include/opcode/

	* mips.h (OP_OPTIONAL_REG): New mips_operand_type.
	(mips_optional_operand_p): New function.

opcodes/
	* mips-formats.h (OPTIONAL_REG, OPTIONAL_MAPPED_REG): New macros.
	* micromips-opc.c (decode_micromips_operand): Use OPTIONAL_REG
	and OPTIONAL_MAPPED_REG.
	* mips-opc.c (decode_mips_operand): Likewise.
	* mips16-opc.c (decode_mips16_operand): Likewise.
	* mips-dis.c (print_insn_arg): Handle OP_OPTIONAL_REG.

gas/
	* config/tc-mips.c (operand_reg_mask, match_operand): Handle
	OP_OPTIONAL_REG.
	(mips_ip, mips16_ip): Use mips_optional_operand_p to check
	for optional operands.

6 files changed, 41 insertions, 13 deletions

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 58cd1076a00..b4840ee5301 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,12 @@
+2013-08-19  Richard Sandiford  <rdsandiford@googlemail.com>
+
+	* mips-formats.h (OPTIONAL_REG, OPTIONAL_MAPPED_REG): New macros.
+	* micromips-opc.c (decode_micromips_operand): Use OPTIONAL_REG
+	and OPTIONAL_MAPPED_REG.
+	* mips-opc.c (decode_mips_operand): Likewise.
+	* mips16-opc.c (decode_mips16_operand): Likewise.
+	* mips-dis.c (print_insn_arg): Handle OP_OPTIONAL_REG.
+
 2013-08-19  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* i386-dis.c (PREFIX_EVEX_0F3A3E): Removed.
diff --git a/opcodes/micromips-opc.c b/opcodes/micromips-opc.c
index 5243d4c8a6b..33dd57e545e 100644
--- a/opcodes/micromips-opc.c
+++ b/opcodes/micromips-opc.c
@@ -53,9 +53,9 @@ decode_micromips_operand (const char *p)
 	{
 	case 'a': MAPPED_REG (0, 0, GP, reg_28_map);
 	case 'b': MAPPED_REG (3, 23, GP, reg_m16_map);
-	case 'c': MAPPED_REG (3, 4, GP, reg_m16_map);
+	case 'c': OPTIONAL_MAPPED_REG (3, 4, GP, reg_m16_map);
 	case 'd': MAPPED_REG (3, 7, GP, reg_m16_map);
-	case 'e': MAPPED_REG (3, 1, GP, reg_m16_map);
+	case 'e': OPTIONAL_MAPPED_REG (3, 1, GP, reg_m16_map);
 	case 'f': MAPPED_REG (3, 3, GP, reg_m16_map);
 	case 'g': MAPPED_REG (3, 0, GP, reg_m16_map);
 	case 'h': REG_PAIR (3, 7, GP, reg_h_map);
@@ -144,7 +144,7 @@ decode_micromips_operand (const char *p)
     case 'R': REG (5, 6, FP);
     case 'S': REG (5, 16, FP);
     case 'T': REG (5, 21, FP);
-    case 'V': REG (5, 16, FP);
+    case 'V': OPTIONAL_REG (5, 16, FP);
 
     case 'a': JUMP (26, 0, 1);
     case 'b': REG (5, 16, GP);
@@ -158,12 +158,12 @@ decode_micromips_operand (const char *p)
     case 'o': SINT (16, 0);
     case 'p': BRANCH (16, 0, 1);
     case 'q': HINT (10, 6);
-    case 'r': REG (5, 16, GP);
+    case 'r': OPTIONAL_REG (5, 16, GP);
     case 's': REG (5, 16, GP);
     case 't': REG (5, 21, GP);
     case 'u': HINT (16, 0);
-    case 'v': REG (5, 16, GP);
-    case 'w': REG (5, 21, GP);
+    case 'v': OPTIONAL_REG (5, 16, GP);
+    case 'w': OPTIONAL_REG (5, 21, GP);
     case 'y': REG (5, 6, GP);
     case 'z': MAPPED_REG (0, 0, GP, reg_0_map);
     }
diff --git a/opcodes/mips-dis.c b/opcodes/mips-dis.c
index 1d1c7245e49..dce4d863e7d 100644
--- a/opcodes/mips-dis.c
+++ b/opcodes/mips-dis.c
@@ -1042,6 +1042,7 @@ print_insn_arg (struct disassemble_info *info,
       break;
 
     case OP_REG:
+    case OP_OPTIONAL_REG:
       {
 	const struct mips_reg_operand *reg_op;
 
diff --git a/opcodes/mips-formats.h b/opcodes/mips-formats.h
index 49a0623da53..4b5aaaf31a3 100644
--- a/opcodes/mips-formats.h
+++ b/opcodes/mips-formats.h
@@ -69,6 +69,14 @@
     return &op.root; \
   }
 
