llvm-gcc-4.0/libffi/src/sh64/ffi.c - llvm-archive - Git at Google

 /* -----------------------------------------------------------------------
    ffi.c - Copyright (c) 2003 Kaz Kojima

    SuperH SHmedia 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 CYGNUS SOLUTIONS 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 <stdlib.h>

 #define NGREGARG 8
 #define NFREGARG 12

 /* If the structure has essentialy an unique element, return its type.  */
 static int
 simple_type (ffi_type *arg)
 {
   if (arg->type != FFI_TYPE_STRUCT)
     return arg->type;
   else if (arg->elements[1])
     return FFI_TYPE_STRUCT;

   return simple_type (arg->elements[0]);
 }

 static int
 return_type (ffi_type *arg)
 {
   unsigned short type;

   if (arg->type != FFI_TYPE_STRUCT)
     return arg->type;

   type = simple_type (arg->elements[0]);
   if (! arg->elements[1])
     {
       switch (type)
 	{
 	case FFI_TYPE_SINT8:
 	case FFI_TYPE_UINT8:
 	case FFI_TYPE_SINT16:
 	case FFI_TYPE_UINT16:
 	case FFI_TYPE_SINT32:
 	case FFI_TYPE_UINT32:
 	case FFI_TYPE_SINT64:
 	case FFI_TYPE_UINT64:
 	  return FFI_TYPE_UINT64;

 	default:
 	  return type;
 	}
     }

   /* gcc uses r2 if the result can be packed in on register.  */
   if (arg->size <= sizeof (UINT64))
     return FFI_TYPE_UINT64;

   return FFI_TYPE_STRUCT;
 }

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

 /*@-exportheader@*/
 void ffi_prep_args(char *stack, extended_cif *ecif)
 /*@=exportheader@*/
 {
   register unsigned int i;
   register unsigned int avn;
   register void **p_argv;
   register char *argp;
   register ffi_type **p_arg;

   argp = stack;

   if (return_type (ecif->cif->rtype) == FFI_TYPE_STRUCT)
     {
       *(void **) argp = ecif->rvalue;
       argp += sizeof (UINT64);
     }

   avn = ecif->cif->nargs;
   p_argv = ecif->avalue;

   for (i = 0, p_arg = ecif->cif->arg_types; i < avn; i++, p_arg++, p_argv++)
     {
       size_t z;

       z = (*p_arg)->size;
       if (z < sizeof (UINT32))
 	{
 	  switch ((*p_arg)->type)
 	    {
 	    case FFI_TYPE_SINT8:
 	      *(SINT64 *) argp = (SINT64) *(SINT8 *)(*p_argv);
 	      break;

 	    case FFI_TYPE_UINT8:
 	      *(UINT64 *) argp = (UINT64) *(UINT8 *)(*p_argv);
 	      break;

 	    case FFI_TYPE_SINT16:
 	      *(SINT64 *) argp = (SINT64) *(SINT16 *)(*p_argv);
 	      break;

 	    case FFI_TYPE_UINT16:
 	      *(UINT64 *) argp = (UINT64) *(UINT16 *)(*p_argv);
 	      break;

 	    case FFI_TYPE_STRUCT:
 	      *(UINT64 *) argp = (UINT64) *(UINT32 *)(*p_argv);
 	      break;

 	    default:
 	      FFI_ASSERT(0);
 	    }
 	  argp += sizeof (UINT64);
 	}
       else if (z == sizeof (UINT32))
 	{
 	  *(UINT64 *) argp = (UINT64) *(UINT32 *) (*p_argv);
 	  argp += sizeof (UINT64);
 	}
       else if (z == sizeof (UINT64))
 	{
 	  *(UINT64 *) argp = *(UINT64 *) (*p_argv);
 	  argp += sizeof (UINT64);
 	}
       else
 	{
 	  int n = (z + sizeof (UINT64) - 1) / sizeof (UINT64);

 	  memcpy (argp, *p_argv, z);
 	  argp += n * sizeof (UINT64);
 	}
     }

   return;
 }

 /* Perform machine dependent cif processing */
 ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
 {
   int i, j;
   int size, type;
   int n, m;
   int greg;
   int freg;

