libffi/src/mips/ffi.c

/* -----------------------------------------------------------------------
   ffi.c - Copyright (c) 2011  Anthony Green
           Copyright (c) 2008  David Daney
           Copyright (c) 1996, 2007, 2008, 2011  Red Hat, Inc.
   
   MIPS Foreign Function Interface 

   Permission is hereby granted, free of charge, to any person obtaining
   a copy of this software and associated documentation files (the
   ``Software''), to deal in the Software without restriction, including
   without limitation the rights to use, copy, modify, merge, publish,
   distribute, sublicense, and/or sell copies of the Software, and to
   permit persons to whom the Software is furnished to do so, subject to
   the following conditions:

   The above copyright notice and this permission notice shall be included
   in all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND,
   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   DEALINGS IN THE SOFTWARE.
   ----------------------------------------------------------------------- */

#include <ffi.h>
#include <ffi_common.h>

#include <stdint.h>
#include <stdlib.h>

#ifdef __GNUC__
#  if (__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 3))
#    define USE__BUILTIN___CLEAR_CACHE 1
#  endif
#endif

#ifndef USE__BUILTIN___CLEAR_CACHE
#  if defined(__FreeBSD__)
#    include <machine/sysarch.h>
#  elif defined(__OpenBSD__)
#    include <mips64/sysarch.h>
#  else
#    include <sys/cachectl.h>
#  endif
#endif

#ifdef FFI_DEBUG
# define FFI_MIPS_STOP_HERE() ffi_stop_here()
#else
# define FFI_MIPS_STOP_HERE() do {} while(0)
#endif

#ifdef FFI_MIPS_N32
#define FIX_ARGP \
FFI_ASSERT(argp <= &stack[bytes]); \
if (argp == &stack[bytes]) \
{ \
  argp = stack; \
  FFI_MIPS_STOP_HERE(); \
}
#else
#define FIX_ARGP 
#endif


/* ffi_prep_args is called by the assembly routine once stack space
   has been allocated for the function's arguments */

static void ffi_prep_args(char *stack, 
			  extended_cif *ecif,
			  int bytes,
			  int flags)
{
  int i;
  void **p_argv;
  char *argp;
  ffi_type **p_arg;

#ifdef FFI_MIPS_N32
  /* If more than 8 double words are used, the remainder go
     on the stack. We reorder stuff on the stack here to 
     support this easily. */
  if (bytes > 8 * sizeof(ffi_arg))
    argp = &stack[bytes - (8 * sizeof(ffi_arg))];
  else
    argp = stack;
#else
  argp = stack;
#endif

  memset(stack, 0, bytes);

#ifdef FFI_MIPS_N32
  if ( ecif->cif->rstruct_flag != 0 )
#else
  if ( ecif->cif->rtype->type == FFI_TYPE_STRUCT )
#endif  
    {
      *(ffi_arg *) argp = (ffi_arg) ecif->rvalue;
      argp += sizeof(ffi_arg);
      FIX_ARGP;
    }

  p_argv = ecif->avalue;

  for (i = 0, p_arg = ecif->cif->arg_types; i < ecif->cif->nargs; i++, p_arg++)
    {
      size_t z;
      unsigned int a;

      /* Align if necessary.  */
      a = (*p_arg)->alignment;
      if (a < sizeof(ffi_arg))
        a = sizeof(ffi_arg);
      
      if ((a - 1) & (unsigned long) argp)
	{
	  argp = (char *) FFI_ALIGN(argp, a);
	  FIX_ARGP;
	}

      z = (*p_arg)->size;
      if (z <= sizeof(ffi_arg))
	{
          int type = (*p_arg)->type;
	  z = sizeof(ffi_arg);

          /* The size of a pointer depends on the ABI */
          if (type == FFI_TYPE_POINTER)
            type = (ecif->cif->abi == FFI_N64
		    || ecif->cif->abi == FFI_N64_SOFT_FLOAT)
	      ? FFI_TYPE_SINT64 : FFI_TYPE_SINT32;

	if (i < 8 && (ecif->cif->abi == FFI_N32_SOFT_FLOAT
		      || ecif->cif->abi == FFI_N64_SOFT_FLOAT))
	  {
	    switch (type)
	      {
	      case FFI_TYPE_FLOAT:
		type = FFI_TYPE_UINT32;
		break;
	      case FFI_TYPE_DOUBLE:
		type = FFI_TYPE_UINT64;
		break;
	      default:
		break;
	      }
	  }
	  switch (type)
	    {
	      case FFI_TYPE_SINT8:
		*(ffi_arg *)argp = *(SINT8 *)(* p_argv);
		break;

