llvm/lib/Target/SPIRV/MCTargetDesc/SPIRVInstPrinter.cpp

   1 //===-- SPIRVInstPrinter.cpp - Output SPIR-V MCInsts as ASM -----*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This class prints a SPIR-V MCInst to a .s file.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "SPIRVInstPrinter.h"
  14 #include "SPIRV.h"
  15 #include "SPIRVBaseInfo.h"
  16 #include "SPIRVInstrInfo.h"
  17 #include "llvm/ADT/APFloat.h"
  18 #include "llvm/CodeGen/Register.h"
  19 #include "llvm/MC/MCAsmInfo.h"
  20 #include "llvm/MC/MCExpr.h"
  21 #include "llvm/MC/MCInst.h"
  22 #include "llvm/MC/MCInstrInfo.h"
  23 #include "llvm/MC/MCSymbol.h"
  24 #include "llvm/Support/Casting.h"
  25 #include "llvm/Support/ErrorHandling.h"
  26 #include "llvm/Support/FormattedStream.h"
  27
  28 using namespace llvm;
  29 using namespace llvm::SPIRV;
  30
  31 #define DEBUG_TYPE "asm-printer"
  32
  33 // Include the auto-generated portion of the assembly writer.
  34 #include "SPIRVGenAsmWriter.inc"
  35
  36 void SPIRVInstPrinter::printRemainingVariableOps(const MCInst *MI,
  37                                                  unsigned StartIndex,
  38                                                  raw_ostream &O,
  39                                                  bool SkipFirstSpace,
  40                                                  bool SkipImmediates) {
  41   const unsigned NumOps = MI->getNumOperands();
  42   for (unsigned i = StartIndex; i < NumOps; ++i) {
  43     if (!SkipImmediates || !MI->getOperand(i).isImm()) {
  44       if (!SkipFirstSpace || i != StartIndex)
  45         O << ' ';
  46       printOperand(MI, i, O);
  47     }
  48   }
  49 }
  50
  51 void SPIRVInstPrinter::printOpConstantVarOps(const MCInst *MI,
  52                                              unsigned StartIndex,
  53                                              raw_ostream &O) {
  54   unsigned IsBitwidth16 = MI->getFlags() & SPIRV::ASM_PRINTER_WIDTH16;
  55   const unsigned NumVarOps = MI->getNumOperands() - StartIndex;
  56
  57   assert((NumVarOps == 1 || NumVarOps == 2) &&
  58          "Unsupported number of bits for literal variable");
  59
  60   O << ' ';
  61
  62   uint64_t Imm = MI->getOperand(StartIndex).getImm();
  63
  64   // Handle 64 bit literals.
  65   if (NumVarOps == 2) {
  66     Imm |= (MI->getOperand(StartIndex + 1).getImm() << 32);
  67   }
  68
  69   // Format and print float values.
  70   if (MI->getOpcode() == SPIRV::OpConstantF && IsBitwidth16 == 0) {
  71     APFloat FP = NumVarOps == 1 ? APFloat(APInt(32, Imm).bitsToFloat())
  72                                 : APFloat(APInt(64, Imm).bitsToDouble());
  73
  74     // Print infinity and NaN as hex floats.
  75     // TODO: Make sure subnormal numbers are handled correctly as they may also
  76     // require hex float notation.
  77     if (FP.isInfinity()) {
  78       if (FP.isNegative())
  79         O << '-';
  80       O << "0x1p+128";
  81       return;
  82     }
  83     if (FP.isNaN()) {
  84       O << "0x1.8p+128";
  85       return;
  86     }
  87
  88     // Format val as a decimal floating point or scientific notation (whichever
  89     // is shorter), with enough digits of precision to produce the exact value.
  90     O << format("%.*g", std::numeric_limits<double>::max_digits10,
  91                 FP.convertToDouble());
  92
  93     return;
  94   }
  95
  96   // Print integer values directly.
