Obvious bug in /sys/i386/include/bus.h (was: bus_at386.h)
NKoch at demig.de
Mon Jun 13 12:52:56 GMT 2005
> >how can I fix this in assembly. I am not an expert with inlined assembly,
> >maybe someone can correct me if I am wrong, but something like this needs
> >be added:
> >or %ecx, %ecx
> >jz 2
> This is wrong beacause the result is stored in ecx. Better using
> JECXZ instruction
> before the loop.
No, it's a correct method to set/reset the zero flag:
(X | X) == X just as (X & X) == X
So, he could also write: "and %ecx, %ecx".
I may be wrong, but in the old 386/486 days the "jecxz" was even less
efficient, wasn't it?
Twenty years ago, my z80 programs had a lot of lines like
Weren't there discussions, if an nmos cpu consumed more electric power with
either "and a" or "or a"? ;-)
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