enum SplitEditor::ComplementSpillMode
Description
ComplementSpillMode - Select how the complement live range should be created. SplitEditor automatically creates interval 0 to contain anything that isn't added to another interval. This complement interval can get quite complicated, and it can sometimes be an advantage to allow it to overlap the other intervals. If it is going to spill anyway, no registers are wasted by keeping a value in two places at the same time.
Declared at: llvm/lib/CodeGen/SplitKit.h:275
Enumerators
| Name | Value | Comment |
|---|---|---|
| SM_Partition | 0 | SM_Partition(Default) - Try to create the complement interval so it doesn't overlap any other intervals, and the original interval is partitioned. This may require a large number of back copies and extra PHI-defs. Only segments marked with overlapIntv will be overlapping. |
| SM_Size | 1 | SM_Size - Overlap intervals to minimize the number of inserted COPY instructions. Copies to the complement interval are hoisted to their common dominator, so only one COPY is required per value in the complement interval. This also means that no extra PHI-defs need to be inserted in the complement interval. |
| SM_Speed | 2 | SM_Speed - Overlap intervals to minimize the expected execution frequency of the inserted copies. This is very similar to SM_Size, but the complement interval may get some extra PHI-defs. |