   greg = (return_type (cif->rtype) == FFI_TYPE_STRUCT ? 1 : 0);
   freg = 0;
   cif->flags2 = 0;

   for (i = j = 0; i < cif->nargs; i++)
     {
       type = (cif->arg_types)[i]->type;
       switch (type)
 	{
 	case FFI_TYPE_FLOAT:
 	  greg++;
 	  cif->bytes += sizeof (UINT64) - sizeof (float);
 	  if (freg >= NFREGARG - 1)
 	    continue;
 	  freg++;
 	  cif->flags2 += ((cif->arg_types)[i]->type) << (2 * j++);
 	  break;

 	case FFI_TYPE_DOUBLE:
 	  if (greg++ >= NGREGARG && (freg + 1) >= NFREGARG)
 	    continue;
 	  if ((freg + 1) < NFREGARG)
 	    {
 	      freg = (freg + 1) & ~1;
 	      freg += 2;
 	      cif->flags2 += ((cif->arg_types)[i]->type) << (2 * j++);
 	    }
 	  else
 	    cif->flags2 += FFI_TYPE_INT << (2 * j++);
 	  break;

 	default:
 	  size = (cif->arg_types)[i]->size;
 	  if (size < sizeof (UINT64))
 	    cif->bytes += sizeof (UINT64) - size;
 	  n = (size + sizeof (UINT64) - 1) / sizeof (UINT64);
 	  if (greg >= NGREGARG)
 	    continue;
 	  else if (greg + n - 1 >= NGREGARG)
 	    greg = NGREGARG;
 	  else
 	    greg += n;
 	  for (m = 0; m < n; m++)
 	    cif->flags2 += FFI_TYPE_INT << (2 * j++);
 	  break;
 	}
     }

   /* Set the return type flag */
   switch (cif->rtype->type)
     {
     case FFI_TYPE_STRUCT:
       cif->flags = return_type (cif->rtype);
       break;

     case FFI_TYPE_VOID:
     case FFI_TYPE_FLOAT:
     case FFI_TYPE_DOUBLE:
     case FFI_TYPE_SINT64:
     case FFI_TYPE_UINT64:
       cif->flags = cif->rtype->type;
       break;

     default:
       cif->flags = FFI_TYPE_INT;
       break;
     }

   return FFI_OK;
 }

 /*@-declundef@*/
 /*@-exportheader@*/
 extern void ffi_call_SYSV(void (*)(char *, extended_cif *),
 			  /*@out@*/ extended_cif *,
 			  unsigned, unsigned, long long,
 			  /*@out@*/ unsigned *,
 			  void (*fn)());
 /*@=declundef@*/
 /*@=exportheader@*/

 void ffi_call(/*@dependent@*/ ffi_cif *cif,
 	      void (*fn)(),
 	      /*@out@*/ void *rvalue,
 	      /*@dependent@*/ void **avalue)
 {
   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))
     {
       /*@-sysunrecog@*/
       ecif.rvalue = alloca(cif->rtype->size);
       /*@=sysunrecog@*/
     }
   else
     ecif.rvalue = rvalue;

   switch (cif->abi)
     {
     case FFI_SYSV:
       /*@-usedef@*/
       ffi_call_SYSV(ffi_prep_args, &ecif, cif->bytes,
 		    cif->flags, cif->flags2, ecif.rvalue, fn);
       /*@=usedef@*/
       break;
     default:
       FFI_ASSERT(0);
       break;
     }
 }

 extern void ffi_closure_SYSV (void);
 extern void __ic_invalidate (void *line);

 ffi_status
 ffi_prep_closure (ffi_closure *closure,
 		  ffi_cif *cif,
 		  void (*fun)(ffi_cif*, void*, void**, void*),
 		  void *user_data)
 {
   unsigned int *tramp;

