HexagonAsmPrinter.cpp revision 263508 
1//===-- HexagonAsmPrinter.cpp - Print machine instrs to Hexagon assembly --===//
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 Hexagon assembly language. This printer is
12// the output mechanism used by `llc'.
13//
14//===----------------------------------------------------------------------===//
15
16#define DEBUG_TYPE "asm-printer"
17#include "Hexagon.h"
18#include "HexagonAsmPrinter.h"
19#include "HexagonMachineFunctionInfo.h"
20#include "HexagonTargetMachine.h"
21#include "HexagonSubtarget.h"
22#include "MCTargetDesc/HexagonMCInst.h"
23#include "InstPrinter/HexagonInstPrinter.h"
24#include "llvm/ADT/SmallString.h"
25#include "llvm/ADT/SmallVector.h"
26#include "llvm/ADT/StringExtras.h"
27#include "llvm/Analysis/ConstantFolding.h"
28#include "llvm/Assembly/Writer.h"
29#include "llvm/CodeGen/AsmPrinter.h"
30#include "llvm/CodeGen/MachineFunctionPass.h"
31#include "llvm/CodeGen/MachineInstr.h"
32#include "llvm/CodeGen/MachineInstrBuilder.h"
33#include "llvm/CodeGen/MachineModuleInfo.h"
34#include "llvm/IR/Constants.h"
35#include "llvm/IR/DataLayout.h"
36#include "llvm/IR/DerivedTypes.h"
37#include "llvm/IR/Module.h"
38#include "llvm/MC/MCAsmInfo.h"
39#include "llvm/MC/MCContext.h"
40#include "llvm/MC/MCExpr.h"
41#include "llvm/MC/MCInst.h"
42#include "llvm/MC/MCSection.h"
43#include "llvm/MC/MCStreamer.h"
44#include "llvm/MC/MCSymbol.h"
45#include "llvm/Support/CommandLine.h"
46#include "llvm/Support/Compiler.h"
47#include "llvm/Support/Debug.h"
48#include "llvm/Support/Format.h"
49#include "llvm/Support/MathExtras.h"
50#include "llvm/Support/TargetRegistry.h"
51#include "llvm/Support/raw_ostream.h"
52#include "llvm/Target/Mangler.h"
53#include "llvm/Target/TargetInstrInfo.h"
54#include "llvm/Target/TargetLoweringObjectFile.h"
55#include "llvm/Target/TargetOptions.h"
56#include "llvm/Target/TargetRegisterInfo.h"
57
58using namespace llvm;
59
60static cl::opt<bool> AlignCalls(
61         "hexagon-align-calls", cl::Hidden, cl::init(true),
62          cl::desc("Insert falign after call instruction for Hexagon target"));
63
64void HexagonAsmPrinter::EmitAlignment(unsigned NumBits,
65                                      const GlobalValue *GV) const {
66  // For basic block level alignment, use ".falign".
67  if (!GV) {
68    OutStreamer.EmitRawText(StringRef("\t.falign"));
69    return;
70  }
71
72  AsmPrinter::EmitAlignment(NumBits, GV);
73}
74
75void HexagonAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
76                                    raw_ostream &O) {
77  const MachineOperand &MO = MI->getOperand(OpNo);
78
79  switch (MO.getType()) {
80  default: llvm_unreachable ("<unknown operand type>");
81  case MachineOperand::MO_Register:
82    O << HexagonInstPrinter::getRegisterName(MO.getReg());
83    return;
84  case MachineOperand::MO_Immediate:
85    O << MO.getImm();
86    return;
87  case MachineOperand::MO_MachineBasicBlock:
88    O << *MO.getMBB()->getSymbol();
89    return;
90  case MachineOperand::MO_JumpTableIndex:
91    O << *GetJTISymbol(MO.getIndex());
92    // FIXME: PIC relocation model.
93    return;
94  case MachineOperand::MO_ConstantPoolIndex:
95    O << *GetCPISymbol(MO.getIndex());
96    return;
97  case MachineOperand::MO_ExternalSymbol:
98    O << *GetExternalSymbolSymbol(MO.getSymbolName());
99    return;
100  case MachineOperand::MO_GlobalAddress:
101    // Computing the address of a global symbol, not calling it.
