Sometimes it's one to big and sometimes one to small.

Right now, you are truncating the numbers. That means you are introducing an error as big as 1.0 

$ perl -e'printf "%d\n", $_ for 4.9999999999, 5'
4
5

[download]

You need to round instead. 

$ perl -e'printf "%.0f\n", $_ for 4.9999999999, 5'
5
5

[download]

But that's not good enough either. 

$ perl -e'printf "%.0f\n", $_ for 5.4999999999, 5.5'
5
6

[download]

You need to round to your tolerance first. 

$ perl -e'printf "%.0f\n", sprintf "%.8f", $_ for 5.4999999999, 5.5'
6
6

[download]

In reply to Re^5: test fails on 64bit uselongdouble Perl by ikegami
in thread test fails on 64bit uselongdouble Perl by frankcox

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