Functions
void	delete_insn (rtx_insn *)

bool	delete_insn_and_edges (rtx_insn *)

void	delete_insn_chain (rtx, rtx_insn *, bool)

basic_block	create_basic_block_structure (rtx_insn , rtx_insn , rtx_note *, basic_block)

void	compute_bb_for_insn (void)

void	free_bb_for_insn (void)

rtx_insn *	entry_of_function (void)

void	update_bb_for_insn (basic_block)

bool	contains_no_active_insn_p (const_basic_block)

bool	forwarder_block_p (const_basic_block)

bool	can_fallthru (basic_block, basic_block)

rtx_note *	bb_note (basic_block)

rtx_code_label *	block_label (basic_block)

edge	try_redirect_by_replacing_jump (edge, basic_block, bool)

void	emit_barrier_after_bb (basic_block bb)

basic_block	force_nonfallthru_and_redirect (edge, basic_block, rtx)

void	insert_insn_on_edge (rtx, edge)

void	prepend_insn_to_edge (rtx, edge)

void	commit_one_edge_insertion (edge e)

void	commit_edge_insertions (void)

void	print_rtl_with_bb (FILE , const rtx_insn , dump_flags_t)

void	update_br_prob_note (basic_block)

rtx_insn *	get_last_bb_insn (basic_block)

void	fixup_partitions (void)

bool	purge_dead_edges (basic_block)

bool	purge_all_dead_edges (void)

bool	fixup_abnormal_edges (void)

void	update_cfg_for_uncondjump (rtx_insn *)

rtx_insn *	unlink_insn_chain (rtx_insn , rtx_insn )

void	relink_block_chain (bool)

rtx_insn *	duplicate_insn_chain (rtx_insn , rtx_insn , class loop , class copy_bb_data )

void	cfg_layout_initialize (int)

void	cfg_layout_finalize (void)

void	break_superblocks (void)

void	init_rtl_bb_info (basic_block)

void	find_bbs_reachable_by_hot_paths (hash_set< basic_block > *)

Function Documentation

◆ bb_note()

rtx_note * bb_note ( basic_block bb )

extern

Return the NOTE_INSN_BASIC_BLOCK of BB.

References BB_HEAD, gcc_assert, ggc_alloc(), LABEL_P, NEXT_INSN(), and NOTE_INSN_BASIC_BLOCK_P.

Referenced by _succ_iter_cond(), create_basic_block_structure(), delete_insn(), emit_common_heads_for_components(), inherit_in_ebb(), move_insn_for_shrink_wrap(), and split_live_ranges_for_shrink_wrap().

◆ block_label()

rtx_code_label * block_label ( basic_block block )

extern

Return the label in the head of basic block BLOCK.  Create one if it doesn't
exist.

References BB_HEAD, cfun, emit_label_before(), EXIT_BLOCK_PTR_FOR_FN, gen_label_rtx(), ggc_alloc(), LABEL_P, and NULL.

Referenced by add_labels_and_missing_jumps(), add_test(), block_has_preserve_label(), create_eh_forwarder_block(), dead_or_predicable(), doloop_modify(), doloop_optimize(), fix_crossing_conditional_branches(), fix_up_fall_thru_edges(), force_nonfallthru_and_redirect(), label_for_bb(), label_rtx_for_bb(), patch_jump_insn(), rtl_lv_add_condition_to_bb(), try_optimize_cfg(), try_redirect_by_replacing_jump(), try_simplify_condjump(), and unroll_loop_runtime_iterations().

◆ break_superblocks()

void break_superblocks ( void )

extern

Splits superblocks.

References bitmap_clear(), bitmap_set_bit, cfun, find_many_sub_basic_blocks(), basic_block_def::flags, FOR_EACH_BB_FN, get_insns(), ggc_alloc(), basic_block_def::index, last_basic_block_for_fn, and rebuild_jump_labels().

Referenced by finish_eh_generation().

◆ can_fallthru()

bool can_fallthru	(	basic_block	src,
		basic_block	target )

extern

Return nonzero if we can reach target from src by falling through.

FIXME: Make this a cfg hook, the result is only valid in cfgrtl mode.

