lib/CodeGen/IntrinsicLowering.cpp

   1 //===-- IntrinsicLowering.cpp - Intrinsic Lowering default implementation -===//
   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 IntrinsicLowering class.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Constants.h"
  15 #include "llvm/DerivedTypes.h"
  16 #include "llvm/Module.h"
  17 #include "llvm/Instructions.h"
  18 #include "llvm/Type.h"
  19 #include "llvm/CodeGen/IntrinsicLowering.h"
  20 #include "llvm/Support/Streams.h"
  21 #include "llvm/Target/TargetData.h"
  22 #include "llvm/ADT/SmallVector.h"
  23 #include "llvm/ADT/STLExtras.h"
  24 using namespace llvm;
  25
  26 template <class ArgIt>
  27 static void EnsureFunctionExists(Module &M, const char *Name,
  28                                  ArgIt ArgBegin, ArgIt ArgEnd,
  29                                  const Type *RetTy) {
  30   // Insert a correctly-typed definition now.
  31   std::vector<const Type *> ParamTys;
  32   for (ArgIt I = ArgBegin; I != ArgEnd; ++I)
  33     ParamTys.push_back(I->getType());
  34   M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false));
  35 }
  36
  37 /// ReplaceCallWith - This function is used when we want to lower an intrinsic
  38 /// call to a call of an external function.  This handles hard cases such as
  39 /// when there was already a prototype for the external function, and if that
  40 /// prototype doesn't match the arguments we expect to pass in.
  41 template <class ArgIt>
  42 static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI,
  43                                  ArgIt ArgBegin, ArgIt ArgEnd,
  44                                  const Type *RetTy, Constant *&FCache) {
  45   if (!FCache) {
  46     // If we haven't already looked up this function, check to see if the
  47     // program already contains a function with this name.
  48     Module *M = CI->getParent()->getParent()->getParent();
  49     // Get or insert the definition now.
  50     std::vector<const Type *> ParamTys;
  51     for (ArgIt I = ArgBegin; I != ArgEnd; ++I)
  52       ParamTys.push_back((*I)->getType());
  53     FCache = M->getOrInsertFunction(NewFn,
  54                                     FunctionType::get(RetTy, ParamTys, false));
  55   }
  56
  57   SmallVector<Value *, 8> Args(ArgBegin, ArgEnd);
  58   CallInst *NewCI = CallInst::Create(FCache, Args.begin(), Args.end(),
  59                                      CI->getName(), CI);
  60   if (!CI->use_empty())
  61     CI->replaceAllUsesWith(NewCI);
  62   return NewCI;
  63 }
  64
  65 void IntrinsicLowering::AddPrototypes(Module &M) {
  66   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
  67     if (I->isDeclaration() && !I->use_empty())
  68       switch (I->getIntrinsicID()) {
  69       default: break;
  70       case Intrinsic::setjmp:
  71         EnsureFunctionExists(M, "setjmp", I->arg_begin(), I->arg_end(),
  72                              Type::Int32Ty);
  73         break;
  74       case Intrinsic::longjmp:
  75         EnsureFunctionExists(M, "longjmp", I->arg_begin(), I->arg_end(),
  76                              Type::VoidTy);
  77         break;
  78       case Intrinsic::siglongjmp:
  79         EnsureFunctionExists(M, "abort", I->arg_end(), I->arg_end(),
  80                              Type::VoidTy);
  81         break;
  82       case Intrinsic::memcpy_i32:
  83       case Intrinsic::memcpy_i64:
  84         M.getOrInsertFunction("memcpy", PointerType::getUnqual(Type::Int8Ty),
  85                               PointerType::getUnqual(Type::Int8Ty),
  86                               PointerType::getUnqual(Type::Int8Ty),
  87                               TD.getIntPtrType(), (Type *)0);
  88         break;
  89       case Intrinsic::memmove_i32:
  90       case Intrinsic::memmove_i64:
  91         M.getOrInsertFunction("memmove", PointerType::getUnqual(Type::Int8Ty),
  92                               PointerType::getUnqual(Type::Int8Ty),
  93                               PointerType::getUnqual(Type::Int8Ty),
  94                               TD.getIntPtrType(), (Type *)0);
  95         break;
  96       case Intrinsic::memset_i32:
  97       case Intrinsic::memset_i64:
  98         M.getOrInsertFunction("memset", PointerType::getUnqual(Type::Int8Ty),
  99                               PointerType::getUnqual(Type::Int8Ty),
 100                               Type::Int32Ty,
 101                               TD.getIntPtrType(), (Type *)0);
 102         break;
 103       case Intrinsic::sqrt:
 104         switch((int)I->arg_begin()->getType()->getTypeID()) {
 105         case Type::FloatTyID:
 106           EnsureFunctionExists(M, "sqrtf", I->arg_begin(), I->arg_end(),
 107                                Type::FloatTy);
 108         case Type::DoubleTyID:
 109           EnsureFunctionExists(M, "sqrt", I->arg_begin(), I->arg_end(),
 110                                Type::DoubleTy);
 111         case Type::X86_FP80TyID:
 112         case Type::FP128TyID:
 113         case Type::PPC_FP128TyID:
 114           EnsureFunctionExists(M, "sqrtl", I->arg_begin(), I->arg_end(),
 115                                I->arg_begin()->getType());
 116         }
 117         break;
 118       case Intrinsic::sin:
 119         switch((int)I->arg_begin()->getType()->getTypeID()) {
 120         case Type::FloatTyID:
 121           EnsureFunctionExists(M, "sinf", I->arg_begin(), I->arg_end(),
 122                                Type::FloatTy);
 123         case Type::DoubleTyID:
 124           EnsureFunctionExists(M, "sin", I->arg_begin(), I->arg_end(),
 125                                Type::DoubleTy);
 126         case Type::X86_FP80TyID:
 127         case Type::FP128TyID:
 128         case Type::PPC_FP128TyID:
 129           EnsureFunctionExists(M, "sinl", I->arg_begin(), I->arg_end(),
 130                                I->arg_begin()->getType());
 131         }
 132         break;
 133       case Intrinsic::cos:
 134         switch((int)I->arg_begin()->getType()->getTypeID()) {
 135         case Type::FloatTyID:
 136           EnsureFunctionExists(M, "cosf", I->arg_begin(), I->arg_end(),
 137                                Type::FloatTy);
 138         case Type::DoubleTyID:
 139           EnsureFunctionExists(M, "cos", I->arg_begin(), I->arg_end(),
 140                                Type::DoubleTy);
 141         case Type::X86_FP80TyID:
 142         case Type::FP128TyID:
 143         case Type::PPC_FP128TyID:
