gcc/emit-rtl.h

   1 /* Exported functions from emit-rtl.c
   2    Copyright (C) 2004-2018 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_EMIT_RTL_H
  21 #define GCC_EMIT_RTL_H
  22
  23 struct temp_slot;
  24 typedef struct temp_slot *temp_slot_p;
  25
  26 /* Information mainlined about RTL representation of incoming arguments.  */
  27 struct GTY(()) incoming_args {
  28   /* Number of bytes of args popped by function being compiled on its return.
  29      Zero if no bytes are to be popped.
  30      May affect compilation of return insn or of function epilogue.  */
  31   poly_int64_pod pops_args;
  32
  33   /* If function's args have a fixed size, this is that size, in bytes.
  34      Otherwise, it is -1.
  35      May affect compilation of return insn or of function epilogue.  */
  36   poly_int64_pod size;
  37
  38   /* # bytes the prologue should push and pretend that the caller pushed them.
  39      The prologue must do this, but only if parms can be passed in
  40      registers.  */
  41   int pretend_args_size;
  42
  43   /* This is the offset from the arg pointer to the place where the first
  44      anonymous arg can be found, if there is one.  */
  45   rtx arg_offset_rtx;
  46
  47   /* Quantities of various kinds of registers
  48      used for the current function's args.  */
  49   CUMULATIVE_ARGS info;
  50
  51   /* The arg pointer hard register, or the pseudo into which it was copied.  */
  52   rtx internal_arg_pointer;
  53 };
  54
  55
  56 /* Datastructures maintained for currently processed function in RTL form.  */
  57 struct GTY(()) rtl_data {
  58   void init_stack_alignment ();
  59
  60   struct expr_status expr;
  61   struct emit_status emit;
  62   struct varasm_status varasm;
  63   struct incoming_args args;
  64   struct function_subsections subsections;
  65   struct rtl_eh eh;
  66
  67   /* For function.c  */
  68
  69   /* # of bytes of outgoing arguments.  If ACCUMULATE_OUTGOING_ARGS is
  70      defined, the needed space is pushed by the prologue.  */
  71   poly_int64_pod outgoing_args_size;
  72
  73   /* If nonzero, an RTL expression for the location at which the current
  74      function returns its result.  If the current function returns its
  75      result in a register, current_function_return_rtx will always be
  76      the hard register containing the result.  */
  77   rtx return_rtx;
  78
  79   /* Vector of initial-value pairs.  Each pair consists of a pseudo
  80      register of approprite mode that stores the initial value a hard
  81      register REGNO, and that hard register itself.  */
  82   /* ??? This could be a VEC but there is currently no way to define an
  83          opaque VEC type.  */
  84   struct initial_value_struct *hard_reg_initial_vals;
  85
  86   /* A variable living at the top of the frame that holds a known value.
  87      Used for detecting stack clobbers.  */
  88   tree stack_protect_guard;
  89
  90   /* List (chain of INSN_LIST) of labels heading the current handlers for
  91      nonlocal gotos.  */
  92   rtx_insn_list *x_nonlocal_goto_handler_labels;
  93
  94   /* Label that will go on function epilogue.
  95      Jumping to this label serves as a "return" instruction
  96      on machines which require execution of the epilogue on all returns.  */
  97   rtx_code_label *x_return_label;
  98
  99   /* Label that will go on the end of function epilogue.
 100      Jumping to this label serves as a "naked return" instruction
 101      on machines which require execution of the epilogue on all returns.  */
 102   rtx_code_label *x_naked_return_label;
 103
 104   /* List (chain of EXPR_LISTs) of all stack slots in this function.
 105      Made for the sake of unshare_all_rtl.  */
 106   vec<rtx, va_gc> *x_stack_slot_list;
 107
 108   /* List of empty areas in the stack frame.  */
 109   struct frame_space *frame_space_list;
 110
 111   /* Place after which to insert the tail_recursion_label if we need one.  */
 112   rtx_note *x_stack_check_probe_note;
 113
 114   /* Location at which to save the argument pointer if it will need to be
 115      referenced.  There are two cases where this is done: if nonlocal gotos
 116      exist, or if vars stored at an offset from the argument pointer will be
 117      needed by inner routines.  */
 118   rtx x_arg_pointer_save_area;
 119
 120   /* Dynamic Realign Argument Pointer used for realigning stack.  */
 121   rtx drap_reg;
 122
 123   /* Offset to end of allocated area of stack frame.
