PR tree-optimization/15826 - don't use "if" to extract a single bit

PR tree-optimization/15826 - don't use "if" to extract a single bit
	bit-field
2016-02-26  Martin Sebor  <msebor@redhat.com>

        PR tree-optimization/15826
        * gcc.dg/tree-ssa/pr15826.c: New test.

From-SVN: r233771

gcc/testsuite/ChangeLog

+2016-02-26  Martin Sebor  <msebor@redhat.com>
+
+	PR tree-optimization/15826
+	* gcc.dg/tree-ssa/pr15826.c: New test.
+
 2016-02-26  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/69969

gcc/testsuite/gcc.dg/tree-ssa/pr15826.c

+/* PR tree-optimization/15826 - don't use "if" to extract a single bit
+   bit-field */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+struct s {
+  unsigned int bit : 1;
+};
+
+unsigned int
+foo (struct s *p)
+{
+  if (p->bit)
+    return 1;
+  else
+    return 0;
+}
+
+unsigned int
+bar (struct s *p)
+{
+  return (unsigned int) (p->bit);
+}
+
+unsigned int
+andrew (struct s *p)
+{
+  int i;
+  if (p->bit)
+    i = 1;
+  else
+    i = 0;
+  return i;
+}
+
+/* { dg-final { scan-tree-dump-times " & | goto " 0 "optimized" } } */