 144           EnsureFunctionExists(M, "cosl", I->arg_begin(), I->arg_end(),
 145                                I->arg_begin()->getType());
 146         }
 147         break;
 148       case Intrinsic::pow:
 149         switch((int)I->arg_begin()->getType()->getTypeID()) {
 150         case Type::FloatTyID:
 151           EnsureFunctionExists(M, "powf", I->arg_begin(), I->arg_end(),
 152                                Type::FloatTy);
 153         case Type::DoubleTyID:
 154           EnsureFunctionExists(M, "pow", I->arg_begin(), I->arg_end(),
 155                                Type::DoubleTy);
 156         case Type::X86_FP80TyID:
 157         case Type::FP128TyID:
 158         case Type::PPC_FP128TyID:
 159           EnsureFunctionExists(M, "powl", I->arg_begin(), I->arg_end(),
 160                                I->arg_begin()->getType());
 161         }
 162         break;
 163       case Intrinsic::log:
 164         switch((int)I->arg_begin()->getType()->getTypeID()) {
 165         case Type::FloatTyID:
 166           EnsureFunctionExists(M, "logf", I->arg_begin(), I->arg_end(),
 167                                Type::FloatTy);
 168         case Type::DoubleTyID:
 169           EnsureFunctionExists(M, "log", I->arg_begin(), I->arg_end(),
 170                                Type::DoubleTy);
 171         case Type::X86_FP80TyID:
 172         case Type::FP128TyID:
 173         case Type::PPC_FP128TyID:
 174           EnsureFunctionExists(M, "logl", I->arg_begin(), I->arg_end(),
 175                                I->arg_begin()->getType());
 176         }
 177         break;
 178       case Intrinsic::log2:
 179         switch((int)I->arg_begin()->getType()->getTypeID()) {
 180         case Type::FloatTyID:
 181           EnsureFunctionExists(M, "log2f", I->arg_begin(), I->arg_end(),
 182                                Type::FloatTy);
 183         case Type::DoubleTyID:
 184           EnsureFunctionExists(M, "log2", I->arg_begin(), I->arg_end(),
 185                                Type::DoubleTy);
 186         case Type::X86_FP80TyID:
 187         case Type::FP128TyID:
 188         case Type::PPC_FP128TyID:
 189           EnsureFunctionExists(M, "log2l", I->arg_begin(), I->arg_end(),
 190                                I->arg_begin()->getType());
 191         }
 192         break;
 193       case Intrinsic::log10:
 194         switch((int)I->arg_begin()->getType()->getTypeID()) {
 195         case Type::FloatTyID:
 196           EnsureFunctionExists(M, "log10f", I->arg_begin(), I->arg_end(),
 197                                Type::FloatTy);
 198         case Type::DoubleTyID:
 199           EnsureFunctionExists(M, "log10", I->arg_begin(), I->arg_end(),
 200                                Type::DoubleTy);
 201         case Type::X86_FP80TyID:
 202         case Type::FP128TyID:
 203         case Type::PPC_FP128TyID:
 204           EnsureFunctionExists(M, "log10l", I->arg_begin(), I->arg_end(),
 205                                I->arg_begin()->getType());
 206         }
 207         break;
 208       case Intrinsic::exp:
 209         switch((int)I->arg_begin()->getType()->getTypeID()) {
 210         case Type::FloatTyID:
 211           EnsureFunctionExists(M, "expf", I->arg_begin(), I->arg_end(),
 212                                Type::FloatTy);
 213         case Type::DoubleTyID:
 214           EnsureFunctionExists(M, "exp", I->arg_begin(), I->arg_end(),
 215                                Type::DoubleTy);
 216         case Type::X86_FP80TyID:
 217         case Type::FP128TyID:
 218         case Type::PPC_FP128TyID:
 219           EnsureFunctionExists(M, "expl", I->arg_begin(), I->arg_end(),
 220                                I->arg_begin()->getType());
 221         }
 222         break;
 223       case Intrinsic::exp2:
 224         switch((int)I->arg_begin()->getType()->getTypeID()) {
 225         case Type::FloatTyID:
 226           EnsureFunctionExists(M, "exp2f", I->arg_begin(), I->arg_end(),
 227                                Type::FloatTy);
 228         case Type::DoubleTyID:
 229           EnsureFunctionExists(M, "exp2", I->arg_begin(), I->arg_end(),
 230                                Type::DoubleTy);
 231         case Type::X86_FP80TyID:
 232         case Type::FP128TyID:
 233         case Type::PPC_FP128TyID:
 234           EnsureFunctionExists(M, "exp2l", I->arg_begin(), I->arg_end(),
 235                                I->arg_begin()->getType());
 236         }
 237         break;
 238       }
 239 }
 240
 241 /// LowerBSWAP - Emit the code to lower bswap of V before the specified
 242 /// instruction IP.
 243 static Value *LowerBSWAP(Value *V, Instruction *IP) {
 244   assert(V->getType()->isInteger() && "Can't bswap a non-integer type!");
 245
 246   unsigned BitSize = V->getType()->getPrimitiveSizeInBits();
 247
 248   switch(BitSize) {
 249   default: assert(0 && "Unhandled type size of value to byteswap!");
 250   case 16: {
 251     Value *Tmp1 = BinaryOperator::CreateShl(V,
 252                                 ConstantInt::get(V->getType(),8),"bswap.2",IP);
 253     Value *Tmp2 = BinaryOperator::CreateLShr(V,
 254                                 ConstantInt::get(V->getType(),8),"bswap.1",IP);
 255     V = BinaryOperator::CreateOr(Tmp1, Tmp2, "bswap.i16", IP);
 256     break;
 257   }
 258   case 32: {
 259     Value *Tmp4 = BinaryOperator::CreateShl(V,
 260                               ConstantInt::get(V->getType(),24),"bswap.4", IP);
 261     Value *Tmp3 = BinaryOperator::CreateShl(V,
 262                               ConstantInt::get(V->getType(),8),"bswap.3",IP);
 263     Value *Tmp2 = BinaryOperator::CreateLShr(V,
 264                               ConstantInt::get(V->getType(),8),"bswap.2",IP);
 265     Value *Tmp1 = BinaryOperator::CreateLShr(V,
 266                               ConstantInt::get(V->getType(),24),"bswap.1", IP);
 267     Tmp3 = BinaryOperator::CreateAnd(Tmp3,
 268                                      ConstantInt::get(Type::Int32Ty, 0xFF0000),
 269                                      "bswap.and3", IP);
 270     Tmp2 = BinaryOperator::CreateAnd(Tmp2,
 271                                      ConstantInt::get(Type::Int32Ty, 0xFF00),
 272                                      "bswap.and2", IP);
 273     Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp3, "bswap.or1", IP);
 274     Tmp2 = BinaryOperator::CreateOr(Tmp2, Tmp1, "bswap.or2", IP);
 275     V = BinaryOperator::CreateOr(Tmp4, Tmp2, "bswap.i32", IP);
 276     break;
 277   }
 278   case 64: {
