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Optimal Code Motion: Theory and Practice
, 1993
"... An implementation oriented algorithm for lazy code motion is presented that minimizes the number of computations in programs while suppressing any unnecessary code motion in order to avoid superfluous register pressure. In particular, this variant of the original algorithm for lazy code motion works ..."
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Cited by 111 (18 self)
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An implementation oriented algorithm for lazy code motion is presented that minimizes the number of computations in programs while suppressing any unnecessary code motion in order to avoid superfluous register pressure. In particular, this variant of the original algorithm for lazy code motion works on flowgraphs whose nodes are basic blocks rather than single statements, as this format is standard in optimizing compilers. The theoretical foundations of the modified algorithm are given in the first part, where trefined flowgraphs are introduced for simplifying the treatment of flowgraphs whose nodes are basic blocks. The second part presents the `basic block' algorithm in standard notation, and gives directions for its implementation in standard compiler environments. Keywords Elimination of partial redundancies, code motion, data flow analysis (bitvector, unidirectional, bidirectional), nondeterministic flowgraphs, trefined flow graphs, critical edges, lifetimes of registers, com...
Acquiring SearchControl Knowledge via Static Analysis
 Artificial Intelligence
, 1993
"... ExplanationBased Learning (EBL) is a widelyused technique for acquiring searchcontrol knowledge. Recently, Prieditis, van Harmelen, and Bundy pointed to the similarity between Partial Evaluation (PE) and EBL. However, EBL utilizes training examples whereas PE does not. It is natural to inquire, th ..."
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Cited by 94 (2 self)
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ExplanationBased Learning (EBL) is a widelyused technique for acquiring searchcontrol knowledge. Recently, Prieditis, van Harmelen, and Bundy pointed to the similarity between Partial Evaluation (PE) and EBL. However, EBL utilizes training examples whereas PE does not. It is natural to inquire, therefore, whether PE can be used to acquire searchcontrol knowledge, and if so at what cost? This paper answers these questions by means of a case study comparing prodigy/ebl, a stateoftheart EBL system, and static, a PEbased analyzer of problemspace definitions. When tested in prodigy/ebl's benchmark problem spaces, static generated searchcontrol knowledge that was up to three times as effective as the knowledge learned by prodigy/ebl, and did so from twentysix to seventyseven times faster. The paper describes static's algorithms, compares its performance to prodigy/ebl's, noting when static's superior performance will scale up and when it will not. The paper concludes with several le...
Putting Pointer Analysis to Work
, 1998
"... This paper addresses the problem of how to apply pointer analysis to a wide variety of compiler applications. We are not presenting a new pointer analysis. Rather, we focus on putting two existing pointer analyses, pointsto analysis and connection analysis, to work. We demonstrate that the fundamen ..."
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Cited by 93 (8 self)
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This paper addresses the problem of how to apply pointer analysis to a wide variety of compiler applications. We are not presenting a new pointer analysis. Rather, we focus on putting two existing pointer analyses, pointsto analysis and connection analysis, to work. We demonstrate that the fundamental problem is that one must be able to compare the memory locations read/written via pointer indirections, at different program points, and one must also be able to summarize the effect of pointer references over regions in the program. It is straightforward to compute read/write sets for indirections involving stackdirected pointers using pointsto information. However, for heapdirected pointers we show that one needs to introduce the notion of anchor handles into the connection analysis and then express read/write sets to the heap with respect to these anchor handles. Based on the read/write sets we show how to extend traditional optimizations like common subexpression elimination, loop...
The Interprocedural Coincidence Theorem
 In Int. Conf. on Comp. Construct
, 1992
"... We present an interprocedural generalization of the wellknown (intraprocedural) Coincidence Theorem of Kam and Ullman, which provides a sufficient condition for the equivalence of the meet over all paths (MOP ) solution and the maximal fixed point (MFP ) solution to a data flow analysis problem. Th ..."
