Merge branch 'master' into gfortran-testdevel/gfortran-test

1 files changed, 16 insertions, 0 deletions

diff --git a/gcc/omp-expand.cc b/gcc/omp-expand.cc
index 648ede2..385fe1c 100644
--- a/gcc/omp-expand.cc
+++ b/gcc/omp-expand.cc
@@ -1895,6 +1895,7 @@ expand_omp_for_init_counts (struct omp_for_data *fd, gimple_stmt_iterator *gsi,
 	}
     }
   bool rect_count_seen = false;
+  bool init_n2 = SSA_VAR_P (fd->loop.n2) && zero_iter1_bb;
   for (i = 0; i < (fd->ordered ? fd->ordered : fd->collapse); i++)
     {
       tree itype = TREE_TYPE (fd->loops[i].v);
@@ -1919,6 +1920,21 @@ expand_omp_for_init_counts (struct omp_for_data *fd, gimple_stmt_iterator *gsi,
 	{
 	  gcond *cond_stmt;
 	  tree n1, n2;
+	  if (init_n2 && i < fd->collapse && !rect_count_seen)
+	    {
+	      /* When called with non-NULL zero_iter1_bb, we won't clear
+		 fd->loop.n2 in the if (zero_iter_bb == NULL) code below
+		 and if it is prior to storing fd->loop.n2 where
+		 rect_count_seen is set, it could be used uninitialized.
+		 As zero_iter1_bb in that case can be reached also if there
+		 are non-zero iterations, the clearing can't be emitted
+		 to the zero_iter1_bb, but needs to be done before the
+		 condition.  */
+	      gassign *assign_stmt
+		= gimple_build_assign (fd->loop.n2, build_zero_cst (type));
+	      gsi_insert_before (gsi, assign_stmt, GSI_SAME_STMT);
+	      init_n2 = false;
+	    }
 	  n1 = fold_convert (itype, unshare_expr (fd->loops[i].n1));
 	  n1 = force_gimple_operand_gsi (gsi, n1, true, NULL_TREE,
 					 true, GSI_SAME_STMT);