 |
Email:
yinma@mtu.edu
Phone:
(906)4825502
Address:
219 Hubbell St. ,Houghton |
|
¡¡
Low-cost Register-pressure
Prediction for Scalar Replacement Using Pseudo-schedules*
Abstract
Scalar
replacement is an effective optimization for removing memory accesses.
However, exposing all possible array reuse with scalars may cause a
significant increase in register pressure, resulting in register
spilling and performance degradation. In this paper, we present a low
cost method to predict the register pressure of a loop before applying
scalar replacement on high-level source code, called Pseudo-schedule
Register Prediction (PRP), that takes into account the effects of both
software pipelining and register allocation. PRP attempts to eliminate
the possibility of degradation from scalar replacement due to register
spilling while providing opportunities for a good speedup. PRP uses
three approximation algorithms: one for constructing a data dependence
graph, one for computing the recurrence constraints of a software
pipelined loop, and one for building a pseudo-schedule. Our experiments
show that PRP predicts the floating-point register pressure within 2
registers and the integer register pressure within 2.7 registers on
average with a time complexity of O(n2) in practice. PRP
achieves similar performance to the best previous approach, having O(n3)
complexity, with less than one-fourth of the compilation time on our
test suite.
-
The paper about this research work has been
published in In the Proceedings of the 2004
International Conference on Parallel Processing (ICPP-04), Page
116-124, Montreal, Canada£¬ 2004£08
-
Download Full Text here.
[PDF]
¡¡
|
|
