From patchwork Mon Jul  2 07:20:37 2012
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Subject: RFA: MEP: Fix use of delete_insn.
Date: Sun, 01 Jul 2012 21:20:37 -0000
From: Nick Clifton <nickc@redhat.com>
X-Patchwork-Id: 168505
Message-Id: <4FF14BC5.9010003@redhat.com>
To: DJ Delorie <dj@redhat.com>
Cc: gcc-patches@gcc.gnu.org

Hi DJ,

> We have this at the top of the loop, so I don't think it matters:
>
> 	  next = NEXT_INSN (insn);
> 	  if (GET_CODE (insn) != INSN)
> 	    continue;

Good point.

> However, I think an insn will be skipped if we use NEXT.  Perhaps we
> want PREV?  Or the loop might need to be altered to account for this
> potential skipping.

Hmm, I think that just using the NEXT_INSN at the head of the loop 
should work.  As far as I can tell from looking at the code in 
mep_reorg_remove() we are never going to delete an insn that might 
involve removing more than one real insn, so we do not have to worry 
about side effects.  Hence I would suggest the following alternative patch.

OK to apply ?

Cheers
   Nick


Index: gcc/config/mep/mep.c
===================================================================
--- gcc/config/mep/mep.c	(revision 189108)
+++ gcc/config/mep/mep.c	(working copy)
@@ -5096,7 +5096,7 @@
  					       follow, where))
  		{
  		  count ++;
-		  next = delete_insn (insn);
+		  delete_insn (insn);
  		  if (dump_file)
  		    {
  		      fprintf (dump_file, "\n----- Success!  new insn:\n\n");