diff --git a/cpp/csp/core/DynamicBitSet.h b/cpp/csp/core/DynamicBitSet.h
index 9ab7c62ed..3d55679ba 100644
--- a/cpp/csp/core/DynamicBitSet.h
+++ b/cpp/csp/core/DynamicBitSet.h
@@ -155,19 +155,12 @@ class DynamicBitSet
 private:
     using nbit_type = uint8_t;
 
-#ifndef WIN32
-#define CLZ_CONSTEXPR constexpr
-#else
-#define CLZ_CONSTEXPR 
-#endif
-
     template<typename value_type, 
         std::enable_if_t<std::is_unsigned<value_type>::value, bool> = true>
     static constexpr nbit_type nbits() { return sizeof( value_type ) * 8; }
 
     template<typename U, std::enable_if_t<std::is_unsigned<U>::value, bool> = true>
-    static CLZ_CONSTEXPR nbit_type log2( U n )           { return nbits<uint32_t>() - clz(static_cast<uint32_t>( n )) - 1; } //upcast to 32 bit to avoid truncation for log2
-    static CLZ_CONSTEXPR nbit_type log2(uint64_t n)      { return nbits<uint64_t>() - clz(n) - 1; }
+    static constexpr nbit_type log2( U n )           { return nbits<U>() - clz( n ) - 1; }
 
     static constexpr node_type mask( nbit_type bitIndex )  { return ( node_type )1 << bitIndex; }
 
@@ -182,7 +175,7 @@ class DynamicBitSet
     }
 
     static constexpr nbit_type _bits               = nbits<NodeT>();
-    static inline CLZ_CONSTEXPR nbit_type _logBits = log2( _bits );
+    static inline constexpr nbit_type _logBits = log2( _bits );
 
     node_type * m_nodes;
     index_type  m_size;
diff --git a/cpp/csp/core/Platform.h b/cpp/csp/core/Platform.h
index 37474faf6..3f3cdd0db 100644
--- a/cpp/csp/core/Platform.h
+++ b/cpp/csp/core/Platform.h
@@ -1,5 +1,6 @@
 #ifndef _IN_CSP_CORE_PLATFORM_H
 #define _IN_CSP_CORE_PLATFORM_H
+#include <bit>
 #include <type_traits>
 #include <stdint.h>
 #include <time.h>
@@ -52,42 +53,6 @@ inline int nanosleep(const timespec* req, timespec* rem)
     return 0;
 }
 
-inline uint8_t clz(uint64_t n)
-{
-    unsigned long index = 0;
-    if (_BitScanReverse64(&index, n))
-	    return 64 - index - 1;
-    return 0;
-}
-
-inline uint8_t clz(uint32_t n)
-{
-    unsigned long index = 0;
-    if (_BitScanReverse(&index, n))
-	    return 32 - index - 1;
-    return 0;
-}
-
-inline uint8_t clz(uint16_t n) { return clz(static_cast<uint32_t>(n)) - 16; }
-inline uint8_t clz(uint8_t n)  { return clz(static_cast<uint32_t>(n)) - 24; }
-
-template<typename U, std::enable_if_t<std::is_unsigned<U>::value, bool> = true>
-inline uint8_t ffs(U n)
-{ 
-    unsigned long index = 0;
-    if (_BitScanForward(&index, n))
-	    return index + 1;
-    return 0;
-}
-
-inline uint8_t ffs(uint64_t n)
-{
-    unsigned long index = 0;
-    if (_BitScanForward64(&index, n))
-	    return index + 1;
-    return 0;
-}
-
 #else
 
 #define CSPIMPL_EXPORT
@@ -100,19 +65,14 @@ inline uint8_t ffs(uint64_t n)
 
 #define NO_INLINE  __attribute__ ((noinline))
 
-inline constexpr uint8_t clz(uint32_t n) { return __builtin_clz(n); }
-inline constexpr uint8_t clz(uint64_t n) { return __builtin_clzl(n); }
+#endif
 
 // clz (count leading zeros) returns number of leading zeros before MSB (i.e. clz(00110..) = 2 )
-// __builtin_clz auto-promotes to 32-bits: need to subtract off extra leading zeros
-inline constexpr uint8_t clz(uint16_t n) { return clz(static_cast<uint32_t>(n)) - 16; }
-inline constexpr uint8_t clz(uint8_t n)  { return clz(static_cast<uint32_t>(n)) - 24; }
+template<typename U, std::enable_if_t<std::is_unsigned<U>::value, bool> = true>
+inline constexpr uint8_t clz( U n )        { return std::countl_zero(n); }
 
 // ffs (find first set) returns offset of first set bit (i.e. ffs(..0110) = 2 ), with ffs(0) = 0
 template<typename U, std::enable_if_t<std::is_unsigned<U>::value, bool> = true>
-inline constexpr uint8_t ffs( U n )        { return __builtin_ffs(n); }
-inline constexpr uint8_t ffs( uint64_t n ) { return __builtin_ffsl(n); }
-
-#endif
+inline constexpr uint8_t ffs( U n )        { return n ? std::countr_zero(n) + 1 : 0; }
 
 #endif