Introduction

What is Universal Machine Code?

Universal Machine Code is an attempt to provide a portable bytecode, similar to WebAssembly. It uses a register-based machine to achieve fast execution, and the reference virtual machine is on par with existing, fast WebAssembly interpreters such as wasmi. The syntax and semantics of UMC have been explicitly designed to make JIT-compilation to common ISAs such as x86, Arm and RISC-V simple and fast.

Below is an example of iterative fibonacci in UMC.

.FIB:
  mov u64:0, #30
  bz .END, u64:0

  mov u64:1, #0 ; int cur = 0
  mov u64:2, #1 ; int next = 1
  mov u64:3, #0 ; int i = 0

.LOOP: ; u64:3 next
  mov u64:4, u64:2        ; int next2 = next
  add u64:4, u64:4, u64:1 ; next2 += cur
  mov u64:1, u64:2        ; cur = next
  mov u64:2, u64:4        ; next = next2
  add u64:3, u64:3, #1

  dbg u64:3
  dbg u64:0

  xor u64:8, u64:3, u64:0 ; Compare :3 and :0
  bnz .LOOP, u64:8
.END:
  dbg u64:1