-;;; ========================================
-;;; The pushr macro pushes x onto the return stack
-;;; The popr macro pops x from the return stack
-macro pushr x {
- sub rbp, 8
- mov [rbp], x
-}
-
-macro popr x {
- mov x, [rbp]
- add rbp, 8
-}
-
-;;; ========================================
-;;; The next macro "moves" execution to the next FORTH instruction,
-;;; using rsi as instruction pointer. It points to the doer field of a
-;;; word, which points to the assembly code that implements the
-;;; execution effect of the word. That doer code is entered with rsi
-;;; referring to the subsequent address in the colling word, and rax
-;;; referring to the doer field of the called word.
-
-macro next {
- lodsq ; mov rax, [rsi] + add rsi,8
- jmp qword [rax] ; goto code of that FORTH word (64 bit jump)
-}
-
-;;; ========================================
-;;; The FORTH macro transitions to inline FORTH execution.
-macro FORTH {
- local forthcode
- mov rsi,forthcode
- next
- ;; align 8
-forthcode:
-}
-
-;;; ========================================
-;;; The ENDFORTH macro transitions back to inline assembler after FORTH
-;;; ========================================
-macro ENDFORTH {
- dq inline_code
-}
-
-;;; ========================================
-;;; The DOFORTH lays out a single FORTH call
-;;; ========================================
-macro DOFORTH label {
- FORTH
- dq label
- ENDFORTH
-}
-
-;;; Macro WORD starts a FORTH word definition in this code
-;;;
- previous_word = 0 ; Used for chaining the words
-
- IMMEDIATE = 1 ; optional flag
-
-macro WORD label, name, doer, flags {
- ;; align 8
-label#_TFA:
- ;; TFA
- dq previous_word
- previous_word = label#_TFA
- ;; PFA
-label#_PFA:
- db flags + 0
- db label - $ - 2
- db name
- db 0
- ;; align 8
-
-label#_OFF:
- dq 0 ; The DOES offset. Defaults to 0.
- ;; also CFA = pointer to "doer"
-label:
- if doer eq
- dq doforth
- else
- if doer in <fasm>
- dq label#_DFA
- else
- dq doer
- end if
- end if
- ;; DFA
-label#_DFA:
-}
-
-;;; ============================================================
-;;; FORTH machine model
-;;; rsp = data stack pointer
-;;; rbp = return stack pointer
-;;; rsi = instruction pointer