Imported Upstream version 6.0.0.172

Former-commit-id: f3cc9b82f3e5bd8f0fd3ebc098f789556b44e9cd

external/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp

@@ -0,0 +1,196 @@
+//===-- RISCVMCCodeEmitter.cpp - Convert RISCV code to machine code -------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the RISCVMCCodeEmitter class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MCTargetDesc/RISCVBaseInfo.h"
+#include "MCTargetDesc/RISCVFixupKinds.h"
+#include "MCTargetDesc/RISCVMCExpr.h"
+#include "MCTargetDesc/RISCVMCTargetDesc.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/EndianStream.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "mccodeemitter"
+
+STATISTIC(MCNumEmitted, "Number of MC instructions emitted");
+STATISTIC(MCNumFixups, "Number of MC fixups created");
+
+namespace {
+class RISCVMCCodeEmitter : public MCCodeEmitter {
+  RISCVMCCodeEmitter(const RISCVMCCodeEmitter &) = delete;
+  void operator=(const RISCVMCCodeEmitter &) = delete;
+  MCContext &Ctx;
+  MCInstrInfo const &MCII;
+
+public:
+  RISCVMCCodeEmitter(MCContext &ctx, MCInstrInfo const &MCII)
+      : Ctx(ctx), MCII(MCII) {}
+
+  ~RISCVMCCodeEmitter() override {}
+
+  void encodeInstruction(const MCInst &MI, raw_ostream &OS,
+                         SmallVectorImpl<MCFixup> &Fixups,
+                         const MCSubtargetInfo &STI) const override;
+
+  /// TableGen'erated function for getting the binary encoding for an
+  /// instruction.
+  uint64_t getBinaryCodeForInstr(const MCInst &MI,
+                                 SmallVectorImpl<MCFixup> &Fixups,
+                                 const MCSubtargetInfo &STI) const;
+
+  /// Return binary encoding of operand. If the machine operand requires
+  /// relocation, record the relocation and return zero.
+  unsigned getMachineOpValue(const MCInst &MI, const MCOperand &MO,
+                             SmallVectorImpl<MCFixup> &Fixups,
+                             const MCSubtargetInfo &STI) const;
+
+  unsigned getImmOpValueAsr1(const MCInst &MI, unsigned OpNo,
+                             SmallVectorImpl<MCFixup> &Fixups,
+                             const MCSubtargetInfo &STI) const;
+
+  unsigned getImmOpValue(const MCInst &MI, unsigned OpNo,
+                         SmallVectorImpl<MCFixup> &Fixups,
+                         const MCSubtargetInfo &STI) const;
+};
+} // end anonymous namespace
+
+MCCodeEmitter *llvm::createRISCVMCCodeEmitter(const MCInstrInfo &MCII,
+                                              const MCRegisterInfo &MRI,
+                                              MCContext &Ctx) {
+  return new RISCVMCCodeEmitter(Ctx, MCII);
+}
+
+void RISCVMCCodeEmitter::encodeInstruction(const MCInst &MI, raw_ostream &OS,
+                                           SmallVectorImpl<MCFixup> &Fixups,
+                                           const MCSubtargetInfo &STI) const {
+  const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
+  // Get byte count of instruction.
+  unsigned Size = Desc.getSize();
+
+  switch (Size) {
+  default:
+    llvm_unreachable("Unhandled encodeInstruction length!");
+  case 2: {
+    uint16_t Bits = getBinaryCodeForInstr(MI, Fixups, STI);
+    support::endian::Writer<support::little>(OS).write<uint16_t>(Bits);
+    break;
+  }
+  case 4: {
