Re: [tree-ssa] Loop header copying on trees

[Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>]

Hello,

>  >> + ftree-ch
>  >> + Common
>  >> + Enable loop header copying on trees
>  >> + 
>  >>
>  >Include a small blurb describing why header copying is beneficial. 
>  >Also, do we really want to control it with a flag?  Some of the -f flags
>  >we have in tree-ssa should probably disappear.
> And in fact, I don't think we really want to have a knob to turn off
> header copying.

why not? At the very least, we probably do not want it enabled at -Os.
Also I do not see why having a precise control over what the compiler
does should be wrong.

Zdenek