[committed] Add testcase for PR tree-optimization/50765

[Jakub Jelinek]

Hi!

This PR got fixed by my recent vectorizable_conversion changes,
in particular the truncation of the vec_oprnds[01] vectors on
multistep type promotion if copies > 1.

Testcase tested on x86_64-linux and i686-linux, checked in as obvious.

2011-11-22  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/50765
        * gcc.dg/pr50765.c: New test.

--- gcc/testsuite/gcc.dg/pr50765.c.jj   2011-11-22 11:43:17.614794630 +0100
+++ gcc/testsuite/gcc.dg/pr50765.c      2011-11-22 11:43:05.000000000 +0100
@@ -0,0 +1,10 @@
+/* PR tree-optimization/50765 */
+/* { dg-do compile } */
+/* { dg-options "-O3 -fno-tree-dce" } */
+
+void
+foo (long *w, long *x, unsigned char *y, int z)
+{
+  for (; z < 429; z++)
+    w[z] = (-19 ^ y[z]) & x[z];
+}

        Jakub