NVPTXAsmPrinter.h revision 263508 
1//===-- NVPTXAsmPrinter.h - NVPTX 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 NVPTX assembly language.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef NVPTXASMPRINTER_H
16#define NVPTXASMPRINTER_H
17
18#include "NVPTX.h"
19#include "NVPTXSubtarget.h"
20#include "NVPTXTargetMachine.h"
21#include "llvm/ADT/SmallString.h"
22#include "llvm/ADT/StringExtras.h"
23#include "llvm/CodeGen/AsmPrinter.h"
24#include "llvm/IR/Function.h"
25#include "llvm/MC/MCAsmInfo.h"
26#include "llvm/MC/MCExpr.h"
27#include "llvm/MC/MCSymbol.h"
28#include "llvm/Support/CommandLine.h"
29#include "llvm/Support/FormattedStream.h"
30#include "llvm/Target/Mangler.h"
31#include "llvm/Target/TargetMachine.h"
32#include <fstream>
33
34// The ptx syntax and format is very different from that usually seem in a .s
35// file,
36// therefore we are not able to use the MCAsmStreamer interface here.
37//
38// We are handcrafting the output method here.
39//
40// A better approach is to clone the MCAsmStreamer to a MCPTXAsmStreamer
41// (subclass of MCStreamer).
42
43// This is defined in AsmPrinter.cpp.
44// Used to process the constant expressions in initializers.
45namespace nvptx {
46const llvm::MCExpr *
47LowerConstant(const llvm::Constant *CV, llvm::AsmPrinter &AP);
48}
49
50namespace llvm {
51
52class LineReader {
53private:
54  unsigned theCurLine;
55  std::ifstream fstr;
56  char buff[512];
57  std::string theFileName;
58  SmallVector<unsigned, 32> lineOffset;
59public:
60  LineReader(std::string filename) {
61    theCurLine = 0;
62    fstr.open(filename.c_str());
63    theFileName = filename;
64  }
65  std::string fileName() { return theFileName; }
66  ~LineReader() { fstr.close(); }
67  std::string readLine(unsigned line);
68};
69
70class LLVM_LIBRARY_VISIBILITY NVPTXAsmPrinter : public AsmPrinter {
71
72  class AggBuffer {
73    // Used to buffer the emitted string for initializing global
74    // aggregates.
75    //
76    // Normally an aggregate (array, vector or structure) is emitted
77    // as a u8[]. However, if one element/field of the aggregate
78    // is a non-NULL address, then the aggregate is emitted as u32[]
79    // or u64[].
80    //
81    // We first layout the aggregate in 'buffer' in bytes, except for
82    // those symbol addresses. For the i-th symbol address in the
83    //aggregate, its corresponding 4-byte or 8-byte elements in 'buffer'
84    // are filled with 0s. symbolPosInBuffer[i-1] records its position
85    // in 'buffer', and Symbols[i-1] records the Value*.
86    //
87    // Once we have this AggBuffer setup, we can choose how to print
88    // it out.