 279     Value *Tmp8 = BinaryOperator::CreateShl(V,
 280                               ConstantInt::get(V->getType(),56),"bswap.8", IP);
 281     Value *Tmp7 = BinaryOperator::CreateShl(V,
 282                               ConstantInt::get(V->getType(),40),"bswap.7", IP);
 283     Value *Tmp6 = BinaryOperator::CreateShl(V,
 284                               ConstantInt::get(V->getType(),24),"bswap.6", IP);
 285     Value *Tmp5 = BinaryOperator::CreateShl(V,
 286                               ConstantInt::get(V->getType(),8),"bswap.5", IP);
 287     Value* Tmp4 = BinaryOperator::CreateLShr(V,
 288                               ConstantInt::get(V->getType(),8),"bswap.4", IP);
 289     Value* Tmp3 = BinaryOperator::CreateLShr(V,
 290                               ConstantInt::get(V->getType(),24),"bswap.3", IP);
 291     Value* Tmp2 = BinaryOperator::CreateLShr(V,
 292                               ConstantInt::get(V->getType(),40),"bswap.2", IP);
 293     Value* Tmp1 = BinaryOperator::CreateLShr(V,
 294                               ConstantInt::get(V->getType(),56),"bswap.1", IP);
 295     Tmp7 = BinaryOperator::CreateAnd(Tmp7,
 296                              ConstantInt::get(Type::Int64Ty,
 297                                0xFF000000000000ULL),
 298                              "bswap.and7", IP);
 299     Tmp6 = BinaryOperator::CreateAnd(Tmp6,
 300                              ConstantInt::get(Type::Int64Ty, 0xFF0000000000ULL),
 301                              "bswap.and6", IP);
 302     Tmp5 = BinaryOperator::CreateAnd(Tmp5,
 303                              ConstantInt::get(Type::Int64Ty, 0xFF00000000ULL),
 304                              "bswap.and5", IP);
 305     Tmp4 = BinaryOperator::CreateAnd(Tmp4,
 306                              ConstantInt::get(Type::Int64Ty, 0xFF000000ULL),
 307                              "bswap.and4", IP);
 308     Tmp3 = BinaryOperator::CreateAnd(Tmp3,
 309                              ConstantInt::get(Type::Int64Ty, 0xFF0000ULL),
 310                              "bswap.and3", IP);
 311     Tmp2 = BinaryOperator::CreateAnd(Tmp2,
 312                              ConstantInt::get(Type::Int64Ty, 0xFF00ULL),
 313                              "bswap.and2", IP);
 314     Tmp8 = BinaryOperator::CreateOr(Tmp8, Tmp7, "bswap.or1", IP);
 315     Tmp6 = BinaryOperator::CreateOr(Tmp6, Tmp5, "bswap.or2", IP);
 316     Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp3, "bswap.or3", IP);
 317     Tmp2 = BinaryOperator::CreateOr(Tmp2, Tmp1, "bswap.or4", IP);
 318     Tmp8 = BinaryOperator::CreateOr(Tmp8, Tmp6, "bswap.or5", IP);
 319     Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp2, "bswap.or6", IP);
 320     V = BinaryOperator::CreateOr(Tmp8, Tmp4, "bswap.i64", IP);
 321     break;
 322   }
 323   }
 324   return V;
 325 }
 326
 327 /// LowerCTPOP - Emit the code to lower ctpop of V before the specified
 328 /// instruction IP.
 329 static Value *LowerCTPOP(Value *V, Instruction *IP) {
 330   assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!");
 331
 332   static const uint64_t MaskValues[6] = {
 333     0x5555555555555555ULL, 0x3333333333333333ULL,
 334     0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL,
 335     0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL
 336   };
 337
 338   unsigned BitSize = V->getType()->getPrimitiveSizeInBits();
 339   unsigned WordSize = (BitSize + 63) / 64;
 340   Value *Count = ConstantInt::get(V->getType(), 0);
 341
 342   for (unsigned n = 0; n < WordSize; ++n) {
 343     Value *PartValue = V;
 344     for (unsigned i = 1, ct = 0; i < (BitSize>64 ? 64 : BitSize);
 345          i <<= 1, ++ct) {
 346       Value *MaskCst = ConstantInt::get(V->getType(), MaskValues[ct]);
 347       Value *LHS = BinaryOperator::CreateAnd(
 348                      PartValue, MaskCst, "cppop.and1", IP);
 349       Value *VShift = BinaryOperator::CreateLShr(PartValue,
 350                         ConstantInt::get(V->getType(), i), "ctpop.sh", IP);
 351       Value *RHS = BinaryOperator::CreateAnd(VShift, MaskCst, "cppop.and2", IP);
 352       PartValue = BinaryOperator::CreateAdd(LHS, RHS, "ctpop.step", IP);
 353     }
 354     Count = BinaryOperator::CreateAdd(PartValue, Count, "ctpop.part", IP);
 355     if (BitSize > 64) {
 356       V = BinaryOperator::CreateLShr(V, ConstantInt::get(V->getType(), 64),
 357                                      "ctpop.part.sh", IP);
 358       BitSize -= 64;
 359     }
 360   }
 361
 362   return Count;
 363 }
 364
 365 /// LowerCTLZ - Emit the code to lower ctlz of V before the specified
 366 /// instruction IP.
 367 static Value *LowerCTLZ(Value *V, Instruction *IP) {
 368
 369   unsigned BitSize = V->getType()->getPrimitiveSizeInBits();
 370   for (unsigned i = 1; i < BitSize; i <<= 1) {
 371     Value *ShVal = ConstantInt::get(V->getType(), i);
 372     ShVal = BinaryOperator::CreateLShr(V, ShVal, "ctlz.sh", IP);
 373     V = BinaryOperator::CreateOr(V, ShVal, "ctlz.step", IP);
 374   }
 375
 376   V = BinaryOperator::CreateNot(V, "", IP);
 377   return LowerCTPOP(V, IP);
 378 }
 379
 380 /// Convert the llvm.part.select.iX.iY intrinsic. This intrinsic takes
 381 /// three integer arguments. The first argument is the Value from which the
 382 /// bits will be selected. It may be of any bit width. The second and third
 383 /// arguments specify a range of bits to select with the second argument
 384 /// specifying the low bit and the third argument specifying the high bit. Both
 385 /// must be type i32. The result is the corresponding selected bits from the
 386 /// Value in the same width as the Value (first argument). If the low bit index
 387 /// is higher than the high bit index then the inverse selection is done and
 388 /// the bits are returned in inverse order.
 389 /// @brief Lowering of llvm.part.select intrinsic.
 390 static Instruction *LowerPartSelect(CallInst *CI) {
 391   // Make sure we're dealing with a part select intrinsic here
 392   Function *F = CI->getCalledFunction();
 393   const FunctionType *FT = F->getFunctionType();
 394   if (!F->isDeclaration() || !FT->getReturnType()->isInteger() ||
 395       FT->getNumParams() != 3 || !FT->getParamType(0)->isInteger() ||
 396       !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger())
 397     return CI;
 398
 399   // Get the intrinsic implementation function by converting all the . to _
 400   // in the intrinsic's function name and then reconstructing the function
 401   // declaration.
