GCC Middle and Back End API Reference
cfghooks.h File Reference
#include "predict.h"
Include dependency graph for cfghooks.h:

Go to the source code of this file.

Data Structures

struct  profile_record
class  copy_bb_data
struct  cfg_hooks


typedef int_hash< unsigned short, 0 > dependence_hash


void verify_flow_info (void)
void checking_verify_flow_info (void)
void dump_bb (FILE *, basic_block, int, dump_flags_t)
void dump_bb_for_graph (pretty_printer *, basic_block)
void dump_flow_info (FILE *, dump_flags_t)
edge redirect_edge_and_branch (edge, basic_block)
basic_block redirect_edge_and_branch_force (edge, basic_block)
edge redirect_edge_succ_nodup (edge, basic_block)
bool can_remove_branch_p (const_edge)
void remove_branch (edge)
void remove_edge (edge)
edge split_block (basic_block, rtx)
edge split_block (basic_block, gimple *)
edge split_block_after_labels (basic_block)
bool move_block_after (basic_block, basic_block)
void delete_basic_block (basic_block)
basic_block split_edge (edge)
basic_block create_basic_block (rtx, rtx, basic_block)
basic_block create_basic_block (gimple_seq, basic_block)
basic_block create_empty_bb (basic_block)
bool can_merge_blocks_p (basic_block, basic_block)
void merge_blocks (basic_block, basic_block)
edge make_forwarder_block (basic_block, bool(*)(edge), void(*)(basic_block))
basic_block force_nonfallthru (edge)
void tidy_fallthru_edge (edge)
void tidy_fallthru_edges (void)
void predict_edge (edge e, enum br_predictor predictor, int probability)
bool predicted_by_p (const_basic_block bb, enum br_predictor predictor)
bool can_duplicate_block_p (const_basic_block)
basic_block duplicate_block (basic_block, edge, basic_block, copy_bb_data *=NULL)
bool block_ends_with_call_p (basic_block bb)
bool empty_block_p (basic_block)
basic_block split_block_before_cond_jump (basic_block)
bool block_ends_with_condjump_p (const_basic_block bb)
int flow_call_edges_add (sbitmap)
void execute_on_growing_pred (edge)
void execute_on_shrinking_pred (edge)
bool cfg_hook_duplicate_loop_body_to_header_edge (class loop *loop, edge, unsigned int ndupl, sbitmap wont_exit, edge orig, vec< edge > *to_remove, int flags)
void lv_flush_pending_stmts (edge)
void extract_cond_bb_edges (basic_block, edge *, edge *)
void lv_adjust_loop_header_phi (basic_block, basic_block, basic_block, edge)
void lv_add_condition_to_bb (basic_block, basic_block, basic_block, void *)
bool can_copy_bbs_p (basic_block *, unsigned)
void copy_bbs (basic_block *, unsigned, basic_block *, edge *, unsigned, edge *, class loop *, basic_block, bool)
void profile_record_check_consistency (profile_record *)
void profile_record_account_profile (profile_record *)
enum ir_type current_ir_type (void)
void rtl_register_cfg_hooks (void)
void cfg_layout_rtl_register_cfg_hooks (void)
void gimple_register_cfg_hooks (void)
struct cfg_hooks get_cfg_hooks (void)
void set_cfg_hooks (struct cfg_hooks)


struct cfg_hooks gimple_cfg_hooks
struct cfg_hooks rtl_cfg_hooks
struct cfg_hooks cfg_layout_rtl_cfg_hooks

Typedef Documentation

◆ dependence_hash

typedef int_hash<unsigned short, 0> dependence_hash

Function Documentation

◆ block_ends_with_call_p()

bool block_ends_with_call_p ( basic_block bb)
Return 1 if BB ends with a call, possibly followed by some
instructions that must stay with the call, 0 otherwise.   

References cfg_hooks::block_ends_with_call_p, internal_error(), and cfg_hooks::name.

Referenced by compute_branch_probabilities(), find_traces_1_round(), is_edge_inconsistent(), and is_inconsistent().

◆ block_ends_with_condjump_p()

bool block_ends_with_condjump_p ( const_basic_block bb)
Return 1 if BB ends with a conditional branch, 0 otherwise.   

