[RyanCahoon]

Originally Posted by Greg McKaskle

I haven't used Pascal in a long time, but seem to remember it storing 2D arrays with different elements adjacent. It was column-major and C was row-major.

I tried reversing the indices and it took 59.1 (vs 11.9) seconds. A couple other websites say Pascal is row-major.

Originally Posted by Ether

I was thinking the extra computation required for this might be the culprit:

#define ELEMENT(M, i,j) (M[(i)*((i)+1)/2+(j)])

I was worried about the same thing. In the most recent version of the code I posted, that macro is only used once (not in a loop) to calculate a pointer to the end of the matrix.