1 //===-- SparcAsmPrinter.cpp - Sparc LLVM assembly writer ------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains a printer that converts from our internal representation
10 // of machine-dependent LLVM code to GAS-format SPARC assembly language.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "MCTargetDesc/SparcInstPrinter.h"
15 #include "MCTargetDesc/SparcMCExpr.h"
16 #include "MCTargetDesc/SparcTargetStreamer.h"
17 #include "Sparc.h"
18 #include "SparcInstrInfo.h"
19 #include "SparcTargetMachine.h"
20 #include "TargetInfo/SparcTargetInfo.h"
21 #include "llvm/CodeGen/AsmPrinter.h"
22 #include "llvm/CodeGen/MachineInstr.h"
23 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
24 #include "llvm/CodeGen/MachineRegisterInfo.h"
25 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
26 #include "llvm/IR/Mangler.h"
27 #include "llvm/MC/MCAsmInfo.h"
28 #include "llvm/MC/MCContext.h"
29 #include "llvm/MC/MCInst.h"
30 #include "llvm/MC/MCStreamer.h"
31 #include "llvm/MC/MCSymbol.h"
32 #include "llvm/MC/TargetRegistry.h"
33 #include "llvm/Support/raw_ostream.h"
34 using namespace llvm;
35 
36 #define DEBUG_TYPE "asm-printer"
37 
38 namespace {
39   class SparcAsmPrinter : public AsmPrinter {
40     SparcTargetStreamer &getTargetStreamer() {
41       return static_cast<SparcTargetStreamer &>(
42           *OutStreamer->getTargetStreamer());
43     }
44   public:
45     explicit SparcAsmPrinter(TargetMachine &TM,
46                              std::unique_ptr<MCStreamer> Streamer)
47         : AsmPrinter(TM, std::move(Streamer)) {}
48 
49     StringRef getPassName() const override { return "Sparc Assembly Printer"; }
50 
51     void printOperand(const MachineInstr *MI, int opNum, raw_ostream &OS);
52     void printMemOperand(const MachineInstr *MI, int opNum, raw_ostream &OS,
53                          const char *Modifier = nullptr);
54 
55     void emitFunctionBodyStart() override;
56     void emitInstruction(const MachineInstr *MI) override;
57 
58     static const char *getRegisterName(MCRegister Reg) {
59       return SparcInstPrinter::getRegisterName(Reg);
60     }
61 
62     bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
63                          const char *ExtraCode, raw_ostream &O) override;
64     bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
65                                const char *ExtraCode, raw_ostream &O) override;
66 
67     void LowerGETPCXAndEmitMCInsts(const MachineInstr *MI,
68                                    const MCSubtargetInfo &STI);
69 
70   };
71 } // end of anonymous namespace
72 
73 static MCOperand createSparcMCOperand(SparcMCExpr::VariantKind Kind,
74                                       MCSymbol *Sym, MCContext &OutContext) {
75   const MCSymbolRefExpr *MCSym = MCSymbolRefExpr::create(Sym,
76                                                          OutContext);
77   const SparcMCExpr *expr = SparcMCExpr::create(Kind, MCSym, OutContext);
78   return MCOperand::createExpr(expr);
79 
80 }
81 static MCOperand createPCXCallOP(MCSymbol *Label,
82                                  MCContext &OutContext) {
83   return createSparcMCOperand(SparcMCExpr::VK_Sparc_WDISP30, Label, OutContext);
84 }
85 
86 static MCOperand createPCXRelExprOp(SparcMCExpr::VariantKind Kind,
87                                     MCSymbol *GOTLabel, MCSymbol *StartLabel,
88                                     MCSymbol *CurLabel,
89                                     MCContext &OutContext)
90 {
91   const MCSymbolRefExpr *GOT = MCSymbolRefExpr::create(GOTLabel, OutContext);
