From: "Steve Smith" <[email protected]> Sent: Tuesday, August 11, 2020 11:07 AM
For the whole register, LGHI, LLILL (or HL, LH, or HH) are best. LLILF, LLIHF take up more space. XGR, SGR, SLGR set the CC.
For only the low half, XR, SR, SLR have the shortness advantage, and LHI the non-CC advantage.
Chances are that the CC setting is irrelevant in timing on modern CPUs.
The worst way to zero a register is more interesting. JCTG Rx,* is my favorite. If Rx is already 0, guess how long that will take.
I think that EX JCTG Rx,* takes longer. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
