4c33cb26d4
2005-04-25 J"orn Rennecke <joern.rennecke@st.com> Stephen Clarke <stevec@superh.com> Roger Sayle <roger@eyesopen.com> PR rtl-optimization/20413 * cfgrtl.c (redirect_edge_and_branch): Use Pmode instead of VOIDmode for LABEL_REF. * final.c (shorten_branches): Likewise. * jump.c (mark_all_labels, redirect_exp_1): Likewise. * loop.c (reg_dead_after_loop): Likewise. * varasm.c (decode_addr_const): Likewise. * doc/rtl.texi: Document mode requirement for LABEL_REF. Co-Authored-By: Roger Sayle <roger@eyesopen.com> Co-Authored-By: Stephen Clarke <stevec@superh.com> From-SVN: r98711
3123 lines
84 KiB
C
3123 lines
84 KiB
C
/* Control flow graph manipulation code for GNU compiler.
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Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
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1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 2, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING. If not, write to the Free
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Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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02111-1307, USA. */
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/* This file contains low level functions to manipulate the CFG and analyze it
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that are aware of the RTL intermediate language.
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Available functionality:
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- Basic CFG/RTL manipulation API documented in cfghooks.h
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- CFG-aware instruction chain manipulation
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delete_insn, delete_insn_chain
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- Edge splitting and committing to edges
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insert_insn_on_edge, commit_edge_insertions
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- CFG updating after insn simplification
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purge_dead_edges, purge_all_dead_edges
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Functions not supposed for generic use:
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- Infrastructure to determine quickly basic block for insn
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compute_bb_for_insn, update_bb_for_insn, set_block_for_insn,
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- Edge redirection with updating and optimizing of insn chain
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block_label, tidy_fallthru_edge, force_nonfallthru */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "tree.h"
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#include "rtl.h"
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#include "hard-reg-set.h"
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#include "basic-block.h"
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#include "regs.h"
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#include "flags.h"
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#include "output.h"
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#include "function.h"
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#include "except.h"
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#include "toplev.h"
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#include "tm_p.h"
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#include "obstack.h"
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#include "insn-config.h"
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#include "cfglayout.h"
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#include "expr.h"
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#include "target.h"
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#include "cfgloop.h"
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/* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */
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/* ??? Should probably be using LABEL_NUSES instead. It would take a
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bit of surgery to be able to use or co-opt the routines in jump. */
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rtx label_value_list;
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static int can_delete_note_p (rtx);
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static int can_delete_label_p (rtx);
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static void commit_one_edge_insertion (edge, int);
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static rtx last_loop_beg_note (rtx);
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static bool back_edge_of_syntactic_loop_p (basic_block, basic_block);
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static basic_block rtl_split_edge (edge);
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static bool rtl_move_block_after (basic_block, basic_block);
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static int rtl_verify_flow_info (void);
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static basic_block cfg_layout_split_block (basic_block, void *);
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static edge cfg_layout_redirect_edge_and_branch (edge, basic_block);
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static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block);
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static void cfg_layout_delete_block (basic_block);
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static void rtl_delete_block (basic_block);
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static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block);
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static edge rtl_redirect_edge_and_branch (edge, basic_block);
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static basic_block rtl_split_block (basic_block, void *);
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static void rtl_dump_bb (basic_block, FILE *, int);
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static int rtl_verify_flow_info_1 (void);
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static void mark_killed_regs (rtx, rtx, void *);
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static void rtl_make_forwarder_block (edge);
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/* Return true if NOTE is not one of the ones that must be kept paired,
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so that we may simply delete it. */
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static int
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can_delete_note_p (rtx note)
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{
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return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED
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|| NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK);
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}
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/* True if a given label can be deleted. */
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static int
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can_delete_label_p (rtx label)
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{
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return (!LABEL_PRESERVE_P (label)
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/* User declared labels must be preserved. */
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&& LABEL_NAME (label) == 0
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&& !in_expr_list_p (forced_labels, label)
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&& !in_expr_list_p (label_value_list, label));
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}
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/* Delete INSN by patching it out. Return the next insn. */
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rtx
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delete_insn (rtx insn)
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{
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rtx next = NEXT_INSN (insn);
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rtx note;
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bool really_delete = true;
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if (LABEL_P (insn))
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{
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/* Some labels can't be directly removed from the INSN chain, as they
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might be references via variables, constant pool etc.
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Convert them to the special NOTE_INSN_DELETED_LABEL note. */
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if (! can_delete_label_p (insn))
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{
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const char *name = LABEL_NAME (insn);
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really_delete = false;
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PUT_CODE (insn, NOTE);
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NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL;
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NOTE_DELETED_LABEL_NAME (insn) = name;
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}
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remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels);
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}
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if (really_delete)
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{
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/* If this insn has already been deleted, something is very wrong. */
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gcc_assert (!INSN_DELETED_P (insn));
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remove_insn (insn);
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INSN_DELETED_P (insn) = 1;
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}
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/* If deleting a jump, decrement the use count of the label. Deleting
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the label itself should happen in the normal course of block merging. */
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if (JUMP_P (insn)
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&& JUMP_LABEL (insn)
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&& LABEL_P (JUMP_LABEL (insn)))
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LABEL_NUSES (JUMP_LABEL (insn))--;
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/* Also if deleting an insn that references a label. */
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else
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{
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while ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX
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&& LABEL_P (XEXP (note, 0)))
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{
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LABEL_NUSES (XEXP (note, 0))--;
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remove_note (insn, note);
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}
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}
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if (JUMP_P (insn)
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&& (GET_CODE (PATTERN (insn)) == ADDR_VEC
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|| GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC))
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{
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rtx pat = PATTERN (insn);
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int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC;
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int len = XVECLEN (pat, diff_vec_p);
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int i;
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for (i = 0; i < len; i++)
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{
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rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0);
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/* When deleting code in bulk (e.g. removing many unreachable
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blocks) we can delete a label that's a target of the vector
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before deleting the vector itself. */
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if (!NOTE_P (label))
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LABEL_NUSES (label)--;
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}
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}
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return next;
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}
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/* Like delete_insn but also purge dead edges from BB. */
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rtx
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delete_insn_and_edges (rtx insn)
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{
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rtx x;
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bool purge = false;
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if (INSN_P (insn)
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&& BLOCK_FOR_INSN (insn)
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&& BB_END (BLOCK_FOR_INSN (insn)) == insn)
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purge = true;
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x = delete_insn (insn);
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if (purge)
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purge_dead_edges (BLOCK_FOR_INSN (insn));
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return x;
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}
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/* Unlink a chain of insns between START and FINISH, leaving notes
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that must be paired. */
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void
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delete_insn_chain (rtx start, rtx finish)
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{
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rtx next;
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/* Unchain the insns one by one. It would be quicker to delete all of these
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with a single unchaining, rather than one at a time, but we need to keep
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the NOTE's. */
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while (1)
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{
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next = NEXT_INSN (start);
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if (NOTE_P (start) && !can_delete_note_p (start))
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;
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else
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next = delete_insn (start);
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if (start == finish)
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break;
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start = next;
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}
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}
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/* Like delete_insn but also purge dead edges from BB. */
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void
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delete_insn_chain_and_edges (rtx first, rtx last)
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{
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bool purge = false;
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if (INSN_P (last)
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&& BLOCK_FOR_INSN (last)
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&& BB_END (BLOCK_FOR_INSN (last)) == last)
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purge = true;
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delete_insn_chain (first, last);
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if (purge)
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purge_dead_edges (BLOCK_FOR_INSN (last));
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}
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/* Create a new basic block consisting of the instructions between HEAD and END
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inclusive. This function is designed to allow fast BB construction - reuses
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the note and basic block struct in BB_NOTE, if any and do not grow
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BASIC_BLOCK chain and should be used directly only by CFG construction code.
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END can be NULL in to create new empty basic block before HEAD. Both END
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and HEAD can be NULL to create basic block at the end of INSN chain.
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AFTER is the basic block we should be put after. */
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basic_block
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create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after)
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{
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basic_block bb;
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if (bb_note
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&& (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL
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&& bb->aux == NULL)
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{
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/* If we found an existing note, thread it back onto the chain. */
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rtx after;
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if (LABEL_P (head))
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after = head;
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else
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{
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after = PREV_INSN (head);
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head = bb_note;
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}
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if (after != bb_note && NEXT_INSN (after) != bb_note)
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reorder_insns_nobb (bb_note, bb_note, after);
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}
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else
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{
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/* Otherwise we must create a note and a basic block structure. */
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bb = alloc_block ();
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if (!head && !end)
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head = end = bb_note
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= emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ());
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else if (LABEL_P (head) && end)
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{
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bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head);
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if (head == end)
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end = bb_note;
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}
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else
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{
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bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head);
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head = bb_note;
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if (!end)
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end = head;
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}
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NOTE_BASIC_BLOCK (bb_note) = bb;
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}
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/* Always include the bb note in the block. */
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if (NEXT_INSN (end) == bb_note)
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end = bb_note;
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BB_HEAD (bb) = head;
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BB_END (bb) = end;
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bb->index = last_basic_block++;
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bb->flags = BB_NEW;
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link_block (bb, after);
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BASIC_BLOCK (bb->index) = bb;
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update_bb_for_insn (bb);
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BB_SET_PARTITION (bb, BB_UNPARTITIONED);
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/* Tag the block so that we know it has been used when considering
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other basic block notes. */
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bb->aux = bb;
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return bb;
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}
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/* Create new basic block consisting of instructions in between HEAD and END
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and place it to the BB chain after block AFTER. END can be NULL in to
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create new empty basic block before HEAD. Both END and HEAD can be NULL to
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create basic block at the end of INSN chain. */
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static basic_block
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rtl_create_basic_block (void *headp, void *endp, basic_block after)
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{
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rtx head = headp, end = endp;
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basic_block bb;
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/* Grow the basic block array if needed. */
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if ((size_t) last_basic_block >= VARRAY_SIZE (basic_block_info))
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{
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size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
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VARRAY_GROW (basic_block_info, new_size);
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}
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n_basic_blocks++;
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bb = create_basic_block_structure (head, end, NULL, after);
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bb->aux = NULL;
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return bb;
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}
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static basic_block
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cfg_layout_create_basic_block (void *head, void *end, basic_block after)
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{
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basic_block newbb = rtl_create_basic_block (head, end, after);
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initialize_bb_rbi (newbb);
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return newbb;
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}
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/* Delete the insns in a (non-live) block. We physically delete every
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non-deleted-note insn, and update the flow graph appropriately.
