Add CPUID check for AVX-512

2 files changed, 9 insertions, 2 deletions

diff --git a/src/utils/cpuid.cpp b/src/utils/cpuid.cpp
index d903b7d41..c727471bc 100644
--- a/src/utils/cpuid.cpp
+++ b/src/utils/cpuid.cpp
@@ -200,10 +200,10 @@ void CPUID::initialize()
 #if defined(BOTAN_TARGET_ARCH_IS_X86_64)
    /*
    * If we don't have access to CPUID, we can still safely assume that
-   * any x86-64 processor has SSE2.
+   * any x86-64 processor has SSE2 and RDTSC
    */
    if(m_x86_processor_flags[0] == 0)
-      m_x86_processor_flags[0] = (1 << CPUID_SSE2_BIT);
+      m_x86_processor_flags[0] = (1 << CPUID_SSE2_BIT) | (1 << CPUID_RDTSC_BIT);
 #endif
    }
 
diff --git a/src/utils/cpuid.h b/src/utils/cpuid.h
index eaf1c1330..008605e0c 100644
--- a/src/utils/cpuid.h
+++ b/src/utils/cpuid.h
@@ -65,6 +65,12 @@ class BOTAN_DLL CPUID
          { return x86_processor_flags_has(CPUID_AVX2_BIT); }
 
       /**
+      * Check if the processor supports AVX-512F
+      */
+      static bool has_avx512f()
+         { return x86_processor_flags_has(CPUID_AVX512F_BIT); }
+
+      /**
       * Check if the processor supports BMI2
       */
       static bool has_bmi2()
@@ -123,6 +129,7 @@ class BOTAN_DLL CPUID
 
          CPUID_AVX2_BIT = 64+5,
          CPUID_BMI2_BIT = 64+8,
+         CPUID_AVX512F_BIT = 64+16,
          CPUID_RDSEED_BIT = 64+18,
          CPUID_ADX_BIT = 64+19,
          CPUID_SHA_BIT = 64+29,