refactor: remove redundant SIMD flags and runtime detection

- Remove duplicate SIMD flags from test/samples/benchmark CMakeLists
  (flags already inherited from nfx-hashing INTERFACE target)
- Remove runtime SSE4.2 detection fallback in crc32c()
  (intrinsics unavailable without compile-time flags anyway)

Author: ronan-fesselier

benchmark/CMakeLists.txt

@@ -80,17 +80,15 @@ foreach(benchmark_source ${benchmark_sources})
         )
 
         #----------------------------------------------
-        # Enable specific CPU features
+        # Compiler warnings
         #----------------------------------------------
 
         target_compile_options(${benchmark_target_name}
             PRIVATE
-                $<$<CXX_COMPILER_ID:MSVC>:/arch:AVX2>
-                $<$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>>:-msse4.2>
-
                 $<$<CXX_COMPILER_ID:MSVC>:/W4 /WX>
                 $<$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>>:-Wall -Wextra -Werror>
         )
+
         #----------------------------------------------
         # Properties
         #----------------------------------------------

include/nfx/detail/hashing/Algorithms.inl

@@ -104,23 +104,7 @@ namespace nfx::hashing
         return _mm_crc32_u8( hash, ch );
 #    endif
 #else
-        // No compile-time SSE4.2 - check at runtime
-        if( internal::hasSse42Support() )
-        {
-#    if defined( __GNUC__ ) || defined( __clang__ )
-            return __builtin_ia32_crc32qi( hash, ch );
-#    elif defined( _MSC_VER )
-            return _mm_crc32_u8( hash, ch );
-#    else
-            // Compiler doesn't support intrinsics, fall back to software
-            return crc32cSoft( hash, ch );
-#    endif
-        }
-        else
-        {
-            // CPU doesn't support SSE4.2, use software implementation
-            return crc32cSoft( hash, ch );
-        }
+        return crc32cSoft( hash, ch );
 #endif
     }
 

samples/CMakeLists.txt

@@ -43,14 +43,11 @@ foreach(sample_source ${sample_sources})
         )
 
         #----------------------------------------------
-        # Enable specific CPU features
+        # Compiler warnings
         #----------------------------------------------
 
         target_compile_options(${sample_target_name}
             PRIVATE
-                $<$<CXX_COMPILER_ID:MSVC>:/arch:AVX2>
-                $<$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>>:-msse4.2>
-
                 $<$<CXX_COMPILER_ID:MSVC>:/W4 /WX>
                 $<$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>>:-Wall -Wextra -Werror>
         )

test/CMakeLists.txt

@@ -98,14 +98,11 @@ foreach(test_source ${test_sources})
         )
 
         #----------------------------------------------
-        # Enable specific CPU features
+        # Compiler warnings
         #----------------------------------------------
 
         target_compile_options(${test_target_name}
             PRIVATE
-                $<$<CXX_COMPILER_ID:MSVC>:/arch:AVX2>
-                $<$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>>:-msse4.2>
-
                 $<$<CXX_COMPILER_ID:MSVC>:/W4 /WX>
                 $<$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>>:-Wall -Wextra -Werror>
         )