Opcodes and assembler support for Nios II R2

2015-07-01  Sandra Loosemore  <sandra@codesourcery.com>
	    Cesar Philippidis  <cesar@codesourcery.com>

	gas/
	* config/tc-nios2.c (nios2_min_align): New.
	(nop): Replace with....
	(nop_r1, nop_r2, nop_r2_cdx, nop32, nop16): New.
	(nios2_align): Handle alignment on 2-byte boundaries when CDX
	instructions may be present.
	(s_nios2_align): Adjust reference to nop.
	(CDXBRANCH, IS_CDXBRANCH): New.
	(CDX_UBRANCH_SUBTYPE, CDX_CBRANCH_SUBTYPE): New.
	(nios2_relax_subtype_size): Handle 2-byte CDX branches.
	(nios2_relax_frag): Likewise.
	(md_convert_frag): Handle R2 encodings.
	(nios2_check_overflow): Check that low-order bits are zero
	before applying rightshift from howto.
	(nios2_check_overflow): Correct negative overflow calculation.
	(nios2_diagnose_overflow): Handle signed_immed12_overflow.  Issue
	generic overflow messages for miscellaneous instruction formats.
	(md_apply_fix): Recognize new R2 relocations.  For pc_relative
	relocations, store fixup in *valP.
	(nios2_reglist_mask, nios2_reglist_dir): New.
	(nios2_parse_reglist): New.
	(nios2_parse_base_register): New.
	(nios2_assemble_expression): Handle constant expressions designated
	by BFD_RELOC_NONE.
	(nios2_assemble_reg3): New.
	(nios2_assemble_arg_c): Handle R2 instruction formats.
	(nios2_assemble_arg_d): Likewise.
	(nios2_assemble_arg_s): Likewise.
	(nios2_assemble_arg_t): Likewise.
	(nios2_assemble_arg_D): New.
	(nios2_assemble_arg_S): New.
	(nios2_assemble_arg_T): New.
	(nios2_assemble_arg_i): Handle R2 instruction formats.
	(nios2_assemble_arg_I): New.
	(nios2_assemble_arg_u): Handle R2 instruction formats.
	(nios2_assemble_arg_U): New.
	(nios2_assemble_arg_V): New.
	(nios2_assemble_arg_W): New.
	(nios2_assemble_arg_X): New.
	(nios2_assemble_arg_Y): New.
	(nios2_assemble_arg_o): Handle R2 instruction formats.
	(nios2_assemble_arg_O): New.
	(nios2_assemble_arg_P): New.
	(nios2_assemble_arg_j): Handle R2 instruction formats.
	(nios2_assemble_arg_k): New.
	(nios2_assemble_arg_l): Handle R2 instruction formats.
	(nios2_assemble_arg_m): Likewise.
	(nios2_assemble_arg_M): New.
	(nios2_assemble_arg_N): New.
	(nios2_assemble_arg_e): New.
	(nios2_assemble_arg_f): New.
	(nios2_assemble_arg_g): New.
	(nios2_assemble_arg_h): New.
	(nios2_assemble_arg_R): New.
	(nios2_assemble_arg_B): New.
	(nios2_assemble_args): Handle new argument letters.
	(nios2_consume_arg): Likewise.
	(nios2_translate_pseudo_insn): Avoid dereferencing null pointer
	in error message.
	(nios2_ps_insn_info_structs): Add nop.n.
	(output_ubranch): Handle CDX branches.
	(output_cbranch): Likewise.
	(output_call): Handle R2 encodings.
	(output_movia): Likewise.
	(md_begin): Initialize nios2_min_align.
	(md_assemble): Align to nios2_min_align.  Adjust nios2_min_align
	if a 16-bit instruction is seen.
	(nios2_cons_align): Use appropriate nop pattern.

	include/opcode/
	* nios2.h (enum iw_format_type): Add R2 formats.
	(enum overflow_type): Add signed_immed12_overflow and
	enumeration_overflow for R2.
	(struct nios2_opcode): Document new argument letters for R2.
	(REG_3BIT, REG_LDWM, REG_POP): Define.
	(includes): Include nios2r2.h.
	(nios2_r2_opcodes, nios2_num_r2_opcodes): Declare.
	(nios2_r2_asi_n_mappings, nios2_num_r2_asi_n_mappings): Declare.
	(nios2_r2_shi_n_mappings, nios2_num_r2_shi_n_mappings): Declare.
	(nios2_r2_andi_n_mappings, nios2_num_r2_andi_n_mappings): Declare.
	(nios2_r2_reg3_mappings, nios2_num_r2_reg3_mappings): Declare.
	(nios2_r2_reg_range_mappings, nios2_num_r2_reg_range_mappings):
	Declare.
	* nios2r2.h: New file.

	opcodes/
	* nios2-dis.c (nios2_extract_opcode): New.
	(nios2_disassembler_state): New.
	(nios2_find_opcode_hash): Use mach parameter to select correct
	disassembler state.
	(nios2_print_insn_arg): Extend to support new R2 argument letters
	and formats.
	(print_insn_nios2): Check for 16-bit instruction at end of memory.
	* nios2-opc.c (nios2_builtin_regs): Add R2 register attributes.
	(NIOS2_NUM_OPCODES): Rename to...
	(NIOS2_NUM_R1_OPCODES): This.
	(nios2_r2_opcodes): New.
	(NIOS2_NUM_R2_OPCODES): New.
	(nios2_num_r2_opcodes): New.
	(nios2_r2_asi_n_mappings, nios2_num_r2_asi_n_mappings): New.
	(nios2_r2_shi_n_mappings, nios2_num_r2_shi_n_mappings): New.
	(nios2_r2_andi_n_mappings, nios2_num_r2_andi_n_mappings): New.
	(nios2_r2_reg3_mappings, nios2_num_r2_reg3_mappings): New.
	(nios2_r2_reg_range_mappings, nios2_num_r2_reg_range_mappings):	New.

2 files changed, 1477 insertions, 107 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 470cd9f7c1a..b18637fdbe7 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,6 +1,77 @@
 2015-07-01  Sandra Loosemore  <sandra@codesourcery.com>
 	    Cesar Philippidis  <cesar@codesourcery.com>
 
+	* config/tc-nios2.c (nios2_min_align): New.
+	(nop): Replace with....
+	(nop_r1, nop_r2, nop_r2_cdx, nop32, nop16): New.
+	(nios2_align): Handle alignment on 2-byte boundaries when CDX
+	instructions may be present.
+	(s_nios2_align): Adjust reference to nop.
+	(CDXBRANCH, IS_CDXBRANCH): New.
+	(CDX_UBRANCH_SUBTYPE, CDX_CBRANCH_SUBTYPE): New.
+	(nios2_relax_subtype_size): Handle 2-byte CDX branches.
+	(nios2_relax_frag): Likewise.
+	(md_convert_frag): Handle R2 encodings.
+	(nios2_check_overflow): Check that low-order bits are zero
+	before applying rightshift from howto.
+	(nios2_check_overflow): Correct negative overflow calculation.
+	(nios2_diagnose_overflow): Handle signed_immed12_overflow.  Issue
+	generic overflow messages for miscellaneous instruction formats.
+	(md_apply_fix): Recognize new R2 relocations.  For pc_relative
+	relocations, store fixup in *valP.
+	(nios2_reglist_mask, nios2_reglist_dir): New.
+	(nios2_parse_reglist): New.
+	(nios2_parse_base_register): New.
+	(nios2_assemble_expression): Handle constant expressions designated
+	by BFD_RELOC_NONE.
+	(nios2_assemble_reg3): New.
+	(nios2_assemble_arg_c): Handle R2 instruction formats.
+	(nios2_assemble_arg_d): Likewise.
+	(nios2_assemble_arg_s): Likewise.
+	(nios2_assemble_arg_t): Likewise.
+	(nios2_assemble_arg_D): New.
+	(nios2_assemble_arg_S): New.
+	(nios2_assemble_arg_T): New.
+	(nios2_assemble_arg_i): Handle R2 instruction formats.
+	(nios2_assemble_arg_I): New.
+	(nios2_assemble_arg_u): Handle R2 instruction formats.
+	(nios2_assemble_arg_U): New.
+	(nios2_assemble_arg_V): New.
+	(nios2_assemble_arg_W): New.
+	(nios2_assemble_arg_X): New.
+	(nios2_assemble_arg_Y): New.
+	(nios2_assemble_arg_o): Handle R2 instruction formats.
+	(nios2_assemble_arg_O): New.
+	(nios2_assemble_arg_P): New.
+	(nios2_assemble_arg_j): Handle R2 instruction formats.
+	(nios2_assemble_arg_k): New.
+	(nios2_assemble_arg_l): Handle R2 instruction formats.
+	(nios2_assemble_arg_m): Likewise.
+	(nios2_assemble_arg_M): New.
+	(nios2_assemble_arg_N): New.
+	(nios2_assemble_arg_e): New.
+	(nios2_assemble_arg_f): New.
+	(nios2_assemble_arg_g): New.
+	(nios2_assemble_arg_h): New.
+	(nios2_assemble_arg_R): New.
+	(nios2_assemble_arg_B): New.
+	(nios2_assemble_args): Handle new argument letters.
+	(nios2_consume_arg): Likewise.
+	(nios2_translate_pseudo_insn): Avoid dereferencing null pointer
+	in error message.
+	(nios2_ps_insn_info_structs): Add nop.n.
+	(output_ubranch): Handle CDX branches.
+	(output_cbranch): Likewise.
+	(output_call): Handle R2 encodings.
+	(output_movia): Likewise.
+	(md_begin): Initialize nios2_min_align.
+	(md_assemble): Align to nios2_min_align.  Adjust nios2_min_align
+	if a 16-bit instruction is seen.
+	(nios2_cons_align): Use appropriate nop pattern.
+
+2015-07-01  Sandra Loosemore  <sandra@codesourcery.com>
+	    Cesar Philippidis  <cesar@codesourcery.com>
+
 	* config/tc-nios2.c: Adjust includes.
 	(OPTION_MARCH): Define.
 	(md_longopts): Add -march option.
diff --git a/gas/config/tc-nios2.c b/gas/config/tc-nios2.c
index 549ca98f5f7..4488a4748bf 100644
--- a/gas/config/tc-nios2.c
+++ b/gas/config/tc-nios2.c
@@ -210,6 +210,11 @@ static int nios2_auto_align_on = 1;
    labels preceeding instructions.  */
 static symbolS *nios2_last_label;
 
