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README.md

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+Automatic CMake CPU Feature Detection
+=====================================
+
+## Usage
+
+Copy `CPUFeatureDetect.cmake` to your project directory.
+
+Add to your `CMakeLists.txt`:
+
+```haskell
+include(${PROJECT_SOURCE_DIR}/CPUFeatureDetect.cmake)
+```
+
+Call `genCPUFeatures(namespace)` to generate variables describing the current build environment's CPU capabilities.
+
+```haskell
+genCPUFeatures(MyProject)
+if(MyProject_FEATURE_AVX2)
+    message(STATUS "[MyProject] Building with AVX2...")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mavx2")
+else()
+    message(STATUS "[MyProject] AVX2 not found!")
+endif()
+```
+
+## How It Works
+
+We parse the llvm compiler CPU feature list (see `./generateCPUDetailsToFeatures.py`)
+for all possible CPU features to generate `CPUFeatureDetect.cmake`, then when you run the 
+`genCPUFeatures()` CMake function, we call potentially dozens of `check_c_source_compiles()` checks
+against all the compile feature flags to determine which CPU features are available given
+your current `CFLAGS` configuration.
+
+If you don't have `-march=` specified or you request `-march=native`,
+we run all the CPU check test programs to determine your capability. If you do specify a `-march=`
+option, we use the CPU architecture name to determine which feature are available _without_ running
+any test programs (for cross compiling, etc).