92   const MCSymbolRefExpr *Start = MCSymbolRefExpr::create(StartLabel,
93                                                          OutContext);
94   const MCSymbolRefExpr *Cur = MCSymbolRefExpr::create(CurLabel,
95                                                        OutContext);
96 
97   const MCBinaryExpr *Sub = MCBinaryExpr::createSub(Cur, Start, OutContext);
98   const MCBinaryExpr *Add = MCBinaryExpr::createAdd(GOT, Sub, OutContext);
99   const SparcMCExpr *expr = SparcMCExpr::create(Kind,
100                                                 Add, OutContext);
101   return MCOperand::createExpr(expr);
102 }
103 
104 static void EmitCall(MCStreamer &OutStreamer,
105                      MCOperand &Callee,
106                      const MCSubtargetInfo &STI)
107 {
108   MCInst CallInst;
109   CallInst.setOpcode(SP::CALL);
110   CallInst.addOperand(Callee);
111   OutStreamer.emitInstruction(CallInst, STI);
112 }
113 
114 static void EmitSETHI(MCStreamer &OutStreamer,
115                       MCOperand &Imm, MCOperand &RD,
116                       const MCSubtargetInfo &STI)
117 {
118   MCInst SETHIInst;
119   SETHIInst.setOpcode(SP::SETHIi);
120   SETHIInst.addOperand(RD);
121   SETHIInst.addOperand(Imm);
122   OutStreamer.emitInstruction(SETHIInst, STI);
123 }
124 
125 static void EmitBinary(MCStreamer &OutStreamer, unsigned Opcode,
126                        MCOperand &RS1, MCOperand &Src2, MCOperand &RD,
127                        const MCSubtargetInfo &STI)
128 {
129   MCInst Inst;
130   Inst.setOpcode(Opcode);
131   Inst.addOperand(RD);
132   Inst.addOperand(RS1);
133   Inst.addOperand(Src2);
134   OutStreamer.emitInstruction(Inst, STI);
135 }
136 
137 static void EmitOR(MCStreamer &OutStreamer,
138                    MCOperand &RS1, MCOperand &Imm, MCOperand &RD,
139                    const MCSubtargetInfo &STI) {
140   EmitBinary(OutStreamer, SP::ORri, RS1, Imm, RD, STI);
141 }
142 
143 static void EmitADD(MCStreamer &OutStreamer,
144                     MCOperand &RS1, MCOperand &RS2, MCOperand &RD,
145                     const MCSubtargetInfo &STI) {
146   EmitBinary(OutStreamer, SP::ADDrr, RS1, RS2, RD, STI);
147 }
148 
149 static void EmitSHL(MCStreamer &OutStreamer,
150                     MCOperand &RS1, MCOperand &Imm, MCOperand &RD,
151                     const MCSubtargetInfo &STI) {
152   EmitBinary(OutStreamer, SP::SLLri, RS1, Imm, RD, STI);
153 }
154 
155 
156 static void EmitHiLo(MCStreamer &OutStreamer,  MCSymbol *GOTSym,
157                      SparcMCExpr::VariantKind HiKind,
158                      SparcMCExpr::VariantKind LoKind,
159                      MCOperand &RD,
160                      MCContext &OutContext,
161                      const MCSubtargetInfo &STI) {
162 
163   MCOperand hi = createSparcMCOperand(HiKind, GOTSym, OutContext);
164   MCOperand lo = createSparcMCOperand(LoKind, GOTSym, OutContext);
165   EmitSETHI(OutStreamer, hi, RD, STI);
166   EmitOR(OutStreamer, RD, lo, RD, STI);
167 }
168 
169 void SparcAsmPrinter::LowerGETPCXAndEmitMCInsts(const MachineInstr *MI,
170                                                 const MCSubtargetInfo &STI)
171 {
172   MCSymbol *GOTLabel   =
173     OutContext.getOrCreateSymbol(Twine("_GLOBAL_OFFSET_TABLE_"));
174 
175   const MachineOperand &MO = MI->getOperand(0);
176   assert(MO.getReg() != SP::O7 &&
177          "%o7 is assigned as destination for getpcx!");
178 
179   MCOperand MCRegOP = MCOperand::createReg(MO.getReg());
180 
181 
182   if (!isPositionIndependent()) {
183     // Just load the address of GOT to MCRegOP.
