<s>
CompCert	B-Application
is	O
a	O
formally	O
verified	O
optimizing	O
compiler	B-Language
for	O
a	O
large	O
subset	O
of	O
the	O
C99	B-Language
programming	I-Language
language	I-Language
(	O
known	O
as	O
Clight	O
)	O
which	O
currently	O
targets	O
PowerPC	B-Architecture
,	O
ARM	B-Architecture
,	O
RISC-V	B-Device
,	O
x86	B-Operating_System
and	O
x86-64	B-Device
architectures	O
.	O
</s>
<s>
The	O
compiler	B-Language
is	O
specified	O
,	O
programmed	O
and	O
proven	O
in	O
Coq	B-Application
.	O
</s>
<s>
The	O
performance	O
of	O
its	O
generated	O
code	O
is	O
often	O
close	O
to	O
that	O
of	O
GCC	B-Application
(	O
version	O
3	O
)	O
at	O
optimization	O
level	O
-O1	O
,	O
and	O
always	O
better	O
than	O
that	O
of	O
GCC	B-Application
without	O
optimizations	O
.	O
</s>
<s>
CompCert	B-Application
is	O
released	O
under	O
a	O
noncommercial	O
license	O
,	O
and	O
is	O
therefore	O
not	O
free	B-Application
software	I-Application
,	O
although	O
some	O
of	O
its	O
source	O
files	O
are	O
dual-licensed	B-License
with	O
the	O
GNU	B-Application
Lesser	I-Application
General	I-Application
Public	I-Application
License	I-Application
version	O
2.1	O
or	O
later	O
or	O
are	O
available	O
under	O
the	O
terms	O
of	O
other	O
licenses	O
.	O
</s>
<s>
For	O
the	O
development	O
of	O
CompCert	B-Application
,	O
the	O
first	O
practically	O
useful	O
optimizing	O
compiler	B-Language
targeting	O
multiple	O
commercial	O
architectures	O
that	O
have	O
a	O
complete	O
,	O
mechanically	O
checked	O
proof	O
of	O
its	O
correctness	O
,	O
Xavier	O
Leroy	O
and	O
the	O
development	O
team	O
of	O
CompCert	B-Application
received	O
the	O
2021	O
ACM	O
Software	O
System	O
Award	O
.	O
</s>
