lib/Target/AMDGPU/AMDGPUPrintfRuntimeBinding.cpp

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