ValueMapper: Pull out helper to resolve cycles, NFC

Pull out a helper for resolving uniquing cycles of `Metadata` to remove
the boiler-plate of downcasting to `MDNode`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244301 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan P. N. Exon Smith 2015-08-07 00:39:26 +00:00
parent e06606ffd1
commit db5b592a6e

View File

@ -183,6 +183,13 @@ static Metadata *mapMetadataOp(Metadata *Op,
return nullptr;
}
/// Resolve uniquing cycles involving the given metadata.
static void resolveCycles(Metadata *MD) {
if (auto *N = dyn_cast_or_null<MDNode>(MD))
if (!N->isResolved())
N->resolveCycles();
}
/// Remap the operands of an MDNode.
static bool remapOperands(MDNode &Node,
SmallVectorImpl<MDNode *> &DistinctWorklist,
@ -321,11 +328,8 @@ Metadata *llvm::MapMetadata(const Metadata *MD, ValueToValueMapTy &VM,
if (Flags & RF_NoModuleLevelChanges)
return NewMD;
// If the top-level metadata was a uniqued MDNode, it could be involved in a
// uniquing cycle.
if (auto *N = dyn_cast<MDNode>(NewMD))
if (!N->isResolved())
N->resolveCycles();
// Resolve cycles involving the entry metadata.
resolveCycles(NewMD);
// Remap the operands of distinct MDNodes.
while (!DistinctWorklist.empty()) {
@ -335,9 +339,7 @@ Metadata *llvm::MapMetadata(const Metadata *MD, ValueToValueMapTy &VM,
if (remapOperands(*N, DistinctWorklist, VM, Flags, TypeMapper,
Materializer))
for (Metadata *MD : N->operands())
if (auto *Op = dyn_cast_or_null<MDNode>(MD))
if (!Op->isResolved())
Op->resolveCycles();
resolveCycles(MD);
}
return NewMD;