xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AMDGPU/AMDGPUPrintfRuntimeBinding.cpp (revision 13ec1e3155c7e9bf037b12af186351b7fa9b9450)
1 //=== AMDGPUPrintfRuntimeBinding.cpp - OpenCL printf implementation -------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 // \file
9 //
10 // The pass bind printfs to a kernel arg pointer that will be bound to a buffer
11 // later by the runtime.
12 //
13 // This pass traverses the functions in the module and converts
14 // each call to printf to a sequence of operations that
15 // store the following into the printf buffer:
16 // - format string (passed as a module's metadata unique ID)
17 // - bitwise copies of printf arguments
18 // The backend passes will need to store metadata in the kernel
19 //===----------------------------------------------------------------------===//
20 
21 #include "AMDGPU.h"
22 #include "llvm/Analysis/InstructionSimplify.h"
23 #include "llvm/Analysis/TargetLibraryInfo.h"
24 #include "llvm/IR/Dominators.h"
25 #include "llvm/IR/IRBuilder.h"
26 #include "llvm/IR/Instructions.h"
27 #include "llvm/InitializePasses.h"
28 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
29 
30 using namespace llvm;
31 
32 #define DEBUG_TYPE "printfToRuntime"
33 #define DWORD_ALIGN 4
34 
35 namespace {
36 class AMDGPUPrintfRuntimeBinding final : public ModulePass {
37 
38 public:
39   static char ID;
40 
41   explicit AMDGPUPrintfRuntimeBinding();
42 
43 private:
44   bool runOnModule(Module &M) override;
45 
46   void getAnalysisUsage(AnalysisUsage &AU) const override {
47     AU.addRequired<TargetLibraryInfoWrapperPass>();
48     AU.addRequired<DominatorTreeWrapperPass>();
49   }
50 };
51 
52 class AMDGPUPrintfRuntimeBindingImpl {
53 public:
54   AMDGPUPrintfRuntimeBindingImpl(
55       function_ref<const DominatorTree &(Function &)> GetDT,
56       function_ref<const TargetLibraryInfo &(Function &)> GetTLI)
57       : GetDT(GetDT), GetTLI(GetTLI) {}
58   bool run(Module &M);
59 
60 private:
61   void getConversionSpecifiers(SmallVectorImpl<char> &OpConvSpecifiers,
62                                StringRef fmt, size_t num_ops) const;
63 
64   bool shouldPrintAsStr(char Specifier, Type *OpType) const;
65   bool lowerPrintfForGpu(Module &M);
66 
67   Value *simplify(Instruction *I, const TargetLibraryInfo *TLI,
68                   const DominatorTree *DT) {
69     return SimplifyInstruction(I, {*TD, TLI, DT});
70   }
71 
72   const DataLayout *TD;
73   function_ref<const DominatorTree &(Function &)> GetDT;
74   function_ref<const TargetLibraryInfo &(Function &)> GetTLI;
75   SmallVector<CallInst *, 32> Printfs;
76 };
77 } // namespace
78 
79 char AMDGPUPrintfRuntimeBinding::ID = 0;
80 
81 INITIALIZE_PASS_BEGIN(AMDGPUPrintfRuntimeBinding,
82                       "amdgpu-printf-runtime-binding", "AMDGPU Printf lowering",
83                       false, false)
84 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
85 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
86 INITIALIZE_PASS_END(AMDGPUPrintfRuntimeBinding, "amdgpu-printf-runtime-binding",
87                     "AMDGPU Printf lowering", false, false)
88 
89 char &llvm::AMDGPUPrintfRuntimeBindingID = AMDGPUPrintfRuntimeBinding::ID;
90 
91 namespace llvm {
92 ModulePass *createAMDGPUPrintfRuntimeBinding() {
93   return new AMDGPUPrintfRuntimeBinding();
94 }
95 } // namespace llvm
96 
97 AMDGPUPrintfRuntimeBinding::AMDGPUPrintfRuntimeBinding() : ModulePass(ID) {
98   initializeAMDGPUPrintfRuntimeBindingPass(*PassRegistry::getPassRegistry());
99 }
100 
101 void AMDGPUPrintfRuntimeBindingImpl::getConversionSpecifiers(
102     SmallVectorImpl<char> &OpConvSpecifiers, StringRef Fmt,
103     size_t NumOps) const {
104   // not all format characters are collected.
