> -----Original Message----- > From: IBM Mainframe Discussion List > [mailto:[EMAIL PROTECTED] On Behalf Of Edward Jaffe > Sent: Monday, April 21, 2008 10:15 AM > To: IBM-MAIN@BAMA.UA.EDU > Subject: Re: "action" in UK33496 > > > McKown, John wrote: > > Why use J *+2 ? It assembles to "A7F4 0001", which would jump to the > > "0001" portion of the instruction. Why not just hard code a > H'0'? Do you > > have some fancy debugger which detects this particular sequence by > > saying something like: "If the abend is a S0C1, and the > opcode is x'00' > > followed by a x'01' and the BEA register points 2 bytes > before the abend > > address, then report a deliberate abend."? > > > > Jumps can be conditional. DC H'0', EX of EX, and all similar > techniques > are "messy" because you must always branch *around* the code to force > the abend. For example: > > CLI 0(R1),C'A' Value too low? > JNL LABEL1 Branch if not > DC H'0' Force logic error" abend > LABEL1 DC 0H > CLI 0(R1),C'9' Value too high? > JNH LABEL2 Branch if not > DC H'0' Force logic error" abend > LABEL2 DC 0H > > vs the very simple ... > > CLI 0(R1),C'A' Value too low? > JL *+2 Force logic error" abend > CLI 0(R1),C'9' Value too high? > JH *+2 Force logic error" abend > > -- > Edward E Jaffe
Ah. Now that is __CLEVER__! I may adopt it myself. In fact, time to rewrite the code that I was rewriting! -- John McKown Senior Systems Programmer HealthMarkets Keeping the Promise of Affordable Coverage Administrative Services Group Information Technology The information contained in this e-mail message may be privileged and/or confidential. It is for intended addressee(s) only. If you are not the intended recipient, you are hereby notified that any disclosure, reproduction, distribution or other use of this communication is strictly prohibited and could, in certain circumstances, be a criminal offense. If you have received this e-mail in error, please notify the sender by reply and delete this message without copying or disclosing it. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
