<s>
In	O
computer	O
software	O
,	O
in	O
compiler	B-Language
theory	O
,	O
an	O
intrinsic	B-Application
function	I-Application
(	O
or	O
built-in	B-Application
function	I-Application
)	O
is	O
a	O
function	O
(	O
subroutine	O
)	O
available	O
for	O
use	O
in	O
a	O
given	O
programming	O
language	O
whose	O
implementation	O
is	O
handled	O
specially	O
by	O
the	O
compiler	B-Language
.	O
</s>
<s>
Typically	O
,	O
it	O
may	O
substitute	O
a	O
sequence	O
of	O
automatically	O
generated	O
instructions	B-General_Concept
for	O
the	O
original	O
function	O
call	O
,	O
similar	O
to	O
an	O
inline	O
function	O
.	O
</s>
<s>
Unlike	O
an	O
inline	O
function	O
,	O
the	O
compiler	B-Language
has	O
an	O
intimate	O
knowledge	O
of	O
an	O
intrinsic	B-Application
function	I-Application
and	O
can	O
thus	O
better	O
integrate	O
and	O
optimize	O
it	O
for	O
a	O
given	O
situation	O
.	O
</s>
<s>
Compilers	B-Language
that	O
implement	O
intrinsic	B-Application
functions	I-Application
generally	O
enable	O
them	O
only	O
when	O
a	O
program	O
requests	O
optimization	B-Application
,	O
otherwise	O
falling	O
back	O
to	O
a	O
default	O
implementation	O
provided	O
by	O
the	O
language	O
runtime	B-Device
system	I-Device
(	O
environment	O
)	O
.	O
</s>
<s>
Intrinsic	B-Application
functions	I-Application
are	O
often	O
used	O
to	O
explicitly	O
implement	O
vectorization	B-General_Concept
and	O
parallelization	O
in	O
languages	O
which	O
do	O
not	O
address	O
such	O
constructs	O
.	O
</s>
<s>
Some	O
application	B-Application
programming	I-Application
interfaces	I-Application
(	O
API	B-Application
)	O
,	O
for	O
example	O
,	O
AltiVec	B-General_Concept
and	O
OpenMP	B-Application
,	O
use	O
intrinsic	B-Application
functions	I-Application
to	O
declare	O
,	O
respectively	O
,	O
vectorizable	O
and	O
multiprocessing-aware	O
operations	O
during	O
compiling	B-Language
.	O
</s>
<s>
The	O
compiler	B-Language
parses	O
the	O
intrinsic	B-Application
functions	I-Application
and	O
converts	O
them	O
into	O
vector	O
math	O
or	O
multiprocessing	B-Operating_System
object	B-Language
code	I-Language
appropriate	O
for	O
the	O
target	O
platform	B-Device
.	O
</s>
<s>
Compilers	B-Language
for	O
C	B-Language
and	O
C++	B-Language
,	O
of	O
Microsoft	O
,	O
</s>
<s>
implement	O
intrinsics	O
that	O
map	O
directly	O
to	O
the	O
x86	B-Operating_System
single	B-Device
instruction	I-Device
,	I-Device
multiple	I-Device
data	I-Device
(	O
SIMD	B-Device
)	O
instructions	B-General_Concept
(	O
MMX	B-Architecture
,	O
Streaming	B-General_Concept
SIMD	I-General_Concept
Extensions	I-General_Concept
(	O
SSE	O
)	O
,	O
SSE2	B-General_Concept
,	O
SSE3	B-General_Concept
,	O
SSSE3	B-General_Concept
,	O
SSE4	B-General_Concept
,	O
AVX	B-General_Concept
,	O
AVX2	O
,	O
AVX512	B-General_Concept
,	O
FMA	B-General_Concept
,	O
...	O
)	O
.	O
</s>
<s>
The	O
Microsoft	B-Application
Visual	I-Application
C++	I-Application
compiler	B-Language
of	O
Microsoft	B-Application
Visual	I-Application
Studio	I-Application
does	O
not	O
support	O
inline	O
assembly	B-Language
for	O
x86-64	B-Device
.	O
</s>
<s>
To	O
compensate	O
for	O
this	O
,	O
new	O
intrinsics	O
have	O
been	O
added	O
that	O
map	O
to	O
standard	O
assembly	B-Language
instructions	B-General_Concept
that	O
are	O
not	O
normally	O
accessible	O
through	O
C/C	O
++	O
,	O
e.g.	O
,	O
bit	O
scan	O
.	O
</s>
<s>
Some	O
C	B-Language
and	O
C++	B-Language
compilers	B-Language
provide	O
non-portable	O
platform-specific	O
intrinsics	O
.	O
</s>
<s>
Other	O
intrinsics	O
(	O
such	O
as	O
GNU	B-Application
built-ins	O
)	O
are	O
slightly	O
more	O
abstracted	O
,	O
approximating	O
the	O
abilities	O
of	O
several	O
contemporary	O
platforms	B-Device
,	O
with	O
portable	O
fall	O
back	O
implementations	O
on	O
platforms	B-Device
with	O
no	O
appropriate	O
instructions	B-General_Concept
.	O
</s>
<s>
It	O
is	O
common	O
for	O
C++	B-Language
libraries	O
,	O
such	O
as	O
glm	O
or	O
Sony	O
's	O
vector	O
maths	O
libraries	O
,	O
to	O
achieve	O
portability	O
via	O
conditional	B-Application
compilation	I-Application
(	O
based	O
on	O
platform	B-Device
specific	O
compiler	B-Language
flags	O
)	O
,	O
providing	O
fully	O
portable	O
high-level	O
primitives	O
(	O
e.g.	O
,	O
a	O
four-element	O
floating-point	O
vector	O
type	O
)	O
mapped	O
onto	O
the	O
appropriate	O
low	B-Language
level	I-Language
programming	I-Language
language	I-Language
implementations	O
,	O
while	O
still	O
benefiting	O
from	O
the	O
C++	B-Language
type	O
system	O
and	O
inlining	O
;	O
hence	O
the	O
advantage	O
over	O
linking	O
to	O
hand-written	O
assembly	B-Language
object	O
files	O
,	O
using	O
the	O
C	B-Language
application	B-Operating_System
binary	I-Operating_System
interface	I-Operating_System
(	O
ABI	O
)	O
.	O
</s>
<s>
The	O
HotSpot	B-Language
Java	B-Language
virtual	I-Language
machine	I-Language
's	O
(	O
JVM	B-Language
)	O
just-in-time	O
compiler	B-Language
also	O
has	O
intrinsics	O
for	O
specific	O
Java	O
APIs	B-Application
.	O
</s>
<s>
Hotspot	B-Language
intrinsics	O
are	O
standard	O
Java	O
APIs	B-Application
which	O
may	O
have	O
one	O
or	O
more	O
optimized	O
implementation	O
on	O
some	O
platforms	B-Device
.	O
</s>