105   // At this time the format characters of interest
106   // are %p and %s, which use to know if we
107   // are either storing a literal string or a
108   // pointer to the printf buffer.
109   static const char ConvSpecifiers[] = "cdieEfgGaosuxXp";
110   size_t CurFmtSpecifierIdx = 0;
111   size_t PrevFmtSpecifierIdx = 0;
112 
113   while ((CurFmtSpecifierIdx = Fmt.find_first_of(
114               ConvSpecifiers, CurFmtSpecifierIdx)) != StringRef::npos) {
115     bool ArgDump = false;
116     StringRef CurFmt = Fmt.substr(PrevFmtSpecifierIdx,
117                                   CurFmtSpecifierIdx - PrevFmtSpecifierIdx);
118     size_t pTag = CurFmt.find_last_of("%");
119     if (pTag != StringRef::npos) {
120       ArgDump = true;
121       while (pTag && CurFmt[--pTag] == '%') {
122         ArgDump = !ArgDump;
123       }
124     }
125 
126     if (ArgDump)
127       OpConvSpecifiers.push_back(Fmt[CurFmtSpecifierIdx]);
128 
129     PrevFmtSpecifierIdx = ++CurFmtSpecifierIdx;
130   }
131 }
132 
133 bool AMDGPUPrintfRuntimeBindingImpl::shouldPrintAsStr(char Specifier,
134                                                       Type *OpType) const {
135   if (Specifier != 's')
136     return false;
137   const PointerType *PT = dyn_cast<PointerType>(OpType);
138   if (!PT || PT->getAddressSpace() != AMDGPUAS::CONSTANT_ADDRESS)
139     return false;
140   Type *ElemType = PT->getContainedType(0);
141   if (ElemType->getTypeID() != Type::IntegerTyID)
142     return false;
143   IntegerType *ElemIType = cast<IntegerType>(ElemType);
144   return ElemIType->getBitWidth() == 8;
145 }
146 
147 bool AMDGPUPrintfRuntimeBindingImpl::lowerPrintfForGpu(Module &M) {
148   LLVMContext &Ctx = M.getContext();
149   IRBuilder<> Builder(Ctx);
150   Type *I32Ty = Type::getInt32Ty(Ctx);
151   unsigned UniqID = 0;
152   // NB: This is important for this string size to be divizable by 4
153   const char NonLiteralStr[4] = "???";
154 
155   for (auto CI : Printfs) {
156     unsigned NumOps = CI->getNumArgOperands();
157 
158     SmallString<16> OpConvSpecifiers;
159     Value *Op = CI->getArgOperand(0);
160 
161     if (auto LI = dyn_cast<LoadInst>(Op)) {
162       Op = LI->getPointerOperand();
163       for (auto Use : Op->users()) {
164         if (auto SI = dyn_cast<StoreInst>(Use)) {
165           Op = SI->getValueOperand();
166           break;
167         }
168       }
169     }
170 
171     if (auto I = dyn_cast<Instruction>(Op)) {
172       Value *Op_simplified =
173           simplify(I, &GetTLI(*I->getFunction()), &GetDT(*I->getFunction()));
174       if (Op_simplified)
175         Op = Op_simplified;
176     }
177 
178     ConstantExpr *ConstExpr = dyn_cast<ConstantExpr>(Op);
179 
180     if (ConstExpr) {
181       GlobalVariable *GVar = dyn_cast<GlobalVariable>(ConstExpr->getOperand(0));
182 
183       StringRef Str("unknown");
184       if (GVar && GVar->hasInitializer()) {
185         auto *Init = GVar->getInitializer();
186         if (auto *CA = dyn_cast<ConstantDataArray>(Init)) {
187           if (CA->isString())
188             Str = CA->getAsCString();
189         } else if (isa<ConstantAggregateZero>(Init)) {
190           Str = "";
191         }
192         //
193         // we need this call to ascertain
194         // that we are printing a string
195         // or a pointer. It takes out the
196         // specifiers and fills up the first
197         // arg
