/* Control flow graph building code for GNU compiler.
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/* Control flow graph building code for GNU compiler.
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Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
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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, 2007, 2008
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1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008
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Free Software Foundation, Inc.
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Free Software Foundation, Inc.
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This file is part of GCC.
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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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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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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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Software Foundation; either version 3, or (at your option) any later
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version.
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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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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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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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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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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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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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<http://www.gnu.org/licenses/>. */
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#include "config.h"
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#include "config.h"
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#include "system.h"
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#include "system.h"
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#include "coretypes.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "tm.h"
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#include "tree.h"
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#include "tree.h"
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#include "rtl.h"
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#include "rtl.h"
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#include "hard-reg-set.h"
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#include "hard-reg-set.h"
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#include "basic-block.h"
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#include "basic-block.h"
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#include "regs.h"
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#include "regs.h"
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#include "flags.h"
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#include "flags.h"
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#include "output.h"
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#include "output.h"
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#include "function.h"
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#include "function.h"
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#include "except.h"
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#include "except.h"
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#include "expr.h"
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#include "expr.h"
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#include "toplev.h"
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#include "toplev.h"
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#include "timevar.h"
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#include "timevar.h"
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static void make_edges (basic_block, basic_block, int);
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static void make_edges (basic_block, basic_block, int);
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static void make_label_edge (sbitmap, basic_block, rtx, int);
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static void make_label_edge (sbitmap, basic_block, rtx, int);
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static void find_bb_boundaries (basic_block);
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static void find_bb_boundaries (basic_block);
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static void compute_outgoing_frequencies (basic_block);
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static void compute_outgoing_frequencies (basic_block);
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|
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/* Return true if insn is something that should be contained inside basic
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/* Return true if insn is something that should be contained inside basic
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block. */
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block. */
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bool
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bool
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inside_basic_block_p (const_rtx insn)
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inside_basic_block_p (const_rtx insn)
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{
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{
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switch (GET_CODE (insn))
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switch (GET_CODE (insn))
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{
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{
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case CODE_LABEL:
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case CODE_LABEL:
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/* Avoid creating of basic block for jumptables. */
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/* Avoid creating of basic block for jumptables. */
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return (NEXT_INSN (insn) == 0
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return (NEXT_INSN (insn) == 0
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|| !JUMP_P (NEXT_INSN (insn))
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|| !JUMP_P (NEXT_INSN (insn))
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|| (GET_CODE (PATTERN (NEXT_INSN (insn))) != ADDR_VEC
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|| (GET_CODE (PATTERN (NEXT_INSN (insn))) != ADDR_VEC
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&& GET_CODE (PATTERN (NEXT_INSN (insn))) != ADDR_DIFF_VEC));
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&& GET_CODE (PATTERN (NEXT_INSN (insn))) != ADDR_DIFF_VEC));
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case JUMP_INSN:
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case JUMP_INSN:
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return (GET_CODE (PATTERN (insn)) != ADDR_VEC
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return (GET_CODE (PATTERN (insn)) != ADDR_VEC
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&& GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC);
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&& GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC);
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case CALL_INSN:
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case CALL_INSN:
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case INSN:
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case INSN:
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case DEBUG_INSN:
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case DEBUG_INSN:
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return true;
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return true;
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case BARRIER:
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case BARRIER:
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case NOTE:
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case NOTE:
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return false;
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return false;
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default:
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default:
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gcc_unreachable ();
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gcc_unreachable ();
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}
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}
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}
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}
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/* Return true if INSN may cause control flow transfer, so it should be last in
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/* Return true if INSN may cause control flow transfer, so it should be last in
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the basic block. */
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the basic block. */
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bool
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bool
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control_flow_insn_p (const_rtx insn)
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control_flow_insn_p (const_rtx insn)
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{
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{
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switch (GET_CODE (insn))
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switch (GET_CODE (insn))
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{
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{
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case NOTE:
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case NOTE:
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case CODE_LABEL:
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case CODE_LABEL:
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case DEBUG_INSN:
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case DEBUG_INSN:
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return false;
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return false;
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case JUMP_INSN:
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case JUMP_INSN:
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/* Jump insn always causes control transfer except for tablejumps. */
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/* Jump insn always causes control transfer except for tablejumps. */
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return (GET_CODE (PATTERN (insn)) != ADDR_VEC
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return (GET_CODE (PATTERN (insn)) != ADDR_VEC
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&& GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC);
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&& GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC);
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case CALL_INSN:
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case CALL_INSN:
