From 4752be4637d8250516dc0d8171b797de2b413d81 Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Mon, 3 Jul 2017 07:21:34 +0000 Subject: [PATCH] Don't tail-merge blocks from different loops 2017-07-03 Tom de Vries 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 --- gcc/ChangeLog | 9 +++++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/pr81192.c | 2 +- gcc/tree-ssa-tail-merge.c | 15 ++++++--------- 4 files changed, 21 insertions(+), 10 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7284fef2806..18f23c09f31 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,12 @@ +2017-07-03 Tom de Vries + + 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. + 2017-07-03 Tom de Vries PR tree-optimization/81192 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index dda405aa9e7..12d441eb010 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-07-03 Tom de Vries + + PR tree-optimization/81192 + * gcc.dg/pr81192.c: Update. + 2017-07-03 Tom de Vries PR tree-optimization/81192 diff --git a/gcc/testsuite/gcc.dg/pr81192.c b/gcc/testsuite/gcc.dg/pr81192.c index 57eb4781d4d..8b3a77a6061 100644 --- a/gcc/testsuite/gcc.dg/pr81192.c +++ b/gcc/testsuite/gcc.dg/pr81192.c @@ -19,4 +19,4 @@ fn2 (void) ; } -/* { dg-final { scan-tree-dump-times "(?n)find_duplicates: duplicate of " 1 "pre" } } */ +/* { dg-final { scan-tree-dump-not "(?n)find_duplicates: duplicate of " "pre" } } */ diff --git a/gcc/tree-ssa-tail-merge.c b/gcc/tree-ssa-tail-merge.c index e88072c1836..6fa4e5b2ad9 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) -- 2.30.2