Micha Riser wrote:
  >> AFAIK at the time 3.5 was released the available compilers were not
>>able to automatically generate SSE2-optimized code for that particular peace
>>of code, and Intel contributed the hand-optimized code you are referring to.
>>Nowadays the situation is much different since, in particular, the Intel C++
>>compiler greatly improved its optimization framework (the GCC compiler did
>>also improve a lot, though it is still not as good as ICPC at optimizing on
>>the P4 architecture; K8 might be slightly different though).  Therefore,
>>the 3.6 codebase didn't need this hand-optimization any longer.
> 
> That is not true. I have recently studied the sse support of icc and gcc in
> detail. It will not do that kind of optimization (performing the noise
> calculation with SIMD parallel instructions) with the unmodified POV-Ray
> noise code. It still needs much care to the code in order for the compiler
> to do automatic optimization.

Nicolas never said the compiler would turn out the same noise code as the 
hand-optimised version. You constructed this assumption on your own. It does 
not change the fact that the compiler optimization for P4 are a whole lot 
better than they were many years ago, which is the relevant point. What 
comilers do to be faster is not relevant for that Nicolas' statement to be true!

	Thorsten

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