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/* Noreturn and sibling call instructions terminate the basic blocks
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/* Noreturn and sibling call instructions terminate the basic blocks
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(but only if they happen unconditionally). */
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(but only if they happen unconditionally). */
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if ((SIBLING_CALL_P (insn)
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if ((SIBLING_CALL_P (insn)
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|| find_reg_note (insn, REG_NORETURN, 0))
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|| find_reg_note (insn, REG_NORETURN, 0))
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&& GET_CODE (PATTERN (insn)) != COND_EXEC)
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&& GET_CODE (PATTERN (insn)) != COND_EXEC)
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return true;
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return true;
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/* Call insn may return to the nonlocal goto handler. */
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/* Call insn may return to the nonlocal goto handler. */
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if (can_nonlocal_goto (insn))
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if (can_nonlocal_goto (insn))
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return true;
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return true;
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break;
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break;
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case INSN:
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case INSN:
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/* Treat trap instructions like noreturn calls (same provision). */
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/* Treat trap instructions like noreturn calls (same provision). */
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if (GET_CODE (PATTERN (insn)) == TRAP_IF
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if (GET_CODE (PATTERN (insn)) == TRAP_IF
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&& XEXP (PATTERN (insn), 0) == const1_rtx)
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&& XEXP (PATTERN (insn), 0) == const1_rtx)
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return true;
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return true;
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if (!flag_non_call_exceptions)
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if (!flag_non_call_exceptions)
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return false;
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return false;
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break;
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break;
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case BARRIER:
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case BARRIER:
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/* It is nonsense to reach barrier when looking for the
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/* It is nonsense to reach barrier when looking for the
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end of basic block, but before dead code is eliminated
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end of basic block, but before dead code is eliminated
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this may happen. */
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this may happen. */
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return false;
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return false;
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default:
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default:
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gcc_unreachable ();
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gcc_unreachable ();
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}
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}
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return can_throw_internal (insn);
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return can_throw_internal (insn);
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}
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}
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/* Create an edge between two basic blocks. FLAGS are auxiliary information
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/* Create an edge between two basic blocks. FLAGS are auxiliary information
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about the edge that is accumulated between calls. */
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about the edge that is accumulated between calls. */
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/* Create an edge from a basic block to a label. */
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/* Create an edge from a basic block to a label. */
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static void
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static void
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make_label_edge (sbitmap edge_cache, basic_block src, rtx label, int flags)
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make_label_edge (sbitmap edge_cache, basic_block src, rtx label, int flags)
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{
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{
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gcc_assert (LABEL_P (label));
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gcc_assert (LABEL_P (label));
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/* If the label was never emitted, this insn is junk, but avoid a
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/* If the label was never emitted, this insn is junk, but avoid a
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crash trying to refer to BLOCK_FOR_INSN (label). This can happen
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crash trying to refer to BLOCK_FOR_INSN (label). This can happen
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as a result of a syntax error and a diagnostic has already been
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as a result of a syntax error and a diagnostic has already been
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printed. */
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printed. */
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if (INSN_UID (label) == 0)
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if (INSN_UID (label) == 0)
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return;
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return;
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cached_make_edge (edge_cache, src, BLOCK_FOR_INSN (label), flags);
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cached_make_edge (edge_cache, src, BLOCK_FOR_INSN (label), flags);
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}
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}
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/* Create the edges generated by INSN in REGION. */
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/* Create the edges generated by INSN in REGION. */
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void
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void
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rtl_make_eh_edge (sbitmap edge_cache, basic_block src, rtx insn)
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rtl_make_eh_edge (sbitmap edge_cache, basic_block src, rtx insn)
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{
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{
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eh_landing_pad lp = get_eh_landing_pad_from_rtx (insn);
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eh_landing_pad lp = get_eh_landing_pad_from_rtx (insn);
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if (lp)
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if (lp)
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{
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{
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rtx label = lp->landing_pad;
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rtx label = lp->landing_pad;
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/* During initial rtl generation, use the post_landing_pad. */
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/* During initial rtl generation, use the post_landing_pad. */
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if (label == NULL)
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if (label == NULL)
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{
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{
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gcc_assert (lp->post_landing_pad);
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gcc_assert (lp->post_landing_pad);
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label = label_rtx (lp->post_landing_pad);
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label = label_rtx (lp->post_landing_pad);
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}
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}
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make_label_edge (edge_cache, src, label,
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make_label_edge (edge_cache, src, label,
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EDGE_ABNORMAL | EDGE_EH
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EDGE_ABNORMAL | EDGE_EH
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| (CALL_P (insn) ? EDGE_ABNORMAL_CALL : 0));
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| (CALL_P (insn) ? EDGE_ABNORMAL_CALL : 0));
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}
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}
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}
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}
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/* States of basic block as seen by find_many_sub_basic_blocks. */
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/* States of basic block as seen by find_many_sub_basic_blocks. */
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enum state {
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enum state {
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/* Basic blocks created via split_block belong to this state.
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/* Basic blocks created via split_block belong to this state.
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make_edges will examine these basic blocks to see if we need to
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make_edges will examine these basic blocks to see if we need to
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create edges going out of them. */
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create edges going out of them. */
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BLOCK_NEW = 0,
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BLOCK_NEW = 0,
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/* Basic blocks that do not need examining belong to this state.
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/* Basic blocks that do not need examining belong to this state.
