XCoreAsmPrinter.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
1//===-- XCoreAsmPrinter.cpp - XCore LLVM assembly writer ------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains a printer that converts from our internal representation
11// of machine-dependent LLVM code to the XAS-format XCore assembly language.
12//
13//===----------------------------------------------------------------------===//
14
15#define DEBUG_TYPE "asm-printer"
16#include "XCore.h"
17#include "InstPrinter/XCoreInstPrinter.h"
18#include "XCoreInstrInfo.h"
19#include "XCoreMCInstLower.h"
20#include "XCoreSubtarget.h"
21#include "XCoreTargetMachine.h"
22#include "XCoreTargetStreamer.h"
23#include "llvm/ADT/SmallString.h"
24#include "llvm/ADT/StringExtras.h"
25#include "llvm/CodeGen/AsmPrinter.h"
26#include "llvm/CodeGen/MachineConstantPool.h"
27#include "llvm/CodeGen/MachineFunctionPass.h"
28#include "llvm/CodeGen/MachineInstr.h"
29#include "llvm/CodeGen/MachineJumpTableInfo.h"
30#include "llvm/CodeGen/MachineModuleInfo.h"
31#include "llvm/IR/Constants.h"
32#include "llvm/IR/DataLayout.h"
33#include "llvm/IR/DebugInfo.h"
34#include "llvm/IR/DerivedTypes.h"
35#include "llvm/IR/Mangler.h"
36#include "llvm/IR/Module.h"
37#include "llvm/MC/MCAsmInfo.h"
38#include "llvm/MC/MCExpr.h"
39#include "llvm/MC/MCInst.h"
40#include "llvm/MC/MCStreamer.h"
41#include "llvm/MC/MCSymbol.h"
42#include "llvm/Support/ErrorHandling.h"
43#include "llvm/Support/TargetRegistry.h"
44#include "llvm/Support/raw_ostream.h"
45#include "llvm/Target/TargetLoweringObjectFile.h"
46#include <algorithm>
47#include <cctype>
48using namespace llvm;
49
50namespace {
51  class XCoreAsmPrinter : public AsmPrinter {
52    const XCoreSubtarget &Subtarget;
53    XCoreMCInstLower MCInstLowering;
54    XCoreTargetStreamer &getTargetStreamer();
55
56  public:
57    explicit XCoreAsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
58      : AsmPrinter(TM, Streamer), Subtarget(TM.getSubtarget<XCoreSubtarget>()),
59        MCInstLowering(*this) {}
60
61    virtual const char *getPassName() const {
62      return "XCore Assembly Printer";
63    }
64
65    void printInlineJT(const MachineInstr *MI, int opNum, raw_ostream &O,
66                       const std::string &directive = ".jmptable");
67    void printInlineJT32(const MachineInstr *MI, int opNum, raw_ostream &O) {
68      printInlineJT(MI, opNum, O, ".jmptable32");
69    }
70    void printOperand(const MachineInstr *MI, int opNum, raw_ostream &O);
71    bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
72                         unsigned AsmVariant, const char *ExtraCode,
73                         raw_ostream &O);
74    bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
75                               unsigned AsmVariant, const char *ExtraCode,
76                               raw_ostream &O) override;
77
78    void emitArrayBound(MCSymbol *Sym, const GlobalVariable *GV);
79    virtual void EmitGlobalVariable(const GlobalVariable *GV);
80
81    void EmitFunctionEntryLabel();
82    void EmitInstruction(const MachineInstr *MI);
83    void EmitFunctionBodyStart();
84    void EmitFunctionBodyEnd();
85  };
86} // end of anonymous namespace
87
88XCoreTargetStreamer &XCoreAsmPrinter::getTargetStreamer() {
89  return static_cast<XCoreTargetStreamer&>(*OutStreamer.getTargetStreamer());
90}
91
92void XCoreAsmPrinter::emitArrayBound(MCSymbol *Sym, const GlobalVariable *GV) {
93  assert( ( GV->hasExternalLinkage() || GV->hasWeakLinkage() ||
94            GV->hasLinkOnceLinkage() || GV->hasCommonLinkage() ) &&
95          "Unexpected linkage");
96  if (ArrayType *ATy = dyn_cast<ArrayType>(
97                        cast<PointerType>(GV->getType())->getElementType())) {
98
99    MCSymbol *SymGlob = OutContext.GetOrCreateSymbol(
100                          Twine(Sym->getName() + StringRef(".globound")));
101    OutStreamer.EmitSymbolAttribute(SymGlob, MCSA_Global);
102    OutStreamer.EmitAssignment(SymGlob,
103                               MCConstantExpr::Create(ATy->getNumElements(),
104                                                      OutContext));
105    if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
106        GV->hasCommonLinkage()) {
107      // TODO Use COMDAT groups for LinkOnceLinkage
108      OutStreamer.EmitSymbolAttribute(SymGlob, MCSA_Weak);
109    }
110  }
111}
112
113void XCoreAsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
114  // Check to see if this is a special global used by LLVM, if so, emit it.