References cfg_hooks::block_ends_with_condjump_p, internal_error(), and cfg_hooks::name.

Referenced by compute_branch_probabilities().

◆ can_copy_bbs_p()

◆ can_duplicate_block_p()

◆ can_merge_blocks_p()

◆ can_remove_branch_p()

bool can_remove_branch_p ( const_edge e)
Returns true if it is possible to remove the edge E by redirecting it
to the destination of the other edge going from its source.   

References cfg_hooks::can_remove_branch_p, EDGE_COUNT, internal_error(), and cfg_hooks::name.

Referenced by remove_path().

◆ cfg_hook_duplicate_loop_body_to_header_edge()

bool cfg_hook_duplicate_loop_body_to_header_edge ( class loop * loop,
edge e,
unsigned int ndupl,
sbitmap wont_exit,
edge orig,
vec< edge > * to_remove,
int flags )
Loop versioning uses the duplicate_loop_body_to_header_edge to create
a new version of the loop basic-blocks, the parameters here are
exactly the same as in duplicate_loop_body_to_header_edge or
tree_duplicate_loop_body_to_header_edge; while in tree-ssa there is
additional work to maintain ssa information that's why there is
a need to call the tree_duplicate_loop_body_to_header_edge rather
than duplicate_loop_body_to_header_edge when we are in tree mode.   

References cfg_hooks::cfg_hook_duplicate_loop_body_to_header_edge, and gcc_assert.

Referenced by loop_version().

◆ cfg_layout_rtl_register_cfg_hooks()

void cfg_layout_rtl_register_cfg_hooks ( void )
Initialization of functions specific to the rtl IR.   

References cfg_layout_rtl_cfg_hooks.

Referenced by cfg_layout_initialize(), and skip_pass().

◆ checking_verify_flow_info()

void checking_verify_flow_info ( void )

◆ copy_bbs()

void copy_bbs ( basic_block * bbs,
unsigned n,
basic_block * new_bbs,
edge * edges,
unsigned num_edges,
edge * new_edges,
class loop * base,
basic_block after,
bool update_dominance )
Duplicates N basic blocks stored in array BBS.  Newly created basic blocks
are placed into array NEW_BBS in the same order.  Edges from basic blocks
in BBS are also duplicated and copies of those that lead into BBS are
redirected to appropriate newly created block.  The function assigns bbs
into loops (copy of basic block bb is assigned to bb->loop_father->copy
loop, so this must be set up correctly in advance)

If UPDATE_DOMINANCE is true then this function updates dominators locally
(LOOPS structure that contains the information about dominators is passed
to enable this), otherwise it does not update the dominator information
and it assumed that the caller will do this, perhaps by destroying and
recreating it instead of trying to do an incremental update like this
function does when update_dominance is true.

BASE is the superloop to that basic block belongs; if its header or latch
is copied, we do not set the new blocks as header or latch.

Created copies of N_EDGES edges in array EDGES are stored in array NEW_EDGES,
also in the same order.

Newly created basic blocks are put after the basic block AFTER in the
instruction stream, and the order of the blocks in BBS array is preserved.   

References CDI_DOMINATORS, duplicate_block(), find_edge(), basic_block_def::flags, FOR_EACH_EDGE, get_bb_copy(), get_immediate_dominator(), loop::header, i, loop::latch, basic_block_def::loop_father, NULL, redirect_edge_and_branch_force(), set_immediate_dominator(), and basic_block_def::succs.

Referenced by duplicate_loop_body_to_header_edge(), back_jt_path_registry::duplicate_thread_path(), gimple_duplicate_seme_region(), gimple_duplicate_sese_tail(), and slpeel_tree_duplicate_loop_to_edge_cfg().

◆ create_basic_block() [1/2]

◆ create_basic_block() [2/2]

basic_block create_basic_block ( rtx head,
rtx end,
basic_block after )

References create_basic_block_1(), and end().

◆ create_empty_bb()

◆ current_ir_type()

◆ delete_basic_block()

◆ dump_bb()

void dump_bb ( FILE * outf,
basic_block bb,
int indent,
dump_flags_t flags )
Print out one basic block BB to file OUTF.  INDENT is printed at the
start of each new line.  FLAGS are the TDF_* flags in dumpfile.h.

