[Lldb-commits] [PATCH] D70644: [DebugInfo] Support for DW_OP_implicit_pointer (llvm.dbg_derefval)

[Alok Kumar Sharma via Phabricator via lldb-commits]

alok created this revision.
alok added reviewers: aprantl, probinson, dblaikie, jmorse, jini.susan.george, 
SouraVX, awpandey.
alok added projects: LLVM, debug-info.
Herald added a reviewer: bollu.
Herald added subscribers: llvm-commits, lldb-commits, jdoerfert, asbirlea, 
george.burgess.iv, hiraditya.
Herald added a project: LLDB.
alok added a child revision: D6: [DebugInfo] Support for 
DW_OP_implicit_pointer (IR Verifier and Bitcode).
alok added a parent revision: D70643: [DebugInfo] Support for 
DW_OP_implicit_pointer (DW_OP_LLVM_implicit_pointer).

This patch (3/N) stems from D69787 as suggested by
This is suggested by @jmorse.
  
New intrinsic llvm.dbg.derefval is introduced.
  
  Summary:
Since dbg.value currently represents (VAR=VALUE), the new intrinsic 
dbg.derefval will represent de-referenced value (*VAR = VAL)
  - Below represents ptr=null
call void @llvm.dbg.value(metadata i32* null, metadata !21, metadata 
!DIExpression())
  - And below represents *ptr=var
call void @llvm.dbg.derefval(metadata !16, metadata !21, metadata 
!DIExpression(DW_OP_LLVM_implicit_pointer, DW_OP_LLVM_arg0, 0))
  - And below represents *ptr=arr[1]
call void @llvm.dbg.derefval(metadata !16, metadata !21, metadata 
!DIExpression(DW_OP_LLVM_implicit_pointer, DW_OP_LLVM_arg0, 4))
  - We should be able to represent the case when a variable points to 
temporary (initialized by constant) and temporary is optimized out.
tmp=[CONST]; ptr=&tmp;
call void @llvm.dbg.derefval(metadata [CONST], metadata !21, metadata 
!DIExpression(DW_OP_LLVM_arg0))


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D70644

Files:
  lldb/source/Expression/IRInterpreter.cpp
  llvm/docs/SourceLevelDebugging.rst
  llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
  llvm/include/llvm/CodeGen/GlobalISel/MachineIRBuilder.h
  llvm/include/llvm/CodeGen/MachineInstrBuilder.h
  llvm/include/llvm/IR/DIBuilder.h
  llvm/include/llvm/IR/InstVisitor.h
  llvm/include/llvm/IR/IntrinsicInst.h
  llvm/include/llvm/IR/Intrinsics.td
  llvm/lib/Analysis/MemorySSA.cpp
  llvm/lib/Analysis/ObjCARCInstKind.cpp
  llvm/lib/Analysis/ValueTracking.cpp
  llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
  llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
  llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
  llvm/lib/CodeGen/LiveDebugValues.cpp
  llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
  llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
  llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
  llvm/lib/IR/DIBuilder.cpp
  llvm/lib/IR/IntrinsicInst.cpp
  llvm/lib/IR/Verifier.cpp
  llvm/lib/Transforms/Utils/Local.cpp
  llvm/lib/Transforms/Utils/SimplifyCFG.cpp
  polly/lib/Support/ScopHelper.cpp

