Implement the default implementation of the intrinsic lowering class

llvm-svn: 10621

lib/CodeGen/IntrinsicLowering.cpp

@@ -0,0 +1,57 @@
+//===-- 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/Constant.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/Module.h"
+#include "llvm/Type.h"
+#include "llvm/iOther.h"
+using namespace llvm;
+
+void DefaultIntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
+  Function *Callee = CI->getCalledFunction();
+  assert(Callee && "Cannot lower an indirect call!");
+  
+  Module *M = Callee->getParent();
+
+  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 default implementation of setjmp/longjmp transforms setjmp into a
+    // noop that always returns zero and longjmp into a call to abort.  This
+    // allows code that never longjmps to work correctly.
+  case Intrinsic::setjmp:
+  case Intrinsic::sigsetjmp:
+    if (CI->getType() != Type::VoidTy)
+      CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
+    break;
+
+  case Intrinsic::longjmp:
+  case Intrinsic::siglongjmp:
+    // Insert the call to abort
+    new CallInst(M->getOrInsertFunction("abort", Type::VoidTy, 0), "", CI);
+    break;
+  }
+
+  assert(CI->use_empty() &&
+         "Lowering should have eliminated any uses of the intrinsic call!");
+  CI->getParent()->getInstList().erase(CI);
+}