xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Sparc/SparcAsmPrinter.cpp (revision 7b8dd078ea3c6b836f514f47587672fd062279c8)
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                          const char *Modifier = nullptr);
55 
56     void emitFunctionBodyStart() override;
57     void emitInstruction(const MachineInstr *MI) override;
58 
59     static const char *getRegisterName(MCRegister Reg) {
60       return SparcInstPrinter::getRegisterName(Reg);
61     }
62 
63     bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
64                          const char *ExtraCode, raw_ostream &O) override;
65     bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
66                                const char *ExtraCode, raw_ostream &O) override;
67 
68     void LowerGETPCXAndEmitMCInsts(const MachineInstr *MI,
69                                    const MCSubtargetInfo &STI);
70 
71   };
72 } // end of anonymous namespace
73 
74 static MCOperand createSparcMCOperand(SparcMCExpr::VariantKind Kind,
75                                       MCSymbol *Sym, MCContext &OutContext) {
76   const MCSymbolRefExpr *MCSym = MCSymbolRefExpr::create(Sym,
77                                                          OutContext);
78   const SparcMCExpr *expr = SparcMCExpr::create(Kind, MCSym, OutContext);
79   return MCOperand::createExpr(expr);
80 
81 }
82 static MCOperand createPCXCallOP(MCSymbol *Label,
83                                  MCContext &OutContext) {
84   return createSparcMCOperand(SparcMCExpr::VK_Sparc_WDISP30, Label, OutContext);
85 }
86 
87 static MCOperand createPCXRelExprOp(SparcMCExpr::VariantKind Kind,
88                                     MCSymbol *GOTLabel, MCSymbol *StartLabel,
89                                     MCSymbol *CurLabel,
90                                     MCContext &OutContext)
91 {
92   const MCSymbolRefExpr *GOT = MCSymbolRefExpr::create(GOTLabel, OutContext);
93   const MCSymbolRefExpr *Start = MCSymbolRefExpr::create(StartLabel,
94                                                          OutContext);
95   const MCSymbolRefExpr *Cur = MCSymbolRefExpr::create(CurLabel,
96                                                        OutContext);
97 
98   const MCBinaryExpr *Sub = MCBinaryExpr::createSub(Cur, Start, OutContext);
99   const MCBinaryExpr *Add = MCBinaryExpr::createAdd(GOT, Sub, OutContext);
100   const SparcMCExpr *expr = SparcMCExpr::create(Kind,
101                                                 Add, OutContext);
102   return MCOperand::createExpr(expr);
103 }
104 
105 static void EmitCall(MCStreamer &OutStreamer,
106                      MCOperand &Callee,
107                      const MCSubtargetInfo &STI)
108 {
109   MCInst CallInst;
110   CallInst.setOpcode(SP::CALL);
111   CallInst.addOperand(Callee);
112   OutStreamer.emitInstruction(CallInst, STI);
113 }
114 
115 static void EmitRDPC(MCStreamer &OutStreamer, MCOperand &RD,
116                      const MCSubtargetInfo &STI) {
117   MCInst RDPCInst;
118   RDPCInst.setOpcode(SP::RDASR);
119   RDPCInst.addOperand(RD);
120   RDPCInst.addOperand(MCOperand::createReg(SP::ASR5));
121   OutStreamer.emitInstruction(RDPCInst, STI);
122 }
123 
124 static void EmitSETHI(MCStreamer &OutStreamer,
125                       MCOperand &Imm, MCOperand &RD,
126                       const MCSubtargetInfo &STI)
127 {
128   MCInst SETHIInst;
129   SETHIInst.setOpcode(SP::SETHIi);
130   SETHIInst.addOperand(RD);
131   SETHIInst.addOperand(Imm);
132   OutStreamer.emitInstruction(SETHIInst, STI);
133 }
134 
135 static void EmitBinary(MCStreamer &OutStreamer, unsigned Opcode,
136                        MCOperand &RS1, MCOperand &Src2, MCOperand &RD,
137                        const MCSubtargetInfo &STI)
138 {
139   MCInst Inst;
140   Inst.setOpcode(Opcode);
141   Inst.addOperand(RD);
142   Inst.addOperand(RS1);
143   Inst.addOperand(Src2);
144   OutStreamer.emitInstruction(Inst, STI);
145 }
146 
147 static void EmitOR(MCStreamer &OutStreamer,