+/* If we saw a 16-bit CDX instruction, we can align on 2-byte boundaries
+   instead of 4-bytes.  Use this to keep track of the minimum power-of-2
+   alignment.  */
+static int nios2_min_align = 2;
+
 #ifdef OBJ_ELF
 /* Pre-defined "_GLOBAL_OFFSET_TABLE_"	*/
 symbolS *GOT_symbol;
@@ -322,8 +327,12 @@ nios2_special_relocation_p (const char *str)
 }
 
 
-/* nop fill pattern for text section.  */
-static char const nop[4] = { 0x3a, 0x88, 0x01, 0x00 };
+/* nop fill patterns for text section.  */
+static char const nop_r1[4] = { 0x3a, 0x88, 0x01, 0x00 };
+static char const nop_r2[4] = { 0x20, 0x00, 0x00, 0xc4 };
+static char const nop_r2_cdx[2] = { 0x3b, 0x00 };
+static char const *nop32 = nop_r1;
+static char const *nop16 = NULL;
 
 /* Handles all machine-dependent alignment needs.  */
 static void
@@ -350,16 +359,26 @@ nios2_align (int log_size, const char *pfill, symbolS *label)
 
   if (align != 0)
     {
-      if (subseg_text_p (now_seg) && align >= 2)
+      if (subseg_text_p (now_seg) && align >= nios2_min_align)
 	{
-	  /* First, make sure we're on a four-byte boundary, in case
+	  /* First, make sure we're on the minimum boundary, in case
 	     someone has been putting .byte values the text section.  */
-	  if (nios2_current_align < 2 || switched_seg_p)
-	    frag_align (2, 0, 0);
+	  if (nios2_current_align < nios2_min_align || switched_seg_p)
+	    frag_align (nios2_min_align, 0, 0);
+
+	  /* If we might be on a 2-byte boundary, first align to a
+	     4-byte boundary using the 2-byte nop as fill.  */
+	  if (nios2_min_align == 1
+	      && align > nios2_min_align
+	      && pfill == nop32 )
+	    {
+	      gas_assert (nop16);
+	      frag_align_pattern (2, nop16, 2, 0);
+	    }
 
 	  /* Now fill in the alignment pattern.  */
 	  if (pfill != NULL)
-	    frag_align_pattern (align, pfill, sizeof nop, 0);
+	    frag_align_pattern (align, pfill, 4, 0);
 	  else
 	    frag_align (align, 0, 0);
 	}
@@ -470,7 +489,7 @@ s_nios2_align (int ignore ATTRIBUTE_UNUSED)
       pfill = (const char *) &fill;
     }
   else if (subseg_text_p (now_seg))
-    pfill = (const char *) &nop;
+    pfill = (const char *) nop32;
   else
     {
       pfill = NULL;
@@ -669,6 +688,11 @@ const pseudo_typeS md_pseudo_table[] = {
      jmp at
      skip:
    respectively.
+
+   16-bit CDX branch instructions are relaxed first into equivalent
+   32-bit branches and then the above transformations are applied
+   if necessary.  
+
 */
 
 /* Arbitrarily limit the number of addis we can insert; we need to be able
@@ -685,7 +709,7 @@ const pseudo_typeS md_pseudo_table[] = {
 /* The fr_subtype field represents the target-specific relocation state.
    It has type relax_substateT (unsigned int).  We use it to track the
    number of addis necessary, plus a bit to track whether this is a
-   conditional branch.
+   conditional branch and a bit for 16-bit CDX instructions.
    Regardless of the smaller RELAX_MAX_ADDI limit, we reserve 16 bits
    in the fr_subtype to encode the number of addis so that the whole
    theoretically-valid range is representable.
@@ -693,10 +717,14 @@ const pseudo_typeS md_pseudo_table[] = {
    represents a branch that needs to be relaxed.  */
 #define UBRANCH (0 << 16)
 #define CBRANCH (1 << 16)
+#define CDXBRANCH (1 << 17)
 #define IS_CBRANCH(SUBTYPE) ((SUBTYPE) & CBRANCH)
 #define IS_UBRANCH(SUBTYPE) (!IS_CBRANCH (SUBTYPE))
+#define IS_CDXBRANCH(SUBTYPE) ((SUBTYPE) & CDXBRANCH)
 #define UBRANCH_SUBTYPE(N) (UBRANCH | (N))
 #define CBRANCH_SUBTYPE(N) (CBRANCH | (N))
+#define CDX_UBRANCH_SUBTYPE(N) (CDXBRANCH | UBRANCH | (N))
+#define CDX_CBRANCH_SUBTYPE(N) (CDXBRANCH | CBRANCH | (N))
 #define SUBTYPE_ADDIS(SUBTYPE) ((SUBTYPE) & 0xffff)
 
 /* For the -relax-section mode, unconditional branches require 2 extra i
@@ -730,7 +758,7 @@ nios2_relax_subtype_size (relax_substateT subtype)
   int n = SUBTYPE_ADDIS (subtype);
   if (n == 0)
     /* Regular conditional/unconditional branch instruction.  */
-    return 4;
+    return (IS_CDXBRANCH (subtype) ? 2 : 4);
   else if (nios2_as_options.relax == relax_all)
     return (IS_CBRANCH (subtype) ? CBRANCH_JUMP_SIZE : UBRANCH_JUMP_SIZE);
   else if (IS_CBRANCH (subtype))
@@ -761,6 +789,7 @@ nios2_relax_frag (segT segment, fragS *fragp, long stretch)
       fragS *sym_frag = symbol_get_frag (symbolp);
       offsetT offset;
       int n;
+      bfd_boolean is_cdx = FALSE;
 
       target += S_GET_VALUE (symbolp);
 
@@ -777,7 +806,15 @@ nios2_relax_frag (segT segment, fragS *fragp, long stretch)
       /* We subtract fr_var (4 for 32-bit insns) because all pc relative
 	 branches are from the next instruction.  */
       offset = target - fragp->fr_address - fragp->fr_fix - fragp->fr_var;
-      if (offset >= -32768 && offset <= 32764)
+      if (IS_CDXBRANCH (subtype) && IS_UBRANCH (subtype)
+	  && offset >= -1024 && offset < 1024)
+	/* PC-relative CDX branch with 11-bit offset.  */
+	is_cdx = TRUE;
+      else if (IS_CDXBRANCH (subtype) && IS_CBRANCH (subtype)
+	       && offset >= -128 && offset < 128)
+	/* PC-relative CDX branch with 8-bit offset.  */
+	is_cdx = TRUE;
+      else if (offset >= -32768 && offset < 32768)
 	/* Fits in PC-relative branch.  */
 	n = 0;
       else if (nios2_as_options.relax == relax_all)
@@ -816,7 +853,9 @@ nios2_relax_frag (segT segment, fragS *fragp, long stretch)
 	/* We cannot handle this case, diagnose overflow later.  */
 	return 0;
 
-      if (IS_CBRANCH (subtype))
+      if (is_cdx)
+	fragp->fr_subtype = subtype;
+      else if (IS_CBRANCH (subtype))
 	fragp->fr_subtype = CBRANCH_SUBTYPE (n);
       else
 	fragp->fr_subtype = UBRANCH_SUBTYPE (n);
@@ -841,16 +880,50 @@ md_convert_frag (bfd *headers ATTRIBUTE_UNUSED, segT segment ATTRIBUTE_UNUSED,
   addressT target = fragp->fr_offset;
   symbolS *symbolp = fragp->fr_symbol;
   offsetT offset;
-  unsigned int addend_mask, addi_mask;
+  unsigned int addend_mask, addi_mask, op;
   offsetT addend, remainder;
   int i;
+  bfd_boolean is_r2 = (bfd_get_mach (stdoutput) == bfd_mach_nios2r2);
+
+  /* If this is a CDX branch we're not relaxing, just generate the fixup.  */
+  if (IS_CDXBRANCH (subtype))
+    {
+      gas_assert (is_r2);
+      fix_new (fragp, fragp->fr_fix, 2, fragp->fr_symbol,
+	       fragp->fr_offset, 1,
+	       (IS_UBRANCH (subtype)
+		? BFD_RELOC_NIOS2_R2_I10_1_PCREL
+		: BFD_RELOC_NIOS2_R2_T1I7_1_PCREL));
+      fragp->fr_fix += 2;
+      return;
+    }
+
+  /* If this is a CDX branch we are relaxing, turn it into an equivalent
+     32-bit branch and then fall through to the normal non-CDX cases.  */
+  if (fragp->fr_var == 2)
+    {
+      unsigned int opcode = md_chars_to_number (buffer, 2);
+      gas_assert (is_r2);
+      if (IS_CBRANCH (subtype))
+	{
+	  unsigned int reg = nios2_r2_reg3_mappings[GET_IW_T1I7_A3 (opcode)];
+	  if (GET_IW_R2_OP (opcode) == R2_OP_BNEZ_N)
+	    opcode = MATCH_R2_BNE | SET_IW_F2I16_A (reg);
+	  else
+	    opcode = MATCH_R2_BEQ | SET_IW_F2I16_A (reg);
+	}
+      else
+	opcode = MATCH_R2_BR;
+      md_number_to_chars (buffer, opcode, 4);
+      fragp->fr_var = 4;
+    }
 
