<s>
SYCL	B-Language
is	O
a	O
higher-level	O
programming	O
model	O
to	O
improve	O
programming	O
productivity	O
on	O
various	O
hardware	B-General_Concept
accelerators	I-General_Concept
.	O
</s>
<s>
It	O
is	O
a	O
single-source	O
embedded	O
domain-specific	O
language	O
(	O
eDSL	O
)	O
based	O
on	O
pure	O
C++17	B-Language
.	O
</s>
<s>
It	O
is	O
a	O
standard	O
developed	O
by	O
Khronos	B-Library
Group	I-Library
,	O
announced	O
in	O
March	O
2014	O
.	O
</s>
<s>
SYCL	B-Language
(	O
pronounced	O
‘	O
sickle’	O
)	O
is	O
a	O
name	O
and	O
not	O
an	O
acronym	O
.	O
</s>
<s>
In	O
particular	O
,	O
SYCL	B-Language
developers	O
made	O
clear	O
that	O
the	O
name	O
contains	O
no	O
reference	O
to	O
OpenCL	B-Application
.	O
</s>
<s>
SYCL	B-Language
is	O
a	O
royalty-free	O
,	O
cross-platform	B-Operating_System
abstraction	O
layer	O
that	O
builds	O
on	O
the	O
underlying	O
concepts	O
,	O
portability	O
and	O
efficiency	O
inspired	O
by	O
OpenCL	B-Application
that	O
enables	O
code	O
for	O
heterogeneous	O
processors	O
to	O
be	O
written	O
in	O
a	O
“	O
single-source	O
”	O
style	O
using	O
completely	O
standard	O
C++	B-Language
.	O
</s>
<s>
SYCL	B-Language
enables	O
single-source	O
development	O
where	O
C++	B-Application
template	I-Application
functions	O
can	O
contain	O
both	O
host	O
and	O
device	O
code	O
to	O
construct	O
complex	O
algorithms	O
that	O
use	O
hardware	B-General_Concept
accelerators	I-General_Concept
,	O
and	O
then	O
re-use	O
them	O
throughout	O
their	O
source	O
code	O
on	O
different	O
types	O
of	O
data	O
.	O
</s>
<s>
While	O
the	O
SYCL	B-Language
standard	O
started	O
as	O
the	O
higher-level	O
programming	O
model	O
sub-group	O
of	O
the	O
OpenCL	B-Application
working	O
group	O
and	O
was	O
originally	O
developed	O
for	O
use	O
with	O
OpenCL	B-Application
and	O
SPIR	B-Application
,	O
SYCL	B-Language
is	O
a	O
Khronos	B-Library
Group	I-Library
workgroup	O
independent	O
from	O
the	O
OpenCL	B-Application
working	O
group	O
since	O
September	O
20	O
,	O
2019	O
and	O
starting	O
with	O
SYCL	B-Language
2020	O
,	O
SYCL	B-Language
has	O
been	O
generalized	O
as	O
a	O
more	O
general	O
heterogeneous	O
framework	O
able	O
to	O
target	O
other	O
systems	O
.	O
</s>
<s>
This	O
is	O
now	O
possible	O
with	O
the	O
concept	O
of	O
a	O
generic	O
backend	B-Architecture
to	O
target	O
any	O
acceleration	O
API	B-Application
while	O
enabling	O
full	O
interoperability	O
with	O
the	O
target	O
API	B-Application
,	O
like	O
using	O
existing	O
native	O
libraries	O
to	O
reach	O
the	O
maximum	O
performance	O
along	O
with	O
simplifying	O
the	O
programming	O
effort	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
Open	O
SYCL	B-Language
implementation	O
targets	O
ROCm	B-Operating_System
and	O
CUDA	B-Architecture
via	O
AMD	O
's	O
cross-vendor	O
HIP	O
.	O
</s>
<s>
The	O
latest	O
version	O
for	O
the	O
previous	O
SYCL	B-Language
1.2.1	O
series	O
is	O
SYCL	B-Language
1.2.1	O
revision	O
7	O
which	O
was	O
published	O
on	O
April	O
27	O
,	O
2020	O
(	O
the	O
first	O
version	O
was	O
published	O
on	O
December	O
6	O
,	O
2017	O
)	O
.	O
</s>
<s>
SYCL	B-Language
2.2	O
provisional	O
was	O
introduced	O
at	O
IWOCL	O
2016	O
in	O
May	O
2016	O
targeting	O
C++14	B-Language
and	O
OpenCL	B-Application
2.2	O
.	O
</s>
<s>
But	O
the	O
SYCL	B-Language
committee	O
preferred	O
not	O
to	O
finalize	O
this	O
version	O
and	O
to	O
move	O
towards	O
a	O
