anchor.diff:  # Select a specific optimization target (other than the default)
   # See https://github.com/xianyi/OpenBLAS/blob/develop/TargetList.txt
   , target ? null
  +# Select whether DYNAMIC_ARCH is enabled or not.
  +, dynamicArch ? null
   , enableStatic ? stdenv.hostPlatform.isStatic
   , enableShared ? !stdenv.hostPlatform.isStatic
   }:
  
positive.code: 
  let
    setTarget = x: if target == null then x else target;
  
    # To add support for a new platform, add an element to this set.
    configs = {
      armv6l-linux = {
        BINARY = 32;
        TARGET = setTarget "ARMV6";
        DYNAMIC_ARCH = false;
        USE_OPENMP = true;
      };
  
      armv7l-linux = {
        BINARY = 32;
        TARGET = setTarget "ARMV7";
        DYNAMIC_ARCH = false;
        USE_OPENMP = true;
      };
  
      aarch64-darwin = {
        BINARY = 64;
        TARGET = setTarget "VORTEX";
        DYNAMIC_ARCH = true;
        USE_OPENMP = false;
        MACOSX_DEPLOYMENT_TARGET = "11.0";
      };
  
negative.code:     aarch64-linux = {
        BINARY = 64;
        TARGET = setTarget "ARMV8";
        DYNAMIC_ARCH = setDynamicArch true;
        USE_OPENMP = true;
      };
  
      i686-linux = {
        BINARY = 32;
        TARGET = setTarget "P2";
        DYNAMIC_ARCH = setDynamicArch true;
        USE_OPENMP = true;
      };
  
      x86_64-darwin = {
        BINARY = 64;
        TARGET = setTarget "ATHLON";
        DYNAMIC_ARCH = setDynamicArch true;
        USE_OPENMP = false;
        MACOSX_DEPLOYMENT_TARGET = "10.7";
      };
  