184     switch(TM.getCodeModel()) {
185     default:
186       llvm_unreachable("Unsupported absolute code model");
187     case CodeModel::Small:
188       EmitHiLo(*OutStreamer, GOTLabel,
189                SparcMCExpr::VK_Sparc_HI, SparcMCExpr::VK_Sparc_LO,
190                MCRegOP, OutContext, STI);
191       break;
192     case CodeModel::Medium: {
193       EmitHiLo(*OutStreamer, GOTLabel,
194                SparcMCExpr::VK_Sparc_H44, SparcMCExpr::VK_Sparc_M44,
195                MCRegOP, OutContext, STI);
196       MCOperand imm = MCOperand::createExpr(MCConstantExpr::create(12,
197                                                                    OutContext));
198       EmitSHL(*OutStreamer, MCRegOP, imm, MCRegOP, STI);
199       MCOperand lo = createSparcMCOperand(SparcMCExpr::VK_Sparc_L44,
200                                           GOTLabel, OutContext);
201       EmitOR(*OutStreamer, MCRegOP, lo, MCRegOP, STI);
202       break;
203     }
204     case CodeModel::Large: {
205       EmitHiLo(*OutStreamer, GOTLabel,
206                SparcMCExpr::VK_Sparc_HH, SparcMCExpr::VK_Sparc_HM,
207                MCRegOP, OutContext, STI);
208       MCOperand imm = MCOperand::createExpr(MCConstantExpr::create(32,
209                                                                    OutContext));
210       EmitSHL(*OutStreamer, MCRegOP, imm, MCRegOP, STI);
211       // Use register %o7 to load the lower 32 bits.
212       MCOperand RegO7 = MCOperand::createReg(SP::O7);
213       EmitHiLo(*OutStreamer, GOTLabel,
214                SparcMCExpr::VK_Sparc_HI, SparcMCExpr::VK_Sparc_LO,
215                RegO7, OutContext, STI);
216       EmitADD(*OutStreamer, MCRegOP, RegO7, MCRegOP, STI);
217     }
218     }
219     return;
220   }
221 
222   MCSymbol *StartLabel = OutContext.createTempSymbol();
223   MCSymbol *EndLabel   = OutContext.createTempSymbol();
224   MCSymbol *SethiLabel = OutContext.createTempSymbol();
225 
226   MCOperand RegO7   = MCOperand::createReg(SP::O7);
227 
228   // <StartLabel>:
229   //   call <EndLabel>
230   // <SethiLabel>:
231   //     sethi %hi(_GLOBAL_OFFSET_TABLE_+(<SethiLabel>-<StartLabel>)), <MO>
232   // <EndLabel>:
233   //   or  <MO>, %lo(_GLOBAL_OFFSET_TABLE_+(<EndLabel>-<StartLabel>))), <MO>
234   //   add <MO>, %o7, <MO>
235 
236   OutStreamer->emitLabel(StartLabel);
237   MCOperand Callee =  createPCXCallOP(EndLabel, OutContext);
238   EmitCall(*OutStreamer, Callee, STI);
239   OutStreamer->emitLabel(SethiLabel);
240   MCOperand hiImm = createPCXRelExprOp(SparcMCExpr::VK_Sparc_PC22,
241                                        GOTLabel, StartLabel, SethiLabel,
242                                        OutContext);
243   EmitSETHI(*OutStreamer, hiImm, MCRegOP, STI);
244   OutStreamer->emitLabel(EndLabel);
245   MCOperand loImm = createPCXRelExprOp(SparcMCExpr::VK_Sparc_PC10,
246                                        GOTLabel, StartLabel, EndLabel,
247                                        OutContext);
248   EmitOR(*OutStreamer, MCRegOP, loImm, MCRegOP, STI);
249   EmitADD(*OutStreamer, MCRegOP, RegO7, MCRegOP, STI);
250 }
251 
252 void SparcAsmPrinter::emitInstruction(const MachineInstr *MI) {
253   Sparc_MC::verifyInstructionPredicates(MI->getOpcode(),
254                                         getSubtargetInfo().getFeatureBits());
255 
256   switch (MI->getOpcode()) {
257   default: break;
258   case TargetOpcode::DBG_VALUE:
259     // FIXME: Debug Value.
