Update hashfuncs, add some missing math funcs.

include/godot_cpp/core/math.hpp

@@ -352,6 +352,22 @@ inline float range_lerp(float p_value, float p_istart, float p_istop, float p_os
 	return Math::lerp(p_ostart, p_ostop, Math::inverse_lerp(p_istart, p_istop, p_value));
 }
 
+inline bool is_nan(float p_val) {
+	return std::isnan(p_val);
+}
+
+inline bool is_nan(double p_val) {
+	return std::isnan(p_val);
+}
+
+inline bool is_inf(float p_val) {
+	return std::isinf(p_val);
+}
+
+inline bool is_inf(double p_val) {
+	return std::isinf(p_val);
+}
+
 inline bool is_equal_approx(real_t a, real_t b) {
 	// Check for exact equality first, required to handle "infinity" values.
 	if (a == b) {

include/godot_cpp/templates/hashfuncs.hpp

@@ -31,6 +31,11 @@
 #ifndef HASHFUNCS_HPP
 #define HASHFUNCS_HPP
 
+// Needed for fastmod.
+#if defined(_MSC_VER)
+#include <intrin.h>
+#endif
+
 #include <godot_cpp/core/math.hpp>
 #include <godot_cpp/core/object.hpp>
 #include <godot_cpp/variant/aabb.hpp>
@@ -59,30 +64,30 @@ namespace godot {
  * @param C String
  * @return 32-bits hashcode
  */
-static inline uint32_t hash_djb2(const char *p_cstr) {
+static _FORCE_INLINE_ uint32_t hash_djb2(const char *p_cstr) {
 	const unsigned char *chr = (const unsigned char *)p_cstr;
 	uint32_t hash = 5381;
 	uint32_t c;
 
 	while ((c = *chr++)) {
-		hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
+		hash = ((hash << 5) + hash) ^ c; /* hash * 33 ^ c */
 	}
 
 	return hash;
 }
 
-static inline uint32_t hash_djb2_buffer(const uint8_t *p_buff, int p_len, uint32_t p_prev = 5381) {
+static _FORCE_INLINE_ uint32_t hash_djb2_buffer(const uint8_t *p_buff, int p_len, uint32_t p_prev = 5381) {
 	uint32_t hash = p_prev;
 
 	for (int i = 0; i < p_len; i++) {
-		hash = ((hash << 5) + hash) + p_buff[i]; /* hash * 33 + c */
+		hash = ((hash << 5) + hash) ^ p_buff[i]; /* hash * 33 + c */
 	}
 
 	return hash;
 }
 
-static inline uint32_t hash_djb2_one_32(uint32_t p_in, uint32_t p_prev = 5381) {
-	return ((p_prev << 5) + p_prev) + p_in;
+static _FORCE_INLINE_ uint32_t hash_djb2_one_32(uint32_t p_in, uint32_t p_prev = 5381) {
+	return ((p_prev << 5) + p_prev) ^ p_in;
 }
 
 /**
@@ -92,7 +97,7 @@ static inline uint32_t hash_djb2_one_32(uint32_t p_in, uint32_t p_prev = 5381) {
  * @param p_int - 64-bit unsigned integer key to be hashed
  * @return unsigned 32-bit value representing hashcode
  */
-static inline uint32_t hash_one_uint64(const uint64_t p_int) {
+static _FORCE_INLINE_ uint32_t hash_one_uint64(const uint64_t p_int) {
 	uint64_t v = p_int;
 	v = (~v) + (v << 18); // v = (v << 18) - v - 1;
 	v = v ^ (v >> 31);
@@ -103,7 +108,134 @@ static inline uint32_t hash_one_uint64(const uint64_t p_int) {
 	return uint32_t(v);
 }
 
