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 #include <stdlib.h>
  31 #include "internal.h"
  32
  33 /* Force FFI_TYPE_LONGDOUBLE to be different than FFI_TYPE_DOUBLE;
  34    all further uses in this file will refer to the 128-bit type.  */
  35 #if defined(__LONG_DOUBLE_128__)
  36 # if FFI_TYPE_LONGDOUBLE != 4
  37 #  error FFI_TYPE_LONGDOUBLE out of date
  38 # endif
  39 #else
  40 # undef FFI_TYPE_LONGDOUBLE
  41 # define FFI_TYPE_LONGDOUBLE 4
  42 #endif
  43
  44 extern void ffi_call_osf(void *stack, void *frame, unsigned flags,
  45                          void *raddr, void (*fn)(void), void *closure)
  46         FFI_HIDDEN;
  47 extern void ffi_closure_osf(void) FFI_HIDDEN;
  48 extern void ffi_go_closure_osf(void) FFI_HIDDEN;
  49
  50 /* Promote a float value to its in-register double representation.
  51    Unlike actually casting to double, this does not trap on NaN.  */
  52 static inline UINT64 lds(void *ptr)
  53 {
  54   UINT64 ret;
  55   asm("lds %0,%1" : "=f"(ret) : "m"(*(UINT32 *)ptr));
  56   return ret;
  57 }
  58
  59 /* And the reverse.  */
  60 static inline void sts(void *ptr, UINT64 val)
  61 {
  62   asm("sts %1,%0" : "=m"(*(UINT32 *)ptr) : "f"(val));
  63 }
  64
  65 ffi_status FFI_HIDDEN
  66 ffi_prep_cif_machdep(ffi_cif *cif)
  67 {
  68   size_t bytes = 0;
  69   int flags, i, avn;
  70   ffi_type *rtype, *itype;
  71
  72   if (cif->abi != FFI_OSF)
  73     return FFI_BAD_ABI;
  74
  75   /* Compute the size of the argument area.  */
  76   for (i = 0, avn = cif->nargs; i < avn; i++)
  77     {
  78       itype = cif->arg_types[i];
  79       switch (itype->type)
  80         {
  81         case FFI_TYPE_INT:
  82         case FFI_TYPE_SINT8:
  83         case FFI_TYPE_UINT8:
  84         case FFI_TYPE_SINT16:
  85         case FFI_TYPE_UINT16:
  86         case FFI_TYPE_SINT32:
  87         case FFI_TYPE_UINT32:
  88         case FFI_TYPE_SINT64:
  89         case FFI_TYPE_UINT64:
  90         case FFI_TYPE_POINTER:
  91         case FFI_TYPE_FLOAT:
  92         case FFI_TYPE_DOUBLE:
  93         case FFI_TYPE_LONGDOUBLE:
  94           /* All take one 8 byte slot.  */
  95           bytes += 8;
  96           break;
  97
  98         case FFI_TYPE_VOID:
  99         case FFI_TYPE_STRUCT:
 100           /* Passed by value in N slots.  */
 101           bytes += FFI_ALIGN(itype->size, FFI_SIZEOF_ARG);
 102           break;
 103
 104         case FFI_TYPE_COMPLEX:
 105           /* _Complex long double passed by reference; others in 2 slots.  */
 106           if (itype->elements[0]->type == FFI_TYPE_LONGDOUBLE)
 107             bytes += 8;
 108           else
 109             bytes += 16;
 110           break;
 111
 112         default:
 113           abort();
 114         }
 115     }
 116
 117   /* Set the return type flag */
 118   rtype = cif->rtype;
 119   switch (rtype->type)
 120     {
 121     case FFI_TYPE_VOID:
 122       flags = ALPHA_FLAGS(ALPHA_ST_VOID, ALPHA_LD_VOID);
 123       break;
 124     case FFI_TYPE_INT:
 125     case FFI_TYPE_UINT32:
 126     case FFI_TYPE_SINT32:
 127       flags = ALPHA_FLAGS(ALPHA_ST_INT, ALPHA_LD_INT32);
 128       break;
 129     case FFI_TYPE_FLOAT:
 130       flags = ALPHA_FLAGS(ALPHA_ST_FLOAT, ALPHA_LD_FLOAT);
 131       break;
 132     case FFI_TYPE_DOUBLE:
 133       flags = ALPHA_FLAGS(ALPHA_ST_DOUBLE, ALPHA_LD_DOUBLE);
 134       break;
 135     case FFI_TYPE_UINT8:
