1//===-- XCoreAsmPrinter.cpp - XCore 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 the XAS-format XCore assembly language.
11//
12//===----------------------------------------------------------------------===//
13
14#include "MCTargetDesc/XCoreInstPrinter.h"
15#include "TargetInfo/XCoreTargetInfo.h"
16#include "XCore.h"
17#include "XCoreInstrInfo.h"
18#include "XCoreMCInstLower.h"
19#include "XCoreSubtarget.h"
20#include "XCoreTargetMachine.h"
21#include "XCoreTargetStreamer.h"
22#include "llvm/ADT/SmallString.h"
23#include "llvm/ADT/StringExtras.h"
24#include "llvm/CodeGen/AsmPrinter.h"
25#include "llvm/CodeGen/MachineConstantPool.h"
26#include "llvm/CodeGen/MachineFunctionPass.h"
27#include "llvm/CodeGen/MachineInstr.h"
28#include "llvm/CodeGen/MachineJumpTableInfo.h"
29#include "llvm/CodeGen/MachineModuleInfo.h"
30#include "llvm/IR/Constants.h"
31#include "llvm/IR/DataLayout.h"
32#include "llvm/IR/DebugInfo.h"
33#include "llvm/IR/DerivedTypes.h"
34#include "llvm/IR/Mangler.h"
35#include "llvm/IR/Module.h"
36#include "llvm/MC/MCAsmInfo.h"
37#include "llvm/MC/MCExpr.h"
38#include "llvm/MC/MCInst.h"
39#include "llvm/MC/MCStreamer.h"
40#include "llvm/MC/MCSymbolELF.h"
41#include "llvm/Support/ErrorHandling.h"
42#include "llvm/Support/TargetRegistry.h"
43#include "llvm/Support/raw_ostream.h"
44#include "llvm/Target/TargetLoweringObjectFile.h"
45#include <algorithm>
46#include <cctype>
47using namespace llvm;
48
49#define DEBUG_TYPE "asm-printer"
50
51namespace {
52  class XCoreAsmPrinter : public AsmPrinter {
53    XCoreMCInstLower MCInstLowering;
54    XCoreTargetStreamer &getTargetStreamer();
55
56  public:
57    explicit XCoreAsmPrinter(TargetMachine &TM,
58                             std::unique_ptr<MCStreamer> Streamer)
59        : AsmPrinter(TM, std::move(Streamer)), MCInstLowering(*this) {}
60
61    StringRef getPassName() const override { return "XCore Assembly Printer"; }
62
63    void printInlineJT(const MachineInstr *MI, int opNum, raw_ostream &O,
64                       const std::string &directive = ".jmptable");
65    void printInlineJT32(const MachineInstr *MI, int opNum, raw_ostream &O) {
66      printInlineJT(MI, opNum, O, ".jmptable32");
67    }
68    void printOperand(const MachineInstr *MI, int opNum, raw_ostream &O);
69    bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
70                         const char *ExtraCode, raw_ostream &O) override;
71    bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
72                               const char *ExtraCode, raw_ostream &O) override;
73
74    void emitArrayBound(MCSymbol *Sym, const GlobalVariable *GV);
75    void emitGlobalVariable(const GlobalVariable *GV) override;
76
77    void emitFunctionEntryLabel() override;
78    void emitInstruction(const MachineInstr *MI) override;
79    void emitFunctionBodyStart() override;
80    void emitFunctionBodyEnd() override;
81  };
82} // end of anonymous namespace
83
84XCoreTargetStreamer &XCoreAsmPrinter::getTargetStreamer() {
85  return static_cast<XCoreTargetStreamer&>(*OutStreamer->getTargetStreamer());
86}
87
88void XCoreAsmPrinter::emitArrayBound(MCSymbol *Sym, const GlobalVariable *GV) {
89  assert( ( GV->hasExternalLinkage() || GV->hasWeakLinkage() ||
90            GV->hasLinkOnceLinkage() || GV->hasCommonLinkage() ) &&
91          "Unexpected linkage");
92  if (ArrayType *ATy = dyn_cast<ArrayType>(GV->getValueType())) {
93
94    MCSymbol *SymGlob = OutContext.getOrCreateSymbol(
95                          Twine(Sym->getName() + StringRef(".globound")));
96    OutStreamer->emitSymbolAttribute(SymGlob, MCSA_Global);
97    OutStreamer->emitAssignment(SymGlob,
98                                MCConstantExpr::create(ATy->getNumElements(),
99                                                       OutContext));
100    if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
101        GV->hasCommonLinkage()) {
102      OutStreamer->emitSymbolAttribute(SymGlob, MCSA_Weak);
103    }
104  }
105}
106
107void XCoreAsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
108  // Check to see if this is a special global used by LLVM, if so, emit it.
