mono/mini/mini-arm64-gsharedvt.c

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