* as.h: Replace flagseen with separate variables.

[binutils-gdb.git] / gas / config / tc-mips.c

/* tc-mips.c -- assemble code for a MIPS chip.
   Copyright (C) 1993 Free Software Foundation, Inc.
   Contributed by the OSF and Ralph Campbell.
   Written by Keith Knowles and Ralph Campbell, working independently.
   Modified for ECOFF and R4000 support by Ian Lance Taylor of Cygnus
   Support.

   This file is part of GAS.

   GAS is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   GAS is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GAS; see the file COPYING.  If not, write to
   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "as.h"
#include "config.h"

#include <ctype.h>

#ifndef __STDC__
#ifndef NO_STDARG
#define NO_STDARG
#endif
#endif

#ifndef NO_STDARG
#include <stdarg.h>
#else
#ifndef NO_VARARGS
#include <varargs.h>
#endif /* NO_VARARGS */
#endif /* NO_STDARG */

#include "opcode/mips.h"

#ifdef OBJ_ELF
#include "elf/mips.h"

static char *mips_regmask_frag;
#endif

#define AT  1
#define PIC_CALL_REG 25
#define GP  28
#define SP  29
#define FP  30
#define RA  31

/* Decide whether to do GP reference optimizations based on the object
   file format.  */
#undef GPOPT
#ifdef OBJ_ECOFF
#define GPOPT
#endif
#ifdef OBJ_ELF
#define GPOPT
#endif

/* The default target format to use.  */
#ifdef OBJ_AOUT
#ifdef TARGET_BYTES_BIG_ENDIAN
#define DEFAULT_TARGET_FORMAT "a.out-mips-big"
#else
#define DEFAULT_TARGET_FORMAT "a.out-mips-little"
#endif
#endif /* OBJ_AOUT */
#ifdef OBJ_ECOFF
#ifdef TARGET_BYTES_BIG_ENDIAN
#define DEFAULT_TARGET_FORMAT "ecoff-bigmips"
#else
#define DEFAULT_TARGET_FORMAT "ecoff-littlemips"
#endif
#endif /* OBJ_ECOFF */
#ifdef OBJ_ELF
#ifdef TARGET_BYTES_BIG_ENDIAN
#define DEFAULT_TARGET_FORMAT "elf32-bigmips"
#else
#define DEFAULT_TARGET_FORMAT "elf32-littlemips"
#endif
#endif /* OBJ_ELF */

const char *mips_target_format = DEFAULT_TARGET_FORMAT;

/* These variables are filled in with the masks of registers used.
   The object format code reads them and puts them in the appropriate
   place.  */
unsigned long mips_gprmask;
unsigned long mips_cprmask[4];

/* MIPS ISA (Instruction Set Architecture) level (may be changed
   temporarily using .set mipsN).  */
static int mips_isa = -1;

/* MIPS ISA we are using for this output file.  */
static int file_mips_isa;

/* MIPS PIC level.  */

enum mips_pic_level
{
  /* Do not generate PIC code.  */
  NO_PIC,

  /* Generate PIC code as in Irix 4.  This is not implemented, and I'm
     not sure what it is supposed to do.  */
  IRIX4_PIC,

  /* Generate PIC code as in the SVR4 MIPS ABI.  */
  SVR4_PIC,

  /* Generate PIC code without using a global offset table: the data
     segment has a maximum size of 64K, all data references are off
     the $gp register, and all text references are PC relative.  This
     is used on some embedded systems.  */
  EMBEDDED_PIC
};

static enum mips_pic_level mips_pic;

/* 1 if trap instructions should used for overflow rather than break
   instructions.  */
static int mips_trap;

static int mips_warn_about_macros;
static int mips_noreorder;
static int mips_any_noreorder;
static int mips_nomove;
static int mips_noat;
static int mips_nobopt;

#ifdef GPOPT
/* The size of the small data section.  */
static int g_switch_value = 8;
/* Whether the -G option was used.  */
static int g_switch_seen = 0;
#endif

#define N_RMASK 0xc4
#define N_VFP   0xd4

/* handle of the OPCODE hash table */
static struct hash_control *op_hash = NULL;

/* This array holds the chars that always start a comment.  If the
    pre-processor is disabled, these aren't very useful */
const char comment_chars[] = "#";

/* This array holds the chars that only start a comment at the beginning of
   a line.  If the line seems to have the form '# 123 filename'
   .line and .file directives will appear in the pre-processed output */
/* Note that input_file.c hand checks for '#' at the beginning of the
   first line of the input file.  This is because the compiler outputs
   #NO_APP at the beginning of its output. */
/* Also note that C style comments are always supported.  */
const char line_comment_chars[] = "#";

/* This array holds machine specific line separator characters. */
const char line_separator_chars[] = "";

/* Chars that can be used to separate mant from exp in floating point nums */
const char EXP_CHARS[] = "eE";

/* Chars that mean this number is a floating point constant */
/* As in 0f12.456 */
/* or    0d1.2345e12 */
const char FLT_CHARS[] = "rRsSfFdDxXpP";

/* Also be aware that MAXIMUM_NUMBER_OF_CHARS_FOR_FLOAT may have to be
   changed in read.c .  Ideally it shouldn't have to know about it at all,
   but nothing is ideal around here.
 */

static char *insn_error;

static int byte_order = BYTE_ORDER;

static int auto_align = 1;

/* Symbol labelling the current insn.  */
static symbolS *insn_label;

/* When outputting SVR4 PIC code, the assembler needs to know the
   offset in the stack frame from which to restore the $gp register.
   This is set by the .cprestore pseudo-op, and saved in this
   variable.  */
static offsetT mips_cprestore_offset = -1;

/* This is the register which holds the stack frame, as set by the
   .frame pseudo-op.  This is needed to implement .cprestore.  */
static int mips_frame_reg = SP;

/* To output NOP instructions correctly, we need to keep information
   about the previous two instructions.  */

/* Whether we are optimizing.  The default value of 2 means to remove
   unneeded NOPs and swap branch instructions when possible.  A value
   of 1 means to not swap branches.  A value of 0 means to always
   insert NOPs.  */
static int mips_optimize = 2;

/* The previous instruction.  */
static struct mips_cl_insn prev_insn;

/* The instruction before prev_insn.  */
static struct mips_cl_insn prev_prev_insn;

/* If we don't want information for prev_insn or prev_prev_insn, we
   point the insn_mo field at this dummy integer.  */
static const struct mips_opcode dummy_opcode = { 0 };

/* Non-zero if prev_insn is valid.  */
static int prev_insn_valid;

/* The frag for the previous instruction.  */
static struct frag *prev_insn_frag;

/* The offset into prev_insn_frag for the previous instruction.  */
static long prev_insn_where;

/* The reloc for the previous instruction, if any.  */
static fixS *prev_insn_fixp;

/* Non-zero if the previous instruction was in a delay slot.  */
static int prev_insn_is_delay_slot;

/* Non-zero if the previous instruction was in a .set noreorder.  */
static int prev_insn_unreordered;

/* Non-zero if the previous previous instruction was in a .set
   noreorder.  */
static int prev_prev_insn_unreordered;
\f
/* Since the MIPS does not have multiple forms of PC relative
   instructions, we do not have to do relaxing as is done on other
   platforms.  However, we do have to handle GP relative addressing
   correctly, which turns out to be a similar problem.

   Every macro that refers to a symbol can occur in (at least) two
   forms, one with GP relative addressing and one without.  For
   example, loading a global variable into a register generally uses
   a macro instruction like this:
     lw $4,i
   If i can be addressed off the GP register (this is true if it is in
   the .sbss or .sdata section, or if it is known to be smaller than
   the -G argument) this will generate the following instruction:
     lw $4,i($gp)
   This instruction will use a GPREL reloc.  If i can not be addressed
   off the GP register, the following instruction sequence will be used:
     lui $at,i
     lw $4,i($at)
   In this case the first instruction will have a HI16 reloc, and the
   second reloc will have a LO16 reloc.  Both relocs will be against
   the symbol i.

   The issue here is that we may not know whether i is GP addressable
   until after we see the instruction that uses it.  Therefore, we
   want to be able to choose the final instruction sequence only at
   the end of the assembly.  This is similar to the way other
   platforms choose the size of a PC relative instruction only at the
   end of assembly.

   When generating position independent code we do not use GP
   addressing in quite the same way, but the issue still arises as
   external symbols and local symbols must be handled differently.

   We handle these issues by actually generating both possible
   instruction sequences.  The longer one is put in a frag_var with
   type rs_machine_dependent.  We encode what to do with the frag in
   the subtype field.  We encode (1) the number of existing bytes to
   replace, (2) the number of new bytes to use, (3) the offset from
   the start of the existing bytes to the first reloc we must generate
   (that is, the offset is applied from the start of the existing
   bytes after they are replaced by the new bytes, if any), (4) the
   offset from the start of the existing bytes to the second reloc,
   (5) whether a third reloc is needed (the third reloc is always four
   bytes after the second reloc), and (6) whether to warn if this
   variant is used (this is sometimes needed if .set nomacro or .set
   noat is in effect).  All these numbers are reasonably small.

   Generating two instruction sequences must be handled carefully to
   ensure that delay slots are handled correctly.  Fortunately, there
   are a limited number of cases.  When the second instruction
   sequence is generated, append_insn is directed to maintain the
   existing delay slot information, so it continues to apply to any
   code after the second instruction sequence.  This means that the
   second instruction sequence must not impose any requirements not
   required by the first instruction sequence.

   These variant frags are then handled in functions called by the
   machine independent code.  md_estimate_size_before_relax returns
   the final size of the frag.  md_convert_frag sets up the final form
   of the frag.  tc_gen_reloc adjust the first reloc and adds a second
   one if needed.  */
#define RELAX_ENCODE(old, new, reloc1, reloc2, reloc3, warn) \
  ((relax_substateT) \
   (((old) << 24) \
    | ((new) << 16) \
    | (((reloc1) + 64) << 9) \
    | (((reloc2) + 64) << 2) \
    | ((reloc3) ? (1 << 1) : 0) \
    | ((warn) ? 1 : 0)))
#define RELAX_OLD(i) (((i) >> 24) & 0xff)
#define RELAX_NEW(i) (((i) >> 16) & 0xff)
#define RELAX_RELOC1(i) ((((i) >> 9) & 0x7f) - 64)
#define RELAX_RELOC2(i) ((((i) >> 2) & 0x7f) - 64)
#define RELAX_RELOC3(i) (((i) >> 1) & 1)
#define RELAX_WARN(i) ((i) & 1)
\f
/* Prototypes for static functions.  */

#ifdef __STDC__
#define internalError() \
    as_fatal ("internal Error, line %d, %s", __LINE__, __FILE__)
#else
#define internalError() as_fatal ("MIPS internal Error");
#endif

static int insn_uses_reg PARAMS ((struct mips_cl_insn *ip,
                                  unsigned int reg, int fpr));
static void append_insn PARAMS ((char *place,
                                 struct mips_cl_insn * ip,
                                 expressionS * p,
                                 bfd_reloc_code_real_type r));
static void mips_no_prev_insn PARAMS ((void));
static void mips_emit_delays PARAMS ((void));
static void macro_build PARAMS ((char *place, int *counter, expressionS * ep,
                                 const char *name, const char *fmt,
                                 ...));
static void macro_build_lui PARAMS ((char *place, int *counter,
                                     expressionS * ep, int regnum));
static void set_at PARAMS ((int *counter, int reg, int unsignedp));
static void check_absolute_expr PARAMS ((struct mips_cl_insn * ip,
                                         expressionS *));
static void load_register PARAMS ((int *counter, int reg, expressionS * ep));
static void load_address PARAMS ((int *counter, int reg, expressionS *ep));
static void macro PARAMS ((struct mips_cl_insn * ip));
#ifdef LOSING_COMPILER
static void macro2 PARAMS ((struct mips_cl_insn * ip));
#endif
static void mips_ip PARAMS ((char *str, struct mips_cl_insn * ip));
static int my_getSmallExpression PARAMS ((expressionS * ep, char *str));
static void my_getExpression PARAMS ((expressionS * ep, char *str));
static symbolS *get_symbol PARAMS ((void));
static void mips_align PARAMS ((int to, int fill, symbolS *label));
static void s_align PARAMS ((int));
static void s_stringer PARAMS ((int));
static void s_change_sec PARAMS ((int));
static void s_cons PARAMS ((int));
static void s_err PARAMS ((int));
static void s_extern PARAMS ((int));
static void s_float_cons PARAMS ((int));
static void s_option PARAMS ((int));
static void s_mipsset PARAMS ((int));
static void s_mips_space PARAMS ((int));
static void s_abicalls PARAMS ((int));
static void s_cpload PARAMS ((int));
static void s_cprestore PARAMS ((int));
static void s_gpword PARAMS ((int));
static void s_cpadd PARAMS ((int));
#ifndef ECOFF_DEBUGGING
static void md_obj_begin PARAMS ((void));
static void md_obj_end PARAMS ((void));
static long get_number PARAMS ((void));
static void s_ent PARAMS ((int));
static void s_mipsend PARAMS ((int));
static void s_file PARAMS ((int));
#if 0
static void s_frame PARAMS ((int));
static void s_loc PARAMS ((int));
static void s_mask PARAMS ((char));
#endif
#endif
\f
/* Pseudo-op table.

   The following pseudo-ops from the Kane and Heinrich MIPS book
   should be defined here, but are currently unsupported: .alias,
   .galive, .gjaldef, .gjrlive, .livereg, .noalias.

   The following pseudo-ops from the Kane and Heinrich MIPS book are
   specific to the type of debugging information being generated, and
   should be defined by the object format: .aent, .begin, .bend,
   .bgnb, .end, .endb, .ent, .fmask, .frame, .loc, .mask, .verstamp,
   .vreg.

   The following pseudo-ops from the Kane and Heinrich MIPS book are
   not MIPS CPU specific, but are also not specific to the object file
   format.  This file is probably the best place to define them, but
   they are not currently supported: .asm0, .endr, .lab, .repeat,
   .struct, .weakext.  */

const pseudo_typeS md_pseudo_table[] =
{
 /* MIPS specific pseudo-ops.  */
  {"option", s_option, 0},
  {"set", s_mipsset, 0},
  {"rdata", s_change_sec, 'r'},
  {"sdata", s_change_sec, 's'},
  {"livereg", s_ignore, 0},
  { "abicalls", s_abicalls, 0},
  { "cpload", s_cpload, 0},
  { "cprestore", s_cprestore, 0},
  { "gpword", s_gpword, 0},
  { "cpadd", s_cpadd, 0},

 /* Relatively generic pseudo-ops that happen to be used on MIPS
     chips.  */
  {"asciiz", s_stringer, 1},
  {"bss", s_change_sec, 'b'},
  {"err", s_err, 0},
  {"half", s_cons, 1},
  {"dword", s_cons, 3},

 /* These pseudo-ops are defined in read.c, but must be overridden
     here for one reason or another.  */
  {"align", s_align, 0},
  {"ascii", s_stringer, 0},
  {"asciz", s_stringer, 1},
  {"byte", s_cons, 0},
  {"data", s_change_sec, 'd'},
  {"double", s_float_cons, 'd'},
  {"extern", s_extern, 0},
  {"float", s_float_cons, 'f'},
  {"hword", s_cons, 1},
  {"int", s_cons, 2},
  {"long", s_cons, 2},
  {"octa", s_cons, 4},
  {"quad", s_cons, 3},
  {"short", s_cons, 1},
  {"single", s_float_cons, 'f'},
  {"space", s_mips_space, 0},
  {"text", s_change_sec, 't'},
  {"word", s_cons, 2},

#ifndef ECOFF_DEBUGGING
 /* These pseudo-ops should be defined by the object file format.
    However, a.out doesn't support them, so we have versions here.  */
  {"aent", s_ent, 1},
  {"bgnb", s_ignore, 0},
  {"end", s_mipsend, 0},
  {"endb", s_ignore, 0},
  {"ent", s_ent, 0},
  {"file", s_file, 0},
  {"fmask", s_ignore, 'F'},
  {"frame", s_ignore, 0},
  {"loc", s_ignore, 0},
  {"mask", s_ignore, 'R'},
  {"verstamp", s_ignore, 0},
#endif

 /* Sentinel.  */
  {NULL}
};
\f
const relax_typeS md_relax_table[] =
{
  { 0 }
};

static char *expr_end;

static expressionS imm_expr;
static expressionS offset_expr;
static bfd_reloc_code_real_type imm_reloc;
static bfd_reloc_code_real_type offset_reloc;

/* FIXME: This should be handled in a different way.  */
extern int target_big_endian;

/*
 * This function is called once, at assembler startup time.  It should
 * set up all the tables, etc. that the MD part of the assembler will need.
 */
void
md_begin ()
{
  boolean ok = false;
  register const char *retval = NULL;
  register unsigned int i = 0;

  if (mips_isa == -1)
    {
      if (strcmp (TARGET_CPU, "mips") == 0)
        mips_isa = 1;
      else if (strcmp (TARGET_CPU, "r6000") == 0
               || strcmp (TARGET_CPU, "mips2") == 0)
        mips_isa = 2;
      else if (strcmp (TARGET_CPU, "mips64") == 0
               || strcmp (TARGET_CPU, "r4000") == 0
               || strcmp (TARGET_CPU, "mips3") == 0)
        mips_isa = 3;
      else
        mips_isa = 1;
    }

  if (mips_isa < 2 && mips_trap)
    as_bad ("trap exception not supported at ISA 1");

  switch (mips_isa)
    {
    case 1:
      ok = bfd_set_arch_mach (stdoutput, bfd_arch_mips, 3000);
      break;
    case 2:
      ok = bfd_set_arch_mach (stdoutput, bfd_arch_mips, 6000);
      break;
    case 3:
      ok = bfd_set_arch_mach (stdoutput, bfd_arch_mips, 4000);
      break;
    }
  if (! ok)
    as_warn ("Could not set architecture and machine");

  file_mips_isa = mips_isa;

  op_hash = hash_new ();

  for (i = 0; i < NUMOPCODES;)
    {
      const char *name = mips_opcodes[i].name;

      retval = hash_insert (op_hash, name, (PTR) &mips_opcodes[i]);
      if (retval != NULL)
        {
          fprintf (stderr, "internal error: can't hash `%s': %s\n",
                   mips_opcodes[i].name, retval);
          as_fatal ("Broken assembler.  No assembly attempted.");
        }
      do
        {
          if (mips_opcodes[i].pinfo != INSN_MACRO
              && ((mips_opcodes[i].match & mips_opcodes[i].mask)
                  != mips_opcodes[i].match))
            {
              fprintf (stderr, "internal error: bad opcode: `%s' \"%s\"\n",
                       mips_opcodes[i].name, mips_opcodes[i].args);
              as_fatal ("Broken assembler.  No assembly attempted.");
            }
          ++i;
        }
      while ((i < NUMOPCODES) && !strcmp (mips_opcodes[i].name, name));
    }

  mips_no_prev_insn ();

  mips_gprmask = 0;
  mips_cprmask[0] = 0;
  mips_cprmask[1] = 0;
  mips_cprmask[2] = 0;
  mips_cprmask[3] = 0;

  /* set the default alignment for the text section (2**2) */
  record_alignment (text_section, 2);

  /* FIXME: This should be handled in a different way.  */
  target_big_endian = byte_order == BIG_ENDIAN;

#ifdef GPOPT
  bfd_set_gp_size (stdoutput, g_switch_value);
#endif

#ifdef OBJ_ELF
  /* Sections must be aligned to 16 byte boundaries.  */
  (void) bfd_set_section_alignment (stdoutput, text_section, 4);
  (void) bfd_set_section_alignment (stdoutput, data_section, 4);
  (void) bfd_set_section_alignment (stdoutput, bss_section, 4);

  /* Create a .reginfo section for register masks and a .mdebug
     section for debugging information.  */
  {
    segT seg;
    subsegT subseg;
    segT sec;

    seg = now_seg;
    subseg = now_subseg;
    sec = subseg_new (".reginfo", (subsegT) 0);

    /* The ABI says this section should be loaded so that the running
       program can access it.  */
    (void) bfd_set_section_flags (stdoutput, sec,
                                  (SEC_ALLOC | SEC_LOAD
                                   | SEC_READONLY | SEC_DATA));
    (void) bfd_set_section_alignment (stdoutput, sec, 2);

    mips_regmask_frag = frag_more (sizeof (Elf32_External_RegInfo));

#ifdef ECOFF_DEBUGGING
    sec = subseg_new (".mdebug", (subsegT) 0);
    (void) bfd_set_section_flags (stdoutput, sec,
                                  SEC_HAS_CONTENTS | SEC_READONLY);
    (void) bfd_set_section_alignment (stdoutput, sec, 2);
#endif

    subseg_set (seg, subseg);
  }
#endif /* OBJ_ELF */

#ifndef ECOFF_DEBUGGING
  md_obj_begin ();
#endif
}

void
md_mips_end ()
{
#ifndef ECOFF_DEBUGGING
  md_obj_end ();
#endif
}

void
md_assemble (str)
     char *str;
{
  struct mips_cl_insn insn;

  imm_expr.X_op = O_absent;
  offset_expr.X_op = O_absent;

  mips_ip (str, &insn);
  if (insn_error)
    {
      as_bad ("%s `%s'", insn_error, str);
      return;
    }
  if (insn.insn_mo->pinfo == INSN_MACRO)
    {
      macro (&insn);
    }
  else
    {
      if (imm_expr.X_op != O_absent)
        append_insn ((char *) NULL, &insn, &imm_expr, imm_reloc);
      else if (offset_expr.X_op != O_absent)
        append_insn ((char *) NULL, &insn, &offset_expr, offset_reloc);
      else
        append_insn ((char *) NULL, &insn, NULL, BFD_RELOC_UNUSED);
    }
}

/* See whether instruction IP reads register REG.  If FPR is non-zero,
   REG is a floating point register.  */

static int
insn_uses_reg (ip, reg, fpr)
     struct mips_cl_insn *ip;
     unsigned int reg;
     int fpr;
{
  /* Don't report on general register 0, since it never changes.  */
  if (! fpr && reg == 0)
    return 0;

  if (fpr)
    {
      /* If we are called with either $f0 or $f1, we must check $f0.
         This is not optimal, because it will introduce an unnecessary
         NOP between "lwc1 $f0" and "swc1 $f1".  To fix this we would
         need to distinguish reading both $f0 and $f1 or just one of
         them.  Note that we don't have to check the other way,
         because there is no instruction that sets both $f0 and $f1
         and requires a delay.  */
      if ((ip->insn_mo->pinfo & INSN_READ_FPR_S)
          && (((ip->insn_opcode >> OP_SH_FS) & OP_MASK_FS)
              == (reg &~ (unsigned) 1)))
        return 1;
      if ((ip->insn_mo->pinfo & INSN_READ_FPR_T)
          && (((ip->insn_opcode >> OP_SH_FT) & OP_MASK_FT)
              == (reg &~ (unsigned) 1)))
        return 1;
    }
  else
    {
      if ((ip->insn_mo->pinfo & INSN_READ_GPR_S)
          && ((ip->insn_opcode >> OP_SH_RS) & OP_MASK_RS) == reg)
        return 1;
      if ((ip->insn_mo->pinfo & INSN_READ_GPR_T)
          && ((ip->insn_opcode >> OP_SH_RT) & OP_MASK_RT) == reg)
        return 1;
    }

  return 0;
}

/* Output an instruction.  PLACE is where to put the instruction; if
   it is NULL, this uses frag_more to get room.  IP is the instruction
   information.  ADDRESS_EXPR is an operand of the instruction to be
   used with RELOC_TYPE.  */

static void
append_insn (place, ip, address_expr, reloc_type)
     char *place;
     struct mips_cl_insn *ip;
     expressionS *address_expr;
     bfd_reloc_code_real_type reloc_type;
{
  register unsigned long prev_pinfo, pinfo;
  char *f;
  fixS *fixp;
  int nops = 0;

  prev_pinfo = prev_insn.insn_mo->pinfo;
  pinfo = ip->insn_mo->pinfo;

  if (place == NULL && ! mips_noreorder)
    {
      /* If the previous insn required any delay slots, see if we need
         to insert a NOP or two.  There are eight kinds of possible
         hazards, of which an instruction can have at most one type.
         (1) a load from memory delay
         (2) a load from a coprocessor delay
         (3) an unconditional branch delay
         (4) a conditional branch delay
         (5) a move to coprocessor register delay
         (6) a load coprocessor register from memory delay
         (7) a coprocessor condition code delay
         (8) a HI/LO special register delay

         There are a lot of optimizations we could do that we don't.
         In particular, we do not, in general, reorder instructions.
         If you use gcc with optimization, it will reorder
         instructions and generally do much more optimization then we
         do here; repeating all that work in the assembler would only
         benefit hand written assembly code, and does not seem worth
         it.  */

      /* This is how a NOP is emitted.  */
#define emit_nop() md_number_to_chars (frag_more (4), 0, 4)

      /* The previous insn might require a delay slot, depending upon
         the contents of the current insn.  */
      if ((prev_pinfo & INSN_LOAD_COPROC_DELAY)
          || (mips_isa < 2
              && (prev_pinfo & INSN_LOAD_MEMORY_DELAY)))
        {
          /* A load from a coprocessor or from memory.  All load
             delays delay the use of general register rt for one
             instruction on the r3000.  The r6000 and r4000 use
             interlocks.  */
          know (prev_pinfo & INSN_WRITE_GPR_T);
          if (mips_optimize == 0
              || insn_uses_reg (ip,
                                ((prev_insn.insn_opcode >> OP_SH_RT)
                                 & OP_MASK_RT),
                                0))
            ++nops;
        }
      else if ((prev_pinfo & INSN_COPROC_MOVE_DELAY)
               || (mips_isa < 2
                   && (prev_pinfo & INSN_COPROC_MEMORY_DELAY)))
        {
          /* A generic coprocessor delay.  The previous instruction
             modified a coprocessor general or control register.  If
             it modified a control register, we need to avoid any
             coprocessor instruction (this is probably not always
             required, but it sometimes is).  If it modified a general
             register, we avoid using that register.

             On the r6000 and r4000 loading a coprocessor register
             from memory is interlocked, and does not require a delay.

             This case is not handled very well.  There is no special
             knowledge of CP0 handling, and the coprocessors other
             than the floating point unit are not distinguished at
             all.  */
          if (prev_pinfo & INSN_WRITE_FPR_T)
            {
              if (mips_optimize == 0
                  || insn_uses_reg (ip,
                                    ((prev_insn.insn_opcode >> OP_SH_FT)
                                     & OP_MASK_FT),
                                    1))
                ++nops;
            }
          else if (prev_pinfo & INSN_WRITE_FPR_S)
            {
              if (mips_optimize == 0
                  || insn_uses_reg (ip,
                                    ((prev_insn.insn_opcode >> OP_SH_FS)
                                     & OP_MASK_FS),
                                    1))
                ++nops;
            }
          else
            {
              /* We don't know exactly what the previous instruction
                 does.  If the current instruction uses a coprocessor
                 register, we must insert a NOP.  If previous
                 instruction may set the condition codes, and the
                 current instruction uses them, we must insert two
                 NOPS.  */
              if (mips_optimize == 0
                  || ((prev_pinfo & INSN_WRITE_COND_CODE)
                      && (pinfo & INSN_READ_COND_CODE)))
                nops += 2;
              else if (pinfo & INSN_COP)
                ++nops;
            }
        }
      else if (prev_pinfo & INSN_WRITE_COND_CODE)
        {
          /* The previous instruction sets the coprocessor condition
             codes, but does not require a general coprocessor delay
             (this means it is a floating point comparison
             instruction).  If this instruction uses the condition
             codes, we need to insert a single NOP.  */
          if (mips_optimize == 0
              || (pinfo & INSN_READ_COND_CODE))
            ++nops;
        }
      else if (prev_pinfo & INSN_READ_LO)
        {
          /* The previous instruction reads the LO register; if the
             current instruction writes to the LO register, we must
             insert two NOPS.  */
          if (mips_optimize == 0
              || (pinfo & INSN_WRITE_LO))
            nops += 2;
        }
      else if (prev_insn.insn_mo->pinfo & INSN_READ_HI)
        {
          /* The previous instruction reads the HI register; if the
             current instruction writes to the HI register, we must
             insert a NOP.  */
          if (mips_optimize == 0
              || (pinfo & INSN_WRITE_HI))
            nops += 2;
        }

      /* There are two cases which require two intervening
         instructions: 1) setting the condition codes using a move to
         coprocessor instruction which requires a general coprocessor
         delay and then reading the condition codes 2) reading the HI
         or LO register and then writing to it.  If we are not already
         emitting a NOP instruction, we must check for these cases
         compared to the instruction previous to the previous
         instruction.  */
      if (nops == 0
          && (((prev_prev_insn.insn_mo->pinfo & INSN_COPROC_MOVE_DELAY)
               && (prev_prev_insn.insn_mo->pinfo & INSN_WRITE_COND_CODE)
               && (pinfo & INSN_READ_COND_CODE))
              || ((prev_prev_insn.insn_mo->pinfo & INSN_READ_LO)
                  && (pinfo & INSN_WRITE_LO))
              || ((prev_prev_insn.insn_mo->pinfo & INSN_READ_HI)
                  && (pinfo & INSN_WRITE_HI))))
        ++nops;

      /* If we are being given a nop instruction, don't bother with
         one of the nops we would otherwise output.  This will only
         happen when a nop instruction is used with mips_optimize set
         to 0.  */
      if (nops > 0 && ip->insn_opcode == 0)
        --nops;

      /* Now emit the right number of NOP instructions.  */
      if (nops > 0)
        {
          emit_nop ();
          if (nops > 1)
            emit_nop ();
          if (listing)
            listing_prev_line ();
          if (insn_label != NULL)
            {
              assert (S_GET_SEGMENT (insn_label) == now_seg);
              insn_label->sy_frag = frag_now;
              S_SET_VALUE (insn_label, (valueT) frag_now_fix ());
            }
        }
    }
  
  if (place == NULL)
    f = frag_more (4);
  else
    f = place;
  fixp = NULL;
  if (address_expr != NULL)
    {
      if (address_expr->X_op == O_constant)
        {
          switch (reloc_type)
            {
            case BFD_RELOC_32:
              ip->insn_opcode |= address_expr->X_add_number;
              break;

            case BFD_RELOC_LO16:
              ip->insn_opcode |= address_expr->X_add_number & 0xffff;
              break;

            case BFD_RELOC_MIPS_JMP:
            case BFD_RELOC_16_PCREL_S2:
              goto need_reloc;

            default:
              internalError ();
            }
        }
      else
        {
          assert (reloc_type != BFD_RELOC_UNUSED);
        need_reloc:
          /* Don't generate a reloc if we are writing into a variant
             frag.  */
          if (place == NULL)
            fixp = fix_new_exp (frag_now, f - frag_now->fr_literal, 4,
                                address_expr,
                                reloc_type == BFD_RELOC_16_PCREL_S2,
                                reloc_type);
        }
    }

  md_number_to_chars (f, ip->insn_opcode, 4);

  /* Update the register mask information.  */
  if (pinfo & INSN_WRITE_GPR_D)
    mips_gprmask |= 1 << ((ip->insn_opcode >> OP_SH_RD) & OP_MASK_RD);
  if ((pinfo & (INSN_WRITE_GPR_T | INSN_READ_GPR_T)) != 0)
    mips_gprmask |= 1 << ((ip->insn_opcode >> OP_SH_RT) & OP_MASK_RT);
  if (pinfo & INSN_READ_GPR_S)
    mips_gprmask |= 1 << ((ip->insn_opcode >> OP_SH_RS) & OP_MASK_RS);
  if (pinfo & INSN_WRITE_GPR_31)
    mips_gprmask |= 1 << 31;
  if (pinfo & INSN_WRITE_FPR_D)
    mips_cprmask[1] |= 1 << ((ip->insn_opcode >> OP_SH_FD) & OP_MASK_FD);
  if ((pinfo & (INSN_WRITE_FPR_S | INSN_READ_FPR_S)) != 0)
    mips_cprmask[1] |= 1 << ((ip->insn_opcode >> OP_SH_FS) & OP_MASK_FS);
  if ((pinfo & (INSN_WRITE_FPR_T | INSN_READ_FPR_T)) != 0)
    mips_cprmask[1] |= 1 << ((ip->insn_opcode >> OP_SH_FT) & OP_MASK_FT);
  if (pinfo & INSN_COP)
    {
      /* We don't keep enough information to sort these cases out.  */
    }
  /* Never set the bit for $0, which is always zero.  */
  mips_gprmask &=~ 1 << 0;

  if (place == NULL && ! mips_noreorder)
    {
      /* Filling the branch delay slot is more complex.  We try to
         switch the branch with the previous instruction, which we can
         do if the previous instruction does not set up a condition
         that the branch tests and if the branch is not itself the
         target of any branch.  */
      if ((pinfo & INSN_UNCOND_BRANCH_DELAY)
          || (pinfo & INSN_COND_BRANCH_DELAY))
        {
          if (mips_optimize < 2
              /* If we have seen .set volatile or .set nomove, don't
                 optimize.  */
              || mips_nomove != 0
              /* If we had to emit any NOP instructions, then we
                 already know we can not swap.  */
              || nops != 0
              /* If we don't even know the previous insn, we can not
                 swap. */
              || ! prev_insn_valid
              /* If the previous insn is already in a branch delay
                 slot, then we can not swap.  */
              || prev_insn_is_delay_slot
              /* If the previous previous insn was in a .set
                 noreorder, we can't swap.  Actually, the MIPS
                 assembler will swap in this situation.  However, gcc
                 configured -with-gnu-as will generate code like
                   .set noreorder
                   lw   $4,XXX
                   .set reorder
                   INSN
                   bne  $4,$0,foo
                 in which we can not swap the bne and INSN.  If gcc is
                 not configured -with-gnu-as, it does not output the
                 .set pseudo-ops.  We don't have to check
                 prev_insn_unreordered, because prev_insn_valid will
                 be 0 in that case.  We don't want to use
                 prev_prev_insn_valid, because we do want to be able
                 to swap at the start of a function.  */
              || prev_prev_insn_unreordered
              /* If the branch is itself the target of a branch, we
                 can not swap.  We cheat on this; all we check for is
                 whether there is a label on this instruction.  If
                 there are any branches to anything other than a
                 label, users must use .set noreorder.  */
              || insn_label != NULL
              /* If the previous instruction is in a variant frag, we
                 can not do the swap.  */
              || prev_insn_frag->fr_type == rs_machine_dependent
              /* If the branch reads the condition codes, we don't
                 even try to swap, because in the sequence
                   ctc1 $X,$31
                   INSN
                   INSN
                   bc1t LABEL
                 we can not swap, and I don't feel like handling that
                 case.  */
              || (pinfo & INSN_READ_COND_CODE)
              /* We can not swap with an instruction that requires a
                 delay slot, becase the target of the branch might
                 interfere with that instruction.  */
              || (prev_pinfo
                  & (INSN_LOAD_COPROC_DELAY
                     | INSN_COPROC_MOVE_DELAY
                     | INSN_WRITE_COND_CODE
                     | INSN_READ_LO
                     | INSN_READ_HI))
              || (mips_isa < 2
                  && (prev_pinfo
                      & (INSN_LOAD_MEMORY_DELAY
                         | INSN_COPROC_MEMORY_DELAY)))
              /* We can not swap with a branch instruction.  */
              || (prev_pinfo
                  & (INSN_UNCOND_BRANCH_DELAY
                     | INSN_COND_BRANCH_DELAY
                     | INSN_COND_BRANCH_LIKELY))
              /* We do not swap with a trap instruction, since it
                 complicates trap handlers to have the trap
                 instruction be in a delay slot.  */
              || (prev_pinfo & INSN_TRAP)
              /* If the branch reads a register that the previous
                 instruction sets, we can not swap.  */
              || ((prev_pinfo & INSN_WRITE_GPR_T)
                  && insn_uses_reg (ip,
                                    ((prev_insn.insn_opcode >> OP_SH_RT)
                                     & OP_MASK_RT),
                                    0))
              || ((prev_pinfo & INSN_WRITE_GPR_D)
                  && insn_uses_reg (ip,
                                    ((prev_insn.insn_opcode >> OP_SH_RD)
                                     & OP_MASK_RD),
                                    0))
              /* If the branch writes a register that the previous
                 instruction sets, we can not swap (we know that
                 branches write only to RD or to $31).  */
              || ((prev_pinfo & INSN_WRITE_GPR_T)
                  && (((pinfo & INSN_WRITE_GPR_D)
                       && (((prev_insn.insn_opcode >> OP_SH_RT) & OP_MASK_RT)
                           == ((ip->insn_opcode >> OP_SH_RD) & OP_MASK_RD)))
                      || ((pinfo & INSN_WRITE_GPR_31)
                          && (((prev_insn.insn_opcode >> OP_SH_RT)
                               & OP_MASK_RT)
                              == 31))))
              || ((prev_pinfo & INSN_WRITE_GPR_D)
                  && (((pinfo & INSN_WRITE_GPR_D)
                       && (((prev_insn.insn_opcode >> OP_SH_RD) & OP_MASK_RD)
                           == ((ip->insn_opcode >> OP_SH_RD) & OP_MASK_RD)))
                      || ((pinfo & INSN_WRITE_GPR_31)
                          && (((prev_insn.insn_opcode >> OP_SH_RD)
                               & OP_MASK_RD)
                              == 31))))
              /* If the branch writes a register that the previous
                 instruction reads, we can not swap (we know that
                 branches only write to RD or to $31).  */
              || ((pinfo & INSN_WRITE_GPR_D)
                  && insn_uses_reg (&prev_insn,
                                    ((ip->insn_opcode >> OP_SH_RD)
                                     & OP_MASK_RD),
                                    0))
              || ((pinfo & INSN_WRITE_GPR_31)
                  && insn_uses_reg (&prev_insn, 31, 0))
              /* If we are generating embedded PIC code, the branch
                 might be expanded into a sequence which uses $at, so
                 we can't swap with an instruction which reads it.  */
              || (mips_pic == EMBEDDED_PIC
                  && insn_uses_reg (&prev_insn, AT, 0))
              /* If the previous previous instruction has a load
                 delay, and sets a register that the branch reads, we
                 can not swap.  */
              || (((prev_prev_insn.insn_mo->pinfo & INSN_LOAD_COPROC_DELAY)
                   || (mips_isa < 2
                       && (prev_prev_insn.insn_mo->pinfo
                           & INSN_LOAD_MEMORY_DELAY)))
                  && insn_uses_reg (ip,
                                    ((prev_prev_insn.insn_opcode >> OP_SH_RT)
                                     & OP_MASK_RT),
                                    0)))
            {
              /* We could do even better for unconditional branches to
                 portions of this object file; we could pick up the
                 instruction at the destination, put it in the delay
                 slot, and bump the destination address.  */
              emit_nop ();
              /* Update the previous insn information.  */
              prev_prev_insn = *ip;
              prev_insn.insn_mo = &dummy_opcode;
            }
          else
            {
              char *prev_f;
              char temp[4];

              /* It looks like we can actually do the swap.  */
              prev_f = prev_insn_frag->fr_literal + prev_insn_where;
              memcpy (temp, prev_f, 4);
              memcpy (prev_f, f, 4);
              memcpy (f, temp, 4);
              if (prev_insn_fixp)
                {
                  prev_insn_fixp->fx_frag = frag_now;
                  prev_insn_fixp->fx_where = f - frag_now->fr_literal;
                }
              if (fixp)
                {
                  fixp->fx_frag = prev_insn_frag;
                  fixp->fx_where = prev_insn_where;
                }
              /* Update the previous insn information; leave prev_insn
                 unchanged.  */
              prev_prev_insn = *ip;
            }
          prev_insn_is_delay_slot = 1;

          /* If that was an unconditional branch, forget the previous
             insn information.  */
          if (pinfo & INSN_UNCOND_BRANCH_DELAY)
            {
              prev_prev_insn.insn_mo = &dummy_opcode;
              prev_insn.insn_mo = &dummy_opcode;
            }
        }
      else if (pinfo & INSN_COND_BRANCH_LIKELY)
        {
          /* We don't yet optimize a branch likely.  What we should do
             is look at the target, copy the instruction found there
             into the delay slot, and increment the branch to jump to
             the next instruction.  */
          emit_nop ();
          /* Update the previous insn information.  */
          prev_prev_insn = *ip;
          prev_insn.insn_mo = &dummy_opcode;
        }
      else
        {
          /* Update the previous insn information.  */
          if (nops > 0)
            prev_prev_insn.insn_mo = &dummy_opcode;
          else
            prev_prev_insn = prev_insn;
          prev_insn = *ip;

          /* Any time we see a branch, we always fill the delay slot
             immediately; since this insn is not a branch, we know it
             is not in a delay slot.  */
          prev_insn_is_delay_slot = 0;
        }

      prev_prev_insn_unreordered = prev_insn_unreordered;
      prev_insn_unreordered = 0;
      prev_insn_frag = frag_now;
      prev_insn_where = f - frag_now->fr_literal;
      prev_insn_fixp = fixp;
      prev_insn_valid = 1;
    }

  /* We just output an insn, so the next one doesn't have a label.  */
  insn_label = NULL;
}

/* This function forgets that there was any previous instruction or
   label.  */

static void
mips_no_prev_insn ()
{
  prev_insn.insn_mo = &dummy_opcode;
  prev_prev_insn.insn_mo = &dummy_opcode;
  prev_insn_valid = 0;
  prev_insn_is_delay_slot = 0;
  prev_insn_unreordered = 0;
  prev_prev_insn_unreordered = 0;
  insn_label = NULL;
}

/* This function must be called whenever we turn on noreorder or emit
   something other than instructions.  It inserts any NOPS which might
   be needed by the previous instruction, and clears the information
   kept for the previous instructions.  */

static void
mips_emit_delays ()
{
  if (! mips_noreorder)
    {
      int nop;

      nop = 0;
      if ((prev_insn.insn_mo->pinfo
           & (INSN_LOAD_COPROC_DELAY
              | INSN_COPROC_MOVE_DELAY
              | INSN_WRITE_COND_CODE
              | INSN_READ_LO
              | INSN_READ_HI))
          || (mips_isa < 2
              && (prev_insn.insn_mo->pinfo
                  & (INSN_LOAD_MEMORY_DELAY
                     | INSN_COPROC_MEMORY_DELAY))))
        {
          nop = 1;
          if ((prev_insn.insn_mo->pinfo & INSN_WRITE_COND_CODE)
              || (prev_insn.insn_mo->pinfo & INSN_READ_HI)
              || (prev_insn.insn_mo->pinfo & INSN_READ_LO))
            emit_nop ();
        }
      else if ((prev_prev_insn.insn_mo->pinfo & INSN_WRITE_COND_CODE)
               || (prev_prev_insn.insn_mo->pinfo & INSN_READ_HI)
               || (prev_prev_insn.insn_mo->pinfo & INSN_READ_LO))
        nop = 1;
      if (nop)
        {
          emit_nop ();
          if (insn_label != NULL)
            {
              assert (S_GET_SEGMENT (insn_label) == now_seg);
              insn_label->sy_frag = frag_now;
              S_SET_VALUE (insn_label, (valueT) frag_now_fix ());
            }
        }
    }

  mips_no_prev_insn ();
}

/* Build an instruction created by a macro expansion.  This is passed
   a pointer to the count of instructions created so far, an
   expression, the name of the instruction to build, an operand format
   string, and corresponding arguments.  */

#ifndef NO_STDARG
static void
macro_build (char *place,
             int *counter,
             expressionS * ep,
             const char *name,
             const char *fmt,
             ...)
#else /* ! defined (NO_STDARG) */
static void
macro_build (place, counter, ep, name, fmt, va_alist)
     char *place;
     int *counter;
     expressionS *ep;
     const char *name;
     const char *fmt;
     va_dcl
#endif /* ! defined (NO_STDARG) */
{
  struct mips_cl_insn insn;
  bfd_reloc_code_real_type r;
  va_list args;

#ifndef NO_STDARG
  va_start (args, fmt);
#else
  va_start (args);
#endif

  /*
   * If the macro is about to expand into a second instruction,
   * print a warning if needed. We need to pass ip as a parameter
   * to generate a better warning message here...
   */
  if (mips_warn_about_macros && place == NULL && *counter == 1)
    as_warn ("Macro instruction expanded into multiple instructions");

  if (place == NULL)
    *counter += 1;              /* bump instruction counter */

  r = BFD_RELOC_UNUSED;
  insn.insn_mo = (struct mips_opcode *) hash_find (op_hash, name);
  assert (insn.insn_mo);
  assert (strcmp (name, insn.insn_mo->name) == 0);

  while (strcmp (fmt, insn.insn_mo->args) != 0
         || insn.insn_mo->pinfo == INSN_MACRO)
    {
      ++insn.insn_mo;
      assert (insn.insn_mo->name);
      assert (strcmp (name, insn.insn_mo->name) == 0);
    }
  insn.insn_opcode = insn.insn_mo->match;
  for (;;)
    {
      switch (*fmt++)
        {
        case '\0':
          break;

        case ',':
        case '(':
        case ')':
          continue;

        case 't':
        case 'w':
        case 'E':
          insn.insn_opcode |= va_arg (args, int) << 16;
          continue;

        case 'c':
        case 'T':
        case 'W':
          insn.insn_opcode |= va_arg (args, int) << 16;
          continue;

        case 'd':
        case 'G':
          insn.insn_opcode |= va_arg (args, int) << 11;
          continue;

        case 'V':
        case 'S':
          insn.insn_opcode |= va_arg (args, int) << 11;
          continue;

        case 'z':
          continue;

        case '<':
          insn.insn_opcode |= va_arg (args, int) << 6;
          continue;

        case 'D':
          insn.insn_opcode |= va_arg (args, int) << 6;
          continue;

        case 'B':
          insn.insn_opcode |= va_arg (args, int) << 6;
          continue;

        case 'b':
        case 's':
        case 'r':
        case 'v':
          insn.insn_opcode |= va_arg (args, int) << 21;
          continue;

        case 'i':
        case 'j':
        case 'o':
          r = (bfd_reloc_code_real_type) va_arg (args, int);
          assert (r == BFD_RELOC_MIPS_GPREL
                  || r == BFD_RELOC_MIPS_LITERAL
                  || r == BFD_RELOC_LO16
                  || r == BFD_RELOC_MIPS_GOT16
                  || r == BFD_RELOC_MIPS_CALL16
                  || (ep->X_op == O_subtract
                      && now_seg == text_section
                      && S_GET_SEGMENT (ep->X_op_symbol) == text_section
                      && r == BFD_RELOC_PCREL_LO16));
          continue;

        case 'u':
          r = (bfd_reloc_code_real_type) va_arg (args, int);
          assert (ep != NULL
                  && (ep->X_op == O_constant
                      || (ep->X_op == O_symbol
                          && (r == BFD_RELOC_HI16_S
                              || r == BFD_RELOC_HI16))
                      || (ep->X_op == O_subtract
                          && now_seg == text_section
                          && S_GET_SEGMENT (ep->X_op_symbol) == text_section
                          && r == BFD_RELOC_PCREL_HI16_S)));
          if (ep->X_op == O_constant)
            {
              insn.insn_opcode |= (ep->X_add_number >> 16) & 0xffff;
              ep = NULL;
              r = BFD_RELOC_UNUSED;
            }
          continue;

        case 'p':
          assert (ep != NULL);
          /*
           * This allows macro() to pass an immediate expression for
           * creating short branches without creating a symbol.
           * Note that the expression still might come from the assembly
           * input, in which case the value is not checked for range nor
           * is a relocation entry generated (yuck).
           */
          if (ep->X_op == O_constant)
            {
              insn.insn_opcode |= (ep->X_add_number >> 2) & 0xffff;
              ep = NULL;
            }
          else
            r = BFD_RELOC_16_PCREL_S2;
          continue;

        case 'a':
          assert (ep != NULL);
          r = BFD_RELOC_MIPS_JMP;
          continue;

        default:
          internalError ();
        }
      break;
    }
  va_end (args);
  assert (r == BFD_RELOC_UNUSED ? ep == NULL : ep != NULL);

  append_insn (place, &insn, ep, r);
}

/*
 * Generate a "lui" instruction.
 */
static void
macro_build_lui (place, counter, ep, regnum)
     char *place;
     int *counter;
     expressionS *ep;
     int regnum;
{
  expressionS high_expr;
  struct mips_cl_insn insn;
  bfd_reloc_code_real_type r;
  CONST char *name = "lui";
  CONST char *fmt = "t,u";

  if (place == NULL)
    high_expr = *ep;
  else
    {
      high_expr.X_op = O_constant;
      high_expr.X_add_number = 0;
    }

  if (high_expr.X_op == O_constant)
    {
      /* we can compute the instruction now without a relocation entry */
      if (high_expr.X_add_number & 0x8000)
        high_expr.X_add_number += 0x10000;
      high_expr.X_add_number =
        ((unsigned long) high_expr.X_add_number >> 16) & 0xffff;
      r = BFD_RELOC_UNUSED;
    }
  else
    {
      assert (ep->X_op == O_symbol);
      /* _gp_disp is a special case, used from s_cpload.  */
      assert (mips_pic == NO_PIC
              || strcmp (S_GET_NAME (ep->X_add_symbol), "_gp_disp") == 0);
      r = BFD_RELOC_HI16_S;
    }

  /*
   * If the macro is about to expand into a second instruction,
   * print a warning if needed. We need to pass ip as a parameter
   * to generate a better warning message here...
   */
  if (mips_warn_about_macros && place == NULL && *counter == 1)
    as_warn ("Macro instruction expanded into multiple instructions");

  if (place == NULL)
    *counter += 1;              /* bump instruction counter */

  insn.insn_mo = (struct mips_opcode *) hash_find (op_hash, name);
  assert (insn.insn_mo);
  assert (strcmp (name, insn.insn_mo->name) == 0);
  assert (strcmp (fmt, insn.insn_mo->args) == 0);

  insn.insn_opcode = insn.insn_mo->match | (regnum << OP_SH_RT);
  if (r == BFD_RELOC_UNUSED)
    {
      insn.insn_opcode |= high_expr.X_add_number;
      append_insn (place, &insn, NULL, r);
    }
  else
    append_insn (place, &insn, &high_expr, r);
}

/*                      set_at()
 * Generates code to set the $at register to true (one)
 * if reg is less than the immediate expression.
 */
static void
set_at (counter, reg, unsignedp)
     int *counter;
     int reg;
     int unsignedp;
{
  if (imm_expr.X_add_number >= -0x8000 && imm_expr.X_add_number < 0x8000)
    macro_build ((char *) NULL, counter, &imm_expr,
                 unsignedp ? "sltiu" : "slti",
                 "t,r,j", AT, reg, (int) BFD_RELOC_LO16);
  else
    {
      load_register (counter, AT, &imm_expr);
      macro_build ((char *) NULL, counter, NULL,
                   unsignedp ? "sltu" : "slt",
                   "d,v,t", AT, reg, AT);
    }
}

/* Warn if an expression is not a constant.  */

static void
check_absolute_expr (ip, ex)
     struct mips_cl_insn *ip;
     expressionS *ex;
{
  if (ex->X_op != O_constant)
    as_warn ("Instruction %s requires absolute expression", ip->insn_mo->name);
}

