GCC Middle and Back End API Reference
ira.c File Reference

Data Structures

struct  equivalence

Functions

static void setup_reg_mode_hard_regset ()
static void setup_class_hard_regs ()
static void setup_alloc_regs ()
static void setup_reg_subclasses ()
static void setup_class_subset_and_memory_move_costs ()
void * ira_allocate ()
void ira_free ()
bitmap ira_allocate_bitmap ()
void ira_free_bitmap ()
void ira_print_disposition ()
void ira_debug_disposition ()
static void setup_stack_reg_pressure_class ()
static void setup_pressure_classes ()
static void setup_uniform_class_p ()
static void setup_allocno_and_important_classes ()
static void setup_class_translate_array (enum reg_class *class_translate, int classes_num, enum reg_class *classes)
static void setup_class_translate ()
static int comp_reg_classes_func ()
static void reorder_important_classes ()
static void setup_reg_class_relations ()
static void print_unform_and_important_classes ()
static void print_translated_classes ()
void ira_debug_allocno_classes ()
static void find_reg_classes ()
static void setup_hard_regno_aclass ()
static void setup_reg_class_nregs ()
static void setup_prohibited_class_mode_regs ()
static void clarify_prohibited_class_mode_regs ()
void ira_init_register_move_cost ()
void ira_init_once ()
static void free_register_move_costs ()
void ira_init ()
void ira_finish_once ()
static void setup_prohibited_mode_move_regs ()
static bool ira_bad_reload_regno_1 ()
bool ira_bad_reload_regno ()
static int insn_contains_asm_1 ()
static bool insn_contains_asm ()
static void compute_regs_asm_clobbered ()
void ira_setup_eliminable_regset ()
static void setup_reg_renumber ()
static void setup_allocno_assignment_flags ()
static void calculate_allocation_cost ()
static void check_allocation ()
static void setup_reg_equiv_init ()
void ira_update_equiv_info_by_shuffle_insn ()
static void fix_reg_equiv_init ()
static void print_redundant_copies ()
static void setup_preferred_alternate_classes_for_new_pseudos ()
static void expand_reg_info ()
static bool too_high_register_pressure_p ()
void mark_elimination ()
void ira_expand_reg_equiv ()
static void init_reg_equiv ()
static void finish_reg_equiv ()
static void validate_equiv_mem_from_store (rtx dest, const_rtx set, void *data)
static int validate_equiv_mem ()
static int equiv_init_varies_p ()
static int equiv_init_movable_p ()
static int contains_replace_regs ()
static int memref_referenced_p ()
static int memref_used_between_p ()
static void no_equiv (rtx reg, const_rtx store, void *data)
static int set_paradoxical_subreg ()
static rtx adjust_cleared_regs ()
static int update_equiv_regs ()
static void setup_reg_equiv ()
static void print_insn_chain ()
static void print_insn_chains ()
static bool pseudo_for_reload_consideration_p ()
static void init_live_subregs (bool init_value, sbitmap *live_subregs, bitmap live_subregs_used, int allocnum, rtx reg)
static void build_insn_chain ()
static bool rtx_moveable_p ()
static bool insn_dominated_by_p ()
static void find_moveable_pseudos ()
static void move_unallocated_pseudos ()
static void allocate_initial_values ()
static void ira ()
static void do_reload ()
static unsigned int rest_of_handle_ira ()
rtl_opt_passmake_pass_ira ()
static unsigned int rest_of_handle_reload ()
rtl_opt_passmake_pass_reload ()

Variables

struct target_ira default_target_ira
struct target_ira_int default_target_ira_int
struct target_irathis_target_ira = &default_target_ira
struct target_ira_intthis_target_ira_int = &default_target_ira_int
int internal_flag_ira_verbose
FILE * ira_dump_file
int ira_spilled_reg_stack_slots_num
struct ira_spilled_reg_stack_slotira_spilled_reg_stack_slots
int ira_overall_cost
int overall_cost_before
int ira_reg_cost
int ira_mem_cost
int ira_load_cost
int ira_store_cost
int ira_shuffle_cost
int ira_move_loops_num
int ira_additional_jumps_num
HARD_REG_SET eliminable_regset
static int max_regno_before_ira
static HARD_REG_SET temp_hard_regset
static struct obstack ira_obstack
static struct bitmap_obstack ira_bitmap_obstack
static int allocno_class_order [N_REG_CLASSES]
short * reg_renumber
static int allocated_reg_info_size
int ira_reg_equiv_len
struct ira_reg_equivira_reg_equiv
static struct equivalencereg_equiv
static rtx equiv_mem
static int equiv_mem_modified
static int recorded_label_ref
int first_moveable_pseudo
int last_moveable_pseudo
static vec< rtxpseudo_replaced_reg
bool ira_use_lra_p
bool ira_conflicts_p
static int saved_flag_ira_share_spill_slots

Function Documentation

static rtx adjust_cleared_regs ( )
static
In DEBUG_INSN location adjust REGs from CLEARED_REGS bitmap to the
   equivalent replacement.   

References bitmap_bit_p(), simplify_replace_fn_rtx(), and equivalence::src_p.

Referenced by update_equiv_regs().

static void allocate_initial_values ( )
static
If the backend knows where to allocate pseudos for hard
   register initial values, register these allocations now.   

References df_get_live_in(), df_get_live_out(), initial_value_entry(), REG_N_SETS(), reg_renumber, and targetm.

Referenced by ira().

static void calculate_allocation_cost ( )
static
Evaluate overall allocation cost and the costs for using hard
   registers and memory for allocnos.   

References internal_flag_ira_verbose, ira_additional_jumps_num, ira_dump_file, ira_hard_reg_in_set_p(), ira_load_cost, ira_mem_cost, ira_move_loops_num, ira_overall_cost, ira_reg_cost, ira_shuffle_cost, and ira_store_cost.

Referenced by ira().

static void check_allocation ( )
static
Check the correctness of the allocation.  We do need this because
   of complicated code to transform more one region internal
   representation into one region representation.   

Referenced by ira().

static void clarify_prohibited_class_mode_regs ( )
static
Clarify IRA_PROHIBITED_CLASS_MODE_REGS by excluding hard registers
   spanning from one register pressure class to another one.  It is
   called after defining the pressure classes.   

References add_to_hard_reg_set().

Referenced by ira_init().

static int comp_reg_classes_func ( )
static
The function used to sort the important classes.   

References allocno_class_order.

Referenced by reorder_important_classes().

static void compute_regs_asm_clobbered ( )
static
Add register clobbers from asm statements.   

