Ported SubStringStub to X64.

src/x64/disasm-x64.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 96 matching lines @@
   { 0xC9, UNSET_OP_ORDER, "leave" },
   { 0xF4, UNSET_OP_ORDER, "hlt" },
   { 0xCC, UNSET_OP_ORDER, "int3" },
   { 0x60, UNSET_OP_ORDER, "pushad" },
   { 0x61, UNSET_OP_ORDER, "popad" },
   { 0x9C, UNSET_OP_ORDER, "pushfd" },
   { 0x9D, UNSET_OP_ORDER, "popfd" },
   { 0x9E, UNSET_OP_ORDER, "sahf" },
   { 0x99, UNSET_OP_ORDER, "cdq" },
   { 0x9B, UNSET_OP_ORDER, "fwait" },
+  { 0xA4, UNSET_OP_ORDER, "movs" },
+  { 0xA5, UNSET_OP_ORDER, "movs" },
+  { 0xA6, UNSET_OP_ORDER, "cmps" },
+  { 0xA7, UNSET_OP_ORDER, "cmps" },
   { -1, UNSET_OP_ORDER, "" }
 };
 
 
 static ByteMnemonic call_jump_instr[] = {
   { 0xE8, UNSET_OP_ORDER, "call" },
   { 0xE9, UNSET_OP_ORDER, "jmp" },
   { -1, UNSET_OP_ORDER, "" }
 };
 
@@ skipping 23 matching lines @@
   TWO_OPERANDS_INSTR,
   JUMP_CONDITIONAL_SHORT_INSTR,
   REGISTER_INSTR,
   PUSHPOP_INSTR,  // Has implicit 64-bit operand size.
   MOVE_REG_INSTR,
   CALL_JUMP_INSTR,
   SHORT_IMMEDIATE_INSTR
 };
 
 
+enum Prefixes {
+  ESCAPE_PREFIX = 0x0F,
+  OPERAND_SIZE_OVERRIDE_PREFIX = 0x66,
+  ADDRESS_SIZE_OVERRIDE_PREFIX = 0x67,
+  REPNE_PREFIX = 0xF2,
+  REP_PREFIX = 0xF3,
+  REPEQ_PREFIX = REP_PREFIX
+};
+
+
 struct InstructionDesc {
   const char* mnem;
   InstructionType type;
   OperandType op_order_;
   bool byte_size_operation;  // Fixed 8-bit operation.
 };
 
 
 class InstructionTable {
  public:
@@ skipping 951 matching lines @@
                                        byte* instr) {
   tmp_buffer_pos_ = 0;  // starting to write as position 0
   byte* data = instr;
   bool processed = true;  // Will be set to false if the current instruction
                           // is not in 'instructions' table.
   byte current;
 
   // Scan for prefixes.
   while (true) {
     current = *data;
-    if (current == 0x66) {  // Group 3 prefix.
+    if (current == OPERAND_SIZE_OVERRIDE_PREFIX) {  // Group 3 prefix.
       operand_size_ = current;
     } else if ((current & 0xF0) == 0x40) {  // REX prefix.
       setRex(current);
       if (rex_w()) AppendToBuffer("REX.W ");
-    } else if ((current & 0xFE) == 0xF2) {  // Group 1 prefix.
+    } else if ((current & 0xFE) == 0xF2) {  // Group 1 prefix (0xF2 or 0xF3).
       group_1_prefix_ = current;
     } 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) {
     case ZERO_OPERANDS_INSTR:
-      AppendToBuffer(idesc.mnem);
+      if (current >= 0xA4 && current <= 0xA7) {
+        // String move or compare operations.
+        if (group_1_prefix_ == REP_PREFIX) {
+          // REP.
+          AppendToBuffer("rep ");
+        }
+        if (rex_w()) AppendToBuffer("REX.W ");
+        AppendToBuffer("%s%c", idesc.mnem, operand_size_code());
+      } else {
+        AppendToBuffer("%s", idesc.mnem, operand_size_code());
+      }
       data++;
       break;
 
     case TWO_OPERANDS_INSTR:
       data++;
       data += PrintOperands(idesc.mnem, idesc.op_order_, data);
       break;
 
     case JUMP_CONDITIONAL_SHORT_INSTR:
       data += JumpConditionalShort(data);
@@ skipping 428 matching lines @@
       fprintf(f, "%02x", *bp);
     }
     for (int i = 6 - static_cast<int>(pc - prev_pc); i >= 0; i--) {
       fprintf(f, "  ");
     }
     fprintf(f, "  %s\n", buffer.start());
   }
 }
 
 }  // namespace disasm