For those wondering what he meant by the "data dependency" issue that zeroing out the upper 32 bits avoids, the first answer to this SO question does a decent j

For those wondering what he meant by the "data dependency" issue that zeroing out the upper 32 bits avoids, the first answer to this SO question does a decent job of explaining it: https://stackoverflow.com/questions/11177137/why-do-most-x64-instructions-zero-the-upper-part-of-a-32-bit-register https://stackoverflow.com/questions/11177137/why-do-most-x64...