Move the IntrinsicLowering header into the CodeGen directory, as per PR346

llvm-svn: 14266

1 files changed, 214 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/IntrinsicLowering.cpp b/llvm/lib/CodeGen/IntrinsicLowering.cpp
new file mode 100644
index 00000000000..6af333e79a5
--- /dev/null
+++ b/llvm/lib/CodeGen/IntrinsicLowering.cpp
@@ -0,0 +1,214 @@
+//===-- IntrinsicLowering.cpp - Intrinsic Lowering default implementation -===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file implements the default intrinsic lowering implementation.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/IntrinsicLowering.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Module.h"
+#include "llvm/iOther.h"
+using namespace llvm;
+
+template <class ArgIt>
+static Function *EnsureFunctionExists(Module &M, const char *Name,
+                                      ArgIt ArgBegin, ArgIt ArgEnd,
+                                      const Type *RetTy) {
+  if (Function *F = M.getNamedFunction(Name)) return F;
+  // It doesn't already exist in the program, insert a new definition now.
+  std::vector<const Type *> ParamTys;
+  for (ArgIt I = ArgBegin; I != ArgEnd; ++I)
+    ParamTys.push_back(I->getType());
+  return M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false));
+}
+
+/// 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, Function *&FCache) {
+  if (!FCache) {
+    // 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();
+    FCache = M->getNamedFunction(NewFn);
+    if (!FCache) {
+      // It doesn't already exist in the program, insert a new definition now.
+      std::vector<const Type *> ParamTys;
+      for (ArgIt I = ArgBegin; I != ArgEnd; ++I)
+        ParamTys.push_back((*I)->getType());
+      FCache = M->getOrInsertFunction(NewFn,
+                                     FunctionType::get(RetTy, ParamTys, false));
+    }
+   }
+
+  const FunctionType *FT = FCache->getFunctionType();
+  std::vector<Value*> Operands;
+  unsigned ArgNo = 0;
+  for (ArgIt I = ArgBegin; I != ArgEnd && ArgNo != FT->getNumParams();
+       ++I, ++ArgNo) {
+    Value *Arg = *I;
+    if (Arg->getType() != FT->getParamType(ArgNo))
+      Arg = new CastInst(Arg, FT->getParamType(ArgNo), Arg->getName(), CI);
+    Operands.push_back(Arg);
+  }
+  // Pass nulls into any additional arguments...
+  for (; ArgNo != FT->getNumParams(); ++ArgNo)
+    Operands.push_back(Constant::getNullValue(FT->getParamType(ArgNo)));
+
+  std::string Name = CI->getName(); CI->setName("");
+  if (FT->getReturnType() == Type::VoidTy) Name.clear();
+  CallInst *NewCI = new CallInst(FCache, Operands, Name, CI);
+  if (!CI->use_empty()) {
+    Value *V = NewCI;
+    if (CI->getType() != NewCI->getType())
+      V = new CastInst(NewCI, CI->getType(), Name, CI);
+    CI->replaceAllUsesWith(V);
+  }
+  return NewCI;
+}
+
+void DefaultIntrinsicLowering::AddPrototypes(Module &M) {
+  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+    if (I->isExternal() && !I->use_empty())
+      switch (I->getIntrinsicID()) {
+      default: break;
+      case Intrinsic::setjmp:
+        EnsureFunctionExists(M, "setjmp", I->abegin(), I->aend(), Type::IntTy);
+        break;
+      case Intrinsic::longjmp:
+        EnsureFunctionExists(M, "longjmp", I->abegin(), I->aend(),Type::VoidTy);
+        break;
+      case Intrinsic::siglongjmp:
+        EnsureFunctionExists(M, "abort", I->aend(), I->aend(), Type::VoidTy);
+        break;
+      case Intrinsic::memcpy:
+        EnsureFunctionExists(M, "memcpy", I->abegin(), --I->aend(),
+                             I->abegin()->getType());
+        break;
+      case Intrinsic::memmove:
+        EnsureFunctionExists(M, "memmove", I->abegin(), --I->aend(),