+#define OPTIONAL_REG(SIZE, LSB, BANK) \
+  { \
+    static const struct mips_reg_operand op = { \
+      { OP_OPTIONAL_REG, SIZE, LSB }, OP_REG_##BANK, 0 \
+    }; \
+    return &op.root; \
+  }
+
 #define MAPPED_REG(SIZE, LSB, BANK, MAP) \
   { \
     typedef char ATTRIBUTE_UNUSED \
@@ -79,6 +87,16 @@
     return &op.root; \
   }
 
+#define OPTIONAL_MAPPED_REG(SIZE, LSB, BANK, MAP) \
+  { \
+    typedef char ATTRIBUTE_UNUSED \
+      static_assert[(1 << (SIZE)) == ARRAY_SIZE (MAP)]; \
+    static const struct mips_reg_operand op = { \
+      { OP_OPTIONAL_REG, SIZE, LSB }, OP_REG_##BANK, MAP \
+    }; \
+    return &op.root; \
+  }
+
 #define REG_PAIR(SIZE, LSB, BANK, MAP) \
   { \
     typedef char ATTRIBUTE_UNUSED \
diff --git a/opcodes/mips-opc.c b/opcodes/mips-opc.c
index feb96a57bf7..7fdc93865a9 100644
--- a/opcodes/mips-opc.c
+++ b/opcodes/mips-opc.c
@@ -134,8 +134,8 @@ decode_mips_operand (const char *p)
     case 'S': REG (5, 11, FP);
     case 'T': REG (5, 16, FP);
     case 'U': SPECIAL (10, 11, CLO_CLZ_DEST);
-    case 'V': REG (5, 11, FP);
-    case 'W': REG (5, 16, FP);
+    case 'V': OPTIONAL_REG (5, 11, FP);
+    case 'W': OPTIONAL_REG (5, 16, FP);
     case 'X': REG (5, 6, VEC);
     case 'Y': REG (5, 11, VEC);
     case 'Z': REG (5, 16, VEC);
@@ -153,12 +153,12 @@ decode_mips_operand (const char *p)
     case 'o': SINT (16, 0);
     case 'p': BRANCH (16, 0, 2);
     case 'q': HINT (10, 6);
-    case 'r': REG (5, 21, GP);
+    case 'r': OPTIONAL_REG (5, 21, GP);
     case 's': REG (5, 21, GP);
     case 't': REG (5, 16, GP);
     case 'u': HINT (16, 0);
-    case 'v': REG (5, 21, GP);
-    case 'w': REG (5, 16, GP);
+    case 'v': OPTIONAL_REG (5, 21, GP);
+    case 'w': OPTIONAL_REG (5, 16, GP);
     case 'x': REG (0, 0, GP);
     case 'z': MAPPED_REG (0, 0, GP, reg_0_map);
     }
diff --git a/opcodes/mips16-opc.c b/opcodes/mips16-opc.c
index 9948741d1de..598f8236f25 100644
--- a/opcodes/mips16-opc.c
+++ b/opcodes/mips16-opc.c
@@ -66,8 +66,8 @@ decode_mips16_operand (char type, bfd_boolean extended_p)
     case 'i': JALX (26, 0, 2);
     case 'l': SPECIAL (6, 5, ENTRY_EXIT_LIST);
     case 'm': SPECIAL (7, 0, SAVE_RESTORE_LIST);
-    case 'v': MAPPED_REG (3, 8, GP, reg_m16_map);
-    case 'w': MAPPED_REG (3, 5, GP, reg_m16_map);
+    case 'v': OPTIONAL_MAPPED_REG (3, 8, GP, reg_m16_map);
+    case 'w': OPTIONAL_MAPPED_REG (3, 5, GP, reg_m16_map);
     case 'x': MAPPED_REG (3, 8, GP, reg_m16_map);
     case 'y': MAPPED_REG (3, 5, GP, reg_m16_map);
     case 'z': MAPPED_REG (3, 2, GP, reg_m16_map);