Index: polly/lib/Support/ScopHelper.cpp
===
--- polly/lib/Support/ScopHelper.cpp
+++ polly/lib/Support/ScopHelper.cpp
@@ -624,6 +624,7 @@
 case llvm::Intrinsic::assume:
 // Some debug info intrinsics are supported/ignored.
 case llvm::Intrinsic::dbg_value:
+case llvm::Intrinsic::dbg_derefval:
 case llvm::Intrinsic::dbg_declare:
   return true;
 default:
Index: llvm/lib/Transforms/Utils/SimplifyCFG.cpp
===
--- llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -4010,6 +4010,7 @@
 switch (IntrinsicID) {
 case Intrinsic::dbg_declare:
 case Intrinsic::dbg_value:
+case Intrinsic::dbg_derefval:
 case Intrinsic::dbg_label:
 case Intrinsic::lifetime_end:
   break;
Index: llvm/lib/Transforms/Utils/Local.cpp
===
--- llvm/lib/Transforms/Utils/Local.cpp
+++ llvm/lib/Transforms/Utils/Local.cpp
@@ -385,6 +385,11 @@
   return false;
 return true;
   }
+  if (DbgDerefValueInst *DVI = dyn_cast(I)) {
+if (DVI->getDerefVariable())
+  return false;
+return true;
+  }
   if (DbgLabelInst *DLI = dyn_cast(I)) {
 if (DLI->getLabel())
   return false;
Index: llvm/lib/IR/Verifier.cpp
===
--- llvm/lib/IR/Verifier.cpp
+++ llvm/lib/IR/Verifier.cpp
@@ -4314,6 +4314,9 @@
   case Intrinsic::dbg_value: // llvm.dbg.value
 visitDbgIntrinsic("value", cast(Call));
 break;
+  case Intrinsic::dbg_derefval: // llvm.dbg.derefval
+visitDbgIntrinsic("derefval", cast(Call));
+break;
   case Intrinsic::dbg_label: // llvm.dbg.label
 visitDbgLabelIntrinsic("label", cast(Call));
 break;
@@ -4836,8 +4839,9 @@
 void Verifier::visitDbgIntrinsic(StringRef Kind, DbgVariableIntrinsic &DII) {
   auto *MD = cast(DII.getArgOperand(0))->getMetadata();
   AssertDI(isa(MD) ||
- (isa(MD) && !cast(MD)->getNumOperands()),
- "invalid llvm.dbg." + Kind + " intrinsic address/value", &DII, MD);
+   (isa(MD) && !cast(MD)->getNumOperands()) ||
+   

[Lldb-commits] [PATCH] D70644: [DebugInfo] Support for DW_OP_implicit_pointer (llvm.dbg_derefval)

[Alok Kumar Sharma via Phabricator via lldb-commits]

alok marked 12 inline comments as done.
alok added inline comments.



Comment at: llvm/docs/SourceLevelDebugging.rst:261
+This intrinsic is identical to `llvm.dbg.value`, except that it is used to
+describe dereferenced value of pointer variable. The first argument is 
metadata.
+The second argument is a `local variable `_

jmorse wrote:
> I'd add some motivation to the first sentence, such as: "it it used to 
> describe the dereferenced value of a pointer variable, when the pointer 
> itself is no longer available in the program".
Thanks for comment. It will be incorporated in next version.



Comment at: llvm/docs/SourceLevelDebugging.rst:266-267
+interpreted based on the third argument. If the third argument represents
+DW_OP_LLVM_implicit_pointer, the first argument is
+ `local variable `_ , otherwise it is the value
+(wrapped as metadata).

jmorse wrote:
> IMO "is" should read "must", i.e. "the first argument must be a local 
> variable", to indicate this is required for correctness.
Thanks for your comment. It will be included in next version.



Comment at: llvm/docs/SourceLevelDebugging.rst:270
+
+An `llvm.dbg.derefval` intrinsic is usefull when location which the variable
+points to is optimized out, but the dereferenced value is known.

StephenTozer wrote:
> Correct usefull -> useful
Thanks for your comment. It will be incorporated in next version.



Comment at: llvm/include/llvm/CodeGen/GlobalISel/MachineIRBuilder.h:369
 
+  /// Build and insert a DBG_VALUE instructions specifying that dereferenced
+  /// value of \p Variable is given by \p V (suitably modified by \p Expr).

jmorse wrote:
> "that the dereferenced"?
Thanks for your comment. It will be incorporated in next version.



