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 "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"
19 #define GET_REGINFO_TARGET_DESC
20 #include "SystemZGenRegisterInfo.inc"
22 SystemZRegisterInfo::SystemZRegisterInfo()
23 : SystemZGenRegisterInfo(SystemZ::R14D) {}
26 SystemZRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
27 static const MCPhysReg CalleeSavedRegs[] = {
28 SystemZ::R6D, SystemZ::R7D, SystemZ::R8D, SystemZ::R9D,
29 SystemZ::R10D, SystemZ::R11D, SystemZ::R12D, SystemZ::R13D,
30 SystemZ::R14D, SystemZ::R15D,
31 SystemZ::F8D, SystemZ::F9D, SystemZ::F10D, SystemZ::F11D,
32 SystemZ::F12D, SystemZ::F13D, SystemZ::F14D, SystemZ::F15D,
36 return CalleeSavedRegs;
40 SystemZRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
41 BitVector Reserved(getNumRegs());
42 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
45 // R11D is the frame pointer. Reserve all aliases.
46 Reserved.set(SystemZ::R11D);
47 Reserved.set(SystemZ::R11L);
48 Reserved.set(SystemZ::R11H);
49 Reserved.set(SystemZ::R10Q);
52 // R15D is the stack pointer. Reserve all aliases.
53 Reserved.set(SystemZ::R15D);
54 Reserved.set(SystemZ::R15L);
55 Reserved.set(SystemZ::R15H);
56 Reserved.set(SystemZ::R14Q);
61 SystemZRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MI,
62 int SPAdj, unsigned FIOperandNum,
63 RegScavenger *RS) const {
64 assert(SPAdj == 0 && "Outgoing arguments should be part of the frame");
66 MachineBasicBlock &MBB = *MI->getParent();
67 MachineFunction &MF = *MBB.getParent();
69 static_cast<const SystemZInstrInfo *>(MF.getTarget().getInstrInfo());
70 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
71 DebugLoc DL = MI->getDebugLoc();
73 // Decompose the frame index into a base and offset.
74 int FrameIndex = MI->getOperand(FIOperandNum).getIndex();
75 unsigned BasePtr = getFrameRegister(MF);
76 int64_t Offset = (TFI->getFrameIndexOffset(MF, FrameIndex) +
77 MI->getOperand(FIOperandNum + 1).getImm());
79 // Special handling of dbg_value instructions.
80 if (MI->isDebugValue()) {
81 MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, /*isDef*/ false);
82 MI->getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
86 // See if the offset is in range, or if an equivalent instruction that
87 // accepts the offset exists.
88 unsigned Opcode = MI->getOpcode();
89 unsigned OpcodeForOffset = TII->getOpcodeForOffset(Opcode, Offset);
91 MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, false);
93 // Create an anchor point that is in range. Start at 0xffff so that
94 // can use LLILH to load the immediate.
95 int64_t OldOffset = Offset;
96 int64_t Mask = 0xffff;
98 Offset = OldOffset & Mask;
99 OpcodeForOffset = TII->getOpcodeForOffset(Opcode, Offset);
101 assert(Mask && "One offset must be OK");
102 } while (!OpcodeForOffset);
104 unsigned ScratchReg =
105 MF.getRegInfo().createVirtualRegister(&SystemZ::ADDR64BitRegClass);
106 int64_t HighOffset = OldOffset - Offset;
108 if (MI->getDesc().TSFlags & SystemZII::HasIndex
109 && MI->getOperand(FIOperandNum + 2).getReg() == 0) {
110 // Load the offset into the scratch register and use it as an index.
111 // The scratch register then dies here.
112 TII->loadImmediate(MBB, MI, ScratchReg, HighOffset);
113 MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, false);
114 MI->getOperand(FIOperandNum + 2).ChangeToRegister(ScratchReg,
117 // Load the anchor address into a scratch register.
118 unsigned LAOpcode = TII->getOpcodeForOffset(SystemZ::LA, HighOffset);
120 BuildMI(MBB, MI, DL, TII->get(LAOpcode),ScratchReg)
121 .addReg(BasePtr).addImm(HighOffset).addReg(0);
123 // Load the high offset into the scratch register and use it as
125 TII->loadImmediate(MBB, MI, ScratchReg, HighOffset);
126 BuildMI(MBB, MI, DL, TII->get(SystemZ::AGR),ScratchReg)
127 .addReg(ScratchReg, RegState::Kill).addReg(BasePtr);
130 // Use the scratch register as the base. It then dies here.
131 MI->getOperand(FIOperandNum).ChangeToRegister(ScratchReg,
135 MI->setDesc(TII->get(OpcodeForOffset));
136 MI->getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
140 SystemZRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
141 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
142 return TFI->hasFP(MF) ? SystemZ::R11D : SystemZ::R15D;