   /* If we didn't or can't relax, this is a regular branch instruction.
      We just need to generate the fixup for the symbol and offset.  */
   if (n == 0)
     {
-      fix_new (fragp, fragp->fr_fix, 4, fragp->fr_symbol, fragp->fr_offset, 1,
-	       BFD_RELOC_16_PCREL);
+      fix_new (fragp, fragp->fr_fix, 4, fragp->fr_symbol,
+	       fragp->fr_offset, 1, BFD_RELOC_16_PCREL);
       fragp->fr_fix += 4;
       return;
     }
@@ -871,35 +944,66 @@ md_convert_frag (bfd *headers ATTRIBUTE_UNUSED, segT segment ATTRIBUTE_UNUSED,
 	nbytes = 12;
 
       br_opcode = md_chars_to_number (buffer, 4);
-      old_op = GET_IW_R1_OP (br_opcode);
-      switch (old_op)
+      if (is_r2)
 	{
-	case R1_OP_BEQ:
-	  new_op = R1_OP_BNE;
-	  break;
-	case R1_OP_BNE:
-	  new_op = R1_OP_BEQ;
-	  break;
-	case R1_OP_BGE:
-	  new_op = R1_OP_BLT;
-	  break;
-	case R1_OP_BGEU:
-	  new_op = R1_OP_BLTU;
-	  break;
-	case R1_OP_BLT:
-	  new_op = R1_OP_BGE;
-	  break;
-	case R1_OP_BLTU:
-	  new_op = R1_OP_BGEU;
-	  break;
-	default:
-	  as_bad_where (fragp->fr_file, fragp->fr_line,
-			_("expecting conditional branch for relaxation\n"));
-	  abort ();
+	  old_op = GET_IW_R2_OP (br_opcode);
+	  switch (old_op)
+	    {
+	    case R2_OP_BEQ:
+	      new_op = R2_OP_BNE;
+	      break;
+	    case R2_OP_BNE:
+	      new_op = R2_OP_BEQ;
+	      break;
+	    case R2_OP_BGE:
+	      new_op = R2_OP_BLT;
+	      break;
+	    case R2_OP_BGEU:
+	      new_op = R2_OP_BLTU;
+	      break;
+	    case R2_OP_BLT:
+	      new_op = R2_OP_BGE;
+	      break;
+	    case R2_OP_BLTU:
+	      new_op = R2_OP_BGEU;
+	      break;
+	    default:
+	      abort ();
+	    }
+	  br_opcode = ((br_opcode & ~IW_R2_OP_SHIFTED_MASK)
+		       | SET_IW_R2_OP (new_op));
+	  br_opcode = br_opcode | SET_IW_F2I16_IMM16 (nbytes);
+	}
+      else
+	{
+	  old_op = GET_IW_R1_OP (br_opcode);
+	  switch (old_op)
+	    {
+	    case R1_OP_BEQ:
+	      new_op = R1_OP_BNE;
+	      break;
+	    case R1_OP_BNE:
+	      new_op = R1_OP_BEQ;
+	      break;
+	    case R1_OP_BGE:
+	      new_op = R1_OP_BLT;
+	      break;
+	    case R1_OP_BGEU:
+	      new_op = R1_OP_BLTU;
+	      break;
+	    case R1_OP_BLT:
+	      new_op = R1_OP_BGE;
+	      break;
+	    case R1_OP_BLTU:
+	      new_op = R1_OP_BGEU;
+	      break;
+	    default:
+	      abort ();
+	    }
+	  br_opcode = ((br_opcode & ~IW_R1_OP_SHIFTED_MASK)
+		       | SET_IW_R1_OP (new_op));
+	  br_opcode = br_opcode | SET_IW_I_IMM16 (nbytes);
 	}
-
-      br_opcode = (br_opcode & ~IW_R1_OP_SHIFTED_MASK) | SET_IW_R1_OP (new_op);
-      br_opcode = br_opcode | SET_IW_I_IMM16 (nbytes);
       md_number_to_chars (buffer, br_opcode, 4);
       fragp->fr_fix += 4;
       buffer += 4;
@@ -909,8 +1013,11 @@ md_convert_frag (bfd *headers ATTRIBUTE_UNUSED, segT segment ATTRIBUTE_UNUSED,
   if (nios2_as_options.relax == relax_section)
     {
       /* Insert the nextpc instruction.  */
-      md_number_to_chars (buffer,
-			  MATCH_R1_NEXTPC | SET_IW_R_C (AT_REGNUM), 4);
+      if (is_r2)
+	op = MATCH_R2_NEXTPC | SET_IW_F3X6L5_C (AT_REGNUM);
+      else
+	op = MATCH_R1_NEXTPC | SET_IW_R_C (AT_REGNUM);
+      md_number_to_chars (buffer, op, 4);
       fragp->fr_fix += 4;
       buffer += 4;
   
@@ -921,12 +1028,20 @@ md_convert_frag (bfd *headers ATTRIBUTE_UNUSED, segT segment ATTRIBUTE_UNUSED,
 	addend = 32767;
       else
 	addend = -32768;
-      addend_mask = SET_IW_I_IMM16 ((unsigned int)addend);
+      if (is_r2)
+	addend_mask = SET_IW_F2I16_IMM16 ((unsigned int)addend);
+      else
+	addend_mask = SET_IW_I_IMM16 ((unsigned int)addend);
 
       /* Insert n-1 addi instructions.  */
-      addi_mask = (MATCH_R1_ADDI
-		   | SET_IW_I_B (AT_REGNUM)
-		   | SET_IW_I_A (AT_REGNUM));
+      if (is_r2)
+	addi_mask = (MATCH_R2_ADDI
+		     | SET_IW_F2I16_B (AT_REGNUM)
+		     | SET_IW_F2I16_A (AT_REGNUM));
+      else
+	addi_mask = (MATCH_R1_ADDI
+		     | SET_IW_I_B (AT_REGNUM)
+		     | SET_IW_I_A (AT_REGNUM));
       for (i = 0; i < n - 1; i ++)
 	{
 	  md_number_to_chars (buffer, addi_mask | addend_mask, 4);
@@ -937,7 +1052,10 @@ md_convert_frag (bfd *headers ATTRIBUTE_UNUSED, segT segment ATTRIBUTE_UNUSED,
       /* Insert the last addi instruction to hold the remainder.  */
       remainder = offset - addend * (n - 1);
       gas_assert (remainder >= -32768 && remainder <= 32767);
-      addend_mask = SET_IW_I_IMM16 ((unsigned int)remainder);
+      if (is_r2)
+	addend_mask = SET_IW_F2I16_IMM16 ((unsigned int)remainder);
+      else
+	addend_mask = SET_IW_I_IMM16 ((unsigned int)remainder);
       md_number_to_chars (buffer, addi_mask | addend_mask, 4);
       fragp->fr_fix += 4;
       buffer += 4;
@@ -946,18 +1064,22 @@ md_convert_frag (bfd *headers ATTRIBUTE_UNUSED, segT segment ATTRIBUTE_UNUSED,
   /* Load at for the absolute case.  */
   else
     {
-      md_number_to_chars (buffer,
-			  (MATCH_R1_ORHI | SET_IW_I_B (AT_REGNUM)
-			   | SET_IW_I_A (0)),
-			  4);
+      if (is_r2)
+	op = MATCH_R2_ORHI | SET_IW_F2I16_B (AT_REGNUM) | SET_IW_F2I16_A (0);
+      else
+	op = MATCH_R1_ORHI | SET_IW_I_B (AT_REGNUM) | SET_IW_I_A (0);
+      md_number_to_chars (buffer, op, 4);
       fix_new (fragp, fragp->fr_fix, 4, fragp->fr_symbol, fragp->fr_offset,
 	       0, BFD_RELOC_NIOS2_HI16);
       fragp->fr_fix += 4;
       buffer += 4;
-      md_number_to_chars (buffer,
-			  (MATCH_R1_ORI | SET_IW_I_B (AT_REGNUM)
-			   | SET_IW_I_A (AT_REGNUM)),
-			  4);
+      if (is_r2)
+	op = (MATCH_R2_ORI | SET_IW_F2I16_B (AT_REGNUM)
+	      | SET_IW_F2I16_A (AT_REGNUM));
+      else
+	op = (MATCH_R1_ORI | SET_IW_I_B (AT_REGNUM)
+	      | SET_IW_I_A (AT_REGNUM));
+      md_number_to_chars (buffer, op, 4);
       fix_new (fragp, fragp->fr_fix, 4, fragp->fr_symbol, fragp->fr_offset,
 	       0, BFD_RELOC_NIOS2_LO16);
       fragp->fr_fix += 4;
@@ -965,7 +1087,11 @@ md_convert_frag (bfd *headers ATTRIBUTE_UNUSED, segT segment ATTRIBUTE_UNUSED,
     }
 
   /* Insert the jmp instruction.  */
-  md_number_to_chars (buffer, MATCH_R1_JMP | SET_IW_R_A (AT_REGNUM), 4);
+  if (is_r2)
+    op = MATCH_R2_JMP | SET_IW_F3X6L5_A (AT_REGNUM);
+  else
+    op = MATCH_R1_JMP | SET_IW_R_A (AT_REGNUM);
+  md_number_to_chars (buffer, op, 4);
   fragp->fr_fix += 4;
   buffer += 4;
 }
@@ -977,8 +1103,15 @@ md_convert_frag (bfd *headers ATTRIBUTE_UNUSED, segT segment ATTRIBUTE_UNUSED,
 static bfd_boolean
 nios2_check_overflow (valueT fixup, reloc_howto_type *howto)
 {
-  /* Apply the rightshift before checking for overflow.  */
-  fixup = ((signed)fixup) >> howto->rightshift;
+  /* If there is a rightshift, check that the low-order bits are
+     zero before applying it.  */
+  if (howto->rightshift)
+    {
+      if ((~(~((valueT) 0) << howto->rightshift) & fixup)
+	  && howto->complain_on_overflow != complain_overflow_dont)
+	return TRUE;
+      fixup = ((signed)fixup) >> howto->rightshift;
+    }
 
   /* Check for overflow - return TRUE if overflow, FALSE if not.  */
   switch (howto->complain_on_overflow)
@@ -994,7 +1127,7 @@ nios2_check_overflow (valueT fixup, reloc_howto_type *howto)
       if ((fixup & 0x80000000) > 0)
 	{
 	  /* Check for negative overflow.  */
-	  if ((signed) fixup < ((signed) 0x80000000 >> howto->bitsize))
+	  if ((signed) fixup < ((signed) ~0 << (howto->bitsize-1)))
 	    return TRUE;
 	}
       else
@@ -1056,14 +1189,24 @@ nios2_diagnose_overflow (valueT fixup, reloc_howto_type *howto,
 			address, range_min, range_max);
 	  break;
 	case branch_target_overflow:
-	  as_bad_where (fixP->fx_file, fixP->fx_line,
-			_("branch offset %d out of range %d to %d"),
-			(int)fixup, -32768, 32767);
+	  if (opcode->format == iw_i_type || opcode->format == iw_F2I16_type)
+	    as_bad_where (fixP->fx_file, fixP->fx_line,
+			  _("branch offset %d out of range %d to %d"),
+			  (int)fixup, -32768, 32767);
+	  else
+	    as_bad_where (fixP->fx_file, fixP->fx_line,
+			  _("branch offset %d out of range"),
+			  (int)fixup);
 	  break;
 	case address_offset_overflow:
-	  as_bad_where (fixP->fx_file, fixP->fx_line,
-			_("%s offset %d out of range %d to %d"),
-			opcode->name, (int)fixup, -32768, 32767);
+	  if (opcode->format == iw_i_type || opcode->format == iw_F2I16_type)
+	    as_bad_where (fixP->fx_file, fixP->fx_line,
+			  _("%s offset %d out of range %d to %d"),
+			  opcode->name, (int)fixup, -32768, 32767);
+	  else
+	    as_bad_where (fixP->fx_file, fixP->fx_line,
+			  _("%s offset %d out of range"),
+			  opcode->name, (int)fixup);
 	  break;
 	case signed_immed16_overflow:
 	  as_bad_where (fixP->fx_file, fixP->fx_line,
@@ -1080,6 +1223,11 @@ nios2_diagnose_overflow (valueT fixup, reloc_howto_type *howto,
 			_("immediate value %u out of range %u to %u"),
 			(unsigned int)fixup, 0, 31);
 	  break;
+	case signed_immed12_overflow:
+	  as_bad_where (fixP->fx_file, fixP->fx_line,
+			_("immediate value %d out of range %d to %d"),
+			(int)fixup, -2048, 2047);
+	  break;
 	case custom_opcode_overflow:
 	  as_bad_where (fixP->fx_file, fixP->fx_line,
 			_("custom instruction opcode %u out of range %u to %u"),
@@ -1137,6 +1285,19 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
 		  || fixP->fx_r_type == BFD_RELOC_NIOS2_GOT_HA
 		  || fixP->fx_r_type == BFD_RELOC_NIOS2_CALL_LO
 		  || fixP->fx_r_type == BFD_RELOC_NIOS2_CALL_HA
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_S12
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_I10_1_PCREL
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_T1I7_1_PCREL
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_T1I7_2
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_T2I4
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_T2I4_1
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_T2I4_2
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_X1I7_2
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_X2L5
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_F1I5_2
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_L5I4X1
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_T1X1I6
+		  || fixP->fx_r_type == BFD_RELOC_NIOS2_R2_T1X1I6_2
 		  /* Add other relocs here as we generate them.  */
 		  ));
 
