[aarch64-port-dev ] Very large code caches

Leslie Zhai lesliezhai at llvm.org.cn
Wed May 16 07:27:48 UTC 2018

Hi Andrew,

Thanks for your response!

在 2018年05月16日 15:23, Andrew Haley 写道:
> On 05/16/2018 03:53 AM, Leslie Zhai wrote:
>> Hi HotSpot developers,
>> I am trying to implement `patch_verified_entry` for other targets, such
>> as riscv, but I found that:
>>> but the real problem is that the resulting call
>>> site is not MT-safe: it can't be patched atomically.  To make that
>>> work we'd have to move the destination address into the constant pool.
> Where is that comment?  I can't find it.

>> So aarch64 hasn't implemented patched *atomically* yet?
> We atomically patch everything correctly.  If you look at the AArch64
> implementation of patch_verified_entry you'll see that we replace a
> direct call instruction if it can reach, and if it can't we jump to a
> trampoline.  The trampoline is a load from a single word followed by
> an indirect call.  In both cases it is atomic.
And could you share your experience to use PRINT_REG alike or something 
else to catch the bugs for logical issue? 
Thanks a lot!

Leslie Zhai

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