gcc/emit-rtl.h

   1 /* Exported functions from emit-rtl.c
   2    Copyright (C) 2004-2017 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   int 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   int 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   int 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   /* If nonxero, an RTL expression for the lcoation at which the current
  79      function returns bounds for its result.  */
  80   rtx return_bnd;
  81
  82   /* Vector of initial-value pairs.  Each pair consists of a pseudo
  83      register of approprite mode that stores the initial value a hard
  84      register REGNO, and that hard register itself.  */
  85   /* ??? This could be a VEC but there is currently no way to define an
  86          opaque VEC type.  */
  87   struct initial_value_struct *hard_reg_initial_vals;
  88
  89   /* A variable living at the top of the frame that holds a known value.
  90      Used for detecting stack clobbers.  */
  91   tree stack_protect_guard;
  92
  93   /* List (chain of INSN_LIST) of labels heading the current handlers for
  94      nonlocal gotos.  */
  95   rtx_insn_list *x_nonlocal_goto_handler_labels;
  96
  97   /* Label that will go on function epilogue.
  98      Jumping to this label serves as a "return" instruction
  99      on machines which require execution of the epilogue on all returns.  */
 100   rtx_code_label *x_return_label;
 101
 102   /* Label that will go on the end of function epilogue.
 103      Jumping to this label serves as a "naked return" instruction
 104      on machines which require execution of the epilogue on all returns.  */
 105   rtx_code_label *x_naked_return_label;
 106
 107   /* List (chain of EXPR_LISTs) of all stack slots in this function.
 108      Made for the sake of unshare_all_rtl.  */
 109   vec<rtx, va_gc> *x_stack_slot_list;
 110
 111   /* List of empty areas in the stack frame.  */
 112   struct frame_space *frame_space_list;
 113
 114   /* Place after which to insert the tail_recursion_label if we need one.  */
 115   rtx_note *x_stack_check_probe_note;
 116
 117   /* Location at which to save the argument pointer if it will need to be
 118      referenced.  There are two cases where this is done: if nonlocal gotos
 119      exist, or if vars stored at an offset from the argument pointer will be
 120      needed by inner routines.  */
 121   rtx x_arg_pointer_save_area;
 122
 123   /* Dynamic Realign Argument Pointer used for realigning stack.  */
 124   rtx drap_reg;
 125
 126   /* Offset to end of allocated area of stack frame.
 127      If stack grows down, this is the address of the last stack slot allocated.
 128      If stack grows up, this is the address for the next slot.  */
 129   HOST_WIDE_INT x_frame_offset;
 130
 131   /* Insn after which register parms and SAVE_EXPRs are born, if nonopt.  */
 132   rtx_insn *x_parm_birth_insn;
 133
 134   /* List of all used temporaries allocated, by level.  */
 135   vec<temp_slot_p, va_gc> *x_used_temp_slots;
 136
 137   /* List of available temp slots.  */
 138   struct temp_slot *x_avail_temp_slots;
 139
 140   /* Current nesting level for temporaries.  */
 141   int x_temp_slot_level;
 142
 143   /* The largest alignment needed on the stack, including requirement
 144      for outgoing stack alignment.  */
 145   unsigned int stack_alignment_needed;
 146
 147   /* Preferred alignment of the end of stack frame, which is preferred
 148      to call other functions.  */
 149   unsigned int preferred_stack_boundary;
 150
 151   /* The minimum alignment of parameter stack.  */
 152   unsigned int parm_stack_boundary;
 153
 154   /* The largest alignment of slot allocated on the stack.  */
 155   unsigned int max_used_stack_slot_alignment;
 156
 157   /* The stack alignment estimated before reload, with consideration of
 158      following factors:
 159      1. Alignment of local stack variables (max_used_stack_slot_alignment)
 160      2. Alignment requirement to call other functions
 161         (preferred_stack_boundary)
 162      3. Alignment of non-local stack variables but might be spilled in
 163         local stack.  */
 164   unsigned int stack_alignment_estimated;
 165
 166   /* For reorg.  */
 167
 168   /* Nonzero if function being compiled called builtin_return_addr or
 169      builtin_frame_address with nonzero count.  */
 170   bool accesses_prior_frames;
 171
 172   /* Nonzero if the function calls __builtin_eh_return.  */
 173   bool calls_eh_return;
 174
 175   /* Nonzero if function saves all registers, e.g. if it has a nonlocal
 176      label that can reach the exit block via non-exceptional paths. */
 177   bool saves_all_registers;
 178
 179   /* Nonzero if function being compiled has nonlocal gotos to parent
 180      function.  */
 181   bool has_nonlocal_goto;
 182
 183   /* Nonzero if function being compiled has an asm statement.  */
 184   bool has_asm_statement;
 185
 186   /* This bit is used by the exception handling logic.  It is set if all
 187      calls (if any) are sibling calls.  Such functions do not have to
 188      have EH tables generated, as they cannot throw.  A call to such a
 189      function, however, should be treated as throwing if any of its callees
 190      can throw.  */
 191   bool all_throwers_are_sibcalls;
 192
 193   /* Nonzero if stack limit checking should be enabled in the current
 194      function.  */
 195   bool limit_stack;
 196
 197   /* Nonzero if profiling code should be generated.  */
 198   bool profile;
 199
 200   /* Nonzero if the current function uses the constant pool.  */
 201   bool uses_const_pool;
 202
 203   /* Nonzero if the current function uses pic_offset_table_rtx.  */
 204   bool uses_pic_offset_table;
 205
 206   /* Nonzero if the current function needs an lsda for exception handling.  */
 207   bool uses_eh_lsda;
 208
 209   /* Set when the tail call has been produced.  */
 210   bool tail_call_emit;
 211
 212   /* Nonzero if code to initialize arg_pointer_save_area has been emitted.  */
 213   bool arg_pointer_save_area_init;
 214
 215   /* Nonzero if current function must be given a frame pointer.
