path: root/contrib/restricted/libffi/src/powerpc/ffi_sysv.c

/* ----------------------------------------------------------------------- 
   ffi_sysv.c - Copyright (C) 2013 IBM 
                Copyright (C) 2011 Anthony Green 
                Copyright (C) 2011 Kyle Moffett 
                Copyright (C) 2008 Red Hat, Inc 
                Copyright (C) 2007, 2008 Free Software Foundation, Inc 
                Copyright (c) 1998 Geoffrey Keating 
 
   PowerPC 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 AUTHOR 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" 
 
#ifndef POWERPC64 
#include "ffi_common.h" 
#include "ffi_powerpc.h" 
 
 
/* About the SYSV ABI.  */ 
#define ASM_NEEDS_REGISTERS 6 
#define NUM_GPR_ARG_REGISTERS 8 
#define NUM_FPR_ARG_REGISTERS 8 
 
 
#if HAVE_LONG_DOUBLE_VARIANT && FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 
/* Adjust size of ffi_type_longdouble.  */ 
void FFI_HIDDEN 
ffi_prep_types_sysv (ffi_abi abi) 
{ 
  if ((abi & (FFI_SYSV | FFI_SYSV_LONG_DOUBLE_128)) == FFI_SYSV) 
    { 
      ffi_type_longdouble.size = 8; 
      ffi_type_longdouble.alignment = 8; 
    } 
  else 
    { 
      ffi_type_longdouble.size = 16; 
      ffi_type_longdouble.alignment = 16; 
    } 
} 
#endif 
 
/* Transform long double, double and float to other types as per abi.  */ 
static int 
translate_float (int abi, int type) 
{ 
#if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 
  if (type == FFI_TYPE_LONGDOUBLE 
      && (abi & FFI_SYSV_LONG_DOUBLE_128) == 0) 
    type = FFI_TYPE_DOUBLE; 
#endif 
  if ((abi & FFI_SYSV_SOFT_FLOAT) != 0) 
    { 
      if (type == FFI_TYPE_FLOAT) 
	type = FFI_TYPE_UINT32; 
      else if (type == FFI_TYPE_DOUBLE) 
	type = FFI_TYPE_UINT64; 
#if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 
      else if (type == FFI_TYPE_LONGDOUBLE) 
	type = FFI_TYPE_UINT128; 
    } 
  else if ((abi & FFI_SYSV_IBM_LONG_DOUBLE) == 0) 
    { 
      if (type == FFI_TYPE_LONGDOUBLE) 
	type = FFI_TYPE_STRUCT; 
#endif 
    } 
  return type; 
} 
 
/* Perform machine dependent cif processing */ 
static ffi_status 
ffi_prep_cif_sysv_core (ffi_cif *cif) 
{ 
  ffi_type **ptr; 
  unsigned bytes; 
  unsigned i, fpr_count = 0, gpr_count = 0, stack_count = 0; 
  unsigned flags = cif->flags; 
  unsigned struct_copy_size = 0; 
  unsigned type = cif->rtype->type; 
  unsigned size = cif->rtype->size; 
 
  /* The machine-independent calculation of cif->bytes doesn't work 
     for us.  Redo the calculation.  */ 
 
  /* Space for the frame pointer, callee's LR, and the asm's temp regs.  */ 
  bytes = (2 + ASM_NEEDS_REGISTERS) * sizeof (int); 
 
  /* Space for the GPR registers.  */ 
  bytes += NUM_GPR_ARG_REGISTERS * sizeof (int); 
 
  /* Return value handling.  The rules for SYSV are as follows: 
     - 32-bit (or less) integer values are returned in gpr3; 
     - Structures of size <= 4 bytes also returned in gpr3; 
     - 64-bit integer values and structures between 5 and 8 bytes are returned 
     in gpr3 and gpr4; 
     - Larger structures are allocated space and a pointer is passed as 
     the first argument. 
     - Single/double FP values are returned in fpr1; 
     - long doubles (if not equivalent to double) are returned in 
     fpr1,fpr2 for Linux and as for large structs for SysV.  */ 
 
  type = translate_float (cif->abi, type); 
 
