diff --git a/src/tools/compiler/compiler.c b/src/tools/compiler/compiler.c
index f421376..b6b3d38 100644
--- a/src/tools/compiler/compiler.c
+++ b/src/tools/compiler/compiler.c
@@ -132,46 +132,11 @@ u32 get_reg(Token token, ScopeTable *st) {
     return get_ref(st, token.start, token.length);
   }
 
-  if (token.type == TOKEN_BIG_MONEY) {
-    token = next_token();
-    return atoi(token.start);
-  }
-
-  fprintf(stderr, "Error: Not a register or symbol at line %d: %.*s\n",
+  fprintf(stderr, "Error: Not a symbol at line %d: %.*s\n",
           token.line, token.length, token.start);
   exit(1);
 }
 
-Token next_id_or_reg() {
-  Token token = next_token();
-  if (token.type == TOKEN_IDENTIFIER) {
-    return token;
-  }
-
-  if (token.type == TOKEN_BIG_MONEY) {
-    token = next_token();
-    return token;
-  }
-
-  printf("Not an ID or register at line %d: %.*s\n", token.line, token.length,
-         token.start);
-  exit(1);
-
-  return token;
-}
-
-Token next_id_or_ptr() {
-  Token token = next_token();
-
-  if (token.type != TOKEN_IDENTIFIER && token.type != TOKEN_LITERAL_NAT &&
-      token.type != TOKEN_LITERAL_INT && token.type != TOKEN_LITERAL_REAL) {
-    printf("Not an ID or register at line %d: %.*s\n", token.line, token.length,
-           token.start);
-    exit(1);
-  }
-  return token;
-}
-
 Token next_token_is(TokenType type) {
   Token token = next_token();
   if (token.type != type) {
@@ -191,10 +156,9 @@ bool parse_const(VM *vm, ScopeTable *st) {
 /**
  * Global .
  */
-bool define_global(VM *vm, ScopeTable *st) {
+bool define_global(VM *vm, ScopeTable *st, Token token_type) {
   Symbol s;
 
-  Token token_type = next_token();
   switch (token_type.type) {
   case TOKEN_TYPE_BOOL:
     s.type = BOOL;
@@ -432,11 +396,8 @@ void define_var(ScopeTable *st, Token regType) {
   s.name_length = name.length;
 
   Token next = next_token();
-  if (next.type == TOKEN_BIG_MONEY) {
-    Token reg_num = next_token_is(TOKEN_LITERAL_INT);
-    s.ref = atoi(reg_num.start);
-  } else if (next.type == TOKEN_SEMICOLON) {
-    s.ref = st->scopes[st->scope_ref].count;
+  if (next.type == TOKEN_SEMICOLON) {
+    s.ref = st->current_reg++;
   } else {
     printf("Unexpected token ERROR at line %d: %.*s\n", regType.line, regType.length,
            regType.start);
@@ -461,6 +422,10 @@ void define_function(VM *vm, ScopeTable *st) {
   Symbol s;
   s.scope = LOCAL;
   s.type = FUNCTION;
+  
+  /* push the last used reg on the stack */
+  st->last_used_registers[st->reg_count++] = st->current_reg;
+  st->current_reg = 0;
 
   Token name = next_token_is(TOKEN_IDENTIFIER);
   if (name.length > MAX_SYMBOL_NAME_LENGTH) {
@@ -499,6 +464,9 @@ void define_function(VM *vm, ScopeTable *st) {
   st->scope_ref = temp; // need to add to the parents scope
   symbol_table_add(st, s);
   st->scope_ref = (i32)st->count;
+
+  /* pop the current reg off the stack */
+  st->current_reg = st->last_used_registers[--st->reg_count];
 }
 
