[DebugInfo][RemoveDIs] Handle dbg.declares in SelectionDAGISel (#73496)

This is a boring mechanical update to support DPValues that look like
dbg.declares in SelectionDAG.

The tests will become "live" once #74090 lands (see for more info).

llvm/include/llvm/CodeGen/FunctionLoweringInfo.h

@@ -191,6 +191,7 @@ class FunctionLoweringInfo {
   /// Collection of dbg.declare instructions handled after argument
   /// lowering and before ISel proper.
   SmallPtrSet<const DbgDeclareInst *, 8> PreprocessedDbgDeclares;
+  SmallPtrSet<const DPValue *, 8> PreprocessedDPVDeclares;
 
   /// set - Initialize this FunctionLoweringInfo with the given Function
   /// and its associated MachineFunction.

llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp

@@ -357,6 +357,7 @@ void FunctionLoweringInfo::clear() {
   StatepointRelocationMaps.clear();
   PreferredExtendType.clear();
   PreprocessedDbgDeclares.clear();
+  PreprocessedDPVDeclares.clear();
 }
 
 /// CreateReg - Allocate a single virtual register for the given type.

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -1148,6 +1148,60 @@ SDValue SelectionDAGBuilder::getControlRoot() {
   return updateRoot(PendingExports);
 }
 
+void SelectionDAGBuilder::handleDebugDeclare(Value *Address,
+                                             DILocalVariable *Variable,
+                                             DIExpression *Expression,
+                                             DebugLoc DL) {
+  assert(Variable && "Missing variable");
+
+  // Check if address has undef value.
+  if (!Address || isa<UndefValue>(Address) ||
+      (Address->use_empty() && !isa<Argument>(Address))) {
+    LLVM_DEBUG(
+        dbgs()
+        << "dbg_declare: Dropping debug info (bad/undef/unused-arg address)\n");
+    return;
+  }
+
+  bool IsParameter = Variable->isParameter() || isa<Argument>(Address);
+
+  SDValue &N = NodeMap[Address];
+  if (!N.getNode() && isa<Argument>(Address))
+    // Check unused arguments map.
+    N = UnusedArgNodeMap[Address];
+  SDDbgValue *SDV;
+  if (N.getNode()) {
+    if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
+      Address = BCI->getOperand(0);
+    // Parameters are handled specially.
+    auto *FINode = dyn_cast<FrameIndexSDNode>(N.getNode());
+    if (IsParameter && FINode) {
+      // Byval parameter. We have a frame index at this point.
+      SDV = DAG.getFrameIndexDbgValue(Variable, Expression, FINode->getIndex(),
+                                      /*IsIndirect*/ true, DL, SDNodeOrder);
+    } else if (isa<Argument>(Address)) {
+      // Address is an argument, so try to emit its dbg value using
+      // virtual register info from the FuncInfo.ValueMap.
+      EmitFuncArgumentDbgValue(Address, Variable, Expression, DL,
+                               FuncArgumentDbgValueKind::Declare, N);
+      return;
+    } else {
+      SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(),
+                            true, DL, SDNodeOrder);
+    }
+    DAG.AddDbgValue(SDV, IsParameter);
+  } else {
+    // If Address is an argument then try to emit its dbg value using
+    // virtual register info from the FuncInfo.ValueMap.
+    if (!EmitFuncArgumentDbgValue(Address, Variable, Expression, DL,
+                                  FuncArgumentDbgValueKind::Declare, N)) {
+      LLVM_DEBUG(dbgs() << "dbg_declare: Dropping debug info"
+                        << " (could not emit func-arg dbg_value)\n");
+    }
+  }
+  return;
+}
+
 void SelectionDAGBuilder::visitDbgInfo(const Instruction &I) {
   // Add SDDbgValue nodes for any var locs here. Do so before updating
   // SDNodeOrder, as this mapping is {Inst -> Locs BEFORE Inst}.
@@ -1182,6 +1236,16 @@ void SelectionDAGBuilder::visitDbgInfo(const Instruction &I) {
     DIExpression *Expression = DPV.getExpression();
     dropDanglingDebugInfo(Variable, Expression);
 
