Check in LLVM r95781.
diff --git a/lib/CodeGen/IntrinsicLowering.cpp b/lib/CodeGen/IntrinsicLowering.cpp
new file mode 100644
index 0000000..9997a48
--- /dev/null
+++ b/lib/CodeGen/IntrinsicLowering.cpp
@@ -0,0 +1,528 @@
+//===-- IntrinsicLowering.cpp - Intrinsic Lowering default implementation -===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the IntrinsicLowering class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Module.h"
+#include "llvm/Type.h"
+#include "llvm/CodeGen/IntrinsicLowering.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/IRBuilder.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/ADT/SmallVector.h"
+using namespace llvm;
+
+template <class ArgIt>
+static void EnsureFunctionExists(Module &M, const char *Name,
+                                 ArgIt ArgBegin, ArgIt ArgEnd,
+                                 const Type *RetTy) {
+  // Insert a correctly-typed definition now.
+  std::vector<const Type *> ParamTys;
+  for (ArgIt I = ArgBegin; I != ArgEnd; ++I)
+    ParamTys.push_back(I->getType());
+  M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false));
+}
+
+static void EnsureFPIntrinsicsExist(Module &M, Function *Fn,
+                                    const char *FName,
+                                    const char *DName, const char *LDName) {
+  // Insert definitions for all the floating point types.
+  switch((int)Fn->arg_begin()->getType()->getTypeID()) {
+  case Type::FloatTyID:
+    EnsureFunctionExists(M, FName, Fn->arg_begin(), Fn->arg_end(),
+                         Type::getFloatTy(M.getContext()));
+    break;
+  case Type::DoubleTyID:
+    EnsureFunctionExists(M, DName, Fn->arg_begin(), Fn->arg_end(),
+                         Type::getDoubleTy(M.getContext()));
+    break;
+  case Type::X86_FP80TyID:
+  case Type::FP128TyID:
+  case Type::PPC_FP128TyID:
+    EnsureFunctionExists(M, LDName, Fn->arg_begin(), Fn->arg_end(),
+                         Fn->arg_begin()->getType());
+    break;
+  }
+}
+
+/// ReplaceCallWith - This function is used when we want to lower an intrinsic
+/// call to a call of an external function.  This handles hard cases such as
+/// when there was already a prototype for the external function, and if that
+/// prototype doesn't match the arguments we expect to pass in.
+template <class ArgIt>
+static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI,
+                                 ArgIt ArgBegin, ArgIt ArgEnd,
+                                 const Type *RetTy) {
+  // If we haven't already looked up this function, check to see if the
+  // program already contains a function with this name.
+  Module *M = CI->getParent()->getParent()->getParent();
+  // Get or insert the definition now.
+  std::vector<const Type *> ParamTys;
+  for (ArgIt I = ArgBegin; I != ArgEnd; ++I)
+    ParamTys.push_back((*I)->getType());
+  Constant* FCache = M->getOrInsertFunction(NewFn,
+                                  FunctionType::get(RetTy, ParamTys, false));
+
+  IRBuilder<> Builder(CI->getParent(), CI);
+  SmallVector<Value *, 8> Args(ArgBegin, ArgEnd);
+  CallInst *NewCI = Builder.CreateCall(FCache, Args.begin(), Args.end());
+  NewCI->setName(CI->getName());
+  if (!CI->use_empty())
+    CI->replaceAllUsesWith(NewCI);
+  return NewCI;
+}
+
+void IntrinsicLowering::AddPrototypes(Module &M) {
+  LLVMContext &Context = M.getContext();
+  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+    if (I->isDeclaration() && !I->use_empty())
+      switch (I->getIntrinsicID()) {
+      default: break;
+      case Intrinsic::setjmp:
+        EnsureFunctionExists(M, "setjmp", I->arg_begin(), I->arg_end(),
+                             Type::getInt32Ty(M.getContext()));
+        break;
+      case Intrinsic::longjmp:
+        EnsureFunctionExists(M, "longjmp", I->arg_begin(), I->arg_end(),
+                             Type::getVoidTy(M.getContext()));
+        break;
+      case Intrinsic::siglongjmp:
+        EnsureFunctionExists(M, "abort", I->arg_end(), I->arg_end(),
+                             Type::getVoidTy(M.getContext()));
+        break;
