From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Guo Ren <ren_guo@c-sky.com>,
Linux-Arch <linux-arch@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Jason Cooper <jason@lakedaemon.net>,
c-sky_gcc_upstream@c-sky.com, gnu-csky@mentor.com,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
wbx@uclibc-ng.org, Greentime Hu <green.hu@gmail.com>
Subject: Re: [PATCH V3 13/26] csky: Library functions
Date: Thu, 6 Sep 2018 17:50:02 +0200 [thread overview]
Message-ID: <CAMuHMdW3GhYGPnPf0ph=ZbVpNqiYhAsSMni7SKTC1ZC9zTUUxw@mail.gmail.com> (raw)
In-Reply-To: <CAK8P3a1xUhyQohifsvs_3th-iPCGL9WKDGj9qKoEaizuu19FeA@mail.gmail.com>
On Thu, Sep 6, 2018 at 4:25 PM Arnd Bergmann <arnd@arndb.de> wrote:
> On Wed, Sep 5, 2018 at 2:08 PM Guo Ren <ren_guo@c-sky.com> wrote:
> > --- /dev/null
> > +++ b/arch/csky/abiv1/memset.c
> > @@ -0,0 +1,38 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
> > +#include <linux/types.h>
> > +
> > +void *memset(void *dest, int c, size_t l)
> > +{
> > + char *d = dest;
> > + int ch = c;
> > + int tmp;
> > +
> > + if ((long)d & 0x3)
> > + while (l--) *d++ = ch;
while ((uintptr_t)d & 0x3) && l--)
*d++ =ch;
and remove the else below?
> > + else {
> > + ch &= 0xff;
> > + tmp = (ch | ch << 8 | ch << 16 | ch << 24);
> > +
> > + while (l >= 16) {
> > + *(((long *)d)) = tmp;
> > + *(((long *)d)+1) = tmp;
> > + *(((long *)d)+2) = tmp;
> > + *(((long *)d)+3) = tmp;
s/long/u32/
> > + l -= 16;
> > + d += 16;
> > + }
> > +
> > + while (l > 3) {
> > + *(((long *)d)) = tmp;
> > + d = d + 4;
> > + l -= 4;
> > + }
> > +
> > + while (l) {
> > + *d++ = ch;
> > + l--;
> > + }
> > + }
> > + return dest;
> > +}
>
> I see that we have a trivial memset() implementation in lib/string.c, but yours
> seems to be better optimized. Where did you get it from? Is this a version
> that works particularly well on C-Sky, or is this a generic optimized memset
> that others could use as well? In the latter case, we could add it to
> lib/string.c and let architectures select it in place of the triivial version.
Sounds good to me, after removing the 32-bit-isms.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2018-09-06 15:50 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-05 12:07 [PATCH V3 00/26] C-SKY(csky) Linux Kernel Port Guo Ren
2018-09-05 12:07 ` [PATCH V3 01/26] csky: Build infrastructure Guo Ren
2018-09-05 12:07 ` [PATCH V3 02/26] csky: defconfig Guo Ren
2018-09-06 13:58 ` Arnd Bergmann
2018-09-07 1:43 ` Guo Ren
2018-09-05 12:07 ` [PATCH V3 03/26] csky: Kernel booting Guo Ren
2018-09-05 12:07 ` [PATCH V3 04/26] csky: Exception handling Guo Ren
2018-09-05 12:07 ` [PATCH V3 05/26] csky: System Call Guo Ren
2018-09-06 14:10 ` Arnd Bergmann
2018-09-07 1:47 ` Guo Ren
