Profile-based optimizations are being used with increasing frequency. Profile information can be used to improve instruction scheduling, code layout, and to increase instruction level parallelism. These optimizations have been shown to be effective when they are applied to the same program from which the profile was gathered. However it is an open question how profile-based optimizations should be applied to library subroutines. If many programs use libraries in the same way, it may be possible to "preoptimize" a library or to use an optimized shared library. This study examines the use of commonly used libraries among 43 C and FORTRAN programs to see if the libraries have common behavior across different programs. We examine the behavior of the most commonly used Unix libraries on Digital Unix. We found that libraries have very predictable behavior between applications. This implies that profile-based compiler optimizations may be effective far libraries across different applications. Therefore, one can use profile optimizations on shared and non-shared libraries before they are shipped, allowing a program using those libraries to take advantage of profile-based optimizations without having to gather any profiles. All results in this study are shown using branch misprediction rates. We feel this metric indicates the likelihood that programs have similar behavior and allows comparison to earlier branch prediction studies.

ATOM (Analysis Tools with OM) is a single framework for building a wide range of customized program analysis tools. It provides the common infrastructure present in all code-instrumenting tools; this is the difficult and time-consuming part. The user simply defines the tool-specific details in instrumentation and analysis routines. Building a basic block counting tool like Pixie with ATOM requires only a page of code.

Compilers for new machines with 64-bit addresses must generate code that works when the memory used by the program is large. Procedures and global variables are accessed indirectly via global address tables, and calling conventions include code to establish the addressability of the appropriate tables. In the common case of a program that does not require a lot of memory, all of this can be simplified considerably, with a corresponding reduction in program size and execution time. We have used our link-time code modification system OM to perform program transformations related to global address use on the Alpha AXP. Though simple, many of these are whole-program optimizations that can be done only when we can see the entire program at once, so link-time is an ideal occasion to perform them. This paper describes the optimizations performed and shows their effects on program size and performance. Relatively modest transformations, possible without moving code, improve the p...

article Free Access Share on A note on Hennessy's “symbolic debugging of optimized code” Authors: David Wall Computer Science Department, Whitmore Laboratory, The Pennsylvania State University, University Park, PA Computer Science Department, Whitmore Laboratory, The Pennsylvania State University, University Park, PAView Profile , Amitabh Srivastava Computer Science Department, Whitmore Laboratory, The Pennsylvania State University, University Park, PA Computer Science Department, Whitmore Laboratory, The Pennsylvania State University, University Park, PAView Profile , Fred Templin Computer Science Department, Whitmore Laboratory, The Pennsylvania State University, University Park, PA Computer Science Department, Whitmore Laboratory, The Pennsylvania State University, University Park, PAView Profile Authors Info & Claims ACM Transactions on Programming Languages and SystemsVolume 7Issue 1pp 176–181https://doi.org/10.1145/2363.215005Published:02 January 1985Publication History 14citation167DownloadsMetricsTotal Citations14Total Downloads167Last 12 Months14Last 6 weeks2 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF