HexagonAsmPrinter.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
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#include "Hexagon.h"
17#include "HexagonAsmPrinter.h"
18#include "HexagonMachineFunctionInfo.h"
19#include "HexagonSubtarget.h"
20#include "HexagonTargetMachine.h"
21#include "InstPrinter/HexagonInstPrinter.h"
22#include "MCTargetDesc/HexagonMCInst.h"
23#include "llvm/ADT/SmallString.h"
24#include "llvm/ADT/SmallVector.h"
25#include "llvm/ADT/StringExtras.h"
26#include "llvm/Analysis/ConstantFolding.h"
27#include "llvm/CodeGen/AsmPrinter.h"
28#include "llvm/CodeGen/MachineFunctionPass.h"
29#include "llvm/CodeGen/MachineInstr.h"
30#include "llvm/CodeGen/MachineInstrBuilder.h"
31#include "llvm/CodeGen/MachineModuleInfo.h"
32#include "llvm/IR/Constants.h"
33#include "llvm/IR/DataLayout.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/MCContext.h"
39#include "llvm/MC/MCExpr.h"
40#include "llvm/MC/MCInst.h"
41#include "llvm/MC/MCSection.h"
42#include "llvm/MC/MCStreamer.h"
43#include "llvm/MC/MCSymbol.h"
44#include "llvm/Support/CommandLine.h"
45#include "llvm/Support/Compiler.h"
46#include "llvm/Support/Debug.h"
47#include "llvm/Support/Format.h"
48#include "llvm/Support/MathExtras.h"
49#include "llvm/Support/TargetRegistry.h"
50#include "llvm/Support/raw_ostream.h"
51#include "llvm/Target/TargetInstrInfo.h"
52#include "llvm/Target/TargetLoweringObjectFile.h"
53#include "llvm/Target/TargetOptions.h"
54#include "llvm/Target/TargetRegisterInfo.h"
55
56using namespace llvm;
57
58#define DEBUG_TYPE "asm-printer"
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::printOperand(const MachineInstr *MI, unsigned OpNo,
65                                    raw_ostream &O) {
66  const MachineOperand &MO = MI->getOperand(OpNo);
67
68  switch (MO.getType()) {
69  default: llvm_unreachable ("<unknown operand type>");
70  case MachineOperand::MO_Register:
71    O << HexagonInstPrinter::getRegisterName(MO.getReg());
72    return;
73  case MachineOperand::MO_Immediate:
74    O << MO.getImm();
75    return;
76  case MachineOperand::MO_MachineBasicBlock:
77    O << *MO.getMBB()->getSymbol();
78    return;
79  case MachineOperand::MO_ConstantPoolIndex:
80    O << *GetCPISymbol(MO.getIndex());
81    return;
82  case MachineOperand::MO_GlobalAddress:
83    // Computing the address of a global symbol, not calling it.
84    O << *getSymbol(MO.getGlobal());
85    printOffset(MO.getOffset(), O);
86    return;
87  }
88}
89
90//
91// isBlockOnlyReachableByFallthrough - We need to override this since the
92// default AsmPrinter does not print labels for any basic block that
93// is only reachable by a fall through. That works for all cases except
94// for the case in which the basic block is reachable by a fall through but
95// through an indirect from a jump table. In this case, the jump table
96// will contain a label not defined by AsmPrinter.
97//
98bool HexagonAsmPrinter::
99isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
100  if (MBB->hasAddressTaken()) {
101    return false;
102  }
103  return AsmPrinter::isBlockOnlyReachableByFallthrough(MBB);
104}
105
106
107/// PrintAsmOperand - Print out an operand for an inline asm expression.
108///
109bool HexagonAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
110                                        unsigned AsmVariant,
111                                        const char *ExtraCode,
112                                        raw_ostream &OS) {
113  // Does this asm operand have a single letter operand modifier?
114  if (ExtraCode && ExtraCode[0]) {
115    if (ExtraCode[1] != 0) return true; // Unknown modifier.
116
117    switch (ExtraCode[0]) {
118    default:
119      // See if this is a generic print operand
120      return AsmPrinter::PrintAsmOperand(MI, OpNo, AsmVariant, ExtraCode, OS);
121    case 'c': // Don't print "$" before a global var name or constant.
