On Tue, May 10, 2011 at 7:50 PM, Nathan Froyd <froy...@codesourcery.com> wrote: > On Tue, May 10, 2011 at 02:28:06PM -0300, Diego Novillo wrote: >> On Tue, May 10, 2011 at 13:15, Nathan Froyd <froy...@codesourcery.com> wrote: >> > Other types can of course be shrunk, but the memory savings from doing >> > so will be negligible >> >> Have you done any measurements on the potential savings? > > Only back-of-the-envelope. I will try to get some numbers after we > start saving memory. :) > >> > +static void >> > +lto_input_ts_type_common_tree_pointers (struct lto_input_block *ib, >> > + struct data_in *data_in, tree expr) >> > +{ >> > + TYPE_SIZE (expr) = lto_input_tree (ib, data_in); >> > + TYPE_SIZE_UNIT (expr) = lto_input_tree (ib, data_in); >> > + TYPE_ATTRIBUTES (expr) = lto_input_tree (ib, data_in); >> > + TYPE_NAME (expr) = lto_input_tree (ib, data_in); >> > + /* Do not stream TYPE_POINTER_TO or TYPE_REFERENCE_TO. */ >> >> Add some wording as to why not? This was copied from existing >> comments, but I do not remember why we were doing this. Not too >> critical, anyway. > > I'm not entirely sure; I'm not intimately familiar with how LTO > streaming works. lto.c's lto_ft_type and lto_ft_common purport to > recreate TYPE_{POINTER,REFERENCE}_TO, but I don't immediately see how > that's supposed to work. I can imagine that we ought to be able to > recreate those fields after reading everything in, and that's why don't > stream them; I just don't know where that's done.
Yes, we're re-creating them to avoid streaming all pointer types that might be unused before streaming. One nit: +struct GTY(()) tree_type_non_common { + struct tree_type_with_lang_specific common; shouldn't that field be named w_lang_specific or something like that, instead of re-using common? Richard. > -Nathan >