-static inline uint32_t hash_djb2_one_float(double p_in, uint32_t p_prev = 5381) {
+#define HASH_MURMUR3_SEED 0x7F07C65
+// Murmurhash3 32-bit version.
+// All MurmurHash versions are public domain software, and the author disclaims all copyright to their code.
+
+static _FORCE_INLINE_ uint32_t hash_murmur3_one_32(uint32_t p_in, uint32_t p_seed = HASH_MURMUR3_SEED) {
+	p_in *= 0xcc9e2d51;
+	p_in = (p_in << 15) | (p_in >> 17);
+	p_in *= 0x1b873593;
+
+	p_seed ^= p_in;
+	p_seed = (p_seed << 13) | (p_seed >> 19);
+	p_seed = p_seed * 5 + 0xe6546b64;
+
+	return p_seed;
+}
+
+static _FORCE_INLINE_ uint32_t hash_murmur3_one_float(float p_in, uint32_t p_seed = HASH_MURMUR3_SEED) {
+	union {
+		float f;
+		uint32_t i;
+	} u;
+
+	// Normalize +/- 0.0 and NaN values so they hash the same.
+	if (p_in == 0.0f) {
+		u.f = 0.0;
+	} else if (Math::is_nan(p_in)) {
+		u.f = NAN;
+	} else {
+		u.f = p_in;
+	}
+
+	return hash_murmur3_one_32(u.i, p_seed);
+}
+
+static _FORCE_INLINE_ uint32_t hash_murmur3_one_64(uint64_t p_in, uint32_t p_seed = HASH_MURMUR3_SEED) {
+	p_seed = hash_murmur3_one_32(p_in & 0xFFFFFFFF, p_seed);
+	return hash_murmur3_one_32(p_in >> 32, p_seed);
+}
+
+static _FORCE_INLINE_ uint32_t hash_murmur3_one_double(double p_in, uint32_t p_seed = HASH_MURMUR3_SEED) {
+	union {
+		double d;
+		uint64_t i;
+	} u;
+
+	// Normalize +/- 0.0 and NaN values so they hash the same.
+	if (p_in == 0.0f) {
+		u.d = 0.0;
+	} else if (Math::is_nan(p_in)) {
+		u.d = NAN;
+	} else {
+		u.d = p_in;
+	}
+
+	return hash_murmur3_one_64(u.i, p_seed);
+}
+
+static _FORCE_INLINE_ uint32_t hash_murmur3_one_real(real_t p_in, uint32_t p_seed = HASH_MURMUR3_SEED) {
+#ifdef REAL_T_IS_DOUBLE
+	return hash_murmur3_one_double(p_in, p_seed);
+#else
+	return hash_murmur3_one_float(p_in, p_seed);
+#endif
+}
+
+static _FORCE_INLINE_ uint32_t hash_rotl32(uint32_t x, int8_t r) {
+	return (x << r) | (x >> (32 - r));
+}
+
+static _FORCE_INLINE_ uint32_t hash_fmix32(uint32_t h) {
+	h ^= h >> 16;
+	h *= 0x85ebca6b;
+	h ^= h >> 13;
+	h *= 0xc2b2ae35;
+	h ^= h >> 16;
+
+	return h;
+}
+
+static _FORCE_INLINE_ uint32_t hash_murmur3_buffer(const void *key, int length, const uint32_t seed = HASH_MURMUR3_SEED) {
+	// Although not required, this is a random prime number.
+	const uint8_t *data = (const uint8_t *)key;
+	const int nblocks = length / 4;
+
+	uint32_t h1 = seed;
+
+	const uint32_t c1 = 0xcc9e2d51;
+	const uint32_t c2 = 0x1b873593;
+
+	const uint32_t *blocks = (const uint32_t *)(data + nblocks * 4);
+
+	for (int i = -nblocks; i; i++) {
+		uint32_t k1 = blocks[i];
+
+		k1 *= c1;
+		k1 = hash_rotl32(k1, 15);
+		k1 *= c2;
+
+		h1 ^= k1;
+		h1 = hash_rotl32(h1, 13);
+		h1 = h1 * 5 + 0xe6546b64;
+	}
+
+	const uint8_t *tail = (const uint8_t *)(data + nblocks * 4);
+
+	uint32_t k1 = 0;
+
+	switch (length & 3) {
+		case 3:
+			k1 ^= tail[2] << 16;
+			[[fallthrough]];
+		case 2:
+			k1 ^= tail[1] << 8;
+			[[fallthrough]];
+		case 1:
+			k1 ^= tail[0];
+			k1 *= c1;
+			k1 = hash_rotl32(k1, 15);
+			k1 *= c2;
+			h1 ^= k1;
+	};
+
+	// Finalize with additional bit mixing.
+	h1 ^= length;
+	return hash_fmix32(h1);
+}
+
+static _FORCE_INLINE_ uint32_t hash_djb2_one_float(double p_in, uint32_t p_prev = 5381) {
 	union {
 		double d;
 		uint64_t i;
@@ -112,7 +244,7 @@ static inline uint32_t hash_djb2_one_float(double p_in, uint32_t p_prev = 5381)
 	// Normalize +/- 0.0 and NaN values so they hash the same.
 	if (p_in == 0.0f) {
 		u.d = 0.0;
-	} else if (std::isnan(p_in)) {
+	} else if (Math::is_nan(p_in)) {
 		u.d = NAN;
 	} else {
 		u.d = p_in;
@@ -122,7 +254,7 @@ static inline uint32_t hash_djb2_one_float(double p_in, uint32_t p_prev = 5381)
 }
 
