Clean up Hash Functions

Clean up and do fixes to hash functions and newly introduced murmur3 hashes in #61934
* Clean up usage of murmur3
* Fixed usages of binary murmur3 on floats (this is invalid)
* Changed DJB2 to use xor (which seems to be better)

3 files changed, 38 insertions, 43 deletions

diff --git a/core/object/callable_method_pointer.cpp b/core/object/callable_method_pointer.cpp
index 1bf926cafc..81f8ab6be2 100644
--- a/core/object/callable_method_pointer.cpp
+++ b/core/object/callable_method_pointer.cpp
@@ -85,9 +85,9 @@ void CallableCustomMethodPointerBase::_setup(uint32_t *p_base_ptr, uint32_t p_pt
 	// Precompute hash.
 	for (uint32_t i = 0; i < comp_size; i++) {
 		if (i == 0) {
-			h = hash_djb2_one_32(comp_ptr[i]);
+			h = hash_murmur3_one_32(comp_ptr[i]);
 		} else {
-			h = hash_djb2_one_32(comp_ptr[i], h);
+			h = hash_murmur3_one_32(comp_ptr[i], h);
 		}
 	}
 }
diff --git a/core/object/class_db.cpp b/core/object/class_db.cpp
index 533cb6e789..3c9f373d12 100644
--- a/core/object/class_db.cpp
+++ b/core/object/class_db.cpp
@@ -164,7 +164,7 @@ uint64_t ClassDB::get_api_hash(APIType p_api) {
 	OBJTYPE_RLOCK;
 #ifdef DEBUG_METHODS_ENABLED
 
-	uint64_t hash = hash_djb2_one_64(HashMapHasherDefault::hash(VERSION_FULL_CONFIG));
+	uint64_t hash = hash_murmur3_one_64(HashMapHasherDefault::hash(VERSION_FULL_CONFIG));
 
 	List<StringName> class_list;
 	ClassDB::get_class_list(&class_list);
@@ -177,8 +177,8 @@ uint64_t ClassDB::get_api_hash(APIType p_api) {
 		if (t->api != p_api || !t->exposed) {
 			continue;
 		}
-		hash = hash_djb2_one_64(t->name.hash(), hash);
-		hash = hash_djb2_one_64(t->inherits.hash(), hash);
+		hash = hash_murmur3_one_64(t->name.hash(), hash);
+		hash = hash_murmur3_one_64(t->inherits.hash(), hash);
 
 		{ //methods
 
@@ -200,27 +200,27 @@ uint64_t ClassDB::get_api_hash(APIType p_api) {
 
 			for (const StringName &F : snames) {
 				MethodBind *mb = t->method_map[F];
-				hash = hash_djb2_one_64(mb->get_name().hash(), hash);
-				hash = hash_djb2_one_64(mb->get_argument_count(), hash);
-				hash = hash_djb2_one_64(mb->get_argument_type(-1), hash); //return
+				hash = hash_murmur3_one_64(mb->get_name().hash(), hash);
+				hash = hash_murmur3_one_64(mb->get_argument_count(), hash);
+				hash = hash_murmur3_one_64(mb->get_argument_type(-1), hash); //return
 
 				for (int i = 0; i < mb->get_argument_count(); i++) {
 					const PropertyInfo info = mb->get_argument_info(i);
-					hash = hash_djb2_one_64(info.type, hash);
-					hash = hash_djb2_one_64(info.name.hash(), hash);
-					hash = hash_djb2_one_64(info.hint, hash);
-					hash = hash_djb2_one_64(info.hint_string.hash(), hash);
+					hash = hash_murmur3_one_64(info.type, hash);
+					hash = hash_murmur3_one_64(info.name.hash(), hash);
+					hash = hash_murmur3_one_64(info.hint, hash);
+					hash = hash_murmur3_one_64(info.hint_string.hash(), hash);
 				}
 
-				hash = hash_djb2_one_64(mb->get_default_argument_count(), hash);
+				hash = hash_murmur3_one_64(mb->get_default_argument_count(), hash);
 
 				for (int i = 0; i < mb->get_default_argument_count(); i++) {
 					//hash should not change, i hope for tis
 					Variant da = mb->get_default_argument(i);
-					hash = hash_djb2_one_64(da.hash(), hash);
+					hash = hash_murmur3_one_64(da.hash(), hash);
 				}
 
-				hash = hash_djb2_one_64(mb->get_hint_flags(), hash);
+				hash = hash_murmur3_one_64(mb->get_hint_flags(), hash);
 			}
 		}
 
