System programming in D (Was: The God Language)

[Iain Buclaw]

On 31 December 2011 00:48, so <so at so.so> wrote:
> On Fri, 30 Dec 2011 20:48:54 +0200, Walter Bright
> <newshound2 at digitalmars.com> wrote:
>
>> On 12/30/2011 7:06 AM, so wrote:
>>>
>>> I agree @inline (which will probably be an extension) in D should mean
>>> force-inline.
>>> Ignoring the impossible-to-inline cases (which in time should get
>>> better),
>>> adding @inline is a few minutes of editing.
>>> It will just bypass the cost function and if it is not possible to
>>> inline, pop
>>> error.
>>
>>
>>
>> Sure, but I think you'll be very disappointed in that it isn't going to
>> deliver the goods.
>
>
> dmd_inl -O -inline test.d
> dmd_inl -O -inline test_inl.d
> time ./test
>
> real    0m4.686s
> user    0m3.516s
> sys     0m0.007s
> time ./test_inl
>
> real    0m1.900s
> user    0m1.503s
> sys     0m0.007s
> time ./test
>

*SNIP*

>
> void main()
> {
>        for(uint i=0; i<1_000_000_000; ++i)
>                test();
> }

A better compiler would see that the function 'test' has no side
effects, and it's return value is unused, so elimates the call to it
completely as dead code.

-- 
Iain Buclaw

*(p < e ? p++ : p) = (c & 0x0f) + '0';