A just-in-time compiler from scratch

Constraints:

• Needs only a c++ compiler to build
• No external dependencies.
• Only Linux API, POSIX compliant whenever possible.
• C++/C standard library fuctions preferred over OS if feasible.
• Code references official Intel/AMD Manuals, and the relevant System V ABI
• No AI
• No PACKAGE MANAGER, cmake, bundlemumble etc. needed.

References: [1] Intel 64 and IA-32 Architectures Software Developer's Manual (June 2026 version) [2] https://wiki.osdev.org/System_V_ABI (System V ABI Application Binary Interface)

First Step

Challenge: Write a just-in-time compiler for a reasonable subset of an experimental language (https://github.com/cepsdev/machines4ceps/blob/master/core/include/vm/vm_base.hpp) which runs on x64 Linux

First goal: JIT and run assembler fragment in figure (A) on x86-64 (post 2013 architectures, i.e. Core iX 6XXX and better).

(A) The fragment to be compiled and its semantics.

(A.1) The assembler fragment

kind Event;

OblectamentaDataLabel counter;                         // section .data
oblectamenta{global{data{counter;0;};};};              // counter dd 0

sm{
 S;
 states{Initial;Final;};
 t{Initial;Final;doIncrementCounter;};
 Actions{
  doIncrementCounter{
   oblectamenta{text{asm{ 

    OblectamentaCodeLabel start_loop, end_loop;       // labels 
    val i = R0;                                       // use 'i' to reference 64 bit wide register R0
    ldi32(counter);                                   // Put value at location counter on the compute stack
    sti32(i);                                         // Store 32 bit wide value at top of compute stack to i aka R0
                                                      // ==> MOV R0,counter
    start_loop;
    ldi32(i);     
    ldi32(10000000);
    blteq(end_loop);
    ldi32(i);
    ldi32(1);
    addi32;
    sti32(i);    
    buc(start_loop);
    end_loop;
   };};};
 };

(A.2) Its meaning in terms of a semantically equivalent Python program

counter:int = 0
while counter <  10000000:
    counter = counter + 1

}; };