Comment at: llvm/include/llvm/CodeGen/MachineInstrBuilder.h:227-238
+  const MachineInstrBuilder &addMetadata(const MDNode *MD,
+ bool IsImplicitPointer = false) const 
{
 MI->addOperand(*MF, MachineOperand::CreateMetadata(MD));
-assert((MI->isDebugValue() ? static_cast(MI->getDebugVariable())
-   : true) &&
+assert(((MI->isDebugValue() && !IsImplicitPointer)
+? static_cast(MI->getDebugVariable())
+: true) &&
"first MDNode argument of a DBG_VALUE not a variable");

jmorse wrote:
> Perhaps it's worth adding a new "add" method, i.e. "addImplicitPtrMetadata"? 
> That avoids the extra argument, and in the call sites below it will be a 
> little clearer what's happening, as a "true" argument isn't especially 
> helpful.
> 
> Plus, then you can assert that only DILocalVariables (or whatever) are added 
> as the implicit pointer metadata.
Thanks for your comment. It will be incorporated in next version.



Comment at: llvm/lib/CodeGen/LiveDebugValues.cpp:717-718
   if (isDbgValueDescribedByReg(MI) || MI.getOperand(0).isImm() ||
-  MI.getOperand(0).isFPImm() || MI.getOperand(0).isCImm()) {
+  MI.getOperand(0).isFPImm() || MI.getOperand(0).isCImm() ||
+  MI.getOperand(0).isMetadata()) {
 // Use normal VarLoc constructor for registers and immediates.

jmorse wrote:
> The main VarLoc constructor called on line 720 is going to not recognise the 
> metadata operand and leave some fields uninitialized (it should probably 
> actually assert in this case). I reckon you'll need to add a new location 
> "Kind", and have it emitted in the BuildDbgValue method.
> 
> The LiveDebugValues algorithm should (TM) handle and propagate this kind of 
> location fine.
Thanks for pointing this out. This will be incorporated in next version.



Comment at: llvm/lib/CodeGen/SelectionDAG/FastISel.cpp:1447
   }
+  case Intrinsic::dbg_derefval: {
+// This form of DBG_VALUE is target-independent.

jmorse wrote:
> Perhaps easier here instead to have dbg_derefval and dbg_value share code, 
> with an additional assertion that MetadataAsValue operands can only come from 
> dbg_value's?
Thanks for your comment. It will be incorporated in next version.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D70644/new/

https://reviews.llvm.org/D70644



___
lldb-commits mailing list
lldb-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits

[Lldb-commits] [PATCH] D70644: [DebugInfo] Support for DW_OP_implicit_pointer (llvm.dbg_derefval)

[Alok Kumar Sharma via Phabricator via lldb-commits]

alok updated this revision to Diff 234356.
alok added a comment.

This version is updated to rebase and to incorporate comments from @jmorse  and 
@StephenTozer.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D70644/new/

https://reviews.llvm.org/D70644

Files:
  lldb/source/Expression/IRInterpreter.cpp
  llvm/docs/SourceLevelDebugging.rst
  llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
  llvm/include/llvm/CodeGen/GlobalISel/MachineIRBuilder.h
  llvm/include/llvm/CodeGen/MachineInstr.h
  llvm/include/llvm/CodeGen/MachineInstrBuilder.h
  llvm/include/llvm/IR/DIBuilder.h
  llvm/include/llvm/IR/InstVisitor.h
  llvm/include/llvm/IR/IntrinsicInst.h
  llvm/include/llvm/IR/Intrinsics.td
  llvm/lib/Analysis/MemorySSA.cpp
  llvm/lib/Analysis/ObjCARCInstKind.cpp
  llvm/lib/Analysis/ValueTracking.cpp
  llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
  llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
  llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
  llvm/lib/CodeGen/LiveDebugValues.cpp
  llvm/lib/CodeGen/MachineInstr.cpp
  llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
  llvm/lib/IR/DIBuilder.cpp
  llvm/lib/IR/IntrinsicInst.cpp
  llvm/lib/IR/Verifier.cpp
  llvm/lib/Transforms/Utils/Local.cpp
  llvm/lib/Transforms/Utils/SimplifyCFG.cpp
  polly/lib/Support/ScopHelper.cpp