109  if (!GV->hasInitializer() || emitSpecialLLVMGlobal(GV))
110    return;
111
112  const DataLayout &DL = getDataLayout();
113  OutStreamer->SwitchSection(getObjFileLowering().SectionForGlobal(GV, TM));
114
115  MCSymbol *GVSym = getSymbol(GV);
116  const Constant *C = GV->getInitializer();
117  const Align Alignment(DL.getPrefTypeAlignment(C->getType()));
118
119  // Mark the start of the global
120  getTargetStreamer().emitCCTopData(GVSym->getName());
121
122  switch (GV->getLinkage()) {
123  case GlobalValue::AppendingLinkage:
124    report_fatal_error("AppendingLinkage is not supported by this target!");
125  case GlobalValue::LinkOnceAnyLinkage:
126  case GlobalValue::LinkOnceODRLinkage:
127  case GlobalValue::WeakAnyLinkage:
128  case GlobalValue::WeakODRLinkage:
129  case GlobalValue::ExternalLinkage:
130  case GlobalValue::CommonLinkage:
131    emitArrayBound(GVSym, GV);
132    OutStreamer->emitSymbolAttribute(GVSym, MCSA_Global);
133
134    if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
135        GV->hasCommonLinkage())
136      OutStreamer->emitSymbolAttribute(GVSym, MCSA_Weak);
137    LLVM_FALLTHROUGH;
138  case GlobalValue::InternalLinkage:
139  case GlobalValue::PrivateLinkage:
140    break;
141  default:
142    llvm_unreachable("Unknown linkage type!");
143  }
144
145  emitAlignment(std::max(Alignment, Align(4)), GV);
146
147  if (GV->isThreadLocal()) {
148    report_fatal_error("TLS is not supported by this target!");
149  }
150  unsigned Size = DL.getTypeAllocSize(C->getType());
151  if (MAI->hasDotTypeDotSizeDirective()) {
152    OutStreamer->emitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
153    OutStreamer->emitELFSize(GVSym, MCConstantExpr::create(Size, OutContext));
154  }
155  OutStreamer->emitLabel(GVSym);
156
157  emitGlobalConstant(DL, C);
158  // The ABI requires that unsigned scalar types smaller than 32 bits
159  // are padded to 32 bits.
160  if (Size < 4)
161    OutStreamer->emitZeros(4 - Size);
162
163  // Mark the end of the global
164  getTargetStreamer().emitCCBottomData(GVSym->getName());
165}
166
167void XCoreAsmPrinter::emitFunctionBodyStart() {
168  MCInstLowering.Initialize(&MF->getContext());
169}
170
171/// EmitFunctionBodyEnd - Targets can override this to emit stuff after
172/// the last basic block in the function.
