1 //===---- IRBuilder.cpp - Builder for LLVM Instrs -------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the IRBuilder class, which is used as a convenient way
11 // to create LLVM instructions with a consistent and simplified interface.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/IR/Function.h"
16 #include "llvm/IR/GlobalVariable.h"
17 #include "llvm/IR/IRBuilder.h"
18 #include "llvm/IR/Intrinsics.h"
19 #include "llvm/IR/LLVMContext.h"
20 #include "llvm/IR/Statepoint.h"
21 using namespace llvm;
22 
23 /// CreateGlobalString - Make a new global variable with an initializer that
24 /// has array of i8 type filled in with the nul terminated string value
25 /// specified.  If Name is specified, it is the name of the global variable
26 /// created.
27 GlobalVariable *IRBuilderBase::CreateGlobalString(StringRef Str,
28                                                   const Twine &Name,
29                                                   unsigned AddressSpace) {
30   Constant *StrConstant = ConstantDataArray::getString(Context, Str);
31   Module &M = *BB->getParent()->getParent();
32   GlobalVariable *GV = new GlobalVariable(M, StrConstant->getType(),
33                                           true, GlobalValue::PrivateLinkage,
34                                           StrConstant, Name, nullptr,
35                                           GlobalVariable::NotThreadLocal,
36                                           AddressSpace);
37   GV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
38   return GV;
39 }
40 
41 Type *IRBuilderBase::getCurrentFunctionReturnType() const {
42   assert(BB && BB->getParent() && "No current function!");
43   return BB->getParent()->getReturnType();
44 }
45 
46 Value *IRBuilderBase::getCastedInt8PtrValue(Value *Ptr) {
47   PointerType *PT = cast<PointerType>(Ptr->getType());
48   if (PT->getElementType()->isIntegerTy(8))
49     return Ptr;
50 
51   // Otherwise, we need to insert a bitcast.
52   PT = getInt8PtrTy(PT->getAddressSpace());
53   BitCastInst *BCI = new BitCastInst(Ptr, PT, "");
54   BB->getInstList().insert(InsertPt, BCI);
55   SetInstDebugLocation(BCI);
56   return BCI;
57 }
58 
59 static CallInst *createCallHelper(Value *Callee, ArrayRef<Value *> Ops,
60                                   IRBuilderBase *Builder,
61                                   const Twine& Name="") {
62   CallInst *CI = CallInst::Create(Callee, Ops, Name);
63   Builder->GetInsertBlock()->getInstList().insert(Builder->GetInsertPoint(),CI);
64   Builder->SetInstDebugLocation(CI);
65   return CI;
66 }
67 
68 static InvokeInst *createInvokeHelper(Value *Invokee, BasicBlock *NormalDest,
69                                       BasicBlock *UnwindDest,
70                                       ArrayRef<Value *> Ops,
71                                       IRBuilderBase *Builder,
72                                       const Twine &Name = "") {
73   InvokeInst *II =
74       InvokeInst::Create(Invokee, NormalDest, UnwindDest, Ops, Name);
75   Builder->GetInsertBlock()->getInstList().insert(Builder->GetInsertPoint(),
76                                                   II);
77   Builder->SetInstDebugLocation(II);
78   return II;
79 }
80 
81 CallInst *IRBuilderBase::
82 CreateMemSet(Value *Ptr, Value *Val, Value *Size, unsigned Align,
83              bool isVolatile, MDNode *TBAATag, MDNode *ScopeTag,
84              MDNode *NoAliasTag) {
85   Ptr = getCastedInt8PtrValue(Ptr);
86   Value *Ops[] = { Ptr, Val, Size, getInt32(Align), getInt1(isVolatile) };
87   Type *Tys[] = { Ptr->getType(), Size->getType() };
88   Module *M = BB->getParent()->getParent();
89   Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::memset, Tys);
90 
91   CallInst *CI = createCallHelper(TheFn, Ops, this);
92 
93   // Set the TBAA info if present.