  switch (type) 
    { 
#if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 
    case FFI_TYPE_LONGDOUBLE: 
      flags |= FLAG_RETURNS_128BITS; 
      /* Fall through.  */ 
#endif 
    case FFI_TYPE_DOUBLE: 
      flags |= FLAG_RETURNS_64BITS; 
      /* Fall through.  */ 
    case FFI_TYPE_FLOAT: 
      flags |= FLAG_RETURNS_FP; 
#ifdef __NO_FPRS__ 
      return FFI_BAD_ABI; 
#endif 
      break; 
 
    case FFI_TYPE_UINT128: 
      flags |= FLAG_RETURNS_128BITS; 
      /* Fall through.  */ 
    case FFI_TYPE_UINT64: 
    case FFI_TYPE_SINT64: 
      flags |= FLAG_RETURNS_64BITS; 
      break; 
 
    case FFI_TYPE_STRUCT: 
      /* The final SYSV ABI says that structures smaller or equal 8 bytes 
	 are returned in r3/r4.  A draft ABI used by linux instead 
	 returns them in memory.  */ 
      if ((cif->abi & FFI_SYSV_STRUCT_RET) != 0 && size <= 8) 
	{ 
	  flags |= FLAG_RETURNS_SMST; 
	  break; 
	} 
      gpr_count++; 
      flags |= FLAG_RETVAL_REFERENCE; 
      /* Fall through.  */ 
    case FFI_TYPE_VOID: 
      flags |= FLAG_RETURNS_NOTHING; 
      break; 
 
    default: 
      /* Returns 32-bit integer, or similar.  Nothing to do here.  */ 
      break; 
    } 
 
  /* The first NUM_GPR_ARG_REGISTERS words of integer arguments, and the 
     first NUM_FPR_ARG_REGISTERS fp arguments, go in registers; the rest 
     goes on the stack.  Structures and long doubles (if not equivalent 
     to double) are passed as a pointer to a copy of the structure. 
     Stuff on the stack needs to keep proper alignment.  */ 
  for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++) 
    { 
      unsigned short typenum = (*ptr)->type; 
 
      typenum = translate_float (cif->abi, typenum); 
 
      switch (typenum) 
	{ 
#if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 
	case FFI_TYPE_LONGDOUBLE: 
	  if (fpr_count >= NUM_FPR_ARG_REGISTERS - 1) 
	    { 
	      fpr_count = NUM_FPR_ARG_REGISTERS; 
	      /* 8-byte align long doubles.  */ 
	      stack_count += stack_count & 1; 
	      stack_count += 4; 
	    } 
	  else 
	    fpr_count += 2; 
#ifdef __NO_FPRS__ 
	  return FFI_BAD_ABI; 
#endif 
	  break; 
#endif 
 
	case FFI_TYPE_DOUBLE: 
	  if (fpr_count >= NUM_FPR_ARG_REGISTERS) 
	    { 
	      /* 8-byte align doubles.  */ 
	      stack_count += stack_count & 1; 
	      stack_count += 2; 
	    } 
	  else 
	    fpr_count += 1; 
#ifdef __NO_FPRS__ 
	  return FFI_BAD_ABI; 
#endif 
	  break; 
 
	case FFI_TYPE_FLOAT: 
	  if (fpr_count >= NUM_FPR_ARG_REGISTERS) 
	    /* Yes, we don't follow the ABI, but neither does gcc.  */ 
	    stack_count += 1; 
	  else 
	    fpr_count += 1; 
#ifdef __NO_FPRS__ 
	  return FFI_BAD_ABI; 
#endif 
	  break; 
 
	case FFI_TYPE_UINT128: 
	  /* A long double in FFI_LINUX_SOFT_FLOAT can use only a set 
	     of four consecutive gprs. If we do not have enough, we 
	     have to adjust the gpr_count value.  */ 
	  if (gpr_count >= NUM_GPR_ARG_REGISTERS - 3) 
	    gpr_count = NUM_GPR_ARG_REGISTERS; 
	  if (gpr_count >= NUM_GPR_ARG_REGISTERS) 
	    stack_count += 4; 
	  else 
	    gpr_count += 4; 
	  break; 
 
	case FFI_TYPE_UINT64: 
	case FFI_TYPE_SINT64: 
	  /* 'long long' arguments are passed as two words, but 
	     either both words must fit in registers or both go 
	     on the stack.  If they go on the stack, they must 
	     be 8-byte-aligned. 
 
