1 //===-- MipsMCInstLower.cpp - Convert Mips MachineInstr to MCInst ---------===//
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 code to lower Mips MachineInstrs to their corresponding
13 //===----------------------------------------------------------------------===//
15 #include "MipsAsmPrinter.h"
16 #include "MipsInstrInfo.h"
17 #include "MipsMCInstLower.h"
18 #include "MCTargetDesc/MipsBaseInfo.h"
19 #include "llvm/CodeGen/MachineFunction.h"
20 #include "llvm/CodeGen/MachineInstr.h"
21 #include "llvm/CodeGen/MachineOperand.h"
22 #include "llvm/MC/MCContext.h"
23 #include "llvm/MC/MCExpr.h"
24 #include "llvm/MC/MCInst.h"
25 #include "llvm/Target/Mangler.h"
29 MipsMCInstLower::MipsMCInstLower(Mangler *mang, const MachineFunction &mf,
30 MipsAsmPrinter &asmprinter)
31 : Ctx(mf.getContext()), Mang(mang), AsmPrinter(asmprinter) {}
33 MCOperand MipsMCInstLower::LowerSymbolOperand(const MachineOperand &MO,
34 MachineOperandType MOTy,
35 unsigned Offset) const {
36 MCSymbolRefExpr::VariantKind Kind;
37 const MCSymbol *Symbol;
39 switch(MO.getTargetFlags()) {
40 default: assert(0 && "Invalid target flag!");
41 case MipsII::MO_NO_FLAG: Kind = MCSymbolRefExpr::VK_None; break;
42 case MipsII::MO_GPREL: Kind = MCSymbolRefExpr::VK_Mips_GPREL; break;
43 case MipsII::MO_GOT_CALL: Kind = MCSymbolRefExpr::VK_Mips_GOT_CALL; break;
44 case MipsII::MO_GOT16: Kind = MCSymbolRefExpr::VK_Mips_GOT16; break;
45 case MipsII::MO_GOT: Kind = MCSymbolRefExpr::VK_Mips_GOT; break;
46 case MipsII::MO_ABS_HI: Kind = MCSymbolRefExpr::VK_Mips_ABS_HI; break;
47 case MipsII::MO_ABS_LO: Kind = MCSymbolRefExpr::VK_Mips_ABS_LO; break;
48 case MipsII::MO_TLSGD: Kind = MCSymbolRefExpr::VK_Mips_TLSGD; break;
49 case MipsII::MO_TLSLDM: Kind = MCSymbolRefExpr::VK_Mips_TLSLDM; break;
50 case MipsII::MO_DTPREL_HI: Kind = MCSymbolRefExpr::VK_Mips_DTPREL_HI; break;
51 case MipsII::MO_DTPREL_LO: Kind = MCSymbolRefExpr::VK_Mips_DTPREL_LO; break;
52 case MipsII::MO_GOTTPREL: Kind = MCSymbolRefExpr::VK_Mips_GOTTPREL; break;
53 case MipsII::MO_TPREL_HI: Kind = MCSymbolRefExpr::VK_Mips_TPREL_HI; break;
54 case MipsII::MO_TPREL_LO: Kind = MCSymbolRefExpr::VK_Mips_TPREL_LO; break;
55 case MipsII::MO_GPOFF_HI: Kind = MCSymbolRefExpr::VK_Mips_GPOFF_HI; break;
56 case MipsII::MO_GPOFF_LO: Kind = MCSymbolRefExpr::VK_Mips_GPOFF_LO; break;
57 case MipsII::MO_GOT_DISP: Kind = MCSymbolRefExpr::VK_Mips_GOT_DISP; break;
58 case MipsII::MO_GOT_PAGE: Kind = MCSymbolRefExpr::VK_Mips_GOT_PAGE; break;
59 case MipsII::MO_GOT_OFST: Kind = MCSymbolRefExpr::VK_Mips_GOT_OFST; break;
63 case MachineOperand::MO_MachineBasicBlock:
64 Symbol = MO.getMBB()->getSymbol();
67 case MachineOperand::MO_GlobalAddress:
68 Symbol = Mang->getSymbol(MO.getGlobal());
71 case MachineOperand::MO_BlockAddress:
72 Symbol = AsmPrinter.GetBlockAddressSymbol(MO.getBlockAddress());
75 case MachineOperand::MO_ExternalSymbol:
76 Symbol = AsmPrinter.GetExternalSymbolSymbol(MO.getSymbolName());
79 case MachineOperand::MO_JumpTableIndex:
80 Symbol = AsmPrinter.GetJTISymbol(MO.getIndex());
83 case MachineOperand::MO_ConstantPoolIndex:
84 Symbol = AsmPrinter.GetCPISymbol(MO.getIndex());
86 Offset += MO.getOffset();
90 llvm_unreachable("<unknown operand type>");
93 const MCSymbolRefExpr *MCSym = MCSymbolRefExpr::Create(Symbol, Kind, Ctx);
96 return MCOperand::CreateExpr(MCSym);
98 // Assume offset is never negative.