94   if (TBAATag)
95     CI->setMetadata(LLVMContext::MD_tbaa, TBAATag);
96 
97   if (ScopeTag)
98     CI->setMetadata(LLVMContext::MD_alias_scope, ScopeTag);
99 
100   if (NoAliasTag)
101     CI->setMetadata(LLVMContext::MD_noalias, NoAliasTag);
102 
103   return CI;
104 }
105 
106 CallInst *IRBuilderBase::
107 CreateMemCpy(Value *Dst, Value *Src, Value *Size, unsigned Align,
108              bool isVolatile, MDNode *TBAATag, MDNode *TBAAStructTag,
109              MDNode *ScopeTag, MDNode *NoAliasTag) {
110   Dst = getCastedInt8PtrValue(Dst);
111   Src = getCastedInt8PtrValue(Src);
112 
113   Value *Ops[] = { Dst, Src, Size, getInt32(Align), getInt1(isVolatile) };
114   Type *Tys[] = { Dst->getType(), Src->getType(), Size->getType() };
115   Module *M = BB->getParent()->getParent();
116   Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::memcpy, Tys);
117 
118   CallInst *CI = createCallHelper(TheFn, Ops, this);
119 
120   // Set the TBAA info if present.
121   if (TBAATag)
122     CI->setMetadata(LLVMContext::MD_tbaa, TBAATag);
123 
124   // Set the TBAA Struct info if present.
125   if (TBAAStructTag)
126     CI->setMetadata(LLVMContext::MD_tbaa_struct, TBAAStructTag);
127 
128   if (ScopeTag)
129     CI->setMetadata(LLVMContext::MD_alias_scope, ScopeTag);
130 
131   if (NoAliasTag)
132     CI->setMetadata(LLVMContext::MD_noalias, NoAliasTag);
133 
134   return CI;
135 }
136 
137 CallInst *IRBuilderBase::
138 CreateMemMove(Value *Dst, Value *Src, Value *Size, unsigned Align,
139               bool isVolatile, MDNode *TBAATag, MDNode *ScopeTag,
140               MDNode *NoAliasTag) {
141   Dst = getCastedInt8PtrValue(Dst);
142   Src = getCastedInt8PtrValue(Src);
143 
144   Value *Ops[] = { Dst, Src, Size, getInt32(Align), getInt1(isVolatile) };
145   Type *Tys[] = { Dst->getType(), Src->getType(), Size->getType() };
146   Module *M = BB->getParent()->getParent();
147   Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::memmove, Tys);
148 
149   CallInst *CI = createCallHelper(TheFn, Ops, this);
150 
151   // Set the TBAA info if present.
152   if (TBAATag)
153     CI->setMetadata(LLVMContext::MD_tbaa, TBAATag);
154 
155   if (ScopeTag)
156     CI->setMetadata(LLVMContext::MD_alias_scope, ScopeTag);
157 
158   if (NoAliasTag)
159     CI->setMetadata(LLVMContext::MD_noalias, NoAliasTag);
160 
161   return CI;
162 }
163 
164 CallInst *IRBuilderBase::CreateLifetimeStart(Value *Ptr, ConstantInt *Size) {
165   assert(isa<PointerType>(Ptr->getType()) &&
166          "lifetime.start only applies to pointers.");
167   Ptr = getCastedInt8PtrValue(Ptr);
168   if (!Size)
169     Size = getInt64(-1);
170   else
171     assert(Size->getType() == getInt64Ty() &&
172            "lifetime.start requires the size to be an i64");
173   Value *Ops[] = { Size, Ptr };
174   Module *M = BB->getParent()->getParent();
175   Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::lifetime_start);
176   return createCallHelper(TheFn, Ops, this);
177 }
178 
179 CallInst *IRBuilderBase::CreateLifetimeEnd(Value *Ptr, ConstantInt *Size) {
180   assert(isa<PointerType>(Ptr->getType()) &&
181          "lifetime.end only applies to pointers.");
182   Ptr = getCastedInt8PtrValue(Ptr);
183   if (!Size)
184     Size = getInt64(-1);
185   else
186     assert(Size->getType() == getInt64Ty() &&
187            "lifetime.end requires the size to be an i64");
188   Value *Ops[] = { Size, Ptr };
189   Module *M = BB->getParent()->getParent();
190   Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::lifetime_end);
191   return createCallHelper(TheFn, Ops, this);
192 }
193 
194 CallInst *IRBuilderBase::CreateInvariantStart(Value *Ptr, ConstantInt *Size) {
195 
196   assert(isa<PointerType>(Ptr->getType()) &&
197          "invariant.start only applies to pointers.");
198   Ptr = getCastedInt8PtrValue(Ptr);
199   if (!Size)
200     Size = getInt64(-1);
201   else
202     assert(Size->getType() == getInt64Ty() &&
203            "invariant.start requires the size to be an i64");
204 
205   Value *Ops[] = {Size, Ptr};
206   // Fill in the single overloaded type: memory object type.
