IR: Add Value::reverseUseList()
I'm going to use this to improve `verify-uselistorder`. Part of PR5680.
llvm-svn: 214594
diff --git a/llvm/lib/IR/Value.cpp b/llvm/lib/IR/Value.cpp
index 1ab2183..555823b 100644
--- a/llvm/lib/IR/Value.cpp
+++ b/llvm/lib/IR/Value.cpp
@@ -614,6 +614,25 @@
LLVMContext &Value::getContext() const { return VTy->getContext(); }
+void Value::reverseUseList() {
+ if (!UseList || !UseList->Next)
+ // No need to reverse 0 or 1 uses.
+ return;
+
+ Use *Head = UseList;
+ Use *Current = UseList->Next;
+ Head->Next = nullptr;
+ while (Current) {
+ Use *Next = Current->Next;
+ Current->Next = Head;
+ Head->setPrev(&Current->Next);
+ Head = Current;
+ Current = Next;
+ }
+ UseList = Head;
+ Head->setPrev(&UseList);
+}
+
//===----------------------------------------------------------------------===//
// ValueHandleBase Class
//===----------------------------------------------------------------------===//