condition flags USE in AD instruct

[Tom Rodriguez]

It might be a case of too string error checking.  If you have a match  
rule then all the USE and DEF effects are taken care of and I don't  
think it would complain about USEing that flags.  Are you going to  
have a match rule on the instruct or are you writing an instruct for  
use in an expand rule?

tom

On Apr 14, 2009, at 10:35 AM, Christian Thalinger wrote:

> Hi!
>
> Is there a way to USE condition flags in instruct effects, like:
>
> instruct foo(rFlagsReg cr) {
>  effect(USE cr)
> ...
> }
>
> ADLC complains about that with:
>
> illegal USE of non-input: rFlagsReg cr
>
> However I see something similar for minI_rReg in x86_64.ad where  
> another
> instruct, namely cmovI_reg_g, uses cr and the later is used in an  
> expand
> inside the former.  Is that a workaround/intentional/the only way to  
> do
> it?
>
> -- Christian
>