hash-table.h: support non-zero empty values in empty_slow (v2)

gcc/cp/ChangeLog:
	* cp-gimplify.c (source_location_table_entry_hash::empty_zero_p):
	New static constant.
	* cp-tree.h (named_decl_hash::empty_zero_p): Likewise.
	(struct named_label_hash::empty_zero_p): Likewise.
	* decl2.c (mangled_decl_hash::empty_zero_p): Likewise.

gcc/ChangeLog:
	* attribs.c (excl_hash_traits::empty_zero_p): New static constant.
	* gcov.c (function_start_pair_hash::empty_zero_p): Likewise.
	* graphite.c (struct sese_scev_hash::empty_zero_p): Likewise.
	* hash-map-tests.c (selftest::test_nonzero_empty_key): New selftest.
	(selftest::hash_map_tests_c_tests): Call it.
	* hash-map-traits.h (simple_hashmap_traits::empty_zero_p):
	New static constant, using the value of = H::empty_zero_p.
	(unbounded_hashmap_traits::empty_zero_p): Likewise, using the value
	from default_hash_traits <Value>.
	* hash-map.h (hash_map::empty_zero_p): Likewise, using the value
	from Traits.
	* hash-set-tests.c (value_hash_traits::empty_zero_p): Likewise.
	* hash-table.h (hash_table::alloc_entries): Guard the loop of
	calls to mark_empty with !Descriptor::empty_zero_p.
	(hash_table::empty_slow): Conditionalize the memset call with a
	check that Descriptor::empty_zero_p; otherwise, loop through the
	entries calling mark_empty on them.
	* hash-traits.h (int_hash::empty_zero_p): New static constant.
	(pointer_hash::empty_zero_p): Likewise.
	(pair_hash::empty_zero_p): Likewise.
	* ipa-devirt.c (default_hash_traits <type_pair>::empty_zero_p):
	Likewise.
	* ipa-prop.c (ipa_bit_ggc_hash_traits::empty_zero_p): Likewise.
	(ipa_vr_ggc_hash_traits::empty_zero_p): Likewise.
	* profile.c (location_triplet_hash::empty_zero_p): Likewise.
	* sanopt.c (sanopt_tree_triplet_hash::empty_zero_p): Likewise.
	(sanopt_tree_couple_hash::empty_zero_p): Likewise.
	* tree-hasher.h (int_tree_hasher::empty_zero_p): Likewise.
	* tree-ssa-sccvn.c (vn_ssa_aux_hasher::empty_zero_p): Likewise.
	* tree-vect-slp.c (bst_traits::empty_zero_p): Likewise.
	* tree-vectorizer.h
	(default_hash_traits<scalar_cond_masked_key>::empty_zero_p):
	Likewise.