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These blocks will be left intact. In particular, make_edges will
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These blocks will be left intact. In particular, make_edges will
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not create edges going out of these basic blocks. */
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not create edges going out of these basic blocks. */
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BLOCK_ORIGINAL,
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BLOCK_ORIGINAL,
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/* Basic blocks that may need splitting (due to a label appearing in
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/* Basic blocks that may need splitting (due to a label appearing in
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the middle, etc) belong to this state. After splitting them,
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the middle, etc) belong to this state. After splitting them,
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make_edges will create edges going out of them as needed. */
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make_edges will create edges going out of them as needed. */
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BLOCK_TO_SPLIT
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BLOCK_TO_SPLIT
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};
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};
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#define STATE(BB) (enum state) ((size_t) (BB)->aux)
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#define STATE(BB) (enum state) ((size_t) (BB)->aux)
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#define SET_STATE(BB, STATE) ((BB)->aux = (void *) (size_t) (STATE))
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#define SET_STATE(BB, STATE) ((BB)->aux = (void *) (size_t) (STATE))
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/* Used internally by purge_dead_tablejump_edges, ORed into state. */
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/* Used internally by purge_dead_tablejump_edges, ORed into state. */
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#define BLOCK_USED_BY_TABLEJUMP 32
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#define BLOCK_USED_BY_TABLEJUMP 32
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#define FULL_STATE(BB) ((size_t) (BB)->aux)
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#define FULL_STATE(BB) ((size_t) (BB)->aux)
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/* Identify the edges going out of basic blocks between MIN and MAX,
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/* Identify the edges going out of basic blocks between MIN and MAX,
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inclusive, that have their states set to BLOCK_NEW or
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inclusive, that have their states set to BLOCK_NEW or
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BLOCK_TO_SPLIT.
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BLOCK_TO_SPLIT.
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UPDATE_P should be nonzero if we are updating CFG and zero if we
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UPDATE_P should be nonzero if we are updating CFG and zero if we
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are building CFG from scratch. */
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are building CFG from scratch. */
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static void
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static void
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make_edges (basic_block min, basic_block max, int update_p)
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make_edges (basic_block min, basic_block max, int update_p)
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{
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{
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basic_block bb;
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basic_block bb;
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sbitmap edge_cache = NULL;
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sbitmap edge_cache = NULL;
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|
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/* Heavy use of computed goto in machine-generated code can lead to
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/* Heavy use of computed goto in machine-generated code can lead to
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nearly fully-connected CFGs. In that case we spend a significant
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nearly fully-connected CFGs. In that case we spend a significant
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amount of time searching the edge lists for duplicates. */
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amount of time searching the edge lists for duplicates. */
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if (forced_labels || cfun->cfg->max_jumptable_ents > 100)
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if (forced_labels || cfun->cfg->max_jumptable_ents > 100)
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edge_cache = sbitmap_alloc (last_basic_block);
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edge_cache = sbitmap_alloc (last_basic_block);
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|
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/* By nature of the way these get numbered, ENTRY_BLOCK_PTR->next_bb block
|
/* By nature of the way these get numbered, ENTRY_BLOCK_PTR->next_bb block
|
is always the entry. */
|
is always the entry. */
|
if (min == ENTRY_BLOCK_PTR->next_bb)
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if (min == ENTRY_BLOCK_PTR->next_bb)
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make_edge (ENTRY_BLOCK_PTR, min, EDGE_FALLTHRU);
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make_edge (ENTRY_BLOCK_PTR, min, EDGE_FALLTHRU);
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|
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FOR_BB_BETWEEN (bb, min, max->next_bb, next_bb)
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FOR_BB_BETWEEN (bb, min, max->next_bb, next_bb)
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{
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{
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rtx insn, x;
|
rtx insn, x;
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enum rtx_code code;
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enum rtx_code code;
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edge e;
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edge e;
