Automatic C to CUDA Code Generation for Affine Programs

113 Pages·2012·1.79 MB·English

by  Singh, Akanksha

CRINK: Automatic CUDA code
generation for affine C programs
A Thesis Submitted
in Partial Fulfillment of the Requirements
for the Degree of
Master of Technology
by
Akanksha Singh
Roll Number : 12111008
under the guidance of
Dr. Amey Karkare and Dr. Sanjeev Kumar
Aggarwal
Department of Computer Science and Engineering
Indian Institute of Technology Kanpur
June, 2014

Abstract
Parallel programming has largely evolved as an efficient solution to a large num-
ber of compute intensive applications. Graphics Processing Unit (GPUs), tradition-
ally designed to process computer graphics, are now widely applied to process large
chunks of data parallely in many computationally expensive applications. While de-
veloping parallel programs to run on parallel computing platforms, such as CUDA,
OpenCL, etc. requires knowledge of platform-specific concepts, it becomes very con-
venient if the process of parallelizing compute intensive sections of the program can
be automated.
We develop a tool CRINK, an end-to-end code transformation system, to con-
vert sequential C programs to their parallel counterparts in CUDA. CRINK targets
to parallelize the expensive sections (sections within loops) of the program while
converting C programs to CUDA C programs. It incorporates handling of both
irregular and regular kernels. We use concepts of Cycle Shrinking and Extended
Cycle Shrinking for parallelism extractions and loop transformations.
To analyse the performance, we run CRINK over the expensive sections taken
from ZERO RC, SPEC, SANDIA RULES, Treepack and Higbie standard bench-
marks. Analysisisdoneover66variedconfigurationsofthebenchmarksanddatasets
where we observe that drastic drops in computation times are achieved as the num-
ber of threads are increased while execution of the code transformed by CRINK.
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Dedicated to
my family, my advisor and my friends.
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Acknowledgement
I would like to express my sincere gratitude to both my thesis supervisors, Dr.
Amey Karkare and Late Dr. Sanjeev Kumar Aggarwal. Sanjeev sir’s guidance
and support helped me develop proper understanding of the subject. His guidance
helped me to approach the problem through the right direction during the initial
stages of my thesis work. Though I started working under Amey sir in the middle
of my thesis duration, he was always very motivating and helpful. His guidance and
encouragements enabled me to bring this thesis to a successful completion. I express
my sincere thanks and respect to both of them.
I am also thankful to all my friends of Computer Science Department, for their
continuous support, both technical and emotional, during my stay at IIT Kanpur.
I am grateful to all of them for creating memories that are really unforgettable.
I am deeply and forever indebted to my family for their encouragement, support
and love throughout my life. It is their well wishes which always gave me inspiration
and courage to face all challenges and made my path easier.
Akanksha Singh
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Contents
Abstract ii
List of Figures ix
List of Algorithms x
List of Tables xi
1 Introduction 1
1.1 Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Motivation of Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Outline of the Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 Contribution of the Thesis . . . . . . . . . . . . . . . . . . . . . . . . 4
1.5 Thesis Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Background 6
2.1 Compute Unified Device Architecture(CUDA) . . . . . . . . . . . . . 6
2.2 Affine and Non-Affine Programs . . . . . . . . . . . . . . . . . . . . . 10
2.3 Data Dependence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.4 Data Dependence Test . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.5 Cycle Shrinking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.6 Extended Cycle Shrinking . . . . . . . . . . . . . . . . . . . . . . . . 26
3 Code Generation Framework 32
3.1 Compilation Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
v
Contents vi
3.2 Dependence Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.3 Parallelism Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.4 Code Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4 A tour to CRINK 45
4.1 Singly Nested Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.2 Multi-Nested Loops with Constant Dependence Distance . . . . . . . 54
4.3 Multi-Nested Loops with Variable Dependence Distance . . . . . . . . 68
5 Literature Survey 75
5.1 Automatic Parallelization . . . . . . . . . . . . . . . . . . . . . . . . 75
5.2 Automatic Code Generation for GPGPUs . . . . . . . . . . . . . . . 77
6 Performance Evaluation 79
6.1 Experimental Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.2 Testing Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
6.3 Standard Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
6.4 Performance Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
6.5 Results Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
7 Conclusion and Future Work 96
Bibliography 98
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List of Figures
1.1 An abstract view of CRINK . . . . . . . . . . . . . . . . . . . . . . . 3
2.1 CUDA Programming Model . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 CUDA Memory Model . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3 Data Dependence in Loops . . . . . . . . . . . . . . . . . . . . . . . . 13
