Re: Erlang JIT and loaded code

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Hello!

On Tue, Apr 19, 2022 at 7:17 AM Vitor Rocha <[email protected]> wrote:

> (1) how do I know if my code is actually being executed as interpreted or
> native?
>

All code loaded from .beam files are run natively if the VM supports JIT
compilation.


> (2) If I compile a module inside Erlang's shell, using the `c:c/1`
> function, is the module going to be compiled to native too? Will its
> execution be switched to native?
>

There is no difference in how it is compiled, it will always be translated
into native code when loaded.


> (3) Where is stored the generated beamasm native code? I would like to get
> its size in bytes?
>

It is stored in memory of the VM. You can get a file dump of the native
code by passing `+JDdump true` when starting `erl`. There is no way to get
the loaded memory size of a single module, but you can get a relatively
close value by checking what `erlang:memory(code)` returns before and after
the module is loaded.


>
> --
> Atenciosamente,
> Vitor Rocha da Silva
>

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<div dir=3D"ltr"><div>Hello!</div><br><div class=3D"gmail_quote"><div dir=
=3D"ltr" class=3D"gmail_attr">On Tue, Apr 19, 2022 at 7:17 AM Vitor Rocha &=
lt;<a href=3D"mailto:[email protected]">[email protected]</a>&gt; wrote=
:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.=
8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir=3D"lt=
r"><div>(1) how do I know if my code is actually being executed as interpre=
ted or native?</div></div></blockquote><div><br></div><div>All code loaded =
from .beam files are run natively if the VM supports JIT compilation.</div>=
<div>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px =
0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir=
=3D"ltr"><div>(2) If I compile a module inside Erlang&#39;s shell, using th=
e `c:c/1` function, is the module going to be compiled to native too? Will =
its execution be switched to native?<br></div></div></blockquote><div><br><=
/div><div>There is no=C2=A0difference in how it is compiled, it will always=
 be translated into native code when loaded.</div><div>=C2=A0</div><blockqu=
ote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px=
 solid rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div></div><div>=
(3) Where is stored the generated beamasm native code? I would like to get =
its size in bytes?<br></div></div></blockquote><div><br></div><div>It is st=
ored in memory of the VM. You can get a file dump of the native code by pas=
sing `+JDdump true` when starting `erl`. There is no way to get the loaded =
memory size of a single module, but you can get a relatively close value by=
 checking what `erlang:memory(code)` returns before and after the module is=
 loaded.</div><div>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"m=
argin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left=
:1ex"><div dir=3D"ltr"><div><br></div><div>-- <br><div dir=3D"ltr"><span st=
yle=3D"font-family:&quot;trebuchet ms&quot;,sans-serif">Atenciosamente,<br>=
Vitor Rocha da Silva</span><br></div></div></div>
</blockquote></div></div>

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