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authorRichard Guenther <rguenther@suse.de>2012-09-10 14:10:09 +0000
committerRichard Biener <rguenth@gcc.gnu.org>2012-09-10 14:10:09 +0000
commit1779dc343a559d1d822e8cbcb998bcde049c5123 (patch)
tree82f94d55b64eee4516e88feb661b06a6158dd92c /gcc
parent8f5a5a8ecd12377ea58ca7ddb326db59d6cd6436 (diff)
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re PR middle-end/54520 (ice in merge_latch_edges with -O3)
2012-09-10 Richard Guenther <rguenther@suse.de> PR tree-optimization/54520 * tree-ssa-threadupdate.c (def_split_header_continue_p): Properly consider sub-loops. * gcc.dg/torture/pr54520.c: New testcase. From-SVN: r191141
Diffstat (limited to 'gcc')
-rw-r--r--gcc/ChangeLog6
-rw-r--r--gcc/testsuite/ChangeLog5
-rw-r--r--gcc/testsuite/gcc.dg/torture/pr54520.c15
-rw-r--r--gcc/tree-ssa-threadupdate.c14
4 files changed, 34 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6e7175a..0e0bc2b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-09-10 Richard Guenther <rguenther@suse.de>
+
+ PR tree-optimization/54520
+ * tree-ssa-threadupdate.c (def_split_header_continue_p):
+ Properly consider sub-loops.
+
2012-09-10 Richard Henderson <rth@redhat.com>
* config/alpha/predicates.md (small_symbolic_operand): Disallow
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 65e31bd..bd4b362 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-09-10 Richard Guenther <rguenther@suse.de>
+
+ PR tree-optimization/54520
+ * gcc.dg/torture/pr54520.c: New testcase.
+
2012-09-10 Jason Merrill <jason@redhat.com>
PR c++/54506
diff --git a/gcc/testsuite/gcc.dg/torture/pr54520.c b/gcc/testsuite/gcc.dg/torture/pr54520.c
new file mode 100644
index 0000000..5884b2f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr54520.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+
+char *a;
+void
+fn1 ()
+{
+ char *p = a;
+ while (p && *p != '\0')
+ {
+ while (*p == '\t')
+ *p++ = '\0';
+ if (*p != '\0')
+ p = 0;
+ }
+}
diff --git a/gcc/tree-ssa-threadupdate.c b/gcc/tree-ssa-threadupdate.c
index 30336a1..ba6d69a 100644
--- a/gcc/tree-ssa-threadupdate.c
+++ b/gcc/tree-ssa-threadupdate.c
@@ -846,8 +846,9 @@ static bool
def_split_header_continue_p (const_basic_block bb, const void *data)
{
const_basic_block new_header = (const_basic_block) data;
- return (bb->loop_father == new_header->loop_father
- && bb != new_header);
+ return (bb != new_header
+ && (loop_depth (bb->loop_father)
+ >= loop_depth (new_header->loop_father)));
}
/* Thread jumps through the header of LOOP. Returns true if cfg changes.
@@ -1031,10 +1032,11 @@ thread_through_loop_header (struct loop *loop, bool may_peel_loop_headers)
nblocks = dfs_enumerate_from (header, 0, def_split_header_continue_p,
bblocks, loop->num_nodes, tgt_bb);
for (i = 0; i < nblocks; i++)
- {
- remove_bb_from_loops (bblocks[i]);
- add_bb_to_loop (bblocks[i], loop_outer (loop));
- }
+ if (bblocks[i]->loop_father == loop)
+ {
+ remove_bb_from_loops (bblocks[i]);
+ add_bb_to_loop (bblocks[i], loop_outer (loop));
+ }
free (bblocks);
/* If the new header has multiple latches mark it so. */