X-Git-Url: https://git.rrq.au/?a=blobdiff_plain;f=rrqforth.asm;h=9709fde6df03a0e85259d8ced4bd970d2ffe0bb1;hb=69125f1514739aa5dcee13a29eb161a229e47eed;hp=673f77166060c23cada4bb1d44514122b7f360b0;hpb=56a9fab0f5bfcfdd455dd1640415e64c63670d9c;p=rrq%2Frrqforth.git

diff --git a/rrqforth.asm b/rrqforth.asm
index 673f771..9709fde 100644
--- a/rrqforth.asm
+++ b/rrqforth.asm
@@ -2,100 +2,7 @@
 	format elf64 executable
 	entry main
 
-;;; ========================================
-;;; 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
+include 'machine.asm'
 
 ;;; ============================================================
 
@@ -119,6 +26,14 @@ DS_TOP:				; The initial rsp
 	;; exit to the calling definition via "jmp exit".
 	jmp qword rsi
 
+	WORD p_exit, 'EXIT',fasm
+	;; ( -- ) ( R: addr -- )
+	;; Returns execution to the calling definition as per the
+	;; return stack.
+exit:
+	popr rsi
+	next
+
 ;;; Execution semantics for FORTH defition word
 ;;; At entry, rsi points into the calling definition, at the cell
 ;;; following the cell indicating this word, rax points to the CFA of
@@ -128,33 +43,36 @@ doforth:
 	lea rsi, [rax+8] 	; rsi = the DFA of the rax word
 	next
 
-	WORD p_exit, 'EXIT',fasm
-	;; ( -- ) ( R: addr -- )
-	;; Returns execution to the calling definition as per the
-	;; return stack.
-exit:
-	popr rsi
+;;; Execution semantics for DOES>
+;;; The cell at [cfa-8] holds an adjustment offset.
+dodoes:
+	pushr rsi
+	lea rsi, [rax+8] 	; rsi = the DFA of the rax word
+	add rsi,[rax-8]		; adjust rsi to the DOES> part
 	next
 
 	;; Execution semantics for a variable ( -- addr )
-	;; rax points to doer field
+	;; rax points to CFA field
 dovariable:
-	push rax+16
+	add rax,8
+	push rax
 	next
 
 	;; Execution semantics for a constant ( -- v )
-	;; rax points to doer field
+	;; rax points to CFA field
 dovalue:
-	push qword [rax+16]
+	push qword [rax+8]
 	next
 
 	;; Execution semantics for a string constant ( -- addr n )
-	;; rax points to doer field
+	;; rax points to CFA field
 dostring:
-	add rax,16
+	add rax,8
+	xor rbx,rbx
 	mov bl,[rax]
-	mov byte [rsp],bl
-	push rax+1
+	inc rax
+	push rax
+	push rbx
 	next
 
 include 'wordlists.asm'
@@ -165,10 +83,7 @@ include 'math.asm'
 include 'stdio.asm'
 
 	WORD p_program_version,'PROGRAM_VERSION',dostring
-	db length
-program_version_string:	
-	db 'RRQ Forth version 0.1 - 2021-05-13',10
-	length = $ - program_version_string
+	STRING 'RRQ Forth version 0.1 - 2021-05-13',10
 
 	WORD p_stdin,'STDIN',dovalue
 	;; Initialised to hold a STREAM for fd 0
@@ -194,8 +109,7 @@ main:
 	ENDFORTH
 
 	push qword 1			; stdout
-	push qword program_version_string ; address of string
-	push qword length 		; length of string (cheating)
+	DOFORTH p_program_version	; version string => ( s n )
 	DOFORTH sys_write		; printout
 	pop rax				; ignore errors