   FFI_ASSERT (cif->abi == FFI_GCC_SYSV);

   tramp = (unsigned int *) &closure->tramp[0];
   /* Since ffi_closure is an aligned object, the ffi trampoline is
      called as an SHcompact code.  Sigh.
      SHcompact part:
      mova @(1,pc),r0; add #1,r0; jmp @r0; nop;
      SHmedia part:
      movi fnaddr >> 16,r1; shori fnaddr,r1; ptabs/l r1,tr0
      movi cxt >> 16,r1; shori cxt,r1; blink tr0,r63  */
 #ifdef __LITTLE_ENDIAN__
   tramp[0] = 0x7001c701;
   tramp[1] = 0x0009402b;
 #else
   tramp[0] = 0xc7017001;
   tramp[1] = 0x402b0009;
 #endif
   tramp[2] = 0xcc000010 | (((UINT32) ffi_closure_SYSV) >> 16) << 10;
   tramp[3] = 0xc8000010 | (((UINT32) ffi_closure_SYSV) & 0xffff) << 10;
   tramp[4] = 0x6bf10600;
   tramp[5] = 0xcc000010 | (((UINT32) closure) >> 16) << 10;
   tramp[6] = 0xc8000010 | (((UINT32) closure) & 0xffff) << 10;
   tramp[7] = 0x4401fff0;

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

   /* Flush the icache.  */
   asm volatile ("ocbwb %0,0; synco; icbi %0,0; synci" : : "r" (tramp));

   return FFI_OK;
 }

 /* Basically the trampoline invokes ffi_closure_SYSV, and on
  * entry, r3 holds the address of the closure.
  * After storing the registers that could possibly contain
  * parameters to be passed into the stack frame and setting
  * up space for a return value, ffi_closure_SYSV invokes the
  * following helper function to do most of the work.
  */

 int
 ffi_closure_helper_SYSV (ffi_closure *closure, UINT64 *rvalue,
 			 UINT64 *pgr, UINT64 *pfr, UINT64 *pst)
 {
   void **avalue;
   ffi_type **p_arg;
   int i, avn;
   int greg, freg;
   ffi_cif *cif;

   cif = closure->cif;
   avalue = alloca (cif->nargs * sizeof (void *));

   /* Copy the caller's structure return value address so that the closure
      returns the data directly to the caller.  */
   if (cif->rtype->type == FFI_TYPE_STRUCT)
     {
       rvalue = *pgr;
       greg = 1;
     }
   else
     greg = 0;

   freg = 0;
   cif = closure->cif;
   avn = cif->nargs;

   /* Grab the addresses of the arguments from the stack frame.  */
   for (i = 0, p_arg = cif->arg_types; i < avn; i++, p_arg++)
     {
       size_t z;
       void *p;

       z = (*p_arg)->size;
       if (z < sizeof (UINT32))
 	{
 	  p = pgr + greg++;

 	  switch ((*p_arg)->type)
 	    {
 	    case FFI_TYPE_SINT8:
 	    case FFI_TYPE_UINT8:
 	    case FFI_TYPE_SINT16:
 	    case FFI_TYPE_UINT16:
 	    case FFI_TYPE_STRUCT:
 #ifdef __LITTLE_ENDIAN__
 	      avalue[i] = p;
 #else
 	      avalue[i] = ((char *) p) + sizeof (UINT32) - z;
 #endif
 	      break;

 	    default:
 	      FFI_ASSERT(0);
 	    }
 	}
       else if (z == sizeof (UINT32))
 	{
 	  if ((*p_arg)->type == FFI_TYPE_FLOAT)
 	    {
 	      if (freg < NFREGARG - 1)
 #ifdef __LITTLE_ENDIAN__
 		avalue[i] = (UINT32 *) pfr + (1 ^ freg++);
 #else
 		avalue[i] = (UINT32 *) pfr + freg++;
 #endif
 	      else
 #ifdef __LITTLE_ENDIAN__
 		avalue[i] = pgr + greg;
 #else
 		avalue[i] = (UINT32 *) (pgr + greg) + 1;
 #endif
 	    }
 	  else
 #ifdef __LITTLE_ENDIAN__
 	    avalue[i] = pgr + greg;
 #else
 	    avalue[i] = (UINT32 *) (pgr + greg) + 1;
 #endif
 	  greg++;
 	}
       else if ((*p_arg)->type == FFI_TYPE_DOUBLE)
 	{
 	  if (freg + 1 >= NFREGARG)
 	    avalue[i] = pgr + greg;
 	  else
 	    {
 	      freg = (freg + 1) & ~1;
 	      avalue[i] = pfr + (freg >> 1);
 	      freg += 2;
 	    }
 	  greg++;
 	}
       else
 	{
 	  int n = (z + sizeof (UINT64) - 1) / sizeof (UINT64);

 	  avalue[i] = pgr + greg;
 	  greg += n;
 	}
     }

   (closure->fun) (cif, rvalue, avalue, closure->user_data);

