Make UtilBitScanForward a header implementation (#22406)

src/openrct2/util/Util.cpp

@@ -25,16 +25,6 @@
 #include <ctime>
 #include <random>
 
-#ifdef _WIN32
-#    ifndef NOMINMAX
-#        define NOMINMAX
-#    endif
-#    ifndef WIN32_LEAN_AND_MEAN
-#        define WIN32_LEAN_AND_MEAN
-#    endif
-#    include <windows.h>
-#endif // _WIN32
-
 int32_t SquaredMetresToSquaredFeet(int32_t squaredMetres)
 {
     // 1 metre squared = 10.7639104 feet squared
@@ -62,50 +52,6 @@ int32_t MphToDmps(int32_t mph)
     return (mph * 73243) >> 14;
 }
 
-int32_t UtilBitScanForward(uint32_t source)
-{
-#if defined(_MSC_VER) && (_MSC_VER >= 1400) // Visual Studio 2005
-    DWORD i;
-    uint8_t success = _BitScanForward(&i, source);
-    return success != 0 ? i : -1;
-#elif defined(__GNUC__)
-    int32_t success = __builtin_ffs(source);
-    return success - 1;
-#else
-#    pragma message("Falling back to iterative bitscan forward, consider using intrinsics")
-    // This is a low-hanging optimisation boost, check if your compiler offers
-    // any intrinsic.
-    // cf. https://github.com/OpenRCT2/OpenRCT2/pull/2093
-    for (int32_t i = 0; i < 32; i++)
-        if (source & (1u << i))
-            return i;
-
-    return -1;
-#endif
-}
-
-int32_t UtilBitScanForward(uint64_t source)
-{
-#if defined(_MSC_VER) && (_MSC_VER >= 1400) && defined(_M_X64) // Visual Studio 2005
-    DWORD i;
-    uint8_t success = _BitScanForward64(&i, source);
-    return success != 0 ? i : -1;
-#elif defined(__GNUC__)
-    int32_t success = __builtin_ffsll(source);
-    return success - 1;
-#else
-#    pragma message("Falling back to iterative bitscan forward, consider using intrinsics")
-    // This is a low-hanging optimisation boost, check if your compiler offers
-    // any intrinsic.
-    // cf. https://github.com/OpenRCT2/OpenRCT2/pull/2093
-    for (int32_t i = 0; i < 64; i++)
-        if (source & (1uLL << i))
-            return i;
-
-    return -1;
-#endif
-}
-
 /* Case insensitive logical compare */
 // Example:
 // - Guest 10

src/openrct2/util/Util.h

@@ -19,13 +19,59 @@
 #include <type_traits>
 #include <vector>
 
+#ifdef _MSC_VER
+#    include <intrin.h>
+#endif
+
 int32_t SquaredMetresToSquaredFeet(int32_t squaredMetres);
 int32_t MetresToFeet(int32_t metres);
 int32_t MphToKmph(int32_t mph);
 int32_t MphToDmps(int32_t mph);
 
-int32_t UtilBitScanForward(uint32_t source);
+inline int32_t UtilBitScanForward(uint32_t source)
-int32_t UtilBitScanForward(uint64_t source);
+{
+#if defined(_MSC_VER) && (_MSC_VER >= 1400) // Visual Studio 2005
+    unsigned long i;
+    uint8_t success = _BitScanForward(&i, source);
+    return success != 0 ? i : -1;
+#elif defined(__GNUC__)
+    int32_t success = __builtin_ffs(source);
+    return success - 1;
+#else
+#    pragma message("Falling back to iterative bitscan forward, consider using intrinsics")
+    // This is a low-hanging optimisation boost, check if your compiler offers
+    // any intrinsic.
+    // cf. https://github.com/OpenRCT2/OpenRCT2/pull/2093
+    for (int32_t i = 0; i < 32; i++)
+        if (source & (1u << i))
+            return i;
+
+    return -1;
+#endif
+}
+
+inline int32_t UtilBitScanForward(uint64_t source)
+{
+#if defined(_MSC_VER) && (_MSC_VER >= 1400) && defined(_M_X64) // Visual Studio 2005
+    unsigned long i;
+    uint8_t success = _BitScanForward64(&i, source);
+    return success != 0 ? i : -1;
+#elif defined(__GNUC__)
+    int32_t success = __builtin_ffsll(source);
+    return success - 1;
+#else
+#    pragma message("Falling back to iterative bitscan forward, consider using intrinsics")
+    // This is a low-hanging optimisation boost, check if your compiler offers
+    // any intrinsic.
+    // cf. https://github.com/OpenRCT2/OpenRCT2/pull/2093
+    for (int32_t i = 0; i < 64; i++)
+        if (source & (1uLL << i))
+            return i;
+
+    return -1;
+#endif
+}
+
 int32_t StrLogicalCmp(char const* a, char const* b);
 char* SafeStrCpy(char* destination, const char* source, size_t num);
 char* SafeStrCat(char* destination, const char* source, size_t size);