Re: [PATCH olang v1 2/2] codegen: x86_64: implement binary operations

["Carlos Maniero" <carlos@maniero.me>]

That's a brilliant work man. I'm inspired in how simple the code is. I
even took a look at our previous work on pipa, and this patch is art
compared with pipa's implementation. Kudos!

There is just one issue with the current implementation:

>                 case AST_BINOP_DIVISION: {
>                     codegen_linux_x86_64_emit_expression(out, bin_op.rhs);
>                     fprintf(out, "    push %%rax\n");
> 
>                     codegen_linux_x86_64_emit_expression(out, bin_op.lhs);
>                     fprintf(out, "    pop %%rcx\n");
>                     fprintf(out, "    div %%rcx\n");
> 
>                     return;
>                 }

You should always ensure *rdx* is zero right before calling the *div*
instruction otherwise the code bellow will return an unexpected value.

  fn main(): u32 {
    return 7 / 3 / 3
  }

The same is valid for the reminder operation.

I also missed integration tests, the issue I described before could only
be catch over an integration test. I know we don't have the best ever
developer experience for integration tests, but following the
*test_cli_compile_minimal_program* test structure could save us a lot of
time in the future during refactors.