ME-Single Static Assignment

Question

Do I have to define variables(a,b,c,d,e) in temp variable before use?

Ans is 6 or 11??

Answer 1

first convert expression into 3 address code and then assign each variableb to separate new variable.

in static single assignment form each variable is assigned to another variable.

3 address code for above expression is

t1=d*4

t2=b/9

t3=a+t2

t4=t3+c

t5=t4-t1

t6=t5+e

STATIC SINGLE ASSIGNMENT FORM IS

p1=d*4

p2=b/9

p3=a+p21

p4=p31+c

p5=p41-p11

p6=p51+e

so total 11 variables are required in ssa

Comments

So, answer to above question is $6$

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Here, while u r using P2 value in next statement, u r giving new name to p2 i.e (p21), and so on. and u count it as new variable. my question is, why it needed at all.

we can write like this.

p1 = d * 4

p2 = b / 9

p3 = a + p2

p4 = p3 + c

p5 = p4 - p1

p6 = p5 + e

 

what do u say ??

a/c to me,  ans should be 6.