198         getConversionSpecifiers(OpConvSpecifiers, Str, NumOps - 1);
199       }
200       // Add metadata for the string
201       std::string AStreamHolder;
202       raw_string_ostream Sizes(AStreamHolder);
203       int Sum = DWORD_ALIGN;
204       Sizes << CI->getNumArgOperands() - 1;
205       Sizes << ':';
206       for (unsigned ArgCount = 1; ArgCount < CI->getNumArgOperands() &&
207                                   ArgCount <= OpConvSpecifiers.size();
208            ArgCount++) {
209         Value *Arg = CI->getArgOperand(ArgCount);
210         Type *ArgType = Arg->getType();
211         unsigned ArgSize = TD->getTypeAllocSizeInBits(ArgType);
212         ArgSize = ArgSize / 8;
213         //
214         // ArgSize by design should be a multiple of DWORD_ALIGN,
215         // expand the arguments that do not follow this rule.
216         //
217         if (ArgSize % DWORD_ALIGN != 0) {
218           llvm::Type *ResType = llvm::Type::getInt32Ty(Ctx);
219           auto *LLVMVecType = llvm::dyn_cast<llvm::FixedVectorType>(ArgType);
220           int NumElem = LLVMVecType ? LLVMVecType->getNumElements() : 1;
221           if (LLVMVecType && NumElem > 1)
222             ResType = llvm::FixedVectorType::get(ResType, NumElem);
223           Builder.SetInsertPoint(CI);
224           Builder.SetCurrentDebugLocation(CI->getDebugLoc());
225           if (OpConvSpecifiers[ArgCount - 1] == 'x' ||
226               OpConvSpecifiers[ArgCount - 1] == 'X' ||
227               OpConvSpecifiers[ArgCount - 1] == 'u' ||
228               OpConvSpecifiers[ArgCount - 1] == 'o')
229             Arg = Builder.CreateZExt(Arg, ResType);
230           else
231             Arg = Builder.CreateSExt(Arg, ResType);
232           ArgType = Arg->getType();
233           ArgSize = TD->getTypeAllocSizeInBits(ArgType);
234           ArgSize = ArgSize / 8;
235           CI->setOperand(ArgCount, Arg);
236         }
237         if (OpConvSpecifiers[ArgCount - 1] == 'f') {
238           ConstantFP *FpCons = dyn_cast<ConstantFP>(Arg);
239           if (FpCons)
240             ArgSize = 4;
241           else {
242             FPExtInst *FpExt = dyn_cast<FPExtInst>(Arg);
243             if (FpExt && FpExt->getType()->isDoubleTy() &&
244                 FpExt->getOperand(0)->getType()->isFloatTy())
245               ArgSize = 4;
246           }
247         }
248         if (shouldPrintAsStr(OpConvSpecifiers[ArgCount - 1], ArgType)) {
249           if (auto *ConstExpr = dyn_cast<ConstantExpr>(Arg)) {
250             auto *GV = dyn_cast<GlobalVariable>(ConstExpr->getOperand(0));
251             if (GV && GV->hasInitializer()) {
252               Constant *Init = GV->getInitializer();
253               bool IsZeroValue = Init->isZeroValue();
254               auto *CA = dyn_cast<ConstantDataArray>(Init);
255               if (IsZeroValue || (CA && CA->isString())) {
256                 size_t SizeStr =
257                     IsZeroValue ? 1 : (strlen(CA->getAsCString().data()) + 1);
258                 size_t Rem = SizeStr % DWORD_ALIGN;
259                 size_t NSizeStr = 0;
260                 LLVM_DEBUG(dbgs() << "Printf string original size = " << SizeStr
261                                   << '\n');
262                 if (Rem) {
263                   NSizeStr = SizeStr + (DWORD_ALIGN - Rem);
264                 } else {
265                   NSizeStr = SizeStr;
