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Postings from October 2014
I just noticed that the nbody benchmark is about 25% slower in 5.21.5
compared with 5.21.4 (and older).
It seems that floating-point arithmetic is considerably slower after this
commit (although I haven't looked at why):
commit 0f83c5a4f945d1919a6ff6564a3a18375f15f949
Author: Jarkko Hietaniemi <jhi@iki.fi>
AuthorDate: Mon Sep 22 21:37:38 2014 -0400
Commit: Jarkko Hietaniemi <jhi@iki.fi>
CommitDate: Tue Sep 23 08:29:53 2014 -0400
Avoid mixing Inf/NaN with IV/UV.
It really makes no sense to ask what's the IV/UV of this Inf/NaN,
or turn on the IOK/UV flags (private or public).
For example,
my $n = 0.0;
my $a = 0.1;
$n += $a*$a + $a*$a + $a*$a for 0..10_000_000;
These two miniperls are ones built non-threaded, -O2 just before and after
that commit:
$ time ~/tmp/miniperl-413 ~/tmp/p; time ~/tmp/miniperl-412 ~/tmp/p
real 0m1.874s
user 0m1.870s
sys 0m0.000s
real 0m2.296s
user 0m2.292s
sys 0m0.001s
--
"Strange women lying in ponds distributing swords is no basis for a system
of government. Supreme executive power derives from a mandate from the
masses, not from some farcical aquatic ceremony."
-- Dennis, "Monty Python and the Holy Grail"
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