lib/CodeGen/IntrinsicLowering.cpp

   1 //===-- IntrinsicLowering.cpp - Intrinsic Lowering default implementation -===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file was developed by the LLVM research group and is distributed under
   6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the default intrinsic lowering implementation.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/CodeGen/IntrinsicLowering.h"
  15 #include "llvm/Constants.h"
  16 #include "llvm/DerivedTypes.h"
  17 #include "llvm/Module.h"
  18 #include "llvm/Instructions.h"
  19 #include "llvm/Type.h"
  20 #include <iostream>
  21
  22 using namespace llvm;
  23
  24 template <class ArgIt>
  25 static Function *EnsureFunctionExists(Module &M, const char *Name,
  26                                       ArgIt ArgBegin, ArgIt ArgEnd,
  27                                       const Type *RetTy) {
  28   if (Function *F = M.getNamedFunction(Name)) return F;
  29   // It doesn't already exist in the program, insert a new definition now.
  30   std::vector<const Type *> ParamTys;
  31   for (ArgIt I = ArgBegin; I != ArgEnd; ++I)
  32     ParamTys.push_back(I->getType());
  33   return M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false));
  34 }
  35
  36 /// ReplaceCallWith - This function is used when we want to lower an intrinsic
  37 /// call to a call of an external function.  This handles hard cases such as
  38 /// when there was already a prototype for the external function, and if that
  39 /// prototype doesn't match the arguments we expect to pass in.
  40 template <class ArgIt>
  41 static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI,
  42                                  ArgIt ArgBegin, ArgIt ArgEnd,
  43                                  const Type *RetTy, Function *&FCache) {
  44   if (!FCache) {
  45     // If we haven't already looked up this function, check to see if the
  46     // program already contains a function with this name.
  47     Module *M = CI->getParent()->getParent()->getParent();
  48     FCache = M->getNamedFunction(NewFn);
  49     if (!FCache) {
  50       // It doesn't already exist in the program, insert a new definition now.
  51       std::vector<const Type *> ParamTys;
  52       for (ArgIt I = ArgBegin; I != ArgEnd; ++I)
  53         ParamTys.push_back((*I)->getType());
  54       FCache = M->getOrInsertFunction(NewFn,
  55                                      FunctionType::get(RetTy, ParamTys, false));
  56     }
  57    }
  58
  59   const FunctionType *FT = FCache->getFunctionType();
  60   std::vector<Value*> Operands;
  61   unsigned ArgNo = 0;
  62   for (ArgIt I = ArgBegin; I != ArgEnd && ArgNo != FT->getNumParams();
  63        ++I, ++ArgNo) {
  64     Value *Arg = *I;
  65     if (Arg->getType() != FT->getParamType(ArgNo))
  66       Arg = new CastInst(Arg, FT->getParamType(ArgNo), Arg->getName(), CI);
  67     Operands.push_back(Arg);
  68   }
  69   // Pass nulls into any additional arguments...
  70   for (; ArgNo != FT->getNumParams(); ++ArgNo)
  71     Operands.push_back(Constant::getNullValue(FT->getParamType(ArgNo)));
  72
  73   std::string Name = CI->getName(); CI->setName("");
  74   if (FT->getReturnType() == Type::VoidTy) Name.clear();
  75   CallInst *NewCI = new CallInst(FCache, Operands, Name, CI);
  76   if (!CI->use_empty()) {
  77     Value *V = NewCI;
  78     if (CI->getType() != NewCI->getType())
  79       V = new CastInst(NewCI, CI->getType(), Name, CI);
  80     CI->replaceAllUsesWith(V);
  81   }
  82   return NewCI;
  83 }
  84
  85 void DefaultIntrinsicLowering::AddPrototypes(Module &M) {
  86   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
  87     if (I->isExternal() && !I->use_empty())
  88       switch (I->getIntrinsicID()) {
  89       default: break;
  90       case Intrinsic::setjmp:
  91         EnsureFunctionExists(M, "setjmp", I->arg_begin(), I->arg_end(),
  92                              Type::IntTy);
  93         break;
  94       case Intrinsic::longjmp:
  95         EnsureFunctionExists(M, "longjmp", I->arg_begin(), I->arg_end(),
  96                              Type::VoidTy);
  97         break;
  98       case Intrinsic::siglongjmp:
  99         EnsureFunctionExists(M, "abort", I->arg_end(), I->arg_end(),
 100                              Type::VoidTy);
 101         break;
 102       case Intrinsic::memcpy:
 103         EnsureFunctionExists(M, "memcpy", I->arg_begin(), --I->arg_end(),
 104                              I->arg_begin()->getType());