	     Also, only certain register pairs can be used for 
	     passing long long int -- specifically (r3,r4), (r5,r6), 
	     (r7,r8), (r9,r10).  */ 
	  gpr_count += gpr_count & 1; 
	  if (gpr_count >= NUM_GPR_ARG_REGISTERS) 
	    { 
	      stack_count += stack_count & 1; 
	      stack_count += 2; 
	    } 
	  else 
	    gpr_count += 2; 
	  break; 
 
	case FFI_TYPE_STRUCT: 
	  /* We must allocate space for a copy of these to enforce 
	     pass-by-value.  Pad the space up to a multiple of 16 
	     bytes (the maximum alignment required for anything under 
	     the SYSV ABI).  */ 
	  struct_copy_size += ((*ptr)->size + 15) & ~0xF; 
	  /* Fall through (allocate space for the pointer).  */ 
 
	case FFI_TYPE_POINTER: 
	case FFI_TYPE_INT: 
	case FFI_TYPE_UINT32: 
	case FFI_TYPE_SINT32: 
	case FFI_TYPE_UINT16: 
	case FFI_TYPE_SINT16: 
	case FFI_TYPE_UINT8: 
	case FFI_TYPE_SINT8: 
	  /* Everything else is passed as a 4-byte word in a GPR, either 
	     the object itself or a pointer to it.  */ 
	  if (gpr_count >= NUM_GPR_ARG_REGISTERS) 
	    stack_count += 1; 
	  else 
	    gpr_count += 1; 
	  break; 
 
	default: 
	  FFI_ASSERT (0); 
	} 
    } 
 
  if (fpr_count != 0) 
    flags |= FLAG_FP_ARGUMENTS; 
  if (gpr_count > 4) 
    flags |= FLAG_4_GPR_ARGUMENTS; 
  if (struct_copy_size != 0) 
    flags |= FLAG_ARG_NEEDS_COPY; 
 
  /* Space for the FPR registers, if needed.  */ 
  if (fpr_count != 0) 
    bytes += NUM_FPR_ARG_REGISTERS * sizeof (double); 
 
  /* Stack space.  */ 
  bytes += stack_count * sizeof (int); 
 
  /* The stack space allocated needs to be a multiple of 16 bytes.  */ 
  bytes = (bytes + 15) & ~0xF; 
 
  /* Add in the space for the copied structures.  */ 
  bytes += struct_copy_size; 
 
  cif->flags = flags; 
  cif->bytes = bytes; 
 
  return FFI_OK; 
} 
 
ffi_status FFI_HIDDEN 
ffi_prep_cif_sysv (ffi_cif *cif) 
{ 
  if ((cif->abi & FFI_SYSV) == 0) 
    { 
      /* This call is from old code.  Translate to new ABI values.  */ 
      cif->flags |= FLAG_COMPAT; 
      switch (cif->abi) 
	{ 
	default: 
	  return FFI_BAD_ABI; 
 
	case FFI_COMPAT_SYSV: 
	  cif->abi = FFI_SYSV | FFI_SYSV_STRUCT_RET | FFI_SYSV_LONG_DOUBLE_128; 
	  break; 
 
	case FFI_COMPAT_GCC_SYSV: 
	  cif->abi = FFI_SYSV | FFI_SYSV_LONG_DOUBLE_128; 
	  break; 
 
	case FFI_COMPAT_LINUX: 
	  cif->abi = (FFI_SYSV | FFI_SYSV_IBM_LONG_DOUBLE 
		      | FFI_SYSV_LONG_DOUBLE_128); 
	  break; 
 
	case FFI_COMPAT_LINUX_SOFT_FLOAT: 
	  cif->abi = (FFI_SYSV | FFI_SYSV_SOFT_FLOAT | FFI_SYSV_IBM_LONG_DOUBLE 
		      | FFI_SYSV_LONG_DOUBLE_128); 
	  break; 
	} 
    } 
  return ffi_prep_cif_sysv_core (cif); 
} 
 
/* ffi_prep_args_SYSV is called by the assembly routine once stack space 
   has been allocated for the function's arguments. 
 
