re PR middle-end/39246 (FAIL: gcc.dg/uninit-13.c)

2014-05-07  Thomas Preud'homme  <thomas.preudhomme@arm.com>

        PR middle-end/39246
        * tree-complex.c (expand_complex_move): Keep line info when expanding
        complex move.
        * tree-ssa-uninit.c (warn_uninit): New argument. Ignore assignment 
        of complex expression. Use new argument to display correct location 
        for values coming from phi statement.
        (warn_uninitialized_vars): Adapt to new signature of warn_uninit.
        (warn_uninitialized_phi): Pass location of phi argument to 
        warn_uninit.
        * tree-ssa.c (ssa_undefined_value_p): For SSA_NAME initialized by a
        COMPLEX_EXPR, recurse on each part of the COMPLEX_EXPR.

testsuite:

        * gcc.dg/uninit-13.c: Move warning on the actual source line where
        the uninitialized complex is used.
        * gcc.dg/uninit-17.c: New test to check partial initialization of
        complex with branches.
        * gcc.dg/uninit-17-O0.c: Likewise.

From-SVN: r210199

1 files changed, 17 insertions, 1 deletions

diff --git a/gcc/tree-ssa.c b/gcc/tree-ssa.c
index 856325e..42a2783 100644
--- a/gcc/tree-ssa.c
+++ b/gcc/tree-ssa.c
@@ -1246,6 +1246,7 @@ tree_ssa_strip_useless_type_conversions (tree exp)
 bool
 ssa_undefined_value_p (tree t)
 {
+  gimple def_stmt;
   tree var = SSA_NAME_VAR (t);
 
   if (!var)
@@ -1262,7 +1263,22 @@ ssa_undefined_value_p (tree t)
     return false;
 
   /* The value is undefined iff its definition statement is empty.  */
-  return gimple_nop_p (SSA_NAME_DEF_STMT (t));
+  def_stmt = SSA_NAME_DEF_STMT (t);
+  if (gimple_nop_p (def_stmt))
+    return true;
+
+  /* Check if the complex was not only partially defined.  */
+  if (is_gimple_assign (def_stmt)
+      && gimple_assign_rhs_code (def_stmt) == COMPLEX_EXPR)
+    {
+      tree rhs1, rhs2;
+
+      rhs1 = gimple_assign_rhs1 (def_stmt);
+      rhs2 = gimple_assign_rhs2 (def_stmt);
+      return (TREE_CODE (rhs1) == SSA_NAME && ssa_undefined_value_p (rhs1))
+	     || (TREE_CODE (rhs2) == SSA_NAME && ssa_undefined_value_p (rhs2));
+    }
+  return false;
 }