   /* Tell ffi_closure_SYSV how to perform return type promotions.  */
   return cif->rtype->type;
 }
	/* -----------------------------------------------------------------------
	ffi.c - Copyright (c) 2003 Kaz Kojima

	SuperH SHmedia 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 CYGNUS SOLUTIONS 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 <stdlib.h>

	#define NGREGARG 8
	#define NFREGARG 12

	/* If the structure has essentialy an unique element, return its type. */
	static int
	simple_type (ffi_type *arg)
	{
	if (arg->type != FFI_TYPE_STRUCT)
	return arg->type;
	else if (arg->elements[1])
	return FFI_TYPE_STRUCT;

	return simple_type (arg->elements[0]);
	}

	static int
	return_type (ffi_type *arg)
	{
	unsigned short type;

	if (arg->type != FFI_TYPE_STRUCT)
	return arg->type;

	type = simple_type (arg->elements[0]);
	if (! arg->elements[1])
	{
	switch (type)
	{
	case FFI_TYPE_SINT8:
	case FFI_TYPE_UINT8:
	case FFI_TYPE_SINT16:
	case FFI_TYPE_UINT16:
	case FFI_TYPE_SINT32:
	case FFI_TYPE_UINT32:
	case FFI_TYPE_SINT64:
	case FFI_TYPE_UINT64:
	return FFI_TYPE_UINT64;

	default:
	return type;
	}
	}

	/* gcc uses r2 if the result can be packed in on register. */
	if (arg->size <= sizeof (UINT64))
	return FFI_TYPE_UINT64;

	return FFI_TYPE_STRUCT;
	}

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

	/@-exportheader@/
	void ffi_prep_args(char stack, extended_cif ecif)
	/@=exportheader@/
	{
	register unsigned int i;
	register unsigned int avn;
	register void **p_argv;
	register char *argp;
	register ffi_type **p_arg;

	argp = stack;

	if (return_type (ecif->cif->rtype) == FFI_TYPE_STRUCT)
	{
	(void *) argp = ecif->rvalue;
	argp += sizeof (UINT64);
	}

	avn = ecif->cif->nargs;
	p_argv = ecif->avalue;

	for (i = 0, p_arg = ecif->cif->arg_types; i < avn; i++, p_arg++, p_argv++)
	{
	size_t z;

	z = (*p_arg)->size;
	if (z < sizeof (UINT32))
	{
	switch ((*p_arg)->type)
	{
	case FFI_TYPE_SINT8:
	(SINT64 ) argp = (SINT64) (SINT8 )(*p_argv);
	break;

	case FFI_TYPE_UINT8:
	(UINT64 ) argp = (UINT64) (UINT8 )(*p_argv);
	break;

	case FFI_TYPE_SINT16:
	(SINT64 ) argp = (SINT64) (SINT16 )(*p_argv);
	break;

	case FFI_TYPE_UINT16:
	(UINT64 ) argp = (UINT64) (UINT16 )(*p_argv);
	break;

	case FFI_TYPE_STRUCT:
	(UINT64 ) argp = (UINT64) (UINT32 )(*p_argv);
	break;

	default:
	FFI_ASSERT(0);
	}
	argp += sizeof (UINT64);
	}
	else if (z == sizeof (UINT32))
	{
	(UINT64 ) argp = (UINT64) (UINT32 ) (*p_argv);
	argp += sizeof (UINT64);
	}
	else if (z == sizeof (UINT64))
	{
	(UINT64 ) argp = (UINT64 ) (*p_argv);
	argp += sizeof (UINT64);
	}
	else
	{
	int n = (z + sizeof (UINT64) - 1) / sizeof (UINT64);

	memcpy (argp, *p_argv, z);
	argp += n * sizeof (UINT64);
	}
	}

	return;
	}

	/* Perform machine dependent cif processing */
	ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
	{
	int i, j;
	int size, type;
	int n, m;
	int greg;
	int freg;

