ALT_FLAG_NOT
#define ALT_NOT(feature) ((ALT_FLAG_NOT << ALT_FLAGS_SHIFT) | (feature))
if (!boot_cpu_has(alt->cpuid) != !(alt->flags & ALT_FLAG_NOT))
if (flags & ~(ALT_FLAG_NOT | ALT_FLAG_DIRECT_CALL))
if (flags & ALT_FLAG_NOT)