From: Andi Kleen <andi@firstfloor.org>
To: Mark Wielaard <mark@klomp.org>
Cc: linux-kernel@vger.kernel.org,
Masahiro Yamada <masahiroy@kernel.org>,
Michal Marek <michal.lkml@markovi.net>,
linux-kbuild@vger.kernel.org, Ian Rogers <irogers@google.com>,
linux-toolchains@vger.kernel.org,
Andi Kleen <andi@firstfloor.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Segher Boessenkool <segher@kernel.crashing.org>,
Florian Weimer <fw@deneb.enyo.de>
Subject: Re: [PATCH] Only add -fno-var-tracking-assignments workaround for old GCC versions.
Date: Wed, 14 Oct 2020 08:17:01 -0700 [thread overview]
Message-ID: <20201014151701.vl3gh5e5teb2hqj7@two.firstfloor.org> (raw)
In-Reply-To: <20201014110132.2680-1-mark@klomp.org>
On Wed, Oct 14, 2020 at 01:01:32PM +0200, Mark Wielaard wrote:
> Some old GCC versions between 4.5.0 and 4.9.1 might miscompile code
> with -fvar-tracking-assingments (which is enabled by default with -g -O2).
> commit 2062afb4f added -fno-var-tracking-assignments unconditionally to
> work around this. But newer versions of GCC no longer have this bug, so
> only add it for versions of GCC before 5.0.
Add
... This allows various tools such as a perf probe or gdb debuggers
or systemtap to resolve variable locations using dwarf locations in
more code.
>
> Signed-off-by: Mark Wielaard <mark@klomp.org>
> Acked-by: Ian Rogers <irogers@google.com>
> Cc: linux-toolchains@vger.kernel.org
> Cc: Andi Kleen <andi@firstfloor.org>
> Cc: Nick Desaulniers <ndesaulniers@google.com>
> Cc: Segher Boessenkool <segher@kernel.crashing.org>
> Cc: Florian Weimer <fw@deneb.enyo.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
-Andi
next prev parent reply other threads:[~2020-10-14 15:25 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAP-5=fUT-1-CR-KMMsrpzgw9b3nBooeY05=YU9XKa5enO9SK+A@mail.gmail.com>
2020-10-14 11:01 ` [PATCH] Only add -fno-var-tracking-assignments workaround for old GCC versions Mark Wielaard
2020-10-14 15:17 ` Andi Kleen [this message]
2020-10-17 12:01 ` [PATCH V2] " Mark Wielaard
2020-10-19 19:30 ` Nick Desaulniers
2020-10-20 15:27 ` Masahiro Yamada
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