diff --git a/include/swift/AST/Types.h b/include/swift/AST/Types.h
index 86fb0cfdae1..1a45e371b14 100644
--- a/include/swift/AST/Types.h
+++ b/include/swift/AST/Types.h
@@ -3396,6 +3396,7 @@ public:
   CanType getBoxedType() const;
   // In SILType.h
   SILType getBoxedAddressType() const;
+  SILType getFieldType(unsigned index) const;
 
   static bool classof(const TypeBase *T) {
     return T->getKind() == TypeKind::SILBox;
diff --git a/include/swift/SIL/Projection.h b/include/swift/SIL/Projection.h
index de59e30dade..085348aeb56 100644
--- a/include/swift/SIL/Projection.h
+++ b/include/swift/SIL/Projection.h
@@ -294,8 +294,7 @@ public:
     case ProjectionKind::Enum:
       return BaseType.getEnumElementType(getEnumElementDecl(BaseType), M);
     case ProjectionKind::Box:
-      return SILType::getPrimitiveAddressType(BaseType.castTo<SILBoxType>()->
-                                              getBoxedType());
+      return BaseType.castTo<SILBoxType>()->getFieldType(getIndex());
     case ProjectionKind::Tuple:
       return BaseType.getTupleElementType(getIndex());
     case ProjectionKind::Upcast:
diff --git a/include/swift/SIL/SILBuilder.h b/include/swift/SIL/SILBuilder.h
index ca94afbeff7..51b0276f14a 100644
--- a/include/swift/SIL/SILBuilder.h
+++ b/include/swift/SIL/SILBuilder.h
@@ -1226,17 +1226,13 @@ public:
     return insert(new (F.getModule()) ProjectValueBufferInst(
         getSILDebugLocation(Loc), valueType, operand));
   }
-  ProjectBoxInst *createProjectBox(SILLocation Loc, SILValue boxOperand) {
-    auto valueTy =
-        boxOperand->getType().castTo<SILBoxType>()->getBoxedAddressType();
+  ProjectBoxInst *createProjectBox(SILLocation Loc, SILValue boxOperand,
+                                   unsigned index) {
+    auto boxTy = boxOperand->getType().castTo<SILBoxType>();
+    auto fieldTy = boxTy->getFieldType(index);
 
     return insert(new (F.getModule()) ProjectBoxInst(
-        getSILDebugLocation(Loc), valueTy, boxOperand));
-  }
-  ProjectBoxInst *createProjectBox(SILLocation Loc, SILType valueTy,
-                                   SILValue boxOperand) {
-    return insert(new (F.getModule()) ProjectBoxInst(
-        getSILDebugLocation(Loc), valueTy, boxOperand));
+        getSILDebugLocation(Loc), boxOperand, index, fieldTy));
   }
   ProjectExistentialBoxInst *createProjectExistentialBox(SILLocation Loc,
                                                          SILType valueTy,
diff --git a/include/swift/SIL/SILCloner.h b/include/swift/SIL/SILCloner.h
index c7462e9a7e1..3406fe006bb 100644
--- a/include/swift/SIL/SILCloner.h
+++ b/include/swift/SIL/SILCloner.h
@@ -1739,8 +1739,8 @@ void SILCloner<ImplClass>::visitProjectBoxInst(ProjectBoxInst *Inst) {
   getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
   doPostProcess(Inst,
     getBuilder().createProjectBox(getOpLocation(Inst->getLoc()),
-                                  getOpType(Inst->getValueType()),
-                                  getOpValue(Inst->getOperand())));
+                                  getOpValue(Inst->getOperand()),
+                                  Inst->getFieldIndex()));
 }
 
 template<typename ImplClass>
@@ -1749,7 +1749,7 @@ void SILCloner<ImplClass>::visitProjectExistentialBoxInst(
   getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
   doPostProcess(Inst,
       getBuilder().createProjectExistentialBox(getOpLocation(Inst->getLoc()),
-                                               getOpType(Inst->getValueType()),
+                                               getOpType(Inst->getType()),
                                                getOpValue(Inst->getOperand())));
 }
 
diff --git a/include/swift/SIL/SILInstruction.h b/include/swift/SIL/SILInstruction.h
index 7f6b989eee5..ed75bd2891d 100644
--- a/include/swift/SIL/SILInstruction.h
+++ b/include/swift/SIL/SILInstruction.h
@@ -4409,12 +4409,18 @@ class ProjectBoxInst :
                               SILInstruction, /*HasResult*/ true> {
   friend SILBuilder;
 
-  ProjectBoxInst(SILDebugLocation DebugLoc, SILType valueType,
-                 SILValue operand)
-      : UnaryInstructionBase(DebugLoc, operand, valueType.getAddressType()) {}
+  unsigned Index;
+
+  ProjectBoxInst(SILDebugLocation DebugLoc,
+                 SILValue operand,
+                 unsigned fieldIndex,
+                 SILType fieldTy)
+      : UnaryInstructionBase(DebugLoc, operand, fieldTy.getAddressType()),
+        Index(fieldIndex) {}
+
 
 public:
-  SILType getValueType() const { return getType().getObjectType(); }
+  unsigned getFieldIndex() const { return Index; }
 };
 
 /// Project out the address of the value in an existential box.
@@ -4426,9 +4432,6 @@ class ProjectExistentialBoxInst :
   ProjectExistentialBoxInst(SILDebugLocation DebugLoc, SILType valueType,
                             SILValue operand)
       : UnaryInstructionBase(DebugLoc, operand, valueType.getAddressType()) {}
-  
-public:
-  SILType getValueType() const { return getType().getObjectType(); }
 };
 
 //===----------------------------------------------------------------------===//
diff --git a/include/swift/SIL/SILLayout.h b/include/swift/SIL/SILLayout.h
index a209495aa63..8f10fba0c6c 100644
--- a/include/swift/SIL/SILLayout.h
+++ b/include/swift/SIL/SILLayout.h
@@ -149,6 +149,17 @@ public:
   }
 };
 
+inline SILType SILBoxType::getFieldType(unsigned index) const {
+  auto fieldTy = getLayout()->getFields()[index].getLoweredType();
+  // Apply generic arguments if the layout is generic.
+  if (!getGenericArgs().empty()) {
+    auto substMap =
+      getLayout()->getGenericSignature()->getSubstitutionMap(getGenericArgs());
+    fieldTy = fieldTy.subst(substMap)->getCanonicalType();
+  }
+  return SILType::getPrimitiveAddressType(fieldTy);
+}
+
 } // end namespace swift
 
 #endif // SWIFT_SIL_LAYOUT_H
diff --git a/include/swift/SILOptimizer/Utils/Local.h b/include/swift/SILOptimizer/Utils/Local.h
index 4b80b6173ae..2685416b0d5 100644
--- a/include/swift/SILOptimizer/Utils/Local.h
+++ b/include/swift/SILOptimizer/Utils/Local.h
@@ -130,7 +130,7 @@ bool canCastValueToABICompatibleType(SILModule &M,
 /// Returns a project_box if it is the next instruction after \p ABI and
 /// and has \p ABI as operand. Otherwise it creates a new project_box right
 /// after \p ABI and returns it.
-ProjectBoxInst *getOrCreateProjectBox(AllocBoxInst *ABI);
+ProjectBoxInst *getOrCreateProjectBox(AllocBoxInst *ABI, unsigned Index);
 
 /// Replace an apply with an instruction that produces the same value,
 /// then delete the apply and the instructions that produce its callee
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 19b8ea3445d..69b7c5527ef 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -4030,7 +4030,8 @@ CanGenericSignature ASTContext::getSingleGenericParameterSignature() const {
     return theSig;
   
   auto param = GenericTypeParamType::get(0, 0, *this);
-  auto sig = GenericSignature::get(param, {});
+  auto witnessReqt = Requirement(RequirementKind::WitnessMarker, param, Type());
+  auto sig = GenericSignature::get(param, witnessReqt);;
   auto canonicalSig = CanGenericSignature(sig);
   Impl.SingleGenericParameterSignature = canonicalSig;
   return canonicalSig;
diff --git a/lib/Parse/ParseSIL.cpp b/lib/Parse/ParseSIL.cpp
index 117bcd0addb..6e2a87c8e90 100644
--- a/lib/Parse/ParseSIL.cpp
+++ b/lib/Parse/ParseSIL.cpp
@@ -1755,9 +1755,24 @@ bool SILParser::parseSILInstruction(SILBasicBlock *BB, SILBuilder &B) {
 
   case ValueKind::ProjectBoxInst: {
     if (parseTypedValueRef(Val, B) ||
-        parseSILDebugLocation(InstLoc, B))
+        P.parseToken(tok::comma, diag::expected_tok_in_sil_instr, ","))
       return true;
-    ResultVal = B.createProjectBox(InstLoc, Val);
+    
+    if (!P.Tok.is(tok::integer_literal)) {
+      P.diagnose(P.Tok, diag::expected_tok_in_sil_instr, "integer");
+      return true;
+    }
+    
+    unsigned Index;
+    bool error = P.Tok.getText().getAsInteger(0, Index);
+    assert(!error && "project_box index did not parse as integer?!");
+    (void)error;
+
+    P.consumeToken(tok::integer_literal);
+    if (parseSILDebugLocation(InstLoc, B))
+      return true;
+    
+    ResultVal = B.createProjectBox(InstLoc, Val, Index);
     break;
   }
       
diff --git a/lib/SIL/Projection.cpp b/lib/SIL/Projection.cpp
index 6e01f5d4daa..5a1667a46d4 100644
--- a/lib/SIL/Projection.cpp
+++ b/lib/SIL/Projection.cpp
@@ -263,7 +263,7 @@ Projection::createAddressProjection(SILBuilder &B, SILLocation Loc,
   case ProjectionKind::TailElems:
     return B.createRefTailAddr(Loc, Base, getCastType(BaseTy));
   case ProjectionKind::Box:
-    return B.createProjectBox(Loc, Base);
+    return B.createProjectBox(Loc, Base, getIndex());
   case ProjectionKind::Upcast:
     return B.createUpcast(Loc, Base, getCastType(BaseTy));
   case ProjectionKind::RefCast:
diff --git a/lib/SIL/SILPrinter.cpp b/lib/SIL/SILPrinter.cpp
index 507c240f62a..45f63c046f2 100644
--- a/lib/SIL/SILPrinter.cpp
+++ b/lib/SIL/SILPrinter.cpp
@@ -1528,10 +1528,11 @@ public:
     *this << PVBI->getValueType() << " in " << getIDAndType(PVBI->getOperand());
   }
   void visitProjectBoxInst(ProjectBoxInst *PBI) {
-    *this << getIDAndType(PBI->getOperand());
+    *this << getIDAndType(PBI->getOperand()) << ", " << PBI->getFieldIndex();
   }
   void visitProjectExistentialBoxInst(ProjectExistentialBoxInst *PEBI) {
-    *this << PEBI->getValueType() << " in " << getIDAndType(PEBI->getOperand());
+    *this << PEBI->getType().getObjectType()
+          << " in " << getIDAndType(PEBI->getOperand());
   }
 
   void visitCondFailInst(CondFailInst *FI) {
diff --git a/lib/SIL/SILType.cpp b/lib/SIL/SILType.cpp
index 0ddc9f66bb1..d1b8be4e822 100644
--- a/lib/SIL/SILType.cpp
+++ b/lib/SIL/SILType.cpp
@@ -583,15 +583,17 @@ CanSILBoxType SILBoxType::get(CanType boxedType) {
 }
 
 SILBoxType::SILBoxType(ASTContext &C,
-                       SILLayout *Layout, ArrayRef<Substitution> Params)
+                       SILLayout *Layout, ArrayRef<Substitution> Args)
   : TypeBase(TypeKind::SILBox, &C,
-             getRecursivePropertiesFromSubstitutions(Params)),
+             getRecursivePropertiesFromSubstitutions(Args)),
     Layout(Layout),
-    NumGenericArgs(Params.size())
+    NumGenericArgs(Args.size())
 {
+  // Check that the generic args are reasonable for the box's signature.
+  assert((Layout->getGenericSignature()->getSubstitutionMap(Args), true));
   auto paramsBuf = getTrailingObjects<Substitution>();
   for (unsigned i = 0; i < NumGenericArgs; ++i)
-    ::new (paramsBuf + i) Substitution(Params[i]);
+    ::new (paramsBuf + i) Substitution(Args[i]);
 }
 
 RecursiveTypeProperties SILBoxType::
@@ -605,10 +607,7 @@ getRecursivePropertiesFromSubstitutions(ArrayRef<Substitution> Params) {
 
 /// TODO: Transitional accessor for single-type boxes.
 CanType SILBoxType::getBoxedType() const {
-  auto layout = getLayout();
-  assert(layout->getFields().size() == 1
-         && layout->getGenericSignature()->getGenericParams().size() == 1
-         && layout->getFields()[0].getLoweredType()->is<GenericTypeParamType>()
+  assert(getLayout()->getFields().size() == 1
          && "is not a single-field box");
-  return CanType(getGenericArgs()[0].getReplacement());
+  return getFieldType(0).getSwiftRValueType();
 }
diff --git a/lib/SILGen/SILGenApply.cpp b/lib/SILGen/SILGenApply.cpp
index b56a230a9d8..4adb534a931 100644
--- a/lib/SILGen/SILGenApply.cpp
+++ b/lib/SILGen/SILGenApply.cpp
@@ -3846,7 +3846,7 @@ ManagedValue SILGenFunction::emitInjectEnum(SILLocation loc,
   if (element->isIndirect() ||
       element->getParentEnum()->isIndirect()) {
     auto *box = B.createAllocBox(loc, payloadTL.getLoweredType());
-    auto *addr = B.createProjectBox(loc, box);
+    auto *addr = B.createProjectBox(loc, box, 0);
 
     CleanupHandle initCleanup = enterDestroyCleanup(box);
     Cleanups.setCleanupState(initCleanup, CleanupState::Dormant);
diff --git a/lib/SILGen/SILGenDecl.cpp b/lib/SILGen/SILGenDecl.cpp
index f7fc1641017..9ff9ceeb885 100644
--- a/lib/SILGen/SILGenDecl.cpp
+++ b/lib/SILGen/SILGenDecl.cpp
@@ -286,7 +286,7 @@ public:
     // it using a box.
     AllocBoxInst *allocBox =
         SGF.B.createAllocBox(decl, lType, {decl->isLet(), ArgNo});
-    SILValue addr = SGF.B.createProjectBox(decl, allocBox);
+    SILValue addr = SGF.B.createProjectBox(decl, allocBox, 0);
 
     // Mark the memory as uninitialized, so DI will track it for us.
     if (NeedsMarkUninit)
@@ -723,7 +723,7 @@ emitEnumMatch(ManagedValue value, EnumElementDecl *ElementDecl,
 
   // If the payload is indirect, project it out of the box.
   if (ElementDecl->isIndirect() || ElementDecl->getParentEnum()->isIndirect()) {
-    SILValue boxedValue = SGF.B.createProjectBox(loc, eltMV.getValue());
+    SILValue boxedValue = SGF.B.createProjectBox(loc, eltMV.getValue(), 0);
     auto &boxedTL = SGF.getTypeLowering(boxedValue->getType());
     if (boxedTL.isLoadable())
       boxedValue = SGF.B.createLoad(loc, boxedValue);
diff --git a/lib/SILGen/SILGenFunction.cpp b/lib/SILGen/SILGenFunction.cpp
index e94b96e0d49..3b82db298f6 100644
--- a/lib/SILGen/SILGenFunction.cpp
+++ b/lib/SILGen/SILGenFunction.cpp
@@ -338,7 +338,7 @@ void SILGenFunction::emitCaptures(SILLocation loc,
         // in-place.
         AllocBoxInst *allocBox =
           B.createAllocBox(loc, vl.value->getType().getObjectType());
-        ProjectBoxInst *boxAddress = B.createProjectBox(loc, allocBox);
+        ProjectBoxInst *boxAddress = B.createProjectBox(loc, allocBox, 0);
         B.createCopyAddr(loc, vl.value, boxAddress, IsNotTake,IsInitialization);
         capturedArgs.push_back(emitManagedRValueWithCleanup(allocBox));
       }
diff --git a/lib/SILGen/SILGenPattern.cpp b/lib/SILGen/SILGenPattern.cpp
index 3491eea7df6..c4fa0416d71 100644
--- a/lib/SILGen/SILGenPattern.cpp
+++ b/lib/SILGen/SILGenPattern.cpp
@@ -1773,7 +1773,7 @@ emitEnumElementDispatch(ArrayRef<RowToSpecialize> rows,
       // If the payload is boxed, project it.
 
       if (elt->isIndirect() || elt->getParentEnum()->isIndirect()) {
-        SILValue boxedValue = SGF.B.createProjectBox(loc, origCMV.getValue());
+        SILValue boxedValue = SGF.B.createProjectBox(loc, origCMV.getValue(), 0);
         eltTL = &SGF.getTypeLowering(boxedValue->getType());
         if (eltTL->isLoadable())
           boxedValue = SGF.B.createLoad(loc, boxedValue);
diff --git a/lib/SILGen/SILGenProlog.cpp b/lib/SILGen/SILGenProlog.cpp
index 6e2544e8fef..742804b87c4 100644
--- a/lib/SILGen/SILGenProlog.cpp
+++ b/lib/SILGen/SILGenProlog.cpp
@@ -390,7 +390,7 @@ static void emitCaptureArguments(SILGenFunction &gen, CapturedValue capture,
     SILType boxTy = SILType::getPrimitiveObjectType(
       SILBoxType::get(ty.getSwiftRValueType()));
     SILValue box = new (gen.SGM.M) SILArgument(gen.F.begin(), boxTy, VD);
-    SILValue addr = gen.B.createProjectBox(VD, box);
+    SILValue addr = gen.B.createProjectBox(VD, box, 0);
     gen.VarLocs[VD] = SILGenFunction::VarLoc::get(addr, box);
     gen.B.createDebugValueAddr(Loc, addr, {/*Constant*/false, ArgNo});
     if (!gen.SGM.M.getOptions().EnableGuaranteedClosureContexts)
diff --git a/lib/SILOptimizer/IPO/CapturePromotion.cpp b/lib/SILOptimizer/IPO/CapturePromotion.cpp
index b5b08337f32..b5a20720872 100644
--- a/lib/SILOptimizer/IPO/CapturePromotion.cpp
+++ b/lib/SILOptimizer/IPO/CapturePromotion.cpp
@@ -949,7 +949,7 @@ processPartialApplyInst(PartialApplyInst *PAI, IndicesSet &PromotableIndices,
       // alloc_box. This makes sure that the project_box dominates the
       // partial_apply.
       if (!Addr)
-        Addr = getOrCreateProjectBox(ABI);
+        Addr = getOrCreateProjectBox(ABI, 0);
 
       auto &typeLowering = M.getTypeLowering(Addr->getType());
       Args.push_back(
diff --git a/lib/SILOptimizer/Mandatory/DefiniteInitialization.cpp b/lib/SILOptimizer/Mandatory/DefiniteInitialization.cpp
index 2e285aea91b..70076ae5d0f 100644
--- a/lib/SILOptimizer/Mandatory/DefiniteInitialization.cpp
+++ b/lib/SILOptimizer/Mandatory/DefiniteInitialization.cpp
@@ -1774,7 +1774,7 @@ void LifetimeChecker::processUninitializedRelease(SILInstruction *Release,
     // since the pointer it contains will be manually cleaned up.
     auto *ABI = dyn_cast<AllocBoxInst>(Release->getOperand(0));
     if (ABI)
-      Pointer = getOrCreateProjectBox(ABI);
+      Pointer = getOrCreateProjectBox(ABI, 0);
 
     if (!consumed) {
       if (Pointer->getType().isAddress())
diff --git a/lib/SILOptimizer/Transforms/AllocBoxToStack.cpp b/lib/SILOptimizer/Transforms/AllocBoxToStack.cpp
index 20daafed4aa..937071c303f 100644
--- a/lib/SILOptimizer/Transforms/AllocBoxToStack.cpp
+++ b/lib/SILOptimizer/Transforms/AllocBoxToStack.cpp
@@ -732,7 +732,7 @@ specializePartialApply(PartialApplyInst *PartialApply,
     // alloc_box. This makes sure that the project_box dominates the
     // partial_apply.
     if (!promoted)
-      promoted = getOrCreateProjectBox(box);
+      promoted = getOrCreateProjectBox(box, 0);
 
     Args.push_back(promoted);
 
diff --git a/lib/SILOptimizer/Utils/Local.cpp b/lib/SILOptimizer/Utils/Local.cpp
index 8088b17bcbe..92f142c079b 100644
--- a/lib/SILOptimizer/Utils/Local.cpp
+++ b/lib/SILOptimizer/Utils/Local.cpp
@@ -753,19 +753,19 @@ bool swift::canCastValueToABICompatibleType(SILModule &M,
   return Result.hasValue();
 }
 
-ProjectBoxInst *swift::getOrCreateProjectBox(AllocBoxInst *ABI) {
+ProjectBoxInst *swift::getOrCreateProjectBox(AllocBoxInst *ABI, unsigned Index){
   SILBasicBlock::iterator Iter(ABI);
   Iter++;
   assert(Iter != ABI->getParent()->end() &&
          "alloc_box cannot be the last instruction of a block");
   SILInstruction *NextInst = &*Iter;
   if (auto *PBI = dyn_cast<ProjectBoxInst>(NextInst)) {
-    if (PBI->getOperand() == ABI)
+    if (PBI->getOperand() == ABI && PBI->getFieldIndex() == Index)
       return PBI;
   }
 
   SILBuilder B(NextInst);
-  return B.createProjectBox(ABI->getLoc(), ABI);
+  return B.createProjectBox(ABI->getLoc(), ABI, Index);
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/lib/Serialization/DeserializeSIL.cpp b/lib/Serialization/DeserializeSIL.cpp
index 2378e46e8d2..cd81a31a371 100644
--- a/lib/Serialization/DeserializeSIL.cpp
+++ b/lib/Serialization/DeserializeSIL.cpp
@@ -802,7 +802,6 @@ bool SILDeserializer::readSILInstruction(
   ONETYPE_ONEOPERAND_INST(ExistentialMetatype)
   ONETYPE_ONEOPERAND_INST(AllocValueBuffer)
   ONETYPE_ONEOPERAND_INST(ProjectValueBuffer)
-  ONETYPE_ONEOPERAND_INST(ProjectBox)
   ONETYPE_ONEOPERAND_INST(ProjectExistentialBox)
   ONETYPE_ONEOPERAND_INST(DeallocValueBuffer)
 #undef ONETYPE_ONEOPERAND_INST
@@ -846,6 +845,17 @@ bool SILDeserializer::readSILInstruction(
   ONEOPERAND_ONETYPE_INST(ProjectBlockStorage)
 #undef ONEOPERAND_ONETYPE_INST
 