References add_to_hard_reg_set(), and insn_contains_asm().

Referenced by ira_setup_eliminable_regset().

static int contains_replace_regs ( )
static
TRUE if X uses any registers for which reg_equiv[REGNO].replace is
   true.   

References equivalence::replace.

Referenced by update_equiv_regs().

static int equiv_init_movable_p ( )
static
Returns nonzero if X (used to initialize register REGNO) is movable.
   X is only movable if the registers it uses have equivalent initializations
   which appear to be within the same loop (or in an inner loop) and movable
   or if they are not candidates for local_alloc and don't vary.   

References loop_depth(), equivalence::replace, rtx_varies_p(), and SET.

Referenced by update_equiv_regs().

static int equiv_init_varies_p ( )
static
Returns zero if X is known to be invariant.   

References equivalence::replace, and rtx_varies_p().

Referenced by update_equiv_regs().

static void expand_reg_info ( void  )
static
Regional allocation can create new pseudo-registers.  This function
   expands some arrays for pseudo-registers.   

References allocated_reg_info_size, max_reg_num(), resize_reg_info(), setup_preferred_alternate_classes_for_new_pseudos(), and setup_reg_classes().

Referenced by find_moveable_pseudos(), and ira().

static void find_moveable_pseudos ( )
static
Look for instances where we have an instruction that is known to increase
   register pressure, and whose result is not used immediately.  If it is
   possible to move the instruction downwards to just before its first use,
   split its lifetime into two ranges.  We create a new pseudo to compute the
   value, and emit a move instruction just before the first use.  If, after
   register allocation, the new pseudo remains unallocated, the function
   move_unallocated_pseudos then deletes the move instruction and places
   the computation just before the first use.

   Such a move is safe and profitable if all the input registers remain live
   and unchanged between the original computation and its first use.  In such
   a situation, the computation is known to increase register pressure, and
   moving it is known to at least not worsen it.

   We restrict moves to only those cases where a register remains unallocated,
   in order to avoid interfering too much with the instruction schedule.  As
   an exception, we may move insns which only modify their input register
   (typically induction variables), as this increases the freedom for our
   intended transformation, and does not limit the second instruction
   scheduler pass.   

References bitmap_and_into(), bitmap_bit_p(), bitmap_clear(), bitmap_clear_bit(), bitmap_copy(), bitmap_set_bit(), calculate_dominance_info(), cc0_rtx, CDI_DOMINATORS, control_flow_insn_p(), dbg_cnt(), df_analyze(), df_get_live_in(), df_get_live_out(), dump_file, emit_insn_after(), emit_insn_before(), expand_reg_info(), first_moveable_pseudo, fix_reg_equiv_init(), free(), free_dominance_info(), gen_move_insn(), get_max_uid(), basic_block_def::index, insn_chain::insn, insn_dominated_by_p(), ira_create_new_reg(), last_moveable_pseudo, live, max_reg_num(), max_uid, modified_between_p(), modified_in_p(), next_nonnote_nondebug_insn(), OP_IN, reg_referenced_p(), regstat_compute_ri(), regstat_free_n_sets_and_refs(), regstat_free_ri(), regstat_init_n_sets_and_refs(), rtx_moveable_p(), set_insn_deleted(), sets_cc0_p(), transp, and validate_change().

Referenced by ira().

static void find_reg_classes ( )
static
Set up different arrays concerning class subsets, allocno and
   important classes.   

References reorder_important_classes(), setup_allocno_and_important_classes(), setup_class_translate(), and setup_reg_class_relations().

Referenced by ira_init().

static void finish_reg_equiv ( )
static

References free().

Referenced by do_reload().

static void fix_reg_equiv_init ( )
static
Fix values of array REG_EQUIV_INIT after live range splitting done
   by IRA.   

References grow_reg_equivs(), max_reg_num(), max_regno, max_regno_before_ira, reg_equivs, and vec_safe_length().

Referenced by find_moveable_pseudos(), and ira().

static void free_register_move_costs ( )
static
Free ira_max_register_move_cost, ira_may_move_in_cost and
   ira_may_move_out_cost for each mode.   

References free(), and memset().

Referenced by ira_finish_once(), and ira_init().

static void init_live_subregs ( bool  init_value,
sbitmap live_subregs,
bitmap  live_subregs_used,
int  allocnum,
rtx  reg 
)
static
Init LIVE_SUBREGS[ALLOCNUM] and LIVE_SUBREGS_USED[ALLOCNUM] using
   REG to the number of nregs, and INIT_VALUE to get the
   initialization.  ALLOCNUM need not be the regno of REG.   

References bitmap_bit_p(), bitmap_clear(), bitmap_ones(), bitmap_set_bit(), regno_reg_rtx, and sbitmap_alloc().

Referenced by build_insn_chain().

static void init_reg_equiv ( )
static

References ira_expand_reg_equiv(), and ira_reg_equiv_len.

Referenced by ira().

static bool insn_contains_asm ( )
static
Return TRUE if INSN contains an ASM.   

References for_each_rtx(), and insn_contains_asm_1().

Referenced by compute_regs_asm_clobbered().

static int insn_contains_asm_1 ( )
static
Return TRUE if *LOC contains an asm.   

Referenced by insn_contains_asm().

static bool insn_dominated_by_p ( )
static
A wrapper around dominated_by_p, which uses the information in UID_LUID
   to give dominance relationships between two insns I1 and I2.   

References CDI_DOMINATORS, and dominated_by_p().

Referenced by find_moveable_pseudos().

static void ira ( )
static
This is the main entry of IRA.   

