1 //===- SparcRegisterInfo.cpp - SPARC Register Information -------*- C++ -*-===//
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 // This file contains the SPARC implementation of the TargetRegisterInfo class.
12 //===----------------------------------------------------------------------===//
15 #include "SparcRegisterInfo.h"
16 #include "SparcSubtarget.h"
17 #include "llvm/CodeGen/MachineInstrBuilder.h"
18 #include "llvm/CodeGen/MachineFunction.h"
19 #include "llvm/CodeGen/MachineFrameInfo.h"
20 #include "llvm/CodeGen/MachineLocation.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Target/TargetInstrInfo.h"
23 #include "llvm/Type.h"
24 #include "llvm/ADT/BitVector.h"
25 #include "llvm/ADT/STLExtras.h"
28 SparcRegisterInfo::SparcRegisterInfo(SparcSubtarget &st,
29 const TargetInstrInfo &tii)
30 : SparcGenRegisterInfo(SP::ADJCALLSTACKDOWN, SP::ADJCALLSTACKUP),
31 Subtarget(st), TII(tii) {
34 const unsigned* SparcRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF)
36 static const unsigned CalleeSavedRegs[] = { 0 };
37 return CalleeSavedRegs;
40 BitVector SparcRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
41 BitVector Reserved(getNumRegs());
55 bool SparcRegisterInfo::hasFP(const MachineFunction &MF) const {
59 void SparcRegisterInfo::
60 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
61 MachineBasicBlock::iterator I) const {
62 MachineInstr &MI = *I;
63 DebugLoc dl = MI.getDebugLoc();
64 int Size = MI.getOperand(0).getImm();
65 if (MI.getOpcode() == SP::ADJCALLSTACKDOWN)
68 BuildMI(MBB, I, dl, TII.get(SP::ADDri), SP::O6).addReg(SP::O6).addImm(Size);
73 SparcRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
74 int SPAdj, FrameIndexValue *Value,
75 RegScavenger *RS) const {
76 assert(SPAdj == 0 && "Unexpected");
79 MachineInstr &MI = *II;
80 DebugLoc dl = MI.getDebugLoc();
81 while (!MI.getOperand(i).isFI()) {
83 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
86 int FrameIndex = MI.getOperand(i).getIndex();
88 // Addressable stack objects are accessed using neg. offsets from %fp
89 MachineFunction &MF = *MI.getParent()->getParent();
90 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
91 MI.getOperand(i+1).getImm();
93 // Replace frame index with a frame pointer reference.
94 if (Offset >= -4096 && Offset <= 4095) {
95 // If the offset is small enough to fit in the immediate field, directly
97 MI.getOperand(i).ChangeToRegister(SP::I6, false);
98 MI.getOperand(i+1).ChangeToImmediate(Offset);
100 // Otherwise, emit a G1 = SETHI %hi(offset). FIXME: it would be better to
101 // scavenge a register here instead of reserving G1 all of the time.
102 unsigned OffHi = (unsigned)Offset >> 10U;
103 BuildMI(*MI.getParent(), II, dl, TII.get(SP::SETHIi), SP::G1).addImm(OffHi);
105 BuildMI(*MI.getParent(), II, dl, TII.get(SP::ADDrr), SP::G1).addReg(SP::G1)
107 // Insert: G1+%lo(offset) into the user.
108 MI.getOperand(i).ChangeToRegister(SP::G1, false);
109 MI.getOperand(i+1).ChangeToImmediate(Offset & ((1 << 10)-1));
114 void SparcRegisterInfo::
115 processFunctionBeforeFrameFinalized(MachineFunction &MF) const {}
117 void SparcRegisterInfo::emitPrologue(MachineFunction &MF) const {
118 MachineBasicBlock &MBB = MF.front();
119 MachineFrameInfo *MFI = MF.getFrameInfo();
120 MachineBasicBlock::iterator MBBI = MBB.begin();
121 DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
123 // Get the number of bytes to allocate from the FrameInfo
124 int NumBytes = (int) MFI->getStackSize();
126 // Emit the correct save instruction based on the number of bytes in
127 // the frame. Minimum stack frame size according to V8 ABI is:
128 // 16 words for register window spill
129 // 1 word for address of returned aggregate-value
130 // + 6 words for passing parameters on the stack
132 // 23 words * 4 bytes per word = 92 bytes
135 // Round up to next doubleword boundary -- a double-word boundary
136 // is required by the ABI.
137 NumBytes = (NumBytes + 7) & ~7;
138 NumBytes = -NumBytes;
140 if (NumBytes >= -4096) {
141 BuildMI(MBB, MBBI, dl, TII.get(SP::SAVEri), SP::O6)
142 .addReg(SP::O6).addImm(NumBytes);
144 // Emit this the hard way. This clobbers G1 which we always know is
146 unsigned OffHi = (unsigned)NumBytes >> 10U;
147 BuildMI(MBB, MBBI, dl, TII.get(SP::SETHIi), SP::G1).addImm(OffHi);
149 BuildMI(MBB, MBBI, dl, TII.get(SP::ORri), SP::G1)
150 .addReg(SP::G1).addImm(NumBytes & ((1 << 10)-1));
151 BuildMI(MBB, MBBI, dl, TII.get(SP::SAVErr), SP::O6)
152 .addReg(SP::O6).addReg(SP::G1);
156 void SparcRegisterInfo::emitEpilogue(MachineFunction &MF,
157 MachineBasicBlock &MBB) const {
158 MachineBasicBlock::iterator MBBI = prior(MBB.end());
159 DebugLoc dl = MBBI->getDebugLoc();
160 assert(MBBI->getOpcode() == SP::RETL &&
161 "Can only put epilog before 'retl' instruction!");
162 BuildMI(MBB, MBBI, dl, TII.get(SP::RESTORErr), SP::G0).addReg(SP::G0)
166 unsigned SparcRegisterInfo::getRARegister() const {
170 unsigned SparcRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
174 unsigned SparcRegisterInfo::getEHExceptionRegister() const {
175 llvm_unreachable("What is the exception register");
179 unsigned SparcRegisterInfo::getEHHandlerRegister() const {
180 llvm_unreachable("What is the exception handler register");
184 int SparcRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
185 return SparcGenRegisterInfo::getDwarfRegNumFull(RegNum, 0);
188 #include "SparcGenRegisterInfo.inc"