+    if (DPV.getType() == DPValue::LocationType::Declare) {
+      if (FuncInfo.PreprocessedDPVDeclares.contains(&DPV))
+        continue;
+      LLVM_DEBUG(dbgs() << "SelectionDAG visiting dbg_declare: " << DPV
+                        << "\n");
+      handleDebugDeclare(DPV.getVariableLocationOp(0), Variable, Expression,
+                         DPV.getDebugLoc());
+      continue;
+    }
+
     // A DPValue with no locations is a kill location.
     SmallVector<Value *, 4> Values(DPV.location_ops());
     if (Values.empty()) {
@@ -6218,61 +6282,15 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
     if (AssignmentTrackingEnabled ||
         FuncInfo.PreprocessedDbgDeclares.count(&DI))
       return;
-    // Assume dbg.declare can not currently use DIArgList, i.e.
-    // it is non-variadic.
-    assert(!DI.hasArgList() && "Only dbg.value should currently use DIArgList");
+    LLVM_DEBUG(dbgs() << "SelectionDAG visiting dbg_declare: " << DI << "\n");
     DILocalVariable *Variable = DI.getVariable();
     DIExpression *Expression = DI.getExpression();
     dropDanglingDebugInfo(Variable, Expression);
-    assert(Variable && "Missing variable");
-    LLVM_DEBUG(dbgs() << "SelectionDAG visiting debug intrinsic: " << DI
-                      << "\n");
-    // Check if address has undef value.
-    const Value *Address = DI.getVariableLocationOp(0);
-    if (!Address || isa<UndefValue>(Address) ||
-        (Address->use_empty() && !isa<Argument>(Address))) {
-      LLVM_DEBUG(dbgs() << "Dropping debug info for " << DI
-                        << " (bad/undef/unused-arg address)\n");
-      return;
-    }
-
-    bool isParameter = Variable->isParameter() || isa<Argument>(Address);
-
-    SDValue &N = NodeMap[Address];
-    if (!N.getNode() && isa<Argument>(Address))
-      // Check unused arguments map.
-      N = UnusedArgNodeMap[Address];
-    SDDbgValue *SDV;
-    if (N.getNode()) {
-      if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
-        Address = BCI->getOperand(0);
-      // Parameters are handled specially.
-      auto FINode = dyn_cast<FrameIndexSDNode>(N.getNode());
-      if (isParameter && FINode) {
-        // Byval parameter. We have a frame index at this point.
-        SDV =
-            DAG.getFrameIndexDbgValue(Variable, Expression, FINode->getIndex(),
-                                      /*IsIndirect*/ true, dl, SDNodeOrder);
-      } else if (isa<Argument>(Address)) {
-        // Address is an argument, so try to emit its dbg value using
-        // virtual register info from the FuncInfo.ValueMap.
-        EmitFuncArgumentDbgValue(Address, Variable, Expression, dl,
-                                 FuncArgumentDbgValueKind::Declare, N);
-        return;
-      } else {
-        SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(),
-                              true, dl, SDNodeOrder);
-      }
-      DAG.AddDbgValue(SDV, isParameter);
-    } else {
-      // If Address is an argument then try to emit its dbg value using
-      // virtual register info from the FuncInfo.ValueMap.
-      if (!EmitFuncArgumentDbgValue(Address, Variable, Expression, dl,
-                                    FuncArgumentDbgValueKind::Declare, N)) {
-        LLVM_DEBUG(dbgs() << "Dropping debug info for " << DI
-                          << " (could not emit func-arg dbg_value)\n");
-      }
-    }
+    // Assume dbg.declare can not currently use DIArgList, i.e.
+    // it is non-variadic.
+    assert(!DI.hasArgList() && "Only dbg.value should currently use DIArgList");
+    handleDebugDeclare(DI.getVariableLocationOp(0), Variable, Expression,
+                       DI.getDebugLoc());
     return;
   }
   case Intrinsic::dbg_label: {

