As you're golfing, there are a few trivial modifications that can save a few characters (update: 4 characters). Omit the semicolons after the sub definitions and for loops, and change ($/*=16)%=O to $/=$/*16%O. 


        $|=print 3.2;sub O{8*($@-$_)+(1,4,5,6)[$:]}sub 
       o{(-4,2,1,1)[$:]/O}while($,=++$@){for$:(0..3){
      for         (0..$@)             {for$"
                  (($/=1)             ..$_){
                  $/=$/*              16%O}
                 $,-=$/                *o}$,
                 -=16**                 $_*o
               for-6..-                   1}printf
             "%x",$,*                   16%16}

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In reply to Re: Hexadecimal representation of pi by ambrus
in thread Hexadecimal representation of pi by weixi

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