+  case ValueKind::ProjectBoxInst: {
+    assert(RecordKind == SIL_ONE_TYPE_ONE_OPERAND &&
+           "Layout should be OneTypeOneOperand.");
+    ResultVal = Builder.createProjectBox(Loc,
+                  getLocalValue(ValID,
+                    getSILType(MF->getType(TyID2),
+                               (SILValueCategory)TyCategory2)),
+                  TyID);
+    break;
+  }
+
   case ValueKind::PointerToAddressInst: {
     assert(RecordKind == SIL_ONE_TYPE_ONE_OPERAND &&
            "Layout should be OneTypeOneOperand.");
diff --git a/lib/Serialization/SerializeSIL.cpp b/lib/Serialization/SerializeSIL.cpp
index 96aa7c4021c..ed299011cfc 100644
--- a/lib/Serialization/SerializeSIL.cpp
+++ b/lib/Serialization/SerializeSIL.cpp
@@ -692,21 +692,31 @@ void SILSerializer::writeSILInstruction(const SILInstruction &SI) {
   case ValueKind::ProjectValueBufferInst: {
     auto PVBI = cast<ProjectValueBufferInst>(&SI);
     writeOneTypeOneOperandLayout(PVBI->getKind(), 0,
-                                 PVBI->getValueType(),
+                                 PVBI->getType(),
                                  PVBI->getOperand());
     break;
   }
   case ValueKind::ProjectBoxInst: {
     auto PBI = cast<ProjectBoxInst>(&SI);
-    writeOneTypeOneOperandLayout(PBI->getKind(), 0,
-                                 PBI->getValueType(),
-                                 PBI->getOperand());
+    
+    // Use SILOneTypeOneOperandLayout with the field index crammed in the TypeID
+    auto boxOperand = PBI->getOperand();
+    auto boxRef = addValueRef(boxOperand);
+    auto boxType = boxOperand->getType();
+    auto boxTypeRef = S.addTypeRef(boxType.getSwiftRValueType());
+    
+    SILOneTypeOneOperandLayout::emitRecord(Out, ScratchRecord,
+          SILAbbrCodes[SILOneTypeOneOperandLayout::Code],
+          unsigned(PBI->getKind()), 0,
+          PBI->getFieldIndex(), 0,
+          boxTypeRef, unsigned(boxType.getCategory()),
+          boxRef);
     break;
   }
   case ValueKind::ProjectExistentialBoxInst: {
     auto PEBI = cast<ProjectExistentialBoxInst>(&SI);
     writeOneTypeOneOperandLayout(PEBI->getKind(), 0,
-                                 PEBI->getValueType(),
+                                 PEBI->getType(),
                                  PEBI->getOperand());
     break;
   }
diff --git a/test/IRGen/dynamic_lookup.sil b/test/IRGen/dynamic_lookup.sil
index 2714a5d8e77..a6d55eec089 100644
--- a/test/IRGen/dynamic_lookup.sil
+++ b/test/IRGen/dynamic_lookup.sil
@@ -55,7 +55,7 @@ bb0(%0 : $X):
 sil @dynamic_lookup_br : $@convention(thin) (AnyObject) -> () {
 bb0(%0 : $AnyObject):
   %1 = alloc_box $AnyObject
-  %1a = project_box %1 : $@box AnyObject
+  %1a = project_box %1 : $@box AnyObject, 0
   store %0 to %1a : $*AnyObject
   %3 = alloc_box $Optional<() -> ()>              
   %4 = load %1a : $*AnyObject
@@ -104,7 +104,7 @@ bb3:
 sil @_T1t23dynamic_lookup_propertyFT1xPSo13AnyObject__T_ : $@convention(thin) (AnyObject) -> () {
   bb0(%0 : $AnyObject):
   %1 = alloc_box $AnyObject
-  %1a = project_box %1 : $@box AnyObject
+  %1a = project_box %1 : $@box AnyObject, 0
   store %0 to %1a : $*AnyObject
   %6 = load %1a : $*AnyObject                // users: %24, %8, %7
   strong_retain %6 : $AnyObject
@@ -127,9 +127,9 @@ bb3:
 sil @_T1t16opt_to_subscriptFT3objPSo13AnyObject_1iSi_T_ : $@convention(thin) (AnyObject, Int) -> () {
 bb0(%0 : $AnyObject, %1 : $Int):
   %2 = alloc_box $AnyObject
-  %2a = project_box %2 : $@box AnyObject
+  %2a = project_box %2 : $@box AnyObject, 0
   %3 = alloc_box $Int
-  %3a = project_box %3 : $@box Int
+  %3a = project_box %3 : $@box Int, 0
   store %0 to %2a : $*AnyObject
   store %1 to %3a : $*Int
   %8 = load %2a : $*AnyObject
diff --git a/test/IRGen/partial_apply.sil b/test/IRGen/partial_apply.sil
index 0c5a786145f..02aec159f98 100644
--- a/test/IRGen/partial_apply.sil
+++ b/test/IRGen/partial_apply.sil
@@ -560,7 +560,7 @@ entry:
   // CHECK: store %swift.refcounted* null
   // CHECK: store %swift.opaque* undef
   %b = alloc_box $()
-  %ba = project_box %b : $@box ()
+  %ba = project_box %b : $@box (), 0
   %f = function_ref @partial_empty_box : $@convention(thin) (@owned @box (), @inout ()) -> ()
   %g = partial_apply %f(%b, %ba) : $@convention(thin) (@owned @box (), @inout ()) -> ()
   return undef : $()
diff --git a/test/IRGen/typed_boxes.sil b/test/IRGen/typed_boxes.sil
index d0d86e823a2..f87c4cc3252 100644
--- a/test/IRGen/typed_boxes.sil
+++ b/test/IRGen/typed_boxes.sil
@@ -14,7 +14,7 @@ entry:
   // CHECK-64: [[BOX_RAW:%.*]] = bitcast %swift.refcounted* [[BOX]] to [[POD_8_8_LAYOUT:<\{ %swift.refcounted, \[8 x i8\] \}>]]*
   // CHECK-64: [[BOX_DATA:%.*]] = getelementptr inbounds [[POD_8_8_LAYOUT]], [[POD_8_8_LAYOUT]]* [[BOX_RAW]], i32 0, i32 1
   // CHECK: [[BOX_DATA_1:%.*]] = bitcast [8 x i8]* [[BOX_DATA]] to i64*
-  %b = project_box %a : $@box Builtin.Int64
+  %b = project_box %a : $@box Builtin.Int64, 0
   // CHECK: call void @swift_rt_swift_deallocObject(%swift.refcounted* [[BOX]], [[WORD]] 24, [[WORD]] 7)
   dealloc_box %a : $@box Builtin.Int64
   return undef : $()
@@ -30,7 +30,7 @@ entry:
   // CHECK-64: [[BOX_RAW:%.*]] = bitcast %swift.refcounted* [[BOX]] to [[POD_8_8_LAYOUT:<\{ %swift.refcounted, \[8 x i8\] \}>]]*
   // CHECK-64: [[BOX_DATA:%.*]] = getelementptr inbounds [[POD_8_8_LAYOUT]], [[POD_8_8_LAYOUT]]* [[BOX_RAW]], i32 0, i32 1
   // CHECK: [[BOX_DATA_1:%.*]] = bitcast [8 x i8]* [[BOX_DATA]] to double*
-  %b = project_box %a : $@box Builtin.FPIEEE64
+  %b = project_box %a : $@box Builtin.FPIEEE64, 0
   // CHECK: call void @swift_rt_swift_deallocObject(%swift.refcounted* [[BOX]], [[WORD]] 24, [[WORD]] 7)
   dealloc_box %a : $@box Builtin.FPIEEE64
   return undef : $()
@@ -50,7 +50,7 @@ entry:
   // CHECK-64: [[BOX_RAW:%.*]] = bitcast %swift.refcounted* [[BOX]] to [[POD_32_32_LAYOUT:<\{ %swift.refcounted, \[16 x i8\], \[32 x i8\] \}>]]*
   // CHECK: [[BOX_DATA:%.*]] = getelementptr inbounds [[POD_32_32_LAYOUT]], [[POD_32_32_LAYOUT]]* [[BOX_RAW]], i32 0, i32 2
   // CHECK: [[BOX_DATA_1:%.*]] = bitcast [32 x i8]* [[BOX_DATA]] to %V11typed_boxes11OverAligned*
-  %b = project_box %a : $@box OverAligned
+  %b = project_box %a : $@box OverAligned, 0
   // CHECK: call void @swift_rt_swift_deallocObject(%swift.refcounted* [[BOX]], [[WORD]] 64, [[WORD]] 31)
   dealloc_box %a : $@box OverAligned
   return undef : $()
@@ -69,7 +69,7 @@ entry:
   // CHECK-64: [[BOX:%.*]] = call noalias %swift.refcounted* @swift_rt_swift_allocObject(%swift.type* {{.*}} [[NATIVE_RC_METADATA:@metadata[0-9.]*]], {{.*}} [[WORD]] 24, [[WORD]] 7)
   %a = alloc_box $C
   // CHECK: bitcast %swift.refcounted** {{%.*}} to %C11typed_boxes1C**
-  %b = project_box %a : $@box C
+  %b = project_box %a : $@box C, 0
   dealloc_box %a : $@box C
   return undef : $()
 }
@@ -82,7 +82,7 @@ entry:
   // CHECK-64: [[BOX:%.*]] = call noalias %swift.refcounted* @swift_rt_swift_allocObject(%swift.type* {{.*}} [[NATIVE_RC_METADATA]], {{.*}} [[WORD]] 24, [[WORD]] 7)
   %a = alloc_box $D
   // CHECK: bitcast %swift.refcounted** {{%.*}} to %C11typed_boxes1D**
-  %b = project_box %a : $@box D
+  %b = project_box %a : $@box D, 0
   dealloc_box %a : $@box D
   return undef : $()
 }
@@ -93,7 +93,7 @@ entry:
   // CHECK-32: [[BOX:%.*]] = call noalias %swift.refcounted* @swift_rt_swift_allocObject(%swift.type* {{.*}} [[UNKNOWN_RC_METADATA:@metadata[0-9.]*]], {{.*}} [[WORD]] 16, [[WORD]] 3)
   // CHECK-64: [[BOX:%.*]] = call noalias %swift.refcounted* @swift_rt_swift_allocObject(%swift.type* {{.*}} [[UNKNOWN_RC_METADATA:@metadata[0-9.]*]], {{.*}} [[WORD]] 24, [[WORD]] 7)
   %a = alloc_box $Builtin.UnknownObject
-  %b = project_box %a : $@box Builtin.UnknownObject
+  %b = project_box %a : $@box Builtin.UnknownObject, 0
   dealloc_box %a : $@box Builtin.UnknownObject
   return undef : $()
 }
@@ -107,7 +107,7 @@ struct Fixed {
 sil @fixed_box : $@convention(thin) () -> () {
 entry:
   %a = alloc_box $Fixed
-  %b = project_box %a : $@box Fixed
+  %b = project_box %a : $@box Fixed, 0
   dealloc_box %a : $@box Fixed
   return undef : $()
 }
@@ -130,7 +130,7 @@ entry:
   // CHECK: [[PTR:%.*]] = extractvalue { %swift.refcounted*, %swift.opaque* } [[ALLOC]], 1
   %a = alloc_box $Dyn<T>
   // CHECK: [[CAST_PTR:%.*]] = bitcast %swift.opaque* [[PTR]] to %V11typed_boxes3Dyn*
-  %b = project_box %a : $@box Dyn<T>
+  %b = project_box %a : $@box Dyn<T>, 0
   %f = function_ref @take_dyn : $@convention(thin) <T> (@in Dyn<T>) -> ()
   // CHECK: call void @take_dyn(%V11typed_boxes3Dyn* {{[^,]*}} [[CAST_PTR]], {{.*}})
   %t = apply %f<T>(%b) : $@convention(thin) <T> (@in Dyn<T>) -> ()
@@ -146,7 +146,7 @@ entry:
   // CHECK: [[BOX:%.*]] = extractvalue { %swift.refcounted*, %swift.opaque* } [[ALLOC]], 0
   // CHECK: [[PTR:%.*]] = extractvalue { %swift.refcounted*, %swift.opaque* } [[ALLOC]], 1
   %a = alloc_box $T
-  %b = project_box %a : $@box T
+  %b = project_box %a : $@box T, 0
   %f = function_ref @take_t : $@convention(thin) <T> (@in T) -> ()
   // CHECK: call void @take_t(%swift.opaque* {{[^,]*}} [[PTR]], {{.*}})
   %t = apply %f<T>(%b) : $@convention(thin) <T> (@in T) -> ()
@@ -163,7 +163,7 @@ entry(%0 : $@box Builtin.Int64):
   // CHECK-64: [[BOX_RAW:%.*]] = bitcast %swift.refcounted* %0 to [[POD_8_8_LAYOUT:<\{ %swift.refcounted, \[8 x i8\] \}>]]*
   // CHECK-64: [[BOX_DATA:%.*]] = getelementptr inbounds [[POD_8_8_LAYOUT]], [[POD_8_8_LAYOUT]]* [[BOX_RAW]], i32 0, i32 1
   // CHECK: [[BOX_DATA_1:%.*]] = bitcast [8 x i8]* [[BOX_DATA]] to i64*
-  %p = project_box %0 : $@box Builtin.Int64
+  %p = project_box %0 : $@box Builtin.Int64, 0
   // CHECK: [[R:%.*]] = load i64, i64* [[BOX_DATA_1]]
   %l = load %p : $*Builtin.Int64
   // CHECK: ret i64 [[R]]
@@ -175,7 +175,7 @@ sil @dyn_proj_box_a : $@convention(thin) <T> (@box Dyn<T>) -> () {
 entry(%0 : $@box Dyn<T>):
   // CHECK: [[PTR:%.*]] = call %swift.opaque* @swift_projectBox(%swift.refcounted* %0)
   // CHECK: [[BOX_DATA_1:%.*]] = bitcast %swift.opaque* [[PTR]] to %V11typed_boxes3Dyn*
-  %p = project_box %0 : $@box Dyn<T>
+  %p = project_box %0 : $@box Dyn<T>, 0
   %f = function_ref @take_dyn : $@convention(thin) <T> (@in Dyn<T>) -> ()
   // CHECK: call void @take_dyn(%V11typed_boxes3Dyn* {{[^,]*}} [[BOX_DATA_1]], {{.*}})
   %t = apply %f<T>(%p) : $@convention(thin) <T> (@in Dyn<T>) -> ()
@@ -187,7 +187,7 @@ entry(%0 : $@box Dyn<T>):
 sil @dyn_proj_box_b : $@convention(thin) <T> (@box T) -> () {
 entry(%0 : $@box T):
   // CHECK: [[PTR:%.*]] = call %swift.opaque* @swift_projectBox(%swift.refcounted* %0)
-  %p = project_box %0 : $@box T
+  %p = project_box %0 : $@box T, 0
   %f = function_ref @take_t : $@convention(thin) <T> (@in T) -> ()
   // CHECK: call void @take_t(%swift.opaque* {{[^,]*}} [[PTR]], {{.*}})
   %t = apply %f<T>(%p) : $@convention(thin) <T> (@in T) -> ()
diff --git a/test/SIL/Parser/apply_with_substitution.sil b/test/SIL/Parser/apply_with_substitution.sil
index 25488e744ea..f2a3ba1f8b6 100644
--- a/test/SIL/Parser/apply_with_substitution.sil
+++ b/test/SIL/Parser/apply_with_substitution.sil
@@ -10,7 +10,7 @@ import Swift
 sil @_TF4test3fooFT1fGSqFT_T___T_ : $@convention(thin) (@owned Optional<@callee_owned (@in ()) -> @out ()>) -> () {
 bb0(%0 : $Optional<@callee_owned (@in ()) -> @out ()>):
   %1 = alloc_box $Optional<@callee_owned (@in ()) -> @out ()>  // var f    // users: %2, %6, %32
-  %1a = project_box %1 : $@box Optional<@callee_owned (@in ()) -> @out ()>
+  %1a = project_box %1 : $@box Optional<@callee_owned (@in ()) -> @out ()>, 0
   store %0 to %1a : $*Optional<@callee_owned (@in ()) -> @out ()>         // id: %2
   %3 = alloc_stack $Optional<()>                  // users: %22, %28, %30, %31
   %4 = alloc_stack $()                            // users: %12, %22, %25
diff --git a/test/SIL/Parser/basic.sil b/test/SIL/Parser/basic.sil
index 7096718e219..5a92ab3151a 100644
--- a/test/SIL/Parser/basic.sil
+++ b/test/SIL/Parser/basic.sil
@@ -66,7 +66,7 @@ bb1:
 bb2:
   %5 = tuple ()                                // CHECK:   %5 = tuple ()
   %6 = alloc_box $Int                          // CHECK:   %6 = alloc_box $Int
-  %7 = project_box %6 : $@box Int              // CHECK:   %7 = project_box %6 : $@box Int
+  %7 = project_box %6 : $@box Int, 0           // CHECK:   %7 = project_box %6 : $@box Int
 
   br bb1                                       // CHECK:   br bb1
 }
@@ -284,7 +284,7 @@ sil @_T4todo18erasure_from_protoFT1xPS_8RuncibleS_8Bendable__PS0__ : $@conventio
 bb0(%0 : $*Runcible, %1 : $*Bendable & Runcible):
   // CHECK: alloc_box
   %2 = alloc_box $Bendable & Runcible
-  %2a = project_box %2 : $@box Bendable & Runcible
+  %2a = project_box %2 : $@box Bendable & Runcible, 0
   // CHECK: copy_addr [take] {{.*}} to [initialization] {{.*}} : $*Bendable & Runcible
   %3 = copy_addr [take] %1 to [initialization] %2a : $*Bendable & Runcible
   // CHECK: alloc_stack
@@ -310,7 +310,7 @@ protocol ClassBound : class {
 sil @_T4todo18class_bound_methodFT1xPS_10ClassBound__T_ : $@convention(thin) (ClassBound) -> () {
 bb0(%0 : $ClassBound):
   %1 = alloc_box $ClassBound                // CHECK: alloc_box
-  %1a = project_box %1 : $@box ClassBound
+  %1a = project_box %1 : $@box ClassBound, 0
   %2 = store %0 to %1a : $*ClassBound      // CHECK: store
   %3 = load %1a : $*ClassBound             // CHECK: load
   %4 = strong_retain %3 : $ClassBound              // CHECK: strong_retain
@@ -356,7 +356,7 @@ sil @_TV6struct5AlephCfMS0_FT_S0_ : $@convention(thin) (@thin Aleph.Type) -> Ale
 bb0(%0 : $@thin Aleph.Type):
   %1 = tuple ()
   %2 = alloc_box $Aleph       // CHECK: alloc_box
-  %2a = project_box %2 : $@box Aleph
+  %2a = project_box %2 : $@box Aleph, 0
   // CHECK: struct_element_addr {{.*}} : $*Aleph, #Aleph.a
   %5 = struct_element_addr %2a : $*Aleph, #Aleph.a
   %6 = load %5 : $*Ref
@@ -422,7 +422,7 @@ sil @_T5tuple5tupleFT_TSiSf_ : $@convention(thin) () -> (Int, Float32)
 sil @_T5tuple13tuple_elementFT1xTSiSf__T_ : $@convention(thin) (Int, Float) -> () {
 bb0(%0 : $Int, %1 : $Float):
   %2 = alloc_box $(Int, Float)
-  %2a = project_box %2 : $@box (Int, Float)
+  %2a = project_box %2 : $@box (Int, Float), 0
   // CHECK: tuple ({{%.*}} : $Int, {{%.*}} : $Float)
   %3 = tuple (%0 : $Int, %1 : $Float)
   %4 = store %3 to %2a : $*(Int, Float)
@@ -458,10 +458,10 @@ class M {
 sil @_TC3ref1C3foofS0_FT1xSi_T_ : $@convention(method) (Int, M) -> () {
 bb0(%0 : $Int, %1 : $M):
   %2 = alloc_box $Int     // CHECK: alloc_box $Int
-  %2a = project_box %2 : $@box Int
+  %2a = project_box %2 : $@box Int, 0
   %3 = store %0 to %2a : $*Int
   %4 = alloc_box $M         // CHECK: alloc_box $M
-  %4a = project_box %4 : $@box M
+  %4a = project_box %4 : $@box M, 0
   %5 = store %1 to %4a : $*M
   %6 = load %2a : $*Int  // CHECK: load {{.*}} : $*Int
   %7 = load %4a : $*M      // CHECK: load {{.*}} : $*M
@@ -498,7 +498,7 @@ class E : B { }
 sil @_T4null3isaFT1bCS_1B_Sb : $@convention(thin) (B) -> Builtin.Int1 {
 bb0(%0 : $B):
   %1 = alloc_box $B                           // CHECK: alloc_box
-  %1a = project_box %1 : $@box B
+  %1a = project_box %1 : $@box B, 0
   %2 = store %0 to %1a : $*B
   %3 = load %1a : $*B                        // CHECK: load
   %4 = strong_retain %3 : $B
@@ -522,9 +522,9 @@ sil @_TSS32_convertFromBuiltinStringLiteralfMSSFT5valueBp17utf8CodeUnitCountBi64
 sil @_T5index5gep64FT1pBp1iBi64__Bp : $@convention(thin) (Builtin.RawPointer, Builtin.Word) -> Builtin.RawPointer {
 bb0(%0 : $Builtin.RawPointer, %1 : $Builtin.Word):
   %2 = alloc_box $Builtin.RawPointer              // CHECK: alloc_box
-  %2a = project_box %2 : $@box Builtin.RawPointer
+  %2a = project_box %2 : $@box Builtin.RawPointer, 0
   %3 = alloc_box $Builtin.Word                   // CHECK: alloc_box
-  %3a = project_box %3 : $@box Builtin.Word
+  %3a = project_box %3 : $@box Builtin.Word, 0
   %4 = store %0 to %2a : $*Builtin.RawPointer
   %5 = store %1 to %3a : $*Builtin.Word
   %7 = load %2a : $*Builtin.RawPointer           // CHECK: load
@@ -564,9 +564,9 @@ class SomeSubclass : SomeClass {}
 sil @test_class_metatype : $@convention(thin) (SomeClass, SomeSubclass) -> (@thick SomeClass.Type, @thick SomeClass.Type) {
 bb0(%0 : $SomeClass, %1 : $SomeSubclass):
   %2 = alloc_box $SomeClass                       // CHECK: alloc_box
-  %2a = project_box %2 : $@box SomeClass
+  %2a = project_box %2 : $@box SomeClass, 0
   %3 = alloc_box $SomeSubclass                    // CHECK: alloc_box
-  %3a = project_box %3 : $@box SomeSubclass
+  %3a = project_box %3 : $@box SomeSubclass, 0
   %4 = store %0 to %2a : $*SomeClass
   %5 = store %1 to %3a : $*SomeSubclass
   %7 = load %2a : $*SomeClass                    // CHECK: load
@@ -589,7 +589,7 @@ bb0(%0 : $SomeClass, %1 : $SomeSubclass):
 sil @test_value_metatype : $@convention(thin) <T> (@in T) -> (@thick T.Type, @thick T.Type) {
 bb0(%0 : $*T):
   %1 = alloc_box $T                               // CHECK: alloc_box
-  %1a = project_box %1 : $@box T
+  %1a = project_box %1 : $@box T, 0
   %2 = copy_addr [take] %0 to [initialization] %1a : $*T
   %3 = metatype $@thick T.Type                       // CHECK: metatype
   %5 = alloc_stack $T                               // CHECK: alloc_stack
@@ -606,7 +606,7 @@ bb0(%0 : $*T):
 sil @test_existential_metatype : $@convention(thin) (@in SomeProtocol) -> @thick SomeProtocol.Type {
 bb0(%0 : $*SomeProtocol):
   %1 = alloc_box $SomeProtocol                    // CHECK: alloc_box
-  %1a = project_box %1 : $@box SomeProtocol
+  %1a = project_box %1 : $@box SomeProtocol, 0
   %2 = copy_addr [take] %0 to [initialization] %1a : $*SomeProtocol
   %4 = alloc_stack $SomeProtocol                    // CHECK: alloc_stack
   %5 = copy_addr %1a to [initialization] %4 : $*SomeProtocol
@@ -673,9 +673,9 @@ bb3(%4 : $Int):
 sil @test_builtin : $@convention(thin) (Builtin.Int1, Builtin.Int1) -> Builtin.Int1 {
 bb0(%0 : $Builtin.Int1, %1 : $Builtin.Int1):
   %2 = alloc_box $Builtin.Int1
-  %2a = project_box %2 : $@box Builtin.Int1
+  %2a = project_box %2 : $@box Builtin.Int1, 0
   %3 = alloc_box $Builtin.Int1
-  %3a = project_box %3 : $@box Builtin.Int1
+  %3a = project_box %3 : $@box Builtin.Int1, 0
   store %0 to %2a : $*Builtin.Int1
   store %1 to %3a : $*Builtin.Int1
   %8 = load %2a : $*Builtin.Int1
@@ -766,7 +766,7 @@ sil @closure0 : $@convention(thin) (@box Int, @inout Int) -> ()
 sil @closure_test : $@convention(thin) () -> () {
 bb0:
   %0 = alloc_box $Int                           // users: %10, %8, %8, %7, %4
-  %0a = project_box %0 : $@box Int
+  %0a = project_box %0 : $@box Int, 0
 
