This is the mail archive of the gcc-help@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: GCC optimization bug?

From: Anubhav Sharma <anubhav at cse dot iitb dot ac dot in>
To: Mason <slash dot tmp at free dot fr>, GCC help <gcc-help at gcc dot gnu dot org>
Date: Tue, 17 Jan 2017 16:51:55 +0530
Subject: Re: GCC optimization bug?
Authentication-results: sourceware.org; auth=none
References: <8bd91f0702cba1bb8ea712e572a52c3b@cse.iitb.ac.in> <3b1dbcdc-ec2f-e235-2780-648f5d04f997@free.fr>

Can someone elaborate what -fno-strict-overflow is supposed to do andhow it differs from -fwrapv? Since the documentation says that with-fstrict-overflow overflow with signed numbers is undefined, wouldn'tthat make overflow with signed numbers *not* undefined with-fno-strict-overflow?


On Tuesday 17 January 2017 04:19 PM, Mason wrote:

-fstrict-overflow
>
>Allow the compiler to assume strict signed overflow rules, depending
>on the language being compiled. For C (and C++) this means that
>overflow when doing arithmetic with signed numbers is undefined,
>which means that the compiler may assume that it does not happen.

References:
- GCC optimization bug?
  - From: anubhav
- Re: GCC optimization bug?
  - From: Mason

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]