 402   std::string Name(F->getName());
 403   for (unsigned i = 4; i < Name.length(); ++i)
 404     if (Name[i] == '.')
 405       Name[i] = '_';
 406   Module* M = F->getParent();
 407   F = cast<Function>(M->getOrInsertFunction(Name, FT));
 408   F->setLinkage(GlobalValue::WeakLinkage);
 409
 410   // If we haven't defined the impl function yet, do so now
 411   if (F->isDeclaration()) {
 412
 413     // Get the arguments to the function
 414     Function::arg_iterator args = F->arg_begin();
 415     Value* Val = args++; Val->setName("Val");
 416     Value* Lo = args++; Lo->setName("Lo");
 417     Value* Hi = args++; Hi->setName("High");
 418
 419     // We want to select a range of bits here such that [Hi, Lo] is shifted
 420     // down to the low bits. However, it is quite possible that Hi is smaller
 421     // than Lo in which case the bits have to be reversed.
 422
 423     // Create the blocks we will need for the two cases (forward, reverse)
 424     BasicBlock* CurBB   = BasicBlock::Create("entry", F);
 425     BasicBlock *RevSize = BasicBlock::Create("revsize", CurBB->getParent());
 426     BasicBlock *FwdSize = BasicBlock::Create("fwdsize", CurBB->getParent());
 427     BasicBlock *Compute = BasicBlock::Create("compute", CurBB->getParent());
 428     BasicBlock *Reverse = BasicBlock::Create("reverse", CurBB->getParent());
 429     BasicBlock *RsltBlk = BasicBlock::Create("result",  CurBB->getParent());
 430
 431     // Cast Hi and Lo to the size of Val so the widths are all the same
 432     if (Hi->getType() != Val->getType())
 433       Hi = CastInst::CreateIntegerCast(Hi, Val->getType(), false,
 434                                          "tmp", CurBB);
 435     if (Lo->getType() != Val->getType())
 436       Lo = CastInst::CreateIntegerCast(Lo, Val->getType(), false,
 437                                           "tmp", CurBB);
 438
 439     // Compute a few things that both cases will need, up front.
 440     Constant* Zero = ConstantInt::get(Val->getType(), 0);
 441     Constant* One = ConstantInt::get(Val->getType(), 1);
 442     Constant* AllOnes = ConstantInt::getAllOnesValue(Val->getType());
 443
 444     // Compare the Hi and Lo bit positions. This is used to determine
 445     // which case we have (forward or reverse)
 446     ICmpInst *Cmp = new ICmpInst(ICmpInst::ICMP_ULT, Hi, Lo, "less",CurBB);
 447     BranchInst::Create(RevSize, FwdSize, Cmp, CurBB);
 448
 449     // First, copmute the number of bits in the forward case.
 450     Instruction* FBitSize =
 451       BinaryOperator::CreateSub(Hi, Lo,"fbits", FwdSize);
 452     BranchInst::Create(Compute, FwdSize);
 453
 454     // Second, compute the number of bits in the reverse case.
 455     Instruction* RBitSize =
 456       BinaryOperator::CreateSub(Lo, Hi, "rbits", RevSize);
 457     BranchInst::Create(Compute, RevSize);
 458
 459     // Now, compute the bit range. Start by getting the bitsize and the shift
 460     // amount (either Hi or Lo) from PHI nodes. Then we compute a mask for
 461     // the number of bits we want in the range. We shift the bits down to the
 462     // least significant bits, apply the mask to zero out unwanted high bits,
 463     // and we have computed the "forward" result. It may still need to be
 464     // reversed.
 465
 466     // Get the BitSize from one of the two subtractions
 467     PHINode *BitSize = PHINode::Create(Val->getType(), "bits", Compute);
 468     BitSize->reserveOperandSpace(2);
 469     BitSize->addIncoming(FBitSize, FwdSize);
 470     BitSize->addIncoming(RBitSize, RevSize);
 471
 472     // Get the ShiftAmount as the smaller of Hi/Lo
 473     PHINode *ShiftAmt = PHINode::Create(Val->getType(), "shiftamt", Compute);
 474     ShiftAmt->reserveOperandSpace(2);
 475     ShiftAmt->addIncoming(Lo, FwdSize);
 476     ShiftAmt->addIncoming(Hi, RevSize);
 477
 478     // Increment the bit size
 479     Instruction *BitSizePlusOne =
 480       BinaryOperator::CreateAdd(BitSize, One, "bits", Compute);
 481
 482     // Create a Mask to zero out the high order bits.
 483     Instruction* Mask =
 484       BinaryOperator::CreateShl(AllOnes, BitSizePlusOne, "mask", Compute);
 485     Mask = BinaryOperator::CreateNot(Mask, "mask", Compute);
 486
 487     // Shift the bits down and apply the mask
 488     Instruction* FRes =
 489       BinaryOperator::CreateLShr(Val, ShiftAmt, "fres", Compute);
 490     FRes = BinaryOperator::CreateAnd(FRes, Mask, "fres", Compute);
 491     BranchInst::Create(Reverse, RsltBlk, Cmp, Compute);
 492
 493     // In the Reverse block we have the mask already in FRes but we must reverse
 494     // it by shifting FRes bits right and putting them in RRes by shifting them
 495     // in from left.
 496
 497     // First set up our loop counters
 498     PHINode *Count = PHINode::Create(Val->getType(), "count", Reverse);
 499     Count->reserveOperandSpace(2);
 500     Count->addIncoming(BitSizePlusOne, Compute);
 501
 502     // Next, get the value that we are shifting.
 503     PHINode *BitsToShift = PHINode::Create(Val->getType(), "val", Reverse);
 504     BitsToShift->reserveOperandSpace(2);
 505     BitsToShift->addIncoming(FRes, Compute);
 506
 507     // Finally, get the result of the last computation
 508     PHINode *RRes = PHINode::Create(Val->getType(), "rres", Reverse);
 509     RRes->reserveOperandSpace(2);
 510     RRes->addIncoming(Zero, Compute);
 511
 512     // Decrement the counter
 513     Instruction *Decr = BinaryOperator::CreateSub(Count, One, "decr", Reverse);
 514     Count->addIncoming(Decr, Reverse);
 515
 516     // Compute the Bit that we want to move
 517     Instruction *Bit =
 518       BinaryOperator::CreateAnd(BitsToShift, One, "bit", Reverse);
 519
 520     // Compute the new value for next iteration.
 521     Instruction *NewVal =
 522       BinaryOperator::CreateLShr(BitsToShift, One, "rshift", Reverse);
 523     BitsToShift->addIncoming(NewVal, Reverse);
 524
 525     // Shift the bit into the low bits of the result.
