Separate SplitAnalysis::getSplitLoops().

This method returns the set of loops with uses that are candidates for
splitting.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121870 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 14 insertions, 7 deletions

diff --git a/lib/CodeGen/SplitKit.cpp b/lib/CodeGen/SplitKit.cpp
index ed2725eed9..fd18729b85 100644
--- a/lib/CodeGen/SplitKit.cpp
+++ b/lib/CodeGen/SplitKit.cpp
@@ -257,12 +257,11 @@ void SplitAnalysis::analyze(const LiveInterval *li) {
   analyzeUses();
 }
 
-const MachineLoop *SplitAnalysis::getBestSplitLoop() {
-  assert(curli_ && "Call analyze() before getBestSplitLoop");
+void SplitAnalysis::getSplitLoops(LoopPtrSet &Loops) {
+  assert(curli_ && "Call analyze() before getSplitLoops");
   if (usingLoops_.empty())
-    return 0;
+    return;
 
-  LoopPtrSet Loops;
   LoopBlocks Blocks;
   BlockPtrSet CriticalExits;
 
@@ -280,11 +279,11 @@ const MachineLoop *SplitAnalysis::getBestSplitLoop() {
       // FIXME: We could split a live range with multiple uses in a peripheral
       // block and still make progress. However, it is possible that splitting
       // another live range will insert copies into a peripheral block, and
-      // there is a small chance we can enter an infinity loop, inserting copies
+      // there is a small chance we can enter an infinite loop, inserting copies
       // forever.
       // For safety, stick to splitting live ranges with uses outside the
       // periphery.
-      DEBUG(dbgs() << ": multiple peripheral uses\n");
+      DEBUG(dbgs() << ": multiple peripheral uses");
       break;
     case ContainedInLoop:
       DEBUG(dbgs() << ": fully contained\n");
@@ -302,9 +301,13 @@ const MachineLoop *SplitAnalysis::getBestSplitLoop() {
     Loops.insert(Loop);
   }
 
-  DEBUG(dbgs() << "  getBestSplitLoop found " << Loops.size()
+  DEBUG(dbgs() << "  getSplitLoops found " << Loops.size()
                << " candidate loops.\n");
+}
 
+const MachineLoop *SplitAnalysis::getBestSplitLoop() {
+  LoopPtrSet Loops;
+  getSplitLoops(Loops);
   if (Loops.empty())
     return 0;
 
diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h
index b1d5a47804..f290eb6461 100644
--- a/lib/CodeGen/SplitKit.h
+++ b/lib/CodeGen/SplitKit.h
@@ -133,6 +133,10 @@ public:
   /// these edges, but they do require special treatment.
   void getCriticalPreds(const LoopBlocks &Blocks, BlockPtrSet &CriticalPreds);
 
+  /// getSplitLoops - Get the set of loops that have curli uses and would be
+  /// profitable to split.
+  void getSplitLoops(LoopPtrSet&);
+
   /// getBestSplitLoop - Return the loop where curli may best be split to a
   /// separate register, or NULL.
   const MachineLoop *getBestSplitLoop();