diff options
Diffstat (limited to 'llvm/lib/VMCore/Metadata.cpp')
| -rw-r--r-- | llvm/lib/VMCore/Metadata.cpp | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/llvm/lib/VMCore/Metadata.cpp b/llvm/lib/VMCore/Metadata.cpp index 17e0bc28da0..b9f97dbf603 100644 --- a/llvm/lib/VMCore/Metadata.cpp +++ b/llvm/lib/VMCore/Metadata.cpp @@ -190,6 +190,8 @@ MDNode *MDNode::getMDNode(LLVMContext &Context, Value *const *Vals, // Add all the operand pointers. Note that we don't have to add the // isFunctionLocal bit because that's implied by the operands. + // Note that if the operands are later nulled out, the node will be + // removed from the uniquing map. FoldingSetNodeID ID; for (unsigned i = 0; i != NumVals; ++i) ID.AddPointer(Vals[i]); @@ -276,6 +278,8 @@ Value *MDNode::getOperand(unsigned i) const { void MDNode::Profile(FoldingSetNodeID &ID) const { // Add all the operand pointers. Note that we don't have to add the // isFunctionLocal bit because that's implied by the operands. + // Note that if the operands are later nulled out, the node will be + // removed from the uniquing map. for (unsigned i = 0, e = getNumOperands(); i != e; ++i) ID.AddPointer(getOperand(i)); } @@ -326,7 +330,8 @@ void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) { // If we are dropping an argument to null, we choose to not unique the MDNode // anymore. This commonly occurs during destruction, and uniquing these - // brings little reuse. + // brings little reuse. Also, this means we don't need to include + // isFunctionLocal bits in FoldingSetNodeIDs for MDNodes. if (To == 0) { setIsNotUniqued(); return; |