102    O << *getSymbol(MO.getGlobal());
103    printOffset(MO.getOffset(), O);
104    return;
105  }
106}
107
108//
109// isBlockOnlyReachableByFallthrough - We need to override this since the
110// default AsmPrinter does not print labels for any basic block that
111// is only reachable by a fall through. That works for all cases except
112// for the case in which the basic block is reachable by a fall through but
113// through an indirect from a jump table. In this case, the jump table
114// will contain a label not defined by AsmPrinter.
115//
116bool HexagonAsmPrinter::
117isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
118  if (MBB->hasAddressTaken()) {
119    return false;
120  }
121  return AsmPrinter::isBlockOnlyReachableByFallthrough(MBB);
122}
123
124
125/// PrintAsmOperand - Print out an operand for an inline asm expression.
126///
127bool HexagonAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
128                                        unsigned AsmVariant,
129                                        const char *ExtraCode,
130                                        raw_ostream &OS) {
131  // Does this asm operand have a single letter operand modifier?
132  if (ExtraCode && ExtraCode[0]) {
133    if (ExtraCode[1] != 0) return true; // Unknown modifier.
134
135    switch (ExtraCode[0]) {
136    default:
137      // See if this is a generic print operand
138      return AsmPrinter::PrintAsmOperand(MI, OpNo, AsmVariant, ExtraCode, OS);
139    case 'c': // Don't print "$" before a global var name or constant.
140      // Hexagon never has a prefix.
141      printOperand(MI, OpNo, OS);
142      return false;
143    case 'L': // Write second word of DImode reference.
144      // Verify that this operand has two consecutive registers.
145      if (!MI->getOperand(OpNo).isReg() ||
146          OpNo+1 == MI->getNumOperands() ||
147          !MI->getOperand(OpNo+1).isReg())
148        return true;
149      ++OpNo;   // Return the high-part.
150      break;
151    case 'I':
152      // Write 'i' if an integer constant, otherwise nothing.  Used to print
153      // addi vs add, etc.
154      if (MI->getOperand(OpNo).isImm())
155        OS << "i";
156      return false;
157    }
158  }
159
160  printOperand(MI, OpNo, OS);
161  return false;
162}
163
164bool HexagonAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
165                                            unsigned OpNo, unsigned AsmVariant,
166                                            const char *ExtraCode,
167                                            raw_ostream &O) {
168  if (ExtraCode && ExtraCode[0])
169    return true; // Unknown modifier.
170
171  const MachineOperand &Base  = MI->getOperand(OpNo);
172  const MachineOperand &Offset = MI->getOperand(OpNo+1);
173
174  if (Base.isReg())
175    printOperand(MI, OpNo, O);
176  else
177    llvm_unreachable("Unimplemented");
178
179  if (Offset.isImm()) {
180    if (Offset.getImm())
181      O << " + #" << Offset.getImm();
182  }
183  else
184    llvm_unreachable("Unimplemented");
185
186  return false;
187}
188
189void HexagonAsmPrinter::printPredicateOperand(const MachineInstr *MI,
190                                              unsigned OpNo,
191                                              raw_ostream &O) {
192  llvm_unreachable("Unimplemented");
193}
194
195
196/// printMachineInstruction -- Print out a single Hexagon MI in Darwin syntax to
197/// the current output stream.
