66370a83

REPLY:  d0f27957

PID: SoupGate-Win32 v1.05
XPost: alt.folklore.computers

Dan Espen  wrote:
> Dennis Lee Bieber  writes:
>
>> On Mon, 4 Jan 2021 11:00:29 +0000, gareth evans 
>> declaimed the following:
>>
>>> Thinking back to my first job, nearly 50 years ago now,
>>> when I had to dis-assemble DEC's paper tape BASIC
>>> interpreter in order to enhance it, I guess that
>>> dis-assemblers and decompilers must now be ten-a-penny,
>>> especially for programs running under Windows where
>>> the structure of Windows programs is well-known with
>>> an assumption that C was the source language?
>>>
>> Actually, I think the use of disassemblers et al has fallen away.
>> Modern processors have so many peephole optimizations and out-of-order
>> execution streams that converting an executable back to assembly source is
>> almost meaningless -- and getting back to a high-level language is near
>> impossible. One would have to be an expert at the assembly for a processor
>> to have any chance of understanding the result.
>
> Well, in my last job I often used disassemblers.
> IBM z/OS.
> Very useful for understanding IBM code.

I was going to say that disassemblers for IBM seem to work fairly well.
I’ve used them a few times.

>
> I can't see what out of order execution has to do with a disassembler.
> You disassemble executables.
>
> Since I understand Assembler, I certainly got meaning out of it
> even if the original was an optimized HLL.  You can see what services
> are being called.
>

I think, for example, that one disassembler might recognize the SVC
number.i think it put the macro name in as a comment (LINK, GETMAIN, etc.)


--
Pete

--- SoupGate-Win32 v1.05