266                 }
267                 ArgSize = NSizeStr;
268               }
269             } else {
270               ArgSize = sizeof(NonLiteralStr);
271             }
272           } else {
273             ArgSize = sizeof(NonLiteralStr);
274           }
275         }
276         LLVM_DEBUG(dbgs() << "Printf ArgSize (in buffer) = " << ArgSize
277                           << " for type: " << *ArgType << '\n');
278         Sizes << ArgSize << ':';
279         Sum += ArgSize;
280       }
281       LLVM_DEBUG(dbgs() << "Printf format string in source = " << Str.str()
282                         << '\n');
283       for (size_t I = 0; I < Str.size(); ++I) {
284         // Rest of the C escape sequences (e.g. \') are handled correctly
285         // by the MDParser
286         switch (Str[I]) {
287         case '\a':
288           Sizes << "\\a";
289           break;
290         case '\b':
291           Sizes << "\\b";
292           break;
293         case '\f':
294           Sizes << "\\f";
295           break;
296         case '\n':
297           Sizes << "\\n";
298           break;
299         case '\r':
300           Sizes << "\\r";
301           break;
302         case '\v':
303           Sizes << "\\v";
304           break;
305         case ':':
306           // ':' cannot be scanned by Flex, as it is defined as a delimiter
307           // Replace it with it's octal representation \72
308           Sizes << "\\72";
309           break;
310         default:
311           Sizes << Str[I];
312           break;
313         }
314       }
315 
316       // Insert the printf_alloc call
317       Builder.SetInsertPoint(CI);
318       Builder.SetCurrentDebugLocation(CI->getDebugLoc());
319 
320       AttributeList Attr = AttributeList::get(Ctx, AttributeList::FunctionIndex,
321                                               Attribute::NoUnwind);
322 
323       Type *SizetTy = Type::getInt32Ty(Ctx);
324 
325       Type *Tys_alloc[1] = {SizetTy};
326       Type *I8Ty = Type::getInt8Ty(Ctx);
327       Type *I8Ptr = PointerType::get(I8Ty, 1);
328       FunctionType *FTy_alloc = FunctionType::get(I8Ptr, Tys_alloc, false);
329       FunctionCallee PrintfAllocFn =
330           M.getOrInsertFunction(StringRef("__printf_alloc"), FTy_alloc, Attr);
331 
332       LLVM_DEBUG(dbgs() << "Printf metadata = " << Sizes.str() << '\n');
333       std::string fmtstr = itostr(++UniqID) + ":" + Sizes.str().c_str();
334       MDString *fmtStrArray = MDString::get(Ctx, fmtstr);
335 
336       // Instead of creating global variables, the
337       // printf format strings are extracted
338       // and passed as metadata. This avoids
339       // polluting llvm's symbol tables in this module.
340       // Metadata is going to be extracted
341       // by the backend passes and inserted
342       // into the OpenCL binary as appropriate.
343       StringRef amd("llvm.printf.fmts");
344       NamedMDNode *metaD = M.getOrInsertNamedMetadata(amd);
345       MDNode *myMD = MDNode::get(Ctx, fmtStrArray);
346       metaD->addOperand(myMD);
347       Value *sumC = ConstantInt::get(SizetTy, Sum, false);
348       SmallVector<Value *, 1> alloc_args;
349       alloc_args.push_back(sumC);
350       CallInst *pcall =
351           CallInst::Create(PrintfAllocFn, alloc_args, "printf_alloc_fn", CI);
352 
353       //
354       // Insert code to split basicblock with a
355       // piece of hammock code.
