On Thu, 3 Sep 2009, Dave Korn wrote: > Brian Ford wrote: > > On Wed, 2 Sep 2009, Marco Atzeri wrote: > > > >> I have no clue if -march=pentium4 is acceptable for AMD cpu's. > > > > FWIW, we have been using -march=pentium4 -mfpmath=sse successfully in a > > very large software project since November 2003 without incident. We have > > run on AMD Opterons and a variety of Intel processors without issue > > (given that they were at least Pentium 4's, of course). > > If we turn on SSE in the distro, we block anyone using Pentium2 or early > (pre-XP) Athlon CPUs from using Cygwin. I think that might be a step too far.
Just to be clear, I'm neutral with respect to this decision, and I wasn't suggesting it should be done. I only wanted to state that this combination of optimization flags is stable, works on the proper subset of AMD as well as Intel processors, and provides a real world performance benefit when the processor compatibility compromise is deemed acceptable. -- Brian Ford Staff Realtime Software Engineer VITAL - Visual Simulation Systems FlightSafety International the best safety device in any aircraft is a well-trained crew...