[Bug c/111760] New: risc-v regression: COND_LEN_* incorrect fold/simplify in middle-end

["juzhe.zhong at rivai dot ai" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111760

            Bug ID: 111760
           Summary: risc-v regression: COND_LEN_* incorrect fold/simplify
                    in middle-end
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: juzhe.zhong at rivai dot ai
  Target Milestone: ---

FAIL: gcc.dg/vect/vect-cond-arith-2.c -flto -ffat-lto-objects  scan-tree-dump
optimized " = \\.COND_(LEN_)?SUB"
FAIL: gcc.dg/vect/vect-cond-arith-2.c scan-tree-dump optimized " =
\\.COND_(LEN_)?SUB"

https://godbolt.org/z/hEz51qf6a

double __GIMPLE (ssa, startwith("loop"))
neg_xi (double *x)
{
  int i;
  long unsigned int index;
  long unsigned int offset;
  double * xi_ptr;
  double xi;
  double neg_xi;
  double res;
  unsigned int ivtmp;

 __BB(5):
  goto __BB2;

 __BB(2):
  res_1 = __PHI (__BB5: 0.0, __BB3: res_2);
  i_4 = __PHI (__BB5: 0, __BB3: i_5);
  ivtmp_6 = __PHI (__BB5: 100U, __BB3: ivtmp_7);
  index = (long unsigned int) i_4;
  offset = index * 8UL;
  xi_ptr = x_8(D) + offset;
  xi = *xi_ptr;
  neg_xi = -xi;
  res_2 = neg_xi + res_1;
  i_5 = i_4 + 1;
  ivtmp_7 = ivtmp_6 - 1U;
  if (ivtmp_7 != 0U)
    goto __BB3;
  else
    goto __BB4;

 __BB(3):
  goto __BB2;

 __BB(4):
  res_3 = __PHI (__BB2: res_2);
  return res_3;
}

There is no COND_LEN_ADD IR here which is incorrect.