356       // basicblock splits after buffer overflow check
357       //
358       ConstantPointerNull *zeroIntPtr =
359           ConstantPointerNull::get(PointerType::get(I8Ty, 1));
360       auto *cmp = cast<ICmpInst>(Builder.CreateICmpNE(pcall, zeroIntPtr, ""));
361       if (!CI->use_empty()) {
362         Value *result =
363             Builder.CreateSExt(Builder.CreateNot(cmp), I32Ty, "printf_res");
364         CI->replaceAllUsesWith(result);
365       }
366       SplitBlock(CI->getParent(), cmp);
367       Instruction *Brnch =
368           SplitBlockAndInsertIfThen(cmp, cmp->getNextNode(), false);
369 
370       Builder.SetInsertPoint(Brnch);
371 
372       // store unique printf id in the buffer
373       //
374       GetElementPtrInst *BufferIdx = GetElementPtrInst::Create(
375           I8Ty, pcall, ConstantInt::get(Ctx, APInt(32, 0)), "PrintBuffID",
376           Brnch);
377 
378       Type *idPointer = PointerType::get(I32Ty, AMDGPUAS::GLOBAL_ADDRESS);
379       Value *id_gep_cast =
380           new BitCastInst(BufferIdx, idPointer, "PrintBuffIdCast", Brnch);
381 
382       new StoreInst(ConstantInt::get(I32Ty, UniqID), id_gep_cast, Brnch);
383 
384       // 1st 4 bytes hold the printf_id
385       // the following GEP is the buffer pointer
386       BufferIdx = GetElementPtrInst::Create(
387           I8Ty, pcall, ConstantInt::get(Ctx, APInt(32, 4)), "PrintBuffGep",
388           Brnch);
389 
390       Type *Int32Ty = Type::getInt32Ty(Ctx);
391       Type *Int64Ty = Type::getInt64Ty(Ctx);
392       for (unsigned ArgCount = 1; ArgCount < CI->getNumArgOperands() &&
393                                   ArgCount <= OpConvSpecifiers.size();
394            ArgCount++) {
395         Value *Arg = CI->getArgOperand(ArgCount);
396         Type *ArgType = Arg->getType();
397         SmallVector<Value *, 32> WhatToStore;
398         if (ArgType->isFPOrFPVectorTy() && !isa<VectorType>(ArgType)) {
399           Type *IType = (ArgType->isFloatTy()) ? Int32Ty : Int64Ty;
400           if (OpConvSpecifiers[ArgCount - 1] == 'f') {
401             if (auto *FpCons = dyn_cast<ConstantFP>(Arg)) {
402               APFloat Val(FpCons->getValueAPF());
403               bool Lost = false;
404               Val.convert(APFloat::IEEEsingle(), APFloat::rmNearestTiesToEven,
405                           &Lost);
406               Arg = ConstantFP::get(Ctx, Val);
407               IType = Int32Ty;
408             } else if (auto *FpExt = dyn_cast<FPExtInst>(Arg)) {
409               if (FpExt->getType()->isDoubleTy() &&
410                   FpExt->getOperand(0)->getType()->isFloatTy()) {
411                 Arg = FpExt->getOperand(0);
412                 IType = Int32Ty;
413               }
414             }
415           }
416           Arg = new BitCastInst(Arg, IType, "PrintArgFP", Brnch);
417           WhatToStore.push_back(Arg);
418         } else if (ArgType->getTypeID() == Type::PointerTyID) {
419           if (shouldPrintAsStr(OpConvSpecifiers[ArgCount - 1], ArgType)) {
420             const char *S = NonLiteralStr;
421             if (auto *ConstExpr = dyn_cast<ConstantExpr>(Arg)) {
422               auto *GV = dyn_cast<GlobalVariable>(ConstExpr->getOperand(0));
423               if (GV && GV->hasInitializer()) {
424                 Constant *Init = GV->getInitializer();
425                 bool IsZeroValue = Init->isZeroValue();
426                 auto *CA = dyn_cast<ConstantDataArray>(Init);