148                    MCOperand &RS1, MCOperand &Imm, MCOperand &RD,
149                    const MCSubtargetInfo &STI) {
150   EmitBinary(OutStreamer, SP::ORri, RS1, Imm, RD, STI);
151 }
152 
153 static void EmitADD(MCStreamer &OutStreamer,
154                     MCOperand &RS1, MCOperand &RS2, MCOperand &RD,
155                     const MCSubtargetInfo &STI) {
156   EmitBinary(OutStreamer, SP::ADDrr, RS1, RS2, RD, STI);
157 }
158 
159 static void EmitSHL(MCStreamer &OutStreamer,
160                     MCOperand &RS1, MCOperand &Imm, MCOperand &RD,
161                     const MCSubtargetInfo &STI) {
162   EmitBinary(OutStreamer, SP::SLLri, RS1, Imm, RD, STI);
163 }
164 
165 
166 static void EmitHiLo(MCStreamer &OutStreamer,  MCSymbol *GOTSym,
167                      SparcMCExpr::VariantKind HiKind,
168                      SparcMCExpr::VariantKind LoKind,
169                      MCOperand &RD,
170                      MCContext &OutContext,
171                      const MCSubtargetInfo &STI) {
172 
173   MCOperand hi = createSparcMCOperand(HiKind, GOTSym, OutContext);
174   MCOperand lo = createSparcMCOperand(LoKind, GOTSym, OutContext);
175   EmitSETHI(OutStreamer, hi, RD, STI);
176   EmitOR(OutStreamer, RD, lo, RD, STI);
177 }
178 
179 void SparcAsmPrinter::LowerGETPCXAndEmitMCInsts(const MachineInstr *MI,
180                                                 const MCSubtargetInfo &STI)
181 {
182   MCSymbol *GOTLabel   =
183     OutContext.getOrCreateSymbol(Twine("_GLOBAL_OFFSET_TABLE_"));
184 
185   const MachineOperand &MO = MI->getOperand(0);
186   assert(MO.getReg() != SP::O7 &&
187          "%o7 is assigned as destination for getpcx!");
188 
189   MCOperand MCRegOP = MCOperand::createReg(MO.getReg());
190 
191 
192   if (!isPositionIndependent()) {
193     // Just load the address of GOT to MCRegOP.
194     switch(TM.getCodeModel()) {
195     default:
196       llvm_unreachable("Unsupported absolute code model");
197     case CodeModel::Small:
198       EmitHiLo(*OutStreamer, GOTLabel,
199                SparcMCExpr::VK_Sparc_HI, SparcMCExpr::VK_Sparc_LO,
200                MCRegOP, OutContext, STI);
201       break;
202     case CodeModel::Medium: {
203       EmitHiLo(*OutStreamer, GOTLabel,
204                SparcMCExpr::VK_Sparc_H44, SparcMCExpr::VK_Sparc_M44,
205                MCRegOP, OutContext, STI);
206       MCOperand imm = MCOperand::createExpr(MCConstantExpr::create(12,
207                                                                    OutContext));
208       EmitSHL(*OutStreamer, MCRegOP, imm, MCRegOP, STI);
209       MCOperand lo = createSparcMCOperand(SparcMCExpr::VK_Sparc_L44,
210                                           GOTLabel, OutContext);
211       EmitOR(*OutStreamer, MCRegOP, lo, MCRegOP, STI);
212       break;
213     }
214     case CodeModel::Large: {
215       EmitHiLo(*OutStreamer, GOTLabel,
216                SparcMCExpr::VK_Sparc_HH, SparcMCExpr::VK_Sparc_HM,
217                MCRegOP, OutContext, STI);
218       MCOperand imm = MCOperand::createExpr(MCConstantExpr::create(32,
219                                                                    OutContext));
220       EmitSHL(*OutStreamer, MCRegOP, imm, MCRegOP, STI);
221       // Use register %o7 to load the lower 32 bits.
222       MCOperand RegO7 = MCOperand::createReg(SP::O7);
223       EmitHiLo(*OutStreamer, GOTLabel,
224                SparcMCExpr::VK_Sparc_HI, SparcMCExpr::VK_Sparc_LO,
225                RegO7, OutContext, STI);
226       EmitADD(*OutStreamer, MCRegOP, RegO7, MCRegOP, STI);
227     }
228     }
229     return;
230   }
231 
232   MCSymbol *StartLabel = OutContext.createTempSymbol();
233   MCSymbol *EndLabel   = OutContext.createTempSymbol();
234   MCSymbol *SethiLabel = OutContext.createTempSymbol();
235 
236   MCOperand RegO7   = MCOperand::createReg(SP::O7);
237 
238   // <StartLabel>:
239   //   <GET-PC> // This will be either `call <EndLabel>` or `rd %pc, %o7`.
