[PATCH] Fix PR56366

[Richard Biener]

This fixes another case where missed sign-conversions during vectorization
need to be handled (outer-loop vectorization induction).

Bootstrap and regtest pending on x86_64-unknown-linux-gnu.

Richard.

2013-02-18  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/56366
        * tree-vect-loop.c (get_initial_def_for_induction): Properly
        handle sign-conversion of outer-loop initial induction value.

        * gcc.dg/torture/pr56366.c: New testcase.

Index: gcc/tree-vect-loop.c
===================================================================
*** gcc/tree-vect-loop.c        (revision 196115)
--- gcc/tree-vect-loop.c        (working copy)
*************** get_initial_def_for_induction (gimple iv
*** 3203,3208 ****
--- 3203,3223 ----
        tree iv_def = PHI_ARG_DEF_FROM_EDGE (iv_phi,
                                             loop_preheader_edge (iv_loop));
        vec_init = vect_get_vec_def_for_operand (iv_def, iv_phi, NULL);
+       /* If the initial value is not of proper type, convert it.  */
+       if (!useless_type_conversion_p (vectype, TREE_TYPE (vec_init)))
+       {
+         new_stmt = gimple_build_assign_with_ops
+             (VIEW_CONVERT_EXPR,
+              vect_get_new_vect_var (vectype, vect_simple_var, "vec_iv_"),
+              build1 (VIEW_CONVERT_EXPR, vectype, vec_init), NULL_TREE);
+         vec_init = make_ssa_name (gimple_assign_lhs (new_stmt), new_stmt);
+         gimple_assign_set_lhs (new_stmt, vec_init);
+         new_bb = gsi_insert_on_edge_immediate (loop_preheader_edge (iv_loop),
+                                                new_stmt);
+         gcc_assert (!new_bb);
+         set_vinfo_for_stmt (new_stmt,
+                             new_stmt_vec_info (new_stmt, loop_vinfo, NULL));
+       }
      }
    else
      {
Index: gcc/testsuite/gcc.dg/torture/pr56366.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr56366.c      (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr56366.c      (working copy)
***************
*** 0 ****
--- 1,17 ----
+ /* { dg-do compile } */
+ 
+ int a, *c, d;
+ unsigned short b;
+ short e;
+ 
+ void f(void)
+ {
+   for(;; d++)
+     {
+       for(a = -9; a < 63; a++)
+       for(d = 0; d < 9; d++)
+         b -= --e;
+ 
+       a = b & *c;
+     }
+ }