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Re: Undefined behavior or gcc is doing additional good job?
- From: Jakub Jelinek <jakub at redhat dot com>
- To: "Bin.Cheng" <amker dot cheng at gmail dot com>
- Cc: "Joseph S. Myers" <joseph at codesourcery dot com>, "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Date: Tue, 7 Jan 2014 09:10:55 +0100
- Subject: Re: Undefined behavior or gcc is doing additional good job?
- Authentication-results: sourceware.org; auth=none
- References: <CAHFci29VzKWxY37Zimq+GE_o4VbC=17cOqfVHu5F_fmsYragmA at mail dot gmail dot com> <20140103082427 dot GS892 at tucnak dot redhat dot com> <CAHFci29L6PS3ZSmM4X+2CcAxofgUXAyMw-bkqkAasFAwySDrXA at mail dot gmail dot com> <20140103091735 dot GX892 at tucnak dot redhat dot com> <CAHFci2_gy9uQzwMqg2s5NePt6c9jPn3SEmi8Rqtphtk5Giqqhg at mail dot gmail dot com>
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
On Tue, Jan 07, 2014 at 04:01:23PM +0800, Bin.Cheng wrote:
> Em, YES, it comes from ivopt rewriting, but, if it's not undefined
> behavior, won't it be annoying (or simply wrong) for compiler to do
> something not written by the code?
If __bss_start of __data_start aren't 32-bit aligned, then it is undefined
behavior, so it is not wrong.
Jakub