[erlang-questions] Clarify: HiPE auto-spawning?

[Mikael Pettersson]

On Fri, 16 Nov 2007 22:01:14 +1000, Philip Robinson wrote:
> Does HiPE automatically spread (spawn) a program across multiple cores?
> 
> For example, if I have a function:
> 
> test(A, B) ->
>     {A + B, A * B}.
> 
> Will HiPE convert it into something like the following?
> 
> test(A, B) ->
>     PidThis = self(),
>     Pid1 = spawn(fun() -> PidThis ! {self(), A + B} end),
>     Pid2 = spawn(fun() -> PidThis ! {self(), A * B} end),
>     Tmp1 = receive {Pid1, Result1} -> Result1 end,
>     Tmp2 = receive {Pid2, Result2} -> Result2 end,
>     {Tmp1, Tmp2}.

HiPE will not perform this transformation.

The transformation you suggest changes the semantics
of the code (Erlang code can have side-effects),
and may reduce its performance. So if you want it,
you need to express it yourself.

/Mikael