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Return nonzero if we deleted an exception handler. */
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/* ??? Preserving all such notes strikes me as wrong. It would be nice
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to post-process the stream to remove empty blocks, loops, ranges, etc. */
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static void
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rtl_delete_block (basic_block b)
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{
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rtx insn, end, tmp;
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/* If the head of this block is a CODE_LABEL, then it might be the
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label for an exception handler which can't be reached. We need
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to remove the label from the exception_handler_label list. */
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insn = BB_HEAD (b);
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if (LABEL_P (insn))
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maybe_remove_eh_handler (insn);
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/* Include any jump table following the basic block. */
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end = BB_END (b);
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if (tablejump_p (end, NULL, &tmp))
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end = tmp;
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/* Include any barriers that may follow the basic block. */
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tmp = next_nonnote_insn (end);
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while (tmp && BARRIER_P (tmp))
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{
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end = tmp;
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tmp = next_nonnote_insn (end);
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}
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/* Selectively delete the entire chain. */
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BB_HEAD (b) = NULL;
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delete_insn_chain (insn, end);
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}
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/* Records the basic block struct in BLOCK_FOR_INSN for every insn. */
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void
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compute_bb_for_insn (void)
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{
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basic_block bb;
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FOR_EACH_BB (bb)
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{
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rtx end = BB_END (bb);
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rtx insn;
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for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn))
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{
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BLOCK_FOR_INSN (insn) = bb;
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if (insn == end)
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break;
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}
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}
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}
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|
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/* Release the basic_block_for_insn array. */
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void
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free_bb_for_insn (void)
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{
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rtx insn;
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for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
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if (!BARRIER_P (insn))
|
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BLOCK_FOR_INSN (insn) = NULL;
|
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}
|
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|
||
/* Return RTX to emit after when we want to emit code on the entry of function. */
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rtx
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entry_of_function (void)
|
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{
|
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return (n_basic_blocks ? BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : get_insns ());
|
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}
|
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|
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/* Update insns block within BB. */
|
||
|
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void
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update_bb_for_insn (basic_block bb)
|
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{
|
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rtx insn;
|
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|
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for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn))
|
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{
|
||
if (!BARRIER_P (insn))
|
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set_block_for_insn (insn, bb);
|
||
if (insn == BB_END (bb))
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Creates a new basic block just after basic block B by splitting
|
||
everything after specified instruction I. */
|
||
|
||
static basic_block
|
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rtl_split_block (basic_block bb, void *insnp)
|
||
{
|
||
basic_block new_bb;
|
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rtx insn = insnp;
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
if (!insn)
|
||
{
|
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insn = first_insn_after_basic_block_note (bb);
|
||
|
||
if (insn)
|
||
insn = PREV_INSN (insn);
|
||
else
|
||
insn = get_last_insn ();
|
||
}
|
||
|
||
/* We probably should check type of the insn so that we do not create
|
||
inconsistent cfg. It is checked in verify_flow_info anyway, so do not
|
||
bother. */
|
||
if (insn == BB_END (bb))
|
||
emit_note_after (NOTE_INSN_DELETED, insn);
|
||
|
||
/* Create the new basic block. */
|
||
new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb);
|
||
BB_COPY_PARTITION (new_bb, bb);
|
||
BB_END (bb) = insn;
|
||
|
||
/* Redirect the outgoing edges. */
|
||
new_bb->succs = bb->succs;
|
||
bb->succs = NULL;
|
||
FOR_EACH_EDGE (e, ei, new_bb->succs)
|
||
e->src = new_bb;
|
||
|
||
if (bb->global_live_at_start)
|
||
{
|
||
new_bb->global_live_at_start = ALLOC_REG_SET (®_obstack);
|
||
new_bb->global_live_at_end = ALLOC_REG_SET (®_obstack);
|
||
COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end);
|
||
|
||
/* We now have to calculate which registers are live at the end
|
||
of the split basic block and at the start of the new basic
|
||
block. Start with those registers that are known to be live
|
||
at the end of the original basic block and get
|
||
propagate_block to determine which registers are live. */
|
||
COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_end);
|
||
propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0);
|
||
COPY_REG_SET (bb->global_live_at_end,
|
||
new_bb->global_live_at_start);
|
||
#ifdef HAVE_conditional_execution
|
||
/* In the presence of conditional execution we are not able to update
|
||
liveness precisely. */
|
||
if (reload_completed)
|
||
{
|
||
bb->flags |= BB_DIRTY;
|
||
new_bb->flags |= BB_DIRTY;
|
||
}
|
||
#endif
|
||
}
|
||
|
||
return new_bb;
|
||
}
|
||
|
||
/* Blocks A and B are to be merged into a single block A. The insns
|
||
are already contiguous. */
|
||
|
||
static void
|
||
rtl_merge_blocks (basic_block a, basic_block b)
|
||
{
|
||
rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a);
|
||
rtx del_first = NULL_RTX, del_last = NULL_RTX;
|
||
int b_empty = 0;
|
||
|
||
/* If there was a CODE_LABEL beginning B, delete it. */
|
||
if (LABEL_P (b_head))
|
||
{
|
||
/* Detect basic blocks with nothing but a label. This can happen
|
||
in particular at the end of a function. */
|
||
if (b_head == b_end)
|
||
b_empty = 1;
|
||
|
||
del_first = del_last = b_head;
|
||
b_head = NEXT_INSN (b_head);
|
||
}
|
||
|
||
/* Delete the basic block note and handle blocks containing just that
|
||
note. */
|
||
if (NOTE_INSN_BASIC_BLOCK_P (b_head))
|
||
{
|
||
if (b_head == b_end)
|
||
b_empty = 1;
|
||
if (! del_last)
|
||
del_first = b_head;
|
||
|
||
del_last = b_head;
|
||
b_head = NEXT_INSN (b_head);
|
||
}
|
||
|
||
/* If there was a jump out of A, delete it. */
|
||
if (JUMP_P (a_end))
|
||
{
|
||
rtx prev;
|
||
|
||
for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev))
|
||
if (!NOTE_P (prev)
|
||
|| NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK
|
||
|| prev == BB_HEAD (a))
|
||
break;
|
||
|
||
del_first = a_end;
|
||
|
||
#ifdef HAVE_cc0
|
||
/* If this was a conditional jump, we need to also delete
|
||
the insn that set cc0. */
|
||
if (only_sets_cc0_p (prev))
|
||
{
|
||
rtx tmp = prev;
|
||
|
||
prev = prev_nonnote_insn (prev);
|
||
if (!prev)
|
||
prev = BB_HEAD (a);
|
||
del_first = tmp;
|
||
}
|
||
#endif
|
||
|
||
a_end = PREV_INSN (del_first);
|
||
}
|
||
else if (BARRIER_P (NEXT_INSN (a_end)))
|
||
del_first = NEXT_INSN (a_end);
|
||
|
||
/* Delete everything marked above as well as crap that might be
|
||
hanging out between the two blocks. */
|
||
BB_HEAD (b) = NULL;
|
||
delete_insn_chain (del_first, del_last);
|
||
|
||
/* Reassociate the insns of B with A. */
|
||
if (!b_empty)
|
||
{
|
||
rtx x;
|
||
|
||
for (x = a_end; x != b_end; x = NEXT_INSN (x))
|
||
set_block_for_insn (x, a);
|
||
|
||
set_block_for_insn (b_end, a);
|
||
|
||
a_end = b_end;
|
||
}
|
||
|
||
BB_END (a) = a_end;
|
||
}
|
||
|
||
/* Return true when block A and B can be merged. */
|
||
static bool
|
||
rtl_can_merge_blocks (basic_block a,basic_block b)
|
||
{
|
||
/* If we are partitioning hot/cold basic blocks, we don't want to
|
||
mess up unconditional or indirect jumps that cross between hot
|
||
and cold sections.
|
||
|
||
Basic block partitioning may result in some jumps that appear to
|
||
be optimizable (or blocks that appear to be mergeable), but which really
|
||
must be left untouched (they are required to make it safely across
|
||
partition boundaries). See the comments at the top of
|
||
bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
|
||
|
||
if (BB_PARTITION (a) != BB_PARTITION (b))
|
||
return false;
|
||
|
||
/* There must be exactly one edge in between the blocks. */
|
||
return (single_succ_p (a)
|
||
&& single_succ (a) == b
|
||
&& single_pred_p (b)
|
||
&& a != b
|
||
/* Must be simple edge. */
|
||
&& !(single_succ_edge (a)->flags & EDGE_COMPLEX)
|
||
&& a->next_bb == b
|
||
&& a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR
|
||
/* If the jump insn has side effects,
|
||
we can't kill the edge. */
|
||
&& (!JUMP_P (BB_END (a))
|
||
|| (reload_completed
|
||
? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a)))));
|
||
}
|
||
|
||
/* Return the label in the head of basic block BLOCK. Create one if it doesn't
|
||
exist. */
|
||
|
||
rtx
|
||
block_label (basic_block block)
|
||
{
|
||
if (block == EXIT_BLOCK_PTR)
|
||
return NULL_RTX;
|
||
|
||
if (!LABEL_P (BB_HEAD (block)))
|
||
{
|
||
BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block));
|
||
}
|
||
|
||
return BB_HEAD (block);
|
||
}
|
||
|
||
/* 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. */
|
||
|
||
edge
|
||
try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout)
|
||
{
|
||
basic_block src = e->src;
|
||
rtx insn = BB_END (src), kill_from;
|
||
rtx set;
|
||
int fallthru = 0;
|
||
|
||
/* If we are partitioning hot/cold basic blocks, we don't want to
|
||
mess up unconditional or indirect jumps that cross between hot
|
||
and cold sections.
|
||
|
||
Basic block partitioning may result in some jumps that appear to
|
||
be optimizable (or blocks that appear to be mergeable), but which really
|
||
must be left untouched (they are required to make it safely across
|
||
partition boundaries). See the comments at the top of
|
||
bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
|
||
|
||
if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX)
|
||
|| BB_PARTITION (src) != BB_PARTITION (target))
|
||
return NULL;
|
||
|
||
/* We can replace or remove a complex jump only when we have exactly
|
||
two edges. Also, if we have exactly one outgoing edge, we can
|
||
redirect that. */
|
||
if (EDGE_COUNT (src->succs) >= 3
|
||
/* Verify that all targets will be TARGET. Specifically, the
|
||
edge that is not E must also go to TARGET. */
|
||
|| (EDGE_COUNT (src->succs) == 2
|
||
&& EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target))
|
||
return NULL;
|
||
|
||
if (!onlyjump_p (insn))
|
||
return NULL;
|
||
if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL))
|
||
return NULL;
|
||
|
||
/* Avoid removing branch with side effects. */
|
||
set = single_set (insn);
|
||
if (!set || side_effects_p (set))
|
||
return NULL;
|
||
|
||
/* In case we zap a conditional jump, we'll need to kill
|
||
the cc0 setter too. */
|
||
kill_from = insn;
|
||
#ifdef HAVE_cc0
|
||
if (reg_mentioned_p (cc0_rtx, PATTERN (insn)))
|
||
kill_from = PREV_INSN (insn);
|
||
#endif
|
||
|
||
/* See if we can create the fallthru edge. */
|
||
if (in_cfglayout || can_fallthru (src, target))
|
||
{
|
||
if (dump_file)
|
||
fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn));
|
||
fallthru = 1;
|
||
|
||
/* Selectively unlink whole insn chain. */
|
||
if (in_cfglayout)
|
||
{
|
||
rtx insn = src->rbi->footer;
|
||
|
||
delete_insn_chain (kill_from, BB_END (src));
|
||
|
||
/* Remove barriers but keep jumptables. */
|
||
while (insn)
|
||
{
|
||
if (BARRIER_P (insn))
|
||
{
|
||
if (PREV_INSN (insn))
|
||
NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn);
|
||
else
|
||
src->rbi->footer = NEXT_INSN (insn);
|
||
if (NEXT_INSN (insn))
|
||
PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn);
|
||
}
|
||
if (LABEL_P (insn))
|
||
break;
|
||
insn = NEXT_INSN (insn);
|
||
}
|
||
}
|
||
else
|
||
delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target)));
|
||
}
|
||
|
||
/* If this already is simplejump, redirect it. */
|
||
else if (simplejump_p (insn))
|
||
{
|
||
if (e->dest == target)
|
||
return NULL;
|
||
if (dump_file)
|
||
fprintf (dump_file, "Redirecting jump %i from %i to %i.\n",
|
||
INSN_UID (insn), e->dest->index, target->index);
|
||
if (!redirect_jump (insn, block_label (target), 0))
|
||
{
|
||
gcc_assert (target == EXIT_BLOCK_PTR);
|
||
return NULL;
|
||
}
|
||
}
|
||
|
||
/* Cannot do anything for target exit block. */
|
||
else if (target == EXIT_BLOCK_PTR)
|
||
return NULL;
|
||
|
||
/* Or replace possibly complicated jump insn by simple jump insn. */
|
||
else
|
||
{
|
||
rtx target_label = block_label (target);
|
||
rtx barrier, label, table;
|
||
|
||
emit_jump_insn_after_noloc (gen_jump (target_label), insn);
|
||
JUMP_LABEL (BB_END (src)) = target_label;
|
||
LABEL_NUSES (target_label)++;
|
||
if (dump_file)
|
||
fprintf (dump_file, "Replacing insn %i by jump %i\n",
|
||
INSN_UID (insn), INSN_UID (BB_END (src)));
|
||
|
||
|
||
delete_insn_chain (kill_from, insn);
|
||
|
||
/* Recognize a tablejump that we are converting to a
|
||
simple jump and remove its associated CODE_LABEL
|
||
and ADDR_VEC or ADDR_DIFF_VEC. */
|
||
if (tablejump_p (insn, &label, &table))
|
||
delete_insn_chain (label, table);
|
||
|
||
barrier = next_nonnote_insn (BB_END (src));
|
||
if (!barrier || !BARRIER_P (barrier))
|
||
emit_barrier_after (BB_END (src));
|
||
else
|
||
{
|
||
if (barrier != NEXT_INSN (BB_END (src)))
|
||
{
|
||
/* Move the jump before barrier so that the notes
|
||
which originally were or were created before jump table are
|
||
inside the basic block. */
|
||
rtx new_insn = BB_END (src);
|
||
rtx tmp;
|
||
|
||
for (tmp = NEXT_INSN (BB_END (src)); tmp != barrier;
|
||
tmp = NEXT_INSN (tmp))
|
||
set_block_for_insn (tmp, src);
|
||
|
||
NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn);
|
||
PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn);
|
||
|
||
NEXT_INSN (new_insn) = barrier;
|
||
NEXT_INSN (PREV_INSN (barrier)) = new_insn;
|
||
|
||
PREV_INSN (new_insn) = PREV_INSN (barrier);
|
||
PREV_INSN (barrier) = new_insn;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Keep only one edge out and set proper flags. */
|
||
if (!single_succ_p (src))
|
||
remove_edge (e);
|
||
gcc_assert (single_succ_p (src));
|
||
|
||
e = single_succ_edge (src);
|
||
if (fallthru)
|
||
e->flags = EDGE_FALLTHRU;
|
||
else
|
||
e->flags = 0;
|
||
|
||
e->probability = REG_BR_PROB_BASE;
|
||
e->count = src->count;
|
||
|
||
/* We don't want a block to end on a line-number note since that has
|
||
the potential of changing the code between -g and not -g. */
|
||
while (NOTE_P (BB_END (e->src))
|
||
&& NOTE_LINE_NUMBER (BB_END (e->src)) >= 0)
|
||
delete_insn (BB_END (e->src));
|
||
|
||
if (e->dest != target)
|
||
redirect_edge_succ (e, target);
|
||
|
||
return e;
|
||
}
|
||
|
||
/* Return last loop_beg note appearing after INSN, before start of next
|
||
basic block. Return INSN if there are no such notes.