   The stack layout we want looks like this: 
 
   |   Return address from ffi_call_SYSV 4bytes	|	higher addresses 
   |--------------------------------------------| 
   |   Previous backchain pointer	4	|       stack pointer here 
   |--------------------------------------------|<+ <<<	on entry to 
   |   Saved r28-r31			4*4	| |	ffi_call_SYSV 
   |--------------------------------------------| | 
   |   GPR registers r3-r10		8*4	| |	ffi_call_SYSV 
   |--------------------------------------------| | 
   |   FPR registers f1-f8 (optional)	8*8	| | 
   |--------------------------------------------| |	stack	| 
   |   Space for copied structures		| |	grows	| 
   |--------------------------------------------| |	down    V 
   |   Parameters that didn't fit in registers  | | 
   |--------------------------------------------| |	lower addresses 
   |   Space for callee's LR		4	| | 
   |--------------------------------------------| |	stack pointer here 
   |   Current backchain pointer	4	|-/	during 
   |--------------------------------------------|   <<<	ffi_call_SYSV 
 
*/ 
 
void FFI_HIDDEN 
ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack) 
{ 
  const unsigned bytes = ecif->cif->bytes; 
  const unsigned flags = ecif->cif->flags; 
 
  typedef union 
  { 
    char *c; 
    unsigned *u; 
    long long *ll; 
    float *f; 
    double *d; 
  } valp; 
 
  /* 'stacktop' points at the previous backchain pointer.  */ 
  valp stacktop; 
 
  /* 'gpr_base' points at the space for gpr3, and grows upwards as 
     we use GPR registers.  */ 
  valp gpr_base; 
  valp gpr_end; 
 
#ifndef __NO_FPRS__ 
  /* 'fpr_base' points at the space for fpr1, and grows upwards as 
     we use FPR registers.  */ 
  valp fpr_base; 
  valp fpr_end; 
#endif 
 
  /* 'copy_space' grows down as we put structures in it.  It should 
     stay 16-byte aligned.  */ 
  valp copy_space; 
 
  /* 'next_arg' grows up as we put parameters in it.  */ 
  valp next_arg; 
 
  int i; 
  ffi_type **ptr; 
#ifndef __NO_FPRS__ 
  double double_tmp; 
#endif 
  union 
  { 
    void **v; 
    char **c; 
    signed char **sc; 
    unsigned char **uc; 
    signed short **ss; 
    unsigned short **us; 
    unsigned int **ui; 
    long long **ll; 
    float **f; 
    double **d; 
  } p_argv; 
  size_t struct_copy_size; 
  unsigned gprvalue; 
 
  stacktop.c = (char *) stack + bytes; 
  gpr_end.u = stacktop.u - ASM_NEEDS_REGISTERS; 
  gpr_base.u = gpr_end.u - NUM_GPR_ARG_REGISTERS; 
#ifndef __NO_FPRS__ 
  fpr_end.d = gpr_base.d; 
  fpr_base.d = fpr_end.d - NUM_FPR_ARG_REGISTERS; 
  copy_space.c = ((flags & FLAG_FP_ARGUMENTS) ? fpr_base.c : gpr_base.c); 
#else 
  copy_space.c = gpr_base.c; 
#endif 
  next_arg.u = stack + 2; 
 
  /* Check that everything starts aligned properly.  */ 
  FFI_ASSERT (((unsigned long) (char *) stack & 0xF) == 0); 
  FFI_ASSERT (((unsigned long) copy_space.c & 0xF) == 0); 
  FFI_ASSERT (((unsigned long) stacktop.c & 0xF) == 0); 
  FFI_ASSERT ((bytes & 0xF) == 0); 
  FFI_ASSERT (copy_space.c >= next_arg.c); 
 
  /* Deal with return values that are actually pass-by-reference.  */ 
  if (flags & FLAG_RETVAL_REFERENCE) 
    *gpr_base.u++ = (unsigned) (char *) ecif->rvalue; 
 
