array13.asm

	org 32768
.core.__START_PROGRAM:
	di
	push ix
	push iy
	exx
	push hl
	exx
	ld (.core.__CALL_BACK__), sp
	ei
	jp .core.__MAIN_PROGRAM__
.core.__CALL_BACK__:
	DEFW 0
.core.ZXBASIC_USER_DATA:
	; Defines USER DATA Length in bytes
.core.ZXBASIC_USER_DATA_LEN EQU .core.ZXBASIC_USER_DATA_END - .core.ZXBASIC_USER_DATA
	.core.__LABEL__.ZXBASIC_USER_DATA_LEN EQU .core.ZXBASIC_USER_DATA_LEN
	.core.__LABEL__.ZXBASIC_USER_DATA EQU .core.ZXBASIC_USER_DATA
_array:
	DEFW .LABEL.__LABEL0
_array.__DATA__.__PTR__:
	DEFW _array.__DATA__
	DEFW _array.__LBOUND__
	DEFW 0
_array.__DATA__:
	DEFB 00h
	DEFB 00h
.LABEL.__LABEL0:
	DEFW 0000h
	DEFB 01h
_array.__LBOUND__:
	DEFW 0001h
.core.ZXBASIC_USER_DATA_END:
.core.__MAIN_PROGRAM__:
	ld hl, _array
	push hl
	call _test
	ld hl, 0
	ld b, h
	ld c, l
.core.__END_PROGRAM:
	di
	ld hl, (.core.__CALL_BACK__)
	ld sp, hl
	exx
	pop hl
	exx
	pop iy
	pop ix
	ei
	ret
_test:
	push ix
	ld ix, 0
	add ix, sp
	ld hl, 0
	push hl
	ld l, (ix-2)
	ld h, (ix-1)
	push hl
	push ix
	pop hl
	ld de, 4
	add hl, de
	call .core.__ARRAY_PTR
	ld a, (hl)
	ld (0), a
_test__leave:
	ld sp, ix
	pop ix
	exx
	pop hl
	ex (sp), hl
	exx
	ret
	;; --- end of user code ---
#line 1 "/zxbasic/src/lib/arch/zx48k/runtime/array/array.asm"
; vim: ts=4:et:sw=4:
	; Copyleft (K) by Jose M. Rodriguez de la Rosa
	;  (a.k.a. Boriel)
;  http://www.boriel.com
	; -------------------------------------------------------------------
	; Simple array Index routine
	; Number of total indexes dimensions - 1 at beginning of memory
	; HL = Start of array memory (First two bytes contains N-1 dimensions)
	; Dimension values on the stack, (top of the stack, highest dimension)
	; E.g. A(2, 4) -> PUSH <4>; PUSH <2>
	; For any array of N dimension A(aN-1, ..., a1, a0)
	; and dimensions D[bN-1, ..., b1, b0], the offset is calculated as
	; O = [a0 + b0 * (a1 + b1 * (a2 + ... bN-2(aN-1)))]
; What I will do here is to calculate the following sequence:
	; ((aN-1 * bN-2) + aN-2) * bN-3 + ...
#line 1 "/zxbasic/src/lib/arch/zx48k/runtime/arith/fmul16.asm"
	;; Performs a faster multiply for little 16bit numbs
#line 1 "/zxbasic/src/lib/arch/zx48k/runtime/arith/mul16.asm"
	    push namespace core
__MUL16:	; Mutiplies HL with the last value stored into de stack
	    ; Works for both signed and unsigned
	    PROC
	    LOCAL __MUL16LOOP
	    LOCAL __MUL16NOADD
	    ex de, hl
	    pop hl		; Return address
	    ex (sp), hl ; CALLEE caller convention
__MUL16_FAST:
	    ld b, 16
	    ld a, h
	    ld c, l
	    ld hl, 0
__MUL16LOOP:
	    add hl, hl  ; hl << 1
	    sla c
	    rla         ; a,c << 1
	    jp nc, __MUL16NOADD
	    add hl, de
__MUL16NOADD:
	    djnz __MUL16LOOP
	    ret	; Result in hl (16 lower bits)
	    ENDP
	    pop namespace
#line 3 "/zxbasic/src/lib/arch/zx48k/runtime/arith/fmul16.asm"
	    push namespace core
__FMUL16:
	    xor a
	    or h
	    jp nz, __MUL16_FAST
	    or l
	    ret z
	    cp 33
	    jp nc, __MUL16_FAST
	    ld b, l
	    ld l, h  ; HL = 0
1:
	    add hl, de
	    djnz 1b
	    ret
