Re: PR 70687: Use wide_int in combine.c:change_zero_ext

[Bernd Schmidt]

On 05/03/2016 11:11 AM, Richard Sandiford wrote:

PR 70687 reports a case where combine.c mishandles integer modes
wider than unsigned HOST_WIDE_INT.  I don't have a testcase since
the PR is just pointing out the hole.

Also, I think a ZERO_EXTEND of a vector mode could in principle satisfy
the subreg condition but wouldn't be equivalent to an AND.  E.g.:

   (zero_extend:V4DI (subreg:V4SI (reg:V4DI R) 0))

Tested on x86_64-linux-gnu.  OK to install?

        PR rtl-optimization/70687
        * combine.c (change_zero_ext): Check for scalar modes.  Use wide_int
        instead of unsigned HOST_WIDE_INT.

Ok.


Bernd