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Subject: Re: [tree-ssa] Out of SSA status and issues
From: Diego Novillo <dnovillo@redhat.com>
To: Michael Matz <matz@suse.de>
Cc: Andrew Macleod <amacleod@redhat.com>,
	gcc mailing list <gcc@gcc.gnu.org>
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On Tue, 2003-05-13 at 05:07, Michael Matz wrote:

> An indirect reference is not a copy.  I don't know if tree-ssa thinks it
> is, but it definitely shouldn't.
> 
Why?

     1. foo()
     2. {
     3.   int i, *p;
     4. 
     5.   p = malloc();
     6.   i = *p;
     7.   return i + 9;
     8. }

I see nothing wrong in replacing 'i + 9' with '*p + 9'.  It would
probably not be efficient, but I can't see it being wrong.

Not that tree-ssa will do anything with this code, the default
type-based aliasing is too conservative, but PTA may disambiguate this.


Diego.