Andrew Walrond <[EMAIL PROTECTED]> writes: > If I have a gcc configured for i686-* target system and I use that compiler > to > build a package without any -m submodel options , is the generated code > 1) only suitable for i686 and better, or > 2) tuned for i686 and better but still OK for i386
The latter. Configuring for i686-* is equivalent to configuring for i386-* with the option --with-cpu=i686. This causes the compiler to be built as though you specified -mtune=i686 for each compile which does not explicitly use -mtune, -march, or -mcpu. > Whatever the answer, is it a generic rule that holds true for submodels of > all > architectures? It should always be true, although of course there may be bugs. > What about 32bit code generated with x86_64 targeted gcc (with -m32)? If you configure for x86-64, I believe the default architecture will be MMX, SSE, and SSE2. I believe that will apply even if you use -m32. But I haven't really tested it. Ian