|
||
|
||
When emitting jump to redirect a fallthru edge, it should always appear
|
||
after the LOOP_BEG notes, as loop optimizer expect loop to either start by
|
||
fallthru edge or jump following the LOOP_BEG note jumping to the loop exit
|
||
test. */
|
||
|
||
static rtx
|
||
last_loop_beg_note (rtx insn)
|
||
{
|
||
rtx last = insn;
|
||
|
||
for (insn = NEXT_INSN (insn); insn && NOTE_P (insn)
|
||
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK;
|
||
insn = NEXT_INSN (insn))
|
||
if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
|
||
last = insn;
|
||
|
||
return last;
|
||
}
|
||
|
||
/* Redirect edge representing branch of (un)conditional jump or tablejump,
|
||
NULL on failure */
|
||
static edge
|
||
redirect_branch_edge (edge e, basic_block target)
|
||
{
|
||
rtx tmp;
|
||
rtx old_label = BB_HEAD (e->dest);
|
||
basic_block src = e->src;
|
||
rtx insn = BB_END (src);
|
||
|
||
/* We can only redirect non-fallthru edges of jump insn. */
|
||
if (e->flags & EDGE_FALLTHRU)
|
||
return NULL;
|
||
else if (!JUMP_P (insn))
|
||
return NULL;
|
||
|
||
/* Recognize a tablejump and adjust all matching cases. */
|
||
if (tablejump_p (insn, NULL, &tmp))
|
||
{
|
||
rtvec vec;
|
||
int j;
|
||
rtx new_label = block_label (target);
|
||
|
||
if (target == EXIT_BLOCK_PTR)
|
||
return NULL;
|
||
if (GET_CODE (PATTERN (tmp)) == ADDR_VEC)
|
||
vec = XVEC (PATTERN (tmp), 0);
|
||
else
|
||
vec = XVEC (PATTERN (tmp), 1);
|
||
|
||
for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j)
|
||
if (XEXP (RTVEC_ELT (vec, j), 0) == old_label)
|
||
{
|
||
RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label);
|
||
--LABEL_NUSES (old_label);
|
||
++LABEL_NUSES (new_label);
|
||
}
|
||
|
||
/* Handle casesi dispatch insns. */
|
||
if ((tmp = single_set (insn)) != NULL
|
||
&& SET_DEST (tmp) == pc_rtx
|
||
&& GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE
|
||
&& GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF
|
||
&& XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label)
|
||
{
|
||
XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode,
|
||
new_label);
|
||
--LABEL_NUSES (old_label);
|
||
++LABEL_NUSES (new_label);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* ?? We may play the games with moving the named labels from
|
||
one basic block to the other in case only one computed_jump is
|
||
available. */
|
||
if (computed_jump_p (insn)
|
||
/* A return instruction can't be redirected. */
|
||
|| returnjump_p (insn))
|
||
return NULL;
|
||
|
||
/* If the insn doesn't go where we think, we're confused. */
|
||
gcc_assert (JUMP_LABEL (insn) == old_label);
|
||
|
||
/* If the substitution doesn't succeed, die. This can happen
|
||
if the back end emitted unrecognizable instructions or if
|
||
target is exit block on some arches. */
|
||
if (!redirect_jump (insn, block_label (target), 0))
|
||
{
|
||
gcc_assert (target == EXIT_BLOCK_PTR);
|
||
return NULL;
|
||
}
|
||
}
|
||
|
||
if (dump_file)
|
||
fprintf (dump_file, "Edge %i->%i redirected to %i\n",
|
||
e->src->index, e->dest->index, target->index);
|
||
|
||
if (e->dest != target)
|
||
e = redirect_edge_succ_nodup (e, target);
|
||
return e;
|
||
}
|
||
|
||
/* Attempt to change code to redirect edge E to TARGET. Don't do that on
|
||
expense of adding new instructions or reordering basic blocks.
|
||
|
||
Function can be also called with edge destination equivalent to the TARGET.
|
||
Then it should try the simplifications and do nothing if none is possible.
|
||
|
||
Return edge representing the branch if transformation succeeded. Return NULL
|
||
on failure.
|
||
We still return NULL in case E already destinated TARGET and we didn't
|
||
managed to simplify instruction stream. */
|
||
|
||
static edge
|
||
rtl_redirect_edge_and_branch (edge e, basic_block target)
|
||
{
|
||
edge ret;
|
||
basic_block src = e->src;
|
||
|
||
if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
|
||
return NULL;
|
||
|
||
if (e->dest == target)
|
||
return e;
|
||
|
||
if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL)
|
||
{
|
||
src->flags |= BB_DIRTY;
|
||
return ret;
|
||
}
|
||
|
||
ret = redirect_branch_edge (e, target);
|
||
if (!ret)
|
||
return NULL;
|
||
|
||
src->flags |= BB_DIRTY;
|
||
return ret;
|
||
}
|
||
|
||
/* Like force_nonfallthru below, but additionally performs redirection
|
||
Used by redirect_edge_and_branch_force. */
|
||
|
||
static basic_block
|
||
force_nonfallthru_and_redirect (edge e, basic_block target)
|
||
{
|
||
basic_block jump_block, new_bb = NULL, src = e->src;
|
||
rtx note;
|
||
edge new_edge;
|
||
int abnormal_edge_flags = 0;
|
||
|
||
/* In the case the last instruction is conditional jump to the next
|
||
instruction, first redirect the jump itself and then continue
|
||
by creating a basic block afterwards to redirect fallthru edge. */
|
||
if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR
|
||
&& any_condjump_p (BB_END (e->src))
|
||
/* When called from cfglayout, fallthru edges do not
|
||
necessarily go to the next block. */
|
||
&& e->src->next_bb == e->dest
|
||
&& JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest))
|
||
{
|
||
rtx note;
|
||
edge b = unchecked_make_edge (e->src, target, 0);
|
||
bool redirected;
|
||
|
||
redirected = redirect_jump (BB_END (e->src), block_label (target), 0);
|
||
gcc_assert (redirected);
|
||
|
||
note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX);
|
||
if (note)
|
||
{
|
||
int prob = INTVAL (XEXP (note, 0));
|
||
|
||
b->probability = prob;
|
||
b->count = e->count * prob / REG_BR_PROB_BASE;
|
||
e->probability -= e->probability;
|
||
e->count -= b->count;
|
||
if (e->probability < 0)
|
||
e->probability = 0;
|
||
if (e->count < 0)
|
||
e->count = 0;
|
||
}
|
||
}
|
||
|
||
if (e->flags & EDGE_ABNORMAL)
|
||
{
|
||
/* Irritating special case - fallthru edge to the same block as abnormal
|
||
edge.
|
||
We can't redirect abnormal edge, but we still can split the fallthru
|
||
one and create separate abnormal edge to original destination.
|
||
This allows bb-reorder to make such edge non-fallthru. */
|
||
gcc_assert (e->dest == target);
|
||
abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU);
|
||
e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU;
|
||
}
|
||
else
|
||
{
|
||
gcc_assert (e->flags & EDGE_FALLTHRU);
|
||
if (e->src == ENTRY_BLOCK_PTR)
|
||
{
|
||
/* We can't redirect the entry block. Create an empty block
|
||
at the start of the function which we use to add the new
|
||
jump. */
|
||
edge tmp;
|
||
edge_iterator ei;
|
||
bool found = false;
|
||
|
||
basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR);
|
||
|
||
/* Change the existing edge's source to be the new block, and add
|
||
a new edge from the entry block to the new block. */
|
||
e->src = bb;
|
||
for (ei = ei_start (ENTRY_BLOCK_PTR->succs); (tmp = ei_safe_edge (ei)); )
|
||
{
|
||
if (tmp == e)
|
||
{
|
||
VEC_unordered_remove (edge, ENTRY_BLOCK_PTR->succs, ei.index);
|
||
found = true;
|
||
break;
|
||
}
|
||
else
|
||
ei_next (&ei);
|
||
}
|
||
|
||
gcc_assert (found);
|
||
|
||
VEC_safe_push (edge, gc, bb->succs, e);
|
||
make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU);
|
||
}
|
||
}
|
||
|
||
if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags)
|
||
{
|
||
/* Create the new structures. */
|
||
|
||
/* If the old block ended with a tablejump, skip its table
|
||
by searching forward from there. Otherwise start searching
|
||
forward from the last instruction of the old block. */
|
||
if (!tablejump_p (BB_END (e->src), NULL, ¬e))
|
||
note = BB_END (e->src);
|
||
|
||
/* Position the new block correctly relative to loop notes. */
|
||
note = last_loop_beg_note (note);
|
||
note = NEXT_INSN (note);
|
||
|
||
jump_block = create_basic_block (note, NULL, e->src);
|
||
jump_block->count = e->count;
|
||
jump_block->frequency = EDGE_FREQUENCY (e);
|
||
jump_block->loop_depth = target->loop_depth;
|
||
|
||
if (target->global_live_at_start)
|
||
{
|
||
jump_block->global_live_at_start = ALLOC_REG_SET (®_obstack);
|
||
jump_block->global_live_at_end = ALLOC_REG_SET (®_obstack);
|
||
COPY_REG_SET (jump_block->global_live_at_start,
|
||
target->global_live_at_start);
|
||
COPY_REG_SET (jump_block->global_live_at_end,
|
||
target->global_live_at_start);
|
||
}
|
||
|
||
/* Make sure new block ends up in correct hot/cold section. */
|
||
|
||
BB_COPY_PARTITION (jump_block, e->src);
|
||
if (flag_reorder_blocks_and_partition
|
||
&& targetm.have_named_sections
|
||
&& JUMP_P (BB_END (jump_block))
|
||
&& !any_condjump_p (BB_END (jump_block))
|
||
&& (EDGE_SUCC (jump_block, 0)->flags & EDGE_CROSSING))
|
||
REG_NOTES (BB_END (jump_block)) = gen_rtx_EXPR_LIST (REG_CROSSING_JUMP,
|
||
NULL_RTX,
|
||
REG_NOTES
|
||
(BB_END
|
||
(jump_block)));
|
||
|
||
/* Wire edge in. */
|
||
new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU);
|
||
new_edge->probability = e->probability;
|
||
new_edge->count = e->count;
|
||
|
||
/* Redirect old edge. */
|
||
redirect_edge_pred (e, jump_block);
|
||
e->probability = REG_BR_PROB_BASE;
|
||
|
||
new_bb = jump_block;
|
||
}
|
||
else
|
||
jump_block = e->src;
|
||
|
||
e->flags &= ~EDGE_FALLTHRU;
|
||
if (target == EXIT_BLOCK_PTR)
|
||
{
|
||
#ifdef HAVE_return
|
||
emit_jump_insn_after_noloc (gen_return (), BB_END (jump_block));
|
||
#else
|
||
gcc_unreachable ();
|
||
#endif
|
||
}
|
||
else
|
||
{
|
||
rtx label = block_label (target);
|
||
emit_jump_insn_after_noloc (gen_jump (label), BB_END (jump_block));
|
||
JUMP_LABEL (BB_END (jump_block)) = label;
|
||
LABEL_NUSES (label)++;
|
||
}
|
||
|
||
emit_barrier_after (BB_END (jump_block));
|
||
redirect_edge_succ_nodup (e, target);
|
||
|
||
if (abnormal_edge_flags)
|
||
make_edge (src, target, abnormal_edge_flags);
|
||
|
||
return new_bb;
|
||
}
|
||
|
||
/* Edge E is assumed to be fallthru edge. Emit needed jump instruction
|
||
(and possibly create new basic block) to make edge non-fallthru.
|
||
Return newly created BB or NULL if none. */
|
||
|
||
basic_block
|
||
force_nonfallthru (edge e)
|
||
{
|
||
return force_nonfallthru_and_redirect (e, e->dest);
|
||
}
|
||
|
||
/* Redirect edge even at the expense of creating new jump insn or
|
||
basic block. Return new basic block if created, NULL otherwise.
|
||
Conversion must be possible. */
|
||
|
||
static basic_block
|
||
rtl_redirect_edge_and_branch_force (edge e, basic_block target)
|
||
{
|
||
if (redirect_edge_and_branch (e, target)
|
||
|| e->dest == target)
|
||
return NULL;
|
||
|
||
/* In case the edge redirection failed, try to force it to be non-fallthru
|
||
and redirect newly created simplejump. */
|
||
return force_nonfallthru_and_redirect (e, target);
|
||
}
|
||
|
||
/* The given edge should potentially be a fallthru edge. If that is in
|
||
fact true, delete the jump and barriers that are in the way. */
|
||
|
||
static void
|
||
rtl_tidy_fallthru_edge (edge e)
|
||
{
|
||
rtx q;
|
||
basic_block b = e->src, c = b->next_bb;
|
||
|
||
/* ??? In a late-running flow pass, other folks may have deleted basic
|
||
blocks by nopping out blocks, leaving multiple BARRIERs between here
|
||
and the target label. They ought to be chastized and fixed.
|
||
|
||
We can also wind up with a sequence of undeletable labels between
|
||
one block and the next.
|
||
|
||
So search through a sequence of barriers, labels, and notes for
|
||
the head of block C and assert that we really do fall through. */
|
||
|
||
for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q))
|
||
if (INSN_P (q))
|
||
return;
|
||
|
||
/* Remove what will soon cease being the jump insn from the source block.
|
||
If block B consisted only of this single jump, turn it into a deleted
|
||
note. */
|
||
q = BB_END (b);
|
||
if (JUMP_P (q)
|
||
&& onlyjump_p (q)
|
||
&& (any_uncondjump_p (q)
|
||
|| single_succ_p (b)))
|
||
{
|
||
#ifdef HAVE_cc0
|
||
/* If this was a conditional jump, we need to also delete
|
||
the insn that set cc0. */
|
||
if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q)))
|
||
q = PREV_INSN (q);
|
||
#endif
|
||
|
||
q = PREV_INSN (q);
|
||
|
||
/* We don't want a block to end on a line-number note since that has
|
||
the potential of changing the code between -g and not -g. */
|
||
while (NOTE_P (q) && NOTE_LINE_NUMBER (q) >= 0)
|
||
q = PREV_INSN (q);
|
||
}
|
||
|
||
/* Selectively unlink the sequence. */
|
||
if (q != PREV_INSN (BB_HEAD (c)))
|
||
delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c)));
|
||
|
||
e->flags |= EDGE_FALLTHRU;
|
||
}
|
||
|
||
/* Helper function for split_edge. Return true in case edge BB2 to BB1
|
||
is back edge of syntactic loop. */
|
||
|
||
static bool
|
||
back_edge_of_syntactic_loop_p (basic_block bb1, basic_block bb2)
|
||
{
|
||
rtx insn;
|
||
int count = 0;
|
||
basic_block bb;
|
||
|
||
if (bb1 == bb2)
|
||
return true;
|
||
|
||
/* ??? Could we guarantee that bb indices are monotone, so that we could
|
||
just compare them? */
|
||
for (bb = bb1; bb && bb != bb2; bb = bb->next_bb)
|
||
continue;
|
||
|
||
if (!bb)
|
||
return false;
|
||
|
||
for (insn = BB_END (bb1); insn != BB_HEAD (bb2) && count >= 0;
|
||
insn = NEXT_INSN (insn))
|
||
if (NOTE_P (insn))
|
||
{
|
||
if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
|
||
count++;
|
||
else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END)
|
||
count--;
|
||
}
|
||
|
||
return count >= 0;
|
||
}
|
||
|
||
/* Should move basic block BB after basic block AFTER. NIY. */
|
||
|
||
static bool
|
||
rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED,
|
||
basic_block after ATTRIBUTE_UNUSED)
|
||
{
|
||
return false;
|
||
}
|
||
|
||
/* Split a (typically critical) edge. Return the new block.
|
||
The edge must not be abnormal.
|
||
|
||
??? The code generally expects to be called on critical edges.
|
||
The case of a block ending in an unconditional jump to a
|
||
block with multiple predecessors is not handled optimally. */
|
||
|
||
static basic_block
|
||
rtl_split_edge (edge edge_in)
|
||
{
|
||
basic_block bb;
|
||
rtx before;
|
||
|
||
/* Abnormal edges cannot be split. */
|
||
gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
|
||
|
||
/* We are going to place the new block in front of edge destination.
|
||
Avoid existence of fallthru predecessors. */
|
||
if ((edge_in->flags & EDGE_FALLTHRU) == 0)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
FOR_EACH_EDGE (e, ei, edge_in->dest->preds)
|
||
if (e->flags & EDGE_FALLTHRU)
|
||
break;
|
||
|
||
if (e)
|
||
force_nonfallthru (e);
|
||
}
|
||
|
||
/* Create the basic block note.
|
||
|
||
Where we place the note can have a noticeable impact on the generated
|
||
code. Consider this cfg:
|
||
|
||
E
|
||
|
|
||
0
|
||
/ \
|
||
+->1-->2--->E
|
||
| |
|
||
+--+
|
||
|
||
If we need to insert an insn on the edge from block 0 to block 1,
|
||
we want to ensure the instructions we insert are outside of any
|
||
loop notes that physically sit between block 0 and block 1. Otherwise
|
||
we confuse the loop optimizer into thinking the loop is a phony. */
|
||
|
||
if (edge_in->dest != EXIT_BLOCK_PTR
|
||
&& PREV_INSN (BB_HEAD (edge_in->dest))
|
||
&& NOTE_P (PREV_INSN (BB_HEAD (edge_in->dest)))
|
||
&& (NOTE_LINE_NUMBER (PREV_INSN (BB_HEAD (edge_in->dest)))
|
||
== NOTE_INSN_LOOP_BEG)
|
||
&& !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src))
|
||
before = PREV_INSN (BB_HEAD (edge_in->dest));
|
||
else if (edge_in->dest != EXIT_BLOCK_PTR)
|
||
before = BB_HEAD (edge_in->dest);
|
||
else
|
||
before = NULL_RTX;
|
||
|
||
/* If this is a fall through edge to the exit block, the blocks might be
|
||
not adjacent, and the right place is the after the source. */
|
||
if (edge_in->flags & EDGE_FALLTHRU && edge_in->dest == EXIT_BLOCK_PTR)
|
||
{
|
||
before = NEXT_INSN (BB_END (edge_in->src));
|
||
if (before
|
||
&& NOTE_P (before)
|
||
&& NOTE_LINE_NUMBER (before) == NOTE_INSN_LOOP_END)
|
||
before = NEXT_INSN (before);
|
||
bb = create_basic_block (before, NULL, edge_in->src);
|
||
BB_COPY_PARTITION (bb, edge_in->src);
|
||
}
|
||
else
|
||
{
|
||
bb = create_basic_block (before, NULL, edge_in->dest->prev_bb);
|
||
/* ??? Why not edge_in->dest->prev_bb here? */
|
||
BB_COPY_PARTITION (bb, edge_in->dest);
|
||
}
|
||
|
||
/* ??? This info is likely going to be out of date very soon. */
|
||
if (edge_in->dest->global_live_at_start)
|
||
{
|
||
bb->global_live_at_start = ALLOC_REG_SET (®_obstack);
|
||
bb->global_live_at_end = ALLOC_REG_SET (®_obstack);
|
||
COPY_REG_SET (bb->global_live_at_start,
|
||
edge_in->dest->global_live_at_start);
|
||
COPY_REG_SET (bb->global_live_at_end,
|
||
edge_in->dest->global_live_at_start);
|
||
}
|
||
|
||
make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU);
|
||
|
||
/* For non-fallthru edges, we must adjust the predecessor's
|
||
jump instruction to target our new block. */
|
||
if ((edge_in->flags & EDGE_FALLTHRU) == 0)
|
||
{
|
||
edge redirected = redirect_edge_and_branch (edge_in, bb);
|
||
gcc_assert (redirected);
|
||
}
|
||
else
|
||
redirect_edge_succ (edge_in, bb);
|
||
|
||
return bb;
|
||
}
|
||
|
||
/* 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. */
|
||
|
||
void
|
||
insert_insn_on_edge (rtx pattern, edge e)
|
||
{
|
||
/* We cannot insert instructions on an abnormal critical edge.
|
||
It will be easier to find the culprit if we die now. */
|
||
gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e)));
|
||
|
||
if (e->insns.r == NULL_RTX)
|
||
start_sequence ();
|
||
else
|
||
push_to_sequence (e->insns.r);
|
||
|
||
emit_insn (pattern);
|
||
|
||
e->insns.r = get_insns ();
|
||
end_sequence ();
|
||
}
|
||
|
||
/* Called from safe_insert_insn_on_edge through note_stores, marks live
|
||
registers that are killed by the store. */
|
||
static void
|
||
mark_killed_regs (rtx reg, rtx set ATTRIBUTE_UNUSED, void *data)
|
||
{
|
||
regset killed = data;
|
||
int regno, i;
|
||
|
||
if (GET_CODE (reg) == SUBREG)
|
||
reg = SUBREG_REG (reg);
|
||
if (!REG_P (reg))
|
||
return;
|
||
regno = REGNO (reg);
|
||
if (regno >= FIRST_PSEUDO_REGISTER)
|
||
SET_REGNO_REG_SET (killed, regno);
|
||
else
|
||
{
|
||
for (i = 0; i < (int) hard_regno_nregs[regno][GET_MODE (reg)]; i++)
|
||
SET_REGNO_REG_SET (killed, regno + i);
|
||
}
|
||
}
|
||
|
||
/* Similar to insert_insn_on_edge, tries to put INSN to edge E. Additionally
|
||
it checks whether this will not clobber the registers that are live on the
|
||
edge (i.e. it requires liveness information to be up-to-date) and if there
|
||
are some, then it tries to save and restore them. Returns true if
|
||
successful. */
|
||
bool
|
||
safe_insert_insn_on_edge (rtx insn, edge e)
|
||
{
|
||
rtx x;
|
||
regset killed;
|
||
rtx save_regs = NULL_RTX;
|
||
unsigned regno;
|
||
int noccmode;
|
||
enum machine_mode mode;
|
||
reg_set_iterator rsi;
|
||
|
||
#ifdef AVOID_CCMODE_COPIES
|
||
noccmode = true;
|
||
#else
|
||
noccmode = false;
|
||
#endif
|
||
|
||
killed = ALLOC_REG_SET (®_obstack);
|
||
|
||
for (x = insn; x; x = NEXT_INSN (x))
|
||
if (INSN_P (x))
|
||
note_stores (PATTERN (x), mark_killed_regs, killed);
|
||
|
||
/* Mark all hard registers as killed. Register allocator/reload cannot
|
||
cope with the situation when life range of hard register spans operation
|
||
for that the appropriate register is needed, i.e. it would be unsafe to
|
||
extend the life ranges of hard registers. */
|
||
for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
|
||
if (!fixed_regs[regno]
|
||
&& !REGNO_PTR_FRAME_P (regno))
|
||
SET_REGNO_REG_SET (killed, regno);
|
||
|
||
bitmap_and_into (killed, e->dest->global_live_at_start);
|
||
|
||
EXECUTE_IF_SET_IN_REG_SET (killed, 0, regno, rsi)
|
||
{
|
||
mode = regno < FIRST_PSEUDO_REGISTER
|
||
? reg_raw_mode[regno]
|
||
: GET_MODE (regno_reg_rtx[regno]);
|
||
if (mode == VOIDmode)
|
||
return false;
|
||
|
||
if (noccmode && mode == CCmode)
|
||
return false;
|
||
|
||
save_regs = alloc_EXPR_LIST (0,
|
||
alloc_EXPR_LIST (0,
|
||
gen_reg_rtx (mode),
|
||
gen_raw_REG (mode, regno)),
|
||
save_regs);
|
||
}
|
||
|
||
if (save_regs)
|
||
{
|
||
rtx from, to;
|
||
|
||
start_sequence ();
|
||
for (x = save_regs; x; x = XEXP (x, 1))
|
||
{
|
||
from = XEXP (XEXP (x, 0), 1);
|
||
to = XEXP (XEXP (x, 0), 0);
|
||
emit_move_insn (to, from);
|
||
}
|
||
emit_insn (insn);
|
||
for (x = save_regs; x; x = XEXP (x, 1))
|
||
{
|
||
from = XEXP (XEXP (x, 0), 0);
|
||
to = XEXP (XEXP (x, 0), 1);
|
||
emit_move_insn (to, from);
|
||
}
|
||
insn = get_insns ();
|
||
end_sequence ();
|
||
free_EXPR_LIST_list (&save_regs);
|
||
}
|
||
insert_insn_on_edge (insn, e);
|
||
|
||
FREE_REG_SET (killed);
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Update the CFG for the instructions queued on edge E. */
|
||
|
||
static void
|
||
commit_one_edge_insertion (edge e, int watch_calls)
|
||
{
|
||
rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last;
|
||
basic_block bb = NULL;
|
||
|
||
/* Pull the insns off the edge now since the edge might go away. */
|
||
insns = e->insns.r;
|
||
e->insns.r = NULL_RTX;
|
||
|
||
/* Special case -- avoid inserting code between call and storing
|
||
its return value. */
|
||
if (watch_calls && (e->flags & EDGE_FALLTHRU)
|
||
&& single_pred_p (e->dest)
|
||
&& e->src != ENTRY_BLOCK_PTR
|
||
&& CALL_P (BB_END (e->src)))
|
||
{
|
||
rtx next = next_nonnote_insn (BB_END (e->src));
|
||
|
||
after = BB_HEAD (e->dest);
|
||
/* The first insn after the call may be a stack pop, skip it. */
|
||
while (next
|
||
&& keep_with_call_p (next))
|
||
{
|
||
after = next;
|
||
next = next_nonnote_insn (next);
|
||
}
|
||
bb = e->dest;
|
||
}
|
||
if (!before && !after)
|
||
{
|
||
/* Figure out where to put these things. If the destination has
|
||
one predecessor, insert there. Except for the exit block. */
|
||
if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR)
|
||
{
|
||
bb = e->dest;
|
||
|
||
/* Get the location correct wrt a code label, and "nice" wrt
|
||
a basic block note, and before everything else. */
|
||
tmp = BB_HEAD (bb);
|
||
if (LABEL_P (tmp))
|
||
tmp = NEXT_INSN (tmp);
|
||
if (NOTE_INSN_BASIC_BLOCK_P (tmp))
|
||
tmp = NEXT_INSN (tmp);
|
||
if (tmp == BB_HEAD (bb))
|
||
before = tmp;
|
||
else if (tmp)
|
||
after = PREV_INSN (tmp);
|
||
else
|
||
after = get_last_insn ();
|
||
}
|
||
|
||
/* If the source has one successor and the edge is not abnormal,
|
||
insert there. Except for the entry block. */
|
||
else if ((e->flags & EDGE_ABNORMAL) == 0
|
||
&& single_succ_p (e->src)
|
||
&& e->src != ENTRY_BLOCK_PTR)
|
||
{
|
||
bb = e->src;
|
||
|
||
/* It is possible to have a non-simple jump here. Consider a target
|
||
where some forms of unconditional jumps clobber a register. This
|
||
happens on the fr30 for example.