 template <class T>
-static inline uint32_t make_uint32_t(T p_in) {
+static _FORCE_INLINE_ uint32_t hash_make_uint32_t(T p_in) {
 	union {
 		T t;
 		uint32_t _u32;
@@ -132,7 +264,7 @@ static inline uint32_t make_uint32_t(T p_in) {
 	return _u._u32;
 }
 
-static inline uint64_t hash_djb2_one_float_64(double p_in, uint64_t p_prev = 5381) {
+static _FORCE_INLINE_ uint64_t hash_djb2_one_float_64(double p_in, uint64_t p_prev = 5381) {
 	union {
 		double d;
 		uint64_t i;
@@ -141,7 +273,7 @@ static inline uint64_t hash_djb2_one_float_64(double p_in, uint64_t p_prev = 538
 	// Normalize +/- 0.0 and NaN values so they hash the same.
 	if (p_in == 0.0f) {
 		u.d = 0.0;
-	} else if (std::isnan(p_in)) {
+	} else if (Math::is_nan(p_in)) {
 		u.d = NAN;
 	} else {
 		u.d = p_in;
@@ -150,12 +282,12 @@ static inline uint64_t hash_djb2_one_float_64(double p_in, uint64_t p_prev = 538
 	return ((p_prev << 5) + p_prev) + u.i;
 }
 
-static inline uint64_t hash_djb2_one_64(uint64_t p_in, uint64_t p_prev = 5381) {
-	return ((p_prev << 5) + p_prev) + p_in;
+static _FORCE_INLINE_ uint64_t hash_djb2_one_64(uint64_t p_in, uint64_t p_prev = 5381) {
+	return ((p_prev << 5) + p_prev) ^ p_in;
 }
 
 template <class T>
-static inline uint64_t make_uint64_t(T p_in) {
+static _FORCE_INLINE_ uint64_t hash_make_uint64_t(T p_in) {
 	union {
 		T t;
 		uint64_t _u64;
@@ -170,42 +302,43 @@ template <class T>
 class Ref;
 
 struct HashMapHasherDefault {
-	static _FORCE_INLINE_ uint32_t hash(const String &p_string) { return p_string.hash(); }
-	static _FORCE_INLINE_ uint32_t hash(const char *p_cstr) { return hash_djb2(p_cstr); }
-	static _FORCE_INLINE_ uint32_t hash(const uint64_t p_int) { return hash_one_uint64(p_int); }
-	static _FORCE_INLINE_ uint32_t hash(const ObjectID &p_id) { return hash_one_uint64(p_id); }
-
-	static _FORCE_INLINE_ uint32_t hash(const int64_t p_int) { return hash(uint64_t(p_int)); }
-	static _FORCE_INLINE_ uint32_t hash(const float p_float) { return hash_djb2_one_float(p_float); }
-	static _FORCE_INLINE_ uint32_t hash(const double p_double) { return hash_djb2_one_float(p_double); }
-	static _FORCE_INLINE_ uint32_t hash(const uint32_t p_int) { return p_int; }
-	static _FORCE_INLINE_ uint32_t hash(const int32_t p_int) { return (uint32_t)p_int; }
-	static _FORCE_INLINE_ uint32_t hash(const uint16_t p_int) { return p_int; }
-	static _FORCE_INLINE_ uint32_t hash(const int16_t p_int) { return (uint32_t)p_int; }
-	static _FORCE_INLINE_ uint32_t hash(const uint8_t p_int) { return p_int; }
-	static _FORCE_INLINE_ uint32_t hash(const int8_t p_int) { return (uint32_t)p_int; }
-	static _FORCE_INLINE_ uint32_t hash(const wchar_t p_wchar) { return (uint32_t)p_wchar; }
-	static _FORCE_INLINE_ uint32_t hash(const char16_t p_uchar) { return (uint32_t)p_uchar; }
-	static _FORCE_INLINE_ uint32_t hash(const char32_t p_uchar) { return (uint32_t)p_uchar; }
-	static _FORCE_INLINE_ uint32_t hash(const RID &p_rid) { return hash_one_uint64(p_rid.get_id()); }
-
-	static _FORCE_INLINE_ uint32_t hash(const StringName &p_string_name) { return p_string_name.hash(); }
-	static _FORCE_INLINE_ uint32_t hash(const NodePath &p_path) { return p_path.hash(); }
-
+	// Generic hash function for any type.
 	template <class T>
 	static _FORCE_INLINE_ uint32_t hash(const T *p_pointer) { return hash_one_uint64((uint64_t)p_pointer); }
 
 	template <class T>
 	static _FORCE_INLINE_ uint32_t hash(const Ref<T> &p_ref) { return hash_one_uint64((uint64_t)p_ref.operator->()); }
 