  /* Now for the arguments.  */ 
  p_argv.v = ecif->avalue; 
  for (ptr = ecif->cif->arg_types, i = ecif->cif->nargs; 
       i > 0; 
       i--, ptr++, p_argv.v++) 
    { 
      unsigned int typenum = (*ptr)->type; 
 
      typenum = translate_float (ecif->cif->abi, typenum); 
 
      /* Now test the translated value */ 
      switch (typenum) 
	{ 
#ifndef __NO_FPRS__ 
# if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 
	case FFI_TYPE_LONGDOUBLE: 
	  double_tmp = (*p_argv.d)[0]; 
 
	  if (fpr_base.d >= fpr_end.d - 1) 
	    { 
	      fpr_base.d = fpr_end.d; 
	      if (((next_arg.u - stack) & 1) != 0) 
		next_arg.u += 1; 
	      *next_arg.d = double_tmp; 
	      next_arg.u += 2; 
	      double_tmp = (*p_argv.d)[1]; 
	      *next_arg.d = double_tmp; 
	      next_arg.u += 2; 
	    } 
	  else 
	    { 
	      *fpr_base.d++ = double_tmp; 
	      double_tmp = (*p_argv.d)[1]; 
	      *fpr_base.d++ = double_tmp; 
	    } 
	  FFI_ASSERT (flags & FLAG_FP_ARGUMENTS); 
	  break; 
# endif 
	case FFI_TYPE_DOUBLE: 
	  double_tmp = **p_argv.d; 
 
	  if (fpr_base.d >= fpr_end.d) 
	    { 
	      if (((next_arg.u - stack) & 1) != 0) 
		next_arg.u += 1; 
	      *next_arg.d = double_tmp; 
	      next_arg.u += 2; 
	    } 
	  else 
	    *fpr_base.d++ = double_tmp; 
	  FFI_ASSERT (flags & FLAG_FP_ARGUMENTS); 
	  break; 
 
	case FFI_TYPE_FLOAT: 
	  double_tmp = **p_argv.f; 
	  if (fpr_base.d >= fpr_end.d) 
	    { 
	      *next_arg.f = (float) double_tmp; 
	      next_arg.u += 1; 
	    } 
	  else 
	    *fpr_base.d++ = double_tmp; 
	  FFI_ASSERT (flags & FLAG_FP_ARGUMENTS); 
	  break; 
#endif /* have FPRs */ 
 
	case FFI_TYPE_UINT128: 
	  /* The soft float ABI for long doubles works like this, a long double 
	     is passed in four consecutive GPRs if available.  A maximum of 2 
	     long doubles can be passed in gprs.  If we do not have 4 GPRs 
	     left, the long double is passed on the stack, 4-byte aligned.  */ 
	  if (gpr_base.u >= gpr_end.u - 3) 
	    { 
	      unsigned int ii; 
	      gpr_base.u = gpr_end.u; 
	      for (ii = 0; ii < 4; ii++) 
		{ 
		  unsigned int int_tmp = (*p_argv.ui)[ii]; 
		  *next_arg.u++ = int_tmp; 
		} 
	    } 
	  else 
	    { 
	      unsigned int ii; 
	      for (ii = 0; ii < 4; ii++) 
		{ 
		  unsigned int int_tmp = (*p_argv.ui)[ii]; 
		  *gpr_base.u++ = int_tmp; 
		} 
	    } 
	  break; 
 
	case FFI_TYPE_UINT64: 
	case FFI_TYPE_SINT64: 
	  if (gpr_base.u >= gpr_end.u - 1) 
	    { 
	      gpr_base.u = gpr_end.u; 
	      if (((next_arg.u - stack) & 1) != 0) 
		next_arg.u++; 
	      *next_arg.ll = **p_argv.ll; 
	      next_arg.u += 2; 
	    } 
	  else 
	    { 
	      /* The abi states only certain register pairs can be 
		 used for passing long long int specifically (r3,r4), 
		 (r5,r6), (r7,r8), (r9,r10).  If next arg is long long 
		 but not correct starting register of pair then skip 
		 until the proper starting register.  */ 
	      if (((gpr_end.u - gpr_base.u) & 1) != 0) 
		gpr_base.u++; 
	      *gpr_base.ll++ = **p_argv.ll; 
	    } 
	  break; 
 
	case FFI_TYPE_STRUCT: 
	  struct_copy_size = ((*ptr)->size + 15) & ~0xF; 
	  copy_space.c -= struct_copy_size; 
	  memcpy (copy_space.c, *p_argv.c, (*ptr)->size); 
 
	  gprvalue = (unsigned long) copy_space.c; 
 
