I think it would be nice to have some speedy optimizations turned on by
default in ghc. Might even be good to win new users.
But I also think that much hacking for and around ghc+tool support needs
a way to achieve what -O0 does today.
So, how about an -O(-1) or flag?
Don Stewart wrote:
duncan.coutts:
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
Hi
As for the specific issue of whether we should turn on -fstrictness with
-O0, I suspect the answer is that the compile-time cost would be too high.
There would also be the issue that it would increase the amount of
Haskell code which works only in GHC, which is probably a bad thing.
Would
Simon Marlow wrote:
This is part of a larger question, namely whether we can get substantial
benefit for doing a tiny bit of extra work in -O0. With -O0 we're
optimising for compile time in preference to code speed, although we do
want to find a good compromise that doesn't generate abysmal
I discovered something today I didn't know.
gcc -O2 can optimise out the computed jumps GHC produces in tight loops.
Consider this program,
import Data.Array.Vector
import Data.Bits
main = print . sumU
. mapU (*2)
. mapU (`shiftL` 2)
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?
--
Best regards,
Bulat
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
duncan.coutts:
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
