mono/mini/mini-arm64-gsharedvt.c

   1 /*
   2  * mini-arm64-gsharedvt.c: gsharedvt support code for arm64
   3  *
   4  * Authors:
   5  *   Zoltan Varga <vargaz@gmail.com>
   6  *
   7  * Copyright 2013 Xamarin, Inc (http://www.xamarin.com)
   8  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
   9  */
  10 #include "mini.h"
  11 #include "mini-arm64.h"
  12 #include "mini-arm64-gsharedvt.h"
  13
  14 /*
  15  * GSHAREDVT
  16  */
  17 #ifdef MONO_ARCH_GSHAREDVT_SUPPORTED
  18
  19 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
  20
  21 void
  22 mono_arm_gsharedvt_init (void)
  23 {
  24         mono_aot_register_jit_icall ("mono_arm_start_gsharedvt_call", mono_arm_start_gsharedvt_call);
  25 }
  26
  27 gboolean
  28 mono_arch_gsharedvt_sig_supported (MonoMethodSignature *sig)
  29 {
  30         /*
  31         if (sig->ret && is_variable_size (sig->ret))
  32                 return FALSE;
  33         */
  34         return TRUE;
  35 }
  36
  37 static inline void
  38 add_to_map (GPtrArray *map, int src, int dst)
  39 {
  40         g_ptr_array_add (map, GUINT_TO_POINTER (src));
  41         g_ptr_array_add (map, GUINT_TO_POINTER (dst));
  42 }
  43
  44 /*
  45  * Slot mapping:
  46  * 0..8  - r0..r8
  47  * 9..16 - d0..d7
  48  * 17..  - stack slots
  49  */
  50
  51 static inline int
  52 map_reg (int reg)
  53 {
  54         return reg;
  55 }
  56
  57 static inline int
  58 map_freg (int reg)
  59 {
  60         return reg + NUM_GSHAREDVT_ARG_GREGS;
  61 }
  62
  63 static inline int
  64 map_stack_slot (int slot)
  65 {
  66         return slot + NUM_GSHAREDVT_ARG_GREGS + NUM_GSHAREDVT_ARG_FREGS;
  67 }
  68
  69 static int
  70 get_arg_slots (ArgInfo *ainfo, int **out_slots)
  71 {
  72         int sreg = ainfo->reg;
  73         int sslot = ainfo->offset / 8;
  74         int *src = NULL;
  75         int i, nsrc;
  76
  77         switch (ainfo->storage) {
  78         case ArgInIReg:
  79         case ArgVtypeByRef:
  80                 nsrc = 1;
  81                 src = g_malloc (nsrc * sizeof (int));
  82                 src [0] = map_reg (sreg);
  83                 break;
  84         case ArgVtypeByRefOnStack:
  85                 nsrc = 1;
  86                 src = g_malloc (nsrc * sizeof (int));
  87                 src [0] = map_stack_slot (sslot);
  88                 break;
  89         case ArgInFReg:
  90         case ArgInFRegR4:
  91                 nsrc = 1;
  92                 src = g_malloc (nsrc * sizeof (int));
  93                 src [0] = map_freg (sreg);
  94                 break;
  95         case ArgHFA:
  96                 nsrc = ainfo->nregs;
  97                 src = g_malloc (nsrc * sizeof (int));
  98                 for (i = 0; i < ainfo->nregs; ++i)
  99                         src [i] = map_freg (sreg + i);
 100                 break;
 101         case ArgVtypeInIRegs:
 102                 nsrc = ainfo->nregs;
 103                 src = g_malloc (nsrc * sizeof (int));
 104                 for (i = 0; i < ainfo->nregs; ++i)
 105                         src [i] = map_reg (sreg + i);
 106                 break;
 107         case ArgOnStack:
 108                 nsrc = 1;
 109                 src = g_malloc (nsrc * sizeof (int));
 110                 src [0] = map_stack_slot (sslot);
 111                 break;
 112         case ArgVtypeOnStack:
 113                 nsrc = ainfo->size / 8;
 114                 src = g_malloc (nsrc * sizeof (int));
 115                 for (i = 0; i < nsrc; ++i)
 116                         src [i] = map_stack_slot (sslot + i);
 117                 break;
 118         default:
 119                 NOT_IMPLEMENTED;
 120                 break;
 121         }
 122
 123         *out_slots = src;
 124         return nsrc;
 125 }
 126
 127 /*
 128  * mono_arch_get_gsharedvt_call_info:
 129  *
 130  *   See mini-x86.c for documentation.
