IntrinsicLowering.cpp revision 3b66ecb05fedbfe0a70b39d73b1ea5998bc8c31b 
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/Constant.h"
16#include "llvm/Intrinsics.h"
17#include "llvm/Module.h"
18#include "llvm/Type.h"
19#include "llvm/iOther.h"
20using namespace llvm;
21
22void DefaultIntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
23  Function *Callee = CI->getCalledFunction();
24  assert(Callee && "Cannot lower an indirect call!");
25
26  Module *M = Callee->getParent();
27
28  switch (Callee->getIntrinsicID()) {
29  case Intrinsic::not_intrinsic:
30    std::cerr << "Cannot lower a call to a non-intrinsic function '"
31              << Callee->getName() << "'!\n";
32    abort();
33  default:
34    std::cerr << "Error: Code generator does not support intrinsic function '"
35              << Callee->getName() << "'!\n";
36    abort();
37
38    // The default implementation of setjmp/longjmp transforms setjmp into a
39    // noop that always returns zero and longjmp into a call to abort.  This
40    // allows code that never longjmps to work correctly.
41  case Intrinsic::setjmp:
42  case Intrinsic::sigsetjmp:
43    if (CI->getType() != Type::VoidTy)
44      CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
45    break;
46
47  case Intrinsic::longjmp:
48  case Intrinsic::siglongjmp:
49    // Insert the call to abort
50    new CallInst(M->getOrInsertFunction("abort", Type::VoidTy, 0), "", CI);
51    break;
52  }
53
54  assert(CI->use_empty() &&
55         "Lowering should have eliminated any uses of the intrinsic call!");
56  CI->getParent()->getInstList().erase(CI);
57}
58