207   Type *ObjectPtr[1] = {Ptr->getType()};
208   Module *M = BB->getParent()->getParent();
209   Value *TheFn =
210       Intrinsic::getDeclaration(M, Intrinsic::invariant_start, ObjectPtr);
211   return createCallHelper(TheFn, Ops, this);
212 }
213 
214 CallInst *IRBuilderBase::CreateAssumption(Value *Cond) {
215   assert(Cond->getType() == getInt1Ty() &&
216          "an assumption condition must be of type i1");
217 
218   Value *Ops[] = { Cond };
219   Module *M = BB->getParent()->getParent();
220   Value *FnAssume = Intrinsic::getDeclaration(M, Intrinsic::assume);
221   return createCallHelper(FnAssume, Ops, this);
222 }
223 
224 /// \brief Create a call to a Masked Load intrinsic.
225 /// \p Ptr      - base pointer for the load
226 /// \p Align    - alignment of the source location
227 /// \p Mask     - vector of booleans which indicates what vector lanes should
228 ///               be accessed in memory
229 /// \p PassThru - pass-through value that is used to fill the masked-off lanes
230 ///               of the result
231 /// \p Name     - name of the result variable
232 CallInst *IRBuilderBase::CreateMaskedLoad(Value *Ptr, unsigned Align,
233                                           Value *Mask, Value *PassThru,
234                                           const Twine &Name) {
235   PointerType *PtrTy = cast<PointerType>(Ptr->getType());
236   Type *DataTy = PtrTy->getElementType();
237   assert(DataTy->isVectorTy() && "Ptr should point to a vector");
238   if (!PassThru)
239     PassThru = UndefValue::get(DataTy);
240   Type *OverloadedTypes[] = { DataTy, PtrTy };
241   Value *Ops[] = { Ptr, getInt32(Align), Mask,  PassThru};
242   return CreateMaskedIntrinsic(Intrinsic::masked_load, Ops,
243                                OverloadedTypes, Name);
244 }
245 
246 /// \brief Create a call to a Masked Store intrinsic.
247 /// \p Val   - data to be stored,
248 /// \p Ptr   - base pointer for the store
249 /// \p Align - alignment of the destination location
250 /// \p Mask  - vector of booleans which indicates what vector lanes should
251 ///            be accessed in memory
252 CallInst *IRBuilderBase::CreateMaskedStore(Value *Val, Value *Ptr,
253                                            unsigned Align, Value *Mask) {
254   PointerType *PtrTy = cast<PointerType>(Ptr->getType());
255   Type *DataTy = PtrTy->getElementType();
256   assert(DataTy->isVectorTy() && "Ptr should point to a vector");
257   Type *OverloadedTypes[] = { DataTy, PtrTy };
258   Value *Ops[] = { Val, Ptr, getInt32(Align), Mask };
259   return CreateMaskedIntrinsic(Intrinsic::masked_store, Ops, OverloadedTypes);
260 }
261 
262 /// Create a call to a Masked intrinsic, with given intrinsic Id,
263 /// an array of operands - Ops, and an array of overloaded types -
264 /// OverloadedTypes.
265 CallInst *IRBuilderBase::CreateMaskedIntrinsic(Intrinsic::ID Id,
266                                                ArrayRef<Value *> Ops,
267                                                ArrayRef<Type *> OverloadedTypes,
268                                                const Twine &Name) {
269   Module *M = BB->getParent()->getParent();
270   Value *TheFn = Intrinsic::getDeclaration(M, Id, OverloadedTypes);
271   return createCallHelper(TheFn, Ops, this, Name);
272 }
273 
274 /// \brief Create a call to a Masked Gather intrinsic.
