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| author | Richard Biener <rguenther@suse.de> | 2014-06-26 07:44:10 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2014-06-26 07:44:10 +0000 |
| commit | 974bb959b2323680a74b5bfffc322d60ac2c2c99 (patch) | |
| tree | d8075f504c928ca52004f69e986f7e34f70483f7 /gcc/tree-ssa-threadupdate.c | |
| parent | 2626fc495bb50774416896f898914977a5071d29 (diff) | |
| download | gcc-974bb959b2323680a74b5bfffc322d60ac2c2c99.zip gcc-974bb959b2323680a74b5bfffc322d60ac2c2c99.tar.gz gcc-974bb959b2323680a74b5bfffc322d60ac2c2c99.tar.bz2 | |
re PR tree-optimization/61607 (DOM missed jump threading and destroyed loops)
2014-06-26 Richard Biener <rguenther@suse.de>
PR tree-optimization/61607
* tree-ssa-threadupdate.c (ssa_redirect_edges): Cancel the
loop if we redirected its latch edge.
(thread_block_1): Do not cancel loops prematurely.
From-SVN: r212011
Diffstat (limited to 'gcc/tree-ssa-threadupdate.c')
| -rw-r--r-- | gcc/tree-ssa-threadupdate.c | 35 |
1 files changed, 8 insertions, 27 deletions
diff --git a/gcc/tree-ssa-threadupdate.c b/gcc/tree-ssa-threadupdate.c index 02cf42c..a0b1be5 100644 --- a/gcc/tree-ssa-threadupdate.c +++ b/gcc/tree-ssa-threadupdate.c @@ -764,6 +764,14 @@ ssa_redirect_edges (struct redirection_data **slot, if ((*path)[1]->type != EDGE_COPY_SRC_JOINER_BLOCK) EDGE_SUCC (rd->dup_blocks[0], 0)->count += e->count; + /* If we redirect a loop latch edge cancel its loop. */ + if (e->src == e->src->loop_father->latch) + { + e->src->loop_father->header = NULL; + e->src->loop_father->latch = NULL; + loops_state_set (LOOPS_NEED_FIXUP); + } + /* Redirect the incoming edge (possibly to the joiner block) to the appropriate duplicate block. */ e2 = redirect_edge_and_branch (e, rd->dup_blocks[0]); @@ -844,7 +852,6 @@ thread_block_1 (basic_block bb, bool noloop_only, bool joiners) edge e, e2; edge_iterator ei; ssa_local_info_t local_info; - struct loop *loop = bb->loop_father; /* To avoid scanning a linear array for the element we need we instead use a hash table. For normal code there should be no noticeable @@ -853,32 +860,6 @@ thread_block_1 (basic_block bb, bool noloop_only, bool joiners) redirection_data = new hash_table<struct redirection_data> (EDGE_COUNT (bb->succs)); - /* If we thread the latch of the loop to its exit, the loop ceases to - exist. Make sure we do not restrict ourselves in order to preserve - this loop. */ - if (loop->header == bb) - { - e = loop_latch_edge (loop); - vec<jump_thread_edge *> *path = THREAD_PATH (e); - - if (path - && (((*path)[1]->type == EDGE_COPY_SRC_JOINER_BLOCK && joiners) - || ((*path)[1]->type == EDGE_COPY_SRC_BLOCK && !joiners))) - { - for (unsigned int i = 1; i < path->length (); i++) - { - edge e2 = (*path)[i]->e; - - if (loop_exit_edge_p (loop, e2)) - { - loop->header = NULL; - loop->latch = NULL; - loops_state_set (LOOPS_NEED_FIXUP); - } - } - } - } - /* Record each unique threaded destination into a hash table for efficient lookups. */ FOR_EACH_EDGE (e, ei, bb->preds) |