 136       flags = ALPHA_FLAGS(ALPHA_ST_INT, ALPHA_LD_UINT8);
 137       break;
 138     case FFI_TYPE_SINT8:
 139       flags = ALPHA_FLAGS(ALPHA_ST_INT, ALPHA_LD_SINT8);
 140       break;
 141     case FFI_TYPE_UINT16:
 142       flags = ALPHA_FLAGS(ALPHA_ST_INT, ALPHA_LD_UINT16);
 143       break;
 144     case FFI_TYPE_SINT16:
 145       flags = ALPHA_FLAGS(ALPHA_ST_INT, ALPHA_LD_SINT16);
 146       break;
 147     case FFI_TYPE_UINT64:
 148     case FFI_TYPE_SINT64:
 149     case FFI_TYPE_POINTER:
 150       flags = ALPHA_FLAGS(ALPHA_ST_INT, ALPHA_LD_INT64);
 151       break;
 152     case FFI_TYPE_LONGDOUBLE:
 153     case FFI_TYPE_STRUCT:
 154       /* Passed in memory, with a hidden pointer.  */
 155       flags = ALPHA_RET_IN_MEM;
 156       break;
 157     case FFI_TYPE_COMPLEX:
 158       itype = rtype->elements[0];
 159       switch (itype->type)
 160         {
 161         case FFI_TYPE_FLOAT:
 162           flags = ALPHA_FLAGS(ALPHA_ST_CPLXF, ALPHA_LD_CPLXF);
 163           break;
 164         case FFI_TYPE_DOUBLE:
 165           flags = ALPHA_FLAGS(ALPHA_ST_CPLXD, ALPHA_LD_CPLXD);
 166           break;
 167         default:
 168           if (rtype->size <= 8)
 169             flags = ALPHA_FLAGS(ALPHA_ST_INT, ALPHA_LD_INT64);
 170           else
 171             flags = ALPHA_RET_IN_MEM;
 172           break;
 173         }
 174       break;
 175     default:
 176       abort();
 177     }
 178   cif->flags = flags;
 179
 180   /* Include the hidden structure pointer in args requirement.  */
 181   if (flags == ALPHA_RET_IN_MEM)
 182     bytes += 8;
 183   /* Minimum size is 6 slots, so that ffi_call_osf can pop them.  */
 184   if (bytes < 6*8)
 185     bytes = 6*8;
 186   cif->bytes = bytes;
 187
 188   return FFI_OK;
 189 }
 190
 191 static unsigned long
 192 extend_basic_type(void *valp, int type, int argn)
 193 {
 194   switch (type)
 195     {
 196     case FFI_TYPE_SINT8:
 197       return *(SINT8 *)valp;
 198     case FFI_TYPE_UINT8:
 199       return *(UINT8 *)valp;
 200     case FFI_TYPE_SINT16:
 201       return *(SINT16 *)valp;
 202     case FFI_TYPE_UINT16:
 203       return *(UINT16 *)valp;
 204
 205     case FFI_TYPE_FLOAT:
 206       if (argn < 6)
 207         return lds(valp);
 208       /* FALLTHRU */
 209
 210     case FFI_TYPE_INT:
 211     case FFI_TYPE_SINT32:
 212     case FFI_TYPE_UINT32:
 213       /* Note that unsigned 32-bit quantities are sign extended.  */
 214       return *(SINT32 *)valp;
 215
 216     case FFI_TYPE_SINT64:
 217     case FFI_TYPE_UINT64:
 218     case FFI_TYPE_POINTER:
 219     case FFI_TYPE_DOUBLE:
 220       return *(UINT64 *)valp;
 221
 222     default:
 223       abort();
 224     }
 225 }
 226
 227 static void
 228 ffi_call_int (ffi_cif *cif, void (*fn)(void), void *rvalue,
 229               void **avalue, void *closure)
 230 {
 231   unsigned long *argp;
 232   long i, avn, argn, flags = cif->flags;
 233   ffi_type **arg_types;
 234   void *frame;
 235
 236   /* If the return value is a struct and we don't have a return
 237      value address then we need to make one.  */
 238   if (rvalue == NULL && flags == ALPHA_RET_IN_MEM)
 239     rvalue = alloca(cif->rtype->size);
 240
 241   /* Allocate the space for the arguments, plus 4 words of temp
 242      space for ffi_call_osf.  */
 243   argp = frame = alloca(cif->bytes + 4*FFI_SIZEOF_ARG);
 244   frame += cif->bytes;
 245
 246   argn = 0;