 105         break;
 106       case Intrinsic::memmove:
 107         EnsureFunctionExists(M, "memmove", I->arg_begin(), --I->arg_end(),
 108                              I->arg_begin()->getType());
 109         break;
 110       case Intrinsic::memset:
 111         M.getOrInsertFunction("memset", PointerType::get(Type::SByteTy),
 112                               PointerType::get(Type::SByteTy),
 113                               Type::IntTy, (--(--I->arg_end()))->getType(), 0);
 114         break;
 115       case Intrinsic::isunordered:
 116         EnsureFunctionExists(M, "isunordered", I->arg_begin(), I->arg_end(),
 117                              Type::BoolTy);
 118         break;
 119       case Intrinsic::sqrt:
 120         if(I->arg_begin()->getType() == Type::FloatTy)
 121           EnsureFunctionExists(M, "sqrtf", I->arg_begin(), I->arg_end(),
 122                                Type::FloatTy);
 123         else
 124           EnsureFunctionExists(M, "sqrt", I->arg_begin(), I->arg_end(),
 125                                Type::DoubleTy);
 126         break;
 127       }
 128 }
 129
 130 void DefaultIntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
 131   Function *Callee = CI->getCalledFunction();
 132   assert(Callee && "Cannot lower an indirect call!");
 133
 134   switch (Callee->getIntrinsicID()) {
 135   case Intrinsic::not_intrinsic:
 136     std::cerr << "Cannot lower a call to a non-intrinsic function '"
 137               << Callee->getName() << "'!\n";
 138     abort();
 139   default:
 140     std::cerr << "Error: Code generator does not support intrinsic function '"
 141               << Callee->getName() << "'!\n";
 142     abort();
 143
 144     // The setjmp/longjmp intrinsics should only exist in the code if it was
 145     // never optimized (ie, right out of the CFE), or if it has been hacked on
 146     // by the lowerinvoke pass.  In both cases, the right thing to do is to
 147     // convert the call to an explicit setjmp or longjmp call.
 148   case Intrinsic::setjmp: {
 149     static Function *SetjmpFCache = 0;
 150     Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(),
 151                                Type::IntTy, SetjmpFCache);
 152     if (CI->getType() != Type::VoidTy)
 153       CI->replaceAllUsesWith(V);
 154     break;
 155   }
 156   case Intrinsic::sigsetjmp:
 157      if (CI->getType() != Type::VoidTy)
 158        CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
 159      break;
 160
 161   case Intrinsic::longjmp: {
 162     static Function *LongjmpFCache = 0;
 163     ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(),
 164                     Type::VoidTy, LongjmpFCache);
 165     break;
 166   }
 167
 168   case Intrinsic::siglongjmp: {
 169     // Insert the call to abort
 170     static Function *AbortFCache = 0;
 171     ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), Type::VoidTy,
 172                     AbortFCache);
 173     break;
 174   }
 175   case Intrinsic::ctpop: {
 176     Value *Src = CI->getOperand(1);
 177     switch (CI->getOperand(0)->getType()->getTypeID())
 178     {
 179     case Type::SByteTyID:
 180     case Type::UByteTyID:
 181       {
 182         Value* SA = ConstantUInt::get(Type::UByteTy, 1);
 183         Value* MA = ConstantUInt::get(Type::UIntTy, 0x55);
 184         Src = BinaryOperator::create(Instruction::Add,
 185                 BinaryOperator::create(Instruction::And, Src, MA),
 186                 BinaryOperator::create(Instruction::And,
 187                                        new ShiftInst(Instruction::Shr, Src, SA),
 188                                        MA));
 189         SA = ConstantUInt::get(Type::UByteTy, 2);
 190         MA = ConstantUInt::get(Type::UIntTy, 0x33);
 191         Src = BinaryOperator::create(Instruction::Add,
 192                 BinaryOperator::create(Instruction::And, Src, MA),
 193                 BinaryOperator::create(Instruction::And,
 194                                        new ShiftInst(Instruction::Shr, Src, SA),
 195                                        MA));
 196         SA = ConstantUInt::get(Type::UByteTy, 4);
 197         MA = ConstantUInt::get(Type::UIntTy, 0x0F);
 198         Src = BinaryOperator::create(Instruction::Add,
 199                 BinaryOperator::create(Instruction::And, Src, MA),
 200                 BinaryOperator::create(Instruction::And,
 201                                        new ShiftInst(Instruction::Shr, Src, SA),
 202                                        MA), "ctpop");
