From: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 21 Nov 2013 19:45:16 +0000 (+0000)
Subject: 	PR tree-optimization/59221
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1a1e103fb402a6b48689a739366b1caba03ded75;p=thirdparty%2Fgcc.git

	PR tree-optimization/59221
	* tree-ssa-threadedge.c (thread_across_edge): Properly manage
	temporary equivalences when threading through joiner blocks.

	PR tree-optimization/59221
	* gcc.c-torture/execute/pr59221.c: New test.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@205229 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a16ae684f914..e63255845bd3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2013-11-21  Jeff Law  <law@redhat.com>
+
+	PR tree-optimization/59221
+	* tree-ssa-threadedge.c (thread_across_edge): Properly manage
+	temporary equivalences when threading through joiner blocks.
+
 2013-11-21  Joseph Myers  <joseph@codesourcery.com>
 
 	PR rtl-optimization/55950
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b29070fb11fd..0b3f8ba9b79c 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2013-11-21  Jeff Law  <law@redhat.com>
+
+	PR tree-optimization/59221
+	* gcc.c-torture/execute/pr59221.c: New test.
+
 2013-11-21  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
 
 	PR libfortran/59227
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr59221.c b/gcc/testsuite/gcc.c-torture/execute/pr59221.c
new file mode 100644
index 000000000000..0cd425948fcb
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr59221.c
@@ -0,0 +1,19 @@
+
+
+int a = 1, b, d;
+short e;
+
+int
+main ()
+{
+  for (; b; b++)
+    ;
+  short f = a;
+  int g = 15;
+  e = f ? f : 1 << g;
+  int h = e;
+  d = h == 83647 ? 0 : h;
+  if (d != 1)
+    __builtin_abort ();
+  return 0;
+}
diff --git a/gcc/tree-ssa-threadedge.c b/gcc/tree-ssa-threadedge.c
index 7bb8829e5cc7..a1448757ead7 100644
--- a/gcc/tree-ssa-threadedge.c
+++ b/gcc/tree-ssa-threadedge.c
@@ -1072,6 +1072,10 @@ thread_across_edge (gimple dummy_cond,
     /* Look at each successor of E->dest to see if we can thread through it.  */
     FOR_EACH_EDGE (taken_edge, ei, e->dest->succs)
       {
+	/* Push a fresh marker so we can unwind the equivalences created
+	   for each of E->dest's successors.  */
+	stack->safe_push (NULL_TREE);
+     
 	/* Avoid threading to any block we have already visited.  */
 	bitmap_clear (visited);
 	bitmap_set_bit (visited, taken_edge->dest->index);
@@ -1118,6 +1122,9 @@ thread_across_edge (gimple dummy_cond,
 	  {
 	    delete_jump_thread_path (path);
 	  }
+
+	/* And unwind the equivalence table.  */
+	remove_temporary_equivalences (stack);
       }
     BITMAP_FREE (visited);
   }