nsz Git - libfirm/blob - ir/be/sparc/sparc_finish.c

   1 /*
   2  * Copyright (C) 1995-2010 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   6  * This file may be distributed and/or modified under the terms of the
   7  * GNU General Public License version 2 as published by the Free Software
   8  * Foundation and appearing in the file LICENSE.GPL included in the
   9  * packaging of this file.
  10  *
  11  * Licensees holding valid libFirm Professional Edition licenses may use
  12  * this file in accordance with the libFirm Commercial License.
  13  * Agreement provided with the Software.
  14  *
  15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file
  22  * @brief    Peephole optimization and legalization of a sparc function
  23  * @author   Matthias Braun
  24  *
  25  * A note on sparc stackpointer (sp) behaviour:
  26  * The ABI expects SPARC_MIN_STACKSIZE bytes to be available at the
  27  * stackpointer. This space will be used to spill register windows,
  28  * and for spilling va_arg arguments (maybe we can optimize this away for
  29  * statically known not-va-arg-functions...)
  30  * This in effect means that we allocate that extra space at the function begin
  31  * which is easy. But this space isn't really fixed at the beginning of the
  32  * stackframe. Instead you should rather imagine the space as always being the
  33  * last-thing on the stack.
  34  * So when addressing anything stack-specific we have to account for this
  35  * area, while our compiler thinks the space is occupied at the beginning
  36  * of the stack frame. The code here among other things adjusts these offsets
  37  * accordingly.
  38  */
  39 #include "config.h"
  40
  41 #include "bearch_sparc_t.h"
  42 #include "gen_sparc_regalloc_if.h"
  43 #include "sparc_new_nodes.h"
  44 #include "sparc_transform.h"
  45 #include "irprog.h"
  46 #include "irgmod.h"
  47 #include "ircons.h"
  48 #include "irgwalk.h"
  49 #include "heights.h"
  50
  51 #include "bepeephole.h"
  52 #include "benode.h"
  53 #include "besched.h"
  54 #include "bespillslots.h"
  55 #include "bestack.h"
  56 #include "beirgmod.h"
  57
  58 static ir_heights_t *heights;
  59
  60 static void kill_unused_stacknodes(ir_node *node)
  61 {
  62         if (get_irn_n_edges(node) > 0)
  63                 return;
  64
  65         if (be_is_IncSP(node)) {
  66                 sched_remove(node);
  67                 kill_node(node);
  68         } else if (is_Phi(node)) {
  69                 int       arity = get_irn_arity(node);
  70                 ir_node **ins   = ALLOCAN(ir_node*, arity);
  71                 int       i;
  72                 sched_remove(node);
  73                 memcpy(ins, get_irn_in(node), arity*sizeof(ins[0]));
  74                 kill_node(node);
  75
  76                 for (i = 0; i < arity; ++i)
  77                         kill_unused_stacknodes(ins[i]);
  78         }
  79 }
  80
  81 static void introduce_epilog(ir_node *ret)
  82 {
  83         const arch_register_t *sp_reg     = &sparc_registers[REG_SP];
  84         ir_graph              *irg        = get_irn_irg(ret);
  85         be_stack_layout_t     *layout     = be_get_irg_stack_layout(irg);
  86         ir_node               *block      = get_nodes_block(ret);
  87         ir_type               *frame_type = get_irg_frame_type(irg);
  88         unsigned               frame_size = get_type_size_bytes(frame_type);
  89         int                    sp_idx     = be_find_return_reg_input(ret, sp_reg);
  90         ir_node               *sp         = get_irn_n(ret, sp_idx);
  91
  92         if (!layout->sp_relative) {
  93                 const arch_register_t *fp_reg = &sparc_registers[REG_FRAME_POINTER];
  94                 ir_node *fp      = be_get_initial_reg_value(irg, fp_reg);
  95                 ir_node *restore = new_bd_sparc_RestoreZero(NULL, block, fp);
  96                 sched_add_before(ret, restore);
  97                 arch_set_irn_register(restore, sp_reg);
  98                 set_irn_n(ret, sp_idx, restore);
  99
 100                 kill_unused_stacknodes(sp);
 101         } else {
 102                 ir_node *incsp  = be_new_IncSP(sp_reg, block, sp, -frame_size, 0);
 103                 set_irn_n(ret, sp_idx, incsp);
 104                 sched_add_before(ret, incsp);
 105         }
 106 }
 107
 108 void sparc_introduce_prolog_epilog(ir_graph *irg)
 109 {
 110         const arch_register_t *sp_reg     = &sparc_registers[REG_SP];
 111         ir_node               *start      = get_irg_start(irg);
 112         be_stack_layout_t     *layout     = be_get_irg_stack_layout(irg);
 113         ir_node               *block      = get_nodes_block(start);
 114         ir_node               *initial_sp = be_get_initial_reg_value(irg, sp_reg);
 115         ir_node               *sp         = initial_sp;
 116         ir_node               *schedpoint = start;
 117         ir_type               *frame_type = get_irg_frame_type(irg);
 118         unsigned               frame_size = get_type_size_bytes(frame_type);
 119
 120         /* introduce epilog for every return node */
 121         {
 122                 ir_node *end_block = get_irg_end_block(irg);
 123                 int      arity     = get_irn_arity(end_block);
 124                 int      i;
 125
 126                 for (i = 0; i < arity; ++i) {
 127                         ir_node *ret = get_irn_n(end_block, i);
 128                         assert(is_sparc_Return(ret));
 129                         introduce_epilog(ret);
 130                 }
 131         }
 132
 133         while (be_is_Keep(sched_next(schedpoint)))
 134                 schedpoint = sched_next(schedpoint);
 135
 136         if (!layout->sp_relative) {
 137                 ir_node *save = new_bd_sparc_Save_imm(NULL, block, sp, NULL,
 138                                                       -SPARC_MIN_STACKSIZE-frame_size);
 139                 arch_set_irn_register(save, sp_reg);
 140                 sched_add_after(schedpoint, save);
 141                 schedpoint = save;
 142
 143                 edges_reroute(initial_sp, save);
 144                 set_irn_n(save, n_sparc_Save_stack, initial_sp);
 145
 146                 /* we still need the Save even if noone is explicitely using the
 147                  * value. (TODO: this isn't 100% correct yet, something at the end of
 148                  * the function should hold the Save, even if we use a restore
 149                  * which just overrides it instead of using the value)
 150                  */
 151                 if (get_irn_n_edges(save) == 0) {
 152                         ir_node *in[] = { save };
 153                         ir_node *keep = be_new_Keep(block, 1, in);
 154                         sched_add_after(schedpoint, keep);
 155                 }
 156         } else {
 157                 ir_node *incsp = be_new_IncSP(sp_reg, block, sp, frame_size, 0);
 158                 edges_reroute(initial_sp, incsp);
 159                 be_set_IncSP_pred(incsp, sp);
 160                 sched_add_after(schedpoint, incsp);
 161         }
 162 }
 163
 164 /**
 165  * Creates a constant from an immediate value.
 166  */
 167 static ir_node *create_constant_from_immediate(ir_node *node, int offset)
 168 {
 169         dbg_info *dbgi  = get_irn_dbg_info(node);
 170         ir_node  *block = get_nodes_block(node);
 171         ir_node  *high  = new_bd_sparc_SetHi(dbgi, block, NULL, offset);
 172
 173         sched_add_before(node, high);
 174         arch_set_irn_register(high, &sparc_registers[REG_G4]);
 175
 176         if ((offset & 0x3ff) != 0) {
 177                 ir_node *low = new_bd_sparc_Or_imm(dbgi, block, high, NULL, offset & 0x3ff);
 178
 179                 sched_add_before(node, low);
 180                 arch_set_irn_register(low, &sparc_registers[REG_G4]);
 181
 182                 return low;
 183         }
 184
 185         return high;
 186 }
 187
 188 static void finish_sparc_Save(ir_node *node)
 189 {
 190         sparc_attr_t *attr = get_sparc_attr(node);
 191         int offset = attr->immediate_value;
 192
 193         if (! sparc_is_value_imm_encodeable(offset)) {
 194                 ir_node               *base     = get_irn_n(node, n_sparc_Save_stack);
 195                 dbg_info              *dbgi     = get_irn_dbg_info(node);
 196                 ir_node               *block    = get_nodes_block(node);
 197                 ir_node               *constant = create_constant_from_immediate(node, offset);
 198                 ir_node               *new_save = new_bd_sparc_Save_reg(dbgi, block, base, constant);
 199                 const arch_register_t *reg      = arch_get_irn_register(node);
 200
 201                 /* we have a Save with immediate */
 202                 assert(get_irn_arity(node) == 1);
 203
 204                 sched_add_before(node, new_save);
 205                 arch_set_irn_register(new_save, reg);
 206                 be_peephole_exchange(node, new_save);
 207         }
 208 }
 209
 210 /**
 211  * SPARC immediates are limited. Split IncSP with bigger immediates if
 212  * necessary.
 213  */
 214 static void finish_be_IncSP(ir_node *node)
 215 {
 216         int offset = be_get_IncSP_offset(node);
 217
 218         /* we might have to break the IncSP apart if the constant has become too big */
 219         if (! sparc_is_value_imm_encodeable(offset) && ! sparc_is_value_imm_encodeable(-offset)) {
 220                 ir_node               *sp       = be_get_IncSP_pred(node);
 221                 dbg_info              *dbgi     = get_irn_dbg_info(node);
 222                 ir_node               *block    = get_nodes_block(node);
 223                 ir_node               *constant = create_constant_from_immediate(node, offset);
 224                 ir_node               *sub      = new_bd_sparc_Sub_reg(dbgi, block, sp, constant);
 225
 226                 sched_add_before(node, sub);
 227                 arch_set_irn_register(sub, &sparc_registers[REG_SP]);
 228                 be_peephole_exchange(node, sub);
 229         }
 230 }
 231
 232 /**
 233  * Adjust sp-relative offsets.
 234  *
 235  * Split into multiple instructions if offset exceeds SPARC immediate range.
 236  */
 237 static void finish_sparc_FrameAddr(ir_node *node)
 238 {
 239         sparc_attr_t *attr   = get_sparc_attr(node);
 240         int           offset = attr->immediate_value;
 241
 242         if (! sparc_is_value_imm_encodeable(offset)) {
 243                 ir_node               *base          = get_irn_n(node, n_sparc_FrameAddr_base);
 244                 dbg_info              *dbgi          = get_irn_dbg_info(node);
 245                 ir_node               *block         = get_nodes_block(node);
 246                 ir_node               *constant      = create_constant_from_immediate(node, offset);
 247                 ir_node               *new_frameaddr = new_bd_sparc_Add_reg(dbgi, block, base, constant);
 248                 const arch_register_t *reg           = arch_get_irn_register(node);
 249
 250                 sched_add_before(node, new_frameaddr);
 251                 arch_set_irn_register(new_frameaddr, reg);
 252                 exchange(node, new_frameaddr);
 253         }
 254 }
 255
 256 static void finish_sparc_Ld(ir_node *node)
 257 {
 258         sparc_attr_t                  *attr            = get_sparc_attr(node);
 259         int                            offset          = attr->immediate_value;
 260         const sparc_load_store_attr_t *load_store_attr = get_sparc_load_store_attr_const(node);
 261
 262         if (! load_store_attr->is_frame_entity)
 263                 return;
 264
 265         if (! sparc_is_value_imm_encodeable(offset)) {
 266                 ir_node                 *ptr             = get_irn_n(node, n_sparc_Ld_ptr);
 267                 dbg_info                *dbgi            = get_irn_dbg_info(node);
 268                 ir_node                 *block           = get_nodes_block(node);
 269                 ir_node                 *mem             = get_irn_n(node, n_sparc_Ld_mem);
 270                 ir_mode                 *load_store_mode = load_store_attr->load_store_mode;
 271                 ir_node                 *constant        = create_constant_from_immediate(node, offset);
 272                 ir_node                 *new_load        = new_bd_sparc_Ld_reg(dbgi, block, ptr, constant, mem, load_store_mode);
 273                 sparc_load_store_attr_t *new_load_attr   = get_sparc_load_store_attr(new_load);
 274                 unsigned                 n_outs          = arch_get_irn_n_outs(node);
 275                 unsigned                 i;
 276
 277                 new_load_attr->is_frame_entity = load_store_attr->is_frame_entity;
 278                 new_load_attr->is_reg_reg      = load_store_attr->is_reg_reg;
 279
 280                 sched_add_before(node, new_load);
