Cache the fairly expensive last split point computation and provide a fast
inlined path for the common case.
Most basic blocks don't contain a call that may throw, so the last split point
os simply the first terminator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128874 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h
index d735f10..bf93632 100644
--- a/lib/CodeGen/SplitKit.h
+++ b/lib/CodeGen/SplitKit.h
@@ -93,16 +93,20 @@
// Current live interval.
const LiveInterval *CurLI;
+ /// LastSplitPoint - Last legal split point in each basic block in the current
+ /// function. The first entry is the first terminator, the second entry is the
+ /// last valid split point for a variable that is live in to a landing pad
+ /// successor.
+ SmallVector<std::pair<SlotIndex, SlotIndex>, 8> LastSplitPoint;
+
+ SlotIndex computeLastSplitPoint(unsigned Num);
+
// Sumarize statistics by counting instructions using CurLI.
void analyzeUses();
/// calcLiveBlockInfo - Compute per-block information about CurLI.
bool calcLiveBlockInfo();
- /// canAnalyzeBranch - Return true if MBB ends in a branch that can be
- /// analyzed.
- bool canAnalyzeBranch(const MachineBasicBlock *MBB);
-
public:
SplitAnalysis(const VirtRegMap &vrm, const LiveIntervals &lis,
const MachineLoopInfo &mli);
@@ -118,6 +122,16 @@
/// getParent - Return the last analyzed interval.
const LiveInterval &getParent() const { return *CurLI; }
+ /// getLastSplitPoint - Return that base index of the last valid split point
+ /// in the basic block numbered Num.
+ SlotIndex getLastSplitPoint(unsigned Num) {
+ // Inline the common simple case.
+ if (LastSplitPoint[Num].first.isValid() &&
+ !LastSplitPoint[Num].second.isValid())
+ return LastSplitPoint[Num].first;
+ return computeLastSplitPoint(Num);
+ }
+
/// hasUses - Return true if MBB has any uses of CurLI.
bool hasUses(const MachineBasicBlock *MBB) const {
return UsingBlocks.lookup(MBB);