@@ -1208,8 +1369,11 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
 	     FIXME : for some reason fixP->fx_pcrel isn't 1 when it should be
 	     so I'm using the howto structure instead to determine this.  */
 	  if (howto->pc_relative == 1)
-	    fixup = fixup - (fixP->fx_frag->fr_address + fixP->fx_where
-			     + fixP->fx_size);
+	    {
+	      fixup = (fixup - (fixP->fx_frag->fr_address + fixP->fx_where
+				+ fixP->fx_size));
+	      *valP = fixup;
+	    }
 
 	  /* Get the instruction or data to be fixed up.  */
 	  buf = fixP->fx_frag->fr_literal + fixP->fx_where;
@@ -1390,6 +1554,198 @@ nios2_parse_reg (const char *token, unsigned long regtype)
   return reg;
 }
 
+/* This function parses a reglist for ldwm/stwm and push.n/pop.n
+   instructions, given as a brace-enclosed register list.  The tokenizer
+   has replaced commas in the token with spaces.
+   The return value is a bitmask of registers in the set.  It also
+   sets nios2_reglist_mask and nios2_reglist_dir to allow error checking
+   when parsing the base register.  */
+
+static unsigned long nios2_reglist_mask;
+static int nios2_reglist_dir;
+
+static unsigned long
+nios2_parse_reglist (char *token, const struct nios2_opcode *op)
+{
+  unsigned long mask = 0;
+  int dir = 0;
+  unsigned long regtype = 0;
+  int last = -1;
+  const char *regname;
+
+  nios2_reglist_mask = 0;
+  nios2_reglist_dir = 0;
+
+  if (op->match == MATCH_R2_LDWM || op->match == MATCH_R2_STWM)
+    {
+      regtype = REG_LDWM;
+      dir = 0;
+    }
+  else if (op->match == MATCH_R2_PUSH_N)
+    {
+      regtype = REG_POP;
+      dir = -1;
+    }
+  else if (op->match == MATCH_R2_POP_N)
+    {
+      regtype = REG_POP;
+      dir = 1;
+    }
+  else
+    bad_opcode (op);
+
+  for (regname = strtok (token, "{ }");
+       regname;
+       regname = strtok (NULL, "{ }"))
+    {
+      int regno;
+      struct nios2_reg *reg = nios2_parse_reg (regname, regtype);
+
+      if (!reg)
+	break;
+      regno = reg->index;
+
+      /* Make sure registers are listed in proper sequence.  */
+      if (last >= 0)
+	{
+	  if (regno == last)
+	    {
+	      as_bad ("duplicate register %s\n", reg->name);
+	      return 0;
+	    }
+	  else if (dir == 0)
+	    dir = (regno < last ? -1 : 1);
+	  else if ((dir > 0 && regno < last)
+		   || (dir < 0 && regno > last)
+		   || (op->match == MATCH_R2_PUSH_N
+		       && ! ((last == 31 && regno == 28)
+			     || (last == 31 && regno <= 23)
+			     || (last == 28 && regno <= 23)
+			     || (regno < 23 && regno == last - 1)))
+		   || (op->match == MATCH_R2_POP_N
+		       && ! ((regno == 31 && last == 28)
+			     || (regno == 31 && last <= 23)
+			     || (regno == 28 && last <= 23)
+			     || (last < 23 && last == regno - 1))))
+	    {
+	      as_bad ("invalid register order");
+	      return 0;
+	    }
+	}
+
+      mask |= 1 << regno;
+      last = regno;
+    }
+
+  /* Check that all ldwm/stwm regs belong to the same set.  */
+  if ((op->match == MATCH_R2_LDWM || op->match == MATCH_R2_STWM)
+      && (mask & 0x00003ffc) && (mask & 0x90ffc000))
+    {
+      as_bad ("invalid register set in reglist");
+      return 0;
+    }
+
+  /* Check that push.n/pop.n regs include RA.  */
+  if ((op->match == MATCH_R2_PUSH_N || op->match == MATCH_R2_POP_N)
+      && ((mask & 0x80000000) == 0))
+    {
+      as_bad ("reglist must include ra (r31)");
+      return 0;
+    }
+
+  /* Check that there is at least one register in the set.  */
+  if (!mask)
+    {
+      as_bad ("reglist must include at least one register");
+      return 0;
+    }
+
+  /* OK, reglist passed validation.  */
+  nios2_reglist_mask = mask;
+  nios2_reglist_dir = dir;
+  return mask;
+}
+
+/* This function parses the base register and options used by the ldwm/stwm
+   instructions.  Returns the base register and sets the option arguments
+   accordingly.  On failure, returns NULL.  */
+static struct nios2_reg *
+nios2_parse_base_register (char *str, int *direction, int *writeback, int *ret)
+{
+  char *regname;
+  struct nios2_reg *reg;
+
+  *direction = 0;
+  *writeback = 0;
+  *ret = 0;
+
+  /* Check for --.  */
+  if (strncmp (str, "--", 2) == 0)
+    {
+      str += 2;
+      *direction -= 1;
+    }
+
+  /* Extract the base register.  */
+  if (*str != '(')
+    {
+      as_bad ("expected '(' before base register");
+      return NULL;
+    }
+  str++;
+  regname = str;
+  str = strchr (str, ')');
+  if (!str)
+    {
+      as_bad ("expected ')' after base register");
+      return NULL;
+    }
+  *str = '\0';
+  str++;
+  reg = nios2_parse_reg (regname, REG_NORMAL);
+  if (reg == NULL)
+    return NULL;
+
+  /* Check for ++.  */
+  if (strncmp (str, "++", 2) == 0)
+    {
+      str += 2;
+      *direction += 1;
+    }
+
+  /* Ensure that either -- or ++ is specified, but not both.  */
+  if (*direction == 0)
+    {
+      as_bad ("invalid base register syntax");
+      return NULL;;
+    }
+
+  /* Check for options.  The tokenizer has replaced commas with spaces.  */
+  while (*str)
+    {
+      while (*str == ' ')
+	str++;
+      if (strncmp (str, "writeback", 9) == 0)
+	{
+	  *writeback = 1;
+	  str += 9;
+	}
+      else if (strncmp (str, "ret", 3) == 0)
+	{
+	  *ret = 1;
+	  str += 3;
+	}
+      else if (*str)
+	{
+	  as_bad ("invalid option syntax");
+	  return NULL;
+	}
+    }
+
+  return reg;
+}
+
+
 /* The various nios2_assemble_* functions call this
    function to generate an expression from a string representing an expression.
    It then tries to evaluate the expression, and if it can, returns its value.
@@ -1398,13 +1754,14 @@ nios2_parse_reg (const char *token, unsigned long regtype)
 static unsigned long
 nios2_assemble_expression (const char *exprstr,
 			   nios2_insn_infoS *insn,
-			   bfd_reloc_code_real_type reloc_type,
+			   bfd_reloc_code_real_type orig_reloc_type,
 			   unsigned int pcrel)
 {
   nios2_insn_relocS *reloc;
   char *saved_line_ptr;
-  unsigned short value;
+  unsigned long value = 0;
   int i;
+  bfd_reloc_code_real_type reloc_type = orig_reloc_type;
 
   gas_assert (exprstr != NULL);
   gas_assert (insn != NULL);
@@ -1431,6 +1788,25 @@ nios2_assemble_expression (const char *exprstr,
 	break;
       }
 
+  /* No relocation allowed; we must have a constant expression.  */
+  if (orig_reloc_type == BFD_RELOC_NONE)
+    {
+      expressionS exp;
+
+      /* Parse the expression string.  */
+      saved_line_ptr = input_line_pointer;
+      input_line_pointer = (char *) exprstr;
+      expression (&exp);
+      input_line_pointer = saved_line_ptr;
+
+      /* If we don't have a constant, give an error.  */
+      if (reloc_type != orig_reloc_type || exp.X_op != O_constant)
+	as_bad (_("expression must be constant"));
+      else
+	value = exp.X_add_number;
+      return (unsigned long) value;
+    }
+
   /* We potentially have a relocation.  */
   reloc = nios2_insn_reloc_new (reloc_type, pcrel);
   reloc->reloc_next = insn->insn_reloc;
@@ -1445,7 +1821,6 @@ nios2_assemble_expression (const char *exprstr,
   /* This is redundant as the fixup will put this into
      the instruction, but it is included here so that
      self-test mode (-r) works.  */
-  value = 0;
   if (nios2_mode == NIOS2_MODE_TEST
       && reloc->reloc_expression.X_op == O_constant)
     value = reloc->reloc_expression.X_add_number;
@@ -1453,8 +1828,29 @@ nios2_assemble_expression (const char *exprstr,
   return (unsigned long) value;
 }
 
+/* Encode a 3-bit register number, giving an error if this is not possible.  */
+static unsigned int
+nios2_assemble_reg3 (const char *token)
+{
+  struct nios2_reg *reg = nios2_parse_reg (token, REG_3BIT);
+  int j;
+
+  if (reg == NULL)
+    return 0;
+
+  for (j = 0; j < nios2_num_r2_reg3_mappings; j++)
+    if (nios2_r2_reg3_mappings[j] == reg->index)
+      return j;
+
+  /* Should never get here if we passed validation.  */
+  as_bad (_("invalid register %s"), token);
+  return 0;
+}
 
