nofib regressions in HEAD since 7.6.2 release

Johan Tibell johan.tibell at
Fri Feb 8 17:47:36 CET 2013

On Fri, Feb 8, 2013 at 8:31 AM, Nicolas Frisby <nicolas.frisby at>wrote:

> I figured Johan is doing O2 for libraries and programs. I have done
> libraries at O2, programs at O1, which likely does explain the difference.
> I'm still in a holding pattern in case there's also some other setting
> he's using.
> Then I'll run both variations on the programs.
> Thanks much.

I use "BuildFlavour = perf" for the compiler and otherwise don't specify
any additional options (including to nofib), which I guess implies that the
benchmarks are compiled with -O? Then I do

cd nofib
make clean && make boot && make -k 2>&1 | tee log1
make clean && make boot WithNofibHc=ghc-7.6.2 && make -k
WithNofibHc=ghc-7.6.2 2>&1 | tee log2
nofib-analyse/nofib-analyse log1 log2

I followed the instructions at

If the defaults for nofib are wrong (e.g. if we want -O2 by default) we
should tweak the settings so people get sensible results by default.
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