On Mon, Aug 22, 2011 at 12:07 PM, Jakub Jelinek <ja...@redhat.com> wrote: > On Mon, Aug 22, 2011 at 11:57:18AM +0200, Richard Guenther wrote: >> And at some point the idea popped up to just dump this whole re-using >> mem-attrs. There is at most a single function in RTL but the whole program >> is available in SSA, so the memory overhead must be small. > > Some functions are extremely large though. Do you mean that MEM itself would > be > enlarged to have the MEM_ATTRS field so that one operand is the address, > then expr, then HWI size, offset, etc.? Because if the mem attrs aren't > shared any longer, it doesn't make sense to keep the indirection. > I still fear we have way too many MEMs in RTL that this would be noticeable.
It would be interesting to have numbers about the amount of sharing that happens - might be not trivial though, as some re-uses would be able to simply modify the attr inplace. Richard. > Jakub >
