$//4$ marks $(3+1$ marks$)$

Note $-$ For part b$,$ you do not need to show the code, just answer qualitatively.

$6\mathrm{.}7$ Consider the following portions of two different programs running at the same time on four processors in a symmetric

multicore processor $($SMP$).$ Assume that before this code is run, both x and y are $0.$

Core $1$:x $=2$;

Core $2$:y $=2$;

Core $3$: w $=$ x $+$ y $+1$;

Core $4$: z $=$ x $+$ y;

$6\mathrm{.}7\mathrm{.}1[10]<6\mathrm{.}5>$ What are all the possible resulting values of

w$,$x$,$y$,$ and z$?$ For each possible outcome, explain how we might arrive at those values. You will need to examine all possible

interleavings of instructions.

$6\mathrm{.}7\mathrm{.}2[5]<6\mathrm{.}5>$ How could you make the execution more deterministic so that only one set of values is possible?