|
||
|
||
We know this block has a single successor, so we can just emit
|
||
the queued insns before the jump. */
|
||
if (JUMP_P (BB_END (bb)))
|
||
for (before = BB_END (bb);
|
||
NOTE_P (PREV_INSN (before))
|
||
&& NOTE_LINE_NUMBER (PREV_INSN (before)) ==
|
||
NOTE_INSN_LOOP_BEG; before = PREV_INSN (before))
|
||
;
|
||
else
|
||
{
|
||
/* We'd better be fallthru, or we've lost track of
|
||
what's what. */
|
||
gcc_assert (e->flags & EDGE_FALLTHRU);
|
||
|
||
after = BB_END (bb);
|
||
}
|
||
}
|
||
/* Otherwise we must split the edge. */
|
||
else
|
||
{
|
||
bb = split_edge (e);
|
||
after = BB_END (bb);
|
||
|
||
if (flag_reorder_blocks_and_partition
|
||
&& targetm.have_named_sections
|
||
&& e->src != ENTRY_BLOCK_PTR
|
||
&& BB_PARTITION (e->src) == BB_COLD_PARTITION
|
||
&& !(e->flags & EDGE_CROSSING))
|
||
{
|
||
rtx bb_note, cur_insn;
|
||
|
||
bb_note = NULL_RTX;
|
||
for (cur_insn = BB_HEAD (bb); cur_insn != NEXT_INSN (BB_END (bb));
|
||
cur_insn = NEXT_INSN (cur_insn))
|
||
if (NOTE_P (cur_insn)
|
||
&& NOTE_LINE_NUMBER (cur_insn) == NOTE_INSN_BASIC_BLOCK)
|
||
{
|
||
bb_note = cur_insn;
|
||
break;
|
||
}
|
||
|
||
if (JUMP_P (BB_END (bb))
|
||
&& !any_condjump_p (BB_END (bb))
|
||
&& (single_succ_edge (bb)->flags & EDGE_CROSSING))
|
||
REG_NOTES (BB_END (bb)) = gen_rtx_EXPR_LIST
|
||
(REG_CROSSING_JUMP, NULL_RTX, REG_NOTES (BB_END (bb)));
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Now that we've found the spot, do the insertion. */
|
||
|
||
if (before)
|
||
{
|
||
emit_insn_before_noloc (insns, before);
|
||
last = prev_nonnote_insn (before);
|
||
}
|
||
else
|
||
last = emit_insn_after_noloc (insns, after);
|
||
|
||
if (returnjump_p (last))
|
||
{
|
||
/* ??? Remove all outgoing edges from BB and add one for EXIT.
|
||
This is not currently a problem because this only happens
|
||
for the (single) epilogue, which already has a fallthru edge
|
||
to EXIT. */
|
||
|
||
e = single_succ_edge (bb);
|
||
gcc_assert (e->dest == EXIT_BLOCK_PTR
|
||
&& single_succ_p (bb) && (e->flags & EDGE_FALLTHRU));
|
||
|
||
e->flags &= ~EDGE_FALLTHRU;
|
||
emit_barrier_after (last);
|
||
|
||
if (before)
|
||
delete_insn (before);
|
||
}
|
||
else
|
||
gcc_assert (!JUMP_P (last));
|
||
|
||
/* Mark the basic block for find_many_sub_basic_blocks. */
|
||
bb->aux = &bb->aux;
|
||
}
|
||
|
||
/* Update the CFG for all queued instructions. */
|
||
|
||
void
|
||
commit_edge_insertions (void)
|
||
{
|
||
basic_block bb;
|
||
sbitmap blocks;
|
||
bool changed = false;
|
||
|
||
#ifdef ENABLE_CHECKING
|
||
verify_flow_info ();
|
||
#endif
|
||
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
if (e->insns.r)
|
||
{
|
||
changed = true;
|
||
commit_one_edge_insertion (e, false);
|
||
}
|
||
}
|
||
|
||
if (!changed)
|
||
return;
|
||
|
||
blocks = sbitmap_alloc (last_basic_block);
|
||
sbitmap_zero (blocks);
|
||
FOR_EACH_BB (bb)
|
||
if (bb->aux)
|
||
{
|
||
SET_BIT (blocks, bb->index);
|
||
/* Check for forgotten bb->aux values before commit_edge_insertions
|
||
call. */
|
||
gcc_assert (bb->aux == &bb->aux);
|
||
bb->aux = NULL;
|
||
}
|
||
find_many_sub_basic_blocks (blocks);
|
||
sbitmap_free (blocks);
|
||
}
|
||
|
||
/* Update the CFG for all queued instructions, taking special care of inserting
|
||
code on edges between call and storing its return value. */
|
||
|
||
void
|
||
commit_edge_insertions_watch_calls (void)
|
||
{
|
||
basic_block bb;
|
||
sbitmap blocks;
|
||
bool changed = false;
|
||
|
||
#ifdef ENABLE_CHECKING
|
||
verify_flow_info ();
|
||
#endif
|
||
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
if (e->insns.r)
|
||
{
|
||
changed = true;
|
||
commit_one_edge_insertion (e, true);
|
||
}
|
||
}
|
||
|
||
if (!changed)
|
||
return;
|
||
|
||
blocks = sbitmap_alloc (last_basic_block);
|
||
sbitmap_zero (blocks);
|
||
FOR_EACH_BB (bb)
|
||
if (bb->aux)
|
||
{
|
||
SET_BIT (blocks, bb->index);
|
||
/* Check for forgotten bb->aux values before commit_edge_insertions
|
||
call. */
|
||
gcc_assert (bb->aux == &bb->aux);
|
||
bb->aux = NULL;
|
||
}
|
||
find_many_sub_basic_blocks (blocks);
|
||
sbitmap_free (blocks);
|
||
}
|
||
|
||
/* Print out RTL-specific basic block information (live information
|
||
at start and end). */
|
||
|
||
static void
|
||
rtl_dump_bb (basic_block bb, FILE *outf, int indent)
|
||
{
|
||
rtx insn;
|
||
rtx last;
|
||
char *s_indent;
|
||
|
||
s_indent = alloca ((size_t) indent + 1);
|
||
memset (s_indent, ' ', (size_t) indent);
|
||
s_indent[indent] = '\0';
|
||
|
||
fprintf (outf, ";;%s Registers live at start: ", s_indent);
|
||
dump_regset (bb->global_live_at_start, outf);
|
||
putc ('\n', outf);
|
||
|
||
for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last;
|
||
insn = NEXT_INSN (insn))
|
||
print_rtl_single (outf, insn);
|
||
|
||
fprintf (outf, ";;%s Registers live at end: ", s_indent);
|
||
dump_regset (bb->global_live_at_end, outf);
|
||
putc ('\n', outf);
|
||
}
|
||
|
||
/* Like print_rtl, but also print out live information for the start of each
|
||
basic block. */
|
||
|
||
void
|
||
print_rtl_with_bb (FILE *outf, rtx rtx_first)
|
||
{
|
||
rtx tmp_rtx;
|
||
|
||
if (rtx_first == 0)
|
||
fprintf (outf, "(nil)\n");
|
||
else
|
||
{
|
||
enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB };
|
||
int max_uid = get_max_uid ();
|
||
basic_block *start = xcalloc (max_uid, sizeof (basic_block));
|
||
basic_block *end = xcalloc (max_uid, sizeof (basic_block));
|
||
enum bb_state *in_bb_p = xcalloc (max_uid, sizeof (enum bb_state));
|
||
|
||
basic_block bb;
|
||
|
||
FOR_EACH_BB_REVERSE (bb)
|
||
{
|
||
rtx x;
|
||
|
||
start[INSN_UID (BB_HEAD (bb))] = bb;
|
||
end[INSN_UID (BB_END (bb))] = bb;
|
||
for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x))
|
||
{
|
||
enum bb_state state = IN_MULTIPLE_BB;
|
||
|
||
if (in_bb_p[INSN_UID (x)] == NOT_IN_BB)
|
||
state = IN_ONE_BB;
|
||
in_bb_p[INSN_UID (x)] = state;
|
||
|
||
if (x == BB_END (bb))
|
||
break;
|
||
}
|
||
}
|
||
|
||
for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx))
|
||
{
|
||
int did_output;
|
||
|
||
if ((bb = start[INSN_UID (tmp_rtx)]) != NULL)
|
||
{
|
||
fprintf (outf, ";; Start of basic block %d, registers live:",
|
||
bb->index);
|
||
dump_regset (bb->global_live_at_start, outf);
|
||
putc ('\n', outf);
|
||
}
|
||
|
||
if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB
|
||
&& !NOTE_P (tmp_rtx)
|
||
&& !BARRIER_P (tmp_rtx))
|
||
fprintf (outf, ";; Insn is not within a basic block\n");
|
||
else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB)
|
||
fprintf (outf, ";; Insn is in multiple basic blocks\n");
|
||
|
||
did_output = print_rtl_single (outf, tmp_rtx);
|
||
|
||
if ((bb = end[INSN_UID (tmp_rtx)]) != NULL)
|
||
{
|
||
fprintf (outf, ";; End of basic block %d, registers live:\n",
|
||
bb->index);
|
||
dump_regset (bb->global_live_at_end, outf);
|
||
putc ('\n', outf);
|
||
}
|
||
|
||
if (did_output)
|
||
putc ('\n', outf);
|
||
}
|
||
|
||
free (start);
|
||
free (end);
|
||
free (in_bb_p);
|
||
}
|
||
|
||
if (current_function_epilogue_delay_list != 0)
|
||
{
|
||
fprintf (outf, "\n;; Insns in epilogue delay list:\n\n");
|
||
for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0;
|
||
tmp_rtx = XEXP (tmp_rtx, 1))
|
||
print_rtl_single (outf, XEXP (tmp_rtx, 0));
|
||
}
|
||
}
|
||
|
||
void
|
||
update_br_prob_note (basic_block bb)
|
||
{
|
||
rtx note;
|
||
if (!JUMP_P (BB_END (bb)))
|
||
return;
|
||
note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX);
|
||
if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability)
|
||
return;
|
||
XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability);
|
||
}
|
||
|
||
/* Verify the CFG and RTL consistency common for both underlying RTL and
|
||
cfglayout RTL.