122      // Hexagon never has a prefix.
123      printOperand(MI, OpNo, OS);
124      return false;
125    case 'L': // Write second word of DImode reference.
126      // Verify that this operand has two consecutive registers.
127      if (!MI->getOperand(OpNo).isReg() ||
128          OpNo+1 == MI->getNumOperands() ||
129          !MI->getOperand(OpNo+1).isReg())
130        return true;
131      ++OpNo;   // Return the high-part.
132      break;
133    case 'I':
134      // Write 'i' if an integer constant, otherwise nothing.  Used to print
135      // addi vs add, etc.
136      if (MI->getOperand(OpNo).isImm())
137        OS << "i";
138      return false;
139    }
140  }
141
142  printOperand(MI, OpNo, OS);
143  return false;
144}
145
146bool HexagonAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
147                                            unsigned OpNo, unsigned AsmVariant,
148                                            const char *ExtraCode,
149                                            raw_ostream &O) {
150  if (ExtraCode && ExtraCode[0])
151    return true; // Unknown modifier.
152
153  const MachineOperand &Base  = MI->getOperand(OpNo);
154  const MachineOperand &Offset = MI->getOperand(OpNo+1);
155
156  if (Base.isReg())
157    printOperand(MI, OpNo, O);
158  else
159    llvm_unreachable("Unimplemented");
160
161  if (Offset.isImm()) {
162    if (Offset.getImm())
163      O << " + #" << Offset.getImm();
164  }
165  else
166    llvm_unreachable("Unimplemented");
167
168  return false;
169}
170
171
172/// printMachineInstruction -- Print out a single Hexagon MI in Darwin syntax to
173/// the current output stream.
174///
175void HexagonAsmPrinter::EmitInstruction(const MachineInstr *MI) {
176  if (MI->isBundle()) {
177    std::vector<const MachineInstr*> BundleMIs;
178
179    const MachineBasicBlock *MBB = MI->getParent();
180    MachineBasicBlock::const_instr_iterator MII = MI;
181    ++MII;
182    unsigned int IgnoreCount = 0;
183    while (MII != MBB->end() && MII->isInsideBundle()) {
184      const MachineInstr *MInst = MII;
185      if (MInst->getOpcode() == TargetOpcode::DBG_VALUE ||
186          MInst->getOpcode() == TargetOpcode::IMPLICIT_DEF) {
187          IgnoreCount++;
188          ++MII;
189          continue;
190      }
191      //BundleMIs.push_back(&*MII);
192      BundleMIs.push_back(MInst);
193      ++MII;
194    }
195    unsigned Size = BundleMIs.size();
196    assert((Size+IgnoreCount) == MI->getBundleSize() && "Corrupt Bundle!");
197    for (unsigned Index = 0; Index < Size; Index++) {
198      HexagonMCInst MCI;
199      MCI.setPacketStart(Index == 0);
200      MCI.setPacketEnd(Index == (Size-1));
201
202      HexagonLowerToMC(BundleMIs[Index], MCI, *this);
203      EmitToStreamer(OutStreamer, MCI);
204    }
205  }
206  else {
207    HexagonMCInst MCI;
208    if (MI->getOpcode() == Hexagon::ENDLOOP0) {
209      MCI.setPacketStart(true);
210      MCI.setPacketEnd(true);
211    }
212    HexagonLowerToMC(MI, MCI, *this);
213    EmitToStreamer(OutStreamer, MCI);
214  }
215
216  return;
217}
218
219static MCInstPrinter *createHexagonMCInstPrinter(const Target &T,
220                                                 unsigned SyntaxVariant,
221                                                 const MCAsmInfo &MAI,
222                                                 const MCInstrInfo &MII,
223                                                 const MCRegisterInfo &MRI,
224                                                 const MCSubtargetInfo &STI) {
225  if (SyntaxVariant == 0)
226    return(new HexagonInstPrinter(MAI, MII, MRI));
227  else
228   return nullptr;
229}
230
231extern "C" void LLVMInitializeHexagonAsmPrinter() {
232  RegisterAsmPrinter<HexagonAsmPrinter> X(TheHexagonTarget);
233
234  TargetRegistry::RegisterMCInstPrinter(TheHexagonTarget,
235                                        createHexagonMCInstPrinter);
236}
237