|
edge_iterator ei;
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edge_iterator ei;
|
|
|
if (STATE (bb) == BLOCK_ORIGINAL)
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if (STATE (bb) == BLOCK_ORIGINAL)
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continue;
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continue;
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|
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/* If we have an edge cache, cache edges going out of BB. */
|
/* If we have an edge cache, cache edges going out of BB. */
|
if (edge_cache)
|
if (edge_cache)
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{
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{
|
sbitmap_zero (edge_cache);
|
sbitmap_zero (edge_cache);
|
if (update_p)
|
if (update_p)
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{
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{
|
FOR_EACH_EDGE (e, ei, bb->succs)
|
FOR_EACH_EDGE (e, ei, bb->succs)
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if (e->dest != EXIT_BLOCK_PTR)
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if (e->dest != EXIT_BLOCK_PTR)
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SET_BIT (edge_cache, e->dest->index);
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SET_BIT (edge_cache, e->dest->index);
|
}
|
}
|
}
|
}
|
|
|
if (LABEL_P (BB_HEAD (bb))
|
if (LABEL_P (BB_HEAD (bb))
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&& LABEL_ALT_ENTRY_P (BB_HEAD (bb)))
|
&& LABEL_ALT_ENTRY_P (BB_HEAD (bb)))
|
cached_make_edge (NULL, ENTRY_BLOCK_PTR, bb, 0);
|
cached_make_edge (NULL, ENTRY_BLOCK_PTR, bb, 0);
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|
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/* Examine the last instruction of the block, and discover the
|
/* Examine the last instruction of the block, and discover the
|
ways we can leave the block. */
|
ways we can leave the block. */
|
|
|
insn = BB_END (bb);
|
insn = BB_END (bb);
|
code = GET_CODE (insn);
|
code = GET_CODE (insn);
|
|
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/* A branch. */
|
/* A branch. */
|
if (code == JUMP_INSN)
|
if (code == JUMP_INSN)
|
{
|
{
|
rtx tmp;
|
rtx tmp;
|
|
|
/* Recognize a non-local goto as a branch outside the
|
/* Recognize a non-local goto as a branch outside the
|
current function. */
|
current function. */
|
if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX))
|
if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX))
|
;
|
;
|
|
|
/* Recognize a tablejump and do the right thing. */
|
/* Recognize a tablejump and do the right thing. */
|
else if (tablejump_p (insn, NULL, &tmp))
|
else if (tablejump_p (insn, NULL, &tmp))
|
{
|
{
|
rtvec vec;
|
rtvec vec;
|
int j;
|
int j;
|
|
|
if (GET_CODE (PATTERN (tmp)) == ADDR_VEC)
|
if (GET_CODE (PATTERN (tmp)) == ADDR_VEC)
|
vec = XVEC (PATTERN (tmp), 0);
|
vec = XVEC (PATTERN (tmp), 0);
|
else
|
else
|
vec = XVEC (PATTERN (tmp), 1);
|
vec = XVEC (PATTERN (tmp), 1);
|
|
|
for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j)
|
for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j)
|
make_label_edge (edge_cache, bb,
|
make_label_edge (edge_cache, bb,
|
XEXP (RTVEC_ELT (vec, j), 0), 0);
|
XEXP (RTVEC_ELT (vec, j), 0), 0);
|
|
|
/* Some targets (eg, ARM) emit a conditional jump that also
|
/* Some targets (eg, ARM) emit a conditional jump that also
|
contains the out-of-range target. Scan for these and
|
contains the out-of-range target. Scan for these and
|
add an edge if necessary. */
|
add an edge if necessary. */
|
if ((tmp = single_set (insn)) != NULL
|
if ((tmp = single_set (insn)) != NULL
|
&& SET_DEST (tmp) == pc_rtx
|
&& SET_DEST (tmp) == pc_rtx
|
&& GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE
|
&& GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE
|
&& GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF)
|
&& GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF)
|
make_label_edge (edge_cache, bb,
|
make_label_edge (edge_cache, bb,
|
XEXP (XEXP (SET_SRC (tmp), 2), 0), 0);
|
XEXP (XEXP (SET_SRC (tmp), 2), 0), 0);
|
}
|
}
|
|
|
/* If this is a computed jump, then mark it as reaching
|
/* If this is a computed jump, then mark it as reaching
|
everything on the forced_labels list. */
|
everything on the forced_labels list. */
|
else if (computed_jump_p (insn))
|
else if (computed_jump_p (insn))
|
{
|
{
|
for (x = forced_labels; x; x = XEXP (x, 1))
|
for (x = forced_labels; x; x = XEXP (x, 1))
|
make_label_edge (edge_cache, bb, XEXP (x, 0), EDGE_ABNORMAL);
|
make_label_edge (edge_cache, bb, XEXP (x, 0), EDGE_ABNORMAL);
|
}
|
}
|
|
|
/* Returns create an exit out. */
|
/* Returns create an exit out. */
|
else if (returnjump_p (insn))
|
else if (returnjump_p (insn))
|
cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR, 0);
|
cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR, 0);
|
|
|
/* Recognize asm goto and do the right thing. */
|
/* Recognize asm goto and do the right thing. */
|
else if ((tmp = extract_asm_operands (PATTERN (insn))) != NULL)
|
else if ((tmp = extract_asm_operands (PATTERN (insn))) != NULL)
|
{
|
{
|
int i, n = ASM_OPERANDS_LABEL_LENGTH (tmp);
|
int i, n = ASM_OPERANDS_LABEL_LENGTH (tmp);
|
for (i = 0; i < n; ++i)
|
for (i = 0; i < n; ++i)
|
make_label_edge (edge_cache, bb,
|
make_label_edge (edge_cache, bb,
|
XEXP (ASM_OPERANDS_LABEL (tmp, i), 0), 0);
|
XEXP (ASM_OPERANDS_LABEL (tmp, i), 0), 0);
|
}
|
}
|
|
|
/* Otherwise, we have a plain conditional or unconditional jump. */
|
/* Otherwise, we have a plain conditional or unconditional jump. */
|
else
|
else
|
{
|
{
|
gcc_assert (JUMP_LABEL (insn));
|
gcc_assert (JUMP_LABEL (insn));
|
make_label_edge (edge_cache, bb, JUMP_LABEL (insn), 0);
|
make_label_edge (edge_cache, bb, JUMP_LABEL (insn), 0);
|
}
|
}
|
}
|
}
|
|
|
/* If this is a sibling call insn, then this is in effect a combined call
|
/* If this is a sibling call insn, then this is in effect a combined call
|
and return, and so we need an edge to the exit block. No need to
|
and return, and so we need an edge to the exit block. No need to
|
worry about EH edges, since we wouldn't have created the sibling call
|
worry about EH edges, since we wouldn't have created the sibling call
|
in the first place. */
|
in the first place. */
|
if (code == CALL_INSN && SIBLING_CALL_P (insn))
|
if (code == CALL_INSN && SIBLING_CALL_P (insn))
|
cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR,
|
cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR,
|
EDGE_SIBCALL | EDGE_ABNORMAL);
|
EDGE_SIBCALL | EDGE_ABNORMAL);
|
|
|
/* If this is a CALL_INSN, then mark it as reaching the active EH
|
/* If this is a CALL_INSN, then mark it as reaching the active EH
|
handler for this CALL_INSN. If we're handling non-call
|
handler for this CALL_INSN. If we're handling non-call
|
exceptions then any insn can reach any of the active handlers.