This function takes care of the purely graph related information.
The cfg hook for the active representation should dump
representation-specific information.   

◆ dump_bb_for_graph()

void dump_bb_for_graph ( pretty_printer * pp,
basic_block bb )
Dumps basic block BB to pretty-printer PP, for use as a label of
a DOT graph record-node.  The implementation of this hook is
expected to write the label to the stream that is attached to PP.
Field separators between instructions are pipe characters printed
verbatim.  Instructions should be written with some characters
escaped, using pp_write_text_as_dot_label_to_stream().   

References basic_block_def::count, cfg_hooks::dump_bb_for_graph, dump_flags, profile_count::initialized_p(), internal_error(), cfg_hooks::name, pp_printf(), pp_write_text_to_stream(), PRId64, TDF_SLIM, and profile_count::to_gcov_type().

Referenced by draw_cfg_node().

◆ dump_flow_info()

void dump_flow_info ( FILE * file,
dump_flags_t flags )

◆ duplicate_block()

basic_block duplicate_block ( basic_block bb,
edge e,
basic_block after,
copy_bb_data * id )
Duplicate basic block BB, place it after AFTER (if non-null) and redirect
edge E to it (if non-null).  Return the new basic block.

If BB contains a returns_twice call, the caller is responsible for recreating
incoming abnormal edges corresponding to the "second return" for the copy.
gimple_can_duplicate_bb_p rejects such blocks, while RTL likes to live

If BB has incoming abnormal edges for some other reason, their destinations
should be tied to label(s) of the original BB and not the copy.   

References add_bb_to_loop(), can_duplicate_block_p(), basic_block_def::count, current_loops, cfg_hooks::duplicate_block, basic_block_def::flags, FOR_EACH_EDGE, gcc_checking_assert, get_loop_copy(), loop::header, internal_error(), loop::latch, basic_block_def::loop_father, loop_outer(), LOOPS_MAY_HAVE_MULTIPLE_LATCHES, loops_state_set(), mark_loop_for_removal(), move_block_after(), cfg_hooks::name, NULL, redirect_edge_and_branch_force(), set_bb_copy(), set_bb_original(), basic_block_def::succs, unchecked_make_edge(), and profile_count::uninitialized().

Referenced by copy_bb(), copy_bbs(), create_block_for_threading(), isolate_path(), maybe_duplicate_computed_goto(), transform_duplicate(), and try_shrink_wrapping().

◆ empty_block_p()

◆ execute_on_growing_pred()

void execute_on_growing_pred ( edge e)
This function is called immediately after edge E is added to the
edge vector E->dest->preds.   

References cfg_hooks::execute_on_growing_pred.

Referenced by redirect_edge_succ(), and unchecked_make_edge().

◆ execute_on_shrinking_pred()

void execute_on_shrinking_pred ( edge e)
This function is called immediately before edge E is removed from
the edge vector E->dest->preds.   

References cfg_hooks::execute_on_shrinking_pred.

Referenced by redirect_edge_succ(), and remove_edge_raw().

◆ extract_cond_bb_edges()

void extract_cond_bb_edges ( basic_block b,
edge * e1,
edge * e2 )
Conditional jumps are represented differently in trees and RTL,
this hook takes a basic block that is known to have a cond jump
at its end and extracts the taken and not taken edges out of it
and store it in E1 and E2 respectively.   

References b, cfg_hooks::extract_cond_bb_edges, and gcc_assert.

◆ flow_call_edges_add()

int flow_call_edges_add ( sbitmap blocks)
Add fake edges to the function exit for any non constant and non noreturn
calls, volatile inline assembly in the bitmap of blocks specified by
BLOCKS or to the whole CFG if BLOCKS is zero.  Return the number of blocks
that were split.

The goal is to expose cases in which entering a basic block does not imply
that all subsequent instructions must be executed.   

References cfg_hooks::flow_call_edges_add, internal_error(), and cfg_hooks::name.

Referenced by branch_prob().

◆ force_nonfallthru()

◆ get_cfg_hooks()

struct cfg_hooks get_cfg_hooks ( void )

References cfg_hooks.

◆ gimple_register_cfg_hooks()

◆ lv_add_condition_to_bb()

void lv_add_condition_to_bb ( basic_block first,
basic_block second,
basic_block new_block,
void * cond )
Conditions in trees and RTL are different so we need
a different handling when we add the condition to the
versioning code.   

