// Replace value from this node's operand list. void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) { Value *From = *Op; // If is possible that someone did GV->RAUW(inst), replacing a global variable // with an instruction or some other function-local object. If this is a // non-function-local MDNode, it can't point to a function-local object. // Handle this case by implicitly dropping the MDNode reference to null. if (!isFunctionLocal() && To && isFunctionLocalValue(To)) To = 0; if (From == To) return; // Update the operand. Op->set(To); // If this node is already not being uniqued (because one of the operands // already went to null), then there is nothing else to do here. if (isNotUniqued()) return; LLVMContextImpl *pImpl = getType()->getContext().pImpl; // Remove "this" from the context map. FoldingSet doesn't have to reprofile // this node to remove it, so we don't care what state the operands are in. pImpl->MDNodeSet.RemoveNode(this); // 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. if (To == 0) { setIsNotUniqued(); return; } // Now that the node is out of the folding set, get ready to reinsert it. // First, check to see if another node with the same operands already exists // in the set. If it doesn't exist, this returns the position to insert it. FoldingSetNodeID ID; Profile(ID); void *InsertPoint; MDNode *N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint); if (N) { N->replaceAllUsesWith(this); N->destroy(); N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint); assert(N == 0 && "shouldn't be in the map now!"); (void)N; } // InsertPoint will have been set by the FindNodeOrInsertPos call. pImpl->MDNodeSet.InsertNode(this, InsertPoint); }
// Replace value from this node's operand list. void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) { Value *From = *Op; // If is possible that someone did GV->RAUW(inst), replacing a global variable // with an instruction or some other function-local object. If this is a // non-function-local MDNode, it can't point to a function-local object. // Handle this case by implicitly dropping the MDNode reference to null. // Likewise if the MDNode is function-local but for a different function. if (To && isFunctionLocalValue(To)) { if (!isFunctionLocal()) To = 0; else { const Function *F = getFunction(); const Function *FV = getFunctionForValue(To); // Metadata can be function-local without having an associated function. // So only consider functions to have changed if non-null. if (F && FV && F != FV) To = 0; } } if (From == To) return; // Update the operand. Op->set(To); // If this node is already not being uniqued (because one of the operands // already went to null), then there is nothing else to do here. if (isNotUniqued()) return; LLVMContextImpl *pImpl = getType()->getContext().pImpl; // Remove "this" from the context map. FoldingSet doesn't have to reprofile // this node to remove it, so we don't care what state the operands are in. pImpl->MDNodeSet.RemoveNode(this); // 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. Also, this means we don't need to include // isFunctionLocal bits in FoldingSetNodeIDs for MDNodes. if (To == 0) { setIsNotUniqued(); return; } // Now that the node is out of the folding set, get ready to reinsert it. // First, check to see if another node with the same operands already exists // in the set. If it doesn't exist, this returns the position to insert it. FoldingSetNodeID ID; Profile(ID); void *InsertPoint; MDNode *N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint); if (N) { N->replaceAllUsesWith(this); N->destroy(); N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint); assert(N == 0 && "shouldn't be in the map now!"); (void)N; } // InsertPoint will have been set by the FindNodeOrInsertPos call. pImpl->MDNodeSet.InsertNode(this, InsertPoint); // If this MDValue was previously function-local but no longer is, clear // its function-local flag. if (isFunctionLocal() && !isFunctionLocalValue(To)) { bool isStillFunctionLocal = false; for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { Value *V = getOperand(i); if (!V) continue; if (isFunctionLocalValue(V)) { isStillFunctionLocal = true; break; } } if (!isStillFunctionLocal) setValueSubclassData(getSubclassDataFromValue() & ~FunctionLocalBit); } }