linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Adrian Ratiu <adrian.ratiu@collabora.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Nathan Chancellor <natechancellor@gmail.com>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Russell King <linux@armlinux.org.uk>,
	Ard Biesheuvel <ardb@kernel.org>,
	Arvind Sankar <nivedita@alum.mit.edu>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	kernel@collabora.com,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [PATCH v3 RESEND 2/2] arm: lib: xor-neon: move pragma options to makefile
Date: Mon, 18 Jan 2021 12:55:57 +0200	[thread overview]
Message-ID: <20210118105557.186614-3-adrian.ratiu@collabora.com> (raw)
In-Reply-To: <20210118105557.186614-1-adrian.ratiu@collabora.com>

Using a pragma like GCC optimize is a bad idea because it tags
all functions with an __attribute__((optimize)) which replaces
optimization options rather than appending so could result in
dropping important flags. Not recommended for production use.

Because these options should always be enabled for this file,
it's better to set them via command line. tree-vectorize is on
by default in Clang, but it doesn't hurt to make it explicit.

Suggested-by: Arvind Sankar <nivedita@alum.mit.edu>
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
---
 arch/arm/lib/Makefile   |  2 +-
 arch/arm/lib/xor-neon.c | 10 ----------
 2 files changed, 1 insertion(+), 11 deletions(-)

diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 6d2ba454f25b..12d31d1a7630 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -45,6 +45,6 @@ $(obj)/csumpartialcopyuser.o:	$(obj)/csumpartialcopygeneric.S
 
 ifeq ($(CONFIG_KERNEL_MODE_NEON),y)
   NEON_FLAGS			:= -march=armv7-a -mfloat-abi=softfp -mfpu=neon
-  CFLAGS_xor-neon.o		+= $(NEON_FLAGS)
+  CFLAGS_xor-neon.o		+= $(NEON_FLAGS) -ftree-vectorize -Wno-unused-variable
   obj-$(CONFIG_XOR_BLOCKS)	+= xor-neon.o
 endif
diff --git a/arch/arm/lib/xor-neon.c b/arch/arm/lib/xor-neon.c
index e1e76186ec23..62b493e386c4 100644
--- a/arch/arm/lib/xor-neon.c
+++ b/arch/arm/lib/xor-neon.c
@@ -14,16 +14,6 @@ MODULE_LICENSE("GPL");
 #error You should compile this file with '-march=armv7-a -mfloat-abi=softfp -mfpu=neon'
 #endif
 
-/*
- * Pull in the reference implementations while instructing GCC (through
- * -ftree-vectorize) to attempt to exploit implicit parallelism and emit
- * NEON instructions.
- */
-#ifdef CONFIG_CC_IS_GCC
-#pragma GCC optimize "tree-vectorize"
-#endif
-
-#pragma GCC diagnostic ignored "-Wunused-variable"
 #include <asm-generic/xor.h>
 
 struct xor_block_template const xor_block_neon_inner = {
-- 
2.30.0


      parent reply	other threads:[~2021-01-18 10:58 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-18 10:55 [PATCH v3 RESEND 0/2] xor-neon: Remove GCC warn & pragmas Adrian Ratiu
2021-01-18 10:55 ` [PATCH v3 RESEND 1/2] arm: lib: xor-neon: remove unnecessary GCC < 4.6 warning Adrian Ratiu
2021-01-18 11:06   ` Arnd Bergmann
2021-01-18 11:28     ` Adrian Ratiu
2021-01-18 11:33       ` Arnd Bergmann
2021-01-18 10:55 ` Adrian Ratiu [this message]

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=20210118105557.186614-3-adrian.ratiu@collabora.com \
    --to=adrian.ratiu@collabora.com \
    --cc=ardb@kernel.org \
    --cc=arnd@arndb.de \
    --cc=clang-built-linux@googlegroups.com \
    --cc=kernel@collabora.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=natechancellor@gmail.com \
    --cc=ndesaulniers@google.com \
    --cc=nivedita@alum.mit.edu \
    /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).