	  FFI_ASSERT (copy_space.c > next_arg.c); 
	  FFI_ASSERT (flags & FLAG_ARG_NEEDS_COPY); 
	  goto putgpr; 
 
	case FFI_TYPE_UINT8: 
	  gprvalue = **p_argv.uc; 
	  goto putgpr; 
	case FFI_TYPE_SINT8: 
	  gprvalue = **p_argv.sc; 
	  goto putgpr; 
	case FFI_TYPE_UINT16: 
	  gprvalue = **p_argv.us; 
	  goto putgpr; 
	case FFI_TYPE_SINT16: 
	  gprvalue = **p_argv.ss; 
	  goto putgpr; 
 
	case FFI_TYPE_INT: 
	case FFI_TYPE_UINT32: 
	case FFI_TYPE_SINT32: 
	case FFI_TYPE_POINTER: 
 
	  gprvalue = **p_argv.ui; 
 
	putgpr: 
	  if (gpr_base.u >= gpr_end.u) 
	    *next_arg.u++ = gprvalue; 
	  else 
	    *gpr_base.u++ = gprvalue; 
	  break; 
	} 
    } 
 
  /* Check that we didn't overrun the stack...  */ 
  FFI_ASSERT (copy_space.c >= next_arg.c); 
  FFI_ASSERT (gpr_base.u <= gpr_end.u); 
#ifndef __NO_FPRS__ 
  FFI_ASSERT (fpr_base.u <= fpr_end.u); 
#endif 
  FFI_ASSERT (((flags & FLAG_4_GPR_ARGUMENTS) != 0) 
	      == (gpr_end.u - gpr_base.u < 4)); 
} 
 
#define MIN_CACHE_LINE_SIZE 8 
 
static void 
flush_icache (char *wraddr, char *xaddr, int size) 
{ 
  int i; 
  for (i = 0; i < size; i += MIN_CACHE_LINE_SIZE) 
    __asm__ volatile ("icbi 0,%0;" "dcbf 0,%1;" 
		      : : "r" (xaddr + i), "r" (wraddr + i) : "memory"); 
  __asm__ volatile ("icbi 0,%0;" "dcbf 0,%1;" "sync;" "isync;" 
		    : : "r"(xaddr + size - 1), "r"(wraddr + size - 1) 
		    : "memory"); 
} 
 
ffi_status FFI_HIDDEN 
ffi_prep_closure_loc_sysv (ffi_closure *closure, 
			   ffi_cif *cif, 
			   void (*fun) (ffi_cif *, void *, void **, void *), 
			   void *user_data, 
			   void *codeloc) 
{ 
  unsigned int *tramp; 
 
  if (cif->abi < FFI_SYSV || cif->abi >= FFI_LAST_ABI) 
    return FFI_BAD_ABI; 
 
  tramp = (unsigned int *) &closure->tramp[0]; 
  tramp[0] = 0x7c0802a6;  /*   mflr    r0 */ 
  tramp[1] = 0x429f0005;  /*   bcl     20,31,.+4 */ 
  tramp[2] = 0x7d6802a6;  /*   mflr    r11 */ 
  tramp[3] = 0x7c0803a6;  /*   mtlr    r0 */ 
  tramp[4] = 0x800b0018;  /*   lwz     r0,24(r11) */ 
  tramp[5] = 0x816b001c;  /*   lwz     r11,28(r11) */ 
  tramp[6] = 0x7c0903a6;  /*   mtctr   r0 */ 
  tramp[7] = 0x4e800420;  /*   bctr */ 
  *(void **) &tramp[8] = (void *) ffi_closure_SYSV; /* function */ 
  *(void **) &tramp[9] = codeloc;                   /* context */ 
 