References allocate_initial_values(), allocated_reg_info_size, bitmap_obstack_initialize(), calculate_allocation_cost(), function::calls_setjmp, CDI_DOMINATORS, cfun, df_d::changeable_flags, check_allocation(), delete_trivially_dead_insns(), delete_unreachable_blocks(), df, df_analyze(), df_clear_flags(), DF_NO_INSN_RESCAN, df_note_add_problem(), df_remove_problem(), DF_VERIFY_SCHEDULED, expand_reg_info(), find_moveable_pseudos(), fix_reg_equiv_init(), free_dominance_info(), generate_setjmp_warnings(), get_insns(), grow_reg_equivs(), init_caller_save(), init_reg_equiv(), internal_flag_ira_verbose, ira_additional_jumps_num, ira_allocate(), ira_bitmap_obstack, ira_build(), ira_color(), ira_conflicts_p, ira_dump_file, ira_emit(), ira_finish_emit_data(), ira_flattening(), ira_initiate_assign(), ira_initiate_emit_data(), ira_load_cost, ira_max_point, ira_mem_cost, ira_move_loops_num, ira_obstack, ira_overall_cost, ira_reassign_conflict_allocnos(), ira_reg_cost, IRA_REGION_ALL, IRA_REGION_MIXED, IRA_REGION_ONE, ira_set_pseudo_classes(), ira_setup_eliminable_regset(), ira_shuffle_cost, ira_spilled_reg_stack_slots_num, ira_store_cost, ira_use_lra_p, leaf_function_p(), loop_optimizer_finalize(), loop_optimizer_init(), LOOPS_HAVE_RECORDED_EXITS, lra_simple_p, max_reg_num(), max_regno, max_regno_before_ira, memset(), move_unallocated_pseudos(), overall_cost_before, print_redundant_copies(), purge_all_dead_edges(), rebuild_jump_labels(), regstat_compute_ri(), regstat_free_n_sets_and_refs(), regstat_free_ri(), regstat_init_n_sets_and_refs(), resize_reg_info(), saved_flag_ira_share_spill_slots, setup_allocno_assignment_flags(), setup_prohibited_mode_move_regs(), setup_reg_equiv(), setup_reg_equiv_init(), setup_reg_renumber(), targetm, timevar_pop(), timevar_push(), too_high_register_pressure_p(), and update_equiv_regs().

Referenced by rest_of_handle_ira().

void* ira_allocate ( )
Allocate memory of size LEN for IRA data.   

References ira_obstack.

bool ira_bad_reload_regno ( )
Return nonzero if REGNO is a particularly bad choice for reloading
   IN or OUT.   

References ira_bad_reload_regno_1().

Referenced by allocate_reload_reg().

static bool ira_bad_reload_regno_1 ( )
static
Return nonzero if REGNO is a particularly bad choice for reloading X.   

References ira_regno_allocno_map, pref, and reg_preferred_class().

Referenced by ira_bad_reload_regno().

void ira_debug_allocno_classes ( void  )
Output all possible allocno and translation classes and the
   translation maps into stderr.   

References print_translated_classes(), and print_unform_and_important_classes().

void ira_debug_disposition ( void  )
Outputs information about allocation of all allocnos into
   stderr.   

References ira_print_disposition().

void ira_expand_reg_equiv ( void  )
Expand ira_reg_equiv if necessary.   

References ira_reg_equiv_len, max_reg_num(), and memset().

Referenced by expand_reg_data(), init_reg_equiv(), and ira_create_new_reg().

void ira_finish_once ( void  )
Function called once at the end of compiler work.   

References free_register_move_costs(), ira_finish_costs_once(), and lra_finish_once().

Referenced by finalize().

void ira_free ( )
Free memory ADDR allocated for IRA data.   

References free().

void ira_free_bitmap ( )
Free bitmap B allocated for IRA.   
void ira_init_once ( void  )
This is called once during compiler work.  It sets up
   different arrays whose values don't depend on the compiled
   function.   

References ira_init_costs_once(), and lra_init_once().

Referenced by backend_init().

void ira_init_register_move_cost ( )
Allocate and initialize IRA_REGISTER_MOVE_COST, IRA_MAY_MOVE_IN_COST
   and IRA_MAY_MOVE_OUT_COST for MODE.   

References register_move_cost().

void ira_print_disposition ( )
Output information about allocation of all allocnos (except for
   caps) into file F.   

References basic_block_def::index, ira_regno_allocno_map, max_reg_num(), and max_regno.

void ira_setup_eliminable_regset ( )
Set up ELIMINABLE_REGSET, IRA_NO_ALLOC_REGS, and REGS_EVER_LIVE.
   If the function is called from IRA (not from the insn scheduler or
   RTL loop invariant motion), FROM_IRA_P is true.   

References function::calls_alloca, cfun, compute_regs_asm_clobbered(), df_set_regs_ever_live(), eliminable_regset, error(), ira_use_lra_p, lra_init_elimination(), and targetm.

Referenced by calculate_bb_reg_pressure(), calculate_loop_reg_pressure(), ira(), and sched_init().

void ira_update_equiv_info_by_shuffle_insn ( )
Update equiv regno from movement of FROM_REGNO to TO_REGNO.  INSNS
   are insns which were generated for such movement.  It is assumed
   that FROM_REGNO and TO_REGNO always have the same value at the
   point of any move containing such registers. This function is used
   to update equiv info for register shuffles on the region borders
   and for caller save/restore insns.   

References ira_reg_equiv::constant, ira_reg_equiv::defined_p, dump_value_slim(), find_reg_note(), ira_reg_equiv::init_insns, internal_flag_ira_verbose, ira_reg_equiv::invariant, ira_dump_file, ira_reg_equiv::memory, rtx_equal_p(), and set_unique_reg_note().

Referenced by emit_move_list().

rtl_opt_pass* make_pass_ira ( )
rtl_opt_pass* make_pass_reload ( )
void mark_elimination ( )
Indicate that hard register number FROM was eliminated and replaced with
   an offset from hard register number TO.  The status of hard registers live
   at the start of a basic block is updated by replacing a use of FROM with
   a use of TO.   

References bitmap_bit_p(), bitmap_clear_bit(), and bitmap_set_bit().

Referenced by reload().

static int memref_referenced_p ( )
static
TRUE if X references a memory location that would be affected by a store
   to MEMREF.   

References SET, and true_dependence().

Referenced by memref_used_between_p().

static int memref_used_between_p ( )
static
TRUE if some insn in the range (START, END] references a memory location
   that would be affected by a store to MEMREF.   

References memref_referenced_p().

Referenced by update_equiv_regs().

static void move_unallocated_pseudos ( )
static
Perform the second half of the transformation started in
   find_moveable_pseudos.  We look for instances where the newly introduced
   pseudo remains unallocated, and remove it by moving the definition to
   just before its use, replacing the move instruction generated by
   find_moveable_pseudos.   

References delete_insn(), dump_file, emit_insn_after(), first_moveable_pseudo, last_moveable_pseudo, move_insn(), reg_renumber, and validate_change().

Referenced by ira().

static void no_equiv ( rtx  reg,
const_rtx  store,
void *  data 
)
static
Mark REG as having no known equivalence.
   Some instructions might have been processed before and furnished
   with REG_EQUIV notes for this register; these notes will have to be
   removed.
   STORE is the piece of RTL that does the non-constant / conflicting
   assignment - a SET, CLOBBER or REG_INC note.  It is currently not used,
   but needs to be there because this function is called from note_stores.   

