Merge pull request #688 from LebedevRI/numActiveBits-widen

numActiveBits(): explicitly widen to at least 32 bits (OlympusDecompressor -1%)

src/librawspeed/adt/Bit.h

@@ -49,11 +49,17 @@ unsigned numSignBits(const T v) {
 }
 
 template <class T>
-  requires std::unsigned_integral<T>
+  requires(std::unsigned_integral<T> && bitwidth<T>() >= bitwidth<uint32_t>())
 unsigned numActiveBits(const T v) {
   return bitwidth(v) - std::countl_zero(v);
 }
 
+template <class T>
+  requires(std::unsigned_integral<T> && bitwidth<T>() < bitwidth<uint32_t>())
+unsigned numActiveBits(const T v) {
+  return numActiveBits(static_cast<uint32_t>(v));
+}
+
 template <class T>
   requires std::unsigned_integral<T>
 unsigned numSignificantBits(const T v) {