re PR tree-optimization/26258 (Wrong alias information for struct addresses in PHIs)

2006-02-14  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/26258
	* tree-ssa-structalias.c (find_func_aliases): Handle aggregates
	in PHI argument processing.

	* gcc.dg/torture/pr26258.c: New testcase.

From-SVN: r110963

gcc/ChangeLog

+2006-02-14  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/26258
+	* tree-ssa-structalias.c (find_func_aliases): Handle aggregates
+	in PHI argument processing.
+
 2006-02-13  Adam Nemet  <anemet@caviumnetworks.com>
 
 	* simplify-rtx.c (simplify_unary_operation_1) <TRUNCATE>: Return

gcc/testsuite/ChangeLog

+2006-02-14  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/26258
+	* gcc.dg/torture/pr26258.c: New testcase.
+
 2006-02-13  Jakub Jelinek  <jakub@redhat.com>
 
 	PR fortran/26246

gcc/testsuite/gcc.dg/torture/pr26258.c

+/* { dg-do run } */
+
+extern void abort(void);
+
+typedef struct Foo { int a; int b; }  Foo;
+
+Foo foo(Foo first, Foo last, _Bool ret_first)
+{
+  Foo t;
+  Foo *t1 = (ret_first ? &first : &last);
+  first.a = 2;
+  last.b = 3;
+  t.a = t1->a;
+  t.b = t1->b;
+  t.a += first.a;
+  t.b += last.b;
+  return t;
+}
+
+int main()
+{
+  Foo first = (Foo){1, 2};
+  Foo last = (Foo){3, 4};
+  Foo ret = foo(first, last, 0);
+  if (ret.b != 6)
+    abort ();
+  return 0;
+}

gcc/tree-ssa-structalias.c

@@ -3239,7 +3239,33 @@ find_func_aliases (tree origt)
 	  get_constraint_for (PHI_RESULT (t), &lhsc);
 	  for (i = 0; i < PHI_NUM_ARGS (t); i++)
 	    { 
+	      tree rhstype;
+	      tree strippedrhs = PHI_ARG_DEF (t, i);
+
+	      STRIP_NOPS (strippedrhs);
+	      rhstype = TREE_TYPE (strippedrhs);
 	      get_constraint_for (PHI_ARG_DEF (t, i), &rhsc);
+
+	      if (TREE_CODE (strippedrhs) == ADDR_EXPR
+		 && AGGREGATE_TYPE_P (TREE_TYPE (rhstype))
+		 && VEC_length (ce_s, rhsc) == 1)
+		{
+		  struct constraint_expr *origrhs;
+		  varinfo_t origvar;
+		  struct constraint_expr tmp;
+
+		  gcc_assert (VEC_length (ce_s, rhsc) == 1);
+		  origrhs = VEC_last (ce_s, rhsc);
+		  tmp = *origrhs;
+		  VEC_pop (ce_s, rhsc);
+		  origvar = get_varinfo (origrhs->var);
+		  for (; origvar; origvar = origvar->next)
+		    {
+		      tmp.var = origvar->id;
+		      VEC_safe_push (ce_s, heap, rhsc, &tmp);
+		    }
+		}
+
 	      for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
 		{
 		  struct constraint_expr *c2;