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| author | Jakub Jelinek <jakub@redhat.com> | 2009-10-26 21:21:09 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2009-10-26 21:21:09 +0100 |
| commit | 7752e52262ccc0eb26d8d58008bd3368650b688c (patch) | |
| tree | 7f67ad702c8066bb4a2237aa09d28bd7f8cfe6ed /gcc/cfgcleanup.c | |
| parent | bde2d108c203ed057b7faa3daba72ecbe223c684 (diff) | |
| download | gcc-7752e52262ccc0eb26d8d58008bd3368650b688c.tar.gz | |
re PR bootstrap/41345 (bootstrap comparison failure with --disable-checking)
PR bootstrap/41345
* cfgcleanup.c (trivially_empty_bb_p): New function.
(try_optimize_bb): Use it instead of checking BB_HEAD == BB_END.
* gcc.dg/pr41345.c: New test.
From-SVN: r153569
Diffstat (limited to 'gcc/cfgcleanup.c')
| -rw-r--r-- | gcc/cfgcleanup.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c index cfb19b60275..ffe36e45a9e 100644 --- a/gcc/cfgcleanup.c +++ b/gcc/cfgcleanup.c @@ -958,7 +958,7 @@ old_insns_match_p (int mode ATTRIBUTE_UNUSED, rtx i1, rtx i2) if (NOTE_INSN_BASIC_BLOCK_P (i1) && NOTE_INSN_BASIC_BLOCK_P (i2)) return true; - p1 = PATTERN (i1); + p1 = PATTERN (i1); p2 = PATTERN (i2); if (GET_CODE (p1) != GET_CODE (p2)) @@ -1814,6 +1814,24 @@ try_crossjump_bb (int mode, basic_block bb) return changed; } +/* Return true if BB contains just bb note, or bb note followed + by only DEBUG_INSNs. */ + +static bool +trivially_empty_bb_p (basic_block bb) +{ + rtx insn = BB_END (bb); + + while (1) + { + if (insn == BB_HEAD (bb)) + return true; + if (!DEBUG_INSN_P (insn)) + return false; + insn = PREV_INSN (insn); + } +} + /* Do simple CFG optimizations - basic block merging, simplifying of jump instructions etc. Return nonzero if changes were made. */ @@ -1865,14 +1883,10 @@ try_optimize_cfg (int mode) __builtin_unreachable (). */ if (EDGE_COUNT (b->preds) == 0 || (EDGE_COUNT (b->succs) == 0 - && BB_HEAD (b) == BB_END (b) + && trivially_empty_bb_p (b) && single_succ_edge (ENTRY_BLOCK_PTR)->dest != b)) { c = b->prev_bb; - if (dump_file) - fprintf (dump_file, "Deleting block %i.\n", - b->index); - delete_basic_block (b); if (!(mode & CLEANUP_CFGLAYOUT)) changed = true; |