+      case Intrinsic::memcpy:
+        M.getOrInsertFunction("memcpy",
+          Type::getInt8PtrTy(Context),
+                              Type::getInt8PtrTy(Context), 
+                              Type::getInt8PtrTy(Context), 
+                              TD.getIntPtrType(Context), (Type *)0);
+        break;
+      case Intrinsic::memmove:
+        M.getOrInsertFunction("memmove",
+          Type::getInt8PtrTy(Context),
+                              Type::getInt8PtrTy(Context), 
+                              Type::getInt8PtrTy(Context), 
+                              TD.getIntPtrType(Context), (Type *)0);
+        break;
+      case Intrinsic::memset:
+        M.getOrInsertFunction("memset",
+          Type::getInt8PtrTy(Context),
+                              Type::getInt8PtrTy(Context), 
+                              Type::getInt32Ty(M.getContext()), 
+                              TD.getIntPtrType(Context), (Type *)0);
+        break;
+      case Intrinsic::sqrt:
+        EnsureFPIntrinsicsExist(M, I, "sqrtf", "sqrt", "sqrtl");
+        break;
+      case Intrinsic::sin:
+        EnsureFPIntrinsicsExist(M, I, "sinf", "sin", "sinl");
+        break;
+      case Intrinsic::cos:
+        EnsureFPIntrinsicsExist(M, I, "cosf", "cos", "cosl");
+        break;
+      case Intrinsic::pow:
+        EnsureFPIntrinsicsExist(M, I, "powf", "pow", "powl");
+        break;
+      case Intrinsic::log:
+        EnsureFPIntrinsicsExist(M, I, "logf", "log", "logl");
+        break;
+      case Intrinsic::log2:
+        EnsureFPIntrinsicsExist(M, I, "log2f", "log2", "log2l");
+        break;
+      case Intrinsic::log10:
+        EnsureFPIntrinsicsExist(M, I, "log10f", "log10", "log10l");
+        break;
+      case Intrinsic::exp:
+        EnsureFPIntrinsicsExist(M, I, "expf", "exp", "expl");
+        break;
+      case Intrinsic::exp2:
+        EnsureFPIntrinsicsExist(M, I, "exp2f", "exp2", "exp2l");
+        break;
+      }
+}
+
+/// LowerBSWAP - Emit the code to lower bswap of V before the specified
+/// instruction IP.
+static Value *LowerBSWAP(LLVMContext &Context, Value *V, Instruction *IP) {
+  assert(V->getType()->isInteger() && "Can't bswap a non-integer type!");
+
+  unsigned BitSize = V->getType()->getPrimitiveSizeInBits();
+  
+  IRBuilder<> Builder(IP->getParent(), IP);
+
+  switch(BitSize) {
+  default: llvm_unreachable("Unhandled type size of value to byteswap!");
+  case 16: {
+    Value *Tmp1 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8),
+                                    "bswap.2");
+    Value *Tmp2 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8),
+                                     "bswap.1");
+    V = Builder.CreateOr(Tmp1, Tmp2, "bswap.i16");
+    break;
+  }
+  case 32: {
+    Value *Tmp4 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 24),
+                                    "bswap.4");
+    Value *Tmp3 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8),
+                                    "bswap.3");
+    Value *Tmp2 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8),
+                                     "bswap.2");
+    Value *Tmp1 = Builder.CreateLShr(V,ConstantInt::get(V->getType(), 24),
+                                     "bswap.1");
+    Tmp3 = Builder.CreateAnd(Tmp3,
+                         ConstantInt::get(Type::getInt32Ty(Context), 0xFF0000),
+                             "bswap.and3");
+    Tmp2 = Builder.CreateAnd(Tmp2,
+                           ConstantInt::get(Type::getInt32Ty(Context), 0xFF00),
+                             "bswap.and2");
+    Tmp4 = Builder.CreateOr(Tmp4, Tmp3, "bswap.or1");
+    Tmp2 = Builder.CreateOr(Tmp2, Tmp1, "bswap.or2");
+    V = Builder.CreateOr(Tmp4, Tmp2, "bswap.i32");
+    break;
+  }
+  case 64: {
+    Value *Tmp8 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 56),
+                                    "bswap.8");
+    Value *Tmp7 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 40),
+                                    "bswap.7");
+    Value *Tmp6 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 24),
