Data dependences, which relate statements that compute data values to statements that use those values, are useful for automating a variety of program-comprehension-related activities, such as reverse engineering, impact analysis, and debugging. Unfortunat

Table3:Classi cationofdef-useassociations:24typesthatresultfromacrossproductofdef-usetypes(Table1)andthesecondalternativeforpathclassi cation(column3ofTable2).

def-usetype1

DUAtype7DUAtype8DUAtype9DUAtype10DUAtype11DUAtype12

def-usetype3

DUADUADUADUADUADUA

typetypetypetypetypetype

192021222324

Table4:Def-useassociations,withtheirtypes,thatoccurinprogramSum.

Def-useassociation(1,8a,sum1)

type2

(3,8a,j)

type3

(8a,8a,sum2)

type3

(12,16,k)

type1

(17,19,q)

(14,20,i)

type1

(19,21,sum)

(9,10a,j)

type7

(14,15,i)

type1

(8a,8a,sum1)

type14

(9,5,j)

type1

(3,4,i)

type3

(6,8a,p)

type14

Typetype2

Def-useassociation(2,8a,sum2)

type3