 526     Instruction *NewRes =
 527       BinaryOperator::CreateShl(RRes, One, "lshift", Reverse);
 528     NewRes = BinaryOperator::CreateOr(NewRes, Bit, "addbit", Reverse);
 529     RRes->addIncoming(NewRes, Reverse);
 530
 531     // Terminate loop if we've moved all the bits.
 532     ICmpInst *Cond =
 533       new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "cond", Reverse);
 534     BranchInst::Create(RsltBlk, Reverse, Cond, Reverse);
 535
 536     // Finally, in the result block, select one of the two results with a PHI
 537     // node and return the result;
 538     CurBB = RsltBlk;
 539     PHINode *BitSelect = PHINode::Create(Val->getType(), "part_select", CurBB);
 540     BitSelect->reserveOperandSpace(2);
 541     BitSelect->addIncoming(FRes, Compute);
 542     BitSelect->addIncoming(NewRes, Reverse);
 543     ReturnInst::Create(BitSelect, CurBB);
 544   }
 545
 546   // Return a call to the implementation function
 547   Value *Args[] = {
 548     CI->getOperand(1),
 549     CI->getOperand(2),
 550     CI->getOperand(3)
 551   };
 552   return CallInst::Create(F, Args, array_endof(Args), CI->getName(), CI);
 553 }
 554
 555 /// Convert the llvm.part.set.iX.iY.iZ intrinsic. This intrinsic takes
 556 /// four integer arguments (iAny %Value, iAny %Replacement, i32 %Low, i32 %High)
 557 /// The first two arguments can be any bit width. The result is the same width
 558 /// as %Value. The operation replaces bits between %Low and %High with the value
 559 /// in %Replacement. If %Replacement is not the same width, it is truncated or
 560 /// zero extended as appropriate to fit the bits being replaced. If %Low is
 561 /// greater than %High then the inverse set of bits are replaced.
 562 /// @brief Lowering of llvm.bit.part.set intrinsic.
 563 static Instruction *LowerPartSet(CallInst *CI) {
 564   // Make sure we're dealing with a part select intrinsic here
 565   Function *F = CI->getCalledFunction();
 566   const FunctionType *FT = F->getFunctionType();
 567   if (!F->isDeclaration() || !FT->getReturnType()->isInteger() ||
 568       FT->getNumParams() != 4 || !FT->getParamType(0)->isInteger() ||
 569       !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger() ||
 570       !FT->getParamType(3)->isInteger())
 571     return CI;
 572
 573   // Get the intrinsic implementation function by converting all the . to _
 574   // in the intrinsic's function name and then reconstructing the function
 575   // declaration.
 576   std::string Name(F->getName());
 577   for (unsigned i = 4; i < Name.length(); ++i)
 578     if (Name[i] == '.')
 579       Name[i] = '_';
 580   Module* M = F->getParent();
 581   F = cast<Function>(M->getOrInsertFunction(Name, FT));
 582   F->setLinkage(GlobalValue::WeakLinkage);
 583
 584   // If we haven't defined the impl function yet, do so now
 585   if (F->isDeclaration()) {
 586     // Get the arguments for the function.
 587     Function::arg_iterator args = F->arg_begin();
 588     Value* Val = args++; Val->setName("Val");
 589     Value* Rep = args++; Rep->setName("Rep");
 590     Value* Lo  = args++; Lo->setName("Lo");
 591     Value* Hi  = args++; Hi->setName("Hi");
 592
 593     // Get some types we need
 594     const IntegerType* ValTy = cast<IntegerType>(Val->getType());
 595     const IntegerType* RepTy = cast<IntegerType>(Rep->getType());
 596     uint32_t ValBits = ValTy->getBitWidth();
 597     uint32_t RepBits = RepTy->getBitWidth();
 598
 599     // Constant Definitions
 600     ConstantInt* RepBitWidth = ConstantInt::get(Type::Int32Ty, RepBits);
 601     ConstantInt* RepMask = ConstantInt::getAllOnesValue(RepTy);
 602     ConstantInt* ValMask = ConstantInt::getAllOnesValue(ValTy);
 603     ConstantInt* One = ConstantInt::get(Type::Int32Ty, 1);
 604     ConstantInt* ValOne = ConstantInt::get(ValTy, 1);
 605     ConstantInt* Zero = ConstantInt::get(Type::Int32Ty, 0);
 606     ConstantInt* ValZero = ConstantInt::get(ValTy, 0);
 607
 608     // Basic blocks we fill in below.
 609     BasicBlock* entry = BasicBlock::Create("entry", F, 0);
 610     BasicBlock* large = BasicBlock::Create("large", F, 0);
 611     BasicBlock* small = BasicBlock::Create("small", F, 0);
 612     BasicBlock* reverse = BasicBlock::Create("reverse", F, 0);
 613     BasicBlock* result = BasicBlock::Create("result", F, 0);
 614
 615     // BASIC BLOCK: entry
 616     // First, get the number of bits that we're placing as an i32
 617     ICmpInst* is_forward =
 618       new ICmpInst(ICmpInst::ICMP_ULT, Lo, Hi, "", entry);
 619     SelectInst* Hi_pn = SelectInst::Create(is_forward, Hi, Lo, "", entry);
 620     SelectInst* Lo_pn = SelectInst::Create(is_forward, Lo, Hi, "", entry);
 621     BinaryOperator* NumBits = BinaryOperator::CreateSub(Hi_pn, Lo_pn, "",entry);
 622     NumBits = BinaryOperator::CreateAdd(NumBits, One, "", entry);
 623     // Now, convert Lo and Hi to ValTy bit width
 624     if (ValBits > 32) {
 625       Lo = new ZExtInst(Lo_pn, ValTy, "", entry);
 626     } else if (ValBits < 32) {
 627       Lo = new TruncInst(Lo_pn, ValTy, "", entry);
 628     }
 629     // Determine if the replacement bits are larger than the number of bits we
 630     // are replacing and deal with it.
 631     ICmpInst* is_large =
 632       new ICmpInst(ICmpInst::ICMP_ULT, NumBits, RepBitWidth, "", entry);
 633     BranchInst::Create(large, small, is_large, entry);
 634
 635     // BASIC BLOCK: large
 636     Instruction* MaskBits =
 637       BinaryOperator::CreateSub(RepBitWidth, NumBits, "", large);
 638     MaskBits = CastInst::CreateIntegerCast(MaskBits, RepMask->getType(),
 639                                            false, "", large);
 640     BinaryOperator* Mask1 =
 641       BinaryOperator::CreateLShr(RepMask, MaskBits, "", large);
 642     BinaryOperator* Rep2 = BinaryOperator::CreateAnd(Mask1, Rep, "", large);
 643     BranchInst::Create(small, large);
 644
 645     // BASIC BLOCK: small
 646     PHINode* Rep3 = PHINode::Create(RepTy, "", small);
 647     Rep3->reserveOperandSpace(2);
 648     Rep3->addIncoming(Rep2, large);
 649     Rep3->addIncoming(Rep, entry);
 650     Value* Rep4 = Rep3;
 651     if (ValBits > RepBits)
 652       Rep4 = new ZExtInst(Rep3, ValTy, "", small);
 653     else if (ValBits < RepBits)
 654       Rep4 = new TruncInst(Rep3, ValTy, "", small);
 655     BranchInst::Create(result, reverse, is_forward, small);
 656
 657     // BASIC BLOCK: reverse (reverses the bits of the replacement)
 658     // Set up our loop counter as a PHI so we can decrement on each iteration.