101 const MCConstantExpr *OffsetExpr = MCConstantExpr::Create(Offset, Ctx);
102 const MCBinaryExpr *AddExpr = MCBinaryExpr::CreateAdd(MCSym, OffsetExpr, Ctx);
103 return MCOperand::CreateExpr(AddExpr);
106 // Lower ".cpload $reg" to
107 // "lui $gp, %hi(_gp_disp)"
108 // "addiu $gp, $gp, %lo(_gp_disp)"
109 // "addu $gp. $gp, $reg"
110 void MipsMCInstLower::LowerCPLOAD(const MachineInstr *MI,
111 SmallVector<MCInst, 4>& MCInsts) {
112 MCInst Lui, Addiu, Addu;
113 StringRef SymName("_gp_disp");
114 const MCSymbol *Symbol = Ctx.GetOrCreateSymbol(SymName);
115 const MCSymbolRefExpr *MCSym;
117 // lui $gp, %hi(_gp_disp)
118 Lui.setOpcode(Mips::LUi);
119 Lui.addOperand(MCOperand::CreateReg(Mips::GP));
120 MCSym = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_Mips_ABS_HI, Ctx);
121 Lui.addOperand(MCOperand::CreateExpr(MCSym));
122 MCInsts.push_back(Lui);
124 // addiu $gp, $gp, %lo(_gp_disp)
125 Addiu.setOpcode(Mips::ADDiu);
126 Addiu.addOperand(MCOperand::CreateReg(Mips::GP));
127 Addiu.addOperand(MCOperand::CreateReg(Mips::GP));
128 MCSym = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_Mips_ABS_LO, Ctx);
129 Addiu.addOperand(MCOperand::CreateExpr(MCSym));
130 MCInsts.push_back(Addiu);
132 // addu $gp. $gp, $reg
133 Addu.setOpcode(Mips::ADDu);
134 Addu.addOperand(MCOperand::CreateReg(Mips::GP));
135 Addu.addOperand(MCOperand::CreateReg(Mips::GP));
136 const MachineOperand &MO = MI->getOperand(0);
137 assert(MO.isReg() && "CPLOAD's operand must be a register.");
138 Addu.addOperand(MCOperand::CreateReg(MO.getReg()));
139 MCInsts.push_back(Addu);
142 // Lower ".cprestore offset" to "sw $gp, offset($sp)".
143 void MipsMCInstLower::LowerCPRESTORE(const MachineInstr *MI,
144 SmallVector<MCInst, 4>& MCInsts) {
145 const MachineOperand &MO = MI->getOperand(0);
146 assert(MO.isImm() && "CPRESTORE's operand must be an immediate.");
147 unsigned Offset = MO.getImm(), Reg = Mips::SP;
150 if (Offset >= 0x8000) {
151 unsigned Hi = (Offset >> 16) + ((Offset & 0x8000) != 0);
158 MCInsts[0].setOpcode(Mips::LUi);
159 MCInsts[0].addOperand(MCOperand::CreateReg(Mips::AT));
160 MCInsts[0].addOperand(MCOperand::CreateImm(Hi));
161 MCInsts[1].setOpcode(Mips::ADDu);
162 MCInsts[1].addOperand(MCOperand::CreateReg(Mips::AT));
163 MCInsts[1].addOperand(MCOperand::CreateReg(Mips::AT));
164 MCInsts[1].addOperand(MCOperand::CreateReg(Mips::SP));
167 Sw.setOpcode(Mips::SW);
168 Sw.addOperand(MCOperand::CreateReg(Mips::GP));
169 Sw.addOperand(MCOperand::CreateReg(Reg));
170 Sw.addOperand(MCOperand::CreateImm(Offset));
171 MCInsts.push_back(Sw);
174 MCOperand MipsMCInstLower::LowerOperand(const MachineOperand& MO,
175 unsigned offset) const {
176 MachineOperandType MOTy = MO.getType();
180 assert(0 && "unknown operand type");
182 case MachineOperand::MO_Register:
183 // Ignore all implicit register operands.
