[Bug c/87962] New: ice in vect_get_vec_def_for_operand_1, at tree-vect-stmts.c:1485

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87962

            Bug ID: 87962
           Summary: ice in vect_get_vec_def_for_operand_1, at
                    tree-vect-stmts.c:1485
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

For this C code:

int a, b;

int c() {
  long d, e;
  while (a) {
    a++;
    b = 0;
    for (; b++ - 2; d = d >> 1)
      e += d;
  }
  return e;
}

compiled by recent gcc trunk and flags -O3 -march=native, does this:

bug474.c:4:5: internal compiler error: in vect_get_vec_def_for_operand_1, at
tree-vect-stmts.c:1485

This code used to work at revision 265846, but fails at revision 265907.

/proc/cpuinfo says

vendor_id       : AuthenticAMD
cpu family      : 21
model           : 2
model name      : AMD FX(tm)-8350 Eight-Core Processor