|
exceptions then any insn can reach any of the active handlers.
|
Also mark the CALL_INSN as reaching any nonlocal goto handler. */
|
Also mark the CALL_INSN as reaching any nonlocal goto handler. */
|
else if (code == CALL_INSN || flag_non_call_exceptions)
|
else if (code == CALL_INSN || flag_non_call_exceptions)
|
{
|
{
|
/* Add any appropriate EH edges. */
|
/* Add any appropriate EH edges. */
|
rtl_make_eh_edge (edge_cache, bb, insn);
|
rtl_make_eh_edge (edge_cache, bb, insn);
|
|
|
if (code == CALL_INSN && nonlocal_goto_handler_labels)
|
if (code == CALL_INSN && nonlocal_goto_handler_labels)
|
{
|
{
|
/* ??? This could be made smarter: in some cases it's possible
|
/* ??? This could be made smarter: in some cases it's possible
|
to tell that certain calls will not do a nonlocal goto.
|
to tell that certain calls will not do a nonlocal goto.
|
For example, if the nested functions that do the nonlocal
|
For example, if the nested functions that do the nonlocal
|
gotos do not have their addresses taken, then only calls to
|
gotos do not have their addresses taken, then only calls to
|
those functions or to other nested functions that use them
|
those functions or to other nested functions that use them
|
could possibly do nonlocal gotos. */
|
could possibly do nonlocal gotos. */
|
if (can_nonlocal_goto (insn))
|
if (can_nonlocal_goto (insn))
|
for (x = nonlocal_goto_handler_labels; x; x = XEXP (x, 1))
|
for (x = nonlocal_goto_handler_labels; x; x = XEXP (x, 1))
|
make_label_edge (edge_cache, bb, XEXP (x, 0),
|
make_label_edge (edge_cache, bb, XEXP (x, 0),
|
EDGE_ABNORMAL | EDGE_ABNORMAL_CALL);
|
EDGE_ABNORMAL | EDGE_ABNORMAL_CALL);
|
}
|
}
|
}
|
}
|
|
|
/* Find out if we can drop through to the next block. */
|
/* Find out if we can drop through to the next block. */
|
insn = NEXT_INSN (insn);
|
insn = NEXT_INSN (insn);
|
e = find_edge (bb, EXIT_BLOCK_PTR);
|
e = find_edge (bb, EXIT_BLOCK_PTR);
|
if (e && e->flags & EDGE_FALLTHRU)
|
if (e && e->flags & EDGE_FALLTHRU)
|
insn = NULL;
|
insn = NULL;
|
|
|
while (insn
|
while (insn
|
&& NOTE_P (insn)
|
&& NOTE_P (insn)
|
&& NOTE_KIND (insn) != NOTE_INSN_BASIC_BLOCK)
|
&& NOTE_KIND (insn) != NOTE_INSN_BASIC_BLOCK)
|
insn = NEXT_INSN (insn);
|
insn = NEXT_INSN (insn);
|
|
|
if (!insn)
|
if (!insn)
|
cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR, EDGE_FALLTHRU);
|
cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR, EDGE_FALLTHRU);
|
else if (bb->next_bb != EXIT_BLOCK_PTR)
|
else if (bb->next_bb != EXIT_BLOCK_PTR)
|
{
|
{
|
if (insn == BB_HEAD (bb->next_bb))
|
if (insn == BB_HEAD (bb->next_bb))
|
cached_make_edge (edge_cache, bb, bb->next_bb, EDGE_FALLTHRU);
|
cached_make_edge (edge_cache, bb, bb->next_bb, EDGE_FALLTHRU);
|
}
|
}
|
}
|
}
|
|
|
if (edge_cache)
|
if (edge_cache)
|
sbitmap_vector_free (edge_cache);
|
sbitmap_vector_free (edge_cache);
|
}
|
}
|
|
|
static void
|
static void
|
mark_tablejump_edge (rtx label)
|
mark_tablejump_edge (rtx label)
|
{
|
{
|
basic_block bb;
|
basic_block bb;
|
|
|
gcc_assert (LABEL_P (label));
|
gcc_assert (LABEL_P (label));
|
/* See comment in make_label_edge. */
|
/* See comment in make_label_edge. */
|
if (INSN_UID (label) == 0)
|
if (INSN_UID (label) == 0)
|
return;
|
return;
|
bb = BLOCK_FOR_INSN (label);
|
bb = BLOCK_FOR_INSN (label);
|
SET_STATE (bb, FULL_STATE (bb) | BLOCK_USED_BY_TABLEJUMP);
|
SET_STATE (bb, FULL_STATE (bb) | BLOCK_USED_BY_TABLEJUMP);
|
}
|
}
|
|
|
static void
|
static void
|
purge_dead_tablejump_edges (basic_block bb, rtx table)
|
purge_dead_tablejump_edges (basic_block bb, rtx table)
|
{
|
{
|
rtx insn = BB_END (bb), tmp;
|
rtx insn = BB_END (bb), tmp;
|
rtvec vec;
|
rtvec vec;
|
int j;
|
int j;
|
edge_iterator ei;
|
edge_iterator ei;
|
edge e;
|
edge e;
|
|
|
if (GET_CODE (PATTERN (table)) == ADDR_VEC)
|
if (GET_CODE (PATTERN (table)) == ADDR_VEC)
|
vec = XVEC (PATTERN (table), 0);
|
vec = XVEC (PATTERN (table), 0);
|
else
|
else
|
vec = XVEC (PATTERN (table), 1);
|
vec = XVEC (PATTERN (table), 1);
|
|
|
for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j)
|
for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j)
|
mark_tablejump_edge (XEXP (RTVEC_ELT (vec, j), 0));
|
mark_tablejump_edge (XEXP (RTVEC_ELT (vec, j), 0));
|
|
|
/* Some targets (eg, ARM) emit a conditional jump that also
|
/* Some targets (eg, ARM) emit a conditional jump that also
|
contains the out-of-range target. Scan for these and
|
contains the out-of-range target. Scan for these and
|
add an edge if necessary. */
|
add an edge if necessary. */
|
if ((tmp = single_set (insn)) != NULL
|
if ((tmp = single_set (insn)) != NULL
|
&& SET_DEST (tmp) == pc_rtx
|
&& SET_DEST (tmp) == pc_rtx
|
&& GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE
|
&& GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE
|
&& GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF)
|
&& GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF)
|
mark_tablejump_edge (XEXP (XEXP (SET_SRC (tmp), 2), 0));
|
mark_tablejump_edge (XEXP (XEXP (SET_SRC (tmp), 2), 0));
|
|
|
for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
|
for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
|
{
|
{
|
if (FULL_STATE (e->dest) & BLOCK_USED_BY_TABLEJUMP)
|
if (FULL_STATE (e->dest) & BLOCK_USED_BY_TABLEJUMP)
|
SET_STATE (e->dest, FULL_STATE (e->dest)
|
SET_STATE (e->dest, FULL_STATE (e->dest)
|
& ~(size_t) BLOCK_USED_BY_TABLEJUMP);
|
& ~(size_t) BLOCK_USED_BY_TABLEJUMP);
|
else if (!(e->flags & (EDGE_ABNORMAL | EDGE_EH)))
|
else if (!(e->flags & (EDGE_ABNORMAL | EDGE_EH)))
|
{
|
{
|
remove_edge (e);
|
remove_edge (e);
|
continue;
|
continue;
|
}
|
}
|
ei_next (&ei);
|
ei_next (&ei);
|
}
|
}
|
}
|
}
|
|
|
/* Scan basic block BB for possible BB boundaries inside the block
|
/* Scan basic block BB for possible BB boundaries inside the block
|
and create new basic blocks in the progress. */
|
and create new basic blocks in the progress. */
|
|
|
static void
|
static void
|
find_bb_boundaries (basic_block bb)
|
find_bb_boundaries (basic_block bb)
|
{
|
{
|
basic_block orig_bb = bb;
|
basic_block orig_bb = bb;
|
rtx insn = BB_HEAD (bb);
|
rtx insn = BB_HEAD (bb);
|
rtx end = BB_END (bb), x;
|
rtx end = BB_END (bb), x;
|
rtx table;
|
rtx table;
|
rtx flow_transfer_insn = NULL_RTX;
|
rtx flow_transfer_insn = NULL_RTX;
|
edge fallthru = NULL;
|
edge fallthru = NULL;
|
|
|
if (insn == BB_END (bb))
|
if (insn == BB_END (bb))
|
return;
|
return;
|
|
|
if (LABEL_P (insn))
|
if (LABEL_P (insn))
|
insn = NEXT_INSN (insn);
|
insn = NEXT_INSN (insn);
|
|
|
/* Scan insn chain and try to find new basic block boundaries. */
|
/* Scan insn chain and try to find new basic block boundaries. */
|
while (1)
|
while (1)
|
{
|
{
|
enum rtx_code code = GET_CODE (insn);
|
enum rtx_code code = GET_CODE (insn);
|
|
|
/* In case we've previously seen an insn that effects a control
|
/* In case we've previously seen an insn that effects a control
|
flow transfer, split the block. */
|
flow transfer, split the block. */
|
if ((flow_transfer_insn || code == CODE_LABEL)
|
if ((flow_transfer_insn || code == CODE_LABEL)
|
&& inside_basic_block_p (insn))
|
&& inside_basic_block_p (insn))
|
{
|
{
|
fallthru = split_block (bb, PREV_INSN (insn));
|
fallthru = split_block (bb, PREV_INSN (insn));
|
if (flow_transfer_insn)
|
if (flow_transfer_insn)
|
{
|
{
|
BB_END (bb) = flow_transfer_insn;
|
BB_END (bb) = flow_transfer_insn;
|
|
|
/* Clean up the bb field for the insns between the blocks. */
|
/* Clean up the bb field for the insns between the blocks. */
|
for (x = NEXT_INSN (flow_transfer_insn);
|
for (x = NEXT_INSN (flow_transfer_insn);
|
x != BB_HEAD (fallthru->dest);
|
x != BB_HEAD (fallthru->dest);
|
x = NEXT_INSN (x))
|
x = NEXT_INSN (x))
|
if (!BARRIER_P (x))
