[Bug rtl-optimization/20331] [3.4/4.0/4.1 Regression] Wrong code generation for the argument of the pure function in PIC

[joern dot rennecke at st dot com]

------- Additional Comments From joern dot rennecke at st dot com  2005-03-10 18:18 -------
Subject: Re:  [3.4/4.0/4.1 Regression] Wrong code generation for the argument of the pure function in PIC

rth at gcc dot gnu dot org wrote:

>------- Additional Comments From rth at gcc dot gnu dot org  2005-03-10 13:57 -------
>I'll agree that modified_{in,between}_p need to check the address for changes,
>since that controls the ultimate value that is accessed.
>
>I do not agree that alias.c needs to check the address for changes.  In that
>case we're trying to determine if assigning a value to one memory reference
>can possibly change the value of another memory reference.  Which is false for
>*all* read-only memory.
>
>  
>
After looking a bit more at true_dependence and friends, I think you are 
right; the callers have
checked or will be checking the address.  And apart from the dependency 
functions in alias.c,
I could find only modified_{in,between}_p using MEM_READONLY_P to 
indicate that the
entire MEM doesn't change.



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20331