From: Yury Gribov <y.gribov@samsung.com>
To: Jakub Jelinek <jakub@redhat.com>, Marat Zakirov <m.zakirov@samsung.com>
Cc: GCC Mailing List <gcc@gcc.gnu.org>,
Richard Biener <richard.guenther@gmail.com>
Subject: Re: [RFC] UBSan unsafely uses VRP
Date: Wed, 12 Nov 2014 08:42:00 -0000 [thread overview]
Message-ID: <54631D7F.80301@samsung.com> (raw)
In-Reply-To: <20141111141521.GE5026@tucnak.redhat.com>
On 11/11/2014 05:15 PM, Jakub Jelinek wrote:
>> There are also some unsafe code in functions
>> ubsan_expand_si_overflow_addsub_check, ubsan_expand_si_overflow_mul_check
>> which uses get_range_info to reduce checks number. As seen before vrp usage
>> for sanitizers may decrease quality of error detection.
>
> Using VRP is completely intentional there, we don't want to generate too
> slow code if you decide you want to optimize your code (for -O0 VRP isn't
> performed of course).
On the other hand detection quality is probably more important than
important regardless of optimization level. When I use a checker, I
don't want it to miss bugs due to overly aggressive optimization.
I wish we had some test to check that sanitizer optimizations are indeed
conservative.
-Y
next prev parent reply other threads:[~2014-11-12 8:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-11 14:03 Marat Zakirov
2014-11-11 14:15 ` Jakub Jelinek
2014-11-11 14:26 ` Richard Biener
2014-11-11 16:13 ` Marat Zakirov
2014-11-11 17:04 ` Jakub Jelinek
2014-11-12 8:42 ` Yury Gribov [this message]
2014-11-12 8:45 ` Marek Polacek
2014-11-12 9:58 ` Yury Gribov
2014-11-12 13:27 ` Jakub Jelinek
2014-11-12 13:56 ` Yury Gribov
2014-11-13 13:37 ` Yury Gribov
2014-11-12 10:05 ` Marat Zakirov
2014-11-12 10:06 ` Marek Polacek
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