275 /// \p Ptrs     - vector of pointers for loading
276 /// \p Align    - alignment for one element
277 /// \p Mask     - vector of booleans which indicates what vector lanes should
278 ///               be accessed in memory
279 /// \p PassThru - pass-through value that is used to fill the masked-off lanes
280 ///               of the result
281 /// \p Name     - name of the result variable
282 CallInst *IRBuilderBase::CreateMaskedGather(Value *Ptrs, unsigned Align,
283                                             Value *Mask,  Value *PassThru,
284                                             const Twine& Name) {
285   auto PtrsTy = cast<VectorType>(Ptrs->getType());
286   auto PtrTy = cast<PointerType>(PtrsTy->getElementType());
287   unsigned NumElts = PtrsTy->getVectorNumElements();
288   Type *DataTy = VectorType::get(PtrTy->getElementType(), NumElts);
289 
290   if (!Mask)
291     Mask = Constant::getAllOnesValue(VectorType::get(Type::getInt1Ty(Context),
292                                      NumElts));
293 
294   Value * Ops[] = {Ptrs, getInt32(Align), Mask, UndefValue::get(DataTy)};
295 
296   // We specify only one type when we create this intrinsic. Types of other
297   // arguments are derived from this type.
298   return CreateMaskedIntrinsic(Intrinsic::masked_gather, Ops, { DataTy }, Name);
299 }
300 
301 /// \brief Create a call to a Masked Scatter intrinsic.
302 /// \p Data  - data to be stored,
303 /// \p Ptrs  - the vector of pointers, where the \p Data elements should be
304 ///            stored
305 /// \p Align - alignment for one element
306 /// \p Mask  - vector of booleans which indicates what vector lanes should
307 ///            be accessed in memory
308 CallInst *IRBuilderBase::CreateMaskedScatter(Value *Data, Value *Ptrs,
309                                              unsigned Align, Value *Mask) {
310   auto PtrsTy = cast<VectorType>(Ptrs->getType());
311   auto DataTy = cast<VectorType>(Data->getType());
312   unsigned NumElts = PtrsTy->getVectorNumElements();
313 
314 #ifndef NDEBUG
315   auto PtrTy = cast<PointerType>(PtrsTy->getElementType());
316   assert(NumElts == DataTy->getVectorNumElements() &&
317          PtrTy->getElementType() == DataTy->getElementType() &&
318          "Incompatible pointer and data types");
319 #endif
320 
321   if (!Mask)
322     Mask = Constant::getAllOnesValue(VectorType::get(Type::getInt1Ty(Context),
323                                      NumElts));
324   Value * Ops[] = {Data, Ptrs, getInt32(Align), Mask};
325 
326   // We specify only one type when we create this intrinsic. Types of other
327   // arguments are derived from this type.
328   return CreateMaskedIntrinsic(Intrinsic::masked_scatter, Ops, { DataTy });
329 }
330 
331 template <typename T0, typename T1, typename T2, typename T3>
332 static std::vector<Value *>
333 getStatepointArgs(IRBuilderBase &B, uint64_t ID, uint32_t NumPatchBytes,
334                   Value *ActualCallee, uint32_t Flags, ArrayRef<T0> CallArgs,
335                   ArrayRef<T1> TransitionArgs, ArrayRef<T2> DeoptArgs,
336                   ArrayRef<T3> GCArgs) {
337   std::vector<Value *> Args;
338   Args.push_back(B.getInt64(ID));
339   Args.push_back(B.getInt32(NumPatchBytes));
340   Args.push_back(ActualCallee);
341   Args.push_back(B.getInt32(CallArgs.size()));
342   Args.push_back(B.getInt32(Flags));
343   Args.insert(Args.end(), CallArgs.begin(), CallArgs.end());
344   Args.push_back(B.getInt32(TransitionArgs.size()));
345   Args.insert(Args.end(), TransitionArgs.begin(), TransitionArgs.end());
346   Args.push_back(B.getInt32(DeoptArgs.size()));
347   Args.insert(Args.end(), DeoptArgs.begin(), DeoptArgs.end());
348   Args.insert(Args.end(), GCArgs.begin(), GCArgs.end());
349 
350   return Args;
351 }
352 
353 template <typename T0, typename T1, typename T2, typename T3>
354 static CallInst *CreateGCStatepointCallCommon(
355     IRBuilderBase *Builder, uint64_t ID, uint32_t NumPatchBytes,
356     Value *ActualCallee, uint32_t Flags, ArrayRef<T0> CallArgs,
357     ArrayRef<T1> TransitionArgs, ArrayRef<T2> DeoptArgs, ArrayRef<T3> GCArgs,
358     const Twine &Name) {
359   // Extract out the type of the callee.