 216      Set in reload1.c or lra-eliminations.c if anything is allocated
 217      on the stack there.  */
 218   bool frame_pointer_needed;
 219
 220   /* When set, expand should optimize for speed.  */
 221   bool maybe_hot_insn_p;
 222
 223   /* Nonzero if function stack realignment is needed.  This flag may be
 224      set twice: before and after reload.  It is set before reload wrt
 225      stack alignment estimation before reload.  It will be changed after
 226      reload if by then criteria of stack realignment is different.
 227      The value set after reload is the accurate one and is finalized.  */
 228   bool stack_realign_needed;
 229
 230   /* Nonzero if function stack realignment is tried.  This flag is set
 231      only once before reload.  It affects register elimination.  This
 232      is used to generate DWARF debug info for stack variables.  */
 233   bool stack_realign_tried;
 234
 235   /* Nonzero if function being compiled needs dynamic realigned
 236      argument pointer (drap) if stack needs realigning.  */
 237   bool need_drap;
 238
 239   /* Nonzero if function stack realignment estimation is done, namely
 240      stack_realign_needed flag has been set before reload wrt estimated
 241      stack alignment info.  */
 242   bool stack_realign_processed;
 243
 244   /* Nonzero if function stack realignment has been finalized, namely
 245      stack_realign_needed flag has been set and finalized after reload.  */
 246   bool stack_realign_finalized;
 247
 248   /* True if dbr_schedule has already been called for this function.  */
 249   bool dbr_scheduled_p;
 250
 251   /* True if current function can not throw.  Unlike
 252      TREE_NOTHROW (current_function_decl) it is set even for overwritable
 253      function where currently compiled version of it is nothrow.  */
 254   bool nothrow;
 255
 256   /* True if we performed shrink-wrapping for the current function.  */
 257   bool shrink_wrapped;
 258
 259   /* True if we performed shrink-wrapping for separate components for
 260      the current function.  */
 261   bool shrink_wrapped_separate;
 262
 263   /* Nonzero if function being compiled doesn't modify the stack pointer
 264      (ignoring the prologue and epilogue).  This is only valid after
 265      pass_stack_ptr_mod has run.  */
 266   bool sp_is_unchanging;
 267
 268   /* Nonzero if function being compiled doesn't contain any calls
 269      (ignoring the prologue and epilogue).  This is set prior to
 270      register allocation in IRA and is valid for the remaining
 271      compiler passes.  */
 272   bool is_leaf;
 273
 274   /* Nonzero if the function being compiled is a leaf function which only
 275      uses leaf registers.  This is valid after reload (specifically after
 276      sched2) and is useful only if the port defines LEAF_REGISTERS.  */
 277   bool uses_only_leaf_regs;
 278
 279   /* Nonzero if the function being compiled has undergone hot/cold partitioning
 280      (under flag_reorder_blocks_and_partition) and has at least one cold
 281      block.  */
 282   bool has_bb_partition;
 283
 284   /* Nonzero if the function being compiled has completed the bb reordering
 285      pass.  */
 286   bool bb_reorder_complete;
 287
 288   /* Like regs_ever_live, but 1 if a reg is set or clobbered from an
 289      asm.  Unlike regs_ever_live, elements of this array corresponding
 290      to eliminable regs (like the frame pointer) are set if an asm
 291      sets them.  */
 292   HARD_REG_SET asm_clobbers;
 293
 294   /* The highest address seen during shorten_branches.  */
 295   int max_insn_address;
 296 };
 297
 298 #define return_label (crtl->x_return_label)
 299 #define naked_return_label (crtl->x_naked_return_label)
 300 #define stack_slot_list (crtl->x_stack_slot_list)
 301 #define parm_birth_insn (crtl->x_parm_birth_insn)
 302 #define frame_offset (crtl->x_frame_offset)
 303 #define stack_check_probe_note (crtl->x_stack_check_probe_note)
 304 #define arg_pointer_save_area (crtl->x_arg_pointer_save_area)
 305 #define used_temp_slots (crtl->x_used_temp_slots)
 306 #define avail_temp_slots (crtl->x_avail_temp_slots)
