Add lock prefix and cmpxchg to X64 disassembler.

runtime/vm/disassembler_x64.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/disassembler.h"
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_IA32.
 #if defined(TARGET_ARCH_X64)
 #include "platform/utils.h"
 #include "vm/allocation.h"
@@ skipping 1071 matching lines @@
   while (true) {
     current = **data;
     if (current == OPERAND_SIZE_OVERRIDE_PREFIX) {  // Group 3 prefix.
       operand_size_ = current;
     } else if ((current & 0xF0) == 0x40) {  // REX prefix.
       setRex(current);
       // TODO(srdjan): Should we enable printing of REX.W?
       // if (rex_w()) AppendToBuffer("REX.W ");
     } else if ((current & 0xFE) == 0xF2) {  // Group 1 prefix (0xF2 or 0xF3).
       group_1_prefix_ = current;
+    } else if (current == 0xF0) {
+      AppendToBuffer("lock ");
     } else {  // Not a prefix - an opcode.
       break;
     }
     (*data)++;
   }
 
   const InstructionDesc& idesc = instruction_table.Get(current);
   byte_size_operand_ = idesc.byte_size_operation;
 
   switch (idesc.type) {
@@ skipping 406 matching lines @@
       AppendToBuffer("shufps %s, ", NameOfXMMRegister(regop));
     }
     current += PrintRightXMMOperand(current);
     AppendToBuffer(" [%x]", *current);
     current++;
   } else if ((opcode & 0xF0) == 0x80) {
     // Jcc: Conditional jump (branch).
     current = data + JumpConditional(data);
 
   } else if (opcode == 0xBE || opcode == 0xBF || opcode == 0xB6 ||
-             opcode == 0xB7 || opcode == 0xAF) {
-    // Size-extending moves, IMUL.
+             opcode == 0xB7 || opcode == 0xAF || opcode == 0xB0 ||
+             opcode == 0xB1) {
+    // Size-extending moves, IMUL, cmpxchg.
     current += PrintOperands(mnemonic, REG_OPER_OP_ORDER, current);
 
   } else if ((opcode & 0xF0) == 0x90) {
     // SETcc: Set byte on condition. Needs pointer to beginning of instruction.
     current = data + SetCC(data);
 
   } else if (((opcode & 0xFE) == 0xA4) || ((opcode & 0xFE) == 0xAC) ||
              (opcode == 0xAB) || (opcode == 0xA3) || (opcode == 0xBD)) {
     // SHLD, SHRD (double-prec. shift), BTS (bit test and set), BT (bit test).
     AppendToBuffer("%s%c ", mnemonic, operand_size_code());
@@ skipping 44 matching lines @@
     case 0xA4:
     case 0xA5:
       return "shld";
     case 0xAB:
       return "bts";
     case 0xAC:
     case 0xAD:
       return "shrd";
     case 0xAF:
       return "imul";
+    case 0xB0:
+    case 0xB1:
+      return "cmpxchg";
     case 0xB6:
       return "movzxb";
     case 0xB7:
       return "movzxw";
     case 0xBE:
       return "movsxb";
     case 0xBD:
       return "bsr";
     case 0xBF:
       return "movsxw";
@@ skipping 352 matching lines @@
   }
   hex_buffer[hex_index] = '\0';
   if (out_instr_len) {
     *out_instr_len = instruction_length;
   }
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64