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 LLVM_LIB_TARGET_NVPTX_NVPTXASMPRINTER_H
16#define LLVM_LIB_TARGET_NVPTX_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/TargetMachine.h"
31#include <fstream>
32
33// The ptx syntax and format is very different from that usually seem in a .s
34// file,
35// therefore we are not able to use the MCAsmStreamer interface here.
36//
37// We are handcrafting the output method here.
38//
39// A better approach is to clone the MCAsmStreamer to a MCPTXAsmStreamer
40// (subclass of MCStreamer).
41
42namespace llvm {
43
44class LineReader {
45private:
46  unsigned theCurLine;
47  std::ifstream fstr;
48  char buff[512];
49  std::string theFileName;
50  SmallVector<unsigned, 32> lineOffset;
51public:
52  LineReader(std::string filename) {
53    theCurLine = 0;
54    fstr.open(filename.c_str());
55    theFileName = filename;
56  }
57  std::string fileName() { return theFileName; }
58  ~LineReader() { fstr.close(); }
59  std::string readLine(unsigned line);
60};
61
62class LLVM_LIBRARY_VISIBILITY NVPTXAsmPrinter : public AsmPrinter {
63
64  class AggBuffer {
65    // Used to buffer the emitted string for initializing global
66    // aggregates.
67    //
68    // Normally an aggregate (array, vector or structure) is emitted
69    // as a u8[]. However, if one element/field of the aggregate
70    // is a non-NULL address, then the aggregate is emitted as u32[]
71    // or u64[].
72    //
73    // We first layout the aggregate in 'buffer' in bytes, except for
74    // those symbol addresses. For the i-th symbol address in the
75    //aggregate, its corresponding 4-byte or 8-byte elements in 'buffer'
76    // are filled with 0s. symbolPosInBuffer[i-1] records its position
77    // in 'buffer', and Symbols[i-1] records the Value*.
78    //
79    // Once we have this AggBuffer setup, we can choose how to print
80    // it out.
81  public:
82    unsigned numSymbols;   // number of symbol addresses
83
84  private:
85    const unsigned size;   // size of the buffer in bytes
86    std::vector<unsigned char> buffer; // the buffer
87    SmallVector<unsigned, 4> symbolPosInBuffer;
88    SmallVector<const Value *, 4> Symbols;
89    unsigned curpos;
90    raw_ostream &O;
91    NVPTXAsmPrinter &AP;
92    bool EmitGeneric;
93
94  public:
95    AggBuffer(unsigned size, raw_ostream &O, NVPTXAsmPrinter &AP)
96        : size(size), buffer(size), O(O), AP(AP) {
97      curpos = 0;
98      numSymbols = 0;
99      EmitGeneric = AP.EmitGeneric;
100    }
101    unsigned addBytes(unsigned char *Ptr, int Num, int Bytes) {
102      assert((curpos + Num) <= size);
103      assert((curpos + Bytes) <= size);
104      for (int i = 0; i < Num; ++i) {
105        buffer[curpos] = Ptr[i];
106        curpos++;
107      }
108      for (int i = Num; i < Bytes; ++i) {
109        buffer[curpos] = 0;
110        curpos++;
111      }
112      return curpos;
113    }
114    unsigned addZeros(int Num) {
115      assert((curpos + Num) <= size);
116      for (int i = 0; i < Num; ++i) {
117        buffer[curpos] = 0;
118        curpos++;
119      }
120      return curpos;
121    }
122    void addSymbol(const Value *GVar) {
123      symbolPosInBuffer.push_back(curpos);
124      Symbols.push_back(GVar);
125      numSymbols++;
126    }
127    void print() {
128      if (numSymbols == 0) {
129        // print out in bytes
130        for (unsigned i = 0; i < size; i++) {
131          if (i)
132            O << ", ";
133          O << (unsigned int) buffer[i];
134        }
135      } else {
136        // print out in 4-bytes or 8-bytes
137        unsigned int pos = 0;
138        unsigned int nSym = 0;
139        unsigned int nextSymbolPos = symbolPosInBuffer[nSym];
140        unsigned int nBytes = 4;
141        if (static_cast<const NVPTXTargetMachine &>(AP.TM).is64Bit())
142          nBytes = 8;
143        for (pos = 0; pos < size; pos += nBytes) {
144          if (pos)
145            O << ", ";
146          if (pos == nextSymbolPos) {
147            const Value *v = Symbols[nSym];
148            if (const GlobalValue *GVar = dyn_cast<GlobalValue>(v)) {
149              MCSymbol *Name = AP.getSymbol(GVar);
150              PointerType *PTy = dyn_cast<PointerType>(GVar->getType());
151              bool IsNonGenericPointer = false;
152              if (PTy && PTy->getAddressSpace() != 0) {
153                IsNonGenericPointer = true;
154              }
155              if (EmitGeneric && !isa<Function>(v) && !IsNonGenericPointer) {
156                O << "generic(";
157                O << *Name;
158                O << ")";
159              } else {
160                O << *Name;
161              }
162            } else if (const ConstantExpr *Cexpr = dyn_cast<ConstantExpr>(v)) {
163              O << *AP.lowerConstant(Cexpr);
164            } else
165              llvm_unreachable("symbol type unknown");
166            nSym++;
167            if (nSym >= numSymbols)
168              nextSymbolPos = size + 1;
169            else
170              nextSymbolPos = symbolPosInBuffer[nSym];
171          } else if (nBytes == 4)
172            O << *(unsigned int *)(&buffer[pos]);
173          else
174            O << *(unsigned long long *)(&buffer[pos]);
