On 10/2/19 3:15 AM, Richard Biener wrote: > External Email > > ---------------------------------------------------------------------- > On Wed, Oct 2, 2019 at 1:43 AM Gary Oblock <gobl...@marvell.com> wrote: >> I'm working on structure reorganization optimizations and one of the >> things that needs to happen is that pointers to arrays of structures >> need to be modified into either being an integer of a structure depending >> on which optimization is required. >> >> I'm seeing something similar happening in omp-low.c where the code in >> install_var_field and fixup_child_record_type both seem to rebuild the >> entire type from scratch if a field is either added or modified. Wouldn't >> it be possible simply modify the field(s) in question and rerun layout_type? >> >> I suspect the answer will be no but reasons as to why that wouldn't work >> will probably be equally valuable to me. > I think it's undesirable at least. When last discussing "structure reorg" > I was always arguing that trying to change the "type" is the wrong angle > to look at (likewise computing something like "type escape"). It's > really individual objects you are transforming and that you need to track > so there may be very well instances of the original type T plus the > modified type T' in the program after the transform. > > Richard. > >> Thanks, >> >> Gary Oblock >> I answered Richard privately yesterday but I was wondering if anybody else had any ideas about modifying type fields. Note, I agreed with Richard and assured him I was already planning to do things that way but I still don't see any reason why rebuilding a type (it's clone of the other type) is better than modifying it. I take my inspiration for relayout_decl and just want to create what in essence would be a relayout_type.
Gary
