D to ASM.js vs D to Dart (VM)

[bearophile via Digitalmars-d]

Paulo Pinto:

> Am 18.05.2014 10:02, schrieb bearophile:
>> But in general isn't it more efficient to not generate bloat 
>> instead of
>> generating it, detecting it, and removing it?
>>
>> Bye,
>> bearophile
>
> Which you can only do if the compiler can see the whole code.
>
> It doesn't work in binary libraries.

I think in this case avoiding part of the problem is better than 
avoiding none of it :-) There are other similar situations where 
avoiding the template bloat is useful. This generates two 
instances of doubleIt in the binary:


T doubleIt(T)(T x) { return x * 2; }
void main() {
     immutable r1 = doubleIt(10);
     immutable r2 = doubleIt(cast(const int)10);
}


The asm, from DMD:

_D4temp15__T8doubleItTiZ8doubleItFNaNbNiNfiZi:
         enter   4,0
         add EAX,EAX
         leave
         ret

_D4temp16__T8doubleItTxiZ8doubleItFNaNbNiNfxiZxi:
         enter   4,0
         add EAX,EAX
         leave
         ret

Bye,
bearophile