[gcc r14-272] Quicker relation check.

[Andrew Macleod <amacleod@gcc.gnu.org>]

https://gcc.gnu.org/g:bf50499a14943b64f19bd72c60422683f7ecd0ee

commit r14-272-gbf50499a14943b64f19bd72c60422683f7ecd0ee
Author: Andrew MacLeod <amacleod@redhat.com>
Date:   Wed Feb 8 12:36:23 2023 -0500

    Quicker relation check.
    
    If either of the SSA names in a comparison do not have any equivalences
    or relations, we can short-circuit the check slightly.
    
            * value-relation.cc (dom_oracle::query_relation): Check early for lack
            of any relation.
            * value-relation.h (equiv_oracle::has_equiv_p): New.

Diff:
---
 gcc/value-relation.cc | 6 ++++++
 gcc/value-relation.h  | 1 +
 2 files changed, 7 insertions(+)

diff --git a/gcc/value-relation.cc b/gcc/value-relation.cc
index 30a02d3c9d3..65cf7694d40 100644
--- a/gcc/value-relation.cc
+++ b/gcc/value-relation.cc
@@ -1374,6 +1374,12 @@ dom_oracle::query_relation (basic_block bb, tree ssa1, tree ssa2)
   if (v1 == v2)
     return VREL_EQ;
 
+  // If v1 or v2 do not have any relations or equivalences, a partial
+  // equivalence is the only possibility.
+  if ((!bitmap_bit_p (m_relation_set, v1) && !has_equiv_p (v1))
+      || (!bitmap_bit_p (m_relation_set, v2) && !has_equiv_p (v2)))
+    return partial_equiv (ssa1, ssa2);
+
   // Check for equivalence first.  They must be in each equivalency set.
   const_bitmap equiv1 = equiv_set (ssa1, bb);
   const_bitmap equiv2 = equiv_set (ssa2, bb);
diff --git a/gcc/value-relation.h b/gcc/value-relation.h
index 3177ecb1ad0..be6e277421b 100644
--- a/gcc/value-relation.h
+++ b/gcc/value-relation.h
@@ -170,6 +170,7 @@ public:
   void dump (FILE *f) const override;
 
 protected:
+  inline bool has_equiv_p (unsigned v) { return bitmap_bit_p (m_equiv_set, v); }
   bitmap_obstack m_bitmaps;
   struct obstack m_chain_obstack;
 private: