Added ret.s

mach/z80/libem/LIST

@@ -40,3 +40,4 @@ xor.s
 nop.s
 outdec.s
 pstrng.s
+ret.s

mach/z80/libem/ret.s

@@ -0,0 +1,57 @@
+.define .ret
+.define .lfr
+
+.sect .text
+.sect .rom
+.sect .data
+.sect .bss
+
+! 'ret' and 'lfr' for sizes > 4 (and <= 8)
+
+retarea: .space 8
+
+.sect .text
+
+.ret:
+! parameters:
+!	de: size in bytes
+!	stack: return value
+
+	pop ix		! save return address
+	ld hl,retarea
+	srl d
+	rr e		! divide size by 2
+1:
+	pop bc
+	ld (hl), c
+	inc hl
+	ld (hl), b
+	inc hl
+	dec de
+	ld a,d
+	or e
+	jr nz,1b	! done?
+	jp (ix)		! yes, return
+
+.lfr:
+! parameters:
+!	de: size in bytes
+!	result on stack: return value
+
+	pop ix		! save return address
+	ld hl,retarea
+	add hl,de
+	srl d
+	rr e		! divide size by 2
+1:
+	dec hl
+	ld b,(hl)
+	dec hl
+	ld c,(hl)
+	push bc
+	dec de
+	ld a,d
+	or e
+	jr nz,1b	! done?
+	jp (ix)		! yes, return
+