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From:   David Laight <David.Laight@ACULAB.COM>
To:     'Adrian Ratiu' <adrian.ratiu@collabora.com>,
        "linux-arm-kernel@lists.infradead.org" 
        <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" <kernel@collabora.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v4 1/2] arm: lib: xor-neon: remove unnecessary GCC < 4.6
 warning
Thread-Topic: [PATCH v4 1/2] arm: lib: xor-neon: remove unnecessary GCC < 4.6
 warning
Thread-Index: AQHW7mdkBLnG67vUeU6WLdpsKRa/+qovgJKw
Date:   Tue, 19 Jan 2021 22:04:20 +0000
Message-ID: <3dbc2ce713e44e3a9a913db5446506a8@AcuMS.aculab.com>
References: <20210119131724.308884-1-adrian.ratiu@collabora.com>
 <20210119131724.308884-2-adrian.ratiu@collabora.com>
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From: Adrian Ratiu
> Sent: 19 January 2021 13:17
> To: linux-arm-kernel@lists.infradead.org
> 
> Drop warning because kernel now requires GCC >= v4.9 after
> commit 6ec4476ac825 ("Raise gcc version requirement to 4.9")
> and clarify that -ftree-vectorize now always needs enabling
> for GCC by directly testing the presence of CONFIG_CC_IS_GCC.
...
> -#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
> +#ifdef CONFIG_CC_IS_GCC
>  #pragma GCC optimize "tree-vectorize"
> -#else

I thought that #pragma optimise was very likely to remove
a random subset of the command line parameters leading to
incorrect/unexpected code.

As such the extra option needs to passed in as a per source
file compiler option.

	David

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