/*                      load_register()
 *  This routine generates the least number of instructions neccessary to load
 *  an absolute expression value into a register.
 */
static void
load_register (counter, reg, ep)
     int *counter;
     int reg;
     expressionS *ep;
{
  assert (ep->X_op == O_constant);
  if (ep->X_add_number >= -0x8000 && ep->X_add_number < 0x8000)
    macro_build ((char *) NULL, counter, ep,
                 mips_isa < 3 ? "addiu" : "daddiu",
                 "t,r,j", reg, 0, (int) BFD_RELOC_LO16);
  else if (ep->X_add_number >= 0 && ep->X_add_number < 0x10000)
    macro_build ((char *) NULL, counter, ep, "ori", "t,r,i", reg, 0,
                 (int) BFD_RELOC_LO16);
  else if ((ep->X_add_number &~ (offsetT) 0x7fffffff) == 0
           || ((ep->X_add_number &~ (offsetT) 0x7fffffff)
               == ~ (offsetT) 0x7fffffff))
    {
      macro_build ((char *) NULL, counter, ep, "lui", "t,u", reg,
                   (int) BFD_RELOC_HI16);
      if ((ep->X_add_number & 0xffff) != 0)
        macro_build ((char *) NULL, counter, ep, "ori", "t,r,i", reg, reg,
                     (int) BFD_RELOC_LO16);
    }
  else if (mips_isa < 3)
    {
      as_bad ("Number larger than 32 bits");
      macro_build ((char *) NULL, counter, ep, "addiu", "t,r,j", reg, 0,
                   (int) BFD_RELOC_LO16);
    }
  else
    {
      int shift;
      expressionS hi32, lo32;

      hi32 = *ep;
      shift = 32;
      hi32.X_add_number >>= shift;
      hi32.X_add_number &= 0xffffffff;
      if ((hi32.X_add_number & 0x80000000) != 0)
        hi32.X_add_number |= ~ (offsetT) 0xffffffff;
      load_register (counter, reg, &hi32);
      lo32 = *ep;
      lo32.X_add_number &= 0xffffffff;
      if ((lo32.X_add_number & 0xffff0000) == 0)
        macro_build ((char *) NULL, counter, NULL, "dsll32", "d,w,<", reg,
                     reg, 0);
      else
        {
          expressionS mid16;

          macro_build ((char *) NULL, counter, NULL, "dsll", "d,w,<", reg,
                       reg, 16);
          mid16 = lo32;
          mid16.X_add_number >>= 16;
          macro_build ((char *) NULL, counter, &mid16, "ori", "t,r,i", reg,
                       reg, (int) BFD_RELOC_LO16);
          macro_build ((char *) NULL, counter, NULL, "dsll", "d,w,<", reg,
                       reg, 16);
        }
      if ((lo32.X_add_number & 0xffff) != 0)
        macro_build ((char *) NULL, counter, &lo32, "ori", "t,r,i", reg, reg,
                     (int) BFD_RELOC_LO16);
    }
}

/* Load an address into a register.  */

static void
load_address (counter, reg, ep)
     int *counter;
     int reg;
     expressionS *ep;
{
  char *p;

  if (ep->X_op != O_constant
      && ep->X_op != O_symbol)
    {
      as_bad ("expression too complex");
      ep->X_op = O_constant;
    }

  if (ep->X_op == O_constant)
    {
      load_register (counter, reg, ep);
      return;
    }

  if (mips_pic == NO_PIC)
    {
      /* If this is a reference to a GP relative symbol, we want
           addiu        $reg,$gp,<sym>          (BFD_RELOC_MIPS_GPREL)
         Otherwise we want
           lui          $reg,<sym>              (BFD_RELOC_HI16_S)
           addiu        $reg,$reg,<sym>         (BFD_RELOC_LO16)
         If we have an addend, we always use the latter form.  */
      if (ep->X_add_number != 0)
        p = NULL;
      else
        {
          frag_grow (20);
          macro_build ((char *) NULL, counter, ep,
                       mips_isa < 3 ? "addiu" : "daddiu",
                       "t,r,j", reg, GP, (int) BFD_RELOC_MIPS_GPREL);
          p = frag_var (rs_machine_dependent, 8, 0,
                        RELAX_ENCODE (4, 8, -4, 0, 0, mips_warn_about_macros),
                        ep->X_add_symbol, (long) 0, (char *) NULL);
        }
      macro_build_lui (p, counter, ep, reg);
      if (p != NULL)
        p += 4;
      macro_build (p, counter, ep,
                   mips_isa < 3 ? "addiu" : "daddiu",
                   "t,r,j", reg, reg, (int) BFD_RELOC_LO16);
    }
  else if (mips_pic == SVR4_PIC)
    {
      expressionS ex;

      /* If this is a reference to an external symbol, we want
           lw           $reg,<sym>($gp)         (BFD_RELOC_MIPS_GOT16)
         Otherwise we want
           lw           $reg,<sym>($gp)         (BFD_RELOC_MIPS_GOT16)
           nop
           addiu        $reg,$reg,<sym>         (BFD_RELOC_LO16)
         If there is a constant, it must be added in after.  */
      ex.X_add_number = ep->X_add_number;
      ep->X_add_number = 0;
      frag_grow (20);
      macro_build ((char *) NULL, counter, ep,
                   mips_isa < 3 ? "lw" : "ld",
                   "t,o(b)", reg, (int) BFD_RELOC_MIPS_GOT16, GP);
      macro_build ((char *) NULL, counter, (expressionS *) NULL, "nop", "");
      p = frag_var (rs_machine_dependent, 4, 0,
                    RELAX_ENCODE (0, 4, -8, 0, 0, mips_warn_about_macros),
                    ep->X_add_symbol, (long) 0, (char *) NULL);
      macro_build (p, counter, ep,
                   mips_isa < 3 ? "addiu" : "daddiu",
                   "t,r,j", reg, reg, (int) BFD_RELOC_LO16);
      if (ex.X_add_number != 0)
        {
          if (ex.X_add_number < -0x8000 || ex.X_add_number >= 0x8000)
            as_bad ("PIC code offset overflow (max 16 signed bits)");
          ex.X_op = O_constant;
          macro_build (p, counter, &ex,
                       mips_isa < 3 ? "addiu" : "daddiu",
                       "t,r,j", reg, reg, (int) BFD_RELOC_LO16);
        }
    }
  else if (mips_pic == EMBEDDED_PIC)
    {
      /* We always do
           addiu        $reg,$gp,<sym>          (BFD_RELOC_MIPS_GPREL)
         */
      macro_build ((char *) NULL, counter, ep,
                   mips_isa < 3 ? "addiu" : "daddiu",
                   "t,r,j", reg, GP, (int) BFD_RELOC_MIPS_GPREL);
    }
  else
    abort ();
}

/*
 *                      Build macros
 *   This routine implements the seemingly endless macro or synthesized
 * instructions and addressing modes in the mips assembly language. Many
 * of these macros are simple and are similar to each other. These could
 * probably be handled by some kind of table or grammer aproach instead of
 * this verbose method. Others are not simple macros but are more like
 * optimizing code generation.
 *   One interesting optimization is when several store macros appear
 * consecutivly that would load AT with the upper half of the same address.
 * The ensuing load upper instructions are ommited. This implies some kind
 * of global optimization. We currently only optimize within a single macro.
 *   For many of the load and store macros if the address is specified as a
 * constant expression in the first 64k of memory (ie ld $2,0x4000c) we
 * first load register 'at' with zero and use it as the base register. The
 * mips assembler simply uses register $zero. Just one tiny optimization
 * we're missing.
 */
static void
macro (ip)
     struct mips_cl_insn *ip;
{
  register int treg, sreg, dreg, breg;
  int tempreg;
  int mask;
  int icnt = 0;
  int used_at;
  expressionS expr1;
  const char *s;
  const char *s2;
  const char *fmt;
  int likely = 0;
  int dbl = 0;
  int coproc = 0;
  offsetT maxnum;
  bfd_reloc_code_real_type r;
  char *p;

  treg = (ip->insn_opcode >> 16) & 0x1f;
  dreg = (ip->insn_opcode >> 11) & 0x1f;
  sreg = breg = (ip->insn_opcode >> 21) & 0x1f;
  mask = ip->insn_mo->mask;

  expr1.X_op = O_constant;
  expr1.X_op_symbol = NULL;
  expr1.X_add_symbol = NULL;
  expr1.X_add_number = 1;

  switch (mask)
    {
    case M_DABS:
      dbl = 1;
    case M_ABS:
      /* bgez $a0,.+12
         move v0,$a0
         sub v0,$zero,$a0
         */

      mips_emit_delays ();
      ++mips_noreorder;
      mips_any_noreorder = 1;

      expr1.X_add_number = 8;
      macro_build ((char *) NULL, &icnt, &expr1, "bgez", "s,p", sreg);
      if (dreg == sreg)
        macro_build ((char *) NULL, &icnt, NULL, "nop", "", 0);
      else
        macro_build ((char *) NULL, &icnt, NULL, "move", "d,s", dreg, sreg, 0);
      macro_build ((char *) NULL, &icnt, NULL,
                   dbl ? "dsub" : "sub",
                   "d,v,t", dreg, 0, sreg);

      --mips_noreorder;
      return;

    case M_ADD_I:
      s = "addi";
      s2 = "add";
      goto do_addi;
    case M_ADDU_I:
      s = "addiu";
      s2 = "addu";
      goto do_addi;
    case M_DADD_I:
      dbl = 1;
      s = "daddi";
      s2 = "dadd";
      goto do_addi;
    case M_DADDU_I:
      dbl = 1;
      s = "daddiu";
      s2 = "daddu";
    do_addi:
      if (imm_expr.X_add_number >= -0x8000 && imm_expr.X_add_number < 0x8000)
        {
          macro_build ((char *) NULL, &icnt, &imm_expr, s, "t,r,j", treg, sreg,
                       (int) BFD_RELOC_LO16);
          return;
        }
      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, NULL, s2, "d,v,t", treg, sreg, AT);
      break;

    case M_AND_I:
      s = "andi";
      s2 = "and";
      goto do_bit;
    case M_OR_I:
      s = "ori";
      s2 = "or";
      goto do_bit;
    case M_NOR_I:
      s = "";
      s2 = "nor";
      goto do_bit;
    case M_XOR_I:
      s = "xori";
      s2 = "xor";
    do_bit:
      if (imm_expr.X_add_number >= 0 && imm_expr.X_add_number < 0x10000)
        {
          if (mask != M_NOR_I)
            macro_build ((char *) NULL, &icnt, &imm_expr, s, "t,r,i", treg,
                         sreg, (int) BFD_RELOC_LO16);
          else
            {
              macro_build ((char *) NULL, &icnt, &imm_expr, "ori", "t,r,i",
                           treg, sreg, (int) BFD_RELOC_LO16);
              macro_build ((char *) NULL, &icnt, NULL, "nor", "d,v,t",
                           treg, treg, 0);
            }
          return;
        }

      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, NULL, s2, "d,v,t", treg, sreg, AT);
      break;

    case M_BEQ_I:
      s = "beq";
      goto beq_i;
    case M_BEQL_I:
      s = "beql";
      likely = 1;
      goto beq_i;
    case M_BNE_I:
      s = "bne";
      goto beq_i;
    case M_BNEL_I:
      s = "bnel";
      likely = 1;
    beq_i:
      if (imm_expr.X_add_number == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr, s, "s,t,p", sreg,
                       0);
          return;
        }
      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, &offset_expr, s, "s,t,p", sreg, AT);
      break;

    case M_BGEL:
      likely = 1;
    case M_BGE:
      if (treg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bgezl" : "bgez",
                       "s,p", sreg);
          return;
        }
      if (sreg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "blezl" : "blez",
                       "s,p", treg);
          return;
        }
      macro_build ((char *) NULL, &icnt, NULL, "slt", "d,v,t", AT, sreg, treg);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "beql" : "beq",
                   "s,t,p", AT, 0);
      break;

    case M_BGTL_I:
      likely = 1;
    case M_BGT_I:
      /* check for > max integer */
      maxnum = 0x7fffffff;
      if (mips_isa >= 3)
        {
          maxnum <<= 16;
          maxnum |= 0xffff;
          maxnum <<= 16;
          maxnum |= 0xffff;
        }
      if (imm_expr.X_add_number >= maxnum)
        {
        do_false:
          /* result is always false */
          if (! likely)
            {
              as_warn ("Branch %s is always false (nop)", ip->insn_mo->name);
              macro_build ((char *) NULL, &icnt, NULL, "nop", "", 0);
            }
          else
            {
              as_warn ("Branch likely %s is always false", ip->insn_mo->name);
              macro_build ((char *) NULL, &icnt, &offset_expr, "bnel",
                           "s,t,p", 0, 0);
            }
          return;
        }
      imm_expr.X_add_number++;
      /* FALLTHROUGH */
    case M_BGE_I:
    case M_BGEL_I:
      if (mask == M_BGEL_I)
        likely = 1;
      if (imm_expr.X_add_number == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bgezl" : "bgez",
                       "s,p", sreg);
          return;
        }
      if (imm_expr.X_add_number == 1)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bgtzl" : "bgtz",
                       "s,p", sreg);
          return;
        }
      maxnum = 0x7fffffff;
      if (mips_isa >= 3)
        {
          maxnum <<= 16;
          maxnum |= 0xffff;
          maxnum <<= 16;
          maxnum |= 0xffff;
        }
      maxnum = - maxnum - 1;
      if (imm_expr.X_add_number <= maxnum)
        {
        do_true:
          /* result is always true */
          as_warn ("Branch %s is always true", ip->insn_mo->name);
          macro_build ((char *) NULL, &icnt, &offset_expr, "b", "p");
          return;
        }
      set_at (&icnt, sreg, 0);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "beql" : "beq",
                   "s,t,p", AT, 0);
      break;

    case M_BGEUL:
      likely = 1;
    case M_BGEU:
      if (treg == 0)
        goto do_true;
      if (sreg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "beql" : "beq",
                       "s,t,p", 0, treg);
          return;
        }
      macro_build ((char *) NULL, &icnt, NULL, "sltu", "d,v,t", AT, sreg,
                   treg);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "beql" : "beq",
                   "s,t,p", AT, 0);
      break;

    case M_BGTUL_I:
      likely = 1;
    case M_BGTU_I:
      if (sreg == 0 || imm_expr.X_add_number == -1)
        goto do_false;
      imm_expr.X_add_number++;
      /* FALLTHROUGH */
    case M_BGEU_I:
    case M_BGEUL_I:
      if (mask == M_BGEUL_I)
        likely = 1;
      if (imm_expr.X_add_number == 0)
        goto do_true;
      if (imm_expr.X_add_number == 1)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bnel" : "bne",
                       "s,t,p", sreg, 0);
          return;
        }
      set_at (&icnt, sreg, 1);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "beql" : "beq",
                   "s,t,p", AT, 0);
      break;

    case M_BGTL:
      likely = 1;
    case M_BGT:
      if (treg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bgtzl" : "bgtz",
                       "s,p", sreg);
          return;
        }
      if (sreg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bltzl" : "bltz",
                       "s,p", treg);
          return;
        }
      macro_build ((char *) NULL, &icnt, NULL, "slt", "d,v,t", AT, treg, sreg);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "bnel" : "bne",
                   "s,t,p", AT, 0);
      break;

    case M_BGTUL:
      likely = 1;
    case M_BGTU:
      if (treg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bnel" : "bne",
                       "s,t,p", sreg, 0);
          return;
        }
      if (sreg == 0)
        goto do_false;
      macro_build ((char *) NULL, &icnt, NULL, "sltu", "d,v,t", AT, treg,
                   sreg);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "bnel" : "bne",
                   "s,t,p", AT, 0);
      break;

    case M_BLEL:
      likely = 1;
    case M_BLE:
      if (treg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "blezl" : "blez",
                       "s,p", sreg);
          return;
        }
      if (sreg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bgezl" : "bgez",
                       "s,p", treg);
          return;
        }
      macro_build ((char *) NULL, &icnt, NULL, "slt", "d,v,t", AT, treg, sreg);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "beql" : "beq",
                   "s,t,p", AT, 0);
      break;

    case M_BLEL_I:
      likely = 1;
    case M_BLE_I:
      maxnum = 0x7fffffff;
      if (mips_isa >= 3)
        {
          maxnum <<= 16;
          maxnum |= 0xffff;
          maxnum <<= 16;
          maxnum |= 0xffff;
        }
      if (imm_expr.X_add_number >= maxnum)
        goto do_true;
      imm_expr.X_add_number++;
      /* FALLTHROUGH */
    case M_BLT_I:
    case M_BLTL_I:
      if (mask == M_BLTL_I)
        likely = 1;
      if (imm_expr.X_add_number == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bltzl" : "bltz",
                       "s,p", sreg);
          return;
        }
      if (imm_expr.X_add_number == 1)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "blezl" : "blez",
                       "s,p", sreg);
          return;
        }
      set_at (&icnt, sreg, 0);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "bnel" : "bne",
                   "s,t,p", AT, 0);
      break;

    case M_BLEUL:
      likely = 1;
    case M_BLEU:
      if (treg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "beql" : "beq",
                       "s,t,p", sreg, 0);
          return;
        }
      if (sreg == 0)
        goto do_true;
      macro_build ((char *) NULL, &icnt, NULL, "sltu", "d,v,t", AT, treg,
                   sreg);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "beql" : "beq",
                   "s,t,p", AT, 0);
      break;

    case M_BLEUL_I:
      likely = 1;
    case M_BLEU_I:
      if (sreg == 0 || imm_expr.X_add_number == -1)
        goto do_true;
      imm_expr.X_add_number++;
      /* FALLTHROUGH */
    case M_BLTU_I:
    case M_BLTUL_I:
      if (mask == M_BLTUL_I)
        likely = 1;
      if (imm_expr.X_add_number == 0)
        goto do_false;
      if (imm_expr.X_add_number == 1)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "beql" : "beq",
                       "s,t,p", sreg, 0);
          return;
        }
      set_at (&icnt, sreg, 1);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "bnel" : "bne",
                   "s,t,p", AT, 0);
      break;

    case M_BLTL:
      likely = 1;
    case M_BLT:
      if (treg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bltzl" : "bltz",
                       "s,p", sreg);
          return;
        }
      if (sreg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bgtzl" : "bgtz",
                       "s,p", treg);
          return;
        }
      macro_build ((char *) NULL, &icnt, NULL, "slt", "d,v,t", AT, sreg, treg);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "bnel" : "bne",
                   "s,t,p", AT, 0);
      break;

    case M_BLTUL:
      likely = 1;
    case M_BLTU:
      if (treg == 0)
        goto do_false;
      if (sreg == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       likely ? "bnel" : "bne",
                       "s,t,p", 0, treg);
          return;
        }
      macro_build ((char *) NULL, &icnt, NULL, "sltu", "d,v,t", AT, sreg,
                   treg);
      macro_build ((char *) NULL, &icnt, &offset_expr,
                   likely ? "bnel" : "bne",
                   "s,t,p", AT, 0);
      break;

    case M_DDIV_3:
      dbl = 1;
    case M_DIV_3:
      s = "mflo";
      goto do_div3;
    case M_DREM_3:
      dbl = 1;
    case M_REM_3:
      s = "mfhi";
    do_div3:
      if (treg == 0)
        {
          as_warn ("Divide by zero.");
          if (mips_trap)
            macro_build ((char *) NULL, &icnt, NULL, "teq", "s,t", 0, 0);
          else
            macro_build ((char *) NULL, &icnt, NULL, "break", "c", 7);
          return;
        }

      mips_emit_delays ();
      ++mips_noreorder;
      mips_any_noreorder = 1;
      macro_build ((char *) NULL, &icnt, NULL,
                   dbl ? "ddiv" : "div",
                   "z,s,t", sreg, treg);
      if (mips_trap)
        macro_build ((char *) NULL, &icnt, NULL, "teq", "s,t", treg, 0);
      else
        {
          expr1.X_add_number = 8;
          macro_build ((char *) NULL, &icnt, &expr1, "bne", "s,t,p", treg, 0);
          macro_build ((char *) NULL, &icnt, NULL, "nop", "", 0);
          macro_build ((char *) NULL, &icnt, NULL, "break", "c", 7);
        }
      expr1.X_add_number = -1;
      macro_build ((char *) NULL, &icnt, &expr1,
                   dbl ? "daddiu" : "addiu",
                   "t,r,j", AT, 0, (int) BFD_RELOC_LO16);
      expr1.X_add_number = mips_trap ? (dbl ? 12 : 8) : (dbl ? 20 : 16);
      macro_build ((char *) NULL, &icnt, &expr1, "bne", "s,t,p", treg, AT);
      if (dbl)
        {
          expr1.X_add_number = 1;
          macro_build ((char *) NULL, &icnt, &expr1, "daddiu", "t,r,j", AT, 0,
                       (int) BFD_RELOC_LO16);
          macro_build ((char *) NULL, &icnt, NULL, "dsll32", "d,w,<", AT, AT,
                       31);
        }
      else
        {
          expr1.X_add_number = 0x80000000;
          macro_build ((char *) NULL, &icnt, &expr1, "lui", "t,u", AT,
                       (int) BFD_RELOC_HI16);
        }
      if (mips_trap)
        macro_build ((char *) NULL, &icnt, NULL, "teq", "s,t", sreg, AT);
      else
        {
          expr1.X_add_number = 8;
          macro_build ((char *) NULL, &icnt, &expr1, "bne", "s,t,p", sreg, AT);
          macro_build ((char *) NULL, &icnt, NULL, "nop", "", 0);
          macro_build ((char *) NULL, &icnt, NULL, "break", "c", 6);
        }
      --mips_noreorder;
      macro_build ((char *) NULL, &icnt, NULL, s, "d", dreg);
      break;

    case M_DIV_3I:
      s = "div";
      s2 = "mflo";
      goto do_divi;
    case M_DIVU_3I:
      s = "divu";
      s2 = "mflo";
      goto do_divi;
    case M_REM_3I:
      s = "div";
      s2 = "mfhi";
      goto do_divi;
    case M_REMU_3I:
      s = "divu";
      s2 = "mfhi";
      goto do_divi;
    case M_DDIV_3I:
      dbl = 1;
      s = "ddiv";
      s2 = "mflo";
      goto do_divi;
    case M_DDIVU_3I:
      dbl = 1;
      s = "ddivu";
      s2 = "mflo";
      goto do_divi;
    case M_DREM_3I:
      dbl = 1;
      s = "ddiv";
      s2 = "mfhi";
      goto do_divi;
    case M_DREMU_3I:
      dbl = 1;
      s = "ddivu";
      s2 = "mfhi";
    do_divi:
      if (imm_expr.X_add_number == 0)
        {
          as_warn ("Divide by zero.");
          if (mips_trap)
            macro_build ((char *) NULL, &icnt, NULL, "teq", "s,t", 0, 0);
          else
            macro_build ((char *) NULL, &icnt, NULL, "break", "c", 7);
          return;
        }
      if (imm_expr.X_add_number == 1)
        {
          if (strcmp (s2, "mflo") == 0)
            macro_build ((char *) NULL, &icnt, NULL, "move", "d,s", dreg,
                         sreg);
          else
            macro_build ((char *) NULL, &icnt, NULL, "move", "d,s", dreg, 0);
          return;
        }
      if (imm_expr.X_add_number == -1
          && s[strlen (s) - 1] != 'u')
        {
          if (strcmp (s2, "mflo") == 0)
            {
              if (dbl)
                macro_build ((char *) NULL, &icnt, NULL, "dneg", "d,w", dreg,
                             sreg);
              else
                macro_build ((char *) NULL, &icnt, NULL, "neg", "d,w", dreg,
                             sreg);
            }
          else
            macro_build ((char *) NULL, &icnt, NULL, "move", "d,s", dreg, 0);
          return;
        }

      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, NULL, s, "z,s,t", sreg, AT);
      macro_build ((char *) NULL, &icnt, NULL, s2, "d", dreg);
      break;

    case M_DIVU_3:
      s = "divu";
      s2 = "mflo";
      goto do_divu3;
    case M_REMU_3:
      s = "divu";
      s2 = "mfhi";
      goto do_divu3;
    case M_DDIVU_3:
      s = "ddivu";
      s2 = "mflo";
      goto do_divu3;
    case M_DREMU_3:
      s = "ddivu";
      s2 = "mfhi";
    do_divu3:
      mips_emit_delays ();
      ++mips_noreorder;
      mips_any_noreorder = 1;
      macro_build ((char *) NULL, &icnt, NULL, s, "z,s,t", sreg, treg);
      if (mips_trap)
        macro_build ((char *) NULL, &icnt, NULL, "teq", "s,t", treg, 0);
      else
        {
          expr1.X_add_number = 8;
          macro_build ((char *) NULL, &icnt, &expr1, "bne", "s,t,p", treg, 0);
          macro_build ((char *) NULL, &icnt, NULL, "nop", "", 0);
          macro_build ((char *) NULL, &icnt, NULL, "break", "c", 7);
        }
      --mips_noreorder;
      macro_build ((char *) NULL, &icnt, NULL, s2, "d", dreg);
      return;

    case M_LA_AB:
      /* Load the address of a symbol into a register.  If breg is not
         zero, we then add a base register to it.  */

      /* When generating embedded PIC code, we permit expressions of
         the form
           la   $4,foo-bar
         where bar is an address in the .text section.  These are used
         when getting the addresses of functions.  We don't permit
         X_add_number to be non-zero, because if the symbol is
         external the relaxing code needs to know that any addend is
         purely the offset to X_op_symbol.  */
      if (mips_pic == EMBEDDED_PIC
          && offset_expr.X_op == O_subtract
          && now_seg == text_section
          && S_GET_SEGMENT (offset_expr.X_op_symbol) == text_section
          && breg == 0
          && offset_expr.X_add_number == 0)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr, "lui", "t,u",
                       treg, (int) BFD_RELOC_PCREL_HI16_S);
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       mips_isa < 3 ? "addiu" : "daddiu",
                       "t,r,j", treg, treg, (int) BFD_RELOC_PCREL_LO16);
          return;
        }

      if (offset_expr.X_op != O_symbol
          && offset_expr.X_op != O_constant)
        {
          as_bad ("expression too complex");
          offset_expr.X_op = O_constant;
        }

      if (treg == breg)
        {
          tempreg = AT;
          used_at = 1;
        }
      else
        {
          tempreg = treg;
          used_at = 0;
        }

      if (offset_expr.X_op == O_constant)
        load_register (&icnt, tempreg, &offset_expr);
      else if (mips_pic == NO_PIC)
        {
          /* If this is a reference to an GP relative symbol, we want
               addiu    $tempreg,$gp,<sym>      (BFD_RELOC_MIPS_GPREL)
             Otherwise we want
               lui      $tempreg,<sym>          (BFD_RELOC_HI16_S)
               addiu    $tempreg,$tempreg,<sym> (BFD_RELOC_LO16)
             If we have a constant, we need two instructions anyhow,
             so we may as well always use the latter form.  */
          if (offset_expr.X_add_number != 0)
            p = NULL;
          else
            {
              frag_grow (20);
              macro_build ((char *) NULL, &icnt, &offset_expr,
                           mips_isa < 3 ? "addiu" : "daddiu",
                           "t,r,j", tempreg, GP, (int) BFD_RELOC_MIPS_GPREL);
              p = frag_var (rs_machine_dependent, 8, 0,
                            RELAX_ENCODE (4, 8, 0, 4, 0,
                                          mips_warn_about_macros),
                            offset_expr.X_add_symbol, (long) 0,
                            (char *) NULL);
            }
          macro_build_lui (p, &icnt, &offset_expr, tempreg);
          if (p != NULL)
            p += 4;
          macro_build (p, &icnt, &offset_expr,
                       mips_isa < 3 ? "addiu" : "daddiu",
                       "t,r,j", tempreg, tempreg, (int) BFD_RELOC_LO16);
        }
      else if (mips_pic == SVR4_PIC)
        {
          /* If this is a reference to an external symbol, and there
             is no constant, we want
               lw       $tempreg,<sym>($gp)     (BFD_RELOC_MIPS_GOT16)
             For a local symbol, we want
               lw       $tempreg,<sym>($gp)     (BFD_RELOC_MIPS_GOT16)
               nop
               addiu    $tempreg,$tempreg,<sym> (BFD_RELOC_LO16)

             If we have a small constant, and this is a reference to
             an external symbol, we want
               lw       $tempreg,<sym>($gp)     (BFD_RELOC_MIPS_GOT16)
               nop
               addiu    $tempreg,$tempreg,<constant>
             For a local symbol, we want the same instruction
             sequence, but we output a BFD_RELOC_LO16 reloc on the
             addiu instruction.

