This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: A potential bug in lra-constraints.c for special_memory_constraint?
- From: David Miller <davem at davemloft dot net>
- To: qing dot zhao at oracle dot com
- Cc: ebotcazou at adacore dot com, gcc-patches at gcc dot gnu dot org
- Date: Wed, 12 Jul 2017 08:28:22 -0700 (PDT)
- Subject: Re: A potential bug in lra-constraints.c for special_memory_constraint?
- Authentication-results: sourceware.org; auth=none
- References: <1B4A781A-504A-4816-9D0B-55F4385853BC@oracle.com> <1655796.mGOc87GxxA@polaris> <E96C34DC-7ABF-458B-A0DC-A79B278741F1@oracle.com>
From: Qing Zhao <qing.zhao@oracle.com>
Date: Wed, 12 Jul 2017 08:49:52 -0500
> and it also clearly mentioned that “specially aligned memory might
> use this constraint”.
It guarantees the achieve the opposite of what you are trying to do.
That is, it can be used to guarantee that something is aligned to a
multiple of X or greater.
What you want is to know that something is guaranteed to be
aligned less strongly that X. And that invariant is not
provided for.