[Bug target/111488] New: ICE ion riscv gcc.dg/vect/vect-126.c

["rdapp at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111488

            Bug ID: 111488
           Summary: ICE ion riscv gcc.dg/vect/vect-126.c
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rdapp at gcc dot gnu.org
  Target Milestone: ---
            Target: riscv

I see an ICE in vect-126.c.  A small reproducer is:

int *a[1024], b[1024];

void
f1 (void)
{
  for (int i = 0; i < 1024; i++)
    {
      int *p = &b[0];
      a[i] = p + i;
    }
}

vect-126.c:18:1: internal compiler error: Segmentation fault
   18 | }
      | ^
0x111e61f crash_signal
        ../../gcc/toplev.cc:314
0xcfc91d mark_label_nuses
        ../../gcc/emit-rtl.cc:3755
0xcfc969 mark_label_nuses
        ../../gcc/emit-rtl.cc:3763
0xcfc969 mark_label_nuses
        ../../gcc/emit-rtl.cc:3763
0xcfc969 mark_label_nuses
        ../../gcc/emit-rtl.cc:3763

This happens after the splitter
(define_insn_and_split "*single_widen_fma<mode>".

At first glance it seems as if the insn sequence is corrupt as we're looking
into a <nil> value but I haven't checked further.  This is likely the same
error that prevents several SPECfp testcases to build.  Can investigate further
tomorrow.