XCoreAsmPrinter.cpp revision 360784 
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() ||
110      EmitSpecialLLVMGlobal(GV))
111    return;
112
113  const DataLayout &DL = getDataLayout();
114  OutStreamer->SwitchSection(getObjFileLowering().SectionForGlobal(GV, TM));
115
116  MCSymbol *GVSym = getSymbol(GV);
117  const Constant *C = GV->getInitializer();
118  const Align Alignment(DL.getPrefTypeAlignment(C->getType()));
119
120  // Mark the start of the global
121  getTargetStreamer().emitCCTopData(GVSym->getName());
122
123  switch (GV->getLinkage()) {
124  case GlobalValue::AppendingLinkage:
125    report_fatal_error("AppendingLinkage is not supported by this target!");
126  case GlobalValue::LinkOnceAnyLinkage:
127  case GlobalValue::LinkOnceODRLinkage:
128  case GlobalValue::WeakAnyLinkage:
129  case GlobalValue::WeakODRLinkage:
130  case GlobalValue::ExternalLinkage:
131  case GlobalValue::CommonLinkage:
132    emitArrayBound(GVSym, GV);
133    OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
134
135    if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
136        GV->hasCommonLinkage())
137      OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Weak);
138    LLVM_FALLTHROUGH;
139  case GlobalValue::InternalLinkage:
140  case GlobalValue::PrivateLinkage:
141    break;
142  default:
143    llvm_unreachable("Unknown linkage type!");
144  }
145
146  EmitAlignment(std::max(Alignment, Align(4)), GV);
147
148  if (GV->isThreadLocal()) {
149    report_fatal_error("TLS is not supported by this target!");
150  }
151  unsigned Size = DL.getTypeAllocSize(C->getType());
152  if (MAI->hasDotTypeDotSizeDirective()) {
153    OutStreamer->EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
154    OutStreamer->emitELFSize(GVSym, MCConstantExpr::create(Size, OutContext));
155  }
156  OutStreamer->EmitLabel(GVSym);
157
158  EmitGlobalConstant(DL, C);
159  // The ABI requires that unsigned scalar types smaller than 32 bits
160  // are padded to 32 bits.
161  if (Size < 4)
162    OutStreamer->EmitZeros(4 - Size);
163
164  // Mark the end of the global
165  getTargetStreamer().emitCCBottomData(GVSym->getName());
166}
167
168void XCoreAsmPrinter::EmitFunctionBodyStart() {
169  MCInstLowering.Initialize(&MF->getContext());
170}
171
172/// EmitFunctionBodyEnd - Targets can override this to emit stuff after
173/// the last basic block in the function.
174void XCoreAsmPrinter::EmitFunctionBodyEnd() {
175  // Emit function end directives
176  getTargetStreamer().emitCCBottomFunction(CurrentFnSym->getName());
177}
178
179void XCoreAsmPrinter::EmitFunctionEntryLabel() {
180  // Mark the start of the function
181  getTargetStreamer().emitCCTopFunction(CurrentFnSym->getName());
182  OutStreamer->EmitLabel(CurrentFnSym);
183}
184
185void XCoreAsmPrinter::
186printInlineJT(const MachineInstr *MI, int opNum, raw_ostream &O,
187              const std::string &directive) {
188  unsigned JTI = MI->getOperand(opNum).getIndex();
189  const MachineFunction *MF = MI->getParent()->getParent();
190  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
191  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
192  const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
193  O << "\t" << directive << " ";
194  for (unsigned i = 0, e = JTBBs.size(); i != e; ++i) {
195    MachineBasicBlock *MBB = JTBBs[i];
196    if (i > 0)
197      O << ",";
198    MBB->getSymbol()->print(O, MAI);
199  }
200}
201
202void XCoreAsmPrinter::printOperand(const MachineInstr *MI, int opNum,
203                                   raw_ostream &O) {
204  const DataLayout &DL = getDataLayout();
205  const MachineOperand &MO = MI->getOperand(opNum);
206  switch (MO.getType()) {
207  case MachineOperand::MO_Register:
208    O << XCoreInstPrinter::getRegisterName(MO.getReg());
209    break;
210  case MachineOperand::MO_Immediate:
211    O << MO.getImm();
212    break;
213  case MachineOperand::MO_MachineBasicBlock:
214    MO.getMBB()->getSymbol()->print(O, MAI);
215    break;
216  case MachineOperand::MO_GlobalAddress:
217    PrintSymbolOperand(MO, O);
218    break;
219  case MachineOperand::MO_ConstantPoolIndex:
220    O << DL.getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << '_'
221      << MO.getIndex();
222    break;
223  case MachineOperand::MO_BlockAddress:
224    GetBlockAddressSymbol(MO.getBlockAddress())->print(O, MAI);
225    break;
226  default:
227    llvm_unreachable("not implemented");
228  }
229}
230
231/// PrintAsmOperand - Print out an operand for an inline asm expression.
232///
233bool XCoreAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
234                                      const char *ExtraCode, raw_ostream &O) {
235  // Print the operand if there is no operand modifier.
236  if (!ExtraCode || !ExtraCode[0]) {
237    printOperand(MI, OpNo, O);
238    return false;
239  }
240
241  // Otherwise fallback on the default implementation.
242  return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O);
243}
244
245bool XCoreAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
246                                            unsigned OpNum,
247                                            const char *ExtraCode,
248                                            raw_ostream &O) {
249  if (ExtraCode && ExtraCode[0]) {
250    return true; // Unknown modifier.
251  }
252  printOperand(MI, OpNum, O);
253  O << '[';
254  printOperand(MI, OpNum + 1, O);
255  O << ']';
256  return false;
257}
258
259void XCoreAsmPrinter::EmitInstruction(const MachineInstr *MI) {
260  SmallString<128> Str;
261  raw_svector_ostream O(Str);
262
263  switch (MI->getOpcode()) {
264  case XCore::DBG_VALUE:
265    llvm_unreachable("Should be handled target independently");
266  case XCore::ADD_2rus:
267    if (MI->getOperand(2).getImm() == 0) {
268      O << "\tmov "
269        << XCoreInstPrinter::getRegisterName(MI->getOperand(0).getReg()) << ", "
270        << XCoreInstPrinter::getRegisterName(MI->getOperand(1).getReg());
271      OutStreamer->EmitRawText(O.str());
272      return;
273    }
274    break;
275  case XCore::BR_JT:
276  case XCore::BR_JT32:
277    O << "\tbru "
278      << XCoreInstPrinter::getRegisterName(MI->getOperand(1).getReg()) << '\n';
279    if (MI->getOpcode() == XCore::BR_JT)
280      printInlineJT(MI, 0, O);
281    else
282      printInlineJT32(MI, 0, O);
283    O << '\n';
284    OutStreamer->EmitRawText(O.str());
285    return;
286  }
287
288  MCInst TmpInst;
289  MCInstLowering.Lower(MI, TmpInst);
290
291  EmitToStreamer(*OutStreamer, TmpInst);
292}
293
294// Force static initialization.
295extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeXCoreAsmPrinter() {
296  RegisterAsmPrinter<XCoreAsmPrinter> X(getTheXCoreTarget());
297}
298