On Saturday 06 October 2001 08:05 pm, Buggs wrote: > On Sunday 07 October 2001 01:16, Bryan C. Warnock wrote: > [...] > > > One of the more interesting discoveries? Adding a 'default:' case to > > the switch slowed down the Linux runs by several percent. > > In that, umh, case: do you have an explanation > or could you provide the code?
http://members.home.net/bcwarno/Perl6/spool/interpreter.c http://members.home.net/bcwarno/Perl6/spool/switch.cinc An assembler diff between adding the default and not. I'd interpret it, but I haven't figured out exactly how yet. (These diffs are repeated later on in the other runops loop. I snipped them for brevity.) The default case wasn't exercised during runtime, so it has to be related to the Athlon, which I know behaves weirdly. 175c175 < ja .L212 --- > ja .L11 179c179 < movl .L213(%eax), %eax --- > movl .L212(%eax), %eax 185c185 < .L213: --- > .L212: 3126,3130d3125 < .L212: < leal -40(%ebp), %eax < addl $4, (%eax) < jmp .L11 < .p2align 4,,7 -- Bryan C. Warnock [EMAIL PROTECTED]
