IR: Remove implicit iterator conversions from lib/IR, NFC

Stop converting implicitly between iterators and pointers/references in
lib/IR.  For convenience, I've added a `getIterator()` accessor to
`ilist_node` so that callers don't need to know how to spell the
iterator class (i.e., they can use `X.getIterator()` instead of
`Function::iterator(X)`).

I'll eventually disallow these implicit conversions entirely, but
there's a lot of code, so it doesn't make sense to do it all in one
patch.  One library or so at a time.

Why?  To root out cases of `getNextNode()` and `getPrevNode()` being
used in iterator logic.  The design of `ilist` makes that invalid when
the current node could be at the back of the list, but it happens to
"work" right now because of a bug where those functions never return
`nullptr` if you're using a half-node sentinel.  Before I can fix the
function, I have to remove uses of it that rely on it misbehaving.
(Maybe the function should just be deleted anyway?  But I don't want
deleting it -- potentially a huge project -- to block fixing
ilist/iplist.)

llvm-svn: 249782

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp
index 6c9fdd6fcea..5ffe288efb6 100644
--- a/llvm/lib/IR/AutoUpgrade.cpp
+++ b/llvm/lib/IR/AutoUpgrade.cpp
@@ -362,7 +362,7 @@ void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
   Function *F = CI->getCalledFunction();
   LLVMContext &C = CI->getContext();
   IRBuilder<> Builder(C);
-  Builder.SetInsertPoint(CI->getParent(), CI);
+  Builder.SetInsertPoint(CI->getParent(), CI->getIterator());
 
   assert(F && "Intrinsic call is not direct?");
 
@@ -388,7 +388,7 @@ void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
                Name == "llvm.x86.avx.movnt.ps.256" ||
                Name == "llvm.x86.avx.movnt.pd.256") {
       IRBuilder<> Builder(C);
-      Builder.SetInsertPoint(CI->getParent(), CI);
+      Builder.SetInsertPoint(CI->getParent(), CI->getIterator());
 
       Module *M = F->getParent();
       SmallVector<Metadata *, 1> Elts;