 247   if (flags == ALPHA_RET_IN_MEM)
 248     argp[argn++] = (unsigned long)rvalue;
 249
 250   avn = cif->nargs;
 251   arg_types = cif->arg_types;
 252
 253   for (i = 0, avn = cif->nargs; i < avn; i++)
 254     {
 255       ffi_type *ty = arg_types[i];
 256       void *valp = avalue[i];
 257       int type = ty->type;
 258       size_t size;
 259
 260       switch (type)
 261         {
 262         case FFI_TYPE_INT:
 263         case FFI_TYPE_SINT8:
 264         case FFI_TYPE_UINT8:
 265         case FFI_TYPE_SINT16:
 266         case FFI_TYPE_UINT16:
 267         case FFI_TYPE_SINT32:
 268         case FFI_TYPE_UINT32:
 269         case FFI_TYPE_SINT64:
 270         case FFI_TYPE_UINT64:
 271         case FFI_TYPE_POINTER:
 272         case FFI_TYPE_FLOAT:
 273         case FFI_TYPE_DOUBLE:
 274           argp[argn] = extend_basic_type(valp, type, argn);
 275           argn++;
 276           break;
 277
 278         case FFI_TYPE_LONGDOUBLE:
 279         by_reference:
 280           /* Note that 128-bit long double is passed by reference.  */
 281           argp[argn++] = (unsigned long)valp;
 282           break;
 283
 284         case FFI_TYPE_VOID:
 285         case FFI_TYPE_STRUCT:
 286           size = ty->size;
 287           memcpy(argp + argn, valp, size);
 288           argn += FFI_ALIGN(size, FFI_SIZEOF_ARG) / FFI_SIZEOF_ARG;
 289           break;
 290
 291         case FFI_TYPE_COMPLEX:
 292           type = ty->elements[0]->type;
 293           if (type == FFI_TYPE_LONGDOUBLE)
 294             goto by_reference;
 295
 296           /* Most complex types passed as two separate arguments.  */
 297           size = ty->elements[0]->size;
 298           argp[argn] = extend_basic_type(valp, type, argn);
 299           argp[argn + 1] = extend_basic_type(valp + size, type, argn + 1);
 300           argn += 2;
 301           break;
 302
 303         default:
 304           abort();
 305         }
 306     }
 307
 308   flags = (flags >> ALPHA_ST_SHIFT) & 0xff;
 309   ffi_call_osf(argp, frame, flags, rvalue, fn, closure);
 310 }
 311
 312 void
 313 ffi_call (ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue)
 314 {
 315   ffi_call_int(cif, fn, rvalue, avalue, NULL);
 316 }
 317
 318 void
 319 ffi_call_go (ffi_cif *cif, void (*fn)(void), void *rvalue,
 320              void **avalue, void *closure)
 321 {
 322   ffi_call_int(cif, fn, rvalue, avalue, closure);
 323 }
 324
 325 ffi_status
 326 ffi_prep_closure_loc (ffi_closure* closure,
 327                       ffi_cif* cif,
 328                       void (*fun)(ffi_cif*, void*, void**, void*),
 329                       void *user_data,
 330                       void *codeloc)
 331 {
 332   unsigned int *tramp;
 333
 334   if (cif->abi != FFI_OSF)
 335     return FFI_BAD_ABI;
 336
 337   tramp = (unsigned int *) &closure->tramp[0];
 338   tramp[0] = 0x47fb0401;        /* mov $27,$1           */
 339   tramp[1] = 0xa77b0010;        /* ldq $27,16($27)      */
 340   tramp[2] = 0x6bfb0000;        /* jmp $31,($27),0      */
 341   tramp[3] = 0x47ff041f;        /* nop                  */
 342   *(void **) &tramp[4] = ffi_closure_osf;
 343
 344   closure->cif = cif;
 345   closure->fun = fun;
 346   closure->user_data = user_data;
 347
 348   /* Flush the Icache.
 349
 350      Tru64 UNIX as doesn't understand the imb mnemonic, so use call_pal
 351      instead, since both Compaq as and gas can handle it.