+                                    "bswap.6");
+    Value *Tmp5 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8),
+                                    "bswap.5");
+    Value* Tmp4 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8),
+                                     "bswap.4");
+    Value* Tmp3 = Builder.CreateLShr(V, 
+                                     ConstantInt::get(V->getType(), 24),
+                                     "bswap.3");
+    Value* Tmp2 = Builder.CreateLShr(V, 
+                                     ConstantInt::get(V->getType(), 40),
+                                     "bswap.2");
+    Value* Tmp1 = Builder.CreateLShr(V, 
+                                     ConstantInt::get(V->getType(), 56),
+                                     "bswap.1");
+    Tmp7 = Builder.CreateAnd(Tmp7,
+                             ConstantInt::get(Type::getInt64Ty(Context),
+                                              0xFF000000000000ULL),
+                             "bswap.and7");
+    Tmp6 = Builder.CreateAnd(Tmp6,
+                             ConstantInt::get(Type::getInt64Ty(Context),
+                                              0xFF0000000000ULL),
+                             "bswap.and6");
+    Tmp5 = Builder.CreateAnd(Tmp5,
+                        ConstantInt::get(Type::getInt64Ty(Context),
+                             0xFF00000000ULL),
+                             "bswap.and5");
+    Tmp4 = Builder.CreateAnd(Tmp4,
+                        ConstantInt::get(Type::getInt64Ty(Context),
+                             0xFF000000ULL),
+                             "bswap.and4");
+    Tmp3 = Builder.CreateAnd(Tmp3,
+                             ConstantInt::get(Type::getInt64Ty(Context),
+                             0xFF0000ULL),
+                             "bswap.and3");
+    Tmp2 = Builder.CreateAnd(Tmp2,
+                             ConstantInt::get(Type::getInt64Ty(Context),
+                             0xFF00ULL),
+                             "bswap.and2");
+    Tmp8 = Builder.CreateOr(Tmp8, Tmp7, "bswap.or1");
+    Tmp6 = Builder.CreateOr(Tmp6, Tmp5, "bswap.or2");
+    Tmp4 = Builder.CreateOr(Tmp4, Tmp3, "bswap.or3");
+    Tmp2 = Builder.CreateOr(Tmp2, Tmp1, "bswap.or4");
+    Tmp8 = Builder.CreateOr(Tmp8, Tmp6, "bswap.or5");
+    Tmp4 = Builder.CreateOr(Tmp4, Tmp2, "bswap.or6");
+    V = Builder.CreateOr(Tmp8, Tmp4, "bswap.i64");
+    break;
+  }
+  }
+  return V;
+}
+
+/// LowerCTPOP - Emit the code to lower ctpop of V before the specified
+/// instruction IP.
+static Value *LowerCTPOP(LLVMContext &Context, Value *V, Instruction *IP) {
+  assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!");
+
+  static const uint64_t MaskValues[6] = {
+    0x5555555555555555ULL, 0x3333333333333333ULL,
+    0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL,
+    0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL
+  };
+
+  IRBuilder<> Builder(IP->getParent(), IP);
+
+  unsigned BitSize = V->getType()->getPrimitiveSizeInBits();
+  unsigned WordSize = (BitSize + 63) / 64;
+  Value *Count = ConstantInt::get(V->getType(), 0);
+
+  for (unsigned n = 0; n < WordSize; ++n) {
+    Value *PartValue = V;
+    for (unsigned i = 1, ct = 0; i < (BitSize>64 ? 64 : BitSize); 
+         i <<= 1, ++ct) {
+      Value *MaskCst = ConstantInt::get(V->getType(), MaskValues[ct]);
+      Value *LHS = Builder.CreateAnd(PartValue, MaskCst, "cppop.and1");
+      Value *VShift = Builder.CreateLShr(PartValue,
+                                        ConstantInt::get(V->getType(), i),
+                                         "ctpop.sh");
+      Value *RHS = Builder.CreateAnd(VShift, MaskCst, "cppop.and2");
+      PartValue = Builder.CreateAdd(LHS, RHS, "ctpop.step");
+    }
+    Count = Builder.CreateAdd(PartValue, Count, "ctpop.part");
+    if (BitSize > 64) {
+      V = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 64),
+                             "ctpop.part.sh");
+      BitSize -= 64;
+    }
+  }
+
+  return Count;
+}
+
+/// LowerCTLZ - Emit the code to lower ctlz of V before the specified
+/// instruction IP.
