src/dst register for andI_rReg_imm255 and andI_rReg_imm65535

Tom Rodriguez Thomas.Rodriguez at Sun.COM
Mon Sep 21 12:26:06 PDT 2009


On Sep 21, 2009, at 12:06 PM, Christian Thalinger wrote:

> Vladimir Kozlov wrote:
>> Christian,
>>
>> Can you tell more about the problem you see?
>> The instructions you pointing use dst register only:
>>
>> "movzbl  $dst, $dst\t# int & 0xFF"
>
> Right.  Well, it's not a problem, I just wonder why it does not use  
> the
> src register:
>
> "movzbl  $dst, $src\t# int & 0xFF"
>
> but instead we have to emit a spill instruction to move src to dst.

That will occur if there are other users of src.  If it's the last use  
then we shouldn't emit the spill.

tom

>
> -- Christian



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