Modules/_ctypes/libffi_msvc/ffi.c - platform/external/python/cpython3 - Gitiles

 /* -----------------------------------------------------------------------
    ffi.c - Copyright (c) 1996, 1998, 1999, 2001  Red Hat, Inc.
            Copyright (c) 2002  Ranjit Mathew
            Copyright (c) 2002  Bo Thorsen
            Copyright (c) 2002  Roger Sayle

    x86 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>

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

 extern void Py_FatalError(const char *msg);

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

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

   p_argv = ecif->avalue;

   for (i = ecif->cif->nargs, p_arg = ecif->cif->arg_types;
        i != 0;
        i--, p_arg++)
     {
       size_t z;

       /* Align if necessary */
       if ((sizeof(void *) - 1) & (size_t) argp)
 	argp = (char *) ALIGN(argp, sizeof(void *));

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

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

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

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

 	    case FFI_TYPE_SINT32:
 	      *(intptr_t *) argp = (intptr_t)*(SINT32 *)(* p_argv);
 	      break;

 	    case FFI_TYPE_UINT32:
 	      *(uintptr_t *) argp = (uintptr_t)*(UINT32 *)(* p_argv);
 	      break;

 	    case FFI_TYPE_FLOAT:
 	      *(uintptr_t *) argp = 0;
 	      *(float *) argp = *(float *)(* p_argv);
 	      break;

 	    // 64-bit value cases should never be used for x86 and AMD64 builds
 	    case FFI_TYPE_SINT64:
 	      *(intptr_t *) argp = (intptr_t)*(SINT64 *)(* p_argv);
 	      break;

 	    case FFI_TYPE_UINT64:
 	      *(uintptr_t *) argp = (uintptr_t)*(UINT64 *)(* p_argv);
 	      break;

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

 	    case FFI_TYPE_DOUBLE:
 	      *(uintptr_t *) argp = 0;
 	      *(double *) argp = *(double *)(* p_argv);
 	      break;

 	    default:
 	      FFI_ASSERT(0);
 	    }
 	}
 #ifdef _WIN64
       else if (z > 8)
         {
           /* On Win64, if a single argument takes more than 8 bytes,
              then it is always passed by reference. */
           *(void **)argp = *p_argv;
           z = 8;
         }
 #endif
       else
 	{
 	  memcpy(argp, *p_argv, z);
 	}
       p_argv++;
       argp += z;
     }

   if (argp >= stack && (unsigned)(argp - stack) > ecif->cif->bytes)
     {
       Py_FatalError("FFI BUG: not enough stack space for arguments");
     }
   return;
 }

 /* Perform machine dependent cif processing */
 ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
 {
   /* Set the return type flag */
   switch (cif->rtype->type)
     {
     case FFI_TYPE_VOID:
     case FFI_TYPE_SINT64:
     case FFI_TYPE_FLOAT:
     case FFI_TYPE_DOUBLE:
     case FFI_TYPE_LONGDOUBLE:
       cif->flags = (unsigned) cif->rtype->type;
       break;

     case FFI_TYPE_STRUCT:
       /* MSVC returns small structures in registers.  Put in cif->flags
          the value FFI_TYPE_STRUCT only if the structure is big enough;
          otherwise, put the 4- or 8-bytes integer type. */
       if (cif->rtype->size <= 4)
         cif->flags = FFI_TYPE_INT;
       else if (cif->rtype->size <= 8)
         cif->flags = FFI_TYPE_SINT64;
       else
         cif->flags = FFI_TYPE_STRUCT;
       break;

     case FFI_TYPE_UINT64:
 #ifdef _WIN64
     case FFI_TYPE_POINTER:
 #endif
       cif->flags = FFI_TYPE_SINT64;
       break;

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

   return FFI_OK;
 }

 #ifdef _WIN32
 extern int
 ffi_call_x86(void (*)(char *, extended_cif *),
 	     /*@out@*/ extended_cif *,
 	     unsigned, unsigned,
 	     /*@out@*/ unsigned *,
 	     void (*fn)());
 #endif