 131  */
 132 gpointer
 133 mono_arch_get_gsharedvt_call_info (gpointer addr, MonoMethodSignature *normal_sig, MonoMethodSignature *gsharedvt_sig, gboolean gsharedvt_in, gint32 vcall_offset, gboolean calli)
 134 {
 135         GSharedVtCallInfo *info;
 136         CallInfo *caller_cinfo, *callee_cinfo;
 137         MonoMethodSignature *caller_sig, *callee_sig;
 138         int aindex, i;
 139         gboolean var_ret = FALSE;
 140         CallInfo *cinfo, *gcinfo;
 141         MonoMethodSignature *sig, *gsig;
 142         GPtrArray *map;
 143
 144         if (gsharedvt_in) {
 145                 caller_sig = normal_sig;
 146                 callee_sig = gsharedvt_sig;
 147                 caller_cinfo = mono_arch_get_call_info (NULL, caller_sig);
 148                 callee_cinfo = mono_arch_get_call_info (NULL, callee_sig);
 149         } else {
 150                 callee_sig = normal_sig;
 151                 caller_sig = gsharedvt_sig;
 152                 callee_cinfo = mono_arch_get_call_info (NULL, callee_sig);
 153                 caller_cinfo = mono_arch_get_call_info (NULL, caller_sig);
 154         }
 155
 156         /*
 157          * If GSHAREDVT_IN is true, this means we are transitioning from normal to gsharedvt code. The caller uses the
 158          * normal call signature, while the callee uses the gsharedvt signature.
 159          * If GSHAREDVT_IN is false, its the other way around.
 160          */
 161
 162         /* sig/cinfo describes the normal call, while gsig/gcinfo describes the gsharedvt call */
 163         if (gsharedvt_in) {
 164                 sig = caller_sig;
 165                 gsig = callee_sig;
 166                 cinfo = caller_cinfo;
 167                 gcinfo = callee_cinfo;
 168         } else {
 169                 sig = callee_sig;
 170                 gsig = caller_sig;
 171                 cinfo = callee_cinfo;
 172                 gcinfo = caller_cinfo;
 173         }
 174
 175         if (gcinfo->ret.gsharedvt) {
 176                 /*
 177                  * The return type is gsharedvt
 178                  */
 179                 var_ret = TRUE;
 180         }
 181
 182         /*
 183          * The stack looks like this:
 184          * <arguments>
 185          * <trampoline frame>
 186          * <call area>
 187          * We have to map the stack slots in <arguments> to the stack slots in <call area>.
 188          */
 189         map = g_ptr_array_new ();
 190
 191         for (aindex = 0; aindex < cinfo->nargs; ++aindex) {
 192                 ArgInfo *ainfo = &caller_cinfo->args [aindex];
 193                 ArgInfo *ainfo2 = &callee_cinfo->args [aindex];
 194                 int *src = NULL, *dst = NULL;
 195                 int nsrc, ndst, nslots, src_slot, arg_marshal;
 196
 197                 /*
 198                  * The src descriptor looks like this:
 199                  * - 6 bits src slot
 200                  * - 12 bits number of slots
 201                  * - 4 bits marshal type (GSHAREDVT_ARG_...)
 202                  * - 4 bits size/sign descriptor (GSHAREDVT_ARG_SIZE)
 203                  * - 4 bits offset inside stack slots
 204                  */
 205                 arg_marshal = GSHAREDVT_ARG_NONE;
 206
 207                 if (ainfo->gsharedvt) {
 208                         /* Pass the value whose address is received in a reg by value */
 209                         g_assert (!ainfo2->gsharedvt);
 210                         ndst = get_arg_slots (ainfo2, &dst);
 211                         nsrc = 1;
 212                         src = g_new0 (int, 1);
 213                         if (ainfo->storage == ArgVtypeByRef)
 214                                 src_slot = map_reg (ainfo->reg);
 215                         else
 216                                 src_slot = map_stack_slot (ainfo->offset / 8);
 217                         g_assert (ndst < 256);
 218                         g_assert (src_slot < 64);
 219                         src [0] = (ndst << 6) | src_slot;
 220                         if (ainfo2->storage == ArgHFA && ainfo2->esize == 4)
 221                                 arg_marshal = GSHAREDVT_ARG_BYREF_TO_BYVAL_HFAR4;
 222                         else if (ainfo2->storage == ArgVtypeByRef || ainfo2->storage == ArgVtypeByRefOnStack)
 223                                 arg_marshal = GSHAREDVT_ARG_BYREF_TO_BYREF;
 224                         else
 225                                 arg_marshal = GSHAREDVT_ARG_BYREF_TO_BYVAL;
 226                 } else {
 227                         nsrc = get_arg_slots (ainfo, &src);
 228                 }
 229                 if (ainfo2->storage == ArgVtypeByRef && ainfo2->gsharedvt) {
 230                         /* Pass the address of the first src slot in a reg */
 231                         if (ainfo->storage != ArgVtypeByRef) {