+static Value *LowerCTLZ(LLVMContext &Context, Value *V, Instruction *IP) {
+
+  IRBuilder<> Builder(IP->getParent(), IP);
+
+  unsigned BitSize = V->getType()->getPrimitiveSizeInBits();
+  for (unsigned i = 1; i < BitSize; i <<= 1) {
+    Value *ShVal = ConstantInt::get(V->getType(), i);
+    ShVal = Builder.CreateLShr(V, ShVal, "ctlz.sh");
+    V = Builder.CreateOr(V, ShVal, "ctlz.step");
+  }
+
+  V = Builder.CreateNot(V);
+  return LowerCTPOP(Context, V, IP);
+}
+
+static void ReplaceFPIntrinsicWithCall(CallInst *CI, const char *Fname,
+                                       const char *Dname,
+                                       const char *LDname) {
+  switch (CI->getOperand(1)->getType()->getTypeID()) {
+  default: llvm_unreachable("Invalid type in intrinsic");
+  case Type::FloatTyID:
+    ReplaceCallWith(Fname, CI, CI->op_begin() + 1, CI->op_end(),
+                  Type::getFloatTy(CI->getContext()));
+    break;
+  case Type::DoubleTyID:
+    ReplaceCallWith(Dname, CI, CI->op_begin() + 1, CI->op_end(),
+                  Type::getDoubleTy(CI->getContext()));
+    break;
+  case Type::X86_FP80TyID:
+  case Type::FP128TyID:
+  case Type::PPC_FP128TyID:
+    ReplaceCallWith(LDname, CI, CI->op_begin() + 1, CI->op_end(),
+                  CI->getOperand(1)->getType());
+    break;
+  }
+}
+
+void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
+  IRBuilder<> Builder(CI->getParent(), CI);
+  LLVMContext &Context = CI->getContext();
+
+  Function *Callee = CI->getCalledFunction();
+  assert(Callee && "Cannot lower an indirect call!");
+
+  switch (Callee->getIntrinsicID()) {
+  case Intrinsic::not_intrinsic:
+    llvm_report_error("Cannot lower a call to a non-intrinsic function '"+
+                      Callee->getName() + "'!");
+  default:
+    llvm_report_error("Code generator does not support intrinsic function '"+
+                      Callee->getName()+"'!");
+
+    // The setjmp/longjmp intrinsics should only exist in the code if it was
+    // never optimized (ie, right out of the CFE), or if it has been hacked on
+    // by the lowerinvoke pass.  In both cases, the right thing to do is to
+    // convert the call to an explicit setjmp or longjmp call.
+  case Intrinsic::setjmp: {
+    Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin() + 1, CI->op_end(),
+                               Type::getInt32Ty(Context));
+    if (!CI->getType()->isVoidTy())
+      CI->replaceAllUsesWith(V);
+    break;
+  }
+  case Intrinsic::sigsetjmp:
+     if (!CI->getType()->isVoidTy())
+       CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
+     break;
+
+  case Intrinsic::longjmp: {
+    ReplaceCallWith("longjmp", CI, CI->op_begin() + 1, CI->op_end(),
+                    Type::getVoidTy(Context));
+    break;
+  }
+
+  case Intrinsic::siglongjmp: {
+    // Insert the call to abort
+    ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), 
+                    Type::getVoidTy(Context));
+    break;
+  }
+  case Intrinsic::ctpop:
+    CI->replaceAllUsesWith(LowerCTPOP(Context, CI->getOperand(1), CI));
+    break;
+
+  case Intrinsic::bswap:
+    CI->replaceAllUsesWith(LowerBSWAP(Context, CI->getOperand(1), CI));
+    break;
+    
+  case Intrinsic::ctlz:
+    CI->replaceAllUsesWith(LowerCTLZ(Context, CI->getOperand(1), CI));
+    break;
+
+  case Intrinsic::cttz: {
+    // cttz(x) -> ctpop(~X & (X-1))
+    Value *Src = CI->getOperand(1);
+    Value *NotSrc = Builder.CreateNot(Src);
+    NotSrc->setName(Src->getName() + ".not");
+    Value *SrcM1 = ConstantInt::get(Src->getType(), 1);
+    SrcM1 = Builder.CreateSub(Src, SrcM1);
+    Src = LowerCTPOP(Context, Builder.CreateAnd(NotSrc, SrcM1), CI);
+    CI->replaceAllUsesWith(Src);
+    break;
+  }
+
+  case Intrinsic::stacksave:
+  case Intrinsic::stackrestore: {
+    if (!Warned)
+      errs() << "WARNING: this target does not support the llvm.stack"
+             << (Callee->getIntrinsicID() == Intrinsic::stacksave ?
+               "save" : "restore") << " intrinsic.\n";
+    Warned = true;
+    if (Callee->getIntrinsicID() == Intrinsic::stacksave)
+      CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
+    break;
+  }
+    
+  case Intrinsic::returnaddress:
+  case Intrinsic::frameaddress:
+    errs() << "WARNING: this target does not support the llvm."
+           << (Callee->getIntrinsicID() == Intrinsic::returnaddress ?