References ira_reg_equiv::defined_p, find_reg_note(), ira_reg_equiv::init_insns, equivalence::init_insns, equivalence::is_arg_equivalence, remove_note(), and equivalence::replacement.

Referenced by update_equiv_regs().

static void print_insn_chain ( )
static
static void print_insn_chains ( )
static
Print all reload_insn_chains to FILE.   

References insn_chain::next, print_insn_chain(), and reload_insn_chain.

Referenced by build_insn_chain().

static void print_redundant_copies ( )
static
static void print_translated_classes ( )
static
Output all possible allocno or pressure classes and their
   translation map into file F.   

References reg_class_names.

Referenced by ira_debug_allocno_classes().

static void print_unform_and_important_classes ( )
static
Output all unifrom and important classes into file F.   

References reg_class_names.

Referenced by ira_debug_allocno_classes().

static bool pseudo_for_reload_consideration_p ( )
static
Return true if pseudo REGNO should be added to set live_throughout
   or dead_or_set of the insn chains for reload consideration.   

References ira_conflicts_p, and reg_renumber.

Referenced by build_insn_chain().

static void reorder_important_classes ( )
static
For correct work of function setup_reg_class_relation we need to
   reorder important classes according to the order of their allocno
   classes.  It places important classes containing the same
   allocatable hard register set adjacent to each other and allocno
   class with the allocatable hard register set right after the other
   important classes with the same set.

   In example from comments of function
   setup_allocno_and_important_classes, it places LEGACY_REGS and
   GENERAL_REGS close to each other and GENERAL_REGS is after
   LEGACY_REGS.   

References allocno_class_order, and comp_reg_classes_func().

Referenced by find_reg_classes().

static unsigned int rest_of_handle_ira ( )
static
Run the integrated register allocator.   

References dump_file, and ira().

static unsigned int rest_of_handle_reload ( )
static

References do_reload().

static bool rtx_moveable_p ( )
static
Examine the rtx found in *LOC, which is read or written to as determined
   by TYPE.  Return false if we find a reason why an insn containing this
   rtx should not be moved (such as accesses to non-constant memory), true
   otherwise.   

References OP_IN, OP_OUT, and SET.

Referenced by find_moveable_pseudos().

static int set_paradoxical_subreg ( )
static
Check whether the SUBREG is a paradoxical subreg and set the result
   in PDX_SUBREGS.   

References paradoxical_subreg_p().

Referenced by update_equiv_regs().

static void setup_alloc_regs ( )
static
Set up global variables defining info about hard registers for the
   allocation.  These depend on USE_HARD_FRAME_P whose TRUE value means
   that we can use the hard frame pointer for the allocation.   

References setup_class_hard_regs().

Referenced by ira_init().

static void setup_allocno_and_important_classes ( )
static
Set up IRA_ALLOCNO_CLASSES, IRA_ALLOCNO_CLASSES_NUM,
   IRA_IMPORTANT_CLASSES, and IRA_IMPORTANT_CLASSES_NUM.

   Target may have many subtargets and not all target hard regiters can
   be used for allocation, e.g. x86 port in 32-bit mode can not use
   hard registers introduced in x86-64 like r8-r15).  Some classes
   might have the same allocatable hard registers, e.g.  INDEX_REGS
   and GENERAL_REGS in x86 port in 32-bit mode.  To decrease different
   calculations efforts we introduce allocno classes which contain
   unique non-empty sets of allocatable hard-registers.

   Pseudo class cost calculation in ira-costs.c is very expensive.
   Therefore we are trying to decrease number of classes involved in
   such calculation.  Register classes used in the cost calculation
   are called important classes.  They are allocno classes and other
   non-empty classes whose allocatable hard register sets are inside
   of an allocno class hard register set.  From the first sight, it
   looks like that they are just allocno classes.  It is not true.  In
   example of x86-port in 32-bit mode, allocno classes will contain
   GENERAL_REGS but not LEGACY_REGS (because allocatable hard
   registers are the same for the both classes).  The important
   classes will contain GENERAL_REGS and LEGACY_REGS.  It is done
   because a machine description insn constraint may refers for
   LEGACY_REGS and code in ira-costs.c is mostly base on investigation
   of the insn constraints.   

References hard_reg_set_equal_p(), hard_reg_set_subset_p(), setup_pressure_classes(), setup_uniform_class_p(), and temp_hard_regset.

Referenced by find_reg_classes().

static void setup_allocno_assignment_flags ( )
static
Set up allocno assignment flags for further allocation
   improvements.   

References ira_free_allocno_updated_costs(), and ira_hard_reg_in_set_p().

Referenced by ira().

static void setup_class_hard_regs ( )
static
The function sets up the three arrays declared above.   

References temp_hard_regset.

Referenced by setup_alloc_regs().

static void setup_class_subset_and_memory_move_costs ( )
static
Set up IRA_MEMORY_MOVE_COST and IRA_MAX_MEMORY_MOVE_COST.   

References hard_reg_set_empty_p(), hard_reg_set_subset_p(), memory_move_cost(), setup_reg_subclasses(), and temp_hard_regset.

Referenced by ira_init().

static void setup_class_translate ( )
static
Set up array IRA_ALLOCNO_CLASS_TRANSLATE and
   IRA_PRESSURE_CLASS_TRANSLATE.   

References setup_class_translate_array().

Referenced by find_reg_classes().

static void setup_class_translate_array ( enum reg_class *  class_translate,
int  classes_num,
enum reg_class *  classes 
)
static
Setup translation in CLASS_TRANSLATE of all classes into a class
   given by array CLASSES of length CLASSES_NUM.  The function is used
   make translation any reg class to an allocno class or to an
   pressure class.  This translation is necessary for some
   calculations when we can use only allocno or pressure classes and
   such translation represents an approximate representation of all
   classes.

   The translation in case when allocatable hard register set of a
   given class is subset of allocatable hard register set of a class
   in CLASSES is pretty simple.  We use smallest classes from CLASSES
   containing a given class.  If allocatable hard register set of a
   given class is not a subset of any corresponding set of a class
   from CLASSES, we use the cheapest (with load/store point of view)
   class from CLASSES whose set intersects with given class set  

References hard_reg_set_empty_p(), and temp_hard_regset.

Referenced by setup_class_translate().

static void setup_hard_regno_aclass ( )
static
Set up the array above.   

Referenced by ira_init().

static void setup_preferred_alternate_classes_for_new_pseudos ( )
static
Setup preferred and alternative classes for new pseudo-registers
   created by IRA starting with START.   

