diff --git a/gas/ChangeLog b/gas/ChangeLog
index a7f4709870..3e2f60fe63 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,8 @@
+2013-02-28  Yufeng Zhang  <yufeng.zhang@arm.com>
+
+	* config/tc-aarch64.c (parse_sys_reg): Allow the full range of CRn
+	for system registers.
+
 2013-02-27  DJ Delorie  <dj@redhat.com>
 
 	* config/tc-rl78.c (reloc_function): Add %code -> BFD_RELOC_RL78_CODE.
diff --git a/gas/config/tc-aarch64.c b/gas/config/tc-aarch64.c
index ce59705189..47c27fee45 100644
--- a/gas/config/tc-aarch64.c
+++ b/gas/config/tc-aarch64.c
@@ -3197,10 +3197,14 @@ parse_sys_reg (char **str, struct hash_control *sys_regs, int imple_defined_p)
 	  unsigned int op0, op1, cn, cm, op2;
 	  if (sscanf (buf, "s%u_%u_c%u_c%u_%u", &op0, &op1, &cn, &cm, &op2) != 5)
 	    return PARSE_FAIL;
-	  /* Register access is encoded as follows:
+	  /* The architecture specifies the encoding space for implementation
+	     defined registers as:
 	     op0  op1  CRn   CRm   op2
-	     11   xxx  1x11  xxxx  xxx.  */
-	  if (op0 != 3 || op1 > 7 || (cn | 0x4) != 0xf || cm > 15 || op2 > 7)
+	     11   xxx  1x11  xxxx  xxx
+	     For convenience GAS accepts a wider encoding space, as follows:
+	     op0  op1  CRn   CRm   op2
+	     11   xxx  xxxx  xxxx  xxx  */
+	  if (op0 != 3 || op1 > 7 || cn > 15 || cm > 15 || op2 > 7)
 	    return PARSE_FAIL;
 	  value = (op0 << 14) | (op1 << 11) | (cn << 7) | (cm << 3) | op2;
 	}
diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog
index 45080429ce..2cf41426be 100644
--- a/gas/testsuite/ChangeLog
+++ b/gas/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2013-02-28  Yufeng Zhang  <yufeng.zhang@arm.com>
+
+	* gas/aarch64/illegal.l: Delete the error message for
+	msr S3_1_C13_C15_1,x7.
+	* gas/aarch64/sysreg.s: Add new tests.
+	* gas/aarch64/sysreg.d: Update.
+
 2013-02-19  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR gas/15159
diff --git a/gas/testsuite/gas/aarch64/illegal.l b/gas/testsuite/gas/aarch64/illegal.l
index 69058665c1..5bc9c3c2ce 100644
--- a/gas/testsuite/gas/aarch64/illegal.l
+++ b/gas/testsuite/gas/aarch64/illegal.l
@@ -520,7 +520,6 @@
 [^:]*:496: Error: .*`str x1,page_table_count'
 [^:]*:498: Error: .*`prfm PLDL3KEEP,\[x9,x15,sxtx#2\]'
 [^:]*:500: Error: .*`mrs x5,S1_0_C13_C8_0'
-[^:]*:501: Error: .*`msr S3_1_C13_C15_1,x7'
 [^:]*:502: Error: .*`msr S3_1_C11_C15_-1,x7'
 [^:]*:503: Error: .*`msr S3_1_11_15_1,x7'
 [^:]*:506: Error: .*`movi w1,#15'
diff --git a/gas/testsuite/gas/aarch64/sysreg.d b/gas/testsuite/gas/aarch64/sysreg.d
index b83b270684..c7cf00efe2 100644
--- a/gas/testsuite/gas/aarch64/sysreg.d
+++ b/gas/testsuite/gas/aarch64/sysreg.d
@@ -23,3 +23,6 @@ Disassembly of section \.text:
   3c:	d5380260 	mrs	x0, id_isar3_el1
   40:	d5380280 	mrs	x0, id_isar4_el1
   44:	d53802a0 	mrs	x0, id_isar5_el1
+  48:	d538cc00 	mrs	x0, s3_0_c12_c12_0
+  4c:	d5384600 	mrs	x0, s3_0_c4_c6_0
+  50:	d5184600 	msr	s3_0_c4_c6_0, x0
diff --git a/gas/testsuite/gas/aarch64/sysreg.s b/gas/testsuite/gas/aarch64/sysreg.s
index e6f770e7f6..328759446f 100644
--- a/gas/testsuite/gas/aarch64/sysreg.s
+++ b/gas/testsuite/gas/aarch64/sysreg.s
@@ -22,3 +22,7 @@
 	mrs x0, id_isar3_el1
 	mrs x0, id_isar4_el1
 	mrs x0, id_isar5_el1
+
+	mrs x0, s3_0_c12_c12_0
+	mrs x0, s3_0_c4_c6_0
+	msr s3_0_c4_c6_0, x0