Review: Vector Programming Model

CS252 Graduate Computer Architecture Lecture 12

Scalar Registers

Vector Registers

r15

v15

r0

v0

Vector Processing (Con’t) Branch Prediction

[0]

[1]

Vector Arithmetic Instructions ADDV v3, v1, v2

Electrical Engineering and Computer Sciences University of California, Berkeley

Base, 3/5/2007

r1

Functional Unit

A Elements 3, 7, 11, …

B

[1]

+

+

+

v1

[VLR-1] Vector Register

Stride, r2 cs252-S07, Lecture 12

C +

Remainder

+

64 elements

+ Memory Subsystem cs252-S07, Lecture 12

[0]

+

Memory

Problem: Vector registers have finite length Solution: Break loops into pieces that fit into vector registers, “Stripmining”

Lane

3/5/2007

+

v3

for (i=0; i