参照元

説明

参考

実装

/* Datastructures maintained for currently processed function in RTL form.  */
struct GTY(()) rtl_data {
  void init_stack_alignment ();

  struct expr_status expr;
  struct emit_status emit;
  struct varasm_status varasm;
  struct incoming_args args;
  struct function_subsections subsections;
  struct rtl_eh eh;
  /* For function.c  */

  /* # of bytes of outgoing arguments.  If ACCUMULATE_OUTGOING_ARGS is
     defined, the needed space is pushed by the prologue.  */
  poly_int64_pod outgoing_args_size;
  /* If nonzero, an RTL expression for the location at which the current
     function returns its result.  If the current function returns its
     result in a register, current_function_return_rtx will always be
     the hard register containing the result.  */
  rtx return_rtx;
  /* If nonxero, an RTL expression for the lcoation at which the current
     function returns bounds for its result.  */
  rtx return_bnd;
  /* Vector of initial-value pairs.  Each pair consists of a pseudo
     register of approprite mode that stores the initial value a hard
     register REGNO, and that hard register itself.  */
  /* ??? This could be a VEC but there is currently no way to define an
	 opaque VEC type.  */
  struct initial_value_struct *hard_reg_initial_vals;
  /* A variable living at the top of the frame that holds a known value.
     Used for detecting stack clobbers.  */
  tree stack_protect_guard;
  /* List (chain of INSN_LIST) of labels heading the current handlers for
     nonlocal gotos.  */
  rtx_insn_list *x_nonlocal_goto_handler_labels;
  /* Label that will go on function epilogue.
     Jumping to this label serves as a "return" instruction
     on machines which require execution of the epilogue on all returns.  */
  rtx_code_label *x_return_label;
  /* Label that will go on the end of function epilogue.
     Jumping to this label serves as a "naked return" instruction
     on machines which require execution of the epilogue on all returns.  */
  rtx_code_label *x_naked_return_label;

  /* List (chain of EXPR_LISTs) of all stack slots in this function.
     Made for the sake of unshare_all_rtl.  */
  vec<rtx, va_gc> *x_stack_slot_list;
  /* List of empty areas in the stack frame.  */
  struct frame_space *frame_space_list;
  /* Place after which to insert the tail_recursion_label if we need one.  */
  rtx_note *x_stack_check_probe_note;
  /* Location at which to save the argument pointer if it will need to be
     referenced.  There are two cases where this is done: if nonlocal gotos
     exist, or if vars stored at an offset from the argument pointer will be
     needed by inner routines.  */
  rtx x_arg_pointer_save_area;

  /* Dynamic Realign Argument Pointer used for realigning stack.  */
  rtx drap_reg;

  /* Offset to end of allocated area of stack frame.
     If stack grows down, this is the address of the last stack slot allocated.
     If stack grows up, this is the address for the next slot.  */
  poly_int64_pod x_frame_offset;

  /* Insn after which register parms and SAVE_EXPRs are born, if nonopt.  */
  rtx_insn *x_parm_birth_insn;
  /* List of all used temporaries allocated, by level.  */
  vec<temp_slot_p, va_gc> *x_used_temp_slots;
  /* List of available temp slots.  */
  struct temp_slot *x_avail_temp_slots;
  /* Current nesting level for temporaries.  */
  int x_temp_slot_level;

  /* The largest alignment needed on the stack, including requirement
     for outgoing stack alignment.  */
  unsigned int stack_alignment_needed;

  /* Preferred alignment of the end of stack frame, which is preferred
     to call other functions.  */
  unsigned int preferred_stack_boundary;

  /* The minimum alignment of parameter stack.  */
  unsigned int parm_stack_boundary;

  /* The largest alignment of slot allocated on the stack.  */
  unsigned int max_used_stack_slot_alignment;

  /* The stack alignment estimated before reload, with consideration of
     following factors:
     1. Alignment of local stack variables (max_used_stack_slot_alignment)
     2. Alignment requirement to call other functions
        (preferred_stack_boundary)
     3. Alignment of non-local stack variables but might be spilled in
        local stack.  */
  unsigned int stack_alignment_estimated;

  /* For reorg.  */

  /* Nonzero if function being compiled called builtin_return_addr or
     builtin_frame_address with nonzero count.  */
  bool accesses_prior_frames;

  /* Nonzero if the function calls __builtin_eh_return.  */
  bool calls_eh_return;