175        }
176      }
177    }
178  };
179
180  friend class AggBuffer;
181
182  void emitSrcInText(StringRef filename, unsigned line);
183
184private:
185  const char *getPassName() const override { return "NVPTX Assembly Printer"; }
186
187  const Function *F;
188  std::string CurrentFnName;
189
190  void EmitBasicBlockStart(const MachineBasicBlock &MBB) const override;
191  void EmitFunctionEntryLabel() override;
192  void EmitFunctionBodyStart() override;
193  void EmitFunctionBodyEnd() override;
194  void emitImplicitDef(const MachineInstr *MI) const override;
195
196  void EmitInstruction(const MachineInstr *) override;
197  void lowerToMCInst(const MachineInstr *MI, MCInst &OutMI);
198  bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp);
199  MCOperand GetSymbolRef(const MCSymbol *Symbol);
200  unsigned encodeVirtualRegister(unsigned Reg);
201
202  void EmitAlignment(unsigned NumBits, const GlobalValue *GV = nullptr) const {}
203
204  void printVecModifiedImmediate(const MachineOperand &MO, const char *Modifier,
205                                 raw_ostream &O);
206  void printMemOperand(const MachineInstr *MI, int opNum, raw_ostream &O,
207                       const char *Modifier = nullptr);
208  void printImplicitDef(const MachineInstr *MI, raw_ostream &O) const;
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, const NVPTXSubtarget &STI);
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 &) override;
229  void printOperand(const MachineInstr *MI, int opNum, raw_ostream &O,
230                    const char *Modifier = nullptr);
231  bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
232                             unsigned AsmVariant, const char *ExtraCode,
233                             raw_ostream &) override;
234protected:
235  bool doInitialization(Module &M) override;
236  bool doFinalization(Module &M) override;
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
252  // Cache the subtarget here.
253  const NVPTXSubtarget *nvptxSubtarget;
254
255  // Build the map between type name and ID based on module's type
256  // symbol table.
257  std::map<const Type *, std::string> TypeNameMap;
258
259  // List of variables demoted to a function scope.
260  std::map<const Function *, std::vector<const GlobalVariable *> > localDecls;
261
262  // To record filename to ID mapping
263  std::map<std::string, unsigned> filenameMap;
264  void recordAndEmitFilenames(Module &);
265
266  void emitPTXGlobalVariable(const GlobalVariable *GVar, raw_ostream &O);
267  void emitPTXAddressSpace(unsigned int AddressSpace, raw_ostream &O) const;
268  std::string getPTXFundamentalTypeStr(const Type *Ty, bool = true) const;
269  void printScalarConstant(const Constant *CPV, raw_ostream &O);
270  void printFPConstant(const ConstantFP *Fp, raw_ostream &O);
271  void bufferLEByte(const Constant *CPV, int Bytes, AggBuffer *aggBuffer);
272  void bufferAggregateConstant(const Constant *CV, AggBuffer *aggBuffer);
273
274  void printOperandProper(const MachineOperand &MO);
275
276  void emitLinkageDirective(const GlobalValue *V, raw_ostream &O);
277  void emitDeclarations(const Module &, raw_ostream &O);
278  void emitDeclaration(const Function *, raw_ostream &O);
279
280  static const char *getRegisterName(unsigned RegNo);
281  void emitDemotedVars(const Function *, raw_ostream &);
282
283  bool lowerImageHandleOperand(const MachineInstr *MI, unsigned OpNo,
284                               MCOperand &MCOp);
285  void lowerImageHandleSymbol(unsigned Index, MCOperand &MCOp);
286
287  bool isLoopHeaderOfNoUnroll(const MachineBasicBlock &MBB) const;
288
289  LineReader *reader;
290  LineReader *getReader(std::string);
291
292  // Used to control the need to emit .generic() in the initializer of
293  // module scope variables.
294  // Although ptx supports the hybrid mode like the following,
295  //    .global .u32 a;
296  //    .global .u32 b;
297  //    .global .u32 addr[] = {a, generic(b)}
298  // we have difficulty representing the difference in the NVVM IR.
299  //
300  // Since the address value should always be generic in CUDA C and always
301  // be specific in OpenCL, we use this simple control here.
302  //
303  bool EmitGeneric;
304
305public:
306  NVPTXAsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
307      : AsmPrinter(TM, std::move(Streamer)),
308        EmitGeneric(static_cast<NVPTXTargetMachine &>(TM).getDrvInterface() ==
309                    NVPTX::CUDA) {
310    CurrentBankselLabelInBasicBlock = "";
311    reader = nullptr;
312  }
313
314  ~NVPTXAsmPrinter() {
315    if (!reader)
316      delete reader;
317  }
318
319  bool runOnMachineFunction(MachineFunction &F) override {
320    nvptxSubtarget = &F.getSubtarget<NVPTXSubtarget>();
321    return AsmPrinter::runOnMachineFunction(F);
322  }
323  void getAnalysisUsage(AnalysisUsage &AU) const override {
324    AU.addRequired<MachineLoopInfo>();
325    AsmPrinter::getAnalysisUsage(AU);
326  }
327
328  bool ignoreLoc(const MachineInstr &);
329
330  std::string getVirtualRegisterName(unsigned) const;
331
332  DebugLoc prevDebugLoc;
333  void emitLineNumberAsDotLoc(const MachineInstr &);
334};
335} // end of namespace
336
337#endif
338