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From: "law at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/78655] gcc doesn't exploit the fact that the result of pointer addition can not be nullptr Date: Wed, 12 Jan 2022 19:21:12 +0000 [thread overview] Message-ID: <bug-78655-4-SSns4X33W9@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-78655-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78655 --- Comment #11 from Jeffrey A. Law <law at gcc dot gnu.org> --- We can assume that the result of a POINTER_PLUS is non-null if either argument is non-null. So X + constant is always non-null. X + Y would be non-null if either X or Y is known to be non-null. If we know that X + Y is non-null via some mechanism (for example the result was dereferenced), then we know that X and Y are non-null.
next prev parent reply other threads:[~2022-01-12 19:21 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <bug-78655-4@http.gcc.gnu.org/bugzilla/> 2020-11-13 14:46 ` amacleod at redhat dot com 2022-01-12 16:33 ` amacleod at redhat dot com 2022-01-12 19:21 ` law at gcc dot gnu.org [this message] 2022-01-13 7:20 ` rguenth at gcc dot gnu.org 2022-01-13 13:43 ` amacleod at redhat dot com 2022-11-16 15:46 ` amacleod at redhat dot com 2022-11-17 7:47 ` rguenther at suse dot de 2022-11-17 14:35 ` amacleod at redhat dot com 2022-11-17 14:47 ` rguenther at suse dot de 2022-11-17 15:47 ` amacleod at redhat dot com
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