re PR tree-optimization/49651 (nested lambdas and -O3 produced incorrect integer…

re PR tree-optimization/49651 (nested lambdas and -O3 produced incorrect integer variable increments)

2011-07-14  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/49651
	* tree-ssa-structalias.c (get_constraint_for_1): Properly
	handle dereferences with subvariables.

	* gcc.dg/torture/pr49651.c: New testcase.

From-SVN: r176274

gcc/ChangeLog

 2011-07-14  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/49651
+	* tree-ssa-structalias.c (get_constraint_for_1): Properly
+	handle dereferences with subvariables.
+
+2011-07-14  Richard Guenther  <rguenther@suse.de>
+
 	* gimple-fold.c (fold_gimple_assign): Remove operand swapping.
 	(fold_stmt_1): Do it here directly on gimple and as a first thing.
 

gcc/testsuite/ChangeLog

+2011-07-14  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/49651
+	* gcc.dg/torture/pr49651.c: New testcase.
+
 2011-07-14  Georg-Johann Lay  <avr@gjlay.de>
 	
 	PR target/43746

gcc/testsuite/gcc.dg/torture/pr49651.c

+/* { dg-do run } */
+
+extern void abort (void);
+
+struct X {
+    int *p;
+    int *q;
+};
+
+void __attribute__((noinline, noclone))
+foo (struct X x) { *x.q = 0; }
+
+volatile int what;
+struct X y;
+
+int main()
+{
+  int i, j;
+  struct X x, *p;
+  x.p = &i;
+  x.q = &j;
+  if (what)
+    p = &y;
+  else
+    p = &x;
+  j = 1;
+  foo (*p);
+  if (j != 0)
+    abort ();
+  return 0;
+}

gcc/tree-ssa-structalias.c

@@ -3258,9 +3258,18 @@ get_constraint_for_1 (tree t, VEC (ce_s, heap) **results, bool address_p,
 
 	      /* If we are not taking the address then make sure to process
 		 all subvariables we might access.  */
+	      if (address_p)
+		return;
+
 	      cs = *VEC_last (ce_s, *results);
-	      if (address_p
-		  || cs.type != SCALAR)
+	      if (cs.type == DEREF)
+		{
+		  /* For dereferences this means we have to defer it
+		     to solving time.  */
+		  VEC_last (ce_s, *results)->offset = UNKNOWN_OFFSET;
+		  return;
+		}
+	      if (cs.type != SCALAR)
 		return;
 
 	      vi = get_varinfo (cs.var);