关键词: 非可规约循环 持续引用 投机并行 失败恢复

Abstract:

Irreducible loop is a kind of loop with multi-entries. These loops are called irreducible because dominated relationship does not exist among the nodes in them. Traditional paralhlized compiler techniques use node splitting to make irreducible loops reducible, but will make code duplicate inevitably.   This paper proposes a speculative method to exploit parllelism in irredudbh loops. This method finds irreducible loops at compile time and predicts the  entry at run time using a strategy called＂persistency reference＂, then parallelizes irreducible loops as natural loops. Experimental results show thatt the method is effective and efficient.

Key words: （irreducible loop, persistency reference, speculative parallel ism, recovery）