 #ifdef _WIN64
 extern int
 ffi_call_AMD64(void (*)(char *, extended_cif *),
 		 /*@out@*/ extended_cif *,
 		 unsigned, unsigned,
 		 /*@out@*/ unsigned *,
 		 void (*fn)());
 #endif

 int
 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)
     {
 #if !defined(_WIN64)
     case FFI_SYSV:
     case FFI_STDCALL:
       return ffi_call_x86(ffi_prep_args, &ecif, cif->bytes,
 			  cif->flags, ecif.rvalue, fn);
       break;
 #else
     case FFI_SYSV:
       /* If a single argument takes more than 8 bytes,
          then a copy is passed by reference. */
       for (unsigned i = 0; i < cif->nargs; i++) {
           size_t z = cif->arg_types[i]->size;
           if (z > 8) {
               void *temp = alloca(z);
               memcpy(temp, avalue[i], z);
               avalue[i] = temp;
           }
       }
       /*@-usedef@*/
       return ffi_call_AMD64(ffi_prep_args, &ecif, cif->bytes,
 			   cif->flags, ecif.rvalue, fn);
       /*@=usedef@*/
       break;
 #endif

     default:
       FFI_ASSERT(0);
       break;
     }
   return -1; /* theller: Hrm. */
 }


 /** private members **/

 static void ffi_prep_incoming_args_SYSV (char *stack, void **ret,
 					  void** args, ffi_cif* cif);
 /* This function is jumped to by the trampoline */

 #ifdef _WIN64
 void *
 #else
 static void __fastcall
 #endif
 ffi_closure_SYSV (ffi_closure *closure, char *argp)
 {
   // this is our return value storage
   long double    res;

   // our various things...
   ffi_cif       *cif;
   void         **arg_area;
   unsigned short rtype;
   void          *resp = (void*)&res;
   void *args = argp + sizeof(void*);

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

   /* this call will initialize ARG_AREA, such that each
    * element in that array points to the corresponding
    * value on the stack; and if the function returns
    * a structure, it will re-set RESP to point to the
    * structure return address.  */

   ffi_prep_incoming_args_SYSV(args, (void**)&resp, arg_area, cif);

   (closure->fun) (cif, resp, arg_area, closure->user_data);

   rtype = cif->flags;

 #if defined(_WIN32) && !defined(_WIN64)
 #ifdef _MSC_VER
   /* now, do a generic return based on the value of rtype */
   if (rtype == FFI_TYPE_INT)
     {
 	    _asm mov eax, resp ;
 	    _asm mov eax, [eax] ;
     }
   else if (rtype == FFI_TYPE_FLOAT)
     {
 	    _asm mov eax, resp ;
 	    _asm fld DWORD PTR [eax] ;
 //      asm ("flds (%0)" : : "r" (resp) : "st" );
     }
   else if (rtype == FFI_TYPE_DOUBLE)
     {
 	    _asm mov eax, resp ;
 	    _asm fld QWORD PTR [eax] ;
 //      asm ("fldl (%0)" : : "r" (resp) : "st", "st(1)" );
     }
   else if (rtype == FFI_TYPE_LONGDOUBLE)
     {
 //      asm ("fldt (%0)" : : "r" (resp) : "st", "st(1)" );
     }
   else if (rtype == FFI_TYPE_SINT64)
     {
 	    _asm mov edx, resp ;
 	    _asm mov eax, [edx] ;
 	    _asm mov edx, [edx + 4] ;
 //      asm ("movl 0(%0),%%eax;"
 //	   "movl 4(%0),%%edx"
 //	   : : "r"(resp)
 //	   : "eax", "edx");
     }
 #else
   /* now, do a generic return based on the value of rtype */
   if (rtype == FFI_TYPE_INT)
     {
       asm ("movl (%0),%%eax" : : "r" (resp) : "eax");
     }
   else if (rtype == FFI_TYPE_FLOAT)
     {
       asm ("flds (%0)" : : "r" (resp) : "st" );
     }
   else if (rtype == FFI_TYPE_DOUBLE)
     {
       asm ("fldl (%0)" : : "r" (resp) : "st", "st(1)" );
     }
   else if (rtype == FFI_TYPE_LONGDOUBLE)
     {
       asm ("fldt (%0)" : : "r" (resp) : "st", "st(1)" );
     }
   else if (rtype == FFI_TYPE_SINT64)
     {
       asm ("movl 0(%0),%%eax;"
 	   "movl 4(%0),%%edx"
 	   : : "r"(resp)
 	   : "eax", "edx");
     }
 #endif
 #endif