References internal_flag_ira_verbose, ira_dump_file, max_reg_num(), max_regno, reg_allocno_class(), reg_alternate_class(), reg_class_names, reg_preferred_class(), regno_reg_rtx, and setup_reg_classes().

Referenced by expand_reg_info().

static void setup_pressure_classes ( )
static
Find pressure classes which are register classes for which we
   calculate register pressure in IRA, register pressure sensitive
   insn scheduling, and register pressure sensitive loop invariant
   motion.

   To make register pressure calculation easy, we always use
   non-intersected register pressure classes.  A move of hard
   registers from one register pressure class is not more expensive
   than load and store of the hard registers.  Most likely an allocno
   class will be a subset of a register pressure class and in many
   cases a register pressure class.  That makes usage of register
   pressure classes a good approximation to find a high register
   pressure.   

References hard_reg_set_empty_p(), hard_reg_set_equal_p(), hard_reg_set_subset_p(), ira_init_register_move_cost_if_necessary(), setup_stack_reg_pressure_class(), and temp_hard_regset.

Referenced by setup_allocno_and_important_classes().

static void setup_prohibited_class_mode_regs ( )
static
Set up IRA_PROHIBITED_CLASS_MODE_REGS and IRA_CLASS_SINGLETON.
   This function is called once IRA_CLASS_HARD_REGS has been initialized.   

References count, in_hard_reg_set_p(), and temp_hard_regset.

Referenced by ira_init().

static void setup_prohibited_mode_move_regs ( )
static
Set up IRA_PROHIBITED_MODE_MOVE_REGS.   

References constrain_operands(), extract_insn(), gen_rtx_REG(), move_insn(), and recog_memoized().

Referenced by ira().

static void setup_reg_class_nregs ( )
static
Form IRA_REG_CLASS_MAX_NREGS and IRA_REG_CLASS_MIN_NREGS maps.   

References targetm.

Referenced by ira_init().

static void setup_reg_class_relations ( )
static
Set up IRA_REG_CLASS_SUBUNION, IRA_REG_CLASS_SUPERUNION,
   IRA_REG_CLASS_SUPER_CLASSES, IRA_REG_CLASSES_INTERSECT, and
   IRA_REG_CLASSES_INTERSECT_P.  For the meaning of the relations,
   please see corresponding comments in ira-int.h.   

References hard_reg_set_empty_p(), hard_reg_set_equal_p(), hard_reg_set_intersect_p(), hard_reg_set_subset_p(), memset(), reg_class_subset_p(), and temp_hard_regset.

Referenced by find_reg_classes().

static void setup_reg_equiv ( )
static
Set up fields memory, constant, and invariant from init_insns in
   the structures of array ira_reg_equiv.   

References ira_reg_equiv::defined_p, find_reg_note(), force_const_mem(), function_invariant_p(), ira_reg_equiv::init_insns, equivalence::init_insns, ira_reg_equiv::invariant, ira_reg_equiv_len, ira_reg_equiv::memory, memory_operand(), rtx_equal_p(), and targetm.

Referenced by ira().

static void setup_reg_equiv_init ( )
static
Allocate REG_EQUIV_INIT.  Set up it from IRA_REG_EQUIV which should
   be already calculated.   

References ira_reg_equiv::init_insns, max_reg_num(), and max_regno.

Referenced by ira().

static void setup_reg_mode_hard_regset ( )
static
The function sets up the map IRA_REG_MODE_HARD_REGSET.   

Referenced by ira_init().

static void setup_reg_renumber ( )
static
Set up REG_RENUMBER and CALLER_SAVE_NEEDED (used by reload) from
   the allocation found by IRA.   

References caller_save_needed, ira_equiv_no_lvalue_p(), ira_free_allocno_updated_costs(), ira_hard_reg_set_intersection_p(), ira_reg_equiv_len, ira_use_lra_p, and reg_renumber.

Referenced by ira().

static void setup_reg_subclasses ( )
static
Initialize the table of subclasses of each reg class.   

References hard_reg_set_empty_p(), hard_reg_set_subset_p(), and temp_hard_regset.

Referenced by setup_class_subset_and_memory_move_costs().

static void setup_stack_reg_pressure_class ( )
static
Set up ira_stack_reg_pressure_class which is the biggest pressure
   register class containing stack registers or NO_REGS if there are
   no stack registers.  To find this class, we iterate through all
   register pressure classes and choose the first register pressure
   class containing all the stack registers and having the biggest
   size.   

References hard_reg_set_size(), and temp_hard_regset.

Referenced by setup_pressure_classes().

static void setup_uniform_class_p ( )
static
Set up IRA_UNIFORM_CLASS_P.  Uniform class is a register class
   whose register move cost between any registers of the class is the
   same as for all its subclasses.  We use the data to speed up the
   2nd pass of calculations of allocno costs.   

References ira_init_register_move_cost_if_necessary().

Referenced by setup_allocno_and_important_classes().

static bool too_high_register_pressure_p ( )
static
Return TRUE if there is too high register pressure in the function.
   It is used to decide when stack slot sharing is worth to do.   

References ira_loop_tree_root, and ira_loop_tree_node::reg_pressure.

Referenced by ira().

static int update_equiv_regs ( )
static
static int validate_equiv_mem ( )
static
Verify that no store between START and the death of REG invalidates
   MEMREF.  MEMREF is invalidated by modifying a register used in MEMREF,
   by storing into an overlapping memory location, or with a non-const
   CALL_INSN.

   Return 1 if MEMREF remains valid.   

References equiv_mem, equiv_mem_modified, find_reg_note(), note_stores(), reg_overlap_mentioned_p(), side_effects_p(), and validate_equiv_mem_from_store().

Referenced by update_equiv_regs().

static void validate_equiv_mem_from_store ( rtx  dest,
const_rtx  set,
void *  data 
)
static
If EQUIV_MEM is modified by modifying DEST, indicate that it is modified.
   Called via note_stores.   

References anti_dependence(), equiv_mem, equiv_mem_modified, and reg_overlap_mentioned_p().

Referenced by validate_equiv_mem().


Variable Documentation

int allocated_reg_info_size
static
The number of entries allocated in teg_info.   

Referenced by expand_reg_info(), and ira().

int allocno_class_order[N_REG_CLASSES]
static
Order numbers of allocno classes in original target allocno class
   array, -1 for non-allocno classes.   

Referenced by comp_reg_classes_func(), and reorder_important_classes().

struct target_ira default_target_ira
@verbatim Integrated Register Allocator (IRA) entry point.