360   PointerType *FuncPtrType = cast<PointerType>(ActualCallee->getType());
361   assert(isa<FunctionType>(FuncPtrType->getElementType()) &&
362          "actual callee must be a callable value");
363 
364   Module *M = Builder->GetInsertBlock()->getParent()->getParent();
365   // Fill in the one generic type'd argument (the function is also vararg)
366   Type *ArgTypes[] = { FuncPtrType };
367   Function *FnStatepoint =
368     Intrinsic::getDeclaration(M, Intrinsic::experimental_gc_statepoint,
369                               ArgTypes);
370 
371   std::vector<llvm::Value *> Args =
372       getStatepointArgs(*Builder, ID, NumPatchBytes, ActualCallee, Flags,
373                         CallArgs, TransitionArgs, DeoptArgs, GCArgs);
374   return createCallHelper(FnStatepoint, Args, Builder, Name);
375 }
376 
377 CallInst *IRBuilderBase::CreateGCStatepointCall(
378     uint64_t ID, uint32_t NumPatchBytes, Value *ActualCallee,
379     ArrayRef<Value *> CallArgs, ArrayRef<Value *> DeoptArgs,
380     ArrayRef<Value *> GCArgs, const Twine &Name) {
381   return CreateGCStatepointCallCommon<Value *, Value *, Value *, Value *>(
382       this, ID, NumPatchBytes, ActualCallee, uint32_t(StatepointFlags::None),
383       CallArgs, None /* No Transition Args */, DeoptArgs, GCArgs, Name);
384 }
385 
386 CallInst *IRBuilderBase::CreateGCStatepointCall(
387     uint64_t ID, uint32_t NumPatchBytes, Value *ActualCallee, uint32_t Flags,
388     ArrayRef<Use> CallArgs, ArrayRef<Use> TransitionArgs,
389     ArrayRef<Use> DeoptArgs, ArrayRef<Value *> GCArgs, const Twine &Name) {
390   return CreateGCStatepointCallCommon<Use, Use, Use, Value *>(
391       this, ID, NumPatchBytes, ActualCallee, Flags, CallArgs, TransitionArgs,
392       DeoptArgs, GCArgs, Name);
393 }
394 
395 CallInst *IRBuilderBase::CreateGCStatepointCall(
396     uint64_t ID, uint32_t NumPatchBytes, Value *ActualCallee,
397     ArrayRef<Use> CallArgs, ArrayRef<Value *> DeoptArgs,
398     ArrayRef<Value *> GCArgs, const Twine &Name) {
399   return CreateGCStatepointCallCommon<Use, Value *, Value *, Value *>(
400       this, ID, NumPatchBytes, ActualCallee, uint32_t(StatepointFlags::None),
401       CallArgs, None, DeoptArgs, GCArgs, Name);
402 }
403 
404 template <typename T0, typename T1, typename T2, typename T3>
405 static InvokeInst *CreateGCStatepointInvokeCommon(
406     IRBuilderBase *Builder, uint64_t ID, uint32_t NumPatchBytes,
407     Value *ActualInvokee, BasicBlock *NormalDest, BasicBlock *UnwindDest,
408     uint32_t Flags, ArrayRef<T0> InvokeArgs, ArrayRef<T1> TransitionArgs,
409     ArrayRef<T2> DeoptArgs, ArrayRef<T3> GCArgs, const Twine &Name) {
410   // Extract out the type of the callee.