more	O
flexible	O
SYCL	B-Language
specification	O
to	O
address	O
the	O
increasing	O
diversity	O
of	O
current	O
hardware	B-General_Concept
accelerators	I-General_Concept
,	O
including	O
artificial	B-Application
intelligence	I-Application
engines	O
,	O
which	O
led	O
to	O
SYCL	B-Language
2020	O
.	O
</s>
<s>
C++17	B-Language
and	O
OpenCL	B-Application
3.0	O
support	O
are	O
main	O
targets	O
of	O
this	O
release	O
.	O
</s>
<s>
Unified	O
shared	O
memory	O
(	O
USM	O
)	O
is	O
one	O
main	O
feature	O
for	O
GPUs	O
with	O
OpenCL	B-Application
and	O
CUDA	B-Architecture
support	O
.	O
</s>
<s>
DPC++	O
,	O
ComputeCpp	O
,	O
Open	O
SYCL	B-Language
,	O
triSYCL	O
and	O
neoSYCL	O
are	O
the	O
main	O
implementations	O
of	O
SYCL	B-Language
.	O
</s>
<s>
Next	O
Target	O
in	O
development	O
is	O
support	O
of	O
C++20	O
in	O
future	O
SYCL	B-Language
202x	O
.	O
</s>
<s>
DPC++	O
:	O
(	O
data	O
parallel	O
C++	B-Language
)	O
is	O
an	O
open	O
source	O
project	O
of	O
Intel	O
to	O
introduce	O
SYCL	B-Language
for	O
LLVM	O
and	O
oneAPI	O
.	O
</s>
<s>
C++17	B-Language
and	O
parts	O
of	O
C++20	O
with	O
SYCL	B-Language
2020	O
are	O
base	O
of	O
this	O
Compiler	O
framework	O
.	O
</s>
<s>
Open	O
SYCL	B-Language
(	O
formerly	O
hipSYCL	O
)	O
:	O
incomplete	O
1.2.1	O
support	O
without	O
OpenCL	B-Application
coupling	O
and	O
images	O
,	O
partly	O
SYCL	B-Language
2020	O
,	O
supports	O
ROCm	B-Operating_System
(	O
AMD	O
)	O
,	O
CUDA	B-Architecture
(	O
Nvidia	O
)	O
,	O
OpenMP	B-Application
(	O
CPUs	O
)	O
and	O
Level	O
Zero	O
(	O
Intel	O
)	O
.	O
</s>
<s>
Sylkan	O
is	O
an	O
implementation	O
of	O
SYCL	B-Language
to	O
Vulkan	B-Application
devices	O
in	O
an	O
experimental	O
state	O
.	O
</s>
<s>
Polygeist	O
has	O
a	O
fork	O
compiling	O
SYCL	B-Language
through	O
MLIR	O
which	O
is	O
backed	O
by	O
the	O
Inteon	O
company	O
.	O
</s>
<s>
Gromacs	B-Application
:	O
SYCL	B-Language
2020	O
is	O
Part	O
of	O
Gromacs	B-Application
Version	O
2021	O
.	O
</s>
<s>
There	O
are	O
a	O
few	O
tutorials	O
in	O
the	O
ComputeCpp	O
SYCL	B-Language
guides	O
.	O
</s>
<s>
The	O
source	O
files	O
for	O
building	O
the	O
specification	O
,	O
such	O
as	O
Makefiles	O
and	O
some	O
scripts	O
,	O
the	O
SYCL	B-Language
headers	O
and	O
the	O
SYCL	B-Language
code	O
samples	O
are	O
under	O
the	O
Apache	O
2.0	O
license	O
.	O
</s>
<s>
The	O
open	O
standards	O
SYCL	B-Language
and	O
OpenCL	B-Application
are	O
similar	O
to	O
the	O
programming	O
models	O
of	O
the	O
proprietary	O
stack	O
CUDA	B-Architecture
from	O
Nvidia	O
,	O
and	O
HIP	O
from	O
the	O
open-source	O
stack	O
ROCm	B-Operating_System
,	O
supported	O
by	O
AMD	O
.	O
</s>
<s>
In	O
the	B-Library
Khronos	I-Library
Group	I-Library
realm	O
,	O
OpenCL	B-Application
and	O
Vulkan	B-Application
are	O
the	O
low-level	O
non-single	O
source	O
API	B-Application
and	O
SYCL	B-Language
is	O
the	O
high-level	O
single-source	O
C++	B-Language
embedded	O
domain-specific	O
language	O
(	O
eDSL	O
)	O
.	O
</s>
<s>
By	O
comparison	O
,	O
the	O
single-source	O
C++	B-Language
embedded	O
domain-specific	O
language	O
version	O
of	O
CUDA	B-Architecture
,	O
which	O
is	O
actually	O
named	O
"	O
CUDA	B-Architecture
Runtime	O
API	B-Application
"	O
,	O
is	O
somewhat	O
similar	O
to	O
SYCL	B-Language
.	O
</s>
<s>
But	O
there	O
is	O
actually	O
a	O
less	O
known	O
non	O
single-source	O
version	O
of	O
CUDA	B-Architecture
which	O
is	O
called	O
"	O
