From: "Salvador Eduardo Tropea (SET)" To: Sengan DOT Short AT durham DOT ac DOT uk, djgpp AT delorie DOT com Subject: Re: Assembly Date: Thu, 20 Jun 1996 17:32:31 +0300 (GMT) Message-ID: <9606201732.aa02162@ailin.inti.edu.ar> Hi all, here SET from Argentine: >> > > The code is "shrd edx, eax, 16". I don't know that much >> >> I believe he's trying the upper 16 bits of one register into the lower >> 16 bits (having the rest of the bits shifting along with it) >> of the second register.. I think this is a 386 instruction... >Yes, it is. I'm not convinced that gas supports all 386/486 instructions. >Am I right on this score? (the info pages don't provide a listing of those >it copes with AFAIK) I don't know if GAS suports SHRD but you can put the values inside the code: from the i486 manual: --------------------------------- SHLD = Shift Left Double TTT=100 SHRD = Shift Right Double TTT=101 --------------------------------- register with immediate [00001111][10TTT100][11 reg2 reg1][imm 8 bits] (takes 2 cycles) In a 32 bits segment is: 000 = EAX 010 = EDX I supose that reg1 is the first (I could be wrong) then the sequence is: [00001111][10101100][11010000][00010000] 0x0F 0xAC 0xD0 0x10 then i supose that you can put: .db 0x0F,0xAC,0xD0,0x10 instead of "shrd edx,eax,16" bye SET ******************************************************************************** Salvador Eduardo Tropea (SET) - salvador AT inti DOT edu DOT ar Work: INTI (National Institute of Industrial Technology) Sector: ICE (Electronic Control & Instrumentation) Post (Home): Curapaligue 2124 - Caseros (1678)- Buenos Aires - Argentina