diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5f56b6161f6..de980128eb6 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2013-06-16  David Holsgrove <david.holsgrove@xilinx.com>
+
+	* gcc/config/microblaze/sync.md: New file.
+	* gcc/config/microblaze/microblaze.md: Add UNSPEC_SYNC_CAS,
+	UNSPEC_SYNC_XCHG and include sync.md.
+	* gcc/config/microblaze/microblaze.c: Add print_operand 'y'.
+	* gcc/config/microblaze/constraints.md: Add memory_contraint
+	'Q' which is a single register.
+
 2013-06-26  Thomas Schwinge  <thomas@codesourcery.com>
 
 	* config/i386/gnu.h [TARGET_LIBC_PROVIDES_SSP]
diff --git a/gcc/config/microblaze/constraints.md b/gcc/config/microblaze/constraints.md
index c6fbc987819..c9c164962cd 100644
--- a/gcc/config/microblaze/constraints.md
+++ b/gcc/config/microblaze/constraints.md
@@ -70,3 +70,8 @@
   "Double word operand."
   (and (match_code "mem")
        (match_test "double_memory_operand (op, GET_MODE (op))")))
+
+(define_memory_constraint "Q"
+  "Memory operand which is a single register."
+  (and (match_code "mem")
+       (match_test "GET_CODE ( XEXP (op, 0)) == REG")))
diff --git a/gcc/config/microblaze/microblaze.c b/gcc/config/microblaze/microblaze.c
index c121c2baec3..ea2b033becb 100644
--- a/gcc/config/microblaze/microblaze.c
+++ b/gcc/config/microblaze/microblaze.c
@@ -2118,6 +2118,7 @@ microblaze_initial_elimination_offset (int from, int to)
    't'  print 't' for EQ, 'f' for NE
    'm'  Print 1<<operand.
    'i'  Print 'i' if MEM operand has immediate value
+   'y'  Print 'y' if MEM operand is single register
    'o'	Print operand address+4
    '?'	Print 'd' if we use a branch with delay slot instead of normal branch.
    'h'  Print high word of const_double (int or float) value as hex
@@ -2288,6 +2289,15 @@ print_operand (FILE * file, rtx op, int letter)
 	rtx op4 = adjust_address (op, GET_MODE (op), 4);
 	output_address (XEXP (op4, 0));
       }
+    else if (letter == 'y')
+      {
+        rtx mem_reg = XEXP (op, 0);
+        if (GET_CODE (mem_reg) == REG)
+        {
+            register int regnum = REGNO (mem_reg);
+            fprintf (file, "%s", reg_names[regnum]);
+        }
+      }
     else
       output_address (XEXP (op, 0));
 
diff --git a/gcc/config/microblaze/microblaze.md b/gcc/config/microblaze/microblaze.md
index 3618cad524b..6e7b72d2267 100644
--- a/gcc/config/microblaze/microblaze.md
+++ b/gcc/config/microblaze/microblaze.md
@@ -41,6 +41,8 @@
   (UNSPEC_CMP		104)    ;; signed compare
   (UNSPEC_CMPU		105)    ;; unsigned compare
   (UNSPEC_TLS           106)    ;; jump table
+  (UNSPEC_SYNC_CAS      107)    ;; Represent atomic compare swap.
+  (UNSPEC_SYNC_XCHG     108)    ;; Represent atomic exchange.
 ])
 
 
@@ -2221,3 +2223,5 @@
   [(set_attr "type"     "arith")
   (set_attr "mode"      "SI")
   (set_attr "length"    "4")])
+
+(include "sync.md")
diff --git a/gcc/config/microblaze/sync.md b/gcc/config/microblaze/sync.md
new file mode 100644
index 00000000000..3be95b4d0af
--- /dev/null
+++ b/gcc/config/microblaze/sync.md
@@ -0,0 +1,65 @@
+;; Machine description for Xilinx MicroBlaze synchronization instructions.
+;; Copyright (C) 2011-2013
+;; Free Software Foundation, Inc.
+;;
+;; This file is part of GCC.
+;;
+;; GCC is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+;;
+;; GCC is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with GCC; see the file COPYING3.  If not see
+;; <http://www.gnu.org/licenses/>.
+
+
+(define_insn "sync_compare_and_swapsi"
+  [(set (match_operand:SI 0 "register_operand" "=&d")          	;; retval
+        (match_operand:SI 1 "nonimmediate_operand" "+Q"))      	;; mem
+    (set (match_dup 1)
+	(unspec
+	    [(match_operand:SI 2 "register_operand" "d")	;; oldval
+	     (match_operand:SI 3 "register_operand" "d")]	;; newval
+			     UNSPEC_SYNC_CAS))
+   (clobber (match_scratch:SI 4 "=&d"))]			;; scratch
+  ""
+  {
+    output_asm_insn ("addc \tr0,r0,r0", operands);
+    output_asm_insn ("lwx  \t%0,%y1,r0", operands);
+    output_asm_insn ("addic\t%4,r0,0", operands);
+    output_asm_insn ("bnei \t%4,.-8", operands);
+    output_asm_insn ("cmp  \t%4,%0,%2", operands);
+    output_asm_insn ("bnei \t%4,.+16", operands);
+    output_asm_insn ("swx  \t%3,%y1,r0", operands);
+    output_asm_insn ("addic\t%4,r0,0", operands);
+    output_asm_insn ("bnei \t%4,.-28", operands);
+    return "";
+  }
+)
+
+(define_insn "sync_test_and_setsi"
+  [(set (match_operand:SI 0 "register_operand" "=&d")        	;; retval
+	(match_operand:SI 1 "nonimmediate_operand" "+Q"))	;; mem
+   (set (match_dup 1)
+	(unspec
+	  [(match_operand:SI 2 "register_operand" "d")]		;; value
+	  UNSPEC_SYNC_XCHG))
+   (clobber (match_scratch:SI 3 "=&d"))]			;; scratch
+  ""
+  {
+    output_asm_insn ("addc \tr0,r0,r0", operands);
+    output_asm_insn ("lwx  \t%0,%y1,r0", operands);
+    output_asm_insn ("addic\t%3,r0,0", operands);
+    output_asm_insn ("bnei \t%3,.-8", operands);
+    output_asm_insn ("swx  \t%2,%y1,r0", operands);
+    output_asm_insn ("addic\t%3,r0,0", operands);
+    output_asm_insn ("bnei \t%3,.-20", operands);
+    return "";
+  }
+)