re PR tree-optimization/61221 (ICE on valid code at -O1 and above on x86_64-linux...

2014-05-19  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/61221
	* tree-ssa-pre.c (eliminate_dom_walker::before_dom_children):
	Do nothing for unreachable blocks.
	* tree-ssa-sccvn.c (cond_dom_walker::before_dom_children):
	Improve unreachability detection.

	* gcc.dg/torture/pr61221.c: New testcase.

From-SVN: r210614

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 90eca0c687b13664e77118e887994a0d4808221e..1cac5d27fb5b9984187297ef71e0faaae2bdeff5 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2014-05-19  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/61221
+       * tree-ssa-pre.c (eliminate_dom_walker::before_dom_children):
+       Do nothing for unreachable blocks.
+       * tree-ssa-sccvn.c (cond_dom_walker::before_dom_children):
+       Improve unreachability detection.
+
 2014-05-19  Richard Biener  <rguenther@suse.de>
 
        PR tree-optimization/61209

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 83b42642cdca02b68172c78c70068c66764f2765..bb657c1b5a917b9f54bdc7a5228b834cd441acb8 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2014-05-19  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/61221
+       * gcc.dg/torture/pr61221.c: New testcase.
+
 2014-05-19  Richard Biener  <rguenther@suse.de>
 
        PR tree-optimization/61209

diff --git a/gcc/testsuite/gcc.dg/torture/pr61221.c b/gcc/testsuite/gcc.dg/torture/pr61221.c
new file mode 100644 (file)
index 0000000..2524382
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr61221.c
@@ -0,0 +1,32 @@
+/* { dg-do compile } */
+
+void __assert_fail (void);
+
+int **a, b, c, e, *j;
+short *d, **f;
+
+int *
+foo ()
+{
+  *a = j;
+  if (!(1 & e)) 
+    __assert_fail ();
+  return 0;
+}
+
+void
+bar ()
+{
+  int *g = &b;
+  short **h = &d;
+  if ((f = &d) != h)
+    for (; b;)
+      {
+       int i = 1;
+       if (i)
+         g = foo ();
+       c = 0;
+      }
+  if (!g)
+    __assert_fail ();
+}

diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index f634f5efd29e076a18829673407eb683b62ae6de..e487d283c28a513c2fd4390d229e80b63137a727 100644 (file)
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -4010,6 +4010,15 @@ eliminate_dom_walker::before_dom_children (basic_block b)
   /* Mark new bb.  */
   el_avail_stack.safe_push (NULL_TREE);
 
+  /* If this block is not reachable do nothing.  */
+  edge_iterator ei;
+  edge e;
+  FOR_EACH_EDGE (e, ei, b->preds)
+    if (e->flags & EDGE_EXECUTABLE)
+      break;
+  if (!e)
+    return;
+
   for (gsi = gsi_start_phis (b); !gsi_end_p (gsi);)
     {
       gimple stmt, phi = gsi_stmt (gsi);

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index bd603729f132f9b98cc60f25722f0573d43a343e..fc00682fcd845a7d773259964c6f0a26b8b3d685 100644 (file)
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -4177,11 +4177,13 @@ cond_dom_walker::before_dom_children (basic_block bb)
   if (fail)
     return;
 
-  /* If any of the predecessor edges are still marked as possibly
-     executable consider this block reachable.  */
+  /* If any of the predecessor edges that do not come from blocks dominated
+     by us are still marked as possibly executable consider this block
+     reachable.  */
   bool reachable = bb == ENTRY_BLOCK_PTR_FOR_FN (cfun);
   FOR_EACH_EDGE (e, ei, bb->preds)
-    reachable |= (e->flags & EDGE_EXECUTABLE);
+    if (!dominated_by_p (CDI_DOMINATORS, e->src, bb))
+      reachable |= (e->flags & EDGE_EXECUTABLE);
 
   /* If the block is not reachable all outgoing edges are not
      executable.  */