 124      If stack grows down, this is the address of the last stack slot allocated.
 125      If stack grows up, this is the address for the next slot.  */
 126   poly_int64_pod x_frame_offset;
 127
 128   /* Insn after which register parms and SAVE_EXPRs are born, if nonopt.  */
 129   rtx_insn *x_parm_birth_insn;
 130
 131   /* List of all used temporaries allocated, by level.  */
 132   vec<temp_slot_p, va_gc> *x_used_temp_slots;
 133
 134   /* List of available temp slots.  */
 135   struct temp_slot *x_avail_temp_slots;
 136
 137   /* Current nesting level for temporaries.  */
 138   int x_temp_slot_level;
 139
 140   /* The largest alignment needed on the stack, including requirement
 141      for outgoing stack alignment.  */
 142   unsigned int stack_alignment_needed;
 143
 144   /* Preferred alignment of the end of stack frame, which is preferred
 145      to call other functions.  */
 146   unsigned int preferred_stack_boundary;
 147
 148   /* The minimum alignment of parameter stack.  */
 149   unsigned int parm_stack_boundary;
 150
 151   /* The largest alignment of slot allocated on the stack.  */
 152   unsigned int max_used_stack_slot_alignment;
 153
 154   /* The stack alignment estimated before reload, with consideration of
 155      following factors:
 156      1. Alignment of local stack variables (max_used_stack_slot_alignment)
 157      2. Alignment requirement to call other functions
 158         (preferred_stack_boundary)
 159      3. Alignment of non-local stack variables but might be spilled in
 160         local stack.  */
 161   unsigned int stack_alignment_estimated;
 162
 163   /* For reorg.  */
 164
 165   /* Nonzero if function being compiled called builtin_return_addr or
 166      builtin_frame_address with nonzero count.  */
 167   bool accesses_prior_frames;
 168
 169   /* Nonzero if the function calls __builtin_eh_return.  */
 170   bool calls_eh_return;
 171
 172   /* Nonzero if function saves all registers, e.g. if it has a nonlocal
 173      label that can reach the exit block via non-exceptional paths. */
 174   bool saves_all_registers;
 175
 176   /* Nonzero if function being compiled has nonlocal gotos to parent
 177      function.  */
 178   bool has_nonlocal_goto;
 179
 180   /* Nonzero if function being compiled has an asm statement.  */
 181   bool has_asm_statement;
 182
 183   /* This bit is used by the exception handling logic.  It is set if all
 184      calls (if any) are sibling calls.  Such functions do not have to
 185      have EH tables generated, as they cannot throw.  A call to such a
 186      function, however, should be treated as throwing if any of its callees
 187      can throw.  */
 188   bool all_throwers_are_sibcalls;
 189
 190   /* Nonzero if stack limit checking should be enabled in the current
 191      function.  */
 192   bool limit_stack;
 193
 194   /* Nonzero if profiling code should be generated.  */
 195   bool profile;
 196
 197   /* Nonzero if the current function uses the constant pool.  */
 198   bool uses_const_pool;
 199
 200   /* Nonzero if the current function uses pic_offset_table_rtx.  */
 201   bool uses_pic_offset_table;
 202
 203   /* Nonzero if the current function needs an lsda for exception handling.  */
 204   bool uses_eh_lsda;
 205
 206   /* Set when the tail call has been produced.  */
 207   bool tail_call_emit;
 208
 209   /* Nonzero if code to initialize arg_pointer_save_area has been emitted.  */
 210   bool arg_pointer_save_area_init;
 211
 212   /* Nonzero if current function must be given a frame pointer.
 213      Set in reload1.c or lra-eliminations.c if anything is allocated
 214      on the stack there.  */
 215   bool frame_pointer_needed;
 216
 217   /* When set, expand should optimize for speed.  */
 218   bool maybe_hot_insn_p;
 219
 220   /* Nonzero if function stack realignment is needed.  This flag may be
 221      set twice: before and after reload.  It is set before reload wrt
 222      stack alignment estimation before reload.  It will be changed after
 223      reload if by then criteria of stack realignment is different.