411   PointerType *FuncPtrType = cast<PointerType>(ActualInvokee->getType());
412   assert(isa<FunctionType>(FuncPtrType->getElementType()) &&
413          "actual callee must be a callable value");
414 
415   Module *M = Builder->GetInsertBlock()->getParent()->getParent();
416   // Fill in the one generic type'd argument (the function is also vararg)
417   Function *FnStatepoint = Intrinsic::getDeclaration(
418       M, Intrinsic::experimental_gc_statepoint, {FuncPtrType});
419 
420   std::vector<llvm::Value *> Args =
421       getStatepointArgs(*Builder, ID, NumPatchBytes, ActualInvokee, Flags,
422                         InvokeArgs, TransitionArgs, DeoptArgs, GCArgs);
423   return createInvokeHelper(FnStatepoint, NormalDest, UnwindDest, Args, Builder,
424                             Name);
425 }
426 
427 InvokeInst *IRBuilderBase::CreateGCStatepointInvoke(
428     uint64_t ID, uint32_t NumPatchBytes, Value *ActualInvokee,
429     BasicBlock *NormalDest, BasicBlock *UnwindDest,
430     ArrayRef<Value *> InvokeArgs, ArrayRef<Value *> DeoptArgs,
431     ArrayRef<Value *> GCArgs, const Twine &Name) {
432   return CreateGCStatepointInvokeCommon<Value *, Value *, Value *, Value *>(
433       this, ID, NumPatchBytes, ActualInvokee, NormalDest, UnwindDest,
434       uint32_t(StatepointFlags::None), InvokeArgs, None /* No Transition Args*/,
435       DeoptArgs, GCArgs, Name);
436 }
437 
438 InvokeInst *IRBuilderBase::CreateGCStatepointInvoke(
439     uint64_t ID, uint32_t NumPatchBytes, Value *ActualInvokee,
440     BasicBlock *NormalDest, BasicBlock *UnwindDest, uint32_t Flags,
441     ArrayRef<Use> InvokeArgs, ArrayRef<Use> TransitionArgs,
442     ArrayRef<Use> DeoptArgs, ArrayRef<Value *> GCArgs, const Twine &Name) {
443   return CreateGCStatepointInvokeCommon<Use, Use, Use, Value *>(
444       this, ID, NumPatchBytes, ActualInvokee, NormalDest, UnwindDest, Flags,
445       InvokeArgs, TransitionArgs, DeoptArgs, GCArgs, Name);
446 }
447 
448 InvokeInst *IRBuilderBase::CreateGCStatepointInvoke(
449     uint64_t ID, uint32_t NumPatchBytes, Value *ActualInvokee,
450     BasicBlock *NormalDest, BasicBlock *UnwindDest, ArrayRef<Use> InvokeArgs,
451     ArrayRef<Value *> DeoptArgs, ArrayRef<Value *> GCArgs, const Twine &Name) {
452   return CreateGCStatepointInvokeCommon<Use, Value *, Value *, Value *>(
453       this, ID, NumPatchBytes, ActualInvokee, NormalDest, UnwindDest,
454       uint32_t(StatepointFlags::None), InvokeArgs, None, DeoptArgs, GCArgs,
455       Name);
456 }
457 
458 CallInst *IRBuilderBase::CreateGCResult(Instruction *Statepoint,
459                                        Type *ResultType,
460                                        const Twine &Name) {
461  Intrinsic::ID ID = Intrinsic::experimental_gc_result;
462  Module *M = BB->getParent()->getParent();
463  Type *Types[] = {ResultType};
464  Value *FnGCResult = Intrinsic::getDeclaration(M, ID, Types);
465 
466  Value *Args[] = {Statepoint};
467  return createCallHelper(FnGCResult, Args, this, Name);
468 }
469 
470 CallInst *IRBuilderBase::CreateGCRelocate(Instruction *Statepoint,
471                                          int BaseOffset,
472                                          int DerivedOffset,
473                                          Type *ResultType,
474                                          const Twine &Name) {
475  Module *M = BB->getParent()->getParent();
476  Type *Types[] = {ResultType};
477  Value *FnGCRelocate =
478    Intrinsic::getDeclaration(M, Intrinsic::experimental_gc_relocate, Types);
479 
480  Value *Args[] = {Statepoint,
481                   getInt32(BaseOffset),
482                   getInt32(DerivedOffset)};
483  return createCallHelper(FnGCRelocate, Args, this, Name);
484 }
485