Too many math instructions for SM2.0

Hi,

today I tried writing a simple Mandelbrot and Julia Shader. That worked but on the platform Windows Phone I got an error. I read that it only supports SM2.0. But with SM2.0 I got following error:

Shader error in 'Custom/Julia': Too many math instructions for SM2.0 (67 needed, max is 64). Try #pragma target 3.0 at line 54 (on d3d11_9x)​

Do you know any workaround for this problem? With only 64 Math instructions I can’t get really far.


Greetings

Johannes

 

There really isn't a workaround unless you can do your shader in some form of multi-pass or multi-buffer form (ie: write out the first set of calculations to a texture, then use that as the input in a second shader).

That said, your only 3 instructions off - you'll likely be able to shave that off..

 

Only solution is to optimise or multipass it.

It's a vector based unit, so abuse that first, then rearrange for assembly op's to aid the rather clumsy compiler. Even stupid stuff eg, MAD explicitly where possible...
This: A = (B*C) + D;
Not this: A = D + B*C;
I know that looks like a bathtub full of retard, but when shaving cycles it's always worth doing this first.