D compiler benchmarks

[bearophile]

- Having a C or C++ (or something better, where necessary) baseline reference can be very useful to know how much far is the D code from the fastest non-ASM versions.
- you can improve the graphs in the dbench.octarineparrot.com page so they can be read better.
- Tune all your tests so they run for 6-15 seconds or more. If they run for less than 3 seconds there's too much measure noise.
- Taking the average of three runs isn't that good, but this is a tricky topic... Take the minimum for now.
- With my browser the label "binarytrees2" is misplaced.
- what's the differece between nsievebits2 and nsievebits? And nbody and nbody2? Reading the source is good, but a small note too is good.
- Both in GDC and LDC it's positive to add what backends they use (for example: ldc version: r1050 using LLVM 2.5).
- Note that currently LDC goes up only to -O3.


Regarding the backend of LDC:
http://leonardo-m.livejournal.com/77877.html

Bye,
bearophile