             If we have a large constant, and this is a reference to
             an external symbol, we want
               lw       $tempreg,<sym>($gp)     (BFD_RELOC_MIPS_GOT16)
               lui      $at,<hiconstant>
               addiu    $at,$at,<loconstant>
               addu     $tempreg,$tempreg,$at
             For a local symbol, we want the same instruction
             sequence, but we output a BFD_RELOC_LO16 reloc on the
             addiu instruction.  */
          expr1.X_add_number = offset_expr.X_add_number;
          offset_expr.X_add_number = 0;
          frag_grow (32);
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       mips_isa < 3 ? "lw" : "ld",
                       "t,o(b)", tempreg, (int) BFD_RELOC_MIPS_GOT16, GP);
          if (expr1.X_add_number == 0)
            {
              int off;

              if (breg == 0)
                off = 0;
              else
                {
                  /* We're going to put in an addu instruction using
                     tempreg, so we may as well insert the nop right
                     now.  */
                  macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                               "nop", "");
                  off = 4;
                }
              p = frag_var (rs_machine_dependent, 8 - off, 0,
                            RELAX_ENCODE (0, 8 - off, -4 - off, 4 - off, 0,
                                          (breg == 0
                                           ? mips_warn_about_macros
                                           : 0)),
                            offset_expr.X_add_symbol, (long) 0,
                            (char *) NULL);
              if (breg == 0)
                {
                  macro_build (p, &icnt, (expressionS *) NULL, "nop", "");
                  p += 4;
                }
              macro_build (p, &icnt, &expr1,
                           mips_isa < 3 ? "addiu" : "daddiu",
                           "t,r,j", tempreg, tempreg, (int) BFD_RELOC_LO16);
              /* FIXME: If breg == 0, and the next instruction uses
                 $tempreg, then if this variant case is used an extra
                 nop will be generated.  */
            }
          else if (expr1.X_add_number >= -0x8000
                   && expr1.X_add_number < 0x8000)
            {
              macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                           "nop", "");
              macro_build ((char *) NULL, &icnt, &expr1,
                           mips_isa < 3 ? "addiu" : "daddiu",
                           "t,r,j", tempreg, tempreg, (int) BFD_RELOC_LO16);
              (void) frag_var (rs_machine_dependent, 0, 0,
                               RELAX_ENCODE (0, 0, -12, -4, 0, 0),
                               offset_expr.X_add_symbol, (long) 0,
                               (char *) NULL);
            }
          else
            {
              int off1;

              /* If we are going to add in a base register, and the
                 target register and the base register are the same,
                 then we are using AT as a temporary register.  Since
                 we want to load the constant into AT, we add our
                 current AT (from the global offset table) and the
                 register into the register now, and pretend we were
                 not using a base register.  */
              if (breg != treg)
                off1 = 0;
              else
                {
                  macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                               "nop", "");
                  macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                               mips_isa < 3 ? "addu" : "daddu",
                               "d,v,t", treg, AT, breg);
                  breg = 0;
                  tempreg = treg;
                  off1 = -8;
                }

              macro_build_lui ((char *) NULL, &icnt, &expr1, AT);
              macro_build ((char *) NULL, &icnt, &expr1,
                           mips_isa < 3 ? "addiu" : "daddiu",
                           "t,r,j", AT, AT, (int) BFD_RELOC_LO16);
              macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                           mips_isa < 3 ? "addu" : "daddu",
                           "d,v,t", tempreg, tempreg, AT);
              (void) frag_var (rs_machine_dependent, 0, 0,
                               RELAX_ENCODE (0, 0, -16 + off1, -8, 0, 0),
                               offset_expr.X_add_symbol, (long) 0,
                               (char *) NULL);
              used_at = 1;
            }
        }
      else if (mips_pic == EMBEDDED_PIC)
        {
          /* We use
               addiu    $tempreg,$gp,<sym>      (BFD_RELOC_MIPS_GPREL)
             */
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       mips_isa < 3 ? "addiu" : "daddiu",
                       "t,r,j", tempreg, GP, (int) BFD_RELOC_MIPS_GPREL);
        }
      else
        abort ();

      if (breg != 0)
        macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                     mips_isa < 3 ? "addu" : "daddu",
                     "d,v,t", treg, tempreg, breg);

      if (! used_at)
        return;

      break;

    case M_J_A:
      /* The j instruction may not be used in PIC code, since it
         requires an absolute address.  We convert it to a b
         instruction.  */
      if (mips_pic == NO_PIC)
        macro_build ((char *) NULL, &icnt, &offset_expr, "j", "a");
      else
        macro_build ((char *) NULL, &icnt, &offset_expr, "b", "p");
      return;

      /* The jal instructions must be handled as macros because when
         generating PIC code they expand to multi-instruction
         sequences.  Normally they are simple instructions.  */
    case M_JAL_1:
      dreg = RA;
      /* Fall through.  */
    case M_JAL_2:
      if (mips_pic == NO_PIC
          || mips_pic == EMBEDDED_PIC)
        macro_build ((char *) NULL, &icnt, (expressionS *) NULL, "jalr",
                     "d,s", dreg, sreg);
      else if (mips_pic == SVR4_PIC)
        {
          if (sreg != PIC_CALL_REG)
            as_warn ("MIPS PIC call to register other than $25");
      
          macro_build ((char *) NULL, &icnt, (expressionS *) NULL, "jalr",
                       "d,s", dreg, sreg);
          if (mips_cprestore_offset < 0)
            as_warn ("No .cprestore pseudo-op used in PIC code");
          else
            {
              expr1.X_add_number = mips_cprestore_offset;
              macro_build ((char *) NULL, &icnt, &expr1,
                           mips_isa < 3 ? "lw" : "ld",
                           "t,o(b)", GP, (int) BFD_RELOC_LO16, mips_frame_reg);
            }
        }
      else
        abort ();

      return;

    case M_JAL_A:
      if (mips_pic == NO_PIC)
        macro_build ((char *) NULL, &icnt, &offset_expr, "jal", "a");
      else if (mips_pic == SVR4_PIC)
        {
          /* If this is a reference to an external symbol, we want
               lw       $25,<sym>($gp)          (BFD_RELOC_MIPS_CALL16)
               nop
               jalr     $25
               nop
               lw       $gp,cprestore($sp)
             The cprestore value is set using the .cprestore
             pseudo-op.  If the symbol is not external, we want
               lw       $25,<sym>($gp)          (BFD_RELOC_MIPS_GOT16)
               nop
               addiu    $25,$25,<sym>           (BFD_RELOC_LO16)
               jalr     $25
               nop
               lw       $gp,cprestore($sp)
             */
          frag_grow (20);
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       mips_isa < 3 ? "lw" : "ld",
                       "t,o(b)", PIC_CALL_REG,
                       (int) BFD_RELOC_MIPS_CALL16, GP);
          macro_build ((char *) NULL, &icnt, (expressionS *) NULL, "nop", "");
          p = frag_var (rs_machine_dependent, 4, 0,
                        RELAX_ENCODE (0, 4, -8, 0, 0, 0),
                        offset_expr.X_add_symbol, (long) 0, (char *) NULL);
          macro_build (p, &icnt, &offset_expr,
                       mips_isa < 3 ? "addiu" : "daddiu",
                       "t,r,j", PIC_CALL_REG, PIC_CALL_REG,
                       (int) BFD_RELOC_LO16);
          macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                       "jalr", "s", PIC_CALL_REG);
          if (mips_cprestore_offset < 0)
            as_warn ("No .cprestore pseudo-op used in PIC code");
          else
            {
              if (mips_noreorder)
                macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                             "nop", "");
              expr1.X_add_number = mips_cprestore_offset;
              macro_build ((char *) NULL, &icnt, &expr1,
                           mips_isa < 3 ? "lw" : "ld",
                           "t,o(b)", GP, (int) BFD_RELOC_LO16,
                           mips_frame_reg);
            }
        }
      else if (mips_pic == EMBEDDED_PIC)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr, "bal", "p");
          /* The linker may expand the call to a longer sequence which
             uses $at, so we must break rather than return.  */
          break;
        }
      else
        abort ();

      return;

    case M_LB_AB:
      s = "lb";
      goto ld;
    case M_LBU_AB:
      s = "lbu";
      goto ld;
    case M_LH_AB:
      s = "lh";
      goto ld;
    case M_LHU_AB:
      s = "lhu";
      goto ld;
    case M_LW_AB:
      s = "lw";
      goto ld;
    case M_LWC0_AB:
      s = "lwc0";
      coproc = 1;
      goto ld;
    case M_LWC1_AB:
      s = "lwc1";
      coproc = 1;
      goto ld;
    case M_LWC2_AB:
      s = "lwc2";
      coproc = 1;
      goto ld;
    case M_LWC3_AB:
      s = "lwc3";
      coproc = 1;
      goto ld;
    case M_LWL_AB:
      s = "lwl";
      goto ld;
    case M_LWR_AB:
      s = "lwr";
      goto ld;
    case M_LDC1_AB:
      s = "ldc1";
      coproc = 1;
      goto ld;
    case M_LDC2_AB:
      s = "ldc2";
      coproc = 1;
      goto ld;
    case M_LDC3_AB:
      s = "ldc3";
      coproc = 1;
      goto ld;
    case M_LDL_AB:
      s = "ldl";
      goto ld;
    case M_LDR_AB:
      s = "ldr";
      goto ld;
    case M_LL_AB:
      s = "ll";
      goto ld;
    case M_LLD_AB:
      s = "lld";
      goto ld;
    case M_LWU_AB:
      s = "lwu";
    ld:
      if (breg == treg || coproc)
        {
          tempreg = AT;
          used_at = 1;
        }
      else
        {
          tempreg = treg;
          used_at = 0;
        }
      goto ld_st;
    case M_SB_AB:
      s = "sb";
      goto st;
    case M_SH_AB:
      s = "sh";
      goto st;
    case M_SW_AB:
      s = "sw";
      goto st;
    case M_SWC0_AB:
      s = "swc0";
      coproc = 1;
      goto st;
    case M_SWC1_AB:
      s = "swc1";
      coproc = 1;
      goto st;
    case M_SWC2_AB:
      s = "swc2";
      coproc = 1;
      goto st;
    case M_SWC3_AB:
      s = "swc3";
      coproc = 1;
      goto st;
    case M_SWL_AB:
      s = "swl";
      goto st;
    case M_SWR_AB:
      s = "swr";
      goto st;
    case M_SC_AB:
      s = "sc";
      goto st;
    case M_SCD_AB:
      s = "scd";
      goto st;
    case M_SDC1_AB:
      s = "sdc1";
      coproc = 1;
      goto st;
    case M_SDC2_AB:
      s = "sdc2";
      coproc = 1;
      goto st;
    case M_SDC3_AB:
      s = "sdc3";
      coproc = 1;
      goto st;
    case M_SDL_AB:
      s = "sdl";
      goto st;
    case M_SDR_AB:
      s = "sdr";
    st:
      tempreg = AT;
      used_at = 1;
    ld_st:
      if (mask == M_LWC1_AB
          || mask == M_SWC1_AB
          || mask == M_LDC1_AB
          || mask == M_SDC1_AB
          || mask == M_L_DAB
          || mask == M_S_DAB)
        fmt = "T,o(b)";
      else if (coproc)
        fmt = "E,o(b)";
      else
        fmt = "t,o(b)";

      if (offset_expr.X_op != O_constant
          && offset_expr.X_op != O_symbol)
        {
          as_bad ("expression too complex");
          offset_expr.X_op = O_constant;
        }

      /* A constant expression in PIC code can be handled just as it
         is in non PIC code.  */
      if (mips_pic == NO_PIC
          || offset_expr.X_op == O_constant)
        {
          /* If this is a reference to a GP relative symbol, and there
             is no base register, we want
               <op>     $treg,<sym>($gp)        (BFD_RELOC_MIPS_GPREL)
             Otherwise, if there is no base register, we want
               lui      $tempreg,<sym>          (BFD_RELOC_HI16_S)
               <op>     $treg,<sym>($tempreg)   (BFD_RELOC_LO16)
             If we have a constant, we need two instructions anyhow,
             so we always use the latter form.

             If we have a base register, and this is a reference to a
             GP relative symbol, we want
               addu     $tempreg,$breg,$gp
               <op>     $treg,<sym>($tempreg)   (BFD_RELOC_MIPS_GPREL)
             Otherwise we want
               lui      $tempreg,<sym>          (BFD_RELOC_HI16_S)
               addu     $tempreg,$tempreg,$breg
               <op>     $treg,<sym>($tempreg)   (BFD_RELOC_LO16)
             With a constant we always use the latter case.  */
          if (breg == 0)
            {
              if (offset_expr.X_add_number != 0)
                p = NULL;
              else
                {
                  frag_grow (20);
                  macro_build ((char *) NULL, &icnt, &offset_expr, s, fmt,
                               treg, (int) BFD_RELOC_MIPS_GPREL, GP);
                  p = frag_var (rs_machine_dependent, 8, 0,
                                RELAX_ENCODE (4, 8, 0, 4, 0,
                                              (mips_warn_about_macros
                                               || (used_at && mips_noat))),
                                offset_expr.X_add_symbol, (long) 0,
                                (char *) NULL);
                  used_at = 0;
                }
              macro_build_lui (p, &icnt, &offset_expr, tempreg);
              if (p != NULL)
                p += 4;
              macro_build (p, &icnt, &offset_expr, s, fmt, treg,
                           (int) BFD_RELOC_LO16, tempreg);
            }
          else
            {
              if (offset_expr.X_add_number != 0)
                p = NULL;
              else
                {
                  frag_grow (28);
                  macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                               mips_isa < 3 ? "addu" : "daddu",
                               "d,v,t", tempreg, breg, GP);
                  macro_build ((char *) NULL, &icnt, &offset_expr, s, fmt,
                               treg, (int) BFD_RELOC_MIPS_GPREL, tempreg);
                  p = frag_var (rs_machine_dependent, 12, 0,
                                RELAX_ENCODE (8, 12, 0, 8, 0, 0),
                                offset_expr.X_add_symbol, (long) 0,
                                (char *) NULL);
                }
              macro_build_lui (p, &icnt, &offset_expr, tempreg);
              if (p != NULL)
                p += 4;
              macro_build (p, &icnt, (expressionS *) NULL,
                           mips_isa < 3 ? "addu" : "daddu",
                           "d,v,t", tempreg, tempreg, breg);
              if (p != NULL)
                p += 4;
              macro_build (p, &icnt, &offset_expr, s, fmt, treg,
                           (int) BFD_RELOC_LO16, tempreg);
            }
        }
      else if (mips_pic == SVR4_PIC)
        {
          /* If this is a reference to an external symbol, we want
               lw       $tempreg,<sym>($gp)     (BFD_RELOC_MIPS_GOT16)
               nop
               <op>     $treg,0($tempreg)
             Otherwise we want
               lw       $tempreg,<sym>($gp)     (BFD_RELOC_MIPS_GOT16)
               nop
               addiu    $tempreg,$tempreg,<sym> (BFD_RELOC_LO16)
               <op>     $treg,0($tempreg)
             If there is a base register, we add it to $tempreg before
             the <op>.  If there is a constant, we stick it in the
             <op> instruction.  We don't handle constants larger than
             16 bits, because we have no way to load the upper 16 bits
             (actually, we could handle them for the subset of cases
             in which we are not using $at).  */
          assert (offset_expr.X_op == O_symbol);
          expr1.X_add_number = offset_expr.X_add_number;
          offset_expr.X_add_number = 0;
          if (expr1.X_add_number < -0x8000
              || expr1.X_add_number >= 0x8000)
            as_bad ("PIC code offset overflow (max 16 signed bits)");
          frag_grow (20);
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       mips_isa < 3 ? "lw" : "ld",
                       "t,o(b)", tempreg, (int) BFD_RELOC_MIPS_GOT16, GP);
          macro_build ((char *) NULL, &icnt, (expressionS *) NULL, "nop", "");
          p = frag_var (rs_machine_dependent, 4, 0, 
                        RELAX_ENCODE (0, 4, -8, 0, 0, 0),
                        offset_expr.X_add_symbol, (long) 0,
                        (char *) NULL);
          macro_build (p, &icnt, &offset_expr,
                       mips_isa < 3 ? "addiu" : "daddiu",
                       "t,r,j", tempreg, tempreg, (int) BFD_RELOC_LO16);
          if (breg != 0)
            macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                         mips_isa < 3 ? "addu" : "daddu",
                         "d,v,t", tempreg, tempreg, breg);
          macro_build ((char *) NULL, &icnt, &expr1, s, fmt, treg,
                       (int) BFD_RELOC_LO16, tempreg);
        }
      else if (mips_pic == EMBEDDED_PIC)
        {
          /* If there is no base register, we want
               <op>     $treg,<sym>($gp)        (BFD_RELOC_MIPS_GPREL)
             If there is a base register, we want
               addu     $tempreg,$breg,$gp
               <op>     $treg,<sym>($tempreg)   (BFD_RELOC_MIPS_GPREL)
             */
          assert (offset_expr.X_op == O_symbol);
          if (breg == 0)
            {
              macro_build ((char *) NULL, &icnt, &offset_expr, s, fmt,
                           treg, (int) BFD_RELOC_MIPS_GPREL, GP);
              used_at = 0;
            }
          else
            {
              macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                           mips_isa < 3 ? "addu" : "daddu",
                           "d,v,t", tempreg, breg, GP);
              macro_build ((char *) NULL, &icnt, &offset_expr, s, fmt,
                           treg, (int) BFD_RELOC_MIPS_GPREL, tempreg);
            }
        }
      else
        abort ();

      if (! used_at)
        return;

      break;

    case M_LI:
    case M_LI_S:
      load_register (&icnt, treg, &imm_expr);
      return;

    case M_LI_SS:
      if (mips_pic == NO_PIC)
        {
          assert (offset_expr.X_op == O_symbol
                  && strcmp (segment_name (S_GET_SEGMENT
                                           (offset_expr.X_add_symbol)),
                             ".lit4") == 0
                  && offset_expr.X_add_number == 0);
          macro_build ((char *) NULL, &icnt, &offset_expr, "lwc1", "T,o(b)",
                       treg, (int) BFD_RELOC_MIPS_LITERAL, GP);
        }
      else if (mips_pic == SVR4_PIC
               || mips_pic == EMBEDDED_PIC)
        {
          assert (imm_expr.X_op == O_constant);
          load_register (&icnt, treg, &imm_expr);
        }
      else
        abort ();

      return;

    case M_LI_D:
      /* We know that sym is in the .rdata section.  First we get the
         upper 16 bits of the address.  */
      if (mips_pic == NO_PIC)
        {
          /* FIXME: This won't work for a 64 bit address.  */
          macro_build_lui ((char *) NULL, &icnt, &offset_expr, AT);
        }
      else if (mips_pic == SVR4_PIC)
        {
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       mips_isa < 3 ? "lw" : "ld",
                       "t,o(b)", AT, (int) BFD_RELOC_MIPS_GOT16, GP);
        }
      else if (mips_pic == EMBEDDED_PIC)
        {
          /* For embedded PIC we pick up the entire address off $gp in
             a single instruction.  */
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       mips_isa < 3 ? "addiu" : "daddiu",
                       "t,r,j", AT, GP, (int) BFD_RELOC_MIPS_GPREL);
          offset_expr.X_op = O_constant;
          offset_expr.X_add_number = 0;
        }
      else
        abort ();
        
      /* Now we load the register(s).  */
      if (mips_isa >= 3)
        macro_build ((char *) NULL, &icnt, &offset_expr, "ld", "t,o(b)",
                     treg, (int) BFD_RELOC_LO16, AT);
      else
        {
          macro_build ((char *) NULL, &icnt, &offset_expr, "lw", "t,o(b)",
                       treg, (int) BFD_RELOC_LO16, AT);
          if (treg != 31)
            {
              /* FIXME: How in the world do we deal with the possible
                 overflow here?  */
              offset_expr.X_add_number += 4;
              macro_build ((char *) NULL, &icnt, &offset_expr, "lw", "t,o(b)",
                           treg + 1, (int) BFD_RELOC_LO16, AT);
            }
        }
               
      break;

    case M_LI_DD:
      if (mips_pic == NO_PIC
          || mips_pic == EMBEDDED_PIC)
        {
          /* Load a floating point number from the .lit8 section.  */
          assert (offset_expr.X_op == O_symbol
                  && strcmp (segment_name (S_GET_SEGMENT
                                           (offset_expr.X_add_symbol)),
                             ".lit8") == 0
                  && offset_expr.X_add_number == 0);
          if (mips_isa >= 2)
            {
              macro_build ((char *) NULL, &icnt, &offset_expr, "ldc1",
                           "T,o(b)", treg, (int) BFD_RELOC_MIPS_LITERAL, GP);
              return;
            }
          breg = GP;
          r = BFD_RELOC_MIPS_LITERAL;
          goto dob;
        }
      else if (mips_pic == SVR4_PIC)
        {
          /* Load the double from the .rdata section.  */
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       mips_isa < 3 ? "lw" : "ld",
                       "t,o(b)", AT, (int) BFD_RELOC_MIPS_GOT16, GP);
          if (mips_isa >= 2)
            {
              macro_build ((char *) NULL, &icnt, &offset_expr, "ldc1",
                           "T,o(b)", treg, (int) BFD_RELOC_LO16, GP);
              break;
            }
          breg = AT;
          r = BFD_RELOC_LO16;
          goto dob;
        }
      else
        abort ();

    case M_L_DOB:
      /* Even on a big endian machine $fn comes before $fn+1.  We have
         to adjust when loading from memory.  */
      r = BFD_RELOC_LO16;
    dob:
      assert (mips_isa < 2);
      macro_build ((char *) NULL, &icnt, &offset_expr, "lwc1", "T,o(b)",
                   byte_order == LITTLE_ENDIAN ? treg : treg + 1,
                   (int) r, breg);
      /* FIXME: A possible overflow which I don't know how to deal
         with.  */
      offset_expr.X_add_number += 4;
      macro_build ((char *) NULL, &icnt, &offset_expr, "lwc1", "T,o(b)",
                   byte_order == LITTLE_ENDIAN ? treg + 1 : treg,
                   (int) r, breg);
      if (breg != AT)
        return;
      break;

    case M_L_DAB:
      /*
       * The MIPS assembler seems to check for X_add_number not
       * being double aligned and generating:
       *        lui     at,%hi(foo+1)
       *        addu    at,at,v1
       *        addiu   at,at,%lo(foo+1)
       *        lwc1    f2,0(at)
       *        lwc1    f3,4(at)
       * But, the resulting address is the same after relocation so why
       * generate the extra instruction?
       */
      coproc = 1;
      if (mips_isa >= 2)
        {
          s = "ldc1";
          goto ld;
        }

      s = "lwc1";
      fmt = "T,o(b)";
      goto ldd_std;

    case M_S_DAB:
      if (mips_isa >= 2)
        {
          s = "sdc1";
          goto st;
        }

      s = "swc1";
      fmt = "T,o(b)";
      coproc = 1;
      goto ldd_std;

    case M_LD_AB:
      if (mips_isa >= 3)
        {
          s = "ld";
          goto ld;
        }

      s = "lw";
      fmt = "t,o(b)";
      goto ldd_std;

    case M_SD_AB:
      if (mips_isa >= 3)
        {
          s = "sd";
          goto st;
        }

      s = "sw";
      fmt = "t,o(b)";

    ldd_std:
      if (offset_expr.X_op != O_symbol
          && offset_expr.X_op != O_constant)
        {
          as_bad ("expression too complex");
          offset_expr.X_op = O_constant;
        }

