> >> > * config/rs6000/rs6000.c (emit_unlikely_jump): Adjust to new branch > >> > probability data type. > >> > > >> > Index: rs6000.c > >> > =================================================================== > >> > --- rs6000.c (revision 249839) > >> > +++ rs6000.c (working copy) > >> > @@ -23514,10 +23514,9 @@ > >> > static void > >> > emit_unlikely_jump (rtx cond, rtx label) > >> > { > >> > - int very_unlikely = REG_BR_PROB_BASE / 100 - 1; > >> > rtx x = gen_rtx_IF_THEN_ELSE (VOIDmode, cond, label, pc_rtx); > >> > rtx_insn *insn = emit_jump_insn (gen_rtx_SET (pc_rtx, x)); > >> > - add_int_reg_note (insn, REG_BR_PROB, very_unlikely); > >> > + add_int_reg_note (insn, REG_BR_PROB, > >> > profile_probability::very_unlikely ()); > >> > >> Hmmm isn't this very unlikely to work :) ? > >> > >> I used this as inspiration to do this for the arm ports but > >> add_int_reg_note expects an integer but very_unlikely returns > >> profile_probability ... > > > > It probably should be converted using to_reg_br_prob_base ? > > The comments in profile-count.h state that this should go away. > > We need advice from Honza about the preferred way to transform these idioms.
I plan to change REG_BR_PROB notes to preserve all information from profile_probability (this is needed to make RTL expansion splitting work as expected), but for now they are still just REG_BR_PROB_BASE fixpoint. I think the code can stay as it is. I will add APIs for emitting/interpretting br_prob_nodes as followup (after debugging fixing issues with profile updating which I can now detect with the new type) Thanks for looking into this. Honza > > Thanks, David