+	static _FORCE_INLINE_ uint32_t hash(const String &p_string) { return p_string.hash(); }
+	static _FORCE_INLINE_ uint32_t hash(const char *p_cstr) { return hash_djb2(p_cstr); }
+	static _FORCE_INLINE_ uint32_t hash(const wchar_t p_wchar) { return hash_fmix32(p_wchar); }
+	static _FORCE_INLINE_ uint32_t hash(const char16_t p_uchar) { return hash_fmix32(p_uchar); }
+	static _FORCE_INLINE_ uint32_t hash(const char32_t p_uchar) { return hash_fmix32(p_uchar); }
+	static _FORCE_INLINE_ uint32_t hash(const RID &p_rid) { return hash_one_uint64(p_rid.get_id()); }
+	static _FORCE_INLINE_ uint32_t hash(const StringName &p_string_name) { return p_string_name.hash(); }
+	static _FORCE_INLINE_ uint32_t hash(const NodePath &p_path) { return p_path.hash(); }
+	static _FORCE_INLINE_ uint32_t hash(const ObjectID &p_id) { return hash_one_uint64(p_id); }
+
+	static _FORCE_INLINE_ uint32_t hash(const uint64_t p_int) { return hash_one_uint64(p_int); }
+	static _FORCE_INLINE_ uint32_t hash(const int64_t p_int) { return hash_one_uint64(p_int); }
+	static _FORCE_INLINE_ uint32_t hash(const float p_float) { return hash_murmur3_one_float(p_float); }
+	static _FORCE_INLINE_ uint32_t hash(const double p_double) { return hash_murmur3_one_double(p_double); }
+	static _FORCE_INLINE_ uint32_t hash(const uint32_t p_int) { return hash_fmix32(p_int); }
+	static _FORCE_INLINE_ uint32_t hash(const int32_t p_int) { return hash_fmix32(p_int); }
+	static _FORCE_INLINE_ uint32_t hash(const uint16_t p_int) { return hash_fmix32(p_int); }
+	static _FORCE_INLINE_ uint32_t hash(const int16_t p_int) { return hash_fmix32(p_int); }
+	static _FORCE_INLINE_ uint32_t hash(const uint8_t p_int) { return hash_fmix32(p_int); }
+	static _FORCE_INLINE_ uint32_t hash(const int8_t p_int) { return hash_fmix32(p_int); }
 	static _FORCE_INLINE_ uint32_t hash(const Vector2i &p_vec) {
-		uint32_t h = hash_djb2_one_32(p_vec.x);
-		return hash_djb2_one_32(p_vec.y, h);
+		uint32_t h = hash_murmur3_one_32(p_vec.x);
+		h = hash_murmur3_one_32(p_vec.y, h);
+		return hash_fmix32(h);
 	}
 	static _FORCE_INLINE_ uint32_t hash(const Vector3i &p_vec) {
-		uint32_t h = hash_djb2_one_32(p_vec.x);
-		h = hash_djb2_one_32(p_vec.y, h);
-		return hash_djb2_one_32(p_vec.z, h);
+		uint32_t h = hash_murmur3_one_32(p_vec.x);
+		h = hash_murmur3_one_32(p_vec.y, h);
+		h = hash_murmur3_one_32(p_vec.z, h);
+		return hash_fmix32(h);
 	}
 	static _FORCE_INLINE_ uint32_t hash(const Vector4i &p_vec) {
 		uint32_t h = hash_murmur3_one_32(p_vec.x);
@@ -214,15 +347,16 @@ struct HashMapHasherDefault {
 		h = hash_murmur3_one_32(p_vec.w, h);
 		return hash_fmix32(h);
 	}
-
