-fprofile-generate and -fprofile-use

[Zdenek Dvorak]

Hello,

> > >you may try adding -fmove-loop-invariants flag, which enables new
> > >invariant motion pass.
> > 
> > That cleaned up both my simplified test case, and the code it
> > originated from.  It also cleaned up a few other cases where I
> > was noticing worse performance with FDO enabled.  Thanks!!
> > 
> > Perhaps this option should be enabled by default when doing FDO
> > to replace the loop invariant motions done by the recently
> > disabled loop optimize pass.
> 
> This sounds like sane idea.  Zdenek, is -fmove-loop-invariants dangerous
> in some way or just disabled because old loop does the same?

-fmove-loop-invariants is enabled by default on killloop-branch, and
passes bootstrap & regtesting on i686 and x86_64; the branch does not
bootstrap for me on ia64 and ppc (but neither does mainline).  I am
not aware of any correctness/ICE problems with -fmove-loop-invariants,
but given that it is disabled by default, this does not say much.

Zdenek