xref: /llvm-project/llvm/lib/Target/Sparc/SparcAsmPrinter.cpp (revision 576b7a781aac6b1d60a72248894b50e565e9185a)
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/SparcMCTargetDesc.h"
17 #include "MCTargetDesc/SparcTargetStreamer.h"
18 #include "Sparc.h"
19 #include "SparcInstrInfo.h"
20 #include "SparcTargetMachine.h"
21 #include "TargetInfo/SparcTargetInfo.h"
22 #include "llvm/CodeGen/AsmPrinter.h"
23 #include "llvm/CodeGen/MachineInstr.h"
24 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
25 #include "llvm/CodeGen/MachineRegisterInfo.h"
26 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
27 #include "llvm/IR/Mangler.h"
28 #include "llvm/MC/MCAsmInfo.h"
29 #include "llvm/MC/MCContext.h"
30 #include "llvm/MC/MCInst.h"
31 #include "llvm/MC/MCStreamer.h"
32 #include "llvm/MC/MCSymbol.h"
33 #include "llvm/MC/TargetRegistry.h"
34 #include "llvm/Support/raw_ostream.h"
35 using namespace llvm;
36 
37 #define DEBUG_TYPE "asm-printer"
38 
39 namespace {
40   class SparcAsmPrinter : public AsmPrinter {
41     SparcTargetStreamer &getTargetStreamer() {
42       return static_cast<SparcTargetStreamer &>(
43           *OutStreamer->getTargetStreamer());
44     }
45   public:
46     explicit SparcAsmPrinter(TargetMachine &TM,
47                              std::unique_ptr<MCStreamer> Streamer)
48         : AsmPrinter(TM, std::move(Streamer)) {}
49 
50     StringRef getPassName() const override { return "Sparc Assembly Printer"; }
51 
52     void printOperand(const MachineInstr *MI, int opNum, raw_ostream &OS);
53     void printMemOperand(const MachineInstr *MI, int opNum, raw_ostream &OS);
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 EmitRDPC(MCStreamer &OutStreamer, MCOperand &RD,
115                      const MCSubtargetInfo &STI) {
116   MCInst RDPCInst;
117   RDPCInst.setOpcode(SP::RDASR);
118   RDPCInst.addOperand(RD);
119   RDPCInst.addOperand(MCOperand::createReg(SP::ASR5));
120   OutStreamer.emitInstruction(RDPCInst, STI);
121 }
122 
123 static void EmitSETHI(MCStreamer &OutStreamer,
124                       MCOperand &Imm, MCOperand &RD,
125                       const MCSubtargetInfo &STI)
126 {
127   MCInst SETHIInst;
128   SETHIInst.setOpcode(SP::SETHIi);
129   SETHIInst.addOperand(RD);
130   SETHIInst.addOperand(Imm);
131   OutStreamer.emitInstruction(SETHIInst, STI);
132 }
133 
134 static void EmitBinary(MCStreamer &OutStreamer, unsigned Opcode,
135                        MCOperand &RS1, MCOperand &Src2, MCOperand &RD,
136                        const MCSubtargetInfo &STI)
137 {
138   MCInst Inst;
139   Inst.setOpcode(Opcode);
140   Inst.addOperand(RD);
141   Inst.addOperand(RS1);
142   Inst.addOperand(Src2);
143   OutStreamer.emitInstruction(Inst, STI);
144 }
145 
146 static void EmitOR(MCStreamer &OutStreamer,
147                    MCOperand &RS1, MCOperand &Imm, MCOperand &RD,
148                    const MCSubtargetInfo &STI) {
149   EmitBinary(OutStreamer, SP::ORri, RS1, Imm, RD, STI);
150 }
151 
152 static void EmitADD(MCStreamer &OutStreamer,
153                     MCOperand &RS1, MCOperand &RS2, MCOperand &RD,
154                     const MCSubtargetInfo &STI) {
155   EmitBinary(OutStreamer, SP::ADDrr, RS1, RS2, RD, STI);
156 }
157 
158 static void EmitSHL(MCStreamer &OutStreamer,
159                     MCOperand &RS1, MCOperand &Imm, MCOperand &RD,
160                     const MCSubtargetInfo &STI) {
161   EmitBinary(OutStreamer, SP::SLLri, RS1, Imm, RD, STI);
162 }
163 
164 
165 static void EmitHiLo(MCStreamer &OutStreamer,  MCSymbol *GOTSym,
166                      SparcMCExpr::VariantKind HiKind,
167                      SparcMCExpr::VariantKind LoKind,
168                      MCOperand &RD,
