[PATCH, rs6000] Fix V16QI vector splat for little endian

[Bill Schmidt]

Hi,

When possible, we translate VEC_PERM_EXPRs into vector splat operations.
A previous patch fixed this up for little endian, but there was an
oversight for V16QI mode.  This patch fixes that oversight.  This fixes
the failing test gcc.dg/torture/vshuf-v16qi.c.

Bootstrapped and tested on powerpc64{,le}-unknown-linux-gnu using
--with-cpu=power7 with no regressions.  Is this ok for trunk?

Thanks,
Bill


2013-11-19  Bill Schmidt  <wschm...@linux.vnet.ibm.com>

        * config/rs6000/rs6000.c (altivec_expand_vec_perm_const): Adjust
        V16QI vector splat case for little endian.


Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c  (revision 205002)
+++ gcc/config/rs6000/rs6000.c  (working copy)
@@ -29849,6 +29849,8 @@ altivec_expand_vec_perm_const (rtx operands[4])
          break;
       if (i == 16)
        {
+          if (!BYTES_BIG_ENDIAN)
+            elt = 15 - elt;
          emit_insn (gen_altivec_vspltb (target, op0, GEN_INT (elt)));
          return true;
        }