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/Support/ErrorHandling.h"
  17 #include "llvm/Support/raw_ostream.h"
  18 #include "llvm/Target/TargetRegisterInfo.h"
  19 #include "llvm/Target/TargetData.h"
  20 #include "llvm/Target/TargetMachine.h"
  21 using namespace llvm;
  22
  23 CCState::CCState(CallingConv::ID CC, bool isVarArg, const TargetMachine &tm,
  24                  SmallVector<CCValAssign, 16> &locs, LLVMContext &C)
  25   : CallingConv(CC), IsVarArg(isVarArg), TM(tm),
  26     TRI(*TM.getRegisterInfo()), Locs(locs), Context(C) {
  27   // No stack is used.
  28   StackOffset = 0;
  29
  30   UsedRegs.resize((TRI.getNumRegs()+31)/32);
  31 }
  32
  33 // HandleByVal - Allocate a stack slot large enough to pass an argument by
  34 // value. The size and alignment information of the argument is encoded in its
  35 // parameter attribute.
  36 void CCState::HandleByVal(unsigned ValNo, EVT ValVT,
  37                           EVT LocVT, CCValAssign::LocInfo LocInfo,
  38                           int MinSize, int MinAlign,
  39                           ISD::ArgFlagsTy ArgFlags) {
  40   unsigned Align = ArgFlags.getByValAlign();
  41   unsigned Size  = ArgFlags.getByValSize();
  42   if (MinSize > (int)Size)
  43     Size = MinSize;
  44   if (MinAlign > (int)Align)
  45     Align = MinAlign;
  46   unsigned Offset = AllocateStack(Size, Align);
  47
  48   addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
  49 }
  50
  51 /// MarkAllocated - Mark a register and all of its aliases as allocated.
  52 void CCState::MarkAllocated(unsigned Reg) {
  53   UsedRegs[Reg/32] |= 1 << (Reg&31);
  54
  55   if (const unsigned *RegAliases = TRI.getAliasSet(Reg))
  56     for (; (Reg = *RegAliases); ++RegAliases)
  57       UsedRegs[Reg/32] |= 1 << (Reg&31);
  58 }
  59
  60 /// AnalyzeFormalArguments - Analyze an array of argument values,
  61 /// incorporating info about the formals into this state.
  62 void
  63 CCState::AnalyzeFormalArguments(const SmallVectorImpl<ISD::InputArg> &Ins,
  64                                 CCAssignFn Fn) {
  65   unsigned NumArgs = Ins.size();
  66
  67   for (unsigned i = 0; i != NumArgs; ++i) {
  68     EVT ArgVT = Ins[i].VT;
  69     ISD::ArgFlagsTy ArgFlags = Ins[i].Flags;
  70     if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) {
  71 #ifndef NDEBUG
  72       errs() << "Formal argument #" << i << " has unhandled type "
  73              << ArgVT.getEVTString();
  74 #endif
  75       llvm_unreachable(0);
  76     }
  77   }
  78 }
  79
  80 /// AnalyzeReturn - Analyze the returned values of a return,
  81 /// incorporating info about the result values into this state.
  82 void CCState::AnalyzeReturn(const SmallVectorImpl<ISD::OutputArg> &Outs,
  83                             CCAssignFn Fn) {
  84   // Determine which register each value should be copied into.
  85   for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
  86     EVT VT = Outs[i].Val.getValueType();
  87     ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
  88     if (Fn(i, VT, VT, CCValAssign::Full, ArgFlags, *this)) {
  89 #ifndef NDEBUG
  90       errs() << "Return operand #" << i << " has unhandled type "
  91              << VT.getEVTString();
  92 #endif
  93       llvm_unreachable(0);
  94     }
  95   }
  96 }
  97
  98
  99 /// AnalyzeCallOperands - Analyze the outgoing arguments to a call,
 100 /// incorporating info about the passed values into this state.
 101 void CCState::AnalyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Outs,
 102                                   CCAssignFn Fn) {
 103   unsigned NumOps = Outs.size();
 104   for (unsigned i = 0; i != NumOps; ++i) {
 105     EVT ArgVT = Outs[i].Val.getValueType();
 106     ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
 107     if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) {
 108 #ifndef NDEBUG
 109       errs() << "Call operand #" << i << " has unhandled type "
 110              << ArgVT.getEVTString();
 111 #endif
 112       llvm_unreachable(0);
 113     }
 114   }
 115 }
 116
 117 /// AnalyzeCallOperands - Same as above except it takes vectors of types
 118 /// and argument flags.
 119 void CCState::AnalyzeCallOperands(SmallVectorImpl<EVT> &ArgVTs,
 120                                   SmallVectorImpl<ISD::ArgFlagsTy> &Flags,
 121                                   CCAssignFn Fn) {
 122   unsigned NumOps = ArgVTs.size();
 123   for (unsigned i = 0; i != NumOps; ++i) {
 124     EVT ArgVT = ArgVTs[i];
 125     ISD::ArgFlagsTy ArgFlags = Flags[i];
 126     if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) {
 127 #ifndef NDEBUG
 128       errs() << "Call operand #" << i << " has unhandled type "
 129              << ArgVT.getEVTString();
 130 #endif
 131       llvm_unreachable(0);
 132     }
 133   }
 134 }
 135
 136 /// AnalyzeCallResult - Analyze the return values of a call,
 137 /// incorporating info about the passed values into this state.
 138 void CCState::AnalyzeCallResult(const SmallVectorImpl<ISD::InputArg> &Ins,
 139                                 CCAssignFn Fn) {
 140   for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
 141     EVT VT = Ins[i].VT;
 142     ISD::ArgFlagsTy Flags = Ins[i].Flags;
 143     if (Fn(i, VT, VT, CCValAssign::Full, Flags, *this)) {
 144 #ifndef NDEBUG
 145       errs() << "Call result #" << i << " has unhandled type "
 146              << VT.getEVTString();
 147 #endif
 148       llvm_unreachable(0);
 149     }
 150   }
 151 }
 152
 153 /// AnalyzeCallResult - Same as above except it's specialized for calls which
 154 /// produce a single value.
 155 void CCState::AnalyzeCallResult(EVT VT, CCAssignFn Fn) {
 156   if (Fn(0, VT, VT, CCValAssign::Full, ISD::ArgFlagsTy(), *this)) {
 157 #ifndef NDEBUG
 158     errs() << "Call result has unhandled type "
 159            << VT.getEVTString();
 160 #endif
 161     llvm_unreachable(0);
 162   }
 163 }