Re: [PATCH] [s390]: Use .rept directive to store/load fpu registers

From: Heiko Carstens
Date: Mon Sep 07 2015 - 10:14:06 EST


On Tue, Sep 01, 2015 at 09:51:32AM +0200, Christian Borntraeger wrote:
> Am 28.08.2015 um 15:49 schrieb Alexander Kuleshov:
> > arch/s390/kernel/swsusp.S | 49 ++++++++++++++++-------------------------------
> > 1 file changed, 17 insertions(+), 32 deletions(-)
> >
> > diff --git a/arch/s390/kernel/swsusp.S b/arch/s390/kernel/swsusp.S
> > index ca62946..8011e14 100644
> > --- a/arch/s390/kernel/swsusp.S
> > +++ b/arch/s390/kernel/swsusp.S
> > @@ -48,22 +48,15 @@ ENTRY(swsusp_arch_suspend)
> > /* Store registers */
> > mvc 0x318(4,%r1),__SF_EMPTY(%r15) /* move prefix to lowcore */
> > stfpc 0x31c(%r1) /* store fpu control */
> > - std 0,0x200(%r1) /* store f0 */
> > - std 1,0x208(%r1) /* store f1 */
> > - std 2,0x210(%r1) /* store f2 */
> > - std 3,0x218(%r1) /* store f3 */
> > - std 4,0x220(%r1) /* store f4 */
> > - std 5,0x228(%r1) /* store f5 */
> > - std 6,0x230(%r1) /* store f6 */
> > - std 7,0x238(%r1) /* store f7 */
> > - std 8,0x240(%r1) /* store f8 */
> > - std 9,0x248(%r1) /* store f9 */
> > - std 10,0x250(%r1) /* store f10 */
> > - std 11,0x258(%r1) /* store f11 */
> > - std 12,0x260(%r1) /* store f12 */
> > - std 13,0x268(%r1) /* store f13 */
> > - std 14,0x270(%r1) /* store f14 */
> > - std 15,0x278(%r1) /* store f15 */
> > +
> > + /* store f0..f15 floating point registers */
> > + .set i, 0
> > + .set f, 0x200
> > + .rept 16
> > + std i, f(%r1)
> > + .set i, (i+1)
> > + .set f, (f+0x8)
> > + .endr
>
> I personally find the existing code easier to read, especially as it matches the
> assembler output and I can directly where the slots are, (e.g. f11 is 0x258)

Yes, I agree with Christian. Let's keep the code as it is.

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