22 files changed, 105 insertions, 3 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f3301b1..4f586fe 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,39 @@
+2020-01-14  David Malcolm  <dmalcolm@redhat.com>
+
+	* attribs.c (excl_hash_traits::empty_zero_p): New static constant.
+	* gcov.c (function_start_pair_hash::empty_zero_p): Likewise.
+	* graphite.c (struct sese_scev_hash::empty_zero_p): Likewise.
+	* hash-map-tests.c (selftest::test_nonzero_empty_key): New selftest.
+	(selftest::hash_map_tests_c_tests): Call it.
+	* hash-map-traits.h (simple_hashmap_traits::empty_zero_p):
+	New static constant, using the value of = H::empty_zero_p.
+	(unbounded_hashmap_traits::empty_zero_p): Likewise, using the value
+	from default_hash_traits <Value>.
+	* hash-map.h (hash_map::empty_zero_p): Likewise, using the value
+	from Traits.
+	* hash-set-tests.c (value_hash_traits::empty_zero_p): Likewise.
+	* hash-table.h (hash_table::alloc_entries): Guard the loop of
+	calls to mark_empty with !Descriptor::empty_zero_p.
+	(hash_table::empty_slow): Conditionalize the memset call with a
+	check that Descriptor::empty_zero_p; otherwise, loop through the
+	entries calling mark_empty on them.
+	* hash-traits.h (int_hash::empty_zero_p): New static constant.
+	(pointer_hash::empty_zero_p): Likewise.
+	(pair_hash::empty_zero_p): Likewise.
+	* ipa-devirt.c (default_hash_traits <type_pair>::empty_zero_p):
+	Likewise.
+	* ipa-prop.c (ipa_bit_ggc_hash_traits::empty_zero_p): Likewise.
+	(ipa_vr_ggc_hash_traits::empty_zero_p): Likewise.
+	* profile.c (location_triplet_hash::empty_zero_p): Likewise.
+	* sanopt.c (sanopt_tree_triplet_hash::empty_zero_p): Likewise.
+	(sanopt_tree_couple_hash::empty_zero_p): Likewise.
+	* tree-hasher.h (int_tree_hasher::empty_zero_p): Likewise.
+	* tree-ssa-sccvn.c (vn_ssa_aux_hasher::empty_zero_p): Likewise.
+	* tree-vect-slp.c (bst_traits::empty_zero_p): Likewise.
+	* tree-vectorizer.h
+	(default_hash_traits<scalar_cond_masked_key>::empty_zero_p):
+	Likewise.
+
 2020-01-14  Kewen Lin  <linkw@gcc.gnu.org>
 
 	* cfgloopanal.c (average_num_loop_insns): Free bbs when early return,
diff --git a/gcc/attribs.c b/gcc/attribs.c
index ca89443..c66d4ae 100644
--- a/gcc/attribs.c
+++ b/gcc/attribs.c
@@ -2048,6 +2048,8 @@ struct excl_hash_traits: typed_noop_remove<excl_pair>
     x = value_type (NULL, NULL);
   }
 
+  static const bool empty_zero_p = false;
+
   static void mark_empty (value_type &x)
   {
     x = value_type ("", "");
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 3fd35b4..004ce0f 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2020-01-14  David Malcolm  <dmalcolm@redhat.com>
+
+	* cp-gimplify.c (source_location_table_entry_hash::empty_zero_p):
+	New static constant.
+	* cp-tree.h (named_decl_hash::empty_zero_p): Likewise.
+	(struct named_label_hash::empty_zero_p): Likewise.
+	* decl2.c (mangled_decl_hash::empty_zero_p): Likewise.
+
 2020-01-14  Jason Merrill  <jason@redhat.com>
 
 	PR c++/92594 - ICE with inherited trivial default ctor.
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index 3d764bb..f3aeb74 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -3045,6 +3045,8 @@ struct source_location_table_entry_hash
     ref.var = NULL_TREE;
   }
 
+  static const bool empty_zero_p = true;
+
   static void
   mark_empty (source_location_table_entry &ref)
   {
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 01fcf66..4e26acc 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -900,6 +900,7 @@ struct named_decl_hash : ggc_remove <tree>
   inline static hashval_t hash (const value_type decl);
   inline static bool equal (const value_type existing, compare_type candidate);
 
+  static const bool empty_zero_p = true;
   static inline void mark_empty (value_type &p) {p = NULL_TREE;}
   static inline bool is_empty (value_type p) {return !p;}
 
@@ -1870,6 +1871,7 @@ struct named_label_hash : ggc_remove <named_label_entry *>
   inline static hashval_t hash (value_type);
   inline static bool equal (const value_type, compare_type);
 
+  static const bool empty_zero_p = true;
   inline static void mark_empty (value_type &p) {p = NULL;}
   inline static bool is_empty (value_type p) {return !p;}
 
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index a641667..042d6fa 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -120,6 +120,7 @@ struct mangled_decl_hash : ggc_remove <tree>
     return candidate == name;
   }
 
