Author: Bruce Moreland
Date: 23:20:17 01/26/99
Go up one level in this thread
On January 27, 1999 at 02:18:41, Bruce Moreland wrote: > >On January 27, 1999 at 01:32:28, Eugene Nalimov wrote: > >>On January 26, 1999 at 22:38:37, James Robertson wrote: >> >>>Once again I show my absolute ignorance of assembly with these two questions: >>>I am trying to acces the 3rd [+ 4th] byte of a register. How? E.g., what is next >>>after al, ah, ? >>>How do I pop something off the stack without moving the stack pointer? >>> >>>Thanks, >>>James >> >>1. Use shift instruction. E.g. >> shr eax, 16 >> mov byte ptr [esi], al >> You can also use rotate instruction (it'll not destruct >> other bytes): >> ror eax, 16 >> mov byte ptr [esi], al >> ror eax, 16 >> But if I remember it correctly, rotate is worse than shift >> (cannot be executed in parallel) on both Pentium and P6 family. > >The shift also sucks, AFAIK. > >>2. mov reg32, dword ptr [esp] > >esp - 4, right? But can you say [esp - 4]? I seem to remember that you can't. I'm wrong, stack grows toward zero. bruce
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.