From: Richard Biener <rguenther@suse.de>
Date: Mon, 25 Apr 2016 10:49:55 +0000 (+0000)
Subject: re PR tree-optimization/70780 (wrong code at -O2 and -O3 on x86_64-linux-gnu)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ab99f46749d0f746c50dde27e845ed6e5f06aee4;p=gcc.git

re PR tree-optimization/70780 (wrong code at -O2 and -O3 on x86_64-linux-gnu)

2016-04-25  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/70780
	* tree-ssa-pre.c (compute_antic_aux): Also return true if the block
	wasn't visited yet.
	(compute_antic): Mark blocks with abnormal preds as visited as
	they have a final empty antic-in solution already.

	* gcc.dg/torture/pr70780.c: New testcase.

From-SVN: r235407
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e70bcaf6ba5..2dac38eff7b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,4 +1,13 @@
+2016-04-25  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/70780
+	* tree-ssa-pre.c (compute_antic_aux): Also return true if the block
+	wasn't visited yet.
+	(compute_antic): Mark blocks with abnormal preds as visited as
+	they have a final empty antic-in solution already.
+
 2016-04-25  Michael Collison  <michael.collison@linaro.org>
+
 	* ChangeLog(2016-04-25): Fix ChangeLog formatting.
 
 2016-04-25  Michael Collison  <michael.collison@linaro.org>
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d49f1895160..bbaa3a2f1a2 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-04-25  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/70780
+	* gcc.dg/torture/pr70780.c: New testcase.
+
 2016-04-25  Michael Collison <michael.collison@arm.com>
 
 	* testsuite/gcc.target/arm/neon-vaddws16.c: New test.
diff --git a/gcc/testsuite/gcc.dg/torture/pr70780.c b/gcc/testsuite/gcc.dg/torture/pr70780.c
new file mode 100644
index 00000000000..2f7a5cbea06
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr70780.c
@@ -0,0 +1,26 @@
+/* { dg-do run } */
+
+int a, b, c, *d, e;
+
+static int
+fn1 () 
+{
+  if (a)
+    goto l1;
+l2: while (b)
+      if (*d)
+	return c;
+    for (e = 0; e; e++)
+      {
+	goto l2;
+l1:;
+      }
+    return 0; 
+}
+
+int
+main ()
+{
+  fn1 ();
+  return 0; 
+}
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index 2d1eb70c03b..7b9eb2e5b9c 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -2077,6 +2077,7 @@ compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
   unsigned int bii;
   edge e;
   edge_iterator ei;
+  bool was_visited = BB_VISITED (block);
 
   old = ANTIC_OUT = S = NULL;
   BB_VISITED (block) = 1;
@@ -2167,7 +2168,7 @@ compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
 
   clean (ANTIC_IN (block));
 
-  if (!bitmap_set_equal (old, ANTIC_IN (block)))
+  if (!was_visited || !bitmap_set_equal (old, ANTIC_IN (block)))
     changed = true;
 
  maybe_dump_sets: