<s>
The	O
zero	B-Algorithm
flag	I-Algorithm
is	O
a	O
single	O
bit	O
flag	O
that	O
is	O
a	O
central	O
feature	O
on	O
most	O
conventional	O
CPU	B-Device
architectures	O
(	O
including	O
x86	B-Operating_System
,	O
ARM	B-Architecture
,	O
PDP-11	B-Device
,	O
68000	B-Device
,	O
6502	B-General_Concept
,	O
and	O
numerous	O
others	O
)	O
.	O
</s>
<s>
It	O
is	O
often	O
stored	O
in	O
a	O
dedicated	O
register	O
,	O
typically	O
called	O
status	B-General_Concept
register	I-General_Concept
or	O
flag	B-General_Concept
register	I-General_Concept
,	O
along	O
with	O
other	O
flags	O
.	O
</s>
<s>
The	O
zero	B-Algorithm
flag	I-Algorithm
is	O
typically	O
abbreviated	O
Z	O
or	O
ZF	O
or	O
similar	O
in	O
most	O
documentation	O
and	O
assembly	O
languages	O
.	O
</s>
<s>
Along	O
with	O
a	O
carry	B-Algorithm
flag	I-Algorithm
,	O
a	O
sign	B-Algorithm
flag	I-Algorithm
and	O
an	O
overflow	B-Algorithm
flag	I-Algorithm
,	O
the	O
zero	B-Algorithm
flag	I-Algorithm
is	O
used	O
to	O
check	O
the	O
result	O
of	O
an	O
arithmetic	O
operation	O
,	O
including	O
bitwise	O
logical	O
instructions	O
.	O
</s>
<s>
This	O
includes	O
results	O
which	O
are	O
not	O
stored	O
,	O
as	O
most	O
traditional	O
instruction	B-General_Concept
sets	I-General_Concept
implement	O
the	O
compare	O
instruction	B-General_Concept
as	O
a	O
subtract	O
where	O
the	O
result	O
is	O
discarded	O
.	O
</s>
<s>
It	O
is	O
also	O
common	O
that	O
processors	O
have	O
a	O
bitwise	O
AND-instruction	O
that	O
does	O
not	O
store	O
the	O
result	O
.	O
</s>
<s>
The	O
logical	O
formula	O
of	O
the	O
zero	B-Algorithm
flag	I-Algorithm
for	O
a	O
twos-complement	O
binary	O
operand	O
is	O
NOT(OR(all bits of the operand in question )	O
)	O
.	O
</s>
<s>
In	O
most	O
processors	O
,	O
the	O
zero	B-Algorithm
flag	I-Algorithm
is	O
mainly	O
used	O
in	O
conditional	B-General_Concept
branch	I-General_Concept
instructions	O
,	O
which	O
alter	O
control	O
flow	O
on	O
previous	O
instruction	B-General_Concept
results	O
,	O
but	O
there	O
are	O
often	O
other	O
uses	O
as	O
well	O
.	O
</s>
<s>
In	O
some	O
instruction	B-General_Concept
sets	I-General_Concept
such	O
as	O
the	O
MIPS	B-Device
architecture	I-Device
,	O
a	O
dedicated	O
flag	B-General_Concept
register	I-General_Concept
is	O
not	O
used	O
;	O
jump	O
instructions	O
instead	O
check	O
a	O
register	O
for	O
zero	O
.	O
</s>
