LEASE prefix hint is the same in non-64-bit modes and in 64-bit mode.</p>
<p>For instructions that do not support the XACQUIRE hint, the presence of the F2H prefix behaves the same way as prior hardware, according to</p>
<ul>
<li>REPNE/REPNZ semantics for string instructions,</li>
<li>Serve as SIMD prefix for legacy SIMD instructions operating on XMM register</li>
<li>Cause #UD if prepending the VEX prefix.</li>
<li>Undefined for non-string instructions or other situations.</li></ul>
<p>For instructions tha