diff options
Diffstat (limited to 'llvm/lib/Transforms/Utils/LoopUnroll.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUnroll.cpp | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp index b1cc76859e9..7b066453cee 100644 --- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp +++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp @@ -301,13 +301,41 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, for (unsigned It = 1; It != Count; ++It) { std::vector<BasicBlock*> NewBlocks; + SmallDenseMap<const Loop *, Loop *, 4> NewLoops; + NewLoops[L] = L; for (LoopBlocksDFS::RPOIterator BB = BlockBegin; BB != BlockEnd; ++BB) { ValueToValueMapTy VMap; BasicBlock *New = CloneBasicBlock(*BB, VMap, "." + Twine(It)); Header->getParent()->getBasicBlockList().push_back(New); - L->addBasicBlockToLoop(New, LI->getBase()); + // Tell LI about New. + if (*BB == Header) { + assert(LI->getLoopFor(*BB) == L && "Header should not be in a sub-loop"); + L->addBasicBlockToLoop(New, LI->getBase()); + } 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); + + // Forget the old loop, since its inputs may have changed. + if (SE) + SE->forgetLoop(OldLoop); + } + NewLoop->addBasicBlockToLoop(New, LI->getBase()); + } if (*BB == Header) // Loop over all of the PHI nodes in the block, changing them to use |
