http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52436
--- Comment #4 from Marc Glisse <glisse at gcc dot gnu.org> 2013-04-02 14:08:57 UTC --- (In reply to comment #3) > I'd re-organize it like Ok, I'll try something like that. > it avoids building a tree just to feed it into get_addr_base_and_unit_offset The idea was that there would be almost no cases where this was done and no simplification occurred. If a transformation is indeed done, building one tree is not that expensive, especially if it avoids code duplication. > It also avoids it if the access is not of byte-granularity which > get_addr_base_and_unit_offset does not even consider (it assumes it is fed > the argument of an ADDR_EXPR which obviously is byte-aligned). > > The tree-flow-inline.h bits look ok. In get_addr_base_and_unit_offset_1 I already check if the offset is a multiple of BITS_PER_UNIT, I should probably check that the size is a multiple as well, no? > I'm not sure what you need the forwprop / tree-ssa-propagate changes for. I need something to call fold on a bit_field_ref of a mem_ref. For PR55266, the vector lowering pass produces a mem_ref and a bit_field_ref in two distinct gimple statements, and nothing tries to combine them.
