Slightly less clumsy check for compiler

cpu/ppc/ppcemu.h

@@ -37,12 +37,6 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 // Uncomment this to have a more graceful approach to illegal opcodes
 //#define ILLEGAL_OP_SAFE 1
 
-// Uncomment this to use GCC built-in functions.
-#define USE_GCC_BUILTINS 1
-
-// Uncomment this to use Visual Studio built-in functions.
-//#define USE_VS_BUILTINS 1
-
 //#define CPU_PROFILING // enable CPU profiling
 
 /** type of compiler used during execution */

cpu/ppc/ppcopcodes.cpp

@@ -546,9 +546,9 @@ void dppc_interpreter::ppc_cntlzw() {
 
     uint32_t bit_check = ppc_result_d;
 
-#ifdef USE_GCC_BUILTINS
+#ifdef __builtin_clz //for GCC and Clang users
     uint32_t lead = !bit_check ? 32 : __builtin_clz(bit_check);
-#elif defined USE_VS_BUILTINS
+#elif defined __lzcnt //for Visual C++ users
     uint32_t lead = __lzcnt(bit_check);
 #else
     uint32_t lead, mask;