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| author | Tom de Vries <tom@codesourcery.com> | 2017-07-03 07:21:34 +0000 |
|---|---|---|
| committer | Tom de Vries <vries@gcc.gnu.org> | 2017-07-03 07:21:34 +0000 |
| commit | 4752be4637d8250516dc0d8171b797de2b413d81 (patch) | |
| tree | f8f4d7078d0922fe65de98e7f897120309acaf7b /gcc/tree-ssa-tail-merge.c | |
| parent | 0bbfd5540d15befe675f8bac6a5aa55df9064436 (diff) | |
| download | gcc-4752be4637d8250516dc0d8171b797de2b413d81.zip gcc-4752be4637d8250516dc0d8171b797de2b413d81.tar.gz gcc-4752be4637d8250516dc0d8171b797de2b413d81.tar.bz2 | |
Don't tail-merge blocks from different loops
2017-07-03 Tom de Vries <tom@codesourcery.com>
PR tree-optimization/81192
* tree-ssa-tail-merge.c (same_succ_hash): Use bb->loop_father->num in
hash.
(same_succ::equal): Don't find bbs to be equal if bb->loop_father
differs.
(find_same_succ_bb): Remove obsolete test on bb->loop_father->latch.
* gcc.dg/pr81192.c: Update.
From-SVN: r249894
Diffstat (limited to 'gcc/tree-ssa-tail-merge.c')
| -rw-r--r-- | gcc/tree-ssa-tail-merge.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/gcc/tree-ssa-tail-merge.c b/gcc/tree-ssa-tail-merge.c index e88072c..6fa4e5b 100644 --- a/gcc/tree-ssa-tail-merge.c +++ b/gcc/tree-ssa-tail-merge.c @@ -479,6 +479,8 @@ same_succ_hash (const same_succ *e) hstate.add_int (size); BB_SIZE (bb) = size; + hstate.add_int (bb->loop_father->num); + for (i = 0; i < e->succ_flags.length (); ++i) { flags = e->succ_flags[i]; @@ -568,6 +570,9 @@ same_succ::equal (const same_succ *e1, const same_succ *e2) if (BB_SIZE (bb1) != BB_SIZE (bb2)) return 0; + if (bb1->loop_father != bb2->loop_father) + return 0; + gsi1 = gsi_start_nondebug_bb (bb1); gsi2 = gsi_start_nondebug_bb (bb2); gsi_advance_fw_nondebug_nonlocal (&gsi1); @@ -695,15 +700,7 @@ find_same_succ_bb (basic_block bb, same_succ **same_p) edge_iterator ei; edge e; - if (bb == NULL - /* Be conservative with loop structure. It's not evident that this test - is sufficient. Before tail-merge, we've just called - loop_optimizer_finalize, and LOOPS_MAY_HAVE_MULTIPLE_LATCHES is now - set, so there's no guarantee that the loop->latch value is still valid. - But we assume that, since we've forced LOOPS_HAVE_SIMPLE_LATCHES at the - start of pre, we've kept that property intact throughout pre, and are - keeping it throughout tail-merge using this test. */ - || bb->loop_father->latch == bb) + if (bb == NULL) return; bitmap_set_bit (same->bbs, bb->index); FOR_EACH_EDGE (e, ei, bb->succs) |