x86 validator: Implement rewriting "movntq" to "movq" on x86-64

src/trusted/validator_ragel/dfa_validate_common.c

 /*
  * Copyright (c) 2012 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /* Implement the functions common for ia32 and x86-64 architectures.  */
 #include "native_client/src/trusted/validator_ragel/dfa_validate_common.h"
 
 #include <string.h>
@@ skipping 74 matching lines @@
     return TRUE;
   } else if (size >= 3 && memcmp(ptr, "\x66\x0f\xe7", 3) == 0) {
     /* movntdq => movdqa */
     ptr[2] = 0x7f;
     return TRUE;
   }
 #elif NACL_BUILD_SUBARCH == 64
   if (size >= 3 && IsREXPrefix(ptr[0]) && ptr[1] == 0x0f) {
     uint8_t opcode_byte2 = ptr[2];
     switch (opcode_byte2) {
+      case 0xe7:
+        /* movntq => movq */
+        ptr[2] = 0x7f;
+        return TRUE;
       case 0x2b:
         /* movntps => movaps */
         ptr[2] = 0x29;
         return TRUE;
       case 0xc3:
         /* movnti => mov, nop */
         if ((info & RESTRICTED_REGISTER_USED) != 0) {
           /*
            * The rewriting for movnti is special because it changes
            * instruction boundary: movnti is replaced by a mov and a nop so
@@ skipping 170 matching lines @@
 
 Bool NaClDfaCodeReplacementIsStubouted(const uint8_t *begin_existing,
                                        size_t instruction_length) {
 
   /* Unsupported instruction must have been replaced with HLTs.  */
   if (memcmp(kStubOutMem, begin_existing, instruction_length) == 0)
     return TRUE;
   else
     return FALSE;
 }