173void XCoreAsmPrinter::emitFunctionBodyEnd() {
174  // Emit function end directives
175  getTargetStreamer().emitCCBottomFunction(CurrentFnSym->getName());
176}
177
178void XCoreAsmPrinter::emitFunctionEntryLabel() {
179  // Mark the start of the function
180  getTargetStreamer().emitCCTopFunction(CurrentFnSym->getName());
181  OutStreamer->emitLabel(CurrentFnSym);
182}
183
184void XCoreAsmPrinter::
185printInlineJT(const MachineInstr *MI, int opNum, raw_ostream &O,
186              const std::string &directive) {
187  unsigned JTI = MI->getOperand(opNum).getIndex();
188  const MachineFunction *MF = MI->getParent()->getParent();
189  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
190  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
191  const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
192  O << "\t" << directive << " ";
193  for (unsigned i = 0, e = JTBBs.size(); i != e; ++i) {
194    MachineBasicBlock *MBB = JTBBs[i];
195    if (i > 0)
196      O << ",";
197    MBB->getSymbol()->print(O, MAI);
198  }
199}
200
201void XCoreAsmPrinter::printOperand(const MachineInstr *MI, int opNum,
202                                   raw_ostream &O) {
203  const DataLayout &DL = getDataLayout();
204  const MachineOperand &MO = MI->getOperand(opNum);
205  switch (MO.getType()) {
206  case MachineOperand::MO_Register:
207    O << XCoreInstPrinter::getRegisterName(MO.getReg());
208    break;
209  case MachineOperand::MO_Immediate:
210    O << MO.getImm();
211    break;
212  case MachineOperand::MO_MachineBasicBlock:
213    MO.getMBB()->getSymbol()->print(O, MAI);
214    break;
215  case MachineOperand::MO_GlobalAddress:
216    PrintSymbolOperand(MO, O);
217    break;
218  case MachineOperand::MO_ConstantPoolIndex:
219    O << DL.getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << '_'
220      << MO.getIndex();
221    break;
222  case MachineOperand::MO_BlockAddress:
223    GetBlockAddressSymbol(MO.getBlockAddress())->print(O, MAI);
224    break;
225  default:
226    llvm_unreachable("not implemented");
227  }
228}
229
230/// PrintAsmOperand - Print out an operand for an inline asm expression.
231///
232bool XCoreAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
233                                      const char *ExtraCode, raw_ostream &O) {
234  // Print the operand if there is no operand modifier.
235  if (!ExtraCode || !ExtraCode[0]) {
236    printOperand(MI, OpNo, O);
237    return false;
238  }
239
240  // Otherwise fallback on the default implementation.
241  return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O);
242}
243
244bool XCoreAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
245                                            unsigned OpNum,
246                                            const char *ExtraCode,
247                                            raw_ostream &O) {
248  if (ExtraCode && ExtraCode[0]) {
249    return true; // Unknown modifier.
250  }
251  printOperand(MI, OpNum, O);
252  O << '[';
253  printOperand(MI, OpNum + 1, O);
254  O << ']';
255  return false;
256}
257
258void XCoreAsmPrinter::emitInstruction(const MachineInstr *MI) {
259  SmallString<128> Str;
260  raw_svector_ostream O(Str);
261
262  switch (MI->getOpcode()) {
263  case XCore::DBG_VALUE:
264    llvm_unreachable("Should be handled target independently");
265  case XCore::ADD_2rus:
266    if (MI->getOperand(2).getImm() == 0) {
267      O << "\tmov "
268        << XCoreInstPrinter::getRegisterName(MI->getOperand(0).getReg()) << ", "
269        << XCoreInstPrinter::getRegisterName(MI->getOperand(1).getReg());
270      OutStreamer->emitRawText(O.str());
271      return;
272    }
273    break;
274  case XCore::BR_JT:
275  case XCore::BR_JT32:
276    O << "\tbru "
277      << XCoreInstPrinter::getRegisterName(MI->getOperand(1).getReg()) << '\n';
278    if (MI->getOpcode() == XCore::BR_JT)
279      printInlineJT(MI, 0, O);
280    else
281      printInlineJT32(MI, 0, O);
282    O << '\n';
283    OutStreamer->emitRawText(O.str());
284    return;
285  }
286
287  MCInst TmpInst;
288  MCInstLowering.Lower(MI, TmpInst);
289
290  EmitToStreamer(*OutStreamer, TmpInst);
291}
292
293// Force static initialization.
294extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeXCoreAsmPrinter() {
295  RegisterAsmPrinter<XCoreAsmPrinter> X(getTheXCoreTarget());
296}
297