ifcvt/crossjump patch: Fix PR 42496, 21803

[Richard Guenther]

On Thu, Sep 23, 2010 at 5:50 PM, Bernd Schmidt <bernds@codesourcery.com> wrote:
> On 09/23/2010 04:41 PM, Richard Guenther wrote:
>>> I now get an bootstrap fail building Ada on x86_64-linux in
>>>
>>> Program received signal SIGSEGV, Segmentation fault.
>>> 0x0000000000c9ebf6 in df_simulate_one_insn_backwards (bb=0x7ffff3f0ad68,
>>>    insn=0x0, live=0x50bab30)
>>>    at /space/rguenther/src/svn/trunk/gcc/df-problems.c:3640
>>> 3640      if (!NONDEBUG_INSN_P (insn))
>
> It found two matching blocks, each of which had 5 insns, but didn't stop
> there since BB_END was a DEBUG_INSN.  The first insns in the two
> following basic blocks matched, so flow_find_head_matching_sequence
> returned 6.
>
> The following patch should fix it; ok after bootstrap/test?

Ok.

Thanks,
Richard.

>
> Bernd
>