+             "return" : "frame") << "address intrinsic.\n";
+    CI->replaceAllUsesWith(ConstantPointerNull::get(
+                                            cast<PointerType>(CI->getType())));
+    break;
+
+  case Intrinsic::prefetch:
+    break;    // Simply strip out prefetches on unsupported architectures
+
+  case Intrinsic::pcmarker:
+    break;    // Simply strip out pcmarker on unsupported architectures
+  case Intrinsic::readcyclecounter: {
+    errs() << "WARNING: this target does not support the llvm.readcyclecoun"
+           << "ter intrinsic.  It is being lowered to a constant 0\n";
+    CI->replaceAllUsesWith(ConstantInt::get(Type::getInt64Ty(Context), 0));
+    break;
+  }
+
+  case Intrinsic::dbg_declare:
+    break;    // Simply strip out debugging intrinsics
+
+  case Intrinsic::eh_exception:
+  case Intrinsic::eh_selector:
+    CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
+    break;
+
+  case Intrinsic::eh_typeid_for:
+    // Return something different to eh_selector.
+    CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1));
+    break;
+
+  case Intrinsic::var_annotation:
+    break;   // Strip out annotate intrinsic
+    
+  case Intrinsic::memcpy: {
+    const IntegerType *IntPtr = TD.getIntPtrType(Context);
+    Value *Size = Builder.CreateIntCast(CI->getOperand(3), IntPtr,
+                                        /* isSigned */ false);
+    Value *Ops[3];
+    Ops[0] = CI->getOperand(1);
+    Ops[1] = CI->getOperand(2);
+    Ops[2] = Size;
+    ReplaceCallWith("memcpy", CI, Ops, Ops+3, CI->getOperand(1)->getType());
+    break;
+  }
+  case Intrinsic::memmove: {
+    const IntegerType *IntPtr = TD.getIntPtrType(Context);
+    Value *Size = Builder.CreateIntCast(CI->getOperand(3), IntPtr,
+                                        /* isSigned */ false);
+    Value *Ops[3];
+    Ops[0] = CI->getOperand(1);
+    Ops[1] = CI->getOperand(2);
+    Ops[2] = Size;
+    ReplaceCallWith("memmove", CI, Ops, Ops+3, CI->getOperand(1)->getType());
+    break;
+  }
+  case Intrinsic::memset: {
+    const IntegerType *IntPtr = TD.getIntPtrType(Context);
+    Value *Size = Builder.CreateIntCast(CI->getOperand(3), IntPtr,
+                                        /* isSigned */ false);
+    Value *Ops[3];
+    Ops[0] = CI->getOperand(1);
+    // Extend the amount to i32.
+    Ops[1] = Builder.CreateIntCast(CI->getOperand(2), Type::getInt32Ty(Context),
+                                   /* isSigned */ false);
+    Ops[2] = Size;
+    ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getOperand(1)->getType());
+    break;
+  }
+  case Intrinsic::sqrt: {
+    ReplaceFPIntrinsicWithCall(CI, "sqrtf", "sqrt", "sqrtl");
+    break;
+  }
+  case Intrinsic::log: {
+    ReplaceFPIntrinsicWithCall(CI, "logf", "log", "logl");
+    break;
+  }
+  case Intrinsic::log2: {
+    ReplaceFPIntrinsicWithCall(CI, "log2f", "log2", "log2l");
+    break;
+  }
+  case Intrinsic::log10: {
+    ReplaceFPIntrinsicWithCall(CI, "log10f", "log10", "log10l");
+    break;
+  }
+  case Intrinsic::exp: {
+    ReplaceFPIntrinsicWithCall(CI, "expf", "exp", "expl");
+    break;
+  }
+  case Intrinsic::exp2: {
+    ReplaceFPIntrinsicWithCall(CI, "exp2f", "exp2", "exp2l");
+    break;
+  }
+  case Intrinsic::pow: {
+    ReplaceFPIntrinsicWithCall(CI, "powf", "pow", "powl");
+    break;
+  }
+  case Intrinsic::flt_rounds:
+     // Lower to "round to the nearest"
+     if (!CI->getType()->isVoidTy())
+       CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1));
+     break;
+  case Intrinsic::invariant_start:
+  case Intrinsic::lifetime_start:
+    // Discard region information.
+    CI->replaceAllUsesWith(UndefValue::get(CI->getType()));
+    break;
+  case Intrinsic::invariant_end:
+  case Intrinsic::lifetime_end:
+    // Discard region information.
+    break;
+  }
+
+  assert(CI->use_empty() &&
+         "Lowering should have eliminated any uses of the intrinsic call!");
+  CI->eraseFromParent();
+}