[DebugInfo] Handle multiple variable location operands in IR

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

1 files changed, 6 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp b/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
index 784d0e4..2c68e4b 100644
--- a/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
+++ b/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
@@ -384,11 +384,14 @@ 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<Value *, DILocalVariable *>, DIExpression *>;
+        std::pair<std::pair<hash_code, DILocalVariable *>, DIExpression *>;
     auto makeHash = [](DbgVariableIntrinsic *D) -> DbgIntrinsicHash {
-      return {{D->getVariableLocationOp(0), D->getVariable()},
+      auto VarLocOps = D->location_ops();
+      return {{hash_combine_range(VarLocOps.begin(), VarLocOps.end()),
+               D->getVariable()},
               D->getExpression()};
     };
     SmallDenseSet<DbgIntrinsicHash, 8> DbgIntrinsics;