Displaying 3 results from an estimated 3 matches for "addliveregs".
2017 Aug 30
2
Register pressure calculation in the machine scheduler and live-through registers
...make this efficient you probably need some form of precomputation over the whole function.
The code in RegisterPressure.cpp is meant to work with LiveIntervals. Those queries only see within a block but are meant to be “seeded” with live-through information. That could be done be directly calling `addLiveRegs`. Alternately you can record live-through pressure separately via `initLiveThru`. It’s just that the MachineScheduler does not bother initializing the live-through information.
As Matthias said, actually determining live-through information requires a separate global liveness analysis, because Liv...
2017 Sep 12
2
Register pressure calculation in the machine scheduler and live-through registers
...make this efficient you probably need some form of precomputation over the whole function.
The code in RegisterPressure.cpp is meant to work with LiveIntervals. Those queries only see within a block but are meant to be “seeded” with live-through information. That could be done be directly calling `addLiveRegs`. Alternately you can record live-through pressure separately via `initLiveThru`. It’s just that the MachineScheduler does not bother initializing the live-through information.
As Matthias said, actually determining live-through information requires a separate global liveness analysis, because Liv...
2017 Aug 30
2
Register pressure calculation in the machine scheduler and live-through registers
Hello,
In a previous email, Matthias mentioned that register pressure estimates in the machine scheduler are not absolute; they only account for the registers that are used in the block.I assume that he meant that registers that are live-through (both live-in and live-out) are not accounted for in register pressure calculations. If a register is either live-in or live-out but not both, it must be