libffi/src/alpha/ffi.c

   1 /* -----------------------------------------------------------------------
   2    ffi.c - Copyright (c) 2012  Anthony Green
   3            Copyright (c) 1998, 2001, 2007, 2008  Red Hat, Inc.
   4
   5    Alpha Foreign Function Interface
   6
   7    Permission is hereby granted, free of charge, to any person obtaining
   8    a copy of this software and associated documentation files (the
   9    ``Software''), to deal in the Software without restriction, including
  10    without limitation the rights to use, copy, modify, merge, publish,
  11    distribute, sublicense, and/or sell copies of the Software, and to
  12    permit persons to whom the Software is furnished to do so, subject to
  13    the following conditions:
  14
  15    The above copyright notice and this permission notice shall be included
  16    in all copies or substantial portions of the Software.
  17
  18    THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND,
  19    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  21    NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  22    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  23    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  25    DEALINGS IN THE SOFTWARE.
  26    ----------------------------------------------------------------------- */
  27
  28 #include <ffi.h>
  29 #include <ffi_common.h>
  30
  31 /* Force FFI_TYPE_LONGDOUBLE to be different than FFI_TYPE_DOUBLE;
  32    all further uses in this file will refer to the 128-bit type.  */
  33 #if defined(__LONG_DOUBLE_128__)
  34 # if FFI_TYPE_LONGDOUBLE != 4
  35 #  error FFI_TYPE_LONGDOUBLE out of date
  36 # endif
  37 #else
  38 # undef FFI_TYPE_LONGDOUBLE
  39 # define FFI_TYPE_LONGDOUBLE 4
  40 #endif
  41
  42 extern void ffi_call_osf(void *, unsigned long, unsigned, void *, void (*)(void))
  43   FFI_HIDDEN;
  44 extern void ffi_closure_osf(void) FFI_HIDDEN;
  45
  46
  47 ffi_status
  48 ffi_prep_cif_machdep(ffi_cif *cif)
  49 {
  50   /* Adjust cif->bytes to represent a minimum 6 words for the temporary
  51      register argument loading area.  */
  52   if (cif->bytes < 6*FFI_SIZEOF_ARG)
  53     cif->bytes = 6*FFI_SIZEOF_ARG;
  54
  55   /* Set the return type flag */
  56   switch (cif->rtype->type)
  57     {
  58     case FFI_TYPE_STRUCT:
  59     case FFI_TYPE_FLOAT:
  60     case FFI_TYPE_DOUBLE:
  61       cif->flags = cif->rtype->type;
  62       break;
  63
  64     case FFI_TYPE_LONGDOUBLE:
  65       /* 128-bit long double is returned in memory, like a struct.  */
  66       cif->flags = FFI_TYPE_STRUCT;
  67       break;
  68
  69     default:
  70       cif->flags = FFI_TYPE_INT;
  71       break;
  72     }
  73
  74   return FFI_OK;
  75 }
  76
  77
  78 void
  79 ffi_call(ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue)
  80 {
  81   unsigned long *stack, *argp;
  82   long i, avn;
  83   ffi_type **arg_types;
  84
  85   /* If the return value is a struct and we don't have a return
  86      value address then we need to make one.  */
  87   if (rvalue == NULL && cif->flags == FFI_TYPE_STRUCT)
  88     rvalue = alloca(cif->rtype->size);
  89
  90   /* Allocate the space for the arguments, plus 4 words of temp
  91      space for ffi_call_osf.  */
  92   argp = stack = alloca(cif->bytes + 4*FFI_SIZEOF_ARG);
  93
  94   if (cif->flags == FFI_TYPE_STRUCT)
  95     *(void **) argp++ = rvalue;
  96
  97   i = 0;
  98   avn = cif->nargs;
  99   arg_types = cif->arg_types;
 100
 101   while (i < avn)
 102     {
 103       size_t size = (*arg_types)->size;
 104
 105       switch ((*arg_types)->type)
 106         {
 107         case FFI_TYPE_SINT8:
 108           *(SINT64 *) argp = *(SINT8 *)(* avalue);
 109           break;
 110
 111         case FFI_TYPE_UINT8:
 112           *(SINT64 *) argp = *(UINT8 *)(* avalue);
 113           break;
 114
 115         case FFI_TYPE_SINT16:
 116           *(SINT64 *) argp = *(SINT16 *)(* avalue);
 117           break;
 118
 119         case FFI_TYPE_UINT16:
 120           *(SINT64 *) argp = *(UINT16 *)(* avalue);
 121           break;
 122
 123         case FFI_TYPE_SINT32:
 124         case FFI_TYPE_UINT32:
 125           /* Note that unsigned 32-bit quantities are sign extended.  */
 126           *(SINT64 *) argp = *(SINT32 *)(* avalue);
 127           break;
 128
 129         case FFI_TYPE_SINT64:
 130         case FFI_TYPE_UINT64:
 131         case FFI_TYPE_POINTER:
 132           *(UINT64 *) argp = *(UINT64 *)(* avalue);
 133           break;
 134
 135         case FFI_TYPE_FLOAT:
 136           if (argp - stack < 6)
 137             {
 138               /* Note the conversion -- all the fp regs are loaded as