Index: polly/lib/Support/ScopHelper.cpp
===
--- polly/lib/Support/ScopHelper.cpp
+++ polly/lib/Support/ScopHelper.cpp
@@ -624,6 +624,7 @@
 case llvm::Intrinsic::assume:
 // Some debug info intrinsics are supported/ignored.
 case llvm::Intrinsic::dbg_value:
+case llvm::Intrinsic::dbg_derefval:
 case llvm::Intrinsic::dbg_declare:
   return true;
 default:
Index: llvm/lib/Transforms/Utils/SimplifyCFG.cpp
===
--- llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -4010,6 +4010,7 @@
 switch (IntrinsicID) {
 case Intrinsic::dbg_declare:
 case Intrinsic::dbg_value:
+case Intrinsic::dbg_derefval:
 case Intrinsic::dbg_label:
 case Intrinsic::lifetime_end:
   break;
Index: llvm/lib/Transforms/Utils/Local.cpp
===
--- llvm/lib/Transforms/Utils/Local.cpp
+++ llvm/lib/Transforms/Utils/Local.cpp
@@ -385,6 +385,11 @@
   return false;
 return true;
   }
+  if (DbgDerefValueInst *DVI = dyn_cast(I)) {
+if (DVI->getDerefVariable())
+  return false;
+return true;
+  }
   if (DbgLabelInst *DLI = dyn_cast(I)) {
 if (DLI->getLabel())
   return false;
Index: llvm/lib/IR/Verifier.cpp
===
--- llvm/lib/IR/Verifier.cpp
+++ llvm/lib/IR/Verifier.cpp
@@ -4322,6 +4322,9 @@
   case Intrinsic::dbg_value: // llvm.dbg.value
 visitDbgIntrinsic("value", cast(Call));
 break;
+  case Intrinsic::dbg_derefval: // llvm.dbg.derefval
+visitDbgIntrinsic("derefval", cast(Call));
+break;
   case Intrinsic::dbg_label: // llvm.dbg.label
 visitDbgLabelIntrinsic("label", cast(Call));
 break;
@@ -4877,8 +4880,9 @@
 void Verifier::visitDbgIntrinsic(StringRef Kind, DbgVariableIntrinsic &DII) {
   auto *MD = cast(DII.getArgOperand(0))->getMetadata();
   AssertDI(isa(MD) ||
- (isa(MD) && !cast(MD)->getNumOperands()),
- "invalid llvm.dbg." + Kind + " intrinsic address/value", &DII, MD);
+   (isa(MD) && !cast(MD)->getNumOperands()) ||
+   isa(DII),
+   "invalid llvm.dbg." + Kind + " intrinsic address/value", &DII, MD);
   AssertDI(isa(DII.getRawVariable()),
  "invalid llvm.dbg." + Kind + " intrinsic variable", &DII,
  DII.getRawVariable());
Index: llvm/lib/IR/IntrinsicInst.cpp
===
--- llvm/lib/IR/IntrinsicInst.cpp
+++ llvm/lib/IR/IntrinsicInst.cpp
@@ -50,6 +50,14 @@
   return nullptr;
 }
 
+Value *DbgVariableIntrinsic::getDerefVariable(bool AllowNullOp) const {
+  Value *Op = getArgOperand(0);
+  if (AllowNullOp && !Op)
+return nullptr;
+
+  return Op;
+}
+
 Optional DbgVariableIntrinsic::getFragmentSizeInBits() const {
   if (auto Fragment = getExpression()->getFragmentInfo())
 return Fragment->SizeInBits;
Index: llvm/lib/IR/DIBuilder.cpp
===
--- llvm/lib/IR/DIBuilder.cpp
+++ llvm/lib/IR/DIBuilder.cpp
@@ -887,6 +887,14 @@
   InsertBefore);
 }
 
+Instruction *DIBuilder::insertDbgDerefValueIntrinsic(
+Value *V, DILocalVariable *VarInfo, DIExpression *Expr,
+const DILocation *DL, Instruction *InsertBefore) {
+  return insertDbgDerefValueIntrinsic(
+  V, VarInfo, Expr, DL, InsertBefore ? InsertBefore->getParent() : nullptr,
+  InsertBefore);
+}
+
 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
 DI

[Lldb-commits] [PATCH] D70644: [DebugInfo] Support for DW_OP_implicit_pointer (llvm.dbg_derefval)

[Alok Kumar Sharma via Phabricator via lldb-commits]

alok updated this revision to Diff 235919.
alok added a comment.