+  static const bool empty_zero_p = true;
   static inline void mark_empty (value_type &p) {p = NULL_TREE;}
   static inline bool is_empty (value_type p) {return !p;}
 
diff --git a/gcc/gcov.c b/gcc/gcov.c
index 1dca304..a291bac 100644
--- a/gcc/gcov.c
+++ b/gcc/gcov.c
@@ -1225,6 +1225,8 @@ struct function_start_pair_hash : typed_noop_remove <function_start>
     ref.start_line = ~1U;
   }
 
+  static const bool empty_zero_p = false;
+
   static void
   mark_empty (function_start &ref)
   {
diff --git a/gcc/graphite.c b/gcc/graphite.c
index 0ac4676..27f1e48 100644
--- a/gcc/graphite.c
+++ b/gcc/graphite.c
@@ -233,6 +233,7 @@ struct sese_scev_hash : typed_noop_remove <seir_cache_key>
 	    && operand_equal_p (key1.expr, key2.expr, 0));
   }
   static void mark_deleted (seir_cache_key &key) { key.expr = NULL_TREE; }
+  static const bool empty_zero_p = false;
   static void mark_empty (seir_cache_key &key) { key.entry_dest = 0; }
   static bool is_deleted (const seir_cache_key &key) { return !key.expr; }
   static bool is_empty (const seir_cache_key &key) { return key.entry_dest == 0; }
diff --git a/gcc/hash-map-tests.c b/gcc/hash-map-tests.c
index 743fb26..63574029 100644
--- a/gcc/hash-map-tests.c
+++ b/gcc/hash-map-tests.c
@@ -280,6 +280,27 @@ test_map_of_type_with_ctor_and_dtor ()
   }
 }
 
+/* Test calling empty on a hash_map that has a key type with non-zero
+   "empty" value.  */
+
+static void
+test_nonzero_empty_key ()
+{
+  typedef int_hash<int, INT_MIN, INT_MAX> IntHash;
+  hash_map<int, int, simple_hashmap_traits<IntHash, int> > x;
+
+  for (int i = 1; i != 32; ++i)
+    x.put (i, i);
+
+  ASSERT_EQ (x.get (0), NULL);
+  ASSERT_EQ (*x.get (1), 1);
+
+  x.empty ();
+
+  ASSERT_EQ (x.get (0), NULL);
+  ASSERT_EQ (x.get (1), NULL);
+}
+
 /* Run all of the selftests within this file.  */
 
 void
@@ -288,6 +309,7 @@ hash_map_tests_c_tests ()
   test_map_of_strings_to_int ();
   test_map_of_int_to_strings ();
   test_map_of_type_with_ctor_and_dtor ();
+  test_nonzero_empty_key ();
 }
 
 } // namespace selftest
diff --git a/gcc/hash-map-traits.h b/gcc/hash-map-traits.h
index 4764380..3b16be3 100644
--- a/gcc/hash-map-traits.h
+++ b/gcc/hash-map-traits.h
@@ -36,6 +36,7 @@ struct simple_hashmap_traits
   static inline hashval_t hash (const key_type &);
   static inline bool equal_keys (const key_type &, const key_type &);
   template <typename T> static inline void remove (T &);
+  static const bool empty_zero_p = H::empty_zero_p;
   template <typename T> static inline bool is_empty (const T &);
   template <typename T> static inline bool is_deleted (const T &);
   template <typename T> static inline void mark_empty (T &);
@@ -113,6 +114,7 @@ template <typename Value>
 struct unbounded_hashmap_traits
 {
   template <typename T> static inline void remove (T &);
+  static const bool empty_zero_p = default_hash_traits <Value>::empty_zero_p;
   template <typename T> static inline bool is_empty (const T &);
   template <typename T> static inline bool is_deleted (const T &);
   template <typename T> static inline void mark_empty (T &);
diff --git a/gcc/hash-map.h b/gcc/hash-map.h
index 7cb4667..5b8fd18 100644
--- a/gcc/hash-map.h
+++ b/gcc/hash-map.h
@@ -66,6 +66,7 @@ class GTY((user)) hash_map
        	return Traits::is_deleted (e);
       }
 