89  public:
90    unsigned size;         // size of the buffer in bytes
91    unsigned char *buffer; // the buffer
92    unsigned numSymbols;   // number of symbol addresses
93    SmallVector<unsigned, 4> symbolPosInBuffer;
94    SmallVector<const Value *, 4> Symbols;
95
96  private:
97    unsigned curpos;
98    raw_ostream &O;
99    NVPTXAsmPrinter &AP;
100
101  public:
102    AggBuffer(unsigned _size, raw_ostream &_O, NVPTXAsmPrinter &_AP)
103        : O(_O), AP(_AP) {
104      buffer = new unsigned char[_size];
105      size = _size;
106      curpos = 0;
107      numSymbols = 0;
108    }
109    ~AggBuffer() { delete[] buffer; }
110    unsigned addBytes(unsigned char *Ptr, int Num, int Bytes) {
111      assert((curpos + Num) <= size);
112      assert((curpos + Bytes) <= size);
113      for (int i = 0; i < Num; ++i) {
114        buffer[curpos] = Ptr[i];
115        curpos++;
116      }
117      for (int i = Num; i < Bytes; ++i) {
118        buffer[curpos] = 0;
119        curpos++;
120      }
121      return curpos;
122    }
123    unsigned addZeros(int Num) {
124      assert((curpos + Num) <= size);
125      for (int i = 0; i < Num; ++i) {
126        buffer[curpos] = 0;
127        curpos++;
128      }
129      return curpos;
130    }
131    void addSymbol(const Value *GVar) {
132      symbolPosInBuffer.push_back(curpos);
133      Symbols.push_back(GVar);
134      numSymbols++;
135    }
136    void print() {
137      if (numSymbols == 0) {
138        // print out in bytes
139        for (unsigned i = 0; i < size; i++) {
140          if (i)
141            O << ", ";
142          O << (unsigned int) buffer[i];
143        }
144      } else {
145        // print out in 4-bytes or 8-bytes
146        unsigned int pos = 0;
147        unsigned int nSym = 0;
148        unsigned int nextSymbolPos = symbolPosInBuffer[nSym];
149        unsigned int nBytes = 4;
150        if (AP.nvptxSubtarget.is64Bit())
151          nBytes = 8;
152        for (pos = 0; pos < size; pos += nBytes) {
153          if (pos)
154            O << ", ";
155          if (pos == nextSymbolPos) {
156            const Value *v = Symbols[nSym];
157            if (const GlobalValue *GVar = dyn_cast<GlobalValue>(v)) {
158              MCSymbol *Name = AP.getSymbol(GVar);
159              O << *Name;
160            } else if (const ConstantExpr *Cexpr = dyn_cast<ConstantExpr>(v)) {
161              O << *nvptx::LowerConstant(Cexpr, AP);
162            } else
163              llvm_unreachable("symbol type unknown");
164            nSym++;
165            if (nSym >= numSymbols)
166              nextSymbolPos = size + 1;
167            else
168              nextSymbolPos = symbolPosInBuffer[nSym];
169          } else if (nBytes == 4)
170            O << *(unsigned int *)(buffer + pos);
171          else
172            O << *(unsigned long long *)(buffer + pos);
173        }
174      }
175    }
176  };
177
178  friend class AggBuffer;
179
180  virtual void emitSrcInText(StringRef filename, unsigned line);
181
182private:
183  virtual const char *getPassName() const { return "NVPTX Assembly Printer"; }
184
185  const Function *F;
186  std::string CurrentFnName;
187
188  void EmitFunctionEntryLabel();
189  void EmitFunctionBodyStart();
190  void EmitFunctionBodyEnd();
191  void emitImplicitDef(const MachineInstr *MI) const;
192
193  void EmitInstruction(const MachineInstr *);
194  void lowerToMCInst(const MachineInstr *MI, MCInst &OutMI);
195  bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp);
196  MCOperand GetSymbolRef(const MachineOperand &MO, const MCSymbol *Symbol);
197  unsigned encodeVirtualRegister(unsigned Reg);
198
199  void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0) const {}
200
201  void printGlobalVariable(const GlobalVariable *GVar);
202  void printVecModifiedImmediate(const MachineOperand &MO, const char *Modifier,
203                                 raw_ostream &O);
204  void printMemOperand(const MachineInstr *MI, int opNum, raw_ostream &O,
205                       const char *Modifier = 0);
206  void printImplicitDef(const MachineInstr *MI, raw_ostream &O) const;
207  // definition autogenerated.
