[Bug c/40172] [4.5 Regression] Revision 147596 breaks bootstrap

[hjl dot tools at gmail dot com]

------- Comment #24 from hjl dot tools at gmail dot com  2009-05-19 02:37 -------
(In reply to comment #23)
> Subject: Re:  [4.5 Regression]  Revision 147596 breaks bootstrap
> 

> I still feel that if this patch is put in, we eventually will have the same
> discussion, as the compiler gets smarter about flow control and propigation,

This particular warning comes from front-end. I don't think front-end
will do such transformation.

> since semantically:
> 
>       if (test1)
>         {
>           if (test2)
>             {
>               /* ... */
>             }
>         }
> 
> is the same as:
> 
>         if (test1 && test2)
>           {
>             /* ... */
>           }
> 

Gcc can eliminate many dead codes today. I don't think we will ever warn
any of them, if at all.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40172