[Liboil] Simple scalar operations in ORC possible?

[David Schleef]

On Tue, Mar 08, 2011 at 06:58:56PM -0800, Nghia Ho wrote:
> Thanks for that. I've been playing around with it a bit and noticed some 
> possible short comings, probably due to my lack of knowledge. It seems every 
> time you call the orc generated function there is some overheard that makes it 
> perform no better than straight C code for simple stuff. Like for example this 
> function that adds a scalar value to an array of float.
> 
> .function add_scalar
> .dest 4 dst float
> .source 4 src float
> .floatparam 4 val
> addf dst, src, val
> 
> is slower then simply doing something like
> 
> for(int i=0; i < N; i++) 
>       data[i] += val;
> 
> An example of the execution time for 100,000 loops are:
> 
> orc: 26.264 ms
> normal: 0.47 ms

Orc compiles the code the first time you execute it.  So I'm not
surprised at this result, if you only took one measurement.



David