 /* Argument assemble functions.  */
+
+
+/* Control register index.  */
 static void 
 nios2_assemble_arg_c (const char *token, nios2_insn_infoS *insn)
 {
@@ -1469,11 +1865,15 @@ nios2_assemble_arg_c (const char *token, nios2_insn_infoS *insn)
     case iw_r_type:
       insn->insn_code |= SET_IW_R_IMM5 (reg->index);
       break;
+    case iw_F3X6L5_type:
+      insn->insn_code |= SET_IW_F3X6L5_IMM5 (reg->index);
+      break;
     default:
       bad_opcode (op);
     }
 }
 
+/* Destination register.  */
 static void 
 nios2_assemble_arg_d (const char *token, nios2_insn_infoS *insn)
 {
@@ -1481,7 +1881,7 @@ nios2_assemble_arg_d (const char *token, nios2_insn_infoS *insn)
   unsigned long regtype = REG_NORMAL;
   struct nios2_reg *reg;
 
-  if (op->format == iw_custom_type)
+  if (op->format == iw_custom_type || op->format == iw_F3X8_type)
     regtype |= REG_COPROCESSOR;
   reg = nios2_parse_reg (token, regtype);
   if (reg == NULL)
@@ -1499,11 +1899,26 @@ nios2_assemble_arg_d (const char *token, nios2_insn_infoS *insn)
       else
 	insn->insn_code |= SET_IW_CUSTOM_READC (1);
       break;
+    case iw_F3X6L5_type:
+    case iw_F3X6_type:
+      insn->insn_code |= SET_IW_F3X6L5_C (reg->index);
+      break;
+    case iw_F3X8_type:
+      insn->insn_code |= SET_IW_F3X8_C (reg->index);
+      if (reg->regtype & REG_COPROCESSOR)
+	insn->insn_code |= SET_IW_F3X8_READC (0);
+      else
+	insn->insn_code |= SET_IW_F3X8_READC (1);
+      break;
+    case iw_F2_type:
+      insn->insn_code |= SET_IW_F2_B (reg->index);
+      break;
     default:
       bad_opcode (op);
     }
 }
 
+/* Source register 1.  */
 static void 
 nios2_assemble_arg_s (const char *token, nios2_insn_infoS *insn)
 {
@@ -1511,7 +1926,7 @@ nios2_assemble_arg_s (const char *token, nios2_insn_infoS *insn)
   unsigned long regtype = REG_NORMAL;
   struct nios2_reg *reg;
 
-  if (op->format == iw_custom_type)
+  if (op->format == iw_custom_type || op->format == iw_F3X8_type)
     regtype |= REG_COPROCESSOR;
   reg = nios2_parse_reg (token, regtype);
   if (reg == NULL)
@@ -1520,6 +1935,8 @@ nios2_assemble_arg_s (const char *token, nios2_insn_infoS *insn)
   switch (op->format)
     {
     case iw_r_type:
+      if (op->match == MATCH_R1_JMP && reg->index == 31)
+	as_bad (_("r31 cannot be used with jmp; use ret instead"));
       insn->insn_code |= SET_IW_R_A (reg->index);
       break;
     case iw_i_type:
@@ -1532,11 +1949,53 @@ nios2_assemble_arg_s (const char *token, nios2_insn_infoS *insn)
       else
 	insn->insn_code |= SET_IW_CUSTOM_READA (1);
       break;
+    case iw_F2I16_type:
+      insn->insn_code |= SET_IW_F2I16_A (reg->index);
+      break;
+    case iw_F2X4I12_type:
+      insn->insn_code |= SET_IW_F2X4I12_A (reg->index);
+      break;
+    case iw_F1X4I12_type:
+      insn->insn_code |= SET_IW_F1X4I12_A (reg->index);
+      break;
+    case iw_F1X4L17_type:
+      insn->insn_code |= SET_IW_F1X4L17_A (reg->index);
+      break;
+    case iw_F3X6L5_type:
+    case iw_F3X6_type:
+      if (op->match == MATCH_R2_JMP && reg->index == 31)
+	as_bad (_("r31 cannot be used with jmp; use ret instead"));
+      insn->insn_code |= SET_IW_F3X6L5_A (reg->index);
+      break;
+    case iw_F2X6L10_type:
+      insn->insn_code |= SET_IW_F2X6L10_A (reg->index);
+      break;
+    case iw_F3X8_type:
+      insn->insn_code |= SET_IW_F3X8_A (reg->index);
+      if (reg->regtype & REG_COPROCESSOR)
+	insn->insn_code |= SET_IW_F3X8_READA (0);
+      else
+	insn->insn_code |= SET_IW_F3X8_READA (1);
+      break;
+    case iw_F1X1_type:
+      if (op->match == MATCH_R2_JMPR_N && reg->index == 31)
+	as_bad (_("r31 cannot be used with jmpr.n; use ret.n instead"));
+      insn->insn_code |= SET_IW_F1X1_A (reg->index);
+      break;
+    case iw_F1I5_type:
+      /* Implicit stack pointer reference.  */
+      if (reg->index != 27)
+	as_bad (_("invalid register %s"), token);
+      break;
+    case iw_F2_type:
+      insn->insn_code |= SET_IW_F2_A (reg->index);
+      break;
     default:
       bad_opcode (op);
     }
 }
 
+/* Source register 2.  */
 static void 
 nios2_assemble_arg_t (const char *token, nios2_insn_infoS *insn)
 {
@@ -1544,7 +2003,7 @@ nios2_assemble_arg_t (const char *token, nios2_insn_infoS *insn)
   unsigned long regtype = REG_NORMAL;
   struct nios2_reg *reg;
 
-  if (op->format == iw_custom_type)
+  if (op->format == iw_custom_type || op->format == iw_F3X8_type)
     regtype |= REG_COPROCESSOR;
   reg = nios2_parse_reg (token, regtype);
   if (reg == NULL)
@@ -1565,11 +2024,147 @@ nios2_assemble_arg_t (const char *token, nios2_insn_infoS *insn)
       else
 	insn->insn_code |= SET_IW_CUSTOM_READB (1);
       break;
+    case iw_F2I16_type:
+      insn->insn_code |= SET_IW_F2I16_B (reg->index);
+      break;
+    case iw_F2X4I12_type:
+      insn->insn_code |= SET_IW_F2X4I12_B (reg->index);
+      break;
+    case iw_F3X6L5_type:
+    case iw_F3X6_type:
+      insn->insn_code |= SET_IW_F3X6L5_B (reg->index);
+      break;
+    case iw_F2X6L10_type:
+      insn->insn_code |= SET_IW_F2X6L10_B (reg->index);
+      break;
+    case iw_F3X8_type:
+      insn->insn_code |= SET_IW_F3X8_B (reg->index);
+      if (reg->regtype & REG_COPROCESSOR)
+	insn->insn_code |= SET_IW_F3X8_READB (0);
+      else
+	insn->insn_code |= SET_IW_F3X8_READB (1);
+      break;
+    case iw_F1I5_type:
+      insn->insn_code |= SET_IW_F1I5_B (reg->index);
+      break;
+    case iw_F2_type:
+      insn->insn_code |= SET_IW_F2_B (reg->index);
+      break;
+    case iw_T1X1I6_type:
+      /* Implicit zero register reference.  */
+      if (reg->index != 0)
+	as_bad (_("invalid register %s"), token);
+      break;
+
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* Destination register w/3-bit encoding.  */
+static void 
+nios2_assemble_arg_D (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  int reg = nios2_assemble_reg3 (token);
+  
+  switch (op->format)
+    {
+    case iw_T1I7_type:
+      insn->insn_code |= SET_IW_T1I7_A3 (reg);
+      break;
+    case iw_T2X1L3_type:
+      insn->insn_code |= SET_IW_T2X1L3_B3 (reg);
+      break;
+    case iw_T2X1I3_type:
+      insn->insn_code |= SET_IW_T2X1I3_B3 (reg);
+      break;
+    case iw_T3X1_type:
+      insn->insn_code |= SET_IW_T3X1_C3 (reg);
+      break;
+    case iw_T2X3_type:
+      /* Some instructions using this encoding take 3 register arguments,
+	 requiring the destination register to be the same as the first
+	 source register.  */
+      if (op->num_args == 3)
+	insn->insn_code |= SET_IW_T2X3_A3 (reg);
+      else
+	insn->insn_code |= SET_IW_T2X3_B3 (reg);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* Source register w/3-bit encoding.  */
+static void 
+nios2_assemble_arg_S (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  int reg = nios2_assemble_reg3 (token);
+  
+  switch (op->format)
+    {
+    case iw_T1I7_type:
+      insn->insn_code |= SET_IW_T1I7_A3 (reg);
+      break;
+    case iw_T2I4_type:
+      insn->insn_code |= SET_IW_T2I4_A3 (reg);
+      break;
+    case iw_T2X1L3_type:
+      insn->insn_code |= SET_IW_T2X1L3_A3 (reg);
+      break;
+    case iw_T2X1I3_type:
+      insn->insn_code |= SET_IW_T2X1I3_A3 (reg);
+      break;
+    case iw_T3X1_type:
+      insn->insn_code |= SET_IW_T3X1_A3 (reg);
+      break;
+    case iw_T2X3_type:
+      /* Some instructions using this encoding take 3 register arguments,
+	 requiring the destination register to be the same as the first
+	 source register.  */
+      if (op->num_args == 3)
+	{
+	  int dreg = GET_IW_T2X3_A3 (insn->insn_code);
+	  if (dreg != reg)
+	    as_bad ("source and destination registers must be the same");
+	}
+      else
+	insn->insn_code |= SET_IW_T2X3_A3 (reg);
+      break;
+    case iw_T1X1I6_type:
+      insn->insn_code |= SET_IW_T1X1I6_A3 (reg);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* Source register 2 w/3-bit encoding.  */
+static void 
+nios2_assemble_arg_T (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  int reg = nios2_assemble_reg3 (token);
+  
+  switch (op->format)
+    {
+    case iw_T2I4_type:
+      insn->insn_code |= SET_IW_T2I4_B3 (reg);
+      break;
+    case iw_T3X1_type:
+      insn->insn_code |= SET_IW_T3X1_B3 (reg);
+      break;
+    case iw_T2X3_type:
+      insn->insn_code |= SET_IW_T2X3_B3 (reg);
+      break;
     default:
       bad_opcode (op);
     }
 }
 
