ffi.c

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        } else {
          cif->flags = FFI_TYPE_STRUCT;
	}
      }
      break;

    case FFI_TYPE_FLOAT:
      is_simple = FALSE;
      cif->flags = FFI_TYPE_FLOAT;
      break;

    case FFI_TYPE_DOUBLE:
      is_simple = FALSE;
      cif->flags = FFI_TYPE_DOUBLE;
      break;

    default:
      cif->flags = FFI_TYPE_INT;
      /* This seems to depend on little endian mode, and the fact that	*/
      /* the return pointer always points to at least 8 bytes.  But 	*/
      /* that also seems to be true for other platforms.		*/
      break;
    }
  
  if (is_simple) cif -> flags |= simple_flag;
  return FFI_OK;
}

extern int ffi_call_unix(bool (*)(struct ia64_args *, extended_cif *, int), 
			 extended_cif *, unsigned, 
			 unsigned, unsigned *, void (*)());

void
ffi_call(ffi_cif *cif, void (*fn)(), void *rvalue, void **avalue)
{
  extended_cif ecif;
  long simple = cif -> flags & FFI_SIMPLE;

  /* Should this also check for Unix ABI? */
  /* This is almost, but not quite, machine independent.  Note that	*/
  /* we can get away with not caring about length of the result because	*/
  /* we assume we are little endian, and the result buffer is large 	*/
  /* enough.								*/
  /* This needs work for HP/UX.						*/
  if (simple) {
    long (*lfn)() = (long (*)())fn;
    long result;
    switch(simple) {
      case FFI_SIMPLE_V:
	result = lfn();
	break;
      case FFI_SIMPLE_I:
	result = lfn(*(int *)avalue[0]);
	break;
      case FFI_SIMPLE_L:
	result = lfn(*(long *)avalue[0]);
	break;
      case FFI_SIMPLE_II:
	result = lfn(*(int *)avalue[0], *(int *)avalue[1]);
	break;
      case FFI_SIMPLE_IL:
	result = lfn(*(int *)avalue[0], *(long *)avalue[1]);
	break;
      case FFI_SIMPLE_LI:
	result = lfn(*(long *)avalue[0], *(int *)avalue[1]);
	break;
      case FFI_SIMPLE_LL:
	result = lfn(*(long *)avalue[0], *(long *)avalue[1]);
	break;
    }
    if ((cif->flags & ~FFI_SIMPLE) != FFI_TYPE_VOID && 0 != rvalue) {
      * (long *)rvalue = result;
    }
    return;
  }
  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) 
    {
    case FFI_UNIX:
      ffi_call_unix(ffi_prep_args, &ecif, cif->bytes,
		    cif->flags, rvalue, fn);
      break;

    default:
      FFI_ASSERT(0);
      break;
    }
}

/*
 * Closures represent a pair consisting of a function pointer, and
 * some user data.  A closure is invoked by reinterpreting the closure
 * as a function pointer, and branching to it.  Thus we can make an
 * interpreted function callable as a C function:  We turn the interpreter
 * itself, together with a pointer specifying the interpreted procedure,
 * into a closure.
 * On X86, the first few words of the closure structure actually contain code,
 * which will do the right thing.  On most other architectures, this
 * would raise some Icache/Dcache coherence issues (which can be solved, but
 * often not cheaply).
 * For IA64, function pointer are already pairs consisting of a code
 * pointer, and a gp pointer.  The latter is needed to access global variables.
 * Here we set up such a pair as the first two words of the closure (in
 * the "trampoline" area), but we replace the gp pointer with a pointer
 * to the closure itself.  We also add the real gp pointer to the
 * closure.  This allows the function entry code to both retrieve the
 * user data, and to restire the correct gp pointer.
 */

static void 
ffi_prep_incoming_args_UNIX(struct ia64_args *args, void **rvalue,
			    void **avalue, ffi_cif *cif);

/* This function is entered with the doctored gp (r1) value.
 * This code is extremely gcc specific.  There is some argument that
 * it should really be written in assembly code, since it depends on
 * gcc properties that might change over time.
 */

/* ffi_closure_UNIX is an assembly routine, which copies the register 	*/
/* state into a struct ia64_args, and then invokes			*/
/* ffi_closure_UNIX_inner.  It also recovers the closure pointer	*/
/* from its fake gp pointer.						*/
void ffi_closure_UNIX();

#ifndef __GNUC__
#   error This requires gcc
#endif
void
ffi_closure_UNIX_inner (ffi_closure *closure, struct ia64_args * args)
/* Hopefully declaring this as a varargs function will force all args	*/
/* to memory.								*/
{
  // this is our return value storage
  long double    res;

  // our various things...
  ffi_cif       *cif;
  unsigned short rtype;
  void          *resp;
  void		**arg_area;

  resp = (void*)&res;
  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_UNIX(args, (void**)&resp, arg_area, cif);
  
  (closure->fun) (cif, resp, arg_area, closure->user_data);

  rtype = cif->flags;

