1 files changed, 33 insertions, 15 deletions
diff --git a/include/llvm/Transforms/Utils/UnrollLoop.h b/include/llvm/Transforms/Utils/UnrollLoop.h
index a3115ad16914..12aa3bc6e770 100644
--- a/include/llvm/Transforms/Utils/UnrollLoop.h
+++ b/include/llvm/Transforms/Utils/UnrollLoop.h
@@ -16,40 +16,57 @@
 #ifndef LLVM_TRANSFORMS_UTILS_UNROLLLOOP_H
 #define LLVM_TRANSFORMS_UTILS_UNROLLLOOP_H
 
-// Needed because we can't forward-declare the nested struct
-// TargetTransformInfo::UnrollingPreferences
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/StringRef.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 
 namespace llvm {
 
-class StringRef;
 class AssumptionCache;
+class BasicBlock;
 class DominatorTree;
 class Loop;
 class LoopInfo;
-class LPPassManager;
 class MDNode;
-class Pass;
 class OptimizationRemarkEmitter;
 class ScalarEvolution;
 
-typedef SmallDenseMap<const Loop *, Loop *, 4> NewLoopsMap;
+using NewLoopsMap = SmallDenseMap<const Loop *, Loop *, 4>;
 
 const Loop* addClonedBlockToLoopInfo(BasicBlock *OriginalBB,
                                      BasicBlock *ClonedBB, LoopInfo *LI,
                                      NewLoopsMap &NewLoops);
 
-bool UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
-                bool AllowRuntime, bool AllowExpensiveTripCount,
-                bool PreserveCondBr, bool PreserveOnlyFirst,
-                unsigned TripMultiple, unsigned PeelCount, LoopInfo *LI,
-                ScalarEvolution *SE, DominatorTree *DT, AssumptionCache *AC,
-                OptimizationRemarkEmitter *ORE, bool PreserveLCSSA);
+/// Represents the result of a \c UnrollLoop invocation.
+enum class LoopUnrollResult {
+  /// The loop was not modified.
+  Unmodified,
+
+  /// The loop was partially unrolled -- we still have a loop, but with a
+  /// smaller trip count.  We may also have emitted epilogue loop if the loop
+  /// had a non-constant trip count.
+  PartiallyUnrolled,
+
+  /// The loop was fully unrolled into straight-line code.  We no longer have
+  /// any back-edges.
+  FullyUnrolled
+};
+
+LoopUnrollResult UnrollLoop(Loop *L, unsigned Count, unsigned TripCount,
+                            bool Force, bool AllowRuntime,
+                            bool AllowExpensiveTripCount, bool PreserveCondBr,
+                            bool PreserveOnlyFirst, unsigned TripMultiple,
+                            unsigned PeelCount, bool UnrollRemainder,
+                            LoopInfo *LI, ScalarEvolution *SE,
+                            DominatorTree *DT, AssumptionCache *AC,
+                            OptimizationRemarkEmitter *ORE, bool PreserveLCSSA);
 
 bool UnrollRuntimeLoopRemainder(Loop *L, unsigned Count,
                                 bool AllowExpensiveTripCount,
-                                bool UseEpilogRemainder, LoopInfo *LI,
+                                bool UseEpilogRemainder, bool UnrollRemainder,
+                                LoopInfo *LI,
                                 ScalarEvolution *SE, DominatorTree *DT,
+                                AssumptionCache *AC,
                                 bool PreserveLCSSA);
 
 void computePeelCount(Loop *L, unsigned LoopSize,
@@ -60,6 +77,7 @@ bool peelLoop(Loop *L, unsigned PeelCount, LoopInfo *LI, ScalarEvolution *SE,
               DominatorTree *DT, AssumptionCache *AC, bool PreserveLCSSA);
 
 MDNode *GetUnrollMetadata(MDNode *LoopID, StringRef Name);
-}
 
-#endif
+} // end namespace llvm
+
+#endif // LLVM_TRANSFORMS_UTILS_UNROLLLOOP_H