 224      The value set after reload is the accurate one and is finalized.  */
 225   bool stack_realign_needed;
 226
 227   /* Nonzero if function stack realignment is tried.  This flag is set
 228      only once before reload.  It affects register elimination.  This
 229      is used to generate DWARF debug info for stack variables.  */
 230   bool stack_realign_tried;
 231
 232   /* Nonzero if function being compiled needs dynamic realigned
 233      argument pointer (drap) if stack needs realigning.  */
 234   bool need_drap;
 235
 236   /* Nonzero if function stack realignment estimation is done, namely
 237      stack_realign_needed flag has been set before reload wrt estimated
 238      stack alignment info.  */
 239   bool stack_realign_processed;
 240
 241   /* Nonzero if function stack realignment has been finalized, namely
 242      stack_realign_needed flag has been set and finalized after reload.  */
 243   bool stack_realign_finalized;
 244
 245   /* True if dbr_schedule has already been called for this function.  */
 246   bool dbr_scheduled_p;
 247
 248   /* True if current function can not throw.  Unlike
 249      TREE_NOTHROW (current_function_decl) it is set even for overwritable
 250      function where currently compiled version of it is nothrow.  */
 251   bool nothrow;
 252
 253   /* True if we performed shrink-wrapping for the current function.  */
 254   bool shrink_wrapped;
 255
 256   /* True if we performed shrink-wrapping for separate components for
 257      the current function.  */
 258   bool shrink_wrapped_separate;
 259
 260   /* Nonzero if function being compiled doesn't modify the stack pointer
 261      (ignoring the prologue and epilogue).  This is only valid after
 262      pass_stack_ptr_mod has run.  */
 263   bool sp_is_unchanging;
 264
 265   /* Nonzero if function being compiled doesn't contain any calls
 266      (ignoring the prologue and epilogue).  This is set prior to
 267      register allocation in IRA and is valid for the remaining
 268      compiler passes.  */
 269   bool is_leaf;
 270
 271   /* Nonzero if the function being compiled is a leaf function which only
 272      uses leaf registers.  This is valid after reload (specifically after
 273      sched2) and is useful only if the port defines LEAF_REGISTERS.  */
 274   bool uses_only_leaf_regs;
 275
 276   /* Nonzero if the function being compiled has undergone hot/cold partitioning
 277      (under flag_reorder_blocks_and_partition) and has at least one cold
 278      block.  */
 279   bool has_bb_partition;
 280
 281   /* Nonzero if the function being compiled has completed the bb reordering
 282      pass.  */
 283   bool bb_reorder_complete;
 284
 285   /* Like regs_ever_live, but 1 if a reg is set or clobbered from an
 286      asm.  Unlike regs_ever_live, elements of this array corresponding
 287      to eliminable regs (like the frame pointer) are set if an asm
 288      sets them.  */
 289   HARD_REG_SET asm_clobbers;
 290
 291   /* The highest address seen during shorten_branches.  */
 292   int max_insn_address;
 293 };
 294
 295 #define return_label (crtl->x_return_label)
 296 #define naked_return_label (crtl->x_naked_return_label)
 297 #define stack_slot_list (crtl->x_stack_slot_list)
 298 #define parm_birth_insn (crtl->x_parm_birth_insn)
 299 #define frame_offset (crtl->x_frame_offset)
 300 #define stack_check_probe_note (crtl->x_stack_check_probe_note)
 301 #define arg_pointer_save_area (crtl->x_arg_pointer_save_area)
 302 #define used_temp_slots (crtl->x_used_temp_slots)
 303 #define avail_temp_slots (crtl->x_avail_temp_slots)
 304 #define temp_slot_level (crtl->x_temp_slot_level)
 305 #define nonlocal_goto_handler_labels (crtl->x_nonlocal_goto_handler_labels)
 306 #define frame_pointer_needed (crtl->frame_pointer_needed)
 307 #define stack_realign_fp (crtl->stack_realign_needed && !crtl->need_drap)
 308 #define stack_realign_drap (crtl->stack_realign_needed && crtl->need_drap)
 309
 310 extern GTY(()) struct rtl_data x_rtl;
 311
 312 /* Accessor to RTL datastructures.  We keep them statically allocated now since
 313    we never keep multiple functions.  For threaded compiler we might however
 314    want to do differently.  */
 315 #define crtl (&x_rtl)
 316
 317 /* Return whether two MEM_ATTRs are equal.  */
 318 bool mem_attrs_eq_p (const struct mem_attrs *, const struct mem_attrs *);
