[Bug rtl-optimization/81423] [6/7/8 Regression] Wrong code at -O2

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81423

--- Comment #7 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Author: segher
Date: Wed Jul 19 19:28:41 2017
New Revision: 250363

URL: https://gcc.gnu.org/viewcvs?rev=250363&root=gcc&view=rev
Log:
simplify-rtx: The truncation of an IOR can have all bits set (PR81423)

... if it is an IOR with a constant with all bits set in the mode
that is truncated to, for example.  Handle that case.


        PR rtl-optimization/81423
        * simplify-rtx.c (simplify_truncation): Handle truncating an IOR
        with a constant that is -1 in the truncated to mode.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/simplify-rtx.c