Copyright (C) 2006-2013 Free Software Foundation, Inc. Contributed by Vladimir Makarov vmaka.nosp@m.rov@.nosp@m.redha.nosp@m.t.co.nosp@m.m.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see http://www.gnu.org/licenses/.

The integrated register allocator (IRA) is a
   regional register allocator performing graph coloring on a top-down
   traversal of nested regions.  Graph coloring in a region is based
   on Chaitin-Briggs algorithm.  It is called integrated because
   register coalescing, register live range splitting, and choosing a
   better hard register are done on-the-fly during coloring.  Register
   coalescing and choosing a cheaper hard register is done by hard
   register preferencing during hard register assigning.  The live
   range splitting is a byproduct of the regional register allocation.

   Major IRA notions are:

     o *Region* is a part of CFG where graph coloring based on
       Chaitin-Briggs algorithm is done.  IRA can work on any set of
       nested CFG regions forming a tree.  Currently the regions are
       the entire function for the root region and natural loops for
       the other regions.  Therefore data structure representing a
       region is called loop_tree_node.

     o *Allocno class* is a register class used for allocation of
       given allocno.  It means that only hard register of given
       register class can be assigned to given allocno.  In reality,
       even smaller subset of (*profitable*) hard registers can be
       assigned.  In rare cases, the subset can be even smaller
       because our modification of Chaitin-Briggs algorithm requires
       that sets of hard registers can be assigned to allocnos forms a
       forest, i.e. the sets can be ordered in a way where any
       previous set is not intersected with given set or is a superset
       of given set.

     o *Pressure class* is a register class belonging to a set of
       register classes containing all of the hard-registers available
       for register allocation.  The set of all pressure classes for a
       target is defined in the corresponding machine-description file
       according some criteria.  Register pressure is calculated only
       for pressure classes and it affects some IRA decisions as
       forming allocation regions.

     o *Allocno* represents the live range of a pseudo-register in a
       region.  Besides the obvious attributes like the corresponding
       pseudo-register number, allocno class, conflicting allocnos and
       conflicting hard-registers, there are a few allocno attributes
       which are important for understanding the allocation algorithm:

       - *Live ranges*.  This is a list of ranges of *program points*
         where the allocno lives.  Program points represent places
         where a pseudo can be born or become dead (there are
         approximately two times more program points than the insns)
         and they are represented by integers starting with 0.  The
         live ranges are used to find conflicts between allocnos.
         They also play very important role for the transformation of
         the IRA internal representation of several regions into a one
         region representation.  The later is used during the reload
         pass work because each allocno represents all of the
         corresponding pseudo-registers.

       - *Hard-register costs*.  This is a vector of size equal to the
         number of available hard-registers of the allocno class.  The
         cost of a callee-clobbered hard-register for an allocno is
         increased by the cost of save/restore code around the calls
         through the given allocno's life.  If the allocno is a move
         instruction operand and another operand is a hard-register of
         the allocno class, the cost of the hard-register is decreased
         by the move cost.

         When an allocno is assigned, the hard-register with minimal
         full cost is used.  Initially, a hard-register's full cost is
         the corresponding value from the hard-register's cost vector.
         If the allocno is connected by a *copy* (see below) to
         another allocno which has just received a hard-register, the
         cost of the hard-register is decreased.  Before choosing a
         hard-register for an allocno, the allocno's current costs of
         the hard-registers are modified by the conflict hard-register
         costs of all of the conflicting allocnos which are not
         assigned yet.

       - *Conflict hard-register costs*.  This is a vector of the same
         size as the hard-register costs vector.  To permit an
         unassigned allocno to get a better hard-register, IRA uses
         this vector to calculate the final full cost of the
         available hard-registers.  Conflict hard-register costs of an
         unassigned allocno are also changed with a change of the
         hard-register cost of the allocno when a copy involving the
         allocno is processed as described above.  This is done to
         show other unassigned allocnos that a given allocno prefers
         some hard-registers in order to remove the move instruction
         corresponding to the copy.

     o *Cap*.  If a pseudo-register does not live in a region but
       lives in a nested region, IRA creates a special allocno called
       a cap in the outer region.  A region cap is also created for a
       subregion cap.

     o *Copy*.  Allocnos can be connected by copies.  Copies are used
       to modify hard-register costs for allocnos during coloring.
       Such modifications reflects a preference to use the same
       hard-register for the allocnos connected by copies.  Usually
       copies are created for move insns (in this case it results in
       register coalescing).  But IRA also creates copies for operands
       of an insn which should be assigned to the same hard-register
       due to constraints in the machine description (it usually
       results in removing a move generated in reload to satisfy
       the constraints) and copies referring to the allocno which is
       the output operand of an instruction and the allocno which is
       an input operand dying in the instruction (creation of such
       copies results in less register shuffling).  IRA *does not*
       create copies between the same register allocnos from different
       regions because we use another technique for propagating
       hard-register preference on the borders of regions.

   Allocnos (including caps) for the upper region in the region tree
   *accumulate* information important for coloring from allocnos with
   the same pseudo-register from nested regions.  This includes
   hard-register and memory costs, conflicts with hard-registers,
   allocno conflicts, allocno copies and more.  *Thus, attributes for
   allocnos in a region have the same values as if the region had no
   subregions*.  It means that attributes for allocnos in the
   outermost region corresponding to the function have the same values
   as though the allocation used only one region which is the entire
   function.  It also means that we can look at IRA work as if the
   first IRA did allocation for all function then it improved the
   allocation for loops then their subloops and so on.

   IRA major passes are:

     o Building IRA internal representation which consists of the
       following subpasses:

       * First, IRA builds regions and creates allocnos (file
         ira-build.c) and initializes most of their attributes.

       * Then IRA finds an allocno class for each allocno and
         calculates its initial (non-accumulated) cost of memory and
         each hard-register of its allocno class (file ira-cost.c).

       * IRA creates live ranges of each allocno, calulates register
         pressure for each pressure class in each region, sets up
         conflict hard registers for each allocno and info about calls
         the allocno lives through (file ira-lives.c).

       * IRA removes low register pressure loops from the regions
         mostly to speed IRA up (file ira-build.c).

       * IRA propagates accumulated allocno info from lower region
         allocnos to corresponding upper region allocnos (file
         ira-build.c).

       * IRA creates all caps (file ira-build.c).

