Speeding up text file parser (BLAST tabular format)

[Fredrik Boulund via Digitalmars-d-learn]

On Monday, 14 September 2015 at 13:37:18 UTC, John Colvin wrote:
> On Monday, 14 September 2015 at 13:05:32 UTC, Andrea Fontana 
> wrote:
>> On Monday, 14 September 2015 at 12:30:21 UTC, Fredrik Boulund 
>> wrote:
>>> [...]
>>
>> Also if problem probabily is i/o related, have you tried with:
>> -O -inline -release -noboundscheck
>> ?
>
> -inline in particular is likely to have a strong impact here
>

Why would -inline be particularly likely to make a big difference 
in this case? I'm trying to learn, but I don't see what inlining 
could be done in this case.

>> Anyway I think it's a good idea to test it against gdc and ldc 
>> that are known to generate faster executables.
>>
>> Andrea
>
> +1 I would expect ldc or gdc to strongly outperform dmd on this 
> code.

Why is that? I would love to learn to understand why they could 
be expected to perform much better on this kind of code.