 /**
@@ -680,7 +648,7 @@ void build_symbol_table(VM *vm, char *source, ScopeTable *st) {
           define_var(st, token);
           next_token_is(TOKEN_SEMICOLON);
         } else {
-          define_global(vm, st);
+          define_global(vm, st, token);
         }
         continue;
       }
@@ -2373,6 +2341,7 @@ bool compile(VM *vm, ScopeTable *st, char *source) {
   build_symbol_table(vm, source, st);
   vm->cp = 0; /* actually start emitting code */
   st->count = 0;
+  st->reg_count = 0;
   emit_bytecode(vm, source, st);
   return true;
 }
diff --git a/src/tools/compiler/compiler.h b/src/tools/compiler/compiler.h
index d28b7be..8593db8 100644
--- a/src/tools/compiler/compiler.h
+++ b/src/tools/compiler/compiler.h
@@ -84,6 +84,9 @@ struct scope_tab_s {
   u32 capacity;
   i32 scope_ref;
   u32 depth;
+  u8 last_used_registers[1024];
+  u32 reg_count;
+  u8 current_reg;
 };
 
 bool compile(VM *vm, ScopeTable *st, char *source);
diff --git a/test/add.uir.ul b/test/add.uir.ul
index 75f4b79..95e3df0 100644
--- a/test/add.uir.ul
+++ b/test/add.uir.ul
@@ -4,15 +4,20 @@ int x = 1;
 int y = 1;
 
 function main () {
-	load_absolute_32 x -> $0;
-	load_absolute_32 y -> $1;
-	call add ($0 $1) -> $2;
-	int_to_string $2 -> $3;
-	call pln ($3);
+	int local_x;
+	int local_y;
+	int result;
+	int result_str;
+
+	load_absolute_32 x -> local_x;
+	load_absolute_32 y -> local_y;
+	call add (local_x local_y) -> result;
+	int_to_string result -> result_str;
+	call pln (result_str);
 	exit 0;
 }
 
-function add (int a, int b) {
+function add (int a, int b) int {
 	int result;
 	add_int a b -> result;
 	return result;
diff --git a/test/fib.uir.ul b/test/fib.uir.ul
index 6843bde..7673736 100644
--- a/test/fib.uir.ul
+++ b/test/fib.uir.ul
@@ -2,30 +2,38 @@ str terminal_namespace = "/dev/term/0";
 str new_line = "\n";
 
 function main () {
+	int result;
 	int str_n;
 
-	load_immediate 35 -> $0;
-	call fib ($0) -> $0;
-	int_to_string $0 -> str_n;
+	load_immediate 35 -> result;
+	call fib (result) -> result;
+	int_to_string result -> str_n;
 	call pln (str_n);
 	exit 0;
 }
 
 function fib (int n) {
-	load_immediate 2 -> $1;
+	int result;
+	load_immediate 2 -> result;
 
-	jump_lt_int base_case n $1;
+	jump_lt_int base_case n result;
 
-	load_immediate 2 -> $3;
-	sub_int n $3 -> $4;
-	call fib ($4) -> $5;
+	int two;
+	int tmp_n;
+	int result_a;
+	int result_b;
 
-	load_immediate 1 -> $3;
-	sub_int n $3 -> $4;
-	call fib ($4) -> $6;
+	load_immediate 2 -> two;
+	sub_int n two -> tmp_n;
+	call fib (tmp_n) -> result_a;
 
-	add_int $6 $5 -> $7;
-	return $7;
+	int one;
+	load_immediate 1 -> one;
+	sub_int n one -> tmp_n;
+	call fib (tmp_n) -> result_b;
+
+	add_int result_b result_a -> result;
+	return result;
 
 	else base_case;
 	return n;
diff --git a/test/loop.uir.ul b/test/loop.uir.ul
index 214d0cb..a47e420 100644
--- a/test/loop.uir.ul
+++ b/test/loop.uir.ul
@@ -5,41 +5,50 @@ str new_line = "\n";
 function main () {
 	real a;
 	int i;
-	int mode $11;
-	str term $10;
+	int mode;
+	str term;
+	int zero;
+	int decrement;
+	real five;
 
 	// do (i = 5000; i >= 0, i = i - 1) 
 	load_immediate 5.0 -> a;
 	load_immediate 5000 -> i;
-	load_immediate 0 -> $2;
-	load_immediate -1 -> $3;
-	load_immediate 5.0 -> $5;
+	load_immediate 0 -> zero;
+	load_immediate -1 -> decrement;
+	load_immediate 5.0 -> five;
 	loop loop_body {
-		add_real a $5 -> a;
-		add_int i $3 -> i;
-		jump_ge_int loop_body i $2;
+		add_real a five -> a;
+		add_int i decrement -> i;
+		jump_ge_int loop_body i zero;
 	}
 
 	load_address terminal_namespace -> term;
 	load_immediate 0 -> mode;
 	syscall OPEN term mode term; // Terminal term = open("/dev/term/0", 0);
 
