Branch Decoupled Architectures

条件分支在典型程序中执行的指令中占很大一部分。在现代流水线处理器实现中，由于下一条指令的不可预测性，分支导致浪费处理器周期。该项目正在探索分支预测和推测执行的替代方案，即将分支计算与它们控制的基本块解耦。分支和计算分支条件的指令从主程序中剥离出来，在单独的处理器上执行。编译器后端开发和处理器实现都受到这种替代方法的影响，该项目对这两种方法都采用实验性方法。

Conditional branches constitute a significant fraction of instructions executed in a typical program. In modern pipelined processor implementations, branches cause wasted processor cycles, due to the unpredictability of the next instruction. This project is exploring an alternative to branch prediction and speculative execution, which is to decouple the branch computations from the basic blocks they control. Branches, and the instructions that compute branch conditions, are peeled out of the main program and executed on a separate processor. Both compiler backend development and processor implementation are affected by this alternative, and the project takes an experimental approach to both.