From eaaa4b88038d4d6eda1b20ab662f1568fd9be31f Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Fri, 29 Sep 2023 15:12:54 +0200 Subject: [PATCH] tree-optimization/115254 - don't account single-lane SLP against discovery limit The following avoids accounting single-lane SLP to the discovery limit. As the two testcases show this makes discovery fail, unfortunately even not the same across targets. The following should fix two FAILs for GCN as a side-effect. PR tree-optimization/115254 * tree-vect-slp.cc (vect_build_slp_tree): Only account multi-lane SLP to limit. * gcc.dg/vect/slp-cond-2-big-array.c: Expect 4 times SLP. * gcc.dg/vect/slp-cond-2.c: Likewise. --- .../gcc.dg/vect/slp-cond-2-big-array.c | 2 +- gcc/testsuite/gcc.dg/vect/slp-cond-2.c | 2 +- gcc/tree-vect-slp.cc | 31 +++++++++++-------- 3 files changed, 20 insertions(+), 15 deletions(-) diff --git a/gcc/testsuite/gcc.dg/vect/slp-cond-2-big-array.c b/gcc/testsuite/gcc.dg/vect/slp-cond-2-big-array.c index cb7eb94b3a3b..9a9f63c0b8d0 100644 --- a/gcc/testsuite/gcc.dg/vect/slp-cond-2-big-array.c +++ b/gcc/testsuite/gcc.dg/vect/slp-cond-2-big-array.c @@ -128,4 +128,4 @@ main () return 0; } -/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 3 "vect" } } */ +/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 4 "vect" } } */ diff --git a/gcc/testsuite/gcc.dg/vect/slp-cond-2.c b/gcc/testsuite/gcc.dg/vect/slp-cond-2.c index 1dcee46cd954..08bbb3dbec61 100644 --- a/gcc/testsuite/gcc.dg/vect/slp-cond-2.c +++ b/gcc/testsuite/gcc.dg/vect/slp-cond-2.c @@ -128,4 +128,4 @@ main () return 0; } -/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 3 "vect" } } */ +/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 4 "vect" } } */ diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc index c7ed520b6294..7a963e28063d 100644 --- a/gcc/tree-vect-slp.cc +++ b/gcc/tree-vect-slp.cc @@ -1725,21 +1725,26 @@ vect_build_slp_tree (vec_info *vinfo, SLP_TREE_SCALAR_STMTS (res) = stmts; bst_map->put (stmts.copy (), res); - if (*limit == 0) + /* Single-lane SLP doesn't have the chance of run-away, do not account + it to the limit. */ + if (stmts.length () > 1) { - if (dump_enabled_p ()) - dump_printf_loc (MSG_NOTE, vect_location, - "SLP discovery limit exceeded\n"); - /* Mark the node invalid so we can detect those when still in use - as backedge destinations. */ - SLP_TREE_SCALAR_STMTS (res) = vNULL; - SLP_TREE_DEF_TYPE (res) = vect_uninitialized_def; - res->failed = XNEWVEC (bool, group_size); - memset (res->failed, 0, sizeof (bool) * group_size); - memset (matches, 0, sizeof (bool) * group_size); - return NULL; + if (*limit == 0) + { + if (dump_enabled_p ()) + dump_printf_loc (MSG_NOTE, vect_location, + "SLP discovery limit exceeded\n"); + /* Mark the node invalid so we can detect those when still in use + as backedge destinations. */ + SLP_TREE_SCALAR_STMTS (res) = vNULL; + SLP_TREE_DEF_TYPE (res) = vect_uninitialized_def; + res->failed = XNEWVEC (bool, group_size); + memset (res->failed, 0, sizeof (bool) * group_size); + memset (matches, 0, sizeof (bool) * group_size); + return NULL; + } + --*limit; } - --*limit; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, -- 2.47.2