|
if (!BARRIER_P (x))
|
set_block_for_insn (x, NULL);
|
set_block_for_insn (x, NULL);
|
}
|
}
|
|
|
bb = fallthru->dest;
|
bb = fallthru->dest;
|
remove_edge (fallthru);
|
remove_edge (fallthru);
|
flow_transfer_insn = NULL_RTX;
|
flow_transfer_insn = NULL_RTX;
|
if (code == CODE_LABEL && LABEL_ALT_ENTRY_P (insn))
|
if (code == CODE_LABEL && LABEL_ALT_ENTRY_P (insn))
|
make_edge (ENTRY_BLOCK_PTR, bb, 0);
|
make_edge (ENTRY_BLOCK_PTR, bb, 0);
|
}
|
}
|
else if (code == BARRIER)
|
else if (code == BARRIER)
|
{
|
{
|
/* __builtin_unreachable () may cause a barrier to be emitted in
|
/* __builtin_unreachable () may cause a barrier to be emitted in
|
the middle of a BB. We need to split it in the same manner as
|
the middle of a BB. We need to split it in the same manner as
|
if the barrier were preceded by a control_flow_insn_p insn. */
|
if the barrier were preceded by a control_flow_insn_p insn. */
|
if (!flow_transfer_insn)
|
if (!flow_transfer_insn)
|
flow_transfer_insn = prev_nonnote_insn_bb (insn);
|
flow_transfer_insn = prev_nonnote_insn_bb (insn);
|
}
|
}
|
|
|
if (control_flow_insn_p (insn))
|
if (control_flow_insn_p (insn))
|
flow_transfer_insn = insn;
|
flow_transfer_insn = insn;
|
if (insn == end)
|
if (insn == end)
|
break;
|
break;
|
insn = NEXT_INSN (insn);
|
insn = NEXT_INSN (insn);
|
}
|
}
|
|
|
/* In case expander replaced normal insn by sequence terminating by
|
/* In case expander replaced normal insn by sequence terminating by
|
return and barrier, or possibly other sequence not behaving like
|
return and barrier, or possibly other sequence not behaving like
|
ordinary jump, we need to take care and move basic block boundary. */
|
ordinary jump, we need to take care and move basic block boundary. */
|
if (flow_transfer_insn)
|
if (flow_transfer_insn)
|
{
|
{
|
BB_END (bb) = flow_transfer_insn;
|
BB_END (bb) = flow_transfer_insn;
|
|
|
/* Clean up the bb field for the insns that do not belong to BB. */
|
/* Clean up the bb field for the insns that do not belong to BB. */
|
x = flow_transfer_insn;
|
x = flow_transfer_insn;
|
while (x != end)
|
while (x != end)
|
{
|
{
|
x = NEXT_INSN (x);
|
x = NEXT_INSN (x);
|
if (!BARRIER_P (x))
|
if (!BARRIER_P (x))
|
set_block_for_insn (x, NULL);
|
set_block_for_insn (x, NULL);
|
}
|
}
|
}
|
}
|
|
|
/* We've possibly replaced the conditional jump by conditional jump
|
/* We've possibly replaced the conditional jump by conditional jump
|
followed by cleanup at fallthru edge, so the outgoing edges may
|
followed by cleanup at fallthru edge, so the outgoing edges may
|
be dead. */
|
be dead. */
|
purge_dead_edges (bb);
|
purge_dead_edges (bb);
|
|
|
/* purge_dead_edges doesn't handle tablejump's, but if we have split the
|
/* purge_dead_edges doesn't handle tablejump's, but if we have split the
|
basic block, we might need to kill some edges. */
|
basic block, we might need to kill some edges. */
|
if (bb != orig_bb && tablejump_p (BB_END (bb), NULL, &table))
|
if (bb != orig_bb && tablejump_p (BB_END (bb), NULL, &table))
|
purge_dead_tablejump_edges (bb, table);
|
purge_dead_tablejump_edges (bb, table);
|
}
|
}
|
|
|
/* Assume that frequency of basic block B is known. Compute frequencies
|
/* Assume that frequency of basic block B is known. Compute frequencies
|
and probabilities of outgoing edges. */
|
and probabilities of outgoing edges. */
|
|
|
static void
|
static void
|
compute_outgoing_frequencies (basic_block b)
|
compute_outgoing_frequencies (basic_block b)
|
{
|
{
|
edge e, f;
|
edge e, f;
|
edge_iterator ei;
|
edge_iterator ei;
|
|
|
if (EDGE_COUNT (b->succs) == 2)
|
if (EDGE_COUNT (b->succs) == 2)
|
{
|
{
|
rtx note = find_reg_note (BB_END (b), REG_BR_PROB, NULL);
|
rtx note = find_reg_note (BB_END (b), REG_BR_PROB, NULL);
|
int probability;
|
int probability;
|
|
|
if (note)
|
if (note)
|
{
|
{
|
probability = INTVAL (XEXP (note, 0));