   %5 = function_ref @takes_closure : $@convention(thin) (@callee_owned () -> ()) -> ()
   %6 = function_ref @closure0 : $@convention(thin) (@box Int, @inout Int) -> ()
@@ -807,7 +807,7 @@ sil @_T6switch1cFT_T_ : $@convention(thin) () -> ()
 sil @test_switch_union : $@convention(thin) (MaybePair) -> () {
 bb0(%0 : $MaybePair):
   %1 = alloc_box $MaybePair
-  %1a = project_box %1 : $@box MaybePair
+  %1a = project_box %1 : $@box MaybePair, 0
   store %0 to %1a : $*MaybePair
   %3 = load %1a : $*MaybePair
   %4 = tuple ()
@@ -969,7 +969,7 @@ struct Spoon : Bendable {
 sil @test_init_existential : $@convention(thin) (Spoon) -> @out Bendable {
 bb0(%0 : $*Bendable, %1 : $Spoon):
   %2 = alloc_box $Spoon
-  %2a = project_box %2 : $@box Spoon
+  %2a = project_box %2 : $@box Spoon, 0
   store %1 to %2a : $*Spoon
   // CHECK: init_existential_addr %{{.*}} : $*Bendable, $Spoon
   %4 = init_existential_addr %0 : $*Bendable, $Spoon
@@ -986,7 +986,7 @@ bb0(%0 : $*Bendable, %1 : $Spoon):
 sil @test_existential_ref : $@convention(thin) (ConcreteClass) -> ClassP {
 bb0(%0 : $ConcreteClass):
   %1 = alloc_box $ConcreteClass
-  %1a = project_box %1 : $@box ConcreteClass
+  %1a = project_box %1 : $@box ConcreteClass, 0
   store %0 to %1a : $*ConcreteClass
   %3 = load %1a : $*ConcreteClass
   strong_retain %3 : $ConcreteClass
@@ -1041,7 +1041,7 @@ class X {
 sil @test_dynamic_lookup_br : $@convention(thin) (AnyObject) -> () {
 bb0(%0 : $AnyObject):
   %1 = alloc_box $AnyObject
-  %1a = project_box %1 : $@box AnyObject
+  %1a = project_box %1 : $@box AnyObject, 0
   store %0 to %1a : $*AnyObject
   %3 = alloc_box $Optional<() -> ()>
   %4 = load %1a : $*AnyObject
@@ -1063,9 +1063,9 @@ bb3:
 // CHECK-LABEL: sil @test_mark_fn_escape
 sil @test_mark_fn_escape : $() -> () {
   %b = alloc_box $Int
-  %ba = project_box %b : $@box Int
+  %ba = project_box %b : $@box Int, 0
   %c = alloc_box $Int
-  %ca = project_box %c : $@box Int
+  %ca = project_box %c : $@box Int, 0
 
   // CHECK: mark_function_escape {{.*}} : $*Int
   mark_function_escape %ba : $*Int
@@ -1458,8 +1458,8 @@ sil @box_type : $@convention(thin) (@box Int, Int) -> () {
 bb0(%0 : $@box Int, %1 : $Int):
   // CHECK-NEXT: strong_retain %0 : $@box Int
   strong_retain %0 : $@box Int
-  // CHECK-NEXT: %3 = project_box %0 : $@box Int
-  %3 = project_box %0 : $@box Int
+  // CHECK-NEXT: %3 = project_box %0 : $@box Int, 0
+  %3 = project_box %0 : $@box Int, 0
   // CHECK-NEXT: store %1 to %3 : $*Int
   store %1 to %3 : $*Int
   // CHECK-NEXT: strong_release %0 : $@box Int
diff --git a/test/SIL/Parser/bound_generic.sil b/test/SIL/Parser/bound_generic.sil
index 489f9a9f9a4..6004cd7d52f 100644
--- a/test/SIL/Parser/bound_generic.sil
+++ b/test/SIL/Parser/bound_generic.sil
@@ -10,7 +10,7 @@ import Swift
 sil @_TF9optional3fooFT1fGSqFT_T___T_ : $@convention(thin) (@owned Optional<@callee_owned (@in ()) -> (@out ())>) -> () {
 bb0(%0 : $Optional<@callee_owned (@in ()) -> (@out ())>):
   %1 = alloc_box $Optional<@callee_owned (@in ()) -> (@out ())> 
-  %1a = project_box %1 : $@box Optional<@callee_owned (@in ()) -> (@out ())>
+  %1a = project_box %1 : $@box Optional<@callee_owned (@in ()) -> (@out ())>, 0
   store %0 to %1a : $*Optional<@callee_owned (@in ()) -> (@out ())>
   %3 = alloc_stack $Optional<()>
   %4 = alloc_stack $()
diff --git a/test/SIL/Parser/global_init_attribute.sil b/test/SIL/Parser/global_init_attribute.sil
index 3f7bdb27bd4..2a3bedd6e27 100644
--- a/test/SIL/Parser/global_init_attribute.sil
+++ b/test/SIL/Parser/global_init_attribute.sil
@@ -15,7 +15,7 @@ import Swift
 sil [global_init] @_TF1gau5MyVarSi : $@convention(thin) () -> Builtin.RawPointer {
 bb0:
   %b = alloc_box $Int
-  %ba = project_box %b : $@box Int
+  %ba = project_box %b : $@box Int, 0
   %p = address_to_pointer %ba : $*Int to $Builtin.RawPointer
   return %p : $Builtin.RawPointer
 }
diff --git a/test/SIL/Parser/indirect_enum.sil b/test/SIL/Parser/indirect_enum.sil
index 572fe3f3f21..93be86f373f 100644
--- a/test/SIL/Parser/indirect_enum.sil
+++ b/test/SIL/Parser/indirect_enum.sil
@@ -24,10 +24,10 @@ enum TreeInt {
 sil @indirect_enum : $@convention(thin) <T> (@owned TreeA<T>) -> () {
 entry(%e : $TreeA<T>):
   %a = unchecked_enum_data %e : $TreeA<T>, #TreeA.Leaf!enumelt.1
-  %b = project_box %a : $@box T
+  %b = project_box %a : $@box T, 0
 
   %c = unchecked_enum_data %e : $TreeA<T>, #TreeA.Branch!enumelt.1
-  %d = project_box %c : $@box (left: TreeA<T>, right: TreeA<T>)
+  %d = project_box %c : $@box (left: TreeA<T>, right: TreeA<T>), 0
 
   return undef : $()
 }
@@ -49,7 +49,7 @@ entry(%e : $TreeInt):
   store %a to undef : $*Int
 
   %c = unchecked_enum_data %e : $TreeInt, #TreeInt.Branch!enumelt.1
-  %d = project_box %c : $@box (left: TreeInt, right: TreeInt)
+  %d = project_box %c : $@box (left: TreeInt, right: TreeInt), 0
 
   return undef : $()
 }
diff --git a/test/SIL/Parser/overloaded_member.sil b/test/SIL/Parser/overloaded_member.sil
index de9e8007662..b1977cfb632 100644
--- a/test/SIL/Parser/overloaded_member.sil
+++ b/test/SIL/Parser/overloaded_member.sil
@@ -19,9 +19,9 @@ struct A {
 sil @_TFCSo1XcfMS_FT1aV11peer_method1A_S_ : $@convention(method) (A, @owned X) -> @owned X {
 bb0(%0 : $A, %1 : $X):
   %2 = alloc_box $X
-  %2a = project_box %2 : $@box X
+  %2a = project_box %2 : $@box X, 0
   %3 = alloc_box $A
-  %3a = project_box %3 : $@box A
+  %3a = project_box %3 : $@box A, 0
   store %0 to %3a : $*A
   %5 = mark_uninitialized [delegatingself] %1 : $X
   store %5 to %2a : $*X
diff --git a/test/SIL/Parser/typed_boxes.sil b/test/SIL/Parser/typed_boxes.sil
index 18d950584f9..fede1984737 100644
--- a/test/SIL/Parser/typed_boxes.sil
+++ b/test/SIL/Parser/typed_boxes.sil
@@ -7,8 +7,8 @@ sil @alloc_dealloc : $@convention(thin) (Int) -> () {
 entry(%x : $Int):
   // CHECK: [[B:%.*]] = alloc_box $Int
   %b = alloc_box $Int
-  // CHECK: [[PB:%.*]] = project_box [[B]] : $@box Int
-  %ba = project_box %b : $@box Int
+  // CHECK: [[PB:%.*]] = project_box [[B]] : $@box Int, 0
+  %ba = project_box %b : $@box Int, 0
   // CHECK: store [[X:%.*]] to [[PB]] : $*Int
   store %x to %ba : $*Int
   // CHECK: dealloc_box [[B]] : $@box Int
diff --git a/test/SILOptimizer/allocbox_to_stack.sil b/test/SILOptimizer/allocbox_to_stack.sil
index d138cd067c8..bf502bcb618 100644
--- a/test/SILOptimizer/allocbox_to_stack.sil
+++ b/test/SILOptimizer/allocbox_to_stack.sil
@@ -14,7 +14,7 @@ struct Bool {
 sil @simple_promotion : $(Int) -> Int {
 bb0(%0 : $Int):
   %1 = alloc_box $Int
-  %1a = project_box %1 : $@box Int
+  %1a = project_box %1 : $@box Int, 0
   %2 = store %0 to %1a : $*Int
   %3 = load %1a : $*Int
   %4 = strong_release %1 : $@box Int
@@ -30,10 +30,10 @@ bb0(%0 : $Int):
 sil @double_project_box : $(Int) -> (Int, Int) {
 bb0(%0 : $Int):
   %1 = alloc_box $Int
-  %1a = project_box %1 : $@box Int
+  %1a = project_box %1 : $@box Int, 0
   %2 = store %0 to %1a : $*Int
   %3 = load %1a : $*Int
-  %1b = project_box %1 : $@box Int
+  %1b = project_box %1 : $@box Int, 0
   %3b = load %1b : $*Int
   %4 = strong_release %1 : $@box Int
   %r = tuple (%3 : $Int, %3b : $Int)
@@ -49,7 +49,7 @@ bb0(%0 : $Int):
 sil @init_var : $() -> Int {
 bb0:
   %1 = alloc_box $Int
-  %1a = project_box %1 : $@box Int
+  %1a = project_box %1 : $@box Int, 0
   %3 = load %1a : $*Int
   %4 = strong_release %1 : $@box Int
   %5 = return %3 : $Int
@@ -66,7 +66,7 @@ bb0:
 sil @multi_strong_release : $() -> Int {
 bb0:
   %1 = alloc_box $Int
-  %1a = project_box %1 : $@box Int
+  %1a = project_box %1 : $@box Int, 0
   %2 = mark_uninitialized [rootself] %1a : $*Int
   %3 = load %2 : $*Int
   %x = strong_retain %1 : $@box Int
@@ -93,9 +93,9 @@ bb1(%0 : $Int):
 // CHECK-DAG: [[STRUCT:%.*]] = alloc_stack $TestStruct
 // CHECK-DAG: [[TUPLE:%.*]] = alloc_stack $(Int, Int)
   %1 = alloc_box $TestStruct
-  %1a = project_box %1 : $@box TestStruct
+  %1a = project_box %1 : $@box TestStruct, 0
   %a = alloc_box $(Int, Int)
-  %aa = project_box %a : $@box (Int, Int)
+  %aa = project_box %a : $@box (Int, Int), 0
   
   %2 = struct_element_addr %1a : $*TestStruct, #TestStruct.Elt
   %3 = store %0 to %2 : $*Int
@@ -126,7 +126,7 @@ sil @inout_nocapture : $@convention(thin) () -> Int {
 bb0:
   // CHECK: alloc_stack
   %1 = alloc_box $Int
-  %1a = project_box %1 : $@box Int
+  %1a = project_box %1 : $@box Int, 0
   %6 = function_ref @callee : $@convention(thin) (@inout Int) -> ()
   %7 = apply %6(%1a) : $@convention(thin) (@inout Int) -> ()
   %8 = load %1a : $*Int
@@ -150,7 +150,7 @@ bb0:
   // CHECK: alloc_stack
   %1 = function_ref @returns_protocol : $@convention(thin) () -> @out P
   %2 = alloc_box $P
-  %2a = project_box %2 : $@box P
+  %2a = project_box %2 : $@box P, 0
   %3 = apply %1(%2a) : $@convention(thin) () -> @out P
   %5 = strong_release %2 : $@box P
   %0 = tuple ()
@@ -164,7 +164,7 @@ class SomeClass {}
 sil @class_promotion : $(SomeClass) -> SomeClass {
 bb0(%0 : $SomeClass):
   %1 = alloc_box $SomeClass
-  %1a = project_box %1 : $@box SomeClass
+  %1a = project_box %1 : $@box SomeClass, 0
   %2 = store %0 to %1a : $*SomeClass
   %3 = load %1a : $*SomeClass
   %4 = strong_release %1 : $@box SomeClass
@@ -185,7 +185,7 @@ protocol LogicValue {
 sil @protocols : $@convention(thin) (@in LogicValue, @thin Bool.Type) -> Bool {
 bb0(%0 : $*LogicValue, %1 : $@thin Bool.Type):
   %2 = alloc_box $LogicValue
-  %2a = project_box %2 : $@box LogicValue
+  %2a = project_box %2 : $@box LogicValue, 0
 // CHECK:  %2 = alloc_stack $LogicValue
   copy_addr [take] %0 to [initialization] %2a : $*LogicValue
   %6 = open_existential_addr %2a : $*LogicValue to $*@opened("01234567-89ab-cdef-0123-000000000000") LogicValue
@@ -230,7 +230,7 @@ sil @union_test : $@convention(thin) () -> () {
 bb0:
 // CHECK: [[UNION:%.*]] = alloc_stack
   %1 = alloc_box $SomeUnion
-  %1a = project_box %1 : $@box SomeUnion
+  %1a = project_box %1 : $@box SomeUnion, 0
   %2 = function_ref @_TO1t9SomeUnion1yfMS0_FCS_9SomeClassS0_ : $@convention(thin) (@owned SomeClass, @thin SomeUnion.Type) -> @owned SomeUnion // user: %7
   %3 = metatype $@thin SomeUnion.Type
   %4 = function_ref @_TC1t9SomeClassCfMS0_FT_S0_ : $@convention(thin) (@thick SomeClass.Type) -> @owned SomeClass // user: %6
@@ -250,7 +250,7 @@ bb0:
 sil @multiple_release_test : $@convention(thin) (Bool) -> Bool {
 bb0(%0 : $Bool):
   %1 = alloc_box $Bool
-  %1a = project_box %1 : $@box Bool
+  %1a = project_box %1 : $@box Bool, 0
   store %0 to %1a : $*Bool
   strong_retain %1 : $@box Bool
   strong_retain %1 : $@box Bool
@@ -313,7 +313,7 @@ extension Int : My_Incrementable { }
 sil @test_mui : $@convention(thin) (Builtin.Int1) -> () {
 bb0(%0 : $Builtin.Int1):
   %2 = alloc_box $SomeClass
-  %2a = project_box %2 : $@box SomeClass
+  %2a = project_box %2 : $@box SomeClass, 0
   // CHECK: [[STACK:%[0-9]+]] = alloc_stack
   %3 = mark_uninitialized [var] %2a : $*SomeClass
   // CHECK: [[MUI:%[0-9]+]] = mark_uninitialized
@@ -373,7 +373,7 @@ bb0(%0 : $Int):
   debug_value %0 : $Int, let, name "t" // id: %1
   // CHECK: alloc_stack
   %2 = alloc_box $Int, var, name "s"                   // users: %3, %6, %7, %7, %9
-  %2a = project_box %2 : $@box Int
+  %2a = project_box %2 : $@box Int, 0
   store %0 to %2a : $*Int                        // id: %3
   // function_ref struct.apply (f : () -> Swift.Int) -> Swift.Int
   %4 = function_ref @_TF6struct5applyFT1fFT_Si_Si : $@convention(thin) (@owned @callee_owned () -> Int) -> Int // user: %8
@@ -394,7 +394,7 @@ bb0(%0 : $Int):
 // struct.(useStack (t : Swift.Int) -> ()).(closure #1)
 sil private @_TFF6struct8useStackFT1tSi_T_U_FT_Si : $@convention(thin) (@owned @box Int) -> Int {
 bb0(%0 : $@box Int):
-  %1 = project_box %0 : $@box Int
+  %1 = project_box %0 : $@box Int, 0
   // function_ref Swift.++ @postfix <A : Swift._Incrementable>(x : @inout A) -> A
   %2 = function_ref @_TFsoP2ppUs14_Incrementable__FT1xRQ__Q_ : $@convention(thin) <τ_0_0 where τ_0_0 : My_Incrementable> (@inout τ_0_0) -> @out τ_0_0 // user: %4
   %3 = alloc_stack $Int                           // users: %4, %5, %6
@@ -415,7 +415,7 @@ bb0(%0 : $Int):
   debug_value %0 : $Int, let, name "t" // id: %1
   // CHECK: alloc_box
   %2 = alloc_box $Int, var, name "s"                   // users: %3, %6, %7, %7, %10
-  %2a = project_box %2 : $@box Int
+  %2a = project_box %2 : $@box Int, 0
   store %0 to %2a : $*Int                        // id: %3
   // function_ref struct.escape (f : () -> Swift.Int) -> () -> Swift.Int
   %4 = function_ref @_TF6struct6escapeFT1fFT_Si_FT_Si : $@convention(thin) (@owned @callee_owned () -> Int) -> @owned @callee_owned () -> Int // user: %8
@@ -434,7 +434,7 @@ bb0(%0 : $Int):
 // struct.(useBox (t : Swift.Int) -> ()).(closure #1)
 sil private @_TFF6struct6useBoxFT1tSi_T_U_FT_Si : $@convention(thin) (@owned @box Int) -> Int {
 bb0(%0 : $@box Int):
-  %1 = project_box %0 : $@box Int
+  %1 = project_box %0 : $@box Int, 0
   // function_ref Swift.++ @postfix <A : Swift._Incrementable>(x : @inout A) -> A
   %2 = function_ref @_TFsoP2ppUs14_Incrementable__FT1xRQ__Q_ : $@convention(thin) <τ_0_0 where τ_0_0 : My_Incrementable> (@inout τ_0_0) -> @out τ_0_0 // user: %4
   %3 = alloc_stack $Int                           // users: %4, %5, %6
@@ -452,7 +452,7 @@ sil @closure : $@convention(thin) (@owned @box Int) -> ()
 sil @no_final_release : $@convention(thin) (Int) -> Bool {
 bb0(%0 : $Int):
   %1 = alloc_box $Int
-  %1a = project_box %1 : $@box Int
+  %1a = project_box %1 : $@box Int, 0
   store %0 to %1a : $*Int
   // function_ref main.(newFoo (Swift.Int) -> Swift.Bool).(modify #1) (())()
   %3 = function_ref @closure : $@convention(thin) (@owned @box Int) -> ()
@@ -492,7 +492,7 @@ bb0(%0 : $*T):
   %3 = function_ref @closure_to_specialize : $@convention(thin) <τ_0_0 where τ_0_0 : P> (@owned @box τ_0_0) -> @out τ_0_0
   // CHECK-NOT: alloc_box
   %4 = alloc_box $T
-  %4a = project_box %4 : $@box T
+  %4a = project_box %4 : $@box T, 0
   // CHECK: copy_addr %0 to [initialization] [[STACK]] : $*T
   copy_addr %0 to [initialization] %4a : $*T
   // CHECK: [[CLOSURE:%[0-9a-zA-Z]+]] = function_ref @_TTSf0n_k__closure_to_specialize
@@ -511,7 +511,7 @@ bb0(%0 : $*T):
 sil shared @closure_to_specialize : $@convention(thin) <T where T : P> (@owned @box T) -> @out T {
 // CHECK: bb0
 bb0(%0 : $*T, %1 : $@box T):
-  %2 = project_box %1 : $@box T
+  %2 = project_box %1 : $@box T, 0
   // CHECK-NEXT: copy_addr
   copy_addr %2 to [initialization] %0 : $*T
   // CHECK-NOT: strong_release
@@ -573,7 +573,7 @@ bb0(%0 : $Int, %1 : $*S<Q>):
   %4 = function_ref @outer : $@convention(thin) (@owned @callee_owned () -> Bool) -> Bool
   %5 = function_ref @closure1 : $@convention(thin) <τ_0_0 where τ_0_0 : Count> (Int, @owned @box S<τ_0_0>) -> Bool
   %6 = alloc_box $S<Q>
-  %6a = project_box %6 : $@box S<Q>
+  %6a = project_box %6 : $@box S<Q>, 0
   copy_addr %1 to [initialization] %6a : $*S<Q>
   %8 = partial_apply %5<Q>(%0, %6) : $@convention(thin) <τ_0_0 where τ_0_0 : Count> (Int, @owned @box S<τ_0_0>) -> Bool
   %9 = apply %4(%8) : $@convention(thin) (@owned @callee_owned () -> Bool) -> Bool
@@ -591,7 +591,7 @@ bb0(%0 : $Int, %1 : $*S<T>):
   %4 = function_ref @outer : $@convention(thin) (@owned @callee_owned () -> Bool) -> Bool
   %5 = function_ref @closure1 : $@convention(thin) <τ_0_0 where τ_0_0 : Count> (Int, @owned @box S<τ_0_0>) -> Bool
   %6 = alloc_box $S<T>
-  %6a = project_box %6 : $@box S<T>
+  %6a = project_box %6 : $@box S<T>, 0
   copy_addr %1 to [initialization] %6a : $*S<T>
   %8 = partial_apply %5<T>(%0, %6) : $@convention(thin) <τ_0_0 where τ_0_0 : Count> (Int, @owned @box S<τ_0_0>) -> Bool
   %9 = apply %4(%8) : $@convention(thin) (@owned @callee_owned () -> Bool) -> Bool
@@ -604,11 +604,11 @@ bb0(%0 : $Int, %1 : $*S<T>):
 sil shared @closure1 : $@convention(thin) <T where T : Count> (Int, @owned @box S<T>) -> Bool {
 // CHECK: bb0
 bb0(%0 : $Int, %1 : $@box S<T>):
-  %2 = project_box %1 : $@box S<T>
+  %2 = project_box %1 : $@box S<T>, 0
   %3 = function_ref @inner : $@convention(thin) (@owned @callee_owned () -> Bool) -> Bool
   %4 = function_ref @closure2 : $@convention(thin) <τ_0_0 where τ_0_0 : Count> (Int, @owned @box S<τ_0_0>) -> Bool
   %5 = alloc_box $S<T>
-  %5a = project_box %5 : $@box S<T>
+  %5a = project_box %5 : $@box S<T>, 0
   copy_addr %2 to [initialization] %5a : $*S<T>
   %7 = partial_apply %4<T>(%0, %5) : $@convention(thin) <τ_0_0 where τ_0_0 : Count> (Int, @owned @box S<τ_0_0>) -> Bool
   %8 = apply %3(%7) : $@convention(thin) (@owned @callee_owned () -> Bool) -> Bool
@@ -626,7 +626,7 @@ bb0(%0 : $Int, %1 : $@box S<T>):
 sil shared @closure2 : $@convention(thin) <T where T : Count> (Int, @owned @box S<T>) -> Bool {
 // CHECK: bb0
 bb0(%0 : $Int, %1 : $@box S<T>):
-  %2 = project_box %1 : $@box S<T>
+  %2 = project_box %1 : $@box S<T>, 0
   %3 = function_ref @binary : $@convention(thin) (Int, Int) -> Bool
   %4 = alloc_stack $S<T>
   copy_addr %2 to [initialization] %4 : $*S<T>
@@ -651,7 +651,7 @@ bb0(%0 : $*T, %1 : $*T):
   // CHECK: [[APPLIED:%.*]] = function_ref
   %3 = function_ref @applied : $@convention(thin) <τ_0_0> (@owned @box τ_0_0) -> ()
   %4 = alloc_box $T
-  %4a = project_box %4 : $@box T
+  %4a = project_box %4 : $@box T, 0
   copy_addr %1 to [initialization] %4a : $*T
   // CHECK: [[PARTIAL:%.*]] = partial_apply [[APPLIED]]<T>([[STACK]])
   %6 = partial_apply %3<T>(%4) : $@convention(thin) <τ_0_0> (@owned @box τ_0_0) -> ()
@@ -673,7 +673,7 @@ bb0(%0 : $*T, %1 : $*T):
 
