Re: Type estimating Octave Compiler

[David Bateman]

Jens Ruecknagel wrote:

> It is done.
>
> As my Student Diploma Thesis (after 5 years at University in Germany, 
> comparable to a Master) I implemented an Octave to C++ compiler 
> prototype using type estimation techniques. A first benchmark shows 
> that the compiled code executes on average 38 times faster.
>
> The techniques used in this compiler are really interesting, if your 
> interested read the thesis and checkout the compiler, download it from 
> http://ruena.gmxhome.de
>
> Please send me your comments.
>
>
> Jens R�ücknagel


Jens,

This is great, and I really think it has to go into the 2.9.x tree asap. 
I'm sick of speed comparison with the other brand that point up the 
absence of JIT in octave.

I notice a couple of points. Firstly, this is a compiler and not a JIT, 
so the functions have to be compield before use. Would it be possible to 
incorporate the code directly in the interpret in the same way as the 
JIT in matlab? Also I see that you seem to only have implemented the 
add, mul and le operators, and the do-until loop structure. What is the 
workload to implement the rest, relative to where you're at? Could there 
be a fallback to the old means of parsing the code for the cases that 
aren't implemented, rather than a compilation failure as currently 
happens? You also only treat complex/real scalars and matrices, there 
are a large number of additional types that were added after 2.1.57, and 
it seems that these will cause problems with the way the code is 
currently structured.. Finally, you use the matrix_value() method of the 
octave_value class to get a Matrix. However, as octave_matrix is now 
based on the NDArray class, by doing this you loose NDArray support? I 
used for the mul operator this is needed, but not for the add operator....

Great Work
Cheers
David