1 2 //===-- Mips16RegisterInfo.cpp - MIPS16 Register Information -== ----------===// 3 // 4 // The LLVM Compiler Infrastructure 5 // 6 // This file is distributed under the University of Illinois Open Source 7 // License. See LICENSE.TXT for details. 8 // 9 //===----------------------------------------------------------------------===// 10 // 11 // This file contains the MIPS16 implementation of the TargetRegisterInfo class. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "Mips16RegisterInfo.h" 16 #include "Mips16InstrInfo.h" 17 #include "Mips.h" 18 #include "Mips16InstrInfo.h" 19 #include "MipsAnalyzeImmediate.h" 20 #include "MipsInstrInfo.h" 21 #include "MipsMachineFunction.h" 22 #include "MipsSubtarget.h" 23 #include "llvm/ADT/BitVector.h" 24 #include "llvm/ADT/STLExtras.h" 25 #include "llvm/CodeGen/MachineFrameInfo.h" 26 #include "llvm/CodeGen/MachineFunction.h" 27 #include "llvm/CodeGen/MachineInstrBuilder.h" 28 #include "llvm/CodeGen/MachineRegisterInfo.h" 29 #include "llvm/CodeGen/ValueTypes.h" 30 #include "llvm/DebugInfo.h" 31 #include "llvm/IR/Constants.h" 32 #include "llvm/IR/Function.h" 33 #include "llvm/IR/Type.h" 34 #include "llvm/Support/CommandLine.h" 35 #include "llvm/Support/Debug.h" 36 #include "llvm/Support/ErrorHandling.h" 37 #include "llvm/Support/raw_ostream.h" 38 #include "llvm/Target/TargetFrameLowering.h" 39 #include "llvm/Target/TargetInstrInfo.h" 40 #include "llvm/Target/TargetMachine.h" 41 #include "llvm/Target/TargetOptions.h" 42 43 using namespace llvm; 44 45 Mips16RegisterInfo::Mips16RegisterInfo(const MipsSubtarget &ST, 46 const Mips16InstrInfo &I) 47 : MipsRegisterInfo(ST), TII(I) {} 48 49 bool Mips16RegisterInfo::requiresRegisterScavenging 50 (const MachineFunction &MF) const { 51 return true; 52 } 53 bool Mips16RegisterInfo::requiresFrameIndexScavenging 54 (const MachineFunction &MF) const { 55 return true; 56 } 57 58 bool Mips16RegisterInfo::useFPForScavengingIndex 59 (const MachineFunction &MF) const { 60 return false; 61 } 62 63 bool Mips16RegisterInfo::saveScavengerRegister 64 (MachineBasicBlock &MBB, 65 MachineBasicBlock::iterator I, 66 MachineBasicBlock::iterator &UseMI, 67 const TargetRegisterClass *RC, 68 unsigned Reg) const { 69 DebugLoc DL; 70 TII.copyPhysReg(MBB, I, DL, Mips::T0, Reg, true); 71 TII.copyPhysReg(MBB, UseMI, DL, Reg, Mips::T0, true); 72 return true; 73 } 74 75 void Mips16RegisterInfo::eliminateFI(MachineBasicBlock::iterator II, 76 unsigned OpNo, int FrameIndex, 77 uint64_t StackSize, 78 int64_t SPOffset) const { 79 MachineInstr &MI = *II; 80 MachineFunction &MF = *MI.getParent()->getParent(); 81 MachineFrameInfo *MFI = MF.getFrameInfo(); 82 83 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo(); 84 int MinCSFI = 0; 85 int MaxCSFI = -1; 86 87 if (CSI.size()) { 88 MinCSFI = CSI[0].getFrameIdx(); 89 MaxCSFI = CSI[CSI.size() - 1].getFrameIdx(); 90 } 91 92 // The following stack frame objects are always 93 // referenced relative to $sp: 94 // 1. Outgoing arguments. 95 // 2. Pointer to dynamically allocated stack space. 96 // 3. Locations for callee-saved registers. 97 // Everything else is referenced relative to whatever register 98 // getFrameRegister() returns. 99 unsigned FrameReg; 100 101 if (FrameIndex >= MinCSFI && FrameIndex <= MaxCSFI) 102 FrameReg = Mips::SP; 103 else { 104 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering(); 105 if (TFI->hasFP(MF)) { 106 FrameReg = Mips::S0; 107 } 108 else { 109 if ((MI.getNumOperands()> OpNo+2) && MI.getOperand(OpNo+2).isReg()) 110 FrameReg = MI.getOperand(OpNo+2).getReg(); 111 else 112 FrameReg = Mips::SP; 113 } 114 } 115 // Calculate final offset. 116 // - There is no need to change the offset if the frame object 117 // is one of the 118 // following: an outgoing argument, pointer to a dynamically allocated 119 // stack space or a $gp restore location, 120 // - If the frame object is any of the following, 121 // its offset must be adjusted 122 // by adding the size of the stack: 123 // incoming argument, callee-saved register location or local variable. 124 int64_t Offset; 125 bool IsKill = false; 126 Offset = SPOffset + (int64_t)StackSize; 127 Offset += MI.getOperand(OpNo + 1).getImm(); 128 129 130 DEBUG(errs() << "Offset : " << Offset << "\n" << "<--------->\n"); 131 132 if (!MI.isDebugValue() && ( ((FrameReg != Mips::SP) && !isInt<16>(Offset)) || 133 ((FrameReg == Mips::SP) && !isInt<15>(Offset)) )) { 134 MachineBasicBlock &MBB = *MI.getParent(); 135 DebugLoc DL = II->getDebugLoc(); 136 unsigned NewImm; 137 FrameReg = TII.loadImmediate(FrameReg, Offset, MBB, II, DL, NewImm); 138 Offset = SignExtend64<16>(NewImm); 139 IsKill = true; 140 } 141 MI.getOperand(OpNo).ChangeToRegister(FrameReg, false, false, IsKill); 142 MI.getOperand(OpNo + 1).ChangeToImmediate(Offset); 143 144 145 } 146