+    static const bool empty_zero_p = Traits::empty_zero_p;
     static void mark_empty (hash_entry &e) { Traits::mark_empty (e); }
     static bool is_empty (const hash_entry &e) { return Traits::is_empty (e); }
 
diff --git a/gcc/hash-set-tests.c b/gcc/hash-set-tests.c
index 696e35e..bb32094 100644
--- a/gcc/hash-set-tests.c
+++ b/gcc/hash-set-tests.c
@@ -199,6 +199,8 @@ struct value_hash_traits: int_hash<int, -1, -2>
     base_type::mark_deleted (v.val);
   }
 
+  static const bool empty_zero_p = false;
+
   static void mark_empty (value_type &v)
   {
     base_type::mark_empty (v.val);
diff --git a/gcc/hash-table.h b/gcc/hash-table.h
index e0ddac5..a1423c7 100644
--- a/gcc/hash-table.h
+++ b/gcc/hash-table.h
@@ -713,8 +713,9 @@ hash_table<Descriptor, Lazy,
     nentries = ::ggc_cleared_vec_alloc<value_type> (n PASS_MEM_STAT);
 
   gcc_assert (nentries != NULL);
-  for (size_t i = 0; i < n; i++)
-    mark_empty (nentries[i]);
+  if (!Descriptor::empty_zero_p)
+    for (size_t i = 0; i < n; i++)
+      mark_empty (nentries[i]);
 
   return nentries;
 }
@@ -867,8 +868,11 @@ hash_table<Descriptor, Lazy, Allocator>::empty_slow ()
       m_size = nsize;
       m_size_prime_index = nindex;
     }
-  else
+  else if (Descriptor::empty_zero_p)
     memset ((void *) entries, 0, size * sizeof (value_type));
+  else
+    for (size_t i = 0; i < size; i++)
+      mark_empty (entries[i]);
 
   m_n_deleted = 0;
   m_n_elements = 0;
diff --git a/gcc/hash-traits.h b/gcc/hash-traits.h
index d259a41..3bca74c 100644
--- a/gcc/hash-traits.h
+++ b/gcc/hash-traits.h
@@ -88,6 +88,7 @@ struct int_hash : typed_noop_remove <Type>
   static inline hashval_t hash (value_type);
   static inline bool equal (value_type existing, value_type candidate);
   static inline void mark_deleted (Type &);
+  static const bool empty_zero_p = Empty == 0;
   static inline void mark_empty (Type &);
   static inline bool is_deleted (Type);
   static inline bool is_empty (Type);
@@ -150,6 +151,7 @@ struct pointer_hash
   static inline bool equal (const value_type &existing,
 			    const compare_type &candidate);
   static inline void mark_deleted (Type *&);
+  static const bool empty_zero_p = true;
   static inline void mark_empty (Type *&);
   static inline bool is_deleted (Type *);
   static inline bool is_empty (Type *);
@@ -323,6 +325,7 @@ struct pair_hash
   static inline bool equal (const value_type &, const compare_type &);
   static inline void remove (value_type &);
   static inline void mark_deleted (value_type &);
+  static const bool empty_zero_p = T1::empty_zero_p;
   static inline void mark_empty (value_type &);
   static inline bool is_deleted (const value_type &);
   static inline bool is_empty (const value_type &);
diff --git a/gcc/ipa-devirt.c b/gcc/ipa-devirt.c
index b888186..f003195 100644
--- a/gcc/ipa-devirt.c
+++ b/gcc/ipa-devirt.c
@@ -150,6 +150,7 @@ struct default_hash_traits <type_pair>
   {
     return TYPE_UID (p.first) ^ TYPE_UID (p.second);
   }
+  static const bool empty_zero_p = true;
   static bool
   is_empty (type_pair p)
   {
diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
index 6dc3cf6..12cdb95 100644
--- a/gcc/ipa-prop.c
+++ b/gcc/ipa-prop.c
@@ -78,6 +78,7 @@ struct ipa_bit_ggc_hash_traits : public ggc_cache_remove <ipa_bits *>
     {
       return a->value == b->value && a->mask == b->mask;
     }
+  static const bool empty_zero_p = true;
   static void
   mark_empty (ipa_bits *&p)
     {
@@ -123,6 +124,7 @@ struct ipa_vr_ggc_hash_traits : public ggc_cache_remove <value_range *>
     {
       return a->equal_p (*b);
     }
+  static const bool empty_zero_p = true;
   static void
   mark_empty (value_range *&p)
     {
diff --git a/gcc/profile.c b/gcc/profile.c
index e124dc6..6a2de21 100644
--- a/gcc/profile.c
+++ b/gcc/profile.c
@@ -932,6 +932,8 @@ struct location_triplet_hash : typed_noop_remove <location_triplet>
     ref.lineno = -1;
   }
 