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h

@@ -368,6 +368,9 @@ class SelectionDAGBuilder {
   void handleKillDebugValue(DILocalVariable *Var, DIExpression *Expr,
                             DebugLoc DbgLoc, unsigned Order);
 
+  void handleDebugDeclare(Value *Address, DILocalVariable *Variable,
+                          DIExpression *Expression, DebugLoc DL);
+
   /// Evict any dangling debug information, attempting to salvage it first.
   void resolveOrClearDbgInfo();
 

llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

@@ -1461,6 +1461,14 @@ static void processDbgDeclares(FunctionLoweringInfo &FuncInfo) {
     if (DI && processDbgDeclare(FuncInfo, DI->getAddress(), DI->getExpression(),
                                 DI->getVariable(), DI->getDebugLoc()))
       FuncInfo.PreprocessedDbgDeclares.insert(DI);
+
+    for (const DPValue &DPV : I.getDbgValueRange()) {
+      if (DPV.getType() == DPValue::LocationType::Declare &&
+          processDbgDeclare(FuncInfo, DPV.getVariableLocationOp(0),
+                            DPV.getExpression(), DPV.getVariable(),
+                            DPV.getDebugLoc()))
+        FuncInfo.PreprocessedDPVDeclares.insert(&DPV);
+    }
   }
 }
 

llvm/test/CodeGen/X86/dbg-combine.ll

@@ -1,4 +1,5 @@
 ; RUN: llc -mtriple x86_64-pc-linux -O0 < %s | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators -mtriple x86_64-pc-linux -O0 < %s | FileCheck %s
 
 ; Make sure that the sequence of debug locations for function foo is correctly
 ; generated. More specifically, .loc entries for lines 4,5,6,7 must appear in

llvm/test/CodeGen/X86/selectiondag-order.ll

@@ -1,6 +1,7 @@
 ; Check that debug intrinsics do not affect code generation.
 
 ; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+avx | FileCheck --check-prefix=X86-CHECK %s
+; RUN: llc --try-experimental-debuginfo-iterators < %s -mtriple=x86_64-unknown-unknown -mattr=+avx | FileCheck --check-prefix=X86-CHECK %s
 
 define i64 @simulate(<2 x i32> %a) {
 entry:

llvm/test/DebugInfo/Generic/2010-06-29-InlinedFnLocalVar.ll

@@ -1,4 +1,5 @@
 ; RUN: %llc_dwarf -O2 %s -o - | FileCheck %s
+; RUN: %llc_dwarf --try-experimental-debuginfo-iterators -O2 %s -o - | FileCheck %s
 ; Check struct X for dead variable xyz from inlined function foo.
 
 ; CHECK: {{.section.*debug_info|.*dwinfo:}}

llvm/test/DebugInfo/Mips/InlinedFnLocalVar.ll

@@ -1,4 +1,5 @@
 ; RUN: llc -mtriple mips-linux-gnu -O2 %s -o - | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators -mtriple mips-linux-gnu -O2 %s -o - | FileCheck %s
 ; Check struct X for dead variable xyz from inlined function foo.
 
 ; CHECK: .section .debug_info,"",@0x7000001e

llvm/test/DebugInfo/X86/DW_AT_const_value.ll

@@ -1,4 +1,5 @@
 ; RUN: llc %s -o - | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators %s -o - | FileCheck %s
 
 ;; Check single location variables of various types with a constant value are
 ;; emitted with a DW_AT_const_value attribute.

llvm/test/DebugInfo/X86/InlinedFnLocalVar.ll

@@ -1,4 +1,5 @@
 ; RUN: llc -mtriple i686-pc-cygwin -O2 %s -o - | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators -mtriple i686-pc-cygwin -O2 %s -o - | FileCheck %s
 ; Check struct X for dead variable xyz from inlined function foo.
 