427                 if (IsZeroValue || (CA && CA->isString())) {
428                   S = IsZeroValue ? "" : CA->getAsCString().data();
429                 }
430               }
431             }
432             size_t SizeStr = strlen(S) + 1;
433             size_t Rem = SizeStr % DWORD_ALIGN;
434             size_t NSizeStr = 0;
435             if (Rem) {
436               NSizeStr = SizeStr + (DWORD_ALIGN - Rem);
437             } else {
438               NSizeStr = SizeStr;
439             }
440             if (S[0]) {
441               char *MyNewStr = new char[NSizeStr]();
442               strcpy(MyNewStr, S);
443               int NumInts = NSizeStr / 4;
444               int CharC = 0;
445               while (NumInts) {
446                 int ANum = *(int *)(MyNewStr + CharC);
447                 CharC += 4;
448                 NumInts--;
449                 Value *ANumV = ConstantInt::get(Int32Ty, ANum, false);
450                 WhatToStore.push_back(ANumV);
451               }
452               delete[] MyNewStr;
453             } else {
454               // Empty string, give a hint to RT it is no NULL
455               Value *ANumV = ConstantInt::get(Int32Ty, 0xFFFFFF00, false);
456               WhatToStore.push_back(ANumV);
457             }
458           } else {
459             uint64_t Size = TD->getTypeAllocSizeInBits(ArgType);
460             assert((Size == 32 || Size == 64) && "unsupported size");
461             Type *DstType = (Size == 32) ? Int32Ty : Int64Ty;
462             Arg = new PtrToIntInst(Arg, DstType, "PrintArgPtr", Brnch);
463             WhatToStore.push_back(Arg);
464           }
465         } else if (isa<FixedVectorType>(ArgType)) {
466           Type *IType = NULL;
467           uint32_t EleCount = cast<FixedVectorType>(ArgType)->getNumElements();
468           uint32_t EleSize = ArgType->getScalarSizeInBits();
469           uint32_t TotalSize = EleCount * EleSize;
470           if (EleCount == 3) {
471             ShuffleVectorInst *Shuffle =
472                 new ShuffleVectorInst(Arg, Arg, ArrayRef<int>{0, 1, 2, 2});
473             Shuffle->insertBefore(Brnch);
474             Arg = Shuffle;
475             ArgType = Arg->getType();
476             TotalSize += EleSize;
477           }
478           switch (EleSize) {
479           default:
480             EleCount = TotalSize / 64;
481             IType = Type::getInt64Ty(ArgType->getContext());
482             break;
483           case 8:
484             if (EleCount >= 8) {
485               EleCount = TotalSize / 64;
486               IType = Type::getInt64Ty(ArgType->getContext());
487             } else if (EleCount >= 3) {
488               EleCount = 1;
489               IType = Type::getInt32Ty(ArgType->getContext());
490             } else {
491               EleCount = 1;
492               IType = Type::getInt16Ty(ArgType->getContext());
493             }
494             break;
495           case 16:
496             if (EleCount >= 3) {
497               EleCount = TotalSize / 64;
498               IType = Type::getInt64Ty(ArgType->getContext());
499             } else {
500               EleCount = 1;
501               IType = Type::getInt32Ty(ArgType->getContext());
502             }
503             break;
504           }
505           if (EleCount > 1) {
506             IType = FixedVectorType::get(IType, EleCount);
507           }
508           Arg = new BitCastInst(Arg, IType, "PrintArgVect", Brnch);