 	static _FORCE_INLINE_ uint32_t hash(const Vector2 &p_vec) {
-		uint32_t h = hash_djb2_one_float(p_vec.x);
-		return hash_djb2_one_float(p_vec.y, h);
+		uint32_t h = hash_murmur3_one_real(p_vec.x);
+		h = hash_murmur3_one_real(p_vec.y, h);
+		return hash_fmix32(h);
 	}
 	static _FORCE_INLINE_ uint32_t hash(const Vector3 &p_vec) {
-		uint32_t h = hash_djb2_one_float(p_vec.x);
-		h = hash_djb2_one_float(p_vec.y, h);
-		return hash_djb2_one_float(p_vec.z, h);
+		uint32_t h = hash_murmur3_one_real(p_vec.x);
+		h = hash_murmur3_one_real(p_vec.y, h);
+		h = hash_murmur3_one_real(p_vec.z, h);
+		return hash_fmix32(h);
 	}
 	static _FORCE_INLINE_ uint32_t hash(const Vector4 &p_vec) {
 		uint32_t h = hash_murmur3_one_real(p_vec.x);
@@ -231,31 +365,29 @@ struct HashMapHasherDefault {
 		h = hash_murmur3_one_real(p_vec.w, h);
 		return hash_fmix32(h);
 	}
-
 	static _FORCE_INLINE_ uint32_t hash(const Rect2i &p_rect) {
-		uint32_t h = hash_djb2_one_32(p_rect.position.x);
-		h = hash_djb2_one_32(p_rect.position.y, h);
-		h = hash_djb2_one_32(p_rect.size.x, h);
-		return hash_djb2_one_32(p_rect.size.y, h);
+		uint32_t h = hash_murmur3_one_32(p_rect.position.x);
+		h = hash_murmur3_one_32(p_rect.position.y, h);
+		h = hash_murmur3_one_32(p_rect.size.x, h);
+		h = hash_murmur3_one_32(p_rect.size.y, h);
+		return hash_fmix32(h);
 	}
-
 	static _FORCE_INLINE_ uint32_t hash(const Rect2 &p_rect) {
-		uint32_t h = hash_djb2_one_float(p_rect.position.x);
-		h = hash_djb2_one_float(p_rect.position.y, h);
-		h = hash_djb2_one_float(p_rect.size.x, h);
-		return hash_djb2_one_float(p_rect.size.y, h);
+		uint32_t h = hash_murmur3_one_real(p_rect.position.x);
+		h = hash_murmur3_one_real(p_rect.position.y, h);
+		h = hash_murmur3_one_real(p_rect.size.x, h);
+		h = hash_murmur3_one_real(p_rect.size.y, h);
+		return hash_fmix32(h);
 	}
-
 	static _FORCE_INLINE_ uint32_t hash(const AABB &p_aabb) {
-		uint32_t h = hash_djb2_one_float(p_aabb.position.x);
-		h = hash_djb2_one_float(p_aabb.position.y, h);
-		h = hash_djb2_one_float(p_aabb.position.z, h);
-		h = hash_djb2_one_float(p_aabb.size.x, h);
-		h = hash_djb2_one_float(p_aabb.size.y, h);
-		return hash_djb2_one_float(p_aabb.size.z, h);
+		uint32_t h = hash_murmur3_one_real(p_aabb.position.x);
+		h = hash_murmur3_one_real(p_aabb.position.y, h);
+		h = hash_murmur3_one_real(p_aabb.position.z, h);
+		h = hash_murmur3_one_real(p_aabb.size.x, h);
+		h = hash_murmur3_one_real(p_aabb.size.y, h);
+		h = hash_murmur3_one_real(p_aabb.size.z, h);
+		return hash_fmix32(h);
 	}
-
-	// static _FORCE_INLINE_ uint32_t hash(const void* p_ptr)  { return uint32_t(uint64_t(p_ptr))*(0x9e3779b1L); }
 };
 