  /* Flush the icache.  */ 
  flush_icache ((char *)tramp, (char *)codeloc, 8 * 4); 
 
  closure->cif = cif; 
  closure->fun = fun; 
  closure->user_data = user_data; 
 
  return FFI_OK; 
} 
 
/* Basically the trampoline invokes ffi_closure_SYSV, and on 
   entry, r11 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_cif *cif, 
			 void (*fun) (ffi_cif *, void *, void **, void *), 
			 void *user_data, 
			 void *rvalue, 
			 unsigned long *pgr, 
			 ffi_dblfl *pfr, 
			 unsigned long *pst) 
{ 
  /* rvalue is the pointer to space for return value in closure assembly */ 
  /* pgr is the pointer to where r3-r10 are stored in ffi_closure_SYSV */ 
  /* pfr is the pointer to where f1-f8 are stored in ffi_closure_SYSV  */ 
  /* pst is the pointer to outgoing parameter stack in original caller */ 
 
  void **          avalue; 
  ffi_type **      arg_types; 
  long             i, avn; 
#ifndef __NO_FPRS__ 
  long             nf = 0;   /* number of floating registers already used */ 
#endif 
  long             ng = 0;   /* number of general registers already used */ 
 
  unsigned       size     = cif->rtype->size; 
  unsigned short rtypenum = cif->rtype->type; 
 
  avalue = alloca (cif->nargs * sizeof (void *)); 
 
  /* First translate for softfloat/nonlinux */ 
  rtypenum = translate_float (cif->abi, rtypenum); 
 
  /* Copy the caller's structure return value address so that the closure 
     returns the data directly to the caller. 
     For FFI_SYSV the result is passed in r3/r4 if the struct size is less 
     or equal 8 bytes.  */ 
  if (rtypenum == FFI_TYPE_STRUCT 
      && !((cif->abi & FFI_SYSV_STRUCT_RET) != 0 && size <= 8)) 
    { 
      rvalue = (void *) *pgr; 
      ng++; 
      pgr++; 
    } 
 
  i = 0; 
  avn = cif->nargs; 
  arg_types = cif->arg_types; 
 
  /* Grab the addresses of the arguments from the stack frame.  */ 
  while (i < avn) { 
    unsigned short typenum = arg_types[i]->type; 
 
    /* We may need to handle some values depending on ABI.  */ 
    typenum = translate_float (cif->abi, typenum); 
 
    switch (typenum) 
      { 
#ifndef __NO_FPRS__ 
      case FFI_TYPE_FLOAT: 
	/* Unfortunately float values are stored as doubles 
	   in the ffi_closure_SYSV code (since we don't check 
	   the type in that routine).  */ 
	if (nf < NUM_FPR_ARG_REGISTERS) 
	  { 
	    /* FIXME? here we are really changing the values 
	       stored in the original calling routines outgoing 
	       parameter stack.  This is probably a really 
	       naughty thing to do but...  */ 
	    double temp = pfr->d; 
	    pfr->f = (float) temp; 
	    avalue[i] = pfr; 
	    nf++; 
	    pfr++; 
	  } 
	else 
	  { 
	    avalue[i] = pst; 
	    pst += 1; 
	  } 
	break; 
 
      case FFI_TYPE_DOUBLE: 
	if (nf < NUM_FPR_ARG_REGISTERS) 
	  { 
	    avalue[i] = pfr; 
	    nf++; 
	    pfr++; 
	  } 
	else 
	  { 
	    if (((long) pst) & 4) 
	      pst++; 
	    avalue[i] = pst; 
	    pst += 2; 
	  } 
	break; 
 
# if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 
      case FFI_TYPE_LONGDOUBLE: 
	if (nf < NUM_FPR_ARG_REGISTERS - 1) 
	  { 
	    avalue[i] = pfr; 
	    pfr += 2; 
	    nf += 2; 
	  } 
	else 
	  { 
	    if (((long) pst) & 4) 
	      pst++; 
	    avalue[i] = pst; 
	    pst += 4; 
	    nf = 8; 
	  } 
	break; 
# endif 
#endif 
 
