
hotspot team.

Cheers, Thomas

On Wed, Apr 3, 2019 at 3:54 PM Dmitry Samersoff <dms at samersoff.net> wrote:

> Thomas,
>
> Just curiosity -
>   did hotspot team consider to start using C++11 sometimes?
>
> e.g. (for this case)
>
> enum lock_mask_constants : uintptr_t { ... };
>
> -Dmitry
>
> On 01.04.2019 7:30, Thomas Stüfe wrote:
> > Hi Alexey,
> >
> > Sorry for breaking aarch64.
> >
> > Kim and me had discussions about this particular fix, see original rfr
> > thread for 8221408.
> >
> > A better solution than adding the cast like you did might be to pull the
> > offending enum  value out and make it a uintx constant too. Or, I could
> > revert my change and make it windows only. Or add a dummy value to the
> enum
> > and cast that to uintptr, to force its size up.
> >
> > I think a good solution would be one that prevents such errors for other
> > enum values and for other platforms as well.
> >
> > Your patch is fine, if you just want to fix your build now.
> >
> > ..thomas
> >
> > On Sun 31. Mar 2019 at 23:36, Aleksey Shipilev <shade at redhat.com> wrote:
> >
> >> Bug:
> >>   https://bugs.openjdk.java.net/browse/JDK-8221725
> >>
> >> Fix:
> >>
> >> diff -r f062188117ad src/hotspot/cpu/aarch64/aarch64.ad
> >> --- a/src/hotspot/cpu/aarch64/aarch64.ad        Sat Mar 30 21:29:37
> 2019
> >> +0100
> >> +++ b/src/hotspot/cpu/aarch64/aarch64.ad        Sun Mar 31 23:30:41
> 2019
> >> +0200
> >> @@ -3443,11 +3443,11 @@
> >>      // Check if the owner is self by comparing the value in the
> >>      // markOop of object (disp_hdr) with the stack pointer.
> >>      __ mov(rscratch1, sp);
> >>      __ sub(disp_hdr, disp_hdr, rscratch1);
> >> -    __ mov(tmp, (address) (~(os::vm_page_size()-1) |
> >> markOopDesc::lock_mask_in_place));
> >> +    __ mov(tmp, (address) (~(os::vm_page_size()-1) |
> >> (uintptr_t)markOopDesc::lock_mask_in_place));
> >>      // If condition is true we are cont and hence we can store 0 as the
> >>      // displaced header in the box, which indicates that it is a
> >> recursive lock.
> >>      __ ands(tmp/*==0?*/, disp_hdr, tmp);   // Sets flags for result
> >>
> >> The offending change pulled some enum constants out, which apparently
> made
> >> enum representation much
> >> smaller. Not sure if putting the constants back does not break Win32
> build
> >> again. So, instead, fix
> >> it up in one place that blows up with build warning-as-error. The fix
> has
> >> some level of ewwness, but
> >> it seems to be the same as what bytecodeInterpreter.cpp is doing. The
> >> alternative is to cast to
> >> uintx, as macroAssembler_arm.cpp is doing.
> >>
> >> Testing: Linux aarch64 fastdebug build, ad-hoc tests
> >>
> >> --
> >> Thanks,
> >> -Aleksey
> >>
> >>
> >>
>