 659     // We will loop for the number of bits in the replacement value.
 660     PHINode *Count = PHINode::Create(Type::Int32Ty, "count", reverse);
 661     Count->reserveOperandSpace(2);
 662     Count->addIncoming(NumBits, small);
 663
 664     // Get the value that we are shifting bits out of as a PHI because
 665     // we'll change this with each iteration.
 666     PHINode *BitsToShift = PHINode::Create(Val->getType(), "val", reverse);
 667     BitsToShift->reserveOperandSpace(2);
 668     BitsToShift->addIncoming(Rep4, small);
 669
 670     // Get the result of the last computation or zero on first iteration
 671     PHINode *RRes = PHINode::Create(Val->getType(), "rres", reverse);
 672     RRes->reserveOperandSpace(2);
 673     RRes->addIncoming(ValZero, small);
 674
 675     // Decrement the loop counter by one
 676     Instruction *Decr = BinaryOperator::CreateSub(Count, One, "", reverse);
 677     Count->addIncoming(Decr, reverse);
 678
 679     // Get the bit that we want to move into the result
 680     Value *Bit = BinaryOperator::CreateAnd(BitsToShift, ValOne, "", reverse);
 681
 682     // Compute the new value of the bits to shift for the next iteration.
 683     Value *NewVal = BinaryOperator::CreateLShr(BitsToShift, ValOne,"", reverse);
 684     BitsToShift->addIncoming(NewVal, reverse);
 685
 686     // Shift the bit we extracted into the low bit of the result.
 687     Instruction *NewRes = BinaryOperator::CreateShl(RRes, ValOne, "", reverse);
 688     NewRes = BinaryOperator::CreateOr(NewRes, Bit, "", reverse);
 689     RRes->addIncoming(NewRes, reverse);
 690
 691     // Terminate loop if we've moved all the bits.
 692     ICmpInst *Cond = new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "", reverse);
 693     BranchInst::Create(result, reverse, Cond, reverse);
 694
 695     // BASIC BLOCK: result
 696     PHINode *Rplcmnt = PHINode::Create(Val->getType(), "", result);
 697     Rplcmnt->reserveOperandSpace(2);
 698     Rplcmnt->addIncoming(NewRes, reverse);
 699     Rplcmnt->addIncoming(Rep4, small);
 700     Value* t0   = CastInst::CreateIntegerCast(NumBits,ValTy,false,"",result);
 701     Value* t1   = BinaryOperator::CreateShl(ValMask, Lo, "", result);
 702     Value* t2   = BinaryOperator::CreateNot(t1, "", result);
 703     Value* t3   = BinaryOperator::CreateShl(t1, t0, "", result);
 704     Value* t4   = BinaryOperator::CreateOr(t2, t3, "", result);
 705     Value* t5   = BinaryOperator::CreateAnd(t4, Val, "", result);
 706     Value* t6   = BinaryOperator::CreateShl(Rplcmnt, Lo, "", result);
 707     Value* Rslt = BinaryOperator::CreateOr(t5, t6, "part_set", result);
 708     ReturnInst::Create(Rslt, result);
 709   }
 710
 711   // Return a call to the implementation function
 712   Value *Args[] = {
 713     CI->getOperand(1),
 714     CI->getOperand(2),
 715     CI->getOperand(3),
 716     CI->getOperand(4)
 717   };
 718   return CallInst::Create(F, Args, array_endof(Args), CI->getName(), CI);
 719 }
 720
 721
 722 void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
 723   Function *Callee = CI->getCalledFunction();
 724   assert(Callee && "Cannot lower an indirect call!");
 725
 726   switch (Callee->getIntrinsicID()) {
 727   case Intrinsic::not_intrinsic:
 728     cerr << "Cannot lower a call to a non-intrinsic function '"
 729          << Callee->getName() << "'!\n";
 730     abort();
 731   default:
 732     cerr << "Error: Code generator does not support intrinsic function '"
 733          << Callee->getName() << "'!\n";
 734     abort();
 735
 736     // The setjmp/longjmp intrinsics should only exist in the code if it was
 737     // never optimized (ie, right out of the CFE), or if it has been hacked on
 738     // by the lowerinvoke pass.  In both cases, the right thing to do is to
 739     // convert the call to an explicit setjmp or longjmp call.
 740   case Intrinsic::setjmp: {
 741     static Constant *SetjmpFCache = 0;
 742     Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(),
 743                                Type::Int32Ty, SetjmpFCache);
 744     if (CI->getType() != Type::VoidTy)
 745       CI->replaceAllUsesWith(V);
 746     break;
 747   }
 748   case Intrinsic::sigsetjmp:
 749      if (CI->getType() != Type::VoidTy)
 750        CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
 751      break;
 752
 753   case Intrinsic::longjmp: {
 754     static Constant *LongjmpFCache = 0;
 755     ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(),
 756                     Type::VoidTy, LongjmpFCache);
 757     break;
 758   }
 759
 760   case Intrinsic::siglongjmp: {
 761     // Insert the call to abort
 762     static Constant *AbortFCache = 0;
 763     ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(),
 764                     Type::VoidTy, AbortFCache);
 765     break;
 766   }
 767   case Intrinsic::ctpop:
 768     CI->replaceAllUsesWith(LowerCTPOP(CI->getOperand(1), CI));
 769     break;
 770
 771   case Intrinsic::bswap:
 772     CI->replaceAllUsesWith(LowerBSWAP(CI->getOperand(1), CI));
 773     break;
 774
 775   case Intrinsic::ctlz:
 776     CI->replaceAllUsesWith(LowerCTLZ(CI->getOperand(1), CI));
 777     break;
 778
 779   case Intrinsic::cttz: {
 780     // cttz(x) -> ctpop(~X & (X-1))
 781     Value *Src = CI->getOperand(1);
 782     Value *NotSrc = BinaryOperator::CreateNot(Src, Src->getName()+".not", CI);
 783     Value *SrcM1 = ConstantInt::get(Src->getType(), 1);
 784     SrcM1 = BinaryOperator::CreateSub(Src, SrcM1, "", CI);
 785     Src = LowerCTPOP(BinaryOperator::CreateAnd(NotSrc, SrcM1, "", CI), CI);
 786     CI->replaceAllUsesWith(Src);
 787     break;
 788   }
 789
 790   case Intrinsic::part_select:
 791     CI->replaceAllUsesWith(LowerPartSelect(CI));
 792     break;
 793
 794   case Intrinsic::part_set:
 795     CI->replaceAllUsesWith(LowerPartSet(CI));
 796     break;
 797
 798   case Intrinsic::stacksave:
 799   case Intrinsic::stackrestore: {
 800     static bool Warned = false;
 801     if (!Warned)
 802       cerr << "WARNING: this target does not support the llvm.stack"
 803            << (Callee->getIntrinsicID() == Intrinsic::stacksave ?