       * Having live-ranges of allocnos and their classes, IRA creates
         conflicting allocnos for each allocno.  Conflicting allocnos
         are stored as a bit vector or array of pointers to the
         conflicting allocnos whatever is more profitable (file
         ira-conflicts.c).  At this point IRA creates allocno copies.

     o Coloring.  Now IRA has all necessary info to start graph coloring
       process.  It is done in each region on top-down traverse of the
       region tree (file ira-color.c).  There are following subpasses:

       * Finding profitable hard registers of corresponding allocno
         class for each allocno.  For example, only callee-saved hard
         registers are frequently profitable for allocnos living
         through colors.  If the profitable hard register set of
         allocno does not form a tree based on subset relation, we use
         some approximation to form the tree.  This approximation is
         used to figure out trivial colorability of allocnos.  The
         approximation is a pretty rare case.

       * Putting allocnos onto the coloring stack.  IRA uses Briggs
         optimistic coloring which is a major improvement over
         Chaitin's coloring.  Therefore IRA does not spill allocnos at
         this point.  There is some freedom in the order of putting
         allocnos on the stack which can affect the final result of
         the allocation.  IRA uses some heuristics to improve the
         order.
         
         We also use a modification of Chaitin-Briggs algorithm which
         works for intersected register classes of allocnos.  To
         figure out trivial colorability of allocnos, the mentioned
         above tree of hard register sets is used.  To get an idea how
         the algorithm works in i386 example, let us consider an
         allocno to which any general hard register can be assigned.
         If the allocno conflicts with eight allocnos to which only
         EAX register can be assigned, given allocno is still
         trivially colorable because all conflicting allocnos might be
         assigned only to EAX and all other general hard registers are
         still free.

         To get an idea of the used trivial colorability criterion, it
         is also useful to read article "Graph-Coloring Register
         Allocation for Irregular Architectures" by Michael D. Smith
         and Glen Holloway.  Major difference between the article
         approach and approach used in IRA is that Smith's approach
         takes register classes only from machine description and IRA
         calculate register classes from intermediate code too
         (e.g. an explicit usage of hard registers in RTL code for
         parameter passing can result in creation of additional
         register classes which contain or exclude the hard
         registers).  That makes IRA approach useful for improving
         coloring even for architectures with regular register files
         and in fact some benchmarking shows the improvement for
         regular class architectures is even bigger than for irregular
         ones.  Another difference is that Smith's approach chooses
         intersection of classes of all insn operands in which a given
         pseudo occurs.  IRA can use bigger classes if it is still
         more profitable than memory usage.

       * Popping the allocnos from the stack and assigning them hard
         registers.  If IRA can not assign a hard register to an
         allocno and the allocno is coalesced, IRA undoes the
         coalescing and puts the uncoalesced allocnos onto the stack in
         the hope that some such allocnos will get a hard register
         separately.  If IRA fails to assign hard register or memory
         is more profitable for it, IRA spills the allocno.  IRA
         assigns the allocno the hard-register with minimal full
         allocation cost which reflects the cost of usage of the
         hard-register for the allocno and cost of usage of the
         hard-register for allocnos conflicting with given allocno.

       * Chaitin-Briggs coloring assigns as many pseudos as possible
         to hard registers.  After coloringh we try to improve
         allocation with cost point of view.  We improve the
         allocation by spilling some allocnos and assigning the freed
         hard registers to other allocnos if it decreases the overall
         allocation cost.

       * After allono assigning in the region, IRA modifies the hard
         register and memory costs for the corresponding allocnos in
         the subregions to reflect the cost of possible loads, stores,
         or moves on the border of the region and its subregions.
         When default regional allocation algorithm is used
         (-fira-algorithm=mixed), IRA just propagates the assignment
         for allocnos if the register pressure in the region for the
         corresponding pressure class is less than number of available
         hard registers for given pressure class.

     o Spill/restore code moving.  When IRA performs an allocation
       by traversing regions in top-down order, it does not know what
       happens below in the region tree.  Therefore, sometimes IRA
       misses opportunities to perform a better allocation.  A simple
       optimization tries to improve allocation in a region having
       subregions and containing in another region.  If the
       corresponding allocnos in the subregion are spilled, it spills
       the region allocno if it is profitable.  The optimization
       implements a simple iterative algorithm performing profitable
       transformations while they are still possible.  It is fast in
       practice, so there is no real need for a better time complexity
       algorithm.

     o Code change.  After coloring, two allocnos representing the
       same pseudo-register outside and inside a region respectively
       may be assigned to different locations (hard-registers or
       memory).  In this case IRA creates and uses a new
       pseudo-register inside the region and adds code to move allocno
       values on the region's borders.  This is done during top-down
       traversal of the regions (file ira-emit.c).  In some
       complicated cases IRA can create a new allocno to move allocno
       values (e.g. when a swap of values stored in two hard-registers
       is needed).  At this stage, the new allocno is marked as
       spilled.  IRA still creates the pseudo-register and the moves
       on the region borders even when both allocnos were assigned to
       the same hard-register.  If the reload pass spills a
       pseudo-register for some reason, the effect will be smaller
       because another allocno will still be in the hard-register.  In
       most cases, this is better then spilling both allocnos.  If
       reload does not change the allocation for the two
       pseudo-registers, the trivial move will be removed by
       post-reload optimizations.  IRA does not generate moves for
       allocnos assigned to the same hard register when the default
       regional allocation algorithm is used and the register pressure
       in the region for the corresponding pressure class is less than
       number of available hard registers for given pressure class.
       IRA also does some optimizations to remove redundant stores and
       to reduce code duplication on the region borders.

     o Flattening internal representation.  After changing code, IRA
       transforms its internal representation for several regions into
       one region representation (file ira-build.c).  This process is
       called IR flattening.  Such process is more complicated than IR
       rebuilding would be, but is much faster.

     o After IR flattening, IRA tries to assign hard registers to all
       spilled allocnos.  This is impelemented by a simple and fast
       priority coloring algorithm (see function
       ira_reassign_conflict_allocnos::ira-color.c).  Here new allocnos
       created during the code change pass can be assigned to hard
       registers.

     o At the end IRA calls the reload pass.  The reload pass
       communicates with IRA through several functions in file
       ira-color.c to improve its decisions in

       * sharing stack slots for the spilled pseudos based on IRA info
         about pseudo-register conflicts.

       * reassigning hard-registers to all spilled pseudos at the end
         of each reload iteration.

       * choosing a better hard-register to spill based on IRA info
         about pseudo-register live ranges and the register pressure
         in places where the pseudo-register lives.

   IRA uses a lot of data representing the target processors.  These
   data are initilized in file ira.c.

   If function has no loops (or the loops are ignored when
   -fira-algorithm=CB is used), we have classic Chaitin-Briggs
   coloring (only instead of separate pass of coalescing, we use hard
   register preferencing).  In such case, IRA works much faster
   because many things are not made (like IR flattening, the
   spill/restore optimization, and the code change).