@@ -235,8 +235,8 @@ uint64_t ClassDB::get_api_hash(APIType p_api) {
 			snames.sort_custom<StringName::AlphCompare>();
 
 			for (const StringName &F : snames) {
-				hash = hash_djb2_one_64(F.hash(), hash);
-				hash = hash_djb2_one_64(t->constant_map[F], hash);
+				hash = hash_murmur3_one_64(F.hash(), hash);
+				hash = hash_murmur3_one_64(t->constant_map[F], hash);
 			}
 		}
 
@@ -252,9 +252,9 @@ uint64_t ClassDB::get_api_hash(APIType p_api) {
 
 			for (const StringName &F : snames) {
 				MethodInfo &mi = t->signal_map[F];
-				hash = hash_djb2_one_64(F.hash(), hash);
+				hash = hash_murmur3_one_64(F.hash(), hash);
 				for (int i = 0; i < mi.arguments.size(); i++) {
-					hash = hash_djb2_one_64(mi.arguments[i].type, hash);
+					hash = hash_murmur3_one_64(mi.arguments[i].type, hash);
 				}
 			}
 		}
@@ -273,23 +273,23 @@ uint64_t ClassDB::get_api_hash(APIType p_api) {
 				PropertySetGet *psg = t->property_setget.getptr(F);
 				ERR_FAIL_COND_V(!psg, 0);
 
-				hash = hash_djb2_one_64(F.hash(), hash);
-				hash = hash_djb2_one_64(psg->setter.hash(), hash);
-				hash = hash_djb2_one_64(psg->getter.hash(), hash);
+				hash = hash_murmur3_one_64(F.hash(), hash);
+				hash = hash_murmur3_one_64(psg->setter.hash(), hash);
+				hash = hash_murmur3_one_64(psg->getter.hash(), hash);
 			}
 		}
 
 		//property list
 		for (const PropertyInfo &F : t->property_list) {
-			hash = hash_djb2_one_64(F.name.hash(), hash);
-			hash = hash_djb2_one_64(F.type, hash);
-			hash = hash_djb2_one_64(F.hint, hash);
-			hash = hash_djb2_one_64(F.hint_string.hash(), hash);
-			hash = hash_djb2_one_64(F.usage, hash);
+			hash = hash_murmur3_one_64(F.name.hash(), hash);
+			hash = hash_murmur3_one_64(F.type, hash);
+			hash = hash_murmur3_one_64(F.hint, hash);
+			hash = hash_murmur3_one_64(F.hint_string.hash(), hash);
+			hash = hash_murmur3_one_64(F.usage, hash);
 		}
 	}
 
-	return hash;
+	return hash_fmix32(hash);
 #else
 	return 0;
 #endif
diff --git a/core/object/method_bind.cpp b/core/object/method_bind.cpp
index a208c1a2b2..a4474ea53b 100644
--- a/core/object/method_bind.cpp
+++ b/core/object/method_bind.cpp
@@ -35,32 +35,27 @@
 #include "method_bind.h"
 
 uint32_t MethodBind::get_hash() const {
-	uint32_t hash = hash_djb2_one_32(has_return() ? 1 : 0);
-	hash = hash_djb2_one_32(get_argument_count(), hash);
-
-#ifndef _MSC_VER
-#warning This needs proper class name and argument type for hashing
-#endif
-#if 0
+	uint32_t hash = hash_murmur3_one_32(has_return() ? 1 : 0);
+	hash = hash_murmur3_one_32(get_argument_count(), hash);
 
 	for (int i = (has_return() ? -1 : 0); i < get_argument_count(); i++) {
 		PropertyInfo pi = i == -1 ? get_return_info() : get_argument_info(i);
-		hash = hash_djb2_one_32(get_argument_type(i), hash);
+		hash = hash_murmur3_one_32(get_argument_type(i), hash);
 		if (pi.class_name != StringName()) {
-			hash = hash_djb2_one_32(pi.class_name.operator String().hash(), hash);
+			hash = hash_murmur3_one_32(pi.class_name.operator String().hash(), hash);
 		}
 	}
-#endif
-	hash = hash_djb2_one_32(get_default_argument_count(), hash);
+
+	hash = hash_murmur3_one_32(get_default_argument_count(), hash);
 	for (int i = 0; i < get_default_argument_count(); i++) {
 		Variant v = get_default_argument(i);
-		hash = hash_djb2_one_32(v.hash(), hash);
+		hash = hash_murmur3_one_32(v.hash(), hash);
 	}
 
-	hash = hash_djb2_one_32(is_const(), hash);
-	hash = hash_djb2_one_32(is_vararg(), hash);
+	hash = hash_murmur3_one_32(is_const(), hash);
+	hash = hash_murmur3_one_32(is_vararg(), hash);
 
-	return hash;
+	return hash_fmix32(hash);
 }
 
 PropertyInfo MethodBind::get_argument_info(int p_argument) const {