[Bug tree-optimization/24169] Address (full struct) escapes even though the called function does not cause it to escape

["dberlin at dberlin dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #2 from dberlin at gcc dot gnu dot org  2006-01-03 14:58 -------
Subject: Re:  Address (full struct) escapes
        even though the called function does not cause it to escape

On Sun, 2006-01-01 at 00:41 +0000, pinskia at gcc dot gnu dot org wrote:
> 
> ------- Comment #1 from pinskia at gcc dot gnu dot org  2006-01-01 00:41 -------
> Just a clarification here, I just want the SFT for k.j to be considered call
> clobbered for this testcase.
> 
This is not anywhere near as easy as you think it is.

In fact, we used to only call clobber k.j.  Because our standards
experts tell us that doing pointer arithmetic magic to get back to k.i
is legal, we could only consider this function to clobber *just* k.j if
the pointer doesn't escape from f, *and* f does not do any pointer
arithmetic on it's arguments.

This is usually *not* the case, making this testcase more or less "not
interesting at all".


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24169