Processor Description Languages

18 CHAPTER 2 ADL-driven Methodologies

Some retargetable compilers including GCC allow users to specify an automaton of

instruction sequences that will minimize/avoid pipeline resource hazards. Instead

of explicitly specifying the automatons in the ADL, some retargetable compilers

deduce reser vation tables from the ADL, which describes the processor pipeline,

and the flow of instructions through it. Reservation tables of instructions can be

combined to detect all resource hazards in a schedule. In the most general case,

operation ta bles can be extracted from the ADL if the pipeline structure of the

processor and the flow of instructions and its operands ...