diff --git a/include/primesieve/cpu_supports_avx512_vbmi2.hpp b/include/primesieve/cpu_supports_avx512_vbmi2.hpp
index 5ab575eb..0e59e47c 100644
--- a/include/primesieve/cpu_supports_avx512_vbmi2.hpp
+++ b/include/primesieve/cpu_supports_avx512_vbmi2.hpp
@@ -11,74 +11,16 @@
 #ifndef CPU_SUPPORTS_AVX512_VBMI2_HPP
 #define CPU_SUPPORTS_AVX512_VBMI2_HPP
 
-#include "cpuid.hpp"
+namespace primesieve {
 
-#if defined(_MSC_VER)
-  #include <immintrin.h>
-#endif
-
-// %ebx bit flags
-#define bit_AVX512F (1 << 16)
-
-// %ecx bit flags
-#define bit_AVX512VBMI  (1 << 1)
-#define bit_AVX512VBMI2 (1 << 6)
+bool has_cpuid_avx512_vbmi2();
 
-// xgetbv bit flags
-#define XSTATE_SSE (1 << 1)
-#define XSTATE_YMM (1 << 2)
-#define XSTATE_ZMM (7 << 5)
+} // namespace
 
 namespace {
 
-// Get Value of Extended Control Register
-inline int get_xcr0()
-{
-  int xcr0;
-
-#if defined(_MSC_VER)
-  xcr0 = (int) _xgetbv(0);
-#else
-  __asm__ ("xgetbv" : "=a" (xcr0) : "c" (0) : "%edx" );
-#endif
-
-  return xcr0;
-}
-
-inline bool run_cpuid_avx512_vbmi2()
-{
-  int abcd[4];
-
-  run_cpuid(1, 0, abcd);
-
-  int osxsave_mask = (1 << 27);
-
-  // Ensure OS supports extended processor state management
-  if ((abcd[2] & osxsave_mask) != osxsave_mask)
-    return false;
-
-  int ymm_mask = XSTATE_SSE | XSTATE_YMM;
-  int zmm_mask = XSTATE_SSE | XSTATE_YMM | XSTATE_ZMM;
-
-  int xcr0 = get_xcr0();
-
-  // Check AVX OS support
-  if ((xcr0 & ymm_mask) != ymm_mask)
-    return false;
-
-  // Check AVX512 OS support
-  if ((xcr0 & zmm_mask) != zmm_mask)
-    return false;
-
-  run_cpuid(7, 0, abcd);
-
-  // PrimeGenerator::fillNextPrimes() requires AVX512F, AVX512VBMI & AVX512VBMI2
-  return ((abcd[1] & bit_AVX512F) == bit_AVX512F &&
-          (abcd[2] & (bit_AVX512VBMI | bit_AVX512VBMI2)) == (bit_AVX512VBMI | bit_AVX512VBMI2));
-}
-
 /// Initialized at startup
-bool cpu_supports_avx512_vbmi2 = run_cpuid_avx512_vbmi2();
+bool cpu_supports_avx512_vbmi2 = primesieve::has_cpuid_avx512_vbmi2();
 
 } // namespace
 
diff --git a/include/primesieve/cpu_supports_popcnt.hpp b/include/primesieve/cpu_supports_popcnt.hpp
index 212c0f3b..ded65c3e 100644
--- a/include/primesieve/cpu_supports_popcnt.hpp
+++ b/include/primesieve/cpu_supports_popcnt.hpp
@@ -11,48 +11,17 @@
 #ifndef CPU_SUPPORTS_POPCNT_HPP
 #define CPU_SUPPORTS_POPCNT_HPP
 
-// Enable CPUID on x86 and x86-64 CPUs
-#if defined(__x86_64__) || \
-    defined(__i386__) || \
-    defined(_M_X64) || \
-    defined(_M_IX86)
-
-// Both GCC and Clang (even Clang on Windows) define the __POPCNT__
-// macro if the user compiles with -mpopcnt. The __POPCNT__
-// macro is even defined if the user compiles with other flags
-// such as -mavx or -march=native.
-#if defined(__POPCNT__)
-  #define HAS_POPCNT
-// The MSVC compiler does not support a POPCNT macro, but if the user
-// compiles with e.g. /arch:AVX or /arch:AVX512 then MSVC defines
-// the __AVX__ macro and POPCNT is also supported.
-#elif defined(_MSC_VER) && defined(__AVX__)
-  #define HAS_POPCNT
-#endif
+namespace primesieve {
 
-#if !defined(HAS_POPCNT)
+bool has_cpuid_popcnt();
 
-#include "cpuid.hpp"
-#define ENABLE_CPUID_POPCNT
+} // namespace
 
 namespace {
 
-inline bool run_cpuid_supports_popcnt()
-{
-  int abcd[4];
-  run_cpuid(1, 0, abcd);
-
-  // %ecx POPCNT bit flag
-  int bit_POPCNT = 1 << 23;
-  return (abcd[2] & bit_POPCNT) == bit_POPCNT;
-}
-
 /// Initialized at startup
-bool cpu_supports_popcnt = run_cpuid_supports_popcnt();
+bool cpu_supports_popcnt = primesieve::has_cpuid_popcnt();
 
 } // namespace
 
-#endif // !defined(HAS_POPCNT)
-#endif // CPUID
-
 #endif