208  void printInstruction(const MachineInstr *MI, raw_ostream &O);
209  void printModuleLevelGV(const GlobalVariable *GVar, raw_ostream &O,
210                          bool = false);
211  void printParamName(int paramIndex, raw_ostream &O);
212  void printParamName(Function::const_arg_iterator I, int paramIndex,
213                      raw_ostream &O);
214  void emitGlobals(const Module &M);
215  void emitHeader(Module &M, raw_ostream &O);
216  void emitKernelFunctionDirectives(const Function &F, raw_ostream &O) const;
217  void emitVirtualRegister(unsigned int vr, raw_ostream &);
218  void emitFunctionExternParamList(const MachineFunction &MF);
219  void emitFunctionParamList(const Function *, raw_ostream &O);
220  void emitFunctionParamList(const MachineFunction &MF, raw_ostream &O);
221  void setAndEmitFunctionVirtualRegisters(const MachineFunction &MF);
222  void emitFunctionTempData(const MachineFunction &MF, unsigned &FrameSize);
223  bool isImageType(const Type *Ty);
224  void printReturnValStr(const Function *, raw_ostream &O);
225  void printReturnValStr(const MachineFunction &MF, raw_ostream &O);
226  bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
227                       unsigned AsmVariant, const char *ExtraCode,
228                       raw_ostream &);
229  void printOperand(const MachineInstr *MI, int opNum, raw_ostream &O,
230                    const char *Modifier = 0);
231  bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
232                             unsigned AsmVariant, const char *ExtraCode,
233                             raw_ostream &);
234protected:
235  bool doInitialization(Module &M);
236  bool doFinalization(Module &M);
237
238private:
239  std::string CurrentBankselLabelInBasicBlock;
240
241  bool GlobalsEmitted;
242
243  // This is specific per MachineFunction.
244  const MachineRegisterInfo *MRI;
245  // The contents are specific for each
246  // MachineFunction. But the size of the
247  // array is not.
248  typedef DenseMap<unsigned, unsigned> VRegMap;
249  typedef DenseMap<const TargetRegisterClass *, VRegMap> VRegRCMap;
250  VRegRCMap VRegMapping;
251  // cache the subtarget here.
252  const NVPTXSubtarget &nvptxSubtarget;
253  // Build the map between type name and ID based on module's type
254  // symbol table.
255  std::map<const Type *, std::string> TypeNameMap;
256
257  // List of variables demoted to a function scope.
258  std::map<const Function *, std::vector<const GlobalVariable *> > localDecls;
259
260  // To record filename to ID mapping
261  std::map<std::string, unsigned> filenameMap;
262  void recordAndEmitFilenames(Module &);
263
264  void emitPTXGlobalVariable(const GlobalVariable *GVar, raw_ostream &O);
265  void emitPTXAddressSpace(unsigned int AddressSpace, raw_ostream &O) const;
266  std::string getPTXFundamentalTypeStr(const Type *Ty, bool = true) const;
267  void printScalarConstant(const Constant *CPV, raw_ostream &O);
268  void printFPConstant(const ConstantFP *Fp, raw_ostream &O);
269  void bufferLEByte(const Constant *CPV, int Bytes, AggBuffer *aggBuffer);
270  void bufferAggregateConstant(const Constant *CV, AggBuffer *aggBuffer);
271
272  void printOperandProper(const MachineOperand &MO);
273
274  void emitLinkageDirective(const GlobalValue *V, raw_ostream &O);
275  void emitDeclarations(const Module &, raw_ostream &O);
276  void emitDeclaration(const Function *, raw_ostream &O);
277
278  static const char *getRegisterName(unsigned RegNo);
279  void emitDemotedVars(const Function *, raw_ostream &);
280
281  LineReader *reader;
282  LineReader *getReader(std::string);
283public:
284  NVPTXAsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
285      : AsmPrinter(TM, Streamer),
286        nvptxSubtarget(TM.getSubtarget<NVPTXSubtarget>()) {
287    CurrentBankselLabelInBasicBlock = "";
288    reader = NULL;
289  }
290
291  ~NVPTXAsmPrinter() {
292    if (!reader)
293      delete reader;
294  }
295
296  bool ignoreLoc(const MachineInstr &);
297
298  std::string getVirtualRegisterName(unsigned) const;
299
300  DebugLoc prevDebugLoc;
301  void emitLineNumberAsDotLoc(const MachineInstr &);
302};
303} // end of namespace
304
305#endif
306