Papers by Benjamin Schwarz
Measurement of frequency response of photoreceivers using self-homodyne method
Electronics Letters, 1989
We present load-balancing strategies to improve the performances of parallel MPI applications run... more We present load-balancing strategies to improve the performances of parallel MPI applications running in a Grid environment. We analyze the data distribution constraints found in two scientific codes and propose adapted code transformations to load-balance computations. Experimental results confirm that such source code transformations can improve Grid application performances.
Machine code disassembly routines form a fundamental component of software systems that staticall... more Machine code disassembly routines form a fundamental component of software systems that statically analyze or modify executable programs. The task of disassembly is complicated by indirect jumps and the presence of nonexecutable data-jump tables, alignment bytes, etc.-in the instruction stream. Existing disassembly algorithms are not always able to cope successfully with executable files containing such features and fail silently-i.e., produce incorrect disassemblies without any indication that the results they are producing are incorrect. This can be a serious problem, since it can compromise the correctness of a binary rewriting tool. In this paper we examine two commonlyused disassembly algorithms and illustrate their shortcomings. We propose a hybrid approach that performs better than these algorithms in the sense that it is able to detect situations where the disassembly may be incorrect and limit the extent of such disassembly errors. Experimental results indicate that the algorithm is quite effective: the amount of code flagged as incurring disassembly errors is usually quite small.
This paper describes PLTO, a link-time instrumentation and optimization tool we have developed fo... more This paper describes PLTO, a link-time instrumentation and optimization tool we have developed for the Intel IA-32 architecture. A number of characteristics of this architecture complicate the task of link-time optimization. These include a large number of op-codes and addressing modes, which increases the complexity of program analysis; variable-length instructions, which complicates disassembly of machine code; a paucity of available registers, which limits the extent of some optimizations; and a reliance on using memory locations for holding values and for parameter passing, which complicates program analysis and optimization. We describe how PLTO addresses these problems and the resulting performance improvements it is able to achieve.
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Papers by Benjamin Schwarz