 #ifdef _WIN64
   /* The result is returned in rax.  This does the right thing for
      result types except for floats; we have to 'mov xmm0, rax' in the
      caller to correct this.
   */
   return *(void **)resp;
 #endif
 }

 /*@-exportheader@*/
 static void
 ffi_prep_incoming_args_SYSV(char *stack, void **rvalue,
 			    void **avalue, ffi_cif *cif)
 /*@=exportheader@*/
 {
   register unsigned int i;
   register void **p_argv;
   register char *argp;
   register ffi_type **p_arg;

   argp = stack;

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

   p_argv = avalue;

   for (i = cif->nargs, p_arg = cif->arg_types; (i != 0); i--, p_arg++)
     {
       size_t z;

       /* Align if necessary */
       if ((sizeof(char *) - 1) & (size_t) argp) {
         argp = (char *) ALIGN(argp, sizeof(char*));
       }

       z = (*p_arg)->size;

       /* because we're little endian, this is what it turns into.   */

 #ifdef _WIN64
       if (z > 8) {
         /* On Win64, if a single argument takes more than 8 bytes,
          * then it is always passed by reference.
          */
         *p_argv = *((void**) argp);
         z = 8;
       }
       else
 #endif
       *p_argv = (void*) argp;

       p_argv++;
       argp += z;
     }

   return;
 }

 /* the cif must already be prep'ed */
 extern void ffi_closure_OUTER();

 ffi_status
 ffi_prep_closure_loc (ffi_closure* closure,
 					  ffi_cif* cif,
 					  void (*fun)(ffi_cif*,void*,void**,void*),
 					  void *user_data,
 					  void *codeloc)
 {
   short bytes;
   char *tramp;
 #ifdef _WIN64
   int mask = 0;
 #endif
   FFI_ASSERT (cif->abi == FFI_SYSV);

   if (cif->abi == FFI_SYSV)
     bytes = 0;
 #if !defined(_WIN64)
   else if (cif->abi == FFI_STDCALL)
     bytes = cif->bytes;
 #endif
   else
     return FFI_BAD_ABI;

   tramp = &closure->tramp[0];

 #define BYTES(text) memcpy(tramp, text, sizeof(text)), tramp += sizeof(text)-1
 #define POINTER(x) *(void**)tramp = (void*)(x), tramp += sizeof(void*)
 #define SHORT(x) *(short*)tramp = x, tramp += sizeof(short)
 #define INT(x) *(int*)tramp = x, tramp += sizeof(int)

 #ifdef _WIN64
   if (cif->nargs >= 1 &&
       (cif->arg_types[0]->type == FFI_TYPE_FLOAT
        || cif->arg_types[0]->type == FFI_TYPE_DOUBLE))
     mask |= 1;
   if (cif->nargs >= 2 &&
       (cif->arg_types[1]->type == FFI_TYPE_FLOAT
        || cif->arg_types[1]->type == FFI_TYPE_DOUBLE))
     mask |= 2;
   if (cif->nargs >= 3 &&
       (cif->arg_types[2]->type == FFI_TYPE_FLOAT
        || cif->arg_types[2]->type == FFI_TYPE_DOUBLE))
     mask |= 4;
   if (cif->nargs >= 4 &&
       (cif->arg_types[3]->type == FFI_TYPE_FLOAT
        || cif->arg_types[3]->type == FFI_TYPE_DOUBLE))
     mask |= 8;

   /* 41 BB ----         mov         r11d,mask */
   BYTES("\x41\xBB"); INT(mask);

   /* 48 B8 --------     mov         rax, closure			*/
   BYTES("\x48\xB8"); POINTER(closure);

   /* 49 BA --------     mov         r10, ffi_closure_OUTER */
   BYTES("\x49\xBA"); POINTER(ffi_closure_OUTER);

   /* 41 FF E2           jmp         r10 */
   BYTES("\x41\xFF\xE2");

 #else

   /* mov ecx, closure */
   BYTES("\xb9"); POINTER(closure);

   /* mov edx, esp */
   BYTES("\x8b\xd4");

   /* call ffi_closure_SYSV */
   BYTES("\xe8"); POINTER((char*)&ffi_closure_SYSV - (tramp + 4));

   /* ret bytes */
   BYTES("\xc2");
   SHORT(bytes);