240   // <SethiLabel>:
241   //     sethi %hi(_GLOBAL_OFFSET_TABLE_+(<SethiLabel>-<StartLabel>)), <MO>
242   // <EndLabel>:
243   //   or  <MO>, %lo(_GLOBAL_OFFSET_TABLE_+(<EndLabel>-<StartLabel>))), <MO>
244   //   add <MO>, %o7, <MO>
245 
246   OutStreamer->emitLabel(StartLabel);
247   if (!STI.getTargetTriple().isSPARC64() ||
248       STI.hasFeature(Sparc::TuneSlowRDPC)) {
249     MCOperand Callee = createPCXCallOP(EndLabel, OutContext);
250     EmitCall(*OutStreamer, Callee, STI);
251   } else {
252     // TODO find out whether it is possible to store PC
253     // in other registers, to enable leaf function optimization.
254     // (On the other hand, approx. over 97.8% of GETPCXes happen
255     // in non-leaf functions, so would this be worth the effort?)
256     EmitRDPC(*OutStreamer, RegO7, STI);
257   }
258   OutStreamer->emitLabel(SethiLabel);
259   MCOperand hiImm = createPCXRelExprOp(SparcMCExpr::VK_Sparc_PC22,
260                                        GOTLabel, StartLabel, SethiLabel,
261                                        OutContext);
262   EmitSETHI(*OutStreamer, hiImm, MCRegOP, STI);
263   OutStreamer->emitLabel(EndLabel);
264   MCOperand loImm = createPCXRelExprOp(SparcMCExpr::VK_Sparc_PC10,
265                                        GOTLabel, StartLabel, EndLabel,
266                                        OutContext);
267   EmitOR(*OutStreamer, MCRegOP, loImm, MCRegOP, STI);
268   EmitADD(*OutStreamer, MCRegOP, RegO7, MCRegOP, STI);
269 }
270 
271 void SparcAsmPrinter::emitInstruction(const MachineInstr *MI) {
272   Sparc_MC::verifyInstructionPredicates(MI->getOpcode(),
273                                         getSubtargetInfo().getFeatureBits());
274 
275   switch (MI->getOpcode()) {
276   default: break;
277   case TargetOpcode::DBG_VALUE:
278     // FIXME: Debug Value.
279     return;
280   case SP::GETPCX:
281     LowerGETPCXAndEmitMCInsts(MI, getSubtargetInfo());
282     return;
283   }
284   MachineBasicBlock::const_instr_iterator I = MI->getIterator();
285   MachineBasicBlock::const_instr_iterator E = MI->getParent()->instr_end();
286   do {
287     MCInst TmpInst;
288     LowerSparcMachineInstrToMCInst(&*I, TmpInst, *this);
289     EmitToStreamer(*OutStreamer, TmpInst);
290   } while ((++I != E) && I->isInsideBundle()); // Delay slot check.
291 }
292 
293 void SparcAsmPrinter::emitFunctionBodyStart() {
294   if (!MF->getSubtarget<SparcSubtarget>().is64Bit())
295     return;
296 
297   const MachineRegisterInfo &MRI = MF->getRegInfo();
298   const unsigned globalRegs[] = { SP::G2, SP::G3, SP::G6, SP::G7, 0 };
299   for (unsigned i = 0; globalRegs[i] != 0; ++i) {
300     unsigned reg = globalRegs[i];
301     if (MRI.use_empty(reg))
302       continue;
303 
304     if  (reg == SP::G6 || reg == SP::G7)
305       getTargetStreamer().emitSparcRegisterIgnore(reg);
306     else
307       getTargetStreamer().emitSparcRegisterScratch(reg);
308   }
309 }
310 
311 void SparcAsmPrinter::printOperand(const MachineInstr *MI, int opNum,
312                                    raw_ostream &O) {
313   const DataLayout &DL = getDataLayout();
314   const MachineOperand &MO = MI->getOperand (opNum);
315   SparcMCExpr::VariantKind TF = (SparcMCExpr::VariantKind) MO.getTargetFlags();
316 
317   bool CloseParen = SparcMCExpr::printVariantKind(O, TF);
318 
319   switch (MO.getType()) {
320   case MachineOperand::MO_Register:
321     O << "%" << StringRef(getRegisterName(MO.getReg())).lower();
322     break;
323 
324   case MachineOperand::MO_Immediate:
325     O << MO.getImm();
326     break;
327   case MachineOperand::MO_MachineBasicBlock:
328     MO.getMBB()->getSymbol()->print(O, MAI);
329     return;
330   case MachineOperand::MO_GlobalAddress:
331     PrintSymbolOperand(MO, O);
332     break;
333   case MachineOperand::MO_BlockAddress:
334     O <<  GetBlockAddressSymbol(MO.getBlockAddress())->getName();
335     break;
336   case MachineOperand::MO_ExternalSymbol:
337     O << MO.getSymbolName();
338     break;
339   case MachineOperand::MO_ConstantPoolIndex:
340     O << DL.getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_"
341       << MO.getIndex();
342     break;
343   case MachineOperand::MO_Metadata:
344     MO.getMetadata()->printAsOperand(O, MMI->getModule());
345     break;
346   default:
347     llvm_unreachable("<unknown operand type>");
348   }
349   if (CloseParen) O << ")";
350 }
351 
352 void SparcAsmPrinter::printMemOperand(const MachineInstr *MI, int opNum,
353                                       raw_ostream &O, const char *Modifier) {
354   printOperand(MI, opNum, O);
355 
356   // If this is an ADD operand, emit it like normal operands.