 ; CHECK: Lsection_info

llvm/test/DebugInfo/X86/block-capture.ll

@@ -1,6 +1,9 @@
 ; RUN: llc %s -o %t -filetype=obj
 ; RUN: llvm-dwarfdump -v -debug-info %t | FileCheck %s
 
+; RUN: llc --try-experimental-debuginfo-iterators %s -o %t -filetype=obj
+; RUN: llvm-dwarfdump -v -debug-info %t | FileCheck %s
+
 ; Checks that we emit debug info for the block variable declare.
 ; CHECK: DW_TAG_subprogram
 ; CHECK: DW_TAG_variable

llvm/test/DebugInfo/X86/dbg-empty-metadata-lowering.ll

@@ -2,13 +2,19 @@
 ; RUN: | FileCheck %s --implicit-check-not=DBG --check-prefixes=AT-DISABLED,BOTH
 ; RUN: llc %s -stop-after=finalize-isel -o - --try-experimental-debuginfo-iterators \
 ; RUN: | FileCheck %s --implicit-check-not=DBG --check-prefixes=AT-DISABLED,BOTH
+; RUN: llc --try-experimental-debuginfo-iterators %s -stop-after=finalize-isel -o - \
+; RUN: | FileCheck %s --implicit-check-not=DBG --check-prefixes=AT-DISABLED,BOTH
+
 ;; Check that dbg.values with empty metadata are treated as kills (i.e. become
 ;; DBG_VALUE $noreg, ...). dbg.declares with empty metadata location operands
 ;; should be ignored.
 
 ; RUN: sed 's/;Uncomment-with-sed//g' < %s \
 ; RUN: | llc -stop-after=finalize-isel -o - \
 ; RUN: | FileCheck %s --implicit-check-not=DBG --check-prefixes=AT-ENABLED,BOTH
+; RUN: sed 's/;Uncomment-with-sed//g' < %s \
+; RUN: | llc --try-experimental-debuginfo-iterators -stop-after=finalize-isel -o - \
+; RUN: | FileCheck %s --implicit-check-not=DBG --check-prefixes=AT-ENABLED,BOTH
 ;; Check the same behaviour occurs with assignment tracking enabled.
 
 ;; First ensure assignment tracking is truly unset/set.

llvm/test/DebugInfo/X86/debug-info-block-captured-self.ll

@@ -1,6 +1,9 @@
 ; RUN: llc -mtriple x86_64-apple-darwin -filetype=obj -o %t.o < %s
 ; RUN: llvm-dwarfdump %t.o | FileCheck %s
 ;
+; RUN: llc --try-experimental-debuginfo-iterators -mtriple x86_64-apple-darwin -filetype=obj -o %t.o < %s
+; RUN: llvm-dwarfdump %t.o | FileCheck %s
+;
 ; Test that DW_AT_location is generated for a captured "self" inside a
 ; block.
 ;

llvm/test/DebugInfo/X86/debug-info-blocks.ll

@@ -1,6 +1,9 @@
 ; RUN: llc -mtriple x86_64-apple-darwin -filetype=obj -o %t.o < %s
 ; RUN: llvm-dwarfdump -v -debug-info %t.o | FileCheck %s
 
+; RUN: llc --try-experimental-debuginfo-iterators -mtriple x86_64-apple-darwin -filetype=obj -o %t.o < %s
+; RUN: llvm-dwarfdump -v -debug-info %t.o | FileCheck %s
+
 ; Generated from llvm/tools/clang/test/CodeGenObjC/debug-info-blocks.m
 ; rdar://problem/9279956
 ; test that the DW_AT_location of self is at ( fbreg +{{[0-9]+}}, deref, +{{[0-9]+}} )

llvm/test/DebugInfo/X86/empty-metadata-dbg-declare.ll

@@ -1,4 +1,5 @@
 ; RUN: llc %s -stop-after=finalize-isel -o - | FileCheck %s --implicit-check-not=DBG
+; RUN: llc --try-experimental-debuginfo-iterators %s -stop-after=finalize-isel -o - | FileCheck %s --implicit-check-not=DBG
 
 ;; Check that a single "empty metadata" dbg.declare doesn't accidentally cause
 ;; other dbg.declares in the function to go missing.

