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/IR/DataLayout.h" 18 #include "llvm/Support/Debug.h" 19 #include "llvm/Support/ErrorHandling.h" 20 #include "llvm/Support/raw_ostream.h" 21 #include "llvm/Target/TargetLowering.h" 22 #include "llvm/Target/TargetMachine.h" 23 #include "llvm/Target/TargetRegisterInfo.h" 24 using namespace llvm; 25 26 CCState::CCState(CallingConv::ID CC, bool isVarArg, MachineFunction &mf, 27 const TargetMachine &tm, SmallVectorImpl<CCValAssign> &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 clearByValRegsInfo(); 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 MF.getFrameInfo()->ensureMaxAlignment(Align); 53 TM.getTargetLowering()->HandleByVal(this, Size, Align); 54 unsigned Offset = AllocateStack(Size, Align); 55 addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo)); 56 } 57 58 /// MarkAllocated - Mark a register and all of its aliases as allocated. 59 void CCState::MarkAllocated(unsigned Reg) { 60 for (MCRegAliasIterator AI(Reg, &TRI, true); AI.isValid(); ++AI) 61 UsedRegs[*AI/32] |= 1 << (*AI&31); 62 } 63 64 /// AnalyzeFormalArguments - Analyze an array of argument values, 65 /// incorporating info about the formals into this state. 66 void 67 CCState::AnalyzeFormalArguments(const SmallVectorImpl<ISD::InputArg> &Ins, 68 CCAssignFn Fn) { 69 unsigned NumArgs = Ins.size(); 70 71 for (unsigned i = 0; i != NumArgs; ++i) { 72 MVT ArgVT = Ins[i].VT; 73 ISD::ArgFlagsTy ArgFlags = Ins[i].Flags; 74 if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) { 75 #ifndef NDEBUG 76 dbgs() << "Formal argument #" << i << " has unhandled type " 77 << EVT(ArgVT).getEVTString() << '\n'; 78 #endif 79 llvm_unreachable(nullptr); 80 } 81 } 82 } 83 84 /// CheckReturn - Analyze the return values of a function, returning true if 85 /// the return can be performed without sret-demotion, and false otherwise. 86 bool CCState::CheckReturn(const SmallVectorImpl<ISD::OutputArg> &Outs, 87 CCAssignFn Fn) { 88 // Determine which register each value should be copied into. 89 for (unsigned i = 0, e = Outs.size(); i != e; ++i) { 90 MVT VT = Outs[i].VT; 91 ISD::ArgFlagsTy ArgFlags = Outs[i].Flags; 92 if (Fn(i, VT, VT, CCValAssign::Full, ArgFlags, *this)) 93 return false; 94 } 95 return true; 96 } 97 98 /// AnalyzeReturn - Analyze the returned values of a return, 99 /// incorporating info about the result values into this state. 100 void CCState::AnalyzeReturn(const SmallVectorImpl<ISD::OutputArg> &Outs, 101 CCAssignFn Fn) { 102 // Determine which register each value should be copied into. 103 for (unsigned i = 0, e = Outs.size(); i != e; ++i) { 104 MVT VT = Outs[i].VT; 105 ISD::ArgFlagsTy ArgFlags = Outs[i].Flags; 106 if (Fn(i, VT, VT, CCValAssign::Full, ArgFlags, *this)) { 107 #ifndef NDEBUG 108 dbgs() << "Return operand #" << i << " has unhandled type " 109 << EVT(VT).getEVTString() << '\n'; 110 #endif 111 llvm_unreachable(nullptr); 112 } 113 } 114 } 115 116 /// AnalyzeCallOperands - Analyze the outgoing arguments to a call, 117 /// incorporating info about the passed values into this state. 118 void CCState::AnalyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Outs, 119 CCAssignFn Fn) { 120 unsigned NumOps = Outs.size(); 121 for (unsigned i = 0; i != NumOps; ++i) { 122 MVT ArgVT = Outs[i].VT; 123 ISD::ArgFlagsTy ArgFlags = Outs[i].Flags; 124 if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) { 125 #ifndef NDEBUG 126 dbgs() << "Call operand #" << i << " has unhandled type " 127 << EVT(ArgVT).getEVTString() << '\n'; 128 #endif 129 llvm_unreachable(nullptr); 130 } 131 } 132 } 133 134 /// AnalyzeCallOperands - Same as above except it takes vectors of types 135 /// and argument flags. 136 void CCState::AnalyzeCallOperands(SmallVectorImpl<MVT> &ArgVTs, 137 SmallVectorImpl<ISD::ArgFlagsTy> &Flags, 138 CCAssignFn Fn) { 139 unsigned NumOps = ArgVTs.size(); 140 for (unsigned i = 0; i != NumOps; ++i) { 141 MVT ArgVT = ArgVTs[i]; 142 ISD::ArgFlagsTy ArgFlags = Flags[i]; 143 if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) { 144 #ifndef NDEBUG 145 dbgs() << "Call operand #" << i << " has unhandled type " 146 << EVT(ArgVT).getEVTString() << '\n'; 147 #endif 148 llvm_unreachable(nullptr); 149 } 150 } 151 } 152 153 /// AnalyzeCallResult - Analyze the return values of a call, 154 /// incorporating info about the passed values into this state. 155 void CCState::AnalyzeCallResult(const SmallVectorImpl<ISD::InputArg> &Ins, 156 CCAssignFn Fn) { 157 for (unsigned i = 0, e = Ins.size(); i != e; ++i) { 158 MVT VT = Ins[i].VT; 159 ISD::ArgFlagsTy Flags = Ins[i].Flags; 160 if (Fn(i, VT, VT, CCValAssign::Full, Flags, *this)) { 161 #ifndef NDEBUG 162 dbgs() << "Call result #" << i << " has unhandled type " 163 << EVT(VT).getEVTString() << '\n'; 164 #endif 165 llvm_unreachable(nullptr); 166 } 167 } 168 } 169 170 /// AnalyzeCallResult - Same as above except it's specialized for calls which 171 /// produce a single value. 172 void CCState::AnalyzeCallResult(MVT VT, CCAssignFn Fn) { 173 if (Fn(0, VT, VT, CCValAssign::Full, ISD::ArgFlagsTy(), *this)) { 174 #ifndef NDEBUG 175 dbgs() << "Call result has unhandled type " 176 << EVT(VT).getEVTString() << '\n'; 177 #endif 178 llvm_unreachable(nullptr); 179 } 180 } 181