  97   O << Imm;
  98 }
  99
 100 void SPIRVInstPrinter::recordOpExtInstImport(const MCInst *MI) {
 101   Register Reg = MI->getOperand(0).getReg();
 102   auto Name = getSPIRVStringOperand(*MI, 1);
 103   auto Set = getExtInstSetFromString(Name);
 104   ExtInstSetIDs.insert({Reg, Set});
 105 }
 106
 107 void SPIRVInstPrinter::printInst(const MCInst *MI, uint64_t Address,
 108                                  StringRef Annot, const MCSubtargetInfo &STI,
 109                                  raw_ostream &OS) {
 110   const unsigned OpCode = MI->getOpcode();
 111   printInstruction(MI, Address, OS);
 112
 113   if (OpCode == SPIRV::OpDecorate) {
 114     printOpDecorate(MI, OS);
 115   } else if (OpCode == SPIRV::OpExtInstImport) {
 116     recordOpExtInstImport(MI);
 117   } else if (OpCode == SPIRV::OpExtInst) {
 118     printOpExtInst(MI, OS);
 119   } else {
 120     // Print any extra operands for variadic instructions.
 121     const MCInstrDesc &MCDesc = MII.get(OpCode);
 122     if (MCDesc.isVariadic()) {
 123       const unsigned NumFixedOps = MCDesc.getNumOperands();
 124       const unsigned LastFixedIndex = NumFixedOps - 1;
 125       const int FirstVariableIndex = NumFixedOps;
 126       if (NumFixedOps > 0 && MCDesc.operands()[LastFixedIndex].OperandType ==
 127                                  MCOI::OPERAND_UNKNOWN) {
 128         // For instructions where a custom type (not reg or immediate) comes as
 129         // the last operand before the variable_ops. This is usually a StringImm
 130         // operand, but there are a few other cases.
 131         switch (OpCode) {
 132         case SPIRV::OpTypeImage:
 133           OS << ' ';
 134           printSymbolicOperand<OperandCategory::AccessQualifierOperand>(
 135               MI, FirstVariableIndex, OS);
 136           break;
 137         case SPIRV::OpVariable:
 138           OS << ' ';
 139           printOperand(MI, FirstVariableIndex, OS);
 140           break;
 141         case SPIRV::OpEntryPoint: {
 142           // Print the interface ID operands, skipping the name's string
 143           // literal.
 144           printRemainingVariableOps(MI, NumFixedOps, OS, false, true);
 145           break;
 146         }
 147         case SPIRV::OpExecutionMode:
 148         case SPIRV::OpExecutionModeId:
 149         case SPIRV::OpLoopMerge: {
 150           // Print any literals after the OPERAND_UNKNOWN argument normally.
 151           printRemainingVariableOps(MI, NumFixedOps, OS);
 152           break;
 153         }
 154         default:
 155           break; // printStringImm has already been handled.
 156         }
 157       } else {
 158         // For instructions with no fixed ops or a reg/immediate as the final
 159         // fixed operand, we can usually print the rest with "printOperand", but
 160         // check for a few cases with custom types first.
 161         switch (OpCode) {
 162         case SPIRV::OpLoad:
 163         case SPIRV::OpStore:
 164           OS << ' ';
 165           printSymbolicOperand<OperandCategory::MemoryOperandOperand>(
 166               MI, FirstVariableIndex, OS);
 167           printRemainingVariableOps(MI, FirstVariableIndex + 1, OS);
 168           break;
 169         case SPIRV::OpImageSampleImplicitLod:
 170         case SPIRV::OpImageSampleDrefImplicitLod:
 171         case SPIRV::OpImageSampleProjImplicitLod:
 172         case SPIRV::OpImageSampleProjDrefImplicitLod:
 173         case SPIRV::OpImageFetch:
 174         case SPIRV::OpImageGather:
 175         case SPIRV::OpImageDrefGather:
 176         case SPIRV::OpImageRead:
 177         case SPIRV::OpImageWrite:
 178         case SPIRV::OpImageSparseSampleImplicitLod:
 179         case SPIRV::OpImageSparseSampleDrefImplicitLod:
 180         case SPIRV::OpImageSparseSampleProjImplicitLod:
 181         case SPIRV::OpImageSparseSampleProjDrefImplicitLod:
 182         case SPIRV::OpImageSparseFetch:
 183         case SPIRV::OpImageSparseGather:
 184         case SPIRV::OpImageSparseDrefGather:
 185         case SPIRV::OpImageSparseRead:
 186         case SPIRV::OpImageSampleFootprintNV:
 187           OS << ' ';
 188           printSymbolicOperand<OperandCategory::ImageOperandOperand>(
 189               MI, FirstVariableIndex, OS);
 190           printRemainingVariableOps(MI, NumFixedOps + 1, OS);
 191           break;
 192         case SPIRV::OpCopyMemory:
 193         case SPIRV::OpCopyMemorySized: {
 194           const unsigned NumOps = MI->getNumOperands();
 195           for (unsigned i = NumFixedOps; i < NumOps; ++i) {
 196             OS << ' ';
 197             printSymbolicOperand<OperandCategory::MemoryOperandOperand>(MI, i,
 198                                                                         OS);
 199             if (MI->getOperand(i).getImm() & MemoryOperand::Aligned) {
 200               assert(i + 1 < NumOps && "Missing alignment operand");
 201               OS << ' ';
 202               printOperand(MI, i + 1, OS);
 203               i += 1;
 204             }
 205           }
 206           break;
 207         }
 208         case SPIRV::OpConstantI:
 209         case SPIRV::OpConstantF:
 210           // The last fixed operand along with any variadic operands that follow
 211           // are part of the variable value.
