Selection DAG scheduler register pressure heuristic fixes.

Added a check for already live regs before claiming HighRegPressure.
Fixed a few cases of checking the wrong number of successors.
Added some tracing until these heuristics are better understood.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123892 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed