PR middle-end/19874

	* tree-ssa.c (tree_ssa_useless_type_conversion_1): A conversion
	between different machine modes is never a "useless" conversion.

	* gcc.c-torture/execute/20050119-2.c: New test case.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@95688 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 40 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.c-torture/execute/20050119-2.c b/gcc/testsuite/gcc.c-torture/execute/20050119-2.c
new file mode 100644
index 00000000000..568109cb2c9
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/20050119-2.c
@@ -0,0 +1,40 @@
+/* PR middle-end/19874 */
+typedef enum { A, B, C, D } E;
+
+struct S {
+  E __attribute__ ((mode (__byte__))) a;
+  E __attribute__ ((mode (__byte__))) b;
+  E __attribute__ ((mode (__byte__))) c;
+  E __attribute__ ((mode (__byte__))) d;
+};
+
+extern void abort (void);
+extern void exit (int);
+
+E
+foo (struct S *s)
+{
+  if (s->a != s->b)
+    abort ();
+  if (s->c != C)
+    abort ();
+  return s->d;
+}
+
+int
+main (void)
+{
+  struct S s[2];
+  s[0].a = B;
+  s[0].b = B;
+  s[0].c = C;
+  s[0].d = D;
+  s[1].a = D;
+  s[1].b = C;
+  s[1].c = B;
+  s[1].d = A;
+  if (foo (s) != D)
+    abort ();
+  exit (0);
+}
+