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/CodeGen/MachineFrameInfo.h" 17 #include "llvm/Support/Debug.h" 18 #include "llvm/Support/ErrorHandling.h" 19 #include "llvm/Support/raw_ostream.h" 20 #include "llvm/Target/TargetRegisterInfo.h" 21 #include "llvm/Target/TargetData.h" 22 #include "llvm/Target/TargetMachine.h" 23 #include "llvm/Target/TargetLowering.h" 24 using namespace llvm; 25 26 CCState::CCState(CallingConv::ID CC, bool isVarArg, MachineFunction &mf, 27 const TargetMachine &tm, SmallVector<CCValAssign, 16> &locs, 28 LLVMContext &C) 29 : CallingConv(CC), IsVarArg(isVarArg), MF(mf), TM(tm), 30 TRI(*TM.getRegisterInfo()), Locs(locs), Context(C), 31 CallOrPrologue(Unknown) { 32 // No stack is used. 33 StackOffset = 0; 34 35 clearFirstByValReg(); 36 UsedRegs.resize((TRI.getNumRegs()+31)/32); 37 } 38 39 // HandleByVal - Allocate space on the stack large enough to pass an argument 40 // by value. The size and alignment information of the argument is encoded in 41 // its parameter attribute. 42 void CCState::HandleByVal(unsigned ValNo, MVT ValVT, 43 MVT LocVT, CCValAssign::LocInfo LocInfo, 44 int MinSize, int MinAlign, 45 ISD::ArgFlagsTy ArgFlags) { 46 unsigned Align = ArgFlags.getByValAlign(); 47 unsigned Size = ArgFlags.getByValSize(); 48 if (MinSize > (int)Size) 49 Size = MinSize; 50 if (MinAlign > (int)Align) 51 Align = MinAlign; 52 if (MF.getFrameInfo()->getMaxAlignment() < Align) 53 MF.getFrameInfo()->setMaxAlignment(Align); 54 TM.getTargetLowering()->HandleByVal(this, Size); 55 unsigned Offset = AllocateStack(Size, Align); 56 addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo)); 57 } 58 59 /// MarkAllocated - Mark a register and all of its aliases as allocated. 60 void CCState::MarkAllocated(unsigned Reg) { 61 for (const unsigned *Alias = TRI.getOverlaps(Reg); 62 unsigned Reg = *Alias; ++Alias) 63 UsedRegs[Reg/32] |= 1 << (Reg&31); 64 } 65 66 /// AnalyzeFormalArguments - Analyze an array of argument values, 67 /// incorporating info about the formals into this state. 68 void 69 CCState::AnalyzeFormalArguments(const SmallVectorImpl<ISD::InputArg> &Ins, 70 CCAssignFn Fn) { 71 unsigned NumArgs = Ins.size(); 72 73 for (unsigned i = 0; i != NumArgs; ++i) { 74 MVT ArgVT = Ins[i].VT; 75 ISD::ArgFlagsTy ArgFlags = Ins[i].Flags; 76 if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) { 77 #ifndef NDEBUG 78 dbgs() << "Formal argument #" << i << " has unhandled type " 79 << EVT(ArgVT).getEVTString(); 80 #endif 81 llvm_unreachable(0); 82 } 83 } 84 } 85 86 /// CheckReturn - Analyze the return values of a function, returning true if 87 /// the return can be performed without sret-demotion, and false otherwise. 88 bool CCState::CheckReturn(const SmallVectorImpl<ISD::OutputArg> &Outs, 89 CCAssignFn Fn) { 90 // Determine which register each value should be copied into. 91 for (unsigned i = 0, e = Outs.size(); i != e; ++i) { 92 MVT VT = Outs[i].VT; 93 ISD::ArgFlagsTy ArgFlags = Outs[i].Flags; 94 if (Fn(i, VT, VT, CCValAssign::Full, ArgFlags, *this)) 95 return false; 96 } 97 return true; 98 } 99 100 /// AnalyzeReturn - Analyze the returned values of a return, 101 /// incorporating info about the result values into this state. 102 void CCState::AnalyzeReturn(const SmallVectorImpl<ISD::OutputArg> &Outs, 103 CCAssignFn Fn) { 104 // Determine which register each value should be copied into. 105 for (unsigned i = 0, e = Outs.size(); i != e; ++i) { 106 MVT VT = Outs[i].VT; 107 ISD::ArgFlagsTy ArgFlags = Outs[i].Flags; 108 if (Fn(i, VT, VT, CCValAssign::Full, ArgFlags, *this)) { 109 #ifndef NDEBUG 110 dbgs() << "Return operand #" << i << " has unhandled type " 111 << EVT(VT).getEVTString(); 112 #endif 113 llvm_unreachable(0); 114 } 115 } 116 } 117 118 /// AnalyzeCallOperands - Analyze the outgoing arguments to a call, 119 /// incorporating info about the passed values into this state. 120 void CCState::AnalyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Outs, 121 CCAssignFn Fn) { 122 unsigned NumOps = Outs.size(); 123 for (unsigned i = 0; i != NumOps; ++i) { 124 MVT ArgVT = Outs[i].VT; 125 ISD::ArgFlagsTy ArgFlags = Outs[i].Flags; 126 if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) { 127 #ifndef NDEBUG 128 dbgs() << "Call operand #" << i << " has unhandled type " 129 << EVT(ArgVT).getEVTString(); 130 #endif 131 llvm_unreachable(0); 132 } 133 } 134 } 135 136 /// AnalyzeCallOperands - Same as above except it takes vectors of types 137 /// and argument flags. 138 void CCState::AnalyzeCallOperands(SmallVectorImpl<MVT> &ArgVTs, 139 SmallVectorImpl<ISD::ArgFlagsTy> &Flags, 140 CCAssignFn Fn) { 141 unsigned NumOps = ArgVTs.size(); 142 for (unsigned i = 0; i != NumOps; ++i) { 143 MVT ArgVT = ArgVTs[i]; 144 ISD::ArgFlagsTy ArgFlags = Flags[i]; 145 if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) { 146 #ifndef NDEBUG 147 dbgs() << "Call operand #" << i << " has unhandled type " 148 << EVT(ArgVT).getEVTString(); 149 #endif 150 llvm_unreachable(0); 151 } 152 } 153 } 154 155 /// AnalyzeCallResult - Analyze the return values of a call, 156 /// incorporating info about the passed values into this state. 157 void CCState::AnalyzeCallResult(const SmallVectorImpl<ISD::InputArg> &Ins, 158 CCAssignFn Fn) { 159 for (unsigned i = 0, e = Ins.size(); i != e; ++i) { 160 MVT VT = Ins[i].VT; 161 ISD::ArgFlagsTy Flags = Ins[i].Flags; 162 if (Fn(i, VT, VT, CCValAssign::Full, Flags, *this)) { 163 #ifndef NDEBUG 164 dbgs() << "Call result #" << i << " has unhandled type " 165 << EVT(VT).getEVTString() << "\n"; 166 #endif 167 llvm_unreachable(0); 168 } 169 } 170 } 171 172 /// AnalyzeCallResult - Same as above except it's specialized for calls which 173 /// produce a single value. 174 void CCState::AnalyzeCallResult(MVT VT, CCAssignFn Fn) { 175 if (Fn(0, VT, VT, CCValAssign::Full, ISD::ArgFlagsTy(), *this)) { 176 #ifndef NDEBUG 177 dbgs() << "Call result has unhandled type " 178 << EVT(VT).getEVTString(); 179 #endif 180 llvm_unreachable(0); 181 } 182 } 183
