From 7e5e44bd1729b7a9b458d512ddf61bfba5031869 Mon Sep 17 00:00:00 2001
From: Aldy Hernandez <aldyh@redhat.com>
Date: Wed, 22 Sep 2021 09:34:15 +0200
Subject: [PATCH] path solver: Use range_on_path_entry instead of looking at
 equivalences.

Cycling through equivalences to improve a range is nowhere near as
efficient as asking the ranger what the range on entry is.

Testing on a hybrid VRP threader, shows that this improves our VRP
threading benefit from 14.5% to 18.5% and our overall jump threads from
0.85% to 1.28%.

Tested on x86-64 Linux.

gcc/ChangeLog:

	* gimple-range-path.cc (path_range_query::internal_range_of_expr):
	Remove call to improve_range_with_equivs.
	(path_range_query::improve_range_with_equivs): Remove
	* gimple-range-path.h: Remove improve_range_with_equivs.
---
 gcc/gimple-range-path.cc | 33 +--------------------------------
 gcc/gimple-range-path.h  |  1 -
 2 files changed, 1 insertion(+), 33 deletions(-)

diff --git a/gcc/gimple-range-path.cc b/gcc/gimple-range-path.cc
index e65c799..d052ebd 100644
--- a/gcc/gimple-range-path.cc
+++ b/gcc/gimple-range-path.cc
@@ -163,10 +163,6 @@ path_range_query::internal_range_of_expr (irange &r, tree name, gimple *stmt)
   if (m_resolve && defined_outside_path (name))
     {
       range_on_path_entry (r, name);
-
-      if (r.varying_p ())
-	improve_range_with_equivs (r, name);
-
       set_cache (r, name);
       return true;
     }
@@ -178,7 +174,7 @@ path_range_query::internal_range_of_expr (irange &r, tree name, gimple *stmt)
 	r.intersect (gimple_range_global (name));
 
       if (m_resolve && r.varying_p ())
-	improve_range_with_equivs (r, name);
+	range_on_path_entry (r, name);
 
       set_cache (r, name);
       return true;
@@ -201,33 +197,6 @@ path_range_query::range_of_expr (irange &r, tree name, gimple *stmt)
   return false;
 }
 
-// Improve the range of NAME with the range of any of its equivalences.
-
-void
-path_range_query::improve_range_with_equivs (irange &r, tree name)
-{
-  if (TREE_CODE (name) != SSA_NAME)
-    return;
-
-  basic_block entry = entry_bb ();
-  relation_oracle *oracle = m_ranger.oracle ();
-
-  if (const bitmap_head *equivs = oracle->equiv_set (name, entry))
-    {
-      int_range_max t;
-      bitmap_iterator bi;
-      unsigned i;
-
-      EXECUTE_IF_SET_IN_BITMAP (equivs, 0, i, bi)
-	if (i != SSA_NAME_VERSION (name) && r.varying_p ())
-	  {
-	    tree equiv = ssa_name (i);
-	    range_on_path_entry (t, equiv);
-	    r.intersect (t);
-	  }
-    }
-}
-
 bool
 path_range_query::unreachable_path_p ()
 {
diff --git a/gcc/gimple-range-path.h b/gcc/gimple-range-path.h
index 6f81f21..f7d9832 100644
--- a/gcc/gimple-range-path.h
+++ b/gcc/gimple-range-path.h
@@ -63,7 +63,6 @@ private:
   void ssa_range_in_phi (irange &r, gphi *phi);
   void precompute_relations (const vec<basic_block> &);
   void precompute_phi_relations (basic_block bb, basic_block prev);
-  void improve_range_with_equivs (irange &r, tree name);
   void add_copies_to_imports ();
   bool add_to_imports (tree name, bitmap imports);
 
-- 
2.7.4