Improving djbHash for MIPS.

Author: nicolasnoble

src/mips/common/util/djbhash.h

@@ -28,8 +28,32 @@ SOFTWARE.
 
 #include <stdint.h>
 
+#ifdef __cplusplus
+#include <concepts>
+
+namespace djb {
+
+template <std::integral T = uint32_t>
+static inline constexpr T process(T hash, const char str[], unsigned n) {
+    return n ? process(((hash << 5) + hash) ^ static_cast<uint8_t>(str[0]), str + 1, n - 1) : hash;
+}
+
+template <std::integral T = uint32_t>
+static inline T constexpr hash(const char* str, unsigned n) {
+    return process(T(5381), str, n);
+}
+
+template <std::integral T = uint32_t, unsigned S>
+static inline T constexpr hash(const char (&str)[S]) {
+    return process(T(5381), str, S - 1);
+}
+
+}  // namespace djb
+
+#endif
+
 static inline uint32_t djbProcess(uint32_t hash, const char str[], unsigned n) {
-    return n ? djbProcess(((hash << 5) + hash) ^ str[0], str + 1, n - 1) : hash;
+    return n ? djbProcess(((hash << 5) + hash) ^ ((uint8_t)str[0]), str + 1, n - 1) : hash;
 }
 
 static inline uint32_t djbHash(const char* str, unsigned n) { return djbProcess(5381, str, n); }