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Re: -O3 and new optimizations in 4.4.0
Thanks for the reply. On the other hand, it seems that PPL and Cloog
are auto-detected by configure; shouldn't that be enough to dynamically
modify what -O3 does (or perhaps enable -O4)? On a related point,
having used my old build script to build gcc I, of course, didn't read
the prerequisites section. I have to rebuild right?
David
On Thu, 2009-04-23 at 15:57 +0000, Joseph S. Myers wrote:
> On Thu, 23 Apr 2009, David Ronis wrote:
>
> > >From the info pages it seems that the new optimizations,
> > -floop-interchange, -floop-strip-mine, and -floop-block, are NOT turned
> > on when -O3 is specified. Is this correct and if so, why aren't they?
>
> Because the behavior of -O3 must not depend on whether optional libraries
> are linked into GCC, and we did not decide to make PPL and CLooG required
> to build GCC, so -O3 cannot enable any optimizations using optional
> libraries.
>