|
probability = INTVAL (XEXP (note, 0));
|
e = BRANCH_EDGE (b);
|
e = BRANCH_EDGE (b);
|
e->probability = probability;
|
e->probability = probability;
|
e->count = ((b->count * probability + REG_BR_PROB_BASE / 2)
|
e->count = ((b->count * probability + REG_BR_PROB_BASE / 2)
|
/ REG_BR_PROB_BASE);
|
/ REG_BR_PROB_BASE);
|
f = FALLTHRU_EDGE (b);
|
f = FALLTHRU_EDGE (b);
|
f->probability = REG_BR_PROB_BASE - probability;
|
f->probability = REG_BR_PROB_BASE - probability;
|
f->count = b->count - e->count;
|
f->count = b->count - e->count;
|
return;
|
return;
|
}
|
}
|
}
|
}
|
|
|
if (single_succ_p (b))
|
if (single_succ_p (b))
|
{
|
{
|
e = single_succ_edge (b);
|
e = single_succ_edge (b);
|
e->probability = REG_BR_PROB_BASE;
|
e->probability = REG_BR_PROB_BASE;
|
e->count = b->count;
|
e->count = b->count;
|
return;
|
return;
|
}
|
}
|
guess_outgoing_edge_probabilities (b);
|
guess_outgoing_edge_probabilities (b);
|
if (b->count)
|
if (b->count)
|
FOR_EACH_EDGE (e, ei, b->succs)
|
FOR_EACH_EDGE (e, ei, b->succs)
|
e->count = ((b->count * e->probability + REG_BR_PROB_BASE / 2)
|
e->count = ((b->count * e->probability + REG_BR_PROB_BASE / 2)
|
/ REG_BR_PROB_BASE);
|
/ REG_BR_PROB_BASE);
|
}
|
}
|
|
|
/* Assume that some pass has inserted labels or control flow
|
/* Assume that some pass has inserted labels or control flow
|
instructions within a basic block. Split basic blocks as needed
|
instructions within a basic block. Split basic blocks as needed
|
and create edges. */
|
and create edges. */
|
|
|
void
|
void
|
find_many_sub_basic_blocks (sbitmap blocks)
|
find_many_sub_basic_blocks (sbitmap blocks)
|
{
|
{
|
basic_block bb, min, max;
|
basic_block bb, min, max;
|
|
|
FOR_EACH_BB (bb)
|
FOR_EACH_BB (bb)
|
SET_STATE (bb,
|
SET_STATE (bb,
|
TEST_BIT (blocks, bb->index) ? BLOCK_TO_SPLIT : BLOCK_ORIGINAL);
|
TEST_BIT (blocks, bb->index) ? BLOCK_TO_SPLIT : BLOCK_ORIGINAL);
|
|
|
FOR_EACH_BB (bb)
|
FOR_EACH_BB (bb)
|
if (STATE (bb) == BLOCK_TO_SPLIT)
|
if (STATE (bb) == BLOCK_TO_SPLIT)
|
find_bb_boundaries (bb);
|
find_bb_boundaries (bb);
|
|
|
FOR_EACH_BB (bb)
|
FOR_EACH_BB (bb)
|
if (STATE (bb) != BLOCK_ORIGINAL)
|
if (STATE (bb) != BLOCK_ORIGINAL)
|
break;
|
break;
|
|
|
min = max = bb;
|
min = max = bb;
|
for (; bb != EXIT_BLOCK_PTR; bb = bb->next_bb)
|
for (; bb != EXIT_BLOCK_PTR; bb = bb->next_bb)
|
if (STATE (bb) != BLOCK_ORIGINAL)
|
if (STATE (bb) != BLOCK_ORIGINAL)
|
max = bb;
|
max = bb;
|
|
|
/* Now re-scan and wire in all edges. This expect simple (conditional)
|
/* Now re-scan and wire in all edges. This expect simple (conditional)
|
jumps at the end of each new basic blocks. */
|
jumps at the end of each new basic blocks. */
|
make_edges (min, max, 1);
|
make_edges (min, max, 1);
|
|
|
/* Update branch probabilities. Expect only (un)conditional jumps
|
/* Update branch probabilities. Expect only (un)conditional jumps
|
to be created with only the forward edges. */
|
to be created with only the forward edges. */
|
if (profile_status != PROFILE_ABSENT)
|
if (profile_status != PROFILE_ABSENT)
|
FOR_BB_BETWEEN (bb, min, max->next_bb, next_bb)
|
FOR_BB_BETWEEN (bb, min, max->next_bb, next_bb)
|
{
|
{
|
edge e;
|
edge e;
|
edge_iterator ei;
|
edge_iterator ei;
|
|
|
if (STATE (bb) == BLOCK_ORIGINAL)
|
if (STATE (bb) == BLOCK_ORIGINAL)
|
continue;
|
continue;
|
if (STATE (bb) == BLOCK_NEW)
|
if (STATE (bb) == BLOCK_NEW)
|
{
|
{
|
bb->count = 0;
|
bb->count = 0;
|
bb->frequency = 0;
|
bb->frequency = 0;
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
{
|
{
|
bb->count += e->count;
|
bb->count += e->count;
|
bb->frequency += EDGE_FREQUENCY (e);
|
bb->frequency += EDGE_FREQUENCY (e);
|
}
|
}
|
}
|
}
|
|
|
compute_outgoing_frequencies (bb);
|
compute_outgoing_frequencies (bb);
|
}
|
}
|
|
|
FOR_EACH_BB (bb)
|
FOR_EACH_BB (bb)
|
SET_STATE (bb, 0);
|
SET_STATE (bb, 0);
|
}
|
}
|
|
|
