Thread (18 messages) 18 messages, 7 authors, 2021-12-17

Re: [PATCH v2 03/13] sh: remove unaligned access for sh4a

From: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Date: 2021-05-14 10:34:50
Also in: linux-arch, lkml

Hi Arnd!

On 5/14/21 12:00 PM, Arnd Bergmann wrote:
Unlike every other architecture, sh4a uses an inline asm implementation
for get_unaligned(). I have shown that this produces better object
code than the asm-generic version. However, there are very few users of
arch/sh/ overall, and most of those seem to use sh4 rather than sh4a CPU
cores, so it seems not worth keeping the complexity in the architecture
independent code.
My Renesas SH4-Boards actually run an sh4a-Kernel, not an sh4-Kernel:

root@tirpitz:~> uname -a
Linux tirpitz 5.11.0-rc4-00012-g10c03c5bf422 #161 PREEMPT Mon Jan 18 21:10:17 CET 2021 sh4a GNU/Linux
root@tirpitz:~>

So, if this change reduces performance on sh4a, I would rather not merge it.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz@debian.org
`. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913
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