Add a runtime unrolling parameter to the LoopUnroll pass constructor

As with the other loop unrolling parameters (the unrolling threshold, partial
unrolling, etc.) runtime unrolling can now also be controlled via the
constructor. This will be necessary for moving non-trivial unrolling late in
the pass manager (after loop vectorization).

No functionality change intended.

llvm-svn: 194027

1 files changed, 10 insertions, 6 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
index d47a3c3b526..08ac38dec5d 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -49,14 +49,16 @@ namespace {
   class LoopUnroll : public LoopPass {
   public:
     static char ID; // Pass ID, replacement for typeid
-    LoopUnroll(int T = -1, int C = -1,  int P = -1) : LoopPass(ID) {
+    LoopUnroll(int T = -1, int C = -1, int P = -1, int R = -1) : LoopPass(ID) {
       CurrentThreshold = (T == -1) ? UnrollThreshold : unsigned(T);
       CurrentCount = (C == -1) ? UnrollCount : unsigned(C);
       CurrentAllowPartial = (P == -1) ? UnrollAllowPartial : (bool)P;
+      CurrentRuntime = (R == -1) ? UnrollRuntime : (bool)R;
 
       UserThreshold = (T != -1) || (UnrollThreshold.getNumOccurrences() > 0);
       UserAllowPartial = (P != -1) ||
                          (UnrollAllowPartial.getNumOccurrences() > 0);
+      UserRuntime = (R != -1) || (UnrollRuntime.getNumOccurrences() > 0);
       UserCount = (C != -1) || (UnrollCount.getNumOccurrences() > 0);
 
       initializeLoopUnrollPass(*PassRegistry::getPassRegistry());
@@ -78,9 +80,11 @@ namespace {
     unsigned CurrentCount;
     unsigned CurrentThreshold;
     bool     CurrentAllowPartial;
+    bool     CurrentRuntime;
     bool     UserCount;            // CurrentCount is user-specified.
     bool     UserThreshold;        // CurrentThreshold is user-specified.
     bool     UserAllowPartial;     // CurrentAllowPartial is user-specified.
+    bool     UserRuntime;          // CurrentRuntime is user-specified.
 
     bool runOnLoop(Loop *L, LPPassManager &LPM);
 
@@ -115,8 +119,9 @@ INITIALIZE_PASS_DEPENDENCY(LCSSA)
 INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
 INITIALIZE_PASS_END(LoopUnroll, "loop-unroll", "Unroll loops", false, false)
 
-Pass *llvm::createLoopUnrollPass(int Threshold, int Count, int AllowPartial) {
-  return new LoopUnroll(Threshold, Count, AllowPartial);
+Pass *llvm::createLoopUnrollPass(int Threshold, int Count, int AllowPartial,
+                                 int Runtime) {
+  return new LoopUnroll(Threshold, Count, AllowPartial, Runtime);
 }
 
 /// ApproximateLoopSize - Approximate the size of the loop.
@@ -155,7 +160,7 @@ bool LoopUnroll::runOnLoop(Loop *L, LPPassManager &LPM) {
   UP.OptSizeThreshold = OptSizeUnrollThreshold;
   UP.Count = CurrentCount;
   UP.Partial = CurrentAllowPartial;
-  UP.Runtime = UnrollRuntime;
+  UP.Runtime = CurrentRuntime;
   TTI.getUnrollingPreferences(L, UP);
 
   // Determine the current unrolling threshold.  While this is normally set
@@ -181,8 +186,7 @@ bool LoopUnroll::runOnLoop(Loop *L, LPPassManager &LPM) {
     TripMultiple = SE->getSmallConstantTripMultiple(L, LatchBlock);
   }
 
-  bool Runtime = UnrollRuntime.getNumOccurrences() == 0 ?
-                 UP.Runtime : UnrollRuntime;
+  bool Runtime = UserRuntime ? CurrentRuntime : UP.Runtime;
 
   // Use a default unroll-count if the user doesn't specify a value
   // and the trip count is a run-time value.  The default is different