References active_insn_p(), BB_END, BB_HEAD, cfun, EXIT_BLOCK_PTR_FOR_FN, FOR_EACH_EDGE, ggc_alloc(), next_active_insn(), basic_block_def::next_bb, NULL, basic_block_def::succs, and tablejump_p().

Referenced by expand_gimple_basic_block(), expand_gimple_tailcall(), fixup_reorder_chain(), try_redirect_by_replacing_jump(), and try_simplify_condjump().

◆ cfg_layout_finalize()

void cfg_layout_finalize ( void )

extern

Finalize the changes: reorder insn list according to the sequence specified
by aux pointers, enter compensation code, rebuild scope forest.

References CDI_DOMINATORS, checking_verify_flow_info(), delete_dead_jumptables(), fixup_fallthru_exit_predecessor(), fixup_reorder_chain(), force_one_exit_fallthru(), free_dominance_info(), get_insns(), ggc_alloc(), rebuild_jump_labels(), reload_completed, rtl_register_cfg_hooks(), targetm, and verify_insn_chain().

Referenced by reorder_loops(), and thread_prologue_and_epilogue_insns().

◆ cfg_layout_initialize()

void cfg_layout_initialize ( int flags )

extern

Main entry point to this module - initialize the datastructures for
CFG layout changes.  It keeps LOOPS up-to-date if not null.

FLAGS is a set of additional flags to pass to cleanup_cfg().

References BLOCK_FOR_INSN(), cfg_layout_rtl_register_cfg_hooks(), cleanup_cfg(), CLEANUP_CFGLAYOUT, crtl, basic_block_def::flags, gcc_assert, ggc_alloc(), initialize_original_copy_tables(), rtx_insn_list::insn(), rtx_insn_list::next(), nonlocal_goto_handler_labels, and record_effective_endpoints().

Referenced by reorder_loops(), and thread_prologue_and_epilogue_insns().

◆ commit_edge_insertions()

void commit_edge_insertions ( void )

extern

Update the CFG for all queued instructions.

References cfun, checking_verify_flow_info(), commit_one_edge_insertion(), currently_expanding_to_rtl, ENTRY_BLOCK_PTR_FOR_FN, EXIT_BLOCK_PTR_FOR_FN, fixup_partitions(), FOR_BB_BETWEEN, FOR_EACH_EDGE, rebuild_jump_labels_chain(), and basic_block_def::succs.

Referenced by bypass_conditional_jumps(), eliminate_partially_redundant_loads(), emit_insn_at_entry(), finish_eh_generation(), insert_prologue_epilogue_for_components(), ira(), ira_emit(), lra(), one_store_motion_pass(), pre_gcse(), reload(), rtl_flow_call_edges_add(), and thread_prologue_and_epilogue_insns().

◆ commit_one_edge_insertion()

void commit_one_edge_insertion ( edge e )

extern

Update the CFG for the instructions queued on edge E.

References BB_END, BB_HEAD, cfun, currently_expanding_to_rtl, delete_insn(), emit_barrier_after(), emit_insn_after_noloc(), emit_insn_before_noloc(), ENTRY_BLOCK_PTR_FOR_FN, EXIT_BLOCK_PTR_FOR_FN, find_sub_basic_blocks(), gcc_assert, get_last_insn(), ggc_alloc(), insns, JUMP_P, LABEL_P, last, NEXT_INSN(), NOTE_INSN_BASIC_BLOCK_P, NULL, PREV_INSN(), prev_nonnote_insn(), rebuild_jump_labels_chain(), returnjump_p(), simplejump_p(), single_pred_p(), single_succ_edge(), single_succ_p(), and split_edge().

Referenced by commit_edge_insertions().

◆ compute_bb_for_insn()

void compute_bb_for_insn ( void )

extern

Records the basic block struct in BLOCK_FOR_INSN for every insn.

References BB_END, BB_HEAD, BLOCK_FOR_INSN(), cfun, end(), FOR_EACH_BB_FN, and NEXT_INSN().

◆ contains_no_active_insn_p()

bool contains_no_active_insn_p ( const_basic_block bb )

extern

Return true if the block has no effect and only forwards control flow to
its single destination.