  /* Nonzero if function saves all registers, e.g. if it has a nonlocal
     label that can reach the exit block via non-exceptional paths. */
  bool saves_all_registers;

  /* Nonzero if function being compiled has nonlocal gotos to parent
     function.  */
  bool has_nonlocal_goto;

  /* Nonzero if function being compiled has an asm statement.  */
  bool has_asm_statement;

  /* This bit is used by the exception handling logic.  It is set if all
     calls (if any) are sibling calls.  Such functions do not have to
     have EH tables generated, as they cannot throw.  A call to such a
     function, however, should be treated as throwing if any of its callees
     can throw.  */
  bool all_throwers_are_sibcalls;

  /* Nonzero if stack limit checking should be enabled in the current
     function.  */
  bool limit_stack;

  /* Nonzero if profiling code should be generated.  */
  bool profile;

  /* Nonzero if the current function uses the constant pool.  */
  bool uses_const_pool;

  /* Nonzero if the current function uses pic_offset_table_rtx.  */
  bool uses_pic_offset_table;

  /* Nonzero if the current function needs an lsda for exception handling.  */
  bool uses_eh_lsda;

  /* Set when the tail call has been produced.  */
  bool tail_call_emit;

  /* Nonzero if code to initialize arg_pointer_save_area has been emitted.  */
  bool arg_pointer_save_area_init;

  /* Nonzero if current function must be given a frame pointer.
     Set in reload1.c or lra-eliminations.c if anything is allocated
     on the stack there.  */
  bool frame_pointer_needed;

  /* When set, expand should optimize for speed.  */
  bool maybe_hot_insn_p;

  /* Nonzero if function stack realignment is needed.  This flag may be
     set twice: before and after reload.  It is set before reload wrt
     stack alignment estimation before reload.  It will be changed after
     reload if by then criteria of stack realignment is different.
     The value set after reload is the accurate one and is finalized.  */
  bool stack_realign_needed;

  /* Nonzero if function stack realignment is tried.  This flag is set
     only once before reload.  It affects register elimination.  This
     is used to generate DWARF debug info for stack variables.  */
  bool stack_realign_tried;

  /* Nonzero if function being compiled needs dynamic realigned
     argument pointer (drap) if stack needs realigning.  */
  bool need_drap;

  /* Nonzero if function stack realignment estimation is done, namely
     stack_realign_needed flag has been set before reload wrt estimated
     stack alignment info.  */
  bool stack_realign_processed;

  /* Nonzero if function stack realignment has been finalized, namely
     stack_realign_needed flag has been set and finalized after reload.  */
  bool stack_realign_finalized;

  /* True if dbr_schedule has already been called for this function.  */
  bool dbr_scheduled_p;

  /* True if current function can not throw.  Unlike
     TREE_NOTHROW (current_function_decl) it is set even for overwritable
     function where currently compiled version of it is nothrow.  */
  bool nothrow;

  /* True if we performed shrink-wrapping for the current function.  */
  bool shrink_wrapped;

  /* True if we performed shrink-wrapping for separate components for
     the current function.  */
  bool shrink_wrapped_separate;

  /* Nonzero if function being compiled doesn't modify the stack pointer
     (ignoring the prologue and epilogue).  This is only valid after
     pass_stack_ptr_mod has run.  */
  bool sp_is_unchanging;

  /* Nonzero if function being compiled doesn't contain any calls
     (ignoring the prologue and epilogue).  This is set prior to
     register allocation in IRA and is valid for the remaining
     compiler passes.  */
  bool is_leaf;

  /* Nonzero if the function being compiled is a leaf function which only
     uses leaf registers.  This is valid after reload (specifically after
     sched2) and is useful only if the port defines LEAF_REGISTERS.  */
  bool uses_only_leaf_regs;

  /* Nonzero if the function being compiled has undergone hot/cold partitioning
     (under flag_reorder_blocks_and_partition) and has at least one cold
     block.  */
  bool has_bb_partition;

  /* Nonzero if the function being compiled has completed the bb reordering
     pass.  */
  bool bb_reorder_complete;

  /* Like regs_ever_live, but 1 if a reg is set or clobbered from an
     asm.  Unlike regs_ever_live, elements of this array corresponding
     to eliminable regs (like the frame pointer) are set if an asm
     sets them.  */
  HARD_REG_SET asm_clobbers;
  /* The highest address seen during shorten_branches.  */
  int max_insn_address;
};

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Last-modified: 2019-05-10 (金) 18:51:44