Testing equality between two __m128i variables

Question

If I want to do a bitwise equality test between two __m128i variables, am I required to use an SSE instruction or can I use ==? If not, which SSE i

Answer 1

Consider using an SSE4.1 instruction ptest:

if(_mm_testc_si128(v0, v1)) {if equal}

else {if not} 

ptest computes the bitwise AND of 128 bits (representing integer data) in a and mask, and return 1 if the result is zero, otherwise return 0.