 #endif

   if (tramp - &closure->tramp[0] > FFI_TRAMPOLINE_SIZE)
     Py_FatalError("FFI_TRAMPOLINE_SIZE too small in " __FILE__);

   closure->cif  = cif;
   closure->user_data = user_data;
   closure->fun  = fun;
   return FFI_OK;
 }
	/* -----------------------------------------------------------------------
	ffi.c - Copyright (c) 1996, 1998, 1999, 2001 Red Hat, Inc.
	Copyright (c) 2002 Ranjit Mathew
	Copyright (c) 2002 Bo Thorsen
	Copyright (c) 2002 Roger Sayle

	x86 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>

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

	extern void Py_FatalError(const char *msg);

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

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

	p_argv = ecif->avalue;

	for (i = ecif->cif->nargs, p_arg = ecif->cif->arg_types;
	i != 0;
	i--, p_arg++)
	{
	size_t z;

	/* Align if necessary */
	if ((sizeof(void *) - 1) & (size_t) argp)
	argp = (char ) ALIGN(argp, sizeof(void ));

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

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

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

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

	case FFI_TYPE_SINT32:
	(intptr_t ) argp = (intptr_t)(SINT32 )(* p_argv);
	break;

	case FFI_TYPE_UINT32:
	(uintptr_t ) argp = (uintptr_t)(UINT32 )(* p_argv);
	break;

	case FFI_TYPE_FLOAT:
	(uintptr_t ) argp = 0;
	(float ) argp = (float )(* p_argv);
	break;

	// 64-bit value cases should never be used for x86 and AMD64 builds
	case FFI_TYPE_SINT64:
	(intptr_t ) argp = (intptr_t)(SINT64 )(* p_argv);
	break;

	case FFI_TYPE_UINT64:
	(uintptr_t ) argp = (uintptr_t)(UINT64 )(* p_argv);
	break;

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

	case FFI_TYPE_DOUBLE:
	(uintptr_t ) argp = 0;
	(double ) argp = (double )(* p_argv);
	break;

	default:
	FFI_ASSERT(0);
	}
	}
	#ifdef _WIN64
	else if (z > 8)
	{
	/* On Win64, if a single argument takes more than 8 bytes,
	then it is always passed by reference. */
	(void )argp = p_argv;
	z = 8;
	}
	#endif
	else
	{
	memcpy(argp, *p_argv, z);
	}
	p_argv++;
	argp += z;
	}

	if (argp >= stack && (unsigned)(argp - stack) > ecif->cif->bytes)
	{
	Py_FatalError("FFI BUG: not enough stack space for arguments");
	}
	return;
	}

	/* Perform machine dependent cif processing */
	ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
	{
	/* Set the return type flag */
	switch (cif->rtype->type)
	{
	case FFI_TYPE_VOID:
	case FFI_TYPE_SINT64:
	case FFI_TYPE_FLOAT:
	case FFI_TYPE_DOUBLE:
	case FFI_TYPE_LONGDOUBLE:
	cif->flags = (unsigned) cif->rtype->type;
	break;

	case FFI_TYPE_STRUCT:
	/* MSVC returns small structures in registers. Put in cif->flags
	the value FFI_TYPE_STRUCT only if the structure is big enough;
	otherwise, put the 4- or 8-bytes integer type. */
	if (cif->rtype->size <= 4)
	cif->flags = FFI_TYPE_INT;
	else if (cif->rtype->size <= 8)
	cif->flags = FFI_TYPE_SINT64;
	else
	cif->flags = FFI_TYPE_STRUCT;
	break;

	case FFI_TYPE_UINT64:
	#ifdef _WIN64
	case FFI_TYPE_POINTER:
	#endif
	cif->flags = FFI_TYPE_SINT64;
	break;

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

	return FFI_OK;
	}

	#ifdef _WIN32
	extern int
	ffi_call_x86(void ()(char , extended_cif *),
	/@out@/ extended_cif *,
	unsigned, unsigned,
	/@out@/ unsigned *,
	void (*fn)());
	#endif

