The TRAP facility was originally implemented in the hardware for Y2K support. It was to be used by products to overlay clock related instructions so different clocks/dates could be simulated. At least that is what I was told many years ago.
Chuck Arney > On Jun 20, 2019, at 4:41 PM, Chuck <[email protected]> wrote: > > The TRAP Instructions work fine John. You have used a product that uses them. > > Chuck Arney > >> On Jun 20, 2019, at 7:16 AM, John McKown <[email protected]> >> wrote: >> >> This is purely speculation, but I like what I've read about the "trap" >> facility. I think it is too bad that z/OS doesn't support the use of TRAP2, >> TRAP4, as well as the compare-and-trap and load-and-trap. I agree that they >> are not _necessary_ since the code can do basically the same thing. The >> only reason that I even bring it up is that the paper "IBM Z / LinuxONE >> System Processor Optimization Primer" by C. Kevin Shum on page 51 >> "Optimization - Instruction Selection (1)" recommends using >> "compare-and-trap" where practical, in particular, for null-pointer >> checking. >> >> Perhaps I should have waited for Friday to post this since it is only >> wishful thinking. >> >> -- >> Money is the root of all evil. >> Evil is the root of all money. >> With that in mind, money is made by the government ... >> >> >> Maranatha! <>< >> John McKown >> >> ---------------------------------------------------------------------- >> For IBM-MAIN subscribe / signoff / archive access instructions, >> send email to [email protected] with the message: INFO IBM-MAIN >> > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
