1 //===-- SystemZRegisterInfo.cpp - SystemZ register information ------------===// 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 #include "SystemZInstrInfo.h" 11 #include "SystemZRegisterInfo.h" 12 #include "SystemZSubtarget.h" 13 #include "llvm/CodeGen/MachineInstrBuilder.h" 14 #include "llvm/CodeGen/MachineRegisterInfo.h" 15 #include "llvm/Target/TargetFrameLowering.h" 16 17 using namespace llvm; 18 19 #define GET_REGINFO_TARGET_DESC 20 #include "SystemZGenRegisterInfo.inc" 21 22 SystemZRegisterInfo::SystemZRegisterInfo() 23 : SystemZGenRegisterInfo(SystemZ::R14D) {} 24 25 const MCPhysReg * 26 SystemZRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const { 27 if (MF->getSubtarget().getTargetLowering()->supportSwiftError() && 28 MF->getFunction()->getAttributes().hasAttrSomewhere( 29 Attribute::SwiftError)) 30 return CSR_SystemZ_SwiftError_SaveList; 31 return CSR_SystemZ_SaveList; 32 } 33 34 const uint32_t * 35 SystemZRegisterInfo::getCallPreservedMask(const MachineFunction &MF, 36 CallingConv::ID CC) const { 37 if (MF.getSubtarget().getTargetLowering()->supportSwiftError() && 38 MF.getFunction()->getAttributes().hasAttrSomewhere( 39 Attribute::SwiftError)) 40 return CSR_SystemZ_SwiftError_RegMask; 41 return CSR_SystemZ_RegMask; 42 } 43 44 BitVector 45 SystemZRegisterInfo::getReservedRegs(const MachineFunction &MF) const { 46 BitVector Reserved(getNumRegs()); 47 const SystemZFrameLowering *TFI = getFrameLowering(MF); 48 49 if (TFI->hasFP(MF)) { 50 // R11D is the frame pointer. Reserve all aliases. 51 Reserved.set(SystemZ::R11D); 52 Reserved.set(SystemZ::R11L); 53 Reserved.set(SystemZ::R11H); 54 Reserved.set(SystemZ::R10Q); 55 } 56 57 // R15D is the stack pointer. Reserve all aliases. 58 Reserved.set(SystemZ::R15D); 59 Reserved.set(SystemZ::R15L); 60 Reserved.set(SystemZ::R15H); 61 Reserved.set(SystemZ::R14Q); 62 return Reserved; 63 } 64 65 void 66 SystemZRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MI, 67 int SPAdj, unsigned FIOperandNum, 68 RegScavenger *RS) const { 69 assert(SPAdj == 0 && "Outgoing arguments should be part of the frame"); 70 71 MachineBasicBlock &MBB = *MI->getParent(); 72 MachineFunction &MF = *MBB.getParent(); 73 auto *TII = 74 static_cast<const SystemZInstrInfo *>(MF.getSubtarget().getInstrInfo()); 75 const SystemZFrameLowering *TFI = getFrameLowering(MF); 76 DebugLoc DL = MI->getDebugLoc(); 77 78 // Decompose the frame index into a base and offset. 79 int FrameIndex = MI->getOperand(FIOperandNum).getIndex(); 80 unsigned BasePtr; 81 int64_t Offset = (TFI->getFrameIndexReference(MF, FrameIndex, BasePtr) + 82 MI->getOperand(FIOperandNum + 1).getImm()); 83 84 // Special handling of dbg_value instructions. 85 if (MI->isDebugValue()) { 86 MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, /*isDef*/ false); 87 MI->getOperand(FIOperandNum + 1).ChangeToImmediate(Offset); 88 return; 89 } 90 91 // See if the offset is in range, or if an equivalent instruction that 92 // accepts the offset exists. 93 unsigned Opcode = MI->getOpcode(); 94 unsigned OpcodeForOffset = TII->getOpcodeForOffset(Opcode, Offset); 95 if (OpcodeForOffset) { 96 if (OpcodeForOffset == SystemZ::LE && 97 MF.getSubtarget<SystemZSubtarget>().hasVector()) { 98 // If LE is ok for offset, use LDE instead on z13. 99 OpcodeForOffset = SystemZ::LDE32; 100 } 101 MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, false); 102 } 103 else { 104 // Create an anchor point that is in range. Start at 0xffff so that 105 // can use LLILH to load the immediate. 106 int64_t OldOffset = Offset; 107 int64_t Mask = 0xffff; 108 do { 109 Offset = OldOffset & Mask; 110 OpcodeForOffset = TII->getOpcodeForOffset(Opcode, Offset); 111 Mask >>= 1; 112 assert(Mask && "One offset must be OK"); 113 } while (!OpcodeForOffset); 114 115 unsigned ScratchReg = 116 MF.getRegInfo().createVirtualRegister(&SystemZ::ADDR64BitRegClass); 117 int64_t HighOffset = OldOffset - Offset; 118 119 if (MI->getDesc().TSFlags & SystemZII::HasIndex 120 && MI->getOperand(FIOperandNum + 2).getReg() == 0) { 121 // Load the offset into the scratch register and use it as an index. 122 // The scratch register then dies here. 123 TII->loadImmediate(MBB, MI, ScratchReg, HighOffset); 124 MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, false); 125 MI->getOperand(FIOperandNum + 2).ChangeToRegister(ScratchReg, 126 false, false, true); 127 } else { 128 // Load the anchor address into a scratch register. 129 unsigned LAOpcode = TII->getOpcodeForOffset(SystemZ::LA, HighOffset); 130 if (LAOpcode) 131 BuildMI(MBB, MI, DL, TII->get(LAOpcode),ScratchReg) 132 .addReg(BasePtr).addImm(HighOffset).addReg(0); 133 else { 134 // Load the high offset into the scratch register and use it as 135 // an index. 136 TII->loadImmediate(MBB, MI, ScratchReg, HighOffset); 137 BuildMI(MBB, MI, DL, TII->get(SystemZ::AGR),ScratchReg) 138 .addReg(ScratchReg, RegState::Kill).addReg(BasePtr); 139 } 140 141 // Use the scratch register as the base. It then dies here. 142 MI->getOperand(FIOperandNum).ChangeToRegister(ScratchReg, 143 false, false, true); 144 } 145 } 146 MI->setDesc(TII->get(OpcodeForOffset)); 147 MI->getOperand(FIOperandNum + 1).ChangeToImmediate(Offset); 148 } 149 150 unsigned 151 SystemZRegisterInfo::getFrameRegister(const MachineFunction &MF) const { 152 const SystemZFrameLowering *TFI = getFrameLowering(MF); 153 return TFI->hasFP(MF) ? SystemZ::R11D : SystemZ::R15D; 154 } 155