 307 #define temp_slot_level (crtl->x_temp_slot_level)
 308 #define nonlocal_goto_handler_labels (crtl->x_nonlocal_goto_handler_labels)
 309 #define frame_pointer_needed (crtl->frame_pointer_needed)
 310 #define stack_realign_fp (crtl->stack_realign_needed && !crtl->need_drap)
 311 #define stack_realign_drap (crtl->stack_realign_needed && crtl->need_drap)
 312
 313 extern GTY(()) struct rtl_data x_rtl;
 314
 315 /* Accessor to RTL datastructures.  We keep them statically allocated now since
 316    we never keep multiple functions.  For threaded compiler we might however
 317    want to do differently.  */
 318 #define crtl (&x_rtl)
 319
 320 /* Return whether two MEM_ATTRs are equal.  */
 321 bool mem_attrs_eq_p (const struct mem_attrs *, const struct mem_attrs *);
 322
 323 /* Set the alias set of MEM to SET.  */
 324 extern void set_mem_alias_set (rtx, alias_set_type);
 325
 326 /* Set the alignment of MEM to ALIGN bits.  */
 327 extern void set_mem_align (rtx, unsigned int);
 328
 329 /* Set the address space of MEM to ADDRSPACE.  */
 330 extern void set_mem_addr_space (rtx, addr_space_t);
 331
 332 /* Set the expr for MEM to EXPR.  */
 333 extern void set_mem_expr (rtx, tree);
 334
 335 /* Set the offset for MEM to OFFSET.  */
 336 extern void set_mem_offset (rtx, HOST_WIDE_INT);
 337
 338 /* Clear the offset recorded for MEM.  */
 339 extern void clear_mem_offset (rtx);
 340
 341 /* Set the size for MEM to SIZE.  */
 342 extern void set_mem_size (rtx, HOST_WIDE_INT);
 343
 344 /* Clear the size recorded for MEM.  */
 345 extern void clear_mem_size (rtx);
 346
 347 /* Set the attributes for MEM appropriate for a spill slot.  */
 348 extern void set_mem_attrs_for_spill (rtx);
 349 extern tree get_spill_slot_decl (bool);
 350
 351 /* Return a memory reference like MEMREF, but with its address changed to
 352    ADDR.  The caller is asserting that the actual piece of memory pointed
 353    to is the same, just the form of the address is being changed, such as
 354    by putting something into a register.  */
 355 extern rtx replace_equiv_address (rtx, rtx, bool = false);
 356
 357 /* Likewise, but the reference is not required to be valid.  */
 358 extern rtx replace_equiv_address_nv (rtx, rtx, bool = false);
 359
 360 extern rtx gen_blockage (void);
 361 extern rtvec gen_rtvec (int, ...);
 362 extern rtx copy_insn_1 (rtx);
 363 extern rtx copy_insn (rtx);
 364 extern rtx_insn *copy_delay_slot_insn (rtx_insn *);
 365 extern rtx gen_int_mode (HOST_WIDE_INT, machine_mode);
 366 extern rtx_insn *emit_copy_of_insn_after (rtx_insn *, rtx_insn *);
 367 extern void set_reg_attrs_from_value (rtx, rtx);
 368 extern void set_reg_attrs_for_parm (rtx, rtx);
 369 extern void set_reg_attrs_for_decl_rtl (tree t, rtx x);
 370 extern void adjust_reg_mode (rtx, machine_mode);
 371 extern int mem_expr_equal_p (const_tree, const_tree);
 372
 373 extern bool need_atomic_barrier_p (enum memmodel, bool);
 374
 375 /* Return the current sequence.  */
 376
 377 static inline struct sequence_stack *
 378 get_current_sequence (void)
 379 {
 380   return &crtl->emit.seq;
 381 }
 382
 383 /* Return the outermost sequence.  */
 384
 385 static inline struct sequence_stack *
 386 get_topmost_sequence (void)
 387 {
 388   struct sequence_stack *seq, *top;
 389
 390   seq = get_current_sequence ();
 391   do
 392     {
 393       top = seq;
 394       seq = seq->next;
 395     } while (seq);
 396   return top;
 397 }
 398
 399 /* Return the first insn of the current sequence or current function.  */
 400
 401 static inline rtx_insn *
 402 get_insns (void)
 403 {
 404   return get_current_sequence ()->first;
 405 }
 406
 407 /* Specify a new insn as the first in the chain.  */
 408
 409 static inline void
 410 set_first_insn (rtx_insn *insn)
 411 {
 412   gcc_checking_assert (!insn || !PREV_INSN (insn));
 413   get_current_sequence ()->first = insn;
 414 }
 415
 416 /* Return the last insn emitted in current sequence or current function.  */
 417
 418 static inline rtx_insn *
 419 get_last_insn (void)
 420 {
 421   return get_current_sequence ()->last;
 422 }
 423
 424 /* Specify a new insn as the last in the chain.  */
