Re: [COMMITTED 03/16] Make some Value_Range's explicitly integer.

[Richard Biener <richard.guenther@gmail.com>]

On Sun, Apr 28, 2024 at 9:07 PM Aldy Hernandez <aldyh@redhat.com> wrote:
>
> Fix some Value_Range's that we know ahead of time will be only
> integers.  This avoids using the polymorphic Value_Range unnecessarily

But isn't Value_Range a variable-size irange but int_range<2> doesn't
support more than two sub-ranges?

So it doesn't look obvious that this isn't actually a regression?

Richard.

> gcc/ChangeLog:
>
>         * gimple-ssa-warn-access.cc (check_nul_terminated_array): Make Value_Range an int_range.
>         (memmodel_to_uhwi): Same
>         * tree-ssa-loop-niter.cc (refine_value_range_using_guard): Same.
>         (determine_value_range): Same.
>         (infer_loop_bounds_from_signedness): Same.
>         (scev_var_range_cant_overflow): Same.
> ---
>  gcc/gimple-ssa-warn-access.cc |  4 ++--
>  gcc/tree-ssa-loop-niter.cc    | 12 ++++++------
>  2 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/gcc/gimple-ssa-warn-access.cc b/gcc/gimple-ssa-warn-access.cc
> index dedaae27b31..450c1caa765 100644
> --- a/gcc/gimple-ssa-warn-access.cc
> +++ b/gcc/gimple-ssa-warn-access.cc
> @@ -330,7 +330,7 @@ check_nul_terminated_array (GimpleOrTree expr, tree src, tree bound)
>    wide_int bndrng[2];
>    if (bound)
>      {
> -      Value_Range r (TREE_TYPE (bound));
> +      int_range<2> r (TREE_TYPE (bound));
>
>        get_range_query (cfun)->range_of_expr (r, bound);
>
> @@ -2816,7 +2816,7 @@ memmodel_to_uhwi (tree ord, gimple *stmt, unsigned HOST_WIDE_INT *cstval)
>      {
>        /* Use the range query to determine constant values in the absence
>          of constant propagation (such as at -O0).  */
> -      Value_Range rng (TREE_TYPE (ord));
> +      int_range<2> rng (TREE_TYPE (ord));
>        if (!get_range_query (cfun)->range_of_expr (rng, ord, stmt)
>           || !rng.singleton_p (&ord))
>         return false;
> diff --git a/gcc/tree-ssa-loop-niter.cc b/gcc/tree-ssa-loop-niter.cc
> index c6d010f6d89..cbc9dbc5a1f 100644
> --- a/gcc/tree-ssa-loop-niter.cc
> +++ b/gcc/tree-ssa-loop-niter.cc
> @@ -214,7 +214,7 @@ refine_value_range_using_guard (tree type, tree var,
>    get_type_static_bounds (type, mint, maxt);
>    mpz_init (minc1);
>    mpz_init (maxc1);
> -  Value_Range r (TREE_TYPE (varc1));
> +  int_range<2> r (TREE_TYPE (varc1));
>    /* Setup range information for varc1.  */
>    if (integer_zerop (varc1))
>      {
> @@ -368,7 +368,7 @@ determine_value_range (class loop *loop, tree type, tree var, mpz_t off,
>        gphi_iterator gsi;
>
>        /* Either for VAR itself...  */
> -      Value_Range var_range (TREE_TYPE (var));
> +      int_range<2> var_range (TREE_TYPE (var));
>        get_range_query (cfun)->range_of_expr (var_range, var);
>        if (var_range.varying_p () || var_range.undefined_p ())
>         rtype = VR_VARYING;
> @@ -382,7 +382,7 @@ determine_value_range (class loop *loop, tree type, tree var, mpz_t off,
>
>        /* Or for PHI results in loop->header where VAR is used as
>          PHI argument from the loop preheader edge.  */
> -      Value_Range phi_range (TREE_TYPE (var));
> +      int_range<2> phi_range (TREE_TYPE (var));
>        for (gsi = gsi_start_phis (loop->header); !gsi_end_p (gsi); gsi_next (&gsi))
>         {
>           gphi *phi = gsi.phi ();
> @@ -408,7 +408,7 @@ determine_value_range (class loop *loop, tree type, tree var, mpz_t off,
>                      involved.  */
>                   if (wi::gt_p (minv, maxv, sgn))
>                     {
> -                     Value_Range vr (TREE_TYPE (var));
> +                     int_range<2> vr (TREE_TYPE (var));
>                       get_range_query (cfun)->range_of_expr (vr, var);
>                       if (vr.varying_p () || vr.undefined_p ())
>                         rtype = VR_VARYING;
> @@ -4367,7 +4367,7 @@ infer_loop_bounds_from_signedness (class loop *loop, gimple *stmt)
>
>    low = lower_bound_in_type (type, type);
>    high = upper_bound_in_type (type, type);
> -  Value_Range r (TREE_TYPE (def));
> +  int_range<2> r (TREE_TYPE (def));
>    get_range_query (cfun)->range_of_expr (r, def);
>    if (!r.varying_p () && !r.undefined_p ())
>      {
> @@ -5426,7 +5426,7 @@ scev_var_range_cant_overflow (tree var, tree step, class loop *loop)
>    if (!def_bb || !dominated_by_p (CDI_DOMINATORS, loop->latch, def_bb))
>      return false;
>
> -  Value_Range r (TREE_TYPE (var));
> +  int_range<2> r (TREE_TYPE (var));
>    get_range_query (cfun)->range_of_expr (r, var);
>    if (r.varying_p () || r.undefined_p ())
>      return false;
> --
> 2.44.0
>