|
||
|
||
Currently it does following checks:
|
||
|
||
- test head/end pointers
|
||
- overlapping of basic blocks
|
||
- headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note)
|
||
- tails of basic blocks (ensure that boundary is necessary)
|
||
- scans body of the basic block for JUMP_INSN, CODE_LABEL
|
||
and NOTE_INSN_BASIC_BLOCK
|
||
- verify that no fall_thru edge crosses hot/cold partition boundaries
|
||
|
||
In future it can be extended check a lot of other stuff as well
|
||
(reachability of basic blocks, life information, etc. etc.). */
|
||
|
||
static int
|
||
rtl_verify_flow_info_1 (void)
|
||
{
|
||
const int max_uid = get_max_uid ();
|
||
rtx last_head = get_last_insn ();
|
||
basic_block *bb_info;
|
||
rtx x;
|
||
int err = 0;
|
||
basic_block bb;
|
||
|
||
bb_info = xcalloc (max_uid, sizeof (basic_block));
|
||
|
||
FOR_EACH_BB_REVERSE (bb)
|
||
{
|
||
rtx head = BB_HEAD (bb);
|
||
rtx end = BB_END (bb);
|
||
|
||
/* Verify the end of the basic block is in the INSN chain. */
|
||
for (x = last_head; x != NULL_RTX; x = PREV_INSN (x))
|
||
if (x == end)
|
||
break;
|
||
|
||
if (!x)
|
||
{
|
||
error ("end insn %d for block %d not found in the insn stream",
|
||
INSN_UID (end), bb->index);
|
||
err = 1;
|
||
}
|
||
|
||
/* Work backwards from the end to the head of the basic block
|
||
to verify the head is in the RTL chain. */
|
||
for (; x != NULL_RTX; x = PREV_INSN (x))
|
||
{
|
||
/* While walking over the insn chain, verify insns appear
|
||
in only one basic block and initialize the BB_INFO array
|
||
used by other passes. */
|
||
if (bb_info[INSN_UID (x)] != NULL)
|
||
{
|
||
error ("insn %d is in multiple basic blocks (%d and %d)",
|
||
INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index);
|
||
err = 1;
|
||
}
|
||
|
||
bb_info[INSN_UID (x)] = bb;
|
||
|
||
if (x == head)
|
||
break;
|
||
}
|
||
if (!x)
|
||
{
|
||
error ("head insn %d for block %d not found in the insn stream",
|
||
INSN_UID (head), bb->index);
|
||
err = 1;
|
||
}
|
||
|
||
last_head = x;
|
||
}
|
||
|
||
/* Now check the basic blocks (boundaries etc.) */
|
||
FOR_EACH_BB_REVERSE (bb)
|
||
{
|
||
int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0;
|
||
edge e, fallthru = NULL;
|
||
rtx note;
|
||
edge_iterator ei;
|
||
|
||
if (JUMP_P (BB_END (bb))
|
||
&& (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX))
|
||
&& EDGE_COUNT (bb->succs) >= 2
|
||
&& any_condjump_p (BB_END (bb)))
|
||
{
|
||
if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability
|
||
&& profile_status != PROFILE_ABSENT)
|
||
{
|
||
error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i",
|
||
INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability);
|
||
err = 1;
|
||
}
|
||
}
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
{
|
||
if (e->flags & EDGE_FALLTHRU)
|
||
{
|
||
n_fallthru++, fallthru = e;
|
||
if ((e->flags & EDGE_CROSSING)
|
||
|| (BB_PARTITION (e->src) != BB_PARTITION (e->dest)
|
||
&& e->src != ENTRY_BLOCK_PTR
|
||
&& e->dest != EXIT_BLOCK_PTR))
|
||
{
|
||
error ("Fallthru edge crosses section boundary (bb %i)",
|
||
e->src->index);
|
||
err = 1;
|
||
}
|
||
}
|
||
|
||
if ((e->flags & ~(EDGE_DFS_BACK
|
||
| EDGE_CAN_FALLTHRU
|
||
| EDGE_IRREDUCIBLE_LOOP
|
||
| EDGE_LOOP_EXIT
|
||
| EDGE_CROSSING)) == 0)
|
||
n_branch++;
|
||
|
||
if (e->flags & EDGE_ABNORMAL_CALL)
|
||
n_call++;
|
||
|
||
if (e->flags & EDGE_EH)
|
||
n_eh++;
|
||
else if (e->flags & EDGE_ABNORMAL)
|
||
n_abnormal++;
|
||
}
|
||
|
||
if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX
|
||
&& !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX))
|
||
{
|
||
error ("Missing REG_EH_REGION note in the end of bb %i", bb->index);
|
||
err = 1;
|
||
}
|
||
if (n_branch
|
||
&& (!JUMP_P (BB_END (bb))
|
||
|| (n_branch > 1 && (any_uncondjump_p (BB_END (bb))
|
||
|| any_condjump_p (BB_END (bb))))))
|
||
{
|
||
error ("Too many outgoing branch edges from bb %i", bb->index);
|
||
err = 1;
|
||
}
|
||
if (n_fallthru && any_uncondjump_p (BB_END (bb)))
|
||
{
|
||
error ("Fallthru edge after unconditional jump %i", bb->index);
|
||
err = 1;
|
||
}
|
||
if (n_branch != 1 && any_uncondjump_p (BB_END (bb)))
|
||
{
|
||
error ("Wrong amount of branch edges after unconditional jump %i", bb->index);
|
||
err = 1;
|
||
}
|
||
if (n_branch != 1 && any_condjump_p (BB_END (bb))
|
||
&& JUMP_LABEL (BB_END (bb)) == BB_HEAD (fallthru->dest))
|
||
{
|
||
error ("Wrong amount of branch edges after conditional jump %i", bb->index);
|
||
err = 1;
|
||
}
|
||
if (n_call && !CALL_P (BB_END (bb)))
|
||
{
|
||
error ("Call edges for non-call insn in bb %i", bb->index);
|
||
err = 1;
|
||
}
|
||
if (n_abnormal
|
||
&& (!CALL_P (BB_END (bb)) && n_call != n_abnormal)
|
||
&& (!JUMP_P (BB_END (bb))
|
||
|| any_condjump_p (BB_END (bb))
|
||
|| any_uncondjump_p (BB_END (bb))))
|
||
{
|
||
error ("Abnormal edges for no purpose in bb %i", bb->index);
|
||
err = 1;
|
||
}
|
||
|
||
for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x))
|
||
/* We may have a barrier inside a basic block before dead code
|
||
elimination. There is no BLOCK_FOR_INSN field in a barrier. */
|
||
if (!BARRIER_P (x) && BLOCK_FOR_INSN (x) != bb)
|
||
{
|
||
debug_rtx (x);
|
||
if (! BLOCK_FOR_INSN (x))
|
||
error
|
||
("insn %d inside basic block %d but block_for_insn is NULL",
|
||
INSN_UID (x), bb->index);
|
||
else
|
||
error
|
||
("insn %d inside basic block %d but block_for_insn is %i",
|
||
INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index);
|
||
|
||
err = 1;
|
||
}
|
||
|
||
/* OK pointers are correct. Now check the header of basic
|
||
block. It ought to contain optional CODE_LABEL followed
|
||
by NOTE_BASIC_BLOCK. */
|
||
x = BB_HEAD (bb);
|
||
if (LABEL_P (x))
|
||
{
|
||
if (BB_END (bb) == x)
|
||
{
|
||
error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
|
||
bb->index);
|
||
err = 1;
|
||
}
|
||
|
||
x = NEXT_INSN (x);
|
||
}
|
||
|
||
if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb)
|
||
{
|
||
error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
|
||
bb->index);
|
||
err = 1;
|
||
}
|
||
|
||
if (BB_END (bb) == x)
|
||
/* Do checks for empty blocks here. */
|
||
;
|
||
else
|
||
for (x = NEXT_INSN (x); x; x = NEXT_INSN (x))
|
||
{
|
||
if (NOTE_INSN_BASIC_BLOCK_P (x))
|
||
{
|
||
error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d",
|
||
INSN_UID (x), bb->index);
|
||
err = 1;
|
||
}
|
||
|
||
if (x == BB_END (bb))
|
||
break;
|
||
|
||
if (control_flow_insn_p (x))
|
||
{
|
||
error ("in basic block %d:", bb->index);
|
||
fatal_insn ("flow control insn inside a basic block", x);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Clean up. */
|
||
free (bb_info);
|
||
return err;
|
||
}
|
||
|
||
/* Verify the CFG and RTL consistency common for both underlying RTL and
|
||
cfglayout RTL.
|
||
|
||
Currently it does following checks:
|
||
- all checks of rtl_verify_flow_info_1
|
||
- check that all insns are in the basic blocks
|
||
(except the switch handling code, barriers and notes)
|
||
- check that all returns are followed by barriers
|
||
- check that all fallthru edge points to the adjacent blocks. */
|
||
static int
|
||
rtl_verify_flow_info (void)
|
||
{
|
||
basic_block bb;
|
||
int err = rtl_verify_flow_info_1 ();
|
||
rtx x;
|
||
int num_bb_notes;
|
||
const rtx rtx_first = get_insns ();
|
||
basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL;
|
||
|
||
FOR_EACH_BB_REVERSE (bb)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
if (e->flags & EDGE_FALLTHRU)
|
||
break;
|
||
if (!e)
|
||
{
|
||
rtx insn;
|
||
|
||
/* Ensure existence of barrier in BB with no fallthru edges. */
|
||
for (insn = BB_END (bb); !insn || !BARRIER_P (insn);
|
||
insn = NEXT_INSN (insn))
|
||
if (!insn
|
||
|| (NOTE_P (insn)
|
||
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK))
|
||
{
|
||
error ("missing barrier after block %i", bb->index);
|
||
err = 1;
|
||
break;
|
||
}
|
||
}
|
||
else if (e->src != ENTRY_BLOCK_PTR
|
||
&& e->dest != EXIT_BLOCK_PTR)
|
||
{
|
||
rtx insn;
|
||
|
||
if (e->src->next_bb != e->dest)
|
||
{
|
||
error
|
||
("verify_flow_info: Incorrect blocks for fallthru %i->%i",
|
||
e->src->index, e->dest->index);
|
||
err = 1;
|
||
}
|
||
else
|
||
for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest);
|
||
insn = NEXT_INSN (insn))
|
||
if (BARRIER_P (insn) || INSN_P (insn))
|
||
{
|
||
error ("verify_flow_info: Incorrect fallthru %i->%i",
|
||
e->src->index, e->dest->index);
|
||
fatal_insn ("wrong insn in the fallthru edge", insn);
|
||
err = 1;
|
||
}
|
||
}
|
||
}
|
||
|
||
num_bb_notes = 0;
|
||
last_bb_seen = ENTRY_BLOCK_PTR;
|
||
|
||
for (x = rtx_first; x; x = NEXT_INSN (x))
|
||
{
|
||
if (NOTE_INSN_BASIC_BLOCK_P (x))
|
||
{
|
||
bb = NOTE_BASIC_BLOCK (x);
|
||
|
||
num_bb_notes++;
|
||
if (bb != last_bb_seen->next_bb)
|
||
internal_error ("basic blocks not laid down consecutively");
|
||
|
||
curr_bb = last_bb_seen = bb;
|
||
}
|
||
|
||
if (!curr_bb)
|
||
{
|
||
switch (GET_CODE (x))
|
||
{
|
||
case BARRIER:
|
||
case NOTE:
|
||
break;
|
||
|
||
case CODE_LABEL:
|
||
/* An addr_vec is placed outside any basic block. */
|
||
if (NEXT_INSN (x)
|
||
&& JUMP_P (NEXT_INSN (x))
|
||
&& (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC
|
||
|| GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC))
|
||
x = NEXT_INSN (x);
|
||
|
||
/* But in any case, non-deletable labels can appear anywhere. */
|
||
break;
|
||
|
||
default:
|
||
fatal_insn ("insn outside basic block", x);
|
||
}
|
||
}
|
||
|
||
if (JUMP_P (x)
|
||
&& returnjump_p (x) && ! condjump_p (x)
|
||
&& ! (NEXT_INSN (x) && BARRIER_P (NEXT_INSN (x))))
|
||
fatal_insn ("return not followed by barrier", x);
|
||
if (curr_bb && x == BB_END (curr_bb))
|
||
curr_bb = NULL;
|
||
}
|
||
|
||
if (num_bb_notes != n_basic_blocks)
|
||
internal_error
|
||
("number of bb notes in insn chain (%d) != n_basic_blocks (%d)",
|
||
num_bb_notes, n_basic_blocks);
|
||
|
||
return err;
|
||
}
|
||
|
||
/* 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. */
|
||
|
||
bool
|
||
purge_dead_edges (basic_block bb)
|
||
{
|
||
edge e;
|
||
rtx insn = BB_END (bb), note;
|
||
bool purged = false;
|
||
bool found;
|
||
edge_iterator ei;
|
||
|
||
/* If this instruction cannot trap, remove REG_EH_REGION notes. */
|
||
if (NONJUMP_INSN_P (insn)
|
||
&& (note = find_reg_note (insn, REG_EH_REGION, NULL)))
|
||
{
|
||
rtx eqnote;
|
||
|
||
if (! may_trap_p (PATTERN (insn))
|
||
|| ((eqnote = find_reg_equal_equiv_note (insn))
|
||
&& ! may_trap_p (XEXP (eqnote, 0))))
|
||
remove_note (insn, note);
|
||
}
|
||
|
||
/* Cleanup abnormal edges caused by exceptions or non-local gotos. */
|
||
for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
|
||
{
|
||
if (e->flags & EDGE_EH)
|
||
{
|
||
if (can_throw_internal (BB_END (bb)))
|
||
{
|
||
ei_next (&ei);
|
||
continue;
|
||
}
|
||
}
|
||
else if (e->flags & EDGE_ABNORMAL_CALL)
|
||
{
|
||
if (CALL_P (BB_END (bb))
|
||
&& (! (note = find_reg_note (insn, REG_EH_REGION, NULL))
|
||
|| INTVAL (XEXP (note, 0)) >= 0))
|
||
{
|
||
ei_next (&ei);
|
||
continue;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
ei_next (&ei);
|
||
continue;
|
||
}
|
||
|
||
remove_edge (e);
|
||
bb->flags |= BB_DIRTY;
|
||
purged = true;
|
||
}
|
||
|
||
if (JUMP_P (insn))
|
||
{
|
||
rtx note;
|
||
edge b,f;
|
||
edge_iterator ei;
|
||
|
||
/* We do care only about conditional jumps and simplejumps. */
|
||
if (!any_condjump_p (insn)
|
||
&& !returnjump_p (insn)
|
||
&& !simplejump_p (insn))
|
||
return purged;
|
||
|
||
/* Branch probability/prediction notes are defined only for
|
||
condjumps. We've possibly turned condjump into simplejump. */
|
||
if (simplejump_p (insn))
|
||
{
|
||
note = find_reg_note (insn, REG_BR_PROB, NULL);
|
||
if (note)
|
||
remove_note (insn, note);
|
||
while ((note = find_reg_note (insn, REG_BR_PRED, NULL)))
|
||
remove_note (insn, note);
|
||
}
|
||
|
||
for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
|
||
{
|
||
/* Avoid abnormal flags to leak from computed jumps turned
|
||
into simplejumps. */
|
||
|
||
e->flags &= ~EDGE_ABNORMAL;
|
||
|
||
/* See if this edge is one we should keep. */
|
||
if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn))
|
||
/* A conditional jump can fall through into the next
|
||
block, so we should keep the edge. */
|
||
{
|
||
ei_next (&ei);
|
||
continue;
|
||
}
|
||
else if (e->dest != EXIT_BLOCK_PTR
|
||
&& BB_HEAD (e->dest) == JUMP_LABEL (insn))
|
||
/* If the destination block is the target of the jump,
|
||
keep the edge. */
|
||
{
|
||
ei_next (&ei);
|
||
continue;
|
||
}
|
||
else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn))
|
||
/* If the destination block is the exit block, and this
|
||
instruction is a return, then keep the edge. */
|
||
{
|
||
ei_next (&ei);
|
||
continue;
|
||
}
|
||
else if ((e->flags & EDGE_EH) && can_throw_internal (insn))
|
||
/* Keep the edges that correspond to exceptions thrown by
|
||
this instruction and rematerialize the EDGE_ABNORMAL
|
||
flag we just cleared above. */
|
||
{
|
||
e->flags |= EDGE_ABNORMAL;
|
||
ei_next (&ei);
|
||
continue;
|
||
}
|
||
|
||
/* We do not need this edge. */
|
||
bb->flags |= BB_DIRTY;
|
||
purged = true;
|
||
remove_edge (e);
|
||
}
|
||
|
||