-	nat b $1;
+	nat b;
+	str prompt_str;
+	nat prompt_len;
 	real_to_nat a -> b;
-	load_address prompt -> $7;
-	string_length $7 -> $8;
-	syscall WRITE term $7 $8; // print prompt
+	load_address prompt -> prompt_str;
+	string_length prompt_str -> prompt_len;
+	syscall WRITE term prompt_str prompt_len; // print prompt
 
-	str user_string $9;
-	load_immediate 32 -> $8;
-	malloc $8 -> user_string;
-	syscall READ term user_string $8; // read in max 32 byte string
+	str user_string;
+        nat user_max_string_size;
+	load_immediate 32 -> user_max_string_size;
+	malloc user_max_string_size -> user_string;
+	syscall READ term user_string user_max_string_size; // read in max 32 byte string
+
+	str b_string;
+	str a_string;
 
 	call pln (user_string);
-	nat_to_string b -> $4;
-	call pln ($4);
-	real_to_string a -> $3;
-	call pln ($3);
+	nat_to_string b -> b_string;
+	call pln (b_string);
+	real_to_string a -> a_string;
+	call pln (a_string);
 	exit 0;
 }
 
diff --git a/test/malloc.uir.ul b/test/malloc.uir.ul
index 68ca279..4806eb3 100644
--- a/test/malloc.uir.ul
+++ b/test/malloc.uir.ul
@@ -10,14 +10,17 @@ function main () {
 	load_immediate 0 -> mode;
 	syscall OPEN term mode term; // Terminal term = open("/dev/term/0", 0);
 
-	load_address prompt -> $7; 
-	string_length $7 -> $8;
-	syscall WRITE term $7 $8; // print prompt
+	str prompt_string;
+    nat prompt_len;
+	load_address prompt -> prompt_string; 
+	string_length prompt_string -> prompt_len;
+	syscall WRITE term prompt_string prompt_len; // print prompt
 
 	str user_string;
-	load_immediate 32 -> $8;
-	malloc $8 -> user_string;
-	syscall READ term user_string $8; // read in max 32 byte string
+    nat user_max_string_size;
+	load_immediate 32 -> user_max_string_size;
+	malloc user_max_string_size -> user_string;
+	syscall READ term user_string user_max_string_size; // read in max 32 byte string
 
 	call pln (user_string);
 	exit 0;
diff --git a/test/paint.uir.ul b/test/paint.uir.ul
index 7c5045b..5e01a28 100644
--- a/test/paint.uir.ul
+++ b/test/paint.uir.ul
@@ -36,32 +36,34 @@ byte SELECTED_COLOR = 255;
 
 function main () {
   // Open screen
-  ptr screen $0;
-  str screen_name $18;
-  int mode $11;
-  nat screen_buffer $21;
+  ptr screen;
+  str screen_name;
+  int mode;
+  nat screen_buffer;
 
   // use load immediate because it a pointer to a string, not a value
   load_address screen_namespace -> screen_name;
   load_immediate 0 -> mode;
   syscall OPEN screen_name mode screen; // Screen screen = open("/dev/screen/0", 0);
 
-  nat width $20;
-  nat size $22;
+  nat width;
+  nat size;
   load_offset_32 screen 8 -> width; // load width
   load_offset_32 screen 12 -> size; // load size
-  load_immediate 16 -> $1; // offset for screen buffer
-  add_nat screen $1 -> screen_buffer;
+
+  nat offset;
+  load_immediate 16 -> offset; // offset for screen buffer
+  add_nat screen offset -> screen_buffer;
 
   // open mouse
-  ptr mouse $15;
-  str mouse_name $16;
+  ptr mouse;
+  str mouse_name;
   load_address mouse_namespace -> mouse_name;
   syscall OPEN mouse_name mode mouse; // Mouse mouse = open("/dev/mouse/0", 0);
 
-  byte color $1;
-  nat x_pos $12;
-  nat y_pos $13;
+  byte color;
+  nat x_pos;
+  nat y_pos;
 
   load_absolute_8 BLACK -> color;
   load_immediate 1 -> x_pos;
@@ -116,23 +118,24 @@ function main () {
   // screen.draw
   syscall WRITE screen screen_buffer size;
 