References BB_END, BB_HEAD, cfun, ENTRY_BLOCK_PTR_FOR_FN, EXIT_BLOCK_PTR_FOR_FN, flow_active_insn_p(), ggc_alloc(), INSN_P, JUMP_P, NEXT_INSN(), simplejump_p(), single_succ_edge(), and single_succ_p().

Referenced by doloop_optimize(), and forwarder_block_p().

◆ create_basic_block_structure()

basic_block create_basic_block_structure	(	rtx_insn *	head,
		rtx_insn *	end,
		rtx_note *	bb_note,
		basic_block	after )

extern

Create a new basic block consisting of the instructions between HEAD and END
inclusive.  This function is designed to allow fast BB construction - reuses
the note and basic block struct in BB_NOTE, if any and do not grow
BASIC_BLOCK chain and should be used directly only by CFG construction code.
END can be NULL in to create new empty basic block before HEAD.  Both END
and HEAD can be NULL to create basic block at the end of INSN chain.
AFTER is the basic block we should be put after.

References alloc_block(), basic_block_def::aux, BB_END, BB_HEAD, bb_note(), BB_SET_PARTITION, BB_UNPARTITIONED, cfun, df_bb_refs_record(), emit_note_after(), emit_note_before(), end(), basic_block_def::flags, get_last_insn(), ggc_alloc(), basic_block_def::index, init_rtl_bb_info(), LABEL_P, last_basic_block_for_fn, link_block(), NEXT_INSN(), NOTE_BASIC_BLOCK, NULL, PREV_INSN(), reorder_insns_nobb(), SET_BASIC_BLOCK_FOR_FN, and update_bb_for_insn().

Referenced by rtl_create_basic_block().

◆ delete_insn()

void delete_insn ( rtx_insn * insn )

extern

Define control flow data structures for the CFG.
   Copyright (C) 2014-2024 Free Software Foundation, Inc.

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/>.

Delete INSN by patching it out.

References BB_END, BB_HEAD, bb_note(), BLOCK_FOR_INSN(), can_delete_label_p(), rtx_insn::deleted(), df_insn_delete(), find_reg_note(), gcc_assert, GET_NUM_ELEM, ggc_alloc(), i, INSN_P, JUMP_LABEL, JUMP_P, LABEL_NAME, LABEL_NUSES, LABEL_P, NEXT_INSN(), nonlocal_goto_handler_labels, NOTE_DELETED_LABEL_NAME, NOTE_INSN_BASIC_BLOCK_P, NOTE_KIND, NOTE_P, NULL, NULL_RTX, PUT_CODE, remove_insn(), remove_node_from_insn_list(), remove_note(), reorder_insns_nobb(), RTVEC_ELT, rtx_insn::set_deleted(), table, and XEXP.

Referenced by add_test(), attempt_change(), find_comparison_dom_walker::before_dom_children(), calculate_needs_all_insns(), cfg_layout_merge_blocks(), cfg_layout_redirect_edge_and_branch(), cleanup_barriers(), combine_and_move_insns(), combine_stack_adjustments_for_block(), commit_one_edge_insertion(), copyprop_hardreg_forward_1(), cprop_jump(), cse_cc_succs(), dead_or_predicable(), delete_address_reloads_1(), delete_caller_save_insns(), delete_dead_jumptables(), delete_dead_store_insn(), delete_insn_and_edges(), delete_insn_chain(), delete_output_reload(), delete_redundant_insns_1(), delete_related_insns(), delete_vta_debug_insn(), doloop_modify(), dse_step5(), duplicate_insn_chain(), eliminate_partially_redundant_load(), expand_gimple_tailcall(), final_1(), final_scan_insn_1(), find_and_remove_re(), find_bb_boundaries(), find_cond_trap(), fix_crossing_unconditional_branches(), fixup_abnormal_edges(), fixup_reorder_chain(), hoist_code(), instantiate_virtual_regs_in_insn(), lra_final_code_change(), maybe_cleanup_end_of_block(), merge_blocks_move_predecessor_nojumps(), merge_blocks_move_successor_nojumps(), merge_if_block(), move_insn_for_shrink_wrap(), move_invariant_reg(), move_unallocated_pseudos(), pre_delete(), reemit_insn_block_notes(), reemit_marker_as_note(), reload(), reload_as_needed(), reload_combine_recognize_const_pattern(), reload_combine_recognize_pattern(), reload_cse_move2add(), replace_store_insn(), resolve_shift_zext(), resolve_simple_move(), resolve_use(), rtl_tidy_fallthru_edge(), split_iv(), try_eliminate_compare(), try_merge_compare(), try_optimize_cfg(), try_split(), and update_cfg_for_uncondjump().