 281                 for (i = 0; i < n_outs; i++) {
 282                         arch_set_irn_register_out(new_load, i, arch_get_irn_register_out(node, i));
 283                 }
 284                 exchange(node, new_load);
 285         }
 286
 287 }
 288
 289 static void finish_sparc_Ldf(ir_node *node)
 290 {
 291         sparc_attr_t                  *attr            = get_sparc_attr(node);
 292         int                            offset          = attr->immediate_value;
 293         const sparc_load_store_attr_t *load_store_attr = get_sparc_load_store_attr_const(node);
 294
 295         if (! load_store_attr->is_frame_entity)
 296                 return;
 297
 298         if (! sparc_is_value_imm_encodeable(offset)) {
 299                 ir_node                 *ptr             = get_irn_n(node, n_sparc_Ldf_ptr);
 300                 dbg_info                *dbgi            = get_irn_dbg_info(node);
 301                 ir_node                 *block           = get_nodes_block(node);
 302                 ir_node                 *mem             = get_irn_n(node, n_sparc_Ldf_mem);
 303                 ir_mode                 *load_store_mode = load_store_attr->load_store_mode;
 304                 ir_node                 *constant        = create_constant_from_immediate(node, offset);
 305                 ir_node                 *new_ptr         = new_bd_sparc_Add_reg(dbgi, block, ptr, constant);
 306                 ir_node                 *new_load        = new_bd_sparc_Ldf_s(dbgi, block, new_ptr, mem, load_store_mode, NULL, 0, true);
 307                 sparc_load_store_attr_t *new_load_attr   = get_sparc_load_store_attr(new_load);
 308                 unsigned                 n_outs          = arch_get_irn_n_outs(node);
 309                 unsigned                 i;
 310
 311                 new_load_attr->is_frame_entity = load_store_attr->is_frame_entity;
 312                 new_load_attr->is_reg_reg      = load_store_attr->is_reg_reg;
 313
 314                 sched_add_before(node, new_load);
 315                 for (i = 0; i < n_outs; i++) {
 316                         arch_set_irn_register_out(new_load, i, arch_get_irn_register_out(node, i));
 317                 }
 318                 exchange(node, new_load);
 319         }
 320
 321 }
 322
 323 static void finish_sparc_St(ir_node *node)
 324 {
 325         sparc_attr_t                  *attr            = get_sparc_attr(node);
 326         int                            offset          = attr->immediate_value;
 327         const sparc_load_store_attr_t *load_store_attr = get_sparc_load_store_attr_const(node);
 328
 329         if (! load_store_attr->is_frame_entity)
 330                 return;
 331
 332         if (! sparc_is_value_imm_encodeable(offset)) {
 333                 ir_node                 *ptr             = get_irn_n(node, n_sparc_St_ptr);
 334                 dbg_info                *dbgi            = get_irn_dbg_info(node);
 335                 ir_node                 *block           = get_nodes_block(node);
 336                 ir_node                 *mem             = get_irn_n(node, n_sparc_St_mem);
 337                 ir_node                 *value           = get_irn_n(node, n_sparc_St_val);
 338                 ir_mode                 *load_store_mode = load_store_attr->load_store_mode;
 339                 ir_node                 *constant        = create_constant_from_immediate(node, offset);
 340                 ir_node                 *new_load        = new_bd_sparc_St_reg(dbgi, block, value, ptr, constant, mem, load_store_mode);
 341                 sparc_load_store_attr_t *new_load_attr   = get_sparc_load_store_attr(new_load);
 342                 unsigned                 n_outs          = arch_get_irn_n_outs(node);
 343                 unsigned                 i;
 344
 345                 new_load_attr->is_frame_entity = load_store_attr->is_frame_entity;
 346                 new_load_attr->is_reg_reg      = load_store_attr->is_reg_reg;
 347
 348                 sched_add_before(node, new_load);
 349                 for (i = 0; i < n_outs; i++) {
 350                         arch_set_irn_register_out(new_load, i, arch_get_irn_register_out(node, i));
 351                 }
 352                 exchange(node, new_load);
 353         }
 354
 355 }
 356
 357 static void finish_sparc_Stf(ir_node *node)
 358 {
 359         sparc_attr_t                  *attr            = get_sparc_attr(node);
 360         int                            offset          = attr->immediate_value;
 361         const sparc_load_store_attr_t *load_store_attr = get_sparc_load_store_attr_const(node);
 362
 363         if (! load_store_attr->is_frame_entity)
 364                 return;
 365
 366         if (! sparc_is_value_imm_encodeable(offset)) {
 367                 ir_node                 *ptr             = get_irn_n(node, n_sparc_Stf_ptr);
 368                 dbg_info                *dbgi            = get_irn_dbg_info(node);
 369                 ir_node                 *block           = get_nodes_block(node);
 370                 ir_node                 *mem             = get_irn_n(node, n_sparc_Stf_mem);
 371                 ir_node                 *value           = get_irn_n(node, n_sparc_Stf_val);
 372                 ir_mode                 *load_store_mode = load_store_attr->load_store_mode;
 373                 ir_node                 *constant        = create_constant_from_immediate(node, offset);
 374                 ir_node                 *new_ptr         = new_bd_sparc_Add_reg(dbgi, block, ptr, constant);
 375                 ir_node                 *new_load        = new_bd_sparc_Stf_s(dbgi, block, value, new_ptr, mem, load_store_mode, NULL, 0, true);
 376                 sparc_load_store_attr_t *new_load_attr   = get_sparc_load_store_attr(new_load);
 377                 unsigned                 n_outs          = arch_get_irn_n_outs(node);
 378                 unsigned                 i;
 379
 380                 new_load_attr->is_frame_entity = load_store_attr->is_frame_entity;
 381                 new_load_attr->is_reg_reg      = load_store_attr->is_reg_reg;
 382
 383                 sched_add_before(node, new_load);
 384                 for (i = 0; i < n_outs; i++) {
 385                         arch_set_irn_register_out(new_load, i, arch_get_irn_register_out(node, i));
 386                 }
 387                 exchange(node, new_load);
 388         }
 389
 390 }
 391
 392 static void peephole_be_IncSP(ir_node *node)
 393 {
 394         ir_node *pred;
 395         node = be_peephole_IncSP_IncSP(node);
 396         if (!be_is_IncSP(node))
 397                 return;
 398
 399         pred = be_get_IncSP_pred(node);
 400         if (is_sparc_Save(pred) && be_has_only_one_user(pred)) {
 401                 int offset = -be_get_IncSP_offset(node);
 402                 sparc_attr_t *attr = get_sparc_attr(pred);
 403                 attr->immediate_value += offset;
 404                 be_peephole_exchange(node, pred);
 405         }
 406 }
 407
 408 static void peephole_sparc_FrameAddr(ir_node *node)
 409 {
 410         /* the peephole code currently doesn't allow this since it changes
 411          * the register. Find out why and how to workaround this... */
 412 #if 0
 413         const sparc_attr_t *attr = get_sparc_attr_const(node);
 414         if (attr->immediate_value == 0) {
 415                 ir_node *base = get_irn_n(node, n_sparc_FrameAddr_base);
 416                 be_peephole_exchange(node, base);
 417         }
 418 #endif
 419         (void) node;
 420 }
 421
 422 /* output must not be local, or out reg. Since the destination of the restore
 423  * is the rotated register-file where only the old in-registers are still
 424  * visible (as out-registers) */
 425 static bool is_restorezeroopt_reg(const arch_register_t *reg)
 426 {
 427         unsigned index = reg->global_index;
 428         return (index >= REG_G0 && index <= REG_G7)
 429             || (index >= REG_I0 && index <= REG_I7);
 430 }
 431
 432 static void replace_with_restore_reg(ir_node *node, ir_node *replaced,
 433                                                                          ir_node *op0, ir_node *op1)
 434 {
 435         dbg_info *dbgi     = get_irn_dbg_info(node);
 436         ir_node  *fp       = get_irn_n(node, n_sparc_RestoreZero_frame_pointer);
 437         ir_node  *block    = get_nodes_block(node);
 438         ir_mode  *mode     = get_irn_mode(node);
 439         ir_node  *new_node = new_bd_sparc_Restore_reg(dbgi, block, fp, op0, op1);
 440         ir_node  *stack    = new_r_Proj(new_node, mode, pn_sparc_Restore_stack);
 441         ir_node  *res      = new_r_Proj(new_node, mode, pn_sparc_Restore_res);
 442         const arch_register_t *reg = arch_get_irn_register(replaced);
 443         const arch_register_t *sp  = &sparc_registers[REG_SP];
 444         arch_set_irn_register_out(new_node, pn_sparc_Restore_stack, sp);
 445         arch_set_irn_register_out(new_node, pn_sparc_Restore_res, reg);
 446
 447         sched_add_before(node, new_node);
 448         be_peephole_exchange(node, stack);
 449         be_peephole_exchange(replaced, res);
 450 }
 451
 452 static void replace_with_restore_imm(ir_node *node, ir_node *replaced,
 453                                                                          ir_node *op, ir_entity *imm_entity,
 454                                                                          int32_t immediate)
 455 {
 456         dbg_info *dbgi     = get_irn_dbg_info(node);
 457         ir_node  *fp       = get_irn_n(node, n_sparc_RestoreZero_frame_pointer);
 458         ir_node  *block    = get_nodes_block(node);
 459         ir_mode  *mode     = get_irn_mode(node);
 460         ir_node  *new_node
 461                 = new_bd_sparc_Restore_imm(dbgi, block, fp, op, imm_entity, immediate);
 462         ir_node  *stack    = new_r_Proj(new_node, mode, pn_sparc_Restore_stack);
 463         ir_node  *res      = new_r_Proj(new_node, mode, pn_sparc_Restore_res);
 464         const arch_register_t *reg = arch_get_irn_register(replaced);
 465         const arch_register_t *sp  = &sparc_registers[REG_SP];
 466         arch_set_irn_register_out(new_node, pn_sparc_Restore_stack, sp);
 467         arch_set_irn_register_out(new_node, pn_sparc_Restore_res, reg);
 468
 469         sched_add_before(node, new_node);
 470         be_peephole_exchange(node, stack);
 471         be_peephole_exchange(replaced, res);
 472 }
 473
 474 static void peephole_sparc_RestoreZero(ir_node *node)
 475 {
 476         /* restore gives us a free "add" instruction, let's try to use that to fold
 477          * an instruction in. We can do the following:
 478          *
 479          * - Copy values                  (g0 + reg)
 480          * - Produce constants            (g0 + immediate)
 481          * - Perform an add               (reg + reg)
 482          * - Perform a sub with immediate (reg + (-immediate))
 483          *
 484          * Note: In an ideal world, this would not be a peephole optimization but
 485          * already performed during code selection. Since about all foldable ops are
 486          * arguments of the return node. However we have a hard time doing this
 487          * since we construct epilogue code only after register allocation
 488          * (and therefore after code selection).
 489          */
 490         int n_tries = 10; /* limit our search */
 491         ir_node *schedpoint = node;
 492
 493         while (sched_has_prev(schedpoint)) {
 494                 const arch_register_t *reg;
 495                 schedpoint = sched_prev(schedpoint);
 496
 497                 if (--n_tries == 0)
 498                         break;
 499
 500                 if (arch_get_irn_n_outs(schedpoint) == 0)
 501                         continue;
 502
 503                 if (!mode_is_data(get_irn_mode(schedpoint)))
 504                         return;
 505
 506                 reg = arch_get_irn_register(schedpoint);
 507                 if (!is_restorezeroopt_reg(reg))
 508                         continue;
 509
 510                 if (be_is_Copy(schedpoint) && be_can_move_before(heights, schedpoint, node)) {
 511                         ir_node *op = get_irn_n(schedpoint, n_be_Copy_op);
 512                         replace_with_restore_imm(node, schedpoint, op, NULL, 0);
 513                 } else if (is_sparc_Or(schedpoint) &&
 514                            arch_get_irn_flags(schedpoint) & ((arch_irn_flags_t)sparc_arch_irn_flag_immediate_form) &&
 515                            arch_get_irn_register_in(schedpoint, 0) == &sparc_registers[REG_G0] &&
 516                            be_can_move_before(heights, schedpoint, node)) {
 517                         /* it's a constant */
 518                         const sparc_attr_t *attr      = get_sparc_attr_const(schedpoint);
 519                         ir_entity          *entity    = attr->immediate_value_entity;
 520                         int32_t             immediate = attr->immediate_value;
 521                         ir_node            *g0        = get_irn_n(schedpoint, 0);
 522                         replace_with_restore_imm(node, schedpoint, g0, entity, immediate);
 523                 } else if (is_sparc_Add(schedpoint) &&
 524                            be_can_move_before(heights, schedpoint, node)) {
 525                         if (arch_get_irn_flags(schedpoint) & ((arch_irn_flags_t)sparc_arch_irn_flag_immediate_form)) {
 526                                 ir_node            *op     = get_irn_n(schedpoint, 0);
 527                                 const sparc_attr_t *attr   = get_sparc_attr_const(schedpoint);
 528                                 ir_entity          *entity = attr->immediate_value_entity;
 529                                 int32_t             imm    = attr->immediate_value;
 530                                 replace_with_restore_imm(node, schedpoint, op, entity, imm);
 531                         } else {
 532                                 ir_node *op0 = get_irn_n(schedpoint, 0);
 533                                 ir_node *op1 = get_irn_n(schedpoint, 1);
 534                                 replace_with_restore_reg(node, schedpoint, op0, op1);
 535                         }
 536                 } else if (is_sparc_Sub(schedpoint) &&
 537                            arch_get_irn_flags(schedpoint) & ((arch_irn_flags_t)sparc_arch_irn_flag_immediate_form) &&
 538                            arch_get_irn_register_in(schedpoint, 0) == &sparc_registers[REG_G0] &&
 539                            be_can_move_before(heights, schedpoint, node)) {
 540                         /* it's a constant */
 541                         const sparc_attr_t *attr   = get_sparc_attr_const(schedpoint);
 542                         ir_entity          *entity = attr->immediate_value_entity;
 543                         int32_t             imm    = attr->immediate_value;
 544                         if (entity == NULL && sparc_is_value_imm_encodeable(-imm)) {
 545                                 ir_node *g0 = get_irn_n(schedpoint, 0);
 546                                 replace_with_restore_imm(node, schedpoint, g0, NULL, -imm);
 547                         } else {
 548                                 continue;
 549                         }
 550                 }
 551                 /* when we're here then we performed a folding and are done */
 552                 return;
 553         }
 554 }
 555
 556 static void finish_sparc_Return(ir_node *node)
 557 {
 558         ir_node *schedpoint = node;
 559         ir_node *restore;
 560         /* see that there is no code between Return and restore, if there is move
 561          * it in front of the restore */
 562         while (true) {
 563                 if (!sched_has_prev(schedpoint))
 564                         return;
 565                 schedpoint = sched_prev(schedpoint);
 566                 if (is_sparc_Restore(schedpoint) || is_sparc_RestoreZero(schedpoint))
 567                         break;
 568         }
 569         restore = schedpoint;
 570         schedpoint = sched_prev(node);
 571         /* move all code between return and restore up */
 572         while (schedpoint != restore) {
 573                 ir_node *next_schedpoint = sched_prev(schedpoint);
 574                 sched_remove(schedpoint);
 575                 sched_add_before(restore, schedpoint);
 576                 schedpoint = next_schedpoint;
 577         }
 578 }
 579
 580 static void register_peephole_optimisation(ir_op *op, peephole_opt_func func)
 581 {
 582         assert(op->ops.generic == NULL);
 583         op->ops.generic = (op_func) func;
 584 }
 585
 586 static void sparc_collect_frame_entity_nodes(ir_node *node, void *data)
 587 {
 588         be_fec_env_t  *env = (be_fec_env_t*)data;
 589         const ir_mode *mode;
 590         int            align;
 591         ir_entity     *entity;
 592         const sparc_load_store_attr_t *attr;
 593
 594         if (be_is_Reload(node) && be_get_frame_entity(node) == NULL) {
 595                 mode  = get_irn_mode(node);
 596                 align = get_mode_size_bytes(mode);
 597                 be_node_needs_frame_entity(env, node, mode, align);
 598                 return;
 599         }
 600
 601         if (!is_sparc_Ld(node) && !is_sparc_Ldf(node))
 602                 return;
 603
 604         attr   = get_sparc_load_store_attr_const(node);
 605         entity = attr->base.immediate_value_entity;
 606         mode   = attr->load_store_mode;
 607         if (entity != NULL)
 608                 return;
 609         if (!attr->is_frame_entity)
 610                 return;
 611         if (arch_get_irn_flags(node) & sparc_arch_irn_flag_needs_64bit_spillslot)
 612                 mode = mode_Lu;
 613         align  = get_mode_size_bytes(mode);
 614         be_node_needs_frame_entity(env, node, mode, align);
 615 }
 616
 617 static void sparc_set_frame_entity(ir_node *node, ir_entity *entity)
 618 {
 619         if (is_be_node(node)) {
 620                 be_node_set_frame_entity(node, entity);
 621         } else {
 622                 /* we only say be_node_needs_frame_entity on nodes with load_store
 623                  * attributes, so this should be fine */
 624                 sparc_load_store_attr_t *attr = get_sparc_load_store_attr(node);
 625                 assert(attr->is_frame_entity);
 626                 assert(attr->base.immediate_value_entity == NULL);
 627                 attr->base.immediate_value_entity = entity;
 628         }
 629 }
 630
 631 void sparc_finish_graph(ir_graph *irg)
 632 {
 633         be_stack_layout_t *stack_layout = be_get_irg_stack_layout(irg);
 634         bool               at_begin     = stack_layout->sp_relative ? true : false;
 635         be_fec_env_t      *fec_env      = be_new_frame_entity_coalescer(irg);
 636
 637         irg_walk_graph(irg, NULL, sparc_collect_frame_entity_nodes, fec_env);
 638         be_assign_entities(fec_env, sparc_set_frame_entity, at_begin);
 639         be_free_frame_entity_coalescer(fec_env);
 640
 641         sparc_introduce_prolog_epilog(irg);
 642
 643         /* fix stack entity offsets */
 644         be_abi_fix_stack_nodes(irg);
 645         sparc_fix_stack_bias(irg);
 646
 647         heights = heights_new(irg);
 648
 649         /* perform peephole optimizations */
 650         ir_clear_opcodes_generic_func();
 651         register_peephole_optimisation(op_be_IncSP,        peephole_be_IncSP);
 652         register_peephole_optimisation(op_sparc_FrameAddr, peephole_sparc_FrameAddr);
 653         register_peephole_optimisation(op_sparc_RestoreZero,
 654                                        peephole_sparc_RestoreZero);
 655         be_peephole_opt(irg);
 656
 657         /* perform legalizations (mostly fix nodes with too big immediates) */
 658         ir_clear_opcodes_generic_func();
 659         register_peephole_optimisation(op_be_IncSP,        finish_be_IncSP);
 660         register_peephole_optimisation(op_sparc_FrameAddr, finish_sparc_FrameAddr);
 661         register_peephole_optimisation(op_sparc_Ld,        finish_sparc_Ld);
 662         register_peephole_optimisation(op_sparc_Ldf,       finish_sparc_Ldf);
 663         register_peephole_optimisation(op_sparc_Return,    finish_sparc_Return);
 664         register_peephole_optimisation(op_sparc_Save,      finish_sparc_Save);
 665         register_peephole_optimisation(op_sparc_St,        finish_sparc_St);
 666         register_peephole_optimisation(op_sparc_Stf,       finish_sparc_Stf);
 667         be_peephole_opt(irg);
 668
 669         heights_free(heights);
 670
 671         be_remove_dead_nodes_from_schedule(irg);
 672 }