4 ms·

I think they always did AOT compilation from the AS/400 instruction set to the actual hardware. In the '90s I worked for an external company that did some compi

by kps 3y ago

I think they always did AOT compilation from the AS/400 instruction set to the actual hardware. In the '90s I worked for an external company that did some compiler work on a horizontally-microcoded implementation that didn't get close to shipping. (I don't remember many details, and if I did, I expect they'd still be under NDA.)

jasomill 3y ago
This is true; at one point, there was even an instruction that deleted the untranslated code ("program template") to save disk space, https://bitsavers.org/pdf/ibm/system38/GA21-9331-1_System_38_Functional_Reference_Manual_Feb81.pdf#page=195 https://bitsavers.org/pdf/ibm/system38/GA21-9331-1_System_38... This instruction is either not present or not documented in the current Machine Interface[1], but I have no idea when or if it was removed. [1] https://www.ibm.com/docs/en/i/7.5?topic=interface-machine-instructions https://www.ibm.com/docs/en/i/7.5?topic=interface-machine-in...
- skissane 3y ago
  > This instruction is either not present or not documented in the current Machine Interface That’s not actually the current Machine Interface, that’s the legacy one. The current one isn’t documented outside of IBM. IBM still supports the legacy MI, which is translated to the current MI - and high-level language programs compiled to current MI can even embed legacy MI calls as a kind of “in-line assembly” - but all that is converted to the new MI as part of the compilation process