(define-module (backend emitter traverse)
  #:export (prog
            subrout
            instr
            allocate
            mov
            ret
            neg
            not
            allocate
            reg
            stack
            imm))


(define (prog srout)
  (string-append/shared srout ".section .note.GNU-stack,\"\",@progbits\n"))

(define (srout label instrs)
  (format #f "    .globl ~a
~a:
\tpushq\t%rbp
\tmovq\t%rsp, %rbp
~a" label label (apply string-append/shared instrs)))

(define (mov src dst)
  (format #f "\tmovl\t~a, ~a\n" src dst))

(define (ret)
  "\tmovq\t%rbp, %rsp
\tpopq\t%rbp
\tret\n")

(define (neg dst)
  (format #f "\tnegl\t~a\n" dst))

(define (not dst)
  (format #f "\tnotl\t~a\n" dst))

(define (alloc size)
  (format #f "\tsubq\t$~a, %rsp\n" size))

(define (reg r)
  (format #f "%~a" r))

(define (stack loc)
  (format #f "~a(%rbp)" loc))

(define (imm int)
  (format #f "$~a" int))