> -----Original Message-----
> From: Richard Earnshaw
> Sent: Wednesday, June 18, 2014 4:31 PM
> To: Terry Guo
> Cc: gcc-patches@gcc.gnu.org; Ramana Radhakrishnan
> Subject: Re: [Patch, GCC/Thumb-1]Mishandle the label type insn in function
> thumb1_reorg
>
> On 10/06/14 12:42, Terry Guo wrote:
> > Hi There,
> >
> > The thumb1_reorg function use macro INSN_CODE to find expected
> instructions.
> > But the macro INSN_CODE doesn’t work for label type instruction. The
> > INSN_CODE(label_insn) will return the label number. When we have a lot
> of
> > labels and current label_insn is the first insn of basic block, the
> > INSN_CODE(label_insn) could accidentally equal to
> CODE_FOR_cbranchsi4_insn
> > in this case. This leads to ICE due to SET_SRC(label_insn) in subsequent
> > code. In general we should skip all such improper insns. This is the purpose
> > of attached small patch.
> >
> > Some failures in recent gcc regression test on thumb1 target are caused by
> > this reason. So with this patch, all of them passed and no new failures. Is
> > it ok to trunk?
> >
> > BR,
> > Terry
> >
> > 2014-06-10 Terry Guo <terry....@arm.com>
> >
> > * config/arm/arm.c (thumb1_reorg): Move to next basic block if the
> head
> > of current basic block isn’t a proper insn.
> >
>
> I think you should just test that "insn != BB_HEAD (bb)". The loop
> immediately above this deals with the !NON-DEBUG insns, so the logic is
> confusing the way you've written it.
>
> R.
>
Thanks for comments. The patch is updated and tested. No more ICE. Is this one
OK?
BR,
Terry
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 85d2114..463707e 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -16946,7 +16946,8 @@ thumb1_reorg (void)
insn = PREV_INSN (insn);
/* Find the last cbranchsi4_insn in basic block BB. */
- if (INSN_CODE (insn) != CODE_FOR_cbranchsi4_insn)
+ if (insn == BB_HEAD (bb)
+ || INSN_CODE (insn) != CODE_FOR_cbranchsi4_insn)
continue;
/* Get the register with which we are comparing. */
