1 files changed, 77 insertions, 0 deletions
diff --git a/lib/Target/BPF/BPFMCInstLower.cpp b/lib/Target/BPF/BPFMCInstLower.cpp
new file mode 100644
index 0000000..5a695f0
--- /dev/null
+++ b/lib/Target/BPF/BPFMCInstLower.cpp
@@ -0,0 +1,77 @@
+//=-- BPFMCInstLower.cpp - Convert BPF MachineInstr to an MCInst ------------=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains code to lower BPF MachineInstrs to their corresponding
+// MCInst records.
+//
+//===----------------------------------------------------------------------===//
+
+#include "BPFMCInstLower.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/ADT/SmallString.h"
+using namespace llvm;
+
+MCSymbol *
+BPFMCInstLower::GetGlobalAddressSymbol(const MachineOperand &MO) const {
+  return Printer.getSymbol(MO.getGlobal());
+}
+
+MCOperand BPFMCInstLower::LowerSymbolOperand(const MachineOperand &MO,
+                                             MCSymbol *Sym) const {
+
+  const MCExpr *Expr = MCSymbolRefExpr::Create(Sym, Ctx);
+
+  if (!MO.isJTI() && MO.getOffset())
+    llvm_unreachable("unknown symbol op");
+
+  return MCOperand::CreateExpr(Expr);
+}
+
+void BPFMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
+  OutMI.setOpcode(MI->getOpcode());
+
+  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+    const MachineOperand &MO = MI->getOperand(i);
+
+    MCOperand MCOp;
+    switch (MO.getType()) {
+    default:
+      MI->dump();
+      llvm_unreachable("unknown operand type");
+    case MachineOperand::MO_Register:
+      // Ignore all implicit register operands.
+      if (MO.isImplicit())
+        continue;
+      MCOp = MCOperand::CreateReg(MO.getReg());
+      break;
+    case MachineOperand::MO_Immediate:
+      MCOp = MCOperand::CreateImm(MO.getImm());
+      break;
+    case MachineOperand::MO_MachineBasicBlock:
+      MCOp = MCOperand::CreateExpr(
+          MCSymbolRefExpr::Create(MO.getMBB()->getSymbol(), Ctx));
+      break;
+    case MachineOperand::MO_RegisterMask:
+      continue;
+    case MachineOperand::MO_GlobalAddress:
+      MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO));
+      break;
+    }
+
+    OutMI.addOperand(MCOp);
+  }
+}