Increasing speed of D applications to Intel C compiled applicaitons' standards

[Walter Bright]

Teoman Soygul wrote:
> My personal benchmarks prove that applications written in D are 5%
> to 20% slower than identical code written in C and compiled with
> Intel C compilter 9. Does anyone know what to do with this
> problem? Is it a compiler specific problem (ie: D compiler lacking
> all the optimisation parameters) or the standard d libary or
> what??
> 
> Any information/idea would be appriciated. Before starting a big
> project, speed issues with D seems to be the biggest obstacle to
> overcome.

If it's identical code, then it's a compiler optimization issue, as 
identical C code compiled with D should produce identical results. You 
can try using the D profiler to see if the slowdown is in any specific 
place.

5% to 20% are generally not big obstacles to overcome, as they are often 
in one or two spots that can be hand optimized (or written in 
assembler). It's also my experience that until it reaches 2:1, few 
people even notice it. Even the same program will vary 5 to 10% in 
execution time from run to run.