+/* 16-bit signed immediate.  */
 static void 
 nios2_assemble_arg_i (const char *token, nios2_insn_infoS *insn)
 {
@@ -1583,11 +2178,41 @@ nios2_assemble_arg_i (const char *token, nios2_insn_infoS *insn)
 				       BFD_RELOC_NIOS2_S16, 0);
       insn->constant_bits |= SET_IW_I_IMM16 (val);
       break;
+    case iw_F2I16_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_S16, 0);
+      insn->constant_bits |= SET_IW_F2I16_IMM16 (val);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* 12-bit signed immediate.  */
+static void 
+nios2_assemble_arg_I (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+
+  switch (op->format)
+    {
+    case iw_F2X4I12_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_S12, 0);
+      insn->constant_bits |= SET_IW_F2X4I12_IMM12 (val);
+      break;
+    case iw_F1X4I12_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_S12, 0);
+      insn->constant_bits |= SET_IW_F2X4I12_IMM12 (val);
+      break;
     default:
       bad_opcode (op);
     }
 }
 
+/* 16-bit unsigned immediate.  */
 static void 
 nios2_assemble_arg_u (const char *token, nios2_insn_infoS *insn)
 {
@@ -1601,11 +2226,128 @@ nios2_assemble_arg_u (const char *token, nios2_insn_infoS *insn)
 				       BFD_RELOC_NIOS2_U16, 0);
       insn->constant_bits |= SET_IW_I_IMM16 (val);
       break;
+    case iw_F2I16_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_U16, 0);
+      insn->constant_bits |= SET_IW_F2I16_IMM16 (val);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* 7-bit unsigned immediate with 2-bit shift.  */
+static void 
+nios2_assemble_arg_U (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+
+  switch (op->format)
+    {
+    case iw_T1I7_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_T1I7_2, 0);
+      insn->constant_bits |= SET_IW_T1I7_IMM7 (val >> 2);
+      break;
+    case iw_X1I7_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_X1I7_2, 0);
+      insn->constant_bits |= SET_IW_X1I7_IMM7 (val >> 2);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* 5-bit unsigned immediate with 2-bit shift.  */
+static void 
+nios2_assemble_arg_V (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+
+  switch (op->format)
+    {
+    case iw_F1I5_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_F1I5_2, 0);
+      insn->constant_bits |= SET_IW_F1I5_IMM5 (val >> 2);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* 4-bit unsigned immediate with 2-bit shift.  */
+static void 
+nios2_assemble_arg_W (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+
+  switch (op->format)
+    {
+    case iw_T2I4_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_T2I4_2, 0);
+      insn->constant_bits |= SET_IW_T2I4_IMM4 (val >> 2);
+      break;
+    case iw_L5I4X1_type:
+      /* This argument is optional for push.n/pop.n, and defaults to 
+	 zero if unspecified.  */
+      if (token == NULL)
+	return;
+
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_L5I4X1, 0);
+      insn->constant_bits |= SET_IW_L5I4X1_IMM4 (val >> 2);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* 4-bit unsigned immediate with 1-bit shift.  */
+static void 
+nios2_assemble_arg_X (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+
+  switch (op->format)
+    {
+    case iw_T2I4_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_T2I4_1, 0);
+      insn->constant_bits |= SET_IW_T2I4_IMM4 (val >> 1);
+      break;
     default:
       bad_opcode (op);
     }
 }
 
+/* 4-bit unsigned immediate without shift.  */
+static void 
+nios2_assemble_arg_Y (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+
+  switch (op->format)
+    {
+    case iw_T2I4_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_T2I4, 0);
+      insn->constant_bits |= SET_IW_T2I4_IMM4 (val);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+
+/* 16-bit signed immediate address offset.  */
 static void 
 nios2_assemble_arg_o (const char *token, nios2_insn_infoS *insn)
 {
@@ -1619,11 +2361,55 @@ nios2_assemble_arg_o (const char *token, nios2_insn_infoS *insn)
 				       BFD_RELOC_16_PCREL, 1);
       insn->constant_bits |= SET_IW_I_IMM16 (val);
       break;
+    case iw_F2I16_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_16_PCREL, 1);
+      insn->constant_bits |= SET_IW_F2I16_IMM16 (val);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* 10-bit signed address offset with 1-bit shift.  */
+static void 
+nios2_assemble_arg_O (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+
+  switch (op->format)
+    {
+    case iw_I10_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_I10_1_PCREL, 1);
+      insn->constant_bits |= SET_IW_I10_IMM10 (val >> 1);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* 7-bit signed address offset with 1-bit shift.  */
+static void 
+nios2_assemble_arg_P (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+
+  switch (op->format)
+    {
+    case iw_T1I7_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_T1I7_1_PCREL, 1);
+      insn->constant_bits |= SET_IW_T1I7_IMM7 (val >> 1);
+      break;
     default:
       bad_opcode (op);
     }
 }
 
+/* 5-bit unsigned immediate.  */
 static void 
 nios2_assemble_arg_j (const char *token, nios2_insn_infoS *insn)
 {
@@ -1637,11 +2423,66 @@ nios2_assemble_arg_j (const char *token, nios2_insn_infoS *insn)
 				       BFD_RELOC_NIOS2_IMM5, 0);
       insn->constant_bits |= SET_IW_R_IMM5 (val);
       break;
+    case iw_F3X6L5_type:
+      if (op->match == MATCH_R2_ENI)
+	/* Value must be constant 0 or 1.  */
+	{
+	  val = nios2_assemble_expression (token, insn, BFD_RELOC_NONE, 0);
+	  if (val != 0 && val != 1)
+	    as_bad ("invalid eni argument %u", val);
+	  insn->insn_code |= SET_IW_F3X6L5_IMM5 (val);
+	}
+      else
+	{
+	  val = nios2_assemble_expression (token, insn,
+					   BFD_RELOC_NIOS2_IMM5, 0);
+	  insn->constant_bits |= SET_IW_F3X6L5_IMM5 (val);
+	}
+      break;
+    case iw_F2X6L10_type:
+      /* Only constant expression without relocation permitted for
+	 bit position.  */
+      val = nios2_assemble_expression (token, insn, BFD_RELOC_NONE, 0);
+      if (val > 31)
+	as_bad ("invalid bit position %u", val);
+      insn->insn_code |= SET_IW_F2X6L10_MSB (val);
+      break;
+    case iw_X2L5_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_X2L5, 0);
+      insn->constant_bits |= SET_IW_X2L5_IMM5 (val);
+      break;
     default:
       bad_opcode (op);
     }
 }
 
+/* Second 5-bit unsigned immediate field.  */
+static void 
+nios2_assemble_arg_k (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+
+  switch (op->format)
+    {
+    case iw_F2X6L10_type:
+      /* Only constant expression without relocation permitted for
+	 bit position.  */
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NONE, 0);
+      if (val > 31)
+	as_bad ("invalid bit position %u", val);
+      else if (GET_IW_F2X6L10_MSB (insn->insn_code) < val)
+	as_bad ("MSB must be greater than or equal to LSB");
+      insn->insn_code |= SET_IW_F2X6L10_LSB (val);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* 8-bit unsigned immediate.  */
 static void 
 nios2_assemble_arg_l (const char *token, nios2_insn_infoS *insn)
 {
@@ -1655,11 +2496,17 @@ nios2_assemble_arg_l (const char *token, nios2_insn_infoS *insn)
 				       BFD_RELOC_NIOS2_IMM8, 0);
       insn->constant_bits |= SET_IW_CUSTOM_N (val);
       break;
+    case iw_F3X8_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_IMM8, 0);
+      insn->constant_bits |= SET_IW_F3X8_N (val);
+      break;
     default:
       bad_opcode (op);
     }
 }
 
