we examine how dependences affect execution in the peline de

we examine how dependences affect execution in the peline described 4.5.Problems in this exercise refer to the following s of instructions: or r1, r2, r3 or 2, 1.r4 or r1, r2 r1. ssume the following cycle times for each of the options related to forwarding. Without Forwarding With Full Forwarding With ALU-ALU Forwarding only 300ps 250ps

Solution

l1: or r1,r2,r3

l2: or r2,r1,r4

l3: or r1,r1,r2

RAW on r1 from l1 to l2 and l3

RAW on r2 from l2 to l3

WAR on r2 from l1 to l2

WAR on r1 from l2 to l3

WAR on r1 from l1 to l3

Instruction sequence	Dependences
l1: or r1,r2,r3 l2: or r2,r1,r4 l3: or r1,r1,r2	RAW on r1 from l1 to l2 and l3 RAW on r2 from l2 to l3 WAR on r2 from l1 to l2 WAR on r1 from l2 to l3 WAR on r1 from l1 to l3