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Re: Proposed resolution to aliasing issue.
- From: Andrew Pinski <pinskia at physics dot uc dot edu>
- To: Mark Mitchell <mark at codesourcery dot com>
- Cc: gcc mailing list <gcc at gcc dot gnu dot org>
- Date: Wed, 11 May 2005 17:41:31 -0400
- Subject: Re: Proposed resolution to aliasing issue.
- References: <428251FD.7030702@codesourcery.com>
On May 11, 2005, at 2:42 PM, Mark Mitchell wrote:
Our proposed approach is to -- by default -- assume that "g" may
access all of "b". However, in the event that the corresponding
parameter to "g" has an attribute (name TBD, possibly the same as the
one that appears in Danny's recent patch), then we may assume that "g"
(and its callees) do not use the pointer to obtain access to any
fields of "b".
For example:
void g(A *p __attribute__((X)));
void f() {
B b;
g(&b.a); /* Compiler may assume the rest of b is not accessed
in "g". */
}
If we go with this proposal, please make sure that all of the un-nested
structs are marked with attribute as this is where I see where most of
the benefit.
Thanks,
Andrew Pinski