X87: [ia32] Fixes a bug in cmpw.

src/x87/disasm-x87.cc

Index: src/x87/disasm-x87.cc
diff --git a/src/x87/disasm-x87.cc b/src/x87/disasm-x87.cc
index be9167bc921bcf514ba699cea839dd38559b4d42..657dc7be24bdf105bf0721b290a0d463a0160b3f 100644
--- a/src/x87/disasm-x87.cc
+++ b/src/x87/disasm-x87.cc
@@ -1289,11 +1289,19 @@ int DisassemblerX87::InstructionDecode(v8::internal::Vector<char> out_buffer,
         while (*data == 0x66) data++;
         if (*data == 0xf && data[1] == 0x1f) {
           AppendToBuffer("nop");  // 0x66 prefix
-        } else if (*data == 0x90) {
-          AppendToBuffer("nop");  // 0x66 prefix
-        } else if (*data == 0x8B) {
+        } else if (*data == 0x39) {
           data++;
-          data += PrintOperands("mov_w", REG_OPER_OP_ORDER, data);
+          data += PrintOperands("cmpw", OPER_REG_OP_ORDER, data);
+        } else if (*data == 0x3B) {
+          data++;
+          data += PrintOperands("cmpw", REG_OPER_OP_ORDER, data);
+        } else if (*data == 0x81) {
+          data++;
+          AppendToBuffer("cmpw ");
+          data += PrintRightOperand(data);
+          int imm = *reinterpret_cast<int16_t*>(data);
+          AppendToBuffer(",0x%x", imm);
+          data += 2;
         } else if (*data == 0x87) {
           data++;
           int mod, regop, rm;
@@ -1307,6 +1315,11 @@ int DisassemblerX87::InstructionDecode(v8::internal::Vector<char> out_buffer,
           AppendToBuffer("mov_w ");
           data += PrintRightOperand(data);
           AppendToBuffer(",%s", NameOfCPURegister(regop));
+        } else if (*data == 0x8B) {
+          data++;
+          data += PrintOperands("mov_w", REG_OPER_OP_ORDER, data);
+        } else if (*data == 0x90) {
+          AppendToBuffer("nop");  // 0x66 prefix
         } else if (*data == 0xC7) {
           data++;
           AppendToBuffer("%s ", "mov_w");