[NFC][RemoveDIs] Bulk update utilities to insert with iterators

As part of the RemoveDIs project we need LLVM to insert instructions using
iterators wherever possible, so that the iterators can carry a bit of
debug-info. This commit implements some of that by updating the contents of
llvm/lib/Transforms/Utils to always use iterator-versions of instruction
constructors.

There are two general flavours of update:
 * Almost all call-sites just call getIterator on an instruction
 * Several make use of an existing iterator (scenarios where the code is
   actually significant for debug-info)
The underlying logic is that any call to getFirstInsertionPt or similar
APIs that identify the start of a block need to have that iterator passed
directly to the insertion function, without being converted to a bare
Instruction pointer along the way.

I've also switched DemotePHIToStack to take an optional iterator: it needs
to take an iterator, and having a no-insert-location behaviour appears to
be important. The constructors for ICmpInst and FCmpInst have been updated
too. They're the only instructions that take block _references_ rather than
pointers for certain calls, and a future patch is going to make use of
default-null block insertion locations.

All of this should be NFC.

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp b/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
index 26b8c79..c7b88d3 100644
--- a/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
@@ -522,7 +522,7 @@ llvm::UnrollAndJamLoop(Loop *L, unsigned Count, unsigned TripCount,
     // unconditional one to this one
     BranchInst *SubTerm =
         cast<BranchInst>(SubLoopBlocksLast[It - 1]->getTerminator());
-    BranchInst::Create(SubLoopBlocksFirst[It], SubTerm);
+    BranchInst::Create(SubLoopBlocksFirst[It], SubTerm->getIterator());
     SubTerm->eraseFromParent();
 
     SubLoopBlocksFirst[It]->replacePhiUsesWith(ForeBlocksLast[It],
@@ -535,7 +535,7 @@ llvm::UnrollAndJamLoop(Loop *L, unsigned Count, unsigned TripCount,
   // Aft blocks successors and phis
   BranchInst *AftTerm = cast<BranchInst>(AftBlocksLast.back()->getTerminator());
   if (CompletelyUnroll) {
-    BranchInst::Create(LoopExit, AftTerm);
+    BranchInst::Create(LoopExit, AftTerm->getIterator());
     AftTerm->eraseFromParent();
   } else {
     AftTerm->setSuccessor(!ContinueOnTrue, ForeBlocksFirst[0]);
@@ -550,7 +550,7 @@ llvm::UnrollAndJamLoop(Loop *L, unsigned Count, unsigned TripCount,
     // unconditional one to this one
     BranchInst *AftTerm =
         cast<BranchInst>(AftBlocksLast[It - 1]->getTerminator());
-    BranchInst::Create(AftBlocksFirst[It], AftTerm);
+    BranchInst::Create(AftBlocksFirst[It], AftTerm->getIterator());
     AftTerm->eraseFromParent();
 
     AftBlocksFirst[It]->replacePhiUsesWith(SubLoopBlocksLast[It],