 203       }
 204       break;
 205     case Type::ShortTyID:
 206     case Type::UShortTyID:
 207       {
 208         Value* SA = ConstantUInt::get(Type::UByteTy, 1);
 209         Value* MA = ConstantUInt::get(Type::UIntTy, 0x5555);
 210         Src = BinaryOperator::create(Instruction::Add,
 211                 BinaryOperator::create(Instruction::And, Src, MA),
 212                 BinaryOperator::create(Instruction::And,
 213                                        new ShiftInst(Instruction::Shr, Src, SA),
 214                                        MA));
 215         SA = ConstantUInt::get(Type::UByteTy, 2);
 216         MA = ConstantUInt::get(Type::UIntTy, 0x3333);
 217         Src = BinaryOperator::create(Instruction::Add,
 218                 BinaryOperator::create(Instruction::And, Src, MA),
 219                 BinaryOperator::create(Instruction::And,
 220                                        new ShiftInst(Instruction::Shr, Src, SA),
 221                                        MA));
 222         SA = ConstantUInt::get(Type::UByteTy, 4);
 223         MA = ConstantUInt::get(Type::UIntTy, 0x0F0F);
 224         Src = BinaryOperator::create(Instruction::Add,
 225                 BinaryOperator::create(Instruction::And, Src, MA),
 226                 BinaryOperator::create(Instruction::And,
 227                                        new ShiftInst(Instruction::Shr, Src, SA),
 228                                        MA));
 229         SA = ConstantUInt::get(Type::UByteTy, 8);
 230         MA = ConstantUInt::get(Type::UIntTy, 0x00FF);
 231         Src = BinaryOperator::create(Instruction::Add,
 232                 BinaryOperator::create(Instruction::And, Src, MA),
 233                 BinaryOperator::create(Instruction::And,
 234                                        new ShiftInst(Instruction::Shr, Src, SA),
 235                                        MA), "ctpop");
 236
 237       }
 238       break;
 239     case Type::IntTyID:
 240     case Type::UIntTyID:
 241       {
 242         Value* SA = ConstantUInt::get(Type::UByteTy, 1);
 243         Value* MA = ConstantUInt::get(Type::UIntTy, 0x55555555);
 244         Src = BinaryOperator::create(Instruction::Add,
 245                 BinaryOperator::create(Instruction::And, Src, MA),
 246                 BinaryOperator::create(Instruction::And,
 247                                        new ShiftInst(Instruction::Shr, Src, SA),
 248                                        MA));
 249         SA = ConstantUInt::get(Type::UByteTy, 2);
 250         MA = ConstantUInt::get(Type::UIntTy, 0x33333333);
 251         Src = BinaryOperator::create(Instruction::Add,
 252                 BinaryOperator::create(Instruction::And, Src, MA),
 253                 BinaryOperator::create(Instruction::And,
 254                                        new ShiftInst(Instruction::Shr, Src, SA),
 255                                        MA));
 256         SA = ConstantUInt::get(Type::UByteTy, 4);
 257         MA = ConstantUInt::get(Type::UIntTy, 0x0F0F0F0F);
 258         Src = BinaryOperator::create(Instruction::Add,
 259                 BinaryOperator::create(Instruction::And, Src, MA),
 260                 BinaryOperator::create(Instruction::And,
 261                                        new ShiftInst(Instruction::Shr, Src, SA),
 262                                        MA));
 263         SA = ConstantUInt::get(Type::UByteTy, 8);
 264         MA = ConstantUInt::get(Type::UIntTy, 0x00FF00FF);
 265         Src = BinaryOperator::create(Instruction::Add,
 266                 BinaryOperator::create(Instruction::And, Src, MA),
 267                 BinaryOperator::create(Instruction::And,
 268                                        new ShiftInst(Instruction::Shr, Src, SA),
 269                                        MA));
 270         SA = ConstantUInt::get(Type::UByteTy, 8);
 271         MA = ConstantUInt::get(Type::UIntTy, 0x0000FFFF);
 272         Src = BinaryOperator::create(Instruction::Add,
 273                 BinaryOperator::create(Instruction::And, Src, MA),
 274                 BinaryOperator::create(Instruction::And,
 275                                        new ShiftInst(Instruction::Shr, Src, SA),
 276                                        MA), "ctpop");
 277       }
 278       break;
 279     case Type::LongTyID:
 280     case Type::ULongTyID:
 281       {
 282         Value* SA = ConstantUInt::get(Type::UByteTy, 1);
 283         Value* MA = ConstantUInt::get(Type::ULongTy, 0x5555555555555555ULL);