References gcc_assert, and cfg_hooks::lv_add_condition_to_bb.

Referenced by lv_adjust_loop_entry_edge().

◆ lv_adjust_loop_header_phi()

void lv_adjust_loop_header_phi ( basic_block first,
basic_block second,
basic_block new_block,
edge e )
Responsible for updating the ssa info (PHI nodes) on the
new condition basic block that guards the versioned loop.   

References cfg_hooks::lv_adjust_loop_header_phi.

Referenced by lv_adjust_loop_entry_edge().

◆ lv_flush_pending_stmts()

void lv_flush_pending_stmts ( edge e)
This is used inside loop versioning when we want to insert
stmts/insns on the edges, which have a different behavior
in tree's and in RTL, so we made a CFG hook.   

References cfg_hooks::flush_pending_stmts.

Referenced by loop_version().

◆ make_forwarder_block()

◆ merge_blocks()

◆ move_block_after()

bool move_block_after ( basic_block bb,
basic_block after )
Moves block BB immediately after block AFTER.  Returns false if the
movement was impossible.   

References internal_error(), cfg_hooks::move_block_after, and cfg_hooks::name.

Referenced by create_preheader(), duplicate_block(), gimple_merge_blocks(), loop_version(), and move_block_to_fn().

◆ predict_edge()

void predict_edge ( edge e,
enum br_predictor predictor,
int probability )

◆ predicted_by_p()

bool predicted_by_p ( const_basic_block bb,
enum br_predictor predictor )

◆ profile_record_account_profile()

void profile_record_account_profile ( profile_record * record)
Work-horse for passes.cc:acount_profile.
Do book-keeping of the CFG for the profile accounting.
Store the counting in RECORD.   

References cfg_hooks::account_profile_record, cfun, FOR_ALL_BB_FN, and gcc_assert.

Referenced by account_profile().

◆ profile_record_check_consistency()

◆ redirect_edge_and_branch()

◆ redirect_edge_and_branch_force()

◆ redirect_edge_succ_nodup()

◆ remove_branch()

void remove_branch ( edge e)
Removes E, by redirecting it to the destination of the other edge going
from its source.  Can_remove_branch_p must be true for E, hence this
operation cannot fail.   

References EDGE_COUNT, EDGE_SUCC, gcc_assert, NULL, and redirect_edge_and_branch().

Referenced by fuse_loops(), and remove_path().

◆ remove_edge()

void remove_edge ( edge e)
Removes edge E from cfg.  Unlike remove_branch, it does not update IL.   

References current_ir_type(), current_loops, IR_GIMPLE, LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS, LOOPS_NEED_FIXUP, loops_state_satisfies_p(), loops_state_set(), NULL, redirect_edge_var_map_clear(), remove_edge_raw(), and rescan_loop_exit().

Referenced by clean_up_after_unswitching(), simplify_using_ranges::cleanup_edges_and_switches(), cleanup_empty_eh(), combine_blocks(), cond_move_process_if_block(), convert_if_conditions_to_switch(), dead_or_predicable(), delete_basic_block(), edge_before_returns_twice_call(), eliminate_unnecessary_stmts(), expand_call_inline(), expand_case(), expand_gimple_tailcall(), expand_omp_for_generic(), expand_omp_for_init_counts(), expand_omp_for_init_vars(), expand_omp_for_ordered_loops(), expand_omp_for_static_chunk(), expand_omp_for_static_nochunk(), expand_omp_simd(), expand_omp_target(), expand_omp_taskloop_for_inner(), expand_omp_taskloop_for_outer(), expand_omp_taskreg(), expand_parallel_call(), expand_thunk(), find_bb_boundaries(), find_cond_trap(), tree_switch_conversion::switch_conversion::gen_inbound_check(), gimple_divmod_fixed_value(), gimple_ic(), gimple_mod_pow2(), gimple_stringop_fixed_value(), isolate_path(), local_cprop_pass(), lower_eh_dispatch(), lower_resx(), maybe_cleanup_end_of_block(), merge_blocks(), move_sese_region_to_fn(), noce_convert_multiple_sets(), noce_process_if_block(), one_cprop_pass(), tree_switch_conversion::switch_conversion::prune_bbs(), purge_dead_edges(), purge_dead_tablejump_edges(), redirect_edge_succ_nodup(), remove_ctrl_stmt_and_useless_edges(), remove_edge_and_dominated_blocks(), remove_fake_predecessors(), remove_phi_nodes_and_edges_for_unreachable_block(), simplify_gimple_switch_label_vec(), split_function(), try_combine(), try_redirect_by_replacing_jump(), unloop(), and unsplit_eh().

