[Bug middle-end/16660] attribute((aligned)) doesn't work for variables on the stack for greater than required alignement

[hjl at lucon dot org]

------- Comment #12 from hjl at lucon dot org  2007-10-04 00:01 -------
(In reply to comment #11)

> This only helps x86 really.  If you look at my patch, it already implements
> (correctly) handling large cases like 128byte alignment (which people use with
> the Cell).  What you are proposing will cause more stack to be used than
> actually required and more complex for the normal case.  If you look at my
> patch, you will see it handles 1-4 issues nicely without any problems (because
> the stack itself is not realigned).  Oh on PPC, the stack pointer has to be
> correct so you cannot use frame pointer to be the old stack pointer.

Does your patch handle register spill which needs a larger alignment? What
is the impact of your approach on performance when stack alignment is needed
for local variable as well as register spill?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16660