+/* 26-bit unsigned immediate.  */
 static void 
 nios2_assemble_arg_m (const char *token, nios2_insn_infoS *insn)
 {
@@ -1676,6 +2523,277 @@ nios2_assemble_arg_m (const char *token, nios2_insn_infoS *insn)
 				       0);
       insn->constant_bits |= SET_IW_J_IMM26 (val);
       break;
+    case iw_L26_type:
+      val = nios2_assemble_expression (token, insn,
+				       (nios2_as_options.noat
+					? BFD_RELOC_NIOS2_CALL26_NOAT
+					: BFD_RELOC_NIOS2_CALL26),
+				       0);
+      insn->constant_bits |= SET_IW_L26_IMM26 (val);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* 6-bit unsigned immediate with no shifting.  */
+static void 
+nios2_assemble_arg_M (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+
+  switch (op->format)
+    {
+    case iw_T1X1I6_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_T1X1I6, 0);
+      insn->constant_bits |= SET_IW_T1X1I6_IMM6 (val);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* 6-bit unsigned immediate with 2-bit shift.  */
+static void 
+nios2_assemble_arg_N (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+
+  switch (op->format)
+    {
+    case iw_T1X1I6_type:
+      val = nios2_assemble_expression (token, insn,
+				       BFD_RELOC_NIOS2_R2_T1X1I6_2, 0);
+      insn->constant_bits |= SET_IW_T1X1I6_IMM6 (val >> 2);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+
+/* Encoded enumeration for addi.n/subi.n.  */
+static void 
+nios2_assemble_arg_e (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+  int i;
+
+  switch (op->format)
+    {
+    case iw_T2X1I3_type:
+      val = nios2_assemble_expression (token, insn, BFD_RELOC_NONE, 0);
+      for (i = 0; i < nios2_num_r2_asi_n_mappings; i++)
+	if (val == nios2_r2_asi_n_mappings[i])
+	  break;
+      if (i == nios2_num_r2_asi_n_mappings)
+	{
+	  as_bad (_("Invalid constant operand %s"), token);
+	  return;
+	}
+      insn->insn_code |= SET_IW_T2X1I3_IMM3 ((unsigned)i);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* Encoded enumeration for slli.n/srli.n.  */
+static void 
+nios2_assemble_arg_f (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+  int i;
+
+  switch (op->format)
+    {
+    case iw_T2X1L3_type:
+      val = nios2_assemble_expression (token, insn, BFD_RELOC_NONE, 0);
+      for (i = 0; i < nios2_num_r2_shi_n_mappings; i++)
+	if (val == nios2_r2_shi_n_mappings[i])
+	  break;
+      if (i == nios2_num_r2_shi_n_mappings)
+	{
+	  as_bad (_("Invalid constant operand %s"), token);
+	  return;
+	}
+      insn->insn_code |= SET_IW_T2X1L3_SHAMT ((unsigned)i);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* Encoded enumeration for andi.n.  */
+static void 
+nios2_assemble_arg_g (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+  int i;
+
+  switch (op->format)
+    {
+    case iw_T2I4_type:
+      val = nios2_assemble_expression (token, insn, BFD_RELOC_NONE, 0);
+      for (i = 0; i < nios2_num_r2_andi_n_mappings; i++)
+	if (val == nios2_r2_andi_n_mappings[i])
+	  break;
+      if (i == nios2_num_r2_andi_n_mappings)
+	{
+	  as_bad (_("Invalid constant operand %s"), token);
+	  return;
+	}
+      insn->insn_code |= SET_IW_T2I4_IMM4 ((unsigned)i);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* Encoded enumeration for movi.n.  */
+static void 
+nios2_assemble_arg_h (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned int val;
+  int i;
+
+  switch (op->format)
+    {
+    case iw_T1I7_type:
+      val = nios2_assemble_expression (token, insn, BFD_RELOC_NONE, 0);
+      i = (signed) val;
+      if ((signed) i == -1)
+	val = 127;
+      else if (i == -2)
+	val = 126;
+      else if (i == 0xff)
+	val = 125;
+      else if (i < 0 || i > 125)
+	{
+	  as_bad (_("Invalid constant operand %s"), token);
+	  return;
+	}
+      insn->insn_code |= SET_IW_T1I7_IMM7 (val);
+      break;
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* Encoded REGMASK for ldwm/stwm or push.n/pop.n.  */
+static void 
+nios2_assemble_arg_R (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  unsigned long mask;
+  char *buf = strdup (token);
+  unsigned long reglist = nios2_parse_reglist (buf, op);
+  free (buf);
+
+  if (reglist == 0)
+    return;
+
+  switch (op->format)
+    {
+    case iw_F1X4L17_type:
+      /* Encoding for ldwm/stwm.  */
+      if (reglist & 0x00003ffc)
+	mask = reglist >> 2;
+      else
+	{
+	  insn->insn_code |= SET_IW_F1X4L17_RS (1);
+	  mask = (reglist & 0x00ffc000) >> 14;
+	  if (reglist & (1 << 28))
+	    mask |= 1 << 10;
+	  if (reglist & (1 << 31))
+	    mask |= 1 << 11;
+	}
+      insn->insn_code |= SET_IW_F1X4L17_REGMASK (mask);
+      break;
+
+    case iw_L5I4X1_type:
+      /* Encoding for push.n/pop.n.  */
+      if (reglist & (1 << 28))
+	insn->insn_code |= SET_IW_L5I4X1_FP (1);
+      mask = reglist & 0x00ff0000;
+      if (mask)
+	{
+	  int i;
+
+	  for (i = 0; i < nios2_num_r2_reg_range_mappings; i++)
+	    if (nios2_r2_reg_range_mappings[i] == mask)
+	      break;
+	  if (i == nios2_num_r2_reg_range_mappings)
+	    {
+	      as_bad ("invalid reglist");
+	      return;
+	    }
+	  insn->insn_code |= SET_IW_L5I4X1_REGRANGE (i);
+	  insn->insn_code |= SET_IW_L5I4X1_CS (1);
+	}
+      break;
+	
+    default:
+      bad_opcode (op);
+    }
+}
+
+/* Base register for ldwm/stwm.  */
+static void 
+nios2_assemble_arg_B (const char *token, nios2_insn_infoS *insn)
+{
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
+  int direction, writeback, ret;
+  char *str = strdup (token);
+  struct nios2_reg *reg
+    = nios2_parse_base_register (str, &direction, &writeback, &ret);
+
+  free (str);
+  if (!reg)
+    return;
+
+  switch (op->format)
+    {
+    case iw_F1X4L17_type:
+      /* For ldwm, check to see if the base register is already inside the 
+	 register list.  */
+      if (op->match == MATCH_R2_LDWM
+	  && (nios2_reglist_mask & (1 << reg->index)))
+	{
+	  as_bad ("invalid base register; %s is inside the reglist", reg->name);
+	  return;
+	}
+
+      /* For stwm, ret option is not allowed.  */
+      if (op->match == MATCH_R2_STWM && ret)
+	{
+	  as_bad ("invalid option syntax");
+	  return;
+	}
+
+      /* Check that the direction matches the ordering of the reglist.  */
+      if (nios2_reglist_dir && direction != nios2_reglist_dir)
+	{
+	  as_bad ("reglist order does not match increment/decrement mode");
+	  return;
+	}
+
+      insn->insn_code |= SET_IW_F1X4L17_A (reg->index);
+      if (direction > 0)
+	insn->insn_code |= SET_IW_F1X4L17_ID (1);
+      if (writeback)
+	insn->insn_code |= SET_IW_F1X4L17_WB (1);
+      if (ret)
+	insn->insn_code |= SET_IW_F1X4L17_PC (1);
+      break;
+
     default:
       bad_opcode (op);
     }
@@ -1723,22 +2841,70 @@ nios2_assemble_args (nios2_insn_infoS *insn)
 	nios2_assemble_arg_t (insn->insn_tokens[tokidx++], insn);
 	break;
 	
+      case 'D':
+	nios2_assemble_arg_D (insn->insn_tokens[tokidx++], insn);
+	break;
+	
+      case 'S':
+	nios2_assemble_arg_S (insn->insn_tokens[tokidx++], insn);
+	break;
+	
+      case 'T':
+	nios2_assemble_arg_T (insn->insn_tokens[tokidx++], insn);
+	break;
+	
       case 'i':
 	nios2_assemble_arg_i (insn->insn_tokens[tokidx++], insn);
 	break;
 	
+      case 'I':
+	nios2_assemble_arg_I (insn->insn_tokens[tokidx++], insn);
+	break;
+	
       case 'u':
 	nios2_assemble_arg_u (insn->insn_tokens[tokidx++], insn);
 	break;
 	
+      case 'U':
+	nios2_assemble_arg_U (insn->insn_tokens[tokidx++], insn);
+	break;
+	
+      case 'V':
+	nios2_assemble_arg_V (insn->insn_tokens[tokidx++], insn);
+	break;
+	
+      case 'W':
+	nios2_assemble_arg_W (insn->insn_tokens[tokidx++], insn);
+	break;
+	
+      case 'X':
+	nios2_assemble_arg_X (insn->insn_tokens[tokidx++], insn);
+	break;
+	
+      case 'Y':
+	nios2_assemble_arg_Y (insn->insn_tokens[tokidx++], insn);
+	break;
+	
       case 'o':
 	nios2_assemble_arg_o (insn->insn_tokens[tokidx++], insn);
 	break;
 	
+      case 'O':
+	nios2_assemble_arg_O (insn->insn_tokens[tokidx++], insn);
+	break;
+	
+      case 'P':
+	nios2_assemble_arg_P (insn->insn_tokens[tokidx++], insn);
+	break;
+
       case 'j':
 	nios2_assemble_arg_j (insn->insn_tokens[tokidx++], insn);
 	break;
 	
+      case 'k':
+	nios2_assemble_arg_k (insn->insn_tokens[tokidx++], insn);
+	break;
+	
       case 'l':
 	nios2_assemble_arg_l (insn->insn_tokens[tokidx++], insn);
 	break;
@@ -1746,7 +2912,39 @@ nios2_assemble_args (nios2_insn_infoS *insn)
       case 'm':
 	nios2_assemble_arg_m (insn->insn_tokens[tokidx++], insn);
 	break;
+
+      case 'M':
+	nios2_assemble_arg_M (insn->insn_tokens[tokidx++], insn);
+	break;
+
+      case 'N':
+	nios2_assemble_arg_N (insn->insn_tokens[tokidx++], insn);
+	break;
+
+      case 'e':
+	nios2_assemble_arg_e (insn->insn_tokens[tokidx++], insn);
+	break;
+	
+      case 'f':
+	nios2_assemble_arg_f (insn->insn_tokens[tokidx++], insn);
+	break;
 	
+      case 'g':
+	nios2_assemble_arg_g (insn->insn_tokens[tokidx++], insn);
+	break;
+	
+      case 'h':
+	nios2_assemble_arg_h (insn->insn_tokens[tokidx++], insn);
+	break;
+	
+      case 'R':
+	nios2_assemble_arg_R (insn->insn_tokens[tokidx++], insn);
+	break;
+
+      case 'B':
+	nios2_assemble_arg_B (insn->insn_tokens[tokidx++], insn);
+	break;
+
       default:
 	bad_opcode (op);
 	break;
@@ -1775,6 +2973,9 @@ nios2_consume_arg (char *argstr, const char *parsestr)
     case 'd':
     case 's':
     case 't':
+    case 'D':
+    case 'S':
+    case 'T':
       break;
 
     case 'i':
@@ -1798,11 +2999,60 @@ nios2_consume_arg (char *argstr, const char *parsestr)
       break;
     case 'm':
     case 'j':
+    case 'k':
     case 'l':
+    case 'I':
+    case 'U':
+    case 'V':
+    case 'W':
+    case 'X':
+    case 'Y':
+    case 'O':
+    case 'P':
+    case 'e':
+    case 'f':
+    case 'g':
+    case 'h':
+    case 'M':
+    case 'N':
+      
       /* We can't have %hi, %lo or %hiadj here.  */
       if (*argstr == '%')
 	as_bad (_("badly formed expression near %s"), argstr);
       break;
+
+    case 'R':
+      /* Register list for ldwm/stwm or push.n/pop.n.  Replace the commas
+	 in the list with spaces so we don't confuse them with separators.  */
+      if (*argstr != '{')
+	{
+	  as_bad ("missing '{' in register list");
+	  break;
+	}
+      for (temp = argstr + 1; *temp; temp++)
+	{
+	  if (*temp == '}')
+	    break;
+	  else if (*temp == ',')
+	    *temp = ' ';
+	}
+      if (!*temp)
+	{
+	  as_bad ("missing '}' in register list");
+	  break;
+	}
+      break;
+
+    case 'B':
+      /* Base register and options for ldwm/stwm.  This is the final argument
+	 and consumes the rest of the argument string; replace commas
+	 with spaces so that the token splitter doesn't think they are
+	 separate arguments.  */
+      for (temp = argstr; *temp; temp++)
+	if (*temp == ',')
+	  *temp = ' ';
+      break;
+
     case 'o':
     case 'E':
       break;
@@ -1839,7 +3089,6 @@ nios2_consume_separator (char *argstr, const char *separator)
   return p;
 }
 