 template <typename T>
@@ -268,28 +400,28 @@ struct HashMapComparatorDefault {
 template <>
 struct HashMapComparatorDefault<float> {
 	static bool compare(const float &p_lhs, const float &p_rhs) {
-		return (p_lhs == p_rhs) || (std::isnan(p_lhs) && std::isnan(p_rhs));
+		return (p_lhs == p_rhs) || (Math::is_nan(p_lhs) && Math::is_nan(p_rhs));
 	}
 };
 
 template <>
 struct HashMapComparatorDefault<double> {
 	static bool compare(const double &p_lhs, const double &p_rhs) {
-		return (p_lhs == p_rhs) || (std::isnan(p_lhs) && std::isnan(p_rhs));
+		return (p_lhs == p_rhs) || (Math::is_nan(p_lhs) && Math::is_nan(p_rhs));
 	}
 };
 
 template <>
 struct HashMapComparatorDefault<Vector2> {
 	static bool compare(const Vector2 &p_lhs, const Vector2 &p_rhs) {
-		return ((p_lhs.x == p_rhs.x) || (std::isnan(p_lhs.x) && std::isnan(p_rhs.x))) && ((p_lhs.y == p_rhs.y) || (std::isnan(p_lhs.y) && std::isnan(p_rhs.y)));
+		return ((p_lhs.x == p_rhs.x) || (Math::is_nan(p_lhs.x) && Math::is_nan(p_rhs.x))) && ((p_lhs.y == p_rhs.y) || (Math::is_nan(p_lhs.y) && Math::is_nan(p_rhs.y)));
 	}
 };
 
 template <>
 struct HashMapComparatorDefault<Vector3> {
 	static bool compare(const Vector3 &p_lhs, const Vector3 &p_rhs) {
-		return ((p_lhs.x == p_rhs.x) || (std::isnan(p_lhs.x) && std::isnan(p_rhs.x))) && ((p_lhs.y == p_rhs.y) || (std::isnan(p_lhs.y) && std::isnan(p_rhs.y))) && ((p_lhs.z == p_rhs.z) || (std::isnan(p_lhs.z) && std::isnan(p_rhs.z)));
+		return ((p_lhs.x == p_rhs.x) || (Math::is_nan(p_lhs.x) && Math::is_nan(p_rhs.x))) && ((p_lhs.y == p_rhs.y) || (Math::is_nan(p_lhs.y) && Math::is_nan(p_rhs.y))) && ((p_lhs.z == p_rhs.z) || (Math::is_nan(p_lhs.z) && Math::is_nan(p_rhs.z)));
 	}
 };
 
@@ -327,6 +459,68 @@ const uint32_t hash_table_size_primes[HASH_TABLE_SIZE_MAX] = {
 	1610612741,
 };
 
+// Computed with elem_i = UINT64_C (0 x FFFFFFFF FFFFFFFF ) / d_i + 1, where d_i is the i-th element of the above array.
+const uint64_t hash_table_size_primes_inv[HASH_TABLE_SIZE_MAX] = {
+	3689348814741910324,
+	1418980313362273202,
+	802032351030850071,
+	392483916461905354,
+	190172619316593316,
+	95578984837873325,
+	47420935922132524,
+	23987963684927896,
+	11955116055547344,
+	5991147799191151,
+	2998982941588287,
+	1501077717772769,
+	750081082979285,
+	375261795343686,
+	187625172388393,
+	93822606204624,
+	46909513691883,
+	23456218233098,
+	11728086747027,
+	5864041509391,
+	2932024948977,
+	1466014921160,
+	733007198436,
+	366503839517,
+	183251896093,
+	91625960335,
+	45812983922,
+	22906489714,
+	11453246088
+};
+
+/**
+ * Fastmod computes ( n mod d ) given the precomputed c much faster than n % d.
+ * The implementation of fastmod is based on the following paper by Daniel Lemire et al.
+ * Faster Remainder by Direct Computation: Applications to Compilers and Software Libraries
+ * https://arxiv.org/abs/1902.01961
+ */
+static _FORCE_INLINE_ uint32_t fastmod(const uint32_t n, const uint64_t c, const uint32_t d) {
+#if defined(_MSC_VER)
+	// Returns the upper 64 bits of the product of two 64-bit unsigned integers.
+	// This intrinsic function is required since MSVC does not support unsigned 128-bit integers.
+#if defined(_M_X64) || defined(_M_ARM64)
+	return __umulh(c * n, d);
+#else
+	// Fallback to the slower method for 32-bit platforms.
+	return n % d;
+#endif // _M_X64 || _M_ARM64
+#else
+#ifdef __SIZEOF_INT128__
+	// Prevent compiler warning, because we know what we are doing.
+	uint64_t lowbits = c * n;
+	__extension__ typedef unsigned __int128 uint128;
+	return static_cast<uint64_t>(((uint128)lowbits * d) >> 64);
+#else
+	// Fallback to the slower method if no 128-bit unsigned integer type is available.
+	return n % d;
+#endif // __SIZEOF_INT128__
+#endif // _MSC_VER
+}
+
 } // namespace godot
 
 #endif // HASHFUNCS_HPP