Duncan P. N. Exon Smith 701b7a130a CodeGen: Give MachineBasicBlock::reverse_iterator a handle to the current MI ... Now that MachineBasicBlock::reverse_instr_iterator knows when it's at the end (since r281168 and r281170), implement MachineBasicBlock::reverse_iterator directly on top of an ilist::reverse_iterator by adding an IsReverse template parameter to MachineInstrBundleIterator. This replaces another hard-to-reason-about use of std::reverse_iterator on list iterators, matching the changes for ilist::reverse_iterator from r280032 (see the "out of scope" section at the end of that commit message). MachineBasicBlock::reverse_iterator now has a handle to the current node and has obvious invalidation semantics. r280032 has a more detailed explanation of how list-style reverse iterators (invalidated when the pointed-at node is deleted) are different from vector-style reverse iterators like std::reverse_iterator (invalidated on every operation). A great motivating example is this commit's changes to lib/CodeGen/DeadMachineInstructionElim.cpp. Note: If your out-of-tree backend deletes instructions while iterating on a MachineBasicBlock::reverse_iterator or converts between MachineBasicBlock::iterator and MachineBasicBlock::reverse_iterator, you'll need to update your code in similar ways to r280032. The following table might help: [Old] ==> [New] delete &*RI, RE = end() delete &*RI++ RI->erase(), RE = end() RI++->erase() reverse_iterator(I) std::prev(I).getReverse() reverse_iterator(I) ++I.getReverse() --reverse_iterator(I) I.getReverse() reverse_iterator(std::next(I)) I.getReverse() RI.base() std::prev(RI).getReverse() RI.base() ++RI.getReverse() --RI.base() RI.getReverse() std::next(RI).base() RI.getReverse() (For more details, have a look at r280032.) llvm-svn: 281172		2016-09-11 18:51:28 +00:00
..
GlobalISel	GlobalISel: use multi-dimensional arrays for legalize actions.	2016-08-29 21:00:00 +00:00
CMakeLists.txt	ADT: Remove all ilist_iterator => pointer casts, NFC	2016-08-12 05:05:36 +00:00
DIEHashTest.cpp
LowLevelTypeTest.cpp	GlobalISel: support loads and stores of strange types.	2016-08-15 21:13:17 +00:00
MachineInstrBundleIteratorTest.cpp	CodeGen: Give MachineBasicBlock::reverse_iterator a handle to the current MI	2016-09-11 18:51:28 +00:00