Rebased and updated.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D70644/new/

https://reviews.llvm.org/D70644

Files:
  lldb/source/Expression/IRInterpreter.cpp
  llvm/docs/SourceLevelDebugging.rst
  llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
  llvm/include/llvm/CodeGen/GlobalISel/MachineIRBuilder.h
  llvm/include/llvm/CodeGen/MachineInstr.h
  llvm/include/llvm/CodeGen/MachineInstrBuilder.h
  llvm/include/llvm/IR/DIBuilder.h
  llvm/include/llvm/IR/InstVisitor.h
  llvm/include/llvm/IR/IntrinsicInst.h
  llvm/include/llvm/IR/Intrinsics.td
  llvm/lib/Analysis/MemorySSA.cpp
  llvm/lib/Analysis/ObjCARCInstKind.cpp
  llvm/lib/Analysis/ValueTracking.cpp
  llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
  llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
  llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
  llvm/lib/CodeGen/LiveDebugValues.cpp
  llvm/lib/CodeGen/MachineInstr.cpp
  llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
  llvm/lib/IR/DIBuilder.cpp
  llvm/lib/IR/IntrinsicInst.cpp
  llvm/lib/IR/Verifier.cpp
  llvm/lib/Transforms/Utils/Local.cpp
  llvm/lib/Transforms/Utils/SimplifyCFG.cpp
  polly/lib/Support/ScopHelper.cpp

Index: polly/lib/Support/ScopHelper.cpp
===
--- polly/lib/Support/ScopHelper.cpp
+++ polly/lib/Support/ScopHelper.cpp
@@ -624,6 +624,7 @@
 case llvm::Intrinsic::assume:
 // Some debug info intrinsics are supported/ignored.
 case llvm::Intrinsic::dbg_value:
+case llvm::Intrinsic::dbg_derefval:
 case llvm::Intrinsic::dbg_declare:
   return true;
 default:
Index: llvm/lib/Transforms/Utils/SimplifyCFG.cpp
===
--- llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -4010,6 +4010,7 @@
 switch (IntrinsicID) {
 case Intrinsic::dbg_declare:
 case Intrinsic::dbg_value:
+case Intrinsic::dbg_derefval:
 case Intrinsic::dbg_label:
 case Intrinsic::lifetime_end:
   break;
Index: llvm/lib/Transforms/Utils/Local.cpp
===
--- llvm/lib/Transforms/Utils/Local.cpp
+++ llvm/lib/Transforms/Utils/Local.cpp
@@ -385,6 +385,11 @@
   return false;
 return true;
   }
+  if (DbgDerefValueInst *DVI = dyn_cast(I)) {
+if (DVI->getDerefVariable())
+  return false;
+return true;
+  }
   if (DbgLabelInst *DLI = dyn_cast(I)) {
 if (DLI->getLabel())
   return false;
Index: llvm/lib/IR/Verifier.cpp
===
--- llvm/lib/IR/Verifier.cpp
+++ llvm/lib/IR/Verifier.cpp
@@ -4322,6 +4322,9 @@
   case Intrinsic::dbg_value: // llvm.dbg.value
 visitDbgIntrinsic("value", cast(Call));
 break;
+  case Intrinsic::dbg_derefval: // llvm.dbg.derefval
+visitDbgIntrinsic("derefval", cast(Call));
+break;
   case Intrinsic::dbg_label: // llvm.dbg.label
 visitDbgLabelIntrinsic("label", cast(Call));
 break;
@@ -4877,8 +4880,9 @@
 void Verifier::visitDbgIntrinsic(StringRef Kind, DbgVariableIntrinsic &DII) {
   auto *MD = cast(DII.getArgOperand(0))->getMetadata();
   AssertDI(isa(MD) ||
- (isa(MD) && !cast(MD)->getNumOperands()),
- "invalid llvm.dbg." + Kind + " intrinsic address/value", &DII, MD);
+   (isa(MD) && !cast(MD)->getNumOperands()) ||
+   isa(DII),
+   "invalid llvm.dbg." + Kind + " intrinsic address/value", &DII, MD);
   AssertDI(isa(DII.getRawVariable()),
  "invalid llvm.dbg." + Kind + " intrinsic variable", &DII,
  DII.getRawVariable());
Index: llvm/lib/IR/IntrinsicInst.cpp
===
--- llvm/lib/IR/IntrinsicInst.cpp
+++ llvm/lib/IR/IntrinsicInst.cpp
@@ -50,6 +50,14 @@
   return nullptr;
 }
 