 232                                 if (ainfo->storage == ArgHFA && ainfo->esize == 4) {
 233                                         arg_marshal = GSHAREDVT_ARG_BYVAL_TO_BYREF_HFAR4;
 234                                         g_assert (src [0] < 64);
 235                                         g_assert (nsrc < 256);
 236                                         src [0] |= (nsrc << 6);
 237                                 } else {
 238                                         arg_marshal = GSHAREDVT_ARG_BYVAL_TO_BYREF;
 239                                 }
 240                         }
 241                         ndst = 1;
 242                         dst = g_new0 (int, 1);
 243                         dst [0] = map_reg (ainfo2->reg);
 244                 } else if (ainfo2->storage == ArgVtypeByRefOnStack && ainfo2->gsharedvt) {
 245                         /* Pass the address of the first src slot in a stack slot */
 246                         if (ainfo->storage != ArgVtypeByRef)
 247                                 arg_marshal = GSHAREDVT_ARG_BYVAL_TO_BYREF;
 248                         ndst = 1;
 249                         dst = g_new0 (int, 1);
 250                         dst [0] = map_stack_slot (ainfo2->offset / 8);
 251                 } else {
 252                         ndst = get_arg_slots (ainfo2, &dst);
 253                 }
 254                 if (nsrc)
 255                         src [0] |= (arg_marshal << 18);
 256                 if (ainfo->storage == ArgOnStack && ainfo->slot_size != 8) {
 257                         GSharedVtArgSize arg_size = GSHAREDVT_ARG_SIZE_NONE;
 258
 259                         /*
 260                          * On IOS, stack arguments smaller than 8 bytes can
 261                          * share a stack slot. Encode this information into
 262                          * the descriptor.
 263                          */
 264                         switch (ainfo->slot_size) {
 265                         case 1:
 266                                 arg_size = ainfo->sign ? GSHAREDVT_ARG_SIZE_I1 : GSHAREDVT_ARG_SIZE_U1;
 267                                 break;
 268                         case 2:
 269                                 arg_size = ainfo->sign ? GSHAREDVT_ARG_SIZE_I2 : GSHAREDVT_ARG_SIZE_U2;
 270                                 break;
 271                         case 4:
 272                                 arg_size = ainfo->sign ? GSHAREDVT_ARG_SIZE_I4 : GSHAREDVT_ARG_SIZE_U4;
 273                                 break;
 274                         default:
 275                                 NOT_IMPLEMENTED;
 276                                 break;
 277                         }
 278                         /* Encode the size/sign */
 279                         src [0] |= (arg_size << 22);
 280                         /* Encode the offset inside the stack slot */
 281                         src [0] |= ((ainfo->offset % 8) << 26);
 282                         if (ainfo2->storage == ArgOnStack)
 283                                 dst [0] |= ((ainfo2->offset % 8) << 26);
 284                 } else if (ainfo2->storage == ArgOnStack && ainfo2->slot_size != 8) {
 285                         /* The caller passes in an address, need to store it into a stack slot */
 286
 287                         GSharedVtArgSize arg_size = GSHAREDVT_ARG_SIZE_NONE;
 288                         switch (ainfo2->slot_size) {
 289                         case 1:
 290                                 arg_size = ainfo2->sign ? GSHAREDVT_ARG_SIZE_I1 : GSHAREDVT_ARG_SIZE_U1;
 291                                 break;
 292                         case 2:
 293                                 arg_size = ainfo2->sign ? GSHAREDVT_ARG_SIZE_I2 : GSHAREDVT_ARG_SIZE_U2;
 294                                 break;
 295                         case 4:
 296                                 arg_size = ainfo2->sign ? GSHAREDVT_ARG_SIZE_I4 : GSHAREDVT_ARG_SIZE_U4;
 297                                 break;
 298                         default:
 299                                 NOT_IMPLEMENTED;
 300                                 break;
 301                         }
 302                         /* Encode the size/sign */
 303                         src [0] |= (arg_size << 22);
 304                         /* Encode the offset inside the stack slot */
 305                         dst [0] |= ((ainfo2->offset % 8) << 26);
 306                 }
 307                 nslots = MIN (nsrc, ndst);
 308
 309                 for (i = 0; i < nslots; ++i)
 310                         add_to_map (map, src [i], dst [i]);
 311
 312                 g_free (src);
 313                 g_free (dst);
 314         }
 315
 316         if (cinfo->ret.storage == ArgVtypeByRef) {
