Re: [PATCH] rs6000 branch probability changes

[Ramana Radhakrishnan <ramana.gcc@googlemail.com>]

On Fri, Jun 30, 2017 at 2:36 PM, David Edelsohn <dje.gcc@gmail.com> wrote:
> Convert the rs6000 port to use the new API for branch probabilities.
>
> Okay?
>
> Thanks, David
>
> * 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  ...

regards
Ramana



Ramana

>  }
>
>  /* A subroutine of the atomic operation splitters.  Emit a load-locked