When DCE clones a live range because it separates into connected components,
make sure that the clones enter the same register allocator stage as the
register they were cloned from.
For instance, clones may be split even when they where created during spilling.
Other registers created during spilling are not candidates for splitting or even
(re-)spilling.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128524 91177308-0d34-0410-b5e6-96231b3b80d8
The instruction to be rematerialized may not be the one defining the register
that is being spilled. The traceSiblingValue() function sees through sibling
copies to find the remat candidate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128449 91177308-0d34-0410-b5e6-96231b3b80d8
I have convinced myself that it can only happen when a phi value dies. When it
happens, allocate new virtual registers for the components.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127827 91177308-0d34-0410-b5e6-96231b3b80d8
This allows the allocator to free any resources used by the virtual register,
including physical register assignments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127560 91177308-0d34-0410-b5e6-96231b3b80d8
This will we used for keeping register allocator data structures up to date
while LiveRangeEdit is trimming live intervals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127300 91177308-0d34-0410-b5e6-96231b3b80d8
LiveRangeEdit::eliminateDeadDefs() will eventually be used by coalescing,
splitting, and spilling for dead code elimination. It can delete chains of dead
instructions as long as there are no dependency loops.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127287 91177308-0d34-0410-b5e6-96231b3b80d8
All registers created during splitting or spilling are assigned to the same
stack slot as the parent register.
When splitting or rematting, we may not spill at all. In that case the stack
slot is still assigned, but it will be dead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116546 91177308-0d34-0410-b5e6-96231b3b80d8
splitting or spillling, and to help with rematerialization.
Use LiveRangeEdit in InlineSpiller and SplitKit. This will eventually make it
possible to share remat code between InlineSpiller and SplitKit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116543 91177308-0d34-0410-b5e6-96231b3b80d8