 sil @applied : $@convention(thin) <T> (@owned @box T) -> () {
 bb0(%0 : $@box T):
-  %1 = project_box %0 : $@box T
+  %1 = project_box %0 : $@box T, 0
   %2 = function_ref @consume : $@convention(thin) <τ_0_0> (@in τ_0_0) -> ()
   %3 = alloc_stack $T
   copy_addr %1 to [initialization] %3 : $*T
diff --git a/test/SILOptimizer/arcsequenceopts.sil b/test/SILOptimizer/arcsequenceopts.sil
index c2e5b2a2e1a..3aa77c02bb2 100644
--- a/test/SILOptimizer/arcsequenceopts.sil
+++ b/test/SILOptimizer/arcsequenceopts.sil
@@ -328,7 +328,7 @@ bb1:
 // SHOULD-NOT: strong_release
 sil @simple_alias_store_use_test : $@convention(thin) (@box Builtin.Int32) -> () {
 bb0(%0 : $@box Builtin.Int32):
-  %1 = project_box %0 : $@box Builtin.Int32
+  %1 = project_box %0 : $@box Builtin.Int32, 0
   %2 = function_ref @user : $@convention(thin) (@box Builtin.Int32) -> ()
   %3 = integer_literal $Builtin.Int32, 2
   strong_retain %0 : $@box Builtin.Int32
@@ -356,7 +356,7 @@ bb0(%0 : $@box Builtin.Int32):
 sil @simple_alias_load_use_test : $@convention(thin) (@inout Builtin.Int32) -> () {
 bb0(%0 : $*Builtin.Int32):
   %1 = alloc_box $Builtin.Int32
-  %1a = project_box %1 : $@box Builtin.Int32
+  %1a = project_box %1 : $@box Builtin.Int32, 0
   %2 = function_ref @user : $@convention(thin) (@box Builtin.Int32) -> ()
   strong_retain %1 : $@box Builtin.Int32
   apply %2 (%1) : $@convention(thin) (@box Builtin.Int32) -> ()
@@ -383,7 +383,7 @@ bb0(%0 : $*Builtin.Int32):
 sil @simple_alias_load_use_test_two_release : $@convention(thin) (@inout Builtin.Int32) -> () {
 bb0(%0 : $*Builtin.Int32):
   %1 = alloc_box $Builtin.Int32
-  %1a = project_box %1 : $@box Builtin.Int32
+  %1a = project_box %1 : $@box Builtin.Int32, 0
   %2 = function_ref @user : $@convention(thin) (@box Builtin.Int32) -> ()
   strong_retain %1 : $@box Builtin.Int32
   strong_retain %1 : $@box Builtin.Int32
diff --git a/test/SILOptimizer/capture_promotion.sil b/test/SILOptimizer/capture_promotion.sil
index 08576a8f113..8040ffeeb04 100644
--- a/test/SILOptimizer/capture_promotion.sil
+++ b/test/SILOptimizer/capture_promotion.sil
@@ -32,19 +32,19 @@ sil @test_capture_promotion : $@convention(thin) () -> @owned @callee_owned () -
 bb0:
   %0 = tuple ()
   %1 = alloc_box $Foo
-  %1a = project_box %1 : $@box Foo
+  %1a = project_box %1 : $@box Foo, 0
   %2 = function_ref @foo_allocating_init : $@convention(thin) (@thick Foo.Type) -> @owned Foo
   %3 = metatype $@thick Foo.Type
   %4 = apply %2(%3) : $@convention(thin) (@thick Foo.Type) -> @owned Foo
   store %4 to %1a : $*Foo
   %6 = alloc_box $Baz
-  %6a = project_box %6 : $@box Baz
+  %6a = project_box %6 : $@box Baz, 0
   %7 = function_ref @baz_init : $@convention(thin) (@thin Baz.Type) -> @owned Baz
   %8 = metatype $@thin Baz.Type
   %9 = apply %7(%8) : $@convention(thin) (@thin Baz.Type) -> @owned Baz
   store %9 to %6a : $*Baz
   %11 = alloc_box $Int
-  %11a = project_box %11 : $@box Int
+  %11a = project_box %11 : $@box Int, 0
   %12 = function_ref @convert_from_integer_literal : $@convention(thin) (Builtin.Word, @thin Int.Type) -> Int
   %13 = metatype $@thin Int.Type
   %14 = integer_literal $Builtin.Word, 3
@@ -91,19 +91,19 @@ sil @test_capture_promotion_indirect : $@convention(thin) () -> @owned @callee_o
 bb0:
   %0 = tuple ()
   %1 = alloc_box $Foo
-  %1a = project_box %1 : $@box Foo
+  %1a = project_box %1 : $@box Foo, 0
   %2 = function_ref @foo_allocating_init : $@convention(thin) (@thick Foo.Type) -> @owned Foo
   %3 = metatype $@thick Foo.Type
   %4 = apply %2(%3) : $@convention(thin) (@thick Foo.Type) -> @owned Foo
   store %4 to %1a : $*Foo
   %6 = alloc_box $Baz
-  %6a = project_box %6 : $@box Baz
+  %6a = project_box %6 : $@box Baz, 0
   %7 = function_ref @baz_init : $@convention(thin) (@thin Baz.Type) -> @owned Baz
   %8 = metatype $@thin Baz.Type
   %9 = apply %7(%8) : $@convention(thin) (@thin Baz.Type) -> @owned Baz
   store %9 to %6a : $*Baz
   %11 = alloc_box $Int
-  %11a = project_box %11 : $@box Int
+  %11a = project_box %11 : $@box Int, 0
   %12 = function_ref @convert_from_integer_literal : $@convention(thin) (Builtin.Word, @thin Int.Type) -> Int
   %13 = metatype $@thin Int.Type
   %14 = integer_literal $Builtin.Word, 3
@@ -173,9 +173,9 @@ bb0:
 
 sil private @closure0 : $@convention(thin) (@owned @box Foo, @owned @box Baz, @owned @box Int) -> Int {
 bb0(%0 : $@box Foo, %2 : $@box Baz, %4 : $@box Int):
-  %1 = project_box %0 : $@box Foo
-  %3 = project_box %2 : $@box Baz
-  %5 = project_box %4 : $@box Int
+  %1 = project_box %0 : $@box Foo, 0
+  %3 = project_box %2 : $@box Baz, 0
+  %5 = project_box %4 : $@box Int, 0
   %6 = tuple ()
   // function_ref test14.plus (a : Swift.Int, b : Swift.Int, c : Swift.Int) -> Swift.Int
   %7 = function_ref @dummy_func : $@convention(thin) (Int, Int, Int) -> Int
@@ -200,7 +200,7 @@ sil @test_unpromotable : $@convention(thin) () -> @owned @callee_owned () -> Int
 bb0:
   %0 = tuple ()
   %1 = alloc_box $Foo
-  %1a = project_box %1 : $@box Foo
+  %1a = project_box %1 : $@box Foo, 0
   %2 = function_ref @foo_allocating_init : $@convention(thin) (@thick Foo.Type) -> @owned Foo
   %3 = metatype $@thick Foo.Type
   %4 = apply %2(%3) : $@convention(thin) (@thick Foo.Type) -> @owned Foo
@@ -217,7 +217,7 @@ sil @mutate_foo : $@convention(thin) (@inout Foo) -> ()
 
 sil private @closure1 : $@convention(thin) (@box Foo) -> Int {
 bb0(%0 : $@box Foo):
-  %1 = project_box %0 : $@box Foo
+  %1 = project_box %0 : $@box Foo, 0
   %6 = tuple ()
   // function_ref test14.plus (a : Swift.Int, b : Swift.Int, c : Swift.Int) -> Swift.Int
   %7 = function_ref @dummy_func : $@convention(thin) (Int, Int, Int) -> Int
@@ -238,10 +238,10 @@ sil @captureWithinGeneric : $@convention(thin) <T> (@inout Int, @inout Int) -> (
 // CHECK: bb0
 bb0(%0 : $*Int, %1 : $*Int):
   %2 = alloc_box $Int
-  %2a = project_box %2 : $@box Int
+  %2a = project_box %2 : $@box Int, 0
   copy_addr %0 to [initialization] %2a : $*Int
   %4 = alloc_box $Int
-  %4a = project_box %4 : $@box Int
+  %4a = project_box %4 : $@box Int, 0
   copy_addr %1 to [initialization] %4a : $*Int
   %6 = function_ref @apply : $@convention(thin) (@owned @callee_owned () -> ()) -> ()
   // CHECK: [[PROMOTED:%[0-9a-zA-Z]+]] = function_ref @_TTSf2n_i__closureWithGenericSignature : $@convention(thin) <τ_0_0> (@owned @box Int, Int) -> ()
@@ -262,8 +262,8 @@ bb0(%0 : $*Int, %1 : $*Int):
 // CHECK: sil @_TTSf2n_i__closureWithGenericSignature : $@convention(thin) <{{[^>]+}}> (@owned @box Int, Int) -> ()
 sil @closureWithGenericSignature : $@convention(thin) <T> (@owned @box Int, @owned @box Int) -> () {
 bb0(%0 : $@box Int, %2 : $@box Int):
-  %1 = project_box %0 : $@box Int
-  %3 = project_box %2 : $@box Int
+  %1 = project_box %0 : $@box Int, 0
+  %3 = project_box %2 : $@box Int, 0
   %4 = function_ref @_TFsoi1pFTSiSi_Si : $@convention(thin) (Int, Int) -> Int
   %5 = load %3 : $*Int
   %6 = load %3 : $*Int
@@ -280,9 +280,9 @@ sil [transparent] [fragile] @_TFsoi1pFTSiSi_Si : $@convention(thin) (Int, Int) -
 
 sil private @closure_indirect_result : $@convention(thin) (@owned @box Foo, @owned @box Baz, @owned @box Int) -> @out Int {
 bb0(%0: $*Int, %1 : $@box Foo, %2 : $@box Baz, %4 : $@box Int):
-  %17 = project_box %1 : $@box Foo
-  %3 = project_box %2 : $@box Baz
-  %5 = project_box %4 : $@box Int
+  %17 = project_box %1 : $@box Foo, 0
+  %3 = project_box %2 : $@box Baz, 0
+  %5 = project_box %4 : $@box Int, 0
   %6 = tuple ()
   // function_ref test14.plus (a : Swift.Int, b : Swift.Int, c : Swift.Int) -> Swift.Int
   %7 = function_ref @dummy_func : $@convention(thin) (Int, Int, Int) -> Int
diff --git a/test/SILOptimizer/capture_promotion_reachability.sil b/test/SILOptimizer/capture_promotion_reachability.sil
index a5be1c68997..4250475a423 100644
--- a/test/SILOptimizer/capture_promotion_reachability.sil
+++ b/test/SILOptimizer/capture_promotion_reachability.sil
@@ -28,11 +28,11 @@ func test_reachability_1(b: Builtin.Int1, x: Builtin.Int64, y: Builtin.Int64) {
 sil @test_reachability_1 : $@convention(thin) (Builtin.Int1, Builtin.Int64, Builtin.Int64) -> () {
 bb0(%0 : $Builtin.Int1, %1 : $Builtin.Int64, %2 : $Builtin.Int64):
   %3 = alloc_box $Builtin.Int1
-  %3a = project_box %3 : $@box Builtin.Int1
+  %3a = project_box %3 : $@box Builtin.Int1, 0
   %4 = alloc_box $Builtin.Int64
-  %4a = project_box %4 : $@box Builtin.Int64
+  %4a = project_box %4 : $@box Builtin.Int64, 0
   %5 = alloc_box $Builtin.Int64
-  %5a = project_box %5 : $@box Builtin.Int64
+  %5a = project_box %5 : $@box Builtin.Int64, 0
   store %0 to %3a : $*Builtin.Int1
   store %1 to %4a : $*Builtin.Int64
   store %2 to %5a : $*Builtin.Int64
@@ -46,7 +46,7 @@ bb1:
 
 bb2:
   %14 = alloc_box $@callee_owned () -> Builtin.Int64
-  %14a = project_box %14 : $@box @callee_owned () -> Builtin.Int64
+  %14a = project_box %14 : $@box @callee_owned () -> Builtin.Int64, 0
   // CHECK: [[CLOSURE0_PROMOTE0:%.*]] = function_ref @_TTSf2i__closure0 :
   %15 = function_ref @closure0 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64
   strong_retain %4 : $@box Builtin.Int64
@@ -77,7 +77,7 @@ bb4:
 // closure0
 sil private @closure0 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64 {
 bb0(%0 : $@box Builtin.Int64):
-  %1 = project_box %0 : $@box Builtin.Int64
+  %1 = project_box %0 : $@box Builtin.Int64, 0
   %2 = tuple ()
   %3 = load %1 : $*Builtin.Int64
   strong_release %0 : $@box Builtin.Int64
@@ -87,7 +87,7 @@ bb0(%0 : $@box Builtin.Int64):
 // closure1
 sil private @closure1 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64 {
 bb0(%0 : $@box Builtin.Int64):
-  %1 = project_box %0 : $@box Builtin.Int64
+  %1 = project_box %0 : $@box Builtin.Int64, 0
   %2 = tuple ()
   %3 = load %1 : $*Builtin.Int64
   strong_release %0 : $@box Builtin.Int64
@@ -110,16 +110,16 @@ func test_reachability_2(b: Builtin.Int1, x: Builtin.Int64, y: Builtin.Int64) {
 sil @test_reachability_2 : $@convention(thin) (Builtin.Int1, Builtin.Int64, Builtin.Int64) -> () {
 bb0(%0 : $Builtin.Int1, %1 : $Builtin.Int64, %2 : $Builtin.Int64):
   %3 = alloc_box $Builtin.Int1
-  %3a = project_box %3 : $@box Builtin.Int1
+  %3a = project_box %3 : $@box Builtin.Int1, 0
   %4 = alloc_box $Builtin.Int64
-  %4a = project_box %4 : $@box Builtin.Int64
+  %4a = project_box %4 : $@box Builtin.Int64, 0
   %5 = alloc_box $Builtin.Int64
-  %5a = project_box %5 : $@box Builtin.Int64
+  %5a = project_box %5 : $@box Builtin.Int64, 0
   store %0 to %3a : $*Builtin.Int1
   store %1 to %4a : $*Builtin.Int64
   store %2 to %5a : $*Builtin.Int64
   %9 = alloc_box $@callee_owned () -> Builtin.Int64
-  %9a = project_box %9 : $@box @callee_owned () -> Builtin.Int64
+  %9a = project_box %9 : $@box @callee_owned () -> Builtin.Int64, 0
   // CHECK: [[CLOSURE2:%.*]] = function_ref @closure2 :
   %10 = function_ref @closure2 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64
   strong_retain %4 : $@box Builtin.Int64
@@ -159,7 +159,7 @@ bb4:
 // closure2
 sil private @closure2 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64 {
 bb0(%0 : $@box Builtin.Int64):
-  %1 = project_box %0 : $@box Builtin.Int64
+  %1 = project_box %0 : $@box Builtin.Int64, 0
   %2 = tuple ()
   %3 = load %1 : $*Builtin.Int64
   strong_release %0 : $@box Builtin.Int64
@@ -169,7 +169,7 @@ bb0(%0 : $@box Builtin.Int64):
 // closure3
 sil private @closure3 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64 {
 bb0(%0 : $@box Builtin.Int64):
-  %1 = project_box %0 : $@box Builtin.Int64
+  %1 = project_box %0 : $@box Builtin.Int64, 0
   %2 = tuple ()
   %3 = load %1 : $*Builtin.Int64
   strong_release %0 : $@box Builtin.Int64
@@ -192,16 +192,16 @@ func test_reachability_3(b: Builtin.Int1, x: Builtin.Int64, y: Builtin.Int64) {
 sil @test_reachability_3 : $@convention(thin) (Builtin.Int1, Builtin.Int64, Builtin.Int64) -> () {
 bb0(%0 : $Builtin.Int1, %1 : $Builtin.Int64, %2 : $Builtin.Int64):
   %3 = alloc_box $Builtin.Int1
-  %3a = project_box %3 : $@box Builtin.Int1
+  %3a = project_box %3 : $@box Builtin.Int1, 0
   %4 = alloc_box $Builtin.Int64
-  %4a = project_box %4 : $@box Builtin.Int64
+  %4a = project_box %4 : $@box Builtin.Int64, 0
   %5 = alloc_box $Builtin.Int64
-  %5a = project_box %5 : $@box Builtin.Int64
+  %5a = project_box %5 : $@box Builtin.Int64, 0
   store %0 to %3a : $*Builtin.Int1
   store %1 to %4a : $*Builtin.Int64
   store %2 to %5a : $*Builtin.Int64
   %9 = alloc_box $@callee_owned () -> Builtin.Int64
-  %9a = project_box %9 : $@box @callee_owned () -> Builtin.Int64
+  %9a = project_box %9 : $@box @callee_owned () -> Builtin.Int64, 0
   // CHECK: [[CLOSURE4:%.*]] = function_ref @closure4 :
   %10 = function_ref @closure4 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64
   strong_retain %4 : $@box Builtin.Int64
@@ -241,7 +241,7 @@ bb4:
 // closure4
 sil private @closure4 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64 {
 bb0(%0 : $@box Builtin.Int64):
-  %1 = project_box %0 : $@box Builtin.Int64
+  %1 = project_box %0 : $@box Builtin.Int64, 0
   %2 = tuple ()
   %3 = load %1 : $*Builtin.Int64
   strong_release %0 : $@box Builtin.Int64
@@ -251,7 +251,7 @@ bb0(%0 : $@box Builtin.Int64):
 // closure5
 sil private @closure5 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64 {
 bb0(%0 : $@box Builtin.Int64):
-  %1 = project_box %0 : $@box Builtin.Int64
+  %1 = project_box %0 : $@box Builtin.Int64, 0
   %2 = tuple ()
   %3 = load %1 : $*Builtin.Int64
   strong_release %0 : $@box Builtin.Int64
@@ -272,16 +272,16 @@ func test_reachability_4(b: Builtin.Int1, x: Builtin.Int64, y: Builtin.Int64) {
 sil @test_reachability_4 : $@convention(thin) (Builtin.Int1, Builtin.Int64, Builtin.Int64) -> () {
 bb0(%0 : $Builtin.Int1, %1 : $Builtin.Int64, %2 : $Builtin.Int64):
   %3 = alloc_box $Builtin.Int1
-  %3a = project_box %3 : $@box Builtin.Int1
+  %3a = project_box %3 : $@box Builtin.Int1, 0
   %4 = alloc_box $Builtin.Int64
-  %4a = project_box %4 : $@box Builtin.Int64
+  %4a = project_box %4 : $@box Builtin.Int64, 0
   %5 = alloc_box $Builtin.Int64
-  %5a = project_box %5 : $@box Builtin.Int64
+  %5a = project_box %5 : $@box Builtin.Int64, 0
   store %0 to %3a : $*Builtin.Int1
   store %1 to %4a : $*Builtin.Int64
   store %2 to %5a : $*Builtin.Int64
   %9 = alloc_box $@callee_owned () -> Builtin.Int64
-  %9a = project_box %9 : $@box @callee_owned () -> Builtin.Int64
+  %9a = project_box %9 : $@box @callee_owned () -> Builtin.Int64, 0
   // CHECK: [[CLOSURE6:%.*]] = function_ref @closure6 :
   %10 = function_ref @closure6 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64
   strong_retain %4 : $@box Builtin.Int64
@@ -317,7 +317,7 @@ bb3:
 // closure6
 sil private @closure6 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64 {
 bb0(%0 : $@box Builtin.Int64):
-  %1 = project_box %0 : $@box Builtin.Int64
+  %1 = project_box %0 : $@box Builtin.Int64, 0
   %2 = tuple ()
   %3 = load %1 : $*Builtin.Int64
   strong_release %0 : $@box Builtin.Int64
@@ -327,7 +327,7 @@ bb0(%0 : $@box Builtin.Int64):
 // closure7
 sil private @closure7 : $@convention(thin) (@owned @box Builtin.Int64) -> Builtin.Int64 {
 bb0(%0 : $@box Builtin.Int64):
-  %1 = project_box %0 : $@box Builtin.Int64
+  %1 = project_box %0 : $@box Builtin.Int64, 0
   %2 = tuple ()
   %3 = load %1 : $*Builtin.Int64
   strong_release %0 : $@box Builtin.Int64
diff --git a/test/SILOptimizer/closure_specialize.sil b/test/SILOptimizer/closure_specialize.sil
index 73e842c1e71..6b9e9cbfd83 100644
--- a/test/SILOptimizer/closure_specialize.sil
+++ b/test/SILOptimizer/closure_specialize.sil
@@ -79,10 +79,10 @@ bb0(%0 : $Int):
 sil shared @_TFF7specgen6callerFSiT_U_FTSiSi_T_ : $@convention(thin) (Int, Int, Int) -> () {
 bb0(%0 : $Int, %1 : $Int, %2 : $Int):
   %5 = alloc_box $Int, var, name "p"                   // users: %6, %10, %14
-  %5a = project_box %5 : $@box Int
+  %5a = project_box %5 : $@box Int, 0
   store %0 to %5a : $*Int                        // id: %6
   %7 = alloc_box $Int, var, name "q"                   // users: %8, %11, %13
-  %7a = project_box %7 : $@box Int
+  %7a = project_box %7 : $@box Int, 0
   store %1 to %7a : $*Int                        // id: %8
   // function_ref specgen.callee (Swift.Int, Swift.Int, Swift.Int) -> ()
   %9 = function_ref @_TF7specgen6calleeFTSiSiSi_T_ : $@convention(thin) (Int, Int, Int) -> () // user: %12
@@ -445,7 +445,7 @@ bb0(%0 : $*Builtin.Int32, %1 : $@callee_owned (Builtin.Int32) -> ()):
 sil @pass_a_closure: $@convention(thin) () -> Builtin.Int32 {
 bb0:
   %0 = alloc_box $Builtin.Int32, var, name "i"
-  %0a = project_box %0 : $@box Builtin.Int32
+  %0a = project_box %0 : $@box Builtin.Int32, 0
   %1 = integer_literal $Builtin.Int32, 0
   store %1 to %0a : $*Builtin.Int32
   %4 = function_ref @closure_with_box_argument : $@convention(thin) (Builtin.Int32, @owned @box Builtin.Int32) -> ()
@@ -468,7 +468,7 @@ bb0:
 // CHECK-LABEL: sil shared @closure_with_box_argument
 sil shared @closure_with_box_argument : $@convention(thin) (Builtin.Int32, @owned @box Builtin.Int32) -> () {
 bb0(%0 : $Builtin.Int32, %1 : $@box Builtin.Int32):
-  %3 = project_box %1 : $@box Builtin.Int32
+  %3 = project_box %1 : $@box Builtin.Int32, 0
   store %0 to %3 : $*Builtin.Int32
   strong_release %1 : $@box Builtin.Int32
   %7 = tuple ()
diff --git a/test/SILOptimizer/cse.sil b/test/SILOptimizer/cse.sil
index 060de454258..a31eaaa5d1d 100644
--- a/test/SILOptimizer/cse.sil
+++ b/test/SILOptimizer/cse.sil
@@ -111,7 +111,7 @@ bb0:
 sil @removeTriviallyDeadInstructions : $@convention(thin) (@owned B) -> () {
 bb0(%0 : $B):
   %1 = alloc_box $B
-  %1a = project_box %1 : $@box B
+  %1a = project_box %1 : $@box B, 0
   %2 = store %0 to %1a : $*B
   %3 = load %1a : $*B
   %4 = strong_retain %3 : $B
@@ -424,8 +424,8 @@ bb0(%0 : $*Interval):
 // CHECK: return
 sil @project_box_test : $(@box Builtin.Int32) -> Builtin.Int32 {
 bb0(%0 : $@box Builtin.Int32):
-  %1 = project_box %0 : $@box Builtin.Int32
-  %2 = project_box %0 : $@box Builtin.Int32
+  %1 = project_box %0 : $@box Builtin.Int32, 0
+  %2 = project_box %0 : $@box Builtin.Int32, 0
   %3 = function_ref @sadd_with_address : $@convention(thin) (@inout Builtin.Int32, @inout Builtin.Int32) -> (Builtin.Int32)
   %4 = apply %3(%1, %2) : $@convention(thin) (@inout Builtin.Int32, @inout Builtin.Int32) -> (Builtin.Int32)
   return %4 : $(Builtin.Int32)
diff --git a/test/SILOptimizer/dead_store_elim.sil b/test/SILOptimizer/dead_store_elim.sil
index 2fcbc76b0aa..3125124d73d 100644
--- a/test/SILOptimizer/dead_store_elim.sil
+++ b/test/SILOptimizer/dead_store_elim.sil
@@ -198,7 +198,7 @@ bb0:
 sil @store_after_store : $@convention(thin) (@owned B) -> () {
 bb0(%0 : $B):
   %1 = alloc_box $B
-  %1a = project_box %1 : $@box B
+  %1a = project_box %1 : $@box B, 0
   %2 = store %0 to %1a : $*B
   %3 = store %0 to %1a : $*B
   %4 = tuple()
diff --git a/test/SILOptimizer/definite_init.sil b/test/SILOptimizer/definite_init.sil
index edcaee8206d..40c78d33c2d 100644
--- a/test/SILOptimizer/definite_init.sil
+++ b/test/SILOptimizer/definite_init.sil
@@ -13,7 +13,7 @@ sil @makesInt : $@convention(thin) () -> Int
 sil @use_before_init : $@convention(thin) () -> Int {
 bb0:
   %0 = alloc_box $Int
-  %0a = project_box %0 : $@box Int
+  %0a = project_box %0 : $@box Int, 0
   %1 = mark_uninitialized [var] %0a : $*Int // expected-note {{variable defined here}}
   %4 = load %1 : $*Int                // expected-error {{variable '<unknown>' used before being initialized}}
   strong_release %0 : $@box Int
@@ -25,7 +25,7 @@ bb0:
 sil @inout_uninit : $@convention(thin) () -> () {
 bb0:
   %0 = alloc_box $Int
-  %0a = project_box %0 : $@box Int
+  %0a = project_box %0 : $@box Int, 0
   %1 = mark_uninitialized [var] %0a : $*Int // expected-note {{variable defined here}}
 