	#ifdef _WIN64
	extern int
	ffi_call_AMD64(void ()(char , extended_cif *),
	/@out@/ extended_cif *,
	unsigned, unsigned,
	/@out@/ unsigned *,
	void (*fn)());
	#endif

	int
	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)
	{
	#if !defined(_WIN64)
	case FFI_SYSV:
	case FFI_STDCALL:
	return ffi_call_x86(ffi_prep_args, &ecif, cif->bytes,
	cif->flags, ecif.rvalue, fn);
	break;
	#else
	case FFI_SYSV:
	/* If a single argument takes more than 8 bytes,
	then a copy is passed by reference. */
	for (unsigned i = 0; i < cif->nargs; i++) {
	size_t z = cif->arg_types[i]->size;
	if (z > 8) {
	void *temp = alloca(z);
	memcpy(temp, avalue[i], z);
	avalue[i] = temp;
	}
	}
	/@-usedef@/
	return ffi_call_AMD64(ffi_prep_args, &ecif, cif->bytes,
	cif->flags, ecif.rvalue, fn);
	/@=usedef@/
	break;
	#endif

	default:
	FFI_ASSERT(0);
	break;
	}
	return -1; /* theller: Hrm. */
	}


	/ private members /

	static void ffi_prep_incoming_args_SYSV (char stack, void *ret,
	void** args, ffi_cif* cif);
	/* This function is jumped to by the trampoline */

	#ifdef _WIN64
	void *
	#else
	static void __fastcall
	#endif
	ffi_closure_SYSV (ffi_closure closure, char argp)
	{
	// this is our return value storage
	long double res;

	// our various things...
	ffi_cif *cif;
	void **arg_area;
	unsigned short rtype;
	void resp = (void)&res;
	void args = argp + sizeof(void);

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

	/* this call will initialize ARG_AREA, such that each
	* element in that array points to the corresponding
	* value on the stack; and if the function returns
	* a structure, it will re-set RESP to point to the
	* structure return address. */

	ffi_prep_incoming_args_SYSV(args, (void**)&resp, arg_area, cif);

	(closure->fun) (cif, resp, arg_area, closure->user_data);

	rtype = cif->flags;

	#if defined(_WIN32) && !defined(_WIN64)
	#ifdef _MSC_VER
	/* now, do a generic return based on the value of rtype */
	if (rtype == FFI_TYPE_INT)
	{
	_asm mov eax, resp ;
	_asm mov eax, [eax] ;
	}
	else if (rtype == FFI_TYPE_FLOAT)
	{
	_asm mov eax, resp ;
	_asm fld DWORD PTR [eax] ;
	// asm ("flds (%0)" : : "r" (resp) : "st" );
	}
	else if (rtype == FFI_TYPE_DOUBLE)
	{
	_asm mov eax, resp ;
	_asm fld QWORD PTR [eax] ;
	// asm ("fldl (%0)" : : "r" (resp) : "st", "st(1)" );
	}
	else if (rtype == FFI_TYPE_LONGDOUBLE)
	{
	// asm ("fldt (%0)" : : "r" (resp) : "st", "st(1)" );
	}
	else if (rtype == FFI_TYPE_SINT64)
	{
	_asm mov edx, resp ;
	_asm mov eax, [edx] ;
	_asm mov edx, [edx + 4] ;
	// asm ("movl 0(%0),%%eax;"
	// "movl 4(%0),%%edx"
	// : : "r"(resp)
	// : "eax", "edx");
	}
	#else
	/* now, do a generic return based on the value of rtype */
	if (rtype == FFI_TYPE_INT)
	{
	asm ("movl (%0),%%eax" : : "r" (resp) : "eax");
	}
	else if (rtype == FFI_TYPE_FLOAT)
	{
	asm ("flds (%0)" : : "r" (resp) : "st" );
	}
	else if (rtype == FFI_TYPE_DOUBLE)
	{
	asm ("fldl (%0)" : : "r" (resp) : "st", "st(1)" );
	}
	else if (rtype == FFI_TYPE_LONGDOUBLE)
	{
	asm ("fldt (%0)" : : "r" (resp) : "st", "st(1)" );
	}
	else if (rtype == FFI_TYPE_SINT64)
	{
	asm ("movl 0(%0),%%eax;"
	"movl 4(%0),%%edx"
	: : "r"(resp)
	: "eax", "edx");
	}
	#endif
	#endif

	#ifdef _WIN64
	/* The result is returned in rax. This does the right thing for
	result types except for floats; we have to 'mov xmm0, rax' in the
	caller to correct this.
	*/
	return (void *)resp;
	#endif
	}

