lib/VMCore/IntrinsicInst.cpp

   1 //===-- InstrinsicInst.cpp - Intrinsic Instruction Wrappers -----*- C++ -*-===//
   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 methods that make it really easy to deal with intrinsic
  11 // functions.
  12 //
  13 // All intrinsic function calls are instances of the call instruction, so these
  14 // are all subclasses of the CallInst class.  Note that none of these classes
  15 // has state or virtual methods, which is an important part of this gross/neat
  16 // hack working.
  17 //
  18 // In some cases, arguments to intrinsics need to be generic and are defined as
  19 // type pointer to empty struct { }*.  To access the real item of interest the
  20 // cast instruction needs to be stripped away.
  21 //
  22 //===----------------------------------------------------------------------===//
  23
  24 #include "llvm/IntrinsicInst.h"
  25 #include "llvm/Constants.h"
  26 #include "llvm/GlobalVariable.h"
  27 #include "llvm/Metadata.h"
  28 using namespace llvm;
  29
  30 //===----------------------------------------------------------------------===//
  31 /// DbgInfoIntrinsic - This is the common base class for debug info intrinsics
  32 ///
  33
  34 static Value *CastOperand(Value *C) {
  35   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
  36     if (CE->isCast())
  37       return CE->getOperand(0);
  38   return NULL;
  39 }
  40
  41 Value *DbgInfoIntrinsic::StripCast(Value *C) {
  42   if (Value *CO = CastOperand(C)) {
  43     C = StripCast(CO);
  44   } else if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) {
  45     if (GV->hasInitializer())
  46       if (Value *CO = CastOperand(GV->getInitializer()))
  47         C = StripCast(CO);
  48   }
  49   return dyn_cast<GlobalVariable>(C);
  50 }
  51
  52 //===----------------------------------------------------------------------===//
  53 /// DbgDeclareInst - This represents the llvm.dbg.declare instruction.
  54 ///
  55
  56 Value *DbgDeclareInst::getAddress() const {
  57   if (MDNode* MD = cast_or_null<MDNode>(getOperand(1)))
  58     return MD->getOperand(0);
  59   else
  60     return NULL;
  61 }
  62
  63 //===----------------------------------------------------------------------===//
  64 /// DbgValueInst - This represents the llvm.dbg.value instruction.
  65 ///
  66
  67 const Value *DbgValueInst::getValue() const {
  68   return cast<MDNode>(getOperand(1))->getOperand(0);
  69 }
  70
  71 Value *DbgValueInst::getValue() {
  72   return cast<MDNode>(getOperand(1))->getOperand(0);
  73 }