   %5 = function_ref @takes_Int_inout : $@convention(thin) (@inout Int) -> ()
@@ -50,7 +50,7 @@ bb0:
 sil @used_by_inout : $@convention(thin) (Int) -> (Int, Int) {
 bb0(%0 : $Int):
   %91 = alloc_box $Int
-  %91a = project_box %91 : $@box Int
+  %91a = project_box %91 : $@box Int, 0
   %1 = mark_uninitialized [var] %91a : $*Int
 
   %2 = store %0 to %1 : $*Int
@@ -77,7 +77,7 @@ sil @returns_generic_struct : $@convention(thin) () -> @out AddressOnlyStruct
 sil @call_struct_return_function : $@convention(thin) () -> Int {
 bb0:
   %0 = alloc_box $AddressOnlyStruct
-  %0a = project_box %0 : $@box AddressOnlyStruct
+  %0a = project_box %0 : $@box AddressOnlyStruct, 0
   %1 = mark_uninitialized [var] %0a : $*AddressOnlyStruct
 
   %2 = function_ref @returns_generic_struct : $@convention(thin) () -> @out AddressOnlyStruct
@@ -93,7 +93,7 @@ bb0:
 sil @tuple_elements1 : $@convention(thin) (Int) -> () {
 bb0(%0 : $Int):
   %2 = alloc_box $(Int, Int)
-  %2a = project_box %2 : $@box (Int, Int)
+  %2a = project_box %2 : $@box (Int, Int), 0
   %3 = mark_uninitialized [var] %2a : $*(Int, Int) // expected-note {{variable defined here}}
   %4 = tuple_element_addr %3 : $*(Int, Int), 0
   %5 = tuple_element_addr %3 : $*(Int, Int), 1
@@ -110,7 +110,7 @@ bb0(%0 : $Int):
 sil @tuple_elements2 : $@convention(thin) (Int) -> (Int, Int) {
 bb0(%0 : $Int):
   %2 = alloc_box $(Int, Int)
-  %2a = project_box %2 : $@box (Int, Int)
+  %2a = project_box %2 : $@box (Int, Int), 0
   %3 = mark_uninitialized [var] %2a : $*(Int, Int) // expected-note {{variable defined here}}
   %18 = tuple_element_addr %3 : $*(Int, Int), 0
   store %0 to %18 : $*Int
@@ -128,7 +128,7 @@ bb0(%0 : $Int):
 sil @copy_addr1 : $@convention(thin) <T> (@in T) -> @out T {
 bb0(%0 : $*T, %1 : $*T):
   %3 = alloc_box $T
-  %3a = project_box %3 : $@box T
+  %3a = project_box %3 : $@box T, 0
   %4 = mark_uninitialized [var] %3a : $*T
   copy_addr [take] %1 to [initialization] %4 : $*T
   copy_addr %4 to [initialization] %0 : $*T
@@ -141,7 +141,7 @@ bb0(%0 : $*T, %1 : $*T):
 sil @copy_addr2 : $@convention(thin) <T> (@in T) -> @out T {
 bb0(%0 : $*T, %1 : $*T):
   %3 = alloc_box $T
-  %3a = project_box %3 : $@box T
+  %3a = project_box %3 : $@box T, 0
   %4 = mark_uninitialized [var] %3a : $*T // expected-note {{variable defined here}}
   copy_addr %4 to [initialization] %0 : $*T   // expected-error {{variable '<unknown>' used before being initialized}}
   strong_release %3 : $@box T
@@ -157,7 +157,7 @@ sil @closure0 : $@convention(thin) (@owned @box Int) -> ()
 sil @closure_test : $@convention(thin) () -> () {
 bb0:
   %1 = alloc_box $Int
-  %1a = project_box %1 : $@box Int
+  %1a = project_box %1 : $@box Int, 0
   %0 = mark_uninitialized [var] %1a : $*Int // expected-note {{variable defined here}}
 
   %5 = function_ref @takes_closure : $@convention(thin) (@callee_owned () -> ()) -> ()
@@ -183,7 +183,7 @@ sil @getSomeOptionalClass : $@convention(thin) () -> Optional<SomeClass>
 sil @assign_test_trivial : $@convention(thin) (Int) -> Int {
 bb0(%0 : $Int):
   %7 = alloc_box $Int
-  %7a = project_box %7 : $@box Int
+  %7a = project_box %7 : $@box Int, 0
   %1 = mark_uninitialized [var] %7a : $*Int
 
   // These assigns are a mix of init + store forms, but because Int is trivial,
@@ -205,7 +205,7 @@ bb0:
   // lone store), the second becomes an assignment (retain/release dance).
 
   %b = alloc_box $SomeClass
-  %ba = project_box %b : $@box SomeClass
+  %ba = project_box %b : $@box SomeClass, 0
   %c = mark_uninitialized [var] %ba : $*SomeClass
 
   %f = function_ref @getSomeClass : $@convention(thin) () -> @owned SomeClass
@@ -237,7 +237,7 @@ bb0:
 sil @assign_test_addressonly : $@convention(thin) <T> (@in T) -> @out T {
 bb0(%0 : $*T, %1 : $*T):
   %b = alloc_box $T
-  %ba = project_box %b : $@box T
+  %ba = project_box %b : $@box T, 0
   %2 = mark_uninitialized [var] %ba : $*T
 
   // CHECK: [[PB:%[0-9]+]] = project_box
@@ -267,7 +267,7 @@ bb0:
   // second becomes an assignment.
 
   %b = alloc_box $@sil_weak Optional<SomeClass>
-  %ba = project_box %b : $@box @sil_weak Optional<SomeClass>
+  %ba = project_box %b : $@box @sil_weak Optional<SomeClass>, 0
   %c = mark_uninitialized [var] %ba : $*@sil_weak Optional<SomeClass> // expected-note {{variable defined here}}
 
   // Invalid load to keep the alloc_box around so we can check init semantics.
@@ -307,7 +307,7 @@ bb0:
   // second becomes an assignment.
 
   %b = alloc_box $@sil_unowned SomeClass
-  %ba = project_box %b : $@box @sil_unowned SomeClass
+  %ba = project_box %b : $@box @sil_unowned SomeClass, 0
   %c = mark_uninitialized [var] %ba : $*@sil_unowned SomeClass
 
   %f = function_ref @getSomeClass : $@convention(thin) () -> @owned SomeClass
@@ -359,7 +359,7 @@ struct ContainsNativeObject {
 sil @test_struct : $@convention(thin) (@inout ContainsNativeObject) -> () {
 bb0(%0 : $*ContainsNativeObject):
   %b = alloc_box $ContainsNativeObject
-  %ba = project_box %b : $@box ContainsNativeObject
+  %ba = project_box %b : $@box ContainsNativeObject, 0
   %c = mark_uninitialized [var] %ba : $*ContainsNativeObject
   %1 = load %0 : $*ContainsNativeObject
   assign %1 to %c : $*ContainsNativeObject
@@ -632,7 +632,7 @@ sil @superinit : $@convention(method) (@owned RootClassWithIVars) -> @owned Root
 sil @derived_test1 :  $@convention(method) (@owned DerivedClassWithIVars) -> @owned DerivedClassWithIVars {
 bb0(%0 : $DerivedClassWithIVars):
   %1 = alloc_box $DerivedClassWithIVars
-  %1a = project_box %1 : $@box DerivedClassWithIVars
+  %1a = project_box %1 : $@box DerivedClassWithIVars, 0
   %3 = mark_uninitialized [derivedself] %1a : $*DerivedClassWithIVars
   store %0 to %3 : $*DerivedClassWithIVars
 
@@ -662,7 +662,7 @@ bb0(%0 : $DerivedClassWithIVars):
 sil @derived_test2 :  $@convention(method) (@owned DerivedClassWithIVars) -> @owned DerivedClassWithIVars {
 bb0(%0 : $DerivedClassWithIVars):
   %1 = alloc_box $DerivedClassWithIVars
-  %1a = project_box %1 : $@box DerivedClassWithIVars
+  %1a = project_box %1 : $@box DerivedClassWithIVars, 0
   %3 = mark_uninitialized [derivedself] %1a : $*DerivedClassWithIVars
   store %0 to %3 : $*DerivedClassWithIVars
 
@@ -852,7 +852,7 @@ bb0(%0 : $DerivedClassWithNontrivialStoredProperties):
 sil @test_delegating_box_release : $@convention(method) (@owned RootClassWithNontrivialStoredProperties) -> () {
 bb0(%0 : $RootClassWithNontrivialStoredProperties):
   %2 = alloc_box $RootClassWithNontrivialStoredProperties
-  %2a = project_box %2 : $@box RootClassWithNontrivialStoredProperties
+  %2a = project_box %2 : $@box RootClassWithNontrivialStoredProperties, 0
   %4 = mark_uninitialized [delegatingself] %2a : $*RootClassWithNontrivialStoredProperties
   store %0 to %4 : $*RootClassWithNontrivialStoredProperties
   strong_release %2 : $@box RootClassWithNontrivialStoredProperties
@@ -876,7 +876,7 @@ bb0(%0 : $RootClassWithNontrivialStoredProperties):
 sil @test_delegating_rvalue_release : $@convention(method) (@owned RootClassWithNontrivialStoredProperties) -> () {
 bb0(%0 : $RootClassWithNontrivialStoredProperties):
   %2 = alloc_box $RootClassWithNontrivialStoredProperties
-  %2a = project_box %2 : $@box RootClassWithNontrivialStoredProperties
+  %2a = project_box %2 : $@box RootClassWithNontrivialStoredProperties, 0
   %4 = mark_uninitialized [delegatingself] %2a : $*RootClassWithNontrivialStoredProperties
   store %0 to %4 : $*RootClassWithNontrivialStoredProperties
   %6 = load %4 : $*RootClassWithNontrivialStoredProperties
@@ -913,7 +913,7 @@ bb0(%0 : $DerivedClassWithNontrivialStoredProperties):
 sil @super_init_out_of_order :  $@convention(method) (@owned DerivedClassWithIVars, Int) -> @owned DerivedClassWithIVars {
 bb0(%0 : $DerivedClassWithIVars, %i : $Int):
   %1 = alloc_box $DerivedClassWithIVars
-  %1a = project_box %1 : $@box DerivedClassWithIVars
+  %1a = project_box %1 : $@box DerivedClassWithIVars, 0
   %3 = mark_uninitialized [derivedself] %1a : $*DerivedClassWithIVars
   store %0 to %3 : $*DerivedClassWithIVars
 
diff --git a/test/SILOptimizer/definite_init_crashes.sil b/test/SILOptimizer/definite_init_crashes.sil
index 4e7fa505b9a..37e3f44762f 100644
--- a/test/SILOptimizer/definite_init_crashes.sil
+++ b/test/SILOptimizer/definite_init_crashes.sil
@@ -16,7 +16,7 @@ struct Triple {
 sil @TripleTest : $@convention(method) (Int, @inout Triple) -> Triple {
 bb0(%0 : $Int, %1 : $*Triple):
   %4 = alloc_box $Triple
-  %4a = project_box %4 : $@box Triple
+  %4a = project_box %4 : $@box Triple, 0
   %5 = load %1 : $*Triple
   store %5 to %4a : $*Triple
   %8 = struct_element_addr %4a : $*Triple, #Triple.b
@@ -35,7 +35,7 @@ struct Single {
 sil @SingleTest : $@convention(method) (@inout Single, Int) -> Single {
 bb0(%0 : $*Single, %1 : $Int):
   %4 = alloc_box $Single
-  %4a = project_box %4 : $@box Single
+  %4a = project_box %4 : $@box Single, 0
   %5 = load %0 : $*Single
   store %5 to %4a : $*Single
   
@@ -64,7 +64,7 @@ sil @test_union_release : $@convention(thin) () -> () {
 bb0:
   %0 = tuple ()
   %1 = alloc_box $SomeUnion                       // users: %9, %8
-  %1a = project_box %1 : $@box SomeUnion
+  %1a = project_box %1 : $@box SomeUnion, 0
   %2 = function_ref @getSomeUnion : $@convention(thin) (@owned SomeClass, @thin SomeUnion.Type) -> @owned SomeUnion // user: %7
   %3 = metatype $@thin SomeUnion.Type               // user: %7
   %4 = function_ref @getSomeClass : $@convention(thin) (@thick SomeClass.Type) -> @owned SomeClass // user: %6
diff --git a/test/SILOptimizer/diagnose_unreachable.sil b/test/SILOptimizer/diagnose_unreachable.sil
index eebd62b834f..493707579d1 100644
--- a/test/SILOptimizer/diagnose_unreachable.sil
+++ b/test/SILOptimizer/diagnose_unreachable.sil
@@ -138,7 +138,7 @@ bb0:
 sil @removeTriviallyDeadInstructions : $@convention(thin) (@owned B) -> () {
 bb0(%0 : $B):
   %1 = alloc_box $B                           
-  %1a = project_box %1 : $@box B
+  %1a = project_box %1 : $@box B, 0
   %2 = store %0 to %1a : $*B                 // CHECK: store
   %3 = load %1a : $*B                        
   %4 = strong_retain %3 : $B                         // CHECK: strong_retain
diff --git a/test/SILOptimizer/escape_analysis.sil b/test/SILOptimizer/escape_analysis.sil
index 5948268a34c..649c6ffd42e 100644
--- a/test/SILOptimizer/escape_analysis.sil
+++ b/test/SILOptimizer/escape_analysis.sil
@@ -398,10 +398,10 @@ sil @call_copy_addr_content : $@convention(thin) () -> () {
 sil @test_partial_apply : $@convention(thin) (Int64, @owned X, @owned Y) -> Int64 {
 bb0(%0 : $Int64, %1 : $X, %2 : $Y):
   %3 = alloc_box $Int64
-  %4 = project_box %3 : $@box Int64
+  %4 = project_box %3 : $@box Int64, 0
   store %0 to %4 : $*Int64
   %6 = alloc_box $Y
-  %7 = project_box %6 : $@box Y
+  %7 = project_box %6 : $@box Y, 0
   store %2 to %7 : $*Y
   %9 = function_ref @closure1 : $@convention(thin) (@owned X, @owned @box Int64, @owned @box Y) -> Int64
   strong_retain %3 : $@box Int64
@@ -429,8 +429,8 @@ bb0(%0 : $Int64, %1 : $X, %2 : $Y):
 // CHECK-NEXT:  End
 sil @closure1 : $@convention(thin) (@owned X, @owned @box Int64, @owned @box Y) -> Int64 {
 bb0(%0 : $X, %1 : $@box Int64, %2 : $@box Y):
-  %3 = project_box %1 : $@box Int64
-  %4 = project_box %2 : $@box Y
+  %3 = project_box %1 : $@box Int64, 0
+  %4 = project_box %2 : $@box Y, 0
   %5 = load %3 : $*Int64
   %6 = function_ref @closure2 : $@convention(thin) (@owned X, @owned @box Y) -> ()
   %7 = partial_apply %6(%2) : $@convention(thin) (@owned X, @owned @box Y) -> ()
@@ -449,7 +449,7 @@ bb0(%0 : $X, %1 : $@box Int64, %2 : $@box Y):
 // CHECK-NEXT:  End
 sil @closure2 : $@convention(thin) (@owned X, @owned @box Y) -> () {
 bb0(%0 : $X, %1 : $@box Y):
-  %2 = project_box %1 : $@box Y
+  %2 = project_box %1 : $@box Y, 0
   %3 = load %2 : $*Y
   %4 = ref_element_addr %3 : $Y, #Y.x
   store %0 to %4 : $*X
@@ -470,7 +470,7 @@ bb0(%0 : $X, %1 : $@box Y):
 sil @test_escaped_box : $@convention(thin) (Int64) -> Int64 {
 bb0(%0 : $Int64):
   %1 = alloc_box $Int64
-  %2 = project_box %1 : $@box Int64
+  %2 = project_box %1 : $@box Int64, 0
   store %0 to %2 : $*Int64
 
   %4 = function_ref @let_box_escape : $@convention(thin) (@owned @box Int64) -> Int64
@@ -491,7 +491,7 @@ bb0(%0 : $Int64):
 // CHECK-NEXT:  End
 sil @let_box_escape : $@convention(thin) (@owned @box Int64) -> Int64 {
 bb0(%0 : $@box Int64):
-  %1 = project_box %0 : $@box Int64
+  %1 = project_box %0 : $@box Int64, 0
   %2 = load %1 : $*Int64
 
   %3 = function_ref @takebox : $@convention(thin) (@owned @box Int64) -> ()
@@ -513,7 +513,7 @@ sil @takebox :  $@convention(thin) (@owned @box Int64) -> ()
 sil @test_escaped_partial_apply : $@convention(thin) (Int64) -> () {
 bb0(%0 : $Int64):
   %1 = alloc_box $Int64
-  %2 = project_box %1 : $@box Int64
+  %2 = project_box %1 : $@box Int64, 0
   store %0 to %2 : $*Int64
   %4 = function_ref @closure3 : $@convention(thin) (@owned @box Int64) -> Int64
   strong_retain %1 : $@box Int64
@@ -533,7 +533,7 @@ bb0(%0 : $Int64):
 // CHECK-NEXT:  End
 sil @closure3 : $@convention(thin) (@owned @box Int64) -> Int64 {
 bb0(%0 : $@box Int64):
-  %1 = project_box %0 : $@box Int64
+  %1 = project_box %0 : $@box Int64, 0
   %2 = load %1 : $*Int64
   strong_release %0 : $@box Int64
   return %2 : $Int64
@@ -750,7 +750,7 @@ sil @unknown_throwing_func : $@convention(thin) (@owned X) -> (@owned X, @error
 sil @test_release_of_partial_apply_with_box : $@convention(thin) (@owned Y) -> () {
 bb0(%0 : $Y):
   %1 = alloc_box $Y
-  %2 = project_box %1 : $@box Y
+  %2 = project_box %1 : $@box Y, 0
   store %0 to %2 : $*Y
   %3 = function_ref @take_y_box : $@convention(thin) (@owned @box Y) -> ()
   %4 = partial_apply %3(%1) : $@convention(thin) (@owned @box Y) -> ()
diff --git a/test/SILOptimizer/looprotate.sil b/test/SILOptimizer/looprotate.sil
index 5bd953224ee..9ff2bc15712 100644
--- a/test/SILOptimizer/looprotate.sil
+++ b/test/SILOptimizer/looprotate.sil
@@ -46,7 +46,7 @@ bb0(%0 : $Int32, %25: $Bar):
   %1 = struct_extract %0 : $Int32, #Int32._value
   %2 = integer_literal $Builtin.Int32, 0
   %30 = alloc_box $Bool
-  %30a = project_box %30 : $@box Bool
+  %30a = project_box %30 : $@box Bool, 0
   br bb1(%1 : $Builtin.Int32, %2 : $Builtin.Int32, %25: $Bar, %30 : $@box Bool, %30a : $*Bool)
 
 bb1(%4 : $Builtin.Int32, %5 : $Builtin.Int32, %26: $Bar, %31 : $@box Bool, %32 : $*Bool):
@@ -121,7 +121,7 @@ bb0(%0 : $Int32, %25: $*P):
   %1 = struct_extract %0 : $Int32, #Int32._value
   %2 = integer_literal $Builtin.Int32, 0
   %30 = alloc_box $Bool
-  %30a = project_box %30 : $@box Bool
+  %30a = project_box %30 : $@box Bool, 0
   %40 = open_existential_addr %25 : $*P to $*@opened("C22498FA-CABF-11E5-B9A9-685B35C48C83") P
   br bb1(%1 : $Builtin.Int32, %2 : $Builtin.Int32, %25: $*P, %30 : $@box Bool, %30a : $*Bool)
 
diff --git a/test/SILOptimizer/lslocation_expansion.sil b/test/SILOptimizer/lslocation_expansion.sil
index 5d7838a9d75..30b079b1707 100644
--- a/test/SILOptimizer/lslocation_expansion.sil
+++ b/test/SILOptimizer/lslocation_expansion.sil
@@ -93,7 +93,7 @@ sil @stack_store : $@convention(thin) () -> () {
 sil @store_after_store : $@convention(thin) (@owned B) -> () {
 bb0(%0 : $B):
   %1 = alloc_box $B
-  %1a = project_box %1 : $@box B
+  %1a = project_box %1 : $@box B, 0
   %2 = store %0 to %1a : $*B
   %3 = store %0 to %1a : $*B
   %4 = tuple()
diff --git a/test/SILOptimizer/lslocation_reduction.sil b/test/SILOptimizer/lslocation_reduction.sil
index 8249812cd81..1daecae2b4f 100644
--- a/test/SILOptimizer/lslocation_reduction.sil
+++ b/test/SILOptimizer/lslocation_reduction.sil
@@ -93,7 +93,7 @@ sil @stack_store : $@convention(thin) () -> () {
 sil @store_after_store : $@convention(thin) (@owned B) -> () {
 bb0(%0 : $B):
   %1 = alloc_box $B
-  %1a = project_box %1 : $@box B
+  %1a = project_box %1 : $@box B, 0
   %2 = store %0 to %1a : $*B
   %3 = store %0 to %1a : $*B
   %4 = tuple()
diff --git a/test/SILOptimizer/mandatory_inlining.sil b/test/SILOptimizer/mandatory_inlining.sil
index 6cf6f84551f..9cede619821 100644
--- a/test/SILOptimizer/mandatory_inlining.sil
+++ b/test/SILOptimizer/mandatory_inlining.sil
@@ -28,7 +28,7 @@ sil @fromLiteral : $@convention(thin) (Builtin.Int128, @thin Int64.Type) -> Int6
 sil [transparent] @test_add : $@convention(thin) (Int64) -> Int64 {
 bb0(%0 : $Int64):
   %1 = alloc_box $Int64
-  %1a = project_box %1 : $@box Int64
+  %1a = project_box %1 : $@box Int64, 0
   store %0 to %1a : $*Int64
   %3 = function_ref @plus : $@convention(thin) (Int64, Int64) -> Int64
   %4 = load %1a : $*Int64
@@ -76,7 +76,7 @@ sil @inline_test_add : $@convention(thin) (Int64) -> Int64 {
 
 bb0(%0 : $Int64):
   %1 = alloc_box $Int64
-  %1a = project_box %1 : $@box Int64
+  %1a = project_box %1 : $@box Int64, 0
   store %0 to %1a : $*Int64
   %3 = function_ref @plus : $@convention(thin) (Int64, Int64) -> Int64
   %4 = function_ref @test_add : $@convention(thin) (Int64) -> Int64
@@ -143,7 +143,7 @@ sil @inline_twice_test_add : $@convention(thin) (Int64) -> Int64 {
 