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Cited by 90 (11 self)
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We present an interprocedural generalization of the wellknown (intraprocedural) Coincidence Theorem of Kam and Ullman, which provides a sufficient condition for the equivalence of the meet over all paths (MOP ) solution and the maximal fixed point (MFP ) solution to a data flow analysis problem. This generalization covers arbitrary imperative programs with recursive procedures, global and local variables, and formal value parameters. In the absence of procedures, it reduces to the classical intraprocedural version. In particular, our stackbased approach generalizes the coincidence theorems of Barth and Sharir/Pnueli for the same setup, which do not properly deal with local variables of recursive procedures. 1 Motivation Data flow analysis is a classical method for the static analysis of programs that supports the generation of efficient object code by "optimizing" compilers (cf. [He, MJ]). For imperative languages, it provides information about the program states that may occur at s...
Abstractions for Recursive Pointer Data Structures: Improving the Analysis and Transformation of Imperative Programs
, 1992
"... Even though impressive progress has been made... ..."
Delocalized plans and program comprehension
 IEEE Software
, 1986
"... A maintainer's understanding cangoawry when it is based on purely local clues. How can we spell out the intentions behindapiece ofcode? ..."
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Cited by 79 (0 self)
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A maintainer's understanding cangoawry when it is based on purely local clues. How can we spell out the intentions behindapiece ofcode?
Connection Analysis: A Practical Interprocedural Heap Analysis for C
 International Journal of Parallel Programming
, 1995
"... This paper presents a practical heap analysis technique, connection analysis, that can be used to disambiguate heap accesses in C programs. The technique is designed for analyzing programs that allocate many disjoint objects in the heap such as dynamicallyallocated arrays in scientific programs. Th ..."
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Cited by 74 (6 self)
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This paper presents a practical heap analysis technique, connection analysis, that can be used to disambiguate heap accesses in C programs. The technique is designed for analyzing programs that allocate many disjoint objects in the heap such as dynamicallyallocated arrays in scientific programs. The method statically estimates connection matrices which encode the connection relationships between all heapdirected pointers at each program point. The results of the analysis can be used by parallelizing compilers to determine when two heapallocated objects are guaranteed to be disjoint, and thus can be used to improve array dependence and interference analysis. The method has been implemented as a contextsensitive interprocedural analysis in the McCAT optimizing/parallelizing C compiler. Experimental results are given to compare the accuracy of connection analysis versus a conservative estimate based on pointsto analysis. This work supported by NSERC, FCAR, and the EPPP project (fin...
Precise Interprocedural Analysis through Linear Algebra
, 2004
"... We apply linear algebra techniques to precise interprocedural dataflow analysis. Specifically, we describe analyses that determine for each program point identities that are valid among the program variables whenever control reaches that program point. Our analyses fully interpret assignment stateme ..."
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Cited by 64 (9 self)
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We apply linear algebra techniques to precise interprocedural dataflow analysis. Specifically, we describe analyses that determine for each program point identities that are valid among the program variables whenever control reaches that program point. Our analyses fully interpret assignment statements with affine expressions on the right hand side while considering other assignments as nondeterministic and ignoring conditions at branches. Under this abstraction, the analysis computes the set of all affine relations and, more generally, all polynomial relations of bounded degree precisely. The running time of our algorithms is linear in the program size and polynomial in the number of occurring variables. We also show how to deal with affine preconditions and local variables and indicate how to handle parameters and return values of procedures.
Concrete Type Inference: Delivering ObjectOriented Applications
, 1995
"... Unlimited copying without fee is permitted provided that the copies are not made nor distributed for direct commercial advantage, and credit to the source is given. Otherwise, no part of this work covered by copyright hereon may be reproduced in any form or by any means graphic, electronic, or mecha ..."
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Cited by 55 (0 self)
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Unlimited copying without fee is permitted provided that the copies are not made nor distributed for direct commercial advantage, and credit to the source is given. Otherwise, no part of this work covered by copyright hereon may be reproduced in any form or by any means graphic, electronic, or mechanical, including photocopying, recording, taping, or storage in an information retrieval system, without the prior written permission of the copyright owner. TRADEMARKS Sun, Sun Microsystems, and the Sun logo are trademarks or registered trademarks of Sun Microsystems, Inc. UNIX is a registered trademark in the United States and other countries, exclusively licensed through X/Open Company, Ltd. All SPARC trademarks, including the SCD Compliant Logo, are trademarks or registered trademarks of SPARC International, Inc. SPARCstation, SPARCserver, SPARCengine, SPARCworks, and SPARCompiler are licensed exclusively to Sun Microsystems, Inc. All other product names mentioned herein are the trademarks of their respective owners.