-
 /* The principal argument parsing function which takes a string argstr
    representing the instruction arguments for insn, and extracts the argument
    tokens matching parsestr into parsed_args.  */
@@ -2022,7 +3271,7 @@ nios2_translate_pseudo_insn (nios2_insn_infoS *insn)
   else
     /* we cannot recover from this.  */
     as_fatal (_("unrecognized pseudo-instruction %s"),
-	      ps_insn->pseudo_insn);
+	      insn->insn_nios2_opcode->name);
   return ps_insn;
 }
 
@@ -2056,7 +3305,8 @@ const nios2_ps_insn_infoS nios2_ps_insn_info_structs[] = {
   {"cmpgtui", "cmpgeui", nios2_modify_arg, "+1", 0, 3, nios2_free_arg},
   {"cmplei", "cmplti", nios2_modify_arg, "+1", 0, 3, nios2_free_arg},
   {"cmpleui", "cmpltui", nios2_modify_arg, "+1", 0, 3, nios2_free_arg},
-  {"subi", "addi", nios2_negate_arg, "", 0, 3, nios2_free_arg}
+  {"subi", "addi", nios2_negate_arg, "", 0, 3, nios2_free_arg},
+  {"nop.n", "mov.n", nios2_append_arg, "zero", 2, 1, NULL}
   /* Add further pseudo-ops here.  */
 };
 
@@ -2101,6 +3351,7 @@ output_ubranch (nios2_insn_infoS *insn)
       symbolS *symp = reloc->reloc_expression.X_add_symbol;
       offsetT offset = reloc->reloc_expression.X_add_number;
       char *f;
+      bfd_boolean is_cdx = (insn->insn_nios2_opcode->size == 2);
 
       /* Tag dwarf2 debug info to the address at the start of the insn.
 	 We must do it before frag_var() below closes off the frag.  */
@@ -2111,7 +3362,8 @@ output_ubranch (nios2_insn_infoS *insn)
 	 this may generate.  */
       f = frag_var (rs_machine_dependent,
 		    UBRANCH_MAX_SIZE, insn->insn_nios2_opcode->size,
-		    UBRANCH_SUBTYPE (0), symp, offset, NULL);
+		    (is_cdx ? CDX_UBRANCH_SUBTYPE (0) : UBRANCH_SUBTYPE (0)),
+		    symp, offset, NULL);
 
       md_number_to_chars (f, insn->insn_code, insn->insn_nios2_opcode->size);
 
@@ -2131,6 +3383,7 @@ output_cbranch (nios2_insn_infoS *insn)
       symbolS *symp = reloc->reloc_expression.X_add_symbol;
       offsetT offset = reloc->reloc_expression.X_add_number;
       char *f;
+      bfd_boolean is_cdx = (insn->insn_nios2_opcode->size == 2);
 
       /* Tag dwarf2 debug info to the address at the start of the insn.
 	 We must do it before frag_var() below closes off the frag.  */
@@ -2141,7 +3394,8 @@ output_cbranch (nios2_insn_infoS *insn)
 	 this may generate.  */
       f = frag_var (rs_machine_dependent,
 		    CBRANCH_MAX_SIZE, insn->insn_nios2_opcode->size,
-		    CBRANCH_SUBTYPE (0), symp, offset, NULL);
+		    (is_cdx ? CDX_CBRANCH_SUBTYPE (0) : CBRANCH_SUBTYPE (0)),
+		    symp, offset, NULL);
 
       md_number_to_chars (f, insn->insn_code, insn->insn_nios2_opcode->size);
 
@@ -2162,23 +3416,50 @@ output_call (nios2_insn_infoS *insn)
      and puts it in the current frag.  */
   char *f = frag_more (12);
   nios2_insn_relocS *reloc = insn->insn_reloc;
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
 
-  md_number_to_chars (f,
-		      (MATCH_R1_ORHI | SET_IW_I_B (AT_REGNUM)
-		       | SET_IW_I_A (0)),
-		      4);
-  dwarf2_emit_insn (4);
-  fix_new_exp (frag_now, f - frag_now->fr_literal, 4,
-	       &reloc->reloc_expression, 0, BFD_RELOC_NIOS2_HI16);
-  md_number_to_chars (f + 4,
-		      (MATCH_R1_ORI | SET_IW_I_B (AT_REGNUM)
-		       | SET_IW_I_A (AT_REGNUM)),
-		      4);
-  dwarf2_emit_insn (4);
-  fix_new_exp (frag_now, f - frag_now->fr_literal + 4, 4,
-	       &reloc->reloc_expression, 0, BFD_RELOC_NIOS2_LO16);
-  md_number_to_chars (f + 8, MATCH_R1_CALLR | SET_IW_R_A (AT_REGNUM), 4);
-  dwarf2_emit_insn (4);
+  switch (op->format)
+    {
+    case iw_j_type:
+      md_number_to_chars (f,
+			  (MATCH_R1_ORHI | SET_IW_I_B (AT_REGNUM)
+			   | SET_IW_I_A (0)),
+			  4);
+      dwarf2_emit_insn (4);
+      fix_new_exp (frag_now, f - frag_now->fr_literal, 4,
+		   &reloc->reloc_expression, 0, BFD_RELOC_NIOS2_HI16);
+      md_number_to_chars (f + 4,
+			  (MATCH_R1_ORI | SET_IW_I_B (AT_REGNUM)
+			   | SET_IW_I_A (AT_REGNUM)),
+			  4);
+      dwarf2_emit_insn (4);
+      fix_new_exp (frag_now, f - frag_now->fr_literal + 4, 4,
+		   &reloc->reloc_expression, 0, BFD_RELOC_NIOS2_LO16);
+      md_number_to_chars (f + 8, MATCH_R1_CALLR | SET_IW_R_A (AT_REGNUM), 4);
+      dwarf2_emit_insn (4);
+      break;
+    case iw_L26_type:
+      md_number_to_chars (f,
+			  (MATCH_R2_ORHI | SET_IW_F2I16_B (AT_REGNUM)
+			   | SET_IW_F2I16_A (0)),
+			  4);
+      dwarf2_emit_insn (4);
+      fix_new_exp (frag_now, f - frag_now->fr_literal, 4,
+		   &reloc->reloc_expression, 0, BFD_RELOC_NIOS2_HI16);
+      md_number_to_chars (f + 4,
+			  (MATCH_R2_ORI | SET_IW_F2I16_B (AT_REGNUM)
+			   | SET_IW_F2I16_A (AT_REGNUM)),
+			  4);
+      dwarf2_emit_insn (4);
+      fix_new_exp (frag_now, f - frag_now->fr_literal + 4, 4,
+		   &reloc->reloc_expression, 0, BFD_RELOC_NIOS2_LO16);
+      md_number_to_chars (f + 8, MATCH_R2_CALLR | SET_IW_F3X6L5_A (AT_REGNUM),
+			  4);
+      dwarf2_emit_insn (4);
+      break;
+    default:
+      bad_opcode (op);
+    }
 }
 
 /* Output a movhi/addi pair for the movia pseudo-op.  */
@@ -2189,21 +3470,33 @@ output_movia (nios2_insn_infoS *insn)
      and puts it in the current frag.  */
   char *f = frag_more (8);
   nios2_insn_relocS *reloc = insn->insn_reloc;
-  unsigned long reg_index = GET_IW_I_B (insn->insn_code);
+  unsigned long reg, code;
+  const struct nios2_opcode *op = insn->insn_nios2_opcode;
 
   /* If the reloc is NULL, there was an error assembling the movia.  */
   if (reloc != NULL)
     {
+      switch (op->format)
+	{
+	case iw_i_type:
+	  reg = GET_IW_I_B (insn->insn_code);
+	  code = MATCH_R1_ADDI | SET_IW_I_A (reg) | SET_IW_I_B (reg);
+	  break;
+	case iw_F2I16_type:
+	  reg = GET_IW_F2I16_B (insn->insn_code);
+	  code = MATCH_R2_ADDI | SET_IW_F2I16_A (reg) | SET_IW_F2I16_B (reg);
+	  break;
+	default:
+	  bad_opcode (op);
+	}
+
       md_number_to_chars (f, insn->insn_code, 4);
       dwarf2_emit_insn (4);
       fix_new (frag_now, f - frag_now->fr_literal, 4,
 	       reloc->reloc_expression.X_add_symbol,
 	       reloc->reloc_expression.X_add_number, 0,
 	       BFD_RELOC_NIOS2_HIADJ16);
-      md_number_to_chars (f + 4,
-			  (MATCH_R1_ADDI | SET_IW_I_A (reg_index)
-			   | SET_IW_I_B (reg_index)),
-			  4);
+      md_number_to_chars (f + 4, code, 4);
       dwarf2_emit_insn (4);
       fix_new (frag_now, f + 4 - frag_now->fr_literal, 4,
 	       reloc->reloc_expression.X_add_symbol,
@@ -2387,6 +3680,7 @@ md_begin (void)
   nios2_current_align_seg = now_seg;
   nios2_last_label = NULL;
   nios2_current_align = 0;
+  nios2_min_align = 2;
 }
 
 
@@ -2400,11 +3694,11 @@ md_assemble (char *op_str)
   nios2_insn_infoS thisinsn;
   nios2_insn_infoS *insn = &thisinsn;
 
-  /* Make sure we are aligned on a 4-byte boundary.  */
-  if (nios2_current_align < 2)
-    nios2_align (2, NULL, nios2_last_label);
-  else if (nios2_current_align > 2)
-    nios2_current_align = 2;
+  /* Make sure we are aligned on an appropriate boundary.  */
+  if (nios2_current_align < nios2_min_align)
+    nios2_align (nios2_min_align, NULL, nios2_last_label);
+  else if (nios2_current_align > nios2_min_align)
+    nios2_current_align = nios2_min_align;
   nios2_last_label = NULL;
 
   /* We don't want to clobber to op_str
@@ -2420,6 +3714,11 @@ md_assemble (char *op_str)
   if (insn->insn_nios2_opcode != NULL)
     {
       nios2_ps_insn_infoS *ps_insn = NULL;
+
+      /* Note if we've seen a 16-bit instruction.  */
+      if (insn->insn_nios2_opcode->size == 2)
+	nios2_min_align = 1;
+
       /* Set the opcode for the instruction.  */
       insn->insn_code = insn->insn_nios2_opcode->match;
       insn->constant_bits = 0;
@@ -2667,7 +3966,7 @@ nios2_cons_align (int size)
     ++log_size;
 
   if (subseg_text_p (now_seg))
-    pfill = (const char *) &nop;
+    pfill = (const char *) nop32;
   else
     pfill = NULL;