I noticed that when compiling with -march=geode the code is actually slower than the one generated with generic options (i386 or i686). This happens with any program, not just with dhrystone
# CFLAGS='-march=i386' ./dry.c Dhrystones per Second: 643501 # CFLAGS='-march=i486' ./dry.c Dhrystones per Second: 712251 # CFLAGS='-march=i586' ./dry.c Dhrystones per Second: 711238 # CFLAGS='-march=i686' ./dry.c Dhrystones per Second: 878735 # CFLAGS='-march=geode' ./dry.c Dhrystones per Second: 684932 -- Summary: Code optimized for AMD Geode is slower than generic Product: gcc Version: 4.4.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: rootkit85 at yahoo dot it http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41989