1 //===-- SystemZRegisterInfo.cpp - SystemZ register information ------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "SystemZRegisterInfo.h"
11 #include "SystemZTargetMachine.h"
12 #include "llvm/CodeGen/MachineInstrBuilder.h"
13 #include "llvm/CodeGen/MachineRegisterInfo.h"
17 #define GET_REGINFO_TARGET_DESC
18 #include "SystemZGenRegisterInfo.inc"
20 SystemZRegisterInfo::SystemZRegisterInfo(SystemZTargetMachine &tm)
21 : SystemZGenRegisterInfo(SystemZ::R14D), TM(tm) {}
24 SystemZRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
25 static const MCPhysReg CalleeSavedRegs[] = {
26 SystemZ::R6D, SystemZ::R7D, SystemZ::R8D, SystemZ::R9D,
27 SystemZ::R10D, SystemZ::R11D, SystemZ::R12D, SystemZ::R13D,
28 SystemZ::R14D, SystemZ::R15D,
29 SystemZ::F8D, SystemZ::F9D, SystemZ::F10D, SystemZ::F11D,
30 SystemZ::F12D, SystemZ::F13D, SystemZ::F14D, SystemZ::F15D,
34 return CalleeSavedRegs;
38 SystemZRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
39 BitVector Reserved(getNumRegs());
40 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
43 // R11D is the frame pointer. Reserve all aliases.
44 Reserved.set(SystemZ::R11D);
45 Reserved.set(SystemZ::R11L);
46 Reserved.set(SystemZ::R11H);
47 Reserved.set(SystemZ::R10Q);
50 // R15D is the stack pointer. Reserve all aliases.
51 Reserved.set(SystemZ::R15D);
52 Reserved.set(SystemZ::R15L);
53 Reserved.set(SystemZ::R15H);
54 Reserved.set(SystemZ::R14Q);
59 SystemZRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MI,
60 int SPAdj, unsigned FIOperandNum,
61 RegScavenger *RS) const {
62 assert(SPAdj == 0 && "Outgoing arguments should be part of the frame");
64 MachineBasicBlock &MBB = *MI->getParent();
65 MachineFunction &MF = *MBB.getParent();
66 auto *TII = static_cast<const SystemZInstrInfo*>(TM.getInstrInfo());
67 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
68 DebugLoc DL = MI->getDebugLoc();
70 // Decompose the frame index into a base and offset.
71 int FrameIndex = MI->getOperand(FIOperandNum).getIndex();
72 unsigned BasePtr = getFrameRegister(MF);
73 int64_t Offset = (TFI->getFrameIndexOffset(MF, FrameIndex) +
74 MI->getOperand(FIOperandNum + 1).getImm());
76 // Special handling of dbg_value instructions.
77 if (MI->isDebugValue()) {
78 MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, /*isDef*/ false);
79 MI->getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
83 // See if the offset is in range, or if an equivalent instruction that
84 // accepts the offset exists.
85 unsigned Opcode = MI->getOpcode();
86 unsigned OpcodeForOffset = TII->getOpcodeForOffset(Opcode, Offset);
88 MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, false);
90 // Create an anchor point that is in range. Start at 0xffff so that
91 // can use LLILH to load the immediate.
92 int64_t OldOffset = Offset;
93 int64_t Mask = 0xffff;
95 Offset = OldOffset & Mask;
96 OpcodeForOffset = TII->getOpcodeForOffset(Opcode, Offset);
98 assert(Mask && "One offset must be OK");
99 } while (!OpcodeForOffset);
101 unsigned ScratchReg =
102 MF.getRegInfo().createVirtualRegister(&SystemZ::ADDR64BitRegClass);
103 int64_t HighOffset = OldOffset - Offset;
105 if (MI->getDesc().TSFlags & SystemZII::HasIndex
106 && MI->getOperand(FIOperandNum + 2).getReg() == 0) {
107 // Load the offset into the scratch register and use it as an index.
108 // The scratch register then dies here.
109 TII->loadImmediate(MBB, MI, ScratchReg, HighOffset);
110 MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, false);
111 MI->getOperand(FIOperandNum + 2).ChangeToRegister(ScratchReg,
114 // Load the anchor address into a scratch register.
115 unsigned LAOpcode = TII->getOpcodeForOffset(SystemZ::LA, HighOffset);
117 BuildMI(MBB, MI, DL, TII->get(LAOpcode),ScratchReg)
118 .addReg(BasePtr).addImm(HighOffset).addReg(0);
120 // Load the high offset into the scratch register and use it as
122 TII->loadImmediate(MBB, MI, ScratchReg, HighOffset);
123 BuildMI(MBB, MI, DL, TII->get(SystemZ::AGR),ScratchReg)
124 .addReg(ScratchReg, RegState::Kill).addReg(BasePtr);
127 // Use the scratch register as the base. It then dies here.
128 MI->getOperand(FIOperandNum).ChangeToRegister(ScratchReg,
132 MI->setDesc(TII->get(OpcodeForOffset));
133 MI->getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
137 SystemZRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
138 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
139 return TFI->hasFP(MF) ? SystemZ::R11D : SystemZ::R15D;