LiveInterval: Add a 'covers' operation to LiveRange.
llvm-svn: 223876
diff --git a/llvm/lib/CodeGen/LiveInterval.cpp b/llvm/lib/CodeGen/LiveInterval.cpp
index ddb0032..bacd619 100644
--- a/llvm/lib/CodeGen/LiveInterval.cpp
+++ b/llvm/lib/CodeGen/LiveInterval.cpp
@@ -185,6 +185,27 @@
return I != begin() && (--I)->end > Start;
}
+bool LiveRange::covers(const LiveRange &Other) const {
+ if (empty())
+ return Other.empty();
+
+ const_iterator I = begin();
+ for (const_iterator O = Other.begin(), OE = Other.end(); O != OE; ++O) {
+ I = advanceTo(I, O->start);
+ if (I == end() || I->start > O->start)
+ return false;
+
+ // Check adjacent live segments and see if we can get behind O->end.
+ while (I->end < O->end) {
+ const_iterator Last = I;
+ // Get next segment and abort if it was not adjacent.
+ ++I;
+ if (I == end() || Last->end != I->start)
+ return false;
+ }
+ }
+ return true;
+}
/// ValNo is dead, remove it. If it is the largest value number, just nuke it
/// (and any other deleted values neighboring it), otherwise mark it as ~1U so