System V Application Binary Interface 0.99.5

[Andrew Haley]

On 01/30/2013 03:55 PM, Andrew Haley wrote:
>> > 
>> > It's incorrect to rely on the extension taking place.  It's not incorrect to
>> > do the extension.
> Sure, I understand that, but I am completely baffled as to how
> extending at a call site avoids partial register stalls if a callee
> cannot assume that a value is already extended.

Ah, sorry.  Thinking about it some more, if the register is extended
at the call site, the partial register stall will be avoided whether
or not the callee extends.  So, we're correct to extend at the call
site, and correct to extend in the callee.  LLVM isn't correct not
to extend at the callee.

Thanks,
Andrew.