2.4 Different Partition for Example 7 . . . . . . . . . . . . . . . . . . . . 27
3.1 Compilation Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.2 Dependence Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.3 Parallelism Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.4 Code Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.1 Upper and Lower Bound Constraints . . . . . . . . . . . . . . . . . . 56
6.1 Plot for CSphd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
6.2 Plot for EVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
6.3 Plot for barth5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
6.4 Plot for p2p-Gnutella04 . . . . . . . . . . . . . . . . . . . . . . . . . 84
6.5 Plot for HEP-th-new . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
6.6 Plot for NotreDame www . . . . . . . . . . . . . . . . . . . . . . . . 84
6.7 Plot for CSphd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
6.8 Plot for EVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
6.9 Plot for barth5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
6.10 Plot for p2p-Gnutella04 . . . . . . . . . . . . . . . . . . . . . . . . . 85
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Contents viii
6.11 Plot for HEP-th-new . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
6.12 Plot for NotreDame www . . . . . . . . . . . . . . . . . . . . . . . . 85
6.13 Plot for CSphd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
6.14 Plot for EVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
6.15 Plot for barth5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
6.16 Plot for p2p-Gnutella04 . . . . . . . . . . . . . . . . . . . . . . . . . 86
6.17 Plot for HEP-th-new . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
6.18 Plot for CSphd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
6.19 Plot for EVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
6.20 Plot for barth5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.21 Plot for p2p-Gnutella04 . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.22 Plot for HEP-th-new . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.23 Plot for NotreDame www . . . . . . . . . . . . . . . . . . . . . . . . 87
6.24 Plot for CSphd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.25 Plot for EVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.26 Plot for barth5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.27 Plot for p2p-Gnutella04 . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.28 Plot for HEP-th-new . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.29 Plot for NotreDame www . . . . . . . . . . . . . . . . . . . . . . . . 88
6.30 Plot for CSphd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.31 Plot for EVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.32 Plot for barth5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
6.33 Plot for p2p-Gnutella04 . . . . . . . . . . . . . . . . . . . . . . . . . 89
6.34 Plot for HEP-th-new . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
6.35 Plot for NotreDame www . . . . . . . . . . . . . . . . . . . . . . . . 89
6.36 Plot for CSphd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
6.37 Plot for EVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
6.38 Plot for barth5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
6.39 Plot for p2p-Gnutella04 . . . . . . . . . . . . . . . . . . . . . . . . . 90
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List of Figures ix
6.40 Plot for HEP-th-new . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
6.41 Plot for NotreDame www . . . . . . . . . . . . . . . . . . . . . . . . 90
6.42 Plot for CSphd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.43 Plot for EVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.44 Plot for barth5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.45 Plot for p2p-Gnutella04 . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.46 Plot for HEP-th-new . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.47 Plot for NotreDame www . . . . . . . . . . . . . . . . . . . . . . . . 91
6.48 Plot for CSphd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.49 Plot for EVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.50 Plot for barth5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.51 Plot for p2p-Gnutella04 . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.52 Plot for HEP-th-new . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.53 Plot for NotreDame www . . . . . . . . . . . . . . . . . . . . . . . . 92
6.54 Plot for CSphd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.55 Plot for EVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.56 Plot for barth5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.57 Plot for p2p-Gnutella04 . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.58 Plot for HEP-th-new . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.59 Plot for NotreDame www . . . . . . . . . . . . . . . . . . . . . . . . 93
6.60 Plot for CSphd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
6.61 Plot for EVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
6.62 Plot for barth5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
6.63 Plot for p2p-Gnutella04 . . . . . . . . . . . . . . . . . . . . . . . . . 94
6.64 Plot for HEP-th-new . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
6.65 Plot for NotreDame www . . . . . . . . . . . . . . . . . . . . . . . . 94
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