	greg = (return_type (cif->rtype) == FFI_TYPE_STRUCT ? 1 : 0);
	freg = 0;
	cif->flags2 = 0;

	for (i = j = 0; i < cif->nargs; i++)
	{
	type = (cif->arg_types)[i]->type;
	switch (type)
	{
	case FFI_TYPE_FLOAT:
	greg++;
	cif->bytes += sizeof (UINT64) - sizeof (float);
	if (freg >= NFREGARG - 1)
	continue;
	freg++;
	cif->flags2 += ((cif->arg_types)[i]->type) << (2 * j++);
	break;

	case FFI_TYPE_DOUBLE:
	if (greg++ >= NGREGARG && (freg + 1) >= NFREGARG)
	continue;
	if ((freg + 1) < NFREGARG)
	{
	freg = (freg + 1) & ~1;
	freg += 2;
	cif->flags2 += ((cif->arg_types)[i]->type) << (2 * j++);
	}
	else
	cif->flags2 += FFI_TYPE_INT << (2 * j++);
	break;

	default:
	size = (cif->arg_types)[i]->size;
	if (size < sizeof (UINT64))
	cif->bytes += sizeof (UINT64) - size;
	n = (size + sizeof (UINT64) - 1) / sizeof (UINT64);
	if (greg >= NGREGARG)
	continue;
	else if (greg + n - 1 >= NGREGARG)
	greg = NGREGARG;
	else
	greg += n;
	for (m = 0; m < n; m++)
	cif->flags2 += FFI_TYPE_INT << (2 * j++);
	break;
	}
	}

	/* Set the return type flag */
	switch (cif->rtype->type)
	{
	case FFI_TYPE_STRUCT:
	cif->flags = return_type (cif->rtype);
	break;

	case FFI_TYPE_VOID:
	case FFI_TYPE_FLOAT:
	case FFI_TYPE_DOUBLE:
	case FFI_TYPE_SINT64:
	case FFI_TYPE_UINT64:
	cif->flags = cif->rtype->type;
	break;

	default:
	cif->flags = FFI_TYPE_INT;
	break;
	}

	return FFI_OK;
	}

	/@-declundef@/
	/@-exportheader@/
	extern void ffi_call_SYSV(void ()(char , extended_cif *),
	/@out@/ extended_cif *,
	unsigned, unsigned, long long,
	/@out@/ unsigned *,
	void (*fn)());
	/@=declundef@/
	/@=exportheader@/

	void ffi_call(/@dependent@/ ffi_cif *cif,
	void (*fn)(),
	/@out@/ void *rvalue,
	/@dependent@/ void **avalue)
	{
	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))
	{
	/@-sysunrecog@/
	ecif.rvalue = alloca(cif->rtype->size);
	/@=sysunrecog@/
	}
	else
	ecif.rvalue = rvalue;

	switch (cif->abi)
	{
	case FFI_SYSV:
	/@-usedef@/
	ffi_call_SYSV(ffi_prep_args, &ecif, cif->bytes,
	cif->flags, cif->flags2, ecif.rvalue, fn);
	/@=usedef@/
	break;
	default:
	FFI_ASSERT(0);
	break;
	}
	}

	extern void ffi_closure_SYSV (void);
	extern void __ic_invalidate (void *line);

	ffi_status
	ffi_prep_closure (ffi_closure *closure,
	ffi_cif *cif,
	void (fun)(ffi_cif, void, void, void),
	void *user_data)
	{
	unsigned int *tramp;

	FFI_ASSERT (cif->abi == FFI_GCC_SYSV);

