Re: Try and prove that DDD correctly emulated by HHH reaches its final halt state

On 2025-05-11 16:23:29 +0000, olcott said:

On 5/11/2025 4:20 AM, Mikko wrote:

On 2025-05-10 15:33:50 +0000, olcott said:
 

On 5/10/2025 2:40 AM, Mikko wrote:

On 2025-05-10 01:26:54 +0000, olcott said:
 

void DDD()
{
   HHH(DDD);
   return;
}
 _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]
 Try to show how DDD emulated by HHH according to the
rules of the x86 language reaches its own "ret"
instruction final halt state.

 If you do the impossible then everything happens, including
the reaching of the final "ret" instruction. In this case
the impossible is a correct emulation of DDD by HHH according
to the rules of the x86 language.
 

 It is not impossible for DDD to be emulated
by HHH according to the rules of the x86 language.

 You may call it possible or impossible but either way, HHH does
not emulate the final "ret" isntruction.
 

Here it is actually doing this.
 _DDD()
[0000219e] 55             push ebp
[0000219f] 8bec           mov ebp,esp
[000021a1] 689e210000     push 0000219e
[000021a6] e843f4ffff     call 000015ee
[000021ab] 83c404         add esp,+04
[000021ae] 5d             pop ebp
[000021af] c3             ret
Size in bytes:(0018) [000021af]
 _main()
[000021be] 55             push ebp
[000021bf] 8bec           mov ebp,esp
[000021c1] 689e210000     push 0000219e
[000021c6] e823f4ffff     call 000015ee
[000021cb] 83c404         add esp,+04
[000021ce] 50             push eax
[000021cf] 685f070000     push 0000075f
[000021d4] e8a5e5ffff     call 0000077e
[000021d9] 83c408         add esp,+08
[000021dc] 33c0           xor eax,eax
[000021de] 5d             pop ebp
[000021df] c3             ret
Size in bytes:(0034) [000021df]
   machine   stack     stack     machine        assembly
  address   address   data      code           language
  ========  ========  ========  ============== =============
[000021be][00103872][00000000] 55             push ebp
[000021bf][00103872][00000000] 8bec           mov ebp,esp
[000021c1][0010386e][0000219e] 689e210000     push 0000219e // push DDD
[000021c6][0010386a][000021cb] e823f4ffff     call 000015ee // call HHH
New slave_stack at:103916
 Begin Local Halt Decider Simulation   Execution Trace Stored at:11391e
[0000219e][0011390e][00113912] 55             push ebp
[0000219f][0011390e][00113912] 8bec           mov ebp,esp
[000021a1][0011390a][0000219e] 689e210000     push 0000219e // push DDD
[000021a6][00113906][000021ab] e843f4ffff     call 000015ee // call HHH
 The following shows the result of HHH emulating
itself emulating DDD. x86utm is a cooperative
multi-tasking operating system.
 New slave_stack at:14e33e
[0000219e][0015e336][0015e33a] 55             push ebp
[0000219f][0015e336][0015e33a] 8bec           mov ebp,esp
[000021a1][0015e332][0000219e] 689e210000     push 0000219e // push DDD
[000021a6][0015e32e][000021ab] e843f4ffff     call 000015ee // call HHH
Local Halt Decider: Infinite Recursion Detected Simulation Stopped
 [000021cb][00103872][00000000] 83c404         add esp,+04
[000021ce][0010386e][00000000] 50             push eax
[000021cf][0010386a][0000075f] 685f070000     push 0000075f
[000021d4][0010386a][0000075f] e8a5e5ffff     call 0000077e
Input_Halts = 0
[000021d9][00103872][00000000] 83c408         add esp,+08
[000021dc][00103872][00000000] 33c0           xor eax,eax
[000021de][00103876][00000018] 5d             pop ebp
[000021df][0010387a][00000000] c3             ret
Number of Instructions Executed(10069) == 150 Pages

 Apparently you said that the last "ret" is not acutally emulated but
only its emulation is emulated.
 Your trace lacks the indication of which lines are actually trace lines
and which are output lines from the emulated program that only look like
trace lines.

 You must use the machine addresses to see what code
is being emulated. New slave_stack indicate that
a new process context has been created. Code following
that is being emulated.

Nowhere is said that a slave stack is disposed. Apparently no emulation
is ever completed. But your output is too defective to be sure.

New slave_stack at:14e33e indicates that HHH is
about to emulate itself emulating DDD.

But not to the completion of the emulated emulation.
--
Mikko