> -----Original Message----- > From: Linuxppc-dev > [mailto:linuxppc-dev-bounces+david.laight=aculab....@lists.ozl abs.org] On Behalf Of Benjamin Herrenschmidt > Sent: 07 June 2012 07:40 > To: Michael Neuling > Cc: mich...@ellerman.id.au; pau...@samba.org; Anton > Blanchard; o...@lixom.net; linuxppc-dev@lists.ozlabs.org > Subject: Re: [PATCH] powerpc: Optimise the 64bit optimised > __clear_user > > On Thu, 2012-06-07 at 16:05 +1000, Michael Neuling wrote: > > > One problem with this is when we construct the > instructions, like using > > anything from ppc-opcode.h. eg. using PPC_POPCNTB would > need to go from: > > PPC_POPCNTB(r3,r3) > > to: > > PPC_POPCNTB(3,3) > > Which is less readable IMHO. > > Yes, I know. Not much to do about this, but it might still be > worth it, > how much time wasted due to mixing up or with ori in asm somewhere ? > > One option would be to #define R3 (or _r3) for use in those macros so > we still have something nicer than just "3"... oh well.
You then need to catch all the other bugs where a register is being used instead of a constant. Time to make the assembler require %r0 (etc) David _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev