cuda.c

   1 /*
   2  * Copyright 2012      Ecole Normale Superieure
   3  *
   4  * Use of this software is governed by the MIT license
   5  *
   6  * Written by Sven Verdoolaege,
   7  * Ecole Normale Superieure, 45 rue d’Ulm, 75230 Paris, France
   8  */
   9
  10 #include <isl/aff.h>
  11 #include <isl/ast.h>
  12
  13 #include "cuda_common.h"
  14 #include "cuda.h"
  15 #include "gpu.h"
  16 #include "gpu_print.h"
  17 #include "print.h"
  18
  19 static __isl_give isl_printer *print_cuda_macros(__isl_take isl_printer *p)
  20 {
  21         const char *macros =
  22                 "#define cudaCheckReturn(ret) \\\n"
  23                 "  do { \\\n"
  24                 "    cudaError_t cudaCheckReturn_e = (ret); \\\n"
  25                 "    if (cudaCheckReturn_e != cudaSuccess) { \\\n"
  26                 "      fprintf(stderr, \"CUDA error: %s\\n\", "
  27                 "cudaGetErrorString(cudaCheckReturn_e)); \\\n"
  28                 "      fflush(stderr); \\\n"
  29                 "    } \\\n"
  30                 "    assert(cudaCheckReturn_e == cudaSuccess); \\\n"
  31                 "  } while(0)\n"
  32                 "#define cudaCheckKernel() \\\n"
  33                 "  do { \\\n"
  34                 "    cudaCheckReturn(cudaGetLastError()); \\\n"
  35                 "  } while(0)\n\n";
  36
  37         p = isl_printer_print_str(p, macros);
  38         return p;
  39 }
  40
  41 /* Print a declaration for the device array corresponding to "array" on "p".
  42  */
  43 static __isl_give isl_printer *declare_device_array(__isl_take isl_printer *p,
  44         struct gpu_array_info *array)
  45 {
  46         int i;
  47
  48         p = isl_printer_start_line(p);
  49         p = isl_printer_print_str(p, array->type);
  50         p = isl_printer_print_str(p, " ");
  51         if (!array->linearize && array->n_index > 1)
  52                 p = isl_printer_print_str(p, "(");
  53         p = isl_printer_print_str(p, "*dev_");
  54         p = isl_printer_print_str(p, array->name);
  55         if (!array->linearize && array->n_index > 1) {
  56                 p = isl_printer_print_str(p, ")");
  57                 for (i = 1; i < array->n_index; i++) {
  58                         p = isl_printer_print_str(p, "[");
  59                         p = isl_printer_print_pw_aff(p, array->bound[i]);
  60                         p = isl_printer_print_str(p, "]");
  61                 }
  62         }
  63         p = isl_printer_print_str(p, ";");
  64         p = isl_printer_end_line(p);
  65
  66         return p;
  67 }
  68
  69 static __isl_give isl_printer *declare_device_arrays(__isl_take isl_printer *p,
  70         struct gpu_prog *prog)
  71 {
  72         int i;
  73
  74         for (i = 0; i < prog->n_array; ++i) {
  75                 if (gpu_array_is_read_only_scalar(&prog->array[i]))
  76                         continue;
  77
  78                 p = declare_device_array(p, &prog->array[i]);
  79         }
  80         p = isl_printer_start_line(p);
  81         p = isl_printer_end_line(p);
  82         return p;
  83 }
  84
  85 static __isl_give isl_printer *allocate_device_arrays(
  86         __isl_take isl_printer *p, struct gpu_prog *prog)
  87 {
  88         int i;
  89
  90         for (i = 0; i < prog->n_array; ++i) {
  91                 if (gpu_array_is_read_only_scalar(&prog->array[i]))
  92                         continue;
  93                 p = isl_printer_start_line(p);
  94                 p = isl_printer_print_str(p,
  95                         "cudaCheckReturn(cudaMalloc((void **) &dev_");
  96                 p = isl_printer_print_str(p, prog->array[i].name);
  97                 p = isl_printer_print_str(p, ", ");
  98                 p = gpu_array_info_print_size(p, &prog->array[i]);
  99                 p = isl_printer_print_str(p, "));");
 100                 p = isl_printer_end_line(p);
 101         }
 102         p = isl_printer_start_line(p);
 103         p = isl_printer_end_line(p);
 104         return p;
 105 }
 106
 107 static __isl_give isl_printer *copy_arrays_to_device(__isl_take isl_printer *p,
 108         struct gpu_prog *prog)
 109 {
 110         int i;
 111
 112         for (i = 0; i < prog->n_array; ++i) {
 113                 isl_space *dim;
 114                 isl_set *read_i;
 115                 int empty;
 116
 117                 if (gpu_array_is_read_only_scalar(&prog->array[i]))
 118                         continue;
 119
 120                 dim = isl_space_copy(prog->array[i].space);
 121                 read_i = isl_union_set_extract_set(prog->copy_in, dim);
 122                 empty = isl_set_fast_is_empty(read_i);
 123                 isl_set_free(read_i);
 124                 if (empty)
 125                         continue;
 126
 127                 p = isl_printer_start_line(p);
 128                 p = isl_printer_print_str(p, "cudaCheckReturn(cudaMemcpy(dev_");
 129                 p = isl_printer_print_str(p, prog->array[i].name);
 130                 p = isl_printer_print_str(p, ", ");
 131
 132                 if (gpu_array_is_scalar(&prog->array[i]))
 133                         p = isl_printer_print_str(p, "&");
 134                 p = isl_printer_print_str(p, prog->array[i].name);
 135                 p = isl_printer_print_str(p, ", ");
 136
 137                 p = gpu_array_info_print_size(p, &prog->array[i]);
 138                 p = isl_printer_print_str(p, ", cudaMemcpyHostToDevice));");
 139                 p = isl_printer_end_line(p);
 140         }
 141         p = isl_printer_start_line(p);
 142         p = isl_printer_end_line(p);
 143         return p;
 144 }
 145
 146 static void print_reverse_list(FILE *out, int len, int *list)
 147 {
 148         int i;
 149
 150         if (len == 0)
 151                 return;
 152
 153         fprintf(out, "(");
 154         for (i = 0; i < len; ++i) {
 155                 if (i)
 156                         fprintf(out, ", ");
 157                 fprintf(out, "%d", list[len - 1 - i]);
 158         }
 159         fprintf(out, ")");
 160 }
 161
 162 /* Print the effective grid size as a list of the sizes in each
 163  * dimension, from innermost to outermost.
 164  */
 165 static __isl_give isl_printer *print_grid_size(__isl_take isl_printer *p,
 166         struct ppcg_kernel *kernel)
 167 {
 168         int i;
 169         int dim;
 170
 171         dim = isl_multi_pw_aff_dim(kernel->grid_size, isl_dim_set);
 172         if (dim == 0)
 173                 return p;
 174
 175         p = isl_printer_print_str(p, "(");
 176         for (i = dim - 1; i >= 0; --i) {
 177                 isl_pw_aff *bound;
 178
 179                 bound = isl_multi_pw_aff_get_pw_aff(kernel->grid_size, i);
 180                 p = isl_printer_print_pw_aff(p, bound);
 181                 isl_pw_aff_free(bound);
 182
 183                 if (i > 0)
 184                         p = isl_printer_print_str(p, ", ");
 185         }
 186
 187         p = isl_printer_print_str(p, ")");
 188
 189         return p;
 190 }
 191
 192 /* Print the grid definition.
 193  */
 194 static __isl_give isl_printer *print_grid(__isl_take isl_printer *p,
 195         struct ppcg_kernel *kernel)
 196 {
 197         p = isl_printer_start_line(p);
 198         p = isl_printer_print_str(p, "dim3 k");
 199         p = isl_printer_print_int(p, kernel->id);
 200         p = isl_printer_print_str(p, "_dimGrid");
 201         p = print_grid_size(p, kernel);
 202         p = isl_printer_print_str(p, ";");
 203         p = isl_printer_end_line(p);
 204
 205         return p;
 206 }
 207
 208 /* Print the arguments to a kernel declaration or call.  If "types" is set,
 209  * then print a declaration (including the types of the arguments).
 210  *
 211  * The arguments are printed in the following order
 212  * - the arrays accessed by the kernel
 213  * - the parameters
 214  * - the host loop iterators
 215  */
 216 static __isl_give isl_printer *print_kernel_arguments(__isl_take isl_printer *p,
 217         struct gpu_prog *prog, struct ppcg_kernel *kernel, int types)
 218 {
 219         int i, n;
 220         int first = 1;
 221         unsigned nparam;
 222         isl_space *space;
 223         const char *type;
 224
 225         for (i = 0; i < prog->n_array; ++i) {
 226                 isl_set *arr;
 227                 int empty;
 228
 229                 space = isl_space_copy(prog->array[i].space);
 230                 arr = isl_union_set_extract_set(kernel->arrays, space);
 231                 empty = isl_set_fast_is_empty(arr);
 232                 isl_set_free(arr);
 233                 if (empty)
 234                         continue;
 235
 236                 if (!first)
 237                         p = isl_printer_print_str(p, ", ");
 238
 239                 if (types)
 240                         p = gpu_array_info_print_declaration_argument(p,
 241                                 &prog->array[i]);
 242                 else
 243                         p = gpu_array_info_print_call_argument(p,
 244                                 &prog->array[i]);
 245
 246                 first = 0;
 247         }
 248
 249         space = isl_union_set_get_space(kernel->arrays);
 250         nparam = isl_space_dim(space, isl_dim_param);
 251         for (i = 0; i < nparam; ++i) {
 252                 const char *name;
 253
 254                 name = isl_space_get_dim_name(space, isl_dim_param, i);
 255
 256                 if (!first)
 257                         p = isl_printer_print_str(p, ", ");
 258                 if (types)
 259                         p = isl_printer_print_str(p, "int ");
 260                 p = isl_printer_print_str(p, name);
 261
 262                 first = 0;
 263         }
 264         isl_space_free(space);
 265
 266         n = isl_space_dim(kernel->space, isl_dim_set);
 267         type = isl_options_get_ast_iterator_type(prog->ctx);
 268         for (i = 0; i < n; ++i) {
 269                 const char *name;
 270                 isl_id *id;
 271
 272                 if (!first)
 273                         p = isl_printer_print_str(p, ", ");
 274                 name = isl_space_get_dim_name(kernel->space, isl_dim_set, i);
 275                 if (types) {
 276                         p = isl_printer_print_str(p, type);
 277                         p = isl_printer_print_str(p, " ");
 278                 }
 279                 p = isl_printer_print_str(p, name);
 280
 281                 first = 0;
 282         }
 283
 284         return p;
 285 }
 286
 287 /* Print the header of the given kernel.
 288  */
 289 static __isl_give isl_printer *print_kernel_header(__isl_take isl_printer *p,
 290         struct gpu_prog *prog, struct ppcg_kernel *kernel)
 291 {
 292         p = isl_printer_start_line(p);
 293         p = isl_printer_print_str(p, "__global__ void kernel");
 294         p = isl_printer_print_int(p, kernel->id);
 295         p = isl_printer_print_str(p, "(");
 296         p = print_kernel_arguments(p, prog, kernel, 1);
 297         p = isl_printer_print_str(p, ")");
 298
 299         return p;
 300 }
 301
 302 /* Print the header of the given kernel to both gen->cuda.kernel_h
 303  * and gen->cuda.kernel_c.
 304  */
 305 static void print_kernel_headers(struct gpu_prog *prog,
 306         struct ppcg_kernel *kernel, struct cuda_info *cuda)
 307 {
 308         isl_printer *p;
 309
 310         p = isl_printer_to_file(prog->ctx, cuda->kernel_h);
 311         p = isl_printer_set_output_format(p, ISL_FORMAT_C);
 312         p = print_kernel_header(p, prog, kernel);
 313         p = isl_printer_print_str(p, ";");
 314         p = isl_printer_end_line(p);
 315         isl_printer_free(p);
 316
 317         p = isl_printer_to_file(prog->ctx, cuda->kernel_c);
 318         p = isl_printer_set_output_format(p, ISL_FORMAT_C);
 319         p = print_kernel_header(p, prog, kernel);
 320         p = isl_printer_end_line(p);
 321         isl_printer_free(p);
 322 }
 323
 324 static void print_indent(FILE *dst, int indent)
 325 {
 326         fprintf(dst, "%*s", indent, "");
 327 }
 328
 329 static void print_kernel_iterators(FILE *out, struct ppcg_kernel *kernel)
 330 {
 331         int i, n_grid;
 332         isl_ctx *ctx = isl_ast_node_get_ctx(kernel->tree);
 333         const char *type;
 334         const char *block_dims[] = { "blockIdx.x", "blockIdx.y" };
 335         const char *thread_dims[] = { "threadIdx.x", "threadIdx.y",
 336                                         "threadIdx.z" };
 337
 338         type = isl_options_get_ast_iterator_type(ctx);
 339
 340         n_grid = isl_multi_pw_aff_dim(kernel->grid_size, isl_dim_set);
 341         if (n_grid > 0) {
 342                 print_indent(out, 4);
 343                 fprintf(out, "%s ", type);
 344                 for (i = 0; i < n_grid; ++i) {
 345                         if (i)
 346                                 fprintf(out, ", ");
 347                         fprintf(out, "b%d = %s",
 348                                 i, block_dims[n_grid - 1 - i]);
 349                 }
 350                 fprintf(out, ";\n");
 351         }
 352
 353         if (kernel->n_block > 0) {
 354                 print_indent(out, 4);
 355                 fprintf(out, "%s ", type);
 356                 for (i = 0; i < kernel->n_block; ++i) {
 357                         if (i)
 358                                 fprintf(out, ", ");
 359                         fprintf(out, "t%d = %s",
 360                                 i, thread_dims[kernel->n_block - 1 - i]);
 361                 }
 362                 fprintf(out, ";\n");
 363         }
 364 }
 365
 366 static __isl_give isl_printer *print_kernel_var(__isl_take isl_printer *p,
 367         struct ppcg_kernel_var *var)
 368 {
 369         int j;
 370
 371         p = isl_printer_start_line(p);
 372         if (var->type == ppcg_access_shared)
 373                 p = isl_printer_print_str(p, "__shared__ ");
 374         p = isl_printer_print_str(p, var->array->type);
 375         p = isl_printer_print_str(p, " ");
 376         p = isl_printer_print_str(p,  var->name);
 377         for (j = 0; j < var->array->n_index; ++j) {
 378                 isl_val *v;
 379
 380                 p = isl_printer_print_str(p, "[");
 381                 v = isl_vec_get_element_val(var->size, j);
 382                 p = isl_printer_print_val(p, v);
 383                 isl_val_free(v);
 384                 p = isl_printer_print_str(p, "]");
 385         }
 386         p = isl_printer_print_str(p, ";");
 387         p = isl_printer_end_line(p);
 388
 389         return p;
 390 }
 391
 392 static __isl_give isl_printer *print_kernel_vars(__isl_take isl_printer *p,
 393         struct ppcg_kernel *kernel)
 394 {
 395         int i;
 396
 397         for (i = 0; i < kernel->n_var; ++i)
 398                 p = print_kernel_var(p, &kernel->var[i]);
 399
 400         return p;
 401 }
 402
 403 /* Print a sync statement.
 404  */
 405 static __isl_give isl_printer *print_sync(__isl_take isl_printer *p,
 406         struct ppcg_kernel_stmt *stmt)
 407 {
 408         p = isl_printer_start_line(p);
 409         p = isl_printer_print_str(p, "__syncthreads();");
 410         p = isl_printer_end_line(p);
 411
 412         return p;
 413 }
 414
 415 /* This function is called for each user statement in the AST,
 416  * i.e., for each kernel body statement, copy statement or sync statement.
 417  */
 418 static __isl_give isl_printer *print_kernel_stmt(__isl_take isl_printer *p,
 419         __isl_take isl_ast_print_options *print_options,
 420         __isl_keep isl_ast_node *node, void *user)
 421 {
 422         isl_id *id;
 423         struct ppcg_kernel_stmt *stmt;
 424
 425         id = isl_ast_node_get_annotation(node);
 426         stmt = isl_id_get_user(id);
 427         isl_id_free(id);
 428
 429         isl_ast_print_options_free(print_options);
 430
 431         switch (stmt->type) {
 432         case ppcg_kernel_copy:
 433                 return ppcg_kernel_print_copy(p, stmt);
 434         case ppcg_kernel_sync:
 435                 return print_sync(p, stmt);
 436         case ppcg_kernel_domain:
 437                 return ppcg_kernel_print_domain(p, stmt);
 438         }
 439
 440         return p;
 441 }
 442
 443 static void print_kernel(struct gpu_prog *prog, struct ppcg_kernel *kernel,
 444         struct cuda_info *cuda)
 445 {
 446         isl_ctx *ctx = isl_ast_node_get_ctx(kernel->tree);
 447         isl_ast_print_options *print_options;
 448         isl_printer *p;
 449
 450         print_kernel_headers(prog, kernel, cuda);
 451         fprintf(cuda->kernel_c, "{\n");
 452         print_kernel_iterators(cuda->kernel_c, kernel);
 453
 454         p = isl_printer_to_file(ctx, cuda->kernel_c);
 455         p = isl_printer_set_output_format(p, ISL_FORMAT_C);
 456         p = isl_printer_indent(p, 4);
 457
 458         p = print_kernel_vars(p, kernel);
 459         p = isl_printer_end_line(p);
 460         p = gpu_print_macros(p, kernel->tree);
 461
 462         print_options = isl_ast_print_options_alloc(ctx);
 463         print_options = isl_ast_print_options_set_print_user(print_options,
 464                                                     &print_kernel_stmt, NULL);
 465         p = isl_ast_node_print(kernel->tree, p, print_options);
 466         isl_printer_free(p);
 467
 468         fprintf(cuda->kernel_c, "}\n");
 469 }
 470
 471 struct print_host_user_data {
 472         struct cuda_info *cuda;
 473         struct gpu_prog *prog;
 474 };
 475
 476 /* Print the user statement of the host code to "p".
 477  *
 478  * In particular, print a block of statements that defines the grid
 479  * and the block and then launches the kernel.
 480  */
 481 static __isl_give isl_printer *print_host_user(__isl_take isl_printer *p,
 482         __isl_take isl_ast_print_options *print_options,
 483         __isl_keep isl_ast_node *node, void *user)
 484 {
 485         isl_id *id;
 486         struct ppcg_kernel *kernel;
 487         struct print_host_user_data *data;
 488
 489         id = isl_ast_node_get_annotation(node);
 490         kernel = isl_id_get_user(id);
 491         isl_id_free(id);
 492
 493         data = (struct print_host_user_data *) user;
 494
 495         p = isl_printer_start_line(p);
 496         p = isl_printer_print_str(p, "{");
 497         p = isl_printer_end_line(p);
 498         p = isl_printer_indent(p, 2);
 499
 500         p = isl_printer_start_line(p);
 501         p = isl_printer_print_str(p, "dim3 k");
 502         p = isl_printer_print_int(p, kernel->id);
 503         p = isl_printer_print_str(p, "_dimBlock");
 504         print_reverse_list(isl_printer_get_file(p),
 505                                 kernel->n_block, kernel->block_dim);
 506         p = isl_printer_print_str(p, ";");
 507         p = isl_printer_end_line(p);
 508
 509         p = print_grid(p, kernel);
 510
 511         p = isl_printer_start_line(p);
 512         p = isl_printer_print_str(p, "kernel");
 513         p = isl_printer_print_int(p, kernel->id);
 514         p = isl_printer_print_str(p, " <<<k");
 515         p = isl_printer_print_int(p, kernel->id);
 516         p = isl_printer_print_str(p, "_dimGrid, k");
 517         p = isl_printer_print_int(p, kernel->id);
 518         p = isl_printer_print_str(p, "_dimBlock>>> (");
 519         p = print_kernel_arguments(p, data->prog, kernel, 0);
 520         p = isl_printer_print_str(p, ");");
 521         p = isl_printer_end_line(p);
 522
 523         p = isl_printer_start_line(p);
 524         p = isl_printer_print_str(p, "cudaCheckKernel();");
 525         p = isl_printer_end_line(p);
 526
 527         p = isl_printer_indent(p, -2);
 528         p = isl_printer_start_line(p);
 529         p = isl_printer_print_str(p, "}");
 530         p = isl_printer_end_line(p);
 531
 532         p = isl_printer_start_line(p);
 533         p = isl_printer_end_line(p);
 534
 535         print_kernel(data->prog, kernel, data->cuda);
 536
 537         isl_ast_print_options_free(print_options);
 538
 539         return p;
 540 }
 541
 542 static __isl_give isl_printer *print_host_code(__isl_take isl_printer *p,
 543         struct gpu_prog *prog, __isl_keep isl_ast_node *tree,
 544         struct cuda_info *cuda)
 545 {
 546         isl_ast_print_options *print_options;
 547         isl_ctx *ctx = isl_ast_node_get_ctx(tree);
 548         struct print_host_user_data data = { cuda, prog };
 549
 550         print_options = isl_ast_print_options_alloc(ctx);
 551         print_options = isl_ast_print_options_set_print_user(print_options,
 552                                                 &print_host_user, &data);
 553
 554         p = gpu_print_macros(p, tree);
 555         p = isl_ast_node_print(tree, p, print_options);
 556
 557         return p;
 558 }
 559
 560 /* For each array that needs to be copied out (based on prog->copy_out),
 561  * copy the contents back from the GPU to the host.
 562  *
 563  * If any element of a given array appears in prog->copy_out, then its
 564  * entire extent is in prog->copy_out.  The bounds on this extent have
 565  * been precomputed in extract_array_info and are used in
 566  * gpu_array_info_print_size.
 567  */
 568 static __isl_give isl_printer *copy_arrays_from_device(
 569         __isl_take isl_printer *p, struct gpu_prog *prog)
 570 {
 571         int i;
 572         isl_union_set *copy_out;
 573         copy_out = isl_union_set_copy(prog->copy_out);
 574
 575         for (i = 0; i < prog->n_array; ++i) {
 576                 isl_space *dim;
 577                 isl_set *copy_out_i;
 578                 int empty;
 579
 580                 dim = isl_space_copy(prog->array[i].space);
 581                 copy_out_i = isl_union_set_extract_set(copy_out, dim);
 582                 empty = isl_set_fast_is_empty(copy_out_i);
 583                 isl_set_free(copy_out_i);
 584                 if (empty)
 585                         continue;
 586
 587                 p = isl_printer_start_line(p);
 588                 p = isl_printer_print_str(p, "cudaCheckReturn(cudaMemcpy(");
 589                 if (gpu_array_is_scalar(&prog->array[i]))
 590                         p = isl_printer_print_str(p, "&");
 591                 p = isl_printer_print_str(p, prog->array[i].name);
 592                 p = isl_printer_print_str(p, ", dev_");
 593                 p = isl_printer_print_str(p, prog->array[i].name);
 594                 p = isl_printer_print_str(p, ", ");
 595                 p = gpu_array_info_print_size(p, &prog->array[i]);
 596                 p = isl_printer_print_str(p, ", cudaMemcpyDeviceToHost));");
 597                 p = isl_printer_end_line(p);
 598         }
 599
 600         isl_union_set_free(copy_out);
 601         p = isl_printer_start_line(p);
 602         p = isl_printer_end_line(p);
 603         return p;
 604 }
 605
 606 static __isl_give isl_printer *free_device_arrays(__isl_take isl_printer *p,
 607         struct gpu_prog *prog)
 608 {
 609         int i;
 610
 611         for (i = 0; i < prog->n_array; ++i) {
 612                 if (gpu_array_is_read_only_scalar(&prog->array[i]))
 613                         continue;
 614                 p = isl_printer_start_line(p);
 615                 p = isl_printer_print_str(p, "cudaCheckReturn(cudaFree(dev_");
 616                 p = isl_printer_print_str(p, prog->array[i].name);
 617                 p = isl_printer_print_str(p, "));");
 618                 p = isl_printer_end_line(p);
 619         }
 620
 621         return p;
 622 }
 623
 624 /* Given a gpu_prog "prog" and the corresponding transformed AST
 625  * "tree", print the entire CUDA code to "p".
 626  * "types" collects the types for which a definition has already
 627  * been printed.
 628  */
 629 static __isl_give isl_printer *print_cuda(__isl_take isl_printer *p,
 630         struct gpu_prog *prog, __isl_keep isl_ast_node *tree,
 631         struct gpu_types *types, void *user)
 632 {
 633         struct cuda_info *cuda = user;
 634         isl_printer *kernel;
 635
 636         kernel = isl_printer_to_file(isl_printer_get_ctx(p), cuda->kernel_c);
 637         kernel = isl_printer_set_output_format(kernel, ISL_FORMAT_C);
 638         kernel = gpu_print_types(kernel, types, prog);
 639         isl_printer_free(kernel);
 640
 641         if (!kernel)
 642                 return isl_printer_free(p);
 643
 644         p = ppcg_start_block(p);
 645
 646         p = print_cuda_macros(p);
 647
 648         p = declare_device_arrays(p, prog);
 649         p = allocate_device_arrays(p, prog);
 650         p = copy_arrays_to_device(p, prog);
 651
 652         p = print_host_code(p, prog, tree, cuda);
 653
 654         p = copy_arrays_from_device(p, prog);
 655         p = free_device_arrays(p, prog);
 656
 657         p = ppcg_end_block(p);
 658
 659         return p;
 660 }
 661
 662 /* Transform the code in the file called "input" by replacing
 663  * all scops by corresponding CUDA code.
 664  * The names of the output files are derived from "input".
 665  *
 666  * We let generate_gpu do all the hard work and then let it call
 667  * us back for printing the AST in print_cuda.
 668  *
 669  * To prepare for this printing, we first open the output files
 670  * and we close them after generate_gpu has finished.
 671  */
 672 int generate_cuda(isl_ctx *ctx, struct ppcg_options *options,
 673         const char *input)
 674 {
 675         struct cuda_info cuda;
 676         int r;
 677
 678         cuda_open_files(&cuda, input);
 679
 680         r = generate_gpu(ctx, input, cuda.host_c, options, &print_cuda, &cuda);
 681
 682         cuda_close_files(&cuda);
 683
 684         return r;
 685 }