<s>
The	O
GNU	B-Application
Assembler	I-Application
,	O
commonly	O
known	O
as	B-Device
gas	O
or	O
as	B-Device
,	O
is	O
the	O
assembler	O
developed	O
by	O
the	B-Application
GNU	I-Application
Project	I-Application
.	O
</s>
<s>
It	O
is	O
the	O
default	O
back-end	B-Architecture
of	O
GCC	B-Application
.	O
</s>
<s>
It	O
is	O
used	O
to	O
assemble	O
the	B-Operating_System
GNU	I-Operating_System
operating	I-Operating_System
system	I-Operating_System
and	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
,	O
and	O
various	O
other	O
software	O
.	O
</s>
<s>
It	O
is	O
a	O
part	O
of	O
the	O
GNU	B-Application
Binutils	I-Application
package	O
.	O
</s>
<s>
The	O
GAS	O
executable	B-Application
is	O
named	O
,	O
the	O
standard	O
name	O
for	O
a	O
Unix	B-Application
assembler	O
.	O
</s>
<s>
GAS	O
is	O
cross-platform	B-Operating_System
,	O
and	O
both	O
runs	O
on	O
and	O
assembles	O
for	O
a	O
number	O
of	O
different	O
computer	B-General_Concept
architectures	I-General_Concept
.	O
</s>
<s>
GAS	O
is	O
free	B-Application
software	I-Application
released	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
v3	O
.	O
</s>
<s>
It	O
was	O
written	O
by	O
Dean	O
Elsner	O
,	O
and	O
supported	O
the	O
VAX	B-Device
architecture	O
.	O
</s>
<s>
GAS	O
uses	O
assembler	O
directives	O
(	O
also	O
known	O
as	B-Device
pseudo	O
ops	O
)	O
,	O
which	O
are	O
keywords	O
beginning	O
with	O
a	O
period	O
that	O
behave	O
similarly	O
to	O
preprocessor	O
directives	O
in	O
the	O
C	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
As	B-Device
in	O
C	B-Language
,	O
multi-line	O
comments	O
start	O
and	O
end	O
with	O
mirroring	O
slash-asterisk	O
pairs	O
:	O
</s>
<s>
Being	O
the	O
back-end	B-Architecture
for	O
a	O
popular	O
compiler	O
suite	O
,	O
namely	O
GCC	B-Application
,	O
the	O
GNU	B-Application
Assembler	I-Application
is	O
very	O
widely	O
used	O
in	O
compiling	O
modern	O
open	O
source	O
software	O
.	O
</s>
<s>
GAS	O
is	O
often	O
used	O
as	B-Device
the	O
assembler	O
on	O
Linux	B-Application
operating	I-Application
systems	I-Application
in	O
conjunction	O
with	O
other	O
GNU	B-Operating_System
software	O
.	O
</s>
<s>
A	O
modified	O
version	O
of	O
GAS	O
can	O
also	O
be	O
found	O
in	O
the	O
macOS	B-Operating_System
development	O
tools	O
package	O
since	O
OS	B-Operating_System
X	I-Operating_System
.	O
</s>
<s>
program	O
for	O
Linux	B-Application
on	O
IA-32	B-Device
:	O
</s>