◆ delete_insn_and_edges()

bool delete_insn_and_edges ( rtx_insn * insn )

extern

Like delete_insn but also purge dead edges from BB.
Return true if any edges are eliminated.

References BB_END, BLOCK_FOR_INSN(), DEBUG_INSN_P, delete_insn(), ggc_alloc(), NEXT_INSN(), NONDEBUG_INSN_P, and purge_dead_edges().

Referenced by cse_cc_succs(), cse_insn(), delete_noop_moves(), delete_trivially_dead_insns(), delete_unmarked_insns(), discover_loops(), reload_cse_simplify(), split_all_insns(), and split_all_insns_noflow().

◆ delete_insn_chain()

void delete_insn_chain	(	rtx	start,
		rtx_insn *	finish,
		bool	clear_bb )

extern

Unlink a chain of insns between START and FINISH, leaving notes
that must be paired.  If CLEAR_BB is true, we set bb field for
insns that cannot be removed to NULL.

References can_delete_note_p(), delete_insn(), rtx_insn::deleted(), ggc_alloc(), NOTE_P, NULL, PREV_INSN(), and set_block_for_insn().

Referenced by cond_exec_process_if_block(), peep2_attempt(), rtl_delete_block(), rtl_merge_blocks(), rtl_tidy_fallthru_edge(), try_head_merge_bb(), and try_redirect_by_replacing_jump().

◆ duplicate_insn_chain()

rtx_insn * duplicate_insn_chain	(	rtx_insn *	from,
		rtx_insn *	to,
		class loop *	loop,
		class copy_bb_data *	id )

extern

◆ emit_barrier_after_bb()

void emit_barrier_after_bb ( basic_block bb )

extern

Emit a barrier after BB, into the footer if we are in CFGLAYOUT mode.

References BARRIER_P, BB_END, BB_FOOTER, current_ir_type(), emit_barrier_after(), gcc_assert, ggc_alloc(), IR_RTL_CFGLAYOUT, IR_RTL_CFGRTL, NEXT_INSN(), SET_NEXT_INSN(), SET_PREV_INSN(), and unlink_insn_chain().

Referenced by add_labels_and_missing_jumps(), create_eh_forwarder_block(), fix_crossing_conditional_branches(), fix_up_fall_thru_edges(), force_nonfallthru_and_redirect(), handle_simple_exit(), local_cprop_pass(), maybe_duplicate_computed_goto(), one_cprop_pass(), try_combine(), try_optimize_cfg(), and try_shrink_wrapping().

◆ entry_of_function()

rtx_insn * entry_of_function ( void )

extern

Return RTX to emit after when we want to emit code on the entry of function.

References BB_HEAD, cfun, ENTRY_BLOCK_PTR_FOR_FN, get_insns(), n_basic_blocks_for_fn, and NUM_FIXED_BLOCKS.

Referenced by expand_builtin_apply_args(), expand_builtin_saveregs(), and get_arg_pointer_save_area().

◆ find_bbs_reachable_by_hot_paths()

void find_bbs_reachable_by_hot_paths ( hash_set< basic_block > * set )

extern

Add all BBs reachable from entry via hot paths into the SET.

References BB_PARTITION, cfun, ENTRY_BLOCK_PTR_FOR_FN, FOR_EACH_EDGE, ggc_alloc(), basic_block_def::succs, and worklist.

Referenced by find_partition_fixes(), and find_rarely_executed_basic_blocks_and_crossing_edges().

◆ fixup_abnormal_edges()

bool fixup_abnormal_edges ( void )

extern

This is used by a few passes that emit some instructions after abnormal
calls, moving the basic block's end, while they in fact do want to emit
them on the fallthru edge.  Look for abnormal call edges, find backward
the call in the block and insert the instructions on the edge instead.

Similarly, handle instructions throwing exceptions internally.

Return true when instructions have been found and inserted on edges.