 bb0(%0 : $Int64):
   %1 = alloc_box $Int64
-  %1a = project_box %1 : $@box Int64
+  %1a = project_box %1 : $@box Int64, 0
   store %0 to %1a : $*Int64
   %3 = function_ref @plus : $@convention(thin) (Int64, Int64) -> Int64
   %4 = function_ref @test_add : $@convention(thin) (Int64) -> Int64
@@ -173,7 +173,7 @@ protocol SomeProtocol {
 sil [transparent] @test_existential_metatype : $@convention(thin) (@in SomeProtocol) -> @thick SomeProtocol.Type {
 bb0(%0 : $*SomeProtocol):
   %1 = alloc_box $SomeProtocol
-  %1a = project_box %1 : $@box SomeProtocol
+  %1a = project_box %1 : $@box SomeProtocol, 0
   copy_addr [take] %0 to [initialization] %1a : $*SomeProtocol
   %4 = alloc_stack $SomeProtocol
   copy_addr %1a to [initialization] %4 : $*SomeProtocol
@@ -222,9 +222,9 @@ sil @bar : $@convention(thin) (Float32) -> Bool
 sil [transparent] @test_control_flow : $@convention(thin) (Float, Float) -> Float {
 bb0(%0 : $Float, %1 : $Float):
   %2 = alloc_box $Float
-  %2a = project_box %2 : $@box Float
+  %2a = project_box %2 : $@box Float, 0
   %3 = alloc_box $Float
-  %3a = project_box %3 : $@box Float
+  %3a = project_box %3 : $@box Float, 0
   store %0 to %2a : $*Float
   store %1 to %3a : $*Float
   %6 = function_ref @get_logic_value : $@convention(method) (@inout Bool) -> Builtin.Int1
@@ -362,7 +362,7 @@ sil @inline_test_control_flow : $@convention(thin) (Float) -> Float {
 
 bb0(%0 : $Float):
   %1 = alloc_box $Float
-  %1a = project_box %1 : $@box Float
+  %1a = project_box %1 : $@box Float, 0
   store %0 to %1a : $*Float
   %3 = function_ref @sub_floats : $@convention(thin) (Float, Float) -> Float
   %4 = function_ref @test_control_flow : $@convention(thin) (Float, Float) -> Float
@@ -454,9 +454,9 @@ sil @true_getter : $@convention(thin) () -> Bool
 sil [transparent] @short_circuit_or : $@convention(thin) (Bool, @callee_owned () -> Bool) -> Bool {
 bb0(%0 : $Bool, %1 : $@callee_owned () -> Bool):
   %2 = alloc_box $Bool
-  %2a = project_box %2 : $@box Bool
+  %2a = project_box %2 : $@box Bool, 0
   %3 = alloc_box $@callee_owned () -> Bool
-  %3a = project_box %3 : $@box @callee_owned () -> Bool
+  %3a = project_box %3 : $@box @callee_owned () -> Bool, 0
   store %0 to %2a : $*Bool
   store %1 to %3a : $*@callee_owned () -> Bool
   %6 = function_ref @get_logic_value : $@convention(method) (@inout Bool) -> Builtin.Int1
@@ -483,7 +483,7 @@ bb3(%16 : $Bool):
 
 sil private [transparent] @closure0 : $@convention(thin) (@owned @box Bool) -> Bool {
 bb0(%0 : $@box Bool):
-  %1 = project_box %0 : $@box Bool
+  %1 = project_box %0 : $@box Bool, 0
   %2 = tuple ()
   %3 = load %1 : $*Bool
   strong_release %0 : $@box Bool
@@ -516,9 +516,9 @@ sil @test_short_circuit : $@convention(thin) (Bool, Bool) -> Bool {
 
 bb0(%0 : $Bool, %1 : $Bool):
   %2 = alloc_box $Bool
-  %2a = project_box %2 : $@box Bool
+  %2a = project_box %2 : $@box Bool, 0
   %3 = alloc_box $Bool
-  %3a = project_box %3 : $@box Bool
+  %3a = project_box %3 : $@box Bool, 0
   store %0 to %2a : $*Bool
   store %1 to %3a : $*Bool
   %6 = function_ref @short_circuit_or : $@convention(thin) (Bool, @callee_owned () -> Bool) -> Bool
@@ -558,9 +558,9 @@ sil @test_short_circuit2 : $@convention(thin) (Bool, Bool) -> Bool {
 
 bb0(%0 : $Bool, %1 : $Bool):
   %2 = alloc_box $Bool
-  %2a = project_box %2 : $@box Bool
+  %2a = project_box %2 : $@box Bool, 0
   %3 = alloc_box $Bool
-  %3a = project_box %3 : $@box Bool
+  %3a = project_box %3 : $@box Bool, 0
   store %0 to %2a : $*Bool
   store %1 to %3a : $*Bool
   %6 = function_ref @short_circuit_or : $@convention(thin) (Bool, @callee_owned () -> Bool) -> Bool
@@ -591,7 +591,7 @@ sil @test_with_dead_argument : $@convention(thin) () -> () {
 bb0:
   %0 = tuple ()
   %1 = alloc_box $Int64
-  %1a = project_box %1 : $@box Int64
+  %1a = project_box %1 : $@box Int64, 0
   %2 = function_ref @convertFromBuiltinIntegerLiteral : $@convention(thin) (Builtin.Int2048, @thin Int64.Type) -> Int64
   %3 = metatype $@thin Int64.Type
   %4 = integer_literal $Builtin.Int2048, 1
diff --git a/test/SILOptimizer/mem2reg.sil b/test/SILOptimizer/mem2reg.sil
index cf952034460..ee9d10cccb8 100644
--- a/test/SILOptimizer/mem2reg.sil
+++ b/test/SILOptimizer/mem2reg.sil
@@ -54,7 +54,7 @@ bb0(%0 : $Int64):
   %1 = alloc_stack $Int64, var, name "c"               // users: %19, %2
   store %0 to %1 : $*Int64                      // id: %2
   %3 = alloc_box $Int64, var, name "x"                 // users: %16, %11, %6
-  %3a = project_box %3 : $@box Int64
+  %3a = project_box %3 : $@box Int64, 0
   %4 = integer_literal $Builtin.Int64, 2          // users: %9, %5
   %5 = struct $Int64 (%4 : $Builtin.Int64)        // users: %12, %6
   store %5 to %3a : $*Int64                      // id: %6
@@ -85,7 +85,7 @@ bb0(%0 : $Int64):
   %1 = alloc_stack $Int64, var, name "c"               // users: %19, %2, (%20)
   store %0 to %1 : $*Int64                      // id: %2
   %3 = alloc_box $Int64, var, name "x"                 // users: %16, %11, %6
-  %3a = project_box %3 : $@box Int64
+  %3a = project_box %3 : $@box Int64, 0
   %4 = integer_literal $Builtin.Int64, 2          // users: %9, %5
   %5 = struct $Int64 (%4 : $Builtin.Int64)        // users: %12, %6
   store %5 to %3a : $*Int64                      // id: %6
diff --git a/test/SILOptimizer/predictable_memopt.sil b/test/SILOptimizer/predictable_memopt.sil
index 4008e2a6f19..2386133d3b6 100644
--- a/test/SILOptimizer/predictable_memopt.sil
+++ b/test/SILOptimizer/predictable_memopt.sil
@@ -8,10 +8,10 @@ import Swift
 sil @simple_reg_promotion : $@convention(thin) (Int) -> Int {
 bb0(%0 : $Int):                         // CHECK: bb0(%0 : $Int):
   %1 = alloc_box $Int
-  %1a = project_box %1 : $@box Int
+  %1a = project_box %1 : $@box Int, 0
   store %0 to %1a : $*Int
   %3 = alloc_box $Int
-  %3a = project_box %3 : $@box Int
+  %3a = project_box %3 : $@box Int, 0
   %4 = load %1a : $*Int
   store %4 to %3a : $*Int
   %6 = load %3a : $*Int
@@ -27,7 +27,7 @@ bb0(%0 : $Int):                         // CHECK: bb0(%0 : $Int):
 sil @tuple_reg_promotion : $@convention(thin) (Int) -> Int {
 bb0(%0 : $Int):                         // CHECK: bb0(%0 : $Int):
   %1 = alloc_box $(Int, Int)
-  %1a = project_box %1 : $@box (Int, Int)
+  %1a = project_box %1 : $@box (Int, Int), 0
   
   %a = tuple_element_addr %1a : $*(Int, Int), 0
   %b = tuple_element_addr %1a : $*(Int, Int), 1
@@ -67,7 +67,7 @@ bb0(%0 : $Int):
   // This alloc_stack can't be removed since it is used by an inout call.
   // CHECK: %1 = alloc_box $Int
   %1 = alloc_box $Int
-  %1a = project_box %1 : $@box Int
+  %1a = project_box %1 : $@box Int, 0
   %2 = store %0 to %1a : $*Int
   
   // This load should be eliminated.
@@ -105,7 +105,7 @@ sil @closure0 : $@convention(thin) (@owned @box Int) -> ()
 sil @closure_test2 : $@convention(thin) (Int) -> Int {
 bb0(%1 : $Int):
   %0 = alloc_box $Int
-  %0a = project_box %0 : $@box Int
+  %0a = project_box %0 : $@box Int, 0
   store %1 to %0a : $*Int  // CHECK: store
 
   %5 = function_ref @takes_closure : $@convention(thin) (@callee_owned () -> ()) -> ()
@@ -133,7 +133,7 @@ sil @getSomeClass : $@convention(thin) () -> @owned SomeClass
 sil @assign_test_trivial : $@convention(thin) (Int) -> Int {
 bb0(%0 : $Int):
   %1 = alloc_box $Int
-  %1a = project_box %1 : $@box Int
+  %1a = project_box %1 : $@box Int, 0
 
   store %0 to %1a : $*Int
   store %0 to %1a : $*Int
@@ -378,7 +378,7 @@ entry(%x : $Int):
   // CHECK: [[BOX:%.*]] = alloc_box $Int
   %b = alloc_box $Int
   // CHECK: [[PB:%.*]] = project_box [[BOX]]
-  %ba = project_box %b : $@box Int
+  %ba = project_box %b : $@box Int, 0
   // CHECK: store [[X]] to [[PB]]
   store %x to %ba : $*Int
   // CHECK: [[E:%.*]] = enum $IndirectCase, #IndirectCase.X!enumelt.1, [[BOX]] : $@box Int
diff --git a/test/SILOptimizer/redundant_load_elim.sil b/test/SILOptimizer/redundant_load_elim.sil
index 537eb6ba5b7..0aa5667bff8 100644
--- a/test/SILOptimizer/redundant_load_elim.sil
+++ b/test/SILOptimizer/redundant_load_elim.sil
@@ -305,7 +305,7 @@ bb0(%0 : $Agg1):
 sil @store_promotion : $@convention(thin) (@owned B) -> () {
 bb0(%0 : $B):
   %1 = alloc_box $B
-  %1a = project_box %1 : $@box B
+  %1a = project_box %1 : $@box B, 0
   %2 = store %0 to %1a : $*B
   %3 = load %1a : $*B
   %4 = load %1a : $*B
@@ -940,8 +940,8 @@ bb10:                                             // Preds: bb7 bb8 bb9
 // CHECK: return [[TP]]
 sil @test_project_box : $@convention(thin) (@box Builtin.Int32) -> (Builtin.Int32, Builtin.Int32) {
 bb0(%0 : $@box Builtin.Int32):
-  %2 = project_box %0 : $@box Builtin.Int32
-  %3 = project_box %0 : $@box Builtin.Int32
+  %2 = project_box %0 : $@box Builtin.Int32, 0
+  %3 = project_box %0 : $@box Builtin.Int32, 0
   %4 = load %2 : $*Builtin.Int32
   %5 = load %3 : $*Builtin.Int32
 
diff --git a/test/SILOptimizer/redundant_load_elim_with_casts.sil b/test/SILOptimizer/redundant_load_elim_with_casts.sil
index 1d483d5670f..c93ed3a7d3b 100644
--- a/test/SILOptimizer/redundant_load_elim_with_casts.sil
+++ b/test/SILOptimizer/redundant_load_elim_with_casts.sil
@@ -73,7 +73,7 @@ struct Wrapper {
 sil @tbaa_class_alias_nonclass : $@convention(thin) (@owned B, @inout Agg1) -> () {
 bb0(%0 : $B, %1 : $*Agg1):
   %2 = alloc_box $B
-  %2a = project_box %2 : $@box B
+  %2a = project_box %2 : $@box B, 0
   %3 = load %1 : $*Agg1
   %4 = store %3 to %1 : $*Agg1
   %5 = load %2a : $*B
diff --git a/test/SILOptimizer/side-effect.sil b/test/SILOptimizer/side-effect.sil
index 80eae0365e0..130e9fc01ac 100644
--- a/test/SILOptimizer/side-effect.sil
+++ b/test/SILOptimizer/side-effect.sil
@@ -177,7 +177,7 @@ bb0(%0 : $Int32):
   %l1 = load %a : $*Int32
 
   %b = alloc_box $Int32
-  %ba = project_box %b : $@box Int32
+  %ba = project_box %b : $@box Int32, 0
   store %0 to %ba : $*Int32
   %l2 = load %ba : $*Int32
  
@@ -279,7 +279,7 @@ bb0(%0 : $Int32):
 // CHECK: <func=,param0=r>
 sil @test_project_box : $@convention(thin) (@box Builtin.Int32) -> Builtin.Int32 {
 bb0(%0 : $@box Builtin.Int32):
-  %a = project_box %0 : $@box Builtin.Int32
+  %a = project_box %0 : $@box Builtin.Int32, 0
   %l = load %a : $*Builtin.Int32
   return %l : $Builtin.Int32
 }
diff --git a/test/SILOptimizer/sil_combine.sil b/test/SILOptimizer/sil_combine.sil
index 86f62e81434..ce92a3f31cb 100644
--- a/test/SILOptimizer/sil_combine.sil
+++ b/test/SILOptimizer/sil_combine.sil
@@ -143,7 +143,7 @@ bb0:
 sil @removeTriviallyDeadInstructions : $@convention(thin) (@owned B) -> () {
 bb0(%0 : $B):
   %1 = alloc_box $B
-  %1a = project_box %1 : $@box B
+  %1a = project_box %1 : $@box B, 0
   %2 = store %0 to %1a : $*B
   %3 = load %1a : $*B
   %4 = strong_retain %3 : $B
diff --git a/test/SILOptimizer/sil_locations.sil b/test/SILOptimizer/sil_locations.sil
index 594cc6fd51d..513797667b4 100644
--- a/test/SILOptimizer/sil_locations.sil
+++ b/test/SILOptimizer/sil_locations.sil
@@ -10,7 +10,7 @@ sil @fromLiteral : $@convention(thin) (Builtin.Int128, @thin Int64.Type) -> Int6
 sil [transparent] @test_add : $@convention(thin) (Int64) -> Int64 {
 bb0(%0 : $Int64):
   %1 = alloc_box $Int64
-  %1a = project_box %1 : $@box Int64
+  %1a = project_box %1 : $@box Int64, 0
   store %0 to %1a : $*Int64
   %3 = function_ref @plus : $@convention(thin) (Int64, Int64) -> Int64
   %4 = load %1a : $*Int64
@@ -26,7 +26,7 @@ bb0(%0 : $Int64):
 sil @inline_test_add : $@convention(thin) (Int64) -> Int64 {
 bb0(%0 : $Int64):
   %1 = alloc_box $Int64
-  %1a = project_box %1 : $@box Int64
+  %1a = project_box %1 : $@box Int64, 0
   store %0 to %1a : $*Int64
   %3 = function_ref @plus : $@convention(thin) (Int64, Int64) -> Int64
   %4 = function_ref @test_add : $@convention(thin) (Int64) -> Int64
diff --git a/test/SILOptimizer/simplify_cfg.sil b/test/SILOptimizer/simplify_cfg.sil
index 74113f240ba..86dda33482d 100644
--- a/test/SILOptimizer/simplify_cfg.sil
+++ b/test/SILOptimizer/simplify_cfg.sil
@@ -2633,7 +2633,7 @@ bb2(%16 : $Error):
 sil @simplified_branch_arg_has_result_value_1 : $@convention(thin) (@in Builtin.Int32) -> Builtin.Int32 {
 entry(%0 : $*Builtin.Int32):
   %b = alloc_box $Builtin.Int32
-  %p = project_box %b : $@box Builtin.Int32
+  %p = project_box %b : $@box Builtin.Int32, 0
   %i = integer_literal $Builtin.Int32, 0
   store %i to %p : $*Builtin.Int32
   br bb1(%p : $*Builtin.Int32)
diff --git a/test/SILOptimizer/specialize.sil b/test/SILOptimizer/specialize.sil
index 37fdb8859c4..2f0dc778755 100644
--- a/test/SILOptimizer/specialize.sil
+++ b/test/SILOptimizer/specialize.sil
@@ -167,7 +167,7 @@ bb0(%0 : $*T):
   // function_ref specialize.(getGenericClosure <A>(t : A) -> () -> A).(tmp #1) (())A
   %2 = function_ref @_TFF10specialize17getGenericClosureU__FT1tQ__FT_Q_L_3tmpfT_Q_ : $@convention(thin) <τ_0_0> (@owned @box τ_0_0) -> @out τ_0_0 // user: %5
   %3 = alloc_box $T                               // users: %4, %5, %5
-  %3a = project_box %3 : $@box T
+  %3a = project_box %3 : $@box T, 0
   copy_addr %0 to [initialization] %3a : $*T     // id: %4
   %5 = partial_apply %2<T>(%3) : $@convention(thin) <τ_0_0> (@owned @box τ_0_0) -> @out τ_0_0 // user: %7
   destroy_addr %0 : $*T                           // id: %6
@@ -177,7 +177,7 @@ bb0(%0 : $*T):
 // specialize.(getGenericClosure <A>(t : A) -> () -> A).(tmp #1) (())
 sil shared @_TFF10specialize17getGenericClosureU__FT1tQ__FT_Q_L_3tmpfT_Q_ : $@convention(thin) <T> (@owned @box T) -> @out T {
 bb0(%0 : $*T, %1 : $@box T):
-  %2 = project_box %1 : $@box T
+  %2 = project_box %1 : $@box T, 0
   copy_addr %2 to [initialization] %0 : $*T       // id: %3
   strong_release %1 : $@box T       // id: %4
   %5 = tuple ()                                   // user: %6
@@ -297,7 +297,7 @@ bb0(%0 : $*U):
   // function_ref test4.(boo <A : test4.P, B>(A) -> (Swift.Int32, B) -> Swift.Int32).(closure #1)
   %2 = function_ref @_TFF5test43booUS_1P___FQ_FTVs5Int32Q0__S1_U_FTS1_Q0__S1_ : $@convention(thin) <τ_0_0, τ_0_1 where τ_0_0 : P> (Int32, @in τ_0_1, @owned @box τ_0_0) -> Int32 // user: %5
   %3 = alloc_box $U                               // users: %4, %5, %5
-  %3a = project_box %3 : $@box U
+  %3a = project_box %3 : $@box U, 0
   copy_addr %0 to [initialization] %3a : $*U     // id: %4
   %5 = partial_apply %2<U, T>(%3) : $@convention(thin) <τ_0_0, τ_0_1 where τ_0_0 : P> (Int32, @in τ_0_1, @owned @box τ_0_0) -> Int32 // user: %7
   destroy_addr %0 : $*U                           // id: %6
@@ -307,7 +307,7 @@ bb0(%0 : $*U):
 // test4.(boo <A : test4.P, B>(A) -> (Swift.Int32, B) -> Swift.Int32).(closure #1)
 sil shared [noinline] @_TFF5test43booUS_1P___FQ_FTVs5Int32Q0__S1_U_FTS1_Q0__S1_ : $@convention(thin) <U, T where U : P> (Int32, @in T, @owned @box U) -> Int32 {
 bb0(%0 : $Int32, %1 : $*T, %2 : $@box U):
-  %3 = project_box %2 : $@box U
+  %3 = project_box %2 : $@box U, 0
   debug_value %0 : $Int32, let, name "x" // id: %4
   debug_value_addr %1 : $*T, let, name "z" // id: %5
   %6 = witness_method $U, #P.get!1 : $@convention(witness_method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> Int32 // user: %7
@@ -375,7 +375,7 @@ bb0(%0 : $*T):
   // function_ref test4.(gen1 <A : test4.P>(A) -> (Swift.Int32) -> Swift.Int32).(closure #1)
   %2 = function_ref @_TFF5test44gen1US_1P__FQ_FVs5Int32S1_U_FS1_S1_ : $@convention(thin) <τ_0_0 where τ_0_0 : P> (Int32, @owned @box τ_0_0) -> Int32 // user: %5
   %3 = alloc_box $T                               // users: %4, %5, %5
-  %3a = project_box %3 : $@box T
+  %3a = project_box %3 : $@box T, 0
   copy_addr %0 to [initialization] %3a : $*T     // id: %4
   %5 = partial_apply %2<T>(%3) : $@convention(thin) <τ_0_0 where τ_0_0 : P> (Int32, @owned @box τ_0_0) -> Int32 // user: %7
   destroy_addr %0 : $*T                           // id: %6
@@ -385,7 +385,7 @@ bb0(%0 : $*T):
 // test4.(gen1 <A : test4.P>(A) -> (Swift.Int32) -> Swift.Int32).(closure #1)
 sil shared [noinline] @_TFF5test44gen1US_1P__FQ_FVs5Int32S1_U_FS1_S1_ : $@convention(thin) <T where T : P> (Int32, @owned @box T) -> Int32 {
 bb0(%0 : $Int32, %1 : $@box T):
-  %2 = project_box %1 : $@box T
+  %2 = project_box %1 : $@box T, 0
   debug_value %0 : $Int32 , let, name "$0"              // id: %3
   %4 = witness_method $T, #P.get!1 : $@convention(witness_method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> Int32 // user: %5
   %5 = apply %4<T>(%2) : $@convention(witness_method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> Int32 // user: %6
diff --git a/test/SILOptimizer/specialize_metatypes_with_nondefault_representation.sil b/test/SILOptimizer/specialize_metatypes_with_nondefault_representation.sil
index 77051889b62..306053a72e5 100644
--- a/test/SILOptimizer/specialize_metatypes_with_nondefault_representation.sil
+++ b/test/SILOptimizer/specialize_metatypes_with_nondefault_representation.sil
@@ -37,18 +37,18 @@ sil @tmp2 : $@convention(thin) () -> () {
 bb0:
   %0 = function_ref @tmp : $@convention(thin) <T> () -> (@out T)
   %1 = alloc_box $@thick AnyObject.Type
-  %1a = project_box %1 : $@box @thick AnyObject.Type
+  %1a = project_box %1 : $@box @thick AnyObject.Type, 0
   %2 = alloc_box $@objc_metatype AnyObject.Type
-  %2a = project_box %2 : $@box @objc_metatype AnyObject.Type
+  %2a = project_box %2 : $@box @objc_metatype AnyObject.Type, 0
   %4 = apply %0<@thick AnyObject.Type>(%1a) : $@convention(thin) <T> () -> (@out T)
   %5 = apply %0<@objc_metatype AnyObject.Type>(%2a) : $@convention(thin) <T> () -> (@out T)
 
   %6 = alloc_box $@thick Builtin.Int32.Type
-  %6a = project_box %6 : $@box @thick Builtin.Int32.Type
+  %6a = project_box %6 : $@box @thick Builtin.Int32.Type, 0
   %7 = alloc_box $@objc_metatype Builtin.Int32.Type
-  %7a = project_box %7 : $@box @objc_metatype Builtin.Int32.Type
+  %7a = project_box %7 : $@box @objc_metatype Builtin.Int32.Type, 0
   %8 = alloc_box $@thin Builtin.Int32.Type
-  %8a = project_box %8 : $@box @thin Builtin.Int32.Type
+  %8a = project_box %8 : $@box @thin Builtin.Int32.Type, 0
   %9 = apply %0<@thick Builtin.Int32.Type>(%6a) : $@convention(thin) <T> () -> (@out T)
   %10 = apply %0<@objc_metatype Builtin.Int32.Type>(%7a) : $@convention(thin) <T> () -> (@out T)
   %11 = apply %0<@thin Builtin.Int32.Type>(%8a) : $@convention(thin) <T> () -> (@out T)
diff --git a/test/SILOptimizer/split_critical_edges.sil b/test/SILOptimizer/split_critical_edges.sil
index 89a68599a4b..ad707e38731 100644
--- a/test/SILOptimizer/split_critical_edges.sil
+++ b/test/SILOptimizer/split_critical_edges.sil
@@ -126,7 +126,7 @@ bb0(%0 : $AnyObject, %10: $Builtin.Int1):
 
 lookup1:
   %1 = alloc_box $AnyObject
-  %1a = project_box %1 : $@box AnyObject
+  %1a = project_box %1 : $@box AnyObject, 0
   store %0 to %1a : $*AnyObject
   %3 = alloc_box $Optional<() -> ()>
   %4 = load %1a : $*AnyObject
@@ -137,7 +137,7 @@ lookup1:
 
 lookup2:
   %21 = alloc_box $AnyObject
-  %21a = project_box %21 : $@box AnyObject
+  %21a = project_box %21 : $@box AnyObject, 0
   store %0 to %21a : $*AnyObject
   %23 = alloc_box $Optional<() -> ()>
   %24 = load %21a : $*AnyObject
diff --git a/test/SILOptimizer/typed-access-tb-aa.sil b/test/SILOptimizer/typed-access-tb-aa.sil
index 7a14432079a..4b9e1c26d33 100644
--- a/test/SILOptimizer/typed-access-tb-aa.sil
+++ b/test/SILOptimizer/typed-access-tb-aa.sil
@@ -87,56 +87,56 @@ bb0:
 
