<s>
The	O
x32	B-Application
ABI	I-Application
is	O
an	O
application	B-Operating_System
binary	I-Operating_System
interface	I-Operating_System
(	O
ABI	O
)	O
and	O
one	O
of	O
the	O
interfaces	B-Application
of	I-Application
the	I-Application
Linux	I-Application
kernel	I-Application
.	O
</s>
<s>
The	O
x32	B-Application
ABI	I-Application
provides	O
32-bit	O
integers	O
,	O
long	O
and	O
pointers	O
(	O
ILP32	O
)	O
on	O
Intel	O
and	O
AMD	O
64-bit	O
hardware	O
.	O
</s>
<s>
The	O
ABI	O
allows	O
programs	O
to	O
take	O
advantage	O
of	O
the	O
benefits	O
of	O
x86-64	B-Device
instruction	O
set	O
(	O
larger	O
number	O
of	O
CPU	B-General_Concept
registers	I-General_Concept
,	O
better	O
floating-point	B-Algorithm
performance	O
,	O
faster	O
position-independent	B-Operating_System
code	I-Operating_System
,	O
shared	O
libraries	O
,	O
function	O
parameters	O
passed	O
via	O
registers	B-General_Concept
,	O
faster	O
syscall	B-Operating_System
instruction	O
)	O
while	O
using	O
32-bit	O
pointers	O
and	O
thus	O
avoiding	O
the	O
overhead	O
of	O
64-bit	B-Device
pointers	O
.	O
</s>
<s>
Though	O
the	O
x32	B-Application
ABI	I-Application
limits	O
the	O
program	O
to	O
a	O
virtual	B-General_Concept
address	I-General_Concept
space	I-General_Concept
of	O
4	O
GiB	O
,	O
it	O
also	O
decreases	O
the	O
memory	B-General_Concept
footprint	O
of	O
the	O
program	O
by	O
making	O
pointers	O
smaller	O
.	O
</s>
<s>
This	O
can	O
allow	O
it	O
to	O
run	O
faster	O
by	O
fitting	O
more	O
code	O
and	O
more	O
data	O
into	O
cache	B-General_Concept
.	O
</s>
<s>
The	O
best	O
results	O
during	O
testing	O
were	O
with	O
the	O
181.mcf	O
SPEC	O
CPU	O
2000	O
benchmark	O
,	O
in	O
which	O
the	O
x32	B-Application
ABI	I-Application
version	O
was	O
40%	O
faster	O
than	O
the	O
x86-64	B-Device
version	O
.	O
</s>
<s>
On	O
average	O
,	O
x32	O
is	O
5	O
–	O
8%	O
faster	O
on	O
the	O
SPEC	O
CPU	O
integer	O
benchmarks	O
compared	O
to	O
x86-64	B-Device
.	O
</s>
<s>
There	O
is	O
no	O
speed	O
advantage	O
over	O
x86-64	B-Device
in	O
the	O
SPEC	O
CPU	O
floating-point	B-Algorithm
benchmarks	O
.	O
</s>
<s>
There	O
are	O
also	O
some	O
application	O
benchmarks	O
that	O
demonstrate	O
the	O
advantages	O
of	O
the	O
x32	B-Application
ABI	I-Application
.	O
</s>
<s>
+	O
ABI	O
comparison	O
Feature	O
i386	B-Device
ABI	O
x32	B-Application
ABI	I-Application
x86-64	B-Device
ABI	O
Pointers	O
4	O
bytes	O
8	O
bytes	O
Max	O
.	O
</s>
<s>
Running	O
a	O
userspace	O
that	O
consists	O
mostly	O
of	O
programs	O
compiled	O
in	O
ILP32	O
mode	O
and	O
which	O
also	O
have	O
principal	O
access	O
to	O
64-bit	B-Device
CPU	I-Device
instructions	O
has	O
not	O
been	O
uncommon	O
,	O
especially	O
in	O
the	O
field	O
of	O
"	O
