RFR: 8256956: RegisterImpl::max_slots_per_register is incorrect on AMD64

[Tobias Hartmann]

On Tue, 24 Nov 2020 15:56:55 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Hi all,
>> 
>> The bug was found while I was learning @iwanowww 's patch [1].
>> 
>> As we know, the slot-size is 32-bit and the registers are 64-bit on AMD64.
>> So RegisterImpl::max_slots_per_register [2] should be 2 on AMD64.
>> 
>> It would be better to fix it.
>> 
>> Testing:
>>   - tier1~3 on Linux/x64
>> 
>> Thanks.
>> Best regards,
>> Jie
>> 
>> [1] https://github.com/openjdk/jdk/pull/1132
>> [2] https://github.com/openjdk/jdk/blob/master/src/hotspot/cpu/x86/register_x86.hpp#L53
>
> Please wait for #1266 integration to get this tested on x86_32. (I think current patch does not affect it directly, but better be safe than sorry).

Just wondering, is that value even used? I did a quick search and couldn't find any usages.

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PR: https://git.openjdk.java.net/jdk/pull/1413