References BARRIER_P, BB_END, BB_HEAD, CALL_P, can_throw_internal(), cfun, delete_insn(), find_fallthru_edge(), FOR_EACH_BB_FN, FOR_EACH_EDGE, ggc_alloc(), insert_insn_on_edge(), inserted, INSN_P, NEXT_INSN(), NONJUMP_INSN_P, NOTE_P, NULL, NULL_RTX, PREV_INSN(), purge_dead_edges(), set_block_for_insn(), SET_NEXT_INSN(), SET_PREV_INSN(), rtx_insn::set_undeleted(), and basic_block_def::succs.

Referenced by lra(), and reload().

◆ fixup_partitions()

void fixup_partitions ( void )

extern

Perform cleanup on the hot/cold bb partitioning after optimization
passes that modify the cfg.

References BB_HEAD, BB_PARTITION, BB_UNPARTITIONED, cfun, crtl, current_ir_type(), delete_unreachable_blocks(), find_partition_fixes(), fixup_new_cold_bb(), FOR_EACH_BB_FN, gcc_assert, ggc_alloc(), IR_RTL_CFGRTL, basic_block_def::next_bb, NULL, basic_block_def::prev_bb, PREV_INSN(), SET_NEXT_INSN(), and SET_PREV_INSN().

Referenced by commit_edge_insertions(), duplicate_computed_gotos(), if_convert(), rest_of_handle_thread_prologue_and_epilogue(), and try_optimize_cfg().

◆ force_nonfallthru_and_redirect()

basic_block force_nonfallthru_and_redirect	(	edge	e,
		basic_block	target,
		rtx	jump_label )

extern

Like force_nonfallthru below, but additionally performs redirection
Used by redirect_edge_and_branch_force.  JUMP_LABEL is used only
when redirecting to the EXIT_BLOCK, it is either ret_rtx or
simple_return_rtx, indicating which kind of returnjump to create.
It should be NULL otherwise.

References add_reg_note(), profile_probability::always(), any_condjump_p(), ASM_OPERANDS_LABEL, ASM_OPERANDS_LABEL_LENGTH, b, BB_COPY_PARTITION, BB_END, BB_HEAD, block_label(), cfun, basic_block_def::count, count, create_basic_block(), df_mark_solutions_dirty(), EDGE_COUNT, ei_next(), ei_safe_edge(), ei_start, emit_barrier_after_bb(), emit_jump_insn_after_setloc(), ENTRY_BLOCK_PTR_FOR_FN, EXIT_BLOCK_PTR_FOR_FN, extract_asm_operands(), find_reg_note(), fixup_partition_crossing(), basic_block_def::flags, profile_probability::from_reg_br_prob_note(), gcc_assert, ggc_alloc(), i, edge_iterator::index, JUMP_LABEL, JUMP_P, LABEL_NUSES, make_edge(), make_single_succ_edge(), NEXT_INSN(), NULL, NULL_RTX, PATTERN(), redirect_edge_pred(), redirect_edge_succ_nodup(), redirect_jump(), remove_note(), ret_rtx, set_return_jump_label(), simple_return_rtx, basic_block_def::succs, table, tablejump_p(), targetm, unchecked_make_edge(), vec_safe_push(), XEXP, and XINT.

Referenced by find_if_case_1(), fixup_reorder_chain(), rtl_force_nonfallthru(), and rtl_redirect_edge_and_branch_force().

◆ forwarder_block_p()

bool forwarder_block_p ( const_basic_block bb )

extern

Likewise, but protect loop latches, headers and preheaders.

FIXME: Make this a cfg hook.

References contains_no_active_insn_p(), current_loops, EDGE_SUCC, loop::header, and basic_block_def::loop_father.

Referenced by add_forwarder_blocks(), find_if_case_1(), notice_new_block(), relink_block_chain(), and update_forwarder_flag().

◆ free_bb_for_insn()

void free_bb_for_insn ( void )

extern

Release the basic_block_for_insn array.

References BARRIER_P, BLOCK_FOR_INSN(), get_insns(), NEXT_INSN(), and NULL.

Referenced by rest_of_clean_state().

◆ get_last_bb_insn()

rtx_insn * get_last_bb_insn ( basic_block bb )

extern

Get the last insn associated with block BB (that includes barriers and
tablejumps after BB).