 352
 353      0x86 is PAL_imb in Tru64 UNIX <alpha/pal.h>.  */
 354   asm volatile ("call_pal 0x86" : : : "memory");
 355
 356   return FFI_OK;
 357 }
 358
 359 ffi_status
 360 ffi_prep_go_closure (ffi_go_closure* closure,
 361                      ffi_cif* cif,
 362                      void (*fun)(ffi_cif*, void*, void**, void*))
 363 {
 364   if (cif->abi != FFI_OSF)
 365     return FFI_BAD_ABI;
 366
 367   closure->tramp = (void *)ffi_go_closure_osf;
 368   closure->cif = cif;
 369   closure->fun = fun;
 370
 371   return FFI_OK;
 372 }
 373
 374 long FFI_HIDDEN
 375 ffi_closure_osf_inner (ffi_cif *cif,
 376                        void (*fun)(ffi_cif*, void*, void**, void*),
 377                        void *user_data,
 378                        void *rvalue, unsigned long *argp)
 379 {
 380   void **avalue;
 381   ffi_type **arg_types;
 382   long i, avn, argn, flags;
 383
 384   avalue = alloca(cif->nargs * sizeof(void *));
 385   flags = cif->flags;
 386   argn = 0;
 387
 388   /* Copy the caller's structure return address to that the closure
 389      returns the data directly to the caller.  */
 390   if (flags == ALPHA_RET_IN_MEM)
 391     {
 392       rvalue = (void *) argp[0];
 393       argn = 1;
 394     }
 395
 396   arg_types = cif->arg_types;
 397
 398   /* Grab the addresses of the arguments from the stack frame.  */
 399   for (i = 0, avn = cif->nargs; i < avn; i++)
 400     {
 401       ffi_type *ty = arg_types[i];
 402       int type = ty->type;
 403       void *valp = &argp[argn];
 404       size_t size;
 405
 406       switch (type)
 407         {
 408         case FFI_TYPE_INT:
 409         case FFI_TYPE_SINT8:
 410         case FFI_TYPE_UINT8:
 411         case FFI_TYPE_SINT16:
 412         case FFI_TYPE_UINT16:
 413         case FFI_TYPE_SINT32:
 414         case FFI_TYPE_UINT32:
 415         case FFI_TYPE_SINT64:
 416         case FFI_TYPE_UINT64:
 417         case FFI_TYPE_POINTER:
 418           argn += 1;
 419           break;
 420
 421         case FFI_TYPE_VOID:
 422         case FFI_TYPE_STRUCT:
 423           size = ty->size;
 424           argn += FFI_ALIGN(size, FFI_SIZEOF_ARG) / FFI_SIZEOF_ARG;
 425           break;
 426
 427         case FFI_TYPE_FLOAT:
 428           /* Floats coming from registers need conversion from double
 429              back to float format.  */
 430           if (argn < 6)
 431             {
 432               valp = &argp[argn - 6];
 433               sts(valp, argp[argn - 6]);
 434             }
 435           argn += 1;
 436           break;
 437
 438         case FFI_TYPE_DOUBLE:
 439           if (argn < 6)
 440             valp = &argp[argn - 6];
 441           argn += 1;
 442           break;
 443
 444         case FFI_TYPE_LONGDOUBLE:
 445         by_reference:
 446           /* 128-bit long double is passed by reference.  */
 447           valp = (void *)argp[argn];
 448           argn += 1;
 449           break;
 450
 451         case FFI_TYPE_COMPLEX:
 452           type = ty->elements[0]->type;
 453           switch (type)
 454             {
 455             case FFI_TYPE_SINT64:
 456             case FFI_TYPE_UINT64:
 457               /* Passed as separate arguments, but they wind up sequential.  */
 458               break;
 459
 460             case FFI_TYPE_INT:
 461             case FFI_TYPE_SINT8:
 462             case FFI_TYPE_UINT8:
 463             case FFI_TYPE_SINT16:
 464             case FFI_TYPE_UINT16:
 465             case FFI_TYPE_SINT32:
 466             case FFI_TYPE_UINT32:
 467               /* Passed as separate arguments.  Disjoint, but there's room
 468                  enough in one slot to hold the pair.  */
 469               size = ty->elements[0]->size;
 470               memcpy(valp + size, valp + 8, size);
 471               break;
 472
 473             case FFI_TYPE_FLOAT:
 474               /* Passed as separate arguments.  Disjoint, and each piece
 475                  may need conversion back to float.  */
 476               if (argn < 6)
 477                 {
 478                   valp = &argp[argn - 6];
 479                   sts(valp, argp[argn - 6]);
 480                 }
 481               if (argn + 1 < 6)
 482                 sts(valp + 4, argp[argn + 1 - 6]);
 483               else
 484                 *(UINT32 *)(valp + 4) = argp[argn + 1];
 485               break;
 486
 487             case FFI_TYPE_DOUBLE:
 488               /* Passed as separate arguments.  Only disjoint if one part
 489                  is in fp regs and the other is on the stack.  */
 490               if (argn < 5)
 491                 valp = &argp[argn - 6];
 492               else if (argn == 5)
 493                 {
 494                   valp = alloca(16);
 495                   ((UINT64 *)valp)[0] = argp[5 - 6];
 496                   ((UINT64 *)valp)[1] = argp[6];
 497                 }
 498               break;
 499
 500             case FFI_TYPE_LONGDOUBLE:
 501               goto by_reference;
 502
 503             default:
 504               abort();
 505             }
 506           argn += 2;
 507           break;
 508
 509         default:
 510           abort ();
 511         }
 512
 513       avalue[i] = valp;
 514     }
 515
 516   /* Invoke the closure.  */
 517   fun (cif, rvalue, avalue, user_data);
 518
 519   /* Tell ffi_closure_osf how to perform return type promotions.  */
 520   return (flags >> ALPHA_LD_SHIFT) & 0xff;
 521 }