6 files changed, 195 insertions, 3 deletions
diff --git a/llvm/lib/Target/BPF/BPFInstrInfo.td b/llvm/lib/Target/BPF/BPFInstrInfo.td
index 1f766bfe21e..a7910dea98d 100644
--- a/llvm/lib/Target/BPF/BPFInstrInfo.td
+++ b/llvm/lib/Target/BPF/BPFInstrInfo.td
@@ -61,6 +61,7 @@ def FIri : ComplexPattern<i64, 2, "SelectFIAddr", [add, or], []>;
 def MEMri : Operand<i64> {
   let PrintMethod = "printMemOperand";
   let EncoderMethod = "getMemoryOpValue";
+  let DecoderMethod = "decodeMemoryOpValue";
   let MIOperandInfo = (ops GPR, i16imm);
 }
 
@@ -267,6 +268,13 @@ def FI_ri
                [(set i64:$dst, FIri:$addr)]> {
   // This is a tentative instruction, and will be replaced
   // with MOV_rr and ADD_ri in PEI phase
+  let Inst{63-61} = 0;
+  let Inst{60-59} = 3;
+  let Inst{51-48} = 0;
+  let Inst{55-52} = 2;
+  let Inst{47-32} = 0;
+  let Inst{31-0} = 0;
+  let BPFClass = 0;
 }
 
 
@@ -476,13 +484,13 @@ class XADD<bits<2> SizeOp, string OpcodeStr, PatFrag OpNode>
               [(set GPR:$dst, (OpNode ADDRri:$addr, GPR:$val))]> {
   bits<3> mode;
   bits<2> size;
-  bits<4> src;
+  bits<4> dst;
   bits<20> addr;
 
   let Inst{63-61} = mode;
   let Inst{60-59} = size;
   let Inst{51-48} = addr{19-16}; // base reg
-  let Inst{55-52} = src;
+  let Inst{55-52} = dst;
   let Inst{47-32} = addr{15-0}; // offset
 
   let mode = 6;     // BPF_XADD
diff --git a/llvm/lib/Target/BPF/CMakeLists.txt b/llvm/lib/Target/BPF/CMakeLists.txt
index 3eac6e9c656..e2654b0465d 100644
--- a/llvm/lib/Target/BPF/CMakeLists.txt
+++ b/llvm/lib/Target/BPF/CMakeLists.txt
@@ -2,6 +2,7 @@ set(LLVM_TARGET_DEFINITIONS BPF.td)
 
 tablegen(LLVM BPFGenRegisterInfo.inc -gen-register-info)
 tablegen(LLVM BPFGenInstrInfo.inc -gen-instr-info)
+tablegen(LLVM BPFGenDisassemblerTables.inc -gen-disassembler)
 tablegen(LLVM BPFGenAsmWriter.inc -gen-asm-writer)
 tablegen(LLVM X86GenAsmMatcher.inc -gen-asm-matcher)
 tablegen(LLVM BPFGenDAGISel.inc -gen-dag-isel)
@@ -22,6 +23,7 @@ add_llvm_target(BPFCodeGen
   BPFTargetMachine.cpp
   )
 
