How bad is the PowerPC backend?

Tim Chevalier catamorphism at
Mon Feb 9 16:11:25 EST 2009

On 2/9/09, Bulat Ziganshin <bulat.ziganshin at> wrote:
> Hello Tim,
>  Monday, February 9, 2009, 11:16:22 PM, you wrote:
>  > So is the PPC backend really this bad, or should I be looking for
>  > something weird with the hardware or configuration on the Mac?
> check GC times too. one possibility is that GC takes much more time
>  due to smaller L2 cache

Hmm, doesn't seem to be happening with this example. On the Mac, I get
(running with +RTS -s -RTS):
11.86 MUT time (13.95s elapsed)
0.08s GC time (0.15s elapsed)
%GC time 0.6% (1.1% elapsed)

and on the PC:
1.07s MUT time (1.34s elapsed)
0.01s GC time (0.02s elapsed)
%GC time 1.1% (1.6% elapsed)

so GC doesn't seem to explain the large difference in running times.


Tim Chevalier * * Often in error, never in doubt
"Maybe I don't want to meet someone who shares my interests. I hate my
interests." -- Ghost World

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