1 //=- WebAssemblyInstPrinter.cpp - WebAssembly assembly instruction printing -=//
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 /// \file
11 /// \brief Print MCInst instructions to wasm format.
12 ///
13 //===----------------------------------------------------------------------===//
14
15 #include "InstPrinter/WebAssemblyInstPrinter.h"
16 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
17 #include "WebAssembly.h"
18 #include "WebAssemblyMachineFunctionInfo.h"
19 #include "llvm/MC/MCExpr.h"
20 #include "llvm/MC/MCInst.h"
21 #include "llvm/MC/MCInstrInfo.h"
22 #include "llvm/MC/MCSubtargetInfo.h"
23 #include "llvm/MC/MCSymbol.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/FormattedStream.h"
26 #include "llvm/Target/TargetRegisterInfo.h"
27 using namespace llvm;
28
29 #define DEBUG_TYPE "asm-printer"
30
31 #include "WebAssemblyGenAsmWriter.inc"
32
WebAssemblyInstPrinter(const MCAsmInfo & MAI,const MCInstrInfo & MII,const MCRegisterInfo & MRI)33 WebAssemblyInstPrinter::WebAssemblyInstPrinter(const MCAsmInfo &MAI,
34 const MCInstrInfo &MII,
35 const MCRegisterInfo &MRI)
36 : MCInstPrinter(MAI, MII, MRI) {}
37
printRegName(raw_ostream & OS,unsigned RegNo) const38 void WebAssemblyInstPrinter::printRegName(raw_ostream &OS,
39 unsigned RegNo) const {
40 assert(RegNo != WebAssemblyFunctionInfo::UnusedReg);
41 // Note that there's an implicit get_local/set_local here!
42 OS << "$" << RegNo;
43 }
44
printInst(const MCInst * MI,raw_ostream & OS,StringRef Annot,const MCSubtargetInfo &)45 void WebAssemblyInstPrinter::printInst(const MCInst *MI, raw_ostream &OS,
46 StringRef Annot,
47 const MCSubtargetInfo & /*STI*/) {
48 // Print the instruction (this uses the AsmStrings from the .td files).
49 printInstruction(MI, OS);
50
51 // Print any additional variadic operands.
52 const MCInstrDesc &Desc = MII.get(MI->getOpcode());
53 if (Desc.isVariadic())
54 for (auto i = Desc.getNumOperands(), e = MI->getNumOperands(); i < e; ++i) {
55 if (i != 0)
56 OS << ", ";
57 printOperand(MI, i, OS);
58 }
59
60 // Print any added annotation.
61 printAnnotation(OS, Annot);
62 }
63
toString(const APFloat & FP)64 static std::string toString(const APFloat &FP) {
65 static const size_t BufBytes = 128;
66 char buf[BufBytes];
67 if (FP.isNaN())
68 assert((FP.bitwiseIsEqual(APFloat::getQNaN(FP.getSemantics())) ||
69 FP.bitwiseIsEqual(
70 APFloat::getQNaN(FP.getSemantics(), /*Negative=*/true))) &&
71 "convertToHexString handles neither SNaN nor NaN payloads");
72 // Use C99's hexadecimal floating-point representation.
73 auto Written = FP.convertToHexString(
74 buf, /*hexDigits=*/0, /*upperCase=*/false, APFloat::rmNearestTiesToEven);
75 (void)Written;
76 assert(Written != 0);
77 assert(Written < BufBytes);
78 return buf;
79 }
80
printOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)81 void WebAssemblyInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
82 raw_ostream &O) {
83 const MCOperand &Op = MI->getOperand(OpNo);
84 if (Op.isReg()) {
85 unsigned WAReg = Op.getReg();
86 if (int(WAReg) >= 0)
87 printRegName(O, WAReg);
88 else if (OpNo >= MII.get(MI->getOpcode()).getNumDefs())
89 O << "$pop" << (WAReg & INT32_MAX);
90 else if (WAReg != WebAssemblyFunctionInfo::UnusedReg)
91 O << "$push" << (WAReg & INT32_MAX);
92 else
93 O << "$discard";
94 // Add a '=' suffix if this is a def.
95 if (OpNo < MII.get(MI->getOpcode()).getNumDefs())
96 O << '=';
97 } else if (Op.isImm()) {
98 switch (MI->getOpcode()) {
99 case WebAssembly::PARAM:
100 case WebAssembly::RESULT:
101 case WebAssembly::LOCAL:
102 O << WebAssembly::TypeToString(MVT::SimpleValueType(Op.getImm()));
103 break;
104 default:
105 O << Op.getImm();
106 break;
107 }
108 } else if (Op.isFPImm())
109 O << toString(APFloat(Op.getFPImm()));
110 else {
111 assert(Op.isExpr() && "unknown operand kind in printOperand");
112 Op.getExpr()->print(O, &MAI);
113 }
114 }
115
TypeToString(MVT Ty)116 const char *llvm::WebAssembly::TypeToString(MVT Ty) {
117 switch (Ty.SimpleTy) {
118 case MVT::i32:
119 return "i32";
120 case MVT::i64:
121 return "i64";
122 case MVT::f32:
123 return "f32";
124 case MVT::f64:
125 return "f64";
126 default:
127 llvm_unreachable("unsupported type");
128 }
129 }
130