* gimplify.c (gimplify_expr): Use main variant type for the temp
destination for a discarded volatile read.
* tree-ssa.c (tree_ssa_useless_type_conversion_1): Don't elide
casts between non-void types that change volatility.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@102169
138bc75d-0d04-0410-961f-
82ee72b054a4
+2005-07-19 Richard Henderson <rth@redhat.com>
+
+ PR tree-opt/22278
+ * gimplify.c (gimplify_expr): Use main variant type for the temp
+ destination for a discarded volatile read.
+ * tree-ssa.c (tree_ssa_useless_type_conversion_1): Don't elide
+ casts between non-void types that change volatility.
+
2005-07-15 DJ Delorie <dj@redhat.com>
* toplev.h: Add comment about the first parameter for warning().
{
/* Historically, the compiler has treated a bare
reference to a volatile lvalue as forcing a load. */
- tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
- *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
+ tree type = TYPE_MAIN_VARIANT (TREE_TYPE (*expr_p));
+ tree tmp = create_tmp_var (type, "vol");
+ *expr_p = build (MODIFY_EXPR, type, tmp, *expr_p);
}
else
/* We can't do anything useful with a volatile reference to
&& TREE_CODE (TREE_TYPE (outer_type)) == VOID_TYPE)
return true;
+ /* Don't lose casts between pointers to volatile and non-volatile
+ qualified types. Doing so would result in changing the semantics
+ of later accesses. */
+ else if (POINTER_TYPE_P (inner_type)
+ && POINTER_TYPE_P (outer_type)
+ && TYPE_VOLATILE (TREE_TYPE (outer_type))
+ != TYPE_VOLATILE (TREE_TYPE (inner_type)))
+ return false;
+
/* Pointers/references are equivalent if their pointed to types
are effectively the same. This allows to strip conversions between
pointer types with different type qualifiers. */