2007-12-05 Richard Guenther <rguenther@suse.de>

	PR tree-optimization/34138
	* tree-ssa-forwprop.c (tree_ssa_forward_propagate_single_use_vars):
	Do not forward propagate addresses if that changes volatileness of
	the pointed-to type.

	* gcc.c-torture/compile/pr34138.c: New testcase.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@130632 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 104b8ea..d257d49 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2007-12-05  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/34138
+       * tree-ssa-forwprop.c (tree_ssa_forward_propagate_single_use_vars):
+       Do not forward propagate addresses if that changes volatileness of
+       the pointed-to type.
+
 2007-12-05  Uros Bizjak  <ubizjak@gmail.com>
 
        PR target/34312

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0778f07..922d4d6 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2007-12-05  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/34138
+       * gcc.c-torture/compile/pr34138.c: New testcase.
+
 2007-12-05  Jakub Jelinek  <jakub@redhat.com>
 
        PR debug/33739

diff --git a/gcc/testsuite/gcc.c-torture/compile/pr34138.c b/gcc/testsuite/gcc.c-torture/compile/pr34138.c
new file mode 100644 (file)
index 0000000..85e8863
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr34138.c
@@ -0,0 +1,21 @@
+extern void free (void *__ptr);
+struct shparam
+{
+  char **p;
+  int foo;
+};
+static struct shparam shellparam;
+inline void freeparam (volatile struct shparam *param, char **ap)
+{
+  free ((void *) (*ap));
+  free ((void *) (param->p));
+}
+void dotcmd (char **p)
+{
+  freeparam (&shellparam, p);
+}
+void evaltree (void)
+{
+  void (*evalfn) (char **);
+  evalfn = dotcmd;
+}

diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index f368c33..2da17c8 100644 (file)
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -956,12 +956,15 @@ tree_ssa_forward_propagate_single_use_vars (void)
                }
 
              if (TREE_CODE (rhs) == ADDR_EXPR
-                 /* We can also disregard changes in CV qualifiers for
+                 /* We can also disregard changes in const qualifiers for
                     the dereferenced value.  */
                  || ((TREE_CODE (rhs) == NOP_EXPR
                       || TREE_CODE (rhs) == CONVERT_EXPR)
                      && TREE_CODE (TREE_OPERAND (rhs, 0)) == ADDR_EXPR
                      && POINTER_TYPE_P (TREE_TYPE (rhs))
+                     /* But do not propagate changes in volatileness.  */
+                     && (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (rhs)))
+                         == TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (rhs, 0)))))
                      && types_compatible_p (TREE_TYPE (TREE_TYPE (TREE_OPERAND (rhs, 0))),
                                             TREE_TYPE (TREE_TYPE (rhs)))))
                {