diff options
Diffstat (limited to 'gcc/jump.c')
| -rw-r--r-- | gcc/jump.c | 82 |
1 files changed, 66 insertions, 16 deletions
diff --git a/gcc/jump.c b/gcc/jump.c index ef031f2a8a1..7c81c742fc5 100644 --- a/gcc/jump.c +++ b/gcc/jump.c @@ -1,6 +1,6 @@ /* Optimize jump instructions, for GNU compiler. Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997 - 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc. + 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. This file is part of GCC. @@ -59,6 +59,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA or even change what is live at any point. So perhaps let combiner do it. */ +static rtx next_nonnote_insn_in_loop PARAMS ((rtx)); static int init_label_info PARAMS ((rtx)); static void mark_all_labels PARAMS ((rtx)); static int duplicate_loop_exit_test PARAMS ((rtx)); @@ -119,6 +120,27 @@ cleanup_barriers () } } +/* Return the next insn after INSN that is not a NOTE and is in the loop, + i.e. when there is no such INSN before NOTE_INSN_LOOP_END return NULL_RTX. + This routine does not look inside SEQUENCEs. */ + +static rtx +next_nonnote_insn_in_loop (insn) + rtx insn; +{ + while (insn) + { + insn = NEXT_INSN (insn); + if (insn == 0 || GET_CODE (insn) != NOTE) + break; + if (GET_CODE (insn) == NOTE + && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) + return NULL_RTX; + } + + return insn; +} + void copy_loop_headers (f) rtx f; @@ -137,7 +159,7 @@ copy_loop_headers (f) the values of regno_first_uid and regno_last_uid. */ if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG - && (temp1 = next_nonnote_insn (insn)) != 0 + && (temp1 = next_nonnote_insn_in_loop (insn)) != 0 && any_uncondjump_p (temp1) && onlyjump_p (temp1)) { temp = PREV_INSN (insn); @@ -293,7 +315,8 @@ duplicate_loop_exit_test (loop_start) rtx insn, set, reg, p, link; rtx copy = 0, first_copy = 0; int num_insns = 0; - rtx exitcode = NEXT_INSN (JUMP_LABEL (next_nonnote_insn (loop_start))); + rtx exitcode + = NEXT_INSN (JUMP_LABEL (next_nonnote_insn_in_loop (loop_start))); rtx lastexit; int max_reg = max_reg_num (); rtx *reg_map = 0; @@ -1057,6 +1080,22 @@ simplejump_p (insn) && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF); } +/* Return 1 if INSN is an tablejump. */ + +int +tablejump_p (insn) + rtx insn; +{ + rtx table; + return (GET_CODE (insn) == JUMP_INSN + && JUMP_LABEL (insn) + && NEXT_INSN (JUMP_LABEL (insn)) + && (table = next_active_insn (JUMP_LABEL (insn))) + && GET_CODE (table) == JUMP_INSN + && (GET_CODE (PATTERN (table)) == ADDR_VEC + || GET_CODE (PATTERN (table)) == ADDR_DIFF_VEC)); +} + /* Return nonzero if INSN is a (possibly) conditional jump and nothing more. @@ -1877,14 +1916,14 @@ delete_for_peephole (from, to) is also an unconditional jump in that case. */ } -/* We have determined that INSN is never reached, and are about to - delete it. Print a warning if the user asked for one. +/* We have determined that AVOIDED_INSN is never reached, and are + about to delete it. If the insn chain between AVOIDED_INSN and + FINISH contains more than one line from the current function, and + contains at least one operation, print a warning if the user asked + for it. If FINISH is NULL, look between AVOIDED_INSN and a LABEL. - To try to make this warning more useful, this should only be called - once per basic block not reached, and it only warns when the basic - block contains more than one line from the current function, and - contains at least one operation. CSE and inlining can duplicate insns, - so it's possible to get spurious warnings from this. */ + CSE and inlining can duplicate insns, so it's possible to get + spurious warnings from this. */ void never_reached_warning (avoided_insn, finish) @@ -1894,15 +1933,26 @@ never_reached_warning (avoided_insn, finish) rtx a_line_note = NULL; int two_avoided_lines = 0, contains_insn = 0, reached_end = 0; - if (! warn_notreached) + if (!warn_notreached) return; - /* Scan forwards, looking at LINE_NUMBER notes, until - we hit a LABEL or we run out of insns. */ + /* Back up to the first of any NOTEs preceding avoided_insn; flow passes + us the head of a block, a NOTE_INSN_BASIC_BLOCK, which often follows + the line note. */ + for (insn = PREV_INSN (avoided_insn); ; insn = PREV_INSN (insn)) + if (GET_CODE (insn) != NOTE) + { + insn = NEXT_INSN (insn); + break; + } + + /* Scan forwards, looking at LINE_NUMBER notes, until we hit a LABEL + in case FINISH is NULL, otherwise until we run out of insns. */ - for (insn = avoided_insn; insn != NULL; insn = NEXT_INSN (insn)) + for (; insn != NULL; insn = NEXT_INSN (insn)) { - if (finish == NULL && GET_CODE (insn) == CODE_LABEL) + if ((finish == NULL && GET_CODE (insn) == CODE_LABEL) + || GET_CODE (insn) == BARRIER) break; if (GET_CODE (insn) == NOTE /* A line number note? */ @@ -1916,7 +1966,7 @@ never_reached_warning (avoided_insn, finish) } else if (INSN_P (insn)) { - if (reached_end || a_line_note == NULL) + if (reached_end) break; contains_insn = 1; } |