commit a09f2586017aeed82fa07c8bfea6c75859295bd9
Author: Andreas Krebbel <krebbel@linux.vnet.ibm.com>
Date:   Mon May 29 12:34:56 2017 +0200

    S/390: Improve error checking for optional operands
    
    So far we only had an instruction flag which made an arbitrary number
    of operands optional.  This limits error checking capabilities for
    instructions marked that way.  With this patch the optparm flag only
    allows a single optional parameter and another one is added (optparm2)
    allowing 2 optional arguments.  Hopefully we won't need more than that
    in the future. So far there will be only a single use of optparm2.
    
    gas/ChangeLog:
    
    2017-05-30  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
    
            * config/tc-s390.c (md_gather_operands): Support new optparm2
            instruction flag.
    
    include/ChangeLog:
    
    2017-05-30  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
    
            * opcode/s390.h: Add new instruction flags optparm2.
    
    opcodes/ChangeLog:
    
    2017-05-30  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
    
            * s390-dis.c (s390_print_insn_with_opcode): Support new optparm2
            instruction flag.
            * s390-mkopc.c (main): Recognize the new instruction flag when
            parsing instruction list.

--- a/include/opcode/s390.h
+++ b/include/opcode/s390.h
@@ -48,10 +48,11 @@ enum s390_opcode_cpu_val
 
 /* Instruction specific flags.  */
 #define S390_INSTR_FLAG_OPTPARM 0x1
+#define S390_INSTR_FLAG_OPTPARM2 0x2
 
-#define S390_INSTR_FLAG_HTM 0x2
-#define S390_INSTR_FLAG_VX 0x4
-#define S390_INSTR_FLAG_FACILITY_MASK 0x6
+#define S390_INSTR_FLAG_HTM 0x4
+#define S390_INSTR_FLAG_VX 0x8
+#define S390_INSTR_FLAG_FACILITY_MASK 0xc
 
 /* The opcode table is an array of struct s390_opcode.  */
 
--- a/opcodes/s390-dis.c
+++ b/opcodes/s390-dis.c
@@ -206,11 +206,20 @@ s390_print_insn_with_opcode (bfd_vma memaddr,
 
       /* For instructions with a last optional operand don't print it
 	 if zero.  */
-      if ((opcode->flags & S390_INSTR_FLAG_OPTPARM)
+      if ((opcode->flags & (S390_INSTR_FLAG_OPTPARM | S390_INSTR_FLAG_OPTPARM2))
 	  && val.u == 0
 	  && opindex[1] == 0)
 	break;
 
+      if ((opcode->flags & S390_INSTR_FLAG_OPTPARM2)
+	  && val.u == 0 && opindex[1] != 0 && opindex[2] == 0)
+	{
+	  union operand_value next_op_val =
+	    s390_extract_operand (buffer, s390_operands + opindex[1]);
+	  if (next_op_val.u == 0)
+	    break;
+	}
+
       if (flags & S390_OPERAND_GPR)
 	info->fprintf_func (info->stream, "%c%%r%u", separator, val.u);
       else if (flags & S390_OPERAND_FPR)
--- a/opcodes/s390-mkopc.c
+++ b/opcodes/s390-mkopc.c
@@ -411,12 +411,16 @@ main (void)
 		&& (str[7] == 0 || str[7] == ',')) {
 	      flag_bits |= S390_INSTR_FLAG_OPTPARM;
 	      str += 7;
+	    } else if (strncmp (str, "optparm2", 8) == 0
+		       && (str[8] == 0 || str[8] == ',')) {
+	      flag_bits |= S390_INSTR_FLAG_OPTPARM2;
+	      str += 8;
 	    } else if (strncmp (str, "htm", 3) == 0
-		&& (str[3] == 0 || str[3] == ',')) {
+		       && (str[3] == 0 || str[3] == ',')) {
 	      flag_bits |= S390_INSTR_FLAG_HTM;
 	      str += 3;
 	    } else if (strncmp (str, "vx", 2) == 0
-		&& (str[2] == 0 || str[2] == ',')) {
+		       && (str[2] == 0 || str[2] == ',')) {
 	      flag_bits |= S390_INSTR_FLAG_VX;
 	      str += 2;
 	    } else {