 804                "save" : "restore") << " intrinsic.\n";
 805     Warned = true;
 806     if (Callee->getIntrinsicID() == Intrinsic::stacksave)
 807       CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
 808     break;
 809   }
 810
 811   case Intrinsic::returnaddress:
 812   case Intrinsic::frameaddress:
 813     cerr << "WARNING: this target does not support the llvm."
 814          << (Callee->getIntrinsicID() == Intrinsic::returnaddress ?
 815              "return" : "frame") << "address intrinsic.\n";
 816     CI->replaceAllUsesWith(ConstantPointerNull::get(
 817                                             cast<PointerType>(CI->getType())));
 818     break;
 819
 820   case Intrinsic::prefetch:
 821     break;    // Simply strip out prefetches on unsupported architectures
 822
 823   case Intrinsic::pcmarker:
 824     break;    // Simply strip out pcmarker on unsupported architectures
 825   case Intrinsic::readcyclecounter: {
 826     cerr << "WARNING: this target does not support the llvm.readcyclecoun"
 827          << "ter intrinsic.  It is being lowered to a constant 0\n";
 828     CI->replaceAllUsesWith(ConstantInt::get(Type::Int64Ty, 0));
 829     break;
 830   }
 831
 832   case Intrinsic::dbg_stoppoint:
 833   case Intrinsic::dbg_region_start:
 834   case Intrinsic::dbg_region_end:
 835   case Intrinsic::dbg_func_start:
 836   case Intrinsic::dbg_declare:
 837     break;    // Simply strip out debugging intrinsics
 838
 839   case Intrinsic::eh_exception:
 840   case Intrinsic::eh_selector_i32:
 841   case Intrinsic::eh_selector_i64:
 842     CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
 843     break;
 844
 845   case Intrinsic::eh_typeid_for_i32:
 846   case Intrinsic::eh_typeid_for_i64:
 847     // Return something different to eh_selector.
 848     CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1));
 849     break;
 850
 851   case Intrinsic::var_annotation:
 852     break;   // Strip out annotate intrinsic
 853
 854   case Intrinsic::memcpy_i32:
 855   case Intrinsic::memcpy_i64: {
 856     static Constant *MemcpyFCache = 0;
 857     Value *Size = CI->getOperand(3);
 858     const Type *IntPtr = TD.getIntPtrType();
 859     if (Size->getType()->getPrimitiveSizeInBits() <
 860         IntPtr->getPrimitiveSizeInBits())
 861       Size = new ZExtInst(Size, IntPtr, "", CI);
 862     else if (Size->getType()->getPrimitiveSizeInBits() >
 863              IntPtr->getPrimitiveSizeInBits())
 864       Size = new TruncInst(Size, IntPtr, "", CI);
 865     Value *Ops[3];
 866     Ops[0] = CI->getOperand(1);
 867     Ops[1] = CI->getOperand(2);
 868     Ops[2] = Size;
 869     ReplaceCallWith("memcpy", CI, Ops, Ops+3, CI->getOperand(1)->getType(),
 870                     MemcpyFCache);
 871     break;
 872   }
 873   case Intrinsic::memmove_i32:
 874   case Intrinsic::memmove_i64: {
 875     static Constant *MemmoveFCache = 0;
 876     Value *Size = CI->getOperand(3);
 877     const Type *IntPtr = TD.getIntPtrType();
 878     if (Size->getType()->getPrimitiveSizeInBits() <
 879         IntPtr->getPrimitiveSizeInBits())
 880       Size = new ZExtInst(Size, IntPtr, "", CI);
 881     else if (Size->getType()->getPrimitiveSizeInBits() >
 882              IntPtr->getPrimitiveSizeInBits())
 883       Size = new TruncInst(Size, IntPtr, "", CI);
 884     Value *Ops[3];
 885     Ops[0] = CI->getOperand(1);
 886     Ops[1] = CI->getOperand(2);
 887     Ops[2] = Size;
 888     ReplaceCallWith("memmove", CI, Ops, Ops+3, CI->getOperand(1)->getType(),
 889                     MemmoveFCache);
 890     break;
 891   }
 892   case Intrinsic::memset_i32:
 893   case Intrinsic::memset_i64: {
 894     static Constant *MemsetFCache = 0;
 895     Value *Size = CI->getOperand(3);
 896     const Type *IntPtr = TD.getIntPtrType();
 897     if (Size->getType()->getPrimitiveSizeInBits() <
 898         IntPtr->getPrimitiveSizeInBits())
 899       Size = new ZExtInst(Size, IntPtr, "", CI);
 900     else if (Size->getType()->getPrimitiveSizeInBits() >
 901              IntPtr->getPrimitiveSizeInBits())
 902       Size = new TruncInst(Size, IntPtr, "", CI);
 903     Value *Ops[3];
 904     Ops[0] = CI->getOperand(1);
 905     // Extend the amount to i32.
