diff mbox series

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

Message ID 20221031055440.3594315-6-npiggin@gmail.com (mailing list archive)
State Superseded
Headers show
Series Remove STACK_FRAME_OVERHEAD | expand

Commit Message

Nicholas Piggin Oct. 31, 2022, 5:54 a.m. UTC 
---
 arch/powerpc/include/asm/ppc_asm.h | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

Comments

Christophe Leroy Nov. 3, 2022, 8:26 a.m. UTC | #1 
It contradicts commit a85c728cb5e1 ("powerpc/32: Don't use lmw/stmw for 
saving/restoring non volatile regs")

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
Nicholas Piggin Nov. 7, 2022, 12:45 p.m. UTC | #2 
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
Christophe Leroy Nov. 7, 2022, 12:51 p.m. UTC | #3 
Le 07/11/2022 à 13:45, Nicholas Piggin a écrit :
> 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.

I think you can make ppc_save_regs() generic.

I don't think the lmw/stmw is worth it in ppc_save_regs(), just drop it.

Christophe

> 
> 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
>
diff mbox series

Patch

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