+Value *DbgVariableIntrinsic::getDerefVariable(bool AllowNullOp) const {
+  Value *Op = getArgOperand(0);
+  if (AllowNullOp && !Op)
+return nullptr;
+
+  return Op;
+}
+
 Optional DbgVariableIntrinsic::getFragmentSizeInBits() const {
   if (auto Fragment = getExpression()->getFragmentInfo())
 return Fragment->SizeInBits;
Index: llvm/lib/IR/DIBuilder.cpp
===
--- llvm/lib/IR/DIBuilder.cpp
+++ llvm/lib/IR/DIBuilder.cpp
@@ -33,7 +33,7 @@
 
 DIBuilder::DIBuilder(Module &m, bool AllowUnresolvedNodes, DICompileUnit *CU)
   : M(m), VMContext(M.getContext()), CUNode(CU),
-  DeclareFn(nullptr), ValueFn(nullptr), LabelFn(nullptr),
+  DeclareFn(nullptr), ValueFn(nullptr), DerefvalFn(nullptr), LabelFn(nullptr),
   AllowUnresolvedNodes(AllowUnresolvedNodes) {}
 
 void DIBuilder::trackIfUnresolved(MDNode *N) {
@@ -887,6 +887,22 @@
   InsertBefore);
 }
 
+Instruction *DIBuilder::insertDbgDerefValueIntrinsic(
+Value *V, DILocalVariable *VarInfo, DIExpression *Expr,
+const DILocation *DL, In

[Lldb-commits] [PATCH] D70644: [DebugInfo] Support for DW_OP_implicit_pointer (llvm.dbg_derefval)

[Alok Kumar Sharma via Phabricator via lldb-commits]

alok updated this revision to Diff 235772.
alok added a comment.

Update to re-base and minor correction.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D70644/new/

https://reviews.llvm.org/D70644

Files:
  lldb/source/Expression/IRInterpreter.cpp
  llvm/docs/SourceLevelDebugging.rst
  llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
  llvm/include/llvm/CodeGen/GlobalISel/MachineIRBuilder.h
  llvm/include/llvm/CodeGen/MachineInstr.h
  llvm/include/llvm/CodeGen/MachineInstrBuilder.h
  llvm/include/llvm/IR/DIBuilder.h
  llvm/include/llvm/IR/InstVisitor.h
  llvm/include/llvm/IR/IntrinsicInst.h
  llvm/include/llvm/IR/Intrinsics.td
  llvm/lib/Analysis/MemorySSA.cpp
  llvm/lib/Analysis/ObjCARCInstKind.cpp
  llvm/lib/Analysis/ValueTracking.cpp
  llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
  llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
  llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
  llvm/lib/CodeGen/LiveDebugValues.cpp
  llvm/lib/CodeGen/MachineInstr.cpp
  llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
  llvm/lib/IR/DIBuilder.cpp
  llvm/lib/IR/IntrinsicInst.cpp
  llvm/lib/IR/Verifier.cpp
  llvm/lib/Transforms/Utils/Local.cpp
  llvm/lib/Transforms/Utils/SimplifyCFG.cpp
  polly/lib/Support/ScopHelper.cpp

