GCC has the __builtin_cpu_supports() function on some architectures, so you may want to use that instead. It's supported: * on x86 since GCC 4.8 * on PowerPC

GCC has the __builtin_cpu_supports() function on some architectures, so you may want to use that instead. It's supported: * on x86 since GCC 4.8 * on PowerPC since GCC 6 (you will also need glibc ≥ 2.23) Documentation: https://gcc.gnu.org/onlinedocs/gcc/x86-Built-in-Functions.html https://gcc.gnu.org/onlinedocs/gcc/x86-Built-in-Functions.ht... https://gcc.gnu.org/onlinedocs/gcc/PowerPC-Built-in-Functions.html https://gcc.gnu.org/onlinedocs/gcc/PowerPC-Built-in-Function...