 425
 426 static inline void
 427 set_last_insn (rtx_insn *insn)
 428 {
 429   gcc_checking_assert (!insn || !NEXT_INSN (insn));
 430   get_current_sequence ()->last = insn;
 431 }
 432
 433 /* Return a number larger than any instruction's uid in this function.  */
 434
 435 static inline int
 436 get_max_uid (void)
 437 {
 438   return crtl->emit.x_cur_insn_uid;
 439 }
 440
 441 extern void set_decl_incoming_rtl (tree, rtx, bool);
 442
 443 /* Return a memory reference like MEMREF, but with its mode changed
 444    to MODE and its address changed to ADDR.
 445    (VOIDmode means don't change the mode.
 446    NULL for ADDR means don't change the address.)  */
 447 extern rtx change_address (rtx, machine_mode, rtx);
 448
 449 /* Return a memory reference like MEMREF, but with its mode changed
 450    to MODE and its address offset by OFFSET bytes.  */
 451 #define adjust_address(MEMREF, MODE, OFFSET) \
 452   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 0, 0)
 453
 454 /* Likewise, but the reference is not required to be valid.  */
 455 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 456   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1, 0, 0)
 457
 458 /* Return a memory reference like MEMREF, but with its mode changed
 459    to MODE and its address offset by OFFSET bytes.  Assume that it's
 460    for a bitfield and conservatively drop the underlying object if we
 461    cannot be sure to stay within its bounds.  */
 462 #define adjust_bitfield_address(MEMREF, MODE, OFFSET) \
 463   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 1, 0)
 464
 465 /* As for adjust_bitfield_address, but specify that the width of
 466    BLKmode accesses is SIZE bytes.  */
 467 #define adjust_bitfield_address_size(MEMREF, MODE, OFFSET, SIZE) \
 468   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 1, SIZE)
 469
 470 /* Likewise, but the reference is not required to be valid.  */
 471 #define adjust_bitfield_address_nv(MEMREF, MODE, OFFSET) \
 472   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1, 1, 0)
 473
 474 /* Return a memory reference like MEMREF, but with its mode changed
 475    to MODE and its address changed to ADDR, which is assumed to be
 476    increased by OFFSET bytes from MEMREF.  */
 477 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 478   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 479
 480 /* Likewise, but the reference is not required to be valid.  */
 481 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 482   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 483
 484 extern rtx adjust_address_1 (rtx, machine_mode, HOST_WIDE_INT, int, int,
 485                              int, HOST_WIDE_INT);
 486 extern rtx adjust_automodify_address_1 (rtx, machine_mode, rtx,
 487                                         HOST_WIDE_INT, int);
 488
 489 /* Return a memory reference like MEMREF, but whose address is changed by
 490    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 491    known to be in OFFSET (possibly 1).  */
 492 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 493
 494 /* Given REF, a MEM, and T, either the type of X or the expression
 495    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 496    if we are making a new object of this type.  */
 497 extern void set_mem_attributes (rtx, tree, int);
 498
 499 /* Similar, except that BITPOS has not yet been applied to REF, so if
 500    we alter MEM_OFFSET according to T then we should subtract BITPOS
 501    expecting that it'll be added back in later.  */
 502 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
 503
 504 /* Return OFFSET if XEXP (MEM, 0) - OFFSET is known to be ALIGN
 505    bits aligned for 0 <= OFFSET < ALIGN / BITS_PER_UNIT, or
 506    -1 if not known.  */
 507 extern int get_mem_align_offset (rtx, unsigned int);
 508
 509 /* Return a memory reference like MEMREF, but with its mode widened to
 510    MODE and adjusted by OFFSET.  */
 511 extern rtx widen_memory_access (rtx, machine_mode, HOST_WIDE_INT);
 512
 513 extern void maybe_set_max_label_num (rtx_code_label *x);
 514
 515 #endif /* GCC_EMIT_RTL_H */