+add_subdirectory(Disassembler)
 add_subdirectory(InstPrinter)
 add_subdirectory(TargetInfo)
 add_subdirectory(MCTargetDesc)
diff --git a/llvm/lib/Target/BPF/Disassembler/BPFDisassembler.cpp b/llvm/lib/Target/BPF/Disassembler/BPFDisassembler.cpp
new file mode 100644
index 00000000000..b0037fbc16a
--- /dev/null
+++ b/llvm/lib/Target/BPF/Disassembler/BPFDisassembler.cpp
@@ -0,0 +1,154 @@
+//===- BPFDisassembler.cpp - Disassembler for BPF ---------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is part of the BPF Disassembler.
+//
+//===----------------------------------------------------------------------===//
+
+#include "BPF.h"
+#include "BPFRegisterInfo.h"
+#include "BPFSubtarget.h"
+#include "MCTargetDesc/BPFMCTargetDesc.h"
+
+#include "llvm/MC/MCDisassembler/MCDisassembler.h"
+#include "llvm/MC/MCFixedLenDisassembler.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/Support/TargetRegistry.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "bpf-disassembler"
+
+typedef MCDisassembler::DecodeStatus DecodeStatus;
+
+namespace {
+
+/// A disassembler class for BPF.
+class BPFDisassembler : public MCDisassembler {
+public:
+  BPFDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx)
+      : MCDisassembler(STI, Ctx) {}
+  virtual ~BPFDisassembler() {}
+
+  DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
+                              ArrayRef<uint8_t> Bytes, uint64_t Address,
+                              raw_ostream &VStream,
+                              raw_ostream &CStream) const override;
+};
+}
+
+static MCDisassembler *createBPFDisassembler(const Target &T,
+                                             const MCSubtargetInfo &STI,
+                                             MCContext &Ctx) {
+  return new BPFDisassembler(STI, Ctx);
+}
+
+
+extern "C" void LLVMInitializeBPFDisassembler() {
+  // Register the disassembler.
+  TargetRegistry::RegisterMCDisassembler(getTheBPFTarget(),
+                                         createBPFDisassembler);
+  TargetRegistry::RegisterMCDisassembler(getTheBPFleTarget(),
+                                         createBPFDisassembler);
+  TargetRegistry::RegisterMCDisassembler(getTheBPFbeTarget(),
+                                         createBPFDisassembler);
+}
+
+static const unsigned GPRDecoderTable[] = {
+    BPF::R0,  BPF::R1,  BPF::R2,  BPF::R3,  BPF::R4,  BPF::R5,
+    BPF::R6,  BPF::R7,  BPF::R8,  BPF::R9,  BPF::R10, BPF::R11};
+
+static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
+                                           uint64_t /*Address*/,
+                                           const void * /*Decoder*/) {
+  if (RegNo > 11)
+    return MCDisassembler::Fail;
+
+  unsigned Reg = GPRDecoderTable[RegNo];
+  Inst.addOperand(MCOperand::createReg(Reg));
+  return MCDisassembler::Success;
+}
+
+static DecodeStatus decodeMemoryOpValue(MCInst &Inst, unsigned Insn,
+                                        uint64_t Address, const void *Decoder) {
+  unsigned Register = (Insn >> 16) & 0xf;
+  Inst.addOperand(MCOperand::createReg(GPRDecoderTable[Register]));
+  unsigned Offset = (Insn & 0xffff);
+  Inst.addOperand(MCOperand::createImm(SignExtend32<16>(Offset)));
+
+  return MCDisassembler::Success;
+}
+
+#include "BPFGenDisassemblerTables.inc"
+
+static DecodeStatus readInstruction64(ArrayRef<uint8_t> Bytes, uint64_t Address,
+                                      uint64_t &Size, uint64_t &Insn) {
+  uint64_t Lo, Hi;
+
+  if (Bytes.size() < 8) {
+    Size = 0;
+    return MCDisassembler::Fail;
+  }
+
+  Size = 8;
+  Hi = (Bytes[0] << 24) | (Bytes[1] << 16) | (Bytes[2] << 0) | (Bytes[3] << 8);
+  Lo = (Bytes[4] << 0) | (Bytes[5] << 8) | (Bytes[6] << 16) | (Bytes[7] << 24);
+  Insn = Make_64(Hi, Lo);
+
+  return MCDisassembler::Success;
+}
+
+DecodeStatus BPFDisassembler::getInstruction(MCInst &Instr, uint64_t &Size,
+                                             ArrayRef<uint8_t> Bytes,
+                                             uint64_t Address,
+                                             raw_ostream &VStream,
+                                             raw_ostream &CStream) const {
+  uint64_t Insn;
+  DecodeStatus Result;
+
+  Result = readInstruction64(Bytes, Address, Size, Insn);
+  if (Result == MCDisassembler::Fail) return MCDisassembler::Fail;
+
+  Result = decodeInstruction(DecoderTableBPF64, Instr, Insn,
+                             Address, this, STI);
+  if (Result == MCDisassembler::Fail) return MCDisassembler::Fail;
+
+  switch (Instr.getOpcode()) {
+  case BPF::LD_imm64: {
+    if (Bytes.size() < 16) {
+      Size = 0;
+      return MCDisassembler::Fail;
+    }
+    Size = 16;
+    uint64_t Hi = (Bytes[12] << 0) | (Bytes[13] << 8) | (Bytes[14] << 16) | (Bytes[15] << 24);
+    auto& Op = Instr.getOperand(1);
+    Op.setImm(Make_64(Hi, Op.getImm()));
+    break;
+  }
+  case BPF::LD_ABS_B:
+  case BPF::LD_ABS_H:
+  case BPF::LD_ABS_W:
+  case BPF::LD_IND_B:
+  case BPF::LD_IND_H:
+  case BPF::LD_IND_W: {
+    auto Op = Instr.getOperand(0);
+    Instr.clear();
+    Instr.addOperand(MCOperand::createReg(BPF::R6));
+    Instr.addOperand(Op);
+    break;
+  }
+  }
+
+  return Result;
+}
+
+typedef DecodeStatus (*DecodeFunc)(MCInst &MI, unsigned insn, uint64_t Address,
+                                   const void *Decoder);
diff --git a/llvm/lib/Target/BPF/Disassembler/CMakeLists.txt b/llvm/lib/Target/BPF/Disassembler/CMakeLists.txt
new file mode 100644
index 00000000000..c6dd1b34ad1
--- /dev/null
+++ b/llvm/lib/Target/BPF/Disassembler/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_llvm_library(LLVMBPFDisassembler
+  BPFDisassembler.cpp
+)
+
diff --git a/llvm/lib/Target/BPF/Disassembler/LLVMBuild.txt b/llvm/lib/Target/BPF/Disassembler/LLVMBuild.txt
new file mode 100644
index 00000000000..786074d51c8
--- /dev/null
+++ b/llvm/lib/Target/BPF/Disassembler/LLVMBuild.txt
@@ -0,0 +1,23 @@
+;===- ./lib/Target/BPF/Disassembler/LLVMBuild.txt --------------*- Conf -*--===;
+;
+;                     The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Library
+name = BPFDisassembler
+parent = BPF
+required_libraries = MCDisassembler BPFInfo Support
+add_to_library_groups = BPF
diff --git a/llvm/lib/Target/BPF/LLVMBuild.txt b/llvm/lib/Target/BPF/LLVMBuild.txt
index 66dbf86fa42..171536d78ea 100644
--- a/llvm/lib/Target/BPF/LLVMBuild.txt
+++ b/llvm/lib/Target/BPF/LLVMBuild.txt
@@ -16,13 +16,14 @@
 ;===------------------------------------------------------------------------===;
 
 [common]
-subdirectories = InstPrinter MCTargetDesc TargetInfo
+subdirectories = InstPrinter Disassembler MCTargetDesc TargetInfo
 
 [component_0]
 type = TargetGroup
 name = BPF
 parent = Target
 has_asmprinter = 1
+has_disassembler = 1
 
 [component_1]
 type = Library