198///
199void HexagonAsmPrinter::EmitInstruction(const MachineInstr *MI) {
200  if (MI->isBundle()) {
201    std::vector<const MachineInstr*> BundleMIs;
202
203    const MachineBasicBlock *MBB = MI->getParent();
204    MachineBasicBlock::const_instr_iterator MII = MI;
205    ++MII;
206    unsigned int IgnoreCount = 0;
207    while (MII != MBB->end() && MII->isInsideBundle()) {
208      const MachineInstr *MInst = MII;
209      if (MInst->getOpcode() == TargetOpcode::DBG_VALUE ||
210          MInst->getOpcode() == TargetOpcode::IMPLICIT_DEF) {
211          IgnoreCount++;
212          ++MII;
213          continue;
214      }
215      //BundleMIs.push_back(&*MII);
216      BundleMIs.push_back(MInst);
217      ++MII;
218    }
219    unsigned Size = BundleMIs.size();
220    assert((Size+IgnoreCount) == MI->getBundleSize() && "Corrupt Bundle!");
221    for (unsigned Index = 0; Index < Size; Index++) {
222      HexagonMCInst MCI;
223      MCI.setPacketStart(Index == 0);
224      MCI.setPacketEnd(Index == (Size-1));
225
226      HexagonLowerToMC(BundleMIs[Index], MCI, *this);
227      OutStreamer.EmitInstruction(MCI);
228    }
229  }
230  else {
231    HexagonMCInst MCI;
232    if (MI->getOpcode() == Hexagon::ENDLOOP0) {
233      MCI.setPacketStart(true);
234      MCI.setPacketEnd(true);
235    }
236    HexagonLowerToMC(MI, MCI, *this);
237    OutStreamer.EmitInstruction(MCI);
238  }
239
240  return;
241}
242
243/// PrintUnmangledNameSafely - Print out the printable characters in the name.
244/// Don't print things like \n or \0.
245// static void PrintUnmangledNameSafely(const Value *V, raw_ostream &OS) {
246//   for (const char *Name = V->getNameStart(), *E = Name+V->getNameLen();
247//        Name != E; ++Name)
248//     if (isprint(*Name))
249//       OS << *Name;
250// }
251
252
253void HexagonAsmPrinter::printAddrModeBasePlusOffset(const MachineInstr *MI,
254                                                    int OpNo, raw_ostream &O) {
255  const MachineOperand &MO1 = MI->getOperand(OpNo);
256  const MachineOperand &MO2 = MI->getOperand(OpNo+1);
257
258  O << HexagonInstPrinter::getRegisterName(MO1.getReg())
259    << " + #"
260    << MO2.getImm();
261}
262
263
264void HexagonAsmPrinter::printGlobalOperand(const MachineInstr *MI, int OpNo,
265                                           raw_ostream &O) {
266  const MachineOperand &MO = MI->getOperand(OpNo);
267  assert( (MO.getType() == MachineOperand::MO_GlobalAddress) &&
268         "Expecting global address");
269
270  O << *getSymbol(MO.getGlobal());
271  if (MO.getOffset() != 0) {
272    O << " + ";
273    O << MO.getOffset();
274  }
275}
276
277void HexagonAsmPrinter::printJumpTable(const MachineInstr *MI, int OpNo,
278                                       raw_ostream &O) {
279  const MachineOperand &MO = MI->getOperand(OpNo);
280  assert( (MO.getType() == MachineOperand::MO_JumpTableIndex) &&
281           "Expecting jump table index");
282
283  // Hexagon_TODO: Do we need name mangling?
284  O << *GetJTISymbol(MO.getIndex());
285}
286
287void HexagonAsmPrinter::printConstantPool(const MachineInstr *MI, int OpNo,
288                                       raw_ostream &O) {
289  const MachineOperand &MO = MI->getOperand(OpNo);
290  assert( (MO.getType() == MachineOperand::MO_ConstantPoolIndex) &&
291          "Expecting constant pool index");
292
293  // Hexagon_TODO: Do we need name mangling?
294  O << *GetCPISymbol(MO.getIndex());
295}
296
297static MCInstPrinter *createHexagonMCInstPrinter(const Target &T,
298                                                 unsigned SyntaxVariant,
299                                                 const MCAsmInfo &MAI,
300                                                 const MCInstrInfo &MII,
301                                                 const MCRegisterInfo &MRI,
302                                                 const MCSubtargetInfo &STI) {
303  if (SyntaxVariant == 0)
304    return(new HexagonInstPrinter(MAI, MII, MRI));
305  else
306   return NULL;
307}
308
309extern "C" void LLVMInitializeHexagonAsmPrinter() {
310  RegisterAsmPrinter<HexagonAsmPrinter> X(TheHexagonTarget);
311
312  TargetRegistry::RegisterMCInstPrinter(TheHexagonTarget,
313                                        createHexagonMCInstPrinter);
314}
315