1 //===-- RISCVMCCodeEmitter.cpp - Convert RISCV 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 //===----------------------------------------------------------------------===//
10 // This file implements the RISCVMCCodeEmitter class.
12 //===----------------------------------------------------------------------===//
14 #include "MCTargetDesc/RISCVBaseInfo.h"
15 #include "MCTargetDesc/RISCVFixupKinds.h"
16 #include "MCTargetDesc/RISCVMCExpr.h"
17 #include "MCTargetDesc/RISCVMCTargetDesc.h"
18 #include "llvm/ADT/Statistic.h"
19 #include "llvm/MC/MCAsmInfo.h"
20 #include "llvm/MC/MCCodeEmitter.h"
21 #include "llvm/MC/MCContext.h"
22 #include "llvm/MC/MCExpr.h"
23 #include "llvm/MC/MCInst.h"
24 #include "llvm/MC/MCInstrInfo.h"
25 #include "llvm/MC/MCRegisterInfo.h"
26 #include "llvm/MC/MCSymbol.h"
27 #include "llvm/Support/Casting.h"
28 #include "llvm/Support/EndianStream.h"
29 #include "llvm/Support/raw_ostream.h"
33 #define DEBUG_TYPE "mccodeemitter"
35 STATISTIC(MCNumEmitted, "Number of MC instructions emitted");
36 STATISTIC(MCNumFixups, "Number of MC fixups created");
39 class RISCVMCCodeEmitter : public MCCodeEmitter {
40 RISCVMCCodeEmitter(const RISCVMCCodeEmitter &) = delete;
41 void operator=(const RISCVMCCodeEmitter &) = delete;
43 MCInstrInfo const &MCII;
46 RISCVMCCodeEmitter(MCContext &ctx, MCInstrInfo const &MCII)
47 : Ctx(ctx), MCII(MCII) {}
49 ~RISCVMCCodeEmitter() override {}
51 void encodeInstruction(const MCInst &MI, raw_ostream &OS,
52 SmallVectorImpl<MCFixup> &Fixups,
53 const MCSubtargetInfo &STI) const override;
55 /// TableGen'erated function for getting the binary encoding for an
57 uint64_t getBinaryCodeForInstr(const MCInst &MI,
58 SmallVectorImpl<MCFixup> &Fixups,
59 const MCSubtargetInfo &STI) const;
61 /// Return binary encoding of operand. If the machine operand requires
62 /// relocation, record the relocation and return zero.
63 unsigned getMachineOpValue(const MCInst &MI, const MCOperand &MO,
64 SmallVectorImpl<MCFixup> &Fixups,
65 const MCSubtargetInfo &STI) const;
67 unsigned getImmOpValueAsr1(const MCInst &MI, unsigned OpNo,
68 SmallVectorImpl<MCFixup> &Fixups,
69 const MCSubtargetInfo &STI) const;
71 unsigned getImmOpValue(const MCInst &MI, unsigned OpNo,
72 SmallVectorImpl<MCFixup> &Fixups,
73 const MCSubtargetInfo &STI) const;
75 } // end anonymous namespace
77 MCCodeEmitter *llvm::createRISCVMCCodeEmitter(const MCInstrInfo &MCII,
78 const MCRegisterInfo &MRI,
80 return new RISCVMCCodeEmitter(Ctx, MCII);
83 void RISCVMCCodeEmitter::encodeInstruction(const MCInst &MI, raw_ostream &OS,
84 SmallVectorImpl<MCFixup> &Fixups,
85 const MCSubtargetInfo &STI) const {
86 const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
87 // Get byte count of instruction.
88 unsigned Size = Desc.getSize();
92 llvm_unreachable("Unhandled encodeInstruction length!");
94 uint16_t Bits = getBinaryCodeForInstr(MI, Fixups, STI);
95 support::endian::Writer<support::little>(OS).write<uint16_t>(Bits);
99 uint32_t Bits = getBinaryCodeForInstr(MI, Fixups, STI);
100 support::endian::Writer<support::little>(OS).write(Bits);
105 ++MCNumEmitted; // Keep track of the # of mi's emitted.