	      case FFI_TYPE_UINT8:
		*(ffi_arg *)argp = *(UINT8 *)(* p_argv);
		break;
		  
	      case FFI_TYPE_SINT16:
		*(ffi_arg *)argp = *(SINT16 *)(* p_argv);
		break;
		  
	      case FFI_TYPE_UINT16:
		*(ffi_arg *)argp = *(UINT16 *)(* p_argv);
		break;
		  
	      case FFI_TYPE_SINT32:
		*(ffi_arg *)argp = *(SINT32 *)(* p_argv);
		break;
		  
	      case FFI_TYPE_UINT32:
#ifdef FFI_MIPS_N32
		/* The N32 ABI requires that 32-bit integers
		   be sign-extended to 64-bits, regardless of
		   whether they are signed or unsigned. */
		*(ffi_arg *)argp = *(SINT32 *)(* p_argv);
#else
		*(ffi_arg *)argp = *(UINT32 *)(* p_argv);
#endif
		break;

	      /* This can only happen with 64bit slots.  */
	      case FFI_TYPE_FLOAT:
		*(float *) argp = *(float *)(* p_argv);
		break;

	      /* Handle structures.  */
	      default:
		memcpy(argp, *p_argv, (*p_arg)->size);
		break;
	    }
	}
      else
	{
#ifdef FFI_MIPS_O32
	  memcpy(argp, *p_argv, z);
#else
	  {
	    unsigned long end = (unsigned long) argp + z;
	    unsigned long cap = (unsigned long) stack + bytes;

	    /* Check if the data will fit within the register space.
	       Handle it if it doesn't.  */

	    if (end <= cap)
	      memcpy(argp, *p_argv, z);
	    else
	      {
		unsigned long portion = cap - (unsigned long)argp;

		memcpy(argp, *p_argv, portion);
		argp = stack;
                z -= portion;
		memcpy(argp, (void*)((unsigned long)(*p_argv) + portion),
                       z);
	      }
	  }
#endif
      }
      p_argv++;
      argp += z;
      FIX_ARGP;
    }
}

#ifdef FFI_MIPS_N32

/* The n32 spec says that if "a chunk consists solely of a double 
   float field (but not a double, which is part of a union), it
   is passed in a floating point register. Any other chunk is
   passed in an integer register". This code traverses structure
   definitions and generates the appropriate flags. */

static unsigned
calc_n32_struct_flags(int soft_float, ffi_type *arg,
		      unsigned *loc, unsigned *arg_reg)
{
  unsigned flags = 0;
  unsigned index = 0;

  ffi_type *e;

  if (soft_float)
    return 0;

  while ((e = arg->elements[index]))
    {
      /* Align this object.  */
      *loc = FFI_ALIGN(*loc, e->alignment);
      if (e->type == FFI_TYPE_DOUBLE)
	{
          /* Already aligned to FFI_SIZEOF_ARG.  */
          *arg_reg = *loc / FFI_SIZEOF_ARG;
          if (*arg_reg > 7)
            break;
	  flags += (FFI_TYPE_DOUBLE << (*arg_reg * FFI_FLAG_BITS));
          *loc += e->size;
	}
      else
        *loc += e->size;
      index++;
    }
  /* Next Argument register at alignment of FFI_SIZEOF_ARG.  */
  *arg_reg = FFI_ALIGN(*loc, FFI_SIZEOF_ARG) / FFI_SIZEOF_ARG;

  return flags;
}

static unsigned
calc_n32_return_struct_flags(int soft_float, ffi_type *arg)
{
  unsigned flags = 0;
  unsigned small = FFI_TYPE_SMALLSTRUCT;
  ffi_type *e;

  /* Returning structures under n32 is a tricky thing.
     A struct with only one or two floating point fields 
     is returned in $f0 (and $f2 if necessary). Any other
     struct results at most 128 bits are returned in $2
     (the first 64 bits) and $3 (remainder, if necessary).
     Larger structs are handled normally. */
  
  if (arg->size > 16)
    return 0;

  if (arg->size > 8)
    small = FFI_TYPE_SMALLSTRUCT2;

  e = arg->elements[0];

  if (e->type == FFI_TYPE_DOUBLE)
    flags = FFI_TYPE_DOUBLE;
  else if (e->type == FFI_TYPE_FLOAT)
    flags = FFI_TYPE_FLOAT;

  if (flags && (e = arg->elements[1]))
    {
      if (e->type == FFI_TYPE_DOUBLE)
	flags += FFI_TYPE_DOUBLE << FFI_FLAG_BITS;
      else if (e->type == FFI_TYPE_FLOAT)
	flags += FFI_TYPE_FLOAT << FFI_FLAG_BITS;
      else 
	return small;

      if (flags && (arg->elements[2]))
	{
	  /* There are three arguments and the first two are 
	     floats! This must be passed the old way. */
	  return small;
	}
      if (soft_float)
	flags += FFI_TYPE_STRUCT_SOFT;
    }
  else
    if (!flags)
      return small;

  return flags;
}

#endif

/* Perform machine dependent cif processing */
static ffi_status ffi_prep_cif_machdep_int(ffi_cif *cif, unsigned nfixedargs)
{
  cif->flags = 0;
  cif->mips_nfixedargs = nfixedargs;

#ifdef FFI_MIPS_O32
  /* Set the flags necessary for O32 processing.  FFI_O32_SOFT_FLOAT
   * does not have special handling for floating point args.
   */

  if (cif->rtype->type != FFI_TYPE_STRUCT && cif->abi == FFI_O32)
    {
      if (cif->nargs > 0 && cif->nargs == nfixedargs)
	{
	  switch ((cif->arg_types)[0]->type)
	    {
	    case FFI_TYPE_FLOAT:
	    case FFI_TYPE_DOUBLE:
	      cif->flags += (cif->arg_types)[0]->type;
	      break;
	      
	    default:
	      break;
	    }

	  if (cif->nargs > 1)
	    {
	      /* Only handle the second argument if the first
		 is a float or double. */
	      if (cif->flags)
		{
		  switch ((cif->arg_types)[1]->type)
		    {
		    case FFI_TYPE_FLOAT:
		    case FFI_TYPE_DOUBLE:
		      cif->flags += (cif->arg_types)[1]->type << FFI_FLAG_BITS;
		      break;
		      
		    default:
		      break;
		    }
		}
	    }
	}
    }
      
  /* Set the return type flag */

  if (cif->abi == FFI_O32_SOFT_FLOAT)
    {
      switch (cif->rtype->type)
        {
        case FFI_TYPE_VOID:
        case FFI_TYPE_STRUCT:
          cif->flags += cif->rtype->type << (FFI_FLAG_BITS * 2);
          break;

        case FFI_TYPE_SINT64:
        case FFI_TYPE_UINT64:
        case FFI_TYPE_DOUBLE:
          cif->flags += FFI_TYPE_UINT64 << (FFI_FLAG_BITS * 2);
          break;
      
        case FFI_TYPE_FLOAT:
        default:
          cif->flags += FFI_TYPE_INT << (FFI_FLAG_BITS * 2);
          break;
        }
    }
  else
    {
      /* FFI_O32 */      
      switch (cif->rtype->type)
        {
        case FFI_TYPE_VOID:
        case FFI_TYPE_STRUCT:
        case FFI_TYPE_FLOAT:
        case FFI_TYPE_DOUBLE:
          cif->flags += cif->rtype->type << (FFI_FLAG_BITS * 2);
          break;

        case FFI_TYPE_SINT64:
        case FFI_TYPE_UINT64:
          cif->flags += FFI_TYPE_UINT64 << (FFI_FLAG_BITS * 2);
          break;
      
        default:
          cif->flags += FFI_TYPE_INT << (FFI_FLAG_BITS * 2);
          break;
        }
    }
#endif

#ifdef FFI_MIPS_N32
  /* Set the flags necessary for N32 processing */
  {
    int type;
    unsigned arg_reg = 0;
    unsigned loc = 0;
    unsigned count = (cif->nargs < 8) ? cif->nargs : 8;
    unsigned index = 0;

    unsigned struct_flags = 0;
    int soft_float = (cif->abi == FFI_N32_SOFT_FLOAT
		      || cif->abi == FFI_N64_SOFT_FLOAT);

    if (cif->rtype->type == FFI_TYPE_STRUCT)
      {
	struct_flags = calc_n32_return_struct_flags(soft_float, cif->rtype);

	if (struct_flags == 0)
	  {
	    /* This means that the structure is being passed as
	       a hidden argument */

	    arg_reg = 1;
	    count = (cif->nargs < 7) ? cif->nargs : 7;

	    cif->rstruct_flag = !0;
	  }
	else
	    cif->rstruct_flag = 0;
      }
    else
      cif->rstruct_flag = 0;

    while (count-- > 0 && arg_reg < 8)
      {
	type = (cif->arg_types)[index]->type;

	// Pass variadic arguments in integer registers even if they're floats
	if (soft_float || index >= nfixedargs)
	  {
	    switch (type)
	      {
	      case FFI_TYPE_FLOAT:
		type = FFI_TYPE_UINT32;
		break;
	      case FFI_TYPE_DOUBLE:
		type = FFI_TYPE_UINT64;
		break;
	      default:
		break;
	      }
	  }
	switch (type)
	  {
	  case FFI_TYPE_FLOAT:
	  case FFI_TYPE_DOUBLE:
	    cif->flags +=
              ((cif->arg_types)[index]->type << (arg_reg * FFI_FLAG_BITS));
	    arg_reg++;
	    break;
          case FFI_TYPE_LONGDOUBLE:
            /* Align it.  */
            arg_reg = FFI_ALIGN(arg_reg, 2);
            /* Treat it as two adjacent doubles.  */
	    if (soft_float || index >= nfixedargs)
	      {
		arg_reg += 2;
	      }
	    else
	      {
		cif->flags +=
		  (FFI_TYPE_DOUBLE << (arg_reg * FFI_FLAG_BITS));
		arg_reg++;
		cif->flags +=
		  (FFI_TYPE_DOUBLE << (arg_reg * FFI_FLAG_BITS));
		arg_reg++;
	      }
            break;

	  case FFI_TYPE_STRUCT:
            loc = arg_reg * FFI_SIZEOF_ARG;
	    cif->flags += calc_n32_struct_flags(soft_float || index >= nfixedargs,
						(cif->arg_types)[index],
						&loc, &arg_reg);
	    break;

	  default:
	    arg_reg++;
            break;
	  }

	index++;
      }

  /* Set the return type flag */
    switch (cif->rtype->type)
      {
      case FFI_TYPE_STRUCT:
	{
	  if (struct_flags == 0)
	    {
	      /* The structure is returned through a hidden
		 first argument. Do nothing, 'cause FFI_TYPE_VOID 
		 is 0 */
	    }
	  else
	    {
	      /* The structure is returned via some tricky
		 mechanism */
	      cif->flags += FFI_TYPE_STRUCT << (FFI_FLAG_BITS * 8);
	      cif->flags += struct_flags << (4 + (FFI_FLAG_BITS * 8));
	    }
	  break;
	}
      
      case FFI_TYPE_VOID:
	/* Do nothing, 'cause FFI_TYPE_VOID is 0 */
	break;

      case FFI_TYPE_POINTER:
	if (cif->abi == FFI_N32_SOFT_FLOAT || cif->abi == FFI_N32)
	  cif->flags += FFI_TYPE_SINT32 << (FFI_FLAG_BITS * 8);
	else
	  cif->flags += FFI_TYPE_INT << (FFI_FLAG_BITS * 8);
	break;

      case FFI_TYPE_FLOAT:
	if (soft_float)
	  {
	    cif->flags += FFI_TYPE_SINT32 << (FFI_FLAG_BITS * 8);
	    break;
	  }
	/* else fall through */
      case FFI_TYPE_DOUBLE:
	if (soft_float)
	  cif->flags += FFI_TYPE_INT << (FFI_FLAG_BITS * 8);
	else
	  cif->flags += cif->rtype->type << (FFI_FLAG_BITS * 8);
	break;

      case FFI_TYPE_LONGDOUBLE:
	/* Long double is returned as if it were a struct containing
	   two doubles.  */
	if (soft_float)
	  {
	    cif->flags += FFI_TYPE_STRUCT << (FFI_FLAG_BITS * 8);
	    cif->flags += FFI_TYPE_SMALLSTRUCT2 << (4 + (FFI_FLAG_BITS * 8));
 	  }
	else
	  {
	    cif->flags += FFI_TYPE_STRUCT << (FFI_FLAG_BITS * 8);
	    cif->flags += (FFI_TYPE_DOUBLE
			   + (FFI_TYPE_DOUBLE << FFI_FLAG_BITS))
					      << (4 + (FFI_FLAG_BITS * 8));
	  }
	break;
      default:
	cif->flags += FFI_TYPE_INT << (FFI_FLAG_BITS * 8);
	break;
      }
  }
#endif
  
  return FFI_OK;
}

ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
{
    return ffi_prep_cif_machdep_int(cif, cif->nargs);
}

ffi_status ffi_prep_cif_machdep_var(ffi_cif *cif,
                                    unsigned nfixedargs,
                                    unsigned ntotalargs MAYBE_UNUSED)
{
    return ffi_prep_cif_machdep_int(cif, nfixedargs);
}

/* Low level routine for calling O32 functions */
extern int ffi_call_O32(void (*)(char *, extended_cif *, int, int), 
			extended_cif *, unsigned, 
			unsigned, unsigned *, void (*)(void), void *closure);

/* Low level routine for calling N32 functions */
extern int ffi_call_N32(void (*)(char *, extended_cif *, int, int), 
			extended_cif *, unsigned, 
			unsigned, void *, void (*)(void), void *closure);

void ffi_call_int(ffi_cif *cif, void (*fn)(void), void *rvalue, 
	      void **avalue, void *closure)
{
  extended_cif ecif;

  ecif.cif = cif;
  ecif.avalue = avalue;
  
  /* If the return value is a struct and we don't have a return	*/
  /* value address then we need to make one		        */
  
  if ((rvalue == NULL) && 
      (cif->rtype->type == FFI_TYPE_STRUCT))
    ecif.rvalue = alloca(cif->rtype->size);
  else
    ecif.rvalue = rvalue;
    
  switch (cif->abi) 
    {
#ifdef FFI_MIPS_O32
    case FFI_O32:
    case FFI_O32_SOFT_FLOAT:
      ffi_call_O32(ffi_prep_args, &ecif, cif->bytes, 
		   cif->flags, ecif.rvalue, fn, closure);
      break;
#endif

#ifdef FFI_MIPS_N32
    case FFI_N32:
    case FFI_N32_SOFT_FLOAT:
    case FFI_N64:
    case FFI_N64_SOFT_FLOAT:
      {
        int copy_rvalue = 0;
	int copy_offset = 0;
        char *rvalue_copy = ecif.rvalue;
        if (cif->rtype->type == FFI_TYPE_STRUCT && cif->rtype->size < 16)
          {
            /* For structures smaller than 16 bytes we clobber memory
               in 8 byte increments.  Make a copy so we don't clobber
               the callers memory outside of the struct bounds.  */
            rvalue_copy = alloca(16);
            copy_rvalue = 1;
          }
	else if (cif->rtype->type == FFI_TYPE_FLOAT
		 && (cif->abi == FFI_N64_SOFT_FLOAT
		     || cif->abi == FFI_N32_SOFT_FLOAT))
	  {
	    rvalue_copy = alloca (8);
	    copy_rvalue = 1;
#if defined(__MIPSEB__) || defined(_MIPSEB)
	    copy_offset = 4;
#endif
	  }
        ffi_call_N32(ffi_prep_args, &ecif, cif->bytes,
                     cif->flags, rvalue_copy, fn, closure);
        if (copy_rvalue)
          memcpy(ecif.rvalue, rvalue_copy + copy_offset, cif->rtype->size);
      }
      break;
#endif

    default:
      FFI_ASSERT(0);
      break;
    }
}

void
ffi_call(ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue)
{
  ffi_call_int (cif, fn, rvalue, avalue, NULL);
}

void
ffi_call_go (ffi_cif *cif, void (*fn)(void), void *rvalue,
	     void **avalue, void *closure)
{
  ffi_call_int (cif, fn, rvalue, avalue, closure);
}


#if FFI_CLOSURES
#if defined(FFI_MIPS_O32)
extern void ffi_closure_O32(void);
extern void ffi_go_closure_O32(void);
#else
extern void ffi_closure_N32(void);
extern void ffi_go_closure_N32(void);
#endif /* FFI_MIPS_O32 */

ffi_status
ffi_prep_closure_loc (ffi_closure *closure,
		      ffi_cif *cif,
		      void (*fun)(ffi_cif*,void*,void**,void*),
		      void *user_data,
		      void *codeloc)
{
  unsigned int *tramp = (unsigned int *) &closure->tramp[0];
  void * fn;
  char *clear_location = (char *) codeloc;

#if defined(FFI_MIPS_O32)
  if (cif->abi != FFI_O32 && cif->abi != FFI_O32_SOFT_FLOAT)
    return FFI_BAD_ABI;
  fn = ffi_closure_O32;
#else
#if _MIPS_SIM ==_ABIN32
  if (cif->abi != FFI_N32
      && cif->abi != FFI_N32_SOFT_FLOAT)
    return FFI_BAD_ABI;
#else
  if (cif->abi != FFI_N64
      && cif->abi != FFI_N64_SOFT_FLOAT)
    return FFI_BAD_ABI;
#endif
  fn = ffi_closure_N32;
#endif /* FFI_MIPS_O32 */

#if defined(FFI_MIPS_O32) || (_MIPS_SIM ==_ABIN32)
  /* lui  $25,high(fn) */
  tramp[0] = 0x3c190000 | ((unsigned)fn >> 16);
  /* ori  $25,low(fn)  */
  tramp[1] = 0x37390000 | ((unsigned)fn & 0xffff);
  /* lui  $12,high(codeloc) */
  tramp[2] = 0x3c0c0000 | ((unsigned)codeloc >> 16);
  /* jr   $25          */
#if !defined(__mips_isa_rev) || (__mips_isa_rev<6)
  tramp[3] = 0x03200008;
#else
  tramp[3] = 0x03200009;
#endif
  /* ori  $12,low(codeloc)  */
  tramp[4] = 0x358c0000 | ((unsigned)codeloc & 0xffff);
#else
  /* N64 has a somewhat larger trampoline.  */
  /* lui  $25,high(fn) */
  tramp[0] = 0x3c190000 | ((unsigned long)fn >> 48);
  /* lui  $12,high(codeloc) */
  tramp[1] = 0x3c0c0000 | ((unsigned long)codeloc >> 48);
  /* ori  $25,mid-high(fn)  */
  tramp[2] = 0x37390000 | (((unsigned long)fn >> 32 ) & 0xffff);
  /* ori  $12,mid-high(codeloc)  */
  tramp[3] = 0x358c0000 | (((unsigned long)codeloc >> 32) & 0xffff);
  /* dsll $25,$25,16 */
  tramp[4] = 0x0019cc38;
  /* dsll $12,$12,16 */
  tramp[5] = 0x000c6438;
  /* ori  $25,mid-low(fn)  */
  tramp[6] = 0x37390000 | (((unsigned long)fn >> 16 ) & 0xffff);
  /* ori  $12,mid-low(codeloc)  */
  tramp[7] = 0x358c0000 | (((unsigned long)codeloc >> 16) & 0xffff);
  /* dsll $25,$25,16 */
  tramp[8] = 0x0019cc38;
  /* dsll $12,$12,16 */
  tramp[9] = 0x000c6438;
  /* ori  $25,low(fn)  */
  tramp[10] = 0x37390000 | ((unsigned long)fn  & 0xffff);
  /* jr   $25          */
#if !defined(__mips_isa_rev) || (__mips_isa_rev<6)
  tramp[11] = 0x03200008;
#else
  tramp[11] = 0x03200009;
#endif
  /* ori  $12,low(codeloc)  */
  tramp[12] = 0x358c0000 | ((unsigned long)codeloc & 0xffff);

#endif

  closure->cif = cif;
  closure->fun = fun;
  closure->user_data = user_data;

#if !defined(__FreeBSD__)
#ifdef USE__BUILTIN___CLEAR_CACHE
  __builtin___clear_cache(clear_location, clear_location + FFI_TRAMPOLINE_SIZE);
#else
  cacheflush (clear_location, FFI_TRAMPOLINE_SIZE, ICACHE);
#endif
#endif /* ! __FreeBSD__ */
  return FFI_OK;
}

/*
 * Decodes the arguments to a function, which will be stored on the
 * stack. AR is the pointer to the beginning of the integer arguments
 * (and, depending upon the arguments, some floating-point arguments
 * as well). FPR is a pointer to the area where floating point
 * registers have been saved, if any.
 *
 * RVALUE is the location where the function return value will be
 * stored. CLOSURE is the prepared closure to invoke.
 *
 * This function should only be called from assembly, which is in
 * turn called from a trampoline.
 *
 * Returns the function return type.
 *
 * Based on the similar routine for sparc.
 */
int
ffi_closure_mips_inner_O32 (ffi_cif *cif,
                            void (*fun)(ffi_cif*, void*, void**, void*),
			    void *user_data,
			    void *rvalue, ffi_arg *ar,
			    double *fpr)
{
  void **avaluep;
  ffi_arg *avalue;
  ffi_type **arg_types;
  int i, avn, argn, seen_int;

  avalue = alloca (cif->nargs * sizeof (ffi_arg));
  avaluep = alloca (cif->nargs * sizeof (ffi_arg));

  seen_int = (cif->abi == FFI_O32_SOFT_FLOAT) || (cif->mips_nfixedargs != cif->nargs);
  argn = 0;

  if ((cif->flags >> (FFI_FLAG_BITS * 2)) == FFI_TYPE_STRUCT)
    {
      rvalue = (void *)(uintptr_t)ar[0];
      argn = 1;
      seen_int = 1;
    }

  i = 0;
  avn = cif->nargs;
  arg_types = cif->arg_types;

  while (i < avn)
    {
      if (arg_types[i]->alignment == 8 && (argn & 0x1))
        argn++;
      if (i < 2 && !seen_int &&
	  (arg_types[i]->type == FFI_TYPE_FLOAT ||
	   arg_types[i]->type == FFI_TYPE_DOUBLE ||
	   arg_types[i]->type == FFI_TYPE_LONGDOUBLE))
	{
#if defined(__MIPSEB__) || defined(_MIPSEB)
	  if (arg_types[i]->type == FFI_TYPE_FLOAT)
	    avaluep[i] = ((char *) &fpr[i]) + sizeof (float);
	  else
#endif
	    avaluep[i] = (char *) &fpr[i];
	}
      else
	{
	  switch (arg_types[i]->type)
	    {
	      case FFI_TYPE_SINT8:
		avaluep[i] = &avalue[i];
		*(SINT8 *) &avalue[i] = (SINT8) ar[argn];
		break;

	      case FFI_TYPE_UINT8:
		avaluep[i] = &avalue[i];
		*(UINT8 *) &avalue[i] = (UINT8) ar[argn];
		break;
		  
	      case FFI_TYPE_SINT16:
		avaluep[i] = &avalue[i];
		*(SINT16 *) &avalue[i] = (SINT16) ar[argn];
		break;
		  
	      case FFI_TYPE_UINT16:
		avaluep[i] = &avalue[i];
		*(UINT16 *) &avalue[i] = (UINT16) ar[argn];
		break;

	      default:
		avaluep[i] = (char *) &ar[argn];
		break;
	    }
	  seen_int = 1;
	}
      argn += FFI_ALIGN(arg_types[i]->size, FFI_SIZEOF_ARG) / FFI_SIZEOF_ARG;
      i++;
    }

  /* Invoke the closure. */
  fun(cif, rvalue, avaluep, user_data);

  if (cif->abi == FFI_O32_SOFT_FLOAT)
    {
      switch (cif->rtype->type)
        {
        case FFI_TYPE_FLOAT:
          return FFI_TYPE_INT;
        case FFI_TYPE_DOUBLE:
          return FFI_TYPE_UINT64;
        default:
          return cif->rtype->type;
        }
    }
  else
    {
      return cif->rtype->type;
    }
}

#if defined(FFI_MIPS_N32)

static void
copy_struct_N32(char *target, unsigned offset, ffi_abi abi, ffi_type *type,
                int argn, unsigned arg_offset, ffi_arg *ar,
                ffi_arg *fpr, int soft_float)
{
  ffi_type **elt_typep = type->elements;
  while(*elt_typep)
    {
      ffi_type *elt_type = *elt_typep;
      unsigned o;
      char *tp;
      char *argp;
      char *fpp;

      o = FFI_ALIGN(offset, elt_type->alignment);
      arg_offset += o - offset;
      offset = o;
      argn += arg_offset / sizeof(ffi_arg);
      arg_offset = arg_offset % sizeof(ffi_arg);

      argp = (char *)(ar + argn);
      fpp = (char *)(argn >= 8 ? ar + argn : fpr + argn);

      tp = target + offset;

      if (elt_type->type == FFI_TYPE_DOUBLE && !soft_float)
        *(double *)tp = *(double *)fpp;
      else
        memcpy(tp, argp + arg_offset, elt_type->size);

      offset += elt_type->size;
      arg_offset += elt_type->size;
      elt_typep++;
      argn += arg_offset / sizeof(ffi_arg);
      arg_offset = arg_offset % sizeof(ffi_arg);
    }
}

/*
 * Decodes the arguments to a function, which will be stored on the
 * stack. AR is the pointer to the beginning of the integer
 * arguments. FPR is a pointer to the area where floating point
 * registers have been saved.
 *
 * RVALUE is the location where the function return value will be
 * stored. CLOSURE is the prepared closure to invoke.
 *
 * This function should only be called from assembly, which is in
 * turn called from a trampoline.
 *
 * Returns the function return flags.
 *
 */
int
ffi_closure_mips_inner_N32 (ffi_cif *cif, 
			    void (*fun)(ffi_cif*, void*, void**, void*),
                            void *user_data,
			    void *rvalue, ffi_arg *ar,
			    ffi_arg *fpr)
{
  void **avaluep;
  ffi_arg *avalue;
  ffi_type **arg_types;
  int i, avn, argn;
  int soft_float;
  ffi_arg *argp;

  soft_float = cif->abi == FFI_N64_SOFT_FLOAT
    || cif->abi == FFI_N32_SOFT_FLOAT;
  avalue = alloca (cif->nargs * sizeof (ffi_arg));
  avaluep = alloca (cif->nargs * sizeof (ffi_arg));

  argn = 0;

  if (cif->rstruct_flag)
    {
#if _MIPS_SIM==_ABIN32
      rvalue = (void *)(UINT32)ar[0];
#else /* N64 */
      rvalue = (void *)ar[0];
#endif
      argn = 1;
    }

  i = 0;
  avn = cif->nargs;
  arg_types = cif->arg_types;

  while (i < avn)
    {
      if (arg_types[i]->type == FFI_TYPE_FLOAT
	  || arg_types[i]->type == FFI_TYPE_DOUBLE
	  || arg_types[i]->type == FFI_TYPE_LONGDOUBLE)
        {
          argp = (argn >= 8 || i >= cif->mips_nfixedargs || soft_float) ? ar + argn : fpr + argn;
          if ((arg_types[i]->type == FFI_TYPE_LONGDOUBLE) && ((uintptr_t)argp & (arg_types[i]->alignment-1)))
            {
              argp=(ffi_arg*)FFI_ALIGN(argp,arg_types[i]->alignment);
              argn++;
            }
#if defined(__MIPSEB__) || defined(_MIPSEB)
          if (arg_types[i]->type == FFI_TYPE_FLOAT && argn < 8)
            avaluep[i] = ((char *) argp) + sizeof (float);
          else
#endif
            avaluep[i] = (char *) argp;
        }
      else
        {
          unsigned type = arg_types[i]->type;

          if (arg_types[i]->alignment > sizeof(ffi_arg))
            argn = FFI_ALIGN(argn, arg_types[i]->alignment / sizeof(ffi_arg));

          argp = ar + argn;

          /* The size of a pointer depends on the ABI */
          if (type == FFI_TYPE_POINTER)
            type = (cif->abi == FFI_N64 || cif->abi == FFI_N64_SOFT_FLOAT)
	      ? FFI_TYPE_SINT64 : FFI_TYPE_SINT32;

	  if (soft_float && type ==  FFI_TYPE_FLOAT)
	    type = FFI_TYPE_UINT32;

          switch (type)
            {
            case FFI_TYPE_SINT8:
              avaluep[i] = &avalue[i];
              *(SINT8 *) &avalue[i] = (SINT8) *argp;
              break;

            case FFI_TYPE_UINT8:
              avaluep[i] = &avalue[i];
              *(UINT8 *) &avalue[i] = (UINT8) *argp;
              break;

            case FFI_TYPE_SINT16:
              avaluep[i] = &avalue[i];
              *(SINT16 *) &avalue[i] = (SINT16) *argp;
              break;

            case FFI_TYPE_UINT16:
              avaluep[i] = &avalue[i];
              *(UINT16 *) &avalue[i] = (UINT16) *argp;
              break;

            case FFI_TYPE_SINT32:
              avaluep[i] = &avalue[i];
              *(SINT32 *) &avalue[i] = (SINT32) *argp;
              break;

            case FFI_TYPE_UINT32:
              avaluep[i] = &avalue[i];
              *(UINT32 *) &avalue[i] = (UINT32) *argp;
              break;

            case FFI_TYPE_STRUCT:
              if (argn < 8)
                {
                  /* Allocate space for the struct as at least part of
                     it was passed in registers.  */
                  avaluep[i] = alloca(arg_types[i]->size);
                  copy_struct_N32(avaluep[i], 0, cif->abi, arg_types[i],
                                  argn, 0, ar, fpr, i >= cif->mips_nfixedargs || soft_float);

                  break;
                }
              /* Else fall through.  */
            default:
              avaluep[i] = (char *) argp;
              break;
            }
        }
      argn += FFI_ALIGN(arg_types[i]->size, sizeof(ffi_arg)) / sizeof(ffi_arg);
      i++;
    }

  /* Invoke the closure. */
  fun (cif, rvalue, avaluep, user_data);

  return cif->flags >> (FFI_FLAG_BITS * 8);
}

#endif /* FFI_MIPS_N32 */

#if defined(FFI_MIPS_O32)
extern void ffi_closure_O32(void);
extern void ffi_go_closure_O32(void);
#else
extern void ffi_closure_N32(void);
extern void ffi_go_closure_N32(void);
#endif /* FFI_MIPS_O32 */

ffi_status
ffi_prep_go_closure (ffi_go_closure* closure, ffi_cif* cif,
		     void (*fun)(ffi_cif*,void*,void**,void*))
{
  void * fn;

#if defined(FFI_MIPS_O32)
  if (cif->abi != FFI_O32 && cif->abi != FFI_O32_SOFT_FLOAT)
    return FFI_BAD_ABI;
  fn = ffi_go_closure_O32;
#else
#if _MIPS_SIM ==_ABIN32
  if (cif->abi != FFI_N32
      && cif->abi != FFI_N32_SOFT_FLOAT)
    return FFI_BAD_ABI;
#else
  if (cif->abi != FFI_N64
      && cif->abi != FFI_N64_SOFT_FLOAT)
    return FFI_BAD_ABI;
#endif
  fn = ffi_go_closure_N32;
#endif /* FFI_MIPS_O32 */

  closure->tramp = (void *)fn;
  closure->cif = cif;
  closure->fun = fun;

  return FFI_OK;
}

#endif /* FFI_CLOSURES */