Lvar source code:

a = 30
b = a
c = -a
d = b - c
b = a + d
c = b + c

---------------

x86_var code:

		read	written		live		interference edges

                                        {}
1 movq $30, a	-	a
                                        {a}
2 movq a, b 	a       b				(NOT a-b)
                                        {a,b}
3 movq a, c     a       c                               b-c, (NOT a-c)
                                        {a,b,c}
4 negq c	c       c				a-c, b-c
                                        {a,b,c}
5 movq b, d     b       d				a-d, c-d
                                        {a,c,d}
6 subq c, d     c,d     d				a-d, c-d
                                        {a,c,d}
7 movq a, b     a       b				c-b, d-b
                                        {b,c,d}
8 addq d, b     b,d     b				c-b
					{b,c}
9 addq b, c     b,c     c
					{}