-  nat m_zero $11;
+  nat zero;
+  load_immediate 0 -> zero;
 
   loop draw_loop {
     // load mouse click data
     syscall REFRESH mouse;
 
-    byte left_down $9;
+    byte left_down;
     load_offset_8 mouse 16 -> left_down; // load btn1 pressed
 
-    jump_eq_nat draw_loop left_down m_zero; // if (!btn1.left) continue;
+    jump_eq_nat draw_loop left_down zero; // if (!btn1.left) continue;
 
-    nat mouse_x $7;
-    nat mouse_y $8;
+    nat mouse_x;
+    nat mouse_y;
     load_offset_32 mouse 8 -> mouse_x; // load x
     load_offset_32 mouse 12 -> mouse_y; // load y
 
-    nat box_size $14;
+    nat box_size;
     load_immediate 20 -> box_size;
 
     // first row
@@ -198,10 +201,10 @@ function main () {
 
     syscall WRITE screen screen_buffer size;
 
-    byte selected_color $25;
+    byte selected_color;
     load_absolute_8 SELECTED_COLOR -> selected_color;
 
-    nat brush_size $19;
+    nat brush_size;
     load_immediate 5 -> brush_size;
 
     call draw_box (screen_buffer width selected_color mouse_x mouse_y brush_size brush_size);
@@ -213,16 +216,15 @@ function main () {
   exit 0;
 }
 
-function set_color_if_clicked (int click_x $0, int click_y $1,
-  int box_x $2, int box_y $3, byte check_color $4, int bsize $5) {
+function set_color_if_clicked (int click_x, int click_y, int box_x, int box_y, byte check_color, int size) {
 
   // Compute right
-  int right_edge $6;
-  add_int box_x bsize -> right_edge;
+  int right_edge;
+  add_int box_x size -> right_edge;
   
-  // Compute bottom = box_y + bsize  
-  int bottom_edge $7;
-  add_int box_y bsize -> bottom_edge;
+  // Compute bottom = box_y + size  
+  int bottom_edge;
+  add_int box_y size -> bottom_edge;
 
   // Bounds check: x in [box_x, right] and y in [box_y, bottom]
   jump_lt_int fail click_x box_x;
@@ -236,8 +238,7 @@ function set_color_if_clicked (int click_x $0, int click_y $1,
     return;
 }
 
-function draw_outlined_swatch(nat base, 
-  byte swatch_color, int x, int y, int width) {
+function draw_outlined_swatch(nat base, byte color, int x, int y, int width) {
 
   // Constants
   nat background_color;
@@ -246,7 +247,7 @@ function draw_outlined_swatch(nat base,
   byte selected_color;
   load_absolute_8 SELECTED_COLOR -> selected_color;
 
-  jump_eq_int set_selected swatch_color selected_color;
+  jump_eq_int set_selected color selected_color;
   jump end_set_selected;
   do set_selected
     load_absolute_8 DARK_GRAY -> background_color;
@@ -265,10 +266,10 @@ function draw_outlined_swatch(nat base,
 
   int x_off;
   int y_off;
-  add_int x offset -> x_off;    // x + 2
+  add_int x offset -> x_off;   // x + 2
   add_int y offset -> y_off;   // y + 2
 
-  call draw_box (base width swatch_color x_off y_off fill_size fill_size);
+  call draw_box (base width color x_off y_off fill_size fill_size);
 
   return;
 }
@@ -278,12 +279,13 @@ function draw_box (nat db_base, nat screen_width,
   nat db_width, nat height) {
 
   // Compute start address: base + y*640 + x
-  nat offset;
-  mul_int y_start screen_width -> offset;
-  add_int offset x_start -> offset;
-  add_nat offset db_base -> offset;
   nat fat_ptr_size;
   load_immediate 4 -> fat_ptr_size;
+
+  nat offset;
+  mul_nat y_start screen_width -> offset;
+  add_nat offset x_start -> offset;
+  add_nat offset db_base -> offset;  
   add_nat offset fat_ptr_size -> offset;      // need to add offset for fat pointer size
 
   int i;