Re: The execution trace of HHH1(DDD) shows the divergence

On 2025-06-07, olcott <polcott333@gmail.com> wrote:

The execution trace of HHH1(DDD) shows the divergence
of DDD emulated by HHH from DDD emulated by HHH1.
>
int main()
{
   HHH1(DDD);
}
>
Shows that DDD emulated by HHH and DDD emulated by
HHH1 diverges as soon as HHH begins emulating itself
emulating DDD.
>
*From the execution trace of HHH1(DDD) shown below*
DDD emulated by HHH1              DDD emulated by HHH
[00002183] push ebp               [00002183] push ebp
[00002184] mov ebp,esp            [00002184] mov ebp,esp
[00002186] push 00002183 ; DDD    [00002186] push 00002183 ; DDD
[0000218b] call 000015c3 ; HHH    [0000218b] call 000015c3 ; HHH
*HHH1 emulates DDD once then HHH emulates DDD once, these match*
>
The next instruction of DDD that HHH emulates is at
the machine address of 00002183.
>
The next instruction of DDD that HHH1 emulates is at
the machine address of 00002190.
>
00002183 != 00002190
>
_DDD()
[00002183] 55             push ebp
[00002184] 8bec           mov ebp,esp
[00002186] 6883210000     push 00002183 ; push DDD
[0000218b] e833f4ffff     call 000015c3 ; call HHH
[00002190] 83c404         add esp,+04
[00002193] 5d             pop ebp
[00002194] c3             ret
Size in bytes:(0018) [00002194]
>
_main()
[000021a3] 55             push ebp
[000021a4] 8bec           mov ebp,esp
[000021a6] 6883210000     push 00002183 ; push DDD
[000021ab] e843f3ffff     call 000014f3 ; call HHH1
[000021b0] 83c404         add esp,+04
[000021b3] 33c0           xor eax,eax
[000021b5] 5d             pop ebp
[000021b6] c3             ret
Size in bytes:(0020) [000021b6]
>
  machine   stack     stack     machine    assembly
  address   address   data      code       language
 ========  ========  ========  ========== =============
<main is executed>
[000021a3][0010382d][00000000] 55         push ebp      ; main()
[000021a4][0010382d][00000000] 8bec       mov ebp,esp   ; main()
[000021a6][00103829][00002183] 6883210000 push 00002183 ; push DDD
[000021ab][00103825][000021b0] e843f3ffff call 000014f3 ; call HHH1
</main is executed>
>
New slave_stack at:1038d1
Begin Local Halt Decider Simulation   Execution Trace Stored at:1138d9
>
<DDD emulated by HHH1>
[00002183][001138c9][001138cd] 55         push ebp      ; DDD of HHH1
[00002184][001138c9][001138cd] 8bec       mov ebp,esp   ; DDD of HHH1
[00002186][001138c5][00002183] 6883210000 push 00002183 ; push DDD
[0000218b][001138c1][00002190] e833f4ffff call 000015c3 ; call HHH
</DDD emulated by HHH1>
>
New slave_stack at:14e2f9
Begin Local Halt Decider Simulation   Execution Trace Stored at:15e301
>
<DDD emulated by HHH>
[00002183][0015e2f1][0015e2f5] 55         push ebp      ; DDD of HHH[0]
[00002184][0015e2f1][0015e2f5] 8bec       mov ebp,esp   ; DDD of HHH[0]
[00002186][0015e2ed][00002183] 6883210000 push 00002183 ; push DDD
[0000218b][0015e2e9][00002190] e833f4ffff call 000015c3 ; call HHH
<DDD emulated by HHH>
>
New slave_stack at:198d21  DDD emulated by HHH
*This is the beginning of the divergence of the behavior*
*HHH is emulating itself emulating DDD, HHH1 never does that*
>
<DDD emulated by HHH emulating itself>
[00002183][001a8d19][001a8d1d] 55         push ebp      ; DDD of HHH[1]
[00002184][001a8d19][001a8d1d] 8bec       mov ebp,esp   ; DDD of HHH[1]
[00002186][001a8d15][00002183] 6883210000 push 00002183 ; push DDD
[0000218b][001a8d11][00002190] e833f4ffff call 000015c3 ; call HHH
</DDD emulated by HHH emulating itself>
>
Local Halt Decider: Infinite Recursion Detected Simulation Stopped
HHH returns to caller
>
<DDD emulated by HHH1>
[00002190][001138c9][001138cd] 83c404     add esp,+04 ; DDD of HHH1
[00002193][001138cd][000015a8] 5d         pop ebp     ; DDD of HHH1
[00002194][001138d1][0003a980] c3         ret         ; DDD of HHH1
</DDD emulated by HHH1>
>
<main is executed>
[000021b0][0010382d][00000000] 83c404     add esp,+04 ; main()
[000021b3][0010382d][00000000] 33c0       xor eax,eax ; main()
[000021b5][00103831][00000018] 5d         pop ebp     ; main()
[000021b6][00103835][00000000] c3         ret         ; main()
</main is executed>
Number of Instructions Executed(352831) == 5266 Pages
>

Lean Lisp first, ideally with Scheme. Go get Concrete Abstractions
and learn about recursivity and taill call optimization.