[Bug target/78445] New: [7 Regression] ICE in maybe_gen_insn, at optabs.c:7014

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78445

            Bug ID: 78445
           Summary: [7 Regression] ICE in maybe_gen_insn, at optabs.c:7014
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---
            Target: x86_64-pc-linux-gnu

gcc-7.0.0-alpha20161120 snapshot ICEs when compiling the following reduced
snippet w/ -O2 (-O3, -Ofast) -mavx2 -ftree-loop-if-convert -ftree-vectorize:

int gp;

void
s3 (int io)
{
  int *nz = gp;

  while (gp != 0)
    if (io != 0)
      {
        *nz = gp;
        io = *nz;
      }
    else
      io = gp;
}

% x86_64-pc-linux-gnu-gcc-7.0.0-alpha20161120 -mavx2 -O2 -ftree-loop-if-convert
-ftree-vectorize -w -c hwbr0lsy.c
hwbr0lsy.c: In function 's3':
hwbr0lsy.c:11:13: internal compiler error: in maybe_gen_insn, at optabs.c:7014
         *nz = gp;
         ~~~~^~~~