This paper uses timed Petri net to model and analyze the problem of instructionlevel loop scheduling with resource constraints, which has been proven to be an NP complete problem. First, we present a new timed Petri n...This paper uses timed Petri net to model and analyze the problem of instructionlevel loop scheduling with resource constraints, which has been proven to be an NP complete problem. First, we present a new timed Petri net model to integrate functional unit allocation, register allocation and spilling ilno a unified theoretical framework.Then we develop a state subgraph, called Register Allocation Solution Graph, which can effectively describe the major behavior of our new model. The maill property of this state subgraph is that the number of all its nodes is polynomial. Finally we present and prove that the optimum loop schedules can be found with polynomial computation complexity, for almost all practical loop prograrns. Our work lightens a new idea of finding the optimum loop schedules.展开更多
Global software pipelining is a complex but efficient compilation technique to exploit instruction-level parallelism for loops with branches. This paper presents a novel global software pipelining technique, called Th...Global software pipelining is a complex but efficient compilation technique to exploit instruction-level parallelism for loops with branches. This paper presents a novel global software pipelining technique, called Thace Software Pipelining,targeted to the instruction-level parallel processors such as Very Long Instruc-tion Word (VLIW) and superscalar machines. Thace software pipelining applies a global code scheduling technique to compact the original loop body. The re-sulting loop is called a trace software pipelined (TSP) code. The trace softwrae pipelined code can be directly executed with special architectural support or call be transformed into a globally software pipelined loop for the current VLIW and superscalar processors. Thus, exploiting parallelism across all iterations of a loop can be completed through compacting the original loop body with any global code scheduling technique. This makes our new technique very promis-ing in practical compilers. Finally, we also present the preliminary experimental results to support our new approach.展开更多
文摘This paper uses timed Petri net to model and analyze the problem of instructionlevel loop scheduling with resource constraints, which has been proven to be an NP complete problem. First, we present a new timed Petri net model to integrate functional unit allocation, register allocation and spilling ilno a unified theoretical framework.Then we develop a state subgraph, called Register Allocation Solution Graph, which can effectively describe the major behavior of our new model. The maill property of this state subgraph is that the number of all its nodes is polynomial. Finally we present and prove that the optimum loop schedules can be found with polynomial computation complexity, for almost all practical loop prograrns. Our work lightens a new idea of finding the optimum loop schedules.
文摘Global software pipelining is a complex but efficient compilation technique to exploit instruction-level parallelism for loops with branches. This paper presents a novel global software pipelining technique, called Thace Software Pipelining,targeted to the instruction-level parallel processors such as Very Long Instruc-tion Word (VLIW) and superscalar machines. Thace software pipelining applies a global code scheduling technique to compact the original loop body. The re-sulting loop is called a trace software pipelined (TSP) code. The trace softwrae pipelined code can be directly executed with special architectural support or call be transformed into a globally software pipelined loop for the current VLIW and superscalar processors. Thus, exploiting parallelism across all iterations of a loop can be completed through compacting the original loop body with any global code scheduling technique. This makes our new technique very promis-ing in practical compilers. Finally, we also present the preliminary experimental results to support our new approach.