 139                  doubles.  The in-register format is the same.  */
 140               *(double *) argp = *(float *)(* avalue);
 141             }
 142           else
 143             *(float *) argp = *(float *)(* avalue);
 144           break;
 145
 146         case FFI_TYPE_DOUBLE:
 147           *(double *) argp = *(double *)(* avalue);
 148           break;
 149
 150         case FFI_TYPE_LONGDOUBLE:
 151           /* 128-bit long double is passed by reference.  */
 152           *(long double **) argp = (long double *)(* avalue);
 153           size = sizeof (long double *);
 154           break;
 155
 156         case FFI_TYPE_STRUCT:
 157           memcpy(argp, *avalue, (*arg_types)->size);
 158           break;
 159
 160         default:
 161           FFI_ASSERT(0);
 162         }
 163
 164       argp += ALIGN(size, FFI_SIZEOF_ARG) / FFI_SIZEOF_ARG;
 165       i++, arg_types++, avalue++;
 166     }
 167
 168   ffi_call_osf(stack, cif->bytes, cif->flags, rvalue, fn);
 169 }
 170
 171
 172 ffi_status
 173 ffi_prep_closure_loc (ffi_closure* closure,
 174                       ffi_cif* cif,
 175                       void (*fun)(ffi_cif*, void*, void**, void*),
 176                       void *user_data,
 177                       void *codeloc)
 178 {
 179   unsigned int *tramp;
 180
 181   if (cif->abi != FFI_OSF)
 182     return FFI_BAD_ABI;
 183
 184   tramp = (unsigned int *) &closure->tramp[0];
 185   tramp[0] = 0x47fb0401;        /* mov $27,$1           */
 186   tramp[1] = 0xa77b0010;        /* ldq $27,16($27)      */
 187   tramp[2] = 0x6bfb0000;        /* jmp $31,($27),0      */
 188   tramp[3] = 0x47ff041f;        /* nop                  */
 189   *(void **) &tramp[4] = ffi_closure_osf;
 190
 191   closure->cif = cif;
 192   closure->fun = fun;
 193   closure->user_data = user_data;
 194
 195   /* Flush the Icache.
 196
 197      Tru64 UNIX as doesn't understand the imb mnemonic, so use call_pal
 198      instead, since both Compaq as and gas can handle it.
 199
 200      0x86 is PAL_imb in Tru64 UNIX <alpha/pal.h>.  */
 201   asm volatile ("call_pal 0x86" : : : "memory");
 202
 203   return FFI_OK;
 204 }
 205
 206
 207 long FFI_HIDDEN
 208 ffi_closure_osf_inner(ffi_closure *closure, void *rvalue, unsigned long *argp)
 209 {
 210   ffi_cif *cif;
 211   void **avalue;
 212   ffi_type **arg_types;
 213   long i, avn, argn;
 214
 215   cif = closure->cif;
 216   avalue = alloca(cif->nargs * sizeof(void *));
 217
 218   argn = 0;
 219
 220   /* Copy the caller's structure return address to that the closure
 221      returns the data directly to the caller.  */
 222   if (cif->flags == FFI_TYPE_STRUCT)
 223     {
 224       rvalue = (void *) argp[0];
 225       argn = 1;
 226     }
 227
 228   i = 0;
 229   avn = cif->nargs;
 230   arg_types = cif->arg_types;
 231
 232   /* Grab the addresses of the arguments from the stack frame.  */
 233   while (i < avn)
 234     {
 235       size_t size = arg_types[i]->size;
 236
 237       switch (arg_types[i]->type)
 238         {
 239         case FFI_TYPE_SINT8:
 240         case FFI_TYPE_UINT8:
 241         case FFI_TYPE_SINT16:
 242         case FFI_TYPE_UINT16:
 243         case FFI_TYPE_SINT32:
 244         case FFI_TYPE_UINT32:
 245         case FFI_TYPE_SINT64:
 246         case FFI_TYPE_UINT64:
 247         case FFI_TYPE_POINTER:
 248         case FFI_TYPE_STRUCT:
 249           avalue[i] = &argp[argn];
 250           break;
 251
 252         case FFI_TYPE_FLOAT:
 253           if (argn < 6)
 254             {
 255               /* Floats coming from registers need conversion from double
 256                  back to float format.  */
 257               *(float *)&argp[argn - 6] = *(double *)&argp[argn - 6];
 258               avalue[i] = &argp[argn - 6];
 259             }
 260           else
 261             avalue[i] = &argp[argn];
 262           break;
 263
 264         case FFI_TYPE_DOUBLE:
 265           avalue[i] = &argp[argn - (argn < 6 ? 6 : 0)];
 266           break;
 267
 268         case FFI_TYPE_LONGDOUBLE:
 269           /* 128-bit long double is passed by reference.  */
 270           avalue[i] = (long double *) argp[argn];
 271           size = sizeof (long double *);
 272           break;
 273
 274         default:
 275           FFI_ASSERT (0);
 276         }
 277
 278       argn += ALIGN(size, FFI_SIZEOF_ARG) / FFI_SIZEOF_ARG;
 279       i++;
 280     }
 281
 282   /* Invoke the closure.  */
 283   closure->fun (cif, rvalue, avalue, closure->user_data);
 284
 285   /* Tell ffi_closure_osf how to perform return type promotions.  */
 286   return cif->rtype->type;
 287 }