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Re: [PATCH] x86-64: don't allow use of %axl as accumulator
>>> On 10.11.17 at 14:27, <hjl.tools@gmail.com> wrote:
> On Fri, Nov 10, 2017 at 4:50 AM, Jan Beulich <JBeulich@suse.com> wrote:
>> Just like %cxl can't be used as shift count register. Otherwise for
>> consistency %cxl would need to gain "ShiftCount" and use of both ought
>> to properly cause REX prefixes to be emitted.
>
> There are no good testcases for
>
> axl, Reg8|Acc|Byte, RegRex64, 0, Dw2Inval, Dw2Inval
> cxl, Reg8, RegRex64, 1, Dw2Inval, Dw2Inval
> dxl, Reg8, RegRex64, 2, Dw2Inval, Dw2Inval
> bxl, Reg8, RegRex64, 3, Dw2Inval, Dw2Inval
> bpl, Reg8, RegRex64, 5, Dw2Inval, Dw2Inval
Not sure I understand: I'm only changing %axl - why would I need
to introduce tests for anything else?
> I am not sure if the whole thing is handled correctly. If we want to change
> them, we should make sure that they work correctly.
"They" being exactly what (and again in the context of what this
patch does)? I'm not overly happy to introduce new unrelated
tests, but I may be looking into adding some if I clearly knew
what you're after. But even then I would submit that as a
separate change, so you'd have to make up your mind on the
change here independent of those anyway.
Jan