> : > Perl seems to be confused making some arithmetic operations (additions). > : > Sometimes the result of $a+=$b, when $a is 0 and $b is 2 happens to be > : > 2.000004192 or something similar. > : > : Fernando, I unfortunately have no idea what is causing this. Please > : provide a short script which shows this behaviour (reliably if possible). > : > : Perl5-porters, is this a known bug? > > No. Another possibility is that the compiler is using single-precision > instead of double-precision floats. I think you get about 7 digits of > accuracy in single precision.
Larry, I've forwarded Fernando's script to perl5-porters. The perl5 package was compiled using Debian's gcc package (gcc 2.6.3) in a.out binary format using '-O2 -fomit-frame-pointer' optimization; the libc is Linux libc-4.6.27. The output differs in the 10th decimal. The weird thing is that it appears when copying the value. I cannot reproduce the bug on the following configurations: FreeBSD 2.1.0, perl 5.001m SunOS 4.1.4, perl 5.000 HP-UX 9, perl 5.000 IRIX 5.3, perl 5.000 perl5-porters, please try to reproduce this - on an non-linux system (with 5.001m) - on a linux system (with a non-debian 5.001m) - on a debian linux system under ELF (my home-machine is not net.connected). Regards, Ray -- LEADERSHIP A form of self-preservation exhibited by people with auto- destructive imaginations in order to ensure that when it comes to the crunch it'll be someone else's bones which go crack and not their own. - The Hipcrime Vocab by Chad C. Mulligan
