diff options
| -rw-r--r-- | llvm/include/llvm/Transforms/Utils/LoopUtils.h | 3 | ||||
| -rw-r--r-- | llvm/lib/Transforms/Utils/LCSSA.cpp | 4 |
2 files changed, 6 insertions, 1 deletions
diff --git a/llvm/include/llvm/Transforms/Utils/LoopUtils.h b/llvm/include/llvm/Transforms/Utils/LoopUtils.h index 8c2527b6ae6..e561a9c5840 100644 --- a/llvm/include/llvm/Transforms/Utils/LoopUtils.h +++ b/llvm/include/llvm/Transforms/Utils/LoopUtils.h @@ -79,7 +79,8 @@ bool formLCSSAForInstructions(SmallVectorImpl<Instruction *> &Worklist, /// /// Looks at all instructions in the loop which have uses outside of the /// current loop. For each, an LCSSA PHI node is inserted and the uses outside -/// the loop are rewritten to use this node. +/// the loop are rewritten to use this node. Sub-loops must be in LCSSA form +/// already. /// /// LoopInfo and DominatorTree are required and preserved. /// diff --git a/llvm/lib/Transforms/Utils/LCSSA.cpp b/llvm/lib/Transforms/Utils/LCSSA.cpp index 53d444b309d..eeeaadc253f 100644 --- a/llvm/lib/Transforms/Utils/LCSSA.cpp +++ b/llvm/lib/Transforms/Utils/LCSSA.cpp @@ -325,6 +325,10 @@ bool llvm::formLCSSA(Loop &L, DominatorTree &DT, LoopInfo *LI, // Look at all the instructions in the loop, checking to see if they have uses // outside the loop. If so, put them into the worklist to rewrite those uses. for (BasicBlock *BB : BlocksDominatingExits) { + // Skip blocks that are part of any sub-loops, they must be in LCSSA + // already. + if (LI->getLoopFor(BB) != &L) + continue; for (Instruction &I : *BB) { // Reject two common cases fast: instructions with no uses (like stores) // and instructions with one use that is in the same block as this. |