169                      MCContext &OutContext,
170                      const MCSubtargetInfo &STI) {
171 
172   MCOperand hi = createSparcMCOperand(HiKind, GOTSym, OutContext);
173   MCOperand lo = createSparcMCOperand(LoKind, GOTSym, OutContext);
174   EmitSETHI(OutStreamer, hi, RD, STI);
175   EmitOR(OutStreamer, RD, lo, RD, STI);
176 }
177 
178 void SparcAsmPrinter::LowerGETPCXAndEmitMCInsts(const MachineInstr *MI,
179                                                 const MCSubtargetInfo &STI)
180 {
181   MCSymbol *GOTLabel   =
182     OutContext.getOrCreateSymbol(Twine("_GLOBAL_OFFSET_TABLE_"));
183 
184   const MachineOperand &MO = MI->getOperand(0);
185   assert(MO.getReg() != SP::O7 &&
186          "%o7 is assigned as destination for getpcx!");
187 
188   MCOperand MCRegOP = MCOperand::createReg(MO.getReg());
189 
190 
191   if (!isPositionIndependent()) {
192     // Just load the address of GOT to MCRegOP.
193     switch(TM.getCodeModel()) {
194     default:
195       llvm_unreachable("Unsupported absolute code model");
196     case CodeModel::Small:
197       EmitHiLo(*OutStreamer, GOTLabel,
198                SparcMCExpr::VK_Sparc_HI, SparcMCExpr::VK_Sparc_LO,
199                MCRegOP, OutContext, STI);
200       break;
201     case CodeModel::Medium: {
202       EmitHiLo(*OutStreamer, GOTLabel,
203                SparcMCExpr::VK_Sparc_H44, SparcMCExpr::VK_Sparc_M44,
204                MCRegOP, OutContext, STI);
205       MCOperand imm = MCOperand::createExpr(MCConstantExpr::create(12,
206                                                                    OutContext));
207       EmitSHL(*OutStreamer, MCRegOP, imm, MCRegOP, STI);
208       MCOperand lo = createSparcMCOperand(SparcMCExpr::VK_Sparc_L44,
209                                           GOTLabel, OutContext);
210       EmitOR(*OutStreamer, MCRegOP, lo, MCRegOP, STI);
211       break;
212     }
213     case CodeModel::Large: {
214       EmitHiLo(*OutStreamer, GOTLabel,
215                SparcMCExpr::VK_Sparc_HH, SparcMCExpr::VK_Sparc_HM,
216                MCRegOP, OutContext, STI);
217       MCOperand imm = MCOperand::createExpr(MCConstantExpr::create(32,
218                                                                    OutContext));
219       EmitSHL(*OutStreamer, MCRegOP, imm, MCRegOP, STI);
220       // Use register %o7 to load the lower 32 bits.
221       MCOperand RegO7 = MCOperand::createReg(SP::O7);
222       EmitHiLo(*OutStreamer, GOTLabel,
223                SparcMCExpr::VK_Sparc_HI, SparcMCExpr::VK_Sparc_LO,
224                RegO7, OutContext, STI);
225       EmitADD(*OutStreamer, MCRegOP, RegO7, MCRegOP, STI);
226     }
227     }
228     return;
229   }
230 
231   MCSymbol *StartLabel = OutContext.createTempSymbol();
232   MCSymbol *EndLabel   = OutContext.createTempSymbol();
233   MCSymbol *SethiLabel = OutContext.createTempSymbol();
234 
235   MCOperand RegO7   = MCOperand::createReg(SP::O7);
236 
237   // <StartLabel>:
238   //   <GET-PC> // This will be either `call <EndLabel>` or `rd %pc, %o7`.
239   // <SethiLabel>:
240   //     sethi %hi(_GLOBAL_OFFSET_TABLE_+(<SethiLabel>-<StartLabel>)), <MO>
241   // <EndLabel>:
242   //   or  <MO>, %lo(_GLOBAL_OFFSET_TABLE_+(<EndLabel>-<StartLabel>))), <MO>
243   //   add <MO>, %o7, <MO>
244 
245   OutStreamer->emitLabel(StartLabel);
246   if (!STI.getTargetTriple().isSPARC64() ||
247       STI.hasFeature(Sparc::TuneSlowRDPC)) {
248     MCOperand Callee = createPCXCallOP(EndLabel, OutContext);
249     EmitCall(*OutStreamer, Callee, STI);
250   } else {
251     // TODO find out whether it is possible to store PC
252     // in other registers, to enable leaf function optimization.
