Description of problem: The list of i586 only CPUs in the Fedora 12 release notes is incorrect. The Geode GX does support CMOV, in fact I think all Cyrix and MediaGX/Geode processors that have MMX have CMOV too. Also, AMD K6 and older should be added to the list. Here is my list: * Intel Pentium MMX and older * AMD K6 and older * pre-MMX Cyrix CPUs (including older MediaGX) * Ezra and Samuel core VIA C3 and all older Centaur processors * All Rise processors
Thanks for reporting this issue. Just double checking, is this the section that you are referring to in your bug report? http://docs.fedoraproject.org/release-notes/f12/en-US/html-single/#sect-Release_Notes-Architecture_Specific_Notes_686 ? thanks, ryanlerch
Yes
Via C3 is i686
Even VIA Samuel is an i686 CPU
Except that it isn't, since it lacks most 686 features, including CMOV. I consider it a 586 CPU in a 686 socket.
Has this been resolved?
I'm having trouble finding too much info about the Geode GX. Do you have a cite or a cpu that shows that it has cmov? I know the LX and NX do. The AMD K6 and older sounds like a good addition to me.
So, the RNs now read as follows: ------ For Fedora 12, we are switching to i686 as the base architecture (including CMOV), and optimize for Atom processors. This means we will loose support for the following CPU families: * Intel i586 (all) * Intel Pentium MMX and older * National Semiconductor Geode processors * VIA C3 (Ezra and Samuel Cores) and all older Centaur processors * AMD Geode GX * AMD K6 and older * pre-MMX Cyrix processors including older MediaGX * All Rise processors AMD Geode LX (as used in the OLPC XO laptop) and later Geode NX processors should still work. Those interested are, of course, welcome to set up a secondary arch for older processors ------ errors. duplication?
"I'm having trouble finding too much info about the Geode GX. Do you have a cite or a cpu that shows that it has cmov? I know the LX and NX do." Geode GX databook is here: http://www.amd.com/files/connectivitysolutions/geode/geode_gx/31505E_gx_databook.zip "* National Semiconductor Geode processors" "* AMD Geode GX" Both do support CMOV, since the MediaGXm does.
ok, that sounds reasonable to me. Notting made the list we used I think, so CC'ing him here to get a sanity check.
As an aside, it's 'lose support', not 'loose support'. I'm not sure why you would distinguish 'Pentium MMX' from 'i586'. As for Geode GX, I seem to recall reading that while it 'supported' cmov from an instruction standpoint, the implementation on that chip didn't actually work right. But I can't find a reference now, so might as well go with the data sheet.
BTW, you can find older chip datasheets here: http://datasheet.chipdb.org That is how I got the datasheets for the Centaur, Cyrix, Rise, and Transmeta CPUs.
F12 notes were corrected with the best information we could get, although agreement on appropriate CPUs seems hard to come by.