 906     Ops[1] = new ZExtInst(CI->getOperand(2), Type::Int32Ty, "", CI);
 907     Ops[2] = Size;
 908     ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getOperand(1)->getType(),
 909                     MemsetFCache);
 910     break;
 911   }
 912   case Intrinsic::sqrt: {
 913     static Constant *sqrtfFCache = 0;
 914     static Constant *sqrtFCache = 0;
 915     static Constant *sqrtLDCache = 0;
 916     switch (CI->getOperand(1)->getType()->getTypeID()) {
 917     default: assert(0 && "Invalid type in sqrt"); abort();
 918     case Type::FloatTyID:
 919       ReplaceCallWith("sqrtf", CI, CI->op_begin()+1, CI->op_end(),
 920                     Type::FloatTy, sqrtfFCache);
 921       break;
 922     case Type::DoubleTyID:
 923       ReplaceCallWith("sqrt", CI, CI->op_begin()+1, CI->op_end(),
 924                     Type::DoubleTy, sqrtFCache);
 925       break;
 926     case Type::X86_FP80TyID:
 927     case Type::FP128TyID:
 928     case Type::PPC_FP128TyID:
 929       ReplaceCallWith("sqrtl", CI, CI->op_begin()+1, CI->op_end(),
 930                     CI->getOperand(1)->getType(), sqrtLDCache);
 931       break;
 932     }
 933     break;
 934   }
 935   case Intrinsic::log: {
 936     static Constant *logfFCache = 0;
 937     static Constant *logFCache = 0;
 938     static Constant *logLDCache = 0;
 939     switch (CI->getOperand(1)->getType()->getTypeID()) {
 940     default: assert(0 && "Invalid type in log"); abort();
 941     case Type::FloatTyID:
 942       ReplaceCallWith("logf", CI, CI->op_begin()+1, CI->op_end(),
 943                     Type::FloatTy, logfFCache);
 944       break;
 945     case Type::DoubleTyID:
 946       ReplaceCallWith("log", CI, CI->op_begin()+1, CI->op_end(),
 947                     Type::DoubleTy, logFCache);
 948       break;
 949     case Type::X86_FP80TyID:
 950     case Type::FP128TyID:
 951     case Type::PPC_FP128TyID:
 952       ReplaceCallWith("logl", CI, CI->op_begin()+1, CI->op_end(),
 953                     CI->getOperand(1)->getType(), logLDCache);
 954       break;
 955     }
 956     break;
 957   }
 958   case Intrinsic::log2: {
 959     static Constant *log2fFCache = 0;
 960     static Constant *log2FCache = 0;
 961     static Constant *log2LDCache = 0;
 962     switch (CI->getOperand(1)->getType()->getTypeID()) {
 963     default: assert(0 && "Invalid type in log2"); abort();
 964     case Type::FloatTyID:
 965       ReplaceCallWith("log2f", CI, CI->op_begin()+1, CI->op_end(),
 966                     Type::FloatTy, log2fFCache);
 967       break;
 968     case Type::DoubleTyID:
 969       ReplaceCallWith("log2", CI, CI->op_begin()+1, CI->op_end(),
 970                     Type::DoubleTy, log2FCache);
 971       break;
 972     case Type::X86_FP80TyID:
 973     case Type::FP128TyID:
 974     case Type::PPC_FP128TyID:
 975       ReplaceCallWith("log2l", CI, CI->op_begin()+1, CI->op_end(),
 976                     CI->getOperand(1)->getType(), log2LDCache);
 977       break;
 978     }
 979     break;
 980   }
 981   case Intrinsic::log10: {
 982     static Constant *log10fFCache = 0;
 983     static Constant *log10FCache = 0;
 984     static Constant *log10LDCache = 0;
 985     switch (CI->getOperand(1)->getType()->getTypeID()) {
 986     default: assert(0 && "Invalid type in log10"); abort();
 987     case Type::FloatTyID:
 988       ReplaceCallWith("log10f", CI, CI->op_begin()+1, CI->op_end(),
 989                     Type::FloatTy, log10fFCache);
 990       break;
 991     case Type::DoubleTyID:
 992       ReplaceCallWith("log10", CI, CI->op_begin()+1, CI->op_end(),
 993                     Type::DoubleTy, log10FCache);
 994       break;
 995     case Type::X86_FP80TyID:
 996     case Type::FP128TyID:
 997     case Type::PPC_FP128TyID:
 998       ReplaceCallWith("log10l", CI, CI->op_begin()+1, CI->op_end(),
 999                     CI->getOperand(1)->getType(), log10LDCache);
1000       break;
1001     }
1002     break;
1003   }
1004   case Intrinsic::exp: {
1005     static Constant *expfFCache = 0;
1006     static Constant *expFCache = 0;
1007     static Constant *expLDCache = 0;
1008     switch (CI->getOperand(1)->getType()->getTypeID()) {
1009     default: assert(0 && "Invalid type in exp"); abort();
1010     case Type::FloatTyID:
1011       ReplaceCallWith("expf", CI, CI->op_begin()+1, CI->op_end(),
1012                     Type::FloatTy, expfFCache);
1013       break;
1014     case Type::DoubleTyID:
1015       ReplaceCallWith("exp", CI, CI->op_begin()+1, CI->op_end(),
1016                     Type::DoubleTy, expFCache);
1017       break;
1018     case Type::X86_FP80TyID:
1019     case Type::FP128TyID:
1020     case Type::PPC_FP128TyID:
1021       ReplaceCallWith("expl", CI, CI->op_begin()+1, CI->op_end(),
1022                     CI->getOperand(1)->getType(), expLDCache);
1023       break;
1024     }
1025     break;
1026   }
1027   case Intrinsic::exp2: {
1028     static Constant *exp2fFCache = 0;
1029     static Constant *exp2FCache = 0;
1030     static Constant *exp2LDCache = 0;
1031     switch (CI->getOperand(1)->getType()->getTypeID()) {
1032     default: assert(0 && "Invalid type in exp2"); abort();
1033     case Type::FloatTyID:
1034       ReplaceCallWith("exp2f", CI, CI->op_begin()+1, CI->op_end(),
1035                     Type::FloatTy, exp2fFCache);
1036       break;
1037     case Type::DoubleTyID:
1038       ReplaceCallWith("exp2", CI, CI->op_begin()+1, CI->op_end(),
1039                     Type::DoubleTy, exp2FCache);
1040       break;
1041     case Type::X86_FP80TyID:
1042     case Type::FP128TyID:
1043     case Type::PPC_FP128TyID:
1044       ReplaceCallWith("exp2l", CI, CI->op_begin()+1, CI->op_end(),
1045                     CI->getOperand(1)->getType(), exp2LDCache);
1046       break;
1047     }
1048     break;
1049   }
1050   case Intrinsic::pow: {
1051     static Constant *powfFCache = 0;
1052     static Constant *powFCache = 0;
1053     static Constant *powLDCache = 0;
1054     switch (CI->getOperand(1)->getType()->getTypeID()) {
1055     default: assert(0 && "Invalid type in pow"); abort();
1056     case Type::FloatTyID:
1057       ReplaceCallWith("powf", CI, CI->op_begin()+1, CI->op_end(),
1058                     Type::FloatTy, powfFCache);
1059       break;
1060     case Type::DoubleTyID:
1061       ReplaceCallWith("pow", CI, CI->op_begin()+1, CI->op_end(),
1062                     Type::DoubleTy, powFCache);
1063       break;
1064     case Type::X86_FP80TyID:
1065     case Type::FP128TyID:
1066     case Type::PPC_FP128TyID:
1067       ReplaceCallWith("powl", CI, CI->op_begin()+1, CI->op_end(),
1068                     CI->getOperand(1)->getType(), powLDCache);
1069       break;
1070     }
1071     break;
1072   }
1073   case Intrinsic::flt_rounds:
1074      // Lower to "round to the nearest"
1075      if (CI->getType() != Type::VoidTy)
1076        CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1));
1077      break;
1078   }
1079
1080   assert(CI->use_empty() &&
1081          "Lowering should have eliminated any uses of the intrinsic call!");
1082   CI->eraseFromParent();
1083 }