 319
 320 /* Set the alias set of MEM to SET.  */
 321 extern void set_mem_alias_set (rtx, alias_set_type);
 322
 323 /* Set the alignment of MEM to ALIGN bits.  */
 324 extern void set_mem_align (rtx, unsigned int);
 325
 326 /* Set the address space of MEM to ADDRSPACE.  */
 327 extern void set_mem_addr_space (rtx, addr_space_t);
 328
 329 /* Set the expr for MEM to EXPR.  */
 330 extern void set_mem_expr (rtx, tree);
 331
 332 /* Set the offset for MEM to OFFSET.  */
 333 extern void set_mem_offset (rtx, poly_int64);
 334
 335 /* Clear the offset recorded for MEM.  */
 336 extern void clear_mem_offset (rtx);
 337
 338 /* Set the size for MEM to SIZE.  */
 339 extern void set_mem_size (rtx, poly_int64);
 340
 341 /* Clear the size recorded for MEM.  */
 342 extern void clear_mem_size (rtx);
 343
 344 /* Set the attributes for MEM appropriate for a spill slot.  */
 345 extern void set_mem_attrs_for_spill (rtx);
 346 extern tree get_spill_slot_decl (bool);
 347
 348 /* Return a memory reference like MEMREF, but with its address changed to
 349    ADDR.  The caller is asserting that the actual piece of memory pointed
 350    to is the same, just the form of the address is being changed, such as
 351    by putting something into a register.  */
 352 extern rtx replace_equiv_address (rtx, rtx, bool = false);
 353
 354 /* Likewise, but the reference is not required to be valid.  */
 355 extern rtx replace_equiv_address_nv (rtx, rtx, bool = false);
 356
 357 extern rtx gen_blockage (void);
 358 extern rtvec gen_rtvec (int, ...);
 359 extern rtx copy_insn_1 (rtx);
 360 extern rtx copy_insn (rtx);
 361 extern rtx_insn *copy_delay_slot_insn (rtx_insn *);
 362 extern rtx gen_int_mode (poly_int64, machine_mode);
 363 extern rtx_insn *emit_copy_of_insn_after (rtx_insn *, rtx_insn *);
 364 extern void set_reg_attrs_from_value (rtx, rtx);
 365 extern void set_reg_attrs_for_parm (rtx, rtx);
 366 extern void set_reg_attrs_for_decl_rtl (tree t, rtx x);
 367 extern void adjust_reg_mode (rtx, machine_mode);
 368 extern int mem_expr_equal_p (const_tree, const_tree);
 369 extern rtx gen_int_shift_amount (machine_mode, poly_int64);
 370
 371 extern bool need_atomic_barrier_p (enum memmodel, bool);
 372
 373 /* Return the current sequence.  */
 374
 375 static inline struct sequence_stack *
 376 get_current_sequence (void)
 377 {
 378   return &crtl->emit.seq;
 379 }
 380
 381 /* Return the outermost sequence.  */
 382
 383 static inline struct sequence_stack *
 384 get_topmost_sequence (void)
 385 {
 386   struct sequence_stack *seq, *top;
 387
 388   seq = get_current_sequence ();
 389   do
 390     {
 391       top = seq;
 392       seq = seq->next;
 393     } while (seq);
 394   return top;
 395 }
 396
 397 /* Return the first insn of the current sequence or current function.  */
 398
 399 static inline rtx_insn *
 400 get_insns (void)
 401 {
 402   return get_current_sequence ()->first;
 403 }
 404
 405 /* Specify a new insn as the first in the chain.  */
 406
 407 static inline void
 408 set_first_insn (rtx_insn *insn)
 409 {
 410   gcc_checking_assert (!insn || !PREV_INSN (insn));
 411   get_current_sequence ()->first = insn;
 412 }
 413
 414 /* Return the last insn emitted in current sequence or current function.  */
 415
 416 static inline rtx_insn *
 417 get_last_insn (void)
 418 {
 419   return get_current_sequence ()->last;
 420 }
 421
 422 /* Specify a new insn as the last in the chain.  */
 423
 424 static inline void
 425 set_last_insn (rtx_insn *insn)
 426 {
 427   gcc_checking_assert (!insn || !NEXT_INSN (insn));
 428   get_current_sequence ()->last = insn;
 429 }
 430
 431 /* Return a number larger than any instruction's uid in this function.  */
 432
 433 static inline int
 434 get_max_uid (void)
 435 {
 436   return crtl->emit.x_cur_insn_uid;
 437 }
 438
 439 extern bool valid_for_const_vector_p (machine_mode, rtx);
 440 extern rtx gen_const_vec_duplicate (machine_mode, rtx);
 441 extern rtx gen_vec_duplicate (machine_mode, rtx);
 442
 443 extern rtx gen_const_vec_series (machine_mode, rtx, rtx);
 444 extern rtx gen_vec_series (machine_mode, rtx, rtx);
 445
 446 extern void set_decl_incoming_rtl (tree, rtx, bool);
 447
 448 /* Return a memory reference like MEMREF, but with its mode changed
 449    to MODE and its address changed to ADDR.
