Optimize LiveIntervals::intervalIsInOneMBB().
No looping and binary searches necessary.
Return a pointer to the containing block instead of just a bool.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150218 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 1d5e3b1..7655cf5 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -1086,23 +1086,28 @@
return true;
}
-bool LiveIntervals::intervalIsInOneMBB(const LiveInterval &li) const {
- LiveInterval::Ranges::const_iterator itr = li.ranges.begin();
+MachineBasicBlock*
+LiveIntervals::intervalIsInOneMBB(const LiveInterval &LI) const {
+ // A local live range must be fully contained inside the block, meaning it is
+ // defined and killed at instructions, not at block boundaries. It is not
+ // live in or or out of any block.
+ //
+ // It is technically possible to have a PHI-defined live range identical to a
+ // single block, but we are going to return false in that case.
- MachineBasicBlock *mbb = indexes_->getMBBCoveringRange(itr->start, itr->end);
+ SlotIndex Start = LI.beginIndex();
+ if (Start.isBlock())
+ return NULL;
- if (mbb == 0)
- return false;
+ SlotIndex Stop = LI.endIndex();
+ if (Stop.isBlock())
+ return NULL;
- for (++itr; itr != li.ranges.end(); ++itr) {
- MachineBasicBlock *mbb2 =
- indexes_->getMBBCoveringRange(itr->start, itr->end);
-
- if (mbb2 != mbb)
- return false;
- }
-
- return true;
+ // getMBBFromIndex doesn't need to search the MBB table when both indexes
+ // belong to proper instructions.
+ MachineBasicBlock *MBB1 = indexes_->getMBBFromIndex(Start);
+ MachineBasicBlock *MBB2 = indexes_->getMBBFromIndex(Stop);
+ return MBB1 == MBB2 ? MBB1 : NULL;
}
float