if (EDGE_COUNT (bb->succs) == 0 || !purged)
|
||
return purged;
|
||
|
||
if (dump_file)
|
||
fprintf (dump_file, "Purged edges from bb %i\n", bb->index);
|
||
|
||
if (!optimize)
|
||
return purged;
|
||
|
||
/* Redistribute probabilities. */
|
||
if (single_succ_p (bb))
|
||
{
|
||
single_succ_edge (bb)->probability = REG_BR_PROB_BASE;
|
||
single_succ_edge (bb)->count = bb->count;
|
||
}
|
||
else
|
||
{
|
||
note = find_reg_note (insn, REG_BR_PROB, NULL);
|
||
if (!note)
|
||
return purged;
|
||
|
||
b = BRANCH_EDGE (bb);
|
||
f = FALLTHRU_EDGE (bb);
|
||
b->probability = INTVAL (XEXP (note, 0));
|
||
f->probability = REG_BR_PROB_BASE - b->probability;
|
||
b->count = bb->count * b->probability / REG_BR_PROB_BASE;
|
||
f->count = bb->count * f->probability / REG_BR_PROB_BASE;
|
||
}
|
||
|
||
return purged;
|
||
}
|
||
else if (CALL_P (insn) && SIBLING_CALL_P (insn))
|
||
{
|
||
/* First, there should not be any EH or ABCALL edges resulting
|
||
from non-local gotos and the like. If there were, we shouldn't
|
||
have created the sibcall in the first place. Second, there
|
||
should of course never have been a fallthru edge. */
|
||
gcc_assert (single_succ_p (bb));
|
||
gcc_assert (single_succ_edge (bb)->flags
|
||
== (EDGE_SIBCALL | EDGE_ABNORMAL));
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* If we don't see a jump insn, we don't know exactly why the block would
|
||
have been broken at this point. Look for a simple, non-fallthru edge,
|
||
as these are only created by conditional branches. If we find such an
|
||
edge we know that there used to be a jump here and can then safely
|
||
remove all non-fallthru edges. */
|
||
found = false;
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU)))
|
||
{
|
||
found = true;
|
||
break;
|
||
}
|
||
|
||
if (!found)
|
||
return purged;
|
||
|
||
for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
|
||
{
|
||
if (!(e->flags & EDGE_FALLTHRU))
|
||
{
|
||
bb->flags |= BB_DIRTY;
|
||
remove_edge (e);
|
||
purged = true;
|
||
}
|
||
else
|
||
ei_next (&ei);
|
||
}
|
||
|
||
gcc_assert (single_succ_p (bb));
|
||
|
||
single_succ_edge (bb)->probability = REG_BR_PROB_BASE;
|
||
single_succ_edge (bb)->count = bb->count;
|
||
|
||
if (dump_file)
|
||
fprintf (dump_file, "Purged non-fallthru edges from bb %i\n",
|
||
bb->index);
|
||
return purged;
|
||
}
|
||
|
||
/* Search all basic blocks for potentially dead edges and purge them. Return
|
||
true if some edge has been eliminated. */
|
||
|
||
bool
|
||
purge_all_dead_edges (void)
|
||
{
|
||
int purged = false;
|
||
basic_block bb;
|
||
|
||
FOR_EACH_BB (bb)
|
||
{
|
||
bool purged_here = purge_dead_edges (bb);
|
||
|
||
purged |= purged_here;
|
||
}
|
||
|
||
return purged;
|
||
}
|
||
|
||
/* Same as split_block but update cfg_layout structures. */
|
||
|
||
static basic_block
|
||
cfg_layout_split_block (basic_block bb, void *insnp)
|
||
{
|
||
rtx insn = insnp;
|
||
basic_block new_bb = rtl_split_block (bb, insn);
|
||
|
||
new_bb->rbi->footer = bb->rbi->footer;
|
||
bb->rbi->footer = NULL;
|
||
|
||
return new_bb;
|
||
}
|
||
|
||
|
||
/* Redirect Edge to DEST. */
|
||
static edge
|
||
cfg_layout_redirect_edge_and_branch (edge e, basic_block dest)
|
||
{
|
||
basic_block src = e->src;
|
||
edge ret;
|
||
|
||
if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
|
||
return NULL;
|
||
|
||
if (e->dest == dest)
|
||
return e;
|
||
|
||
if (e->src != ENTRY_BLOCK_PTR
|
||
&& (ret = try_redirect_by_replacing_jump (e, dest, true)))
|
||
{
|
||
src->flags |= BB_DIRTY;
|
||
return ret;
|
||
}
|
||
|
||
if (e->src == ENTRY_BLOCK_PTR
|
||
&& (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX))
|
||
{
|
||
if (dump_file)
|
||
fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n",
|
||
e->src->index, dest->index);
|
||
|
||
e->src->flags |= BB_DIRTY;
|
||
redirect_edge_succ (e, dest);
|
||
return e;
|
||
}
|
||
|
||
/* Redirect_edge_and_branch may decide to turn branch into fallthru edge
|
||
in the case the basic block appears to be in sequence. Avoid this
|
||
transformation. */
|
||
|
||
if (e->flags & EDGE_FALLTHRU)
|
||
{
|
||
/* Redirect any branch edges unified with the fallthru one. */
|
||
if (JUMP_P (BB_END (src))
|
||
&& label_is_jump_target_p (BB_HEAD (e->dest),
|
||
BB_END (src)))
|
||
{
|
||
edge redirected;
|
||
|
||
if (dump_file)
|
||
fprintf (dump_file, "Fallthru edge unified with branch "
|
||
"%i->%i redirected to %i\n",
|
||
e->src->index, e->dest->index, dest->index);
|
||
e->flags &= ~EDGE_FALLTHRU;
|
||
redirected = redirect_branch_edge (e, dest);
|
||
gcc_assert (redirected);
|
||
e->flags |= EDGE_FALLTHRU;
|
||
e->src->flags |= BB_DIRTY;
|
||
return e;
|
||
}
|
||
/* In case we are redirecting fallthru edge to the branch edge
|
||
of conditional jump, remove it. */
|
||
if (EDGE_COUNT (src->succs) == 2)
|
||
{
|
||
/* Find the edge that is different from E. */
|
||
edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e);
|
||
|
||
if (s->dest == dest
|
||
&& any_condjump_p (BB_END (src))
|
||
&& onlyjump_p (BB_END (src)))
|
||
delete_insn (BB_END (src));
|
||
}
|
||
ret = redirect_edge_succ_nodup (e, dest);
|
||
if (dump_file)
|
||
fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n",
|
||
e->src->index, e->dest->index, dest->index);
|
||
}
|
||
else
|
||
ret = redirect_branch_edge (e, dest);
|
||
|
||
/* We don't want simplejumps in the insn stream during cfglayout. */
|
||
gcc_assert (!simplejump_p (BB_END (src)));
|
||
|
||
src->flags |= BB_DIRTY;
|
||
return ret;
|
||
}
|
||
|
||
/* Simple wrapper as we always can redirect fallthru edges. */
|
||
static basic_block
|
||
cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest)
|
||
{
|
||
edge redirected = cfg_layout_redirect_edge_and_branch (e, dest);
|
||
|
||
gcc_assert (redirected);
|
||
return NULL;
|
||
}
|
||
|
||
/* Same as delete_basic_block but update cfg_layout structures. */
|
||
|
||
static void
|
||
cfg_layout_delete_block (basic_block bb)
|
||
{
|
||
rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints;
|
||
|
||
if (bb->rbi->header)
|
||
{
|
||
next = BB_HEAD (bb);
|
||
if (prev)
|
||
NEXT_INSN (prev) = bb->rbi->header;
|
||
else
|
||
set_first_insn (bb->rbi->header);
|
||
PREV_INSN (bb->rbi->header) = prev;
|
||
insn = bb->rbi->header;
|
||
while (NEXT_INSN (insn))
|
||
insn = NEXT_INSN (insn);
|
||
NEXT_INSN (insn) = next;
|
||
PREV_INSN (next) = insn;
|
||
}
|
||
next = NEXT_INSN (BB_END (bb));
|
||
if (bb->rbi->footer)
|
||
{
|
||
insn = bb->rbi->footer;
|
||
while (insn)
|
||
{
|
||
if (BARRIER_P (insn))
|
||
{
|
||
if (PREV_INSN (insn))
|
||
NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn);
|
||
else
|
||
bb->rbi->footer = NEXT_INSN (insn);
|
||
if (NEXT_INSN (insn))
|
||
PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn);
|
||
}
|
||
if (LABEL_P (insn))
|
||
break;
|
||
insn = NEXT_INSN (insn);
|
||
}
|
||
if (bb->rbi->footer)
|
||
{
|
||
insn = BB_END (bb);
|
||
NEXT_INSN (insn) = bb->rbi->footer;
|
||
PREV_INSN (bb->rbi->footer) = insn;
|
||
while (NEXT_INSN (insn))
|
||
insn = NEXT_INSN (insn);
|
||
NEXT_INSN (insn) = next;
|
||
if (next)
|
||
PREV_INSN (next) = insn;
|
||
else
|
||
set_last_insn (insn);
|
||
}
|
||
}
|
||
if (bb->next_bb != EXIT_BLOCK_PTR)
|
||
to = &bb->next_bb->rbi->header;
|
||
else
|
||
to = &cfg_layout_function_footer;
|
||
|
||
bb->rbi = NULL;
|
||
|
||
rtl_delete_block (bb);
|
||
|
||
if (prev)
|
||
prev = NEXT_INSN (prev);
|
||
else
|
||
prev = get_insns ();
|
||
if (next)
|
||
next = PREV_INSN (next);
|
||
else
|
||
next = get_last_insn ();
|
||
|
||
if (next && NEXT_INSN (next) != prev)
|
||
{
|
||
remaints = unlink_insn_chain (prev, next);
|
||
insn = remaints;
|
||
while (NEXT_INSN (insn))
|
||
insn = NEXT_INSN (insn);
|
||
NEXT_INSN (insn) = *to;
|
||
if (*to)
|
||
PREV_INSN (*to) = insn;
|
||
*to = remaints;
|
||
}
|
||
}
|
||
|
||
/* Return true when blocks A and B can be safely merged. */
|
||
static bool
|
||
cfg_layout_can_merge_blocks_p (basic_block a, basic_block b)
|
||
{
|
||
/* If we are partitioning hot/cold basic blocks, we don't want to
|
||
mess up unconditional or indirect jumps that cross between hot
|
||
and cold sections.
|
||
|
||
Basic block partitioning may result in some jumps that appear to
|
||
be optimizable (or blocks that appear to be mergeable), but which really
|
||
must be left untouched (they are required to make it safely across
|
||
partition boundaries). See the comments at the top of
|
||
bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
|
||
|
||
if (BB_PARTITION (a) != BB_PARTITION (b))
|
||
return false;
|
||
|
||
/* There must be exactly one edge in between the blocks. */
|
||
return (single_succ_p (a)
|
||
&& single_succ (a) == b
|
||
&& single_pred_p (b) == 1
|
||
&& a != b
|
||
/* Must be simple edge. */
|
||
&& !(single_succ_edge (a)->flags & EDGE_COMPLEX)
|
||
&& a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR
|
||
/* If the jump insn has side effects,
|
||
we can't kill the edge. */
|
||
&& (!JUMP_P (BB_END (a))
|
||
|| (reload_completed
|
||
? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a)))));
|
||
}
|
||
|
||
/* Merge block A and B. The blocks must be mergeable. */
|
||
|
||
static void
|
||
cfg_layout_merge_blocks (basic_block a, basic_block b)
|
||
{
|
||
#ifdef ENABLE_CHECKING
|
||
gcc_assert (cfg_layout_can_merge_blocks_p (a, b));
|
||
#endif
|
||
|
||
/* If there was a CODE_LABEL beginning B, delete it. */
|
||
if (LABEL_P (BB_HEAD (b)))
|
||
delete_insn (BB_HEAD (b));
|
||
|
||
/* We should have fallthru edge in a, or we can do dummy redirection to get
|
||
it cleaned up. */
|
||
if (JUMP_P (BB_END (a)))
|
||
try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true);
|
||
gcc_assert (!JUMP_P (BB_END (a)));
|
||
|
||
/* Possible line number notes should appear in between. */
|
||
if (b->rbi->header)
|
||
{
|
||
rtx first = BB_END (a), last;
|
||
|
||
last = emit_insn_after_noloc (b->rbi->header, BB_END (a));
|
||
delete_insn_chain (NEXT_INSN (first), last);
|
||
b->rbi->header = NULL;
|
||
}
|
||
|
||
/* In the case basic blocks are not adjacent, move them around. */
|
||
if (NEXT_INSN (BB_END (a)) != BB_HEAD (b))
|
||
{
|
||
rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b));
|
||
|
||
emit_insn_after_noloc (first, BB_END (a));
|
||
/* Skip possible DELETED_LABEL insn. */
|
||
if (!NOTE_INSN_BASIC_BLOCK_P (first))
|
||
first = NEXT_INSN (first);
|
||
gcc_assert (NOTE_INSN_BASIC_BLOCK_P (first));
|
||
BB_HEAD (b) = NULL;
|
||
delete_insn (first);
|
||
}
|
||
/* Otherwise just re-associate the instructions. */
|
||
else
|
||
{
|
||
rtx insn;
|
||
|
||
for (insn = BB_HEAD (b);
|
||
insn != NEXT_INSN (BB_END (b));
|
||
insn = NEXT_INSN (insn))
|
||
set_block_for_insn (insn, a);
|
||
insn = BB_HEAD (b);
|
||
/* Skip possible DELETED_LABEL insn. */
|
||
if (!NOTE_INSN_BASIC_BLOCK_P (insn))
|
||
insn = NEXT_INSN (insn);
|
||
gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn));
|
||
BB_HEAD (b) = NULL;
|
||
BB_END (a) = BB_END (b);
|
||
delete_insn (insn);
|
||
}
|
||
|
||
/* Possible tablejumps and barriers should appear after the block. */
|
||
if (b->rbi->footer)
|
||
{
|
||
if (!a->rbi->footer)
|
||
a->rbi->footer = b->rbi->footer;
|
||
else
|
||
{
|
||
rtx last = a->rbi->footer;
|
||
|
||
while (NEXT_INSN (last))
|
||
last = NEXT_INSN (last);
|
||
NEXT_INSN (last) = b->rbi->footer;
|
||
PREV_INSN (b->rbi->footer) = last;
|
||
}
|
||
b->rbi->footer = NULL;
|
||
}
|
||
|
||
if (dump_file)
|
||
fprintf (dump_file, "Merged blocks %d and %d.\n",
|
||
a->index, b->index);
|
||
}
|
||
|
||
/* Split edge E. */
|
||
|
||
static basic_block
|
||
cfg_layout_split_edge (edge e)
|
||
{
|
||
basic_block new_bb =
|
||
create_basic_block (e->src != ENTRY_BLOCK_PTR
|
||
? NEXT_INSN (BB_END (e->src)) : get_insns (),
|
||
NULL_RTX, e->src);
|
||
|
||
/* ??? This info is likely going to be out of date very soon, but we must
|
||
create it to avoid getting an ICE later. */
|
||
if (e->dest->global_live_at_start)
|
||
{
|
||
new_bb->global_live_at_start = ALLOC_REG_SET (®_obstack);
|
||
new_bb->global_live_at_end = ALLOC_REG_SET (®_obstack);
|
||
COPY_REG_SET (new_bb->global_live_at_start,
|
||
e->dest->global_live_at_start);
|
||
COPY_REG_SET (new_bb->global_live_at_end,
|
||
e->dest->global_live_at_start);
|
||
}
|
||
|
||
make_edge (new_bb, e->dest, EDGE_FALLTHRU);
|
||
redirect_edge_and_branch_force (e, new_bb);
|
||
|
||
return new_bb;
|
||
}
|
||
|
||
/* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */
|
||
|
||
static void
|
||
rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED)
|
||
{
|
||
}
|
||
|
||
/* Return 1 if BB ends with a call, possibly followed by some
|
||
instructions that must stay with the call, 0 otherwise. */
|
||
|
||
static bool
|
||
rtl_block_ends_with_call_p (basic_block bb)
|
||
{
|
||
rtx insn = BB_END (bb);
|
||
|
||
while (!CALL_P (insn)
|
||
&& insn != BB_HEAD (bb)
|
||
&& keep_with_call_p (insn))
|
||
insn = PREV_INSN (insn);
|
||
return (CALL_P (insn));
|
||
}
|
||
|
||
/* Return 1 if BB ends with a conditional branch, 0 otherwise. */
|
||
|
||
static bool
|
||
rtl_block_ends_with_condjump_p (basic_block bb)
|
||
{
|
||
return any_condjump_p (BB_END (bb));
|
||
}
|
||
|
||
/* Return true if we need to add fake edge to exit.
