[PING] Re: [RFA 1/n] Fix if conversion interactions with block partitioning

Submitted by Matthew Gretton-Dann on Oct. 9, 2012, 1:17 p.m.

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Message ID CADSXKXpL-wyymj07UW6chiVPD-OQpDKqM9Zed09ewWtMD0Ag=w@mail.gmail.com
State New
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Matthew Gretton-Dann Oct. 9, 2012, 1:17 p.m.
PING.

On 24 September 2012 11:34, Matthew Gretton-Dann
<matthew.gretton-dann@linaro.org> wrote:
> On Wednesday 05 September 2012 13:47:19 Steven Bosscher wrote:
>> On Wed, Sep 5, 2012 at 1:25 PM, Matthew Gretton-Dann wrote:
>> > +  /* If the two blocks are in different partitions we do not want to mark
>> > +     this as a fallthru edge.  */
>> > +  if (BB_PARTITION (b) != BB_PARTITION (c))
>> > +    return;
>> > +
>>
>> I think you should look for a REG_CROSSING_JUMP note on BB_END instead
>> of comparing BB_PARTITION.
>
> Sorry for the delay in getting  back to this.
>
> Anyway, I had a look at how other parts of cfgrtl.c handled this and it seems
> as if they do both your suggestion and the check against different partitions.
>
> So this is what I have implemented in the attached patch.
>
> Cross tested arm-none-linux-gnueabi with QEmu.
>
> OK for trunk?
>
> Thanks,
>
> Matt
>
> gcc/ChangeLog:
>
> 2012-09-24  Matthew Gretton-Dann  <matthew.gretton-dann@linaro.org>
>
>         * cfgrtl.c (rtl_tidy_fallthru_edge): Don't tidy edges which
>           cross partitions.
>
> --
> Matthew Gretton-Dann
> Linaro Toolchain Working Group
> matthew.gretton-dann@linaro.org

Patch hide | download patch | download mbox

diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c
index c62b5bc..8fcf7e4 100644
--- a/gcc/cfgrtl.c
+++ b/gcc/cfgrtl.c
@@ -1572,6 +1572,12 @@  rtl_tidy_fallthru_edge (edge e)
     if (INSN_P (q))
       return;
 
+  /* If the two blocks are in different partitions we do not want to mark
+     this as a fallthru edge.  */
+  if (find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX)
+      || BB_PARTITION (b) != BB_PARTITION (c))
+    return;
+
   /* Remove what will soon cease being the jump insn from the source block.
      If block B consisted only of this single jump, turn it into a deleted
      note.  */