No one has said anything in 48 hours. By the power vested in me, I
declare it approved.
Pushed.
On Mon, Nov 29, 2021 at 5:21 PM Aldy Hernandez <al...@redhat.com> wrote:
>
> We're using a temporary range cache while computing ranges for PHIs to
> make sure the real cache doesn't get set until all PHIs are computed.
> With the ltrans beast in LTO mode this causes undue overhead.
>
> Since we already have a bitmap to indicate whether there's a cache
> entry, we can avoid the extra cache object by clearing it while PHIs
> are being calculated.
>
> Tested on x86-64 Linux.
>
> OK for trunk?
>
> gcc/ChangeLog:
>
> PR tree-optimization/103409
> * gimple-range-path.cc (path_range_query::compute_ranges_in_phis):
> Do all the work with just one ssa_global_cache.
> * gimple-range-path.h: Remove m_tmp_phi_cache.
> ---
> gcc/gimple-range-path.cc | 23 +++++++++++------------
> gcc/gimple-range-path.h | 2 --
> 2 files changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/gcc/gimple-range-path.cc b/gcc/gimple-range-path.cc
> index b9c71226c1c..15ef72fd492 100644
> --- a/gcc/gimple-range-path.cc
> +++ b/gcc/gimple-range-path.cc
> @@ -375,30 +375,29 @@ void
> path_range_query::compute_ranges_in_phis (basic_block bb)
> {
> int_range_max r;
> - gphi_iterator iter;
> + auto_bitmap phi_set;
>
> // PHIs must be resolved simultaneously on entry to the block
> // because any dependencies must be satistifed with values on entry.
> // Thus, we calculate all PHIs first, and then update the cache at
> // the end.
>
> - m_tmp_phi_cache.clear ();
> - for (iter = gsi_start_phis (bb); !gsi_end_p (iter); gsi_next (&iter))
> + for (auto iter = gsi_start_phis (bb); !gsi_end_p (iter); gsi_next (&iter))
> {
> gphi *phi = iter.phi ();
> tree name = gimple_phi_result (phi);
>
> if (import_p (name) && range_defined_in_block (r, name, bb))
> - m_tmp_phi_cache.set_global_range (name, r);
> - }
> - for (iter = gsi_start_phis (bb); !gsi_end_p (iter); gsi_next (&iter))
> - {
> - gphi *phi = iter.phi ();
> - tree name = gimple_phi_result (phi);
> -
> - if (m_tmp_phi_cache.get_global_range (r, name))
> - set_cache (r, name);
> + {
> + unsigned v = SSA_NAME_VERSION (name);
> + set_cache (r, name);
> + bitmap_set_bit (phi_set, v);
> + // Pretend we don't have a cache entry for this name until
> + // we're done with all PHIs.
> + bitmap_clear_bit (m_has_cache_entry, v);
> + }
> }
> + bitmap_ior_into (m_has_cache_entry, phi_set);
> }
>
> // Compute ranges defined in the current block, or exported to the
> diff --git a/gcc/gimple-range-path.h b/gcc/gimple-range-path.h
> index 57a9ae9bdcd..77c92c07bc1 100644
> --- a/gcc/gimple-range-path.h
> +++ b/gcc/gimple-range-path.h
> @@ -82,8 +82,6 @@ private:
> // Range cache for SSA names.
> ssa_global_cache *m_cache;
>
> - ssa_global_cache m_tmp_phi_cache;
> -
> // Set for each SSA that has an active entry in the cache.
> bitmap m_has_cache_entry;
>
> --
> 2.31.1
>
