Re: [PATCH 1/3] rtl-ssa: Provide easier access to debug uses [PR113089]

[Richard Sandiford <richard.sandiford@arm.com>]

Alex Coplan <alex.coplan@arm.com> writes:
> This patch adds some accessors to set_info and use_info to make it
> easier to get at and iterate through uses in debug insns.
>
> It is used by the aarch64 load/store pair fusion pass in a subsequent
> patch to fix PR113089, i.e. to update debug uses in the pass.
>
> Bootstrapped/regtested as a series on aarch64-linux-gnu (with/without
> the load/store pair pass enabled), OK for trunk?
>
> gcc/ChangeLog:
>
> 	PR target/113089
> 	* rtl-ssa/accesses.h (use_info::next_debug_insn_use): New.
> 	(debug_insn_use_iterator): New.
> 	(set_info::first_debug_insn_use): New.
> 	(set_info::debug_insn_uses): New.
> 	* rtl-ssa/member-fns.inl (use_info::next_debug_insn_use): New.
> 	(set_info::first_debug_insn_use): New.
> 	(set_info::debug_insn_uses): New.

OK, thanks.

Richard

> ---
>  gcc/rtl-ssa/accesses.h     | 13 +++++++++++++
>  gcc/rtl-ssa/member-fns.inl | 29 +++++++++++++++++++++++++++++
>  2 files changed, 42 insertions(+)
>
> diff --git a/gcc/rtl-ssa/accesses.h b/gcc/rtl-ssa/accesses.h
> index 6a3ecd32848..c57b8a8b7b5 100644
> --- a/gcc/rtl-ssa/accesses.h
> +++ b/gcc/rtl-ssa/accesses.h
> @@ -357,6 +357,10 @@ public:
>    //    next_use () && next_use ()->is_in_any_insn () ? next_use () : nullptr
>    use_info *next_any_insn_use () const;
>  
> +  // Return the next use by a debug instruction, or null if none.
> +  // This is only valid if if is_in_debug_insn ().
> +  use_info *next_debug_insn_use () const;
> +
>    // Return the previous use by a phi node in the list, or null if none.
>    //
>    // This is only valid if is_in_phi ().  It is equivalent to:
> @@ -458,6 +462,8 @@ using reverse_use_iterator = list_iterator<use_info, &use_info::prev_use>;
>  // of use in the same definition.
>  using nondebug_insn_use_iterator
>    = list_iterator<use_info, &use_info::next_nondebug_insn_use>;
> +using debug_insn_use_iterator
> +  = list_iterator<use_info, &use_info::next_debug_insn_use>;
>  using any_insn_use_iterator
>    = list_iterator<use_info, &use_info::next_any_insn_use>;
>  using phi_use_iterator = list_iterator<use_info, &use_info::prev_phi_use>;
> @@ -680,6 +686,10 @@ public:
>    use_info *first_nondebug_insn_use () const;
>    use_info *last_nondebug_insn_use () const;
>  
> +  // Return the first use of the set by debug instructions, or null if
> +  // there is no such use.
> +  use_info *first_debug_insn_use () const;
> +
>    // Return the first use of the set by any kind of instruction, or null
>    // if there are no such uses.  The uses are in the order described above.
>    use_info *first_any_insn_use () const;
> @@ -731,6 +741,9 @@ public:
>    // List the uses of the set by nondebug instructions, in reverse postorder.
>    iterator_range<nondebug_insn_use_iterator> nondebug_insn_uses () const;
>  
> +  // List the uses of the set by debug instructions, in reverse postorder.
> +  iterator_range<debug_insn_use_iterator> debug_insn_uses () const;
> +
>    // Return nondebug_insn_uses () in reverse order.
>    iterator_range<reverse_use_iterator> reverse_nondebug_insn_uses () const;
>  
> diff --git a/gcc/rtl-ssa/member-fns.inl b/gcc/rtl-ssa/member-fns.inl
> index 8e1c17ced95..e4825ad2a18 100644
> --- a/gcc/rtl-ssa/member-fns.inl
> +++ b/gcc/rtl-ssa/member-fns.inl
> @@ -119,6 +119,15 @@ use_info::next_any_insn_use () const
>    return nullptr;
>  }
>  
> +inline use_info *
> +use_info::next_debug_insn_use () const
> +{
> +  if (auto use = next_use ())
> +    if (use->is_in_debug_insn ())
> +      return use;
> +  return nullptr;
> +}
> +
>  inline use_info *
>  use_info::prev_phi_use () const
>  {
> @@ -212,6 +221,20 @@ set_info::last_nondebug_insn_use () const
>    return nullptr;
>  }
>  
> +inline use_info *
> +set_info::first_debug_insn_use () const
> +{
> +  use_info *use;
> +  if (has_nondebug_insn_uses ())
> +    use = last_nondebug_insn_use ()->next_use ();
> +  else
> +    use = first_use ();
> +
> +  if (use && use->is_in_debug_insn ())
> +    return use;
> +  return nullptr;
> +}
> +
>  inline use_info *
>  set_info::first_any_insn_use () const
>  {
> @@ -310,6 +333,12 @@ set_info::nondebug_insn_uses () const
>    return { first_nondebug_insn_use (), nullptr };
>  }
>  
> +inline iterator_range<debug_insn_use_iterator>
> +set_info::debug_insn_uses () const
> +{
> +  return { first_debug_insn_use (), nullptr };
> +}
> +
>  inline iterator_range<reverse_use_iterator>
>  set_info::reverse_nondebug_insn_uses () const
>  {