      /* Even on a big endian machine $fn comes before $fn+1.  We have
         to adjust when loading from memory.  We set coproc if we must
         load $fn+1 first.  */
      if (byte_order == LITTLE_ENDIAN)
        coproc = 0;

      if (mips_pic == NO_PIC
          || offset_expr.X_op == O_constant)
        {
          /* If this is a reference to a GP relative symbol, we want
               <op>     $treg,<sym>($gp)        (BFD_RELOC_MIPS_GPREL)
               <op>     $treg+1,<sym>+4($gp)    (BFD_RELOC_MIPS_GPREL)
             If we have a base register, we use this
               addu     $at,$breg,$gp
               <op>     $treg,<sym>($at)        (BFD_RELOC_MIPS_GPREL)
               <op>     $treg+1,<sym>+4($at)    (BFD_RELOC_MIPS_GPREL)
             If this is not a GP relative symbol, we want
               lui      $at,<sym>               (BFD_RELOC_HI16_S)
               <op>     $treg,<sym>($at)        (BFD_RELOC_LO16)
               <op>     $treg+1,<sym>+4($at)    (BFD_RELOC_LO16)
             If there is a base register, we add it to $at after the
             lui instruction.  If there is a constant, we always use
             the last case.  */
          if (offset_expr.X_add_number != 0)
            {
              p = NULL;
              used_at = 1;
            }
          else
            {
              int off;

              if (breg == 0)
                {
                  frag_grow (28);
                  tempreg = GP;
                  off = 0;
                  used_at = 0;
                }
              else
                {
                  frag_grow (36);
                  macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                               mips_isa < 3 ? "addu" : "daddu",
                               "d,v,t", AT, breg, GP);
                  tempreg = AT;
                  off = 4;
                  used_at = 1;
                }

              macro_build ((char *) NULL, &icnt, &offset_expr, s, fmt,
                           coproc ? treg + 1 : treg,
                           (int) BFD_RELOC_MIPS_GPREL, tempreg);
              offset_expr.X_add_number += 4;
              macro_build ((char *) NULL, &icnt, &offset_expr, s, fmt,
                           coproc ? treg : treg + 1,
                           (int) BFD_RELOC_MIPS_GPREL, tempreg);
              p = frag_var (rs_machine_dependent, 12 + off, 0,
                            RELAX_ENCODE (8 + off, 12 + off, 0, 4 + off, 1,
                                          used_at && mips_noat),
                            offset_expr.X_add_symbol, (long) 0,
                            (char *) NULL);

              /* We just generated two relocs.  When tc_gen_reloc
                 handles this case, it will skip the first reloc and
                 handle the second.  The second reloc already has an
                 extra addend of 4, which we added above.  We must
                 subtract it out, and then subtract another 4 to make
                 the first reloc come out right.  The second reloc
                 will come out right because we are going to add 4 to
                 offset_expr when we build its instruction below.  */
              offset_expr.X_add_number -= 8;
              offset_expr.X_op = O_constant;
            }
          macro_build_lui (p, &icnt, &offset_expr, AT);
          if (p != NULL)
            p += 4;
          if (breg != 0)
            {
              macro_build (p, &icnt, (expressionS *) NULL,
                           mips_isa < 3 ? "addu" : "daddu",
                           "d,v,t", AT, breg, AT);
              if (p != NULL)
                p += 4;
            }
          macro_build (p, &icnt, &offset_expr, s, fmt,
                       coproc ? treg + 1 : treg,
                       (int) BFD_RELOC_LO16, AT);
          if (p != NULL)
            p += 4;
          /* FIXME: How do we handle overflow here?  */
          offset_expr.X_add_number += 4;
          macro_build (p, &icnt, &offset_expr, s, fmt,
                       coproc ? treg : treg + 1,
                       (int) BFD_RELOC_LO16, AT);
        }         
      else if (mips_pic == SVR4_PIC)
        {
          int off;

          /* If this is a reference to an external symbol, we want
               lw       $at,<sym>($gp)          (BFD_RELOC_MIPS_GOT16)
               nop
               <op>     $treg,0($at)
               <op>     $treg+1,4($at)
             Otherwise we want
               lw       $at,<sym>($gp)          (BFD_RELOC_MIPS_GOT16)
               nop
               <op>     $treg,<sym>($at)        (BFD_RELOC_LO16)
               <op>     $treg+1,<sym>+4($at)    (BFD_RELOC_LO16)
             If there is a base register we add it to $at before the
             lwc1 instructions.  If there is a constant we include it
             in the lwc1 instructions.  */
          used_at = 1;
          expr1.X_add_number = offset_expr.X_add_number;
          offset_expr.X_add_number = 0;
          if (expr1.X_add_number < -0x8000
              || expr1.X_add_number >= 0x8000 - 4)
            as_bad ("PIC code offset overflow (max 16 signed bits)");
          if (breg == 0)
            off = 0;
          else
            off = 4;
          frag_grow (24 + off);
          macro_build ((char *) NULL, &icnt, &offset_expr,
                       mips_isa < 3 ? "lw" : "ld",
                       "t,o(b)", AT, (int) BFD_RELOC_MIPS_GOT16, GP);
          macro_build ((char *) NULL, &icnt, (expressionS *) NULL, "nop", "");
          if (breg != 0)
            macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                         mips_isa < 3 ? "addu" : "daddu",
                         "d,v,t", AT, breg, AT);
          macro_build ((char *) NULL, &icnt, &expr1, s, fmt,
                       coproc ? treg + 1 : treg,
                       (int) BFD_RELOC_LO16, AT);
          expr1.X_add_number += 4;
          macro_build ((char *) NULL, &icnt, &expr1, s, fmt,
                       coproc ? treg : treg + 1,
                       (int) BFD_RELOC_LO16, AT);
          (void) frag_var (rs_machine_dependent, 0, 0,
                           RELAX_ENCODE (0, 0, -16 - off, -8, 1, 0),
                           offset_expr.X_add_symbol, (long) 0,
                           (char *) NULL);
        }
      else if (mips_pic == EMBEDDED_PIC)
        {
          /* If there is no base register, we use
               <op>     $treg,<sym>($gp)        (BFD_RELOC_MIPS_GPREL)
               <op>     $treg+1,<sym>+4($gp)    (BFD_RELOC_MIPS_GPREL)
             If we have a base register, we use
               addu     $at,$breg,$gp
               <op>     $treg,<sym>($at)        (BFD_RELOC_MIPS_GPREL)
               <op>     $treg+1,<sym>+4($at)    (BFD_RELOC_MIPS_GPREL)
             */
          if (breg == 0)
            {
              tempreg = GP;
              used_at = 0;
            }
          else
            {
              macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
                           mips_isa < 3 ? "addu" : "daddu",
                           "d,v,t", AT, breg, GP);
              tempreg = AT;
              used_at = 1;
            }

          macro_build ((char *) NULL, &icnt, &offset_expr, s, fmt,
                       coproc ? treg + 1 : treg,
                       (int) BFD_RELOC_MIPS_GPREL, tempreg);
          offset_expr.X_add_number += 4;
          macro_build ((char *) NULL, &icnt, &offset_expr, s, fmt,
                       coproc ? treg : treg + 1,
                       (int) BFD_RELOC_MIPS_GPREL, tempreg);
        }
      else
        abort ();

      if (! used_at)
        return;

      break;

    case M_LD_OB:
      s = "lw";
      goto sd_ob;
    case M_SD_OB:
      s = "sw";
    sd_ob:
      assert (mips_isa < 3);
      macro_build ((char *) NULL, &icnt, &offset_expr, s, "t,o(b)", treg,
                   (int) BFD_RELOC_LO16, breg);
      offset_expr.X_add_number += 4;
      macro_build ((char *) NULL, &icnt, &offset_expr, s, "t,o(b)", treg + 1,
                   (int) BFD_RELOC_LO16, breg);
      return;
#ifdef LOSING_COMPILER
    default:
      macro2 (ip);
      return;
    }
  if (mips_noat)
    as_warn ("Macro used $at after \".set noat\"");
}
          
static void
macro2 (ip)
     struct mips_cl_insn *ip;
{
  register int treg, sreg, dreg, breg;
  int tempreg;
  int mask;
  int icnt = 0;
  int used_at;
  expressionS expr1;
  const char *s;
  const char *s2;
  const char *fmt;
  int likely = 0;
  int dbl = 0;
  int coproc = 0;
  offsetT maxnum;
  bfd_reloc_code_real_type r;
  char *p;
          
  treg = (ip->insn_opcode >> 16) & 0x1f;
  dreg = (ip->insn_opcode >> 11) & 0x1f;
  sreg = breg = (ip->insn_opcode >> 21) & 0x1f;
  mask = ip->insn_mo->mask;
          
  expr1.X_op = O_constant;
  expr1.X_op_symbol = NULL;
  expr1.X_add_symbol = NULL;
  expr1.X_add_number = 1;
          
  switch (mask)
    {
#endif /* LOSING_COMPILER */

    case M_DMUL:
      dbl = 1;
    case M_MUL:
      macro_build ((char *) NULL, &icnt, NULL,
                   dbl ? "dmultu" : "multu",
                   "s,t", sreg, treg);
      macro_build ((char *) NULL, &icnt, NULL, "mflo", "d", dreg);
      return;

    case M_DMUL_I:
      dbl = 1;
    case M_MUL_I:
      /* The MIPS assembler some times generates shifts and adds.  I'm
         not trying to be that fancy. GCC should do this for us
         anyway.  */
      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, NULL,
                   dbl ? "dmult" : "mult",
                   "s,t", sreg, AT);
      macro_build ((char *) NULL, &icnt, NULL, "mflo", "d", dreg);
      break;

    case M_DMULO:
      dbl = 1;
    case M_MULO:
      mips_emit_delays ();
      ++mips_noreorder;
      mips_any_noreorder = 1;
      macro_build ((char *) NULL, &icnt, NULL,
                   dbl ? "dmult" : "mult",
                   "s,t", sreg, treg);
      macro_build ((char *) NULL, &icnt, NULL, "mflo", "d", dreg);
      macro_build ((char *) NULL, &icnt, NULL,
                   dbl ? "dsra32" : "sra",
                   "d,w,<", dreg, dreg, 31);
      macro_build ((char *) NULL, &icnt, NULL, "mfhi", "d", AT);
      if (mips_trap)
        macro_build ((char *) NULL, &icnt, NULL, "tne", "s,t", dreg, AT);
      else
        {
          expr1.X_add_number = 8;
          macro_build ((char *) NULL, &icnt, &expr1, "beq", "s,t,p", dreg, AT);
          macro_build ((char *) NULL, &icnt, NULL, "nop", "", 0);
          macro_build ((char *) NULL, &icnt, NULL, "break", "c", 6);
        }
      --mips_noreorder;
      macro_build ((char *) NULL, &icnt, NULL, "mflo", "d", dreg);
      break;

    case M_DMULOU:
      dbl = 1;
    case M_MULOU:
      mips_emit_delays ();
      ++mips_noreorder;
      mips_any_noreorder = 1;
      macro_build ((char *) NULL, &icnt, NULL,
                   dbl ? "dmultu" : "multu",
                   "s,t", sreg, treg);
      macro_build ((char *) NULL, &icnt, NULL, "mfhi", "d", AT);
      macro_build ((char *) NULL, &icnt, NULL, "mflo", "d", dreg);
      if (mips_trap)
        macro_build ((char *) NULL, &icnt, NULL, "tne", "s,t", AT, 0);
      else
        {
          expr1.X_add_number = 8;
          macro_build ((char *) NULL, &icnt, &expr1, "beq", "s,t,p", AT, 0);
          macro_build ((char *) NULL, &icnt, NULL, "nop", "", 0);
          macro_build ((char *) NULL, &icnt, NULL, "break", "c", 6);
        }
      --mips_noreorder;
      break;

    case M_ROL:
      macro_build ((char *) NULL, &icnt, NULL, "subu", "d,v,t", AT, 0, treg);
      macro_build ((char *) NULL, &icnt, NULL, "srlv", "d,t,s", AT, sreg, AT);
      macro_build ((char *) NULL, &icnt, NULL, "sllv", "d,t,s", dreg, sreg,
                   treg);
      macro_build ((char *) NULL, &icnt, NULL, "or", "d,v,t", dreg, dreg, AT);
      break;

    case M_ROL_I:
      macro_build ((char *) NULL, &icnt, NULL, "sll", "d,w,<", AT, sreg,
                   imm_expr.X_add_number & 0x1f);
      macro_build ((char *) NULL, &icnt, NULL, "srl", "d,w,<", dreg, sreg,
                   (0 - imm_expr.X_add_number) & 0x1f);
      macro_build ((char *) NULL, &icnt, NULL, "or", "d,v,t", dreg, dreg, AT);
      break;

    case M_ROR:
      macro_build ((char *) NULL, &icnt, NULL, "subu", "d,v,t", AT, 0, treg);
      macro_build ((char *) NULL, &icnt, NULL, "sllv", "d,t,s", AT, sreg, AT);
      macro_build ((char *) NULL, &icnt, NULL, "srlv", "d,t,s", dreg, sreg,
                   treg);
      macro_build ((char *) NULL, &icnt, NULL, "or", "d,v,t", dreg, dreg, AT);
      break;

    case M_ROR_I:
      macro_build ((char *) NULL, &icnt, NULL, "srl", "d,w,<", AT, sreg,
                   imm_expr.X_add_number & 0x1f);
      macro_build ((char *) NULL, &icnt, NULL, "sll", "d,w,<", dreg, sreg,
                   (0 - imm_expr.X_add_number) & 0x1f);
      macro_build ((char *) NULL, &icnt, NULL, "or", "d,v,t", dreg, dreg, AT);
      break;

    case M_S_DOB:
      assert (mips_isa < 2);
      /* Even on a big endian machine $fn comes before $fn+1.  We have
         to adjust when storing to memory.  */
      macro_build ((char *) NULL, &icnt, &offset_expr, "swc1", "T,o(b)",
                   byte_order == LITTLE_ENDIAN ? treg : treg + 1,
                   (int) BFD_RELOC_LO16, breg);
      offset_expr.X_add_number += 4;
      macro_build ((char *) NULL, &icnt, &offset_expr, "swc1", "T,o(b)",
                   byte_order == LITTLE_ENDIAN ? treg + 1 : treg,
                   (int) BFD_RELOC_LO16, breg);
      return;

    case M_SEQ:
      if (sreg == 0)
        macro_build ((char *) NULL, &icnt, &expr1, "sltiu", "t,r,j", dreg,
                     treg, (int) BFD_RELOC_LO16);
      else if (treg == 0)
        macro_build ((char *) NULL, &icnt, &expr1, "sltiu", "t,r,j", dreg,
                     sreg, (int) BFD_RELOC_LO16);
      else
        {
          macro_build ((char *) NULL, &icnt, NULL, "xor", "d,v,t", dreg,
                       sreg, treg);
          macro_build ((char *) NULL, &icnt, &expr1, "sltiu", "t,r,j", dreg,
                       dreg, (int) BFD_RELOC_LO16);
        }
      return;

    case M_SEQ_I:
      if (imm_expr.X_add_number == 0)
        {
          macro_build ((char *) NULL, &icnt, &expr1, "sltiu", "t,r,j", dreg,
                       sreg, (int) BFD_RELOC_LO16);
          return;
        }
      if (sreg == 0)
        {
          as_warn ("Instruction %s: result is always false",
                   ip->insn_mo->name);
          macro_build ((char *) NULL, &icnt, NULL, "move", "d,s", dreg, 0);
          return;
        }
      if (imm_expr.X_add_number >= 0 && imm_expr.X_add_number < 0x10000)
        {
          macro_build ((char *) NULL, &icnt, &imm_expr, "xori", "t,r,i", dreg,
                       sreg, (int) BFD_RELOC_LO16);
          used_at = 0;
        }
      else if (imm_expr.X_add_number > -0x8000 && imm_expr.X_add_number < 0)
        {
          imm_expr.X_add_number = -imm_expr.X_add_number;
          macro_build ((char *) NULL, &icnt, &imm_expr,
                       mips_isa < 3 ? "addiu" : "daddiu",
                       "t,r,j", dreg, sreg,
                       (int) BFD_RELOC_LO16);
          used_at = 0;
        }
      else
        {
          load_register (&icnt, AT, &imm_expr);
          macro_build ((char *) NULL, &icnt, NULL, "xor", "d,v,t", dreg,
                       sreg, AT);
          used_at = 1;
        }
      macro_build ((char *) NULL, &icnt, &expr1, "sltiu", "t,r,j", dreg, dreg,
                   (int) BFD_RELOC_LO16);
      if (used_at)
        break;
      return;

    case M_SGE:         /* sreg >= treg <==> not (sreg < treg) */
      s = "slt";
      goto sge;
    case M_SGEU:
      s = "sltu";
    sge:
      macro_build ((char *) NULL, &icnt, NULL, s, "d,v,t", dreg, sreg, treg);
      macro_build ((char *) NULL, &icnt, &expr1, "xori", "t,r,i", dreg, dreg,
                   (int) BFD_RELOC_LO16);
      return;

    case M_SGE_I:               /* sreg >= I <==> not (sreg < I) */
    case M_SGEU_I:
      if (imm_expr.X_add_number >= -0x8000 && imm_expr.X_add_number < 0x8000)
        {
          macro_build ((char *) NULL, &icnt, &expr1,
                       mask == M_SGE_I ? "slti" : "sltiu",
                       "t,r,j", dreg, sreg, (int) BFD_RELOC_LO16);
          used_at = 0;
        }
      else
        {
          load_register (&icnt, AT, &imm_expr);
          macro_build ((char *) NULL, &icnt, NULL,
                       mask == M_SGE_I ? "slt" : "sltu",
                       "d,v,t", dreg, sreg, AT);
          used_at = 1;
        }
      macro_build ((char *) NULL, &icnt, &expr1, "xori", "t,r,i", dreg, dreg,
                   (int) BFD_RELOC_LO16);
      if (used_at)
        break;
      return;

    case M_SGT:         /* sreg > treg  <==>  treg < sreg */
      s = "slt";
      goto sgt;
    case M_SGTU:
      s = "sltu";
    sgt:
      macro_build ((char *) NULL, &icnt, NULL, s, "d,v,t", dreg, treg, sreg);
      return;

    case M_SGT_I:               /* sreg > I  <==>  I < sreg */
      s = "slt";
      goto sgti;
    case M_SGTU_I:
      s = "sltu";
    sgti:
      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, NULL, s, "d,v,t", dreg, AT, sreg);
      break;

    case M_SLE:         /* sreg <= treg  <==>  treg >= sreg  <==>  not (treg < sreg) */
      s = "slt";
      goto sle;
    case M_SLEU:
      s = "sltu";
    sle:
      macro_build ((char *) NULL, &icnt, NULL, s, "d,v,t", dreg, treg, sreg);
      macro_build ((char *) NULL, &icnt, &expr1, "xori", "t,r,i", dreg, dreg,
                   (int) BFD_RELOC_LO16);
      return;

    case M_SLE_I:               /* sreg <= I <==> I >= sreg <==> not (I < sreg) */
      s = "slt";
      goto slei;
    case M_SLEU_I:
      s = "sltu";
    slei:
      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, NULL, s, "d,v,t", dreg, AT, sreg);
      macro_build ((char *) NULL, &icnt, &expr1, "xori", "t,r,i", dreg, dreg,
                   (int) BFD_RELOC_LO16);
      break;

    case M_SLT_I:
      if (imm_expr.X_add_number >= -0x8000 && imm_expr.X_add_number < 0x8000)
        {
          macro_build ((char *) NULL, &icnt, &imm_expr, "slti", "t,r,j",
                       dreg, sreg, (int) BFD_RELOC_LO16);
          return;
        }
      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, NULL, "slt", "d,v,t", dreg, sreg, AT);
      break;

    case M_SLTU_I:
      if (imm_expr.X_add_number >= -0x8000 && imm_expr.X_add_number < 0x8000)
        {
          macro_build ((char *) NULL, &icnt, &imm_expr, "sltiu", "t,r,j",
                       dreg, sreg, (int) BFD_RELOC_LO16);
          return;
        }
      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, NULL, "sltu", "d,v,t", dreg, sreg,
                   AT);
      break;

    case M_SNE:
      if (sreg == 0)
        macro_build ((char *) NULL, &icnt, NULL, "sltu", "d,v,t", dreg, 0,
                     treg);
      else if (treg == 0)
        macro_build ((char *) NULL, &icnt, NULL, "sltu", "d,v,t", dreg, 0,
                     sreg);
      else
        {
          macro_build ((char *) NULL, &icnt, NULL, "xor", "d,v,t", dreg,
                       sreg, treg);
          macro_build ((char *) NULL, &icnt, NULL, "sltu", "d,v,t", dreg, 0,
                       dreg);
        }
      return;

    case M_SNE_I:
      if (imm_expr.X_add_number == 0)
        {
          macro_build ((char *) NULL, &icnt, NULL, "sltu", "d,v,t", dreg, 0,
                       sreg);
          return;
        }
      if (sreg == 0)
        {
          as_warn ("Instruction %s: result is always true",
                   ip->insn_mo->name);
          macro_build ((char *) NULL, &icnt, &expr1,
                       mips_isa < 3 ? "addiu" : "daddiu",
                       "t,r,j", dreg, 0, (int) BFD_RELOC_LO16);
          return;
        }
      if (imm_expr.X_add_number >= 0 && imm_expr.X_add_number < 0x10000)
        {
          macro_build ((char *) NULL, &icnt, &imm_expr, "xori", "t,r,i",
                       dreg, sreg, (int) BFD_RELOC_LO16);
          used_at = 0;
        }
      else if (imm_expr.X_add_number > -0x8000 && imm_expr.X_add_number < 0)
        {
          imm_expr.X_add_number = -imm_expr.X_add_number;
          macro_build ((char *) NULL, &icnt, &imm_expr,
                       mips_isa < 3 ? "addiu" : "daddiu",
                       "t,r,j", dreg, sreg, (int) BFD_RELOC_LO16);
          used_at = 0;
        }
      else
        {
          load_register (&icnt, AT, &imm_expr);
          macro_build ((char *) NULL, &icnt, NULL, "xor", "d,v,t", dreg,
                       sreg, AT);
          used_at = 1;
        }
      macro_build ((char *) NULL, &icnt, NULL, "sltu", "d,v,t", dreg, 0, dreg);
      if (used_at)
        break;
      return;

    case M_DSUB_I:
      dbl = 1;
    case M_SUB_I:
      if (imm_expr.X_add_number > -0x8000 && imm_expr.X_add_number <= 0x8000)
        {
          imm_expr.X_add_number = -imm_expr.X_add_number;
          macro_build ((char *) NULL, &icnt, &imm_expr,
                       dbl ? "daddi" : "addi",
                       "t,r,j", dreg, sreg, (int) BFD_RELOC_LO16);
          return;
        }
      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, NULL,
                   dbl ? "dsub" : "sub",
                   "d,v,t", dreg, sreg, AT);
      break;

    case M_DSUBU_I:
      dbl = 1;
    case M_SUBU_I:
      if (imm_expr.X_add_number > -0x8000 && imm_expr.X_add_number <= 0x8000)
        {
          imm_expr.X_add_number = -imm_expr.X_add_number;
          macro_build ((char *) NULL, &icnt, &imm_expr,
                       dbl ? "daddiu" : "addiu",
                       "t,r,j", dreg, sreg, (int) BFD_RELOC_LO16);
          return;
        }
      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, NULL,
                   dbl ? "dsubu" : "subu",
                   "d,v,t", dreg, sreg, AT);
      break;

    case M_TEQ_I:
      s = "teq";
      goto trap;
    case M_TGE_I:
      s = "tge";
      goto trap;
    case M_TGEU_I:
      s = "tgeu";
      goto trap;
    case M_TLT_I:
      s = "tlt";
      goto trap;
    case M_TLTU_I:
      s = "tltu";
      goto trap;
    case M_TNE_I:
      s = "tne";
    trap:
      load_register (&icnt, AT, &imm_expr);
      macro_build ((char *) NULL, &icnt, NULL, s, "s,t", sreg, AT);
      break;

    case M_TRUNCWD:
    case M_TRUNCWS:
      assert (mips_isa < 2);
      sreg = (ip->insn_opcode >> 11) & 0x1f;    /* floating reg */
      dreg = (ip->insn_opcode >> 06) & 0x1f;    /* floating reg */

