Index: gas/config/tc-i386.c
===================================================================
RCS file: /cvs/src/src/gas/config/tc-i386.c,v
retrieving revision 1.354
diff -u -r1.354 tc-i386.c
--- gas/config/tc-i386.c	12 Oct 2008 12:37:09 -0000	1.354
+++ gas/config/tc-i386.c	26 Nov 2008 17:48:43 -0000
@@ -424,6 +424,8 @@
   }
 sse_check;
 
+static int prefer_direction_flag = 0;
+
 /* Register prefix used for error message.  */
 static const char *register_prefix = "%";
 
@@ -1357,6 +1359,8 @@
 
 static const i386_operand_type acc32 = OPERAND_TYPE_ACC32;
 static const i386_operand_type acc64 = OPERAND_TYPE_ACC64;
+static const i386_operand_type reg32 = OPERAND_TYPE_REG32;
+static const i386_operand_type reg64 = OPERAND_TYPE_REG64;
 static const i386_operand_type control = OPERAND_TYPE_CONTROL;
 static const i386_operand_type inoutportreg
   = OPERAND_TYPE_INOUTPORTREG;
@@ -3543,6 +3547,7 @@
   unsigned int j;
   unsigned int found_cpu_match;
   unsigned int check_register;
+  unsigned int op0 = 0, op1 = 1;
 
 #if MAX_OPERANDS != 5
 # error "MAX_OPERANDS must be 5."
@@ -3712,16 +3717,28 @@
 	      && operand_type_equal (&i.types [0], &acc32)
 	      && operand_type_equal (&i.types [1], &acc32))
 	    continue;
+          if(prefer_direction_flag && t->opcode_modifier.d
+             && ((operand_type_equal (&i.types [0], &reg32) && operand_type_equal (&i.types [1], &reg32))
+                  || (operand_type_equal (&i.types [0], &reg64) && operand_type_equal (&i.types [1], &reg64)))) {
+              found_reverse_match = Opcode_D;
+              op0 = 1;
+              op1 = 0;
+          } else {
+              found_reverse_match = 0;
+              op0 = 0;
+              op1 = 1;
+          }
+
 	case 3:
 	case 4:
 	case 5:
-	  overlap1 = operand_type_and (i.types[1], operand_types[1]);
-	  if (!operand_type_match (overlap0, i.types[0])
-	      || !operand_type_match (overlap1, i.types[1])
+	  overlap1 = operand_type_and (i.types[op1], operand_types[1]);
+	  if (!operand_type_match (overlap0, i.types[op0])
+	      || !operand_type_match (overlap1, i.types[op1])
 	      || (check_register
-		  && !operand_type_register_match (overlap0, i.types[0],
+		  && !operand_type_register_match (overlap0, i.types[op0],
 						   operand_types[0],
-						   overlap1, i.types[1],
+						   overlap1, i.types[op1],
 						   operand_types[1])))
 	    {
 	      /* Check if other direction is valid ...  */
@@ -3729,16 +3746,16 @@
 		continue;
 
 	      /* Try reversing direction of operands.  */
-	      overlap0 = operand_type_and (i.types[0], operand_types[1]);
-	      overlap1 = operand_type_and (i.types[1], operand_types[0]);
-	      if (!operand_type_match (overlap0, i.types[0])
-		  || !operand_type_match (overlap1, i.types[1])
+	      overlap0 = operand_type_and (i.types[op0], operand_types[1]);
+	      overlap1 = operand_type_and (i.types[op1], operand_types[0]);
+	      if (!operand_type_match (overlap0, i.types[op0])
+		  || !operand_type_match (overlap1, i.types[op1])
 		  || (check_register
 		      && !operand_type_register_match (overlap0,
-						       i.types[0],
+						       i.types[op0],
 						       operand_types[1],
 						       overlap1,
-						       i.types[1],
+						       i.types[op1],
 						       operand_types[0])))
 		{
 		  /* Does not match either direction.  */
@@ -3747,7 +3764,7 @@
 	      /* found_reverse_match holds which of D or FloatDR
 		 we've found.  */
 	      if (t->opcode_modifier.d)
-		found_reverse_match = Opcode_D;
+		found_reverse_match ^= Opcode_D;
 	      else if (t->opcode_modifier.floatd)
 		found_reverse_match = Opcode_FloatD;
 	      else
@@ -3801,7 +3818,7 @@
 		  if (!operand_type_match (overlap2, i.types[2])
 		      || (check_register
 			  && !operand_type_register_match (overlap1,
-							   i.types[1],
+							   i.types[op1],
 							   operand_types[1],
 							   overlap2,
 							   i.types[2],
@@ -7988,6 +8005,7 @@
 #define OPTION_MOLD_GCC (OPTION_MD_BASE + 9)
 #define OPTION_MSSE2AVX (OPTION_MD_BASE + 10)
 #define OPTION_MSSE_CHECK (OPTION_MD_BASE + 11)
+#define OPTION_PREFER_DIRECTION_FLAG (OPTION_MD_BASE + 12)
 
 struct option md_longopts[] =
 {
@@ -8005,6 +8023,7 @@
   {"mold-gcc", no_argument, NULL, OPTION_MOLD_GCC},
   {"msse2avx", no_argument, NULL, OPTION_MSSE2AVX},
   {"msse-check", required_argument, NULL, OPTION_MSSE_CHECK},
+  {"mprefer-direction-flag", no_argument, NULL, OPTION_PREFER_DIRECTION_FLAG},
   {NULL, no_argument, NULL, 0}
 };
 size_t md_longopts_size = sizeof (md_longopts);
@@ -8209,6 +8228,9 @@
 	as_fatal (_("Invalid -msse-check= option: `%s'"), arg);
       break;
 
+    case OPTION_PREFER_DIRECTION_FLAG:
+        prefer_direction_flag = 1;
+        break; 
     default:
       return 0;
     }
@@ -8275,6 +8297,9 @@
   -mnaked-reg             don't require `%%' prefix for registers\n"));
   fprintf (stream, _("\
   -mold-gcc               support old (<= 2.8.1) versions of gcc\n"));
+  fprintf (stream, _("\
+  -mprefer-direction-flag prefer direction inversed instructions in register\n\
+                          to register operations\n"));
 }
 
 #if ((defined (OBJ_MAYBE_COFF) && defined (OBJ_MAYBE_AOUT)) \
Index: gas/doc/c-i386.texi
===================================================================
RCS file: /cvs/src/src/gas/doc/c-i386.texi,v
retrieving revision 1.30
diff -u -r1.30 c-i386.texi
--- gas/doc/c-i386.texi	3 Sep 2008 15:44:33 -0000	1.30
+++ gas/doc/c-i386.texi	26 Nov 2008 17:48:43 -0000
@@ -170,6 +170,13 @@
 @option{-msse-check=@var{error}} will make the assembler issue an error
 for any SSE intruction.
 
+@cindex @samp{-mprefer-direction-flag} option, i386
+@cindex @samp{-mprefer-direction-flag} option, x86-64
+@item -mprefer-direction-flag
+This option instructs the assembler to prefer direction inversed instructions for
+register to register operations. For example, this will assemble "mov %esp, %ebp"
+to "8b ec" instead of "89 e5".
+
 @cindex @samp{-mmnemonic=} option, i386
 @cindex @samp{-mmnemonic=} option, x86-64
 @item -mmnemonic=@var{att}