LPM: Make callers of LPM.deleteLoopFromQueue update LoopInfo directly. NFC

As of r255720, the loop pass manager will DTRT when passes update the
loop info for removed loops, so they no longer need to reach into
LPPassManager APIs to do this kind of transformation. This change very
nearly removes the need for the LPPassManager to even be passed into
loop passes - the only remaining pass that uses the LPM argument is
LoopUnswitch.

llvm-svn: 255797

1 files changed, 5 insertions, 8 deletions

diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
index bd074b7..2499b887 100644
--- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
@@ -153,16 +153,13 @@ FoldBlockIntoPredecessor(BasicBlock *BB, LoopInfo* LI, ScalarEvolution *SE,
 ///
 /// The LoopInfo Analysis that is passed will be kept consistent.
 ///
-/// If a LoopPassManager is passed in, and the loop is fully removed, it will be
-/// removed from the LoopPassManager as well. LPM can also be NULL.
-///
 /// This utility preserves LoopInfo. It will also preserve ScalarEvolution and
 /// DominatorTree if they are non-null.
 bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount,
                       bool AllowRuntime, bool AllowExpensiveTripCount,
                       unsigned TripMultiple, LoopInfo *LI, ScalarEvolution *SE,
                       DominatorTree *DT, AssumptionCache *AC,
-                      bool PreserveLCSSA, LPPassManager *LPM) {
+                      bool PreserveLCSSA) {
   BasicBlock *Preheader = L->getLoopPreheader();
   if (!Preheader) {
     DEBUG(dbgs() << "  Can't unroll; loop preheader-insertion failed.\n");
@@ -529,9 +526,9 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount,
   ++NumUnrolled;
 
   Loop *OuterL = L->getParentLoop();
-  // Remove the loop from the LoopPassManager if it's completely removed.
-  if (CompletelyUnroll && LPM != nullptr)
-    LPM->deleteLoopFromQueue(L);
+  // Update LoopInfo if the loop is completely removed.
+  if (CompletelyUnroll)
+    LI->updateUnloop(L);;
 
   // If we have a pass and a DominatorTree we should re-simplify impacted loops
   // to ensure subsequent analyses can rely on this form. We want to simplify
@@ -545,7 +542,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount,
 
       // LCSSA must be performed on the outermost affected loop. The unrolled
       // loop's last loop latch is guaranteed to be in the outermost loop after
-      // deleteLoopFromQueue updates LoopInfo.
+      // LoopInfo's been updated by updateUnloop.
       Loop *LatchLoop = LI->getLoopFor(Latches.back());
       if (!OuterL->contains(LatchLoop))
         while (OuterL->getParentLoop() != LatchLoop)