llvm/test/DebugInfo/X86/pieces-3.ll

@@ -1,4 +1,5 @@
 ; RUN: llc %s -filetype=obj -o - -experimental-debug-variable-locations=true | llvm-dwarfdump -v - | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators %s -filetype=obj -o - -experimental-debug-variable-locations=true | llvm-dwarfdump -v - | FileCheck %s
 ;
 ;    // Compile with -O1
 ;    typedef struct {

llvm/test/DebugInfo/X86/pieces-4.ll

@@ -1,5 +1,7 @@
 ; RUN: llc < %s -experimental-debug-variable-locations=true | FileCheck %s
 ; RUN: llc -filetype=obj < %s -experimental-debug-variable-locations=true | llvm-dwarfdump -debug-loc - | FileCheck %s --check-prefix=DWARF
+; RUN: llc --try-experimental-debuginfo-iterators < %s -experimental-debug-variable-locations=true | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators -filetype=obj < %s -experimental-debug-variable-locations=true | llvm-dwarfdump -debug-loc - | FileCheck %s --check-prefix=DWARF
 
 ; Compile the following with -O1:
 

llvm/test/DebugInfo/X86/safestack-byval.ll

@@ -3,6 +3,8 @@
 ; SafeStack for unsafe byval arguments.
 ; RUN: llc -mtriple=x86_64-unknown-unknown --experimental-debug-variable-locations=false -stop-after finalize-isel %s -o - | FileCheck %s --check-prefixes=CHECK,NORMAL
 ; RUN: llc -mtriple=x86_64-unknown-unknown --experimental-debug-variable-locations -stop-after finalize-isel %s -o - | FileCheck %s --check-prefixes=CHECK,INSTRREF
+; RUN: llc --try-experimental-debuginfo-iterators -mtriple=x86_64-unknown-unknown --experimental-debug-variable-locations=false -stop-after finalize-isel %s -o - | FileCheck %s --check-prefixes=CHECK,NORMAL
+; RUN: llc --try-experimental-debuginfo-iterators -mtriple=x86_64-unknown-unknown --experimental-debug-variable-locations -stop-after finalize-isel %s -o - | FileCheck %s --check-prefixes=CHECK,INSTRREF
 
 ; This was built by compiling the following source with SafeStack and
 ; simplifying the result a little.

llvm/test/DebugInfo/X86/salvage-add-node-indirect.ll

@@ -1,5 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 3
 ; RUN: llc -mtriple=x86_64 %s -start-before=x86-isel -o - -stop-after=x86-isel | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators -mtriple=x86_64 %s -start-before=x86-isel -o - -stop-after=x86-isel | FileCheck %s
 
 ; Verify that we don't crash due to attempting to turn the indirect debug value
 ; in @test_non_constant variadic when salvaging the ADD node with non-constant

llvm/test/DebugInfo/X86/spill-indirect-nrvo.ll

@@ -3,6 +3,13 @@
 ; RUN: llc < %s -experimental-debug-variable-locations=true | FileCheck -check-prefixes=CHECK,OPT %s
 ; RUN: llc -O0 < %s -experimental-debug-variable-locations=true | FileCheck -check-prefixes=CHECK,OPTNONE %s
 
+; RUN: llc --try-experimental-debuginfo-iterators < %s -experimental-debug-variable-locations=false | FileCheck -check-prefixes=CHECK,OPT %s
+;; FIXME: RemoveDIs - enable when FastISel support is added.
+; run: llc --try-experimental-debuginfo-iterators -O0 < %s -experimental-debug-variable-locations=false | FileCheck -check-prefixes=CHECK,OPTNONE %s
+; RUN: llc --try-experimental-debuginfo-iterators < %s -experimental-debug-variable-locations=true | FileCheck -check-prefixes=CHECK,OPT %s
+;; FIXME: RemoveDIs - enable when FastISel support is added.
+; run: llc --try-experimental-debuginfo-iterators -O0 < %s -experimental-debug-variable-locations=true | FileCheck -check-prefixes=CHECK,OPTNONE %s
+
 ; Make sure we insert DW_OP_deref when spilling indirect DBG_VALUE instructions.
 