+                             I->abegin()->getType());
+        break;
+      case Intrinsic::memset:
+        EnsureFunctionExists(M, "memset", I->abegin(), --I->aend(),
+                             I->abegin()->getType());
+        break;
+      case Intrinsic::isunordered:
+        EnsureFunctionExists(M, "isunordered", I->abegin(), I->aend(), Type::BoolTy);
+        break;
+      }
+
+}
+
+void DefaultIntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
+  Function *Callee = CI->getCalledFunction();
+  assert(Callee && "Cannot lower an indirect call!");
+  
+  switch (Callee->getIntrinsicID()) {
+  case Intrinsic::not_intrinsic:
+    std::cerr << "Cannot lower a call to a non-intrinsic function '"
+              << Callee->getName() << "'!\n";
+    abort();
+  default:
+    std::cerr << "Error: Code generator does not support intrinsic function '"
+              << Callee->getName() << "'!\n";
+    abort();
+
+    // 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: {
+    static Function *SetjmpFCache = 0;
+    Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(),
+                               Type::IntTy, SetjmpFCache);
+    if (CI->getType() != Type::VoidTy)
+      CI->replaceAllUsesWith(V);
+    break;
+  }
+  case Intrinsic::sigsetjmp: 
+     if (CI->getType() != Type::VoidTy)
+       CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
+     break;
+
+  case Intrinsic::longjmp: {
+    static Function *LongjmpFCache = 0;
+    ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(),
+                    Type::VoidTy, LongjmpFCache);
+    break;
+  }
+
+  case Intrinsic::siglongjmp: {
+    // Insert the call to abort
+    static Function *AbortFCache = 0;
+    ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), Type::VoidTy,
+                    AbortFCache);
+    break;
+  }
+
+  case Intrinsic::returnaddress:
+  case Intrinsic::frameaddress:
+    std::cerr << "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::dbg_stoppoint:
+  case Intrinsic::dbg_region_start:
+  case Intrinsic::dbg_region_end:
+  case Intrinsic::dbg_declare:
+  case Intrinsic::dbg_func_start:
+    if (CI->getType() != Type::VoidTy)
+      CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
+    break;    // Simply strip out debugging intrinsics
+
+  case Intrinsic::memcpy: {
+    // The memcpy intrinsic take an extra alignment argument that the memcpy
+    // libc function does not.
+    static Function *MemcpyFCache = 0;
+    ReplaceCallWith("memcpy", CI, CI->op_begin()+1, CI->op_end()-1,
+                    (*(CI->op_begin()+1))->getType(), MemcpyFCache);
+    break;
+  }
+  case Intrinsic::memmove: {
+    // The memmove intrinsic take an extra alignment argument that the memmove
+    // libc function does not.
+    static Function *MemmoveFCache = 0;
+    ReplaceCallWith("memmove", CI, CI->op_begin()+1, CI->op_end()-1,
+                    (*(CI->op_begin()+1))->getType(), MemmoveFCache);
+    break;
+  }
+  case Intrinsic::memset: {
+    // The memset intrinsic take an extra alignment argument that the memset
+    // libc function does not.
+    static Function *MemsetFCache = 0;
+    ReplaceCallWith("memset", CI, CI->op_begin()+1, CI->op_end()-1,
+                    (*(CI->op_begin()+1))->getType(), MemsetFCache);
+    break;
+  }
+  case Intrinsic::isunordered: {
+    static Function *isunorderedFCache = 0;
+    ReplaceCallWith("isunordered", CI, CI->op_begin()+1, CI->op_end(),
+                    Type::BoolTy, isunorderedFCache);
+    break;
+  }
+  }
+  
+  assert(CI->use_empty() &&
+         "Lowering should have eliminated any uses of the intrinsic call!");
+  CI->getParent()->getInstList().erase(CI);
+}