System Overview

  SALTO is composed of three parts: a kernel, a machine description file and an optimization or instrumentation module provided by the user. Figure 1.1 illustrates the organization of these three components.

  

Figure 1.1: System Overview

• The kernel performs common house-keeping tasks the user doesn't want to worry about. The parsing of the machine description file and the assembly code, and the construction of the internal representation are done automatically. The internal representation is then available via the kernel's user interface.
• The machine description file provides a model of hardware configuration and the complete description of the instruction set, including per-instruction resource reservation tables.
• The optimization or instrumentation module is supplied by the user, and provides two entry points: the main function Salto_hook, and (optionally) the initialization function Salto_init_hook. If supplied, the initialization function is called immediately after parsing command line arguments. The system then reads the machine description file and the assembly code. Once the internal representation is successfully built, the control is passed to the user by calling Salto_hook.