◆ rtl_register_cfg_hooks()

void rtl_register_cfg_hooks ( void )
Initialization of functions specific to the rtl IR.   

References rtl_cfg_hooks.

Referenced by cfg_layout_finalize(), function_reader::create_function(), and skip_pass().

◆ set_cfg_hooks()

void set_cfg_hooks ( struct cfg_hooks new_cfg_hooks)

◆ split_block() [1/2]

edge split_block ( basic_block bb,
gimple * i )

References i, and split_block_1().

Referenced by branch_fixup(), rt_bb_visited::check(), copy_edges_for_bb(), create_call_for_reduction_1(), create_cond_insert_point(), decompose_multiword_subregs(), tree_switch_conversion::switch_decision_tree::do_jump_if_equal(), tree_switch_conversion::jump_table_cluster::emit(), tree_switch_conversion::switch_decision_tree::emit_cmp_and_jump_insns(), expand_call_inline(), expand_complex_div_wide(), expand_oacc_for(), expand_omp_for_generic(), expand_omp_for_init_counts(), expand_omp_for_init_vars(), expand_omp_for_ordered_loops(), expand_omp_for_static_chunk(), expand_omp_for_static_nochunk(), expand_omp_ordered_sink(), expand_omp_simd(), expand_omp_target(), expand_omp_taskloop_for_outer(), expand_omp_taskreg(), find_bb_boundaries(), fixup_noreturn_call(), tree_switch_conversion::switch_conversion::gen_inbound_check(), gimple_divmod_fixed_value(), gimple_find_sub_bbs(), gimple_flow_call_edges_add(), gimple_ic(), gimple_lower_bitint(), gimple_mod_pow2(), gimple_mod_subtract(), gimple_split_block_before_cond_jump(), gimple_stringop_fixed_value(), gsi_insert_finally_seq_after_call(), tree_switch_conversion::bit_test_cluster::hoist_edge_and_branch_if_true(), hoist_guard(), insert_cond_bb(), insert_trap(), local_cprop_pass(), oacc_entry_exit_single_gang(), omp_sese_split_blocks(), one_cprop_pass(), optimize_mask_stores(), peep2_attempt(), remove_exits_and_undefined_stmts(), rtl_flow_call_edges_add(), rtl_split_block_before_cond_jump(), shrink_wrap_one_built_in_call_with_conds(), simd_clone_adjust(), split_bb_make_tm_edge(), split_function(), try_combine(), try_crossjump_to_edge(), tree_switch_conversion::switch_decision_tree::try_switch_expansion(), ubsan_expand_null_ifn(), ubsan_expand_ptr_ifn(), vect_loop_versioning(), worker_single_copy(), and worker_single_simple().

◆ split_block() [2/2]

edge split_block ( basic_block bb,
rtx i )

References i, and split_block_1().

◆ split_block_after_labels()

◆ split_block_before_cond_jump()

basic_block split_block_before_cond_jump ( basic_block bb)
Split a basic block if it ends with a conditional branch and if
the other part of the block is not empty.   

References gcc_assert, and cfg_hooks::split_block_before_cond_jump.

Referenced by transform_to_exit_first_loop_alt().

◆ split_edge()

basic_block split_edge ( edge e)
Splits edge E and returns the newly created basic block.   

References add_bb_to_loop(), profile_probability::always(), CDI_DOMINATORS, basic_block_def::count, count, current_loops, dom_info_available_p(), dom_info_state(), DOM_NO_FAST_QUERY, dominated_by_p(), find_common_loop(), basic_block_def::flags, FOR_EACH_EDGE, get_immediate_dominator(), loop::header, internal_error(), loop::latch, basic_block_def::loop_father, cfg_hooks::name, NULL, rescan_loop_exit(), set_immediate_dominator(), single_pred(), single_pred_edge(), single_succ(), single_succ_edge(), and cfg_hooks::split_edge.

