On Fri, Aug 27, 2010 at 5:02 PM, Corey Kasten <co...@materialintelligencellc.com> wrote: > On Fri, 2010-08-27 at 06:50 -0700, Nathan Froyd wrote: >> On Fri, Aug 27, 2010 at 09:44:25AM -0400, Corey Kasten wrote: >> > I find that the executable compiled on system A runs faster (on both >> > systems) than the executable compiled on system B (on both system), by a >> > factor about approximately 4 times. I have attempted to play with the >> > GCC optimizer flags and have not been able to get System B (with the >> > later GCC version) to compile code with any better performance. Could >> > someone please help figure this out? >> >> It's almost impossible to tell what's going on without an actual >> testcase. You might not be able to provide the actual code, but you >> could try distilling it down to something you could release. >> >> -Nathan > > Thanks for the reply Nathan. > > I have attached an archive with the test case code. The code is built by > build.sh and outputs the number of microseconds to complete the > processing. > > Compiling with GCC version "4.1.2 20070925 (Red Hat 4.1.2-33)" produces > code that runs in about 66% of the time than does GCC version "4.3.0 > 20080428 (Red Hat 4.3.0-8)"
-fcx-limited-range or -fcx-fortran-rules. 4.3 now is more conforming than 4.1. Richard. > Thanks > > Corey >