 450    (VOIDmode means don't change the mode.
 451    NULL for ADDR means don't change the address.)  */
 452 extern rtx change_address (rtx, machine_mode, rtx);
 453
 454 /* Return a memory reference like MEMREF, but with its mode changed
 455    to MODE and its address offset by OFFSET bytes.  */
 456 #define adjust_address(MEMREF, MODE, OFFSET) \
 457   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 0, 0)
 458
 459 /* Likewise, but the reference is not required to be valid.  */
 460 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 461   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1, 0, 0)
 462
 463 /* Return a memory reference like MEMREF, but with its mode changed
 464    to MODE and its address offset by OFFSET bytes.  Assume that it's
 465    for a bitfield and conservatively drop the underlying object if we
 466    cannot be sure to stay within its bounds.  */
 467 #define adjust_bitfield_address(MEMREF, MODE, OFFSET) \
 468   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 1, 0)
 469
 470 /* As for adjust_bitfield_address, but specify that the width of
 471    BLKmode accesses is SIZE bytes.  */
 472 #define adjust_bitfield_address_size(MEMREF, MODE, OFFSET, SIZE) \
 473   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 1, SIZE)
 474
 475 /* Likewise, but the reference is not required to be valid.  */
 476 #define adjust_bitfield_address_nv(MEMREF, MODE, OFFSET) \
 477   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1, 1, 0)
 478
 479 /* Return a memory reference like MEMREF, but with its mode changed
 480    to MODE and its address changed to ADDR, which is assumed to be
 481    increased by OFFSET bytes from MEMREF.  */
 482 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 483   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 484
 485 /* Likewise, but the reference is not required to be valid.  */
 486 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 487   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 488
 489 extern rtx adjust_address_1 (rtx, machine_mode, poly_int64, int, int,
 490                              int, poly_int64);
 491 extern rtx adjust_automodify_address_1 (rtx, machine_mode, rtx,
 492                                         poly_int64, int);
 493
 494 /* Return a memory reference like MEMREF, but whose address is changed by
 495    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 496    known to be in OFFSET (possibly 1).  */
 497 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 498
 499 /* Given REF, a MEM, and T, either the type of X or the expression
 500    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 501    if we are making a new object of this type.  */
 502 extern void set_mem_attributes (rtx, tree, int);
 503
 504 /* Similar, except that BITPOS has not yet been applied to REF, so if
 505    we alter MEM_OFFSET according to T then we should subtract BITPOS
 506    expecting that it'll be added back in later.  */
 507 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, poly_int64);
 508
 509 /* Return OFFSET if XEXP (MEM, 0) - OFFSET is known to be ALIGN
 510    bits aligned for 0 <= OFFSET < ALIGN / BITS_PER_UNIT, or
 511    -1 if not known.  */
 512 extern int get_mem_align_offset (rtx, unsigned int);
 513
 514 /* Return a memory reference like MEMREF, but with its mode widened to
 515    MODE and adjusted by OFFSET.  */
 516 extern rtx widen_memory_access (rtx, machine_mode, poly_int64);
 517
 518 extern void maybe_set_max_label_num (rtx_code_label *x);
 519
 520 #endif /* GCC_EMIT_RTL_H */