Effectiveness of GCC optmization on bit operations

Question

Here are two ways to set an individual bit in C on x86-64:

inline void SetBitC(long *array, int bit) {
   //Pure C version
   *array |= 1<

        

Answer 1

Can you post the code that you are using to do the timing? This sort of operation can be tricky to time accurately.

In theory the two code sequences should be equally fast, so the most likely explanation (to my mind) is that something is causing your timing code to give bogus results.