Profile-Guided Automatic Inline Expansion for C Programs

Coordinated Science Laboratory was formerly known as Control Systems LaboratoryNational Science Foundation / MIP-8809478NCRAMD 29K Advanced Processor Development DivisionNational Aeronautics and Space Administration / NASA NAG 1-61

Evaluating inlining techniques

Abstract For eciency and ease of implementation, many compilers implicitly impose an``inlining policy'' to restrict the conditions under which a procedure may be inlined. An inlining technique consists of an inlining policy and a strategy for choosing a sequence of inlining operations that is consistent with the policy. The eectiveness of an inlining technique is aected by the restrictiveness of the inlining policy as well as the eectiveness of the (heuristic) inlining strategy. The focus of this paper is on the comparison of inlining policies and techniques, and the notions of power and¯exibility are introduced. As a major case study, we identify and compare policies based on the version of the inlined procedure that is used

Path splitting--a technique for improving data flow analysis

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.Includes bibliographical references (p. 83-87).by Massimiliano Antonio Poletto.M.Eng

The exploitation of parallelism on shared memory multiprocessors

PhD ThesisWith the arrival of many general purpose shared memory multiple processor (multiprocessor) computers into the commercial arena during the mid-1980's, a rift has opened between the raw processing power offered by the emerging hardware and the relative inability of its operating software to effectively deliver this power to potential users. This rift stems from the fact that, currently, no computational model with the capability to elegantly express parallel activity is mature enough to be universally accepted, and used as the basis for programming languages to exploit the parallelism that multiprocessors offer. To add to this, there is a lack of software tools to assist programmers in the processes of designing and debugging parallel programs. Although much research has been done in the field of programming languages, no undisputed candidate for the most appropriate language for programming shared memory multiprocessors has yet been found. This thesis examines why this state of affairs has arisen and proposes programming language constructs, together with a programming methodology and environment, to close the ever widening hardware to software gap. The novel programming constructs described in this thesis are intended for use in imperative languages even though they make use of the synchronisation inherent in the dataflow model by using the semantics of single assignment when operating on shared data, so giving rise to the term shared values. As there are several distinct parallel programming paradigms, matching flavours of shared value are developed to permit the concise expression of these paradigms.The Science and Engineering Research Council

Compilation techniques for multicomputers

This thesis considers problems in process and data partitioning when compiling programs for distributed-memory parallel computers (or multicomputers). These partitions may be specified by the user through the use of language constructs, or automatically determined by the compiler. Data and process partitioning techniques are developed for two models of compilation. The first compilation model focusses on the loop nests present in a serial program. Executing the iterations of these loop nests in parallel accounts for a significant amount of the parallelism which can be exploited in these programs. The parallelism is exploited by applying a set of transformations to the loop nests. The iterations of the transformed loop nests are in a form which can be readily distributed amongst the processors of a multicomputer. The manner in which the arrays, referenced within these loop nests, are partitioned between the processors is determined by the distribution of the loop iterations. The second compilation model is based on the data parallel paradigm, in which operations are applied to many different data items collectively. High Performance Fortran is used as an example of this paradigm. Novel collective communication routines are developed, and are applied to provide the communication associated with the data partitions for both compilation models. Furthermore, it is shown that by using these routines the communication associated with partitioning data on a multicomputer is greatly simplified. These routines are developed as part of this thesis. The experimental context for this thesis is the development of a compiler for the Fujitsu AP1000 multicomputer. A prototype compiler is presented. Experimental results for a variety of applications are included

1977 ACM Student Award Paper: First Place An Analysis of Inline Substitution for a Structured Programming Language

An optimization technique known as inline substitution is analyzed. The optimization consists of replacing a procedure invocation by a modified copy of the procedure body. The general problem of using inline substitution to minimize execution time subject to size constraints is formulated, and an approximate algorithmic solution is proposed. The algorithm depends on run-time statistics about the program to be optimized. Preliminary results for the CLU structured programming language indicate that, in programs with a low degree of recursion, over 90 percent of all procedure calls can be eliminated, with little increase in the size of compiled code and a small savings in execution time. Other conclusions based on these results are also presented. Key Words and Phrases: inline substitution, open coding, open compilation, program optimization