classic	O
RISC	O
"	O
chips	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
Solaris	B-Application
operating	I-Application
system	I-Application
does	O
so	O
for	O
both	O
SPARC	B-Architecture
and	O
x86-64	B-Device
.	O
</s>
<s>
On	O
the	O
Linux	B-Application
side	O
,	O
Debian	O
also	O
ships	O
an	O
ILP32	O
userspace	O
.	O
</s>
<s>
The	O
underlying	O
reason	O
is	O
the	O
somewhat	O
"	O
more	O
expensive	O
"	O
nature	O
of	O
LP64	O
code	O
,	O
just	O
like	O
it	O
has	O
been	O
shown	O
for	O
x86-64	B-Device
.	O
</s>
<s>
In	O
that	O
regard	O
,	O
the	O
x32	B-Application
ABI	I-Application
extends	O
the	O
ILP32-on-64bit	O
concept	O
to	O
the	O
x86-64	B-Device
platform	O
.	O
</s>
<s>
Several	O
people	O
had	O
discussed	O
the	O
benefits	O
of	O
an	O
x86-64	B-Device
ABI	O
with	O
32-bit	O
pointers	O
in	O
the	O
years	O
since	O
the	O
Athlon	O
64	O
's	O
release	O
in	O
2003	O
,	O
notably	O
Donald	O
Knuth	O
in	O
2008	O
.	O
</s>
<s>
There	O
was	O
little	O
publicly	O
visible	O
progress	O
towards	O
implementing	O
such	O
a	O
mode	O
until	O
August	O
27	O
,	O
2011	O
,	O
when	O
Hans	O
Peter	O
Anvin	O
announced	O
to	O
the	O
Linux	B-Application
kernel	I-Application
mailing	I-Application
list	I-Application
that	O
he	O
and	O
H	O
.	O
J	O
.	O
Lu	O
had	O
been	O
working	O
on	O
the	O
x32	B-Application
ABI	I-Application
.	O
</s>
<s>
That	O
same	O
day	O
,	O
Linus	O
Torvalds	O
replied	O
with	O
a	O
concern	O
that	O
the	O
use	O
of	O
32-bit	O
time	B-Operating_System
values	I-Operating_System
in	O
the	O
x32	B-Application
ABI	I-Application
could	O
cause	O
problems	O
in	O
the	O
future	O
.	O
</s>
<s>
This	O
is	O
because	O
the	O
use	O
of	O
32-bit	O
time	B-Operating_System
values	I-Operating_System
would	O
cause	O
the	O
time	B-Operating_System
values	I-Operating_System
to	O
overflow	O
in	O
the	O
year	B-Application
2038	I-Application
.	O
</s>
<s>
Following	O
this	O
request	O
,	O
the	O
developers	O
of	O
the	O
x32	B-Application
ABI	I-Application
changed	O
the	O
time	B-Operating_System
values	I-Operating_System
to	O
64-bit	B-Device
.	O
</s>
<s>
A	O
presentation	O
at	O
the	O
Linux	B-Application
Plumbers	O
Conference	O
on	O
September	O
7	O
,	O
2011	O
,	O
covered	O
the	O
x32	B-Application
ABI	I-Application
.	O
</s>
<s>
The	O
x32	B-Application
ABI	I-Application
was	O
merged	O
into	O
the	O
Linux	B-Application
kernel	O
for	O
the	O
3.4	O
release	O
with	O
support	O
being	O
added	O
to	O
the	O
GNU	B-Language
C	I-Language
Library	I-Language
in	O
version	O
2.16	O
.	O
</s>
<s>
In	O
December	O
2018	O
there	O
was	O
discussion	O
as	O
to	O
whether	O
to	O
deprecate	O
the	O
x32	B-Application
ABI	I-Application
,	O
which	O
has	O
not	O
happened	O
as	O
of	O
April	O
2023	O
.	O
</s>
