On Thu, Feb 21, 2013 at 1:10 AM, Steven Bosscher <stevenb....@gmail.com> wrote: > Hello, > > The attached patch splits a new function df_insn_info_delete from > df_insn_delete. The original motivation was to get rid of the silly > "deleting insn with uid = ..." messages when re-scanning an insn, > because the mentioned insn isn't deleted at all (it's just rescanned). > But it turns out that there is also a modest but measurable speed-up > (especially at -O0), probably because of avoiding the overhead of > df_grow_bb_info and df_grow_reg_info in common usage of > df_insn_delete. > > Bootstrapped&tested on powerpc64-unknown-linux-gnu and on > x86_64-unknown-linux-gnu. OK for trunk?
+/* Delete all of the refs information from the insn with UID. + Internal helper for df_insn_info_delete, df_insn_rescan, and other df_insn_delete I suppose + df-scan routines that don't have to work in deferred mode and don't + have to mark basic blocks for re-processing. */ -void -df_insn_delete (basic_block bb, unsigned int uid) +static void +df_insn_info_delete (unsigned int uid) { +/* Delete all of the refs information from INSN, either right now + or marked for later in deferred mode. + + FIXME: BB must be passed in, to mark the basic block containing + the insn as dirty, but emit-rtl.c doesn't do so. */ you mean the remove_insn call? So it should call df_insn_info_delete instead? It _does_ mark the block as dirtly later, if it is not a debug insn. Your change changes behavior for df->changeable_flags & DF_DEFER_INSN_RESCAN btw, so it needs someone DF aware to review and that makes it stage1 material as well I think. It's also odd how insn_info == NULL is handled here. Richard. > Ciao! > Steven