lib/CodeGen/SelectionDAG/CallingConvLower.cpp

   1 //===-- CallingConvLower.cpp - Calling Conventions ------------------------===//
   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 the CCState class, used for lowering and implementing
  11 // calling conventions.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/CodeGen/CallingConvLower.h"
  16 #include "llvm/Target/TargetRegisterInfo.h"
  17 #include "llvm/Target/TargetData.h"
  18 #include "llvm/Target/TargetMachine.h"
  19 using namespace llvm;
  20
  21 CCState::CCState(unsigned CC, bool isVarArg, const TargetMachine &tm,
  22                  SmallVector<CCValAssign, 16> &locs)
  23   : CallingConv(CC), IsVarArg(isVarArg), TM(tm),
  24     TRI(*TM.getRegisterInfo()), Locs(locs) {
  25   // No stack is used.
  26   StackOffset = 0;
  27
  28   UsedRegs.resize((TRI.getNumRegs()+31)/32);
  29 }
  30
  31 // HandleByVal - Allocate a stack slot large enough to pass an argument by
  32 // value. The size and alignment information of the argument is encoded in its
  33 // parameter attribute.
  34 void CCState::HandleByVal(unsigned ValNo, MVT ValVT,
  35                           MVT LocVT, CCValAssign::LocInfo LocInfo,
  36                           int MinSize, int MinAlign,
  37                           ISD::ArgFlagsTy ArgFlags) {
  38   unsigned Align = ArgFlags.getByValAlign();
  39   unsigned Size  = ArgFlags.getByValSize();
  40   if (MinSize > (int)Size)
  41     Size = MinSize;
  42   if (MinAlign > (int)Align)
  43     Align = MinAlign;
  44   unsigned Offset = AllocateStack(Size, Align);
  45
  46   addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
  47 }
  48
  49 /// MarkAllocated - Mark a register and all of its aliases as allocated.
  50 void CCState::MarkAllocated(unsigned Reg) {
  51   UsedRegs[Reg/32] |= 1 << (Reg&31);
  52
  53   if (const unsigned *RegAliases = TRI.getAliasSet(Reg))
  54     for (; (Reg = *RegAliases); ++RegAliases)
  55       UsedRegs[Reg/32] |= 1 << (Reg&31);
  56 }
  57
  58 /// AnalyzeFormalArguments - Analyze an ISD::FORMAL_ARGUMENTS node,
  59 /// incorporating info about the formals into this state.
  60 void CCState::AnalyzeFormalArguments(SDNode *TheArgs, CCAssignFn Fn) {
  61   unsigned NumArgs = TheArgs->getNumValues()-1;
  62
  63   for (unsigned i = 0; i != NumArgs; ++i) {
  64     MVT ArgVT = TheArgs->getValueType(i);
  65     ISD::ArgFlagsTy ArgFlags =
  66       cast<ARG_FLAGSSDNode>(TheArgs->getOperand(3+i))->getArgFlags();
  67     if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) {
  68       cerr << "Formal argument #" << i << " has unhandled type "
  69            << ArgVT.getMVTString() << "\n";
  70       abort();
  71     }
  72   }
  73 }
  74
  75 /// AnalyzeReturn - Analyze the returned values of an ISD::RET node,
  76 /// incorporating info about the result values into this state.
  77 void CCState::AnalyzeReturn(SDNode *TheRet, CCAssignFn Fn) {
  78   // Determine which register each value should be copied into.
  79   for (unsigned i = 0, e = TheRet->getNumOperands() / 2; i != e; ++i) {
  80     MVT VT = TheRet->getOperand(i*2+1).getValueType();
  81     ISD::ArgFlagsTy ArgFlags =
  82       cast<ARG_FLAGSSDNode>(TheRet->getOperand(i*2+2))->getArgFlags();
  83     if (Fn(i, VT, VT, CCValAssign::Full, ArgFlags, *this)){
  84       cerr << "Return operand #" << i << " has unhandled type "
  85            << VT.getMVTString() << "\n";
  86       abort();
  87     }
  88   }
  89 }
  90
  91
  92 /// AnalyzeCallOperands - Analyze an ISD::CALL node, incorporating info
  93 /// about the passed values into this state.
  94 void CCState::AnalyzeCallOperands(CallSDNode *TheCall, CCAssignFn Fn) {
  95   unsigned NumOps = TheCall->getNumArgs();
  96   for (unsigned i = 0; i != NumOps; ++i) {
  97     MVT ArgVT = TheCall->getArg(i).getValueType();
  98     ISD::ArgFlagsTy ArgFlags = TheCall->getArgFlags(i);
  99     if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) {
 100       cerr << "Call operand #" << i << " has unhandled type "
 101            << ArgVT.getMVTString() << "\n";
 102       abort();
 103     }
 104   }
 105 }
 106
 107 /// AnalyzeCallOperands - Same as above except it takes vectors of types
 108 /// and argument flags.
 109 void CCState::AnalyzeCallOperands(SmallVectorImpl<MVT> &ArgVTs,
 110                                   SmallVectorImpl<ISD::ArgFlagsTy> &Flags,
 111                                   CCAssignFn Fn) {
 112   unsigned NumOps = ArgVTs.size();
 113   for (unsigned i = 0; i != NumOps; ++i) {
 114     MVT ArgVT = ArgVTs[i];
 115     ISD::ArgFlagsTy ArgFlags = Flags[i];
 116     if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) {
 117       cerr << "Call operand #" << i << " has unhandled type "
 118            << ArgVT.getMVTString() << "\n";
 119       abort();
 120     }
 121   }
 122 }
 123
 124 /// AnalyzeCallResult - Analyze the return values of an ISD::CALL node,
 125 /// incorporating info about the passed values into this state.
 126 void CCState::AnalyzeCallResult(CallSDNode *TheCall, CCAssignFn Fn) {
 127   for (unsigned i = 0, e = TheCall->getNumRetVals(); i != e; ++i) {
 128     MVT VT = TheCall->getRetValType(i);
 129     ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
 130     if (TheCall->isInreg())
 131       Flags.setInReg();
 132     if (Fn(i, VT, VT, CCValAssign::Full, Flags, *this)) {
 133       cerr << "Call result #" << i << " has unhandled type "
 134            << VT.getMVTString() << "\n";
 135       abort();
 136     }
 137   }
 138 }
 139
 140 /// AnalyzeCallResult - Same as above except it's specialized for calls which
 141 /// produce a single value.
 142 void CCState::AnalyzeCallResult(MVT VT, CCAssignFn Fn) {
 143   if (Fn(0, VT, VT, CCValAssign::Full, ISD::ArgFlagsTy(), *this)) {
 144     cerr << "Call result has unhandled type "
 145          << VT.getMVTString() << "\n";
 146     abort();
 147   }
 148 }