 284         Src = BinaryOperator::create(Instruction::Add,
 285                 BinaryOperator::create(Instruction::And, Src, MA),
 286                 BinaryOperator::create(Instruction::And,
 287                                        new ShiftInst(Instruction::Shr, Src, SA),
 288                                        MA));
 289         SA = ConstantUInt::get(Type::UByteTy, 2);
 290         MA = ConstantUInt::get(Type::ULongTy, 0x3333333333333333ULL);
 291         Src = BinaryOperator::create(Instruction::Add,
 292                 BinaryOperator::create(Instruction::And, Src, MA),
 293                 BinaryOperator::create(Instruction::And,
 294                                        new ShiftInst(Instruction::Shr, Src, SA),
 295                                        MA));
 296         SA = ConstantUInt::get(Type::UByteTy, 4);
 297         MA = ConstantUInt::get(Type::ULongTy, 0x0F0F0F0F0F0F0F0FULL);
 298         Src = BinaryOperator::create(Instruction::Add,
 299                 BinaryOperator::create(Instruction::And, Src, MA),
 300                 BinaryOperator::create(Instruction::And,
 301                                        new ShiftInst(Instruction::Shr, Src, SA),
 302                                        MA));
 303         SA = ConstantUInt::get(Type::UByteTy, 8);
 304         MA = ConstantUInt::get(Type::ULongTy, 0x00FF00FF00FF00FFULL);
 305         Src = BinaryOperator::create(Instruction::Add,
 306                 BinaryOperator::create(Instruction::And, Src, MA),
 307                 BinaryOperator::create(Instruction::And,
 308                                        new ShiftInst(Instruction::Shr, Src, SA),
 309                                        MA));
 310         SA = ConstantUInt::get(Type::UByteTy, 16);
 311         MA = ConstantUInt::get(Type::ULongTy, 0x00000000FFFFFFFFULL);
 312         Src = BinaryOperator::create(Instruction::Add,
 313                 BinaryOperator::create(Instruction::And, Src, MA),
 314                 BinaryOperator::create(Instruction::And,
 315                                        new ShiftInst(Instruction::Shr, Src, SA),
 316                                        MA), "ctpop");
 317       }
 318       break;
 319     default:
 320       abort();
 321     }
 322
 323     CI->replaceAllUsesWith(Src);
 324     break;
 325   }
 326   case Intrinsic::ctlz: {
 327     Value *Src = CI->getOperand(1);
 328     Value* SA;
 329     switch (CI->getOperand(0)->getType()->getTypeID())
 330     {
 331     case Type::LongTyID:
 332     case Type::ULongTyID:
 333       SA = ConstantUInt::get(Type::UByteTy, 32);
 334       Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
 335     case Type::IntTyID:
 336     case Type::UIntTyID:
 337       SA = ConstantUInt::get(Type::UByteTy, 16);
 338       Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
 339     case Type::ShortTyID:
 340     case Type::UShortTyID:
 341       SA = ConstantUInt::get(Type::UByteTy, 8);
 342       Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
 343     default:
 344       SA = ConstantUInt::get(Type::UByteTy, 1);
 345       Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
 346       SA = ConstantUInt::get(Type::UByteTy, 2);
 347       Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
 348       SA = ConstantUInt::get(Type::UByteTy, 4);
 349       Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
 350     };
 351     Src = BinaryOperator::createNot(Src);
 352
 353     Src = new CallInst(new Function(CI->getCalledFunction()->getFunctionType(),
 354                                     CI->getCalledFunction()->getLinkage(),
 355                                     "llvm.ctpop"), Src);
 356     CI->replaceAllUsesWith(Src);
 357     break;
 358   }
 359   case Intrinsic::cttz: {
 360     Value *Src = CI->getOperand(1);
 361     Src = BinaryOperator::create(Instruction::And, BinaryOperator::createNot(Src),
 362             BinaryOperator::create(Instruction::Sub, Src,
 363                             ConstantUInt::get(CI->getOperand(0)->getType(), 1)));
 364     Src = new CallInst(new Function(CI->getCalledFunction()->getFunctionType(),
 365                                     CI->getCalledFunction()->getLinkage(),
 366                                     "llvm.ctpop"), Src);
 367     CI->replaceAllUsesWith(Src);
 368     break;
 369   }
 370
 371   case Intrinsic::returnaddress:
 372   case Intrinsic::frameaddress:
 373     std::cerr << "WARNING: this target does not support the llvm."
