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Re: [PATCH] Pass down branch probability through dojump.c functions (PR middle-end/42233)


On Thu, Feb 18, 2010 at 12:20 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> Hi!
>
> While the gimple_boolify patch I've just sent fixes the regression
> on the case where __builtin_expect's second argument is 0, when it is 1
> there is another problem - add_reg_br_prob_note is a hack which can only
> handle the most simple jumps, in particular it doesn't handle the case when
> there is more than one jump and on the testcase from this PR we have two
> jumps.
>
> The following patch fixes it by passing down probability from
> expand_gimple_cond (or other callers that know probabilities) down to
> the myriad of dojump.c functions down to do_compare_rtx_and_jump
> and inserts REG_BR_PROB note there. ?The passed PROB argument is
> the probability of jump to the if_true_label in functions that
> have 2 label arguments, or -1 if REG_BR_PROB note should not be inserted
> (when probability is unknown).
>
> Bootstrapped/regtested on x86_64-linux and i686-linux. ?Ok for trunk?
>
> 2010-02-18 ?Jakub Jelinek ?<jakub@redhat.com>
>
> ? ? ? ?PR middle-end/42233
> ? ? ? ?* expr.h (jumpifnot, jumpifnot_1, jumpif, jumpif_1, do_jump,
> ? ? ? ?do_jump_1, do_compare_rtx_and_jump): Add PROB argument.
> ? ? ? ?* dojump.c: Include output.h.
> ? ? ? ?(inv): New inline function.
> ? ? ? ?(jumpifnot, jumpifnot_1, jumpif, jumpif_1, do_jump_1, do_jump,
> ? ? ? ?do_jump_by_parts_greater_rtx, do_jump_by_parts_greater,
> ? ? ? ?do_jump_by_parts_zero_rtx, do_jump_by_parts_equality_rtx,
> ? ? ? ?do_jump_by_parts_equality, do_compare_and_jump): Add PROB
> ? ? ? ?argument, pass it down to other calls.
> ? ? ? ?(do_compare_rtx_and_jump): Likewise. ?If PROB is not -1,
> ? ? ? ?add REG_BR_PROB note to the conditional jump.
> ? ? ? ?* cfgexpand.c (add_reg_br_prob_note): Removed.
> ? ? ? ?(expand_gimple_cond): Don't call it, add the probability
> ? ? ? ?as last argument to jumpif_1/jumpifnot_1.
> ? ? ? ?* Makefile.in (dojump.o): Depend on output.h.
> ? ? ? ?* builtins.c (expand_errno_check): Adjust do_compare_rtx_and_jump
> ? ? ? ?callers.
> ? ? ? ?* expmed.c (emit_store_flag_force, do_cmp_and_jump): Likewise.
> ? ? ? ?* stmt.c (do_jump_if_equal): Likewise.
> ? ? ? ?* cfgrtl.c (rtl_lv_add_condition_to_bb): Likewise.
> ? ? ? ?* loop-unswitch.c (compare_and_jump_seq): Likewise.
> ? ? ? ?* config/rs6000/rs6000.c (rs6000_aix_emit_builtin_unwind_init):
> ? ? ? ?Likewise.
> ? ? ? ?* optabs.c (expand_doubleword_shift, expand_abs): Likewise.
> ? ? ? ?* expr.c (expand_expr_real_1): Adjust do_jump, jumpifnot and
> ? ? ? ?jumpifnot_1 callers.
> ? ? ? ?(expand_expr_real_2): Adjust jumpifnot_1 and do_compare_rtx_and_jump
> ? ? ? ?callers.
> ? ? ? ?(store_expr): Adjust jumpifnot caller.
> ? ? ? ?(store_constructor): Adjust jumpif caller.

This caused:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43121


H.J.


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