From: Stefan Agner <stefan@agner.ch>
To: linux@armlinux.org.uk
Cc: clang-built-linux@googlegroups.com, arnd@arndb.de,
ard.biesheuvel@linaro.org, ndesaulniers@google.com,
linux-kernel@vger.kernel.org, Stefan Agner <stefan@agner.ch>,
jiancai@google.com, yamada.masahiro@socionext.com,
manojgupta@google.com, robin.murphy@arm.com,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 0/3] ARM: make use of UAL VFP mnemonics when possible
Date: Sun, 19 Apr 2020 14:35:48 +0200 [thread overview]
Message-ID: <cover.1587299429.git.stefan@agner.ch> (raw)
To build the kernel with Clang's integrated assembler the VFP code needs
to make use of the unified assembler language (UAL) VFP mnemonics.
At first I tried to get rid of the co-processor instructions to access
the floating point unit along with the macros completely. However, due
to missing FPINST/FPINST2 argument support in older binutils versions we
have to keep them around. Once we drop support for binutils 2.24 and
older, the move to UAL VFP mnemonics will be straight forward with this
changes applied.
Tested using Clang with integrated assembler as well as external
(binutils assembler), various gcc/binutils version down to 4.7/2.23.
Disassembled and compared the object files in arch/arm/vfp/ to make
sure this changes leads to the same code. Besides different inlining
behavior I was not able to spot a difference.
In v2 the check for FPINST argument support is now made in Kconfig.
--
Stefan
Stefan Agner (3):
ARM: use .fpu assembler directives instead of assembler arguments
ARM: use VFP assembler mnemonics in register load/store macros
ARM: use VFP assembler mnemonics if available
arch/arm/Kconfig | 2 ++
arch/arm/Kconfig.assembler | 6 ++++++
arch/arm/include/asm/vfp.h | 2 ++
arch/arm/include/asm/vfpmacros.h | 31 ++++++++++++++++++++++---------
arch/arm/vfp/Makefile | 2 --
arch/arm/vfp/vfphw.S | 31 ++++++++++++++++++++-----------
arch/arm/vfp/vfpinstr.h | 23 +++++++++++++++++++----
7 files changed, 71 insertions(+), 26 deletions(-)
create mode 100644 arch/arm/Kconfig.assembler
--
2.25.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2020-04-19 12:36 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-19 12:35 Stefan Agner [this message]
2020-04-19 12:35 ` [PATCH v2 1/3] ARM: use .fpu assembler directives instead of assembler arguments Stefan Agner
2020-04-19 14:04 ` Russell King - ARM Linux admin
2020-04-19 12:35 ` [PATCH v2 2/3] ARM: use VFP assembler mnemonics in register load/store macros Stefan Agner
2020-04-19 12:35 ` [PATCH v2 3/3] ARM: use VFP assembler mnemonics if available Stefan Agner
2020-04-19 14:12 ` [PATCH v2 0/3] ARM: make use of UAL VFP mnemonics when possible Russell King - ARM Linux admin
2020-04-19 21:20 ` Stefan Agner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=cover.1587299429.git.stefan@agner.ch \
--to=stefan@agner.ch \
--cc=ard.biesheuvel@linaro.org \
--cc=arnd@arndb.de \
--cc=clang-built-linux@googlegroups.com \
--cc=jiancai@google.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=manojgupta@google.com \
--cc=ndesaulniers@google.com \
--cc=robin.murphy@arm.com \
--cc=yamada.masahiro@socionext.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).