//=- WebAssemblyInstPrinter.cpp - WebAssembly assembly instruction printing -=// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// /// /// \file /// \brief Print MCInst instructions to wasm format. /// //===----------------------------------------------------------------------===// #include "InstPrinter/WebAssemblyInstPrinter.h" #include "MCTargetDesc/WebAssemblyMCTargetDesc.h" #include "WebAssembly.h" #include "WebAssemblyMachineFunctionInfo.h" #include "llvm/ADT/SmallSet.h" #include "llvm/ADT/StringExtras.h" #include "llvm/MC/MCExpr.h" #include "llvm/MC/MCInst.h" #include "llvm/MC/MCInstrInfo.h" #include "llvm/MC/MCSubtargetInfo.h" #include "llvm/MC/MCSymbol.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/FormattedStream.h" #include "llvm/Target/TargetRegisterInfo.h" using namespace llvm; #define DEBUG_TYPE "asm-printer" #include "WebAssemblyGenAsmWriter.inc" WebAssemblyInstPrinter::WebAssemblyInstPrinter(const MCAsmInfo &MAI, const MCInstrInfo &MII, const MCRegisterInfo &MRI) : MCInstPrinter(MAI, MII, MRI), ControlFlowCounter(0) {} void WebAssemblyInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const { assert(RegNo != WebAssemblyFunctionInfo::UnusedReg); // Note that there's an implicit get_local/set_local here! OS << "$" << RegNo; } void WebAssemblyInstPrinter::printInst(const MCInst *MI, raw_ostream &OS, StringRef Annot, const MCSubtargetInfo & /*STI*/) { // Print the instruction (this uses the AsmStrings from the .td files). printInstruction(MI, OS); // Print any additional variadic operands. const MCInstrDesc &Desc = MII.get(MI->getOpcode()); if (Desc.isVariadic()) for (auto i = Desc.getNumOperands(), e = MI->getNumOperands(); i < e; ++i) { if (i != 0) OS << ", "; printOperand(MI, i, OS); } // Print any added annotation. printAnnotation(OS, Annot); if (CommentStream) { // Observe any effects on the control flow stack, for use in annotating // control flow label references. switch (MI->getOpcode()) { default: break; case WebAssembly::LOOP: { // Grab the TopLabel value first so that labels print in numeric order. uint64_t TopLabel = ControlFlowCounter++; ControlFlowStack.push_back(std::make_pair(ControlFlowCounter++, false)); printAnnotation(OS, "label" + utostr(TopLabel) + ':'); ControlFlowStack.push_back(std::make_pair(TopLabel, true)); break; } case WebAssembly::BLOCK: ControlFlowStack.push_back(std::make_pair(ControlFlowCounter++, false)); break; case WebAssembly::END_LOOP: ControlFlowStack.pop_back(); printAnnotation( OS, "label" + utostr(ControlFlowStack.pop_back_val().first) + ':'); break; case WebAssembly::END_BLOCK: printAnnotation( OS, "label" + utostr(ControlFlowStack.pop_back_val().first) + ':'); break; } // Annotate any control flow label references. unsigned NumFixedOperands = Desc.NumOperands; SmallSet<uint64_t, 8> Printed; for (unsigned i = 0, e = MI->getNumOperands(); i < e; ++i) { const MCOperandInfo &Info = Desc.OpInfo[i]; if (!