Use a separate LiveRangeCalc for the complement in spill modes.

The complement interval may overlap the other intervals created, so use
a separate LiveRangeCalc instance to compute its live range.

A LiveRangeCalc instance can only be shared among non-overlapping
intervals.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139603 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h
index c00b8d3..cd6a306 100644
--- a/lib/CodeGen/SplitKit.h
+++ b/lib/CodeGen/SplitKit.h
@@ -273,8 +273,17 @@
   ///    The new value has no live ranges anywhere.
   ValueMap Values;
 
-  /// LRCalc - Cache for computing live ranges and SSA update.
-  LiveRangeCalc LRCalc;
+  /// LRCalc - Cache for computing live ranges and SSA update.  Each instance
+  /// can only handle non-overlapping live ranges, so use a separate
+  /// LiveRangeCalc instance for the complement interval when in spill mode.
+  LiveRangeCalc LRCalc[2];
+
+  /// getLRCalc - Return the LRCalc to use for RegIdx.  In spill mode, the
+  /// complement interval can overlap the other intervals, so it gets its own
+  /// LRCalc instance.  When not in spill mode, all intervals can share one.
+  LiveRangeCalc &getLRCalc(unsigned RegIdx) {
+    return LRCalc[SpillMode != SM_Partition && RegIdx != 0];
+  }
 
   /// defValue - define a value in RegIdx from ParentVNI at Idx.
   /// Idx does not have to be ParentVNI->def, but it must be contained within