Lesson 14--Framework for Parallelizing Load-Stores

Question 1

X-Y memory architecture

Answer 1

There are two parallel banks of memory. Each has its own address calculator and its own bus.

Question 2

Edge between two variables in the same memory bank

Answer 2

0

Question 3

Edge between two variables in different memory banks

Answer 3

1

Question 4

Motion Schedule Graph (MSG)

Answer 4

Graph to determine which loads and stores can be moved

Question 5

Rematerialization

Answer 5

Recomputing a value and storing it in another bank

Question 6

Motion Range Determination

Answer 6

The interval between program points where a load/store can be legally moved, restrained by dependencies

Question 7

Pseudo fixed-boundary

Answer 7

For Store: move as early as possible, assuming other instructions are fixed.
For Load: Move as late as possible, assuming other instructions are fixed.

Question 8

Cross basic block merge

Answer 8

­–To guarantee profitability: move to where the reference is live. If the reference is not live,
all we do is increase register pressure causing more spills
­–Move the stores using the extended basic blocks
­–Move the loads on reverse Extended basic blocks
­–Make sure: if moving load/stores in basic blocks that we are able to combine them with something else. So make sure it can be combined if pushed to at least one of the live predecessors/successors.

Question 9

Variable duplication

Answer 9

Adding stores for a variable to a different bank in order to take advantage of parallelization