(i < NumFixedOperands ? (Info.OperandType == WebAssembly::OPERAND_BASIC_BLOCK) : (Desc.TSFlags & WebAssemblyII::VariableOpImmediateIsLabel))) continue; uint64_t Depth = MI->getOperand(i).getImm(); if (!Printed.insert(Depth).second) continue; const auto &Pair = ControlFlowStack.rbegin()[Depth]; printAnnotation(OS, utostr(Depth) + ": " + (Pair.second ? "up" : "down") + " to label" + utostr(Pair.first)); } } } static std::string toString(const APFloat &FP) { // Print NaNs with custom payloads specially. if (FP.isNaN() && !FP.bitwiseIsEqual(APFloat::getQNaN(FP.getSemantics())) && !FP.bitwiseIsEqual(APFloat::getQNaN(FP.getSemantics(), /*Negative=*/true))) { APInt AI = FP.bitcastToAPInt(); return std::string(AI.isNegative() ? "-" : "") + "nan:0x" + utohexstr(AI.getZExtValue() & (AI.getBitWidth() == 32 ? INT64_C(0x007fffff) : INT64_C(0x000fffffffffffff)), /*LowerCase=*/true); } // Use C99's hexadecimal floating-point representation. static const size_t BufBytes = 128; char buf[BufBytes]; auto Written = FP.convertToHexString( buf, /*hexDigits=*/0, /*upperCase=*/false, APFloat::rmNearestTiesToEven); (void)Written; assert(Written != 0); assert(Written < BufBytes); return buf; } void WebAssemblyInstPrinter::printOperand(const MCInst *MI, unsigned OpNo, raw_ostream &O) { const MCOperand &Op = MI->getOperand(OpNo); if (Op.isReg()) { assert((OpNo < MII.get(MI->getOpcode()).getNumOperands() || MII.get(MI->getOpcode()).TSFlags == 0) && "WebAssembly variable_ops register ops don't use TSFlags"); unsigned WAReg = Op.getReg(); if (int(WAReg) >= 0) printRegName(O, WAReg); else if (OpNo >= MII.get(MI->getOpcode()).getNumDefs()) O << "$pop" << WebAssemblyFunctionInfo::getWARegStackId(WAReg); else if (WAReg != WebAssemblyFunctionInfo::UnusedReg) O << "$push" << WebAssemblyFunctionInfo::getWARegStackId(WAReg); else O << "$drop"; // Add a '=' suffix if this is a def. if (OpNo < MII.get(MI->getOpcode()).getNumDefs()) O << '='; } else if (Op.isImm()) { assert((OpNo < MII.get(MI->getOpcode()).getNumOperands() || (MII.get(MI->getOpcode()).TSFlags & WebAssemblyII::VariableOpIsImmediate)) && "WebAssemblyII::VariableOpIsImmediate should be set for " "variable_ops immediate ops"); // TODO: (MII.get(MI->getOpcode()).TSFlags & // WebAssemblyII::VariableOpImmediateIsLabel) // can tell us whether this is an immediate referencing a label in the // control flow stack, and it may be nice to pretty-print. O << Op.getImm(); } else if (Op.isFPImm()) { const MCInstrDesc &Desc = MII.get(MI->getOpcode()); assert(OpNo < Desc.getNumOperands() && "Unexpected floating-point immediate as a non-fixed operand"); assert(Desc.TSFlags == 0 && "WebAssembly variable_ops floating point ops don't use TSFlags"); const MCOperandInfo &Info = Desc.OpInfo[OpNo]; if (Info.OperandType == WebAssembly::OPERAND_FP32IMM) { // TODO: MC converts all floating point immediate operands to double. // This is fine for numeric values, but may cause NaNs to change bits. O << toString(APFloat(float(Op.getFPImm()))); } else { assert(Info.OperandType == WebAssembly::OPERAND_FP64IMM); O << toString(APFloat(Op.getFPImm())); } } else { assert((OpNo < MII.get(MI->getOpcode()).getNumOperands() || (MII.get(MI->getOpcode()).TSFlags & WebAssemblyII::VariableOpIsImmediate)) && "WebAssemblyII::VariableOpIsImmediate should be set for " "variable_ops expr ops"); assert(Op.isExpr() && "unknown operand kind in printOperand"); Op.getExpr()->print(O, &MAI); } } void WebAssemblyInstPrinter::printWebAssemblyP2AlignOperand(const MCInst *MI, unsigned OpNo, raw_ostream &O) { int64_t Imm = MI->getOperand(OpNo).getImm(); if (Imm == WebAssembly::GetDefaultP2Align(MI->getOpcode())) return; O << ":p2align=" << Imm; } const char *llvm::WebAssembly::TypeToString(MVT Ty) { switch (Ty.SimpleTy) { case MVT::i32: return "i32"; case MVT::i64: return "i64"; case MVT::f32: return "f32"; case MVT::f64: return "f64"; default: llvm_unreachable("unsupported type"); } }