  /* now, do a generic return based on the value of rtype */
  if (rtype == FFI_TYPE_INT)
    {
      asm volatile ("ld8 r8=[%0]" : : "r" (resp) : "r8");
    }
  else if (rtype == FFI_TYPE_FLOAT)
    {
      asm volatile ("ldfs f8=[%0]" : : "r" (resp) : "f8");
    }
  else if (rtype == FFI_TYPE_DOUBLE)
    {
      asm volatile ("ldfd f8=[%0]" : : "r" (resp) : "f8");
    }
  else if (rtype == FFI_IS_SMALL_STRUCT2)
    {
      asm volatile ("ld8 r8=[%0]; ld8 r9=[%1]"
		    : : "r" (resp), "r" (resp+8) : "r8","r9");
    }
  else if (rtype == FFI_IS_SMALL_STRUCT3)
    {
      asm volatile ("ld8 r8=[%0]; ld8 r9=[%1]; ld8 r10=[%2]"
		    : : "r" (resp), "r" (resp+8), "r" (resp+16)
		    : "r8","r9","r10");
    }
  else if (rtype == FFI_IS_SMALL_STRUCT4)
    {
      asm volatile ("ld8 r8=[%0]; ld8 r9=[%1]; ld8 r10=[%2]; ld8 r11=[%3]"
		    : : "r" (resp), "r" (resp+8), "r" (resp+16), "r" (resp+24)
		    : "r8","r9","r10","r11");
    }
  else if (rtype != FFI_TYPE_VOID && rtype != FFI_TYPE_STRUCT)
    {
      /* Can only happen for homogeneous FP aggregates?	*/
      abort();
    }
}

static void 
ffi_prep_incoming_args_UNIX(struct ia64_args *args, void **rvalue,
			    void **avalue, ffi_cif *cif)
{
  register unsigned int i;
  register unsigned int avn;
  register void **p_argv;
  register unsigned long *argp = args -> out_regs;
  unsigned fp_reg_num = 0;
  register ffi_type **p_arg;

  avn = cif->nargs;
  p_argv = avalue;

  for (i = cif->nargs, p_arg = cif->arg_types; i != 0; i--, p_arg++)
    {
      size_t z; /* In units of words or argument slots.	*/

      switch ((*p_arg)->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:
	case FFI_TYPE_POINTER:
	  z = 1;
	  *p_argv = (void *)argp;
	  break;
		  
	case FFI_TYPE_FLOAT:
	  z = 1;
	  /* Convert argument back to float in place from the saved value */
	  if (fp_reg_num < 8) {
	      *(float *)argp = args -> fp_regs[fp_reg_num++];
	  } else {
	      *(float *)argp = *(double *)argp;
	  }
	  *p_argv = (void *)argp;
	  break;

	case FFI_TYPE_DOUBLE:
	  z = 1;
	  if (fp_reg_num < 8) {
	      *p_argv = args -> fp_regs + fp_reg_num++;
	  } else {
	      *p_argv = (void *)argp;
	  }
	  break;

	case FFI_TYPE_STRUCT:
	  {
	      size_t sz = (*p_arg)->size;
	      unsigned short element_type;
              z = ((*p_arg)->size + SIZEOF_ARG - 1)/SIZEOF_ARG;
	      if (is_homogeneous_fp_aggregate(*p_arg, 8, &element_type)) {
		int nelements = sz/float_type_size(element_type);
		if (nelements + fp_reg_num >= 8) {
		  /* hard case NYI.	*/
		  abort();
		}
		if (element_type == FFI_TYPE_DOUBLE) {
	          *p_argv = args -> fp_regs + fp_reg_num;
		  fp_reg_num += nelements;
		  break;
		}
		if (element_type == FFI_TYPE_FLOAT) {
		  int j;
		  for (j = 0; j < nelements; ++ j) {
		     ((float *)argp)[j] = args -> fp_regs[fp_reg_num + j];
		  }
	          *p_argv = (void *)argp;
		  fp_reg_num += nelements;
		  break;
		}
		abort();  /* Other fp types NYI */
	      }
	  }
	  break;

	default:
	  FFI_ASSERT(0);
	}

      argp += z;
      p_argv++;

    }
  
  return;
}


/* Fill in a closure to refer to the specified fun and user_data.	*/
/* cif specifies the argument and result types for fun.			*/
/* the cif must already be prep'ed */

/* The layout of a function descriptor.  A C function pointer really 	*/
/* points to one of these.						*/
typedef struct ia64_fd_struct {
    void *code_pointer;
    void *gp;
} ia64_fd;

ffi_status
ffi_prep_closure (ffi_closure* closure,
		  ffi_cif* cif,
		  void (*fun)(ffi_cif*,void*,void**,void*),
		  void *user_data)
{
  struct ffi_ia64_trampoline_struct *tramp =
    (struct ffi_ia64_trampoline_struct *) (closure -> tramp);
  ia64_fd *fd = (ia64_fd *)(void *)ffi_closure_UNIX;

  FFI_ASSERT (cif->abi == FFI_UNIX);

  tramp -> code_pointer = fd -> code_pointer;
  tramp -> real_gp = fd -> gp;
  tramp -> fake_gp = closure;
  closure->cif  = cif;
  closure->user_data = user_data;
  closure->fun  = fun;

  return FFI_OK;
}