Teach LiveInterval::isZeroLength about null SlotIndexes.
When instructions are deleted, they leave tombstone SlotIndex entries.
The isZeroLength method should ignore these null indexes.
This causes RABasic to sometimes spill a callee-saved register in the
abi-isel.ll test, so don't run that test with -regalloc=basic. Prioritizing
register allocation according to spill weight can cause more registers to be
used.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131436 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CalcSpillWeights.cpp b/lib/CodeGen/CalcSpillWeights.cpp
index e5894b8..5d722ee 100644
--- a/lib/CodeGen/CalcSpillWeights.cpp
+++ b/lib/CodeGen/CalcSpillWeights.cpp
@@ -165,7 +165,7 @@
return;
// Mark li as unspillable if all live ranges are tiny.
- if (li.isZeroLength()) {
+ if (li.isZeroLength(LIS.getSlotIndexes())) {
li.markNotSpillable();
return;
}