more work on creating arrays

src/basic/engine_variables/array_create.s

@@ -22,36 +22,48 @@ array_create:
 	lda FOUR6
 	pha
 
-	// Push 0 to mark end of the dimensions
+	// Check if the array dimension is given - if not, assume '10' was specified
-
-	lda #$00
-	pha
-
-	// Now check if the array dimension is given - if not, assume '10' was specified
 
 	bit DIMFLG
 	bmi array_create_fetch_dims
 
 	lda #$0A
 	pha
+	lda #$00
+	pha
+	ldx #$01
 	bne array_create_store_dims                  // branch always
 
 array_create_fetch_dims:
 
+	ldx #$00                                     // counts number of dimensions
+
+	// FALLTROUGH
+
+array_create_fetch_dims_loop:
+
+	inx
+
 	// XXX check if stack has reasonable space free
 
 	// Fetch the dimension, put it on the stack - confirmed with orioginal ROM,
 	// that it also stores dimensions in the reverse order
 
-	jsr fetch_uint8
+	jsr fetch_uint16
 	bcs_16 do_SYNTAX_error
+
+	// XXX we probably need to increment LINNUM first
+
+	lda LINNUM+0
+	pha
+	lda LINNUM+1
 	pha
 
 	// Check if more dimensions are given
 
 	jsr fetch_character_skip_spaces
 	cmp #$2C                                     // ','
-	beq array_create_fetch_dims
+	beq array_create_fetch_dims_loop
 	cmp #$29                                     // ')'
 	bne_16 do_SYNTAX_error
 
@@ -62,40 +74,93 @@ array_create_store_dims:
 	// We got the dimensions, time to alocate memory. Arrays are not declared too often,
 	// it will be easier if we perform the garbage collection now
 
+	phx_trash_a
 	jsr varstr_garbage_collect
 
-	// Create the initial array structure
+	// __FAC1+0/+1 will be used to calculate number of elements
-
-	// Bytes 0/1 - array name, but we can not fetch it easily now, so skip it
-	// Bytes 2/3 - offset to the next array - our will be the last one, so 0 - but we will set it later
-	// Byte  4   - number of dimensions, determine it
-	// Bytes 5+  - size in each dimension
-
-	// INDEX+2/+3 will be used to calculate number of 'records'
 
 	ldy #$01
-	sty INDEX+3
+	sty __FAC1+0
 	dey
-	sty INDEX+4
+	sty __FAC1+1
 
-	ldy #$05
+	// Create the initial array structure (format checked by creating arrays with original ROM)
-!:
+
+	// Bytes 0/1 - array name, but we can not fetch it easily now, so skip it for now
+	// Bytes 2/3 - offset to the next array, skip it for now too
+	// Byte  4   - number of dimensions
+	// Bytes 5+  - max index in each dimension (big endian!), this will be set in a loop
+
+	ldy #$04
 	pla
-	beq array_create_store_num_dims
 
-	// XXX implement this
+#if CONFIG_MEMORY_MODEL_60K
 	
+	// XXX
+	// XXX: implement this
+	// XXX
 
-array_create_store_num_dims:
+#else // CONFIG_MEMORY_MODEL_38K || CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
 
-	// .Y contains number of dimensions + 5
+	sta (STREND), y
 
-	// XXX rework code below
+#endif
 
+	iny                                          // .Y - index to store dimension sizes
+	tax                                          // .X - dimensions not sotred yet
 
+	// FALLTROUGH
 
+array_create_store_loop:
 
+#if CONFIG_MEMORY_MODEL_60K
 	
+	// XXX
+	// XXX: implement this
+	// XXX
 
+#else // CONFIG_MEMORY_MODEL_38K || CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
+
+	pla
+	sta (STREND), y
+	sta __FAC1+3
+	iny
+	pla
+	sta (STREND), y
+	sta __FAC1+2
+	iny
+
+#endif
+
+	jsr helper_array_create_mul
+
+	dex
+	bne array_create_store_loop
+
+	// FALLTROUGH
+
+array_create_store_dims_done:
+
+	// Restore FOUR6, calculate number of bytes needed for storage
+
+	pha
+	sta FOUR6 // XXX do we need to store this value in FOUR6?
+	sta __FAC1+2
+	stx __FAC1+3                       // .X is 0 at this point
+
+	jsr helper_array_create_mul
+
+	// XXX check if we have enough memory
+
+	// XXX retrieve and store array name
+
+	// XXX calculate and store offset to the next array
+
+	// XXX clear area
+
+	// XXX adjust STREND
+
+	// XXX adjust offset of the previous array
+
+	jmp do_NOT_IMPLEMENTED_error
 
-	jsr do_NOT_IMPLEMENTED_error

src/basic/engine_variables/helper_array_create_mul.s

@@ -0,0 +1,76 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+// 16-bit multiplication, INDEX+0/+1 = __FAC1+0/+1 * __FAC1+2/+3; __FAC1+0/+1 = INDEX+0/+1
+// uses INDEX+2/+3 (for helper routine) as work area
+
+
+helper_array_create_mul: // preserves .X and .Y
+
+	phx_trash_a
+
+	// We will reuse 8x8 multiplication routine used by floating point operations
+
+	// __FAC1+0 (lo byte) * __FAC1+2 (lo byte)
+
+	lda __FAC1+0
+	sta INDEX+2
+	lda __FAC1+2
+	jsr mul_FAC2_FAC1_8x8                        // this preserves .Y
+
+	sta INDEX+0                                  // result - lo byte
+	stx INDEX+1                                  // result - hi byte
+
+	// __FAC1+0 (lo byte) * __FAC1+3 (hi byte)
+
+	lda __FAC1+0
+	sta INDEX+2
+	lda __FAC1+3
+	jsr helper_array_create_mul_8x8_add          // multiply and add to high byte of the result
+
+	// __FAC1+1 (hi byte) * __FAC1+2 (lo byte)
+
+	lda __FAC1+1
+	sta INDEX+2
+	lda __FAC1+2
+	jsr helper_array_create_mul_8x8_add          // multiply and add to high byte of the result
+
+	// __FAC1+1 (hi byte) * __FAC1+3 (hi byte) has to be 0,
+	// otherwise the result would be out of range
+	// do not calculate
+
+	lda __FAC1+0
+	beq helper_array_create_mul_success
+	lda __FAC1+3
+	beq helper_array_create_mul_success
+
+	// FALLTROUGH
+
+helper_array_create_mul_error:
+
+	jmp do_OUT_OF_MEMORY_error
+
+helper_array_create_mul_success:
+
+	lda INDEX+0
+	sta __FAC+0
+	lda INDEX+1
+	sta __FAC+1
+
+	plx_trash_a
+	rts
+
+helper_array_create_mul_add:
+
+	jsr mul_FAC2_FAC1_8x8
+
+	cpx #$00
+	bne helper_array_create_mul_error
+
+	clc
+	adc INDEX+1 
+	bcs helper_array_create_mul_error
+	sta INDEX+1
+
+	rts