Most performant way of converting int to string

[H. S. Teoh via Digitalmars-d-learn]

On Tue, Dec 22, 2015 at 08:54:35PM +0100, Daniel Kozák via Digitalmars-d-learn wrote:
> V Tue, 22 Dec 2015 09:43:00 -0800
> "H. S. Teoh via Digitalmars-d-learn"
> <digitalmars-d-learn at puremagic.com> napsáno:
> 
> > On Tue, Dec 22, 2015 at 05:23:11PM +0000, Andrew Chapman via
> > Digitalmars-d-learn wrote: [...]
> > >         for({int i; i = 0;} i < num; i++) {
> > >                 //string s = to!string(i);
> > >                 Customer c = Customer(i, "Customer", "99998888", i
> > > * 2); string result = objS.serialize(c);
> > >         }
> > > 
> > > If I uncomment the "string s" line I'm seeing a 20% increase in
> > > running time, which given what's going on the rest of the code is
> > > quite surprising.  I've tried compiling with both dmd and ldc2 -
> > > it's the same under both.  
> > [...]
> > 
> > I wonder if the slowdown is caused by GC collection cycles (because
> > calling to!string will allocate, and here you're making a very large
> > number of small allocations, which is known to cause GC performance
> > issues).
> > 
> > Try inserting this before the loop:
> > 
> > 	import core.memory;
> > 	GC.disable();
> > 
> > Does this make a difference in the running time?
> > 
> > 
> > T
> > 
> This would  not help. It would probably be worse.

I was not suggesting this as a solution, it's merely a way to determine
whether the performance issue is GC-related.


T

-- 
"Hi." "'Lo."