260     return;
261   case SP::GETPCX:
262     LowerGETPCXAndEmitMCInsts(MI, getSubtargetInfo());
263     return;
264   }
265   MachineBasicBlock::const_instr_iterator I = MI->getIterator();
266   MachineBasicBlock::const_instr_iterator E = MI->getParent()->instr_end();
267   do {
268     MCInst TmpInst;
269     LowerSparcMachineInstrToMCInst(&*I, TmpInst, *this);
270     EmitToStreamer(*OutStreamer, TmpInst);
271   } while ((++I != E) && I->isInsideBundle()); // Delay slot check.
272 }
273 
274 void SparcAsmPrinter::emitFunctionBodyStart() {
275   if (!MF->getSubtarget<SparcSubtarget>().is64Bit())
276     return;
277 
278   const MachineRegisterInfo &MRI = MF->getRegInfo();
279   const unsigned globalRegs[] = { SP::G2, SP::G3, SP::G6, SP::G7, 0 };
280   for (unsigned i = 0; globalRegs[i] != 0; ++i) {
281     unsigned reg = globalRegs[i];
282     if (MRI.use_empty(reg))
283       continue;
284 
285     if  (reg == SP::G6 || reg == SP::G7)
286       getTargetStreamer().emitSparcRegisterIgnore(reg);
287     else
288       getTargetStreamer().emitSparcRegisterScratch(reg);
289   }
290 }
291 
292 void SparcAsmPrinter::printOperand(const MachineInstr *MI, int opNum,
293                                    raw_ostream &O) {
294   const DataLayout &DL = getDataLayout();
295   const MachineOperand &MO = MI->getOperand (opNum);
296   SparcMCExpr::VariantKind TF = (SparcMCExpr::VariantKind) MO.getTargetFlags();
297 
298 #ifndef NDEBUG
299   // Verify the target flags.
300   if (MO.isGlobal() || MO.isSymbol() || MO.isCPI()) {
301     if (MI->getOpcode() == SP::CALL)
302       assert(TF == SparcMCExpr::VK_Sparc_None &&
303              "Cannot handle target flags on call address");
304     else if (MI->getOpcode() == SP::SETHIi || MI->getOpcode() == SP::SETHIXi)
305       assert((TF == SparcMCExpr::VK_Sparc_HI
306               || TF == SparcMCExpr::VK_Sparc_H44
307               || TF == SparcMCExpr::VK_Sparc_HH
308               || TF == SparcMCExpr::VK_Sparc_LM
309               || TF == SparcMCExpr::VK_Sparc_TLS_GD_HI22
310               || TF == SparcMCExpr::VK_Sparc_TLS_LDM_HI22
311               || TF == SparcMCExpr::VK_Sparc_TLS_LDO_HIX22
312               || TF == SparcMCExpr::VK_Sparc_TLS_IE_HI22
313               || TF == SparcMCExpr::VK_Sparc_TLS_LE_HIX22) &&
314              "Invalid target flags for address operand on sethi");
315     else if (MI->getOpcode() == SP::TLS_CALL)
316       assert((TF == SparcMCExpr::VK_Sparc_None
317               || TF == SparcMCExpr::VK_Sparc_TLS_GD_CALL
318               || TF == SparcMCExpr::VK_Sparc_TLS_LDM_CALL) &&
319              "Cannot handle target flags on tls call address");
320     else if (MI->getOpcode() == SP::TLS_ADDrr)
321       assert((TF == SparcMCExpr::VK_Sparc_TLS_GD_ADD
322               || TF == SparcMCExpr::VK_Sparc_TLS_LDM_ADD
323               || TF == SparcMCExpr::VK_Sparc_TLS_LDO_ADD
324               || TF == SparcMCExpr::VK_Sparc_TLS_IE_ADD) &&
325              "Cannot handle target flags on add for TLS");
326     else if (MI->getOpcode() == SP::TLS_LDrr)
327       assert(TF == SparcMCExpr::VK_Sparc_TLS_IE_LD &&
328              "Cannot handle target flags on ld for TLS");
329     else if (MI->getOpcode() == SP::TLS_LDXrr)
330       assert(TF == SparcMCExpr::VK_Sparc_TLS_IE_LDX &&
331              "Cannot handle target flags on ldx for TLS");
332     else if (MI->getOpcode() == SP::XORri || MI->getOpcode() == SP::XORXri)
333       assert((TF == SparcMCExpr::VK_Sparc_TLS_LDO_LOX10
334               || TF == SparcMCExpr::VK_Sparc_TLS_LE_LOX10) &&
335              "Cannot handle target flags on xor for TLS");
336     else
337       assert((TF == SparcMCExpr::VK_Sparc_LO
338               || TF == SparcMCExpr::VK_Sparc_M44