	/@-exportheader@/
	static void
	ffi_prep_incoming_args_SYSV(char stack, void *rvalue,
	void *avalue, ffi_cif cif)
	/@=exportheader@/
	{
	register unsigned int i;
	register void **p_argv;
	register char *argp;
	register ffi_type **p_arg;

	argp = stack;

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

	p_argv = avalue;

	for (i = cif->nargs, p_arg = cif->arg_types; (i != 0); i--, p_arg++)
	{
	size_t z;

	/* Align if necessary */
	if ((sizeof(char *) - 1) & (size_t) argp) {
	argp = (char ) ALIGN(argp, sizeof(char));
	}

	z = (*p_arg)->size;

	/* because we're little endian, this is what it turns into. */

	#ifdef _WIN64
	if (z > 8) {
	/* On Win64, if a single argument takes more than 8 bytes,
	* then it is always passed by reference.
	*/
	p_argv = ((void**) argp);
	z = 8;
	}
	else
	#endif
	p_argv = (void) argp;

	p_argv++;
	argp += z;
	}

	return;
	}

	/* the cif must already be prep'ed */
	extern void ffi_closure_OUTER();

	ffi_status
	ffi_prep_closure_loc (ffi_closure* closure,
	ffi_cif* cif,
	void (fun)(ffi_cif,void,void,void),
	void *user_data,
	void *codeloc)
	{
	short bytes;
	char *tramp;
	#ifdef _WIN64
	int mask = 0;
	#endif
	FFI_ASSERT (cif->abi == FFI_SYSV);

	if (cif->abi == FFI_SYSV)
	bytes = 0;
	#if !defined(_WIN64)
	else if (cif->abi == FFI_STDCALL)
	bytes = cif->bytes;
	#endif
	else
	return FFI_BAD_ABI;

	tramp = &closure->tramp[0];

	#define BYTES(text) memcpy(tramp, text, sizeof(text)), tramp += sizeof(text)-1
	#define POINTER(x) (void)tramp = (void)(x), tramp += sizeof(void*)
	#define SHORT(x) (short)tramp = x, tramp += sizeof(short)
	#define INT(x) (int)tramp = x, tramp += sizeof(int)

	#ifdef _WIN64
	if (cif->nargs >= 1 &&
	(cif->arg_types[0]->type == FFI_TYPE_FLOAT
	\|\| cif->arg_types[0]->type == FFI_TYPE_DOUBLE))
	mask \|= 1;
	if (cif->nargs >= 2 &&
	(cif->arg_types[1]->type == FFI_TYPE_FLOAT
	\|\| cif->arg_types[1]->type == FFI_TYPE_DOUBLE))
	mask \|= 2;
	if (cif->nargs >= 3 &&
	(cif->arg_types[2]->type == FFI_TYPE_FLOAT
	\|\| cif->arg_types[2]->type == FFI_TYPE_DOUBLE))
	mask \|= 4;
	if (cif->nargs >= 4 &&
	(cif->arg_types[3]->type == FFI_TYPE_FLOAT
	\|\| cif->arg_types[3]->type == FFI_TYPE_DOUBLE))
	mask \|= 8;

	/* 41 BB ---- mov r11d,mask */
	BYTES("\x41\xBB"); INT(mask);

	/* 48 B8 -------- mov rax, closure */
	BYTES("\x48\xB8"); POINTER(closure);

	/* 49 BA -------- mov r10, ffi_closure_OUTER */
	BYTES("\x49\xBA"); POINTER(ffi_closure_OUTER);

	/* 41 FF E2 jmp r10 */
	BYTES("\x41\xFF\xE2");

	#else

	/* mov ecx, closure */
	BYTES("\xb9"); POINTER(closure);

	/* mov edx, esp */
	BYTES("\x8b\xd4");

	/* call ffi_closure_SYSV */
	BYTES("\xe8"); POINTER((char*)&ffi_closure_SYSV - (tramp + 4));

	/* ret bytes */
	BYTES("\xc2");
	SHORT(bytes);

	#endif

	if (tramp - &closure->tramp[0] > FFI_TRAMPOLINE_SIZE)
	Py_FatalError("FFI_TRAMPOLINE_SIZE too small in " __FILE__);

	closure->cif = cif;
	closure->user_data = user_data;
	closure->fun = fun;
	return FFI_OK;
	}