357   if (Modifier && !strcmp(Modifier, "arith")) {
358     O << ", ";
359     printOperand(MI, opNum+1, O);
360     return;
361   }
362 
363   if (MI->getOperand(opNum+1).isReg() &&
364       MI->getOperand(opNum+1).getReg() == SP::G0)
365     return;   // don't print "+%g0"
366   if (MI->getOperand(opNum+1).isImm() &&
367       MI->getOperand(opNum+1).getImm() == 0)
368     return;   // don't print "+0"
369 
370   O << "+";
371   printOperand(MI, opNum+1, O);
372 }
373 
374 /// PrintAsmOperand - Print out an operand for an inline asm expression.
375 ///
376 bool SparcAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
377                                       const char *ExtraCode,
378                                       raw_ostream &O) {
379   if (ExtraCode && ExtraCode[0]) {
380     if (ExtraCode[1] != 0) return true; // Unknown modifier.
381 
382     switch (ExtraCode[0]) {
383     default:
384       // See if this is a generic print operand
385       return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O);
386     case 'L': // Low order register of a twin word register operand
387     case 'H': // High order register of a twin word register operand
388     {
389       const SparcSubtarget &Subtarget = MF->getSubtarget<SparcSubtarget>();
390       const MachineOperand &MO = MI->getOperand(OpNo);
391       const SparcRegisterInfo *RegisterInfo = Subtarget.getRegisterInfo();
392       Register MOReg = MO.getReg();
393 
394       Register HiReg, LoReg;
395       if (!SP::IntPairRegClass.contains(MOReg)) {
396         // If we aren't given a register pair already, find out which pair it
397         // belongs to. Note that here, the specified register operand, which
398         // refers to the high part of the twinword, needs to be an even-numbered
399         // register.
400         MOReg = RegisterInfo->getMatchingSuperReg(MOReg, SP::sub_even,
401                                                   &SP::IntPairRegClass);
402         if (!MOReg) {
403           SMLoc Loc;
404           OutContext.reportError(
405               Loc, "Hi part of pair should point to an even-numbered register");
406           OutContext.reportError(
407               Loc, "(note that in some cases it might be necessary to manually "
408                    "bind the input/output registers instead of relying on "
409                    "automatic allocation)");
410           return true;
411         }
412       }
413 
414       HiReg = RegisterInfo->getSubReg(MOReg, SP::sub_even);
415       LoReg = RegisterInfo->getSubReg(MOReg, SP::sub_odd);
416 
417       Register Reg;
418       switch (ExtraCode[0]) {
419       case 'L':
420         Reg = LoReg;
421         break;
422       case 'H':
423         Reg = HiReg;
424         break;
425       }
426 
427       O << '%' << SparcInstPrinter::getRegisterName(Reg);
428       return false;
429     }
430     case 'f':
431     case 'r':
432      break;
433     }
434   }
435 
436   printOperand(MI, OpNo, O);
437 
438   return false;
439 }
440 
441 bool SparcAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
442                                             unsigned OpNo,
443                                             const char *ExtraCode,
444                                             raw_ostream &O) {
445   if (ExtraCode && ExtraCode[0])
446     return true;  // Unknown modifier
447 
448   O << '[';
449   printMemOperand(MI, OpNo, O);
450   O << ']';
451 
452   return false;
453 }
454 
455 // Force static initialization.
456 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeSparcAsmPrinter() {
457   RegisterAsmPrinter<SparcAsmPrinter> X(getTheSparcTarget());
458   RegisterAsmPrinter<SparcAsmPrinter> Y(getTheSparcV9Target());
459   RegisterAsmPrinter<SparcAsmPrinter> Z(getTheSparcelTarget());
460 }
461