115  if (!GV->hasInitializer() ||
116      EmitSpecialLLVMGlobal(GV))
117    return;
118
119  const DataLayout *TD = TM.getDataLayout();
120  OutStreamer.SwitchSection(
121      getObjFileLowering().SectionForGlobal(GV, *Mang, TM));
122
123  MCSymbol *GVSym = getSymbol(GV);
124  const Constant *C = GV->getInitializer();
125  unsigned Align = (unsigned)TD->getPreferredTypeAlignmentShift(C->getType());
126
127  // Mark the start of the global
128  getTargetStreamer().emitCCTopData(GVSym->getName());
129
130  switch (GV->getLinkage()) {
131  case GlobalValue::AppendingLinkage:
132    report_fatal_error("AppendingLinkage is not supported by this target!");
133  case GlobalValue::LinkOnceAnyLinkage:
134  case GlobalValue::LinkOnceODRLinkage:
135  case GlobalValue::WeakAnyLinkage:
136  case GlobalValue::WeakODRLinkage:
137  case GlobalValue::ExternalLinkage:
138  case GlobalValue::CommonLinkage:
139    emitArrayBound(GVSym, GV);
140    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
141
142    // TODO Use COMDAT groups for LinkOnceLinkage
143    if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
144        GV->hasCommonLinkage())
145      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
146    // FALL THROUGH
147  case GlobalValue::InternalLinkage:
148  case GlobalValue::PrivateLinkage:
149    break;
150  default:
151    llvm_unreachable("Unknown linkage type!");
152  }
153
154  EmitAlignment(Align > 2 ? Align : 2, GV);
155
156  if (GV->isThreadLocal()) {
157    report_fatal_error("TLS is not supported by this target!");
158  }
159  unsigned Size = TD->getTypeAllocSize(C->getType());
160  if (MAI->hasDotTypeDotSizeDirective()) {
161    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
162    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
163  }
164  OutStreamer.EmitLabel(GVSym);
165
166  EmitGlobalConstant(C);
167  // The ABI requires that unsigned scalar types smaller than 32 bits
168  // are padded to 32 bits.
169  if (Size < 4)
170    OutStreamer.EmitZeros(4 - Size);
171
172  // Mark the end of the global
173  getTargetStreamer().emitCCBottomData(GVSym->getName());
174}
175
176void XCoreAsmPrinter::EmitFunctionBodyStart() {
177  MCInstLowering.Initialize(Mang, &MF->getContext());
178}
179
180/// EmitFunctionBodyEnd - Targets can override this to emit stuff after
181/// the last basic block in the function.
