return int(_BitScanForward64(&index, (unsigned long long)x) ? index + 1 : 0);
}
+FOLLY_ALWAYS_INLINE int __builtin_popcount(unsigned int x) {
+ return int(__popcnt(x));
+}
+
FOLLY_ALWAYS_INLINE int __builtin_popcountll(unsigned long long x) {
return int(__popcnt64(x));
}