 212           printOpConstantVarOps(MI, NumFixedOps - 1, OS);
 213           break;
 214         default:
 215           printRemainingVariableOps(MI, NumFixedOps, OS);
 216           break;
 217         }
 218       }
 219     }
 220   }
 221
 222   printAnnotation(OS, Annot);
 223 }
 224
 225 void SPIRVInstPrinter::printOpExtInst(const MCInst *MI, raw_ostream &O) {
 226   // The fixed operands have already been printed, so just need to decide what
 227   // type of ExtInst operands to print based on the instruction set and number.
 228   const MCInstrDesc &MCDesc = MII.get(MI->getOpcode());
 229   unsigned NumFixedOps = MCDesc.getNumOperands();
 230   const auto NumOps = MI->getNumOperands();
 231   if (NumOps == NumFixedOps)
 232     return;
 233
 234   O << ' ';
 235
 236   // TODO: implement special printing for OpenCLExtInst::vstor*.
 237   printRemainingVariableOps(MI, NumFixedOps, O, true);
 238 }
 239
 240 void SPIRVInstPrinter::printOpDecorate(const MCInst *MI, raw_ostream &O) {
 241   // The fixed operands have already been printed, so just need to decide what
 242   // type of decoration operands to print based on the Decoration type.
 243   const MCInstrDesc &MCDesc = MII.get(MI->getOpcode());
 244   unsigned NumFixedOps = MCDesc.getNumOperands();
 245
 246   if (NumFixedOps != MI->getNumOperands()) {
 247     auto DecOp = MI->getOperand(NumFixedOps - 1);
 248     auto Dec = static_cast<Decoration::Decoration>(DecOp.getImm());
 249
 250     O << ' ';
 251
 252     switch (Dec) {
 253     case Decoration::BuiltIn:
 254       printSymbolicOperand<OperandCategory::BuiltInOperand>(MI, NumFixedOps, O);
 255       break;
 256     case Decoration::UniformId:
 257       printSymbolicOperand<OperandCategory::ScopeOperand>(MI, NumFixedOps, O);
 258       break;
 259     case Decoration::FuncParamAttr:
 260       printSymbolicOperand<OperandCategory::FunctionParameterAttributeOperand>(
 261           MI, NumFixedOps, O);
 262       break;
 263     case Decoration::FPRoundingMode:
 264       printSymbolicOperand<OperandCategory::FPRoundingModeOperand>(
 265           MI, NumFixedOps, O);
 266       break;
 267     case Decoration::FPFastMathMode:
 268       printSymbolicOperand<OperandCategory::FPFastMathModeOperand>(
 269           MI, NumFixedOps, O);
 270       break;
 271     case Decoration::LinkageAttributes:
 272     case Decoration::UserSemantic:
 273       printStringImm(MI, NumFixedOps, O);
 274       break;
 275     case Decoration::HostAccessINTEL:
 276       printOperand(MI, NumFixedOps, O);
 277       if (NumFixedOps + 1 < MI->getNumOperands()) {
 278         O << ' ';
 279         printStringImm(MI, NumFixedOps + 1, O);
 280       }
 281       break;
 282     default:
 283       printRemainingVariableOps(MI, NumFixedOps, O, true);
 284       break;
 285     }
 286   }
 287 }
 288
 289 static void printExpr(const MCExpr *Expr, raw_ostream &O) {
 290 #ifndef NDEBUG
 291   const MCSymbolRefExpr *SRE;
 292
 293   if (const MCBinaryExpr *BE = dyn_cast<MCBinaryExpr>(Expr))