253     // (On the other hand, approx. over 97.8% of GETPCXes happen
254     // in non-leaf functions, so would this be worth the effort?)
255     EmitRDPC(*OutStreamer, RegO7, STI);
256   }
257   OutStreamer->emitLabel(SethiLabel);
258   MCOperand hiImm = createPCXRelExprOp(SparcMCExpr::VK_Sparc_PC22,
259                                        GOTLabel, StartLabel, SethiLabel,
260                                        OutContext);
261   EmitSETHI(*OutStreamer, hiImm, MCRegOP, STI);
262   OutStreamer->emitLabel(EndLabel);
263   MCOperand loImm = createPCXRelExprOp(SparcMCExpr::VK_Sparc_PC10,
264                                        GOTLabel, StartLabel, EndLabel,
265                                        OutContext);
266   EmitOR(*OutStreamer, MCRegOP, loImm, MCRegOP, STI);
267   EmitADD(*OutStreamer, MCRegOP, RegO7, MCRegOP, STI);
268 }
269 
270 void SparcAsmPrinter::emitInstruction(const MachineInstr *MI) {
271   Sparc_MC::verifyInstructionPredicates(MI->getOpcode(),
272                                         getSubtargetInfo().getFeatureBits());
273 
274   switch (MI->getOpcode()) {
275   default: break;
276   case TargetOpcode::DBG_VALUE:
277     // FIXME: Debug Value.
278     return;
279   case SP::CASArr:
280   case SP::SWAPrr:
281   case SP::SWAPri:
282     if (MF->getSubtarget<SparcSubtarget>().fixTN0011())
283       OutStreamer->emitCodeAlignment(Align(16), &getSubtargetInfo());
284     break;
285   case SP::GETPCX:
286     LowerGETPCXAndEmitMCInsts(MI, getSubtargetInfo());
287     return;
288   }
289   MachineBasicBlock::const_instr_iterator I = MI->getIterator();
290   MachineBasicBlock::const_instr_iterator E = MI->getParent()->instr_end();
291   do {
292     MCInst TmpInst;
293     LowerSparcMachineInstrToMCInst(&*I, TmpInst, *this);
294     EmitToStreamer(*OutStreamer, TmpInst);
295   } while ((++I != E) && I->isInsideBundle()); // Delay slot check.
296 }
297 
298 void SparcAsmPrinter::emitFunctionBodyStart() {
299   if (!MF->getSubtarget<SparcSubtarget>().is64Bit())
300     return;
301 
302   const MachineRegisterInfo &MRI = MF->getRegInfo();
303   const unsigned globalRegs[] = { SP::G2, SP::G3, SP::G6, SP::G7, 0 };
304   for (unsigned i = 0; globalRegs[i] != 0; ++i) {
305     unsigned reg = globalRegs[i];
306     if (MRI.use_empty(reg))
307       continue;
308 
309     if  (reg == SP::G6 || reg == SP::G7)
310       getTargetStreamer().emitSparcRegisterIgnore(reg);
311     else
312       getTargetStreamer().emitSparcRegisterScratch(reg);
313   }
314 }
315 
316 void SparcAsmPrinter::printOperand(const MachineInstr *MI, int opNum,
317                                    raw_ostream &O) {
318   const DataLayout &DL = getDataLayout();
319   const MachineOperand &MO = MI->getOperand (opNum);
320   SparcMCExpr::VariantKind TF = (SparcMCExpr::VariantKind) MO.getTargetFlags();
321 
322   bool CloseParen = SparcMCExpr::printVariantKind(O, TF);
323 
324   switch (MO.getType()) {
325   case MachineOperand::MO_Register:
326     O << "%" << StringRef(getRegisterName(MO.getReg())).lower();
327     break;
328 
329   case MachineOperand::MO_Immediate:
330     O << MO.getImm();
331     break;
332   case MachineOperand::MO_MachineBasicBlock:
333     MO.getMBB()->getSymbol()->print(O, MAI);
334     return;
335   case MachineOperand::MO_GlobalAddress:
336     PrintSymbolOperand(MO, O);
337     break;
338   case MachineOperand::MO_BlockAddress:
339     O <<  GetBlockAddressSymbol(MO.getBlockAddress())->getName();
340     break;
341   case MachineOperand::MO_ExternalSymbol:
342     O << MO.getSymbolName();
343     break;
344   case MachineOperand::MO_ConstantPoolIndex:
345     O << DL.getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_"
346       << MO.getIndex();
347     break;
348   case MachineOperand::MO_Metadata:
349     MO.getMetadata()->printAsOperand(O, MMI->getModule());
350     break;
351   default:
352     llvm_unreachable("<unknown operand type>");
