Show HN: Cj–tiny no-deps JIT in C for x86-64 and ARM64

Summary

cj is a small JIT framework written in C, with x86 and arm64 backends. what multi-architecture support : generates native code for: x86-64 ARM64 (except for 26 SIMD different-size instructions) : generates native code for: low-level API : direct instruction emission, no high level constructs : direct instruction emission, no high level constructs no dependencies: pure C with clib, nothing else how the backends are autogenerated (check out codegen ). x86 uses asmdb as a data source, arm64 uses a handgenerated file from mra_tools. register definitions are hand-crafted. the rest is handwritten and basically trivial in the grand scheme of jit compilation. examples, tests, and codegen docs contain some llm-generation, so peruse at your own peril. why because i wanted to understand the isa for both processor architectures and it seemed like a fun project. quick start build # dev build make dev # "prod" build make all # install (don't) make install basic usage #include "ctx.h" #include "op.h" int main ( void ) { // Create JIT context cj_ctx * cj = create_cj_ctx (); // Emit instructions cj_nop ( cj ); // NOP cj_ret ( cj ); // RET // Create executable function cj_fn f = create_cj_fn ( cj ); // Execute JIT-compiled code! f (); // Cleanup destroy_cj_fn ( cj , f ); destroy_cj_ctx ( cj ); return 0 ; } you can find some more examples in the examples directory. builder helpers For reusable building blocks, the optional builder helpers provide prologue/epilogue setup and structured loops: #include <stdio.h> #include "builder.h" typedef int ( * sum_fn )( int ); int main ( void ) { cj_ctx * cj = create_cj_ctx (); cj_builder_frame frame ; cj_builder_fn_prologue ( cj , 0 , & frame ); cj_operand n = cj_builder_arg_int ( cj , 0 ); cj_operand sum = cj_builder_scratch_reg ( 0 ); cj_operand i = cj_builder_scratch_reg ( 1 ); cj_operand one = cj_make_constant ( 1 ); cj_builder_assign ( cj , sum , cj_builder_zero_operand ()); cj_builder_for_loop loop = cj_builder_for_begin ( cj , i , one , n ,...