+  static const bool empty_zero_p = false;
+
   static void
   mark_empty (location_triplet &ref)
   {
diff --git a/gcc/sanopt.c b/gcc/sanopt.c
index 8a29abe..619aae4 100644
--- a/gcc/sanopt.c
+++ b/gcc/sanopt.c
@@ -129,6 +129,8 @@ struct sanopt_tree_triplet_hash : typed_noop_remove <sanopt_tree_triplet>
     ref.t1 = reinterpret_cast<tree> (1);
   }
 
+  static const bool empty_zero_p = true;
+
   static void
   mark_empty (sanopt_tree_triplet &ref)
   {
@@ -184,6 +186,8 @@ struct sanopt_tree_couple_hash : typed_noop_remove <sanopt_tree_couple>
     ref.ptr = reinterpret_cast<tree> (1);
   }
 
+  static const bool empty_zero_p = true;
+
   static void
   mark_empty (sanopt_tree_couple &ref)
   {
diff --git a/gcc/tree-hasher.h b/gcc/tree-hasher.h
index 787d1ad..9194d62 100644
--- a/gcc/tree-hasher.h
+++ b/gcc/tree-hasher.h
@@ -40,6 +40,7 @@ struct int_tree_hasher
     }
   static void mark_deleted (value_type &v) { v.to = reinterpret_cast<tree> (0x1); }
   static bool is_empty (const value_type &v) { return v.to == NULL; }
+  static const bool empty_zero_p = true;
   static void mark_empty (value_type &v) { v.to = NULL; }
   static void remove (value_type &) {}
 };
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 6f6b19e..3b27c50 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -335,6 +335,7 @@ struct vn_ssa_aux_hasher : typed_noop_remove <vn_ssa_aux_t>
   static inline hashval_t hash (const value_type &);
   static inline bool equal (const value_type &, const compare_type &);
   static inline void mark_deleted (value_type &) {}
+  static const bool empty_zero_p = true;
   static inline void mark_empty (value_type &e) { e = NULL; }
   static inline bool is_deleted (value_type &) { return false; }
   static inline bool is_empty (value_type &e) { return e == NULL; }
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index 9cb724b..d164937 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -1193,6 +1193,7 @@ struct bst_traits
   static inline bool equal (value_type existing, value_type candidate);
   static inline bool is_empty (value_type x) { return !x.exists (); }
   static inline bool is_deleted (value_type x) { return !x.exists (); }
+  static const bool empty_zero_p = true;
   static inline void mark_empty (value_type &x) { x.release (); }
   static inline void mark_deleted (value_type &x) { x.release (); }
   static inline void remove (value_type &x) { x.release (); }
diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h
index 375fba2..ed7fcb0 100644
--- a/gcc/tree-vectorizer.h
+++ b/gcc/tree-vectorizer.h
@@ -232,6 +232,8 @@ struct default_hash_traits<scalar_cond_masked_key>
            && operand_equal_p (existing.op1, candidate.op1, 0));
   }
 
+  static const bool empty_zero_p = true;
+
   static inline void
   mark_empty (value_type &v)
   {