[NDS32] Do not use multiple load/store instructions for volatile memory access.

gcc/
	* config/nds32/nds32-multiple.md(load_multiple): Disallow
	volatile memory.
	(store_multiple): Ditto.

Co-Authored-By: Chung-Ju Wu <jasonwucj@gmail.com>

From-SVN: r257983

gcc/ChangeLog

 2018-02-26  Kito Cheng  <kito.cheng@gmail.com>
+	    Chung-Ju Wu  <jasonwucj@gmail.com>
+
+	* config/nds32/nds32-multiple.md (load_multiple): Disallow
+	volatile memory.
+	(store_multiple): Ditto.
+
+2018-02-26  Kito Cheng  <kito.cheng@gmail.com>
 
 	* config.gcc: Add --with-cpu support for nds32 target.
-	* config/nds32/nds32-opts.h(nds32_cpu_type): New.
+	* config/nds32/nds32-opts.h (nds32_cpu_type): New.
 	* config/nds32/nds32.opt: Add -mcpu= option.
 
 2018-02-25  Segher Boessenkool  <segher@kernel.crashing.org>

gcc/config/nds32/nds32-multiple.md

@@ -54,12 +54,14 @@
 	  (based on this nds32-multiple.md design).
        4. operands[0] must be register for sure.
        5. operands[1] must be memory for sure.
-       6. Do not cross $r15 register because it is not allocatable.  */
+       6. operands[1] is not volatile memory access.
+       7. Do not cross $r15 register because it is not allocatable.  */
   if (GET_CODE (operands[2]) != CONST_INT
       || INTVAL (operands[2]) > maximum
       || INTVAL (operands[2]) < 2
       || GET_CODE (operands[0]) != REG
       || GET_CODE (operands[1]) != MEM
+      || MEM_VOLATILE_P (operands[1])
       || REGNO (operands[0]) + INTVAL (operands[2]) > TA_REGNUM)
     FAIL;
 
@@ -236,12 +238,14 @@
 	  (based on this nds32-multiple.md design).
        4. operands[0] must be memory for sure.
        5. operands[1] must be register for sure.
-       6. Do not cross $r15 register because it is not allocatable.  */
+       6. operands[0] is not volatile memory access.
+       7. Do not cross $r15 register because it is not allocatable.  */
   if (GET_CODE (operands[2]) != CONST_INT
       || INTVAL (operands[2]) > maximum
       || INTVAL (operands[2]) < 2
       || GET_CODE (operands[0]) != MEM
       || GET_CODE (operands[1]) != REG
+      || MEM_VOLATILE_P (operands[0])
       || REGNO (operands[1]) + INTVAL (operands[2]) > TA_REGNUM)
     FAIL;