[RFC PATCH 05/19] powerpc/32: Use load and store multiple in GPR save/restore macros

[Nicholas Piggin]

On Thu Nov 3, 2022 at 6:26 PM AEST, Christophe Leroy wrote:
> It contradicts commit a85c728cb5e1 ("powerpc/32: Don't use lmw/stmw for 
> saving/restoring non volatile regs")

Hmm okay. Do you want to keep the #ifdef case in ppc_save_regs for ppc32
to save ~124 bytes of text? I don't mind either way.

Thanks,
Nick

>
> Le 31/10/2022 à 06:54, Nicholas Piggin a écrit :
> > ---
> >   arch/powerpc/include/asm/ppc_asm.h | 18 ++++++++++++++++--
> >   1 file changed, 16 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
> > index 753a2757bcd4..ac44383d350a 100644
> > --- a/arch/powerpc/include/asm/ppc_asm.h
> > +++ b/arch/powerpc/include/asm/ppc_asm.h
> > @@ -57,8 +57,22 @@
> >   #define SAVE_NVGPRS(base)		SAVE_GPRS(14, 31, base)
> >   #define REST_NVGPRS(base)		REST_GPRS(14, 31, base)
> >   #else
> > -#define SAVE_GPRS(start, end, base)	OP_REGS stw, 4, start, end, base, GPR0
> > -#define REST_GPRS(start, end, base)	OP_REGS lwz, 4, start, end, base, GPR0
> > +.macro __SAVE_GPRS start, end, base, offset
> > +	.if \end == 31
> > +		stmw	\start,\offset(\base)
> > +	.else
> > +		OP_REGS stw, 4, \start, \end, \base, \offset
> > +	.endif
> > +.endm
> > +.macro __REST_GPRS start, end, base, offset
> > +	.if \end == 31
> > +		lmw	\start,\offset(\base)
> > +	.else
> > +		OP_REGS lwz, 4, \start, \end, \base, \offset
> > +	.endif
> > +.endm
> > +#define SAVE_GPRS(start, end, base)	__SAVE_GPRS start, end, base, GPR0
> > +#define REST_GPRS(start, end, base)	__REST_GPRS start, end, base, GPR0
> >   #define SAVE_NVGPRS(base)		SAVE_GPRS(13, 31, base)
> >   #define REST_NVGPRS(base)		REST_GPRS(13, 31, base)
> >   #endif