References BARRIER_P, BB_END, end(), ggc_alloc(), next_nonnote_nondebug_insn_bb(), NULL, table, and tablejump_p().

Referenced by cond_exec_process_if_block(), rtl_delete_block(), rtl_split_edge(), and try_optimize_cfg().

◆ init_rtl_bb_info()

void init_rtl_bb_info ( basic_block bb )

extern

References gcc_assert, ggc_alloc(), basic_block_def::basic_block_il_dependent::head_, basic_block_def::il, NULL, basic_block_def::basic_block_il_dependent::rtl, and basic_block_def::basic_block_il_dependent::x.

Referenced by construct_init_block(), create_basic_block_structure(), function_reader::create_function(), expand_gimple_basic_block(), and function_reader::parse_block().

◆ insert_insn_on_edge()

void insert_insn_on_edge	(	rtx	pattern,
		edge	e )

extern

Queue instructions for insertion on an edge between two basic blocks.
The new instructions and basic blocks (if any) will not appear in the
CFG until commit_edge_insertions is called.  If there are already
queued instructions on the edge, PATTERN is appended to them.

References EDGE_CRITICAL_P, emit_insn(), end_sequence(), gcc_assert, get_insns(), ggc_alloc(), NULL_RTX, push_to_sequence(), and start_sequence().

Referenced by bypass_block(), eliminate_partially_redundant_load(), emit_insn_at_entry(), emit_moves(), fixup_abnormal_edges(), insert_part_to_rtx_on_edge(), insert_partition_copy_on_edge(), insert_prologue_epilogue_for_components(), insert_rtx_to_part_on_edge(), insert_store(), insert_value_copy_on_edge(), ira(), pre_edge_insert(), rtl_flow_call_edges_add(), sjlj_emit_function_enter(), and thread_prologue_and_epilogue_insns().

◆ prepend_insn_to_edge()

void prepend_insn_to_edge	(	rtx	pattern,
		edge	e )

extern

Like insert_insn_on_edge, but if there are already queued instructions
on the edge, PATTERN is prepended to them.

References EDGE_CRITICAL_P, emit_insn(), end_sequence(), gcc_assert, get_insns(), ggc_alloc(), and start_sequence().

Referenced by expand_asm_stmt().

◆ print_rtl_with_bb()

void print_rtl_with_bb	(	FILE *	outf,
		const rtx_insn *	rtx_first,
		dump_flags_t	flags )

extern

Like dump_function_to_file, but for RTL.  Print out dataflow information
for the start of each basic block.  FLAGS are the TDF_* masks documented
in dumpfile.h.

References BARRIER_P, BB_END, BB_HEAD, cfun, df, df_dump_bottom(), df_dump_insn_bottom(), df_dump_insn_top(), df_dump_start(), df_dump_top(), dump_bb_info(), dump_flags, dump_insn_slim(), EDGE_COUNT, end(), find_fallthru_edge(), FOR_EACH_BB_REVERSE_FN, free(), gcc_assert, get_max_uid(), ggc_alloc(), basic_block_def::index, INSN_UID(), max_uid, NEXT_INSN(), NONDEBUG_INSN_P, NOTE_P, NULL, NULL_RTX, print_rtl_single(), print_rtx_head, PROP_cfg, basic_block_def::succs, TDF_BLOCKS, TDF_DETAILS, and TDF_SLIM.

Referenced by execute_function_dump(), if_convert(), and rtl_verify_edges().

◆ purge_all_dead_edges()

bool purge_all_dead_edges ( void )

extern

Search all basic blocks for potentially dead edges and purge them.  Return
true if some edge has been eliminated.

References cfun, FOR_EACH_BB_FN, ggc_alloc(), and purge_dead_edges().

Referenced by combine_instructions(), indirect_jump_optimize(), rest_of_handle_cse_after_global_opts(), rest_of_handle_dse(), and rest_of_handle_thread_prologue_and_epilogue().

◆ purge_dead_edges()

bool purge_dead_edges ( basic_block bb )

extern

Assume that the preceding pass has possibly eliminated jump instructions
or converted the unconditional jumps.  Eliminate the edges from CFG.
Return true if any edges are eliminated.