      /*
       * Is the double cfc1 instruction a bug in the mips assembler;
       * or is there a reason for it?
       */
      mips_emit_delays ();
      ++mips_noreorder;
      mips_any_noreorder = 1;
      macro_build ((char *) NULL, &icnt, NULL, "cfc1", "t,G", treg, 31);
      macro_build ((char *) NULL, &icnt, NULL, "cfc1", "t,G", treg, 31);
      macro_build ((char *) NULL, &icnt, NULL, "nop", "");
      expr1.X_add_number = 3;
      macro_build ((char *) NULL, &icnt, &expr1, "ori", "t,r,i", AT, treg,
                   (int) BFD_RELOC_LO16);
      expr1.X_add_number = 2;
      macro_build ((char *) NULL, &icnt, &expr1, "xori", "t,r,i", AT, AT,
                     (int) BFD_RELOC_LO16);
      macro_build ((char *) NULL, &icnt, NULL, "ctc1", "t,G", AT, 31);
      macro_build ((char *) NULL, &icnt, NULL, "nop", "");
      macro_build ((char *) NULL, &icnt, NULL,
              mask == M_TRUNCWD ? "cvt.w.d" : "cvt.w.s", "D,S", dreg, sreg);
      macro_build ((char *) NULL, &icnt, NULL, "ctc1", "t,G", treg, 31);
      macro_build ((char *) NULL, &icnt, NULL, "nop", "");
      --mips_noreorder;
      break;

    case M_ULH:
      s = "lb";
      goto ulh;
    case M_ULHU:
      s = "lbu";
    ulh:
      if (offset_expr.X_add_number >= 0x7fff)
        as_bad ("operand overflow");
      /* avoid load delay */
      if (byte_order == LITTLE_ENDIAN)
        offset_expr.X_add_number += 1;
      macro_build ((char *) NULL, &icnt, &offset_expr, s, "t,o(b)", treg,
                   (int) BFD_RELOC_LO16, breg);
      if (byte_order == LITTLE_ENDIAN)
        offset_expr.X_add_number -= 1;
      else
        offset_expr.X_add_number += 1;
      macro_build ((char *) NULL, &icnt, &offset_expr, "lbu", "t,o(b)", AT,
                   (int) BFD_RELOC_LO16, breg);
      macro_build ((char *) NULL, &icnt, NULL, "sll", "d,w,<", treg, treg, 8);
      macro_build ((char *) NULL, &icnt, NULL, "or", "d,v,t", treg, treg, AT);
      break;

    case M_ULW:
      if (offset_expr.X_add_number >= 0x7ffd)
        as_bad ("operand overflow");
      if (byte_order == LITTLE_ENDIAN)
        offset_expr.X_add_number += 3;
      macro_build ((char *) NULL, &icnt, &offset_expr, "lwl", "t,o(b)", treg,
                   (int) BFD_RELOC_LO16, breg);
      if (byte_order == LITTLE_ENDIAN)
        offset_expr.X_add_number -= 3;
      else
        offset_expr.X_add_number += 3;
      macro_build ((char *) NULL, &icnt, &offset_expr, "lwr", "t,o(b)", treg,
                   (int) BFD_RELOC_LO16, breg);
      return;

    case M_ULH_A:
    case M_ULHU_A:
    case M_ULW_A:
      load_address (&icnt, AT, &offset_expr);
      if (mask == M_ULW_A)
        {
          if (byte_order == LITTLE_ENDIAN)
            expr1.X_add_number = 3;
          else
            expr1.X_add_number = 0;
          macro_build ((char *) NULL, &icnt, &expr1, "lwl", "t,o(b)", treg,
                       (int) BFD_RELOC_LO16, AT);
          if (byte_order == LITTLE_ENDIAN)
            expr1.X_add_number = 0;
          else
            expr1.X_add_number = 3;
          macro_build ((char *) NULL, &icnt, &expr1, "lwr", "t,o(b)", treg,
                       (int) BFD_RELOC_LO16, AT);
        }
      else
        {
          if (byte_order == BIG_ENDIAN)
            expr1.X_add_number = 0;
          macro_build ((char *) NULL, &icnt, &expr1,
                       mask == M_ULH_A ? "lb" : "lbu", "t,o(b)", treg,
                       (int) BFD_RELOC_LO16, AT);
          if (byte_order == BIG_ENDIAN)
            expr1.X_add_number = 1;
          else
            expr1.X_add_number = 0;
          macro_build ((char *) NULL, &icnt, &expr1, "lbu", "t,o(b)", AT,
                       (int) BFD_RELOC_LO16, AT);
          macro_build ((char *) NULL, &icnt, NULL, "sll", "d,w,<", treg,
                       treg, 8);
          macro_build ((char *) NULL, &icnt, NULL, "or", "d,v,t", treg,
                       treg, AT);
        }
      break;

    case M_USH:
      if (offset_expr.X_add_number >= 0x7fff)
        as_bad ("operand overflow");
      if (byte_order == BIG_ENDIAN)
        offset_expr.X_add_number += 1;
      macro_build ((char *) NULL, &icnt, &offset_expr, "sb", "t,o(b)", treg,
                   (int) BFD_RELOC_LO16, breg);
      macro_build ((char *) NULL, &icnt, NULL, "srl", "d,w,<", AT, treg, 8);
      if (byte_order == BIG_ENDIAN)
        offset_expr.X_add_number -= 1;
      else
        offset_expr.X_add_number += 1;
      macro_build ((char *) NULL, &icnt, &offset_expr, "sb", "t,o(b)", AT,
                   (int) BFD_RELOC_LO16, breg);
      break;

    case M_USW:
      if (offset_expr.X_add_number >= 0x7ffd)
        as_bad ("operand overflow");
      if (byte_order == LITTLE_ENDIAN)
        offset_expr.X_add_number += 3;
      macro_build ((char *) NULL, &icnt, &offset_expr, "swl", "t,o(b)", treg,
                   (int) BFD_RELOC_LO16, breg);
      if (byte_order == LITTLE_ENDIAN)
        offset_expr.X_add_number -= 3;
      else
        offset_expr.X_add_number += 3;
      macro_build ((char *) NULL, &icnt, &offset_expr, "swr", "t,o(b)", treg,
                   (int) BFD_RELOC_LO16, breg);
      return;

    case M_USH_A:
    case M_USW_A:
      load_address (&icnt, AT, &offset_expr);
      if (mask == M_USW_A)
        {
          if (byte_order == LITTLE_ENDIAN)
            expr1.X_add_number = 3;
          else
            expr1.X_add_number = 0;
          macro_build ((char *) NULL, &icnt, &expr1, "swl", "t,o(b)", treg,
                       (int) BFD_RELOC_LO16, AT);
          if (byte_order == LITTLE_ENDIAN)
            expr1.X_add_number = 0;
          else
            expr1.X_add_number = 3;
          macro_build ((char *) NULL, &icnt, &expr1, "swr", "t,o(b)", treg,
                       (int) BFD_RELOC_LO16, AT);
        }
      else
        {
          if (byte_order == LITTLE_ENDIAN)
            expr1.X_add_number = 0;
          macro_build ((char *) NULL, &icnt, &expr1, "sb", "t,o(b)", treg,
                       (int) BFD_RELOC_LO16, AT);
          macro_build ((char *) NULL, &icnt, NULL, "srl", "d,w,<", treg,
                       treg, 8);
          if (byte_order == LITTLE_ENDIAN)
            expr1.X_add_number = 1;
          else
            expr1.X_add_number = 0;
          macro_build ((char *) NULL, &icnt, &expr1, "sb", "t,o(b)", treg,
                       (int) BFD_RELOC_LO16, AT);
          if (byte_order == LITTLE_ENDIAN)
            expr1.X_add_number = 0;
          else
            expr1.X_add_number = 1;
          macro_build ((char *) NULL, &icnt, &expr1, "lbu", "t,o(b)", AT,
                       (int) BFD_RELOC_LO16, AT);
          macro_build ((char *) NULL, &icnt, NULL, "sll", "d,w,<", treg,
                       treg, 8);
          macro_build ((char *) NULL, &icnt, NULL, "or", "d,v,t", treg,
                       treg, AT);
        }
      break;

    default:
      as_bad ("Macro %s not implemented yet", ip->insn_mo->name);
      break;
    }
  if (mips_noat)
    as_warn ("Macro used $at after \".set noat\"");
}


/*
This routine assembles an instruction into its binary format.  As a side
effect it sets one of the global variables imm_reloc or offset_reloc to the
type of relocation to do if one of the operands is an address expression.
*/
static void
mips_ip (str, ip)
     char *str;
     struct mips_cl_insn *ip;
{
  char *s;
  const char *args;
  char c;
  struct mips_opcode *insn;
  char *argsStart;
  unsigned int regno;
  unsigned int lastregno = 0;
  char *s_reset;

  insn_error = NULL;

  for (s = str; islower (*s) || (*s >= '0' && *s <= '3') || *s == '.'; ++s)
    continue;
  switch (*s)
    {
    case '\0':
      break;

    case ' ':
      *s++ = '\0';
      break;

    default:
      as_warn ("Unknown opcode: `%s'", str);
      exit (1);
    }
  if ((insn = (struct mips_opcode *) hash_find (op_hash, str)) == NULL)
    {
      as_warn ("`%s' not in hash table.", str);
      insn_error = "ERROR: Unrecognized opcode";
      return;
    }
  argsStart = s;
  for (;;)
    {
      int insn_isa;

      assert (strcmp (insn->name, str) == 0);

      if (insn->pinfo == INSN_MACRO)
        insn_isa = insn->match;
      else if (insn->pinfo & INSN_ISA2)
        insn_isa = 2;
      else if (insn->pinfo & INSN_ISA3)
        insn_isa = 3;
      else
        insn_isa = 1;

      if (insn_isa > mips_isa)
        {
          if (insn + 1 < &mips_opcodes[NUMOPCODES]
              && strcmp (insn->name, insn[1].name) == 0)
            {
              ++insn;
              continue;
            }
          as_warn ("Instruction not supported on this processor");
        }

      ip->insn_mo = insn;
      ip->insn_opcode = insn->match;
      for (args = insn->args;; ++args)
        {
          if (*s == ' ')
            ++s;
          switch (*args)
            {
            case '\0':          /* end of args */
              if (*s == '\0')
                return;
              break;

            case ',':
              if (*s++ == *args)
                continue;
              s--;
              switch (*++args)
                {
                case 'r':
                case 'v':
                  ip->insn_opcode |= lastregno << 21;
                  continue;

                case 'w':
                case 'W':
                  ip->insn_opcode |= lastregno << 16;
                  continue;

                case 'V':
                  ip->insn_opcode |= lastregno << 11;
                  continue;
                }
              break;

            case '(':
              /* handle optional base register.
                 Either the base register is omitted or
                 we must have a left paren. */
              /* this is dependent on the next operand specifier
                 is a 'b' for base register */
              assert (args[1] == 'b');
              if (*s == '\0')
                return;

            case ')':           /* these must match exactly */
              if (*s++ == *args)
                continue;
              break;

            case '<':           /* must be at least one digit */
              /*
               * According to the manual, if the shift amount is greater
               * than 31 or less than 0 the the shift amount should be
               * mod 32. In reality the mips assembler issues an error.
               * We issue a warning and mask out all but the low 5 bits.
               */
              my_getExpression (&imm_expr, s);
              check_absolute_expr (ip, &imm_expr);
              if ((unsigned long) imm_expr.X_add_number > 31)
                {
                  as_warn ("Improper shift amount (%ld)",
                           (long) imm_expr.X_add_number);
                  imm_expr.X_add_number = imm_expr.X_add_number & 0x1f;
                }
              ip->insn_opcode |= imm_expr.X_add_number << 6;
              imm_expr.X_op = O_absent;
              s = expr_end;
              continue;

            case '>':           /* shift amount minus 32 */
              my_getExpression (&imm_expr, s);
              check_absolute_expr (ip, &imm_expr);
              if ((unsigned long) imm_expr.X_add_number < 32
                  || (unsigned long) imm_expr.X_add_number > 63)
                break;
              ip->insn_opcode |= (imm_expr.X_add_number - 32) << 6;
              imm_expr.X_op = O_absent;
              s = expr_end;
              continue;

            case 'k':           /* cache code */
              my_getExpression (&imm_expr, s);
              check_absolute_expr (ip, &imm_expr);
              if ((unsigned long) imm_expr.X_add_number > 31)
                {
                  as_warn ("Invalid cahce opcode (%lu)",
                           (unsigned long) imm_expr.X_add_number);
                  imm_expr.X_add_number &= 0x1f;
                }
              ip->insn_opcode |= imm_expr.X_add_number << OP_SH_CACHE;
              imm_expr.X_op = O_absent;
              s = expr_end;
              continue;

            case 'c':           /* break code */
              my_getExpression (&imm_expr, s);
              check_absolute_expr (ip, &imm_expr);
              if ((unsigned) imm_expr.X_add_number > 1023)
                as_warn ("Illegal break code (%ld)",
                         (long) imm_expr.X_add_number);
              ip->insn_opcode |= imm_expr.X_add_number << 16;
              imm_expr.X_op = O_absent;
              s = expr_end;
              continue;

            case 'B':           /* syscall code */
              my_getExpression (&imm_expr, s);
              check_absolute_expr (ip, &imm_expr);
              if ((unsigned) imm_expr.X_add_number > 0xfffff)
                as_warn ("Illegal syscall code (%ld)",
                         (long) imm_expr.X_add_number);
              ip->insn_opcode |= imm_expr.X_add_number << 6;
              imm_expr.X_op = O_absent;
              s = expr_end;
              continue;

            case 'C':           /* Coprocessor code */
              my_getExpression (&imm_expr, s);
              check_absolute_expr (ip, &imm_expr);
              if ((unsigned long) imm_expr.X_add_number >= (1<<25))
                {
                  as_warn ("Coproccesor code > 25 bits (%ld)",
                           (long) imm_expr.X_add_number);
                  imm_expr.X_add_number &= ((1<<25) - 1);
                }
              ip->insn_opcode |= imm_expr.X_add_number;
              imm_expr.X_op = O_absent;
              s = expr_end;
              continue;

            case 'b':           /* base register */
            case 'd':           /* destination register */
            case 's':           /* source register */
            case 't':           /* target register */
            case 'r':           /* both target and source */
            case 'v':           /* both dest and source */
            case 'w':           /* both dest and target */
            case 'E':           /* coprocessor target register */
            case 'G':           /* coprocessor destination register */
            case 'x':           /* ignore register name */
            case 'z':           /* must be zero register */
              s_reset = s;
              if (s[0] == '$')
                {
                  if (isdigit (s[1]))
                    {
                      ++s;
                      regno = 0;
                      do
                        {
                          regno *= 10;
                          regno += *s - '0';
                          ++s;
                        }
                      while (isdigit (*s));
                      if (regno > 31)
                        as_bad ("Invalid register number (%d)", regno);
                    }
                  else if (*args == 'E' || *args == 'G')
                    goto notreg;
                  else
                    {
                      if (s[1] == 'f' && s[2] == 'p')
                        {
                          s += 3;
                          regno = FP;
                        }
                      else if (s[1] == 's' && s[2] == 'p')
                        {
                          s += 3;
                          regno = SP;
                        }
                      else if (s[1] == 'g' && s[2] == 'p')
                        {
                          s += 3;
                          regno = GP;
                        }
                      else if (s[1] == 'a' && s[2] == 't')
                        {
                          s += 3;
                          regno = AT;
                        }
                      else
                        goto notreg;
                    }
                  if (regno == AT && ! mips_noat)
                    as_warn ("Used $at without \".set noat\"");
                  c = *args;
                  if (*s == ' ')
                    s++;
                  if (args[1] != *s)
                    {
                      if (c == 'r' || c == 'v' || c == 'w')
                        {
                          regno = lastregno;
                          s = s_reset;
                          args++;
                        }
                    }
                  /* 'z' only matches $0.  */
                  if (c == 'z' && regno != 0)
                    break;
                  switch (c)
                    {
                    case 'r':
                    case 's':
                    case 'v':
                    case 'b':
                      ip->insn_opcode |= regno << 21;
                      break;
                    case 'd':
                    case 'G':
                      ip->insn_opcode |= regno << 11;
                      break;
                    case 'w':
                    case 't':
                    case 'E':
                      ip->insn_opcode |= regno << 16;
                      break;
                    case 'x':
                      /* This case exists because on the r3000 trunc
                         expands into a macro which requires a gp
                         register.  On the r6000 or r4000 it is
                         assembled into a single instruction which
                         ignores the register.  Thus the insn version
                         is MIPS_ISA2 and uses 'x', and the macro
                         version is MIPS_ISA1 and uses 't'.  */
                      break;
                    case 'z':
                      /* This case is for the div instruction, which
                         acts differently if the destination argument
                         is $0.  This only matches $0, and is checked
                         outside the switch.  */
                      break;
                    }
                  lastregno = regno;
                  continue;
                }
            notreg:
              switch (*args++)
                {
                case 'r':
                case 'v':
                  ip->insn_opcode |= lastregno << 21;
                  continue;
                case 'w':
                  ip->insn_opcode |= lastregno << 16;
                  continue;
                }
              break;

            case 'D':           /* floating point destination register */
            case 'S':           /* floating point source register */
            case 'T':           /* floating point target register */
            case 'V':
            case 'W':
              s_reset = s;
              if (s[0] == '$' && s[1] == 'f' && isdigit (s[2]))
                {
                  s += 2;
                  regno = 0;
                  do
                    {
                      regno *= 10;
                      regno += *s - '0';
                      ++s;
                    }
                  while (isdigit (*s));

                  if (regno > 31)
                    as_bad ("Invalid float register number (%d)", regno);

                  if ((regno & 1) != 0
                      && mips_isa < 3
                      && ! (strcmp (str, "mtc1") == 0 ||
                            strcmp (str, "mfc1") == 0 ||
                            strcmp (str, "lwc1") == 0 ||
                            strcmp (str, "swc1") == 0))
                    as_warn ("Float register should be even, was %d",
                             regno);

                  c = *args;
                  if (*s == ' ')
                    s++;
                  if (args[1] != *s)
                    {
                      if (c == 'V' || c == 'W')
                        {
                          regno = lastregno;
                          s = s_reset;
                          args++;
                        }
                    }
                  switch (c)
                    {
                    case 'D':
                      ip->insn_opcode |= regno << 6;
                      break;
                    case 'V':
                    case 'S':
                      ip->insn_opcode |= regno << 11;
                      break;
                    case 'W':
                    case 'T':
                      ip->insn_opcode |= regno << 16;
                    }
                  lastregno = regno;
                  continue;
                }
              switch (*args++)
                {
                case 'V':
                  ip->insn_opcode |= lastregno << 11;
                  continue;
                case 'W':
                  ip->insn_opcode |= lastregno << 16;
                  continue;
                }
              break;

            case 'I':
              my_getExpression (&imm_expr, s);
              check_absolute_expr (ip, &imm_expr);
              s = expr_end;
              continue;

            case 'A':
              my_getExpression (&offset_expr, s);
              imm_reloc = BFD_RELOC_32;
              s = expr_end;
              continue;

            case 'F':
            case 'L':
            case 'f':
            case 'l':
              {
                int f64;
                char *save_in;
                char *err;
                unsigned char temp[8];
                int len;
                unsigned int length;
                segT seg;
                subsegT subseg;
                char *p;

                /* These only appear as the last operand in an
                   instruction, and every instruction that accepts
                   them in any variant accepts them in all variants.
                   This means we don't have to worry about backing out
                   any changes if the instruction does not match.

                   The difference between them is the size of the
                   floating point constant and where it goes.  For 'F'
                   and 'L' the constant is 64 bits; for 'f' and 'l' it
                   is 32 bits.  Where the constant is placed is based
                   on how the MIPS assembler does things:
                    F -- .rdata
                    L -- .lit8
                    f -- immediate value
                    l -- .lit4

                    When generating SVR4 PIC code, we do not use the
                    .lit8 or .lit4 sections at all, in order to
                    reserve the entire global offset table.  When
                    generating embedded PIC code, we use the .lit8
                    section but not the .lit4 section (we can do .lit4
                    inline easily; we need to put .lit8 somewhere in
                    the data segment, and using .lit8 permits the
                    linker to eventually combine identical .lit8
                    entries).  */

                f64 = *args == 'F' || *args == 'L';

                save_in = input_line_pointer;
                input_line_pointer = s;
                err = md_atof (f64 ? 'd' : 'f', (char *) temp, &len);
                length = len;
                s = input_line_pointer;
                input_line_pointer = save_in;
                if (err != NULL && *err != '\0')
                  {
                    as_bad ("Bad floating point constant: %s", err);
                    memset (temp, '\0', sizeof temp);
                    length = f64 ? 8 : 4;
                  }

                assert (length == (f64 ? 8 : 4));

                if (*args == 'f'
                    || (mips_pic != NO_PIC && *args == 'l'))
                  {
                    imm_expr.X_op = O_constant;
                    if (byte_order == LITTLE_ENDIAN)
                      imm_expr.X_add_number =
                        (((((((int) temp[3] << 8)
                             | temp[2]) << 8)
                           | temp[1]) << 8)
                         | temp[0]);
                    else
                      imm_expr.X_add_number =
                        (((((((int) temp[0] << 8)
                             | temp[1]) << 8)
                           | temp[2]) << 8)
                         | temp[3]);
                  }
                else
                  {
                    const char *newname;
                    segT new_seg;

                    /* Switch to the right section.  */
                    seg = now_seg;
                    subseg = now_subseg;
                    switch (*args)
                      {
                      default: /* unused default case avoids warnings.  */
                      case 'L':
                        newname = (mips_pic != SVR4_PIC ? ".lit8" : ".rdata");
                        break;
                      case 'F':
                        newname = ".rdata";
                        break;
                      case 'l':
                        assert (mips_pic == NO_PIC);
                        newname = ".lit4";
                        break;
                      }
                    new_seg = subseg_new (newname, (subsegT) 0);
                    frag_align (*args == 'l' ? 2 : 3, 0);
#ifdef OBJ_ELF
                    record_alignment (new_seg, 4);
#else
                    record_alignment (new_seg, *args == 'l' ? 2 : 3);
#endif
                    if (seg == now_seg)
                      as_bad ("Can't use floating point insn in this section");

                    /* Set the argument to the current address in the
                       section.  */
                    offset_expr.X_op = O_symbol;
                    offset_expr.X_add_symbol =
                      symbol_new ("L0\001", now_seg,
                                  (valueT) frag_now_fix (), frag_now);
                    offset_expr.X_add_number = 0;

                    /* Put the floating point number into the section.  */
                    p = frag_more ((int) length);
                    memcpy (p, temp, length);

                    /* Switch back to the original section.  */
                    subseg_set (seg, subseg);
                  }
              }
              continue;

            case 'i':           /* 16 bit unsigned immediate */
            case 'j':           /* 16 bit signed immediate */
              imm_reloc = BFD_RELOC_LO16;
              c = my_getSmallExpression (&imm_expr, s);
              if (c)
                {
                  if (c != 'l')
                    {
                      if (imm_expr.X_op == O_constant)
                        imm_expr.X_add_number =
                          (imm_expr.X_add_number >> 16) & 0xffff;
                      else if (c == 'h')
                        imm_reloc = BFD_RELOC_HI16_S;
                      else
                        imm_reloc = BFD_RELOC_HI16;
                    }
                }
              else
                check_absolute_expr (ip, &imm_expr);
              if (*args == 'i')
                {
                  if (imm_expr.X_add_number < 0
                      || imm_expr.X_add_number >= 0x10000)
                    {
                      if (insn + 1 < &mips_opcodes[NUMOPCODES] &&
                          !strcmp (insn->name, insn[1].name))
                        break;
                      as_bad ("16 bit expression not in range 0..65535");
                    }
                }
              else
                {
                  int more;
                  offsetT max;

                  /* The upper bound should be 0x8000, but
                     unfortunately the MIPS assembler accepts numbers
                     from 0x8000 to 0xffff and sign extends them, and
                     we want to be compatible.  We only permit this
                     extended range for an instruction which does not
                     provide any further alternates, since those
                     alternates may handle other cases.  People should
                     use the numbers they mean, rather than relying on
                     a mysterious sign extension.  */
                  more = (insn + 1 < &mips_opcodes[NUMOPCODES] &&
                          strcmp (insn->name, insn[1].name) == 0);
                  if (more)
                    max = 0x8000;
                  else
                    max = 0x10000;
                  if (imm_expr.X_add_number < -0x8000 ||
                      imm_expr.X_add_number >= max)
                    {
                      if (more)
                        break;
                      as_bad ("16 bit expression not in range -32768..32767");
                    }
                }
              s = expr_end;
              continue;

            case 'o':           /* 16 bit offset */
              c = my_getSmallExpression (&offset_expr, s);

              /* If this value won't fit into a 16 bit offset, then go
                 find a macro that will generate the 32 bit offset
                 code pattern.  As a special hack, we accept the
                 difference of two local symbols as a constant.  This
                 is required to suppose embedded PIC switches, which
                 use an instruction which looks like
                     lw $4,$L12-$LS12($4)
                 The problem with handling this in a more general
                 fashion is that the macro function doesn't expect to
                 see anything which can be handled in a single
                 constant instruction.  */
              if ((offset_expr.X_op != O_constant
                   || offset_expr.X_add_number >= 0x8000
                   || offset_expr.X_add_number < -0x8000)
                  && (mips_pic != EMBEDDED_PIC
                      || offset_expr.X_op != O_subtract
                      || ! S_IS_LOCAL (offset_expr.X_add_symbol)
                      || ! S_IS_LOCAL (offset_expr.X_op_symbol)))
                break;

              offset_reloc = BFD_RELOC_LO16;
              if (c == 'h' || c == 'H')
                {
                  assert (offset_expr.X_op == O_constant);
                  offset_expr.X_add_number =
                    (offset_expr.X_add_number >> 16) & 0xffff;
                }
              s = expr_end;
              continue;

            case 'p':           /* pc relative offset */
              offset_reloc = BFD_RELOC_16_PCREL_S2;
              my_getExpression (&offset_expr, s);
              s = expr_end;
              continue;

            case 'u':           /* upper 16 bits */
              c = my_getSmallExpression (&imm_expr, s);
              if (imm_expr.X_op != O_constant
                  || imm_expr.X_add_number < 0
                  || imm_expr.X_add_number >= 0x10000)
                as_bad ("lui expression not in range 0..65535");
              imm_reloc = BFD_RELOC_LO16;
              if (c)
                {
                  if (c != 'l')
                    {
                      if (imm_expr.X_op == O_constant)
                        imm_expr.X_add_number =
                          (imm_expr.X_add_number >> 16) & 0xffff;
                      else if (c == 'h')
                        imm_reloc = BFD_RELOC_HI16_S;
                      else
                        imm_reloc = BFD_RELOC_HI16;
                    }
                }
              s = expr_end;
              continue;

            case 'a':           /* 26 bit address */
              my_getExpression (&offset_expr, s);
              s = expr_end;
              offset_reloc = BFD_RELOC_MIPS_JMP;
              continue;

            default:
              fprintf (stderr, "bad char = '%c'\n", *args);
              internalError ();
            }
          break;
        }
      /* Args don't match.  */
      if (insn + 1 < &mips_opcodes[NUMOPCODES] &&
          !strcmp (insn->name, insn[1].name))
        {
          ++insn;
          s = argsStart;
          continue;
        }
      insn_error = "ERROR: Illegal operands";
      return;
    }
}

#define LP '('
#define RP ')'

static int
my_getSmallExpression (ep, str)
     expressionS *ep;
     char *str;
{
  char *sp;
  int c = 0;

  if (*str == ' ')
    str++;
  if (*str == LP
      || (*str == '%' &&
          ((str[1] == 'h' && str[2] == 'i')
           || (str[1] == 'H' && str[2] == 'I')
           || (str[1] == 'l' && str[2] == 'o'))
          && str[3] == LP))
    {
      if (*str == LP)
        c = 0;
      else
        {
          c = str[1];
          str += 3;
        }

