Revert "[DebugInfo] Handle multiple variable location operands in IR"

This caused non-deterministic compiler output; see comment on the
code review.

> This patch updates the various IR passes to correctly handle dbg.values with a
> DIArgList location. This patch does not actually allow DIArgLists to be produced
> by salvageDebugInfo, and it does not affect any pass after codegen-prepare.
> Other than that, it should cover every IR pass.
>
> Most of the changes simply extend code that operated on a single debug value to
> operate on the list of debug values in the style of any_of, all_of, for_each,
> etc. Instances of setOperand(0, ...) have been replaced with with
> replaceVariableLocationOp, which takes the value that is being replaced as an
> additional argument. In places where this value isn't readily available, we have
> to track the old value through to the point where it gets replaced.
>
> Differential Revision: https://reviews.llvm.org/D88232

This reverts commit df69c69427dea7f5b3b3a4d4564bc77b0926ec88.

1 files changed, 3 insertions, 6 deletions

diff --git a/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp b/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
index 2c68e4b..784d0e4 100644
--- a/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
+++ b/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
@@ -384,14 +384,11 @@ bool LoopRotate::rotateLoop(Loop *L, bool SimplifiedLatch) {
     // possible or create a clone in the OldPreHeader if not.
     Instruction *LoopEntryBranch = OrigPreheader->getTerminator();
 
-    // Record all debug intrinsics preceding LoopEntryBranch to avoid
-    // duplication.
+    // Record all debug intrinsics preceding LoopEntryBranch to avoid duplication.
     using DbgIntrinsicHash =
-        std::pair<std::pair<hash_code, DILocalVariable *>, DIExpression *>;
+      std::pair<std::pair<Value *, DILocalVariable *>, DIExpression *>;
     auto makeHash = [](DbgVariableIntrinsic *D) -> DbgIntrinsicHash {
-      auto VarLocOps = D->location_ops();
-      return {{hash_combine_range(VarLocOps.begin(), VarLocOps.end()),
-               D->getVariable()},
+      return {{D->getVariableLocationOp(0), D->getVariable()},
               D->getExpression()};
     };
     SmallDenseSet<DbgIntrinsicHash, 8> DbgIntrinsics;