References profile_probability::always(), any_condjump_p(), b, BB_END, BB_HEAD, BRANCH_EDGE, CALL_P, can_nonlocal_goto(), can_throw_internal(), cfun, DEBUG_INSN_P, df_set_bb_dirty(), dump_file, EDGE_COMPLEX, EDGE_COUNT, ei_next(), ei_safe_edge(), ei_start, EXIT_BLOCK_PTR_FOR_FN, FALLTHRU_EDGE, find_reg_equal_equiv_note(), find_reg_note(), FOR_EACH_EDGE, profile_probability::from_reg_br_prob_note(), gcc_assert, ggc_alloc(), basic_block_def::index, JUMP_LABEL, JUMP_P, may_trap_p(), NONJUMP_INSN_P, NOTE_P, NULL, PATTERN(), PREV_INSN(), remove_edge(), remove_note(), returnjump_p(), SIBLING_CALL_P, simplejump_p(), single_succ_edge(), single_succ_p(), basic_block_def::succs, XEXP, and XINT.

Referenced by find_comparison_dom_walker::before_dom_children(), cprop_jump(), cse_extended_basic_block(), delete_insn_and_edges(), find_bb_boundaries(), fixup_abnormal_edges(), peep2_attempt(), purge_all_dead_edges(), and update_cfg_for_uncondjump().

◆ relink_block_chain()

void relink_block_chain ( bool stay_in_cfglayout_mode )

extern

Link the basic blocks in the correct order, compacting the basic
block queue while at it.  If STAY_IN_CFGLAYOUT_MODE is false, this
function also clears the basic block header and footer fields.

This function is usually called after a pass (e.g. tracer) finishes
some transformations while in cfglayout mode.  The required sequence
of the basic blocks is in a linked list along the bb->aux field.
This functions re-links the basic block prev_bb and next_bb pointers
accordingly, and it compacts and renumbers the blocks.

FIXME: This currently works only for RTL, but the only RTL-specific
bits are the STAY_IN_CFGLAYOUT_MODE bits.  The tracer pass was moved
to GIMPLE a long time ago, but it doesn't relink the basic block
chain.  It could do that (to give better initial RTL) if this function
is made IR-agnostic (and moved to cfganal.cc or cfg.cc while at it).

References basic_block_def::aux, BB_FOOTER, BB_HEAD, BB_HEADER, cfun, compact_blocks(), dump_file, ENTRY_BLOCK_PTR_FOR_FN, EXIT_BLOCK_PTR_FOR_FN, FOR_ALL_BB_FN, forwarder_block_p(), free_original_copy_tables(), get_bb_original(), ggc_alloc(), basic_block_def::index, initialize_original_copy_tables(), LABEL_P, basic_block_def::next_bb, NULL, NUM_FIXED_BLOCKS, original_copy_tables_initialized_p(), and basic_block_def::prev_bb.

Referenced by fixup_reorder_chain(), and reorder_basic_blocks().

◆ try_redirect_by_replacing_jump()

edge try_redirect_by_replacing_jump	(	edge	e,
		basic_block	target,
		bool	in_cfglayout )

extern

Attempt to perform edge redirection by replacing possibly complex jump
instruction by unconditional jump or removing jump completely.  This can
apply only if all edges now point to the same block.  The parameters and
return values are equivalent to redirect_edge_and_branch.

References profile_probability::always(), BARRIER_P, BB_END, BB_HEAD, BB_PARTITION, block_label(), can_fallthru(), cfun, delete_insn_chain(), dump_file, EDGE_COUNT, EDGE_SUCC, emit_barrier_after(), emit_jump_insn_after_noloc(), EXIT_BLOCK_PTR_FOR_FN, gcc_assert, ggc_alloc(), basic_block_def::index, INSN_UID(), JUMP_LABEL, LABEL_NUSES, NEXT_INSN(), next_nonnote_nondebug_insn(), NULL, onlyjump_p(), PREV_INSN(), redirect_edge_succ(), redirect_jump(), reload_completed, remove_barriers_from_footer(), remove_edge(), SET_NEXT_INSN(), SET_PREV_INSN(), side_effects_p(), simplejump_p(), single_set(), single_succ_edge(), single_succ_p(), basic_block_def::succs, table, tablejump_p(), targetm, and update_bb_for_insn_chain().