339               || TF == SparcMCExpr::VK_Sparc_L44
340               || TF == SparcMCExpr::VK_Sparc_HM
341               || TF == SparcMCExpr::VK_Sparc_TLS_GD_LO10
342               || TF == SparcMCExpr::VK_Sparc_TLS_LDM_LO10
343               || TF == SparcMCExpr::VK_Sparc_TLS_IE_LO10 ) &&
344              "Invalid target flags for small address operand");
345   }
346 #endif
347 
348 
349   bool CloseParen = SparcMCExpr::printVariantKind(O, TF);
350 
351   switch (MO.getType()) {
352   case MachineOperand::MO_Register:
353     O << "%" << StringRef(getRegisterName(MO.getReg())).lower();
354     break;
355 
356   case MachineOperand::MO_Immediate:
357     O << MO.getImm();
358     break;
359   case MachineOperand::MO_MachineBasicBlock:
360     MO.getMBB()->getSymbol()->print(O, MAI);
361     return;
362   case MachineOperand::MO_GlobalAddress:
363     PrintSymbolOperand(MO, O);
364     break;
365   case MachineOperand::MO_BlockAddress:
366     O <<  GetBlockAddressSymbol(MO.getBlockAddress())->getName();
367     break;
368   case MachineOperand::MO_ExternalSymbol:
369     O << MO.getSymbolName();
370     break;
371   case MachineOperand::MO_ConstantPoolIndex:
372     O << DL.getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_"
373       << MO.getIndex();
374     break;
375   case MachineOperand::MO_Metadata:
376     MO.getMetadata()->printAsOperand(O, MMI->getModule());
377     break;
378   default:
379     llvm_unreachable("<unknown operand type>");
380   }
381   if (CloseParen) O << ")";
382 }
383 
384 void SparcAsmPrinter::printMemOperand(const MachineInstr *MI, int opNum,
385                                       raw_ostream &O, const char *Modifier) {
386   printOperand(MI, opNum, O);
387 
388   // If this is an ADD operand, emit it like normal operands.
389   if (Modifier && !strcmp(Modifier, "arith")) {
390     O << ", ";
391     printOperand(MI, opNum+1, O);
392     return;
393   }
394 
395   if (MI->getOperand(opNum+1).isReg() &&
396       MI->getOperand(opNum+1).getReg() == SP::G0)
397     return;   // don't print "+%g0"
398   if (MI->getOperand(opNum+1).isImm() &&
399       MI->getOperand(opNum+1).getImm() == 0)
400     return;   // don't print "+0"
401 
402   O << "+";
403   printOperand(MI, opNum+1, O);
404 }
405 
406 /// PrintAsmOperand - Print out an operand for an inline asm expression.
407 ///
408 bool SparcAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
409                                       const char *ExtraCode,
410                                       raw_ostream &O) {
411   if (ExtraCode && ExtraCode[0]) {
412     if (ExtraCode[1] != 0) return true; // Unknown modifier.
413 
414     switch (ExtraCode[0]) {
415     default:
416       // See if this is a generic print operand
417       return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O);
418     case 'f':
419     case 'r':
420      break;
421     }
422   }
423 
424   printOperand(MI, OpNo, O);
425 
426   return false;
427 }
428 
429 bool SparcAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
430                                             unsigned OpNo,
431                                             const char *ExtraCode,
432                                             raw_ostream &O) {
433   if (ExtraCode && ExtraCode[0])
434     return true;  // Unknown modifier
435 
436   O << '[';
437   printMemOperand(MI, OpNo, O);
438   O << ']';
439 
440   return false;
441 }
442 
443 // Force static initialization.
444 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeSparcAsmPrinter() {
445   RegisterAsmPrinter<SparcAsmPrinter> X(getTheSparcTarget());
446   RegisterAsmPrinter<SparcAsmPrinter> Y(getTheSparcV9Target());
447   RegisterAsmPrinter<SparcAsmPrinter> Z(getTheSparcelTarget());
448 }
449