109 RISCVMCCodeEmitter::getMachineOpValue(const MCInst &MI, const MCOperand &MO,
110 SmallVectorImpl<MCFixup> &Fixups,
111 const MCSubtargetInfo &STI) const {
114 return Ctx.getRegisterInfo()->getEncodingValue(MO.getReg());
117 return static_cast<unsigned>(MO.getImm());
119 llvm_unreachable("Unhandled expression!");
124 RISCVMCCodeEmitter::getImmOpValueAsr1(const MCInst &MI, unsigned OpNo,
125 SmallVectorImpl<MCFixup> &Fixups,
126 const MCSubtargetInfo &STI) const {
127 const MCOperand &MO = MI.getOperand(OpNo);
130 unsigned Res = MO.getImm();
131 assert((Res & 1) == 0 && "LSB is non-zero");
135 return getImmOpValue(MI, OpNo, Fixups, STI);
138 unsigned RISCVMCCodeEmitter::getImmOpValue(const MCInst &MI, unsigned OpNo,
139 SmallVectorImpl<MCFixup> &Fixups,
140 const MCSubtargetInfo &STI) const {
142 const MCOperand &MO = MI.getOperand(OpNo);
144 MCInstrDesc const &Desc = MCII.get(MI.getOpcode());
145 unsigned MIFrm = Desc.TSFlags & RISCVII::InstFormatMask;
147 // If the destination is an immediate, there is nothing to do
151 assert(MO.isExpr() &&
152 "getImmOpValue expects only expressions or immediates");
153 const MCExpr *Expr = MO.getExpr();
154 MCExpr::ExprKind Kind = Expr->getKind();
155 RISCV::Fixups FixupKind = RISCV::fixup_riscv_invalid;
156 if (Kind == MCExpr::Target) {
157 const RISCVMCExpr *RVExpr = cast<RISCVMCExpr>(Expr);
159 switch (RVExpr->getKind()) {
160 case RISCVMCExpr::VK_RISCV_None:
161 case RISCVMCExpr::VK_RISCV_Invalid:
162 llvm_unreachable("Unhandled fixup kind!");
163 case RISCVMCExpr::VK_RISCV_LO:
164 FixupKind = MIFrm == RISCVII::InstFormatI ? RISCV::fixup_riscv_lo12_i
165 : RISCV::fixup_riscv_lo12_s;
167 case RISCVMCExpr::VK_RISCV_HI:
168 FixupKind = RISCV::fixup_riscv_hi20;
170 case RISCVMCExpr::VK_RISCV_PCREL_LO:
171 FixupKind = MIFrm == RISCVII::InstFormatI
172 ? RISCV::fixup_riscv_pcrel_lo12_i
173 : RISCV::fixup_riscv_pcrel_lo12_s;
175 case RISCVMCExpr::VK_RISCV_PCREL_HI:
176 FixupKind = RISCV::fixup_riscv_pcrel_hi20;
179 } else if (Kind == MCExpr::SymbolRef &&
180 cast<MCSymbolRefExpr>(Expr)->getKind() == MCSymbolRefExpr::VK_None) {
181 if (Desc.getOpcode() == RISCV::JAL) {
182 FixupKind = RISCV::fixup_riscv_jal;
183 } else if (MIFrm == RISCVII::InstFormatB) {
184 FixupKind = RISCV::fixup_riscv_branch;
185 } else if (MIFrm == RISCVII::InstFormatCJ) {
186 FixupKind = RISCV::fixup_riscv_rvc_jump;
187 } else if (MIFrm == RISCVII::InstFormatCB) {
188 FixupKind = RISCV::fixup_riscv_rvc_branch;
192 assert(FixupKind != RISCV::fixup_riscv_invalid && "Unhandled expression!");
195 MCFixup::create(0, Expr, MCFixupKind(FixupKind), MI.getLoc()));
201 #include "RISCVGenMCCodeEmitter.inc"