RFR (S) 8202705: ARM32 build crashes on long JavaThread offsets

[Aleksey Shipilev]

On 06/04/2018 01:58 PM, Boris Ulasevich wrote:
> Hello all,
> 
> Please review this patch to allow ARM32 MacroAssembler to handle updated JavaThread offsets:
>   http://cr.openjdk.java.net/~bulasevich/8202705/webrev.01/
>   https://bugs.openjdk.java.net/browse/JDK-8202705

Looks okay, but Rthread becomes misnomer in the middle of the method.

Maybe like this?

 // Borrow the Rthread for alloc counter
 Register Ralloc = Rthread;
 Rthread = NULL;
 add(Ralloc, Ralloc, in_bytes(JavaThread::allocated_bytes_offset());

 ...
 <work with Ralloc>
 ...

 // Unborrow the Rthread
 sub(Ralloc, Ralloc, in_bytes(JavaThread::allocated_bytes_offset()
 Rthread = Ralloc;
 Ralloc = NULL;

-Aleksey