      /*
       * A small expression may be followed by a base register.
       * Scan to the end of this operand, and then back over a possible
       * base register.  Then scan the small expression up to that
       * point.  (Based on code in sparc.c...)
       */
      for (sp = str; *sp && *sp != ','; sp++)
        ;
      if (sp - 4 >= str && sp[-1] == RP)
        {
          if (isdigit (sp[-2]))
            {
              for (sp -= 3; sp >= str && isdigit (*sp); sp--)
                ;
              if (*sp == '$' && sp > str && sp[-1] == LP)
                {
                  sp--;
                  goto do_it;
                }
            }
          else if (sp - 5 >= str
                   && sp[-5] == LP
                   && sp[-4] == '$'
                   && ((sp[-3] == 'f' && sp[-2] == 'p')
                       || (sp[-3] == 's' && sp[-2] == 'p')
                       || (sp[-3] == 'g' && sp[-2] == 'p')
                       || (sp[-3] == 'a' && sp[-2] == 't')))
            {
              sp -= 5;
            do_it:
              if (sp == str)
                {
                  /* no expression means zero offset */
                  if (c)
                    {
                      /* %xx(reg) is an error */
                      ep->X_op = O_absent;
                      expr_end = str - 3;
                    }
                  else
                    {
                      ep->X_op = O_constant;
                      expr_end = sp;
                    }
                  ep->X_add_symbol = NULL;
                  ep->X_op_symbol = NULL;
                  ep->X_add_number = 0;
                }
              else
                {
                  *sp = '\0';
                  my_getExpression (ep, str);
                  *sp = LP;
                }
              return c;
            }
        }
    }
  my_getExpression (ep, str);
  return c;                     /* => %hi or %lo encountered */
}

static void
my_getExpression (ep, str)
     expressionS *ep;
     char *str;
{
  char *save_in;

  save_in = input_line_pointer;
  input_line_pointer = str;
  expression (ep);
  expr_end = input_line_pointer;
  input_line_pointer = save_in;
}

/* Turn a string in input_line_pointer into a floating point constant
   of type type, and store the appropriate bytes in *litP.  The number
   of LITTLENUMS emitted is stored in *sizeP .  An error message is
   returned, or NULL on OK.  */

char *
md_atof (type, litP, sizeP)
     int type;
     char *litP;
     int *sizeP;
{
  int prec;
  LITTLENUM_TYPE words[4];
  char *t;
  int i;

  switch (type)
    {
    case 'f':
      prec = 2;
      break;

    case 'd':
      prec = 4;
      break;

    default:
      *sizeP = 0;
      return "bad call to md_atof";
    }

  t = atof_ieee (input_line_pointer, type, words);
  if (t)
    input_line_pointer = t;

  *sizeP = prec * 2;

  if (byte_order == LITTLE_ENDIAN)
    {
      for (i = prec - 1; i >= 0; i--)
        {
          md_number_to_chars (litP, (valueT) words[i], 2);
          litP += 2;
        }
    }
  else
    {
      for (i = 0; i < prec; i++)
        {
          md_number_to_chars (litP, (valueT) words[i], 2);
          litP += 2;
        }
    }
     
  return NULL;
}

void
md_number_to_chars (buf, val, n)
     char *buf;
     valueT val;
     int n;
{
  switch (byte_order)
    {
    case LITTLE_ENDIAN:
      number_to_chars_littleendian (buf, val, n);
      break;

    case BIG_ENDIAN:
      number_to_chars_bigendian (buf, val, n);
      break;

    default:
      internalError ();
    }
}
\f
#ifdef GPOPT
CONST char *md_shortopts = "E:O::g::G:";
#else
CONST char *md_shortopts = "E:O::g::";
#endif
struct option md_longopts[] = {
#define OPTION_MIPS1 (OPTION_MD_BASE + 1)
  {"mips0", no_argument, NULL, OPTION_MIPS1},
  {"mips1", no_argument, NULL, OPTION_MIPS1},
#define OPTION_MIPS2 (OPTION_MD_BASE + 2)
  {"mips2", no_argument, NULL, OPTION_MIPS2},
#define OPTION_MIPS3 (OPTION_MD_BASE + 3)
  {"mips3", no_argument, NULL, OPTION_MIPS3},
#define OPTION_MCPU (OPTION_MD_BASE + 4)
  {"mcpu", required_argument, NULL, OPTION_MCPU},
#define OPTION_MEMBEDDED_PIC (OPTION_MD_BASE + 5)
  {"membedded-pic", no_argument, NULL, OPTION_MEMBEDDED_PIC},
#define OPTION_TRAP (OPTION_MD_BASE + 8)
  {"trap", no_argument, NULL, OPTION_TRAP},
  {"no-break", no_argument, NULL, OPTION_TRAP},
#define OPTION_BREAK (OPTION_MD_BASE + 9)
  {"break", no_argument, NULL, OPTION_BREAK},
  {"no-trap", no_argument, NULL, OPTION_BREAK},

#ifdef OBJ_ELF
#define OPTION_CALL_SHARED (OPTION_MD_BASE + 6)
  {"KPIC", no_argument, NULL, OPTION_CALL_SHARED},
  {"call_shared", no_argument, NULL, OPTION_CALL_SHARED},
#define OPTION_NON_SHARED (OPTION_MD_BASE + 7)
  {"non_shared", no_argument, NULL, OPTION_NON_SHARED},
#endif

  {NULL, no_argument, NULL, 0}
};
size_t md_longopts_size = sizeof(md_longopts);

int
md_parse_option (c, arg)
     int c;
     char *arg;
{
  switch (c)
    {
    case OPTION_TRAP:
      mips_trap = 1;
      break;

    case OPTION_BREAK:
      mips_trap = 0;
      break;

    case 'E':
      if (arg[1] == 'B')
        byte_order = BIG_ENDIAN;
      else if (arg[1] == 'L')
        byte_order = LITTLE_ENDIAN;
      else
        {
          as_bad("invalid endianness -E%c", arg[1]);
          return 0;
        }

#ifdef OBJ_AOUT
      if (arg[1] == 'B')
        mips_target_format = "a.out-mips-big";
      else
        mips_target_format = "a.out-mips-little";
#endif
#ifdef OBJ_ECOFF
      if (arg[1] == 'B')
        mips_target_format = "ecoff-bigmips";
      else
        mips_target_format = "ecoff-littlemips";
#endif
#ifdef OBJ_ELF
      if (arg[1] == 'B')
        mips_target_format = "elf32-bigmips";
      else
        mips_target_format = "elf32-littlemips";
#endif

      /* FIXME: This breaks -L -EL.  */
      flag_keep_locals = 0;
      break;

    case 'O':
      if (arg && arg[1] == '0')
        mips_optimize = 1;
      else
        mips_optimize = 2;
      break;

    case 'g':
      if (arg == NULL || arg[1] == '2')
        mips_optimize = 0;
      break;

    case OPTION_MIPS1:
      mips_isa = 1;
      break;

    case OPTION_MIPS2:
      mips_isa = 2;
      break;

    case OPTION_MIPS3:
      mips_isa = 3;
      break;

    case OPTION_MCPU:
      {
        char *p;

        /* Identify the processor type */
        p = arg;
        if (strcmp (p, "default") == 0
            || strcmp (p, "DEFAULT") == 0)
          mips_isa = -1;
        else
          {
            if (*p == 'r' || *p == 'R')
              p++;

            mips_isa = -1;
            switch (*p)
              {
              case '2':
                if (strcmp (p, "2000") == 0
                    || strcmp (p, "2k") == 0
                    || strcmp (p, "2K") == 0)
                  mips_isa = 1;
                break;

              case '3':
                if (strcmp (p, "3000") == 0
                    || strcmp (p, "3k") == 0
                    || strcmp (p, "3K") == 0)
                  mips_isa = 1;
                break;

              case '4':
                if (strcmp (p, "4000") == 0
                    || strcmp (p, "4k") == 0
                    || strcmp (p, "4K") == 0)
                  mips_isa = 3;
                break;

              case '6':
                if (strcmp (p, "6000") == 0
                    || strcmp (p, "6k") == 0
                    || strcmp (p, "6K") == 0)
                  mips_isa = 2;
                break;
              }

            if (mips_isa == -1)
              {
                as_bad ("invalid architecture -mcpu=%s", arg);
                return 0;
              }
          }
      }
      break;

    case OPTION_MEMBEDDED_PIC:
      mips_pic = EMBEDDED_PIC;
#ifdef GPOPT
      if (g_switch_seen)
        {
          as_bad ("-G may not be used with embedded PIC code");
          return 0;
        }
      g_switch_value = 0x7fffffff;
#endif
      break;

#ifdef OBJ_ELF
  /* When generating ELF code, we permit -KPIC and -call_shared to
     select SVR4_PIC, and -non_shared to select no PIC.  This is
     intended to be compatible with Irix 5.  */
    case OPTION_CALL_SHARED:
      mips_pic = SVR4_PIC;
      if (g_switch_seen && g_switch_value != 0)
        {
          as_bad ("-G may not be used with SVR4 PIC code");
          return 0;
        }
      g_switch_value = 0;
      break;

    case OPTION_NON_SHARED:
      mips_pic = NO_PIC;
      break;
#endif /* OBJ_ELF */

#ifdef GPOPT
    case 'G':
      if (mips_pic == SVR4_PIC || mips_pic == EMBEDDED_PIC)
        {
          as_bad ("-G may not be used with SVR4 or embedded PIC code");
          return 0;
        }
      else
        g_switch_value = atoi (arg);
      g_switch_seen = 1;
      break;
#endif

    default:
      return 0;
    }

  return 1;
}

void
md_show_usage (stream)
     FILE *stream;
{
  fprintf(stream, "\
MIPS options:\n\
-membedded-pic          generate embedded position independent code\n\
-nocpp                  ignored\n\
-EB                     generate big endian output\n\
-EL                     generate little endian output\n\
-g, -g2                 do not remove uneeded NOPs or swap branches\n\
-G NUM                  allow referencing objects up to NUM bytes\n\
                        implicitly with the gp register [default 8]\n\
-mips1, -mcpu=r{2,3}000 generate code for r2000 and r3000\n\
-mips2, -mcpu=r6000     generate code for r6000\n\
-mips3, -mcpu=r4000     generate code for r4000\n\
-O0                     remove unneeded NOPs, do not swap branches\n\
-O                      remove unneeded NOPs and swap branches\n\
--trap, --no-break      trap exception on div by 0 and mult overflow\n\
--break, --no-trap      break exception on div by 0 and mult overflow\n");
#ifdef OBJ_ELF
  fprintf(stream, "\
-KPIC, -call_shared     generate SVR4 position independent code\n\
-non_shared             do not generate position independent code\n");
#endif
}
\f
long
md_pcrel_from (fixP)
     fixS *fixP;
{
#ifndef OBJ_AOUT
  if (fixP->fx_addsy != (symbolS *) NULL
      && ! S_IS_DEFINED (fixP->fx_addsy))
    {
      /* This makes a branch to an undefined symbol be a branch to the
         current location.  */
      return 4;
    }
#endif

  /* return the address of the delay slot */
  return fixP->fx_size + fixP->fx_where + fixP->fx_frag->fr_address;
}

/* This is called by emit_expr via TC_CONS_FIX_NEW when creating a
   reloc for a cons.  We could use the definition there, except that
   we want to handle 64 bit relocs specially.  */

void
cons_fix_new_mips (frag, where, nbytes, exp)
     fragS *frag;
     int where;
     unsigned int nbytes;
     expressionS *exp;
{
  /* If we are assembling in 32 bit mode, turn an 8 byte reloc into a
     4 byte reloc.  
     FIXME: There is no way to select anything but 32 bit mode right
     now.  */
  if (nbytes == 8)
    {
      if (byte_order == BIG_ENDIAN)
        where += 4;
      nbytes = 4;
    }

  if (nbytes != 2 && nbytes != 4)
    as_bad ("Unsupported reloc size %d", nbytes);

  fix_new_exp (frag_now, where, (int) nbytes, exp, 0,
               nbytes == 2 ? BFD_RELOC_16 : BFD_RELOC_32);
}

/* When generating embedded PIC code we need to use a special
   relocation to represent the difference of two symbols in the .text
   section (switch tables use a difference of this sort).  See
   include/coff/mips.h for details.  This macro checks whether this
   fixup requires the special reloc.  */
#define SWITCH_TABLE(fixp) \
  ((fixp)->fx_r_type == BFD_RELOC_32 \
   && (fixp)->fx_addsy != NULL \
   && (fixp)->fx_subsy != NULL \
   && S_GET_SEGMENT ((fixp)->fx_addsy) == text_section \
   && S_GET_SEGMENT ((fixp)->fx_subsy) == text_section)

/* When generating embedded PIC code we must keep all PC relative
   relocations, in case the linker has to relax a call.  We also need
   to keep relocations for switch table entries.  */

/*ARGSUSED*/
int
mips_force_relocation (fixp)
     fixS *fixp;
{
  return (mips_pic == EMBEDDED_PIC
          && (fixp->fx_pcrel
              || SWITCH_TABLE (fixp)
              || fixp->fx_r_type == BFD_RELOC_PCREL_HI16_S
              || fixp->fx_r_type == BFD_RELOC_PCREL_LO16));
}

/* Apply a fixup to the object file.  */

int
md_apply_fix (fixP, valueP)
     fixS *fixP;
     valueT *valueP;
{
  unsigned char *buf;
  long insn, value;

  assert (fixP->fx_size == 4);

  value = *valueP;
  fixP->fx_addnumber = value;   /* Remember value for tc_gen_reloc */

  if (fixP->fx_addsy == NULL && ! fixP->fx_pcrel)
    fixP->fx_done = 1;

  switch (fixP->fx_r_type)
    {
    case BFD_RELOC_MIPS_JMP:
    case BFD_RELOC_HI16:
    case BFD_RELOC_HI16_S:
    case BFD_RELOC_MIPS_GPREL:
    case BFD_RELOC_MIPS_LITERAL:
    case BFD_RELOC_MIPS_CALL16:
    case BFD_RELOC_MIPS_GOT16:
    case BFD_RELOC_MIPS_GPREL32:
      if (fixP->fx_pcrel)
        as_bad ("Invalid PC relative reloc");
      /* Nothing needed to do. The value comes from the reloc entry */
      break;

    case BFD_RELOC_PCREL_HI16_S:
      /* The addend for this is tricky if it is internal, so we just
         do everything here rather than in bfd_perform_relocation.  */
      if ((fixP->fx_addsy->bsym->flags & BSF_SECTION_SYM) == 0)
        {
          /* For an external symbol adjust by the address to make it
             pcrel_offset.  We use the address of the RELLO reloc
             which follows this one.  */
          value += (fixP->fx_next->fx_frag->fr_address
                    + fixP->fx_next->fx_where);
        }
      if (value & 0x8000)
        value += 0x10000;
      value >>= 16;
      buf = (unsigned char *) fixP->fx_frag->fr_literal + fixP->fx_where;
      if (byte_order == BIG_ENDIAN)
        buf += 2;
      md_number_to_chars (buf, value, 2);
      break;

    case BFD_RELOC_PCREL_LO16:
      /* The addend for this is tricky if it is internal, so we just
         do everything here rather than in bfd_perform_relocation.  */
      if ((fixP->fx_addsy->bsym->flags & BSF_SECTION_SYM) == 0)
        value += fixP->fx_frag->fr_address + fixP->fx_where;
      buf = (unsigned char *) fixP->fx_frag->fr_literal + fixP->fx_where;
      if (byte_order == BIG_ENDIAN)
        buf += 2;
      md_number_to_chars (buf, value, 2);
      break;

    case BFD_RELOC_32:
      /* If we are deleting this reloc entry, we must fill in the
         value now.  This can happen if we have a .word which is not
         resolved when it appears but is later defined.  We also need
         to fill in the value if this is an embedded PIC switch table
         entry.  */
      if (fixP->fx_done
          || (mips_pic == EMBEDDED_PIC && SWITCH_TABLE (fixP)))
        md_number_to_chars (fixP->fx_frag->fr_literal + fixP->fx_where,
                            value, 4);
      break;

    case BFD_RELOC_LO16:
      /* When handling an embedded PIC switch statement, we can wind
         up deleting a LO16 reloc.  See the 'o' case in mips_ip.  */
      if (fixP->fx_done)
        {
          if (value < -0x8000 || value > 0x7fff)
            as_bad_where (fixP->fx_file, fixP->fx_line,
                          "relocation overflow");
          buf = (unsigned char *) fixP->fx_frag->fr_literal + fixP->fx_where;
          if (byte_order == BIG_ENDIAN)
            buf += 2;
          md_number_to_chars (buf, value, 2);
        }
      break;

    case BFD_RELOC_16_PCREL_S2:
      /*
       * We need to save the bits in the instruction since fixup_segment()
       * might be deleting the relocation entry (i.e., a branch within
       * the current segment).
       */
      if (value & 0x3)
        as_warn ("Branch to odd address (%lx)", value);
      value >>= 2;
      if ((value & ~0xFFFF) && (value & ~0xFFFF) != (-1 & ~0xFFFF))
        as_bad ("Relocation overflow");

      /* update old instruction data */
      buf = (unsigned char *) (fixP->fx_where + fixP->fx_frag->fr_literal);
      switch (byte_order)
        {
        case LITTLE_ENDIAN:
          insn = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
          break;

        case BIG_ENDIAN:
          insn = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
          break;

        default:
          internalError ();
          return 0;
        }
      insn |= value & 0xFFFF;
      md_number_to_chars ((char *) buf, (valueT) insn, 4);
      break;

    default:
      internalError ();
    }

  return 1;
}

#if 0
void
printInsn (oc)
     unsigned long oc;
{
  const struct mips_opcode *p;
  int treg, sreg, dreg, shamt;
  short imm;
  const char *args;
  int i;

  for (i = 0; i < NUMOPCODES; ++i)
    {
      p = &mips_opcodes[i];
      if (((oc & p->mask) == p->match) && (p->pinfo != INSN_MACRO))
        {
          printf ("%08lx %s\t", oc, p->name);
          treg = (oc >> 16) & 0x1f;
          sreg = (oc >> 21) & 0x1f;
          dreg = (oc >> 11) & 0x1f;
          shamt = (oc >> 6) & 0x1f;
          imm = oc;
          for (args = p->args;; ++args)
            {
              switch (*args)
                {
                case '\0':
                  printf ("\n");
                  break;

                case ',':
                case '(':
                case ')':
                  printf ("%c", *args);
                  continue;

                case 'r':
                  assert (treg == sreg);
                  printf ("$%d,$%d", treg, sreg);
                  continue;

                case 'd':
                case 'G':
                  printf ("$%d", dreg);
                  continue;

                case 't':
                case 'E':
                  printf ("$%d", treg);
                  continue;

                case 'k':
                  printf ("0x%x", treg);
                  continue;

                case 'b':
                case 's':
                  printf ("$%d", sreg);
                  continue;

                case 'a':
                  printf ("0x%08lx", oc & 0x1ffffff);
                  continue;

                case 'i':
                case 'j':
                case 'o':
                case 'u':
                  printf ("%d", imm);
                  continue;

                case '<':
                case '>':
                  printf ("$%d", shamt);
                  continue;

                default:
                  internalError ();
                }
              break;
            }
          return;
        }
    }
  printf ("%08lx  UNDEFINED\n", oc);
}
#endif

static symbolS *
get_symbol ()
{
  int c;
  char *name;
  symbolS *p;

  name = input_line_pointer;
  c = get_symbol_end ();
  p = (symbolS *) symbol_find_or_make (name);
  *input_line_pointer = c;
  return p;
}

/* Align the current frag to a given power of two.  The MIPS assembler
   also automatically adjusts any preceding label.  */

static void
mips_align (to, fill, label)
     int to;
     int fill;
     symbolS *label;
{
  mips_emit_delays ();
  frag_align (to, fill);
  record_alignment (now_seg, to);
  if (label != NULL)
    {
      assert (S_GET_SEGMENT (label) == now_seg);
      label->sy_frag = frag_now;
      S_SET_VALUE (label, (valueT) frag_now_fix ());
    }
}

/* Align to a given power of two.  .align 0 turns off the automatic
   alignment used by the data creating pseudo-ops.  */

static void
s_align (x)
     int x;
{
  register int temp;
  register long temp_fill;
  long max_alignment = 15;

  /*

    o  Note that the assembler pulls down any immediately preceeding label
       to the aligned address.
    o  It's not documented but auto alignment is reinstated by
       a .align pseudo instruction.
    o  Note also that after auto alignment is turned off the mips assembler
       issues an error on attempt to assemble an improperly aligned data item.
       We don't.

    */

  temp = get_absolute_expression ();
  if (temp > max_alignment)
    as_bad ("Alignment too large: %d. assumed.", temp = max_alignment);
  else if (temp < 0)
    {
      as_warn ("Alignment negative: 0 assumed.");
      temp = 0;
    }
  if (*input_line_pointer == ',')
    {
      input_line_pointer++;
      temp_fill = get_absolute_expression ();
    }
  else
    temp_fill = 0;
  if (temp)
    {
      auto_align = 1;
      mips_align (temp, (int) temp_fill, insn_label);
    }
  else
    {
      auto_align = 0;
    }

  demand_empty_rest_of_line ();
}

/* Handle .ascii and .asciiz.  This just calls stringer and forgets
   that there was a previous instruction.  */

static void
s_stringer (append_zero)
     int append_zero;
{
  mips_emit_delays ();
  insn_label = NULL;
  stringer (append_zero);
}

static void
s_change_sec (sec)
     int sec;
{
#ifdef GPOPT
  segT seg;
#endif

  /* When generating embedded PIC code, we only use the .text, .lit8,
     .sdata and .sbss sections.  We change the .data and .rdata
     pseudo-ops to use .sdata.  */
  if (mips_pic == EMBEDDED_PIC
      && (sec == 'd' || sec == 'r'))
    sec = 's';

  mips_emit_delays ();
  switch (sec)
    {
    case 't':
      s_text (0);
      break;
    case 'd':
      s_data (0);
      break;
    case 'b':
      subseg_set (bss_section, (subsegT) get_absolute_expression ());
      demand_empty_rest_of_line ();
      break;

    case 'r':
#ifdef OBJ_ECOFF
      subseg_new (".rdata", (subsegT) get_absolute_expression ());
      demand_empty_rest_of_line ();
      break;
#else /* ! defined (OBJ_ECOFF) */
#ifdef OBJ_ELF
      seg = subseg_new (".rodata", (subsegT) get_absolute_expression ());
      bfd_set_section_flags (stdoutput, seg,
                             (SEC_ALLOC
                              | SEC_LOAD
                              | SEC_READONLY
                              | SEC_RELOC
                              | SEC_DATA));
      bfd_set_section_alignment (stdoutput, seg, 4);
      demand_empty_rest_of_line ();
      break;
#else /* ! defined (OBJ_ELF) */
      s_data (0);
      break;
#endif /* ! defined (OBJ_ELF) */
#endif /* ! defined (OBJ_ECOFF) */

    case 's':
#ifdef GPOPT
      seg = subseg_new (".sdata", (subsegT) get_absolute_expression ());
#ifdef OBJ_ELF
      bfd_set_section_flags (stdoutput, seg,
                             SEC_ALLOC | SEC_LOAD | SEC_RELOC | SEC_DATA);
      bfd_set_section_alignment (stdoutput, seg, 4);
#endif
      demand_empty_rest_of_line ();
      break;
#else /* ! defined (GPOPT) */
      as_bad ("Global pointers not supported; recompile -G 0");
      demand_empty_rest_of_line ();
      return;
#endif /* ! defined (GPOPT) */
    }

  auto_align = 1;
}

static void
s_cons (log_size)
     int log_size;
{
  symbolS *label;

  label = insn_label;
  mips_emit_delays ();
  if (log_size > 0 && auto_align)
    mips_align (log_size, 0, label);
  insn_label = NULL;
  cons (1 << log_size);
}

static void
s_err (x)
     int x;
{
  as_fatal ("Encountered `.err', aborting assembly");
}

static void
s_extern (x)
     int x;
{
  valueT size;
  symbolS *symbolP;

  symbolP = get_symbol ();
  if (*input_line_pointer == ',')
    input_line_pointer++;
  size = get_absolute_expression ();
  S_SET_EXTERNAL (symbolP);

#ifdef ECOFF_DEBUGGING
  symbolP->ecoff_extern_size = size;
#endif
}

static void
s_float_cons (type)
     int type;
{
  symbolS *label;

  label = insn_label;

  mips_emit_delays ();

  if (auto_align)
    if (type == 'd')
      mips_align (3, 0, label);
    else
      mips_align (2, 0, label);

  insn_label = NULL;

  float_cons (type);
}

static void
s_option (x)
     int x;
{
  char *opt;
  char c;

  opt = input_line_pointer;
  c = get_symbol_end ();

  if (*opt == 'O')
    {
      /* FIXME: What does this mean?  */
    }
  else if (strncmp (opt, "pic", 3) == 0)
    {
      int i;

      i = atoi (opt + 3);
      if (i == 0)
        mips_pic = NO_PIC;
      else if (i == 2)
        mips_pic = SVR4_PIC;
      else
        as_bad (".option pic%d not supported", i);

#ifdef GPOPT
      if (mips_pic == SVR4_PIC)
        {
          if (g_switch_seen && g_switch_value != 0)
            as_warn ("-G may not be used with SVR4 PIC code");
          g_switch_value = 0;
          bfd_set_gp_size (stdoutput, 0);
        }
#endif
    }
  else
    as_warn ("Unrecognized option \"%s\"", opt);

  *input_line_pointer = c;
  demand_empty_rest_of_line ();
}

static void
s_mipsset (x)
     int x;
{
  char *name = input_line_pointer, ch;

  while (!is_end_of_line[(unsigned char) *input_line_pointer])
    input_line_pointer++;
  ch = *input_line_pointer;
  *input_line_pointer = '\0';

  if (strcmp (name, "reorder") == 0)
    {
      if (mips_noreorder)
        {
          prev_insn_unreordered = 1;
          prev_prev_insn_unreordered = 1;
        }
      mips_noreorder = 0;
    }
  else if (strcmp (name, "noreorder") == 0)
    {
      mips_emit_delays ();
      mips_noreorder = 1;
      mips_any_noreorder = 1;
    }
  else if (strcmp (name, "at") == 0)
    {
      mips_noat = 0;
    }
  else if (strcmp (name, "noat") == 0)
    {
      mips_noat = 1;
    }
  else if (strcmp (name, "macro") == 0)
    {
      mips_warn_about_macros = 0;
    }
  else if (strcmp (name, "nomacro") == 0)
    {
      if (mips_noreorder == 0)
        as_bad ("`noreorder' must be set before `nomacro'");
      mips_warn_about_macros = 1;
    }
  else if (strcmp (name, "move") == 0 || strcmp (name, "novolatile") == 0)
    {
      mips_nomove = 0;
    }
  else if (strcmp (name, "nomove") == 0 || strcmp (name, "volatile") == 0)
    {
      mips_nomove = 1;
    }
  else if (strcmp (name, "bopt") == 0)
    {
      mips_nobopt = 0;
    }
  else if (strcmp (name, "nobopt") == 0)
    {
      mips_nobopt = 1;
    }
  else if (strncmp (name, "mips", 4) == 0)
    {
      int isa;

