Is it possible to unroll loops in D2.0? I have a templated struct with a static array with length set through a template parameter. Does that get automatically unrolled with 4 elements (I doubt it), do I have to use some magic string mixin, or could I fix this with tuples and their automatic loop unrolling?

Actually, that latter one is worth a question of its own. Can I convert a static array into a tuplem and if so, how?

-- Simen

"Simen Kjaeraas" <simen.kjaras@gmail.com> wrote in message news:fr4ec8$kd3$1@digitalmars.com...
> Is it possible to unroll loops in D2.0? I have a templated struct with a static array with length set through a template parameter. Does that get automatically unrolled with 4 elements (I doubt it), do I have to use some magic string mixin, or could I fix this with tuples and their automatic loop unrolling?
>
> Actually, that latter one is worth a question of its own. Can I convert a static array into a tuplem and if so, how?
>
> -- Simen

In the presentation Walter and Andrei gave at the D con last year, they presented a "static loop" feature that would unroll the loop at compile time.

static foreach(blah; something)
{
    //...
}

So it's "in the works" for D2, I guess, but who knows when it'll actually be implemented.

Reply to Jarrett,

> "Simen Kjaeraas" <simen.kjaras@gmail.com> wrote in message
> news:fr4ec8$kd3$1@digitalmars.com...
> 
>> Is it possible to unroll loops in D2.0? I have a templated struct
>> with a static array with length set through a template parameter.
>> Does that get automatically unrolled with 4 elements (I doubt it), do
>> I have to use some magic string mixin, or could I fix this with
>> tuples and their automatic loop unrolling?
>> 
>> Actually, that latter one is worth a question of its own. Can I
>> convert a static array into a tuplem and if so, how?
>> 
>> -- Simen
>> 
> In the presentation Walter and Andrei gave at the D con last year,
> they presented a "static loop" feature that would unroll the loop at
> compile time.
> 
> static foreach(blah; something)
> {
> //...
> }
> So it's "in the works" for D2, I guess, but who knows when it'll
> actually be implemented.
> 

you can do it with tuple a foreach, but it's not very clean

Simen Kjaeraas wrote:
> Is it possible to unroll loops in D2.0? I have a templated struct with a static array with length set through a template parameter. Does that get automatically unrolled with 4 elements (I doubt it), do I have to use some magic string mixin, or could I fix this with tuples and their automatic loop unrolling?
> 
> Actually, that latter one is worth a question of its own. Can I convert a static array into a tuplem and if so, how?
> 
> -- Simen

If the compiler knows it to be 4 elements at the code generation stage (which it will if it's a static array - template resolution is done in the semantic pass, so it doesn't matter if it's from a template or coded directly in), it should probably unroll it. Check the assembly.

Simen Kjaeraas wrote:
> Is it possible to unroll loops in D2.0? I have a templated struct with a static array with length set through a template parameter. Does that get automatically unrolled with 4 elements (I doubt it), do I have to use some magic string mixin, or could I fix this with tuples and their automatic loop unrolling?
> 
> Actually, that latter one is worth a question of its own. Can I convert a static array into a tuplem and if so, how?

Use a union :)

union TupleAndStaticArrayTest {
	uint[4] whee;
	Repeat!(uint, 4) whoo;
}

> 
> -- Simen

Simen Kjaeraas wrote:
> Is it possible to unroll loops in D2.0? I have a templated struct with a static array with length set through a template parameter. Does that get automatically unrolled with 4 elements (I doubt it), do I have to use some magic string mixin, or could I fix this with tuples and their automatic loop unrolling?
> 
> Actually, that latter one is worth a question of its own. Can I convert a static array into a tuplem and if so, how?
> 
> -- Simen

Also I believe GDC can do automatic loop unrolling.  At least it happily accepts the flag  "-funroll-loops".

--bb