Revert "PowerPC shrink-wrap support 3 of 3"

[Richard Guenther]

On Thu, Nov 10, 2011 at 12:43 PM, Hans-Peter Nilsson
<hans-peter.nilsson@axis.com> wrote:
>> From: Richard Guenther <richard.guenther@gmail.com>
>> Date: Thu, 10 Nov 2011 12:22:56 +0100
>
>> On Thu, Nov 10, 2011 at 11:38 AM, Hans-Peter Nilsson
>> <hans-peter.nilsson@axis.com> wrote:
>> >> From: Hans-Peter Nilsson <hp@axis.com>
>> >> Date: Wed, 9 Nov 2011 09:55:59 +0100
>> >
>> >> > From: Alan Modra <amodra@gmail.com>
>> >> > Date: Tue, 1 Nov 2011 16:33:40 +0100
>> >>
>> >> > On Tue, Nov 01, 2011 at 12:57:22AM +1030, Alan Modra wrote:
>> >>
>> >> >         * function.c (bb_active_p): Delete.
>> >> >         (dup_block_and_redirect, active_insn_between): New functions.
>> >> >         (convert_jumps_to_returns, emit_return_for_exit): New functions,
>> >> >         split out from..
>> >> >         (thread_prologue_and_epilogue_insns): ..here.  Delete
>> >> >         shadowing variables.  Don't do prologue register clobber tests
>> >> >         when shrink wrapping already failed.  Delete all last_bb_active
>> >> >         code.  Instead compute tail block candidates for duplicating
>> >> >         exit path.  Remove these from antic set.  Duplicate tails when
>> >> >         reached from both blocks needing a prologue/epilogue and
>> >> >         blocks not needing such.
>> >> >         * ifcvt.c (dead_or_predicable): Test both flag_shrink_wrap and
>> >> >         HAVE_simple_return.
>> >> >         * bb-reorder.c (get_uncond_jump_length): Make global.
>> >> >         * bb-reorder.h (get_uncond_jump_length): Declare.
>> >> >         * cfgrtl.c (rtl_create_basic_block): Comment typo fix.
>> >> >         (rtl_split_edge): Likewise.  Warning fix.
>> >> >         (rtl_duplicate_bb): New function.
>> >> >         (rtl_cfg_hooks): Enable can_duplicate_block_p and duplicate_block.
>> >>
>> >> This (a revision in the range 181187:181189) broke build for
>> >> cris-elf like so:
>> >> See PR51051.
>> >
>> > Given that this also broke arm-linux-gnueabi, a primary
>> > platform, and Alan being absent until the 15th according to a
>> > message on IRC, I move to revert r181188.
>>
>> Is there a PR for the arm issue?
>
> It's covered by the same PR, see comment #1.
> I've now updated the target field.
>
>> > I think I need someone with appropriate write privileges to
>> > agree with that, and to also give 48h for someone to fix the
>> > problem.  Sorry for not forthcoming on the second point.
>>
>> Did you or somebody else try to look into the problem?  To decide
>> whether it's the "best course of action" it would be nice to know if
>> it's a simple error in the patch that is easy to fix.
>
> Nope, not really.  Wouldn't FWIW, de jure matter, me not having
> write privileges to the affected area.  Though, I had a quick
> look at the patch and nothing stood out except its
> intrusiveness, and it seems the patch wasn't tested on a
> !simple_return target (just "powerpc-linux" according to the
> replied-to message).

Fair enough.  You can count me as "one" then, and I'll defer to Bernd
to either provide a fix or ack the revert.

Thanks,
Richard.

> brgds, H-P
>