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From: Mikko <mikko.levanto@iki.fi>
Newsgroups: comp.theory
Subject: Re: People are still trying to get away with disagreeing with the semantics of the x86 language
Date: Tue, 2 Jul 2024 09:59:09 +0300
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On 2024-07-01 12:44:57 +0000, olcott said:

> On 7/1/2024 1:05 AM, Mikko wrote:
>> On 2024-06-30 17:18:09 +0000, olcott said:
>>> 
>>> Richard just said that he affirms that when DDD correctly
>>> simulated by HHH calls HHH(DDD) that this call returns even
>>> though the semantics of the x86 language disagrees.
>>> 
>>> On 6/30/2024 7:34 AM, Richard Damon wrote:
>>>  > It is still true that the xemantics of the x86
>>>  > language define the behavior of a set of bytes,
>>>  > as the behavior when you ACTUALLY RUN THEM,
>>>  > and nothing else.
>>> 
>>> _DDD()
>>> [00002172] 55               push ebp      ; housekeeping
>>> [00002173] 8bec             mov ebp,esp   ; housekeeping
>>> [00002175] 6872210000       push 00002172 ; push DDD
>>> [0000217a] e853f4ffff       call 000015d2 ; call HHH(DDD)
>>> [0000217f] 83c404           add esp,+04
>>> [00002182] 5d               pop ebp
>>> [00002183] c3               ret
>>> Size in bytes:(0018) [00002183]
>>> 
>>> Richard thinks that he can get away with disagreeing with this
>>> verified fact:
>>> 
>>> The call from DDD to HHH(DDD) when N steps of DDD are correctly
>>> emulated by any pure function x86 emulator HHH cannot possibly
>>> return.
>> 
>> It is your HHH so you should know whether it returns. Others may
>> have wrong impression about it if they have trusted your lies.
> 
> I have never lied about this.

At least you have claimed more than proven.

> _DDD()
> [00002172] 55               push ebp      ; housekeeping
> [00002173] 8bec             mov ebp,esp   ; housekeeping
> [00002175] 6872210000       push 00002172 ; push DDD
> [0000217a] e853f4ffff       call 000015d2 ; call HHH(DDD)
> [0000217f] 83c404           add esp,+04
> [00002182] 5d               pop ebp
> [00002183] c3               ret
> Size in bytes:(0018) [00002183]
> 
> DDD is correctly emulated by HHH which calls an
> emulated HHH(DDD) to repeat the process until aborted.

The correctness remain unproven.

> Once aborted the DDD emulated by HHH immediately stops.

No, it does not. DDD stops when it executes the ret instruction at 2183
or the function at 15d2 calls exit.

> At no point in this emulation does the call from DDD
> correctly emulated by HHH to HHH(DDD) ever return.

Everyone who knows x86 machine or assembly language can see that
DDD terminates normally if and only if HHH terminates normally.

-- 
Mikko