2012-02-06 Richard Guenther <rguenther@suse.de>

	PR tree-optimization/52115
	* tree-sra.c (access_has_replacements_p): New function.
	(sra_modify_assign): Use it to decide whether a use is uninitialized.

	* gcc.c-torture/compile/pr52115.c: New testcase.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@183937 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 53 insertions, 3 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index bf5e93b3f78..28f130f3501 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-02-06  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/52115
+	* tree-sra.c (access_has_replacements_p): New function.
+	(sra_modify_assign): Use it to decide whether a use is uninitialized.
+
 2012-02-06  Patrick Marlier  <patrick.marlier@gmail.com>
 
 	PR middle-end/52047
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6361ab0e0e5..305a6894795 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-02-06  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/52115
+	* gcc.c-torture/compile/pr52115.c: New testcase.
+
 2012-02-06  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/52129
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr52115.c b/gcc/testsuite/gcc.c-torture/compile/pr52115.c
new file mode 100644
index 00000000000..789d08f4d98
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr52115.c
@@ -0,0 +1,26 @@
+struct S
+{
+  float f;
+  long l;
+};
+
+extern int gi;
+extern float gf;
+
+long foo (long p)
+{
+  struct S s;
+  float *pf;
+
+  s.l = p;
+
+  pf = &s.f;
+
+  pf++;
+  pf--;
+
+  gf = *pf + 3.3;
+  gi = *((short *)pf) + 2;
+
+  return s.l + 6;
+}
diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index e3bf38230dc..e2091e5fda4 100644
--- a/gcc/tree-sra.c
+++ b/gcc/tree-sra.c
@@ -440,6 +440,20 @@ access_has_children_p (struct access *acc)
   return acc && acc->first_child;
 }
 
+/* Return true iff ACC is (partly) covered by at least one replacement.  */
+
+static bool
+access_has_replacements_p (struct access *acc)
+{
+  struct access *child;
+  if (acc->grp_to_be_replaced)
+    return true;
+  for (child = acc->first_child; child; child = child->next_sibling)
+    if (access_has_replacements_p (child))
+      return true;
+  return false;
+}
+
 /* Return a vector of pointers to accesses for the variable given in BASE or
    NULL if there is none.  */
 
@@ -2992,10 +3006,9 @@ sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi)
       sra_stats.exprs++;
     }
   else if (racc
-	   && !access_has_children_p (racc)
-	   && !racc->grp_to_be_replaced
 	   && !racc->grp_unscalarized_data
-	   && TREE_CODE (lhs) == SSA_NAME)
+	   && TREE_CODE (lhs) == SSA_NAME
+	   && !access_has_replacements_p (racc))
     {
       rhs = get_repl_default_def_ssa_name (racc);
       modify_this_stmt = true;