Re: [edk2-devel] MOV64 and CLANGPDB

["Michael Kubacki via groups.io" <mikuback=linux.microsoft.com@groups.io>]

Thanks https://github.com/tianocore/edk2/pull/10760 is updated.

I don't have a strong need for it to make the stable tag. I have a local 
solution that can be used in the meantime.

On 2/14/2025 5:48 AM, Leif Lindholm wrote:
> On Fri, 14 Feb 2025 at 01:54, Michael Kubacki
> <mikuback@linux.microsoft.com> wrote:
>> That worked.
> 
> Splendid! Thanks.
> 
> Ard figured out how to reproduce the issue as well - the behaviour
> changes between
> -target aarch64-windows-none and -target aarch64-linux-gnu, so more LLP64 fun.
> 
>> Let me know what you'd like to do with
>> https://github.com/tianocore/edk2/pull/10760.
> 
> I would prefer to fix the MOV64 macro and leave the invocation alone for now.
> If the optimization ot doing the direct mov is important enough, that
> can be done
> separately at a later point.
> 
> I pushed a fix to
> https://github.com/leiflindholm/edk2/commit/a7ff8aebcad1a6621ac52007b6dc530972b26125
> that you could cherry-pick into the PR.
> 
> Are you looking for this PR to hit the stable tag?
> If not, the MOVx4 fix can wait too.
> 
> /
>      Leif
> 
>> ---
>>
>> Before (original code)
>>
>> ...ModuleEntryPoint.iiii:58:12: error: immediate must be an integer in
>> range [0, 65535].
>>
>> movz x9, (-1) >> 48, lsl #48 ; movk x9, ((-1) >> 32) & 0xffff, lsl #32 ;
>> movk x9, ((-1) >> 16) & 0xffff, lsl #16 ; movk x9, (-1) & 0xffff
>>
>> ---
>>
>> After (new code)
>>
>>     svc #0
>>
>>     movz x9, ((-1) >> 48) & 0xffff, lsl #48 ; movk x9, ((-1) >> 32) &
>> 0xffff, lsl #32 ; movk x9, ((-1) >> 16) & 0xffff, lsl #16 ; movk x9,
>> (-1) & 0xffff
>>     cmp x0, x9
>>     cset x0, ne
>>     mov x9, xzr
>>     ret
>>
>> ---
>>
>> On 2/13/2025 5:33 PM, Leif Lindholm via groups.io wrote:
>>> I would very much like to have a MOV64 that's universally usable.
>>> That's sort of the point.
>>>
>>> However, I'm wondering if the error is in fact triggered by the first
>>> stanza (movz), which doesn't mask its result, and will have 48 sign
>>> extended bits above the ones we care about for the instruction.
>>>
>>> Annoyingly I cannot reproduce the build error in my setup, so I can't
>>> verify if that is the problem.
>>>
>>> Michael, could you possibly do a test and change
>>>     movz      Reg, (Val) >> 48, lsl #48             ; \
>>> to
>>>     movz      Reg, ((Val) >> 48) & 0xffff, lsl #48             ; \
>>>
>>> on line 51 in MdePkg/Include/AArch64/AsmMacroLib.h ?
>>>
>>> And then rebuild the MOV64 version of ArmStandaloneMmCoreEntryPoint?
>>>
>>> /
>>>       Leif
>>>
>>>
>>> 
>>>
>>



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