Scheduling instructions in SelectionDAG
So far, we have had SelectionDAG nodes consisting of target-supported instructions and operands. However, the code is still in DAG representation. The target architecture executes instructions in sequential form. So, the next logical step is to schedule the SelectionDAG nodes.
A scheduler assigns the order of execution of instructions from the DAG. In this process, it takes into account various heuristics, such as register pressure, to optimize the execution order of instructions and to minimize latencies in instruction execution. After assigning the order of execution to the DAG nodes, the nodes are converted into a list of MachineInstrs and the SelectionDAG nodes are destroyed.
How to do it…
There are several ...
Get LLVM Cookbook now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
