On Tue, Mar 16, 2010 at 2:03 PM, Paolo Carlini <paolo.carl...@oracle.com> wrote: > On 03/16/2010 09:58 PM, Jakub Jelinek wrote: >> I don't think it is a good idea to change the meaning of the macros years >> after they have been introduced. >> You could add a different macro if you want. >> Why should be __i686 special? i686 does have __i586 features too, should it >> define also __i586, __i486? > Probably it should, in my opinion. > > But maybe I'm missing something about the whole logic of the recent > changes: wasn't about having the default for an i686 target similar, if > not identical, to passing by hand -march=i686? I'm really, really > confused... How is people supposed to figure out with macros that the > new default configuration supports everything -march=i686 supports vs > the previous status when it was identical to -march=i386?!? > > Paolo. >
Checking __iX86 is a good idea for ISAs since it's meaning isn't well defined nor enforced. For libstdc++ purpose, can you check __SSE2__ in addition to __i686? -- H.J.
