diff options
| -rw-r--r-- | llvm/lib/Transforms/Utils/ValueMapper.cpp | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/llvm/lib/Transforms/Utils/ValueMapper.cpp b/llvm/lib/Transforms/Utils/ValueMapper.cpp index 85c751f311d..c9e474da8af 100644 --- a/llvm/lib/Transforms/Utils/ValueMapper.cpp +++ b/llvm/lib/Transforms/Utils/ValueMapper.cpp @@ -191,12 +191,18 @@ static void resolveCycles(Metadata *MD) { } /// Remap the operands of an MDNode. +/// +/// If \c Node is temporary, uniquing cycles are ignored. If \c Node is +/// distinct, uniquing cycles are resolved as they're found. +/// +/// \pre \c Node.isDistinct() or \c Node.isTemporary(). static bool remapOperands(MDNode &Node, SmallVectorImpl<MDNode *> &DistinctWorklist, ValueToValueMapTy &VM, RemapFlags Flags, ValueMapTypeRemapper *TypeMapper, ValueMaterializer *Materializer) { assert(!Node.isUniqued() && "Expected temporary or distinct node"); + const bool IsDistinct = Node.isDistinct(); bool AnyChanged = false; for (unsigned I = 0, E = Node.getNumOperands(); I != E; ++I) { @@ -206,6 +212,11 @@ static bool remapOperands(MDNode &Node, if (Old != New) { AnyChanged = true; Node.replaceOperandWith(I, New); + + // Resolve uniquing cycles underneath distinct nodes on the fly so they + // don't infect later operands. + if (IsDistinct) + resolveCycles(New); } } @@ -332,15 +343,9 @@ Metadata *llvm::MapMetadata(const Metadata *MD, ValueToValueMapTy &VM, resolveCycles(NewMD); // Remap the operands of distinct MDNodes. - while (!DistinctWorklist.empty()) { - auto *N = DistinctWorklist.pop_back_val(); - - // If an operand changes, then it may be involved in a uniquing cycle. - if (remapOperands(*N, DistinctWorklist, VM, Flags, TypeMapper, - Materializer)) - for (Metadata *MD : N->operands()) - resolveCycles(MD); - } + while (!DistinctWorklist.empty()) + remapOperands(*DistinctWorklist.pop_back_val(), DistinctWorklist, VM, Flags, + TypeMapper, Materializer); return NewMD; } |