 317                 /* Both the caller and the callee pass the vtype ret address in r8 */
 318                 g_assert (cinfo->ret.storage == gcinfo->ret.storage);
 319                 add_to_map (map, map_reg (ARMREG_R8), map_reg (ARMREG_R8));
 320         }
 321
 322         info = mono_domain_alloc0 (mono_domain_get (), sizeof (GSharedVtCallInfo) + (map->len * sizeof (int)));
 323         info->addr = addr;
 324         info->stack_usage = callee_cinfo->stack_usage;
 325         info->ret_marshal = GSHAREDVT_RET_NONE;
 326         info->gsharedvt_in = gsharedvt_in ? 1 : 0;
 327         info->vret_slot = -1;
 328         info->calli = calli;
 329
 330         if (var_ret) {
 331                 g_assert (gcinfo->ret.gsharedvt);
 332                 info->vret_arg_reg = map_reg (ARMREG_R8);
 333         } else {
 334                 info->vret_arg_reg = -1;
 335         }
 336
 337         info->vcall_offset = vcall_offset;
 338         info->map_count = map->len / 2;
 339         for (i = 0; i < map->len; ++i)
 340                 info->map [i] = GPOINTER_TO_UINT (g_ptr_array_index (map, i));
 341         g_ptr_array_free (map, TRUE);
 342
 343         /* Compute return value marshalling */
 344         if (var_ret) {
 345                 switch (cinfo->ret.storage) {
 346                 case ArgInIReg:
 347                         if (!gsharedvt_in || sig->ret->byref) {
 348                                 info->ret_marshal = GSHAREDVT_RET_I8;
 349                         } else {
 350                                 switch (sig->ret->type) {
 351                                 case MONO_TYPE_I1:
 352                                         info->ret_marshal = GSHAREDVT_RET_I1;
 353                                         break;
 354                                 case MONO_TYPE_U1:
 355                                 case MONO_TYPE_BOOLEAN:
 356                                         info->ret_marshal = GSHAREDVT_RET_U1;
 357                                         break;
 358                                 case MONO_TYPE_I2:
 359                                         info->ret_marshal = GSHAREDVT_RET_I2;
 360                                         break;
 361                                 case MONO_TYPE_U2:
 362                                 case MONO_TYPE_CHAR:
 363                                         info->ret_marshal = GSHAREDVT_RET_U2;
 364                                         break;
 365                                 case MONO_TYPE_I4:
 366                                         info->ret_marshal = GSHAREDVT_RET_I4;
 367                                         break;
 368                                 case MONO_TYPE_U4:
 369                                         info->ret_marshal = GSHAREDVT_RET_U4;
 370                                         break;
 371                                 default:
 372                                         info->ret_marshal = GSHAREDVT_RET_I8;
 373                                         break;
 374                                 }
 375                         }
 376                         break;
 377                 case ArgInFReg:
 378                         info->ret_marshal = GSHAREDVT_RET_R8;
 379                         break;
 380                 case ArgInFRegR4:
 381                         info->ret_marshal = GSHAREDVT_RET_R4;
 382                         break;
 383                 case ArgVtypeInIRegs:
 384                         info->ret_marshal = GSHAREDVT_RET_IREGS_1 - 1 + cinfo->ret.nregs;
 385                         break;
 386                 case ArgHFA:
 387                         if (cinfo->ret.esize == 4)
 388                                 info->ret_marshal = GSHAREDVT_RET_HFAR4_1 - 1 + cinfo->ret.nregs;
 389                         else
 390                                 info->ret_marshal = GSHAREDVT_RET_HFAR8_1 - 1 + cinfo->ret.nregs;
 391                         break;
 392                 case ArgVtypeByRef:
 393                         /* No conversion needed */
 394                         break;
 395                 default:
 396                         g_assert_not_reached ();
 397                 }
 398         }
 399
 400         if (gsharedvt_in && var_ret && cinfo->ret.storage != ArgVtypeByRef) {
 401                 /* Allocate stack space for the return value */
 402                 info->vret_slot = map_stack_slot (info->stack_usage / sizeof (gpointer));
 403                 info->stack_usage += mono_type_stack_size_internal (normal_sig->ret, NULL, FALSE) + sizeof (gpointer);
 404         }
 405
 406         info->stack_usage = ALIGN_TO (info->stack_usage, MONO_ARCH_FRAME_ALIGNMENT);
 407
 408         return info;
 409 }
 410
 411 #else
 412
 413 void
 414 mono_arm_gsharedvt_init (void)
 415 {
 416 }
 417
 418 #endif /* MONO_ARCH_GSHAREDVT_SUPPORTED */