On Thu, 11 May 2017 10:44:25 -0700, Charles Mills wrote: >What is *wrong* with DC H'0'? It has the advantage of being incredibly >straightforward. I had to spend a minute thinking about J *+2; I pretty much >guarantee you anyone with six months of HLASM experience would "get" DC H'0'.
I wouldn't say that anything is wrong with it. But when it is included in code for a condition that should never occur and you haven't (yet) coded a proper error routine, the instruction before it is typically a branch over it. I don't know how big the branch taken hit on the pipeline is in that case. But in the J *+2 case, the normal path is to fall through, and only take the branch under the error condition. -- Tom Marchant
