Daniel Sanders f380a26222 [globalisel][combiner] Make the CombinerChangeObserver a MachineFunction::Delegate ... Summary: This allows us to register it with the MachineFunction delegate and be notified automatically about erasure and creation of instructions. However, we still need explicit notification for modifications such as those caused by setReg() or replaceRegWith(). There is a catch with this though. The notification for creation is delivered before any operands can be added. While appropriate for scheduling combiner work. This is unfortunate for debug output since an opcode by itself doesn't provide sufficient information on what happened. As a result, the work list remembers the instructions (when debug output is requested) and emits a more complete dump later. Another nit is that the MachineFunction::Delegate provides const pointers which is inconvenient since we want to use it to schedule future modification. To resolve this GISelWorkList now has an optional pointer to the MachineFunction which describes the scope of the work it is permitted to schedule. If a given MachineInstr* is in this function then it is permitted to schedule work to be performed on the MachineInstr's. An alternative to this would be to remove the const from the MachineFunction::Delegate interface, however delegates are not permitted to modify the MachineInstr's they receive. In addition to this, the observer has three interface changes. * erasedInstr() is now erasingInstr() to indicate it is about to be erased but still exists at the moment. * changingInstr() and changedInstr() have been added to report changes before and after they are made. This allows us to trace the changes in the debug output. * As a convenience changingAllUsesOfReg() and finishedChangingAllUsesOfReg() will report changingInstr() and changedInstr() for each use of a given register. This is primarily useful for changes caused by MachineRegisterInfo::replaceRegWith() With this in place, both combine rules have been updated to report their changes to the observer. Finally, make some cosmetic changes to the debug output and make Combiner and CombinerHelp Reviewers: aditya_nandakumar, bogner, volkan, rtereshin, javed.absar Reviewed By: aditya_nandakumar Subscribers: mgorny, rovka, kristof.beyls, llvm-commits Differential Revision: https://reviews.llvm.org/D52947 llvm-svn: 349167		2018-12-14 17:50:14 +00:00
..
CMakeLists.txt	Revert "Revert rr340111 "[GISel]: Add Legalization/lowering code for bit counting operations""	2018-08-21 17:30:31 +00:00
LegalizerHelperTest.cpp	[globalisel][combiner] Make the CombinerChangeObserver a MachineFunction::Delegate	2018-12-14 17:50:14 +00:00
LegalizerHelperTest.h	[GISel]: Provide standard interface to observe changes in GISel passes	2018-12-05 20:14:52 +00:00
LegalizerInfoTest.cpp
PatternMatchTest.cpp	[GISel]: Refactor MachineIRBuilder to allow passing additional parameters to build Instrs	2018-12-11 00:48:50 +00:00