509           WhatToStore.push_back(Arg);
510         } else {
511           WhatToStore.push_back(Arg);
512         }
513         for (unsigned I = 0, E = WhatToStore.size(); I != E; ++I) {
514           Value *TheBtCast = WhatToStore[I];
515           unsigned ArgSize =
516               TD->getTypeAllocSizeInBits(TheBtCast->getType()) / 8;
517           SmallVector<Value *, 1> BuffOffset;
518           BuffOffset.push_back(ConstantInt::get(I32Ty, ArgSize));
519 
520           Type *ArgPointer = PointerType::get(TheBtCast->getType(), 1);
521           Value *CastedGEP =
522               new BitCastInst(BufferIdx, ArgPointer, "PrintBuffPtrCast", Brnch);
523           StoreInst *StBuff = new StoreInst(TheBtCast, CastedGEP, Brnch);
524           LLVM_DEBUG(dbgs() << "inserting store to printf buffer:\n"
525                             << *StBuff << '\n');
526           (void)StBuff;
527           if (I + 1 == E && ArgCount + 1 == CI->getNumArgOperands())
528             break;
529           BufferIdx = GetElementPtrInst::Create(I8Ty, BufferIdx, BuffOffset,
530                                                 "PrintBuffNextPtr", Brnch);
531           LLVM_DEBUG(dbgs() << "inserting gep to the printf buffer:\n"
532                             << *BufferIdx << '\n');
533         }
534       }
535     }
536   }
537 
538   // erase the printf calls
539   for (auto CI : Printfs)
540     CI->eraseFromParent();
541 
542   Printfs.clear();
543   return true;
544 }
545 
546 bool AMDGPUPrintfRuntimeBindingImpl::run(Module &M) {
547   Triple TT(M.getTargetTriple());
548   if (TT.getArch() == Triple::r600)
549     return false;
550 
551   auto PrintfFunction = M.getFunction("printf");
552   if (!PrintfFunction)
553     return false;
554 
555   for (auto &U : PrintfFunction->uses()) {
556     if (auto *CI = dyn_cast<CallInst>(U.getUser())) {
557       if (CI->isCallee(&U))
558         Printfs.push_back(CI);
559     }
560   }
561 
562   if (Printfs.empty())
563     return false;
564 
565   if (auto HostcallFunction = M.getFunction("__ockl_hostcall_internal")) {
566     for (auto &U : HostcallFunction->uses()) {
567       if (auto *CI = dyn_cast<CallInst>(U.getUser())) {
568         M.getContext().emitError(
569             CI, "Cannot use both printf and hostcall in the same module");
570       }
571     }
572   }
573 
574   TD = &M.getDataLayout();
575 
576   return lowerPrintfForGpu(M);
577 }
578 
579 bool AMDGPUPrintfRuntimeBinding::runOnModule(Module &M) {
580   auto GetDT = [this](Function &F) -> DominatorTree & {
581     return this->getAnalysis<DominatorTreeWrapperPass>(F).getDomTree();
582   };
583   auto GetTLI = [this](Function &F) -> TargetLibraryInfo & {
584     return this->getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F);
585   };
586 
587   return AMDGPUPrintfRuntimeBindingImpl(GetDT, GetTLI).run(M);
588 }
589 
590 PreservedAnalyses
591 AMDGPUPrintfRuntimeBindingPass::run(Module &M, ModuleAnalysisManager &AM) {
592   FunctionAnalysisManager &FAM =
593       AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
594   auto GetDT = [&FAM](Function &F) -> DominatorTree & {
595     return FAM.getResult<DominatorTreeAnalysis>(F);
596   };
597   auto GetTLI = [&FAM](Function &F) -> TargetLibraryInfo & {
598     return FAM.getResult<TargetLibraryAnalysis>(F);
599   };
600   bool Changed = AMDGPUPrintfRuntimeBindingImpl(GetDT, GetTLI).run(M);
601   return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all();
602 }
603