 // Check that a raw pointer address may alias everything.
 // CHECK: PAIR #134.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #135.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #136.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #137.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %11 = project_box %4 : $@box Builtin.Int32
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %11 = project_box %4 : $@box Builtin.Int32, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #138.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #139.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %13 = project_box %6 : $@box Builtin.FPIEEE64
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %13 = project_box %6 : $@box Builtin.FPIEEE64, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #140.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %14 = project_box %0 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %14 = project_box %0 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #141.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %15 = project_box %1 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %15 = project_box %1 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #142.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %16 = project_box %2 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %16 = project_box %2 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #143.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %17 = project_box %3 : $@box Builtin.Int8
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %17 = project_box %3 : $@box Builtin.Int8, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #144.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %18 = project_box %4 : $@box Builtin.Int32
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %18 = project_box %4 : $@box Builtin.Int32, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #145.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %19 = project_box %5 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %19 = project_box %5 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #146.
-// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer
-// CHECK-NEXT:   %20 = project_box %6 : $@box Builtin.FPIEEE64
+// CHECK-NEXT:   %7 = project_box %0 : $@box Builtin.RawPointer, 0
+// CHECK-NEXT:   %20 = project_box %6 : $@box Builtin.FPIEEE64, 0
 // CHECK-NEXT: MayAlias
 
 // Now check that a native object address may:
@@ -150,178 +150,178 @@ bb0:
 // 4. May alias addresses to other Builtin.NativeObjects
 
 // CHECK: PAIR #149.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #150.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #151.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %11 = project_box %4 : $@box Builtin.Int32
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %11 = project_box %4 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #152.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #153.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %13 = project_box %6 : $@box Builtin.FPIEEE64
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %13 = project_box %6 : $@box Builtin.FPIEEE64, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #154.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %14 = project_box %0 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %14 = project_box %0 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #155.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %15 = project_box %1 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %15 = project_box %1 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #156.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %16 = project_box %2 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %16 = project_box %2 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #157.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %17 = project_box %3 : $@box Builtin.Int8
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %17 = project_box %3 : $@box Builtin.Int8, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #158.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %18 = project_box %4 : $@box Builtin.Int32
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %18 = project_box %4 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #159.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %19 = project_box %5 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %19 = project_box %5 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #160.
-// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject
-// CHECK-NEXT:   %20 = project_box %6 : $@box Builtin.FPIEEE64
+// CHECK-NEXT:   %8 = project_box %1 : $@box Builtin.NativeObject, 0
+// CHECK-NEXT:   %20 = project_box %6 : $@box Builtin.FPIEEE64, 0
 // CHECK-NEXT: NoAlias
 
 // Check that unknown object addresses may only alias raw pointer addresses and
 // other unknown object addresses. Anything else should be no alias.
 // CHECK: PAIR #163.
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #164.
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
-// CHECK-NEXT:   %11 = project_box %4 : $@box Builtin.Int32
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+// CHECK-NEXT:   %11 = project_box %4 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #165.
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #166.
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
-// CHECK-NEXT:   %13 = project_box %6 : $@box Builtin.FPIEEE64
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+// CHECK-NEXT:   %13 = project_box %6 : $@box Builtin.FPIEEE64, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #167.
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
-// CHECK-NEXT:   %14 = project_box %0 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+// CHECK-NEXT:   %14 = project_box %0 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #168.
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
-// CHECK-NEXT:   %15 = project_box %1 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+// CHECK-NEXT:   %15 = project_box %1 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #169.
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
-// CHECK-NEXT:   %16 = project_box %2 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+// CHECK-NEXT:   %16 = project_box %2 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #170.
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
-// CHECK-NEXT:   %17 = project_box %3 : $@box Builtin.Int8
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+// CHECK-NEXT:   %17 = project_box %3 : $@box Builtin.Int8, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #171.
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
-// CHECK-NEXT:   %18 = project_box %4 : $@box Builtin.Int32
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+// CHECK-NEXT:   %18 = project_box %4 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #172.
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
-// CHECK-NEXT:   %19 = project_box %5 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+// CHECK-NEXT:   %19 = project_box %5 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #173.
-// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject
-// CHECK-NEXT:   %20 = project_box %6 : $@box Builtin.FPIEEE64
+// CHECK-NEXT:   %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+// CHECK-NEXT:   %20 = project_box %6 : $@box Builtin.FPIEEE64, 0
 // CHECK-NEXT: NoAlias
 
 // Next check that Int8 addresses can only alias Int8 addresses and raw
 // pointers. This includes ensuring that Int8 cannot alias Int32 addresses.
 // CHECK: PAIR #176.
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
-// CHECK-NEXT:   %11 = project_box %4 : $@box Builtin.Int32
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
+// CHECK-NEXT:   %11 = project_box %4 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #177.
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #178.
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
-// CHECK-NEXT:   %13 = project_box %6 : $@box Builtin.FPIEEE64
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
+// CHECK-NEXT:   %13 = project_box %6 : $@box Builtin.FPIEEE64, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #179.
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
-// CHECK-NEXT:   %14 = project_box %0 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
+// CHECK-NEXT:   %14 = project_box %0 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #180.
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
-// CHECK-NEXT:   %15 = project_box %1 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
+// CHECK-NEXT:   %15 = project_box %1 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #181.
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
-// CHECK-NEXT:   %16 = project_box %2 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
+// CHECK-NEXT:   %16 = project_box %2 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #182.
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
-// CHECK-NEXT:   %17 = project_box %3 : $@box Builtin.Int8
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
+// CHECK-NEXT:   %17 = project_box %3 : $@box Builtin.Int8, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #183.
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
-// CHECK-NEXT:   %18 = project_box %4 : $@box Builtin.Int32
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
+// CHECK-NEXT:   %18 = project_box %4 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #184.
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
-// CHECK-NEXT:   %19 = project_box %5 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
+// CHECK-NEXT:   %19 = project_box %5 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #185.
-// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8
-// CHECK-NEXT:   %20 = project_box %6 : $@box Builtin.FPIEEE64
+// CHECK-NEXT:   %10 = project_box %3 : $@box Builtin.Int8, 0
+// CHECK-NEXT:   %20 = project_box %6 : $@box Builtin.FPIEEE64, 0
 // CHECK-NEXT: NoAlias
 
 // Finally conclude by checking that FPIEEE32 addresses only can alias raw
 // pointer addresses and other FPIEEE32 addresses. Again this includes proving
 // that FPIEEE64 addresses cannot alias FPIEEE32.
 // CHECK: PAIR #199.
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
-// CHECK-NEXT:   %13 = project_box %6 : $@box Builtin.FPIEEE64
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
+// CHECK-NEXT:   %13 = project_box %6 : $@box Builtin.FPIEEE64, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #200.
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
-// CHECK-NEXT:   %14 = project_box %0 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
+// CHECK-NEXT:   %14 = project_box %0 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #201.
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
-// CHECK-NEXT:   %15 = project_box %1 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
+// CHECK-NEXT:   %15 = project_box %1 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #202.
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
-// CHECK-NEXT:   %16 = project_box %2 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
+// CHECK-NEXT:   %16 = project_box %2 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #203.
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
-// CHECK-NEXT:   %17 = project_box %3 : $@box Builtin.Int8
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
+// CHECK-NEXT:   %17 = project_box %3 : $@box Builtin.Int8, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #204.
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
-// CHECK-NEXT:   %18 = project_box %4 : $@box Builtin.Int32
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
+// CHECK-NEXT:   %18 = project_box %4 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #205.
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
-// CHECK-NEXT:   %19 = project_box %5 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
+// CHECK-NEXT:   %19 = project_box %5 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #206.
-// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32
-// CHECK-NEXT:   %20 = project_box %6 : $@box Builtin.FPIEEE64
+// CHECK-NEXT:   %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
+// CHECK-NEXT:   %20 = project_box %6 : $@box Builtin.FPIEEE64, 0
 // CHECK-NEXT: NoAlias
 
 sil @builtin_test : $@convention(thin) () -> () {
@@ -334,25 +334,25 @@ bb0:
   %5 = alloc_box $Builtin.FPIEEE32
   %6 = alloc_box $Builtin.FPIEEE64
 
-  %7 = project_box %0 : $@box Builtin.RawPointer
-  %8 = project_box %1 : $@box Builtin.NativeObject
-  %9 = project_box %2 : $@box Builtin.UnknownObject
-  %10 = project_box %3 : $@box Builtin.Int8
-  %11 = project_box %4 : $@box Builtin.Int32
-  %12 = project_box %5 : $@box Builtin.FPIEEE32
-  %13 = project_box %6 : $@box Builtin.FPIEEE64
+  %7 = project_box %0 : $@box Builtin.RawPointer, 0
+  %8 = project_box %1 : $@box Builtin.NativeObject, 0
+  %9 = project_box %2 : $@box Builtin.UnknownObject, 0
+  %10 = project_box %3 : $@box Builtin.Int8, 0
+  %11 = project_box %4 : $@box Builtin.Int32, 0
+  %12 = project_box %5 : $@box Builtin.FPIEEE32, 0
+  %13 = project_box %6 : $@box Builtin.FPIEEE64, 0
 
   // This second block ensures that we gain the benefits of not repeating
   // already known values with being able to have associated with the output for
   // each type each of the items we are trying to check aliasing against. This
   // makes it simpler to write these tests.
-  %14 = project_box %0 : $@box Builtin.RawPointer
-  %15 = project_box %1 : $@box Builtin.NativeObject
-  %16 = project_box %2 : $@box Builtin.UnknownObject
-  %17 = project_box %3 : $@box Builtin.Int8
-  %18 = project_box %4 : $@box Builtin.Int32
-  %19 = project_box %5 : $@box Builtin.FPIEEE32
-  %20 = project_box %6 : $@box Builtin.FPIEEE64
+  %14 = project_box %0 : $@box Builtin.RawPointer, 0
+  %15 = project_box %1 : $@box Builtin.NativeObject, 0
+  %16 = project_box %2 : $@box Builtin.UnknownObject, 0
+  %17 = project_box %3 : $@box Builtin.Int8, 0
+  %18 = project_box %4 : $@box Builtin.Int32, 0
+  %19 = project_box %5 : $@box Builtin.FPIEEE32, 0
+  %20 = project_box %6 : $@box Builtin.FPIEEE64, 0
 
   %21 = tuple()
   return %21 : $()
@@ -367,52 +367,52 @@ bb0:
 
 // CHECK-LABEL: @struct_tests
 // CHECK: PAIR #339.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %14 = project_box %0 : $@box STest_S1
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %14 = project_box %0 : $@box STest_S1, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #340.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %15 = project_box %1 : $@box STest_S2
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %15 = project_box %1 : $@box STest_S2, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #341.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %16 = project_box %2 : $@box STest_E1
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %16 = project_box %2 : $@box STest_E1, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #342.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %17 = project_box %3 : $@box STest_E2
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %17 = project_box %3 : $@box STest_E2, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #343.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %18 = project_box %4 : $@box STest_C1
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %18 = project_box %4 : $@box STest_C1, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #344.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %19 = project_box %5 : $@box STest_C2
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %19 = project_box %5 : $@box STest_C2, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #345.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %20 = project_box %6 : $@box STest_S3
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %20 = project_box %6 : $@box STest_S3, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #351.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %26 = project_box %21 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %26 = project_box %21 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #352.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %27 = project_box %22 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %27 = project_box %22 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #353.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %28 = project_box %23 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %28 = project_box %23 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #354.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %29 = project_box %24 : $@box Builtin.Int32
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %29 = project_box %24 : $@box Builtin.Int32, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #355.
-// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3
-// CHECK-NEXT:   %30 = project_box %25 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %13 = project_box %6 : $@box STest_S3, 0
+// CHECK-NEXT:   %30 = project_box %25 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 
 struct STest_S1 {
@@ -455,21 +455,21 @@ sil @struct_tests : $@convention(thin) () -> () {
   %5 = alloc_box $STest_C2
   %6 = alloc_box $STest_S3
 
-  %7 = project_box %0 : $@box STest_S1
-  %8 = project_box %1 : $@box STest_S2
-  %9 = project_box %2 : $@box STest_E1
-  %10 = project_box %3 : $@box STest_E2
-  %11 = project_box %4 : $@box STest_C1
-  %12 = project_box %5 : $@box STest_C2
-  %13 = project_box %6 : $@box STest_S3
+  %7 = project_box %0 : $@box STest_S1, 0
+  %8 = project_box %1 : $@box STest_S2, 0
+  %9 = project_box %2 : $@box STest_E1, 0
+  %10 = project_box %3 : $@box STest_E2, 0
+  %11 = project_box %4 : $@box STest_C1, 0
+  %12 = project_box %5 : $@box STest_C2, 0
+  %13 = project_box %6 : $@box STest_S3, 0
 
-  %14 = project_box %0 : $@box STest_S1
-  %15 = project_box %1 : $@box STest_S2
-  %16 = project_box %2 : $@box STest_E1
-  %17 = project_box %3 : $@box STest_E2
-  %18 = project_box %4 : $@box STest_C1
-  %19 = project_box %5 : $@box STest_C2
-  %20 = project_box %6 : $@box STest_S3
+  %14 = project_box %0 : $@box STest_S1, 0
+  %15 = project_box %1 : $@box STest_S2, 0
+  %16 = project_box %2 : $@box STest_E1, 0
+  %17 = project_box %3 : $@box STest_E2, 0
+  %18 = project_box %4 : $@box STest_C1, 0
+  %19 = project_box %5 : $@box STest_C2, 0
+  %20 = project_box %6 : $@box STest_S3, 0
 
   %21 = alloc_box $Builtin.RawPointer
   %22 = alloc_box $Builtin.NativeObject
@@ -477,11 +477,11 @@ sil @struct_tests : $@convention(thin) () -> () {
   %24 = alloc_box $Builtin.Int32
   %25 = alloc_box $Builtin.FPIEEE32
 
-  %26 = project_box %21 : $@box Builtin.RawPointer
-  %27 = project_box %22 : $@box Builtin.NativeObject
-  %28 = project_box %23 : $@box Builtin.UnknownObject
-  %29 = project_box %24 : $@box Builtin.Int32
-  %30 = project_box %25 : $@box Builtin.FPIEEE32
+  %26 = project_box %21 : $@box Builtin.RawPointer, 0
+  %27 = project_box %22 : $@box Builtin.NativeObject, 0
+  %28 = project_box %23 : $@box Builtin.UnknownObject, 0
+  %29 = project_box %24 : $@box Builtin.Int32, 0
+  %30 = project_box %25 : $@box Builtin.FPIEEE32, 0
 
   %9999 = tuple()
   return %9999 : $()
@@ -489,52 +489,52 @@ sil @struct_tests : $@convention(thin) () -> () {
 
 // CHECK-LABEL: @enum_tests
 // CHECK: PAIR #339.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %14 = project_box %0 : $@box ETest_S1
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %14 = project_box %0 : $@box ETest_S1, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #340.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %15 = project_box %1 : $@box ETest_S2
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %15 = project_box %1 : $@box ETest_S2, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #341.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %16 = project_box %2 : $@box ETest_E1
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %16 = project_box %2 : $@box ETest_E1, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #342.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %17 = project_box %3 : $@box ETest_E2
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %17 = project_box %3 : $@box ETest_E2, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #343.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %18 = project_box %4 : $@box ETest_C1
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %18 = project_box %4 : $@box ETest_C1, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #344.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %19 = project_box %5 : $@box ETest_C2
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %19 = project_box %5 : $@box ETest_C2, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #345.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %20 = project_box %6 : $@box ETest_E3
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %20 = project_box %6 : $@box ETest_E3, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #351.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %26 = project_box %21 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %26 = project_box %21 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #352.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %27 = project_box %22 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %27 = project_box %22 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #353.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %28 = project_box %23 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %28 = project_box %23 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #354.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %29 = project_box %24 : $@box Builtin.Int32
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %29 = project_box %24 : $@box Builtin.Int32, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #355.
-// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3
-// CHECK-NEXT:   %30 = project_box %25 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %13 = project_box %6 : $@box ETest_E3, 0
+// CHECK-NEXT:   %30 = project_box %25 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 
 struct ETest_S1 {
@@ -577,21 +577,21 @@ sil @enum_tests : $@convention(thin) () -> () {
   %5 = alloc_box $ETest_C2
   %6 = alloc_box $ETest_E3
 
-  %7 = project_box %0 : $@box ETest_S1
-  %8 = project_box %1 : $@box ETest_S2
-  %9 = project_box %2 : $@box ETest_E1
-  %10 = project_box %3 : $@box ETest_E2
-  %11 = project_box %4 : $@box ETest_C1
-  %12 = project_box %5 : $@box ETest_C2
-  %13 = project_box %6 : $@box ETest_E3
+  %7 = project_box %0 : $@box ETest_S1, 0
+  %8 = project_box %1 : $@box ETest_S2, 0
+  %9 = project_box %2 : $@box ETest_E1, 0
+  %10 = project_box %3 : $@box ETest_E2, 0
+  %11 = project_box %4 : $@box ETest_C1, 0
+  %12 = project_box %5 : $@box ETest_C2, 0
+  %13 = project_box %6 : $@box ETest_E3, 0
 
-  %14 = project_box %0 : $@box ETest_S1
-  %15 = project_box %1 : $@box ETest_S2
-  %16 = project_box %2 : $@box ETest_E1
-  %17 = project_box %3 : $@box ETest_E2
-  %18 = project_box %4 : $@box ETest_C1
-  %19 = project_box %5 : $@box ETest_C2
-  %20 = project_box %6 : $@box ETest_E3
+  %14 = project_box %0 : $@box ETest_S1, 0
+  %15 = project_box %1 : $@box ETest_S2, 0
+  %16 = project_box %2 : $@box ETest_E1, 0
+  %17 = project_box %3 : $@box ETest_E2, 0
+  %18 = project_box %4 : $@box ETest_C1, 0
+  %19 = project_box %5 : $@box ETest_C2, 0
+  %20 = project_box %6 : $@box ETest_E3, 0
 
   %21 = alloc_box $Builtin.RawPointer
   %22 = alloc_box $Builtin.NativeObject
@@ -599,11 +599,11 @@ sil @enum_tests : $@convention(thin) () -> () {
   %24 = alloc_box $Builtin.Int32
   %25 = alloc_box $Builtin.FPIEEE32
 
-  %26 = project_box %21 : $@box Builtin.RawPointer
-  %27 = project_box %22 : $@box Builtin.NativeObject
-  %28 = project_box %23 : $@box Builtin.UnknownObject
-  %29 = project_box %24 : $@box Builtin.Int32
-  %30 = project_box %25 : $@box Builtin.FPIEEE32
+  %26 = project_box %21 : $@box Builtin.RawPointer, 0
+  %27 = project_box %22 : $@box Builtin.NativeObject, 0
+  %28 = project_box %23 : $@box Builtin.UnknownObject, 0
+  %29 = project_box %24 : $@box Builtin.Int32, 0
+  %30 = project_box %25 : $@box Builtin.FPIEEE32, 0
 
   %9999 = tuple()
   return %9999 : $()
@@ -612,130 +612,130 @@ sil @enum_tests : $@convention(thin) () -> () {
 // CHECK-LABEL: @class_tests
 
 // CHECK: PAIR #72.
-// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1
-// CHECK-NEXT:   %6 = project_box %0 : $@box CTest_C1
+// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1, 0
+// CHECK-NEXT:   %6 = project_box %0 : $@box CTest_C1, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #73.
-// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1
-// CHECK-NEXT:   %7 = project_box %1 : $@box CTest_C2
+// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1, 0
+// CHECK-NEXT:   %7 = project_box %1 : $@box CTest_C2, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #74.
-// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1
-// CHECK-NEXT:   %8 = project_box %2 : $@box CTest_C3
+// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1, 0
+// CHECK-NEXT:   %8 = project_box %2 : $@box CTest_C3, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #82.
-// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1
-// CHECK-NEXT:   %16 = project_box %9 : $@box AnyObject
+// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1, 0
+// CHECK-NEXT:   %16 = project_box %9 : $@box AnyObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #83.
-// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1
-// CHECK-NEXT:   %17 = project_box %10 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1, 0
+// CHECK-NEXT:   %17 = project_box %10 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #84.
-// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1
-// CHECK-NEXT:   %18 = project_box %11 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1, 0
+// CHECK-NEXT:   %18 = project_box %11 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #85.
-// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1
-// CHECK-NEXT:   %19 = project_box %12 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1, 0
+// CHECK-NEXT:   %19 = project_box %12 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #86.
-// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1
-// CHECK-NEXT:   %20 = project_box %13 : $@box Builtin.Int8
+// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1, 0
+// CHECK-NEXT:   %20 = project_box %13 : $@box Builtin.Int8, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #87.
-// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1
-// CHECK-NEXT:   %21 = project_box %14 : $@box Builtin.Int32
+// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1, 0
+// CHECK-NEXT:   %21 = project_box %14 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #88.
-// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1
-// CHECK-NEXT:   %22 = project_box %15 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %3 = project_box %0 : $@box CTest_C1, 0
+// CHECK-NEXT:   %22 = project_box %15 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 
 // CHECK: PAIR #91.
-// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2
-// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3
+// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2, 0
+// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #92.
-// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2
-// CHECK-NEXT:   %6 = project_box %0 : $@box CTest_C1
+// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2, 0
+// CHECK-NEXT:   %6 = project_box %0 : $@box CTest_C1, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #93.
-// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2
-// CHECK-NEXT:   %7 = project_box %1 : $@box CTest_C2
+// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2, 0
+// CHECK-NEXT:   %7 = project_box %1 : $@box CTest_C2, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #94.
-// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2
-// CHECK-NEXT:   %8 = project_box %2 : $@box CTest_C3
+// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2, 0
+// CHECK-NEXT:   %8 = project_box %2 : $@box CTest_C3, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #102.
-// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2
-// CHECK-NEXT:   %16 = project_box %9 : $@box AnyObject
+// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2, 0
+// CHECK-NEXT:   %16 = project_box %9 : $@box AnyObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #103.
-// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2
-// CHECK-NEXT:   %17 = project_box %10 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2, 0
+// CHECK-NEXT:   %17 = project_box %10 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #104.
-// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2
-// CHECK-NEXT:   %18 = project_box %11 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2, 0
+// CHECK-NEXT:   %18 = project_box %11 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #105.
-// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2
-// CHECK-NEXT:   %19 = project_box %12 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2, 0
+// CHECK-NEXT:   %19 = project_box %12 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #106.
-// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2
-// CHECK-NEXT:   %20 = project_box %13 : $@box Builtin.Int8
+// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2, 0
+// CHECK-NEXT:   %20 = project_box %13 : $@box Builtin.Int8, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #107.
-// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2
-// CHECK-NEXT:   %21 = project_box %14 : $@box Builtin.Int32
+// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2, 0
+// CHECK-NEXT:   %21 = project_box %14 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #108.
-// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2
-// CHECK-NEXT:   %22 = project_box %15 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %4 = project_box %1 : $@box CTest_C2, 0
+// CHECK-NEXT:   %22 = project_box %15 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 
 // CHECK: PAIR #111.
-// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3
-// CHECK-NEXT:   %6 = project_box %0 : $@box CTest_C1
+// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3, 0
+// CHECK-NEXT:   %6 = project_box %0 : $@box CTest_C1, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #112.
-// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3
-// CHECK-NEXT:   %7 = project_box %1 : $@box CTest_C2
+// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3, 0
+// CHECK-NEXT:   %7 = project_box %1 : $@box CTest_C2, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #113.
-// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3
-// CHECK-NEXT:   %8 = project_box %2 : $@box CTest_C3
+// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3, 0
+// CHECK-NEXT:   %8 = project_box %2 : $@box CTest_C3, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #121.
-// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3
-// CHECK-NEXT:   %16 = project_box %9 : $@box AnyObject
+// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3, 0
+// CHECK-NEXT:   %16 = project_box %9 : $@box AnyObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #122.
-// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3
-// CHECK-NEXT:   %17 = project_box %10 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3, 0
+// CHECK-NEXT:   %17 = project_box %10 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #123.
-// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3
-// CHECK-NEXT:   %18 = project_box %11 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3, 0
+// CHECK-NEXT:   %18 = project_box %11 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #124.
-// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3
-// CHECK-NEXT:   %19 = project_box %12 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3, 0
+// CHECK-NEXT:   %19 = project_box %12 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #125.
-// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3
-// CHECK-NEXT:   %20 = project_box %13 : $@box Builtin.Int8
+// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3, 0
+// CHECK-NEXT:   %20 = project_box %13 : $@box Builtin.Int8, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #126.
-// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3
-// CHECK-NEXT:   %21 = project_box %14 : $@box Builtin.Int32
+// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3, 0
+// CHECK-NEXT:   %21 = project_box %14 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #127.
-// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3
-// CHECK-NEXT:   %22 = project_box %15 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %5 = project_box %2 : $@box CTest_C3, 0
+// CHECK-NEXT:   %22 = project_box %15 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 
 class CTest_C1 {
@@ -763,13 +763,13 @@ sil @class_tests : $@convention(thin) () -> () {
   %1 = alloc_box $CTest_C2
   %2 = alloc_box $CTest_C3
 
