Salto: SYSTEM FOR ASSEMBLY-LANGUAGE TRANSFORMATION AND OPTIMIZATION

On critical applications, particularly embedded systems, the performance tuning requires multiple passes. Salto (System for Assembly Language Transformation and Optimization) is a retargetable framework for developing all the spectrum of tools that are needed for performance tuning on low-level codes (assembly-languages) on uniprocessors. Salto enables the building of pro ling, tracing and optimization tools. The user is responsible for giving a machine description of the target architecture, which includes instruction-set of the processor, precise hardware con guration and reservation-tables for all instructions, but high-level functions are provided to him for writing any tool corresponding to his needs. Moreover Salto will be a part of a global solution for manipulating assembly-code to implement low-level code restructuration as well as to provide a high-level code restructurer with useful information collected from the assembler code and from instruction pro ling. Salto has been tested on Intel platforms running Linux (i486) and Solaris (PentiumPro) and on a Sparcstation running SunOs 4.1. A machine description for the Sparc v7 architecture is currently available. Two examples, a basic block instrumentation and a local reordering optimization, are given in the paper as illustration. Key-words: assembly language, optimization, embedded systems, reservation tables, user interface, object oriented, compilation process