      /* Permit the user to change the ISA on the fly.  Needless to
         say, misuse can cause serious problems.  */
      isa = atoi (name + 4);
      if (isa == 0)
        mips_isa = file_mips_isa;
      else if (isa < 1 || isa > 3)
        as_bad ("unknown ISA level");
      else
        mips_isa = isa;
    }
  else
    {
      as_warn ("Tried to set unrecognized symbol: %s\n", name);
    }
  *input_line_pointer = ch;
  demand_empty_rest_of_line ();
}

/* The same as the usual .space directive, except that we have to
   forget about any previous instruction.  */

static void
s_mips_space (param)
     int param;
{
  mips_emit_delays ();
  insn_label = NULL;
  s_space (param);
}

/* Handle the .abicalls pseudo-op.  I believe this is equivalent to
   .option pic2.  It means to generate SVR4 PIC calls.  */

static void
s_abicalls (ignore)
     int ignore;
{
  mips_pic = SVR4_PIC;
#ifdef GPOPT
  if (g_switch_seen && g_switch_value != 0)
    as_warn ("-G may not be used with SVR4 PIC code");
  g_switch_value = 0;
#endif
  bfd_set_gp_size (stdoutput, 0);
  demand_empty_rest_of_line ();
}

/* Handle the .cpload pseudo-op.  This is used when generating SVR4
   PIC code.  It sets the $gp register for the function based on the
   function address, which is in the register named in the argument.
   This uses a relocation against _gp_disp, which is handled specially
   by the linker.  The result is:
        lui     $gp,%hi(_gp_disp)
        addiu   $gp,$gp,%lo(_gp_disp)
        addu    $gp,$gp,.cpload argument
   The .cpload argument is normally $25 == $t9.  */

static void
s_cpload (ignore)
     int ignore;
{
  expressionS ex;
  int icnt = 0;

  /* If we are not generating SVR4 PIC code, .cpload is ignored.  */
  if (mips_pic != SVR4_PIC)
    {
      s_ignore (0);
      return;
    }

  /* .cpload should be a in .set noreorder section.  */
  if (mips_noreorder == 0)
    as_warn (".cpload not in noreorder section");

  ex.X_op = O_symbol;
  ex.X_add_symbol = symbol_find_or_make ("_gp_disp");
  ex.X_op_symbol = NULL;
  ex.X_add_number = 0;

  macro_build_lui ((char *) NULL, &icnt, &ex, GP);
  macro_build ((char *) NULL, &icnt, &ex, "addiu", "t,r,j", GP, GP,
               (int) BFD_RELOC_LO16);

  macro_build ((char *) NULL, &icnt, (expressionS *) NULL, "addu", "d,v,t",
               GP, GP, tc_get_register (0));

  demand_empty_rest_of_line ();
}

/* Handle the .cprestore pseudo-op.  This stores $gp into a given
   offset from $sp.  The offset is remembered, and after making a PIC
   call $gp is restored from that location.  */

static void
s_cprestore (ignore)
     int ignore;
{
  expressionS ex;
  int icnt = 0;

  /* If we are not generating SVR4 PIC code, .cprestore is ignored.  */
  if (mips_pic != SVR4_PIC)
    {
      s_ignore (0);
      return;
    }

  mips_cprestore_offset = get_absolute_expression ();

  ex.X_op = O_constant;
  ex.X_add_symbol = NULL;
  ex.X_op_symbol = NULL;
  ex.X_add_number = mips_cprestore_offset;

  macro_build ((char *) NULL, &icnt, &ex,
               mips_isa < 3 ? "sw" : "sd",
               "t,o(b)", GP, (int) BFD_RELOC_LO16, SP);

  demand_empty_rest_of_line ();
}

/* Handle the .gpword pseudo-op.  This is used when generating PIC
   code.  It generates a 32 bit GP relative reloc.  */

static void
s_gpword (ignore)
     int ignore;
{
  symbolS *label;
  expressionS ex;
  char *p;

  /* When not generating PIC code, this is treated as .word.  */
  if (mips_pic != SVR4_PIC)
    {
      s_cons (2);
      return;
    }

  label = insn_label;
  mips_emit_delays ();
  if (auto_align)
    mips_align (2, 0, label);
  insn_label = NULL;

  expression (&ex);

  if (ex.X_op != O_symbol || ex.X_add_number != 0)
    {
      as_bad ("Unsupported use of .gpword");
      ignore_rest_of_line ();
    }

  p = frag_more (4);
  md_number_to_chars (p, (valueT) 0, 4);
  fix_new_exp (frag_now, p - frag_now->fr_literal, 4, &ex, 0,
               BFD_RELOC_MIPS_GPREL32);

  demand_empty_rest_of_line ();
}

/* Handle the .cpadd pseudo-op.  This is used when dealing with switch
   tables in SVR4 PIC code.  */

static void
s_cpadd (ignore)
     int ignore;
{
  int icnt = 0;
  int reg;

  /* This is ignored when not generating SVR4 PIC code.  */
  if (mips_pic != SVR4_PIC)
    {
      s_ignore (0);
      return;
    }

  /* Add $gp to the register named as an argument.  */
  reg = tc_get_register (0);
  macro_build ((char *) NULL, &icnt, (expressionS *) NULL,
               mips_isa < 3 ? "addu" : "daddu",
               "d,v,t", reg, reg, GP);

  demand_empty_rest_of_line ();  
}

/* Parse a register string into a number.  Called from the ECOFF code
   to parse .frame.  The argument is non-zero if this is the frame
   register, so that we can record it in mips_frame_reg.  */

int
tc_get_register (frame)
     int frame;
{
  int reg;

  SKIP_WHITESPACE ();
  if (*input_line_pointer++ != '$')
    {
      as_warn ("expected `$'");
      reg = 0;
    }
  else if (isdigit ((unsigned char) *input_line_pointer))
    {
      reg = get_absolute_expression ();
      if (reg < 0 || reg >= 32)
        {
          as_warn ("Bad register number");
          reg = 0;
        }
    }
  else
    {
      if (strncmp (input_line_pointer, "fp", 2) == 0)
        reg = FP;
      else if (strncmp (input_line_pointer, "sp", 2) == 0)
        reg = SP;
      else if (strncmp (input_line_pointer, "gp", 2) == 0)
        reg = GP;
      else if (strncmp (input_line_pointer, "at", 2) == 0)
        reg = AT;
      else
        {
          as_warn ("Unrecognized register name");
          reg = 0;
        }
      input_line_pointer += 2;
    }
  if (frame)
    mips_frame_reg = reg != 0 ? reg : SP;
  return reg;
}

valueT
md_section_align (seg, addr)
     asection *seg;
     valueT addr;
{
  int align = bfd_get_section_alignment (stdoutput, seg);

  return ((addr + (1 << align) - 1) & (-1 << align));
}

/* Estimate the size of a frag before relaxing.  We are not really
   relaxing here, and the final size is encoded in the subtype
   information.  */

/*ARGSUSED*/
int
md_estimate_size_before_relax (fragp, segtype)
     fragS *fragp;
     asection *segtype;
{
  int change;

  if (mips_pic == NO_PIC)
    {
#ifdef GPOPT
      const char *symname;

      /* Find out whether this symbol can be referenced off the GP
         register.  It can be if it is smaller than the -G size or if
         it is in the .sdata or .sbss section.  Certain symbols can
         not be referenced off the GP, although it appears as though
         they can.  */
      symname = S_GET_NAME (fragp->fr_symbol);
      if (symname != (const char *) NULL
          && (strcmp (symname, "eprol") == 0
              || strcmp (symname, "etext") == 0
              || strcmp (symname, "_gp") == 0
              || strcmp (symname, "edata") == 0
              || strcmp (symname, "_fbss") == 0
              || strcmp (symname, "_fdata") == 0
              || strcmp (symname, "_ftext") == 0
              || strcmp (symname, "end") == 0
              || strcmp (symname, "_gp_disp") == 0))
        change = 1;
      else if (! S_IS_DEFINED (fragp->fr_symbol)
               && ((fragp->fr_symbol->ecoff_extern_size != 0
                    && fragp->fr_symbol->ecoff_extern_size <= g_switch_value)
                   || (S_GET_VALUE (fragp->fr_symbol) != 0
                       && S_GET_VALUE (fragp->fr_symbol) <= g_switch_value)))
        change = 0;
      else
        {
          const char *segname;

          segname = segment_name (S_GET_SEGMENT (fragp->fr_symbol));
          assert (strcmp (segname, ".lit8") != 0
                  && strcmp (segname, ".lit4") != 0);
          change = (strcmp (segname, ".sdata") != 0
                    && strcmp (segname, ".sbss") != 0);
        }
#else /* ! defined (GPOPT) */
      /* We are not optimizing for the GP register.  */
      change = 1;
#endif /* ! defined (GPOPT) */  
    }
  else if (mips_pic == SVR4_PIC)
    {
      asection *symsec = fragp->fr_symbol->bsym->section;

      /* This must duplicate the test in adjust_reloc_syms.  */
      change = (symsec != &bfd_und_section
                && symsec != &bfd_abs_section
                && ! bfd_is_com_section (symsec));
    }
  else
    abort ();

  if (change)
    {
      /* Record the offset to the first reloc in the fr_opcode field.
         This lets md_convert_frag and tc_gen_reloc know that the code
         must be expanded.  */
      fragp->fr_opcode = (fragp->fr_literal
                          + fragp->fr_fix
                          - RELAX_OLD (fragp->fr_subtype)
                          + RELAX_RELOC1 (fragp->fr_subtype));
      /* FIXME: This really needs as_warn_where.  */
      if (RELAX_WARN (fragp->fr_subtype))
        as_warn ("AT used after \".set noat\" or macro used after \".set nomacro\"");
    }

  if (! change)
    return 0;
  else
    return RELAX_NEW (fragp->fr_subtype) - RELAX_OLD (fragp->fr_subtype);
}

/* Translate internal representation of relocation info to BFD target
   format.  */

arelent **
tc_gen_reloc (section, fixp)
     asection *section;
     fixS *fixp;
{
  static arelent *retval[4];
  arelent *reloc;

  reloc = retval[0] = (arelent *) xmalloc (sizeof (arelent));
  retval[1] = NULL;

  reloc->sym_ptr_ptr = &fixp->fx_addsy->bsym;
  reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;

  if (mips_pic == EMBEDDED_PIC
      && SWITCH_TABLE (fixp))
    {
      /* For a switch table entry we use a special reloc.  The addend
         is actually the difference between the reloc address and the
         subtrahend.  */
      reloc->addend = reloc->address - S_GET_VALUE (fixp->fx_subsy);
#ifndef OBJ_ECOFF
      as_fatal ("Double check fx_r_type in tc-mips.c:tc_gen_reloc");
#endif
      fixp->fx_r_type = BFD_RELOC_GPREL32;
    }
  else if (fixp->fx_r_type == BFD_RELOC_PCREL_LO16)
    {
      /* We use a special addend for an internal RELLO reloc.  */
      if (fixp->fx_addsy->bsym->flags & BSF_SECTION_SYM)
        reloc->addend = reloc->address - S_GET_VALUE (fixp->fx_subsy);
      else
        reloc->addend = fixp->fx_addnumber + reloc->address;
    }
  else if (fixp->fx_r_type == BFD_RELOC_PCREL_HI16_S)
    {
      assert (fixp->fx_next != NULL
              && fixp->fx_next->fx_r_type == BFD_RELOC_PCREL_LO16);
      /* We use a special addend for an internal RELHI reloc.  The
         reloc is relative to the RELLO; adjust the addend
         accordingly.  */
      if (fixp->fx_addsy->bsym->flags & BSF_SECTION_SYM)
        reloc->addend = (fixp->fx_next->fx_frag->fr_address
                         + fixp->fx_next->fx_where
                         - S_GET_VALUE (fixp->fx_subsy));
      else
        reloc->addend = (fixp->fx_addnumber
                         + fixp->fx_next->fx_frag->fr_address
                         + fixp->fx_next->fx_where);
    }
  else if (fixp->fx_pcrel == 0)
    reloc->addend = fixp->fx_addnumber;
  else
    {
#ifndef OBJ_AOUT
      /* A gruesome hack which is a result of the gruesome gas reloc
         handling.  */
      reloc->addend = reloc->address;
#else
      reloc->addend = -reloc->address;
#endif
    }

  /* If this is a variant frag, we may need to adjust the existing
     reloc and generate a new one.  */
  if (fixp->fx_frag->fr_opcode != NULL
      && (fixp->fx_r_type == BFD_RELOC_MIPS_GPREL
          || fixp->fx_r_type == BFD_RELOC_MIPS_GOT16
          || fixp->fx_r_type == BFD_RELOC_MIPS_CALL16))
    {
      arelent *reloc2;

      /* If this is not the last reloc in this frag, then we have two
         GPREL relocs, both of which are being replaced.  Let the
         second one handle all of them.  */
      if (fixp->fx_next != NULL
          && fixp->fx_frag == fixp->fx_next->fx_frag)
        {
          assert (fixp->fx_r_type == BFD_RELOC_MIPS_GPREL
                  && fixp->fx_next->fx_r_type == BFD_RELOC_MIPS_GPREL);
          retval[0] = NULL;
          return retval;
        }

      fixp->fx_where = fixp->fx_frag->fr_opcode - fixp->fx_frag->fr_literal;
      reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;
      reloc2 = retval[1] = (arelent *) xmalloc (sizeof (arelent));
      retval[2] = NULL;
      reloc2->sym_ptr_ptr = &fixp->fx_addsy->bsym;
      reloc2->address = (reloc->address
                         + (RELAX_RELOC2 (fixp->fx_frag->fr_subtype)
                            - RELAX_RELOC1 (fixp->fx_frag->fr_subtype)));
      reloc2->addend = fixp->fx_addnumber;
      reloc2->howto = bfd_reloc_type_lookup (stdoutput, BFD_RELOC_LO16);
      assert (reloc2->howto != NULL);

      if (RELAX_RELOC3 (fixp->fx_frag->fr_subtype))
        {
          arelent *reloc3;

          reloc3 = retval[2] = (arelent *) xmalloc (sizeof (arelent));
          retval[3] = NULL;
          *reloc3 = *reloc2;
          reloc3->address += 4;
        }

      if (mips_pic == NO_PIC)
        {
          assert (fixp->fx_r_type == BFD_RELOC_MIPS_GPREL);
          fixp->fx_r_type = BFD_RELOC_HI16_S;
        }
      else if (mips_pic == SVR4_PIC)
        {
          if (fixp->fx_r_type != BFD_RELOC_MIPS_GOT16)
            {
              assert (fixp->fx_r_type == BFD_RELOC_MIPS_CALL16);
              fixp->fx_r_type = BFD_RELOC_MIPS_GOT16;
            }
        }
      else
        abort ();
    }

  /* To support a PC relative reloc when generating embedded PIC code
     for ECOFF, we use a Cygnus extension.  We check for that here to
     make sure that we don't let such a reloc escape normally.  */
#ifdef OBJ_ECOFF
  if (fixp->fx_r_type == BFD_RELOC_16_PCREL_S2
      && mips_pic != EMBEDDED_PIC)
    reloc->howto = NULL;
  else
#endif
    reloc->howto = bfd_reloc_type_lookup (stdoutput, fixp->fx_r_type);

  if (reloc->howto == NULL)
    {
      as_bad_where (fixp->fx_file, fixp->fx_line,
                    "Can not represent relocation in this object file format");
      retval[0] = NULL;
    }

  return retval;
}

/* Convert a machine dependent frag.  */

void
md_convert_frag (abfd, asec, fragp)
     bfd *abfd;
     segT asec;
     fragS *fragp;
{
  int old, new;
  char *fixptr;

  if (fragp->fr_opcode == NULL)
    return;

  old = RELAX_OLD (fragp->fr_subtype);
  new = RELAX_NEW (fragp->fr_subtype);
  fixptr = fragp->fr_literal + fragp->fr_fix;

  if (new > 0)
    memcpy (fixptr - old, fixptr, new);

  fragp->fr_fix += new - old;
}

/* This function is called whenever a label is defined.  It is used
   when handling branch delays; if a branch has a label, we assume we
   can not move it.  */

void
mips_define_label (sym)
     symbolS *sym;
{
  insn_label = sym;
}
\f
#ifdef OBJ_ELF

/* Some special processing for a MIPS ELF file.  */

void
mips_elf_final_processing ()
{
  Elf32_RegInfo s;

  /* Write out the .reginfo section.  */
  s.ri_gprmask = mips_gprmask;
  s.ri_cprmask[0] = mips_cprmask[0];
  s.ri_cprmask[1] = mips_cprmask[1];
  s.ri_cprmask[2] = mips_cprmask[2];
  s.ri_cprmask[3] = mips_cprmask[3];
  /* The gp_value field is set by the MIPS ELF backend.  */

  bfd_mips_elf32_swap_reginfo_out (stdoutput, &s,
                                   ((Elf32_External_RegInfo *)
                                    mips_regmask_frag));

  /* Set the MIPS ELF flag bits.  FIXME: There should probably be some
     sort of BFD interface for this.  */
  if (mips_any_noreorder)
    elf_elfheader (stdoutput)->e_flags |= EF_MIPS_NOREORDER;
  if (mips_pic != NO_PIC)
    elf_elfheader (stdoutput)->e_flags |= EF_MIPS_PIC;
}

#endif /* OBJ_ELF */
\f
#ifndef ECOFF_DEBUGGING

/* These functions should really be defined by the object file format,
   since they are related to debugging information.  However, this
   code has to work for the a.out format, which does not define them,
   so we provide simple versions here.  These don't actually generate
   any debugging information, but they do simple checking and someday
   somebody may make them useful.  */

typedef struct loc
{
  struct loc *loc_next;
  unsigned long loc_fileno;
  unsigned long loc_lineno;
  unsigned long loc_offset;
  unsigned short loc_delta;
  unsigned short loc_count;
#if 0
  fragS *loc_frag;
#endif
}
locS;

typedef struct proc
  {
    struct proc *proc_next;
    struct symbol *proc_isym;
    struct symbol *proc_end;
    unsigned long proc_reg_mask;
    unsigned long proc_reg_offset;
    unsigned long proc_fpreg_mask;
    unsigned long proc_fpreg_offset;
    unsigned long proc_frameoffset;
    unsigned long proc_framereg;
    unsigned long proc_pcreg;
    locS *proc_iline;
    struct file *proc_file;
    int proc_index;
  }
procS;

typedef struct file
  {
    struct file *file_next;
    unsigned long file_fileno;
    struct symbol *file_symbol;
    struct symbol *file_end;
    struct proc *file_proc;
    int file_numprocs;
  }
fileS;

static struct obstack proc_frags;
static procS *proc_lastP;
static procS *proc_rootP;
static int numprocs;

static void
md_obj_begin ()
{
  obstack_begin (&proc_frags, 0x2000);
}

static void
md_obj_end ()
{
  /* check for premature end, nesting errors, etc */
  if (proc_lastP && proc_lastP->proc_end == NULL)
    as_warn ("missing `.end' at end of assembly");
}

extern char hex_value[];

static long
get_number ()
{
  int negative = 0;
  long val = 0;

  if (*input_line_pointer == '-')
    {
      ++input_line_pointer;
      negative = 1;
    }
  if (!isdigit (*input_line_pointer))
    as_bad ("Expected simple number.");
  if (input_line_pointer[0] == '0')
    {
      if (input_line_pointer[1] == 'x')
        {
          input_line_pointer += 2;
          while (isxdigit (*input_line_pointer))
            {
              val <<= 4;
              val |= hex_value[(int) *input_line_pointer++];
            }
          return negative ? -val : val;
        }
      else
        {
          ++input_line_pointer;
          while (isdigit (*input_line_pointer))
            {
              val <<= 3;
              val |= *input_line_pointer++ - '0';
            }
          return negative ? -val : val;
        }
    }
  if (!isdigit (*input_line_pointer))
    {
      printf (" *input_line_pointer == '%c' 0x%02x\n",
              *input_line_pointer, *input_line_pointer);
      as_warn ("Invalid number");
      return -1;
    }
  while (isdigit (*input_line_pointer))
    {
      val *= 10;
      val += *input_line_pointer++ - '0';
    }
  return negative ? -val : val;
}

/* The .file directive; just like the usual .file directive, but there
   is an initial number which is the ECOFF file index.  */

static void
s_file (x)
     int x;
{
  int line;

  line = get_number ();
  s_app_file (0);
}


/* The .end directive.  */

static void
s_mipsend (x)
     int x;
{
  symbolS *p;

  if (!is_end_of_line[(unsigned char) *input_line_pointer])
    {
      p = get_symbol ();
      demand_empty_rest_of_line ();
    }
  else
    p = NULL;
  if (now_seg != text_section)
    as_warn (".end not in text section");
  if (!proc_lastP)
    {
      as_warn (".end and no .ent seen yet.");
      return;
    }

  if (p != NULL)
    {
      assert (S_GET_NAME (p));
      if (strcmp (S_GET_NAME (p), S_GET_NAME (proc_lastP->proc_isym)))
        as_warn (".end symbol does not match .ent symbol.");
    }

  proc_lastP->proc_end = (symbolS *) 1;
}

/* The .aent and .ent directives.  */

static void
s_ent (aent)
     int aent;
{
  int number = 0;
  procS *procP;
  symbolS *symbolP;

  symbolP = get_symbol ();
  if (*input_line_pointer == ',')
    input_line_pointer++;
  SKIP_WHITESPACE ();
  if (isdigit (*input_line_pointer) || *input_line_pointer == '-')
    number = get_number ();
  if (now_seg != text_section)
    as_warn (".ent or .aent not in text section.");

  if (!aent && proc_lastP && proc_lastP->proc_end == NULL)
    as_warn ("missing `.end'");

  if (!aent)
    {
      procP = (procS *) obstack_alloc (&proc_frags, sizeof (*procP));
      procP->proc_isym = symbolP;
      procP->proc_reg_mask = 0;
      procP->proc_reg_offset = 0;
      procP->proc_fpreg_mask = 0;
      procP->proc_fpreg_offset = 0;
      procP->proc_frameoffset = 0;
      procP->proc_framereg = 0;
      procP->proc_pcreg = 0;
      procP->proc_end = NULL;
      procP->proc_next = NULL;
      if (proc_lastP)
        proc_lastP->proc_next = procP;
      else
        proc_rootP = procP;
      proc_lastP = procP;
      numprocs++;
    }
  demand_empty_rest_of_line ();
}

/* The .frame directive.  */

#if 0
static void
s_frame (x)
     int x;
{
  char str[100];
  symbolS *symP;
  int frame_reg;
  int frame_off;
  int pcreg;

  frame_reg = tc_get_register (1);
  if (*input_line_pointer == ',')
    input_line_pointer++;
  frame_off = get_absolute_expression ();
  if (*input_line_pointer == ',')
    input_line_pointer++;
  pcreg = tc_get_register (0);

  /* bob third eye */
  assert (proc_rootP);
  proc_rootP->proc_framereg = frame_reg;
  proc_rootP->proc_frameoffset = frame_off;
  proc_rootP->proc_pcreg = pcreg;
  /* bob macho .frame */

  /* We don't have to write out a frame stab for unoptimized code. */
  if (!(frame_reg == FP && frame_off == 0))
    {
      if (!proc_lastP)
        as_warn ("No .ent for .frame to use.");
      (void) sprintf (str, "R%d;%d", frame_reg, frame_off);
      symP = symbol_new (str, N_VFP, 0, frag_now);
      S_SET_TYPE (symP, N_RMASK);
      S_SET_OTHER (symP, 0);
      S_SET_DESC (symP, 0);
      symP->sy_forward = proc_lastP->proc_isym;
      /* bob perhaps I should have used pseudo set */
    }
  demand_empty_rest_of_line ();
}
#endif

/* The .fmask and .mask directives.  */

#if 0
static void
s_mask (reg_type)
     char reg_type;
{
  char str[100], *strP;
  symbolS *symP;
  int i;
  unsigned int mask;
  int off;

  mask = get_number ();
  if (*input_line_pointer == ',')
    input_line_pointer++;
  off = get_absolute_expression ();

  /* bob only for coff */
  assert (proc_rootP);
  if (reg_type == 'F')
    {
      proc_rootP->proc_fpreg_mask = mask;
      proc_rootP->proc_fpreg_offset = off;
    }
  else
    {
      proc_rootP->proc_reg_mask = mask;
      proc_rootP->proc_reg_offset = off;
    }

  /* bob macho .mask + .fmask */

  /* We don't have to write out a mask stab if no saved regs. */
  if (!(mask == 0))
    {
      if (!proc_lastP)
        as_warn ("No .ent for .mask to use.");
      strP = str;
      for (i = 0; i < 32; i++)
        {
          if (mask % 2)
            {
              sprintf (strP, "%c%d,", reg_type, i);
              strP += strlen (strP);
            }
          mask /= 2;
        }
      sprintf (strP, ";%d,", off);
      symP = symbol_new (str, N_RMASK, 0, frag_now);
      S_SET_TYPE (symP, N_RMASK);
      S_SET_OTHER (symP, 0);
      S_SET_DESC (symP, 0);
      symP->sy_forward = proc_lastP->proc_isym;
      /* bob perhaps I should have used pseudo set */
    }
}
#endif

/* The .loc directive.  */

#if 0
static void
s_loc (x)
     int x;
{
  symbolS *symbolP;
  int lineno;
  int addroff;

  assert (now_seg == text_section);

  lineno = get_number ();
  addroff = obstack_next_free (&frags) - frag_now->fr_literal;

  symbolP = symbol_new ("", N_SLINE, addroff, frag_now);
  S_SET_TYPE (symbolP, N_SLINE);
  S_SET_OTHER (symbolP, 0);
  S_SET_DESC (symbolP, lineno);
  symbolP->sy_segment = now_seg;
}
#endif

#endif /* ! defined (ECOFF_DEBUGGING) */