Handle polynomial DR_INIT

The idea with the main 107-patch poly_int series (latterly 109-patch)
was to change the mode sizes and vector element counts to poly_int and
then propagate those changes as far as they needed to go to fix build
failures from incompatible types.  This means that DR_INIT is now
constructed as a poly_int64:

  poly_int64 pbytepos;
  if (!multiple_p (pbitpos, BITS_PER_UNIT, &pbytepos))
    {
      if (dump_file && (dump_flags & TDF_DETAILS))
	fprintf (dump_file, "failed: bit offset alignment.\n");
      return false;
    }
  [...]
  init = ssize_int (pbytepos);

This patch adjusts other references to DR_INIT accordingly.  Unlike
the above, the adjustments weren't needed to avoid a build-time type
incompatibility, but they are needed to make the producer and consumers
of DR_INIT logically consistent.

Tested on aarch64-linux-gnu, x86_64-linux-gnu and powerpc64le-linux-gnu.
Also tested by comparing the before-and-after assembly output for at
least one target per CPU directory.  OK to install?

Thanks,
Richard


2018-01-12  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* tree-predcom.c (aff_combination_dr_offset): Use wi::to_poly_widest
	rather than wi::to_widest for DR_INITs.
	* tree-vect-data-refs.c (vect_find_same_alignment_drs): Use
	wi::to_poly_offset rather than wi::to_offset for DR_INIT.
	(vect_analyze_data_ref_accesses): Require both DR_INITs to be
	INTEGER_CSTs.
	(vect_analyze_group_access_1): Note that here.

On Fri, Jan 12, 2018 at 2:47 PM, Richard Sandiford
<richard.sandiford@linaro.org> wrote:
> The idea with the main 107-patch poly_int series (latterly 109-patch)
> was to change the mode sizes and vector element counts to poly_int and
> then propagate those changes as far as they needed to go to fix build
> failures from incompatible types.  This means that DR_INIT is now
> constructed as a poly_int64:
>
>   poly_int64 pbytepos;
>   if (!multiple_p (pbitpos, BITS_PER_UNIT, &pbytepos))
>     {
>       if (dump_file && (dump_flags & TDF_DETAILS))
>         fprintf (dump_file, "failed: bit offset alignment.\n");
>       return false;
>     }
>   [...]
>   init = ssize_int (pbytepos);
>
> This patch adjusts other references to DR_INIT accordingly.  Unlike
> the above, the adjustments weren't needed to avoid a build-time type
> incompatibility, but they are needed to make the producer and consumers
> of DR_INIT logically consistent.
>
> Tested on aarch64-linux-gnu, x86_64-linux-gnu and powerpc64le-linux-gnu.
> Also tested by comparing the before-and-after assembly output for at
> least one target per CPU directory.  OK to install?

Ok.

Richard.

> Thanks,
> Richard
>
>
> 2018-01-12  Richard Sandiford  <richard.sandiford@linaro.org>
>
> gcc/
>         * tree-predcom.c (aff_combination_dr_offset): Use wi::to_poly_widest
>         rather than wi::to_widest for DR_INITs.
>         * tree-vect-data-refs.c (vect_find_same_alignment_drs): Use
>         wi::to_poly_offset rather than wi::to_offset for DR_INIT.
>         (vect_analyze_data_ref_accesses): Require both DR_INITs to be
>         INTEGER_CSTs.
>         (vect_analyze_group_access_1): Note that here.
>
> Index: gcc/tree-predcom.c
> ===================================================================
> --- gcc/tree-predcom.c  2018-01-12 13:45:27.360582269 +0000
> +++ gcc/tree-predcom.c  2018-01-12 13:45:27.533575091 +0000
> @@ -680,7 +680,7 @@ aff_combination_dr_offset (struct data_r
>
>    tree_to_aff_combination_expand (DR_OFFSET (dr), type, offset,
>                                   &name_expansions);
> -  aff_combination_const (&delta, type, wi::to_widest (DR_INIT (dr)));
> +  aff_combination_const (&delta, type, wi::to_poly_widest (DR_INIT (dr)));
>    aff_combination_add (offset, &delta);
>  }
>
> Index: gcc/tree-vect-data-refs.c
> ===================================================================
> --- gcc/tree-vect-data-refs.c   2018-01-12 13:45:27.360582269 +0000
> +++ gcc/tree-vect-data-refs.c   2018-01-12 13:45:27.533575091 +0000
> @@ -2227,9 +2227,9 @@ vect_find_same_alignment_drs (struct dat
>      return;
>
>    /* Two references with distance zero have the same alignment.  */
> -  offset_int diff = (wi::to_offset (DR_INIT (dra))
> -                    - wi::to_offset (DR_INIT (drb)));
> -  if (diff != 0)
> +  poly_offset_int diff = (wi::to_poly_offset (DR_INIT (dra))
> +                         - wi::to_poly_offset (DR_INIT (drb)));
> +  if (maybe_ne (diff, 0))
>      {
>        /* Get the wider of the two alignments.  */
>        unsigned int align_a = (vect_calculate_target_alignment (dra)
> @@ -2239,7 +2239,7 @@ vect_find_same_alignment_drs (struct dat
>        unsigned int max_align = MAX (align_a, align_b);
>
>        /* Require the gap to be a multiple of the larger vector alignment.  */
> -      if (!wi::multiple_of_p (diff, max_align, SIGNED))
> +      if (!multiple_p (diff, max_align))
>         return;
>      }
>
> @@ -2475,6 +2475,7 @@ vect_analyze_group_access_1 (struct data
>        gimple *prev = stmt;
>        HOST_WIDE_INT diff, gaps = 0;
>
> +      /* By construction, all group members have INTEGER_CST DR_INITs.  */
>        while (next)
>          {
>            /* Skip same data-refs.  In case that two or more stmts share
> @@ -2864,6 +2865,11 @@ vect_analyze_data_ref_accesses (vec_info
>                                    TREE_TYPE (DR_REF (drb))))
>             break;
>
> +         /* Check that the DR_INITs are compile-time constants.  */
> +         if (TREE_CODE (DR_INIT (dra)) != INTEGER_CST
> +             || TREE_CODE (DR_INIT (drb)) != INTEGER_CST)
> +           break;
> +
>           /* Sorting has ensured that DR_INIT (dra) <= DR_INIT (drb).  */
>           HOST_WIDE_INT init_a = TREE_INT_CST_LOW (DR_INIT (dra));
>           HOST_WIDE_INT init_b = TREE_INT_CST_LOW (DR_INIT (drb));