Re: Question on TIMI implementation.

[Jon Paris <Jon.Paris@xxxxxxxxxxxxxx>]

On 12-Dec-08, at 6:54 PM, midrange-l-request@xxxxxxxxxxxx wrote:

> The compilers generate MI (nowadays NMI, "new MI"), then call an OS
> component called the "Optimizing Translator", which generates PowerPC
> machine instructions.

My understanding is that ity is slightly more complex than Dave's  
explanation so I'll add it to the mix. ILE compilers generate  
something called W-code which is a platform-neutral MI (kind of an  
assembler for a machine that doesn't exist!).  The compiler also  
generates "hints" for the target platform's translator to ensure that  
it can generate the most efficient code stream.  On other platforms  
(e.g. Windows, AIX) the W-code is then converted to machine  
instructions.  On IBM i the W-code is translated to "new MI" (aka MI- 
prime) and it is this that is subsequently converted to machine code.   
Not sure what happens with OPM programs these days - I would assume  
that the (old) MI instructions they generate are converted to MI-prime  
and then follow the same process, but I don't know that as a fact.

Jon Paris

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www.SystemiDeveloper.com