1 //=- WebAssemblyMCCodeEmitter.cpp - Convert WebAssembly code to machine code -//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
11 /// \brief This file implements the WebAssemblyMCCodeEmitter class.
13 //===----------------------------------------------------------------------===//
15 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/Statistic.h"
18 #include "llvm/MC/MCCodeEmitter.h"
19 #include "llvm/MC/MCFixup.h"
20 #include "llvm/MC/MCInst.h"
21 #include "llvm/MC/MCInstrInfo.h"
22 #include "llvm/MC/MCRegisterInfo.h"
23 #include "llvm/MC/MCSubtargetInfo.h"
24 #include "llvm/MC/MCSymbol.h"
25 #include "llvm/Support/raw_ostream.h"
28 #define DEBUG_TYPE "mccodeemitter"
30 STATISTIC(MCNumEmitted, "Number of MC instructions emitted.");
31 STATISTIC(MCNumFixups, "Number of MC fixups created.");
34 class WebAssemblyMCCodeEmitter final : public MCCodeEmitter {
35 const MCInstrInfo &MCII;
38 // Implementation generated by tablegen.
39 uint64_t getBinaryCodeForInstr(const MCInst &MI,
40 SmallVectorImpl<MCFixup> &Fixups,
41 const MCSubtargetInfo &STI) const;
43 void encodeInstruction(const MCInst &MI, raw_ostream &OS,
44 SmallVectorImpl<MCFixup> &Fixups,
45 const MCSubtargetInfo &STI) const override;
48 WebAssemblyMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx)
49 : MCII(mcii), Ctx(ctx) {}
51 } // end anonymous namespace
53 MCCodeEmitter *llvm::createWebAssemblyMCCodeEmitter(const MCInstrInfo &MCII,
55 return new WebAssemblyMCCodeEmitter(MCII, Ctx);
58 void WebAssemblyMCCodeEmitter::encodeInstruction(
59 const MCInst &MI, raw_ostream &OS, SmallVectorImpl<MCFixup> &Fixups,
60 const MCSubtargetInfo &STI) const {
61 // FIXME: This is not the real binary encoding. This is an extremely
62 // over-simplified encoding where we just use uint64_t for everything. This
63 // is a temporary measure.
64 support::endian::Writer<support::little>(OS).write<uint64_t>(MI.getOpcode());
65 const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
66 if (Desc.isVariadic())
67 support::endian::Writer<support::little>(OS).write<uint64_t>(
68 MI.getNumOperands() - Desc.NumOperands);
69 for (unsigned i = 0, e = MI.getNumOperands(); i < e; ++i) {
70 const MCOperand &MO = MI.getOperand(i);
72 support::endian::Writer<support::little>(OS).write<uint64_t>(MO.getReg());
73 } else if (MO.isImm()) {
74 support::endian::Writer<support::little>(OS).write<uint64_t>(MO.getImm());
75 } else if (MO.isFPImm()) {
76 support::endian::Writer<support::little>(OS).write<double>(MO.getFPImm());
77 } else if (MO.isExpr()) {
78 support::endian::Writer<support::little>(OS).write<uint64_t>(0);
79 Fixups.push_back(MCFixup::create(
80 (1 + MCII.get(MI.getOpcode()).isVariadic() + i) * sizeof(uint64_t),
81 MO.getExpr(), STI.getTargetTriple().isArch64Bit() ? FK_Data_8 : FK_Data_4,
85 llvm_unreachable("unexpected operand kind");
89 ++MCNumEmitted; // Keep track of the # of mi's emitted.
92 #include "WebAssemblyGenMCCodeEmitter.inc"