• C. Dunn (4/10) Aug 10 2007 Yes. 20% is a good rule of thumb. That's what we usually see, for gener...

C. Dunn <cdunn2001 gmail.com> writes:

renoX Wrote:
 2x?
 Your code must do a lot of 64b computation!

Yes.  Lots of 64-bit integer shifts of pointer values.  The only other
difference is that 32-bit pointer addresses are closer together.  The result:
The exact same code compiled for 32- or 64-bit has a 2x speed difference.


 
 When the AMD64 was released benchmarks made showed at best a 20% 
 improvement, which is quite a lot to get with a simple recompilation 
 assuming the code is 64b clean of course but is nowhere 2x.

Yes. 20% is a good rule of thumb.  That's what we usually see, for general
object-oriented programming.  System-level programming is different.

I'll try gdc someday....