Re: perl: 64-bit integers and long doubles
On Sun, May 09, 2010 at 11:37:24PM +0300, Niko Tyni wrote:
> Testing 5.12.0 with and without use64bitint on x86 shows an approximately
> 10% increase with scalars and arrays:
>
> perl -e '${"v$i"} = $i while ($i++ < $ARGV[0]); system("ps -o rss $$")' 1000000
> perl -e '$a[$i++] = $i while ($i++ < $ARGV[0]); system("ps -o rss $$")' 10000000
>
> and a 7-8% increase for hashes:
>
> perl -e '$h{$i++} = $i while ($i++ < $ARGV[0]); system("ps -o rss $$")' 5000000
To supplement these pathological cases, I compared a possibly more relevant
/usr/bin/time -f %M dpkg-reconfigure tzdata
on i386 with debconf-english and whiptail installed, and got
5.10.1/32bitint 23008
5.12.0/32bitint 23744
5.12.0/64bitint 24512
which means a 3% increase or thereabouts.
> I'm partial to enabling use64bitint on all architectures, if only for the
> sake of uniformity already mentioned in the uselongdouble discussion: bugs
> that only happen on the "smaller" architectures because of differences
> like this are not nice to isolate and debug.
To conclude, I'm going ahead with use64bitint but not uselongdouble on all
architectures. 5.12.0-2 is now in experimental with this configuration,
and I don't intend to change it for sid.
Many thanks for your comments,
--
Niko Tyni ntyni@debian.org
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