VECT: Apply LEN_MASK_GATHER_LOAD/SCATTER_STORE into vectorizer

VECT: Apply LEN_MASK_GATHER_LOAD/SCATTER_STORE into vectorizer

Hi, Richard and Richi.

Address comments from Richi.

Make gs_info.ifn = LEN_MASK_GATHER_LOAD/LEN_MASK_SCATTER_STORE.

I have fully tested these 4 format:

length = vf is a dummpy length,
mask = {-1,-1, ... } is a dummy mask.

1. no length, no mask
   LEN_MASK_GATHER_LOAD (..., length = vf, mask = {-1,-1,...})
2. exist length, no mask
   LEN_MASK_GATHER_LOAD (..., len, mask = {-1,-1,...})
3. exist mask, no length
   LEN_MASK_GATHER_LOAD (..., length = vf, mask)
4. both mask and length exist
   LEN_MASK_GATHER_LOAD (..., length, mask)

All of these work fine in this patch.

Here is the example:

void
f (int *restrict a,
   int *restrict b, int n,
   int base, int step,
   int *restrict cond)
{
  for (int i = 0; i < n; ++i)
    {
      if (cond[i])
        a[i * 4] = b[i];
    }
}

Gimple IR:

  <bb 3> [local count: 105119324]:
  _58 = (unsigned long) n_13(D);

  <bb 4> [local count: 630715945]:
  # vectp_cond.7_45 = PHI <vectp_cond.7_46(4), cond_14(D)(3)>
  # vectp_b.11_51 = PHI <vectp_b.11_52(4), b_15(D)(3)>
  # vectp_a.14_55 = PHI <vectp_a.14_56(4), a_16(D)(3)>
  # ivtmp_59 = PHI <ivtmp_60(4), _58(3)>
  _61 = .SELECT_VL (ivtmp_59, POLY_INT_CST [2, 2]);
  ivtmp_44 = _61 * 4;
  vect__4.9_47 = .LEN_MASK_LOAD (vectp_cond.7_45, 32B, _61, 0, { -1, ... });
  mask__24.10_49 = vect__4.9_47 != { 0, ... };
  vect__8.13_53 = .LEN_MASK_LOAD (vectp_b.11_51, 32B, _61, 0, mask__24.10_49);
  ivtmp_54 = _61 * 16;
  .LEN_MASK_SCATTER_STORE (vectp_a.14_55, { 0, 16, 32, ... }, 1, vect__8.13_53, _61, 0, mask__24.10_49);
  vectp_cond.7_46 = vectp_cond.7_45 + ivtmp_44;
  vectp_b.11_52 = vectp_b.11_51 + ivtmp_44;
  vectp_a.14_56 = vectp_a.14_55 + ivtmp_54;
  ivtmp_60 = ivtmp_59 - _61;
  if (ivtmp_60 != 0)
    goto <bb 4>; [83.33%]
  else
    goto <bb 5>; [16.67%]

Ok for trunk ?

gcc/ChangeLog:

	* internal-fn.cc (internal_fn_len_index): Apply
	LEN_MASK_GATHER_LOAD/SCATTER_STORE into vectorizer.
	(internal_fn_mask_index): Ditto.
	* optabs-query.cc (supports_vec_gather_load_p): Ditto.
	(supports_vec_scatter_store_p): Ditto.
	* tree-vect-data-refs.cc (vect_gather_scatter_fn_p): Ditto.
	* tree-vect-patterns.cc (vect_recog_gather_scatter_pattern): Ditto.
	* tree-vect-stmts.cc (check_load_store_for_partial_vectors): Ditto.
	(vect_get_strided_load_store_ops): Ditto.
	(vectorizable_store): Ditto.
	(vectorizable_load): Ditto.