re PR tree-optimization/82387 (wrong code at -O1 and -Os on x86_64-linux-gnu in 64-bit mode)

	PR tree-optimization/82387
	PR tree-optimization/82388
	PR tree-optimization/82389
	* tree-ssa-dse.c (dse_classify_store): Test byte_tracking_enabled
	instead of live_bytes non-NULL.

	* gcc.c-torture/compile/pr82389.c: New test.
	* gcc.c-torture/execute/pr82387.c: New test.
	* gcc.c-torture/execute/pr82388.c: New test.

From-SVN: r253356

gcc/ChangeLog

+2017-10-02  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/82387
+	PR tree-optimization/82388
+	PR tree-optimization/82389
+	* tree-ssa-dse.c (dse_classify_store): Test byte_tracking_enabled
+	instead of live_bytes non-NULL.
+
 2017-10-02  Georg-Johann Lay  <avr@gjlay.de>
 
 	PR target/41076

gcc/testsuite/ChangeLog

+2017-10-02  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/82387
+	PR tree-optimization/82388
+	PR tree-optimization/82389
+	* gcc.c-torture/compile/pr82389.c: New test.
+	* gcc.c-torture/execute/pr82387.c: New test.
+	* gcc.c-torture/execute/pr82388.c: New test.
+
 2017-10-02  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/79180

gcc/testsuite/gcc.c-torture/compile/pr82389.c

+/* PR tree-optimization/82389 */
+
+void bar (short);
+
+void
+foo (void)
+{
+  short a[5];
+  int b;
+  for (b = -1290603998; b < 5; b++)
+    a[b] = 0;
+  bar (a[3]);
+}

gcc/testsuite/gcc.c-torture/execute/pr82387.c

+/* PR tree-optimization/82387 */
+
+struct A { int b; };
+int f = 1;
+
+struct A
+foo (void)
+{
+  struct A h[] = { 
+    {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, 
+    {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, 
+    {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, 
+    {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, 
+    {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, 
+    {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, 
+    {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, {1}, 
+  };
+  return h[24];
+}
+
+int
+main ()
+{
+  struct A i = foo (), j = i;
+  j.b && (f = 0);
+  return f; 
+}

gcc/testsuite/gcc.c-torture/execute/pr82388.c

+/* PR tree-optimization/82388 */
+
+struct A { int b; int c; int d; } e;
+
+struct A
+foo (void)
+{
+  struct A h[30] = {{0,0,0}};
+  return h[29]; 
+}
+
+int
+main ()
+{
+  e = foo ();
+  return e.b; 
+}

gcc/tree-ssa-dse.c

@@ -577,10 +577,10 @@ dse_classify_store (ao_ref *ref, gimple *stmt, gimple **use_stmt,
 	  /* If the statement is a use the store is not dead.  */
 	  else if (ref_maybe_used_by_stmt_p (use_stmt, ref))
 	    {
-	      /* Handle common cases where we can easily build a ao_ref
+	      /* Handle common cases where we can easily build an ao_ref
 		 structure for USE_STMT and in doing so we find that the
 		 references hit non-live bytes and thus can be ignored.  */
-	      if (live_bytes && (!gimple_vdef (use_stmt) || !temp))
+	      if (byte_tracking_enabled && (!gimple_vdef (use_stmt) || !temp))
 		{
 		  if (is_gimple_assign (use_stmt))
 		    {