	tramp = (unsigned int *) &closure->tramp[0];
	/* Since ffi_closure is an aligned object, the ffi trampoline is
	called as an SHcompact code. Sigh.
	SHcompact part:
	mova @(1,pc),r0; add #1,r0; jmp @r0; nop;
	SHmedia part:
	movi fnaddr >> 16,r1; shori fnaddr,r1; ptabs/l r1,tr0
	movi cxt >> 16,r1; shori cxt,r1; blink tr0,r63 */
	#ifdef __LITTLE_ENDIAN__
	tramp[0] = 0x7001c701;
	tramp[1] = 0x0009402b;
	#else
	tramp[0] = 0xc7017001;
	tramp[1] = 0x402b0009;
	#endif
	tramp[2] = 0xcc000010 \| (((UINT32) ffi_closure_SYSV) >> 16) << 10;
	tramp[3] = 0xc8000010 \| (((UINT32) ffi_closure_SYSV) & 0xffff) << 10;
	tramp[4] = 0x6bf10600;
	tramp[5] = 0xcc000010 \| (((UINT32) closure) >> 16) << 10;
	tramp[6] = 0xc8000010 \| (((UINT32) closure) & 0xffff) << 10;
	tramp[7] = 0x4401fff0;

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

	/* Flush the icache. */
	asm volatile ("ocbwb %0,0; synco; icbi %0,0; synci" : : "r" (tramp));

	return FFI_OK;
	}

	/* Basically the trampoline invokes ffi_closure_SYSV, and on
	* entry, r3 holds the address of the closure.
	* After storing the registers that could possibly contain
	* parameters to be passed into the stack frame and setting
	* up space for a return value, ffi_closure_SYSV invokes the
	* following helper function to do most of the work.
	*/

	int
	ffi_closure_helper_SYSV (ffi_closure closure, UINT64 rvalue,
	UINT64 pgr, UINT64 pfr, UINT64 *pst)
	{
	void **avalue;
	ffi_type **p_arg;
	int i, avn;
	int greg, freg;
	ffi_cif *cif;

	cif = closure->cif;
	avalue = alloca (cif->nargs * sizeof (void *));

	/* Copy the caller's structure return value address so that the closure
	returns the data directly to the caller. */
	if (cif->rtype->type == FFI_TYPE_STRUCT)
	{
	rvalue = *pgr;
	greg = 1;
	}
	else
	greg = 0;

	freg = 0;
	cif = closure->cif;
	avn = cif->nargs;

	/* Grab the addresses of the arguments from the stack frame. */
	for (i = 0, p_arg = cif->arg_types; i < avn; i++, p_arg++)
	{
	size_t z;
	void *p;

	z = (*p_arg)->size;
	if (z < sizeof (UINT32))
	{
	p = pgr + greg++;

	switch ((*p_arg)->type)
	{
	case FFI_TYPE_SINT8:
	case FFI_TYPE_UINT8:
	case FFI_TYPE_SINT16:
	case FFI_TYPE_UINT16:
	case FFI_TYPE_STRUCT:
	#ifdef __LITTLE_ENDIAN__
	avalue[i] = p;
	#else
	avalue[i] = ((char *) p) + sizeof (UINT32) - z;
	#endif
	break;

	default:
	FFI_ASSERT(0);
	}
	}
	else if (z == sizeof (UINT32))
	{
	if ((*p_arg)->type == FFI_TYPE_FLOAT)
	{
	if (freg < NFREGARG - 1)
	#ifdef __LITTLE_ENDIAN__
	avalue[i] = (UINT32 *) pfr + (1 ^ freg++);
	#else
	avalue[i] = (UINT32 *) pfr + freg++;
	#endif
	else
	#ifdef __LITTLE_ENDIAN__
	avalue[i] = pgr + greg;
	#else
	avalue[i] = (UINT32 *) (pgr + greg) + 1;
	#endif
	}
	else
	#ifdef __LITTLE_ENDIAN__
	avalue[i] = pgr + greg;
	#else
	avalue[i] = (UINT32 *) (pgr + greg) + 1;
	#endif
	greg++;
	}
	else if ((*p_arg)->type == FFI_TYPE_DOUBLE)
	{
	if (freg + 1 >= NFREGARG)
	avalue[i] = pgr + greg;
	else
	{
	freg = (freg + 1) & ~1;
	avalue[i] = pfr + (freg >> 1);
	freg += 2;
	}
	greg++;
	}
	else
	{
	int n = (z + sizeof (UINT64) - 1) / sizeof (UINT64);

	avalue[i] = pgr + greg;
	greg += n;
	}
	}

	(closure->fun) (cif, rvalue, avalue, closure->user_data);

	/* Tell ffi_closure_SYSV how to perform return type promotions. */
	return cif->rtype->type;
	}