On Sun, 2005-02-27 at 17:47 -0500, Andrew Pinski wrote: > s the proper way or set of options for me to: > > > > 1) optionally have POWER4 optimisations (that must be independant on > > the rest below) > > 2) be able to use altivec instructions in assembly > > 3) be able to use altivec in a few selected bits of C code > > 4) never have altivec code implicitely generated by the compiler > > Use -mcpu=970 -mno-altivec this will cause not altivec instructions to > be created. -mcpu=970 implies you are compiling for 970 and want the > best code produced.
Ok, but, will the above allow me to explicitely use altivec instructions in the RAID6 code and the assembly ? Also, if I have CONIFG_POWER4 not enabled (which mean I need code that will work on POWER3 for example), what should I use so can I still use altivec instructions in the RAID6 code and assembly ? The problem is that when CONFIG_POWER4 is not set, the kernel should still boot any machine. When CONFIG_POWER4 is set, it's just an optimisation to generate code for POWER4 and later only, but it should have no impact on the kind of code I am _able_ to generate in selected places. Ben.