Referenced by analyze_insns_in_loop(), branch_prob(), build_and_add_sum(), commit_one_edge_insertion(), connect_loops(), convert_if_conditions_to_switch(), create_bb_after_loop(), create_empty_if_region_on_edge(), create_empty_loop_on_edge(), create_new_iv(), create_parallel_loop(), create_preheader(), disambiguate_multiple_latches(), do_split_loop_on_cond(), doloop_modify(), tree_switch_conversion::switch_decision_tree::emit_case_nodes(), execute_sm_if_changed(), expand_complex_libcall(), expand_omp_for_generic(), expand_omp_for_static_chunk(), expand_omp_for_static_nochunk(), expand_omp_simd(), expand_phi_nodes(), find_implicit_sets(), fixup_reorder_chain(), force_one_exit_fallthru(), force_single_succ_latches(), gimple_duplicate_sese_tail(), gimple_find_edge_insert_loc(), gimple_gen_ic_func_profiler(), gimple_gen_time_profiler(), gimple_ic(), ifcvt_split_critical_edges(), insert_edge_check_and_trap(), insert_prologue_epilogue_for_components(), loop_version(), lv_adjust_loop_entry_edge(), make_forwarders_with_degenerate_phis(), move_insn_for_shrink_wrap(), move_invariant_reg(), move_sese_in_condition(), remove_forwarder_block_with_phi(), remove_path(), separate_decls_in_region(), shrink_wrap_one_built_in_call_with_conds(), sjlj_emit_function_enter(), slpeel_add_loop_guard(), slpeel_tree_duplicate_loop_to_edge_cfg(), split_critical_edges(), split_edge_and_insert(), split_loop_exit_edge(), fwd_jt_path_registry::thread_through_loop_header(), transform_to_exit_first_loop_alt(), tree_function_versioning(), tree_optimize_tail_calls_1(), tree_transform_and_unroll_loop(), try_shrink_wrapping(), tree_switch_conversion::switch_decision_tree::try_switch_expansion(), unroll_loop_runtime_iterations(), vect_do_peeling(), vect_loop_versioning(), vect_transform_loop(), worker_single_copy(), and worker_single_simple().

◆ tidy_fallthru_edge()

void tidy_fallthru_edge ( edge e)
Try to make the edge fallthru.   

References cfg_hooks::tidy_fallthru_edge.

Referenced by merge_if_block(), tidy_fallthru_edges(), and try_simplify_condjump().

◆ tidy_fallthru_edges()

void tidy_fallthru_edges ( void )
Fix up edges that now fall through, or rather should now fall through
but previously required a jump around now deleted blocks.  Simplify
the search by only examining blocks numerically adjacent, since this
is how they were created.

??? This routine is currently RTL specific.   

References b, BB_END, cfun, CROSSING_JUMP_P, EDGE_COMPLEX, ENTRY_BLOCK_PTR_FOR_FN, EXIT_BLOCK_PTR_FOR_FN, FOR_BB_BETWEEN, JUMP_P, basic_block_def::next_bb, single_succ_edge(), single_succ_p(), cfg_hooks::tidy_fallthru_edge, and tidy_fallthru_edge().

Referenced by delete_unreachable_blocks(), and post_order_compute().

◆ verify_flow_info()

Variable Documentation

◆ cfg_layout_rtl_cfg_hooks

struct cfg_hooks cfg_layout_rtl_cfg_hooks
Implementation of CFG manipulation for cfg layout RTL, where
basic block connected via fallthru edges does not have to be adjacent.
This representation will hopefully become the default one in future
version of the compiler.   

Referenced by cfg_layout_rtl_register_cfg_hooks(), and current_ir_type().

◆ gimple_cfg_hooks

struct cfg_hooks gimple_cfg_hooks
Hooks containers.   

Referenced by current_ir_type(), and gimple_register_cfg_hooks().

◆ rtl_cfg_hooks

struct cfg_hooks rtl_cfg_hooks
Implementation of CFG manipulation for linearized RTL.   

Referenced by current_ir_type(), and rtl_register_cfg_hooks().