A diff for LibFileZilla to compile with clang-cl and for x86. Ref: https://svn.filezilla-project.org/filezilla/libfilezilla/trunk/lib/util.cpp?view=markup

libfilezilla-x86.diff

--- a/libfilezilla/lib/util.cpp 2020-07-01 12:30:29
+++ b/libfilezilla/lib/util.cpp 2020-07-04 15:32:17
@@ -125,8 +125,22 @@

 uint64_t bitscan(uint64_t v)
 {
-#if !FZ_WINDOWS || defined(__MINGW32__) || defined(__MINGW64__)
+#if !FZ_WINDOWS || defined(__MINGW32__) || defined(__MINGW64__) || defined(__clang__)
 	return __builtin_ctzll(v);
+#elif defined(_M_IX86)
+   /*
+    * Modified from:
+    *   https://github.com/google/re2/commit/35febd432d9e6d8630845285c7f29eabd1df7beb
+    */
+    unsigned long i;
+
+    if (static_cast<uint32_t>(v) != 0) {
+      _BitScanForward(&i, static_cast<uint32_t>(v));
+      return static_cast<uint64_t>(i);
+    }
+    _BitScanForward(&i, static_cast<uint32_t>(v >> 32));
+    return static_cast<uint64_t>(i) + 32;
+
 #else
 	unsigned long i;
 	_BitScanForward64(&i, v);
@@ -137,8 +151,19 @@

 uint64_t bitscan_reverse(uint64_t v)
 {
-#if !FZ_WINDOWS || defined(__MINGW32__) || defined(__MINGW64__)
+#if !FZ_WINDOWS || defined(__MINGW32__) || defined(__MINGW64__) || defined(__clang__)
 	return 63 - __builtin_clzll(v);
+#elif defined(_M_IX86)
+    unsigned long i;
+    uint32_t x = static_cast<uint32_t>(v >> 32);
+
+    if (_BitScanReverse(&i, x))
+       return (i + 1 + 32);
+
+    x = static_cast<uint32_t>(v);
+    if (_BitScanReverse(&i, x))
+       return (i + 1);
+    return (0ULL);
 #else
 	unsigned long i;
 	_BitScanReverse64(&i, v);