Re: LocalVariablesSorter performance

This is a multi-part message in MIME format...

------------=_1613565814-2833-5
Content-Type: multipart/alternative; boundary="000000000000e7f68705bb879040"

--000000000000e7f68705bb879040
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

Hi,

In an effort to make this easier to digest, I extracted JMH benchmark into
a self-contained performance demo available here:

https://github.com/eirbjo/asm-lv-prepender

The LocalVariablesPrepender class itself:
https://github.com/eirbjo/asm-lv-prepender/blob/main/src/main/java/com/gith=
ub/eirbjo/LocalVariablesDemo.java#L63

The subclass using LocalVariablesPrepender:
https://github.com/eirbjo/asm-lv-prepender/blob/main/src/main/java/com/gith=
ub/eirbjo/LocalVariablesDemo.java#L221

Eirik.

On Wed, Feb 17, 2021 at 11:37 AM Eirik Bj=C3=B8rsn=C3=B8s <[email protected]=
> wrote:

> Hi,
>
> I've been looking into the performance of LocalVariablesSorter. This class
> currently only supports expanded frames, which means we need to use the
> ClassReader.EXPAND_FRAMES option when reading the class.
>
> As my use case only requires prepending variables at the very start of
> methods, I don't need to support adding variables at arbitrary code
> locations. Taking this into consideration, I made a LocalVariablesPrepend=
er
> class which simply shifts local variables forward by the amount needed for
> injecting the new variables. It also remaps all FULL frames and converts
> first-frame SAME/APPEND frames into remapped FULL frames.
>
> This allows LocalVariablesPrepender to be used without
> ClassReader.EXPAND_FRAMES.
>
> I then did a JMH benchmark comparing the throughput of injecting a single
> local variable (injects ICONST_M1, ISTORE x)  using LocalVariablesSorter =
to
> that of my LocalVariablesPrepender. The class used for testing was Jetty's
> Server class.
>
> Here are the results:
>
> Benchmark                                        Mode  Cnt     Score
> Error  Units
> LocalVariableInjectors.localVariablesPrepender  thrpt   25  3940.191 =C2=
=B1
>  42.010  ops/s
> LocalVariableInjectors.localVariablesSorter     thrpt   25  2681.776 =C2=
=B1
> 175.943  ops/s
>
> That's a significant performance improvement for not expanding frames!
>
> What would it take to rewrite LocalVariablesSorter to not require expanded
> frames? If that task is too complex, then perhaps ASM should have somethi=
ng
> similar to a LocalVariablesPrepender?
>
> Cheers,
> Eirik.
>
>
>

--000000000000e7f68705bb879040
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><br><div>Hi,</div><div><br></div><div>In an effort to make=
 this easier to digest, I extracted JMH benchmark into a self-contained per=
formance demo available here:</div><div><br></div><div><a href=3D"https://g=
ithub.com/eirbjo/asm-lv-prepender">https://github.com/eirbjo/asm-lv-prepend=
er</a><br></div><div><br></div><div>The LocalVariablesPrepender class itsel=
f: <a href=3D"https://github.com/eirbjo/asm-lv-prepender/blob/main/src/main=
/java/com/github/eirbjo/LocalVariablesDemo.java#L63">https://github.com/eir=
bjo/asm-lv-prepender/blob/main/src/main/java/com/github/eirbjo/LocalVariabl=
esDemo.java#L63</a></div><div><br></div><div>The subclass using LocalVariab=
lesPrepender: <a href=3D"https://github.com/eirbjo/asm-lv-prepender/blob/ma=
in/src/main/java/com/github/eirbjo/LocalVariablesDemo.java#L221">https://gi=
thub.com/eirbjo/asm-lv-prepender/blob/main/src/main/java/com/github/eirbjo/=
LocalVariablesDemo.java#L221</a></div><div><br></div><div>Eirik.</div></div=
><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On We=
d, Feb 17, 2021 at 11:37 AM Eirik Bj=C3=B8rsn=C3=B8s &lt;<a href=3D"mailto:=
[email protected]">[email protected]</a>&gt; wrote:<br></div><blockquote clas=
s=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid r=
gb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div dir=3D"ltr">Hi,<div=
><br></div><div>I&#39;ve been looking into the performance of LocalVariable=
sSorter. This class currently only supports expanded frames, which means we=
 need to use the ClassReader.EXPAND_FRAMES option when reading the class.</=
div><div><br></div><div>As my use case only requires prepending variables a=
t the very start of methods, I don&#39;t need to support adding variables a=
t arbitrary code locations. Taking this=C2=A0into consideration, I made a L=
ocalVariablesPrepender class which simply shifts local variables forward by=
 the amount needed for injecting the new variables. It also remaps all FULL=
 frames and converts first-frame SAME/APPEND frames into remapped FULL fram=
es.</div><div><br></div><div>This allows=C2=A0LocalVariablesPrepender to be=
 used without ClassReader.EXPAND_FRAMES.</div><div><br></div><div>I then di=
d a JMH benchmark comparing the throughput of injecting a single local vari=
able (injects ICONST_M1, ISTORE x)=C2=A0 using LocalVariablesSorter to that=
 of my=C2=A0LocalVariablesPrepender. The class used for=C2=A0testing was Je=
tty&#39;s Server class.</div><div><br></div><div>Here are the results:</div=
><div><br></div><div><font face=3D"monospace">Benchmark =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Mode =C2=A0Cnt =C2=A0 =C2=
=A0 Score =C2=A0 =C2=A0 Error =C2=A0Units<br>LocalVariableInjectors.localVa=
riablesPrepender =C2=A0thrpt =C2=A0 25 =C2=A03940.191 =C2=B1 =C2=A042.010 =
=C2=A0ops/s<br>LocalVariableInjectors.localVariablesSorter =C2=A0 =C2=A0 th=
rpt =C2=A0 25 =C2=A02681.776 =C2=B1 175.943 =C2=A0ops/s</font><br></div><di=
v><br></div><div>That&#39;s a significant performance improvement for not e=
xpanding frames!</div><div><br></div><div>What would it take to rewrite Loc=
alVariablesSorter to not require expanded frames? If that task is too compl=
ex, then perhaps ASM should have something similar to a LocalVariablesPrepe=
nder?</div><div><br></div><div>Cheers,</div><div>Eirik.</div><div><br></div=
><div><br></div></div></div>
</blockquote></div>

--000000000000e7f68705bb879040--

------------=_1613565814-2833-5
Content-Type: text/plain; charset="UTF-8"
Content-Disposition: inline
Content-Transfer-Encoding: 8bit


-- 
You receive this message as a subscriber of the [email protected] mailing list.
To unsubscribe: mailto:[email protected]
For general help: mailto:[email protected]?subject=help
OW2 mailing lists service home page: http://www.ow2.org/wws

------------=_1613565814-2833-5--