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| author | Richard Biener <rguenther@suse.de> | 2017-08-01 13:36:50 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2017-08-01 13:36:50 +0000 |
| commit | 813485c661151465e415f2eaf8b5316fd7b63cbe (patch) | |
| tree | 8d9f46ae668919828ec4ce3acf9fd6c67419891d /gcc | |
| parent | 4df612fa6076bd12d105a8b1d4cdbeb26e646ec1 (diff) | |
| download | gcc-813485c661151465e415f2eaf8b5316fd7b63cbe.zip gcc-813485c661151465e415f2eaf8b5316fd7b63cbe.tar.gz gcc-813485c661151465e415f2eaf8b5316fd7b63cbe.tar.bz2 | |
re PR tree-optimization/81181 (ICE in compute_antic, at tree-ssa-pre.c:2410)
2017-08-01 Richard Biener <rguenther@suse.de>
PR tree-optimization/81181
* tree-ssa-pre.c (compute_antic_aux): Defer clean() to ...
(compute_antic): ... end of iteration here.
* gcc.dg/torture/pr81181.c: New testcase.
From-SVN: r250777
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr81181.c | 30 | ||||
| -rw-r--r-- | gcc/tree-ssa-pre.c | 12 |
4 files changed, 51 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d5fc875..83f9b49 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2017-08-01 Richard Biener <rguenther@suse.de> + + PR tree-optimization/81181 + * tree-ssa-pre.c (compute_antic_aux): Defer clean() to ... + (compute_antic): ... end of iteration here. + 2017-08-01 James Greenhalgh <james.greenhalgh@arm.com> * common.opt (ftree-vectorize): No longer set flag_tree_vectorize. diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index c25f021..768321d 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-08-01 Richard Biener <rguenther@suse.de> + + PR tree-optimization/81181 + * gcc.dg/torture/pr81181.c: New testcase. + 2017-08-01 Martin Liska <mliska@suse.cz> PR middle-end/70140 diff --git a/gcc/testsuite/gcc.dg/torture/pr81181.c b/gcc/testsuite/gcc.dg/torture/pr81181.c new file mode 100644 index 0000000..e7216d7b --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr81181.c @@ -0,0 +1,30 @@ +/* { dg-do compile } */ + +unsigned int lh; + +void +ny (int t3, int ys, int rt, int p8) +{ + if (lh != 0) + { + if (0) + { +oo: + do + { + rt = (p8 != 0) ? t3 : 0; + rt = (rt != 0 || lh != (unsigned int)ys); + rt += lh + ys; + } + while (t3 <= 0); + + lh = ys; + ys = rt; + } + + if (lh != 0) + p8 = lh; + } + + goto oo; +} diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c index eaadaad..afe898b 100644 --- a/gcc/tree-ssa-pre.c +++ b/gcc/tree-ssa-pre.c @@ -2120,7 +2120,8 @@ static sbitmap has_abnormal_preds; ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)]) ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK]) -*/ + + Note that clean() is deferred until after the iteration. */ static bool compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge) @@ -2220,7 +2221,8 @@ compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge) bitmap_value_insert_into_set (ANTIC_IN (block), expression_for_id (bii)); - clean (ANTIC_IN (block)); + /* clean (ANTIC_IN (block)) is defered to after the iteration converged + because it can cause non-convergence, see for example PR81181. */ if (!was_visited || !bitmap_set_equal (old, ANTIC_IN (block))) changed = true; @@ -2456,6 +2458,12 @@ compute_antic (void) gcc_checking_assert (num_iterations < 500); } + /* We have to clean after the dataflow problem converged as cleaning + can cause non-convergence because it is based on expressions + rather than values. */ + FOR_EACH_BB_FN (block, cfun) + clean (ANTIC_IN (block)); + statistics_histogram_event (cfun, "compute_antic iterations", num_iterations); |