   Literature is worth to read for better understanding the code:

   o Preston Briggs, Keith D. Cooper, Linda Torczon.  Improvements to
     Graph Coloring Register Allocation.

   o David Callahan, Brian Koblenz.  Register allocation via
     hierarchical graph coloring.

   o Keith Cooper, Anshuman Dasgupta, Jason Eckhardt. Revisiting Graph
     Coloring Register Allocation: A Study of the Chaitin-Briggs and
     Callahan-Koblenz Algorithms.

   o Guei-Yuan Lueh, Thomas Gross, and Ali-Reza Adl-Tabatabai. Global
     Register Allocation Based on Graph Fusion.

   o Michael D. Smith and Glenn Holloway.  Graph-Coloring Register
     Allocation for Irregular Architectures

   o Vladimir Makarov. The Integrated Register Allocator for GCC.

   o Vladimir Makarov.  The top-down register allocator for irregular
     register file architectures.
struct target_ira_int default_target_ira_int
rtx equiv_mem
static
Used for communication between the following two functions: contains
   a MEM that we wish to ensure remains unchanged.   

Referenced by validate_equiv_mem(), and validate_equiv_mem_from_store().

int equiv_mem_modified
static
Set nonzero if EQUIV_MEM is modified.   

Referenced by validate_equiv_mem(), and validate_equiv_mem_from_store().

int first_moveable_pseudo
Record the range of register numbers added by find_moveable_pseudos.   

Referenced by find_costs_and_classes(), find_moveable_pseudos(), and move_unallocated_pseudos().

int ira_additional_jumps_num
struct bitmap_obstack ira_bitmap_obstack
static
Obstack used for storing all bitmaps of the IRA.   

Referenced by do_reload(), ira(), and ira_allocate_bitmap().

int ira_load_cost
int ira_mem_cost

Referenced by calculate_allocation_cost(), and ira().

int ira_move_loops_num
struct obstack ira_obstack
static
Obstack used for storing all dynamic data (except bitmaps) of the
   IRA.   

Referenced by do_reload(), ira(), and ira_allocate().

int ira_overall_cost
Correspondingly overall cost of the allocation, overall cost before
   reload, cost of the allocnos assigned to hard-registers, cost of
   the allocnos assigned to memory, cost of loads, stores and register
   move insns generated for pseudo-register live range splitting (see
   ira-emit.c).   

Referenced by allocno_reload_assign(), calculate_allocation_cost(), do_reload(), emit_move_list(), ira(), and ira_mark_allocation_change().

int ira_reg_cost

Referenced by calculate_allocation_cost(), and ira().

Info about equiv. info for each register.   
int ira_shuffle_cost
struct ira_spilled_reg_stack_slot* ira_spilled_reg_stack_slots
The following array contains info about spilled pseudo-registers
   stack slots used in current function so far.   

Referenced by ira_mark_new_stack_slot(), and ira_reuse_stack_slot().

int ira_spilled_reg_stack_slots_num
The number of elements in the following array.   

Referenced by ira(), ira_mark_new_stack_slot(), ira_reuse_stack_slot(), and ira_sort_regnos_for_alter_reg().

int ira_store_cost
bool ira_use_lra_p
True when we use LRA instead of reload pass for the current
   function.   

Referenced by based_loc_descr(), compute_frame_pointer_to_fb_displacement(), do_reload(), emit_move_list(), ira(), ira_setup_eliminable_regset(), and setup_reg_renumber().

int last_moveable_pseudo
int max_regno_before_ira
static
Value of max_reg_num () before IRA work start.  This value helps
   us to recognize a situation when new pseudos were created during
   IRA work.   

Referenced by fix_reg_equiv_init(), and ira().

int overall_cost_before

Referenced by do_reload(), and ira().

vec<rtx> pseudo_replaced_reg
static
These two vectors hold data for every register added by
   find_movable_pseudos, with index 0 holding data for the
   first_moveable_pseudo.   
The original home register.   
int recorded_label_ref
static
Nonzero if we recorded an equivalence for a LABEL_REF.   

Referenced by update_equiv_regs().

struct equivalence* reg_equiv
static
reg_equiv[N] (where N is a pseudo reg number) is the equivalence
   structure for that register.   
short* reg_renumber
Vector of substitutions of register numbers,
   used to map pseudo regs into hardware regs.
   This is set up as a result of register allocation.
   Element N is the hard reg assigned to pseudo reg N,
   or is -1 if no hard reg was assigned.
   If N is a hard reg number, element N is N.   

Referenced by add_used_regs_1(), allocate_initial_values(), allocate_reg_info(), allocno_reload_assign(), alter_reg(), assign_by_spills(), assign_mem_slot(), build_insn_chain(), calculate_elim_costs_all_insns(), calculate_needs_all_insns(), calculate_spill_cost(), check_and_process_move(), compute_use_by_pseudos(), constrain_operands(), count_pseudo(), count_spilled_pseudo(), create_live_range_start_chains(), cselib_invalidate_regno(), curr_insn_transform(), delete_output_reload(), eliminate_regs_1(), elimination_effects(), emit_input_reload_insns(), find_reloads(), find_reloads_address_1(), find_reloads_toplev(), finish_spills(), free_reg_info(), gimple_expand_cfg(), improve_inheritance(), inherit_in_ebb(), init_regno_assign_info(), ira_mark_allocation_change(), ira_reassign_pseudos(), lra_assign(), lra_create_live_ranges(), lra_get_regno_hard_regno(), lra_setup_reg_renumber(), lra_undo_inheritance(), mark_home_live(), mark_home_live_1(), mark_referenced_regs(), mem_move_p(), move_unallocated_pseudos(), need_for_call_save_p(), need_for_split_p(), prepare_function_start(), process_bb_lives(), pseudo_for_reload_consideration_p(), push_reload(), regno_ok_for_base_p(), reload(), resize_reg_info(), rtx_renumbered_equal_p(), save_call_clobbered_regs(), setup_live_pseudos_and_spill_after_risky_transforms(), setup_reg_renumber(), setup_save_areas(), spill_for(), spill_hard_reg(), spill_pseudos(), split_reg(), subst_indexed_address(), true_regnum(), undo_optional_reloads(), update_hard_regno_preference(), and update_lives().

int saved_flag_ira_share_spill_slots
static
Saved between IRA and reload.   

Referenced by do_reload(), and ira().

struct target_ira* this_target_ira = &default_target_ira
struct target_ira_int* this_target_ira_int = &default_target_ira_int