Xref: utzoo comp.os.msdos.programmer:761 comp.sys.ibm.pc.misc:1394 Newsgroups: comp.os.msdos.programmer,comp.sys.ibm.pc.misc Path: utzoo!utgpu!watserv1!maytag!watstat.waterloo.edu!dmurdoch From: dmurdoch@watstat.waterloo.edu (Duncan Murdoch) Subject: Re: TASM bug? (no, not at all) Message-ID: <1990Sep5.013539.22227@maytag.waterloo.edu> Sender: daemon@maytag.waterloo.edu (Admin) Organization: University of Waterloo References: <4691@bdt.UUCP> <38580@shemp.CS.UCLA.EDU> <2953@amc-gw.amc.com> Distribution: na Date: Wed, 5 Sep 90 01:35:39 GMT Lines: 14 In article <2953@amc-gw.amc.com> jwbirdsa@europa.amc.com (James Birdsall) writes: > There's also MOVZX, an obscure instruction that is available on all 80x86. >It will extend a byte to a word, zeroing the high byte. I don't know how the >execution time compares to an XOR/MOV pair, but I suspect it is faster. > Unfortunately, the complementary instruction (MOVSX, move with sign >extend) is only available on the 386. MOVZX is only available in TASM in 386 mode, and doesn't seem to work on my 8086. Is there some special encoding that TASM doesn't know about to get it to work there, or do you mean all 80x86 except mine? Duncan Murdoch