[Bug middle-end/69546] [5 Regression] wrong code with -O and simple int128 arithmetics

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69546

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Feb 10 18:44:07 2016
New Revision: 233300

URL: https://gcc.gnu.org/viewcvs?rev=233300&root=gcc&view=rev
Log:
        Backported from mainline
        2016-01-30  Jakub Jelinek  <jakub@redhat.com>

        PR tree-optimization/69546
        * wide-int.cc (wi::divmod_internal): For unsigned division
        where both operands fit into uhwi, if o1 is 1 and o0 has
        msb set, if divident_prec is larger than bits per hwi,
        clear another quotient word and return 2 instead of 1.
        Similarly for remainder with msb in HWI set, if dividend_prec
        is larger than bits per hwi.

        * gcc.dg/torture/pr69546.c: New test.

Added:
    branches/gcc-5-branch/gcc/testsuite/gcc.dg/torture/pr69546-1.c
    branches/gcc-5-branch/gcc/testsuite/gcc.dg/torture/pr69546-2.c
Modified:
    branches/gcc-5-branch/gcc/ChangeLog
    branches/gcc-5-branch/gcc/testsuite/ChangeLog
    branches/gcc-5-branch/gcc/wide-int.cc