 374               << (Callee->getIntrinsicID() == Intrinsic::returnaddress ?
 375                   "return" : "frame") << "address intrinsic.\n";
 376     CI->replaceAllUsesWith(ConstantPointerNull::get(
 377                                             cast<PointerType>(CI->getType())));
 378     break;
 379
 380   case Intrinsic::prefetch:
 381     break;    // Simply strip out prefetches on unsupported architectures
 382
 383   case Intrinsic::pcmarker:
 384     break;    // Simply strip out pcmarker on unsupported architectures
 385
 386   case Intrinsic::dbg_stoppoint:
 387   case Intrinsic::dbg_region_start:
 388   case Intrinsic::dbg_region_end:
 389   case Intrinsic::dbg_declare:
 390   case Intrinsic::dbg_func_start:
 391     if (CI->getType() != Type::VoidTy)
 392       CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
 393     break;    // Simply strip out debugging intrinsics
 394
 395   case Intrinsic::memcpy: {
 396     // The memcpy intrinsic take an extra alignment argument that the memcpy
 397     // libc function does not.
 398     static Function *MemcpyFCache = 0;
 399     ReplaceCallWith("memcpy", CI, CI->op_begin()+1, CI->op_end()-1,
 400                     (*(CI->op_begin()+1))->getType(), MemcpyFCache);
 401     break;
 402   }
 403   case Intrinsic::memmove: {
 404     // The memmove intrinsic take an extra alignment argument that the memmove
 405     // libc function does not.
 406     static Function *MemmoveFCache = 0;
 407     ReplaceCallWith("memmove", CI, CI->op_begin()+1, CI->op_end()-1,
 408                     (*(CI->op_begin()+1))->getType(), MemmoveFCache);
 409     break;
 410   }
 411   case Intrinsic::memset: {
 412     // The memset intrinsic take an extra alignment argument that the memset
 413     // libc function does not.
 414     static Function *MemsetFCache = 0;
 415     ReplaceCallWith("memset", CI, CI->op_begin()+1, CI->op_end()-1,
 416                     (*(CI->op_begin()+1))->getType(), MemsetFCache);
 417     break;
 418   }
 419   case Intrinsic::isunordered: {
 420     Value *L = CI->getOperand(1);
 421     Value *R = CI->getOperand(2);
 422
 423     Value *LIsNan = new SetCondInst(Instruction::SetNE, L, L, "LIsNan", CI);
 424     Value *RIsNan = new SetCondInst(Instruction::SetNE, R, R, "RIsNan", CI);
 425     CI->replaceAllUsesWith(
 426       BinaryOperator::create(Instruction::Or, LIsNan, RIsNan,
 427                              "isunordered", CI));
 428     break;
 429   }
 430   case Intrinsic::sqrt: {
 431     static Function *sqrtFCache = 0;
 432     static Function *sqrtfFCache = 0;
 433     if(CI->getType() == Type::FloatTy)
 434       ReplaceCallWith("sqrtf", CI, CI->op_begin()+1, CI->op_end(),
 435                       Type::FloatTy, sqrtfFCache);
 436     else
 437       ReplaceCallWith("sqrt", CI, CI->op_begin()+1, CI->op_end(),
 438                       Type::DoubleTy, sqrtFCache);
 439     break;
 440   }
 441   }
 442
 443   assert(CI->use_empty() &&
 444          "Lowering should have eliminated any uses of the intrinsic call!");
 445   CI->getParent()->getInstList().erase(CI);
 446 }