 294     SRE = cast<MCSymbolRefExpr>(BE->getLHS());
 295   else
 296     SRE = cast<MCSymbolRefExpr>(Expr);
 297
 298   MCSymbolRefExpr::VariantKind Kind = SRE->getKind();
 299
 300   assert(Kind == MCSymbolRefExpr::VK_None);
 301 #endif
 302   O << *Expr;
 303 }
 304
 305 void SPIRVInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
 306                                     raw_ostream &O, const char *Modifier) {
 307   assert((Modifier == 0 || Modifier[0] == 0) && "No modifiers supported");
 308   if (OpNo < MI->getNumOperands()) {
 309     const MCOperand &Op = MI->getOperand(OpNo);
 310     if (Op.isReg())
 311       O << '%' << (Register::virtReg2Index(Op.getReg()) + 1);
 312     else if (Op.isImm())
 313       O << formatImm((int64_t)Op.getImm());
 314     else if (Op.isDFPImm())
 315       O << formatImm((double)Op.getDFPImm());
 316     else if (Op.isExpr())
 317       printExpr(Op.getExpr(), O);
 318     else
 319       llvm_unreachable("Unexpected operand type");
 320   }
 321 }
 322
 323 void SPIRVInstPrinter::printStringImm(const MCInst *MI, unsigned OpNo,
 324                                       raw_ostream &O) {
 325   const unsigned NumOps = MI->getNumOperands();
 326   unsigned StrStartIndex = OpNo;
 327   while (StrStartIndex < NumOps) {
 328     if (MI->getOperand(StrStartIndex).isReg())
 329       break;
 330
 331     std::string Str = getSPIRVStringOperand(*MI, StrStartIndex);
 332     if (StrStartIndex != OpNo)
 333       O << ' '; // Add a space if we're starting a new string/argument.
 334     O << '"';
 335     for (char c : Str) {
 336       // Escape ", \n characters (might break for complex UTF-8).
 337       if (c == '\n') {
 338         O.write("\\n", 2);
 339       } else {
 340         if (c == '"')
 341           O.write('\\');
 342         O.write(c);
 343       }
 344     }
 345     O << '"';
 346
 347     unsigned numOpsInString = (Str.size() / 4) + 1;
 348     StrStartIndex += numOpsInString;
 349
 350     // Check for final Op of "OpDecorate %x %stringImm %linkageAttribute".
 351     if (MI->getOpcode() == SPIRV::OpDecorate &&
 352         MI->getOperand(1).getImm() ==
 353             static_cast<unsigned>(Decoration::LinkageAttributes)) {
 354       O << ' ';
 355       printSymbolicOperand<OperandCategory::LinkageTypeOperand>(
 356           MI, StrStartIndex, O);
 357       break;
 358     }
 359   }
 360 }
 361
 362 void SPIRVInstPrinter::printExtension(const MCInst *MI, unsigned OpNo,
 363                                       raw_ostream &O) {
 364   auto SetReg = MI->getOperand(2).getReg();
 365   auto Set = ExtInstSetIDs[SetReg];
 366   auto Op = MI->getOperand(OpNo).getImm();
 367   O << getExtInstName(Set, Op);
 368 }
 369
 370 template <OperandCategory::OperandCategory category>
 371 void SPIRVInstPrinter::printSymbolicOperand(const MCInst *MI, unsigned OpNo,
 372                                             raw_ostream &O) {
 373   if (OpNo < MI->getNumOperands()) {
 374     O << getSymbolicOperandMnemonic(category, MI->getOperand(OpNo).getImm());
 375   }
 376 }