2018-09-05 12:07 ` [PATCH V3 06/26] csky: Cache and TLB routines Guo Ren
2018-09-06 14:31 ` Arnd Bergmann
2018-09-07 3:04 ` Guo Ren
2018-09-07 8:14 ` Arnd Bergmann
2018-09-07 12:55 ` Guo Ren
2018-09-07 14:13 ` Arnd Bergmann
2018-09-08 2:20 ` Guo Ren
2018-09-05 12:07 ` [PATCH V3 07/26] csky: MMU and page table management Guo Ren
2018-09-05 12:07 ` [PATCH V3 08/26] csky: Process management and Signal Guo Ren
2018-09-05 12:07 ` [PATCH V3 09/26] csky: VDSO and rt_sigreturn Guo Ren
2018-09-06 14:02 ` Arnd Bergmann
2018-09-07 3:07 ` Guo Ren
2018-09-05 12:07 ` [PATCH V3 10/26] csky: IRQ handling Guo Ren
2018-09-06 13:39 ` Thomas Gleixner
2018-09-10 7:30 ` Guo Ren
2018-09-05 12:07 ` [PATCH V3 11/26] csky: Atomic operations Guo Ren
2018-09-05 12:07 ` [PATCH V3 12/26] csky: ELF and module probe Guo Ren
2018-09-05 12:07 ` [PATCH V3 13/26] csky: Library functions Guo Ren
2018-09-06 14:24 ` Arnd Bergmann
2018-09-06 15:50 ` Geert Uytterhoeven [this message]
2018-09-07 5:14 ` Guo Ren
2018-09-07 5:08 ` Guo Ren
2018-09-05 12:07 ` [PATCH V3 14/26] csky: User access Guo Ren
2018-09-05 12:07 ` [PATCH V3 15/26] csky: Debug and Ptrace GDB Guo Ren
2018-09-05 12:07 ` [PATCH V3 16/26] csky: SMP support Guo Ren
2018-09-05 12:07 ` [PATCH V3 17/26] csky: Misc headers Guo Ren
2018-09-06 14:16 ` Arnd Bergmann
2018-09-07 5:17 ` Guo Ren
2018-09-07 8:01 ` Arnd Bergmann
2018-09-07 8:08 ` Guo Ren
2018-09-05 12:07 ` [PATCH V3 18/26] dt-bindings: csky CPU Bindings Guo Ren
2018-09-06 0:37 ` Rob Herring
2018-09-06 1:49 ` Guo Ren
2018-09-05 12:07 ` [PATCH V3 19/26] dt-bindings: timer: gx6605s SOC timer Guo Ren
2018-09-06 0:47 ` Rob Herring
2018-09-06 2:02 ` Guo Ren
2018-09-07 6:41 ` Guo Ren
2018-09-05 12:07 ` [PATCH V3 20/26] dt-bindings: timer: C-SKY Multi-processor timer Guo Ren
2018-09-05 12:08 ` [PATCH V3 21/26] dt-bindings: interrupt-controller: C-SKY APB intc Guo Ren
2018-09-06 0:43 ` Rob Herring
2018-09-06 2:12 ` Guo Ren
2018-09-06 13:05 ` Arnd Bergmann
2018-09-07 5:40 ` Guo Ren
2018-09-07 15:13 ` Rob Herring
2018-09-08 2:05 ` Guo Ren
2018-09-05 12:08 ` [PATCH V3 22/26] dt-bindings: interrupt-controller: C-SKY SMP intc Guo Ren
2018-09-06 0:45 ` Rob Herring
2018-09-06 2:23 ` Guo Ren
2018-09-06 13:03 ` Arnd Bergmann
2018-09-07 6:07 ` Guo Ren
2018-09-05 12:08 ` [PATCH V3 23/26] clocksource: add gx6605s SOC system timer Guo Ren
2018-09-05 12:08 ` [PATCH V3 24/26] clocksource: add C-SKY SMP timer Guo Ren
2018-09-05 12:08 ` [PATCH V3 25/26] clocksource: add C-SKY timers' build infrastructure Guo Ren
2018-09-05 12:08 ` [PATCH V3 26/26] irqchip: add C-SKY irqchip drivers Guo Ren
2018-09-06 14:35 ` [PATCH V3 00/26] C-SKY(csky) Linux Kernel Port Arnd Bergmann
2018-09-07 2:08 ` Guenter Roeck
2018-09-07 6:40 ` Guo Ren
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