On Fri, 22 Mar 2024 at 13:46, Dan Greiner <[email protected]> wrote:
> [...] > One newer facility that might prove to be a significant benefit to older > code – and worthy of upgrade – is the vector packed-decimal facility > (introduced on the z14) and its enhancements 1 and 2 (introduced on the z15 > and z16, respectively). For packed-decimal workloads, avoiding all of the > memory accesses inherent to the Chapter 8 decimal instructions – and having > 32 128-bit registers – is a real attraction. An alternative to branchy > dual-path code might be to have separate load modules – one for the > original-recipe code and one for the extra-crispy code – that are > dynamically invoked based on the presence (or absence) of the particular > facility. > There was talk from IBM some years ago about supporting "fat binaries" i.e. Program Objects that contain two or more alternative modules, along with some environment-based mechanism to choose which one gets invoked by z/OS. IIRC it was Bob Rogers who presented on it, and of course various other OSs and architectures have had this kind of thing for a long time. https://en.wikipedia.org/wiki/Fat_binary I don't think it was ever shipped in z/OS, but it would seem like a good solution to this aspect of the problem. Tony H.