-  %3 = project_box %0 : $@box CTest_C1
-  %4 = project_box %1 : $@box CTest_C2
-  %5 = project_box %2 : $@box CTest_C3
+  %3 = project_box %0 : $@box CTest_C1, 0
+  %4 = project_box %1 : $@box CTest_C2, 0
+  %5 = project_box %2 : $@box CTest_C3, 0
 
-  %6 = project_box %0 : $@box CTest_C1
-  %7 = project_box %1 : $@box CTest_C2
-  %8 = project_box %2 : $@box CTest_C3
+  %6 = project_box %0 : $@box CTest_C1, 0
+  %7 = project_box %1 : $@box CTest_C2, 0
+  %8 = project_box %2 : $@box CTest_C3, 0
 
   %9 = alloc_box $AnyObject
   %10 = alloc_box $Builtin.RawPointer
@@ -779,13 +779,13 @@ sil @class_tests : $@convention(thin) () -> () {
   %14 = alloc_box $Builtin.Int32
   %15 = alloc_box $Builtin.FPIEEE32
 
-  %16 = project_box %9 : $@box AnyObject
-  %17 = project_box %10 : $@box Builtin.RawPointer
-  %18 = project_box %11 : $@box Builtin.NativeObject
-  %19 = project_box %12 : $@box Builtin.UnknownObject
-  %20 = project_box %13 : $@box Builtin.Int8
-  %21 = project_box %14 : $@box Builtin.Int32
-  %22 = project_box %15 : $@box Builtin.FPIEEE32
+  %16 = project_box %9 : $@box AnyObject, 0
+  %17 = project_box %10 : $@box Builtin.RawPointer, 0
+  %18 = project_box %11 : $@box Builtin.NativeObject, 0
+  %19 = project_box %12 : $@box Builtin.UnknownObject, 0
+  %20 = project_box %13 : $@box Builtin.Int8, 0
+  %21 = project_box %14 : $@box Builtin.Int32, 0
+  %22 = project_box %15 : $@box Builtin.FPIEEE32, 0
 
   %9999 = tuple()
   return %9999 : $()
@@ -793,104 +793,104 @@ sil @class_tests : $@convention(thin) () -> () {
 
 // CHECK-LABEL: @tuple_tests
 // CHECK: PAIR #66.
-// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
-// CHECK-NEXT:   %6 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
+// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
+// CHECK-NEXT:   %6 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #67.
-// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
-// CHECK-NEXT:   %7 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
+// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
+// CHECK-NEXT:   %7 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #68.
-// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
-// CHECK-NEXT:   %8 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
+// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
+// CHECK-NEXT:   %8 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #75.
-// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
-// CHECK-NEXT:   %15 = project_box %9 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
+// CHECK-NEXT:   %15 = project_box %9 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #76.
-// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
-// CHECK-NEXT:   %16 = project_box %10 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
+// CHECK-NEXT:   %16 = project_box %10 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #77.
-// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
-// CHECK-NEXT:   %17 = project_box %11 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
+// CHECK-NEXT:   %17 = project_box %11 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #78.
-// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
-// CHECK-NEXT:   %18 = project_box %12 : $@box Builtin.Int8
+// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
+// CHECK-NEXT:   %18 = project_box %12 : $@box Builtin.Int8, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #79.
-// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
-// CHECK-NEXT:   %19 = project_box %13 : $@box Builtin.Int32
+// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
+// CHECK-NEXT:   %19 = project_box %13 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #80.
-// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
-// CHECK-NEXT:   %20 = project_box %14 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
+// CHECK-NEXT:   %20 = project_box %14 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #85.
-// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
-// CHECK-NEXT:   %7 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
+// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
+// CHECK-NEXT:   %7 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #86.
-// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
-// CHECK-NEXT:   %8 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
+// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
+// CHECK-NEXT:   %8 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #93.
-// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
-// CHECK-NEXT:   %15 = project_box %9 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
+// CHECK-NEXT:   %15 = project_box %9 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #94.
-// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
-// CHECK-NEXT:   %16 = project_box %10 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
+// CHECK-NEXT:   %16 = project_box %10 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #95.
-// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
-// CHECK-NEXT:   %17 = project_box %11 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
+// CHECK-NEXT:   %17 = project_box %11 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #96.
-// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
-// CHECK-NEXT:   %18 = project_box %12 : $@box Builtin.Int8
+// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
+// CHECK-NEXT:   %18 = project_box %12 : $@box Builtin.Int8, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #97.
-// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
-// CHECK-NEXT:   %19 = project_box %13 : $@box Builtin.Int32
+// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
+// CHECK-NEXT:   %19 = project_box %13 : $@box Builtin.Int32, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #98.
-// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
-// CHECK-NEXT:   %20 = project_box %14 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
+// CHECK-NEXT:   %20 = project_box %14 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #102.
-// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
-// CHECK-NEXT:   %7 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
+// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
+// CHECK-NEXT:   %7 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #103.
-// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
-// CHECK-NEXT:   %8 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
+// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
+// CHECK-NEXT:   %8 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #110.
-// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
-// CHECK-NEXT:   %15 = project_box %9 : $@box Builtin.RawPointer
+// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
+// CHECK-NEXT:   %15 = project_box %9 : $@box Builtin.RawPointer, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #111.
-// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
-// CHECK-NEXT:   %16 = project_box %10 : $@box Builtin.NativeObject
+// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
+// CHECK-NEXT:   %16 = project_box %10 : $@box Builtin.NativeObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #112.
-// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
-// CHECK-NEXT:   %17 = project_box %11 : $@box Builtin.UnknownObject
+// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
+// CHECK-NEXT:   %17 = project_box %11 : $@box Builtin.UnknownObject, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #113.
-// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
-// CHECK-NEXT:   %18 = project_box %12 : $@box Builtin.Int8
+// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
+// CHECK-NEXT:   %18 = project_box %12 : $@box Builtin.Int8, 0
 // CHECK-NEXT: MayAlias
 // CHECK: PAIR #114.
-// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
-// CHECK-NEXT:   %19 = project_box %13 : $@box Builtin.Int32
+// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
+// CHECK-NEXT:   %19 = project_box %13 : $@box Builtin.Int32, 0
 // CHECK-NEXT: NoAlias
 // CHECK: PAIR #115.
-// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
-// CHECK-NEXT:   %20 = project_box %14 : $@box Builtin.FPIEEE32
+// CHECK-NEXT:   %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
+// CHECK-NEXT:   %20 = project_box %14 : $@box Builtin.FPIEEE32, 0
 // CHECK-NEXT: NoAlias
 
 struct TTest_S1 {
@@ -907,13 +907,13 @@ sil @tuple_tests : $@convention(thin) () -> () {
   %1 = alloc_box $(TTest_S1, Builtin.Int64)
   %2 = alloc_box $(TTest_E1, Builtin.Int64)
 
-  %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
-  %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
-  %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
+  %3 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
+  %4 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
+  %5 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
 
-  %6 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64)
-  %7 = project_box %1 : $@box (TTest_S1, Builtin.Int64)
-  %8 = project_box %2 : $@box (TTest_E1, Builtin.Int64)
+  %6 = project_box %0 : $@box (Builtin.RawPointer, Builtin.Int64), 0
+  %7 = project_box %1 : $@box (TTest_S1, Builtin.Int64), 0
+  %8 = project_box %2 : $@box (TTest_E1, Builtin.Int64), 0
 
   %9 = alloc_box $Builtin.RawPointer
   %10 = alloc_box $Builtin.NativeObject
@@ -922,12 +922,12 @@ sil @tuple_tests : $@convention(thin) () -> () {
   %13 = alloc_box $Builtin.Int32
   %14 = alloc_box $Builtin.FPIEEE32
 
-  %15 = project_box %9 : $@box Builtin.RawPointer
-  %16 = project_box %10 : $@box Builtin.NativeObject
-  %17 = project_box %11 : $@box Builtin.UnknownObject
-  %18 = project_box %12 : $@box Builtin.Int8
-  %19 = project_box %13 : $@box Builtin.Int32
-  %20 = project_box %14 : $@box Builtin.FPIEEE32
+  %15 = project_box %9 : $@box Builtin.RawPointer, 0
+  %16 = project_box %10 : $@box Builtin.NativeObject, 0
+  %17 = project_box %11 : $@box Builtin.UnknownObject, 0
+  %18 = project_box %12 : $@box Builtin.Int8, 0
+  %19 = project_box %13 : $@box Builtin.Int32, 0
+  %20 = project_box %14 : $@box Builtin.FPIEEE32, 0
 
   %9999 = tuple()
   return %9999 : $()
@@ -967,13 +967,13 @@ bb0(%0 : $*Builtin.Int64):
 
 // CHECK-LABEL: @test_project_box
 // CHECK:      PAIR #10.
-// CHECK-NEXT:   %2 = project_box %0 : $@box Builtin.Int32
-// CHECK-NEXT:   %3 = project_box %1 : $@box Builtin.Int64
+// CHECK-NEXT:   %2 = project_box %0 : $@box Builtin.Int32, 0
+// CHECK-NEXT:   %3 = project_box %1 : $@box Builtin.Int64, 0
 // CHECK-NEXT: NoAlias
 sil @test_project_box : $@convention(thin) (@box Builtin.Int32, @box Builtin.Int64) -> () {
 bb0(%0 : $@box Builtin.Int32, %1 : $@box Builtin.Int64):
-  %2 = project_box %0 : $@box Builtin.Int32
-  %3 = project_box %1 : $@box Builtin.Int64
+  %2 = project_box %0 : $@box Builtin.Int32, 0
+  %3 = project_box %1 : $@box Builtin.Int64, 0
 
   %r = tuple()
   return %r : $()
diff --git a/test/Serialization/Inputs/def_basic.sil b/test/Serialization/Inputs/def_basic.sil
index 5bf65abbf54..af62f9d2bb7 100644
--- a/test/Serialization/Inputs/def_basic.sil
+++ b/test/Serialization/Inputs/def_basic.sil
@@ -92,7 +92,7 @@ bb1:
 bb2:
   %5 = tuple ()
   %6 = alloc_box $Int
-  %7 = project_box %6 : $@box Int
+  %7 = project_box %6 : $@box Int, 0
   br bb1
 }
 
@@ -252,7 +252,7 @@ sil [fragile] @_TF4todo18erasure_from_protoFT1xPS_8RuncibleS_8Bendable__PS0__ :
 bb0(%0 : $*Runcible, %1 : $*Bendable & Runcible):
   // CHECK: alloc_box
   %2 = alloc_box $Bendable & Runcible
-  %2a = project_box %2 : $@box Bendable & Runcible
+  %2a = project_box %2 : $@box Bendable & Runcible, 0
   // CHECK: copy_addr [take] {{.*}} to [initialization] {{.*}} : $*Bendable & Runcible
   %3 = copy_addr [take] %1 to [initialization] %2a : $*Bendable & Runcible
   // CHECK: alloc_stack
@@ -277,7 +277,7 @@ protocol ClassBound : class {
 sil [fragile] @_TF4todo18class_bound_methodFT1xPS_10ClassBound__T_ : $@convention(thin) (@owned ClassBound) -> () {
 bb0(%0 : $ClassBound):
   %1 = alloc_box $ClassBound
-  %1a = project_box %1 : $@box ClassBound
+  %1a = project_box %1 : $@box ClassBound, 0
   %2 = store %0 to %1a : $*ClassBound
   %3 = load %1a : $*ClassBound
   %4 = strong_retain %3 : $ClassBound              // CHECK: strong_retain
@@ -321,7 +321,7 @@ sil [fragile] @_TFV6struct5AlephCfMS0_FT_S0_ : $@convention(thin) (@thin Aleph.T
 bb0(%0 : $@thin Aleph.Type):
   %1 = tuple ()
   %2 = alloc_box $Aleph       // CHECK: alloc_box
-  %2a = project_box %2 : $@box Aleph
+  %2a = project_box %2 : $@box Aleph, 0
   // CHECK: struct_element_addr {{.*}} : $*Aleph, #Aleph.a
   %5 = struct_element_addr %2a : $*Aleph, #Aleph.a
   %6 = load %5 : $*Ref
@@ -389,7 +389,7 @@ sil [fragile] @_TF5tuple5tupleFT_TSiSf_ : $@convention(thin) () -> (Int, Float32
 sil [fragile] @_TF5tuple13tuple_elementFT1xTSiSf__T_ : $@convention(thin) (Int, Float) -> () {
 bb0(%0 : $Int, %1 : $Float32):
   %2 = alloc_box $(Int, Float32)
-  %2a = project_box %2 : $@box (Int, Float32)
+  %2a = project_box %2 : $@box (Int, Float32), 0
   %3 = tuple (%0 : $Int, %1 : $Float32)
   %4 = store %3 to %2a : $*(Int, Float32)
   // CHECK: tuple_element_addr {{%.*}} : $*(Int, Float), 0
@@ -422,10 +422,10 @@ class M {
 sil [fragile] @_TFC3ref1C3foofS0_FT1xSi_T_ : $@convention(method) (Int, @guaranteed M) -> () {
 bb0(%0 : $Int, %1 : $M):
   %2 = alloc_box $Int
-  %2a = project_box %2 : $@box Int
+  %2a = project_box %2 : $@box Int, 0
   %3 = store %0 to %2a : $*Int
   %4 = alloc_box $M
-  %4a = project_box %4 : $@box M
+  %4a = project_box %4 : $@box M, 0
   %5 = store %1 to %4a : $*M
   %6 = load %2a : $*Int
   %7 = load %4a : $*M
@@ -447,7 +447,7 @@ class E : B { }
 sil [fragile] @_TF4null3isaFT1bCS_1B_Sb : $@convention(thin) (B) -> Builtin.Int1 {
 bb0(%0 : $B):
   %1 = alloc_box $B
-  %1a = project_box %1 : $@box B
+  %1a = project_box %1 : $@box B, 0
   %2 = store %0 to %1a : $*B
   %3 = load %1a : $*B
   %4 = strong_retain %3 : $B
@@ -473,9 +473,9 @@ sil [fragile] @_TFSS32_convertFromBuiltinStringLiteralfMSSFT5valueBp17utf8CodeUn
 sil [fragile] @_TF5index5gep64FT1pBp1iBi64__Bp : $@convention(thin) (Builtin.RawPointer, Builtin.Word) -> Builtin.RawPointer {
 bb0(%0 : $Builtin.RawPointer, %1 : $Builtin.Word):
   %2 = alloc_box $Builtin.RawPointer
-  %2a = project_box %2 : $@box Builtin.RawPointer
+  %2a = project_box %2 : $@box Builtin.RawPointer, 0
   %3 = alloc_box $Builtin.Word
-  %3a = project_box %3 : $@box Builtin.Word
+  %3a = project_box %3 : $@box Builtin.Word, 0
   %4 = store %0 to %2a : $*Builtin.RawPointer
   %5 = store %1 to %3a : $*Builtin.Word
   %7 = load %2a : $*Builtin.RawPointer
@@ -514,9 +514,9 @@ class SomeSubclass : SomeClass {}
 sil [fragile] @test_class_metatype : $@convention(thin) (SomeClass, SomeSubclass) -> (@thick SomeClass.Type, @thick SomeClass.Type) {
 bb0(%0 : $SomeClass, %1 : $SomeSubclass):
   %2 = alloc_box $SomeClass
-  %2a = project_box %2 : $@box SomeClass
+  %2a = project_box %2 : $@box SomeClass, 0
   %3 = alloc_box $SomeSubclass
-  %3a = project_box %3 : $@box SomeSubclass
+  %3a = project_box %3 : $@box SomeSubclass, 0
   %4 = store %0 to %2a : $*SomeClass
   %5 = store %1 to %3a : $*SomeSubclass
   %7 = load %2a : $*SomeClass
@@ -543,7 +543,7 @@ bb0(%0 : $SomeClass, %1 : $SomeSubclass):
 sil [fragile] @test_existential_metatype : $@convention(thin) (@in SomeProtocol) -> @thick SomeProtocol.Type {
 bb0(%0 : $*SomeProtocol):
   %1 = alloc_box $SomeProtocol
-  %1a = project_box %1 : $@box SomeProtocol
+  %1a = project_box %1 : $@box SomeProtocol, 0
   // CHECK: copy_addr [take] %0 to [initialization] %{{.*}} : $*SomeProtocol
   %2 = copy_addr [take] %0 to [initialization] %1a : $*SomeProtocol
   // CHECK: alloc_stack
@@ -615,9 +615,9 @@ bb3(%4 : $Int):
 sil [fragile] @test_builtin_func_ref : $@convention(thin) (Builtin.Int1, Builtin.Int1) -> Builtin.Int1 {
 bb0(%0 : $Builtin.Int1, %1 : $Builtin.Int1):
   %2 = alloc_box $Builtin.Int1
-  %2a = project_box %2 : $@box Builtin.Int1
+  %2a = project_box %2 : $@box Builtin.Int1, 0
   %3 = alloc_box $Builtin.Int1
-  %3a = project_box %3 : $@box Builtin.Int1
+  %3a = project_box %3 : $@box Builtin.Int1, 0
   store %0 to %2a : $*Builtin.Int1
   store %1 to %3a : $*Builtin.Int1
   %8 = load %2a : $*Builtin.Int1
@@ -707,7 +707,7 @@ sil [fragile] @closure0 : $@convention(thin) (@box Int, @inout Int) -> ()
 sil [fragile] @closure_test : $@convention(thin) () -> () {
 bb0:
   %0 = alloc_box $Int                           // users: %10, %8, %8, %7, %4
-  %0a = project_box %0 : $@box Int
+  %0a = project_box %0 : $@box Int, 0
 
   %5 = function_ref @takes_closure : $@convention(thin) (@callee_owned () -> ()) -> ()
   %6 = function_ref @closure0 : $@convention(thin) (@box Int, @inout Int) -> ()
@@ -735,7 +735,7 @@ sil [fragile] @_TF6switch1cFT_T_ : $@convention(thin) () -> ()
 sil [fragile] @test_switch_union : $@convention(thin) (MaybePair) -> () {
 bb0(%0 : $MaybePair):
   %1 = alloc_box $MaybePair
-  %1a = project_box %1 : $@box MaybePair
+  %1a = project_box %1 : $@box MaybePair, 0
   store %0 to %1a : $*MaybePair
   %3 = load %1a : $*MaybePair
   %4 = tuple ()
@@ -825,7 +825,7 @@ struct Spoon : Bendable {
 sil [fragile] @test_init_existential : $@convention(thin) (Spoon) -> @out Bendable {
 bb0(%0 : $*Bendable, %1 : $Spoon):
   %2 = alloc_box $Spoon
-  %2a = project_box %2 : $@box Spoon
+  %2a = project_box %2 : $@box Spoon, 0
   store %1 to %2a : $*Spoon
   // CHECK: init_existential_addr %{{.*}} : $*Bendable, $Spoon
   %4 = init_existential_addr %0 : $*Bendable, $Spoon
@@ -842,7 +842,7 @@ bb0(%0 : $*Bendable, %1 : $Spoon):
 sil [fragile] @test_existential_ref : $@convention(thin) (ConcreteClass) -> ClassP {
 bb0(%0 : $ConcreteClass):
   %1 = alloc_box $ConcreteClass
-  %1a = project_box %1 : $@box ConcreteClass
+  %1a = project_box %1 : $@box ConcreteClass, 0
   store %0 to %1a : $*ConcreteClass
   %3 = load %1a : $*ConcreteClass
   strong_retain %3 : $ConcreteClass
@@ -924,7 +924,7 @@ class X {
 sil [fragile] @test_dynamic_lookup_br : $@convention(thin) (AnyObject) -> () {
 bb0(%0 : $AnyObject):
   %1 = alloc_box $AnyObject
-  %1a = project_box %1 : $@box AnyObject
+  %1a = project_box %1 : $@box AnyObject, 0
   store %0 to %1a : $*AnyObject
   %3 = alloc_box $Optional<() -> ()>
   %4 = load %1a : $*AnyObject
@@ -948,9 +948,9 @@ bb3:
 // CHECK-LABEL: sil public_external [fragile] @test_mark_fn_escape
 sil [fragile] @test_mark_fn_escape : $@convention(thin) () -> () {
   %b = alloc_box $Int
-  %ba = project_box %b : $@box Int
+  %ba = project_box %b : $@box Int, 0
   %c = alloc_box $Int
-  %ca = project_box %c : $@box Int
+  %ca = project_box %c : $@box Int, 0
 
   //mark_function_escape %ba : $*Int
   //mark_function_escape %ba : $*Int, %ca : $*Int
@@ -1085,8 +1085,8 @@ sil [fragile] @box_type : $@convention(thin) (@box Int, Int) -> () {
 bb0(%0 : $@box Int, %1 : $Int):
   // CHECK-NEXT: strong_retain %0 : $@box Int
   strong_retain %0 : $@box Int
-  // CHECK-NEXT: %3 = project_box %0 : $@box Int
-  %3 = project_box %0 : $@box Int
+  // CHECK-NEXT: %3 = project_box %0 : $@box Int, 0
+  %3 = project_box %0 : $@box Int, 0
   // CHECK-NEXT: store %1 to %3 : $*Int
   store %1 to %3 : $*Int
   // CHECK-NEXT: strong_release %0 : $@box Int
diff --git a/test/sil-extract/basic.sil b/test/sil-extract/basic.sil
index 91b9aac3b1c..2bc01605efa 100644
--- a/test/sil-extract/basic.sil
+++ b/test/sil-extract/basic.sil
@@ -18,7 +18,7 @@ sil @makesInt : $@convention(thin) () -> Int64
 sil @use_before_init : $@convention(thin) () -> Int64 {
 bb0:
   %1 = alloc_box $Int64
-  %1a = project_box %1 : $@box Int64
+  %1a = project_box %1 : $@box Int64, 0
   %2 = load %1a : $*Int64
   %3 = function_ref @inout_uninit : $@convention(thin)() -> ()
   apply %3() : $@convention(thin) () -> ()
@@ -30,7 +30,7 @@ bb0:
 sil @inout_uninit : $@convention(thin) () -> () {
 bb0:
   %1 = alloc_box $Int64
-  %1a = project_box %1 : $@box Int64
+  %1a = project_box %1 : $@box Int64, 0
   %5 = function_ref @takes_Int_inout : $@convention(thin) (@inout Int64) -> ()
   %6 = apply %5(%1a) : $@convention(thin) (@inout Int64) -> ()