Index: polly/lib/Support/ScopHelper.cpp
===
--- polly/lib/Support/ScopHelper.cpp
+++ polly/lib/Support/ScopHelper.cpp
@@ -624,6 +624,7 @@
 case llvm::Intrinsic::assume:
 // Some debug info intrinsics are supported/ignored.
 case llvm::Intrinsic::dbg_value:
+case llvm::Intrinsic::dbg_derefval:
 case llvm::Intrinsic::dbg_declare:
   return true;
 default:
Index: llvm/lib/Transforms/Utils/SimplifyCFG.cpp
===
--- llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -4010,6 +4010,7 @@
 switch (IntrinsicID) {
 case Intrinsic::dbg_declare:
 case Intrinsic::dbg_value:
+case Intrinsic::dbg_derefval:
 case Intrinsic::dbg_label:
 case Intrinsic::lifetime_end:
   break;
Index: llvm/lib/Transforms/Utils/Local.cpp
===
--- llvm/lib/Transforms/Utils/Local.cpp
+++ llvm/lib/Transforms/Utils/Local.cpp
@@ -385,6 +385,11 @@
   return false;
 return true;
   }
+  if (DbgDerefValueInst *DVI = dyn_cast(I)) {
+if (DVI->getDerefVariable())
+  return false;
+return true;
+  }
   if (DbgLabelInst *DLI = dyn_cast(I)) {
 if (DLI->getLabel())
   return false;
Index: llvm/lib/IR/Verifier.cpp
===
--- llvm/lib/IR/Verifier.cpp
+++ llvm/lib/IR/Verifier.cpp
@@ -4322,6 +4322,9 @@
   case Intrinsic::dbg_value: // llvm.dbg.value
 visitDbgIntrinsic("value", cast(Call));
 break;
+  case Intrinsic::dbg_derefval: // llvm.dbg.derefval
+visitDbgIntrinsic("derefval", cast(Call));
+break;
   case Intrinsic::dbg_label: // llvm.dbg.label
 visitDbgLabelIntrinsic("label", cast(Call));
 break;
@@ -4877,8 +4880,9 @@
 void Verifier::visitDbgIntrinsic(StringRef Kind, DbgVariableIntrinsic &DII) {
   auto *MD = cast(DII.getArgOperand(0))->getMetadata();
   AssertDI(isa(MD) ||
- (isa(MD) && !cast(MD)->getNumOperands()),
- "invalid llvm.dbg." + Kind + " intrinsic address/value", &DII, MD);
+   (isa(MD) && !cast(MD)->getNumOperands()) ||
+   isa(DII),
+   "invalid llvm.dbg." + Kind + " intrinsic address/value", &DII, MD);
   AssertDI(isa(DII.getRawVariable()),
  "invalid llvm.dbg." + Kind + " intrinsic variable", &DII,
  DII.getRawVariable());
Index: llvm/lib/IR/IntrinsicInst.cpp
===
--- llvm/lib/IR/IntrinsicInst.cpp
+++ llvm/lib/IR/IntrinsicInst.cpp
@@ -50,6 +50,14 @@
   return nullptr;
 }
 
+Value *DbgVariableIntrinsic::getDerefVariable(bool AllowNullOp) const {
+  Value *Op = getArgOperand(0);
+  if (AllowNullOp && !Op)
+return nullptr;
+
+  return Op;
+}
+
 Optional DbgVariableIntrinsic::getFragmentSizeInBits() const {
   if (auto Fragment = getExpression()->getFragmentInfo())
 return Fragment->SizeInBits;
Index: llvm/lib/IR/DIBuilder.cpp
===
--- llvm/lib/IR/DIBuilder.cpp
+++ llvm/lib/IR/DIBuilder.cpp
@@ -33,7 +33,7 @@
 
 DIBuilder::DIBuilder(Module &m, bool AllowUnresolvedNodes, DICompileUnit *CU)
   : M(m), VMContext(M.getContext()), CUNode(CU),
-  DeclareFn(nullptr), ValueFn(nullptr), LabelFn(nullptr),
+  DeclareFn(nullptr), ValueFn(nullptr), DerefvalFn(nullptr), LabelFn(nullptr),
   AllowUnresolvedNodes(AllowUnresolvedNodes) {}
 
 void DIBuilder::trackIfUnresolved(MDNode *N) {
@@ -887,6 +887,14 @@
   InsertBefore);
 }
 
+Instruction *DIBuilder::insertDbgDerefValueIntrinsic(
+Value *V, DILocalVariable *VarInfo, DIExpression *Expr,
+const