184 if (MO.isImplicit()) break;
185 return MCOperand::CreateReg(MO.getReg());
186 case MachineOperand::MO_Immediate:
187 return MCOperand::CreateImm(MO.getImm() + offset);
188 case MachineOperand::MO_MachineBasicBlock:
189 case MachineOperand::MO_GlobalAddress:
190 case MachineOperand::MO_ExternalSymbol:
191 case MachineOperand::MO_JumpTableIndex:
192 case MachineOperand::MO_ConstantPoolIndex:
193 case MachineOperand::MO_BlockAddress:
194 return LowerSymbolOperand(MO, MOTy, offset);
200 void MipsMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
201 OutMI.setOpcode(MI->getOpcode());
203 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
204 const MachineOperand &MO = MI->getOperand(i);
205 MCOperand MCOp = LowerOperand(MO);
208 OutMI.addOperand(MCOp);
212 void MipsMCInstLower::LowerUnalignedLoadStore(const MachineInstr *MI,
215 unsigned Opc = MI->getOpcode();
216 MCInst instr1, instr2, instr3, move;
218 bool two_instructions = false;
220 assert(MI->getNumOperands() == 3);
221 assert(MI->getOperand(0).isReg());
222 assert(MI->getOperand(1).isReg());
224 MCOperand target = LowerOperand(MI->getOperand(0));
225 MCOperand base = LowerOperand(MI->getOperand(1));
226 MCOperand atReg = MCOperand::CreateReg(Mips::AT);
227 MCOperand zeroReg = MCOperand::CreateReg(Mips::ZERO);
229 MachineOperand unloweredName = MI->getOperand(2);
230 MCOperand name = LowerOperand(unloweredName);
232 move.setOpcode(Mips::ADDu);
233 move.addOperand(target);
234 move.addOperand(atReg);
235 move.addOperand(zeroReg);
239 // FIXME: only works for little endian right now
240 MCOperand adj_name = LowerOperand(unloweredName, 3);
241 if (base.getReg() == (target.getReg())) {
242 instr1.setOpcode(Mips::LWL);
243 instr1.addOperand(atReg);
244 instr1.addOperand(base);
245 instr1.addOperand(adj_name);
246 instr2.setOpcode(Mips::LWR);
247 instr2.addOperand(atReg);
248 instr2.addOperand(base);
249 instr2.addOperand(name);
252 two_instructions = true;
253 instr1.setOpcode(Mips::LWL);
254 instr1.addOperand(target);
255 instr1.addOperand(base);
256 instr1.addOperand(adj_name);
257 instr2.setOpcode(Mips::LWR);
258 instr2.addOperand(target);
259 instr2.addOperand(base);
260 instr2.addOperand(name);
265 // FIXME: only works for little endian right now
266 MCOperand adj_name = LowerOperand(unloweredName, 1);
267 instr1.setOpcode(Mips::LBu);
268 instr1.addOperand(atReg);
269 instr1.addOperand(base);
270 instr1.addOperand(adj_name);
271 instr2.setOpcode(Mips::LBu);
272 instr2.addOperand(target);
273 instr2.addOperand(base);
274 instr2.addOperand(name);
275 instr3.setOpcode(Mips::INS);
276 instr3.addOperand(target);
277 instr3.addOperand(atReg);
278 instr3.addOperand(MCOperand::CreateImm(0x8));
279 instr3.addOperand(MCOperand::CreateImm(0x18));
284 // FIXME: only works for little endian right now
285 assert (base.getReg() != target.getReg());
286 two_instructions = true;
287 MCOperand adj_name = LowerOperand(unloweredName, 3);
288 instr1.setOpcode(Mips::SWL);
289 instr1.addOperand(target);
290 instr1.addOperand(base);
291 instr1.addOperand(adj_name);
292 instr2.setOpcode(Mips::SWR);
293 instr2.addOperand(target);
294 instr2.addOperand(base);
295 instr2.addOperand(name);
299 MCOperand adj_name = LowerOperand(unloweredName, 1);
300 instr1.setOpcode(Mips::SB);
301 instr1.addOperand(target);
302 instr1.addOperand(base);
303 instr1.addOperand(name);
304 instr2.setOpcode(Mips::SRL);
305 instr2.addOperand(atReg);
306 instr2.addOperand(target);
307 instr2.addOperand(MCOperand::CreateImm(8));
308 instr3.setOpcode(Mips::SB);
309 instr3.addOperand(atReg);
310 instr3.addOperand(base);
311 instr3.addOperand(adj_name);
315 // FIXME: need to add others
316 assert(0 && "unaligned instruction not processed");
319 MCInsts.push_back(instr1);
320 MCInsts.push_back(instr2);
321 if (!two_instructions) MCInsts.push_back(instr3);