[NFC][DebugInfo] Use iterator moveBefore at many call-sites (#123583)

As part of the "RemoveDIs" project, BasicBlock::iterator now carries a
debug-info bit that's needed when getFirstNonPHI and similar feed into
instruction insertion positions. Call-sites where that's necessary were
updated a year ago; but to ensure some type safety however, we'd like to
have all calls to moveBefore use iterators.

This patch adds a (guaranteed dereferenceable) iterator-taking
moveBefore, and changes a bunch of call-sites where it's obviously safe
to change to use it by just calling getIterator() on an instruction
pointer. A follow-up patch will contain less-obviously-safe changes.

We'll eventually deprecate and remove the instruction-pointer
insertBefore, but not before adding concise documentation of what
considerations are needed (very few).

1 files changed, 5 insertions, 5 deletions

diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 2d6f6a3..94cf118 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1715,7 +1715,7 @@ static void insertDbgValueOrDbgVariableRecordAfter(
   if (!UseNewDbgInfoFormat) {
     auto DbgVal = Builder.insertDbgValueIntrinsic(DV, DIVar, DIExpr, NewLoc,
                                                   (Instruction *)nullptr);
-    cast<Instruction *>(DbgVal)->insertAfter(&*Instr);
+    cast<Instruction *>(DbgVal)->insertAfter(Instr);
   } else {
     // RemoveDIs: if we're using the new debug-info format, allocate a
     // DbgVariableRecord directly instead of a dbg.value intrinsic.
@@ -2197,7 +2197,7 @@ void llvm::insertDebugValuesForPHIs(BasicBlock *BB,
     auto *NewDbgII = DI.second;
     auto InsertionPt = Parent->getFirstInsertionPt();
     assert(InsertionPt != Parent->end() && "Ill-formed basic block");
-    NewDbgII->insertBefore(&*InsertionPt);
+    NewDbgII->insertBefore(InsertionPt);
   }
 }
 
@@ -2975,7 +2975,7 @@ CallInst *llvm::createCallMatchingInvoke(InvokeInst *II) {
 CallInst *llvm::changeToCall(InvokeInst *II, DomTreeUpdater *DTU) {
   CallInst *NewCall = createCallMatchingInvoke(II);
   NewCall->takeName(II);
-  NewCall->insertBefore(II);
+  NewCall->insertBefore(II->getIterator());
   II->replaceAllUsesWith(NewCall);
 
   // Follow the call by a branch to the normal destination.
@@ -4307,9 +4307,9 @@ Value *llvm::invertCondition(Value *Condition) {
   auto *Inverted =
       BinaryOperator::CreateNot(Condition, Condition->getName() + ".inv");
   if (Inst && !isa<PHINode>(Inst))
-    Inverted->insertAfter(Inst);
+    Inverted->insertAfter(Inst->getIterator());
   else
-    Inverted->insertBefore(&*Parent->getFirstInsertionPt());
+    Inverted->insertBefore(Parent->getFirstInsertionPt());
   return Inverted;
 }