16 May 00:31
Re: -optc-O2 considered useful
Duncan Coutts <duncan.coutts <at> worc.ox.ac.uk>
2008-05-15 22:31:51 GMT
2008-05-15 22:31:51 GMT
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. Duncan
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