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| author | Richard Biener <rguenther@suse.de> | 2018-01-09 13:35:43 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2018-01-09 13:35:43 +0000 |
| commit | 82c066f587fe99cc3d5cd0d685582f0272d3a40f (patch) | |
| tree | 87bc765c4b2faf45547a43111b2ab530ff3bfad8 /gcc/graphite.c | |
| parent | e96a5786c75a9fb7c1720a0a4860e990bcc830bf (diff) | |
| download | gcc-82c066f587fe99cc3d5cd0d685582f0272d3a40f.zip gcc-82c066f587fe99cc3d5cd0d685582f0272d3a40f.tar.gz gcc-82c066f587fe99cc3d5cd0d685582f0272d3a40f.tar.bz2 | |
re PR tree-optimization/83668 (wrong code with -O -fno-tree-dominator-opts -fgraphite-identity)
2018-01-09 Richard Biener <rguenther@suse.de>
PR tree-optimization/83668
* graphite.c (canonicalize_loop_closed_ssa): Add edge argument,
move prologue...
(canonicalize_loop_form): ... here, renamed from ...
(canonicalize_loop_closed_ssa_form): ... this and amended to
swap successor edges for loop exit blocks to make us use
the RPO order we need for initial schedule generation.
* gcc.dg/graphite/pr83668.c: New testcase.
From-SVN: r256381
Diffstat (limited to 'gcc/graphite.c')
| -rw-r--r-- | gcc/graphite.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/gcc/graphite.c b/gcc/graphite.c index e5f318d..3b7f46b 100644 --- a/gcc/graphite.c +++ b/gcc/graphite.c @@ -227,15 +227,11 @@ free_scops (vec<scop_p> scops) /* Transforms LOOP to the canonical loop closed SSA form. */ static void -canonicalize_loop_closed_ssa (loop_p loop) +canonicalize_loop_closed_ssa (loop_p loop, edge e) { - edge e = single_exit (loop); basic_block bb; gphi_iterator psi; - if (!e || (e->flags & EDGE_COMPLEX)) - return; - bb = e->dest; /* Make the loop-close PHI node BB contain only PHIs and have a @@ -314,14 +310,34 @@ canonicalize_loop_closed_ssa (loop_p loop) other statements. - there exist only one phi node per definition in the loop. + + In addition to that we also make sure that loop exit edges are + first in the successor edge vector. This is to make RPO order + as computed by pre_and_rev_post_order_compute be consistent with + what initial schedule generation expects. */ static void -canonicalize_loop_closed_ssa_form (void) +canonicalize_loop_form (void) { loop_p loop; FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) - canonicalize_loop_closed_ssa (loop); + { + edge e = single_exit (loop); + if (!e || (e->flags & EDGE_COMPLEX)) + continue; + + canonicalize_loop_closed_ssa (loop, e); + + /* If the exit is not first in the edge vector make it so. */ + if (e != EDGE_SUCC (e->src, 0)) + { + unsigned ei; + for (ei = 0; EDGE_SUCC (e->src, ei) != e; ++ei) + ; + std::swap (EDGE_SUCC (e->src, ei), EDGE_SUCC (e->src, 0)); + } + } /* We can end up releasing duplicate exit PHIs and also introduce additional copies so the cached information isn't correct anymore. */ @@ -360,7 +376,7 @@ graphite_transform_loops (void) the_isl_ctx = ctx; sort_sibling_loops (cfun); - canonicalize_loop_closed_ssa_form (); + canonicalize_loop_form (); /* Print the loop structure. */ if (dump_file && (dump_flags & TDF_DETAILS)) |