- compiler works for basic maths expressions and functions

- basic pointers and reading values from pointers works
- writing to pointers not yet implemented (looks painful so a problem
  for tomorrow)
- updated print library. the compiler has this hardcoded in all programs
  for now

resources/dsa/lib/io/print.dsa

@@ -40,7 +40,7 @@ dw display: 0x20000
 dw current: 0x20000
 
 // ------------------------------------------
-// prints the string at addr(arg[0]) to the screen.
+// prints the string at addr(arg[0]) to the screen. (no trailing whitespace unless explicitly provided)
 print:
     push bpr
     mov spr, bpr
@@ -50,13 +50,36 @@ print:
 
 _print_loop:
 	ldb rg0, acc
+	cmp acc, zero
+	jeq _end
 	stb acc, rg1
 
 	addi rg0, 1
 	addi rg1, 1
 
-    cmp acc, zero
-	jne _print_loop
+	jmp _print_loop
+
+// ------------------------------------------
+println:
+    push bpr
+    mov spr, bpr
+
+    ldw bpr, rg0, 8
+    ldw current, rg1
+
+_println_loop:
+	ldb rg0, acc
+	cmp acc, zero
+	jeq _println_end
+	stb acc, rg1
+
+	addi rg0, 1
+	addi rg1, 1
+
+	jmp _println_loop
+
+_println_end:
+    call print_newline
     jmp _end
 
 // ------------------------------------------

resources/dsa/lib/maths/core.dsa

@@ -59,3 +59,46 @@ _divmod_end:
 	mov bpr, spr
 	pop bpr
 	return
+
+// multiply.dsa - improved version
+// Multiplies two 32-bit numbers using shift-and-add
+//
+// Usage:
+// push operand2  (multiplier)
+// push operand1  (multiplicand)
+// call multiply::multiply
+// pop result
+// pop zero       (discard second argument)
+
+new_multiply:
+    push bpr
+    mov spr, bpr
+
+    ldw bpr, rg0, 8     // rg0 = multiplicand
+    ldw bpr, rg1, 12    // rg1 = multiplier
+
+    lli 0, rg2          // rg2 = result (accumulator)
+    lli 32, rg3         // rg3 = bit counter
+
+mult_loop:
+    // Check if lowest bit of multiplier is 1
+    lli 1, acc
+    and rg1, acc, acc   // acc = rg1 & 1
+    cmp acc, zero
+    jeq skip_add        // if (rg1 & 1) == 0, skip addition
+
+    // Add multiplicand to result
+    add rg2, rg0, rg2
+
+skip_add:
+    shl rg0, 1          // shift multiplicand left
+    shr rg1, 1          // shift multiplier right
+
+    dec rg3
+    cmp rg3, zero
+    jgt mult_loop
+
+    stw rg2, bpr, 8     // store result
+    mov bpr, spr
+    pop bpr
+    return

resources/dsa/lib/memory/alloc.dsa

@@ -0,0 +1,37 @@
+dw global_arena_start: 0x30000
+dw global_arena_current: 0x30000
+dw global_arena_end: 0x40000
+
+arena_alloc:
+    // Just like bump allocator
+    push bpr
+    mov spr, bpr
+
+    ldw bpr, rg0, 8           // size argument
+    ldw global_arena_current, rg1
+
+    add rg1, rg0, rg2         // new_current = current + size
+    ldw global_arena_end, rg3
+
+    cmp rg2, rg3
+    jgt out_of_memory
+
+    stw rg2, global_arena_current
+    mov rg1, acc              // return old current
+    stw acc, bpr, 8
+
+    mov bpr, spr
+    pop bpr
+    return
+
+arena_reset:
+    // Reset to start
+    push bpr
+    mov spr, bpr
+
+    ldw global_arena_start, rg0
+    stw rg0, global_arena_current
+
+    mov bpr, spr
+    pop bpr
+    return