182void XCoreAsmPrinter::EmitFunctionBodyEnd() {
183  // Emit function end directives
184  getTargetStreamer().emitCCBottomFunction(CurrentFnSym->getName());
185}
186
187void XCoreAsmPrinter::EmitFunctionEntryLabel() {
188  // Mark the start of the function
189  getTargetStreamer().emitCCTopFunction(CurrentFnSym->getName());
190  OutStreamer.EmitLabel(CurrentFnSym);
191}
192
193void XCoreAsmPrinter::
194printInlineJT(const MachineInstr *MI, int opNum, raw_ostream &O,
195              const std::string &directive) {
196  unsigned JTI = MI->getOperand(opNum).getIndex();
197  const MachineFunction *MF = MI->getParent()->getParent();
198  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
199  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
200  const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
201  O << "\t" << directive << " ";
202  for (unsigned i = 0, e = JTBBs.size(); i != e; ++i) {
203    MachineBasicBlock *MBB = JTBBs[i];
204    if (i > 0)
205      O << ",";
206    O << *MBB->getSymbol();
207  }
208}
209
210void XCoreAsmPrinter::printOperand(const MachineInstr *MI, int opNum,
211                                   raw_ostream &O) {
212  const DataLayout *DL = TM.getDataLayout();
213  const MachineOperand &MO = MI->getOperand(opNum);
214  switch (MO.getType()) {
215  case MachineOperand::MO_Register:
216    O << XCoreInstPrinter::getRegisterName(MO.getReg());
217    break;
218  case MachineOperand::MO_Immediate:
219    O << MO.getImm();
220    break;
221  case MachineOperand::MO_MachineBasicBlock:
222    O << *MO.getMBB()->getSymbol();
223    break;
224  case MachineOperand::MO_GlobalAddress:
225    O << *getSymbol(MO.getGlobal());
226    break;
227  case MachineOperand::MO_ConstantPoolIndex:
228    O << DL->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber()
229      << '_' << MO.getIndex();
230    break;
231  case MachineOperand::MO_BlockAddress:
232    O << *GetBlockAddressSymbol(MO.getBlockAddress());
233    break;
234  default:
235    llvm_unreachable("not implemented");
236  }
237}
238
239/// PrintAsmOperand - Print out an operand for an inline asm expression.
240///
241bool XCoreAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
242                                      unsigned AsmVariant,const char *ExtraCode,
243                                      raw_ostream &O) {
244  // Print the operand if there is no operand modifier.
245  if (!ExtraCode || !ExtraCode[0]) {
246    printOperand(MI, OpNo, O);
247    return false;
248  }
249
250  // Otherwise fallback on the default implementation.
251  return AsmPrinter::PrintAsmOperand(MI, OpNo, AsmVariant, ExtraCode, O);
252}
253
254bool XCoreAsmPrinter::
255PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
256                      unsigned AsmVariant, const char *ExtraCode,
257                      raw_ostream &O) {
258  if (ExtraCode && ExtraCode[0]) {
259    return true; // Unknown modifier.
260  }
261  printOperand(MI, OpNum, O);
262  O << '[';
263  printOperand(MI, OpNum + 1, O);
264  O << ']';
265  return false;
266}
267
268void XCoreAsmPrinter::EmitInstruction(const MachineInstr *MI) {
269  SmallString<128> Str;
270  raw_svector_ostream O(Str);
271
272  switch (MI->getOpcode()) {
273  case XCore::DBG_VALUE:
274    llvm_unreachable("Should be handled target independently");
275  case XCore::ADD_2rus:
276    if (MI->getOperand(2).getImm() == 0) {
277      O << "\tmov "
278        << XCoreInstPrinter::getRegisterName(MI->getOperand(0).getReg()) << ", "
279        << XCoreInstPrinter::getRegisterName(MI->getOperand(1).getReg());
280      OutStreamer.EmitRawText(O.str());
281      return;
282    }
283    break;
284  case XCore::BR_JT:
285  case XCore::BR_JT32:
286    O << "\tbru "
287      << XCoreInstPrinter::getRegisterName(MI->getOperand(1).getReg()) << '\n';
288    if (MI->getOpcode() == XCore::BR_JT)
289      printInlineJT(MI, 0, O);
290    else
291      printInlineJT32(MI, 0, O);
292    O << '\n';
293    OutStreamer.EmitRawText(O.str());
294    return;
295  }
296
297  MCInst TmpInst;
298  MCInstLowering.Lower(MI, TmpInst);
299
300  EmitToStreamer(OutStreamer, TmpInst);
301}
302
303// Force static initialization.
304extern "C" void LLVMInitializeXCoreAsmPrinter() {
305  RegisterAsmPrinter<XCoreAsmPrinter> X(TheXCoreTarget);
306}
307