公开(公告)号：US07114063B1

公开(公告)日：2006-09-26

申请号：US09727744

申请日：2000-12-01

申请人： Lawrence Richard Fontaine ,  John Steven Kuslak ,  Gary John Lucas ,  Michael David Pelarski

发明人： Lawrence Richard Fontaine ,  John Steven Kuslak ,  Gary John Lucas ,  Michael David Pelarski

IPC分类号： G06F9/44

CPC分类号： G06F9/3844 ,  G06F9/30094 ,  G06F9/3867 ,  G06F9/3873

摘要： A branch prediction method and system are provided that accurately predict a branch condition early in an instruction pipeline of a data processing system. By accurately predicting the branch condition, the correct target instruction can be fetched early, thereby avoiding many of the inefficiencies associated with branch mispredictions. To accurately predict if a branch condition is satisfied, one or more pre-calculated status bits are stored along with a digital value that is read by the conditional branch instruction to determine if the branch condition is satisfied. By including such a status bit, the condition of the conditional branch instruction may be immediately determined, without waiting for the instruction to be processed by an arithmetic unit or the like in a subsequent pipeline stage.

摘要翻译： 提供了一种分支预测方法和系统，其在数据处理系统的指令流水线中提前准确预测分支条件。 通过准确预测分支条件，可以提前获取正确的目标指令，从而避免与分支错误预测相关的许多低效率。 为了准确地预测分支条件是否满足，一个或多个预先计算的状态位与由条件转移指令读取的数字值一起存储以确定分支条件是否满足。 通过包括这样的状态位，可以立即确定条件转移指令的条件，而不必等待在随后的流水线级中由算术单元等处理的指令。