Maybe it's optimized for reversing arrays but not for reversing ranges:

I had to stop the second version because the swapping started to freeze my system: 

lanx@nc10-ubuntu:~$ perl -e'for my $i ( 0 .. 1e8 ) { $x*=-1; $x+=$i };
+print "$x\n"' 
50000000
lanx@nc10-ubuntu:~$ perl -e'for my $i ( reverse 0 .. 1e8 ) { $x*=-1; $
+x+=$i };print "$x\n"' 
^C^C^C
lanx@nc10-ubuntu:~$ perl -version

This is perl, v5.10.0 built for i486-linux-gnu-thread-multi

...

[download]

Reversing ranges was what BUK did, but AnoMonk replied with a reference to a fix for reversing arrays!

Cheers Rolf

In reply to Re^5: counting backward (optimize foreach reverse low .. high by LanX
in thread counting backward by ag4ve

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