diff options
| -rw-r--r-- | llvm/include/llvm/Transforms/Utils/UnrollLoop.h | 6 | ||||
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUnroll.cpp | 50 |
2 files changed, 39 insertions, 17 deletions
diff --git a/llvm/include/llvm/Transforms/Utils/UnrollLoop.h b/llvm/include/llvm/Transforms/Utils/UnrollLoop.h index 2ea28f2d4e1..f322bea7aa2 100644 --- a/llvm/include/llvm/Transforms/Utils/UnrollLoop.h +++ b/llvm/include/llvm/Transforms/Utils/UnrollLoop.h @@ -33,6 +33,12 @@ class Pass; class OptimizationRemarkEmitter; class ScalarEvolution; +typedef SmallDenseMap<const Loop *, Loop *, 4> NewLoopsMap; + +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, diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp index e551e4b47ac..f9a602bc268 100644 --- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp +++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp @@ -172,6 +172,36 @@ static bool needToInsertPhisForLCSSA(Loop *L, std::vector<BasicBlock *> Blocks, return false; } +/// Adds ClonedBB to LoopInfo, creates a new loop for ClonedBB if necessary +/// and adds a mapping from the original loop to the new loop to NewLoops. +/// Returns nullptr if no new loop was created and a pointer to the +/// original loop OriginalBB was part of otherwise. +const Loop* llvm::addClonedBlockToLoopInfo(BasicBlock *OriginalBB, + BasicBlock *ClonedBB, LoopInfo *LI, + NewLoopsMap &NewLoops) { + // Figure out which loop New is in. + const Loop *OldLoop = LI->getLoopFor(OriginalBB); + assert(OldLoop && "Should (at least) be in the loop being unrolled!"); + + Loop *&NewLoop = NewLoops[OldLoop]; + if (!NewLoop) { + // Found a new sub-loop. + assert(OriginalBB == OldLoop->getHeader() && + "Header should be first in RPO"); + + Loop *NewLoopParent = NewLoops.lookup(OldLoop->getParentLoop()); + assert(NewLoopParent && + "Expected parent loop before sub-loop in RPO"); + NewLoop = new Loop; + NewLoopParent->addChildLoop(NewLoop); + NewLoop->addBasicBlockToLoop(ClonedBB, *LI); + return OldLoop; + } else { + NewLoop->addBasicBlockToLoop(ClonedBB, *LI); + return nullptr; + } +} + /// Unroll the given loop by Count. The loop must be in LCSSA form. Returns true /// if unrolling was successful, or false if the loop was unmodified. Unrolling /// can only fail when the loop's latch block is not terminated by a conditional @@ -428,28 +458,14 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force, assert(LI->getLoopFor(*BB) == L && "Header should not be in a sub-loop"); L->addBasicBlockToLoop(New, *LI); } else { - // Figure out which loop New is in. - const Loop *OldLoop = LI->getLoopFor(*BB); - assert(OldLoop && "Should (at least) be in the loop being unrolled!"); - - Loop *&NewLoop = NewLoops[OldLoop]; - if (!NewLoop) { - // Found a new sub-loop. - assert(*BB == OldLoop->getHeader() && - "Header should be first in RPO"); - - Loop *NewLoopParent = NewLoops.lookup(OldLoop->getParentLoop()); - assert(NewLoopParent && - "Expected parent loop before sub-loop in RPO"); - NewLoop = new Loop; - NewLoopParent->addChildLoop(NewLoop); - LoopsToSimplify.insert(NewLoop); + const Loop *OldLoop = addClonedBlockToLoopInfo(*BB, New, LI, NewLoops); + if (OldLoop) { + LoopsToSimplify.insert(NewLoops[OldLoop]); // Forget the old loop, since its inputs may have changed. if (SE) SE->forgetLoop(OldLoop); } - NewLoop->addBasicBlockToLoop(New, *LI); } if (*BB == Header) |
