GNU Fortran

N8TM@aol.com N8TM@aol.com
Fri Jan 22 20:34:00 GMT 1999


In a message dated 1/22/99 1:40:37 PM Pacific Standard Time, d.love@dl.ac.uk
writes:

<<  Ray> IRIX 5.3 (100 mhz IP20 processor)
 
  Ray>    Everything compiled fine, apprears to run ok, but execution
  Ray>    time is horrid. At least 2 time longer than SG f77.
 
 Targeting the wrong CPU, perhaps? >>
My memory is a bit short here.  If the IP20 is like the R8000, there are lots
of scheduling requirements for good performance which g77 and gnu-as can't
deal with, and this kind of performance problem is likely.  With the R10000,
using SGI as, g77 usually gives 80% of the speed of SGI fortran.  As g77
doesn't optimize for any particular mips cpu, you can't expect top performance
on the more esoteric versions.



More information about the Gcc-bugs mailing list