Hi, Riccardo Mottola wrote: > > This causes a big issue if you want to compile a non-Altivec build on > a capable processor like the G4: it will automatically enabled even if > you don't want. > E.g. if I want to build on a G4 a binary working on the G3, I can't. I > specify -mcpu=750 -mtune=750, but the compiler will accept -maltivec > and create an incompatible binary.
I actually just tested and "debian shipped firefox" fires an illegal instruction on a G3, so it is having a similar issue than my own ArcticFox builds. I also did a test and tried to compile on my G3 (and yes, it is an old iBook which has a classic non-altivec 750 PPC, GX if I am right) and -maltivec gets just accepted by gcc 10 now. So, essentially Adrian's patch is wrong in concept: you cannot use the compiler even on a native CPU to test for altivec This means double-issue: using a higher-spec'd CPU cannot be used to compile for a lower-spec, but also a native build will fail. I would try to follow to possibilities: - just a "hard switch" like --enable-altivec --disable-altivec for PCP - try to parse the optimization flas one might extra use, so if the compiler is invoked with "gcc -maltivec" (common practive) a HAVE_ALTIVEC build is automatically enabled What do you think? Riccardo