 ; C++ source:

llvm/test/DebugInfo/X86/spill-nontrivial-param.ll

@@ -1,5 +1,7 @@
 ; RUN: llc < %s -experimental-debug-variable-locations=false | FileCheck %s
 ; RUN: llc < %s -experimental-debug-variable-locations=true | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators < %s -experimental-debug-variable-locations=false | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators < %s -experimental-debug-variable-locations=true | FileCheck %s
 
 ; Make sure we insert DW_OP_deref when spilling indirect DBG_VALUE instructions.
 ; In this example, 'nt' is passed by address because it is not trivially

llvm/test/DebugInfo/X86/sret.ll

@@ -1,5 +1,8 @@
 ; RUN: llc -split-dwarf-file=foo.dwo -O0 %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o %t
 ; RUN: llvm-dwarfdump -debug-info %t | FileCheck %s --check-prefix=CHECK-DWO
+;; FIXME: RemoveDIs - enable when FastISel support is added.
+; run: llc --try-experimental-debuginfo-iterators -split-dwarf-file=foo.dwo -O0 %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o %t
+; run: llvm-dwarfdump -debug-info %t | FileCheck %s --check-prefix=CHECK-DWO
 
 ; Based on the debuginfo-tests/sret.cpp code.
 
@@ -8,6 +11,11 @@
 
 ; RUN: llc -O0 -fast-isel=true -mtriple=x86_64-apple-darwin -filetype=obj -o - %s | llvm-dwarfdump -debug-info - | FileCheck -check-prefixes=CHECK,FASTISEL %s
 ; RUN: llc -O0 -fast-isel=false -mtriple=x86_64-apple-darwin -filetype=obj -o - %s | llvm-dwarfdump -debug-info - | FileCheck -check-prefixes=CHECK,SDAG %s
+
+; RUN: llc --try-experimental-debuginfo-iterators -O0 -fast-isel=false -mtriple=x86_64-apple-darwin -filetype=obj -o - %s | llvm-dwarfdump -debug-info - | FileCheck -check-prefixes=CHECK,SDAG %s
+;; FIXME: RemoveDIs - enable when FastISel support is added.
+; run: llc --try-experimental-debuginfo-iterators -O0 -fast-isel=false -mtriple=x86_64-apple-darwin -filetype=obj -o - %s | llvm-dwarfdump -debug-info - | FileCheck -check-prefixes=CHECK,SDAG %s
+
 ; CHECK: _ZN1B9AInstanceEv
 ; CHECK: DW_TAG_variable
 ; CHECK-NEXT:   DW_AT_location (0x00000000

llvm/test/DebugInfo/X86/union-const.ll

@@ -1,4 +1,6 @@
 ; RUN: llc -filetype=obj < %s | llvm-dwarfdump -v -debug-info - | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators -filetype=obj < %s | llvm-dwarfdump -v -debug-info - | FileCheck %s
+
 ; CHECK: DW_TAG_variable
 ; CHECK-NEXT: DW_AT_const_value [DW_FORM_udata]	(0)
 ; CHECK-NEXT: DW_AT_name {{.*}}"a"

llvm/test/DebugInfo/X86/vla-global.ll

@@ -1,4 +1,6 @@
 ; RUN: llc -mtriple=x86_64-apple-darwin %s -o - -filetype=obj | llvm-dwarfdump - | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators -mtriple=x86_64-apple-darwin %s -o - -filetype=obj | llvm-dwarfdump - | FileCheck %s
+
 ; CHECK: 0x00000[[G:.*]]:     DW_TAG_variable
 ; CHECK-NEXT:                DW_AT_name	("g")
 ; CHECK: DW_TAG_array_type

llvm/test/DebugInfo/X86/vla-multi.ll

@@ -1,4 +1,6 @@
 ; RUN: llc -mtriple=x86_64-apple-darwin %s -o - -filetype=obj | llvm-dwarfdump - | FileCheck %s
+; RUN: llc --try-experimental-debuginfo-iterators -mtriple=x86_64-apple-darwin %s -o - -filetype=obj | llvm-dwarfdump - | FileCheck %s
+
 ; Test debug info for multidimensional arrays.
 ;
 ; void f(int i, int j, int k, int r) {