Re: [PATCH] sched1: Fix -fcompare-debug issue in schedule_region [PR105586]

[Peter Bergner <bergner@linux.ibm.com>]

On 8/23/22 6:49 AM, Surya Kumari Jangala wrote:
> sched1: Fix -fcompare-debug issue in schedule_region [PR105586]
> 
> In schedule_region(), a basic block that does not contain any real insns
> is not scheduled and the dfa state at the entry of the bb is not copied
> to the fallthru basic block. However a DEBUG insn is treated as a real
> insn, and if a bb contains non-real insns and a DEBUG insn, it's dfa
> state is copied to the fallthru bb. This was resulting in
> -fcompare-debug failure as the incoming dfa state of the fallthru block
> is different with -g. We should always copy the dfa state of a bb to
> it's fallthru bb even if the bb does not contain real insns.
> 
> 2022-08-22  Surya Kumari Jangala  <jskumari@linux.ibm.com>
> 
> gcc/
> 	PR rtl-optimization/105586
> 	* sched-rgn.cc (schedule_region): Always copy dfa state to
> 	fallthru block.


It looks good to me, but I cannot approve it.  That said, you're missing
a ChangeLog entry for your new helper function.  The ChangeLog mentions
what changed, not why it changed.  Maybe something like the following?


gcc/
	PR rtl-optimization/105586
	* sched-rgn.cc (save_state_for_fallthru_edge): New function.
	(schedule_region): Use it for all blocks.


Peter