Referenced by cfg_layout_merge_blocks(), cfg_layout_redirect_edge_and_branch(), rtl_redirect_edge_and_branch(), and try_optimize_cfg().

◆ unlink_insn_chain()

rtx_insn * unlink_insn_chain	(	rtx_insn *	first,
		rtx_insn *	last )

extern

Cut the insns from FIRST to LAST out of the insns stream.

References ggc_alloc(), last, NEXT_INSN(), NULL, PREV_INSN(), set_first_insn(), set_last_insn(), SET_NEXT_INSN(), and SET_PREV_INSN().

Referenced by cfg_layout_delete_block(), cfg_layout_duplicate_bb(), cfg_layout_merge_blocks(), emit_barrier_after_bb(), record_effective_endpoints(), and reload_as_needed().

◆ update_bb_for_insn()

void update_bb_for_insn ( basic_block bb )

extern

Update BLOCK_FOR_INSN of insns in BB to BB,
and notify df of the change.

References BB_END, BB_HEAD, and update_bb_for_insn_chain().

Referenced by construct_exit_block(), construct_init_block(), create_basic_block_structure(), emit_to_new_bb_before(), expand_gimple_basic_block(), expand_gimple_cond(), and expand_gimple_tailcall().

◆ update_br_prob_note()

void update_br_prob_note ( basic_block bb )

extern

Update the branch probability of BB if a REG_BR_PROB is present.

References BB_END, BRANCH_EDGE, find_reg_note(), ggc_alloc(), JUMP_P, NULL_RTX, REG_NOTES, XEXP, and XINT.

Referenced by add_test(), dead_or_predicable(), find_many_sub_basic_blocks(), fix_up_fall_thru_edges(), fixup_reorder_chain(), force_edge_cold(), try_crossjump_to_edge(), try_forward_edges(), try_optimize_cfg(), try_simplify_condjump(), and unroll_loop_constant_iterations().

◆ update_cfg_for_uncondjump()

void update_cfg_for_uncondjump ( rtx_insn * insn )

extern

Delete the unconditional jump INSN and adjust the CFG correspondingly.
Note that the INSN should be deleted *after* removing dead edges, so
that the kept edge is the fallthrough edge for a (set (pc) (pc))
but not for a (set (pc) (label_ref FOO)).

References BARRIER_P, BB_END, BB_FOOTER, BLOCK_FOR_INSN(), current_ir_type(), delete_insn(), EDGE_COUNT, emit_barrier_after(), find_fallthru_edge(), gcc_assert, ggc_alloc(), IR_RTL_CFGLAYOUT, LABEL_P, NEXT_INSN(), next_nonnote_nondebug_insn(), PREV_INSN(), purge_dead_edges(), SET_NEXT_INSN(), SET_PREV_INSN(), single_succ_edge(), and basic_block_def::succs.

Referenced by try_combine().

Functions

Function Documentation

◆ bb_note()

◆ block_label()

◆ break_superblocks()

◆ can_fallthru()

◆ cfg_layout_finalize()

◆ cfg_layout_initialize()

◆ commit_edge_insertions()

◆ commit_one_edge_insertion()

◆ compute_bb_for_insn()

◆ contains_no_active_insn_p()

◆ create_basic_block_structure()

◆ delete_insn()

◆ delete_insn_and_edges()

◆ delete_insn_chain()

◆ duplicate_insn_chain()

◆ emit_barrier_after_bb()

◆ entry_of_function()

◆ find_bbs_reachable_by_hot_paths()

◆ fixup_abnormal_edges()

◆ fixup_partitions()

◆ force_nonfallthru_and_redirect()

◆ forwarder_block_p()

◆ free_bb_for_insn()

◆ get_last_bb_insn()

◆ init_rtl_bb_info()

◆ insert_insn_on_edge()

◆ prepend_insn_to_edge()

◆ print_rtl_with_bb()

◆ purge_all_dead_edges()

◆ purge_dead_edges()

◆ relink_block_chain()

◆ try_redirect_by_replacing_jump()

◆ unlink_insn_chain()

◆ update_bb_for_insn()

◆ update_br_prob_note()

◆ update_cfg_for_uncondjump()