Hi,

This patch makes both outputs of neon_vzip/vuzp/vtrn_internal
explicitly dependent on both inputs, preventing incorrect
optimization:
for
(a,b)<- vzip (c,d)
and
(e,f) <- vzip (g,d)
CSE decides that b==f, since b and f depend only on d.

Tested on arm-linux-gnueabi. OK for trunk?
OK for 4.6 after testing?

Thanks,
Ira

ChangeLog:

2011-04-07  Ulrich Weigand  <ulrich.weigand@linaro.org>
                  Ira Rosen  <ira.rosen@linaro.org>

     PR target/48252
     * config/arm/arm.c (neon_emit_pair_result_insn): Swap arguments
     to match neon_vzip/vuzp/vtrn_internal.
     * config/arm/neon.md (neon_vtrn<mode>_internal): Make both
     outputs explicitly dependent on both inputs.
     (neon_vzip<mode>_internal, neon_vuzp<mode>_internal): Likewise.

testsuite/Changelog:

     PR target/48252
     * gcc.target/arm/pr48252.c: New test.