-optc-O2 considered useful
duncan.coutts at worc.ox.ac.uk
Thu May 15 18:31:51 EDT 2008
On Thu, 2008-05-15 at 23:00 +0400, Bulat Ziganshin wrote:
> Hello Don,
> Thursday, May 15, 2008, 10:47:20 PM, you wrote:
> > I discovered something today I didn't know.
> > gcc -O2 can optimise out the computed jumps GHC produces in tight loops.
> seems that decision to use native backend in ghc -O2 was too early?
Though note that the native backend never introduced the computed jump.
I think it's clear that -fvia-C -O should imply -optc-O2 if it does not
already. gcc -O0 is for painfully obvious C translation into assembler,
-O is for quick optimisations. gcc -O2 is the "standard" optimisation
level used for building packages for most distros.
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