1 files changed, 107 insertions, 0 deletions
diff --git a/lib/Target/BPF/MCTargetDesc/BPFInstPrinter.cpp b/lib/Target/BPF/MCTargetDesc/BPFInstPrinter.cpp
new file mode 100644
index 000000000000..079202994c8d
--- /dev/null
+++ b/lib/Target/BPF/MCTargetDesc/BPFInstPrinter.cpp
@@ -0,0 +1,107 @@
+//===-- BPFInstPrinter.cpp - Convert BPF MCInst to asm syntax -------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This class prints an BPF MCInst to a .s file.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MCTargetDesc/BPFInstPrinter.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FormattedStream.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "asm-printer"
+
+// Include the auto-generated portion of the assembly writer.
+#include "BPFGenAsmWriter.inc"
+
+void BPFInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
+                               StringRef Annot, const MCSubtargetInfo &STI) {
+  printInstruction(MI, O);
+  printAnnotation(O, Annot);
+}
+
+static void printExpr(const MCExpr *Expr, raw_ostream &O) {
+#ifndef NDEBUG
+  const MCSymbolRefExpr *SRE;
+
+  if (const MCBinaryExpr *BE = dyn_cast<MCBinaryExpr>(Expr))
+    SRE = dyn_cast<MCSymbolRefExpr>(BE->getLHS());
+  else
+    SRE = dyn_cast<MCSymbolRefExpr>(Expr);
+  assert(SRE && "Unexpected MCExpr type.");
+
+  MCSymbolRefExpr::VariantKind Kind = SRE->getKind();
+
+  assert(Kind == MCSymbolRefExpr::VK_None);
+#endif
+  O << *Expr;
+}
+
+void BPFInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
+                                  raw_ostream &O, const char *Modifier) {
+  assert((Modifier == 0 || Modifier[0] == 0) && "No modifiers supported");
+  const MCOperand &Op = MI->getOperand(OpNo);
+  if (Op.isReg()) {
+    O << getRegisterName(Op.getReg());
+  } else if (Op.isImm()) {
+    O << formatImm((int32_t)Op.getImm());
+  } else {
+    assert(Op.isExpr() && "Expected an expression");
+    printExpr(Op.getExpr(), O);
+  }
+}
+
+void BPFInstPrinter::printMemOperand(const MCInst *MI, int OpNo, raw_ostream &O,
+                                     const char *Modifier) {
+  const MCOperand &RegOp = MI->getOperand(OpNo);
+  const MCOperand &OffsetOp = MI->getOperand(OpNo + 1);
+
+  // register
+  assert(RegOp.isReg() && "Register operand not a register");
+  O << getRegisterName(RegOp.getReg());
+
+  // offset
+  if (OffsetOp.isImm()) {
+    auto Imm = OffsetOp.getImm();
+    if (Imm >= 0)
+      O << " + " << formatImm(Imm);
+    else
+      O << " - " << formatImm(-Imm);
+  } else {
+    assert(0 && "Expected an immediate");
+  }
+}
+
+void BPFInstPrinter::printImm64Operand(const MCInst *MI, unsigned OpNo,
+                                       raw_ostream &O) {
+  const MCOperand &Op = MI->getOperand(OpNo);
+  if (Op.isImm())
+    O << formatImm(Op.getImm());
+  else if (Op.isExpr())
+    printExpr(Op.getExpr(), O);
+  else
+    O << Op;
+}
+
+void BPFInstPrinter::printBrTargetOperand(const MCInst *MI, unsigned OpNo,
+                                       raw_ostream &O) {
+  const MCOperand &Op = MI->getOperand(OpNo);
+  if (Op.isImm()) {
+    int16_t Imm = Op.getImm();
+    O << ((Imm >= 0) ? "+" : "") << formatImm(Imm);
+  } else if (Op.isExpr()) {
+    printExpr(Op.getExpr(), O);
+  } else {
+    O << Op;
+  }
+}