	    pop namespace
#line 20 "/zxbasic/src/lib/arch/zx48k/runtime/array/array.asm"
#line 24 "/zxbasic/src/lib/arch/zx48k/runtime/array/array.asm"
	    push namespace core
__ARRAY_PTR:   ;; computes an array offset from a pointer
	    ld c, (hl)
	    inc hl
	    ld h, (hl)
	    ld l, c    ;; HL <-- [HL]
__ARRAY:
	    PROC
	    LOCAL LOOP
	    LOCAL ARRAY_END
	    LOCAL TMP_ARR_PTR            ; Ptr to Array DATA region. Stored temporarily
	    LOCAL LBOUND_PTR, UBOUND_PTR ; LBound and UBound PTR indexes
	    LOCAL RET_ADDR               ; Contains the return address popped from the stack
	LBOUND_PTR EQU 23698           ; Uses MEMBOT as a temporary variable
	UBOUND_PTR EQU LBOUND_PTR + 2  ; Next 2 bytes for UBOUND PTR
	RET_ADDR EQU UBOUND_PTR + 2    ; Next 2 bytes for RET_ADDR
	TMP_ARR_PTR EQU RET_ADDR + 2   ; Next 2 bytes for TMP_ARR_PTR
	    ld e, (hl)
	    inc hl
	    ld d, (hl)
	    inc hl      ; DE <-- PTR to Dim sizes table
	    ld (TMP_ARR_PTR), hl  ; HL = Array __DATA__.__PTR__
	    inc hl
	    inc hl
	    ld c, (hl)
	    inc hl
	    ld b, (hl)  ; BC <-- Array __LBOUND__ PTR
	    ld (LBOUND_PTR), bc  ; Store it for later
#line 66 "/zxbasic/src/lib/arch/zx48k/runtime/array/array.asm"
	    ex de, hl   ; HL <-- PTR to Dim sizes table, DE <-- dummy
	    ex (sp), hl	; Return address in HL, PTR Dim sizes table onto Stack
	    ld (RET_ADDR), hl ; Stores it for later
	    exx
	    pop hl		; Will use H'L' as the pointer to Dim sizes table
	    ld c, (hl)	; Loads Number of dimensions from (hl)
	    inc hl
	    ld b, (hl)
	    inc hl		; Ready
	    exx
	    ld hl, 0	; HL = Element Offset "accumulator"
LOOP:
	    ex de, hl   ; DE = Element Offset
	    ld hl, (LBOUND_PTR)
	    ld a, h
	    or l
	    ld b, h
	    ld c, l
	    jr z, 1f
	    ld c, (hl)
	    inc hl
	    ld b, (hl)
	    inc hl
	    ld (LBOUND_PTR), hl
1:
	    pop hl      ; Get next index (Ai) from the stack
	    sbc hl, bc  ; Subtract LBOUND
#line 116 "/zxbasic/src/lib/arch/zx48k/runtime/array/array.asm"
	    add hl, de	; Adds current index
	    exx			; Checks if B'C' = 0
	    ld a, b		; Which means we must exit (last element is not multiplied by anything)
	    or c
	    jr z, ARRAY_END		; if B'Ci == 0 we are done
	    dec bc				; Decrements loop counter
	    ld e, (hl)			; Loads next dimension size into D'E'
	    inc hl
	    ld d, (hl)
	    inc hl
	    push de
	    exx
	    pop de				; DE = Max bound Number (i-th dimension)
	    call __FMUL16        ; HL <= HL * DE mod 65536
	    jp LOOP
ARRAY_END:
	    ld a, (hl)
	    exx
#line 146 "/zxbasic/src/lib/arch/zx48k/runtime/array/array.asm"
	    LOCAL ARRAY_SIZE_LOOP
	    ex de, hl
	    ld hl, 0
	    ld b, a
ARRAY_SIZE_LOOP:
	    add hl, de
	    djnz ARRAY_SIZE_LOOP
#line 156 "/zxbasic/src/lib/arch/zx48k/runtime/array/array.asm"
	    ex de, hl
	    ld hl, (TMP_ARR_PTR)
	    ld a, (hl)
	    inc hl
	    ld h, (hl)
	    ld l, a
	    add hl, de  ; Adds element start
	    ld de, (RET_ADDR)
	    push de
	    ret
	    ENDP
	    pop namespace
#line 44 "arch/zx48k/array13.bas"
	END