+    uint32_t Bits = getBinaryCodeForInstr(MI, Fixups, STI);
+    support::endian::Writer<support::little>(OS).write(Bits);
+    break;
+  }
+  }
+
+  ++MCNumEmitted; // Keep track of the # of mi's emitted.
+}
+
+unsigned
+RISCVMCCodeEmitter::getMachineOpValue(const MCInst &MI, const MCOperand &MO,
+                                      SmallVectorImpl<MCFixup> &Fixups,
+                                      const MCSubtargetInfo &STI) const {
+
+  if (MO.isReg())
+    return Ctx.getRegisterInfo()->getEncodingValue(MO.getReg());
+
+  if (MO.isImm())
+    return static_cast<unsigned>(MO.getImm());
+
+  llvm_unreachable("Unhandled expression!");
+  return 0;
+}
+
+unsigned
+RISCVMCCodeEmitter::getImmOpValueAsr1(const MCInst &MI, unsigned OpNo,
+                                      SmallVectorImpl<MCFixup> &Fixups,
+                                      const MCSubtargetInfo &STI) const {
+  const MCOperand &MO = MI.getOperand(OpNo);
+
+  if (MO.isImm()) {
+    unsigned Res = MO.getImm();
+    assert((Res & 1) == 0 && "LSB is non-zero");
+    return Res >> 1;
+  }
+
+  return getImmOpValue(MI, OpNo, Fixups, STI);
+}
+
+unsigned RISCVMCCodeEmitter::getImmOpValue(const MCInst &MI, unsigned OpNo,
+                                           SmallVectorImpl<MCFixup> &Fixups,
+                                           const MCSubtargetInfo &STI) const {
+
+  const MCOperand &MO = MI.getOperand(OpNo);
+
+  MCInstrDesc const &Desc = MCII.get(MI.getOpcode());
+  unsigned MIFrm = Desc.TSFlags & RISCVII::InstFormatMask;
+
+  // If the destination is an immediate, there is nothing to do
+  if (MO.isImm())
+    return MO.getImm();
+
+  assert(MO.isExpr() &&
+         "getImmOpValue expects only expressions or immediates");
+  const MCExpr *Expr = MO.getExpr();
+  MCExpr::ExprKind Kind = Expr->getKind();
+  RISCV::Fixups FixupKind = RISCV::fixup_riscv_invalid;
+  if (Kind == MCExpr::Target) {
+    const RISCVMCExpr *RVExpr = cast<RISCVMCExpr>(Expr);
+
+    switch (RVExpr->getKind()) {
+    case RISCVMCExpr::VK_RISCV_None:
+    case RISCVMCExpr::VK_RISCV_Invalid:
+      llvm_unreachable("Unhandled fixup kind!");
+    case RISCVMCExpr::VK_RISCV_LO:
+      FixupKind = MIFrm == RISCVII::InstFormatI ? RISCV::fixup_riscv_lo12_i
+                                                : RISCV::fixup_riscv_lo12_s;
+      break;
+    case RISCVMCExpr::VK_RISCV_HI:
+      FixupKind = RISCV::fixup_riscv_hi20;
+      break;
+    case RISCVMCExpr::VK_RISCV_PCREL_HI:
+      FixupKind = RISCV::fixup_riscv_pcrel_hi20;
+      break;
+    }
+  } else if (Kind == MCExpr::SymbolRef &&
+             cast<MCSymbolRefExpr>(Expr)->getKind() == MCSymbolRefExpr::VK_None) {
+    if (Desc.getOpcode() == RISCV::JAL) {
+      FixupKind = RISCV::fixup_riscv_jal;
+    } else if (MIFrm == RISCVII::InstFormatB) {
+      FixupKind = RISCV::fixup_riscv_branch;
+    } else if (MIFrm == RISCVII::InstFormatCJ) {
+      FixupKind = RISCV::fixup_riscv_rvc_jump;
+    } else if (MIFrm == RISCVII::InstFormatCB) {
+      FixupKind = RISCV::fixup_riscv_rvc_branch;
+    }
+  }
+
+  assert(FixupKind != RISCV::fixup_riscv_invalid && "Unhandled expression!");
+
+  Fixups.push_back(
+      MCFixup::create(0, Expr, MCFixupKind(FixupKind), MI.getLoc()));
+  ++MCNumFixups;
+
+  return 0;
+}
+
+#include "RISCVGenMCCodeEmitter.inc"