      case FFI_TYPE_UINT128: 
	/* Test if for the whole long double, 4 gprs are available. 
	   otherwise the stuff ends up on the stack.  */ 
	if (ng < NUM_GPR_ARG_REGISTERS - 3) 
	  { 
	    avalue[i] = pgr; 
	    pgr += 4; 
	    ng += 4; 
	  } 
	else 
	  { 
	    avalue[i] = pst; 
	    pst += 4; 
	    ng = 8+4; 
	  } 
	break; 
 
      case FFI_TYPE_SINT8: 
      case FFI_TYPE_UINT8: 
#ifndef __LITTLE_ENDIAN__ 
	if (ng < NUM_GPR_ARG_REGISTERS) 
	  { 
	    avalue[i] = (char *) pgr + 3; 
	    ng++; 
	    pgr++; 
	  } 
	else 
	  { 
	    avalue[i] = (char *) pst + 3; 
	    pst++; 
	  } 
	break; 
#endif 
 
      case FFI_TYPE_SINT16: 
      case FFI_TYPE_UINT16: 
#ifndef __LITTLE_ENDIAN__ 
	if (ng < NUM_GPR_ARG_REGISTERS) 
	  { 
	    avalue[i] = (char *) pgr + 2; 
	    ng++; 
	    pgr++; 
	  } 
	else 
	  { 
	    avalue[i] = (char *) pst + 2; 
	    pst++; 
	  } 
	break; 
#endif 
 
      case FFI_TYPE_SINT32: 
      case FFI_TYPE_UINT32: 
      case FFI_TYPE_POINTER: 
	if (ng < NUM_GPR_ARG_REGISTERS) 
	  { 
	    avalue[i] = pgr; 
	    ng++; 
	    pgr++; 
	  } 
	else 
	  { 
	    avalue[i] = pst; 
	    pst++; 
	  } 
	break; 
 
      case FFI_TYPE_STRUCT: 
	/* Structs are passed by reference. The address will appear in a 
	   gpr if it is one of the first 8 arguments.  */ 
	if (ng < NUM_GPR_ARG_REGISTERS) 
	  { 
	    avalue[i] = (void *) *pgr; 
	    ng++; 
	    pgr++; 
	  } 
	else 
	  { 
	    avalue[i] = (void *) *pst; 
	    pst++; 
	  } 
	break; 
 
      case FFI_TYPE_SINT64: 
      case FFI_TYPE_UINT64: 
	/* Passing long long ints are complex, they must 
	   be passed in suitable register pairs such as 
	   (r3,r4) or (r5,r6) or (r6,r7), or (r7,r8) or (r9,r10) 
	   and if the entire pair aren't available then the outgoing 
	   parameter stack is used for both but an alignment of 8 
	   must will be kept.  So we must either look in pgr 
	   or pst to find the correct address for this type 
	   of parameter.  */ 
	if (ng < NUM_GPR_ARG_REGISTERS - 1) 
	  { 
	    if (ng & 1) 
	      { 
		/* skip r4, r6, r8 as starting points */ 
		ng++; 
		pgr++; 
	      } 
	    avalue[i] = pgr; 
	    ng += 2; 
	    pgr += 2; 
	  } 
	else 
	  { 
	    if (((long) pst) & 4) 
	      pst++; 
	    avalue[i] = pst; 
	    pst += 2; 
	    ng = NUM_GPR_ARG_REGISTERS; 
	  } 
	break; 
 
      default: 
	FFI_ASSERT (0); 
      } 
 
    i++; 
  } 
 
  (*fun) (cif, rvalue, avalue, user_data); 
 
  /* Tell ffi_closure_SYSV how to perform return type promotions. 
     Because the FFI_SYSV ABI returns the structures <= 8 bytes in 
     r3/r4 we have to tell ffi_closure_SYSV how to treat them.  We 
     combine the base type FFI_SYSV_TYPE_SMALL_STRUCT with the size of 
     the struct less one.  We never have a struct with size zero. 
     See the comment in ffitarget.h about ordering.  */ 
  if (rtypenum == FFI_TYPE_STRUCT 
      && (cif->abi & FFI_SYSV_STRUCT_RET) != 0 && size <= 8) 
    return FFI_SYSV_TYPE_SMALL_STRUCT - 1 + size; 
  return rtypenum; 
} 
#endif