|
||
Helper function for rtl_flow_call_edges_add. */
|
||
|
||
static bool
|
||
need_fake_edge_p (rtx insn)
|
||
{
|
||
if (!INSN_P (insn))
|
||
return false;
|
||
|
||
if ((CALL_P (insn)
|
||
&& !SIBLING_CALL_P (insn)
|
||
&& !find_reg_note (insn, REG_NORETURN, NULL)
|
||
&& !CONST_OR_PURE_CALL_P (insn)))
|
||
return true;
|
||
|
||
return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS
|
||
&& MEM_VOLATILE_P (PATTERN (insn)))
|
||
|| (GET_CODE (PATTERN (insn)) == PARALLEL
|
||
&& asm_noperands (insn) != -1
|
||
&& MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0)))
|
||
|| GET_CODE (PATTERN (insn)) == ASM_INPUT);
|
||
}
|
||
|
||
/* 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. */
|
||
|
||
static int
|
||
rtl_flow_call_edges_add (sbitmap blocks)
|
||
{
|
||
int i;
|
||
int blocks_split = 0;
|
||
int last_bb = last_basic_block;
|
||
bool check_last_block = false;
|
||
|
||
if (n_basic_blocks == 0)
|
||
return 0;
|
||
|
||
if (! blocks)
|
||
check_last_block = true;
|
||
else
|
||
check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
|
||
|
||
/* In the last basic block, before epilogue generation, there will be
|
||
a fallthru edge to EXIT. Special care is required if the last insn
|
||
of the last basic block is a call because make_edge folds duplicate
|
||
edges, which would result in the fallthru edge also being marked
|
||
fake, which would result in the fallthru edge being removed by
|
||
remove_fake_edges, which would result in an invalid CFG.
|
||
|
||
Moreover, we can't elide the outgoing fake edge, since the block
|
||
profiler needs to take this into account in order to solve the minimal
|
||
spanning tree in the case that the call doesn't return.
|
||
|
||
Handle this by adding a dummy instruction in a new last basic block. */
|
||
if (check_last_block)
|
||
{
|
||
basic_block bb = EXIT_BLOCK_PTR->prev_bb;
|
||
rtx insn = BB_END (bb);
|
||
|
||
/* Back up past insns that must be kept in the same block as a call. */
|
||
while (insn != BB_HEAD (bb)
|
||
&& keep_with_call_p (insn))
|
||
insn = PREV_INSN (insn);
|
||
|
||
if (need_fake_edge_p (insn))
|
||
{
|
||
edge e;
|
||
|
||
e = find_edge (bb, EXIT_BLOCK_PTR);
|
||
if (e)
|
||
{
|
||
insert_insn_on_edge (gen_rtx_USE (VOIDmode, const0_rtx), e);
|
||
commit_edge_insertions ();
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Now add fake edges to the function exit for any non constant
|
||
calls since there is no way that we can determine if they will
|
||
return or not... */
|
||
|
||
for (i = 0; i < last_bb; i++)
|
||
{
|
||
basic_block bb = BASIC_BLOCK (i);
|
||
rtx insn;
|
||
rtx prev_insn;
|
||
|
||
if (!bb)
|
||
continue;
|
||
|
||
if (blocks && !TEST_BIT (blocks, i))
|
||
continue;
|
||
|
||
for (insn = BB_END (bb); ; insn = prev_insn)
|
||
{
|
||
prev_insn = PREV_INSN (insn);
|
||
if (need_fake_edge_p (insn))
|
||
{
|
||
edge e;
|
||
rtx split_at_insn = insn;
|
||
|
||
/* Don't split the block between a call and an insn that should
|
||
remain in the same block as the call. */
|
||
if (CALL_P (insn))
|
||
while (split_at_insn != BB_END (bb)
|
||
&& keep_with_call_p (NEXT_INSN (split_at_insn)))
|
||
split_at_insn = NEXT_INSN (split_at_insn);
|
||
|
||
/* The handling above of the final block before the epilogue
|
||
should be enough to verify that there is no edge to the exit
|
||
block in CFG already. Calling make_edge in such case would
|
||
cause us to mark that edge as fake and remove it later. */
|
||
|
||
#ifdef ENABLE_CHECKING
|
||
if (split_at_insn == BB_END (bb))
|
||
{
|
||
e = find_edge (bb, EXIT_BLOCK_PTR);
|
||
gcc_assert (e == NULL);
|
||
}
|
||
#endif
|
||
|
||
/* Note that the following may create a new basic block
|
||
and renumber the existing basic blocks. */
|
||
if (split_at_insn != BB_END (bb))
|
||
{
|
||
e = split_block (bb, split_at_insn);
|
||
if (e)
|
||
blocks_split++;
|
||
}
|
||
|
||
make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
|
||
}
|
||
|
||
if (insn == BB_HEAD (bb))
|
||
break;
|
||
}
|
||
}
|
||
|
||
if (blocks_split)
|
||
verify_flow_info ();
|
||
|
||
return blocks_split;
|
||
}
|
||
|
||
/* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is
|
||
the conditional branch target, SECOND_HEAD should be the fall-thru
|
||
there is no need to handle this here the loop versioning code handles
|
||
this. the reason for SECON_HEAD is that it is needed for condition
|
||
in trees, and this should be of the same type since it is a hook. */
|
||
static void
|
||
rtl_lv_add_condition_to_bb (basic_block first_head ,
|
||
basic_block second_head ATTRIBUTE_UNUSED,
|
||
basic_block cond_bb, void *comp_rtx)
|
||
{
|
||
rtx label, seq, jump;
|
||
rtx op0 = XEXP ((rtx)comp_rtx, 0);
|
||
rtx op1 = XEXP ((rtx)comp_rtx, 1);
|
||
enum rtx_code comp = GET_CODE ((rtx)comp_rtx);
|
||
enum machine_mode mode;
|
||
|
||
|
||
label = block_label (first_head);
|
||
mode = GET_MODE (op0);
|
||
if (mode == VOIDmode)
|
||
mode = GET_MODE (op1);
|
||
|
||
start_sequence ();
|
||
op0 = force_operand (op0, NULL_RTX);
|
||
op1 = force_operand (op1, NULL_RTX);
|
||
do_compare_rtx_and_jump (op0, op1, comp, 0,
|
||
mode, NULL_RTX, NULL_RTX, label);
|
||
jump = get_last_insn ();
|
||
JUMP_LABEL (jump) = label;
|
||
LABEL_NUSES (label)++;
|
||
seq = get_insns ();
|
||
end_sequence ();
|
||
|
||
/* Add the new cond , in the new head. */
|
||
emit_insn_after(seq, BB_END(cond_bb));
|
||
}
|
||
|
||
|
||
/* Given a block B with unconditional branch at its end, get the
|
||
store the return the branch edge and the fall-thru edge in
|
||
BRANCH_EDGE and FALLTHRU_EDGE respectively. */
|
||
static void
|
||
rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge,
|
||
edge *fallthru_edge)
|
||
{
|
||
edge e = EDGE_SUCC (b, 0);
|
||
|
||
if (e->flags & EDGE_FALLTHRU)
|
||
{
|
||
*fallthru_edge = e;
|
||
*branch_edge = EDGE_SUCC (b, 1);
|
||
}
|
||
else
|
||
{
|
||
*branch_edge = e;
|
||
*fallthru_edge = EDGE_SUCC (b, 1);
|
||
}
|
||
}
|
||
|
||
|
||
/* Implementation of CFG manipulation for linearized RTL. */
|
||
struct cfg_hooks rtl_cfg_hooks = {
|
||
"rtl",
|
||
rtl_verify_flow_info,
|
||
rtl_dump_bb,
|
||
rtl_create_basic_block,
|
||
rtl_redirect_edge_and_branch,
|
||
rtl_redirect_edge_and_branch_force,
|
||
rtl_delete_block,
|
||
rtl_split_block,
|
||
rtl_move_block_after,
|
||
rtl_can_merge_blocks, /* can_merge_blocks_p */
|
||
rtl_merge_blocks,
|
||
rtl_predict_edge,
|
||
rtl_predicted_by_p,
|
||
NULL, /* can_duplicate_block_p */
|
||
NULL, /* duplicate_block */
|
||
rtl_split_edge,
|
||
rtl_make_forwarder_block,
|
||
rtl_tidy_fallthru_edge,
|
||
rtl_block_ends_with_call_p,
|
||
rtl_block_ends_with_condjump_p,
|
||
rtl_flow_call_edges_add,
|
||
NULL, /* execute_on_growing_pred */
|
||
NULL, /* execute_on_shrinking_pred */
|
||
NULL, /* duplicate loop for trees */
|
||
NULL, /* lv_add_condition_to_bb */
|
||
NULL, /* lv_adjust_loop_header_phi*/
|
||
NULL, /* extract_cond_bb_edges */
|
||
NULL /* flush_pending_stmts */
|
||
};
|
||
|
||
/* 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. */
|
||
|
||
/* We do not want to declare these functions in a header file, since they
|
||
should only be used through the cfghooks interface, and we do not want to
|
||
move them here since it would require also moving quite a lot of related
|
||
code. */
|
||
extern bool cfg_layout_can_duplicate_bb_p (basic_block);
|
||
extern basic_block cfg_layout_duplicate_bb (basic_block);
|
||
|
||
struct cfg_hooks cfg_layout_rtl_cfg_hooks = {
|
||
"cfglayout mode",
|
||
rtl_verify_flow_info_1,
|
||
rtl_dump_bb,
|
||
cfg_layout_create_basic_block,
|
||
cfg_layout_redirect_edge_and_branch,
|
||
cfg_layout_redirect_edge_and_branch_force,
|
||
cfg_layout_delete_block,
|
||
cfg_layout_split_block,
|
||
rtl_move_block_after,
|
||
cfg_layout_can_merge_blocks_p,
|
||
cfg_layout_merge_blocks,
|
||
rtl_predict_edge,
|
||
rtl_predicted_by_p,
|
||
cfg_layout_can_duplicate_bb_p,
|
||
cfg_layout_duplicate_bb,
|
||
cfg_layout_split_edge,
|
||
rtl_make_forwarder_block,
|
||
NULL,
|
||
rtl_block_ends_with_call_p,
|
||
rtl_block_ends_with_condjump_p,
|
||
rtl_flow_call_edges_add,
|
||
NULL, /* execute_on_growing_pred */
|
||
NULL, /* execute_on_shrinking_pred */
|
||
duplicate_loop_to_header_edge, /* duplicate loop for trees */
|
||
rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
|
||
NULL, /* lv_adjust_loop_header_phi*/
|
||
rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */
|
||
NULL /* flush_pending_stmts */
|
||
};
|
||
|