353   }
354   if (CloseParen) O << ")";
355 }
356 
357 void SparcAsmPrinter::printMemOperand(const MachineInstr *MI, int opNum,
358                                       raw_ostream &O) {
359   printOperand(MI, opNum, O);
360 
361   if (MI->getOperand(opNum+1).isReg() &&
362       MI->getOperand(opNum+1).getReg() == SP::G0)
363     return;   // don't print "+%g0"
364   if (MI->getOperand(opNum+1).isImm() &&
365       MI->getOperand(opNum+1).getImm() == 0)
366     return;   // don't print "+0"
367 
368   O << "+";
369   printOperand(MI, opNum+1, O);
370 }
371 
372 /// PrintAsmOperand - Print out an operand for an inline asm expression.
373 ///
374 bool SparcAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
375                                       const char *ExtraCode,
376                                       raw_ostream &O) {
377   if (ExtraCode && ExtraCode[0]) {
378     if (ExtraCode[1] != 0) return true; // Unknown modifier.
379 
380     switch (ExtraCode[0]) {
381     default:
382       // See if this is a generic print operand
383       return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O);
384     case 'L': // Low order register of a twin word register operand
385     case 'H': // High order register of a twin word register operand
386     {
387       const SparcSubtarget &Subtarget = MF->getSubtarget<SparcSubtarget>();
388       const MachineOperand &MO = MI->getOperand(OpNo);
389       const SparcRegisterInfo *RegisterInfo = Subtarget.getRegisterInfo();
390       Register MOReg = MO.getReg();
391 
392       Register HiReg, LoReg;
393       if (!SP::IntPairRegClass.contains(MOReg)) {
394         // If we aren't given a register pair already, find out which pair it
395         // belongs to. Note that here, the specified register operand, which
396         // refers to the high part of the twinword, needs to be an even-numbered
397         // register.
398         MOReg = RegisterInfo->getMatchingSuperReg(MOReg, SP::sub_even,
399                                                   &SP::IntPairRegClass);
400         if (!MOReg) {
401           SMLoc Loc;
402           OutContext.reportError(
403               Loc, "Hi part of pair should point to an even-numbered register");
404           OutContext.reportError(
405               Loc, "(note that in some cases it might be necessary to manually "
406                    "bind the input/output registers instead of relying on "
407                    "automatic allocation)");
408           return true;
409         }
410       }
411 
412       HiReg = RegisterInfo->getSubReg(MOReg, SP::sub_even);
413       LoReg = RegisterInfo->getSubReg(MOReg, SP::sub_odd);
414 
415       Register Reg;
416       switch (ExtraCode[0]) {
417       case 'L':
418         Reg = LoReg;
419         break;
420       case 'H':
421         Reg = HiReg;
422         break;
423       }
424 
425       O << '%' << SparcInstPrinter::getRegisterName(Reg);
426       return false;
427     }
428     case 'f':
429     case 'r':
430      break;
431     }
432   }
433 
434   printOperand(MI, OpNo, O);
435 
436   return false;
437 }
438 
439 bool SparcAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
440                                             unsigned OpNo,
441                                             const char *ExtraCode,
442                                             raw_ostream &O) {
443   if (ExtraCode && ExtraCode[0])
444     return true;  // Unknown modifier
445 
446   O << '[';
447   printMemOperand(MI, OpNo, O);
448   O << ']';
449 
450   return false;
451 }
452 
453 // Force static initialization.
454 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeSparcAsmPrinter() {
455   RegisterAsmPrinter<SparcAsmPrinter> X(getTheSparcTarget());
456   RegisterAsmPrinter<SparcAsmPrinter> Y(getTheSparcV9Target());
457   RegisterAsmPrinter<SparcAsmPrinter> Z(getTheSparcelTarget());
458 }
459