Indeed... one of the few omissions of the z/Architecture instruction set is the lack of LLI* instructions that operate only on the traditional 32-bit registers. Seems to me they probably should have been named LLGI* to be consistent.
sas On Fri, Jan 13, 2017 at 1:40 AM, John Dravnieks <dr...@au1.ibm.com> wrote: > There is always some method in the instructions. > > All Load Logical instructions update the part of the register as asked > for, and then zero the rest of the first operand > (for example LLC - load logical character loads > the low order byte from the second operand and zeroes the rest of the > register) > All Insert Immediate instructions update the part of the register as asked > for - the rest of the first operand is left as is > (for example, IILL - the much older IC could be > considered as an Insert Immediate Character) > All Load instructions sign extend the second operand if required and use > that result to update the first operand. > (for example, LB - Load Byte - sign extends the > one byte second operand and updates the register with the result > > Kind Regards > > John > > Internet: dr...@au.ibm.com > > > > From: Charles Mills <charl...@mcn.org> > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Date: 13/01/2017 10:45 > Subject: Re: curious: MVHI vs XC to "zero" a halfword. > Sent by: IBM Mainframe Assembler List > <ASSEMBLER-LIST@LISTSERV.UGA.EDU> > > > > Noooooooooooooooooo! > > What do a senior z/OS developer and I have in common? We both got our > butts bitten by this! > > LLILF: "The second operand is placed in bit positions of the first > operand. The remainder of the first operand is set to zeros." > > Charles > > -----Original Message----- > From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU > ] On Behalf Of Blaicher, Christopher Y. > Sent: Thursday, January 12, 2017 6:34 PM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: curious: MVHI vs XC to "zero" a halfword. > > Sorry, LLILF only load bits 32 to 63, not 0 to 63. So, LLILF meets your > requirement to load only 32 bits/ > -- sas