CUDA	B-Architecture
Driver	O
API	B-Application
"	O
,	O
similar	O
to	O
OpenCL	B-Application
,	O
and	O
used	O
for	O
example	O
by	O
the	O
CUDA	B-Architecture
Runtime	O
API	B-Application
implementation	O
itself	O
.	O
</s>
<s>
SYCL	B-Language
extends	O
the	O
C++	B-Language
AMP	I-Language
features	O
relieving	O
the	O
programmer	O
from	O
explicitly	O
transferring	O
the	O
data	O
between	O
the	O
host	O
and	O
devices	O
by	O
using	O
buffers	O
and	O
accessors	O
,	O
by	O
opposition	O
to	O
CUDA	B-Architecture
(	O
before	O
the	O
introduction	O
of	O
Unified	O
Memory	O
in	O
CUDA	B-Architecture
6	O
)	O
.	O
</s>
<s>
But	O
starting	O
with	O
SYCL	B-Language
2020	O
,	O
it	O
is	O
also	O
possible	O
to	O
use	O
USM	O
instead	O
of	O
buffers	O
and	O
accessors	O
to	O
use	O
a	O
lower-level	O
programming	O
model	O
similar	O
to	O
Unified	O
Memory	O
in	O
CUDA	B-Architecture
.	O
</s>
<s>
Unlike	O
C++	B-Language
AMP	I-Language
and	O
CUDA	B-Architecture
,	O
SYCL	B-Language
is	O
a	O
pure	O
C++	B-Language
eDSL	O
without	O
any	O
C++	B-Language
extension	O
,	O
allowing	O
a	O
basic	O
CPU	O
implementation	O
relying	O
on	O
pure	O
runtime	O
without	O
any	O
specific	O
compiler	O
.	O
</s>
<s>
There	O
are	O
at	O
least	O
3	O
known	O
SYCL	B-Language
implementations	O
targeting	O
the	O
CUDA	B-Architecture
backend	B-Architecture
.	O
</s>
<s>
ROCm	B-Operating_System
HIP	O
can	O
be	O
seen	O
as	O
a	O
clone	O
of	O
CUDA	B-Architecture
targeting	O
Nvidia	O
GPU	O
,	O
AMD	O
GPU	O
and	O
x86	O
CPU	O
.	O
</s>
<s>
Thus	O
ROCm	B-Operating_System
HIP	O
is	O
a	O
lower-level	O
API	B-Application
compared	O
to	O
SYCL	B-Language
and	O
most	O
of	O
the	O
comments	O
mentioned	O
in	O
the	O
comparison	O
with	O
CUDA	B-Architecture
do	O
apply	O
.	O
</s>
<s>
ROCm	B-Operating_System
HIP	O
has	O
some	O
similarities	O
to	O
SYCL	B-Language
in	O
the	O
sense	O
that	O
it	O
can	O
target	O
various	O
vendors	O
(	O
AMD	O
and	O
Nvidia	O
)	O
and	O
accelerator	O
types	O
(	O
GPU	O
and	O
CPU	O
)	O
.	O
</s>
<s>
But	O
SYCL	B-Language
can	O
target	O
according	O
to	O
the	O
implementation	O
any	O
type	O
of	O
accelerators	O
and	O
any	O
vendors	O
,	O
potentially	O
at	O
the	O
same	O
time	O
,	O
in	O
a	O
single	O
application	O
with	O
the	O
concept	O
of	O
backend	B-Architecture
.	O
</s>
<s>
SYCL	B-Language
is	O
also	O
pure	O
C++	B-Language
while	O
HIP	O
uses	O
some	O
extensions	O
inherited	O
from	O
CUDA	B-Architecture
,	O
which	O
prevents	O
using	O
a	O
normal	O
C++	B-Language
compiler	O
to	O
target	O
any	O
CPU	O
.	O
</s>
<s>
There	O
are	O
at	O
least	O
2	O
known	O
implementations	O
of	O
SYCL	B-Language
targeting	O
the	O
HIP	O
backend	B-Architecture
,	O
oneAPI	O
DPC++	O
and	O
Open	O
SYCL	B-Language
.	O
</s>
<s>
The	O
implementation	O
,	O
over	O
HIP	O
,	O
adds	O
SYCL	B-Language
programming	O
to	O
CUDA	B-Architecture
and	O
HIP	O
.	O
</s>
<s>
SYCL	B-Language
has	O
many	O
similarities	O
to	O
the	O
Kokkos	B-Language
programming	O
model	O
,	O
including	O
the	O
use	O
of	O
opaque	O
multi-dimensional	O
array	O
objects	O
(	O
SYCL	B-Language
buffers	O
and	O
Kokkos	B-Language
arrays	O
)	O
,	O
multi-dimensional	O
ranges	O
for	O
parallel	O
execution	O
,	O
and	O
reductions	O
(	O
added	O
in	O
SYCL	B-Language
2020	O
)	O
.	O
</s>
<s>
Numerous	O
features	O
in	O
SYCL	B-Language
2020	O
were	O
added	O
in	O
response	O
to	O
feedback	O
from	O
the	O
Kokkos	B-Language
community	O
.	O
</s>
