Did you remember to swap the order of the array dimensions? FORTRAN stores arrays in column-major order, while Pascal uses row-major, correct? This will affect cache hits and misses...
On Oct 25, 2004, at 10:02 AM, Waldek Hebisch wrote:
Silvio a Beccara wrote:
I ran some tests that make extensive use of large (up to 10000 elements) arrays, up to three dimensions both in GPC and in Fortran (Intel). Even turning on optimisations, GPC is at least five times slower than Fortran in completing the tests. Anyone can tell me why, and possibly some way to make GPC recover some of this lag?
There are many reasons why GPC may be slower and many ways to speed up programs. Post the code (or a link if it is large) -- otherwise all what we can say would be pure speculation. Also, it may be usefull to compare GNU Fortran and Intel Fortran -- since GNU Pascal and GNU Fortran use the same backend, such comparison would separate effect of different language from differences in backends.
-- Waldek Hebisch hebisch@math.uni.wroc.pl
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